Sample records for a-beta drg neurons

  1. CFTR mediates noradrenaline-induced ATP efflux from DRG neurons.

    PubMed

    Kanno, Takeshi; Nishizaki, Tomoyuki

    2011-09-24

    In our earlier study, noradrenaline (NA) stimulated ATP release from dorsal root ganglion (DRG) neurons as mediated via β(3) adrenoceptors linked to G(s) protein involving protein kinase A (PKA) activation, to cause allodynia. The present study was conducted to understand how ATP is released from DRG neurons. In an outside-out patch-clamp configuration from acutely dissociated rat DRG neurons, single-channel currents, sensitive to the P2X receptor inhibitor PPADS, were evoked by approaching the patch-electrode tip close to a neuron, indicating that ATP is released from DRG neurons, to activate P2X receptor. NA increased the frequency of the single-channel events, but such NA effect was not found for DRG neurons transfected with the siRNA to silence the cystic fibrosis transmembrane conductance regulator (CFTR) gene. In the immunocytochemical study using acutely dissociated rat DRG cells, CFTR was expressed in neurons alone, but not satellite cells, fibroblasts, or Schwann cells. It is concluded from these results that CFTR mediates NA-induced ATP efflux from DRG neurons as an ATP channel.

  2. Comparative functional expression of nAChR subtypes in rodent DRG neurons.

    PubMed

    Smith, Nathan J; Hone, Arik J; Memon, Tosifa; Bossi, Simon; Smith, Thomas E; McIntosh, J Michael; Olivera, Baldomero M; Teichert, Russell W

    2013-01-01

    We investigated the functional expression of nicotinic acetylcholine receptors (nAChRs) in heterogeneous populations of dissociated rat and mouse lumbar dorsal root ganglion (DRG) neurons by calcium imaging. By this experimental approach, it is possible to investigate the functional expression of multiple receptor and ion-channel subtypes across more than 100 neuronal and glial cells simultaneously. Based on nAChR expression, DRG neurons could be divided into four subclasses: (1) neurons that express predominantly α3β4 and α6β4 nAChRs; (2) neurons that express predominantly α7 nAChRs; (3) neurons that express a combination of α3β4/α6β4 and α7 nAChRs; and (4) neurons that do not express nAChRs. In this comparative study, the same four neuronal subclasses were observed in mouse and rat DRG. However, the expression frequency differed between species: substantially more rat DRG neurons were in the first three subclasses than mouse DRG neurons, at all developmental time points tested in our study. Approximately 70-80% of rat DRG neurons expressed functional nAChRs, in contrast to only ~15-30% of mouse DRG neurons. Our study also demonstrated functional coupling between nAChRs, voltage-gated calcium channels, and mitochondrial Ca(2) (+) transport in discrete subsets of DRG neurons. In contrast to the expression of nAChRs in DRG neurons, we demonstrated that a subset of non-neuronal DRG cells expressed muscarinic acetylcholine receptors and not nAChRs. The general approach to comparative cellular neurobiology outlined in this paper has the potential to better integrate molecular and systems neuroscience by uncovering the spectrum of neuronal subclasses present in a given cell population and the functionally integrated signaling components expressed in each subclass.

  3. Protease-Mediated Suppression of DRG Neuron Excitability by Commensal Bacteria.

    PubMed

    Sessenwein, Jessica L; Baker, Corey C; Pradhananga, Sabindra; Maitland, Megan E; Petrof, Elaine O; Allen-Vercoe, Emma; Noordhof, Curtis; Reed, David E; Vanner, Stephen J; Lomax, Alan E

    2017-11-29

    Peripheral pain signaling reflects a balance of pronociceptive and antinociceptive influences; the contribution by the gastrointestinal microbiota to this balance has received little attention. Disorders, such as inflammatory bowel disease and irritable bowel syndrome, are associated with exaggerated visceral nociceptive actions that may involve altered microbial signaling, particularly given the evidence for bacterial dysbiosis. Thus, we tested whether a community of commensal gastrointestinal bacteria derived from a healthy human donor (microbial ecosystem therapeutics; MET-1) can affect the excitability of male mouse DRG neurons. MET-1 reduced the excitability of DRG neurons by significantly increasing rheobase, decreasing responses to capsaicin (2 μm) and reducing action potential discharge from colonic afferent nerves. The increase in rheobase was accompanied by an increase in the amplitude of voltage-gated K + currents. A mixture of bacterial protease inhibitors abrogated the effect of MET-1 effects on DRG neuron rheobase. A serine protease inhibitor but not inhibitors of cysteine proteases, acid proteases, metalloproteases, or aminopeptidases abolished the effects of MET-1. The serine protease cathepsin G recapitulated the effects of MET-1 on DRG neurons. Inhibition of protease-activated receptor-4 (PAR-4), but not PAR-2, blocked the effects of MET-1. Furthermore, Faecalibacterium prausnitzii recapitulated the effects of MET-1 on excitability of DRG neurons. We conclude that serine proteases derived from commensal bacteria can directly impact the excitability of DRG neurons, through PAR-4 activation. The ability of microbiota-neuronal interactions to modulate afferent signaling suggests that therapies that induce or correct microbial dysbiosis may impact visceral pain. SIGNIFICANCE STATEMENT Commercially available probiotics have the potential to modify visceral pain. Here we show that secretory products from gastrointestinal microbiota derived from a human

  4. CRISPR Epigenome Editing of AKAP150 in DRG Neurons Abolishes Degenerative IVD-Induced Neuronal Activation.

    PubMed

    Stover, Joshua D; Farhang, Niloofar; Berrett, Kristofer C; Gertz, Jason; Lawrence, Brandon; Bowles, Robby D

    2017-09-06

    Back pain is a major contributor to disability and has significant socioeconomic impacts worldwide. The degenerative intervertebral disc (IVD) has been hypothesized to contribute to back pain, but a better understanding of the interactions between the degenerative IVD and nociceptive neurons innervating the disc and treatment strategies that directly target these interactions is needed to improve our understanding and treatment of back pain. We investigated degenerative IVD-induced changes to dorsal root ganglion (DRG) neuron activity and utilized CRISPR epigenome editing as a neuromodulation strategy. By exposing DRG neurons to degenerative IVD-conditioned media under both normal and pathological IVD pH levels, we demonstrate that degenerative IVDs trigger interleukin (IL)-6-induced increases in neuron activity to thermal stimuli, which is directly mediated by AKAP and enhanced by acidic pH. Utilizing this novel information on AKAP-mediated increases in nociceptive neuron activity, we developed lentiviral CRISPR epigenome editing vectors that modulate endogenous expression of AKAP150 by targeted promoter histone methylation. When delivered to DRG neurons, these epigenome-modifying vectors abolished degenerative IVD-induced DRG-elevated neuron activity while preserving non-pathologic neuron activity. This work elucidates the potential for CRISPR epigenome editing as a targeted gene-based pain neuromodulation strategy. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  5. Nociceptive DRG neurons express muscle lim protein upon axonal injury.

    PubMed

    Levin, Evgeny; Andreadaki, Anastasia; Gobrecht, Philipp; Bosse, Frank; Fischer, Dietmar

    2017-04-04

    Muscle lim protein (MLP) has long been regarded as a cytosolic and nuclear muscular protein. Here, we show that MLP is also expressed in a subpopulation of adult rat dorsal root ganglia (DRG) neurons in response to axonal injury, while the protein was not detectable in naïve cells. Detailed immunohistochemical analysis of L4/L5 DRG revealed ~3% of MLP-positive neurons 2 days after complete sciatic nerve crush and maximum ~10% after 4-14 days. Similarly, in mixed cultures from cervical, thoracic, lumbar and sacral DRG ~6% of neurons were MLP-positive after 2 days and maximal 17% after 3 days. In both, histological sections and cell cultures, the protein was detected in the cytosol and axons of small diameter cells, while the nucleus remained devoid. Moreover, the vast majority could not be assigned to any of the well characterized canonical DRG subpopulations at 7 days after nerve injury. However, further analysis in cell culture revealed that the largest population of MLP expressing cells originated from non-peptidergic IB4-positive nociceptive neurons, which lose their ability to bind the lectin upon axotomy. Thus, MLP is mostly expressed in a subset of axotomized nociceptive neurons and can be used as a novel marker for this population of cells.

  6. Metabolic changes of cultured DRG neurons induced by adenosine using confocal microscopy imaging

    NASA Astrophysics Data System (ADS)

    Zheng, Liqin; Huang, Yimei; Chen, Jiangxu; Wang, Yuhua; Yang, Hongqin; Zhang, Yanding; Xie, Shusen

    2012-12-01

    Adenosine exerts multiple effects on pain transmission in the peripheral nervous system. This study was performed to use confocal microscopy to evaluate whether adenosine could affect dorsal root ganglia (DRG) neurons in vitro and test which adenosine receptor mediates the effect of adenosine on DRG neurons. After adding adenosine with different concentration, we compared the metabolic changes by the real time imaging of calcium and mitochondria membrane potential using confocal microscopy. The results showed that the effect of 500 μM adenosine on the metabolic changes of DRG neurons was more significant than others. Furthermore, four different adenosine receptor antagonists were used to study which receptor mediated the influences of adenosine on the cultured DRG neurons. All adenosine receptor antagonists especially A1 receptor antagonist (DPCPX) had effect on the Ca2+ and mitochondria membrane potential dynamics of DRG neurons. The above studies demonstrated that the effect of adenosine which may be involved in the signal transmission on the sensory neurons was dose-dependent, and all the four adenosine receptors especially the A1R may mediate the transmission.

  7. Neto2 Assembles with Kainate Receptors in DRG Neurons during Development and Modulates Neurite Outgrowth in Adult Sensory Neurons.

    PubMed

    Vernon, Claire G; Swanson, Geoffrey T

    2017-03-22

    Peripheral sensory neurons in the dorsal root ganglia (DRG) are the initial transducers of sensory stimuli, including painful stimuli, from the periphery to central sensory and pain-processing centers. Small- to medium-diameter non-peptidergic neurons in the neonatal DRG express functional kainate receptors (KARs), one of three subfamilies of ionotropic glutamate receptors, as well as the putative KAR auxiliary subunit Neuropilin- and tolloid-like 2 (Neto2). Neto2 alters recombinant KAR function markedly but has yet to be confirmed as an auxiliary subunit that assembles with and alters the function of endogenous KARs. KARs in neonatal DRG require the GluK1 subunit as a necessary constituent, but it is unclear to what extent other KAR subunits contribute to the function and proposed roles of KARs in sensory ganglia, which include promotion of neurite outgrowth and modulation of glutamate release at the DRG-dorsal horn synapse. In addition, KARs containing the GluK1 subunit are implicated in modes of persistent but not acute pain signaling. We show here that the Neto2 protein is highly expressed in neonatal DRG and modifies KAR gating in DRG neurons in a developmentally regulated fashion in mice. Although normally at very low levels in adult DRG neurons, Neto2 protein expression can be upregulated via MEK/ERK signaling and after sciatic nerve crush and Neto2 -/- neurons from adult mice have stunted neurite outgrowth. These data confirm that Neto2 is a bona fide KAR auxiliary subunit that is an important constituent of KARs early in sensory neuron development and suggest that Neto2 assembly is critical to KAR modulation of DRG neuron process outgrowth. SIGNIFICANCE STATEMENT Pain-transducing peripheral sensory neurons of the dorsal root ganglia (DRG) express kainate receptors (KARs), a subfamily of glutamate receptors that modulate neurite outgrowth and regulate glutamate release at the DRG-dorsal horn synapse. The putative KAR auxiliary subunit Neuropilin- and

  8. Neto2 Assembles with Kainate Receptors in DRG Neurons during Development and Modulates Neurite Outgrowth in Adult Sensory Neurons

    PubMed Central

    Vernon, Claire G.

    2017-01-01

    Peripheral sensory neurons in the dorsal root ganglia (DRG) are the initial transducers of sensory stimuli, including painful stimuli, from the periphery to central sensory and pain-processing centers. Small- to medium-diameter non-peptidergic neurons in the neonatal DRG express functional kainate receptors (KARs), one of three subfamilies of ionotropic glutamate receptors, as well as the putative KAR auxiliary subunit Neuropilin- and tolloid-like 2 (Neto2). Neto2 alters recombinant KAR function markedly but has yet to be confirmed as an auxiliary subunit that assembles with and alters the function of endogenous KARs. KARs in neonatal DRG require the GluK1 subunit as a necessary constituent, but it is unclear to what extent other KAR subunits contribute to the function and proposed roles of KARs in sensory ganglia, which include promotion of neurite outgrowth and modulation of glutamate release at the DRG–dorsal horn synapse. In addition, KARs containing the GluK1 subunit are implicated in modes of persistent but not acute pain signaling. We show here that the Neto2 protein is highly expressed in neonatal DRG and modifies KAR gating in DRG neurons in a developmentally regulated fashion in mice. Although normally at very low levels in adult DRG neurons, Neto2 protein expression can be upregulated via MEK/ERK signaling and after sciatic nerve crush and Neto2−/− neurons from adult mice have stunted neurite outgrowth. These data confirm that Neto2 is a bona fide KAR auxiliary subunit that is an important constituent of KARs early in sensory neuron development and suggest that Neto2 assembly is critical to KAR modulation of DRG neuron process outgrowth. SIGNIFICANCE STATEMENT Pain-transducing peripheral sensory neurons of the dorsal root ganglia (DRG) express kainate receptors (KARs), a subfamily of glutamate receptors that modulate neurite outgrowth and regulate glutamate release at the DRG–dorsal horn synapse. The putative KAR auxiliary subunit Neuropilin- and

  9. Sustained neurochemical plasticity in central terminals of mouse DRG neurons following colitis.

    PubMed

    Benson, Jessica R; Xu, Jiameng; Moynes, Derek M; Lapointe, Tamia K; Altier, Christophe; Vanner, Stephen J; Lomax, Alan E

    2014-05-01

    Sensitization of dorsal root ganglia (DRG) neurons is an important mechanism underlying the expression of chronic abdominal pain caused by intestinal inflammation. Most studies have focused on changes in the peripheral terminals of DRG neurons in the inflamed intestine but recent evidence suggests that the sprouting of central nerve terminals in the dorsal horn is also important. Therefore, we examine the time course and reversibility of changes in the distribution of immunoreactivity for substance P (SP), a marker of the central terminals of DRG neurons, in the spinal cord during and following dextran sulphate sodium (DSS)-induced colitis in mice. Acute and chronic treatment with DSS significantly increased SP immunoreactivity in thoracic and lumbosacral spinal cord segments. This increase developed over several weeks and was evident in both the superficial laminae of the dorsal horn and in lamina X. These increases persisted for 5 weeks following cessation of both the acute and chronic models. The increase in SP immunoreactivity was not observed in segments of the cervical spinal cord, which were not innervated by the axons of colonic afferent neurons. DRG neurons dissociated following acute DSS-colitis exhibited increased neurite sprouting compared with neurons dissociated from control mice. These data suggest significant colitis-induced enhancements in neuropeptide expression in DRG neuron central terminals. Such neurotransmitter plasticity persists beyond the period of active inflammation and might contribute to a sustained increase in nociceptive signaling following the resolution of inflammation.

  10. The Effects of IGF-1 on Trk Expressing DRG Neurons with HIV-gp120- Induced Neurotoxicity.

    PubMed

    Li, Hao; Liu, Zhen; Chi, Heng; Bi, Yanwen; Song, Lijun; Liu, Huaxiang

    2016-01-01

    HIV envelope glycoprotein gp120 is the main protein that causes HIVassociated sensory neuropathy. However, the underlying mechanisms of gp120-induced neurotoxicity are still unclear. There are lack effective treatments for relieving HIV-related neuropathic symptoms caused by gp120-induced neurotoxicity. In the present study, tyrosine kinase receptor (Trk)A, TrkB, and TrkC expression in primary cultured dorsal root ganglion (DRG) neurons with gp120-induced neurotoxicity was investigated. The effects of IGF-1 on distinct Trk-positive DRG neurons with gp120-induced neurotoxicity were also determined. The results showed that gp120 not only dose-dependently induced DRG neuronal apoptosis and inhibited neuronal survival and neurite outgrowth, but also decreased distinct Trk expression levels. IGF-1 rescued DRG neurons from apoptosis and improved neuronal survival of gp120 neurotoxic DRG neurons in vitro. IGF-1 also improved TrkA and TrkB, but not TrkC, expression in gp120 neurotoxic conditions. The effects of IGF-1 could be blocked by preincubation with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. These results suggested that gp120 may have a wide range of neurotoxicity on different subpopulations of DRG neurons, while IGF-1 might only relieve some subpopulations of DRG neurons with gp120-induced neurotoxicity. These data provide novel information of mechanisms of gp120 neurotoxicity on primary sensory neurons and the potential therapeutic effects of IGF-1 on gp120-induced neurotoxicity.

  11. [Effect of nitric oxide on the somatic membrane of rat DRG neurons].

    PubMed

    Cheng, Hong-Ju; Ma, Ke-Tao; Zhao, Lei; Li, Li; Cao, Ying-Ying; Si, Jun-Qiang

    2009-11-01

    To observe the role of nitric oxide in dorsal root ganglion (DRG) neurons and its related ionic mechanisms, and explore the function of NO in pain transmission process. In freshly isolated rat DRG samples, using intracellular recording technique, we perfused sodium nitroprusside (NO donor) to observe the role of NO in DRG neurons. In 77.45% of the bath cells, application of sodium nitroprusside (10 -100 mmol/L) induced concentration-dependent membrane hyperpolarization (79/102), and remaining neurons had no response. The membrane conductance increased from control value of (21.06 +/- 1.94) nS to (23.08 +/- 0.92) nS during sodium nitroprusside induced hyperpolarization. L-NAME (1 mmol/L), CdCl2 (0.1 mmol/L) and non-sodium BSS failed to change the amplitude of sodium nitroprusside induced hyperpolarization. When BSS containing 10 mmol/L TEA was used, sodium nitroprusside induced hyperpolarization was obviously inhibited. Sodium nitroprusside could cause concentration-dependent hyperpolarization in DRG neurons by activating K+ channels.

  12. A Bacterial Toxin with Analgesic Properties: Hyperpolarization of DRG Neurons by Mycolactone.

    PubMed

    Song, Ok-Ryul; Kim, Han-Byul; Jouny, Samuel; Ricard, Isabelle; Vandeputte, Alexandre; Deboosere, Nathalie; Marion, Estelle; Queval, Christophe J; Lesport, Pierre; Bourinet, Emmanuel; Henrion, Daniel; Oh, Seog Bae; Lebon, Guillaume; Sandoz, Guillaume; Yeramian, Edouard; Marsollier, Laurent; Brodin, Priscille

    2017-07-18

    Mycolactone, a polyketide molecule produced by Mycobacterium ulcerans , is the etiological agent of Buruli ulcer. This lipid toxin is endowed with pleiotropic effects, presents cytotoxic effects at high doses, and notably plays a pivotal role in host response upon colonization by the bacillus. Most remarkably, mycolactone displays intriguing analgesic capabilities: the toxin suppresses or alleviates the pain of the skin lesions it inflicts. We demonstrated that the analgesic capability of mycolactone was not attributable to nerve damage, but instead resulted from the triggering of a cellular pathway targeting AT₂ receptors (angiotensin II type 2 receptors; AT₂R), and leading to potassium-dependent hyperpolarization. This demonstration paves the way to new nature-inspired analgesic protocols. In this direction, we assess here the hyperpolarizing properties of mycolactone on nociceptive neurons. We developed a dedicated medium-throughput assay based on membrane potential changes, and visualized by confocal microscopy of bis-oxonol-loaded Dorsal Root Ganglion (DRG) neurons. We demonstrate that mycolactone at non-cytotoxic doses triggers the hyperpolarization of DRG neurons through AT₂R, with this action being not affected by known ligands of AT₂R. This result points towards novel AT₂R-dependent signaling pathways in DRG neurons underlying the analgesic effect of mycolactone, with the perspective for the development of new types of nature-inspired analgesics.

  13. Differing patterns of neurotrophin-receptor expressing neurons allow distinction of the transient Frorieps' ganglia from normal DRG before morphological differences appear.

    PubMed

    Avivi, Camila; Goldstein, Ronald S

    2003-10-10

    The Frorieps' ganglia are dorsal root ganglia (DRG) that form and then degenerate during normal embryonic development of amniotes. Their degeneration or survival has been shown to be modulated by modifying expression of Hox-family and other genes involved in pattern formation, and by the mesodermal microenvironment of the cranial somites in which they develop. In ovo application of the neurotrophin NGF partially rescues DRG2 from degeneration. To further examine the potential role of neurotrophins in the life cycle of Frorieps' DRG we have now quantified the numbers of neurons expressing neurotrophin receptors trkA and trkC in avian Frorieps' ganglia (DRG2) and normal cervical DRG (DRG5). We have found that the Frorieps' DRG are different from normal DRG in terms of the numbers of neurons expressing these receptors. trkC-expressing neurons are generally lacking in DRG2, this is the earliest (St 18, E2.5) described difference between DRG2 and normal DRG, preceding morphological differences between these ganglia that appear at St 20. The difference between DRG2 and DRG5 in terms of numbers of trkA-expressing neurons is evident only at later embryonic stages, where DRG2 contains a higher proportion of trkA neurons than normal cervical DRG. The few trkC+ neurons present late in DRG2 development are not concentrated in the VL portion of the ganglion, the zone where trkC+ neurons are generally found in normal DRG. We also find that DRG2 neurons are smaller than those of normal DRG, this is true for both trkA+ and trkC+ populations. These data together therefore suggest that the neurons that survive in the Frorieps' ganglia at later stages belong almost exclusively to the trkA-expressing DM class DRG neurons. We further find that the differences in the populations of trkA/trkC between DRG2 and DRG5 result from signals from the mesodermal microenvironment, since DRG arising in cranial somites transplanted caudally contain few trkC+ neurons and a higher proportion of trkA

  14. A Bacterial Toxin with Analgesic Properties: Hyperpolarization of DRG Neurons by Mycolactone

    PubMed Central

    Song, Ok-Ryul; Kim, Han-Byul; Jouny, Samuel; Ricard, Isabelle; Vandeputte, Alexandre; Deboosere, Nathalie; Marion, Estelle; Queval, Christophe J.; Lesport, Pierre; Henrion, Daniel; Oh, Seog Bae; Lebon, Guillaume; Sandoz, Guillaume; Yeramian, Edouard; Marsollier, Laurent; Brodin, Priscille

    2017-01-01

    Mycolactone, a polyketide molecule produced by Mycobacterium ulcerans, is the etiological agent of Buruli ulcer. This lipid toxin is endowed with pleiotropic effects, presents cytotoxic effects at high doses, and notably plays a pivotal role in host response upon colonization by the bacillus. Most remarkably, mycolactone displays intriguing analgesic capabilities: the toxin suppresses or alleviates the pain of the skin lesions it inflicts. We demonstrated that the analgesic capability of mycolactone was not attributable to nerve damage, but instead resulted from the triggering of a cellular pathway targeting AT2 receptors (angiotensin II type 2 receptors; AT2R), and leading to potassium-dependent hyperpolarization. This demonstration paves the way to new nature-inspired analgesic protocols. In this direction, we assess here the hyperpolarizing properties of mycolactone on nociceptive neurons. We developed a dedicated medium-throughput assay based on membrane potential changes, and visualized by confocal microscopy of bis-oxonol-loaded Dorsal Root Ganglion (DRG) neurons. We demonstrate that mycolactone at non-cytotoxic doses triggers the hyperpolarization of DRG neurons through AT2R, with this action being not affected by known ligands of AT2R. This result points towards novel AT2R-dependent signaling pathways in DRG neurons underlying the analgesic effect of mycolactone, with the perspective for the development of new types of nature-inspired analgesics. PMID:28718822

  15. Allotransplanted DRG neurons or Schwann cells affect functional recovery in a rodent model of sciatic nerve injury.

    PubMed

    Dayawansa, Samantha; Wang, Ernest W; Liu, Weimin; Markman, John D; Gelbard, Harris A; Huang, Jason H

    2014-11-01

    In this study, the functional recoveries of Sprague-Dawley rats following repair of a complete sciatic nerve transection using allotransplanted dorsal root ganglion (DRG) neurons or Schwann cells were examined using a number of outcome measures. Four groups were compared: (1) repair with a nerve guide conduit seeded with allotransplanted Schwann cells harvested from Wistar rats, (2) repair with a nerve guide conduit seeded with DRG neurons, (3) repair with solely a nerve guide conduit, and (4) sham-surgery animals where the sciatic nerve was left intact. The results corroborated our previous reported histology findings and measures of immunogenicity. The Wistar-DRG-treated group achieved the best recovery, significantly outperforming both the Wistar-Schwann group and the nerve guide conduit group in the Von Frey assay of touch response (P < 0.05). Additionally, Wistar-DRG and Wistar-Schwann seeded repairs showed lower frequency and severity in an autotomy measure of the self-mutilation of the injured leg because of neuralgia. These results suggest that in complete peripheral nerve transections, surgical repair using nerve guide conduits with allotransplanted DRG and Schwann cells may improve recovery, especially DRG neurons, which elicit less of an immune response.

  16. Stress activates pronociceptive endogenous opioid signalling in DRG neurons during chronic colitis.

    PubMed

    Guerrero-Alba, Raquel; Valdez-Morales, Eduardo E; Jimenez-Vargas, Nestor N; Lopez-Lopez, Cintya; Jaramillo-Polanco, Josue; Okamoto, Takanobu; Nasser, Yasmin; Bunnett, Nigel W; Lomax, Alan E; Vanner, Stephen J

    2017-12-01

    Psychological stress accompanies chronic inflammatory diseases such as IBD, and stress hormones can exacerbate pain signalling. In contrast, the endogenous opioid system has an important analgesic action during chronic inflammation. This study examined the interaction of these pathways. Mouse nociceptive dorsal root ganglia (DRG) neurons were incubated with supernatants from segments of inflamed colon collected from patients with chronic UC and mice with dextran sodium sulfate (cDSS)-induced chronic colitis. Stress effects were studied by adding stress hormones (epinephrine and corticosterone) to dissociated neurons or by exposing cDSS mice to water avoidance stress. Changes in excitability of colonic DRG nociceptors were measured using patch clamp and Ca 2+ imaging techniques. Supernatants from patients with chronic UC and from colons of mice with chronic colitis caused a naloxone-sensitive inhibition of neuronal excitability and capsaicin-evoked Ca 2+ responses. Stress hormones decreased signalling induced by human and mouse supernatants. This effect resulted from stress hormones signalling directly to DRG neurons and indirectly through signalling to the immune system, leading to decreased opioid levels and increased acute inflammation. The net effect of stress was a change endogenous opioid signalling in DRG neurons from an inhibitory to an excitatory effect. This switch was associated with a change in G protein-coupled receptor excitatory signalling to a pathway sensitive to inhibitors of protein kinase A-protein, phospholipase C-protein and G protein βϒ subunits. Stress hormones block the inhibitory actions of endogenous opioids and can change the effect of opioid signalling in DRG neurons to excitation. Targeting these pathways may prevent heavy opioid use in IBD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Mycolactone-mediated neurite degeneration and functional effects in cultured human and rat DRG neurons

    PubMed Central

    Sinisi, M; Fox, M; MacQuillan, A; Quick, T; Korchev, Y; Bountra, C; McCarthy, T; Anand, P

    2016-01-01

    Background Mycolactone is a polyketide toxin secreted by the mycobacterium Mycobacterium ulcerans, responsible for the extensive hypoalgesic skin lesions characteristic of patients with Buruli ulcer. A recent pre-clinical study proposed that mycolactone may produce analgesia via activation of the angiotensin II type 2 receptor (AT2R). In contrast, AT2R antagonist EMA401 has shown analgesic efficacy in animal models and clinical trials for neuropathic pain. We therefore investigated the morphological and functional effects of mycolactone in cultured human and rat dorsal root ganglia (DRG) neurons and the role of AT2R using EMA401. Primary sensory neurons were prepared from avulsed cervical human DRG and rat DRG; 24 h after plating, neurons were incubated for 24 to 96 h with synthetic mycolactone A/B, followed by immunostaining with antibodies to PGP9.5, Gap43, β tubulin, or Mitotracker dye staining. Acute functional effects were examined by measuring capsaicin responses with calcium imaging in DRG neuronal cultures treated with mycolactone. Results Morphological effects: Mycolactone-treated cultures showed dramatically reduced numbers of surviving neurons and non-neuronal cells, reduced Gap43 and β tubulin expression, degenerating neurites and reduced cell body diameter, compared with controls. Dose-related reduction of neurite length was observed in mycolactone-treated cultures. Mitochondria were distributed throughout the length of neurites and soma of control neurons, but clustered in the neurites and soma of mycolactone-treated neurons. Functional effects: Mycolactone-treated human and rat DRG neurons showed dose-related inhibition of capsaicin responses, which were reversed by calcineurin inhibitor cyclosporine and phosphodiesterase inhibitor 3-isobutyl-1-Methylxanthine, indicating involvement of cAMP/ATP reduction. The morphological and functional effects of mycolactone were not altered by Angiotensin II or AT2R antagonist EMA401. Conclusion Mycolactone

  18. High-voltage-activated calcium current subtypes in mouse DRG neurons adapt in a subpopulation-specific manner after nerve injury.

    PubMed

    Murali, Swetha S; Napier, Ian A; Mohammadi, Sarasa A; Alewood, Paul F; Lewis, Richard J; Christie, MacDonald J

    2015-03-01

    Changes in ion channel function and expression are characteristic of neuropathic pain. Voltage-gated calcium channels (VGCCs) are integral for neurotransmission and membrane excitability, but relatively little is known about changes in their expression after nerve injury. In this study, we investigate whether peripheral nerve ligation is followed by changes in the density and proportion of high-voltage-activated (HVA) VGCC current subtypes in dorsal root ganglion (DRG) neurons, the contribution of presynaptic N-type calcium channels in evoked excitatory postsynaptic currents (EPSCs) recorded from dorsal horn neurons in the spinal cord, and the changes in expression of mRNA encoding VGCC subunits in DRG neurons. Using C57BL/6 mice [8- to 11-wk-old males (n = 91)] for partial sciatic nerve ligation or sham surgery, we performed whole cell patch-clamp recordings on isolated DRG neurons and dorsal horn neurons and measured the expression of all VGCC subunits with RT-PCR in DRG neurons. After nerve injury, the density of P/Q-type current was reduced overall in DRG neurons. There was an increase in the percentage of N-type and a decrease in that of P/Q-type current in medium- to large-diameter neurons. No changes were found in the contribution of presynaptic N-type calcium channels in evoked EPSCs recorded from dorsal horn neurons. The α2δ-1 subunit was upregulated by 1.7-fold and γ-3, γ-2, and β-4 subunits were all downregulated 1.7-fold in injured neurons compared with sham-operated neurons. This comprehensive characterization of HVA VGCC subtypes in mouse DRG neurons after nerve injury revealed changes in N- and P/Q-type current proportions only in medium- to large-diameter neurons. Copyright © 2015 the American Physiological Society.

  19. Inflammation-induced increase in nicotinic acetylcholine receptor current in cutaneous nociceptive DRG neurons from the adult rat.

    PubMed

    Zhang, X-L; Albers, K M; Gold, M S

    2015-01-22

    The goals of the present study were to determine (1) the properties of the nicotinic acetylcholine receptor (nAChR) currents in rat cutaneous dorsal root ganglion (DRG) neurons; (2) the impact of nAChR activation on the excitability of cutaneous DRG neurons; and (3) the impact of inflammation on the density and distribution of nAChR currents among cutaneous DRG neurons. Whole-cell patch-clamp techniques were used to study retrogradely labeled DRG neurons from naïve and complete Freund's adjuvant inflamed rats. Nicotine-evoked currents were detectable in ∼70% of the cutaneous DRG neurons, where only one of two current types, fast or slow currents based on rates of activation and inactivation, was present in each neuron. The biophysical and pharmacological properties of the fast current were consistent with nAChRs containing an α7 subunit while those of the slow current were consistent with nAChRs containing α3/β4 subunits. The majority of small diameter neurons with fast current were IB4- while the majority of small diameter neurons with slow current were IB4+. Preincubation with nicotine (1 μM) produced a transient (1 min) depolarization and increase in the excitability of neurons with fast current and a decrease in the amplitude of capsaicin-evoked current in neurons with slow current. Inflammation increased the current density of both slow and fast currents in small diameter neurons and increased the percentage of neurons with the fast current. With the relatively selective distribution of nAChR currents in putative nociceptive cutaneous DRG neurons, our results suggest that the role of these receptors in inflammatory hyperalgesia is likely to be complex and dependent on the concentration and timing of acetylcholine release in the periphery. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Parathyroid hormone-related peptide activates and modulates TRPV1 channel in human DRG neurons.

    PubMed

    Shepherd, A J; Mickle, A D; McIlvried, L A; Gereau, R W; Mohapatra, D P

    2018-05-24

    Parathyroid hormone-related peptide (PTHrP) is associated with advanced tumor growth and metastasis, especially in breast, prostate and myeloma cancers that metastasize to bones, resulting in debilitating chronic pain conditions. Our recent studies revealed that the receptor for PTHrP, PTH1R, is expressed in mouse DRG sensory neurons, and its activation leads to flow-activation and modulation of TRPV1 channel function, resulting in peripheral heat and mechanical hypersensitivity. In order to verify the translatability of our findings in rodents to humans, we explored whether this signalling axis operates in primary human DRG sensory neurons. Analysis of gene expression data from recently reported RNA deep sequencing experiments performed on mouse and human DRGs reveals that PTH1R is expressed in DRG and tibial nerve. Furthermore, exposure of cultured human DRG neurons to PTHrP leads to slow-sustained activation of TRPV1 and modulation of capsaicin-induced channel activation. Both activation and modulation of TRPV1 by PTHrP were dependent on PKC activity. Our findings suggest that functional PTHrP/PTH1R-TRPV1 signalling exists in human DRG neurons, which could contribute to local nociceptor excitation in the vicinity of metastatic bone tumor microenvironment. © 2018 European Pain Federation - EFIC®.

  1. Ectodomain shedding of Limbic System-Associated Membrane Protein (LSAMP) by ADAM Metallopeptidases promotes neurite outgrowth in DRG neurons.

    PubMed

    Sanz, Ricardo L; Ferraro, Gino B; Girouard, Marie-Pier; Fournier, Alyson E

    2017-08-11

    IgLONs are members of the immunoglobulin superfamily of cell adhesion proteins implicated in the process of neuronal outgrowth, cell adhesion and subdomain target recognition. IgLONs form homophilic and heterophilic complexes on the cell surface that repress or promote growth depending on the neuronal population, the developmental stage and surface repertoire of IgLON family members. In the present study, we identified a metalloproteinase-dependent mechanism necessary to promote growth in embryonic dorsal root ganglion cells (DRGs). Treatment of embryonic DRG neurons with pan-metalloproteinase inhibitors, tissue inhibitor of metalloproteinase-3, or an inhibitor of ADAM Metallopeptidase Domain 10 (ADAM10) reduces outgrowth from DRG neurons indicating that metalloproteinase activity is important for outgrowth. The IgLON family members Neurotrimin (NTM) and Limbic System-Associated Membrane Protein (LSAMP) were identified as ADAM10 substrates that are shed from the cell surface of DRG neurons. Overexpression of LSAMP and NTM suppresses outgrowth from DRG neurons. Furthermore, LSAMP loss of function decreases the outgrowth sensitivity to an ADAM10 inhibitor. Together our findings support a role for ADAM-dependent shedding of cell surface LSAMP in promoting outgrowth from DRG neurons.

  2. Calcineurin Dysregulation Underlies Spinal Cord Injury-Induced K+ Channel Dysfunction in DRG Neurons

    PubMed Central

    Zemel, Benjamin M.; Brown, Eric V.; Urban, Mark W.; Tymanskyj, Stephen R.; Lepore, Angelo C.

    2017-01-01

    Dysfunction of the fast-inactivating Kv3.4 potassium current in dorsal root ganglion (DRG) neurons contributes to the hyperexcitability associated with persistent pain induced by spinal cord injury (SCI). However, the underlying mechanism is not known. In light of our previous work demonstrating modulation of the Kv3.4 channel by phosphorylation, we investigated the role of the phosphatase calcineurin (CaN) using electrophysiological, molecular, and imaging approaches in adult female Sprague Dawley rats. Pharmacological inhibition of CaN in small-diameter DRG neurons slowed repolarization of the somatic action potential (AP) and attenuated the Kv3.4 current. Attenuated Kv3.4 currents also exhibited slowed inactivation. We observed similar effects on the recombinant Kv3.4 channel heterologously expressed in Chinese hamster ovary cells, supporting our findings in DRG neurons. Elucidating the molecular basis of these effects, mutation of four previously characterized serines within the Kv3.4 N-terminal inactivation domain eliminated the effects of CaN inhibition on the Kv3.4 current. SCI similarly induced concurrent Kv3.4 current attenuation and slowing of inactivation. Although there was little change in CaN expression and localization after injury, SCI induced upregulation of the native regulator of CaN 1 (RCAN1) in the DRG at the transcript and protein levels. Consistent with CaN inhibition resulting from RCAN1 upregulation, overexpression of RCAN1 in naive DRG neurons recapitulated the effects of pharmacological CaN inhibition on the Kv3.4 current and the AP. Overall, these results demonstrate a novel regulatory pathway that links CaN, RCAN1, and Kv3.4 in DRG neurons. Dysregulation of this pathway might underlie a peripheral mechanism of pain sensitization induced by SCI. SIGNIFICANCE STATEMENT Pain sensitization associated with spinal cord injury (SCI) involves poorly understood maladaptive modulation of neuronal excitability. Although central mechanisms have

  3. Calcineurin Dysregulation Underlies Spinal Cord Injury-Induced K+ Channel Dysfunction in DRG Neurons.

    PubMed

    Zemel, Benjamin M; Muqeem, Tanziyah; Brown, Eric V; Goulão, Miguel; Urban, Mark W; Tymanskyj, Stephen R; Lepore, Angelo C; Covarrubias, Manuel

    2017-08-23

    Dysfunction of the fast-inactivating Kv3.4 potassium current in dorsal root ganglion (DRG) neurons contributes to the hyperexcitability associated with persistent pain induced by spinal cord injury (SCI). However, the underlying mechanism is not known. In light of our previous work demonstrating modulation of the Kv3.4 channel by phosphorylation, we investigated the role of the phosphatase calcineurin (CaN) using electrophysiological, molecular, and imaging approaches in adult female Sprague Dawley rats. Pharmacological inhibition of CaN in small-diameter DRG neurons slowed repolarization of the somatic action potential (AP) and attenuated the Kv3.4 current. Attenuated Kv3.4 currents also exhibited slowed inactivation. We observed similar effects on the recombinant Kv3.4 channel heterologously expressed in Chinese hamster ovary cells, supporting our findings in DRG neurons. Elucidating the molecular basis of these effects, mutation of four previously characterized serines within the Kv3.4 N-terminal inactivation domain eliminated the effects of CaN inhibition on the Kv3.4 current. SCI similarly induced concurrent Kv3.4 current attenuation and slowing of inactivation. Although there was little change in CaN expression and localization after injury, SCI induced upregulation of the native regulator of CaN 1 (RCAN1) in the DRG at the transcript and protein levels. Consistent with CaN inhibition resulting from RCAN1 upregulation, overexpression of RCAN1 in naive DRG neurons recapitulated the effects of pharmacological CaN inhibition on the Kv3.4 current and the AP. Overall, these results demonstrate a novel regulatory pathway that links CaN, RCAN1, and Kv3.4 in DRG neurons. Dysregulation of this pathway might underlie a peripheral mechanism of pain sensitization induced by SCI. SIGNIFICANCE STATEMENT Pain sensitization associated with spinal cord injury (SCI) involves poorly understood maladaptive modulation of neuronal excitability. Although central mechanisms have

  4. Enhanced excitability and down-regulated voltage-gated potassium channels in colonic drg neurons from neonatal maternal separation rats.

    PubMed

    Luo, Jia-Lie; Qin, Hong-Yan; Wong, Chun-Kit; Tsang, Suk-Ying; Huang, Yu; Bian, Zhao-Xiang

    2011-05-01

    Irritable bowel syndrome (IBS), characterized mainly by abdominal pain, is a functional bowel disorder. The present study aimed to examine changes in the excitability and the activity of the voltage-gated K(+) channel in dorsal root ganglia (DRG) neurons innervating the colon of rats subjected to neonatal maternal separation (NMS). Colonic DRG neurons from NMS rats as identified by FAST DiI™ labeling showed an increased cell size compared with those from nonhandled (NH) rats. Whole cell current-clamp recordings showed that colonic DRG neurons from NMS rats displayed: 1) depolarized resting membrane potential; 2) increased input resistance; 3) a dramatic reduction in rheobase; and 4) a significant increase in the number of action potentials evoked at twice rheobase. Whole cell voltage-clamp recordings revealed that neurons from both groups exhibited transient A-type (I(A)) and delayed rectifier (I(K)) K(+) currents. Compared with NH rat neurons, the averaged density of I(K) was significantly reduced in NMS rat neurons. Furthermore, the Kv1.2 expression was significantly decreased in NMS rat colonic DRG neurons. These results suggest that NMS increases the excitability of colonic DRG neurons mainly by suppressing the I(K) current, which is likely accounted for by the downregulation of the Kv1.2 expression and somal hypertrophy. This study demonstrates the alteration of delayed rectifier K current and Kv1.2 expression in DRG neurons from IBS model rats, representing a molecular mechanism underlying visceral pain and sensitization in IBS, suggesting the potential of Kv1.2 as a therapeutic target for the treatment of IBS. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

  5. Blockade of persistent sodium currents contributes to the riluzole-induced inhibition of spontaneous activity and oscillations in injured DRG neurons.

    PubMed

    Xie, Rou-Gang; Zheng, Da-Wei; Xing, Jun-Ling; Zhang, Xu-Jie; Song, Ying; Xie, Ya-Bin; Kuang, Fang; Dong, Hui; You, Si-Wei; Xu, Hui; Hu, San-Jue

    2011-04-25

    In addition to a fast activating and immediately inactivating inward sodium current, many types of excitable cells possess a noninactivating or slowly inactivating component: the persistent sodium current (I(NaP)). The I(NaP) is found in normal primary sensory neurons where it is mediated by tetrodotoxin-sensitive sodium channels. The dorsal root ganglion (DRG) is the gateway for ectopic impulses that originate in pathological pain signals from the periphery. However, the role of I(NaP) in DRG neurons remains unclear, particularly in neuropathic pain states. Using in vivo recordings from single medium- and large-diameter fibers isolated from the compressed DRG in Sprague-Dawley rats, we show that local application of riluzole, which blocks the I(NaP), also inhibits the spontaneous activity of A-type DRG neurons in a dose-dependent manner. Significantly, riluzole also abolished subthreshold membrane potential oscillations (SMPOs), although DRG neurons still responded to intracellular current injection with a single full-sized spike. In addition, the I(NaP) was enhanced in medium- and large-sized neurons of the compressed DRG, while bath-applied riluzole significantly inhibited the I(NaP) without affecting the transient sodium current (I(NaT)). Taken together, these results demonstrate for the first time that the I(NaP) blocker riluzole selectively inhibits I(NaP) and thereby blocks SMPOs and the ectopic spontaneous activity of injured A-type DRG neurons. This suggests that the I(NaP) of DRG neurons is a potential target for treating neuropathic pain at the peripheral level.

  6. Down-regulation of A-type potassium channel in gastric-specific DRG neurons in a rat model of functional dyspepsia.

    PubMed

    Li, S; Chen, J D Z

    2014-07-01

    Although without evidence of organic structural abnormalities, pain or discomfort is a prominent symptom of functional dyspepsia and considered to reflect visceral hypersensitivity whose underlying mechanism is poorly understood. Here, we studied electrophysiological properties and expression of voltage-gated potassium channels in dorsal root ganglion (DRG) neurons in a rat model of functional dyspepsia induced by neonatal gastric irritation. Male Sprague-Dawley rat pups at 10-day old received 0.1% iodoacetamide (IA) or vehicle by oral gavage for 6 days and studied at adulthood. Retrograde tracer-labeled gastric-specific T8 -T12 DRG neurons were harvested for the patch-clamp study in voltage and current-clamp modes and protein expression of K(+) channel in T8 -T12 DRGs was examined by western blotting. (1) Gastric specific but not non-gastric DRG neurons showed an enhanced excitability in neonatal IA-treated rats compared to the control: depolarized resting membrane potentials, a lower current threshold for action potential (AP) activation, and an increase in the number of APs in response to current stimulation. (2) The current density of tetraethylammonium insensitive (transiently inactivating A-type current), but not the tetraethylammonium sensitive (slow-inactivating delayed rectifier K(+) currents), was significantly smaller in IA-treated rats (65.4 ± 6.9 pA/pF), compared to that of control (93.1 ± 8.3 pA/pF). (3) Protein expression of KV 4.3 was down-regulated in IA-treated rats. A-type potassium channels are significantly down-regulated in the gastric-specific DRG neurons in adult rats with mild neonatal gastric irritation, which in part contribute to the enhanced DRG neuron excitabilities that leads to the development of gastric hypersensitivity. © 2014 John Wiley & Sons Ltd.

  7. Human Nav1.8: enhanced persistent and ramp currents contribute to distinct firing properties of human DRG neurons

    PubMed Central

    Han, Chongyang; Estacion, Mark; Huang, Jianying; Vasylyev, Dymtro; Zhao, Peng; Dib-Hajj, Sulayman D.

    2015-01-01

    Although species-specific differences in ion channel properties are well-documented, little has been known about the properties of the human Nav1.8 channel, an important contributor to pain signaling. Here we show, using techniques that include voltage clamp, current clamp, and dynamic clamp in dorsal root ganglion (DRG) neurons, that human Nav1.8 channels display slower inactivation kinetics and produce larger persistent current and ramp current than previously reported in other species. DRG neurons expressing human Nav1.8 channels unexpectedly produce significantly longer-lasting action potentials, including action potentials with half-widths in some cells >10 ms, and increased firing frequency compared with the narrower and usually single action potentials generated by DRG neurons expressing rat Nav1.8 channels. We also show that native human DRG neurons recapitulate these properties of Nav1.8 current and the long-lasting action potentials. Together, our results demonstrate strikingly distinct properties of human Nav1.8, which contribute to the firing properties of human DRG neurons. PMID:25787950

  8. c-Maf is required for the development of dorsal horn laminae III/IV neurons and mechanoreceptive DRG axon projections.

    PubMed

    Hu, Jia; Huang, Tianwen; Li, Tingting; Guo, Zhen; Cheng, Leping

    2012-04-18

    Establishment of proper connectivity between peripheral sensory neurons and their central targets is required for an animal to sense and respond to various external stimuli. Dorsal root ganglion (DRG) neurons convey sensory signals of different modalities via their axon projections to distinct laminae in the dorsal horn of the spinal cord. In this study, we found that c-Maf was expressed predominantly in the interneurons of laminae III/IV, which primarily receive inputs from mechanoreceptive DRG neurons. In the DRG, c-Maf⁺ neurons also coexpressed neurofilament-200, a marker for the medium- and large-diameter myelinated afferents that transmit non-noxious information. Furthermore, mouse embryos deficient in c-Maf displayed abnormal development of dorsal horn laminae III/IV neurons, as revealed by the marked reduction in the expression of several marker genes for these neurons, including those for transcription factors MafA and Rora, GABA(A) receptor subunit α5, and neuropeptide cholecystokinin. In addition, among the four major subpopulations of DRG neurons marked by expression of TrkA, TrkB, TrkC, and MafA/GFRα2/Ret, c-Maf was required selectively for the proper differentiation of MafA⁺/Ret⁺/GFRα2⁺ low-threshold mechanoreceptors (LTMs). Last, we found that the central and peripheral projections of mechanoreceptive DRG neurons were compromised in c-Maf deletion mice. Together, our results indicate that c-Maf is required for the proper development of MafA⁺/Ret⁺/GFRα2⁺ LTMs in the DRG, their afferent projections in the dorsal horn and Pacinian corpuscles, as well as neurons in laminae III/IV of the spinal cord.

  9. Human Na(v)1.8: enhanced persistent and ramp currents contribute to distinct firing properties of human DRG neurons.

    PubMed

    Han, Chongyang; Estacion, Mark; Huang, Jianying; Vasylyev, Dymtro; Zhao, Peng; Dib-Hajj, Sulayman D; Waxman, Stephen G

    2015-05-01

    Although species-specific differences in ion channel properties are well-documented, little has been known about the properties of the human Nav1.8 channel, an important contributor to pain signaling. Here we show, using techniques that include voltage clamp, current clamp, and dynamic clamp in dorsal root ganglion (DRG) neurons, that human Na(v)1.8 channels display slower inactivation kinetics and produce larger persistent current and ramp current than previously reported in other species. DRG neurons expressing human Na(v)1.8 channels unexpectedly produce significantly longer-lasting action potentials, including action potentials with half-widths in some cells >10 ms, and increased firing frequency compared with the narrower and usually single action potentials generated by DRG neurons expressing rat Na(v)1.8 channels. We also show that native human DRG neurons recapitulate these properties of Na(v)1.8 current and the long-lasting action potentials. Together, our results demonstrate strikingly distinct properties of human Na(v)1.8, which contribute to the firing properties of human DRG neurons.

  10. CX3CL1-mediated macrophage activation contributed to paclitaxel-induced DRG neuronal apoptosis and painful peripheral neuropathy.

    PubMed

    Huang, Zhen-Zhen; Li, Dai; Liu, Cui-Cui; Cui, Yu; Zhu, He-Quan; Zhang, Wen-Wen; Li, Yong-Yong; Xin, Wen-Jun

    2014-08-01

    Painful peripheral neuropathy is a dose-limiting side effect of paclitaxel therapy, which hampers the optimal clinical management of chemotherapy in cancer patients. Currently the underlying mechanisms remain largely unknown. Here we showed that the clinically relevant dose of paclitaxel (3×8mg/kg, cumulative dose 24mg/kg) induced significant upregulation of the chemokine CX3CL1 in the A-fiber primary sensory neurons in vivo and in vitro and infiltration of macrophages into the dorsal root ganglion (DRG) in rats. Paclitaxel treatment also increased cleaved caspase-3 expression, induced the loss of primary afferent terminal fibers and decreased sciatic-evoked A-fiber responses in the spinal dorsal horn, indicating DRG neuronal apoptosis induced by paclitaxel. In addition, the paclitaxel-induced DRG neuronal apoptosis occurred exclusively in the presence of macrophage in vitro study. Intrathecal or systemic injection of CX3CL1 neutralizing antibody blocked paclitaxel-induced macrophage recruitment and neuronal apoptosis in the DRG, and also attenuated paclitaxel-induced allodynia. Furthermore, depletion of macrophage by systemic administration of clodronate inhibited paclitaxel-induced allodynia. Blocking CX3CL1 decreased activation of p38 MAPK in the macrophage, and inhibition of p38 MAPK activity blocked the neuronal apoptosis and development of mechanical allodynia induced by paclitaxel. These findings provide novel evidence that CX3CL1-recruited macrophage contributed to paclitaxel-induced DRG neuronal apoptosis and painful peripheral neuropathy. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Mycolactone-mediated neurite degeneration and functional effects in cultured human and rat DRG neurons: Mechanisms underlying hypoalgesia in Buruli ulcer.

    PubMed

    Anand, U; Sinisi, M; Fox, M; MacQuillan, A; Quick, T; Korchev, Y; Bountra, C; McCarthy, T; Anand, P

    2016-01-01

    Mycolactone is a polyketide toxin secreted by the mycobacterium Mycobacterium ulcerans, responsible for the extensive hypoalgesic skin lesions characteristic of patients with Buruli ulcer. A recent pre-clinical study proposed that mycolactone may produce analgesia via activation of the angiotensin II type 2 receptor (AT2R). In contrast, AT2R antagonist EMA401 has shown analgesic efficacy in animal models and clinical trials for neuropathic pain. We therefore investigated the morphological and functional effects of mycolactone in cultured human and rat dorsal root ganglia (DRG) neurons and the role of AT2R using EMA401. Primary sensory neurons were prepared from avulsed cervical human DRG and rat DRG; 24 h after plating, neurons were incubated for 24 to 96 h with synthetic mycolactone A/B, followed by immunostaining with antibodies to PGP9.5, Gap43, β tubulin, or Mitotracker dye staining. Acute functional effects were examined by measuring capsaicin responses with calcium imaging in DRG neuronal cultures treated with mycolactone. Morphological effects: Mycolactone-treated cultures showed dramatically reduced numbers of surviving neurons and non-neuronal cells, reduced Gap43 and β tubulin expression, degenerating neurites and reduced cell body diameter, compared with controls. Dose-related reduction of neurite length was observed in mycolactone-treated cultures. Mitochondria were distributed throughout the length of neurites and soma of control neurons, but clustered in the neurites and soma of mycolactone-treated neurons. Functional effects: Mycolactone-treated human and rat DRG neurons showed dose-related inhibition of capsaicin responses, which were reversed by calcineurin inhibitor cyclosporine and phosphodiesterase inhibitor 3-isobutyl-1-Methylxanthine, indicating involvement of cAMP/ATP reduction. The morphological and functional effects of mycolactone were not altered by Angiotensin II or AT2R antagonist EMA401. Mycolactone induces toxic effects in DRG

  12. Upregulation of Ih expressed in IB4-negative Aδ nociceptive DRG neurons contributes to mechanical hypersensitivity associated with cervical radiculopathic pain

    PubMed Central

    Liu, Da-Lu; Lu, Na; Han, Wen-Juan; Chen, Rong-Gui; Cong, Rui; Xie, Rou-Gang; Zhang, Yu-Fei; Kong, Wei-Wei; Hu, San-Jue; Luo, Ceng

    2015-01-01

    Cervical radiculopathy represents aberrant mechanical hypersensitivity. Primary sensory neuron’s ability to sense mechanical force forms mechanotransduction. However, whether this property undergoes activity-dependent plastic changes and underlies mechanical hypersensitivity associated with cervical radiculopathic pain (CRP) is not clear. Here we show a new CRP model producing stable mechanical compression of dorsal root ganglion (DRG), which induces dramatic behavioral mechanical hypersensitivity. Amongst nociceptive DRG neurons, a mechanically sensitive neuron, isolectin B4 negative Aδ-type (IB4− Aδ) DRG neuron displays spontaneous activity with hyperexcitability after chronic compression of cervical DRGs. Focal mechanical stimulation on somata of IB4- Aδ neuron induces abnormal hypersensitivity. Upregulated HCN1 and HCN3 channels and increased Ih current on this subset of primary nociceptors underlies the spontaneous activity together with neuronal mechanical hypersensitivity, which further contributes to the behavioral mechanical hypersensitivity associated with CRP. This study sheds new light on the functional plasticity of a specific subset of nociceptive DRG neurons to mechanical stimulation and reveals a novel mechanism that could underlie the mechanical hypersensitivity associated with cervical radiculopathy. PMID:26577374

  13. Wnt3 and Gata4 regulate axon regeneration in adult mouse DRG neurons.

    PubMed

    Duan, Run-Shan; Liu, Pei-Pei; Xi, Feng; Wang, Wei-Hua; Tang, Gang-Bin; Wang, Rui-Ying; Saijilafu; Liu, Chang-Mei

    2018-05-05

    Neurons in the adult central nervous system (CNS) have a poor intrinsic axon growth potential after injury, but the underlying mechanisms are largely unknown. Wingless-related mouse mammary tumor virus integration site (WNT) family members regulate neural stem cell proliferation, axon tract and forebrain development in the nervous system. Here we report that Wnt3 is an important modulator of axon regeneration. Downregulation or overexpression of Wnt3 in adult dorsal root ganglion (DRG) neurons enhances or inhibits their axon regeneration ability respectively in vitro and in vivo. Especially, we show that Wnt3 modulates axon regeneration by repressing mRNA translation of the important transcription factor Gata4 via binding to the three prime untranslated region (3'UTR). Downregulation of Gata4 could restore the phenotype exhibited by Wnt3 downregulation in DRG neurons. Taken together, these data indicate that Wnt3 is a key intrinsic regulator of axon growth ability of the nervous system. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Differential upregulation in DRG neurons of an α2δ-1 splice variant with a lower affinity for gabapentin after peripheral sensory nerve injury

    PubMed Central

    Lana, Beatrice; Schlick, Bettina; Martin, Stuart; Pratt, Wendy S.; Page, Karen M.; Goncalves, Leonor; Rahman, Wahida; Dickenson, Anthony H.; Bauer, Claudia S.; Dolphin, Annette C.

    2014-01-01

    The α2δ-1 protein is an auxiliary subunit of voltage-gated calcium channels, critical for neurotransmitter release. It is upregulated in dorsal root ganglion (DRG) neurons following sensory nerve injury, and is also the therapeutic target of the gabapentinoid drugs, which are efficacious in both experimental and human neuropathic pain conditions. α2δ-1 has 3 spliced regions: A, B, and C. A and C are cassette exons, whereas B is introduced via an alternative 3′ splice acceptor site. Here we have examined the presence of α2δ-1 splice variants in DRG neurons, and have found that although the main α2δ-1 splice variant in DRG is the same as that in brain (α2δ-1 ΔA+B+C), there is also another α2δ-1 splice variant (ΔA+BΔC), which is expressed in DRG neurons and is differentially upregulated compared to the main DRG splice variant α2δ-1 ΔA+B+C following spinal nerve ligation. Furthermore, this differential upregulation occurs preferentially in a small nonmyelinated DRG neuron fraction, obtained by density gradient separation. The α2δ-1 ΔA+BΔC splice variant supports CaV2 calcium currents with unaltered properties compared to α2δ-1 ΔA+B+C, but shows a significantly reduced affinity for gabapentin. This variant could therefore play a role in determining the efficacy of gabapentin in neuropathic pain. PMID:24315988

  15. AKAP localizes in a specific subset of TRPV1 and CaV1.2 positive nociceptive rat DRG neurons

    PubMed Central

    Brandao, Katherine E.; Dell’Acqua, Mark L.; Levinson, Simon R.

    2016-01-01

    Modulation of phosphorylation states of ion channels is a critical step in the development of hyperalgesia during inflammation. Modulatory enhancement of channel activity may increase neuronal excitability and affect downstream targets such as gene transcription. The specificity required for such regulation of ion channels quickly occurs via targeting of protein kinases and phosphatases by the scaffolding A-kinase anchoring protein 79/150 (AKAP79/150). AKAP79/150 has been implicated in inflammatory pain by targeting PKA and PKC to the TRPV1 channel in peripheral sensory neurons, thus lowering threshold for activation by multiple inflammatory reagents. However, the expression pattern of AKAP79/150 in peripheral sensory neurons is unknown. In this study we use immunofluorescence microscopy to identify in DRG sections the peripheral neuron subtypes that express the rodent isoform AKAP150, as well as the subcellular distribution of AKAP150 and its potential target ion channels. We found that AKAP150 is predominantly expressed in a subset of small DRG sensory neurons where it is localized at the plasma membrane of the soma, axon initial segment and small fibers. The majority of these neurons is peripherin positive and produces c-fibers, though a small portion produces Aδ-fibers. Furthermore, we demonstrate that AKAP79/150 colocalizes with TRPV1 and CaV1.2 in the soma and axon initial segment. Thus AKAP150 is expressed in small, nociceptive DRG neurons where it is targeted to membrane regions and where it may play a role in the modulation of ion channel phosphorylation states required for hyperalgesia. PMID:21674494

  16. Emodin down-regulates expression of TRPV1 mRNA and its function in DRG neurons in vitro.

    PubMed

    Sui, Feng; Huo, Hai-Ru; Zhang, Chang-Bin; Yang, Na; Guo, Jian-You; Du, Xin-Liang; Zhao, Bao-Sheng; Liu, Hong-Bin; Li, Lan-Fang; Guo, Shu-Ying; Jiang, Ting-Liang

    2010-01-01

    Emodin is a principle ingredient isolated from rhubarb rhizome, which is commonly used for constipation or pain-related diseases in traditional Chinese medicine (TCM) practice. The transient receptor potential vanilloid 1 ion channel proteins (TRPV1) are abundantly expressed in the peripheral sensory neurons and are assumed to act as a kind of nociceptor involved in the perception of pain and development of hyperalgesia. The aim of this study was to further unravel the analgesic mechanisms of rhubarb through investigating the effects of its main constitutive ingredient emodin on the expression of TRPV1 mRNA as well as on its calcium- mediating functions in vitro. The primary DRG neurons with a high purity and viability were obtained, and the TRPV1 mRNA expression levels were examined by using real-time RT-PCR and the elevated amplitudes of intracellular [Ca(2+)]i in the DRG neurons evoked by TRPV1 agonist capsaicin were examined by confocal microscopy. The results showed that emodin could significantly down-regulate both the mRNA expression of TRPV1 and the capsaicin-evoked intracellular fluorescent intensity in the DRG neurons under both 37 degrees C and 39 degrees C in vitro. Concomitantly, all of the changes induced by emodin could not be blocked by pretreatment of the primary neurons with capsazepine, an antagonist of TRPV1. In conclusion, we established that the mRNA expression level of TRPV1 and its calcium-mediating function in naive DRG neurons could be down-regulated by emodin through perhaps the non-TRPV1 channel pathways, and this might be the molecular mechanisms for rhubarb to inhibit hyperalgesia induced by inflammatory stimuli.

  17. Upregulation of T-type Ca2+ channels in long-term diabetes determines increased excitability of a specific type of capsaicin-insensitive DRG neurons.

    PubMed

    Duzhyy, Dmytro E; Viatchenko-Karpinski, Viacheslav Y; Khomula, Eugen V; Voitenko, Nana V; Belan, Pavel V

    2015-05-20

    Previous studies have shown that increased excitability of capsaicin-sensitive DRG neurons and thermal hyperalgesia in rats with short-term (2-4 weeks) streptozotocin-induced diabetes is mediated by upregulation of T-type Ca(2+) current. In longer-term diabetes (after the 8th week) thermal hyperalgesia is changed to hypoalgesia that is accompanied by downregulation of T-type current in capsaicin-sensitive small-sized nociceptors. At the same time pain symptoms of diabetic neuropathy other than thermal persist in STZ-diabetic animals and patients during progression of diabetes into later stages suggesting that other types of DRG neurons may be sensitized and contribute to pain. In this study, we examined functional expression of T-type Ca(2+) channels in capsaicin-insensitive DRG neurons and excitability of these neurons in longer-term diabetic rats and in thermally hypoalgesic diabetic rats. Here we have demonstrated that in STZ-diabetes T-type current was upregulated in capsaicin-insensitive low-pH-sensitive small-sized nociceptive DRG neurons of longer-term diabetic rats and thermally hypoalgesic diabetic rats. This upregulation was not accompanied by significant changes in biophysical properties of T-type channels suggesting that a density of functionally active channels was increased. Sensitivity of T-type current to amiloride (1 mM) and low concentration of Ni(2+) (50 μM) implicates prevalence of Cav3.2 subtype of T-type channels in the capsaicin-insensitive low-pH-sensitive neurons of both naïve and diabetic rats. The upregulation of T-type channels resulted in the increased neuronal excitability of these nociceptive neurons revealed by a lower threshold for action potential initiation, prominent afterdepolarizing potentials and burst firing. Sodium current was not significantly changed in these neurons during long-term diabetes and could not contribute to the diabetes-induced increase of neuronal excitability. Capsaicin-insensitive low-pH-sensitive type

  18. Depolarized inactivation overcomes impaired activation to produce DRG neuron hyperexcitability in a Nav1.7 mutation in a patient with distal limb pain.

    PubMed

    Huang, Jianying; Yang, Yang; Dib-Hajj, Sulayman D; van Es, Michael; Zhao, Peng; Salomon, Jody; Drenth, Joost P H; Waxman, Stephen G

    2014-09-10

    Sodium channel Nav1.7, encoded by SCN9A, is expressed in DRG neurons and regulates their excitability. Genetic and functional studies have established a critical contribution of Nav1.7 to human pain disorders. We have now characterized a novel Nav1.7 mutation (R1279P) from a female human subject with distal limb pain, in which depolarized fast inactivation overrides impaired activation to produce hyperexcitability and spontaneous firing in DRG neurons. Whole-cell voltage-clamp recordings in human embryonic kidney (HEK) 293 cells demonstrated that R1279P significantly depolarizes steady-state fast-, slow-, and closed-state inactivation. It accelerates deactivation, decelerates inactivation, and facilitates repriming. The mutation increases ramp currents in response to slow depolarizations. Our voltage-clamp analysis showed that R1279P depolarizes channel activation, a change that was supported by our multistate structural modeling. Because this mutation confers both gain-of-function and loss-of-function attributes on the Nav1.7 channel, we tested the impact of R1279P expression on DRG neuron excitability. Current-clamp studies reveal that R1279P depolarizes resting membrane potential, decreases current threshold, and increases firing frequency of evoked action potentials within small DRG neurons. The populations of spontaneously firing and repetitively firing neurons were increased by expressing R1279P. These observations indicate that the dominant proexcitatory gating changes associated with this mutation, including depolarized steady-state fast-, slow-, and closed-state inactivation, faster repriming, and larger ramp currents, override the depolarizing shift of activation, to produce hyperexcitability and spontaneous firing of nociceptive neurons that underlie pain. Copyright © 2014 the authors 0270-6474/14/3412328-13$15.00/0.

  19. Differential upregulation in DRG neurons of an α2δ-1 splice variant with a lower affinity for gabapentin after peripheral sensory nerve injury.

    PubMed

    Lana, Beatrice; Schlick, Bettina; Martin, Stuart; Pratt, Wendy S; Page, Karen M; Goncalves, Leonor; Rahman, Wahida; Dickenson, Anthony H; Bauer, Claudia S; Dolphin, Annette C

    2014-03-01

    The α2δ-1 protein is an auxiliary subunit of voltage-gated calcium channels, critical for neurotransmitter release. It is upregulated in dorsal root ganglion (DRG) neurons following sensory nerve injury, and is also the therapeutic target of the gabapentinoid drugs, which are efficacious in both experimental and human neuropathic pain conditions. α2δ-1 has 3 spliced regions: A, B, and C. A and C are cassette exons, whereas B is introduced via an alternative 3' splice acceptor site. Here we have examined the presence of α2δ-1 splice variants in DRG neurons, and have found that although the main α2δ-1 splice variant in DRG is the same as that in brain (α2δ-1 ΔA+B+C), there is also another α2δ-1 splice variant (ΔA+BΔC), which is expressed in DRG neurons and is differentially upregulated compared to the main DRG splice variant α2δ-1 ΔA+B+C following spinal nerve ligation. Furthermore, this differential upregulation occurs preferentially in a small nonmyelinated DRG neuron fraction, obtained by density gradient separation. The α2δ-1 ΔA+BΔC splice variant supports CaV2 calcium currents with unaltered properties compared to α2δ-1 ΔA+B+C, but shows a significantly reduced affinity for gabapentin. This variant could therefore play a role in determining the efficacy of gabapentin in neuropathic pain. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  20. The Protective Effects of IGF-1 on Different Subpopulations of DRG Neurons with Neurotoxicity Induced by gp120 and Dideoxycytidine In Vitro.

    PubMed

    Lu, Lin; Dong, Haixia; Liu, Guixiang; Yuan, Bin; Li, Yizhao; Liu, Huaxiang

    2014-11-01

    Peripheral neuropathy induced by human immunodeficiency virus (HIV) infection and antiretroviral therapy is not only difficult to distinguish in clinical practice, but also difficult to relieve the pain symptoms by analgesics because of the severity of the disease at the later stage. Hence, to explore the mechanisms of HIV-related neuropathy and find new therapeutic options are particularly important for relieving neuropathic pain symptoms of the patients. In the present study, primary cultured embryonic rat dorsal root ganglion (DRG) neurons were used to determine the neurotoxic effects of HIV-gp120 protein and/or antiretroviral drug dideoxycytidine (ddC) and the therapeutic actions of insulin-like growth factor-1 (IGF-1) on gp120- or ddC-induced neurotoxicity. DRG neurons were exposed to gp120 (500 pmol/L), ddC (50 μmol/L), gp120 (500 pmol/L) plus ddC (50 μmol/L), gp120 (500 pmol/L) plus IGF-1 (20 nmol/L), ddC (50 μmol/L) plus IGF-1 (20 nmol/L), gp120 (500 pmol/L) plus ddC (50 μmol/L) plus IGF-1 (20 nmol/L), respectively, for 72 hours. The results showed that gp120 and/or ddC caused neurotoxicity of primary cultured DRG neurons. Interestingly, the severity of neurotoxicity induced by gp120 and ddC was different in different subpopulation of DRG neurons. gp120 mainly affected large diameter DRG neurons (>25 μm), whereas ddC mainly affected small diameter DRG neurons (≤25 μm). IGF-1 could reverse the neurotoxicity induced by gp120 and/or ddC on small, but not large, DRG neurons. These data provide new insights in elucidating the pathogenesis of HIV infection- or antiretroviral therapy-related peripheral neuropathy and facilitating the development of novel treatment strategies.

  1. The Protective Effects of IGF-1 on Different Subpopulations of DRG Neurons with Neurotoxicity Induced by gp120 and Dideoxycytidine In Vitro

    PubMed Central

    Lu, Lin; Dong, Haixia; Liu, Guixiang; Yuan, Bin; Li, Yizhao; Liu, Huaxiang

    2014-01-01

    Peripheral neuropathy induced by human immunodeficiency virus (HIV) infection and antiretroviral therapy is not only difficult to distinguish in clinical practice, but also difficult to relieve the pain symptoms by analgesics because of the severity of the disease at the later stage. Hence, to explore the mechanisms of HIV-related neuropathy and find new therapeutic options are particularly important for relieving neuropathic pain symptoms of the patients. In the present study, primary cultured embryonic rat dorsal root ganglion (DRG) neurons were used to determine the neurotoxic effects of HIV-gp120 protein and/or antiretroviral drug dideoxycytidine (ddC) and the therapeutic actions of insulin-like growth factor-1 (IGF-1) on gp120- or ddC-induced neurotoxicity. DRG neurons were exposed to gp120 (500 pmol/L), ddC (50 μmol/L), gp120 (500 pmol/L) plus ddC (50 μmol/L), gp120 (500 pmol/L) plus IGF-1 (20 nmol/L), ddC (50 μmol/L) plus IGF-1 (20 nmol/L), gp120 (500 pmol/L) plus ddC (50 μmol/L) plus IGF-1 (20 nmol/L), respectively, for 72 hours. The results showed that gp120 and/or ddC caused neurotoxicity of primary cultured DRG neurons. Interestingly, the severity of neurotoxicity induced by gp120 and ddC was different in different subpopulation of DRG neurons. gp120 mainly affected large diameter DRG neurons (>25 μm), whereas ddC mainly affected small diameter DRG neurons (≤25 μm). IGF-1 could reverse the neurotoxicity induced by gp120 and/or ddC on small, but not large, DRG neurons. These data provide new insights in elucidating the pathogenesis of HIV infection- or antiretroviral therapy-related peripheral neuropathy and facilitating the development of novel treatment strategies. PMID:25489421

  2. Adjuvant-induced joint inflammation causes very rapid transcription of beta-preprotachykinin and alpha-CGRP genes in innervating sensory ganglia.

    PubMed

    Bulling, D G; Kelly, D; Bond, S; McQueen, D S; Seckl, J R

    2001-04-01

    Neuropeptides synthesized in dorsal root ganglia (DRG) have been implicated in neurogenic inflammation and nociception in experimental and clinical inflammatory arthritis. We examined the very early changes in response to adjuvant injection in a rat model of unilateral tibio-tarsal joint inflammation and subsequent monoarthritis. Within 30 min of adjuvant injection ipsilateral swelling and hyperalgesia were apparent, and marked increases in beta-preprotachykinin-A (beta-PPT-A) and alpha-calcitonin gene-related peptide (CGRP)-encoding mRNAs were observed in small-diameter L5 DRG neurones innervating the affected joint. This response was augmented by recruitment of additional small-diameter DRG neurones expressing beta-PPT-A and CGRP transcripts. The increased mRNA was paralleled by initial increases in L5 DRG content of the protein products, substance P and calcitonin gene-related peptide. Within 15 min of adjuvant injection there were increases in electrical activity in sensory nerves innervating a joint. Blockade of this activity prevented the rapid induction in beta-PPT-A and CGRP mRNA expression in DRG neurones. Increased expression of heteronuclear (intron E) beta-PPT-A RNA suggests that increases in beta-PPT-A mRNA levels were, at least in part, due to transcription. Pre-treatment with the protein synthesis inhibitor cycloheximide had no effect upon the early rise in neuropeptide mRNAS: This and the rapid time course of these changes suggest that increased sensory neural discharge and activation of a latent modulator of transcription are involved.

  3. Anti-nociceptive mechanism of baicalin involved in intervention of TRPV1 in DRG neurons in vitro.

    PubMed

    Sui, Feng; Zhang, Chang-Bin; Yang, Na; Li, Lan-Fang; Guo, Shu-Ying; Huo, Hai-Ru; Jiang, Ting-Liang

    2010-06-16

    Scutellaria baicalensis Georgi (Lamiaceae) is often included as an ingredient in traditional Chinese compound prescriptions for the treatment of fever-related or inflammatory conditions. The present work was to further uncover the analgesic mechanisms of baicalin (a known principal constituent of Scutellaria baicalensis) by investigating its effects on the expression of TRPV1 mRNA as well as on its functions as mediators of calcium entrance into the cytoplasm of dorsal root ganglion (DRG) neurons in vitro. By using CPT as an agent to eliminate the non-neuronal cells and using serum-free neurobasal as culture medium, primary cultures of rat DRG neurons with high purity and viability were established. On this basis, effects of baicalin on both the expression of TRPV1 mRNA and on the function of TRPV1 in vitro under two various temperature conditions were studied. The TRPV1 mRNA expression levels were examined by using qRT-PCR and analyzed by the method of 2(-DeltaDeltaCT). The elevation amplitudes of intracellular [Ca(2+)]i evoked by TRPV1 agonist capsaicin in DRG neurons were examined by the calcium fluorescence imaging method under confocal microscopy. Baicalin was shown to down-regulate the mRNA expression levels of TRPV1 at both 37 and 39 degrees C, and under the latter temperature, the intracellular fluorescent intensity evoked by capsaicin was significantly decreased following incubation with baicalin in vitro. We also demonstrated that the actions of baicalin to TRPV1 were not achieved through pathways of TRPA1 or TRPV subfamily members. Collectively, these results provide compelling evidence that the down-regulated actions of baicalin to TRPV1 in DRG neurons might account for part of the anti-nociceptive mechanism of baicalin. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  4. Activation of ATP-sensitive potassium channels antagonize nociceptive behavior and hyperexcitability of DRG neurons from rats.

    PubMed

    Du, Xiaona; Wang, Chao; Zhang, Hailin

    2011-05-14

    Nociceptive responses to noxious stimuli are initiated at peripheral nociceptor terminals. Ion channels play a vital role in pain signal initiation and conduction. Activation of KATP channels has been implicated in mediating the analgesic effects of agents such as morphine. However, systematic studies regarding the effects of KATP activators on nociception and neuronal excitability are scarce. In this study, we describe the antagonistic effects of KATP activators pinacidil and diazoxide on nocifensive behavior induced by bradykinin (BK), thermo and mechanical stimuli, and the bradykinin-induced hyperexcitability of DRG neurons. We also found that KATP activators can moderately activate KATP in DRG neurons. Because the effects of KATP activators can be reversed by the KATP blocker glyburide, direct activation of KATP is most likely the underlying mechanism. This systematic study clearly demonstrates that activation of KATP could have significant modulatory effects on the excitability of sensory neurons and thus on sensory behaviors, such as nociception. KATP activators can be evaluated clinically for the treatment of pain symptoms.

  5. Capsaicin-induced activation of ERK1/2 and its involvement in GAP-43 expression and CGRP depletion in organotypically cultured DRG neurons.

    PubMed

    Li, Yunfeng; Liu, Guixiang; Li, Hao; Xu, Youzheng; Zhang, Hong; Liu, Zhen

    2013-04-01

    Low concentrations of capsaicin (CAP) stimulate and high concentrations of CAP can be toxic to the primary sensory neurons of the dorsal root ganglion (DRG). CAP induces the phosphorylation of extracellular signal-regulated protein kinases 1/2 (ERK1/2) in DRG neurons. The effect of the activation of ERK1/2 by different concentrations of CAP on growth-associated protein 43 (GAP-43) expression and calcitonin gene-related peptide (CGRP) depletion in DRG neurons remains unknown. In the present study, organotypic embryonic 15-day-old rat DRG explants were used to determine the effect of different concentrations of CAP on GAP-43 expression and CGRP depletion. The results showed that, compared to unstimulated control cultures, GAP-43 and pERK1/2 protein levels increased at a low concentration (2 μmol/L) of CAP and decreased at a higher concentration (10 μmol/L). The number of CGRP-immunoreactive (IR) migrating neurons also decreased in CAP-treated cultures. The increase in GAP-43 levels and CGRP depletion could be blocked by the administration of ERK1/2 inhibitor PD98059. The results of the present study imply that CAP at different concentrations has different effects on GAP-43 expression and CGRP depletion. These effects were involved in the activation of ERK1/2 in organotypically cultured DRG neurons stimulated with CAP. These data may provide new insights for further development potential therapeutic applications of CAP with moderate dose on neurogenic inflammation.

  6. Delayed onset of changes in soma action potential genesis in nociceptive A-beta DRG neurons in vivo in a rat model of osteoarthritis

    PubMed Central

    Wu, Qi; Henry, James L

    2009-01-01

    Background Clinical data on osteoarthritis (OA) suggest widespread changes in sensory function that vary during the progression of OA. In previous studies on a surgically-induced animal model of OA we have observed that changes in structure and gene expression follow a variable trajectory over the initial days and weeks. To investigate mechanisms underlying changes in sensory function in this model, the present electrophysiological study compared properties of primary sensory nociceptive neurons at one and two months after model induction with properties in naïve control animals. Pilot data indicated no difference in C- or Aδ-fiber associated neurons and therefore the focus is on Aβ-fiber nociceptive neurons. Results At one month after unilateral derangement of the knee by cutting the anterior cruciate ligament and removing the medial meniscus, the only changes observed in Aβ-fiber dorsal root ganglion (DRG) neurons were in nociceptor-like unresponsive neurons bearing a hump on the repolarization phase; these changes consisted of longer half width, reflecting slowed dynamics of AP genesis, a depolarized Vm and an increased AP amplitude. At two months, changes observed were in Aβ-fiber high threshold mechanoreceptors, which exhibited shorter AP duration at base and half width, shorter rise time and fall time, and faster maximum rising rate/maximum falling rate, reflecting accelerated dynamics of AP genesis. Conclusion These data indicate that Aβ nociceptive neurons undergo significant changes that vary in time and occur later than changes in structure and in nociceptive scores in this surgically induced OA model. Thus, if changes in Aβ-fiber nociceptive neurons in this model reflect a role in OA pain, they may relate to mechanisms underlying pain associated with advanced OA. PMID:19785765

  7. Role of laser fluence in protein synthesis of cultured DRG neurons following low-level laser irradiation

    NASA Astrophysics Data System (ADS)

    Zheng, Liqin; Qiu, Caimin; Wang, Yuhua; Zeng, Yixiu; Yang, Hongqin; Zhang, Yanding; Xie, Shusen

    2014-11-01

    Low-level lasers have been used to relieve pain in clinical for many years. But the mechanism is not fully clear. In animal models, nitric oxide (NO) has been reported involving in the transmission and modulation of nociceptive signals. So the objective of this study was to establish whether low-level laser with different fluence could stimulate the production of nitric oxide synthese (NOS), which produces NO in cultured primary dorsal root ganglion neurons (DRG neurons). The primary DRG neurons were isolated from healthy Sprague Dawley rats (8-12 weeks of age) and spread on 35 mm culture dishes specially used for confocal microscopy. 24 hours after spreading, cells were irradiated with 658 nm laser for two consecutive days at the energy density of 20, 40, 60 and 80 mJ·cm-2 respectively. Control groups were not exposed to the laser, but were kept under the same conditions as the irradiated ones. The synthesis of NOS after laser irradiation was detected by immunofluorescence assay, and the changes of NOS were evaluated using confocal microscopy and Image J software. The results showed that all the laser fluence could promote the production of NOS in DRG neurons, especially the 60 mJ·cm-2 . These results demonstrated that low-level laser irradiation could modify protein synthesis in a dose- or fluence- dependent manner, and indicated that low-level laser irradiation might achieve the analgesic effect through modulation of NO production.

  8. [Neuron differential attachment purification and its influence factor].

    PubMed

    Li, Jun; Feng, Daxiong; Huang, Yize; Ye, Fei

    2010-02-01

    Neuron purification is essential to procedure of various nerve cell experimental research, however, at present there is few reports on the effect of various factors on neural axons during purification. To find out a simple method of neuron purification, and to investigate the influence factors of corresponding purification culture in dorsal root ganglion (DRG) tissue culture on beta3-tubulin positive axon. The DRGs were obtained from the 3 days neonatal SD rat microscopically and were made into cell suspension. Then, the amount of attached DRG neurons and nonneuronal cells in poly-D-lysine (PDL) group, PDL/Laminin (PDL/LN) group and collagen-I (Col I) group was observed from 10 to 100 minutes. Then, the extension and arborization of beta3-tubulin positive axons were observed after 72 hours completely randomised DRG tissue culture for the research of the influences among culture substrates (PDL, PDL/LN, and Col I), FBS (0, 5%, and 10%), 5 fluorouracil (5-Fu, 0, 20, and 40 micromol/L), and cytarabine (Ara-C, 0, 10, and 20 micromol/L). Adherent cells were observed instantly after inoculation by inverted phase contrast microscope and inverted fluorescence microscope; after cell suspension was removed, adherent growth of DRGn cells and non-DRGn cells were still seen. In PDL group, the amount of NSE negative cells was significantly higher than that of NSE positive cells at 10 and 30 minutes (P < 0.05); the amount of NSE positive cells was significantly higher than that of NSE negative cells at 80, 90 and 100 minutes (P < 0.05). In PDL/LN group, there was no significant difference (P > 0.05) in the amount of NSE negative cells and NSE positive cells at 10, 20, 30, 40, and 50 minutes; the amount of NSE positive cells was significantly higher (P < 0.05) than that of NSE negative cells at 60, 70, 80, 90, 100 minutes. In Col I group, the amount of NSE negative cells was higher than that of NSE positive cells at 10-40 minutes, but showing no significant difference (P > 0

  9. [The effect of niflumic acid on gamma aminobutyric acid activated current in DRG neurons].

    PubMed

    Li, Li; Li, Jing; Ma, Ke-Tao; Cheng, Hong-Ju; Zhao, Lei; Wang, Yang; Si, Jun-Qiang

    2013-01-01

    To explore the modulatory effect of niflumic acid (NFA) on gamma aminobutyric acid (GABA)-activated currents of dorsal root ganglion (DRG) neurons in rat. The whole-cell patch-clamp technique was used to record the NFA- and GABA-activated currents in neurons freshly dissociated from rat DRG neurons. Application of NFA(0.1 - 100 micromol/L) could induce concentration-dependent outward currents in some cells (21/48,43.75%), and GABA (0.1 - 100 micromol/L) could induce concentration-dependent inward currents in some cells(150/159,94.32%). NFA-(100 micromol/L) and GABA-(100 micromol/L) activated currents were (0.27 +/- 0.06) nA (n = 12) and (1.29 +/- 0.72) nA (n = 53) respectively. However, pre-application of NFA (0.1 - 100 micromol/L) could inhibit the GABA-activated inward current which was identified to be GABAA receptor-mediated current. The inhibitory effects of NFA were concentration-dependent. NFA could not alter the EC50 (about 30 micromol/L) and inverse potential (about -10 mV) of GABA-activated current (P > 0.05). Pre-application of NFA exerts a more strong inhibitory effect on the peak value of GABA-activated current.

  10. TNF-α contributes to up-regulation of Nav1.3 and Nav1.8 in DRG neurons following motor fiber injury.

    PubMed

    He, Xin-Hua; Zang, Ying; Chen, Xi; Pang, Rui-Ping; Xu, Ji-Tian; Zhou, Xiang; Wei, Xu-Hong; Li, Yong-Yong; Xin, Wen-Jun; Qin, Zhi-Hai; Liu, Xian-Guo

    2010-11-01

    A large body of evidence has demonstrated that the ectopic discharges of action potentials in primary afferents, resulted from the abnormal expression of voltage gated sodium channels (VGSCs) in dorsal root ganglion (DRG) neurons following peripheral nerve injury are important for the development of neuropathic pain. However, how nerve injury affects the expression of VGSCs is largely unknown. Here, we reported that selective injury of motor fibers by L5 ventral root transection (L5-VRT) up-regulated Nav1.3 and Nav1.8 at both mRNA and protein level and increased current densities of TTX-S and TTX-R channels in DRG neurons, suggesting that nerve injury may up-regulate functional VGSCs in sensory neurons indirectly. As the up-regulated Nav1.3 and Nav1.8 were highly co-localized with TNF-α, we tested the hypothesis that the increased TNF-α may lead to over-expression of the sodium channels. Indeed, we found that peri-sciatic administration of recombinant rat TNF-α (rrTNF) without any nerve injury, which produced lasting mechanical allodynia, also up-regulated Nav1.3 and Nav1.8 in DRG neurons in vivo and that rrTNF enhanced the expression of Nav1.3 and Nav1.8 in cultured adult rat DRG neurons in a dose-dependent manner. Furthermore, inhibition of TNF-α synthesis, which prevented neuropathic pain, strongly inhibited the up-regulation of Nav1.3 and Nav1.8. The up-regulation of the both channels following L5-VRT was significantly lower in TNF receptor 1 knockout mice than that in wild type mice. These data suggest that increased TNF-α may be responsible for up-regulation of Nav1.3 and Nav1.8 in uninjured DRG neurons following nerve injury. Copyright © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  11. Upregulation of the sodium channel NaVβ4 subunit and its contributions to mechanical hypersensitivity and neuronal hyperexcitability in a rat model of radicular pain induced by local DRG inflammation

    PubMed Central

    Xie, Wenrui; Tan, Zhi-Yong; Barbosa, Cindy; Strong, Judith A.; Cummins, Theodore R.; Zhang, Jun-Ming

    2016-01-01

    High frequency spontaneous firing in myelinated sensory neurons plays a key role in initiating pain behaviors in several different models, including the radicular pain model in which the rat lumbar dorsal root ganglia (DRG) are locally inflamed. The sodium channel isoform NaV1.6 contributes to pain behaviors and spontaneous activity in this model. Among all the isoforms in adult DRG, NaV1.6 is the main carrier of TTX-sensitive resurgent Na currents that allow high-frequency firing. Resurgent currents flow after a depolarization or action potential, as a blocking particle exits the pore. In most neurons the regulatory β4 subunit is potentially the endogenous blocker. We used in vivo siRNA mediated knockdown of NaVβ4 to examine its role in the DRG inflammation model. NaVβ4 but not control siRNA almost completely blocked mechanical hypersensitivity induced by DRG inflammation. Microelectrode recordings in isolated whole DRGs showed that NaVβ4 siRNA blocked the inflammation-induced increase in spontaneous activity of Aβ neurons, and reduced repetitive firing and other measures of excitability. NaVβ4 was preferentially expressed in larger diameter cells; DRG inflammation increased its expression and this was reversed by NaVβ4 siRNA, based on immunohistochemistry and Western blotting. NaVβ4 siRNA also reduced immunohistochemical NaV1.6 expression. Patch clamp recordings of TTX-sensitive Na currents in acutely cultured medium diameter DRG neurons showed that DRG inflammation increased transient and especially resurgent current; effects blocked by NaVβ4 siRNA. NaVβ4 may represent a more specific target for pain conditions that depend on myelinated neurons expressing NaV1.6. PMID:26785322

  12. Functional interaction of TRPV4 channel protein with annexin A2 in DRG.

    PubMed

    Ning, Liping; Wang, Chuanwei; Ding, Xinli; Zhang, Yang; Wang, Xuping; Yue, Shouwei

    2012-09-01

    Transient receptor potential vanilloid 4 (TRPV4) is a Ca(2+)-permeable, non-selective cation channel that is involved in the transmission of pain signals mediated by dorsal root ganglion (DRG). Annexin A2 belongs to a class of membrane-binding proteins that plays an important role in the regulation of ion channels. Nevertheless, little is known about the interaction between them in DRG. In this paper, we evaluated the functional interaction of TRPV4 with annexin A2 in DRG. We have used immunocytochemistry and co-immunoprecipitation assays to investigate the interaction between annexin A2 and TRPV4 in DRG. The role of annexin A2 in the regulation of TRPV4 activity in DRG was further verified by measurement of intracellular free calcium concentrations ([Ca(2+)](i)) and substance P (SP) release. First, annexin A2 was showed partial co-localization with TRPV4 in DRG neurons. Then, annexin A2 and TRPV4 were co-precipitated with each other in DRG lysates. Furthermore, the downregulation of annexin A2 using specific small interfering RNA significantly inhibited Ca(2+) influx and SP mediated by TRPV4. Our results provide evidence that annexin A2 is associated with TRPV4 and regulates TRPV4-mediated Ca(2+) influx and SP release in DRG neurons. The objective of this work is to determine the influence of annexin A2 on TRPV4 in DRG neurons, which may be the basis for treatment of pain relief.

  13. Comparison of the force exerted by hippocampal and DRG growth cones.

    PubMed

    Amin, Ladan; Ercolini, Erika; Ban, Jelena; Torre, Vincent

    2013-01-01

    Mechanical properties such as force generation are fundamental for neuronal motility, development and regeneration. We used optical tweezers to compare the force exerted by growth cones (GCs) of neurons from the Peripheral Nervous System (PNS), such as Dorsal Root Ganglia (DRG) neurons, and from the Central Nervous System (CNS) such as hippocampal neurons. Developing GCs from dissociated DRG and hippocampal neurons were obtained from P1-P2 and P10-P12 rats. Comparing their morphology, we observed that the area of GCs of hippocampal neurons was 8-10 µm(2) and did not vary between P1-P2 and P10-P12 rats, but GCs of DRG neurons were larger and their area increased from P1-P2 to P10-P12 by 2-4 times. The force exerted by DRG filopodia was in the order of 1-2 pN and never exceeded 5 pN, while hippocampal filopodia exerted a larger force, often in the order of 5 pN. Hippocampal and DRG lamellipodia exerted lateral forces up to 20 pN, but lamellipodia of DRG neurons could exert a vertical force larger than that of hippocampal neurons. Force-velocity relationships (Fv) in both types of neurons had the same qualitative behaviour, consistent with a common autocatalytic model of force generation. These results indicate that molecular mechanisms of force generation of GC from CNS and PNS neurons are similar but the amplitude of generated force is influenced by their cytoskeletal properties.

  14. Comparison of the Force Exerted by Hippocampal and DRG Growth Cones

    PubMed Central

    Amin, Ladan; Ercolini, Erika; Ban, Jelena; Torre, Vincent

    2013-01-01

    Mechanical properties such as force generation are fundamental for neuronal motility, development and regeneration. We used optical tweezers to compare the force exerted by growth cones (GCs) of neurons from the Peripheral Nervous System (PNS), such as Dorsal Root Ganglia (DRG) neurons, and from the Central Nervous System (CNS) such as hippocampal neurons. Developing GCs from dissociated DRG and hippocampal neurons were obtained from P1-P2 and P10-P12 rats. Comparing their morphology, we observed that the area of GCs of hippocampal neurons was 8-10 µm2 and did not vary between P1-P2 and P10-P12 rats, but GCs of DRG neurons were larger and their area increased from P1-P2 to P10-P12 by 2-4 times. The force exerted by DRG filopodia was in the order of 1-2 pN and never exceeded 5 pN, while hippocampal filopodia exerted a larger force, often in the order of 5 pN. Hippocampal and DRG lamellipodia exerted lateral forces up to 20 pN, but lamellipodia of DRG neurons could exert a vertical force larger than that of hippocampal neurons. Force-velocity relationships (Fv) in both types of neurons had the same qualitative behaviour, consistent with a common autocatalytic model of force generation. These results indicate that molecular mechanisms of force generation of GC from CNS and PNS neurons are similar but the amplitude of generated force is influenced by their cytoskeletal properties. PMID:23991169

  15. Mouse DRG Cell Line with Properties of Nociceptors.

    PubMed

    Doran, Ciara; Chetrit, Jonathan; Holley, Matthew C; Grundy, David; Nassar, Mohammed A

    2015-01-01

    In vitro cell lines from DRG neurons aid drug discovery because they can be used for early stage, high-throughput screens for drugs targeting pain pathways, with minimal dependence on animals. We have established a conditionally immortal DRG cell line from the Immortomouse. Using immunocytochemistry, RT-PCR and calcium microfluorimetry, we demonstrate that the cell line MED17.11 expresses markers of cells committed to the sensory neuron lineage. Within a few hours under differentiating conditions, MED17.11 cells extend processes and following seven days of differentiation, express markers of more mature DRG neurons, such as NaV1.7 and Piezo2. However, at least at this time-point, the nociceptive marker NaV1.8 is not expressed, but the cells respond to compounds known to excite nociceptors, including the TRPV1 agonist capsaicin, the purinergic receptor agonist ATP and the voltage gated sodium channel agonist, veratridine. Robust calcium transients are observed in the presence of the inflammatory mediators bradykinin, histamine and norepinephrine. MED17.11 cells have the potential to replace or reduce the use of primary DRG culture in sensory, pain and developmental research by providing a simple model to study acute nociception, neurite outgrowth and the developmental specification of DRG neurons.

  16. Upregulation of N-type calcium channels in the soma of uninjured dorsal root ganglion neurons contributes to neuropathic pain by increasing neuronal excitability following peripheral nerve injury.

    PubMed

    Yang, Jie; Xie, Man-Xiu; Hu, Li; Wang, Xiao-Fang; Mai, Jie-Zhen; Li, Yong-Yong; Wu, Ning; Zhang, Cheng; Li, Jin; Pang, Rui-Ping; Liu, Xian-Guo

    2018-07-01

    N-type voltage-gated calcium (Cav2.2) channels are expressed in the central terminals of dorsal root ganglion (DRG) neurons, and are critical for neurotransmitter release. Cav2.2 channels are also expressed in the soma of DRG neurons, where their function remains largely unknown. Here, we showed that Cav2.2 was upregulated in the soma of uninjured L4 DRG neurons, but downregulated in those of injured L5 DRG neurons following L5 spinal nerve ligation (L5-SNL). Local application of specific Cav2.2 blockers (ω-conotoxin GVIA, 1-100 μM or ZC88, 10-1000 μM) onto L4 and 6 DRGs on the operated side, but not the contralateral side, dose-dependently reversed mechanical allodynia induced by L5-SNL. Patch clamp recordings revealed that both ω-conotoxin GVIA (1 μM) and ZC88 (10 μM) depressed hyperexcitability in L4 but not in L5 DRG neurons of L5-SNL rats. Consistent with this, knockdown of Cav2.2 in L4 DRG neurons with AAV-Cav2.2 shRNA substantially prevented L5-SNL-induced mechanical allodynia and hyperexcitability of L4 DRG neurons. Furthermore, in L5-SNL rats, interleukin-1 beta (IL-1β) and IL-10 were upregulated in L4 DRGs and L5 DRGs, respectively. Intrathecal injection of IL-1β induced mechanical allodynia and Cav2.2 upregulation in bilateral L4-6 DRGs of naïve rats, whereas injection of IL-10 substantially prevented mechanical allodynia and Cav2.2 upregulation in L4 DRGs in L5-SNL rats. Finally, in cultured DRG neurons, Cav2.2 was dose-dependently upregulated by IL-1β and downregulated by IL-10. These data indicate that the upregulation of Cav2.2 in uninjured DRG neurons via IL-1β over-production contributes to neuropathic pain by increasing neuronal excitability following peripheral nerve injury. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Interactions of Notch1 and TLR4 signaling pathways in DRG neurons of in vivo and in vitro models of diabetic neuropathy.

    PubMed

    Chen, Tianhua; Li, Hao; Yin, Yiting; Zhang, Yuanpin; Liu, Zhen; Liu, Huaxiang

    2017-11-02

    Understanding the interactions between Notch1 and toll-like receptor 4 (TLR4) signaling pathways in the development of diabetic peripheral neuropathy may lead to interpretation of the mechanisms and novel approaches for preventing diabetic neuropathic pain. In the present study, the interactions between Notch1 and TLR4 signaling pathways were investigated by using dorsal root ganglion (DRG) from diabetic neuropathic pain rats and cultured DRG neurons under high glucose challenge. The results showed that high glucose induced not only Notch1 mRNA, HES1 mRNA, and TLR4 mRNA expression, but also Notch1 intracellular domain (NICD1) and TLR4 protein expression in DRG neurons. The proportion of NICD1-immunoreactive (IR) and TLR4-IR neurons in DRG cultures was also increased after high glucose challenge. The above alterations could be partially reversed by inhibition of either Notch1 or TLR4 signaling pathway. Inhibition of either Notch1 or TLR4 signaling pathway could improve mechanical allodynia and thermal hyperalgesia thresholds. Inhibition of Notch1 or TLR4 signaling also decreased tumor necrosis factor-α (TNF-α) levels in DRG from diabetic neuropathic rats. These data imply that the interaction between Notch1 and TLR4 signaling pathways is one of the important mechanisms in the development or progression of diabetic neuropathy.

  18. Physically disconnected non-diffusible cell-to-cell communication between neuroblastoma SH-SY5Y and DRG primary sensory neurons.

    PubMed

    Chaban, Victor V; Cho, Taehoon; Reid, Christopher B; Norris, Keith C

    2013-01-01

    Cell-cell communication occurs via a variety of mechanisms, including long distances (hormonal), short distances (paracrine and synaptic) or direct coupling via gap junctions, antigen presentation, or ligand-receptor interactions. We evaluated the possibility of neuro-hormonal independent, non-diffusible, physically disconnected pathways for cell-cell communication using dorsal root ganglion (DRG) neurons. We assessed intracellular calcium ([Ca(2+)]) in primary culture DRG neurons that express ATP-sensitive P2X3, capsaicinsensitive TRPV1 receptors modulated by estradiol. Physically disconnected (dish-in-dish system; inner chamber enclosed) mouse DRG were cultured for 12 hours near: a) media alone (control 1), b) mouse DRG (control 2), c) human neuroblastoma SHSY-5Y cells (cancer intervention), or d) mouse DRG treated with KCl (apoptosis intervention). Chemosensitive receptors [Ca(2+)](i) signaling did not differ between control 1 and 2. ATP (10 μM) and capsaicin (100nM) increased [Ca(2+)](i) transients to 425.86 + 49.5 nM, and 399.21 ± 44.5 nM, respectively. 17β-estradiol (100 nM) exposure reduced ATP (171.17 ± 48.9 nM) and capsaicin (175.01±34.8 nM) [Ca(2+)](i) transients. The presence of cancer cells reduced ATP- and capsaicin-induced [Ca(2+)](i) by >50% (p<0.05) and abolished the 17β-estradiol effect. By contrast, apoptotic DRG cells increased initial ATP-induced [Ca(2+)](i), flux four fold and abolished subsequent [Ca(2+)](i), responses to ATP stimulation (p<0.001). Capsaicin (100nM) induced [Ca(2+)](i) responses were totally abolished. The local presence of apoptotic DRG or human neuroblastoma cells induced differing abnormal ATP and capsaicin-mediated [Ca(2+)](i) fluxes in normal DRG. These findings support physically disconnected, non-diffusible cell-to-cell signaling. Further studies are needed to delineate the mechanism(s) of and model(s) of communication.

  19. Increase of transcription factor EB (TFEB) and lysosomes in rat DRG neurons and their transportation to the central nerve terminal in dorsal horn after nerve injury.

    PubMed

    Jung, J; Uesugi, N; Jeong, N Y; Park, B S; Konishi, H; Kiyama, H

    2016-01-28

    In the spinal dorsal horn (DH), nerve injury activates microglia and induces neuropathic pain. Several studies clarified an involvement of adenosine triphosphate (ATP) in the microglial activation. However, the origin of ATP together with the release mechanism is unclear. Recent in vitro study revealed that an ATP marker, quinacrine, in lysosomes was released from neurite terminal of dorsal root ganglion (DRG) neurons to extracellular space via lysosomal exocytosis. Here, we demonstrate a possibility that the lysosomal ingredient including ATP released from DRG neurons by lysosomal-exocytosis is an additional source of the glial activation in DH after nerve injury. After rat L5 spinal nerve ligation (SNL), mRNA for transcription factor EB (TFEB), a transcription factor controlling lysosomal activation and exocytosis, was induced in the DRG. Simultaneously both lysosomal protein, LAMP1- and vesicular nuclear transporter (VNUT)-positive vesicles were increased in L5 DRG neurons and ipsilateral DH. The quinacrine staining in DH was increased and co-localized with LAMP1 immunoreactivity after nerve injury. In DH, LAMP1-positive vesicles were also co-localized with a peripheral nerve marker, Isolectin B4 (IB4) lectin. Injection of the adenovirus encoding mCherry-LAMP1 into DRG showed that mCherry-positive lysosomes are transported to the central nerve terminal in DH. These findings suggest that activation of lysosome synthesis including ATP packaging in DRG, the central transportation of the lysosome, and subsequent its exocytosis from the central nerve terminal of DRG neurons in response to nerve injury could be a partial mechanism for activation of microglia in DH. This lysosome-mediated microglia activation mechanism may provide another clue to control nociception and pain. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. [The effect of acupuncture and endogenous c-Fos, c-Jun on regeneration of neuronal dendrite of spared DRG in vitro following partial ganglionectomy].

    PubMed

    Wang, Te-wei; Wang, Ting-hua; Zhou, Xue; Zhang, Lian-shuang; Xu, Xin-yun

    2007-09-01

    To explore the effect of acupuncture, endogenous c-Fos and c-Jun on the regeneration of neuronal dendrite of spared dorsal root ganglion (DRG) in vitro following partial ganglionectomy. Five adult male cats were used in this experiment. Their bilateral L1-L5, L7-S2 DRG were removed, and L6 DRG were spared. Then unilaterally, two sets of acupoints (Zusanli(St. 36) and Xuanzhong(G. B. 39); Futu (St. 32) and Sanyinjiao (Sp. 6) located in the distribution area of spinal nerve L6) were electro-stimulated alternately 30 min everyday by electro-needling. Seven days after operation, bilateral L6 DRGs were taken out and were cultured respectively in vitro. Some cultured mediums of the acupuncture lateral wells were totally replaced by each corresponding antibody-cultured medium including respectively 100 ng/mL anti-c-Fos and anti-c-Jun antibody at the 24th hour and terminated after 7 days. The length of the neurite was measured by upside-down light microscopy. Then, cultured cells were stained by the immunohistochemistry ABC method. Data were analyzed by One-way ANOVA and q test. Immunocytochemical staining revealed that over 95% cells were NSE positive cells which were the typical neuron of DRG in vitro. On the 7th day, the average neurite length of the spared DRG group, the anti-c-Fos antibody and the anti-c-Jun antibody group were shorter than that of the acupuncture group (P < 0.05); the average neurite length of the two antibody groups were longer than that of the spared DRG group (P < 0.05). These results indicate that acupuncture, endogenous c-Fos and c-Jun probably promote regeneration of neuronal dendrite of spared DRG in vitro.

  1. Action Potential Broadening in Capsaicin-Sensitive DRG Neurons from Frequency-Dependent Reduction of Kv3 Current

    PubMed Central

    Liu, Pin W.; Blair, Nathaniel T.

    2017-01-01

    Action potential (AP) shape is a key determinant of cellular electrophysiological behavior. We found that in small-diameter, capsaicin-sensitive dorsal root ganglia neurons corresponding to nociceptors (from rats of either sex), stimulation at frequencies as low as 1 Hz produced progressive broadening of the APs. Stimulation at 10 Hz for 3 s resulted in an increase in AP width by an average of 76 ± 7% at 22°C and by 38 ± 3% at 35°C. AP clamp experiments showed that spike broadening results from frequency-dependent reduction of potassium current during spike repolarization. The major current responsible for frequency-dependent reduction of overall spike-repolarizing potassium current was identified as Kv3 current by its sensitivity to low concentrations of 4-aminopyridine (IC50 <100 μm) and block by the peptide inhibitor blood depressing substance I (BDS-I). There was a small component of Kv1-mediated current during AP repolarization, but this current did not show frequency-dependent reduction. In a small fraction of cells, there was a component of calcium-dependent potassium current that showed frequency-dependent reduction, but the contribution to overall potassium current reduction was almost always much smaller than that of Kv3-mediated current. These results show that Kv3 channels make a major contribution to spike repolarization in small-diameter DRG neurons and undergo frequency-dependent reduction, leading to spike broadening at moderate firing frequencies. Spike broadening from frequency-dependent reduction in Kv3 current could mitigate the frequency-dependent decreases in conduction velocity typical of C-fiber axons. SIGNIFICANCE STATEMENT Small-diameter dorsal root ganglia (DRG) neurons mediating nociception and other sensory modalities express many types of potassium channels, but how they combine to control firing patterns and conduction is not well understood. We found that action potentials of small-diameter rat DRG neurons showed spike

  2. Microstimulation of the lumbar DRG recruits primary afferent neurons in localized regions of lower limb.

    PubMed

    Ayers, Christopher A; Fisher, Lee E; Gaunt, Robert A; Weber, Douglas J

    2016-07-01

    Patterned microstimulation of the dorsal root ganglion (DRG) has been proposed as a method for delivering tactile and proprioceptive feedback to amputees. Previous studies demonstrated that large- and medium-diameter afferent neurons could be recruited separately, even several months after implantation. However, those studies did not examine the anatomical localization of sensory fibers recruited by microstimulation in the DRG. Achieving precise recruitment with respect to both modality and receptive field locations will likely be crucial to create a viable sensory neuroprosthesis. In this study, penetrating microelectrode arrays were implanted in the L5, L6, and L7 DRG of four isoflurane-anesthetized cats instrumented with nerve cuff electrodes around the proximal and distal branches of the sciatic and femoral nerves. A binary search was used to find the recruitment threshold for evoking a response in each nerve cuff. The selectivity of DRG stimulation was characterized by the ability to recruit individual distal branches to the exclusion of all others at threshold; 84.7% (n = 201) of the stimulation electrodes recruited a single nerve branch, with 9 of the 15 instrumented nerves recruited selectively. The median stimulation threshold was 0.68 nC/phase, and the median dynamic range (increase in charge while stimulation remained selective) was 0.36 nC/phase. These results demonstrate the ability of DRG microstimulation to achieve selective recruitment of the major nerve branches of the hindlimb, suggesting that this approach could be used to drive sensory input from localized regions of the limb. This sensory input might be useful for restoring tactile and proprioceptive feedback to a lower-limb amputee. Copyright © 2016 the American Physiological Society.

  3. Amitriptyline Activates TrkA to Aid Neuronal Growth and Attenuate Anesthesia-Induced Neurodegeneration in Rat Dorsal Root Ganglion Neurons.

    PubMed

    Zheng, Xiaochun; Chen, Feng; Zheng, Ting; Huang, Fengyi; Chen, Jianghu; Tu, Wenshao

    2016-05-01

    Tricyclic antidepressant amitriptyline (AM) has been shown to exert neurotrophic activity on neurons. We thus explored whether AM may aid the neuronal development and protect anesthesia-induced neuro-injury in young spinal cord dorsal root ganglion (DRG) neurons.The DRG explants were prepared from 1-day-old rats. The effect of AM on aiding DRG neural development was examined by immunohistochemistry at dose-dependent manner. AM-induced changes in gene and protein expressions, and also phosphorylation states of tyrosine kinases receptor A (TrkA) and B (TrkB) in DRG, were examined by quantitative real-time polymerase chain reaction and western blot. The effect of AM on attenuating lidocaine-induced DRG neurodegeneration was examined by immunohistochemistry, and small interfering RNA (siRNA)-mediated TrkA/B down-regulation.Amitriptyline stimulated DRG neuronal development in dose-dependent manner, but exerted toxic effect at concentrations higher than 10 M. AM activated TrkA in DRG through phosphorylation, whereas it had little effect on TrkB-signaling pathway. AM reduced lidocaine-induced DRG neurodegeneration by regenerating neurites and growth cones. Moreover, the neuroprotection of AM on lidocaine-injured neurodegeneration was blocked by siRNA-mediated TrkA down-regulation, but not by TrkB down-regulation.Amitriptyline facilitated neuronal development and had protective effect on lidocaine-induced neurodegeneration, very likely through the activation of TrkA-signaling pathway in DRG.

  4. Amitriptyline Activates TrkA to Aid Neuronal Growth and Attenuate Anesthesia-Induced Neurodegeneration in Rat Dorsal Root Ganglion Neurons

    PubMed Central

    Zheng, Xiaochun; Chen, Feng; Zheng, Ting; Huang, Fengyi; Chen, Jianghu; Tu, Wenshao

    2016-01-01

    Abstract Tricyclic antidepressant amitriptyline (AM) has been shown to exert neurotrophic activity on neurons. We thus explored whether AM may aid the neuronal development and protect anesthesia-induced neuro-injury in young spinal cord dorsal root ganglion (DRG) neurons. The DRG explants were prepared from 1-day-old rats. The effect of AM on aiding DRG neural development was examined by immunohistochemistry at dose-dependent manner. AM-induced changes in gene and protein expressions, and also phosphorylation states of tyrosine kinases receptor A (TrkA) and B (TrkB) in DRG, were examined by quantitative real-time polymerase chain reaction and western blot. The effect of AM on attenuating lidocaine-induced DRG neurodegeneration was examined by immunohistochemistry, and small interfering RNA (siRNA)-mediated TrkA/B down-regulation. Amitriptyline stimulated DRG neuronal development in dose-dependent manner, but exerted toxic effect at concentrations higher than 10 M. AM activated TrkA in DRG through phosphorylation, whereas it had little effect on TrkB-signaling pathway. AM reduced lidocaine-induced DRG neurodegeneration by regenerating neurites and growth cones. Moreover, the neuroprotection of AM on lidocaine-injured neurodegeneration was blocked by siRNA-mediated TrkA down-regulation, but not by TrkB down-regulation. Amitriptyline facilitated neuronal development and had protective effect on lidocaine-induced neurodegeneration, very likely through the activation of TrkA-signaling pathway in DRG. PMID:27149473

  5. Action Potential Broadening in Capsaicin-Sensitive DRG Neurons from Frequency-Dependent Reduction of Kv3 Current.

    PubMed

    Liu, Pin W; Blair, Nathaniel T; Bean, Bruce P

    2017-10-04

    Action potential (AP) shape is a key determinant of cellular electrophysiological behavior. We found that in small-diameter, capsaicin-sensitive dorsal root ganglia neurons corresponding to nociceptors (from rats of either sex), stimulation at frequencies as low as 1 Hz produced progressive broadening of the APs. Stimulation at 10 Hz for 3 s resulted in an increase in AP width by an average of 76 ± 7% at 22°C and by 38 ± 3% at 35°C. AP clamp experiments showed that spike broadening results from frequency-dependent reduction of potassium current during spike repolarization. The major current responsible for frequency-dependent reduction of overall spike-repolarizing potassium current was identified as Kv3 current by its sensitivity to low concentrations of 4-aminopyridine (IC 50 <100 μm) and block by the peptide inhibitor blood depressing substance I (BDS-I). There was a small component of Kv1-mediated current during AP repolarization, but this current did not show frequency-dependent reduction. In a small fraction of cells, there was a component of calcium-dependent potassium current that showed frequency-dependent reduction, but the contribution to overall potassium current reduction was almost always much smaller than that of Kv3-mediated current. These results show that Kv3 channels make a major contribution to spike repolarization in small-diameter DRG neurons and undergo frequency-dependent reduction, leading to spike broadening at moderate firing frequencies. Spike broadening from frequency-dependent reduction in Kv3 current could mitigate the frequency-dependent decreases in conduction velocity typical of C-fiber axons. SIGNIFICANCE STATEMENT Small-diameter dorsal root ganglia (DRG) neurons mediating nociception and other sensory modalities express many types of potassium channels, but how they combine to control firing patterns and conduction is not well understood. We found that action potentials of small-diameter rat DRG neurons showed spike

  6. Adult Mouse DRG Explant and Dissociated Cell Models to Investigate Neuroplasticity and Responses to Environmental Insults Including Viral Infection.

    PubMed

    Fornaro, Michele; Sharthiya, Harsh; Tiwari, Vaibhav

    2018-03-09

    This protocol describes an ex vivo model of mouse-derived dorsal root ganglia (DRG) explant and in vitro DRG-derived co-culture of dissociated sensory neurons and glial satellite cells. These are useful and versatile models to investigate a variety of biological responses associated with physiological and pathological conditions of the peripheral nervous system (PNS) ranging from neuron-glial interaction, neuroplasticity, neuroinflammation, and viral infection. The usage of DRG explant is scientifically advantageous compared to simplistic single cells models for multiple reasons. For instance, as an organotypic culture, the DRG explant allows ex vivo transfer of an entire neuronal network including the extracellular microenvironment that play a significant role in all the neuronal and glial functions. Further, DRG explants can also be maintained ex vivo for several days and the culture conditions can be perturbed as desired. In addition, the harvested DRG can be further dissociated into an in vitro co-culture of primary sensory neurons and satellite glial cells to investigate neuronal-glial interaction, neuritogenesis, axonal cone interaction with the extracellular microenvironment, and more general, any aspect associated with the neuronal metabolism. Therefore, the DRG-explant system offers a great deal of flexibility to study a wide array of events related to biological, physiological, and pathological conditions in a cost-effective manner.

  7. Beta-phenylethylamine inhibits K+ currents in neocortical neurons of the rat: a possible mechanism of beta-phenylethylamine-induced seizures.

    PubMed

    Kitamura, Taro; Munakata, Mitsutoshi; Haginoya, Kazuhiro; Tsuchiya, Shigeru; Iinuma, Kazuie

    2008-08-01

    beta-Phenylethylamine (beta-PEA), an endogenous amine synthesized in the brain, serves as a neuromodulator and is involved in the pathophysiology of various neurological disorders such as depression, schizophrenia, and attention-deficit hyperactivity disorder. beta-PEA fully exerts the physiological effects within the nanomolar concentration range via the trace amine receptors, but beta-PEA also causes convulsions at much higher concentrations via an as yet unknown mechanism. To investigate the electrophysiological mechanism by which beta-PEA induces convulsions, we examined the effect of beta-PEA on ionic currents passing through the cell membrane of dissociated rat cerebral cortical neurons, using a patch-clamp technique. The external application of beta-PEA suppressed ionic currents which continuously flowed when the membrane potential was held at -25 mV. The suppression was in a concentration-dependent manner and a half-maximal effective concentration was 540 muM. These currents suppressed by beta-PEA consisted of two K(+) currents: a time- and voltage-dependent K(+) current (M-current) and a leakage K(+) current. The suppression of the M-current reduces the efficacy of the current in limiting excessive neuronal firing, and the suppression of the leakage K(+) current can cause membrane depolarization and thus promote neuronal excitation. Reducing both of these currents in concert may produce neuronal seizing activity, which could conceivably underlie the convulsions induced by high-dose beta-PEA.

  8. Delta-catenin/NPRAP: A new member of the glycogen synthase kinase-3beta signaling complex that promotes beta-catenin turnover in neurons.

    PubMed

    Bareiss, Sonja; Kim, Kwonseop; Lu, Qun

    2010-08-15

    Through a multiprotein complex, glycogen synthase kinase-3beta (GSK-3beta) phosphorylates and destabilizes beta-catenin, an important signaling event for neuronal growth and proper synaptic function. delta-Catenin, or NPRAP (CTNND2), is a neural enriched member of the beta-catenin superfamily and is also known to modulate neurite outgrowth and synaptic activity. In this study, we investigated the possibility that delta-catenin expression is also affected by GSK-3beta signaling and participates in the molecular complex regulating beta-catenin turnover in neurons. Immunofluorescent light microscopy revealed colocalization of delta-catenin with members of the molecular destruction complex: GSK-3beta, beta-catenin, and adenomatous polyposis coli proteins in rat primary neurons. GSK-3beta formed a complex with delta-catenin, and its inhibition resulted in increased delta-catenin and beta-catenin expression levels. LY294002 and amyloid peptide, known activators of GSK-3beta signaling, reduced delta-catenin expression levels. Furthermore, delta-catenin immunoreactivity increased and protein turnover decreased when neurons were treated with proteasome inhibitors, suggesting that the stability of delta-catenin, like that of beta-catenin, is regulated by proteasome-mediated degradation. Coimmunoprecipitation experiments showed that delta-catenin overexpression promoted GSK-3beta and beta-catenin interactions. Primary cortical neurons and PC12 cells expressing delta-catenin treated with proteasome inhibitors showed increased ubiquitinated beta-catenin forms. Consistent with the hypothesis that delta-catenin promotes the interaction of the destruction complex molecules, cycloheximide treatment of cells overexpressing delta-catenin showed enhanced beta-catenin turnover. These studies identify delta-catenin as a new member of the GSK-3beta signaling pathway and further suggest that delta-catenin is potentially involved in facilitating the interaction, ubiquitination, and

  9. Coupled Activation of Primary Sensory Neurons Contributes to Chronic Pain.

    PubMed

    Kim, Yu Shin; Anderson, Michael; Park, Kyoungsook; Zheng, Qin; Agarwal, Amit; Gong, Catherine; Saijilafu; Young, LeAnne; He, Shaoqiu; LaVinka, Pamela Colleen; Zhou, Fengquan; Bergles, Dwight; Hanani, Menachem; Guan, Yun; Spray, David C; Dong, Xinzhong

    2016-09-07

    Primary sensory neurons in the DRG play an essential role in initiating pain by detecting painful stimuli in the periphery. Tissue injury can sensitize DRG neurons, causing heightened pain sensitivity, often leading to chronic pain. Despite the functional importance, how DRG neurons function at a population level is unclear due to the lack of suitable tools. Here we developed an imaging technique that allowed us to simultaneously monitor the activities of >1,600 neurons/DRG in live mice and discovered a striking neuronal coupling phenomenon that adjacent neurons tend to activate together following tissue injury. This coupled activation occurs among various neurons and is mediated by an injury-induced upregulation of gap junctions in glial cells surrounding DRG neurons. Blocking gap junctions attenuated neuronal coupling and mechanical hyperalgesia. Therefore, neuronal coupling represents a new form of neuronal plasticity in the DRG and contributes to pain hypersensitivity by "hijacking" neighboring neurons through gap junctions. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Neuropathic pain in experimental autoimmune neuritis is associated with altered electrophysiological properties of nociceptive DRG neurons.

    PubMed

    Taha, Omneya; Opitz, Thoralf; Mueller, Marcus; Pitsch, Julika; Becker, Albert; Evert, Bernd Oliver; Beck, Heinz; Jeub, Monika

    2017-11-01

    Guillain-Barré syndrome (GBS) is an acute, immune-mediated polyradiculoneuropathy characterized by rapidly progressive paresis and sensory disturbances. Moderate to severe and often intractable neuropathic pain is a common symptom of GBS, but its underlying mechanisms are unknown. Pathology of GBS is classically attributed to demyelination of large, myelinated peripheral fibers. However, there is increasing evidence that neuropathic pain in GBS is associated with impaired function of small, unmyelinated, nociceptive fibers. We therefore examined the functional properties of small DRG neurons, the somata of nociceptive fibers, in a rat model of GBS (experimental autoimmune neuritis=EAN). EAN rats developed behavioral signs of neuropathic pain. This was accompanied by a significant shortening of action potentials due to a more rapid repolarization and an increase in repetitive firing in a subgroup of capsaicin-responsive DRG neurons. Na + current measurements revealed a significant increase of the fast TTX-sensitive current and a reduction of the persistent TTX-sensitive current component. These changes of Na + currents may account for the significant decrease in AP duration leading to an overall increase in excitability and are therefore possibly directly linked to pathological pain behavior. Thus, like in other animal models of neuropathic and inflammatory pain, Na + channels seem to be crucially involved in the pathology of GBS and may constitute promising targets for pain modulating pharmaceuticals. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Nicergoline, a drug used for age-dependent cognitive impairment, protects cultured neurons against beta-amyloid toxicity.

    PubMed

    Caraci, Filippo; Chisari, Mariangela; Frasca, Giuseppina; Canonico, Pier Luigi; Battaglia, Angelo; Calafiore, Marco; Battaglia, Giuseppe; Bosco, Paolo; Nicoletti, Ferdinando; Copani, Agata; Sortino, Maria Angela

    2005-06-14

    Nicergoline, a drug used for the treatment of Alzheimer's disease and other types of dementia, was tested for its ability to protect neurons against beta-amyloid toxicity. Pure cultures of rat cortical neurons were challenged with a toxic fragment of beta-amyloid peptide (betaAP(25-35)) and toxicity was assessed after 24 h. Micromolar concentrations of nicergoline or its metabolite, MDL, attenuated betaAP(25-35)-induced neuronal death, whereas MMDL (another metabolite of nicergoline), the alpha1-adrenergic receptor antagonist, prazosin, or the serotonin 5HT-2 receptor antagonist, methysergide, were inactive. Nicergoline increased the basal levels of Bcl-2 and reduced the increase in Bax levels induced by beta-amyloid, indicating that the drug inhibits the execution of an apoptotic program in cortical neurons. In mixed cultures of rat cortical cells containing both neurons and astrocytes, nicergoline and MDL were more efficacious than in pure neuronal cultures in reducing beta-amyloid neurotoxicity. Experiments carried out in pure cultures of astrocytes showed that a component of neuroprotection was mediated by a mechanism of glial-neuronal interaction. The conditioned medium of cultured astrocytes treated with nicergoline or MDL for 72-96 h (collected 24 h after drug withdrawal) was neuroprotective when transferred to pure neuronal cultures challenged with beta-amyloid. In cultured astrocytes, nicergoline increased the intracellular levels of transforming-growth factor-beta and glial-derived neurotrophic factor, two trophic factors that are known to protect neurons against beta-amyloid toxicity. These results raise the possibility that nicergoline reduces neurodegeneration in the Alzheimer's brain.

  12. Functional, electrophysiological recoveries of rats with sciatic nerve lesions following transplantation of elongated DRG cells.

    PubMed

    Dayawansa, Samantha; Zhang, Jun; Shih, Chung-Hsuan; Tharakan, Binu; Huang, Jason H

    2016-04-01

    Functional data are essential when confirming the efficacy of elongated dorsal root ganglia (DRG) cells as a substitute for autografting. We present the quantitative functional motor, electrophysiological findings of engineered DRG recipients for the first time. Elongated DRG neurons and autografts were transplanted to bridge 1-cm sciatic nerve lesions of Sprague Dawley (SD) rats. Motor recoveries of elongated DRG recipients (n=9), autograft recipients (n=9), unrepaired rats (n=9) and intact rats (n=6) were investigated using the angle board challenge test following 16 weeks of recovery. Electrophysiology studies were conducted to assess the functional recovery at 16 weeks. In addition, elongated DRGs were subjected to histology assessments. At threshold levels (35° angle) of the angle board challenge test, the autograft recipients', DRG recipients' and unrepaired group's performances were equal to each other and were less than the intact group (p<0.05). However, during the subthreshold (30°) angle board challenge test, the elongated DRG recipients' performance was similar to both the intact group and the autograft nerve recipients, and was better (p<0.05) than the unrepaired group. The autograft recipients' performance was similar to the unrepaired group and was significantly different (p<0.05) compared with the performance of the intact group. During electrophysiological testing, the rats with transplanted engineered DRG constructs had intact signal transmission when recorded over the lesion, while the unrepaired rats did not. It was observed that elongated DRG neurons closely resembled an autograft during histological assessments. Performances of autograft and elongated DRG construct recipients were similar. Elongated DRG neurons should be further investigated as a substitute for autografting.

  13. Overexpression of GDNF in the uninjured DRG exerts analgesic effects on neuropathic pain following segmental spinal nerve ligation in mice.

    PubMed

    Takasu, Kumiko; Sakai, Atsushi; Hanawa, Hideki; Shimada, Takashi; Suzuki, Hidenori

    2011-11-01

    Glial cell line-derived neurotrophic factor (GDNF), a survival-promoting factor for a subset of nociceptive small-diameter neurons, has been shown to exert analgesic effects on neuropathic pain. However, its detailed mechanisms of action are still unknown. In the present study, we investigated the site-specific analgesic effects of GDNF in the neuropathic pain state using lentiviral vector-mediated GDNF overexpression in mice with left fifth lumbar (L5) spinal nerve ligation (SNL) as a neuropathic pain model. A lentiviral vector expressing both GDNF and enhanced green fluorescent protein (EGFP) was constructed and injected into the left dorsal spinal cord, uninjured fourth lumbar (L4) dorsal root ganglion (DRG), injured L5 DRG, or plantar skin of mice. In SNL mice, injection of the GDNF-EGFP-expressing lentivirus into the dorsal spinal cord or uninjured L4 DRG partially but significantly reduced the mechanical allodynia in association with an increase in GDNF protein expression in each virus injection site, whereas injection into the injured L5 DRG or plantar skin had no effects. These results suggest that GDNF exerts its analgesic effects in the neuropathic pain state by acting on the central terminals of uninjured DRG neurons and/or on the spinal cells targeted by the uninjured DRG neurons. This article shows that GDNF exerts its analgesic effects on neuropathic pain by acting on the central terminals of uninjured DRG neurons and/or on the spinal cells targeted by these neurons. Therefore, research focusing on these GDNF-dependent neurons in the uninjured DRG would provide a new strategy for treating neuropathic pain. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

  14. Neurokinin B potentiates ATP-activated currents in rat DRG neurons.

    PubMed

    Wang, M J; Xiong, S H; Li, Z W

    2001-12-27

    This study aimed to explore whether NKB could modulate the responses mediated by ATP receptor (P2X purinoceptor). Whole-cell patch clamp and repatch experiments were performed on cultured rat DRG neurons. The majority of neurons examined were sensitive both to ATP and to NKB (77.1%, 54/70). NKB preapplied could potentiate ATP-activated currents (I(ATP)) markedly; this effect was concentration-dependent and could be blocked by SR 142801, an NK3 receptor antagonist. Preapplication of 0.001, 0.01, 0.1 and 1.0 microM NKB increased ATP-activated currents by 55.1+/-18.8, 75.2+/-17.4, 84.1+/-18.8 and 81.0+/-21.7%, respectively. The concentration-response curves for ATP with and without preapplication of NKB show that: (1) preapplication of NKB shifted the curve upwards; (2) the maximal amplitude of I(ATP) with NKB preapplication increased by 78.5%, while the threshold value remained unchanged; (3) the EC(50) values of the two curves were very close (44 vs. 42 microM). Intracellular dialysis of H-7 by using repatch clamp technique could block the potentiation of I(ATP) by NKB. It suggests that this potentiating effect was caused by phosphorylation of ATP receptor, which resulted from the activation of G protein coupled NK3 receptor and consequential intracellular signal transduction cascade.

  15. Ca2+ toxicity due to reverse Na+/Ca2+ exchange contributes to degeneration of neurites of DRG neurons induced by a neuropathy-associated Nav1.7 mutation

    PubMed Central

    Estacion, M.; Vohra, B. P. S; Liu, S.; Hoeijmakers, J.; Faber, C. G.; Merkies, I. S. J.; Lauria, G.; Black, J. A.

    2015-01-01

    Gain-of-function missense mutations in voltage-gated sodium channel Nav1.7 have been linked to small-fiber neuropathy, which is characterized by burning pain, dysautonomia and a loss of intraepidermal nerve fibers. However, the mechanistic cascades linking Nav1.7 mutations to axonal degeneration are incompletely understood. The G856D mutation in Nav1.7 produces robust changes in channel biophysical properties, including hyperpolarized activation, depolarized inactivation, and enhanced ramp and persistent currents, which contribute to the hyperexcitability exhibited by neurons containing Nav1.8. We report here that cell bodies and neurites of dorsal root ganglion (DRG) neurons transfected with G856D display increased levels of intracellular Na+ concentration ([Na+]) and intracellular [Ca2+] following stimulation with high [K+] compared with wild-type (WT) Nav1.7-expressing neurons. Blockade of reverse mode of the sodium/calcium exchanger (NCX) or of sodium channels attenuates [Ca2+] transients evoked by high [K+] in G856D-expressing DRG cell bodies and neurites. We also show that treatment of WT or G856D-expressing neurites with high [K+] or 2-deoxyglucose (2-DG) does not elicit degeneration of these neurites, but that high [K+] and 2-DG in combination evokes degeneration of G856D neurites but not WT neurites. Our results also demonstrate that 0 Ca2+ or blockade of reverse mode of NCX protects G856D-expressing neurites from degeneration when exposed to high [K+] and 2-DG. These results point to [Na+] overload in DRG neurons expressing mutant G856D Nav1.7, which triggers reverse mode of NCX and contributes to Ca2+ toxicity, and suggest subtype-specific blockade of Nav1.7 or inhibition of reverse NCX as strategies that might slow or prevent axon degeneration in small-fiber neuropathy. PMID:26156380

  16. [Botulinum toxin type A does not affect spontaneous discharge but blocks sympathetic-sensory coupling in chronically compressed rat dorsal root ganglion neurons].

    PubMed

    Yang, Hong-jun; Peng, Kai-run; Hu, San-jue; Duan, Jian-hong

    2007-11-01

    To study the effect of botulinum toxin type A (BTXA) on spontaneous discharge and sympathetic- sensory coupling in chronically compressed dorsal root ganglion (DRG) neurons in rats. In chronically compressed rat DRG, spontaneous activities of the single fibers from DRG neurons were recorded and their changes observed after BTAX application on the damaged DGR. Sympathetic modulation of the spontaneous discharge from the compressed DRG neurons was observed by electric stimulation of the lumbar sympathetic trunk, and the changes in this effect were evaluated after intravenous BTXA injection in the rats. Active spontaneous discharges were recorded in the injured DRG neurons, and 47 injured DRG neurons responded to Ca2+-free artificial cerebrospinal fluid but not to BTXA treatment. Sixty-four percent of the neurons in the injured DRG responded to sympathetic stimulation, and this response was blocked by intravenously injection of BTXA. BTXA does not affect spontaneous activities of injured DRG neurons, but blocks sympathetic-sensory coupling in these neurons.

  17. [Effect of spontaneous firing of injured dorsal root ganglion neuron on excitability of wide dynamic range neuron in rat spinal dorsal horn].

    PubMed

    Song, Ying; Zhang, Yong-Mei; Xu, Jie; Wu, Jing-Ru; Qin, Xia; Hua, Rong

    2013-10-25

    The aim of the paper is to study the effect of spontaneous firing of injured dorsal root ganglion (DRG) neuron in chronic compression of DRG (CCD) model on excitability of wide dynamic range (WDR) neuron in rat spinal dorsal horn. In vivo intracellular recording was done in DRG neurons and in vivo extracellular recording was done in spinal WDR neurons. After CCD, incidence of spontaneous discharge and firing frequency enhanced to 59.46% and (4.30 ± 0.69) Hz respectively from 22.81% and (0.60 ± 0.08) Hz in normal control group (P < 0.05). Local administration of 50 nmol/L tetrodotoxin (TTX) on DRG neuron in CCD rats decreased the spontaneous activities of WDR neurons from (191.97 ± 45.20)/min to (92.50 ± 30.32)/min (P < 0.05). On the other side, local administration of 100 mmol/L KCl on DRG neuron evoked spontaneous firing in a reversible way (n = 5) in silent WDR neurons of normal rats. There was 36.36% (12/33) WDR neuron showing after-discharge in response to innocuous mechanical stimuli on cutaneous receptive field in CCD rats, while after-discharge was not seen in control rats. Local administration of TTX on DRG with a concentration of 50 nmol/L attenuated innocuous electric stimuli-evoked after-discharge of WDR neurons in CCD rats in a reversible manner, and the frequency was decreased from (263 ± 56.5) Hz to (117 ± 30) Hz (P < 0.05). The study suggests that the excitability of WDR neurons is influenced by spontaneous firings of DRG neurons after CCD.

  18. PAd-shRNA-PTN reduces pleiotrophin of pancreatic cancer cells and inhibits neurite outgrowth of DRG

    PubMed Central

    Yao, Jun; Zhang, Min; Ma, Qing-Yong; Wang, Zheng; Wang, Lian-Cai; Zhang, Dong

    2011-01-01

    AIM: To investigate the silencing effects of pAd-shRNA-pleiotrophin (PTN) on PTN in pancreatic cancer cells, and to observe the inhibition of pAd-shRNA-PTN on neurite outgrowth from dorsal root ganglion (DRG) neurons in vitro. METHODS: PAd-shRNA-PTN was used to infect pancreatic cancer BxPC-3 cells; assays were conducted for knockdown of the PTN gene on the 0th, 1st, 3rd, 5th, 7th and 9th d after infection using immunocytochemistry, real-time quantitative polymerase chain reaction (PCR), and Western blotting analysis. The morphologic changes of cultured DRG neurons were observed by mono-culture of DRG neurons and co-culture with BXPC-3 cells in vitro. RESULTS: The real-time quantitative PCR showed that the inhibition rates of PTN mRNA expression in the BxPC-3 cells were 20%, 80%, 50% and 25% on the 1st, 3rd, 5th and 7th d after infection. Immunocytochemistry and Western blotting analysis also revealed the same tendency. In contrast to the control, the DRG neurons co-cultured with the infected BxPC-3 cells shrunk; the number and length of neurites were significantly decreased. CONCLUSION: Efficient and specific knockdown of PTN in pancreatic cancer cells and the reduction in PTN expression resulted in the inhibition of neurite outgrowth from DRG neurons. PMID:21677838

  19. Activation of ERK1/2 and PI3K/Akt by IGF-1 on GAP-43 expression in DRG neurons with excitotoxicity induced by glutamate in vitro.

    PubMed

    Liu, Zhen; Cai, Heng; Zhang, Ping; Li, Hao; Liu, Huaxiang; Li, Zhenzhong

    2012-03-01

    Insulin-like growth factor-1 (IGF-1) is a neurotrophic factor and plays an important role in promoting axonal growth from dorsal root ganglion (DRG) neurons. Whether IGF-1 influences growth-associated protein 43 (GAP-43) expression and activates the extracellular signal-regulated protein kinase (ERK1/2) and the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways in DRG neurons with excitotoxicity induced by glutamate (Glu) remains unknown. In this study, embryonic 15-day-old rat DRG explants were cultured for 48 h and then exposed to IGF-1, Glu, Glu + IGF-1, Glu + IGF-1 + PD98059, Glu + IGF-1 + LY294002, Glu + IGF-1 + PD98059 + LY294002 for additional 12 h. The DRG explants were continuously exposed to growth media as control. The levels of GAP-43 mRNA were detected by real time-PCR analysis. The protein levels of GAP-43, phosphorylated ERK1/2, phosphorylated Akt, total ERK1/2, and total Akt were detected by Western blot assay. GAP-43 expression in situ was determined by immunofluorescent labeling. Apoptotic cell death was monitored by Hoechst 33342 staining. IGF-1 alone increased GAP-43 and its mRNA levels in the absence of Glu. The decreased GAP-43 and its mRNA levels caused by Glu could be partially reversed by the presence of IGF-1. IGF-1 rescued neuronal cell death caused by Glu. Neither the ERK1/2 inhibitor PD98059 nor the PI3K inhibitor LY294002 blocked the effect of IGF-1, but both inhibitors together were effective. To validate the impact of GAP-43 expression by IGF-1, GAP-43 induction was blocked by administration of dexamethasone (DEX). IGF-1 partially rescued the decrease of GAP-43 and its mRNA levels induced by DEX. DEX induced an increase of cell apoptosis. IGF-1 may play an important role in neuroprotective effects on DRG neurons through regulating GAP-43 expression with excitotoxicity induced by Glu and the process was involved in both ERK1/2 and PI3K/Akt signaling pathways.

  20. M2 receptors exert analgesic action on DRG sensory neurons by negatively modulating VR1 activity.

    PubMed

    De Angelis, Federica; Marinelli, Sara; Fioretti, Bernard; Catacuzzeno, Luigi; Franciolini, Fabio; Pavone, Flaminia; Tata, Ada Maria

    2014-06-01

    The peripheral application of the M2 cholinergic agonist arecaidine on sensory nerve endings shows anti-nociceptive properties. In this work, we analyze in vitro, the mechanisms downstream M2 receptor activation causing the analgesic effects, and in vivo the effects produced by M2 agonist arecaidine administration on nociceptive responses in a murine model of nerve growth factor (NGF)-induced pain. Cultured DRG neurons treated with arecaidine showed a decreased level of VR1 and SP transcripts. Conversely, we found an increased expression of VR1 and SP transcripts in DRG from M2/M4(-/-) mice compared to WT and M1(-/-) mice, confirming the inhibitory effect in particular of M2 receptors on SP and VR1 expression. Patch-clamp experiments in the whole-cell configuration showed that arecaidine treatment caused a reduction of the fraction of capsaicin-responsive cells, without altering the mean capsaicin-activated current in responsive cells. We also demonstrated that arecaidine prevents PKCϵ translocation to the plasma membrane after inflammatory agent stimulation, mainly in medium-small sensory neurons. Finally, in mice, we have observed that intraperitoneal injection of arecaidine reduces VR1 expression blocking hyperalgesia and allodynia caused by NGF intraplantar administration. In conclusion, our data demonstrate that in vivo M2 receptor activation induces desensitization to mechanical and heat stimuli by a down-regulation of VR1 expression and by the inhibition of PKCϵ activity hindering its translocation to the plasma membrane, as suggested by in vitro experiments. © 2013 Wiley Periodicals, Inc.

  1. Nogo Receptor Homolog NgR2 Expressed in Sensory DRG Neurons Controls Epidermal Innervation by Interaction with Versican

    PubMed Central

    Bäumer, Bastian E.; Kurz, Antje; Borrie, Sarah C.; Sickinger, Stephan; Dours-Zimmermann, María T.; Zimmermann, Dieter R.

    2014-01-01

    Primary sensory afferents of the dorsal root ganglion (DRG) that innervate the skin detect a wide range of stimuli, such as touch, temperature, pain, and itch. Different functional classes of nociceptors project their axons to distinct target zones within the developing skin, but the molecular mechanisms that regulate target innervation are less clear. Here we report that the Nogo66 receptor homolog NgR2 is essential for proper cutaneous innervation. NgR2−/− mice display increased density of nonpeptidergic nociceptors in the footpad and exhibit enhanced sensitivity to mechanical force and innocuous cold temperatures. These sensory deficits are not associated with any abnormality in morphology or density of DRG neurons. However, deletion of NgR2 renders nociceptive nonpeptidergic sensory neurons insensitive to the outgrowth repulsive activity of skin-derived Versican. Biochemical evidence shows that NgR2 specifically interacts with the G3 domain of Versican. The data suggest that Versican/NgR2 signaling at the dermo-epidermal junction acts in vivo as a local suppressor of axonal plasticity to control proper density of epidermal sensory fiber innervation. Our findings not only reveal the existence of a novel and unsuspected mechanism regulating epidermal target innervation, but also provide the first evidence for a physiological role of NgR2 in the peripheral nervous system. PMID:24478347

  2. Nogo receptor homolog NgR2 expressed in sensory DRG neurons controls epidermal innervation by interaction with Versican.

    PubMed

    Bäumer, Bastian E; Kurz, Antje; Borrie, Sarah C; Sickinger, Stephan; Dours-Zimmermann, María T; Zimmermann, Dieter R; Bandtlow, Christine E

    2014-01-29

    Primary sensory afferents of the dorsal root ganglion (DRG) that innervate the skin detect a wide range of stimuli, such as touch, temperature, pain, and itch. Different functional classes of nociceptors project their axons to distinct target zones within the developing skin, but the molecular mechanisms that regulate target innervation are less clear. Here we report that the Nogo66 receptor homolog NgR2 is essential for proper cutaneous innervation. NgR2(-/-) mice display increased density of nonpeptidergic nociceptors in the footpad and exhibit enhanced sensitivity to mechanical force and innocuous cold temperatures. These sensory deficits are not associated with any abnormality in morphology or density of DRG neurons. However, deletion of NgR2 renders nociceptive nonpeptidergic sensory neurons insensitive to the outgrowth repulsive activity of skin-derived Versican. Biochemical evidence shows that NgR2 specifically interacts with the G3 domain of Versican. The data suggest that Versican/NgR2 signaling at the dermo-epidermal junction acts in vivo as a local suppressor of axonal plasticity to control proper density of epidermal sensory fiber innervation. Our findings not only reveal the existence of a novel and unsuspected mechanism regulating epidermal target innervation, but also provide the first evidence for a physiological role of NgR2 in the peripheral nervous system.

  3. [Decreased A-type potassium current mediates the hyperexcitability of nociceptive neurons in the chronically compressed dorsal root ganglia].

    PubMed

    Yan, Ni; Li, Xiao-Han; Cheng, Qi; Yan, Jin; Ni, Xin; Sun, Ji-Hu

    2007-04-25

    The excitability of nociceptive neurons increases in the intact dorsal root ganglion (DRG) after a chronic compression, but the underlying mechanisms are still unclear. The aim of this study was to investigate the ionic mechanisms underlying the hyperexcitability of nociceptive neurons in the compressed ganglion. Chronic compression of DRG (CCD) was produced in adult rats by inserting two rods through the intervertebral foramina to compress the L4 DRG and the ipsilateral L5 DRG. After 5-7 d, DRG somata were dissociated and placed in culture for 12-18 h. In sharp electrode recording model, the lower current threshold and the depolarized membrane potential in the acutely dissociated CCD neurons were detected, indicating that hyperexcitability is intrinsic to the soma. Since voltage-gated K(+) (Kv) channels in the primary sensory neurons are important for the regulation of excitability, we hypothesized that CCD would alter K(+) current properties in the primary sensory neurons. We examined the effects of 4-aminopyridine (4-AP), a specific antagonist of A-type potassium channel, on the excitability of the control DRG neurons. With 4-AP in the external solution, the control DRG neurons depolarized (with discharges in some cells) and their current threshold decreased as the CCD neurons demonstrated, indicating the involvement of decreased A-type potassium current in the hyperexcitability of the injured neurons. Furthermore, the alteration of A-type potassium current in nociceptive neurons in the compressed ganglion was investigated with the whole-cell patch-clamp recording model. CCD significantly decreased A-type potassium current density in nociceptive DRG neurons. These data suggest that a reduction in A-type potassium current contributes, at least in part, to the increase in neuron excitability that may lead to the development of pain and hyperalgesia associated with CCD.

  4. Distinct subclassification of DRG neurons innervating the distal colon and glans penis/distal urethra based on the electrophysiological current signature

    PubMed Central

    Petruska, Jeffrey C.; Cooper, Brian Y.; Johnson, Richard D.

    2014-01-01

    Spinal sensory neurons innervating visceral and mucocutaneous tissues have unique microanatomic distribution, peripheral modality, and physiological, pharmacological, and biophysical characteristics compared with those neurons that innervate muscle and cutaneous tissues. In previous patch-clamp electrophysiological studies, we have demonstrated that small- and medium-diameter dorsal root ganglion (DRG) neurons can be subclassified on the basis of their patterns of voltage-activated currents (VAC). These VAC-based subclasses were highly consistent in their action potential characteristics, responses to algesic compounds, immunocytochemical expression patterns, and responses to thermal stimuli. For this study, we examined the VAC of neurons retrogradely traced from the distal colon and the glans penis/distal urethra in the adult male rat. The afferent population from the distal colon contained at least two previously characterized cell types observed in somatic tissues (types 5 and 8), as well as four novel cell types (types 15, 16, 17, and 18). In the glans penis/distal urethra, two previously described cell types (types 6 and 8) and three novel cell types (types 7, 14, and 15) were identified. Other characteristics, including action potential profiles, responses to algesic compounds (acetylcholine, capsaicin, ATP, and pH 5.0 solution), and neurochemistry (expression of substance P, CGRP, neurofilament, TRPV1, TRPV2, and isolectin B4 binding) were consistent for each VAC-defined subgroup. With identification of distinct DRG cell types that innervate the distal colon and glans penis/distal urethra, future in vitro studies related to the gastrointestinal and urogenital sensory function in normal as well as abnormal/pathological conditions may be benefitted. PMID:24872531

  5. [Effect of partial ganglionectomy and acupuncture on culturing spared DRG in vitro].

    PubMed

    Wang, Te-Wei; Wang, Ting-Hua; Zhou, Xue; Zhang, Lian-Shuang; Xu, Xin-Yun

    2005-09-01

    To explore the effect of partial dorsal root rhizotomy and Acup on culturing dorsal root ganglion(DRG) in vitro. Ten adult cats were divided into 2 groups: normal control group; Acup spared DRG 7 d group, in which bilateral L1-L5, L7-S2 DRG were removed; and L6DRG were spared; then unilaterally two sets of acupoints [Zusanlily (St. 36) and Xuanzhong (G. B. 39): Futu (St. 32) and Sanyinjiao (Sp. 6) located in the distribution area of spinal nerve L6] were electro-stimulated alternatively 30 min everyday by electro-needling. Five cats were used in every group. Bilateral L6 DRGs of every group were taken out on the condition of asepsis and were cultured respectively in vitro. Cultures were terminated after day 7. Then the cultured cells were stained under the same condition using specific NSE (1 : 200) antibody, a neuron-specific marker, by the immunohistochemistry ABC method. The neurite length was measured by micro-measured ruler in upside-down light microscope on the 1st, 3rd, 5th, 7th day. Immunocytochemical staining revealed that over 95% cells were NSE positive cells which were the typical neuron of DRG in vitro; on the 1st, 3rd, 5th, 7th day, the average neurite length of the normal group was shorter than that of the spared DRG group(P < 0. 05), and the spared DRG group's was shorter than the Acup group's at each time stage (P < 0.05). These results indicated that DRG had plasticity and acupuncture probably promoted the plasticity, which were probably in close relation with the spinal plasticity.

  6. Inflammatory sensitization of nociceptors depends on activation of NMDA receptors in DRG satellite cells.

    PubMed

    Ferrari, Luiz Fernando; Lotufo, Celina Monteiro; Araldi, Dionéia; Rodrigues, Marcos A; Macedo, Larissa P; Ferreira, Sérgio H; Parada, Carlos Amilcar

    2014-12-23

    The present study evaluated the role of N-methyl-D-aspartate receptors (NMDARs) expressed in the dorsal root ganglia (DRG) in the inflammatory sensitization of peripheral nociceptor terminals to mechanical stimulation. Injection of NMDA into the fifth lumbar (L5)-DRG induced hyperalgesia in the rat hind paw with a profile similar to that of intraplantar injection of prostaglandin E2 (PGE2), which was significantly attenuated by injection of the NMDAR antagonist D(-)-2-amino-5-phosphonopentanoic acid (D-AP-5) in the L5-DRG. Moreover, blockade of DRG AMPA receptors by the antagonist 6,7-dinitroquinoxaline-2,3-dione had no effect in the PGE2-induced hyperalgesia in the paw, showing specific involvement of NMDARs in this modulatory effect and suggesting that activation of NMDAR in the DRG plays an important role in the peripheral inflammatory hyperalgesia. In following experiments we observed attenuation of PGE2-induced hyperalgesia in the paw by the knockdown of NMDAR subunits NR1, NR2B, NR2D, and NR3A with antisense-oligodeoxynucleotide treatment in the DRG. Also, in vitro experiments showed that the NMDA-induced sensitization of cultured DRG neurons depends on satellite cell activation and on those same NMDAR subunits, suggesting their importance for the PGE2-induced hyperalgesia. In addition, fluorescent calcium imaging experiments in cultures of DRG cells showed induction of calcium transients by glutamate or NMDA only in satellite cells, but not in neurons. Together, the present results suggest that the mechanical inflammatory nociceptor sensitization is dependent on glutamate release at the DRG and subsequent NMDAR activation in satellite glial cells, supporting the idea that the peripheral hyperalgesia is an event modulated by a glutamatergic system in the DRG.

  7. Trafficking of cell surface beta-amyloid precursor protein: retrograde and transcytotic transport in cultured neurons

    PubMed Central

    1995-01-01

    Amyloid beta-protein (A beta), the principal constituent of senile plaques seen in Alzheimer's disease (AD), is derived by proteolysis from the beta-amyloid precursor protein (beta PP). The mechanism of A beta production in neurons, which are hypothesized to be a rich source of A beta in brain, remains to be defined. In this study, we describe a detailed localization of cell surface beta PP and its subsequent trafficking in primary cultured neurons. Full-length cell surface beta PP was present primarily on perikarya and axons, the latter with a characteristic discontinuous pattern. At growth cones, cell surface beta PP was inconsistently detected. By visualizing the distribution of beta PP monoclonal antibodies added to intact cultures, beta PP was shown to be internalized from distal axons or terminals and retrogradely transported back to perikarya in organelles which colocalized with fluid-phase endocytic markers. Retrograde transport of beta PP was shown in both hippocampal and peripheral sympathetic neurons, the latter using a compartment culture system that isolated cell bodies from distal axons and terminals. In addition, we demonstrated that beta PP from distal axons was transcytotically transported to the surface of perikarya from distal axons in sympathetic neurons. Indirect evidence of this transcytotic pathway was obtained in hippocampal neurons using antisense oligonucleotide to the kinesin heavy chain to inhibit anterograde beta PP transport. Taken together, these results demonstrate novel aspects of beta PP trafficking in neurons, including retrograde axonal transport and transcytosis. Moreover, the axonal predominance of cell surface beta PP is unexpected in view of the recent report of polarized sorting of beta PP to the basolateral domain of MDCK cells. PMID:7721945

  8. Distinct subclassification of DRG neurons innervating the distal colon and glans penis/distal urethra based on the electrophysiological current signature.

    PubMed

    Rau, Kristofer K; Petruska, Jeffrey C; Cooper, Brian Y; Johnson, Richard D

    2014-09-15

    Spinal sensory neurons innervating visceral and mucocutaneous tissues have unique microanatomic distribution, peripheral modality, and physiological, pharmacological, and biophysical characteristics compared with those neurons that innervate muscle and cutaneous tissues. In previous patch-clamp electrophysiological studies, we have demonstrated that small- and medium-diameter dorsal root ganglion (DRG) neurons can be subclassified on the basis of their patterns of voltage-activated currents (VAC). These VAC-based subclasses were highly consistent in their action potential characteristics, responses to algesic compounds, immunocytochemical expression patterns, and responses to thermal stimuli. For this study, we examined the VAC of neurons retrogradely traced from the distal colon and the glans penis/distal urethra in the adult male rat. The afferent population from the distal colon contained at least two previously characterized cell types observed in somatic tissues (types 5 and 8), as well as four novel cell types (types 15, 16, 17, and 18). In the glans penis/distal urethra, two previously described cell types (types 6 and 8) and three novel cell types (types 7, 14, and 15) were identified. Other characteristics, including action potential profiles, responses to algesic compounds (acetylcholine, capsaicin, ATP, and pH 5.0 solution), and neurochemistry (expression of substance P, CGRP, neurofilament, TRPV1, TRPV2, and isolectin B4 binding) were consistent for each VAC-defined subgroup. With identification of distinct DRG cell types that innervate the distal colon and glans penis/distal urethra, future in vitro studies related to the gastrointestinal and urogenital sensory function in normal as well as abnormal/pathological conditions may be benefitted. Copyright © 2014 the American Physiological Society.

  9. Inflammation and nerve injury induce expression of pancreatitis-associated protein-II in primary sensory neurons.

    PubMed

    He, Shao-Qiu; Yao, Jun-Ru; Zhang, Fang-Xiong; Wang, Qiong; Bao, Lan; Zhang, Xu

    2010-04-26

    Pancreatitis-associated protein (PAP)-I and -II, lectin-related secretory proteins, are members of the regenerating gene (Reg) family. Although expression of PAP-I was found in the dorsal root ganglion (DRG) neurons following peripheral nerve injury and cystitis, whether PAP-II could be expressed in DRG neurons in chronic pain models remains unclear. The present study shows an inflammation- and nerve injury-triggered expression of PAP-II in rat DRG neurons. In situ hybridization showed that only a few DRG neurons normally contained PAP-I and -II mRNAs. After peripheral inflammation, PAP-I and -II mRNAs were present in over half of small DRG neurons. Such an elevated expression of PAP-I and -II reached the peak level on the second day. Immunostaining showed that the expression of PAP-II was mostly increased in the isolectin B4-positive subset of small DRG neurons after inflammation. Furthermore, the expression of PAP-II was also induced in DRG neurons after peripheral nerve injury. Interestingly, PAP-II expression was shifted from small neurons on day 2 to large DRG neurons that expressed neuropeptide Y during the later post-injury days. These results suggest that PAP-II may play potential roles in the modulation of spinal sensory pathways in pathological pain states.

  10. Neurotoxicity to DRG neurons varies between rodent strains treated with cisplatin and bortezomib.

    PubMed

    Podratz, Jewel L; Kulkarni, Amit; Pleticha, Josef; Kanwar, Rahul; Beutler, Andreas S; Staff, Nathan P; Windebank, Anthony J

    2016-03-15

    Chemotherapy-induced peripheral neuropathy (CIPN) is a major dose limiting side effect that can lead to long-term morbidity. Approximately one-third of patients receiving chemotherapy with taxanes, vinca alkaloids, platinum compounds or proteasome inhibitors develop this toxic side effect. It is not possible to predict who will get CIPN, however, genetic susceptibility may play a role. We explored this hypothesis using an established in vitro dorsal root ganglia neurite outgrowth (DRG-NOG) assay to assess possible genetic influences for cisplatin- and bortezomib-induced neurotoxicity. Almost all previous in vitro studies have used rats or mice. We compared DRG-NOG between four genetically defined, inbred mouse strains (C57BL/6J, DBA/2J, BALB/cJ, and C3H/HeJ) and one rat strain (Sprague Dawley). Our studies found differences in cisplatin and bortezomib-induced neurotoxicity between mouse and rat strains and between the different mouse strains. C57BL/6J and Balb/cJ DRG-NOG was more sensitive to cisplatin than DBA/2J and C3H/HeJ DRG-NOG, and all mouse strains were more sensitive to cisplatin than rat. Bortezomib induced a biphasic dose response in DBA/2J and C3H/H3J mice. C57BL/6J DRG-NOG was most sensitive and Balb/cJ DRG-NOG was least sensitive to bortezomib. Our animal data supports the hypothesis that genetic background may play a role in CIPN and care must be taken when rodent models are used to better understand the contribution of genetics in patient susceptibility to CIPN. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. [The neurotrophic effect of endogenous NT-3 from adult cat spared dorsal root ganglion on ganglionic neurons].

    PubMed

    Zhang, Wei; Zhou, Xue; Wang, Ting-hua; Wang, Te-wei; Liu, Su; Chen, Si-xiu; Ou, Ke-qun

    2004-01-01

    To investigate the neurotrophic effect of endogenous NT-3 from adult cat dorsal root ganglion (DRG) on ganglionic neurons. Rhizotomy of bilateral L1, L3, L5 and L7 dorsal roots of cats was performed, leaving L2, L4 and L6 DRG as spared DRGs. The separate neurons of normal (control) DRG, spared DRG and anti-NT-3 antibody blocking DRG were cultured in vitro respectively. The number of survival neurons and the length of neurites were measured and used for comparison in the control, spared DRG, and block groups. There were survival neurons and cell clusters in every group. The number of survival neurons and cell clusters of spared DRG group were much larger than those of the control and block groups. The neurite length of neurons, the neurite number and the length of cell clusters of spared DRG group were much greater than those of control and block groups. Endogenous NT-3 from spared DRG may act on ganglionic neurons to maintain survival of neuron and stimulate growth of neurite.

  12. Growth Cone Biomechanics in Peripheral and Central Nervous System Neurons

    NASA Astrophysics Data System (ADS)

    Urbach, Jeffrey; Koch, Daniel; Rosoff, Will; Geller, Herbert

    2012-02-01

    The growth cone, a highly motile structure at the tip of an axon, integrates information about the local environment and modulates outgrowth and guidance, but little is known about effects of external mechanical cues and internal mechanical forces on growth-cone mediated guidance. We have investigated neurite outgrowth, traction forces and cytoskeletal substrate coupling on soft elastic substrates for dorsal root ganglion (DRG) neurons (from the peripheral nervous system) and hippocampal neurons (from the central) to see how the mechanics of the microenvironment affect different populations. We find that the biomechanics of DRG neurons are dramatically different from hippocampal, with DRG neurons displaying relatively large, steady traction forces and maximal outgrowth and forces on substrates of intermediate stiffness, while hippocampal neurons display weak, intermittent forces and limited dependence of outgrowth and forces on substrate stiffness. DRG growth cones have slower rates of retrograde actin flow and higher density of localized paxillin (a protein associated with substrate adhesion complexes) compared to hippocampal neurons, suggesting that the difference in force generation is due to stronger adhesions and therefore stronger substrate coupling in DRG growth cones.

  13. Protein kinase A-induced internalization of Slack channels from the neuronal membrane occurs by adaptor protein-2/clathrin-mediated endocytosis.

    PubMed

    Gururaj, Sushmitha; Evely, Katherine M; Pryce, Kerri D; Li, Jun; Qu, Jun; Bhattacharjee, Arin

    2017-11-24

    The sodium-activated potassium (K Na ) channel Kcnt1 (Slack) is abundantly expressed in nociceptor (pain-sensing) neurons of the dorsal root ganglion (DRG), where they transmit the large outward conductance I KNa and arbitrate membrane excitability. Slack channel expression at the DRG membrane is necessary for their characteristic firing accommodation during maintained stimulation, and reduced membrane channel density causes hyperexcitability. We have previously shown that in a pro-inflammatory state, a decrease in membrane channel expression leading to reduced Slack-mediated I KNa expression underlies DRG neuronal sensitization. An important component of the inflammatory milieu, PKA internalizes Slack channels from the DRG membrane, reduces I KNa , and produces DRG neuronal hyperexcitability when activated in cultured primary DRG neurons. Here, we show that this PKA-induced retrograde trafficking of Slack channels also occurs in intact spinal cord slices and that it is carried out by adaptor protein-2 (AP-2) via clathrin-mediated endocytosis. We provide mass spectrometric and biochemical evidence of an association of native neuronal AP-2 adaptor proteins with Slack channels, facilitated by a dileucine motif housed in the cytoplasmic Slack C terminus that binds AP-2. By creating a competitive peptide blocker of AP-2-Slack binding, we demonstrated that this interaction is essential for clathrin recruitment to the DRG membrane, Slack channel endocytosis, and DRG neuronal hyperexcitability after PKA activation. Together, these findings uncover AP-2 and clathrin as players in Slack channel regulation. Given the significant role of Slack in nociceptive neuronal excitability, the AP-2 clathrin-mediated endocytosis trafficking mechanism may enable targeting of peripheral and possibly, central neuronal sensitization. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Isolated dorsal root ganglion neurones inhibit receptor-dependent adenylyl cyclase activity in associated glial cells

    PubMed Central

    Ng, KY; Yeung, BHS; Wong, YH; Wise, H

    2013-01-01

    Background and Purpose Hyper-nociceptive PGE2 EP4 receptors and prostacyclin (IP) receptors are present in adult rat dorsal root ganglion (DRG) neurones and glial cells in culture. The present study has investigated the cell-specific expression of two other Gs-protein coupled hyper-nociceptive receptor systems: β-adrenoceptors and calcitonin gene-related peptide (CGRP) receptors in isolated DRG cells and has examined the influence of neurone–glial cell interactions in regulating adenylyl cyclase (AC) activity. Experimental Approach Agonist-stimulated AC activity was determined in mixed DRG cell cultures from adult rats and compared with activity in DRG neurone-enriched cell cultures and pure DRG glial cell cultures. Key Results Pharmacological analysis showed the presence of Gs-coupled β2-adrenoceptors and CGRP receptors, but not β1-adrenoceptors, in all three DRG cell preparations. Agonist-stimulated AC activity was weakest in DRG neurone-enriched cell cultures. DRG neurones inhibited IP receptor-stimulated glial cell AC activity by a process dependent on both cell–cell contact and neurone-derived soluble factors, but this is unlikely to involve purine or glutamine receptor activation. Conclusions and Implications Gs-coupled hyper-nociceptive receptors are readily expressed on DRG glial cells in isolated cell cultures and the activity of CGRP, EP4 and IP receptors, but not β2-adrenoceptors, in glial cells is inhibited by DRG neurones. Studies using isolated DRG cells should be aware that hyper-nociceptive ligands may stimulate receptors on glial cells in addition to neurones, and that variable numbers of neurones and glial cells will influence absolute measures of AC activity and affect downstream functional responses. PMID:22924655

  15. Interleukin-1beta-induced airway hyperresponsiveness enhances substance P in intrinsic neurons of ferret airway.

    PubMed

    Wu, Z-X; Satterfield, B E; Fedan, J S; Dey, R D

    2002-11-01

    Interleukin (IL)-1beta causes airway inflammation, enhances airway smooth muscle responsiveness, and alters neurotransmitter expression in sensory, sympathetic, and myenteric neurons. This study examines the role of intrinsic airway neurons in airway hyperresponsiveness (AHR) induced by IL-1beta. Ferrets were instilled intratracheally with IL-1beta (0.3 microg/0.3 ml) or saline (0.3 ml) once daily for 5 days. Tracheal smooth muscle contractility in vitro and substance P (SP) expression in tracheal neurons were assessed. Tracheal smooth muscle reactivity to acetylcholine (ACh) and methacholine (MCh) and smooth muscle contractions to electric field stimulation (EFS) both increased after IL-1beta. The IL-1beta-induced AHR was maintained in tracheal segments cultured for 24 h, a procedure that depletes SP from sensory nerves while maintaining viability of intrinsic airway neurons. Pretreatment with CP-99994, an antagonist of neurokinin 1 receptor, attenuated the IL-1beta-induced hyperreactivity to ACh and MCh and to EFS in cultured tracheal segments. SP-containing neurons in longitudinal trunk, SP innervation of superficial muscular plexus neurons, and SP nerve fiber density in tracheal smooth muscle all increased after treatment with IL-1beta. These results show that IL-1beta-enhanced cholinergic airway smooth muscle contractile responses are mediated by the actions of SP released from intrinsic airway neurons.

  16. TRPV2, a capsaicin receptor homologue, is expressed predominantly in the neurotrophin-3-dependent subpopulation of primary sensory neurons.

    PubMed

    Tamura, S; Morikawa, Y; Senba, E

    2005-01-01

    TRPV2, a member of transient receptor potential ion channels, responds to high-threshold noxious heat, but neither to capsaicin nor to proton. Although TRPV2 is expressed in medium- to large-sized dorsal root ganglion (DRG) neurons with myelinated fibers in adult rodents, little is known about the neurotrophin dependence of TRPV2-positive neurons in the developing and adult DRGs of mice. In the present study, using immunohistochemistry, we found that TRPV2 was first expressed in DRG neurons at embryonic day (E) 11.5, when neither TRPV1 nor TRPM8 was detected yet. Double-immunofluorescence staining revealed that tyrosine kinase receptor C (TrkC) was expressed in most of TRPV2-positive DRG neurons at E11.5 and E13.5. In addition, the percentage of TRPV2-positive neurons in the total DRG neurons at E13.5 reached the same as that of adulthood. In adult DRGs, TrkC and Ret were expressed in 68% and 25% of TRPV2-positive neurons, respectively. These results suggest that TRPV2 is expressed predominantly in the NT-3-dependent subpopulation of DRG neurons throughout development and in adult mice.

  17. Localization of beta and gamma subunits of ENaC in sensory nerve endings in the rat foot pad.

    PubMed

    Drummond, H A; Abboud, F M; Welsh, M J

    2000-11-24

    The molecular mechanisms underlying mechanoelectrical transduction and the receptors that detect light touch remain uncertain. Studies in Caenorhabditis elegans suggest that members of the DEG/ENaC cation channel family may be mechanoreceptors. Therefore, we tested the hypothesis that subunits of the mammalian epithelial Na(+) channel (ENaC) family are expressed in touch receptors in rat hairless skin. We detected betaENaC and gammaENaC, but not alphaENaC transcripts in cervical and lumbar dorsal root ganglia (DRG). Using immunofluorescence, we found betaENaC and gammaENaC expressed in medium to large lumbar DRG neurons. Moreover, we detected these two subunits in Merkel cell-neurite complexes, Meissner-like corpuscles, and small lamellated corpuscles, specialized mechanosensory structures of the skin. Within these structures, betaENaC and gammaENaC were localized in the nerve fibers believed to contain the sensors responsive to mechanical stress. Thus beta and gammaENaC subunits are good candidates as components of the molecular sensor that detects touch.

  18. Characterization of Na+ and Ca2+ Channels in Zebrafish Dorsal Root Ganglion Neurons

    PubMed Central

    Won, Yu-Jin; Ono, Fumihito; Ikeda, Stephen R.

    2012-01-01

    Background Dorsal root ganglia (DRG) somata from rodents have provided an excellent model system to study ion channel properties and modulation using electrophysiological investigation. As in other vertebrates, zebrafish (Danio rerio) DRG are organized segmentally and possess peripheral axons that bifurcate into each body segment. However, the electrical properties of zebrafish DRG sensory neurons, as compared with their mammalian counterparts, are relatively unexplored because a preparation suitable for electrophysiological studies has not been available. Methodology/Principal Findings We show enzymatically dissociated DRG neurons from juvenile zebrafish expressing Isl2b-promoter driven EGFP were easily identified with fluorescence microscopy and amenable to conventional whole-cell patch-clamp studies. Two kinetically distinct TTX-sensitive Na+ currents (rapidly- and slowly-inactivating) were discovered. Rapidly-inactivating INa were preferentially expressed in relatively large neurons, while slowly-inactivating INa was more prevalent in smaller DRG neurons. RT-PCR analysis suggests zscn1aa/ab, zscn8aa/ab, zscn4ab and zscn5Laa are possible candidates for these INa components. Voltage-gated Ca2+ currents (ICa) were primarily (87%) comprised of a high-voltage activated component arising from ω-conotoxin GVIA-sensitive CaV2.2 (N-type) Ca2+ channels. A few DRG neurons (8%) displayed a miniscule low-voltage-activated component. ICa in zebrafish DRG neurons were modulated by neurotransmitters via either voltage-dependent or -independent G-protein signaling pathway with large cell-to-cell response variability. Conclusions/Significance Our present results indicate that, as in higher vertebrates, zebrafish DRG neurons are heterogeneous being composed of functionally distinct subpopulations that may correlate with different sensory modalities. These findings provide the first comparison of zebrafish and rodent DRG neuron electrical properties and thus provide a basis for

  19. The intriguing nature of dorsal root ganglion neurons: linking structure with polarity and function.

    PubMed

    Nascimento, Ana Isabel; Mar, Fernando Milhazes; Sousa, Mónica Mendes

    2018-05-02

    Dorsal root ganglion (DRG) neurons are the first neurons of the sensory pathway. They are activated by a variety of sensory stimuli that are then transmitted to the central nervous system. An important feature of DRG neurons is their unique morphology where a single process -the stem axon- bifurcates into a peripheral and a central axonal branch, with different functions and cellular properties. Distinctive structural aspects of the two DRG neuron branches may have important implications for their function in health and disease. However, the link between DRG axonal branch structure, polarity and function has been largely neglected in the field, and relevant information is rather scattered across the literature. In particular, ultrastructural differences between the two axonal branches are likely to account for the higher transport and regenerative ability of the peripheral DRG neuron axon when compared to the central one. Nevertheless, the cell intrinsic factors contributing to this central-peripheral asymmetry are still unknown. Here we critically review the factors that may underlie the functional asymmetry between the peripheral and central DRG axonal branches. Also, we discuss the hypothesis that DRG neurons may assemble a structure resembling the axon initial segment that may be responsible, at least in part, for their polarity and electrophysiological features. Ultimately, we suggest that the clarification of the axonal ultrastructure of DRG neurons using state-of-the-art techniques will be crucial to understand the physiology of this peculiar cell type. Copyright © 2018. Published by Elsevier Ltd.

  20. Pathological effects of chronic myocardial infarction on peripheral neurons mediating cardiac neurotransmission.

    PubMed

    Nakamura, Keijiro; Ajijola, Olujimi A; Aliotta, Eric; Armour, J Andrew; Ardell, Jeffrey L; Shivkumar, Kalyanam

    2016-05-01

    To determine whether chronic myocardial infarction (MI) induces structural and neurochemical changes in neurons within afferent and efferent ganglia mediating cardiac neurotransmission. Neuronal somata in i) right atrial (RAGP) and ii) ventral interventricular ganglionated plexi (VIVGP), iii) stellate ganglia (SG) and iv) T1-2 dorsal root ganglia (DRG) bilaterally derived from normal (n=8) vs. chronic MI (n=8) porcine subjects were studied. We examined whether the morphology and neuronal nitric oxide synthase (nNOS) expression in soma of RAGP, VIVGP, DRG and SG neurons were altered as a consequence of chronic MI. In DRG, we also examined immunoreactivity of calcitonin gene related peptide (CGRP), a marker of afferent neurons. Chronic MI increased neuronal size and nNOS immunoreactivity in VIVGP (but not RAGP), as well as in the SG bilaterally. Across these ganglia, the increase in neuronal size was more pronounced in nNOS immunoreactive neurons. In the DRG, chronic MI also caused neuronal enlargement, and increased CGRP immunoreactivity. Further, DRG neurons expressing both nNOS and CGRP were increased in MI animals compared to controls, and represented a shift from double negative neurons. Chronic MI impacts diverse elements within the peripheral cardiac neuraxis. That chronic MI imposes such widespread, diverse remodeling of the peripheral cardiac neuraxis must be taken into consideration when contemplating neuronal regulation of the ischemic heart. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. PATHOLOGICAL EFFECTS OF CHRONIC MYOCARDIAL INFARCTION ON PERIPHERAL NEURONS MEDIATING CARDIAC NEUROTRANSMISSION

    PubMed Central

    Nakamura, Keijiro; Ajijola, Olujimi A.; Aliotta, Eric; Armour, J. Andrew; Ardell, Jeffrey L.; Shivkumar, Kalyanam

    2016-01-01

    Objective To determine whether chronic myocardial infarction (MI) induces structural and neurochemical changes in neurons within afferent and efferent ganglia mediating cardiac neurotransmission. Methods Neuronal somata in i) right atrial (RAGP) and ii) ventral interventricular ganglionated plexi (VIVGP), iii) stellate ganglia (SG) and iv) T1-2 dorsal root ganglia (DRG) bilaterally derived from normal (n = 8) vs. chronic MI (n = 8) porcine subjects were studied. We examined whether the morphology and neuronal nitric oxide synthase (nNOS) expression in soma of RAGP, VIVGP, DRG and SG neurons were altered as a consequence of chronic MI. In DRG, we also examined immunoreactivity of calcitonin gene related peptide (CGRP), a marker of afferent neurons. Results Chronic MI increased neuronal size and nNOS immunoreactivity in VIVGP (but not RAGP), as well as in the SG bilaterally. Across these ganglia, the increase in neuronal size was more pronounced in nNOS immunoreacitive neurons. In the DRG, chronic MI also caused neuronal enlargement, and increased CGRP immunoreactivity. Further, DRG neurons expressing both nNOS and CGRP were increased in MI animals compared to controls, and represented a shift from double negative neurons. Conclusions Chronic MI impacts diverse elements within the peripheral cardiac neuraxis. That chronic MI imposes such widespread, diverse remodeling of the peripheral cardiac neuraxis must be taken into consideration when contemplating neuronal regulation of the ischemic heart. PMID:27209472

  2. Hyperexcitable neurons and altered non-neuronal cells in the compressed spinal ganglion

    PubMed Central

    LaMotte, Robert H.; Chao, MA

    2009-01-01

    The cell body or soma in the dosal root ganglion (DRG) is normally excitable and this excitability can increase and persist after an injury of peripheral sensory neurons. In a rat model of radicular pain, an intraforaminal implantation of a rod that chronically compressed the lumbar DRG (“CCD” model) resulted in neuronal somal hyperexcitability and spontaneous activity that was accompanied by hyperalgesia in the ipsilateral hind paw. By the 5th day after onset of CCD, there was a novel upregulation in neuronal expression of the chemokine, monocyte chemoattractant protein-1 (MCP-1 or CCL2) and also its receptor, CCR2. The neurons developed, in response to topically applied MCP-1, an excitatory response that they normally do not have. CCD also activated non-neuronal cells including, for example, the endothelial cells as evidenced by angiogenesis in the form of an increased number of capillaries in the DRG after 7 days. A working hypothesis is that the CCD induced changes in neurons and non-neuronal cells that may act together to promote the survival of the injured tissue. The release of ligands such as CCL2, in addition to possibly activating nociceptive neurons (maintaining the pain), may also act to preserve injured cells in the face of ischemia and hypoxia, for example, by promoting angiogenesis. Thus, somal hyperexcitability, as often said of inflammation, may represent a double edged sword. PMID:18958366

  3. DRG axon elongation and growth cone collapse rate induced by Sema3A are differently dependent on NGF concentration.

    PubMed

    Kaselis, Andrius; Treinys, Rimantas; Vosyliūtė, Rūta; Šatkauskas, Saulius

    2014-03-01

    Regeneration of embryonic and adult dorsal root ganglion (DRG) sensory axons is highly impeded when they encounter neuronal growth cone-collapsing factor semaphorin3A (Sema3A). On the other hand, increasing evidence shows that DRG axon's regeneration can be stimulated by nerve growth factor (NGF). In this study, we aimed to evaluate whether increased NGF concentrations can counterweight Sema3A-induced inhibitory responses in 15-day-old mouse embryo (E15) DRG axons. The DRG explants were grown in Neurobasal-based medium with different NGF concentrations ranging from 0 to 100 ng/mL and then treated with Sema3A at constant 10 ng/mL concentration. To evaluate interplay between NGF and Sema3A number of DRG axons, axon outgrowth distance and collapse rate were measured. We found that the increased NGF concentrations abolish Sema3A-induced inhibitory effect on axon outgrowth, while they have no effect on Sema3A-induced collapse rate.

  4. Amyloid beta peptide as a physiological modulator of neuronal 'A'-type K+ current.

    PubMed

    Plant, Leigh D; Webster, Nicola J; Boyle, John P; Ramsden, Martin; Freir, Darragh B; Peers, Chris; Pearson, Hugh A

    2006-11-01

    Control of neuronal spiking patterns resides, in part, in the type and degree of expression of voltage-gated K(+) channel subunits. Previous studies have revealed that soluble forms of the Alzheimer's disease associated amyloid beta protein (Abeta) can increase the 'A'-type current in neurones. In this study, we define the molecular basis for this increase and show that endogenous production of Abeta is important in the modulation of Kv4.2 and Kv4.3 subunit expression in central neurones. A-type K(+) currents, and Kv4.2 and Kv4.3 subunit expression, were transiently increased in cerebellar granule neurones by the 1-40 and 1-42 forms of Abeta (100nM, 2-24h). Currents through recombinant Kv4.2 channels expressed in HEK293 cells were increased in a similar fashion to those through the native channels. Increases in 'A'-type current could be prevented by the use of cycloheximide and brefeldin A, indicating that protein expression and trafficking processes were altered by Abeta, rather than protein degredation. Endogenous Abeta production in cerebellar granule neurones was blocked using inhibitors of either gamma- or beta-secretase and resulted in decreased K(+) current. Crucially this could be prevented by co-application of exogenous Abeta (1nM), however, no change in Kv4.2 or Kv4.3 subunit expression occurred. These data show that Abeta is a modulator of Kv4 subunit expression in neurones at both the functional and the molecular level. Thus Abeta is not only involved in Alzheimer pathology, but is also an important physiological regulator of ion channel expression and hence neuronal excitability.

  5. Accumulation of methylglyoxal increases the advanced glycation end-product levels in DRG and contributes to lumbar disk herniation-induced persistent pain.

    PubMed

    Liu, Cui-Cui; Zhang, Xin-Sheng; Ruan, Yu-Ting; Huang, Zhu-Xi; Zhang, Su-Bo; Liu, Meng; Luo, Hai-Jie; Wu, Shao-Ling; Ma, Chao

    2017-08-01

    Lumbar disk herniation (LDH) with discogenic low back pain and sciatica is a common and complicated musculoskeletal disorder. The underlying mechanisms are poorly understood, and there are no effective therapies for LDH-induced pain. In the present study, we found that the patients who suffered from LDH-induced pain had elevated plasma methylglyoxal (MG) levels. In rats, implantation of autologous nucleus pulposus (NP) to the left lumbar 5 spinal nerve root, which mimicked LDH, induced mechanical allodynia, increased MG level in plasma and dorsal root ganglion (DRG), and enhanced the excitability of small DRG neurons (<30 μm in diameter). Intrathecal injection of MG also induced mechanical allodynia, and its application to DRG neurons ex vivo increased the number of action potentials evoked by depolarizing current pulses. Furthermore, inhibition of MG accumulation by aminoguanidine attenuated the enhanced excitability of small DRG neurons and the mechanical allodynia induced by NP implantation. In addition, NP implantation increased levels of advanced glycation end products (AGEs) in DRG, and intrathecal injection of MG-derived AGEs induced the mechanical allodynia and DRG neuronal hyperactivity. Intrathecal injection of MG also significantly increased the expression of AGEs in DRG. Importantly, scavenging of MG by aminoguanidine also attenuated the increase in AGEs induced by NP implantation. These results suggested that LDH-induced MG accumulation contributed to persistent pain by increasing AGE levels. Thus generation of AGEs from MG may represent a target for treatment of LDH-induced pain. NEW & NOTEWORTHY Our study demonstrates that methylglyoxal accumulation via increasing advanced glycation end-product levels in dorsal root ganglion contributes to the persistent pain induced by lumbar disk herniation, which proposed potential targets for the treatment of lumbar disk herniation-induced persistent pain. Copyright © 2017 the American Physiological Society.

  6. A-type voltage-gated K+ currents influence firing properties of isolectin B4-positive but not isolectin B4-negative primary sensory neurons.

    PubMed

    Vydyanathan, Amaresh; Wu, Zi-Zhen; Chen, Shao-Rui; Pan, Hui-Lin

    2005-06-01

    Voltage-gated K+ channels (Kv) in primary sensory neurons are important for regulation of neuronal excitability. The dorsal root ganglion (DRG) neurons are heterogeneous, and the types of native Kv currents in different groups of nociceptive DRG neurons are not fully known. In this study, we determined the difference in the A-type Kv current and its influence on the firing properties between isolectin B4 (IB4)-positive and -negative DRG neurons. Whole cell voltage- and current-clamp recordings were performed on acutely dissociated small DRG neurons of rats. The total Kv current density was significantly higher in IB+-positive than that in IB(4)-negative neurons. Also, 4-aminopyridine (4-AP) produced a significantly greater reduction in Kv currents in IB4-positive than in IB4-negative neurons. In contrast, IB4-negative neurons exhibited a larger proportion of tetraethylammonium-sensitive Kv currents. Furthermore, IB4-positive neurons showed a longer latency of firing and required a significantly larger amount of current injection to evoke action potentials. 4-AP significantly decreased the latency of firing and increased the firing frequency in IB4-positive but not in IB4-negative neurons. Additionally, IB4-positive neurons are immunoreactive to Kv1.4 but not to Kv1.1 and Kv1.2 subunits. Collectively, this study provides new information that 4-AP-sensitive A-type Kv currents are mainly present in IB4-positive DRG neurons and preferentially dampen the initiation of action potentials of this subpopulation of nociceptors. The difference in the density of A-type Kv currents contributes to the distinct electrophysiological properties of IB4-positive and -negative DRG neurons.

  7. Neurochemical diversity of afferent neurons that transduce sensory signals from dog ventricular myocardium

    PubMed Central

    Hoover, Donald B.; Shepherd, Angela V.; Southerland, E. Marie; Armour, J. Andrew; Ardell, Jeffrey L.

    2008-01-01

    While much is known about the influence of ventricular afferent neurons on cardiovascular function in the dog, identification of the neurochemicals transmitting cardiac afferent signals to central neurons is lacking. Accordingly, we identified ventricular afferent neurons in canine dorsal root ganglia (DRG) and nodose ganglia by retrograde labeling after injecting horseradish peroxidase (HRP) into the anterior right and left ventricles. Primary antibodies from three host species were used in immunohistochemical experiments to simultaneously evaluate afferent somata for the presence of HRP and markers for two neurotransmitters. Only a small percentage (2%) of afferent somata were labeled with HRP. About half of the HRP-identified ventricular afferent neurons in T3 DRG also stained for substance P (SP), calcitonin gene-related peptide (CGRP), or neuronal nitric oxide synthase (nNOS), either alone or with two markers colocalized. Ventricular afferent neurons and the general population of T3 DRG neurons showed the same labeling profiles; CGRP (alone or colocalized with SP) being the most common (30–40% of ventricular afferent somata in T3 DRG). About 30% of the ventricular afferent neurons in T2 DRG displayed CGRP immunoreactivity and binding of the putative nociceptive marker IB4. Ventricular afferent neurons of the nodose ganglia were distinct from those in the DRG by having smaller size and lacking immunoreactivity for SP, CGRP, and nNOS. These findings suggest that ventricular sensory information is transferred to the central nervous system by relatively small populations of vagal and spinal afferent neurons and that spinal afferents use a variety of neurotransmitters. PMID:18558516

  8. Neurochemical diversity of afferent neurons that transduce sensory signals from dog ventricular myocardium.

    PubMed

    Hoover, Donald B; Shepherd, Angela V; Southerland, E Marie; Armour, J Andrew; Ardell, Jeffrey L

    2008-08-18

    While much is known about the influence of ventricular afferent neurons on cardiovascular function in the dog, identification of the neurochemicals transmitting cardiac afferent signals to central neurons is lacking. Accordingly, we identified ventricular afferent neurons in canine dorsal root ganglia (DRG) and nodose ganglia by retrograde labeling after injecting horseradish peroxidase (HRP) into the anterior right and left ventricles. Primary antibodies from three host species were used in immunohistochemical experiments to simultaneously evaluate afferent somata for the presence of HRP and markers for two neurotransmitters. Only a small percentage (2%) of afferent somata were labeled with HRP. About half of the HRP-identified ventricular afferent neurons in T(3) DRG also stained for substance P (SP), calcitonin gene-related peptide (CGRP), or neuronal nitric oxide synthase (nNOS), either alone or with two markers colocalized. Ventricular afferent neurons and the general population of T(3) DRG neurons showed the same labeling profiles; CGRP (alone or colocalized with SP) being the most common (30-40% of ventricular afferent somata in T(3) DRG). About 30% of the ventricular afferent neurons in T(2) DRG displayed CGRP immunoreactivity and binding of the putative nociceptive marker IB(4). Ventricular afferent neurons of the nodose ganglia were distinct from those in the DRG by having smaller size and lacking immunoreactivity for SP, CGRP, and nNOS. These findings suggest that ventricular sensory information is transferred to the central nervous system by relatively small populations of vagal and spinal afferent neurons and that spinal afferents use a variety of neurotransmitters.

  9. DNA methyltransferase DNMT3a contributes to neuropathic pain by repressing Kcna2 in primary afferent neurons

    PubMed Central

    Zhao, Jian-Yuan; Liang, Lingli; Gu, Xiyao; Li, Zhisong; Wu, Shaogen; Sun, Linlin; Atianjoh, Fidelis E.; Feng, Jian; Mo, Kai; Jia, Shushan; Lutz, Brianna Marie; Bekker, Alex; Nestler, Eric J.; Tao, Yuan-Xiang

    2017-01-01

    Nerve injury induces changes in gene transcription in dorsal root ganglion (DRG) neurons, which may contribute to nerve injury-induced neuropathic pain. DNA methylation represses gene expression. Here, we report that peripheral nerve injury increases expression of the DNA methyltransferase DNMT3a in the injured DRG neurons via the activation of the transcription factor octamer transcription factor 1. Blocking this increase prevents nerve injury-induced methylation of the voltage-dependent potassium (Kv) channel subunit Kcna2 promoter region and rescues Kcna2 expression in the injured DRG and attenuates neuropathic pain. Conversely, in the absence of nerve injury, mimicking this increase reduces the Kcna2 promoter activity, diminishes Kcna2 expression, decreases Kv current, increases excitability in DRG neurons and leads to spinal cord central sensitization and neuropathic pain symptoms. These findings suggest that DNMT3a may contribute to neuropathic pain by repressing Kcna2 expression in the DRG. PMID:28270689

  10. Co-culture of osteocytes and neurons on a unique patterned surface.

    PubMed

    Boggs, Mary E; Thompson, William R; Farach-Carson, Mary C; Duncan, Randall L; Beebe, Thomas P

    2011-12-01

    Neural and skeletal communication is essential for the maintenance of bone mass and transmission of pain, yet the mechanism(s) of signal transduction between these tissues is unknown. The authors established a novel system to co-culture murine long bone osteocyte-like cells (MLO-Y4) and primary murine dorsal root ganglia (DRG) neurons. Assessment of morphology and maturation marker expression on perlecan domain IV peptide (PlnDIV) and collagen type-1 (Col1) demonstrated that PlnDIV was an optimal matrix for MLO-Y4 culture. A novel matrix-specificity competition assay was developed to expose these cells to several extracellular matrix proteins such as PlnDIV, Col1, and laminin (Ln). The competition assay showed that approximately 70% of MLO-Y4 cells preferred either PlnDIV or Col1 to Ln. To co-culture MLO-Y4 and DRG, we developed patterned surfaces using micro-contact printing to create 40 μm × 1 cm alternating stripes of PlnDIV and Ln or PlnDIV and Col1. Co-culture on PlnDIV/Ln surfaces demonstrated that these matrix molecules provided unique cues for each cell type, with MLO-Y4 preferentially attaching to the PlnDIV lanes and DRG neurons to the Ln lanes. Approximately 80% of DRG were localized to Ln. Cellular processes from MLO-Y4 were closely associated with axonal extensions of DRG neurons. Approximately 57% of neuronal processes were in close proximity to nearby MLO-Y4 cells at the PlnDIV-Ln interface. The surfaces in this new assay provided a unique model system with which to study the communication between osteocyte-like cells and neurons in an in vitro environment.

  11. Synergy between TGF-beta 3 and NT-3 to promote the survival of spiral ganglia neurones in vitro.

    PubMed

    Marzella, P L; Clark, G M; Shepherd, R K; Bartlett, P F; Kilpatrick, T J

    1998-01-09

    Transforming growth factor-betas (TGF-betas) have been implicated in normal inner ear development and in promoting neuronal survival. Early rat post-natal spiral ganglion cells (SGC) in dissociated cell culture were used as a model of auditory innervation to test the trophic factors TGF-beta3 and neurotrophin-3 (NT-3) for their ability, individually or in combination, to promote neuronal survival. The findings from this study suggest that TGF-beta3 supports neuronal survival in a concentration-dependent manner. Moreover TGF-beta3 and NT-3-potentiated spiral ganglion neuronal survival in a synergistic fashion.

  12. Effects of oxymatrine on sympathoexcitatory reflex induced by myocardial ischemic signaling mediated by P2X₃ receptors in rat SCG and DRG.

    PubMed

    Li, Guilin; Liu, Shuangmei; Yang, Yang; Xie, Jinyan; Liu, Jun; Kong, Fanjun; Tu, Guihua; Wu, Raoping; Li, Guodong; Liang, Shangdong

    2011-04-05

    Sympathoexcitatory reflex is characterized by an increase in blood pressure and sympathetic nerve activity. P2X₃ receptors in SCG neurons are involved in increasing sympathoexcitatory reflex after myocardial ischemic (MI) injury. The present study is aimed to explore the effects of oxymatrine (Oxy) on the transmission of myocardial ischemic signaling mediated by P2X₃ receptors in rat superior cervical ganglia (SCG) and cervical dorsal root ganglia (DRG) in the sympathoexcitatory reflex after myocardial ischemic injury. In this study, the expression levels of P2X₃ immunoreactivity, mRNA and protein were analyzed in SCG and DRG neurons by immunohistochemistry, in situ hybridization and Western blotting. The results show that the myocardial ischemic injury induces the increase of the systolic blood pressure and heart rate and upregulates the expression of P2X₃ receptors in SCG and DRG neurons. Upregulated expression of P2X₃ receptors in SCG and DRG neurons subsequently leads to the aggravated sympathoexcitatory reflex. Oxymatrine reduces the systolic blood pressure and heart rate in myocardial ischemic rats. After myocardial ischemic rats are treated with oxymatrine, the expression levels of P2X₃ immunoreactivity, mRNA and protein are lower than those in myocardial ischemic rats. Oxymatrine may decrease the expression of P2X₃ receptor and depress the aggravated sympathoexcitatory reflex induced by the nociceptive transmission of myocardial ischemic injury via P2X₃ receptors of rat SCG and DRG neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Calpain-2 contributes to neuropathic pain following motor nerve injury via up-regulating interleukin-6 in DRG neurons.

    PubMed

    Zang, Ying; Chen, Shao-Xia; Liao, Guang-Jie; Zhu, He-Quan; Wei, Xu-Hong; Cui, Yu; Na, Xiao-Dong; Pang, Rui-Ping; Xin, Wen-Jun; Zhou, Li-Jun; Liu, Xian-Guo

    2015-02-01

    Motor nerve injury by L5 ventral root transection (L5-VRT) initiates interleukin-6 (IL-6) up-regulation in primary afferent system contributing to neuropathic pain. However, the early upstream regulatory mechanisms of IL-6 after L5-VRT are still unknown. Here, we monitored both the activity of calpain, a calcium-dependent protease suggested as one of the earliest mediators for cytokine regulation, and the expression of IL-6 in bilateral L4-L6 dorsal root ganglias (DRGs) soon after L5-VRT. We found that the protein level of calpain-2 in DRGs, but not calpain-1 was increased transiently in the first 10 min(-1)h ipsilaterally and 20 min(-1)h contralaterally after L5-VRT, long before mechanical allodynia was initiated (5-15 h ipsilaterally and 15 h(-1)d contralaterally). The early activation of calpain evaluated by the generation of spectrin breakdown products (SBDP) correlated well with IL-6 up-regulation in bilateral DRGs. Double immunofluorescence staining revealed that almost all the calpain-2 positive neurons expressed IL-6, indicating an association between calpain-2 and IL-6. Inhibition of calpain by pre-treatment with MDL28170 (25mg/kg, i.p.) attenuated the rat mechanical allodynia and prevented the early up-regulation of IL-6 following L5-VRT. Addition of exogenous calpain-2 onto the surface of left L5 DRG triggered a temporal allodynia and increased IL-6 in bilateral DRGs simultaneously. Taken together, the early increase of calpain-2 in L5-VRT rats might be responsible for the induction of allodynia via up-regulating IL-6 in DRG neurons. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Voltage-gated sodium channel expression in mouse DRG after SNI leads to re-evaluation of projections of injured fibers.

    PubMed

    Laedermann, Cédric J; Pertin, Marie; Suter, Marc R; Decosterd, Isabelle

    2014-03-11

    Dysregulation of voltage-gated sodium channels (Na(v)s) is believed to play a major role in nerve fiber hyperexcitability associated with neuropathic pain. A complete transcriptional characterization of the different isoforms of Na(v)s under normal and pathological conditions had never been performed on mice, despite their widespread use in pain research. Na(v)s mRNA levels in mouse dorsal root ganglia (DRG) were studied in the spared nerve injury (SNI) and spinal nerve ligation (SNL) models of neuropathic pain. In the SNI model, injured and non-injured neurons were intermingled in lumbar DRG, which were pooled to increase the tissue available for experiments. A strong downregulation was observed for every Na(v)s isoform expressed except for Na(v)1.2; even Na(v)1.3, known to be upregulated in rat neuropathic pain models, was lower in the SNI mouse model. This suggests differences between these two species. In the SNL model, where the cell bodies of injured and non-injured fibers are anatomically separated between different DRG, most Na(v)s were observed to be downregulated in the L5 DRG receiving axotomized fibers. Transcription was then investigated independently in the L3, L4 and L5 DRG in the SNI model, and an important downregulation of many Na(v)s isoforms was observed in the L3 DRG, suggesting the presence of numerous injured neurons there after SNI. Consequently, the proportion of axotomized neurons in the L3, L4 and L5 DRG after SNI was characterized by studying the expression of activating transcription factor 3 (ATF3). Using this marker of nerve injury confirmed that most injured fibers find their cell bodies in the L3 and L4 DRG after SNI in C57BL/6 J mice; this contrasts with their L4 and L5 DRG localization in rats. The spared sural nerve, through which pain hypersensitivity is measured in behavioral studies, mostly projects into the L4 and L5 DRG. The complex regulation of Na(v)s, together with the anatomical rostral shift of the DRG harboring injured

  15. Voltage-gated sodium channel expression in mouse DRG after SNI leads to re-evaluation of projections of injured fibers

    PubMed Central

    2014-01-01

    Background Dysregulation of voltage-gated sodium channels (Navs) is believed to play a major role in nerve fiber hyperexcitability associated with neuropathic pain. A complete transcriptional characterization of the different isoforms of Navs under normal and pathological conditions had never been performed on mice, despite their widespread use in pain research. Navs mRNA levels in mouse dorsal root ganglia (DRG) were studied in the spared nerve injury (SNI) and spinal nerve ligation (SNL) models of neuropathic pain. In the SNI model, injured and non-injured neurons were intermingled in lumbar DRG, which were pooled to increase the tissue available for experiments. Results A strong downregulation was observed for every Navs isoform expressed except for Nav1.2; even Nav1.3, known to be upregulated in rat neuropathic pain models, was lower in the SNI mouse model. This suggests differences between these two species. In the SNL model, where the cell bodies of injured and non-injured fibers are anatomically separated between different DRG, most Navs were observed to be downregulated in the L5 DRG receiving axotomized fibers. Transcription was then investigated independently in the L3, L4 and L5 DRG in the SNI model, and an important downregulation of many Navs isoforms was observed in the L3 DRG, suggesting the presence of numerous injured neurons there after SNI. Consequently, the proportion of axotomized neurons in the L3, L4 and L5 DRG after SNI was characterized by studying the expression of activating transcription factor 3 (ATF3). Using this marker of nerve injury confirmed that most injured fibers find their cell bodies in the L3 and L4 DRG after SNI in C57BL/6 J mice; this contrasts with their L4 and L5 DRG localization in rats. The spared sural nerve, through which pain hypersensitivity is measured in behavioral studies, mostly projects into the L4 and L5 DRG. Conclusions The complex regulation of Navs, together with the anatomical rostral shift of the DRG

  16. Brn3a/Pou4f1 Regulates Dorsal Root Ganglion Sensory Neuron Specification and Axonal Projection into the Spinal Cord

    PubMed Central

    Zou, Min; Li, Shengguo; Klein, William H.; Xiang, Mengqing

    2012-01-01

    The sensory neurons of the dorsal root ganglia (DRG) must project accurately to their central targets to convey proprioceptive, nociceptive and mechanoreceptive information to the spinal cord. How these different sensory modalities and central connectivities are specified and coordinated still remains unclear. Given the expression of the POU homeodomain transcription factors Brn3a/Pou4f1 and Brn3b/Pou4f2 in DRG and spinal cord sensory neurons, we determined the subtype specification of DRG and spinal cord sensory neurons as well as DRG central projections in Brn3a and Brn3b single and double mutant mice. Inactivation of either or both genes causes no gross abnormalities in early spinal cord neurogenesis; however, in Brn3a single and Brn3a;Brn3b double mutant mice, sensory afferent axons from the DRG fail to form normal trajectories in the spinal cord. The TrkA+ afferents remain outside the dorsal horn and fail to extend into the spinal cord, while the projections of TrkC+ proprioceptive afferents into the ventral horn are also impaired. Moreover, Brn3a mutant DRGs are defective in sensory neuron specification, as marked by the excessive generation of TrkB+ and TrkC+ neurons as well as TrkA+/TrkB+ and TrkA+/TrkC+ double positive cells at early embryonic stages. At later stages in the mutant, TrkB+, TrkC+ and parvalbumin+ neurons diminish while there is a significant increase of CGRP+ and c-ret+ neurons. In addition, Brn3a mutant DRGs display a dramatic down-regulation of Runx1 expression, suggesting that the regulation of DRG sensory neuron specification by Brn3a is mediated in part by Runx1. Our results together demonstrate a critical role for Brn3a in generating DRG sensory neuron diversity and regulating sensory afferent projections to the central targets. PMID:22326227

  17. Sensory neuronal sensitisation occurs through HMGB-1/ RAGE and TRPV1 in high glucose conditions.

    PubMed

    Bestall, S M; Hulse, R P; Blackley, Z; Swift, M; Ved, N; Paton, K; Beazley-Long, N; Bates, D O; Donaldson, L F

    2018-06-21

    Many potential causes for painful diabetic neuropathy have been proposed including actions of cytokines and growth factors. High mobility group protein B1 (HMGB1) is a RAGE agonist, increased in diabetes, that contributes to pain by modulating peripheral inflammatory responses. HMGB1 enhances nociceptive behaviour in naïve animals through an unknown mechanism. We tested the hypothesis that HMGB1 causes pain through direct neuronal activation of RAGE and alteration of nociceptive neuronal responsiveness.HMGB1 and RAGE expression were increased in skin and primary sensory (DRG) neurons of diabetic rats at times when pain behaviour was enhanced. Agonist-evoked TRPV1-mediated calcium responses increased in cultured DRG neurons from diabetic rats and in neurons from naïve rats exposed to high glucose concentrations. HMGB1-mediated increases in TRPV1-evoked calcium responses in DRG neurons were RAGE and PKC-dependent, and this was blocked by co-administration of the growth factor splice variant, VEGF-A 165 b. Pain behaviour and DRG RAGE expression increases were blocked by VEGF-A 165 b treatment of diabetic rats in vivo HMGB-1-RAGE activation sensitizes DRG neurons in vitro VEGF-A 165 b blocks HMGB-1/RAGE DRG activation, which may contribute to its analgesic properties in vivo . © 2018. Published by The Company of Biologists Ltd.

  18. MiR-34a Regulates Axonal Growth of Dorsal Root Ganglia Neurons by Targeting FOXP2 and VAT1 in Postnatal and Adult Mouse.

    PubMed

    Jia, Longfei; Chopp, Michael; Wang, Lei; Lu, Xuerong; Zhang, Yi; Szalad, Alexandra; Zhang, Zheng Gang

    2018-04-10

    Hyperglycemia impairs nerve fibers of dorsal root ganglia (DRG) neurons, leading to diabetic peripheral neuropathy (DPN). However, the molecular mechanisms underlying DPN are not fully understood. Using a mouse model of type II diabetes (db/db mouse), we found that microRNA-34a (miR-34a) was over-expressed in DRG, sciatic nerve, and foot pad tissues of db/db mice. In vitro, high glucose significantly upregulated miR-34a in postnatal and adult DRG neurons, which was associated with inhibition of axonal growth. Overexpression and attenuation of miR-34a in postnatal and adult DRG neurons suppressed and promoted, respectively, axonal growth. Bioinformatic analysis suggested that miR-34a putatively targets forkhead box protein P2 (FOXP2) and vesicle amine transport 1 (VAT1), which were decreased in diabetic tissues and in cultured DRG neurons under high glucose conditions. Dual-luciferase assay showed that miR-34a downregulated FOXP2 and VAT1 expression by targeting their 3' UTR. Gain-of- and loss-of-function analysis showed an inverse relation between augmentation of miR-34a and reduction of FOXP2 and VAT1 proteins in postnatal and adult DRG neurons. Knockdown of FOXP2 and VAT1 reduced axonal growth. Together, these findings suggest that miR-34a and its target genes of FOXP2 and VAT1 are involved in DRG neuron damage under hyperglycemia.

  19. Heterogeneity of European DRG systems and potentials for a common EuroDRG system

    PubMed Central

    Geissler, Alexander; Quentin, Wilm; Busse, Reinhard

    2015-01-01

    Diagnosis-Related Group (DRG) systems across Europe are very heterogeneous, in particular because of different classification variables and algorithms as well as costing methodologies. But, given the challenge of increasing patient mobility within Europe, health systems are forced to incorporate a common patient classification language in order to compare and identify similar patients e.g. for reimbursement purposes. Beside the national adoption of DRGs for a wide range of purposes (measuring hospital activity vs. paying hospitals), a common DRG system can serve as an international communication basis among health administrators and can reduce the national development efforts as it is demonstrated by the NordDRG consortium. PMID:25905484

  20. 7, 8, 3′-Trihydroxyflavone Promotes Neurite Outgrowth and Protects Against Bupivacaine-Induced Neurotoxicity in Mouse Dorsal Root Ganglion Neurons

    PubMed Central

    Shi, Haohong; Luo, Xingjing

    2016-01-01

    Background 7, 8, 3′-trihydroxyflavone (THF) is a novel pro-neuronal small molecule that acts as a TrkB agonist. In this study, we examined the effect of THF on promoting neuronal growth and protecting anesthetics-induced neurotoxicity in dorsal root ganglion (DRG) neurons in vitro. Material/Methods Neonatal mouse DRG neurons were cultured in vitro and treated with various concentrations of THF. The effect of THF on neuronal growth was investigated by neurite outgrowth assay and Western blot. In addition, the protective effects of THF on bupivacaine-induced neurotoxicity were investigated by apoptosis TUNEL assay, neurite outgrowth assay, and Western blot, respectively. Results THF promoted neurite outgrowth of DRG neurons in dose-dependent manner, with an EC50 concentration of 67.4 nM. Western blot analysis showed THF activated TrkB signaling pathway by inducing TrkB phosphorylation. THF also rescued bupivacaine-induced neurotoxicity by reducing apoptosis and protecting neurite retraction in DRG neurons. Furthermore, the protection of THF in bupivacaine-injured neurotoxicity was directly associated with TrkB phosphorylation in a concentration-dependent manner in DRG neurons. Conclusions THF has pro-neuronal effect on DRG neurons by promoting neurite growth and protecting against bupivacaine-induced neurotoxicity, likely through TrkB activation. PMID:27371503

  1. [Substance P and/or calcitonin gene-related peptide immunoreactive neurons in dorsal root ganglia possibly involved in the transmission of nociception in rat penile frenulum].

    PubMed

    Wu, Zhong-Min; Ni, Jing-Jing; Ling, Shu-Cai

    2007-12-01

    To study the relationship between substance P (SP) and/or calcitonin gene-related peptide (CGRP) immunoreactive neurons in dorsal root ganglia (DRG) and the transmission of nociception in the penile frenulum of rats. The fluoro-gold (FG) retrograde tracing method was used to trace the origin of nerve terminals in the penile frenulum of rats. And SP and/or CGRP immunofluorescence labeling was employed to detect the distribution of SP and/or CGRP immunoreactive neurons in DRG. FG retrograde tracing showed that the FG retrolabeled neurons were localized in L6-DRG and S1-DRG. SP and/or CGRP immunofluorescence labeling indicated that a large number of DRG neurons were SP- and CGRP-immunoreactive, different in size, bright red and bright green respectively in color, and arranged in rows or spots among nerve bundles. All the FG/SP and FG/CGRP double-labeled neurons were medium or small-sized. One third of the FG-labeled neurons were SP-immunoreactive, and a half of them CGRP-immunoreactive in L6-DRG and S1-DRG respectively. The FG/SP/CGRP-labeled neurons accounted for one fifth of the FG retro labeled neurons. SP- and CGRP-immunoreactive neurons in L6-DRG and SI-DRG of rats may be involved in the transmission of nociception in rat penile frenulum.

  2. Enhanced excitability of small dorsal root ganglion neurons in rats with bone cancer pain

    PubMed Central

    2012-01-01

    Background Primary and metastatic cancers that affect bone are frequently associated with severe and intractable pain. The mechanisms underlying the development of bone cancer pain are largely unknown. The aim of this study was to determine whether enhanced excitability of primary sensory neurons contributed to peripheral sensitization and tumor-induced hyperalgesia during cancer condition. In this study, using techniques of whole-cell patch-clamp recording associated with immunofluorescent staining, single-cell reverse-transcriptase PCR and behavioral test, we investigated whether the intrinsic membrane properties and the excitability of small-sized dorsal root ganglion (DRG) neurons altered in a rat model of bone cancer pain, and whether suppression of DRG neurons activity inhibited the bone cancer-induced pain. Results Our present study showed that implantation of MRMT-1 tumor cells into the tibial canal in rats produced significant mechanical and thermal hyperalgesia in the ipsilateral hind paw. Moreover, implantation of tumor cells provoked spontaneous discharges and tonic excitatory discharges evoked by a depolarizing current pulse in small-sized DRG neurons. In line with these findings, alterations in intrinsic membrane properties that reflect the enhanced neuronal excitability were observed in small DRG neurons in bone cancer rats, of which including: 1) depolarized resting membrane potential (RMP); 2) decreased input resistance (Rin); 3) a marked reduction in current threshold (CT) and voltage threshold (TP) of action potential (AP); 4) a dramatic decrease in amplitude, overshot, and duration of evoked action potentials as well as in amplitude and duration of afterhyperpolarization (AHP); and 5) a significant increase in the firing frequency of evoked action potentials. Here, the decreased AP threshold and increased firing frequency of evoked action potentials implicate the occurrence of hyperexcitability in small-sized DRG neurons in bone cancer rats. In

  3. Somatosensory neuron types identified by high-coverage single-cell RNA-sequencing and functional heterogeneity

    PubMed Central

    Li, Chang-Lin; Li, Kai-Cheng; Wu, Dan; Chen, Yan; Luo, Hao; Zhao, Jing-Rong; Wang, Sa-Shuang; Sun, Ming-Ming; Lu, Ying-Jin; Zhong, Yan-Qing; Hu, Xu-Ye; Hou, Rui; Zhou, Bei-Bei; Bao, Lan; Xiao, Hua-Sheng; Zhang, Xu

    2016-01-01

    Sensory neurons are distinguished by distinct signaling networks and receptive characteristics. Thus, sensory neuron types can be defined by linking transcriptome-based neuron typing with the sensory phenotypes. Here we classify somatosensory neurons of the mouse dorsal root ganglion (DRG) by high-coverage single-cell RNA-sequencing (10 950 ± 1 218 genes per neuron) and neuron size-based hierarchical clustering. Moreover, single DRG neurons responding to cutaneous stimuli are recorded using an in vivo whole-cell patch clamp technique and classified by neuron-type genetic markers. Small diameter DRG neurons are classified into one type of low-threshold mechanoreceptor and five types of mechanoheat nociceptors (MHNs). Each of the MHN types is further categorized into two subtypes. Large DRG neurons are categorized into four types, including neurexophilin 1-expressing MHNs and mechanical nociceptors (MNs) expressing BAI1-associated protein 2-like 1 (Baiap2l1). Mechanoreceptors expressing trafficking protein particle complex 3-like and Baiap2l1-marked MNs are subdivided into two subtypes each. These results provide a new system for cataloging somatosensory neurons and their transcriptome databases. PMID:26691752

  4. Differential regulation of amyloid-. beta. -protein mRNA expression within hippocampal neuronal subpopulations in Alzheimer disease

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Higgins, G.A.; Lewis, D.A.; Bahmanyar, S.

    1988-02-01

    The authors have mapped the neuroanatomical distribution of amyloid-..beta..-protein mRNA within neuronal subpopulations of the hippocampal formation in the cynomolgus monkey (Macaca fascicularis), normal aged human, and patients with Alzheimer disease. Amyloid-..beta..-protein mRNA appears to be expressed in all hippocampal neurons, but at different levels of abundance. In the central nervous system of monkey and normal aged human, image analysis shows that neurons of the dentate gyrus and cornu Ammonis fields contain a 2.5-times-greater hybridization signal than is present in neurons of the subiculum and entorhinal cortex. In contrast, in the Alzheimer disease hippocampal formation, the levels of amyloid-..beta..-protein mRNAmore » in the cornu Ammonis field 3 and parasubiculum are equivalent. These findings suggest that within certain neuronal subpopulations cell type-specific regulation of amyloid-..beta..-protein gene expression may be altered in Alzheimer disease.« less

  5. A role for Runx transcription factor signaling in dorsal root ganglion sensory neuron diversification.

    PubMed

    Kramer, Ina; Sigrist, Markus; de Nooij, Joriene C; Taniuchi, Ichiro; Jessell, Thomas M; Arber, Silvia

    2006-02-02

    Subpopulations of sensory neurons in the dorsal root ganglion (DRG) can be characterized on the basis of sensory modalities that convey distinct peripheral stimuli, but the molecular mechanisms that underlie sensory neuronal diversification remain unclear. Here, we have used genetic manipulations in the mouse embryo to examine how Runx transcription factor signaling controls the acquisition of distinct DRG neuronal subtype identities. Runx3 acts to diversify an Ngn1-independent neuronal cohort by promoting the differentiation of proprioceptive sensory neurons through erosion of TrkB expression in prospective TrkC+ sensory neurons. In contrast, Runx1 controls neuronal diversification within Ngn1-dependent TrkA+ neurons by repression of neuropeptide CGRP expression and controlling the fine pattern of laminar termination in the dorsal spinal cord. Together, our findings suggest that Runx transcription factor signaling plays a key role in sensory neuron diversification.

  6. Neuronal Subtype and Satellite Cell Tropism Are Determinants of Varicella-Zoster Virus Virulence in Human Dorsal Root Ganglia Xenografts In Vivo

    PubMed Central

    Zerboni, Leigh; Arvin, Ann

    2015-01-01

    Varicella zoster virus (VZV), a human alphaherpesvirus, causes varicella during primary infection. VZV reactivation from neuronal latency may cause herpes zoster, post herpetic neuralgia (PHN) and other neurologic syndromes. To investigate VZV neuropathogenesis, we developed a model using human dorsal root ganglia (DRG) xenografts in immunodeficient (SCID) mice. The SCID DRG model provides an opportunity to examine characteristics of VZV infection that occur in the context of the specialized architecture of DRG, in which nerve cell bodies are ensheathed by satellite glial cells (SGC) which support neuronal homeostasis. We hypothesized that VZV exhibits neuron-subtype specific tropism and that VZV tropism for SGC contributes to VZV-related ganglionopathy. Based on quantitative analyses of viral and cell protein expression in DRG tissue sections, we demonstrated that, whereas DRG neurons had an immature neuronal phenotype prior to implantation, subtype heterogeneity was observed within 20 weeks and SGC retained the capacity to maintain neuronal homeostasis longterm. Profiling VZV protein expression in DRG neurons showed that VZV enters peripherin+ nociceptive and RT97+ mechanoreceptive neurons by both axonal transport and contiguous spread from SGC, but replication in RT97+ neurons is blocked. Restriction occurs even when the SGC surrounding the neuronal cell body were infected and after entry and ORF61 expression, but before IE62 or IE63 protein expression. Notably, although contiguous VZV spread with loss of SGC support would be predicted to affect survival of both nociceptive and mechanoreceptive neurons, RT97+ neurons showed selective loss relative to peripherin+ neurons at later times in DRG infection. Profiling cell factors that were upregulated in VZV-infected DRG indicated that VZV infection induced marked pro-inflammatory responses, as well as proteins of the interferon pathway and neuroprotective responses. These neuropathologic changes observed in sensory

  7. Increased production of 4 kDa amyloid beta peptide in serum deprived human primary neuron cultures: possible involvement of apoptosis.

    PubMed

    LeBlanc, A

    1995-12-01

    The etiology of the amyloid beta peptide in sporadic Alzheimer's disease (AD) is not known. Amyloid beta peptide (A beta), a proteolytic product of the amyloid precursor protein (APP), is deposited in the senile plaques and cerebrovascular tissues of individuals with either sporadic or familial AD (FAD). Increased A beta production from mutant APPs in FAD fosters the hypothesis that overexpression of A beta plays a primary role in the pathogenesis of AD. The absence of APP mutations in sporadic AD which displays identical pathological features than FAD such as synapse and neuronal loss, senile plaques and neurofibrillary tangles, suggests other causes for overexpression and/or deposition of A beta. To investigate the effect of neuronal death on APP metabolism and A beta secretion, human primary neuron cultures were induced to undergo apoptosis by serum deprivation. Serum deprived neurons display shrunken and rounded morphology, contain condensed chromatine and fragmented DNA, which are characteristic of apoptosis. In serum deprived neurons, metabolism of APP through the nonamyloidogenic secretory pathway is decreased to 20% from 40% in control cultures whereas 4kDa A beta is increased three- to fourfold. The results suggest that human neurons undergoing apoptosis generate excess A beta and indicates a possible mechanism for increased A beta in the absence of APP mutations.

  8. Reduction of voltage gated sodium channel protein in DRG by vector mediated miRNA reduces pain in rats with painful diabetic neuropathy.

    PubMed

    Chattopadhyay, Munmun; Zhou, Zhigang; Hao, Shuanglin; Mata, Marina; Fink, David J

    2012-03-22

    Painful neuropathy is a common complication of diabetes. Previous studies have identified significant increases in the amount of voltage gated sodium channel isoforms Na(V)1.7 and Na(V)1.3 protein in the dorsal root ganglia (DRG) of rats with streptozotocin (STZ)-induced diabetes. We found that gene transfer-mediated release of the inhibitory neurotransmitters enkephalin or gamma amino butyric acid (GABA) from DRG neurons in diabetic animals reduced pain-related behaviors coincident with a reduction in Na(V)1.7 protein levels in DRG in vivo. To further evaluate the role of Na(V)α subunit levels in DRG in the pathogenesis of pain in diabetic neuropathy, we constructed a non-replicating herpes simplex virus (HSV)-based vector expressing a microRNA (miRNA) against Na(V)α subunits. Subcutaneous inoculation of the miRNA-expressing HSV vector into the feet of diabetic rats to transduce DRG resulted in a reduction in Na(V)α subunit levels in DRG neurons, coincident with a reduction in cold allodynia, thermal hyperalgesia and mechanical hyperalgesia. These data support the role of increased Na(V)α protein in DRG in the pathogenesis of pain in diabetic neuropathy, and provide a proof-of-principle demonstration for the development of a novel therapy that could be used to treat intractable pain in patients with diabetic neuropathy.

  9. Immunization Elicits Antigen-Specific Antibody Sequestration in Dorsal Root Ganglia Sensory Neurons

    PubMed Central

    Gunasekaran, Manojkumar; Chatterjee, Prodyot K.; Shih, Andrew; Imperato, Gavin H.; Addorisio, Meghan; Kumar, Gopal; Lee, Annette; Graf, John F.; Meyer, Dan; Marino, Michael; Puleo, Christopher; Ashe, Jeffrey; Cox, Maureen A.; Mak, Tak W.; Bouton, Chad; Sherry, Barbara; Diamond, Betty; Andersson, Ulf; Coleman, Thomas R.; Metz, Christine N.; Tracey, Kevin J.; Chavan, Sangeeta S.

    2018-01-01

    The immune and nervous systems are two major organ systems responsible for host defense and memory. Both systems achieve memory and learning that can be retained, retrieved, and utilized for decades. Here, we report the surprising discovery that peripheral sensory neurons of the dorsal root ganglia (DRGs) of immunized mice contain antigen-specific antibodies. Using a combination of rigorous molecular genetic analyses, transgenic mice, and adoptive transfer experiments, we demonstrate that DRGs do not synthesize these antigen-specific antibodies, but rather sequester primarily IgG1 subtype antibodies. As revealed by RNA-seq and targeted quantitative PCR (qPCR), dorsal root ganglion (DRG) sensory neurons harvested from either naïve or immunized mice lack enzymes (i.e., RAG1, RAG2, AID, or UNG) required for generating antibody diversity and, therefore, cannot make antibodies. Additionally, transgenic mice that express a reporter fluorescent protein under the control of Igγ1 constant region fail to express Ighg1 transcripts in DRG sensory neurons. Furthermore, neural sequestration of antibodies occurs in mice rendered deficient in neuronal Rag2, but antibody sequestration is not observed in DRG sensory neurons isolated from mice that lack mature B cells [e.g., Rag1 knock out (KO) or μMT mice]. Finally, adoptive transfer of Rag1-deficient bone marrow (BM) into wild-type (WT) mice or WT BM into Rag1 KO mice revealed that antibody sequestration was observed in DRG sensory neurons of chimeric mice with WT BM but not with Rag1-deficient BM. Together, these results indicate that DRG sensory neurons sequester and retain antigen-specific antibodies released by antibody-secreting plasma cells. Coupling this work with previous studies implicating DRG sensory neurons in regulating antigen trafficking during immunization raises the interesting possibility that the nervous system collaborates with the immune system to regulate antigen-mediated responses. PMID:29755449

  10. Beta oscillatory neurons in the motor thalamus of movement disorder and pain patients.

    PubMed

    Basha, Diellor; Dostrovsky, Jonathan O; Lopez Rios, Adriana L; Hodaie, Mojgan; Lozano, Andres M; Hutchison, William D

    2014-11-01

    Excessive beta oscillations (15-25Hz) in the basal ganglia have been linked to the akineto-rigid symptoms of Parkinson's disease (PD) although it remains unclear whether the underlying mechanism is causative or associative. While a number of studies have reported beta activity in the subthalamic nucleus and globus pallidus internus, relatively little is known about the beta rhythm of the motor thalamus and its relation to movement disorders. To test whether thalamic beta oscillations are related to parkinsonian symptoms, we examined the spectral properties of neuronal activity in the ventral thalamic nuclei of five Parkinson's disease patients (two female, age range 50-72years) and compared them to five essential tremor (three female, aged 41-75) and four central pain patients (one female, aged 38-60). Spike and local field potential recordings were obtained during microelectrode-guided localization of thalamic nuclei prior to the implantation of deep brain stimulating electrodes. A total of 118 movement-related neurons in the region of the ventral intermediate nucleus (Vim) were analyzed across all patient groups. Eighty of these neurons (68%) displayed significant oscillatory firing in the beta range with the limbs at rest. In contrast, only 5.7% of the ventral oral posterior (Vop) (χ(2) test, p<0.05) and only 7.2% of the ventral caudal (Vc) neurons fired rhythmically at beta frequency (χ(2) test, p<0.05). Beta power was significantly decreased during limb movements (ANOVA, p<0.05) and was inversely related to tremor-frequency power during tremor epochs in ET and PD (r(2)=0.44). Comparison between patient groups showed that Vim beta power was significantly higher in ET patients versus pain and PD groups (ANOVA, p<0.05). The findings suggest that beta oscillations are found predominantly in Vim and are involved in movement but are not enhanced in tremor-dominant Parkinson's patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. In situ hybridization evidence for the coexistence of ASIC and TRPV1 within rat single sensory neurons.

    PubMed

    Ugawa, Shinya; Ueda, Takashi; Yamamura, Hisao; Shimada, Shoichi

    2005-05-20

    The activation of nociceptors by protons plays a crucial role in the initiation and maintenance of acidosis-linked pain. Acid-sensing ion channel (ASIC) and transient receptor potential/vanilloid receptor subtype-1 (TRPV1) encode proton-activated cation channels expressed by nociceptors and the opening of these channels results in nociceptor excitation. Histological relations among ASIC clones and the colocalization of each ASIC subunit and TRPV1 within single sensory neurons were examined on serial sections of rat dorsal root ganglia (DRG) using in situ hybridization histochemistry. ASIC1a transcripts were expressed in 20-25% of the DRG neurons, and most of the neurons had small (<30 microm)-diameter cell bodies. ASIC1b transcripts and ASIC3 transcripts were expressed in approximately 10% and 30-35% of the DRG neurons, respectively, and the greater part of each population was located in small-to-medium (30-50 microm)-diameter cells. The ASIC1a transcripts and ASIC1b transcripts were basically localized in the distinct populations of the DRG neurons, while approximately 20% of the ASIC1a-positive neurons and approximately 10% of the ASIC1b-positive neurons expressed ASIC3 transcripts. TRPV1 transcripts were expressed in 35-40% of the DRG neurons, and most of the TRPV1-positive neurons had small-diameter cell bodies. Intense expression signals for ASIC1a transcripts were detected in 40-45% of the TRPV1-positive neurons. Neurons expressing both ASIC1b and TRPV1 transcripts were barely detected in the DRG. Approximately 30% of the TRPV1-positive neurons expressed ASIC3 transcripts, and the double-labeled neurons were comprised of both small-diameter and medium-diameter cells. Approximately 13% of the TRPV1-positive neurons expressed both ASIC1a and ASIC3 transcripts.

  12. Puerarin blocks the signaling transmission mediated by P2X3 in SG and DRG to relieve myocardial ischemic damage.

    PubMed

    Liu, Shuangmei; Zhang, Chunping; Shi, Qingming; Li, Guilin; Song, Miaomiao; Gao, Yun; Xu, Changshui; Xu, Hong; Fan, Bo; Yu, Shicheng; Zheng, Chaoran; Zhu, Qicheng; Wu, Bing; Peng, Lichao; Xiong, Huangui; Wu, Qin; Liang, Shangdong

    2014-02-01

    P2X₃ receptors in stellate ganglia (SG) and cervical dorsal root ganglia (DRG) neurons are involved in sympathoexcitatory reflex induced by myocardial ischemic damage. Puerarin, a major active ingredient extracted from the traditional Chinese plant medicine Ge-gen, has been widely used in treatment of myocardial and cerebral ischemia. The present study is aimed to observe the effects of puerarin on the signaling transmission mediated by P2X₃ receptor in SG and DRG after myocardial ischemic damage. Our results showed that systolic blood pressure and heart rate increased, and the expression levels of P2X₃ mRNA and protein in SG and DRG were up-regulated after myocardial ischemic damage. Puerarin reduced systolic blood pressure and heart rate, relieved pain and decreased up-regulated expression of P2X₃ mRNA and protein in SG and DRG after myocardial ischemia. Puerarin inhibited the up-regulated ATP-activated currents in DRG neurons after myocardial ischemia. Thus, puerarin can relieve myocardial ischemic damage through blocking the P2X₃ signaling transmission and then depressed the aggravated sympathoexcitatory reflex. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. The neuron-specific isoform of glycogen synthase kinase-3beta is required for axon growth.

    PubMed

    Castaño, Zafira; Gordon-Weeks, Phillip R; Kypta, Robert M

    2010-04-01

    Glycogen synthase kinase-3 (GSK-3) has become an important target for the treatment of mood disorders and neurodegenerative disease. It comprises three enzymes, GSK-3alpha, beta and the neuron-specific isoform, beta2. GSK-3 regulates axon growth by phosphorylating microtubule-associated proteins including Tau. A genetic polymorphism that leads to an increase in the ratio of GSK-3beta1 to GSK-3beta2 interacts with Tau haplotypes to modify disease risk in Parkinson's and Alzheimer's disease. We have examined the roles of each isoform of GSK-3 in neurons. Silencing of GSK-3beta2 inhibited retinoic acid-induced neurite outgrowth in SH-SY5Y neuroblastoma cells and axon growth in rat cortical neurons. Inhibition of neurite outgrowth was prevented by co-expression of GSK-3beta2 but not by co-expression of GSK-3alpha or GSK-3beta1. Ectopic expression GSK-3beta2 enhanced the effects of retinoic acid on neurite length and induced neurite formation in the absence of retinoic acid. GSK-3beta2 phosphorylated Tau at a subset of those sites phosphorylated by GSK-3beta1. In addition, Axin, which regulates responses to Wnt signals, associated more readily with GSK-3beta1 than with GSK-3beta2. Our results suggest that GSK-3 inhibitors that target the Axin-binding site in GSK-3 will preserve the beneficial effects of GSK-3beta2 on axon growth.

  14. Modulation of extracellular ATP content of mast cells and DRG neurons by irradiation: studies on underlying mechanism of low-level-laser therapy.

    PubMed

    Wang, Lina; Hu, Lei; Grygorczyk, Ryszard; Shen, Xueyong; Schwarz, Wolfgang

    2015-01-01

    Low-level-laser therapy (LLLT) is an effective complementary treatment, especially for anti-inflammation and wound healing in which dermis or mucus mast cells (MCs) are involved. In periphery, MCs crosstalk with neurons via purinergic signals and participate in various physiological and pathophysiological processes. Whether extracellular ATP, an important purine in purinergic signaling, of MCs and neurons could be modulated by irradiation remains unknown. In this study, effects of red-laser irradiation on extracellular ATP content of MCs and dorsal root ganglia (DRG) neurons were investigated and underlying mechanisms were explored in vitro. Our results show that irradiation led to elevation of extracellular ATP level in the human mast cell line HMC-1 in a dose-dependent manner, which was accompanied by elevation of intracellular ATP content, an indicator for ATP synthesis, together with [Ca(2+)]i elevation, a trigger signal for exocytotic ATP release. In contrast to MCs, irradiation attenuated the extracellular ATP content of neurons, which could be abolished by ARL 67156, a nonspecific ecto-ATPases inhibitor. Our results suggest that irradiation potentiates extracellular ATP of MCs by promoting ATP synthesis and release and attenuates extracellular ATP of neurons by upregulating ecto-ATPase activity. The opposite responses of these two cell types indicate complex mechanisms underlying LLLT.

  15. Difference of acute dissociation and 1-day culture on the electrophysiological properties of rat dorsal root ganglion neurons.

    PubMed

    Song, Yuanlong; Zhang, Miaomiao; Tao, Xiaoqing; Xu, Zifen; Zheng, Yunjie; Zhu, Minjie; Zhang, Liangpin; Qiao, Jinhan; Gao, Linlin

    2018-01-19

    The dissociated dorsal root ganglion (DRG) neurons with or without culture were widely used for investigation of their electrophysiological properties. The culture procedures, however, may alter the properties of these neurons and the effects are not clear. In the present study, we recorded the action potentials (AP) and the voltage-gated Na + , K + , and Ca 2+ currents with patch clamp technique and measured the mRNA of Nav1.6-1.9 and Cav2.1-2.2 with real-time PCR technique from acutely dissociated and 1-day (1-d) cultured DRG neurons. The effects of the nerve growth factor (NGF) on the expression of Nav1.6-1.9 and Cav2.1-2.2 were evaluated. The neurons were classified as small (DRG-S), medium (DRG-M), and large (DRG-L), according to their size frequency distribution pattern. We found 1-d culture increased the AP size but reduced the excitability, and reduced the voltage-gated Na + and Ca 2+ currents and their corresponding mRNA expression in all types of neurons. The lack of NGF in the culture medium may contribute to the reduced Na + and Ca 2+ current, as the application of NGF recovered some of the reduced transcripts (Nav1.9, Cav2.1, and Cav2.2). 1-d culture showed neuron-type specific effects on some of the AP properties: it increased the maximum AP depolarizing rate (MDR) and hyperpolarized the resting membrane potential (RP) in DRG-M and DRG-L neurons, but slowed the maximum AP repolarizing rate (MRR) in DRG-S neurons. In conclusion, the 1-d cultured neurons had different properties with those of the acutely dissociated neurons, and lack of NGF may contribute to some of these differences.

  16. Effect of nerve injury on the number of dorsal root ganglion neurons and autotomy behavior in adult Bax-deficient mice.

    PubMed

    Lyu, Chuang; Lyu, Gong-Wei; Martinez, Aurora; Shi, Tie-Jun Sten

    2017-01-01

    The proapoptotic molecule BAX, plays an important role in mitochondrial apoptotic pathway. Dorsal root ganglion (DRG) neurons depend on neurotrophic factors for survival at early developmental stages. Withdrawal of neurotrophic factors will induce apoptosis in DRG neurons, but this type of cell death can be delayed or prevented in neonatal Bax knockout (KO) mice. In adult animals, evidence also shows that DRG neurons are less dependent upon neurotrophic factors for survival. However, little is known about the effect of Bax deletion on the survival of normal and denervated DRG neurons in adult mice. A unilateral sciatic nerve transection was performed in adult Bax KO mice and wild-type (WT) littermates. Stereological method was employed to quantify the number of lumbar-5 DRG neurons 1 month post-surgery. Nerve injury-induced autotomy behavior was also examined on days 1, 3, and 7 post-surgery. There were significantly more neurons in contralateral DRGs of KO mice as compared with WT mice. The number of neurons was reduced in ipsilateral DRGs in both KO and WT mice. No changes in size distributions of DRG neuron profiles were detected before or after nerve injury. Injury-induced autotomy behavior developed much earlier and was more serious in KO mice. Although postnatal death or loss of DRG neurons is partially prevented by Bax deletion, this effect cannot interfere with long-term nerve injury-induced neuronal loss. The exaggerated self-amputation behavior observed in the mutant mice indicates that Bax deficiency may enhance the development of spontaneous pain following nerve injury.

  17. Nf2-Yap signaling controls the expansion of DRG progenitors and glia during DRG development.

    PubMed

    Serinagaoglu, Yelda; Paré, Joshua; Giovannini, Marco; Cao, Xinwei

    2015-02-01

    Molecular mechanisms governing the maintenance and proliferation of dorsal root ganglia (DRG) progenitors are largely unknown. Here we reveal that the Hippo pathway regulates the expansion of DRG progenitors and glia during mammalian DRG development. The key effectors of this pathway, transcriptional coactivators Yap and Taz, are expressed in DRG progenitors and glia during DRG development but are at least partially inhibited from activating transcription. Aberrant YAP activation leads to overexpansion of DRG progenitor and glial populations. We further show that the Neurofibromatosis 2 (Nf2) tumor suppressor inhibits Yap during DRG development. Loss of Nf2 leads to similar phenotypes as does YAP hyperactivation, and deleting Yap suppresses these phenotypes. Our study demonstrates that Nf2-Yap signaling plays important roles in controlling the expansion of DRG progenitors and glia during DRG development. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Nf2-Yap signaling controls the expansion of DRG progenitors and glia during DRG development

    PubMed Central

    Serinagaoglu, Yelda; Paré, Joshua; Giovannini, Marco; Cao, Xinwei

    2014-01-01

    Molecular mechanisms governing the maintenance and proliferation of dorsal root ganglia (DRG) progenitors are largely unknown. Here we reveal that the Hippo pathway regulates the expansion of DRG progenitors and glia during mammalian DRG development. The key effectors of this pathway, transcriptional coactivators Yap and Taz, are expressed in DRG progenitors and glia during DRG development but are at least partially inhibited from activating transcription. Aberrant YAP activation leads to overexpansion of DRG progenitor and glial populations. We further show that the Neurofibromatosis 2 (Nf2) tumor suppressor inhibits Yap during DRG development. Loss of Nf2 leads to similar phenotypes as does YAP hyperactivation, and deleting Yap suppresses these phenotypes. Our study demonstrates that Nf2-Yap signaling plays important roles in controlling the expansion of DRG progenitors and glia during DRG development. PMID:25433207

  19. Inflammatory mediator bradykinin increases population of sensory neurons expressing functional T-type Ca2+ channels

    PubMed Central

    Huang, Dongyang; Liang, Ce; Zhang, Fan; Men, Hongchao; Du, Xiaona; Gamper, Nikita; Zhang, Hailin

    2016-01-01

    T-type Ca2+ channels are important regulators of peripheral sensory neuron excitability. Accordingly, T-type Ca2+ currents are often increased in various pathological pain conditions, such as inflammation or nerve injury. Here we investigated effects of inflammation on functional expression of T-type Ca2+ channels in small-diameter cultured dorsal root ganglion (DRG) neurons. We found that overnight treatment of DRG cultures with a cocktail of inflammatory mediators bradykinin (BK), adenosine triphosphate (ATP), norepinephrine (NE) and prostaglandin E2 (PGE2) strongly increased the population size of the small-diameter neurons displaying low-voltage activated (LVA, T-type) Ca2+ currents while having no effect on the peak LVA current amplitude. When applied individually, BK and ATP also increased the population size of LVA-positive neurons while NE and PGE2 had no effect. The PLC inhibitor U-73122 and B2 receptor antagonist, Hoe-140, both abolished the increase of the population of LVA-positive DRG neurons. Inflammatory treatment did not affect CaV3.2 mRNA or protein levels in DRG cultures. Furthermore, an ubiquitination inhibitor, MG132, did not increase the population of LVA-positive neurons. Our data suggest that inflammatory mediators BK and ATP increase the abundance of LVA-positive DRG neurons in total neuronal population by stimulating the recruitment of a ‘reserve pool’ of CaV3.2 channels, particularly in neurons that do not display measurable LVA currents under control conditions. PMID:26944020

  20. Impact of the Sensory Neurons on Melanoma Growth In Vivo

    PubMed Central

    Tapias, Victor; Watkins, Simon C.; Ma, Yang; Shurin, Michael R.; Shurin, Galina V.

    2016-01-01

    Nerve endings are often identified within solid tumors, but their impact on the tumor growth and progression remains poorly understood. Emerging data suggests that the central nervous system may affect cancer development and spreading via the hypothalamic-pituitary-adrenal axis and autonomous nervous system. However, the role of the afferent sensory neurons in tumor growth is unclear, except some reports on perineural invasion in prostate and pancreatic cancer and cancer-related pain syndrome. Here, we provide the results of primary testing of the concept that the interaction between melanoma cells and sensory neurons may induce the formation of tumor-supporting microenvironment via attraction of immune regulatory cells by the tumor-activated dorsal root ganglion (DRG) neurons. We report that despite DRG cells not directly up-regulating proliferation of melanoma cells in vitro, presence of DRG neurons allows tumors to grow significantly faster in vivo. This effect has been associated with increased production of chemokines by tumor-activated DRG neurons and attraction of myeloid-derived suppressor cells both in vitro and in vivo. These initial proof-of-concept results justify further investigations of the sensory (afferent) nervous system in the context of tumorigenesis and the local protumorigenic immunoenvironment. PMID:27227315

  1. Insulin-like growth factor-1 attenuates apoptosis and protects neurochemical phenotypes of dorsal root ganglion neurons with paclitaxel-induced neurotoxicity in vitro.

    PubMed

    Chen, Cheng; Bai, Xue; Bi, Yanwen; Liu, Guixiang; Li, Hao; Liu, Zhen; Liu, Huaxiang

    2017-02-01

    Paclitaxel (PT)-induced neurotoxicity is a significant problem associated with successful treatment of cancers. Insulin-like growth factor-1 (IGF-1) is a neurotrophic factor and plays an important role in promoting axonal growth from dorsal root ganglion (DRG) neurons. Whether IGF-1 has protective effects on neurite growth, cell viability, neuronal apoptosis and neuronal phenotypes in DRG neurons with PT-induced neurotoxicity is still unclear. In this study, primary cultured rat DRG neurons were used to assess the effects of IGF-1 on DRG neurons with PT-induced neurotoxicity. The results showed that PT exposure caused neurite retraction in a dose-dependent manner. PT exposure caused a decrease of cell viability and an increase in the ratio of apoptotic cells which could be reversed by IGF-1. The percentage of calcitonin gene-related peptide immunoreactive (CGRP-IR) neurons and neurofilament (NF)-200-IR neurons, mRNA, and protein levels of CGRP and NF-200 decreased significantly after treatment with PT. IGF-1 administration had protective effects on CGRP-IR neurons, but not on NF-200-IR neurons. Either extracellular signal-regulated protein kinase (ERK1/2) inhibitor PD98059 or phosphatidylinositol 3-kinase (PI3 K) inhibitor LY294002 blocked the effect of IGF-1. The results imply that IGF-1 may attenuate apoptosis to improve neuronal cell viability and promote neurite growth of DRG neurons with PT-induced neurotoxicity. Moreover, these results support an important neuroprotective role of exogenous IGF-1 on distinct subpopulations of DRG neurons which is responsible for skin sensation. The effects of IGF-1 might be through ERK1/2 or PI3 K/Akt signaling pathways. These findings provide experimental evidence for IGF-1 administration to alleviate neurotoxicity of distinct subpopulations of DRG neurons induced by PT.

  2. Pathogenic prions deviate PrPC signaling in neuronal cells and impair A-beta clearance

    PubMed Central

    Pradines, E; Hernandez-Rapp, J; Villa-Diaz, A; Dakowski, C; Ardila-Osorio, H; Haik, S; Schneider, B; Launay, J-M; Kellermann, O; Torres, J-M; Mouillet-Richard, S

    2013-01-01

    The subversion of the normal function exerted by the cellular prion protein (PrPC) in neurons by pathogenic prions is assumed to have a central role in the pathogenesis of transmissible spongiform encephalopathies. Using two murine models of prion infection, the 1C11 neuronal cell line and neurospheres, we document that prion infection is associated with the constitutive activation of signaling targets normally coupled with PrPC, including the Fyn kinase, the mitogen-associated protein kinases ERK1/2 and the CREB transcription factor. PrPC-dependent signaling overactivation in infected cells is associated with the recruitment of p38 and JNK stress-associated kinases. Downstream from CREB, prion-infected cells exhibit reduced activity of the matrix metalloprotease (MMP)-9. As MMP-9 catalyzes the degradation of the amyloid A-beta peptide, the decrease in MMP-9 activity in prion-infected cells causes a significant impairment of the clearance of A-beta, leading to its accumulation. By exploiting two 1C11-infected clones accumulating high or moderate levels of prions, we show that the prion-induced changes are correlated with the level of infectivity. Of note, a dose-dependent increase in A-beta levels was also found in the cerebrospinal fluid of mice inoculated with these infected clones. By demonstrating that pathogenic prions trigger increases in A-beta levels through the deviation of PrPC signaling, our data argue that A-beta may exacerbate prion-induced toxicity. PMID:23303130

  3. [Effects of phoxim and fenvalerate on TTX-S and TTX-R sodium channels in the DRG neurons of adult rat].

    PubMed

    Wang, X; Xiao, H; Dai, X; Liu, X; Yu, X; Wu, J

    2000-05-01

    To study the joint neurotoxic effects of phoxim (Pho) and fenvalerate (Fen) on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) Na(+) currents in dorsal root ganglion (DRG) neurons of adult rat. Whole cell patch clamp technique was used to test the effects of Pho and Fen on TTX-S and TTX-R sodium currents in DRG neurons. The inactivation of TTX-R sodium channel was obviously slowed down by Fen. The tau(Na) of peak currents at doses of 10, 50 and 100 micromol/L Fen and control groups were (8.10 +/- 2.41) ms, (11.78 +/- 2.76) ms, P < 0.01, (8.76 +/-1.94) ms, P < 0.05 and (6.41 +/- 1.32) ms respectively. The inactivation of TTX-R sodium channel tail currents was also significantly delayed by Fen. The tau(Na) of the tail currents at doses of 10, 50, 100 micromol/L Fen and control groups were 6.11 +/- 0.52 (P < 0.05), 7.82 +/- 0.82 (P < 0.05), 7.23 +/- 1.09 (P < 0.05) and (4.91 +/- 0.97) ms separately. As compared with TTX-R sodium channel, the TTX-S sodium channel was less responsive to Fen exposure, which only led to slowly decay TTX-S sodium tail currents. There was no any effect of Pho on the TTX-S and TTX-R sodium channels. The mixed treatment of a Pho and Fen did not show joint effect on the sodium currents. Both the peak and tail currents are changed by Fen, however, Fen has more remarkable effects on TTX-R than on TTX-S sodium channel. The combined exposure to Pho and Fen shows no joint effect on the sodium channel.

  4. Effects of beta-phenylethylamine on dopaminergic neurons of the ventral tegmental area in the rat: a combined electrophysiological and microdialysis study.

    PubMed

    Ishida, Kota; Murata, Mikio; Katagiri, Nobuyuki; Ishikawa, Masago; Abe, Kenji; Kato, Masatoshi; Utsunomiya, Iku; Taguchi, Kyoji

    2005-08-01

    The effects of systemic administration of beta-phenylethylamine (beta-PEA) and microiontophoretically applied beta-PEA on the spontaneous discharge of dopamine (DA) neurons in the ventral tegmental area (VTA) of the anesthetized rat were examined. Intravenous administration of beta-PEA (1.0, 2.5, and 5.0 mg/kg) and microiontophoretic applications of beta-PEA caused inhibitory responses in DA neurons. Systemic administration and microiontophoretic applications of beta-PEA induced dose- or current-dependent responses. The systemic beta-PEA-induced inhibitory responses were reversed by pretreatment with the DA D(2) receptor antagonists haloperidol (0.5 mg/kg i.p.) and sulpiride (10 mg/kg i.p). Pretreatment with reserpine (5 mg/kg i.p. 24 h earlier) did not completely block the systemic administration of beta-PEA (2.5 mg/kg) inhibition. A microdialysis study of freely moving rats demonstrated that the extracellular DA level increased significantly in response to local application of beta-PEA (100 muM) in the VTA via a microdialysis probe, and local application of beta-PEA-stimulated somatodendritic DA release in the VTA. The beta-PEA-induced release of DA was calcium ion-independent and was enhanced by pretreatment with pertussis toxin. These findings indicate that beta-phenylethylamine inhibits DA neuron activity via DA D(2) autoreceptors in the rat VTA and that this inhibitory effect is mediated by the somatodendritic DA release.

  5. Role of platinum DNA damage-induced transcriptional inhibition in chemotherapy-induced neuronal atrophy and peripheral neurotoxicity.

    PubMed

    Yan, Fang; Liu, Johnson J; Ip, Virginia; Jamieson, Stephen M F; McKeage, Mark J

    2015-12-01

    Platinum-based anticancer drugs cause peripheral neurotoxicity by damaging sensory neurons within the dorsal root ganglia (DRG), but the mechanisms are incompletely understood. The roles of platinum DNA binding, transcription inhibition and altered cell size were investigated in primary cultures of rat DRG cells. Click chemistry quantitative fluorescence imaging of RNA-incorporated 5-ethynyluridine showed high, but wide ranging, global levels of transcription in individual neurons that correlated with their cell body size. Treatment with platinum drugs reduced neuronal transcription and cell body size to an extent that corresponded to the amount of preceding platinum DNA binding, but without any loss of neuronal cells. The effects of platinum drugs on neuronal transcription and cell body size were inhibited by blocking platinum DNA binding with sodium thiosulfate, and mimicked by treatment with a model transcriptional inhibitor, actinomycin D. In vivo oxaliplatin treatment depleted the total RNA content of DRG tissue concurrently with altering DRG neuronal size. These findings point to a mechanism of chemotherapy-induced peripheral neurotoxicity, whereby platinum DNA damage induces global transcriptional arrest leading in turn to neuronal atrophy. DRG neurons may be particularly vulnerable to this mechanism of toxicity because of their requirements for high basal levels of global transcriptional activity. Findings point to a new stepwise mechanism of chemotherapy-induced peripheral neurotoxicity, whereby platinum DNA damage induces global transcriptional arrest leading in turn to neuronal atrophy. Dorsal root ganglion neurons may be particularly vulnerable to this neurotoxicity because of their high global transcriptional outputs, demonstrated in this study by click chemistry quantitative fluorescence imaging. © 2015 International Society for Neurochemistry.

  6. Distinct Expression of Phenotypic Markers in Placodes- and Neural Crest-Derived Afferent Neurons Innervating the Rat Stomach.

    PubMed

    Trancikova, Alzbeta; Kovacova, Eva; Ru, Fei; Varga, Kristian; Brozmanova, Mariana; Tatar, Milos; Kollarik, Marian

    2018-02-01

    Visceral pain is initiated by activation of primary afferent neurons among which the capsaicin-sensitive (TRPV1-positive) neurons play an important role. The stomach is a common source of visceral pain. Similar to other organs, the stomach receives dual spinal and vagal afferent innervation. Developmentally, spinal dorsal root ganglia (DRG) and vagal jugular neurons originate from embryonic neural crest and vagal nodose neurons originate from placodes. In thoracic organs the neural crest- and placodes-derived TRPV1-positive neurons have distinct phenotypes differing in activation profile, neurotrophic regulation and reflex responses. It is unknown to whether such distinction exists in the stomach. We hypothesized that gastric neural crest- and placodes-derived TRPV1-positive neurons express phenotypic markers indicative of placodes and neural crest phenotypes. Gastric DRG and vagal neurons were retrogradely traced by DiI injected into the rat stomach wall. Single-cell RT-PCR was performed on traced gastric neurons. Retrograde tracing demonstrated that vagal gastric neurons locate exclusively into the nodose portion of the rat jugular/petrosal/nodose complex. Gastric DRG TRPV1-positive neurons preferentially expressed markers PPT-A, TrkA and GFRα 3 typical for neural crest-derived TRPV1-positive visceral neurons. In contrast, gastric nodose TRPV1-positive neurons preferentially expressed markers P2X 2 and TrkB typical for placodes-derived TRPV1-positive visceral neurons. Differential expression of neural crest and placodes markers was less pronounced in TRPV1-negative DRG and nodose populations. There are phenotypic distinctions between the neural crest-derived DRG and placodes-derived vagal nodose TRPV1-positive neurons innervating the rat stomach that are similar to those described in thoracic organs.

  7. THE PROSTAGLANDIN E2 RECEPTOR, EP2, IS UPREGULATED IN THE DRG AFTER PAINFUL CERVICAL FACET JOINT INJURY IN THE RAT

    PubMed Central

    Kras, Jeffrey V.; Dong, Ling; Winkelstein, Beth A.

    2012-01-01

    Study Design This study implemented immunohistochemistry to assay prostaglandin E2 (PGE2) receptor EP2 expression in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury. Objective The objective of this study was to identify if inflammatory cascades are induced in association with cervical facet joint distraction-induced pain by investigating the time course of EP2 expression in the DRG. Summary of Background Data The cervical facet joint is a common source of neck pain and non-physiological stretch of the facet capsular ligament can initiate pain from the facet joint via mechanical injury. PGE2 levels are elevated in painful inflamed and arthritic joints, and PGE2 sensitizes joint afferents to mechanical stimulation. Although in vitro studies suggest the EP2 receptor subtype contributes to painful joint disease the EP2 response has not been investigated for any association with painful mechanical joint injury. Methods Separate groups of male Holtzman rats underwent either a painful cervical facet joint distraction injury or sham procedure. Bilateral forepaw mechanical allodynia was assessed, and immunohistochemical techniques were used to quantify EP2 expression in the DRG at days 1 and 7. Results Facet joint distraction induced mechanical allodynia that was significant (p<0.024) at all time points. Painful joint injury also significantly elevated total EP2 expression in the DRG at day 1 (p=0.009), which was maintained also at day 7 (p<0.001). Neuronal expression of EP2 in the DRG was only increased over sham levels at day 1 (p=0.013). Conclusions Painful cervical facet joint distraction induces an immediate and sustained increase of EP2 expression in the DRG, implicating peripheral inflammation in the initiation and maintenance of facet joint pain. The transient increase in neuronal EP2 suggests, as in other painful joint conditions, that after joint injury non-neuronal cells may migrate to the DRG, some of which likely express EP2

  8. Characterization of Different Types of Excitability in Large Somatosensory Neurons and Its Plastic Changes in Pathological Pain States

    PubMed Central

    Xie, Rou-Gang; Chu, Wen-Guang; Hu, San-Jue; Luo, Ceng

    2018-01-01

    Sensory neuron types have been distinguished by distinct morphological and transcriptional characteristics. Excitability is the most fundamental functional feature of neurons. Mathematical models described by Hodgkin have revealed three types of neuronal excitability based on the relationship between firing frequency and applied current intensity. However, whether natural sensory neurons display different functional characteristics in terms of excitability and whether this excitability type undergoes plastic changes under pathological pain states have remained elusive. Here, by utilizing whole-cell patch clamp recordings, behavioral and pharmacological assays, we demonstrated that large dorsal root ganglion (DRG) neurons can be classified into three classes and four subclasses based on their excitability patterns, which is similar to mathematical models raised by Hodgkin. Analysis of hyperpolarization-activated cation current (Ih) revealed different magnitude of Ih in different excitability types of large DRG neurons, with higher Ih in Class 2-1 than that in Class 1, 2-2 and 3. This indicates a crucial role of Ih in the determination of excitability type of large DRG neurons. More importantly, this pattern of excitability displays plastic changes and transition under pathological pain states caused by peripheral nerve injury. This study sheds new light on the functional characteristics of large DRG neurons and extends functional classification of large DRG neurons by integration of transcriptomic and morphological characteristics. PMID:29303989

  9. Dync1h1 Mutation Causes Proprioceptive Sensory Neuron Loss and Impaired Retrograde Axonal Transport of Dorsal Root Ganglion Neurons.

    PubMed

    Zhao, Jing; Wang, Yi; Xu, Huan; Fu, Yuan; Qian, Ting; Bo, Deng; Lu, Yan-Xin; Xiong, Yi; Wan, Jun; Zhang, Xiang; Dong, Qiang; Chen, Xiang-Jun

    2016-07-01

    Sprawling (Swl) is a radiation-induced mutation which has been identified to have a nine base pair deletion in dynein heavy chain 1 (DYNC1H1: encoded by a single gene Dync1h1). This study is to investigate the phenotype and the underlying mechanism of the Dync1h1 mutant. To display the phenotype of Swl mutant mice, we examined the embryos of homozygous (Swl/Swl) and heterozygous (Swl/+) mice and their postnatal dorsal root ganglion (DRG) of surviving Swl/+ mice. The Swl/+ mice could survive for a normal life span, while Swl/Swl could only survive till embryonic (E) 8.5 days. Excessive apoptosis of Swl/+ DRG neurons was revealed during E11.5-E15.5 days, and the peak rate was at E13.5 days. In vitro study of mutated DRG neurons showed impaired retrograde transport of dynein-driven nerve growth factor (NGF). Mitochondria, another dynein-driven cargo, demonstrated much slower retrograde transport velocity in Swl/+ neurons than in wild-type (WT) neurons. Nevertheless, the Swl, Loa, and Cra mutations did not affect homodimerization of DYNC1H1. The Swl/Swl mutation of Dync1h1 gene led to embryonic mal-development and lethality, whereas the Swl/+ DRG neurons demonstrated deficient retrograde transport in dynein-driven cargos and excessive apoptosis during mid- to late-developmental stages. The underlying mechanism of the mutation may not be due to impaired homodimerization of DYNC1H1. © 2016 John Wiley & Sons Ltd.

  10. Nav1.7-A1632G Mutation from a Family with Inherited Erythromelalgia: Enhanced Firing of Dorsal Root Ganglia Neurons Evoked by Thermal Stimuli.

    PubMed

    Yang, Yang; Huang, Jianying; Mis, Malgorzata A; Estacion, Mark; Macala, Lawrence; Shah, Palak; Schulman, Betsy R; Horton, Daniel B; Dib-Hajj, Sulayman D; Waxman, Stephen G

    2016-07-13

    Voltage-gated sodium channel Nav1.7 is a central player in human pain. Mutations in Nav1.7 produce several pain syndromes, including inherited erythromelalgia (IEM), a disorder in which gain-of-function mutations render dorsal root ganglia (DRG) neurons hyperexcitable. Although patients with IEM suffer from episodes of intense burning pain triggered by warmth, the effects of increased temperature on DRG neurons expressing mutant Nav1.7 channels have not been well documented. Here, using structural modeling, voltage-clamp, current-clamp, and multielectrode array recordings, we have studied a newly identified Nav1.7 mutation, Ala1632Gly, from a multigeneration family with IEM. Structural modeling suggests that Ala1632 is a molecular hinge and that the Ala1632Gly mutation may affect channel gating. Voltage-clamp recordings revealed that the Nav1.7-A1632G mutation hyperpolarizes activation and depolarizes fast-inactivation, both gain-of-function attributes at the channel level. Whole-cell current-clamp recordings demonstrated increased spontaneous firing, lower current threshold, and enhanced evoked firing in rat DRG neurons expressing Nav1.7-A1632G mutant channels. Multielectrode array recordings further revealed that intact rat DRG neurons expressing Nav1.7-A1632G mutant channels are more active than those expressing Nav1.7 WT channels. We also showed that physiologically relevant thermal stimuli markedly increase the mean firing frequencies and the number of active rat DRG neurons expressing Nav1.7-A1632G mutant channels, whereas the same thermal stimuli only increase these parameters slightly in rat DRG neurons expressing Nav1.7 WT channels. The response of DRG neurons expressing Nav1.7-A1632G mutant channels upon increase in temperature suggests a cellular basis for warmth-triggered pain in IEM. Inherited erythromelalgia (IEM), a severe pain syndrome characterized by episodes of intense burning pain triggered by warmth, is caused by mutations in sodium channel Nav

  11. Neuron-glial communication mediated by TNF-α and glial activation in dorsal root ganglia in visceral inflammatory hypersensitivity.

    PubMed

    Song, Dan-dan; Li, Yong; Tang, Dong; Huang, Li-ya; Yuan, Yao-zong

    2014-05-01

    Communication between neurons and glia in the dorsal root ganglia (DRG) and the central nervous system is critical for nociception. Both glial activation and proinflammatory cytokine induction underlie this communication. We investigated whether satellite glial cell (SGC) and tumor necrosis factor-α (TNF-α) activation in DRG participates in a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced rat model of visceral hyperalgesia. In TNBS-treated rats, TNF-α expression increased in DRG and was colocalized to SGCs enveloping a given neuron. These SGCs were activated as visualized under electron microscopy: they had more elongated processes projecting into the connective tissue space and more gap junctions. When nerves attached to DRG (L6-S1) were stimulated with a series of electrical stimulations, TNF-α were released from DRG in TNBS-treated animals compared with controls. Using a current clamp, we noted that exogenous TNF-α (2.5 ng/ml) increased DRG neuron activity, and visceral pain behavioral responses were reversed by intrathecal administration of anti-TNF-α (10 μg·kg(-1)·day(-1)). Based on our findings, TNF-α and SGC activation in neuron-glial communication are critical in inflammatory visceral hyperalgesia.

  12. Neuronal somatic ATP release triggers neuron–satellite glial cell communication in dorsal root ganglia

    PubMed Central

    Zhang, X.; Chen, Y.; Wang, C.; Huang, L.-Y. M.

    2007-01-01

    It has been generally assumed that the cell body (soma) of a neuron, which contains the nucleus, is mainly responsible for synthesis of macromolecules and has a limited role in cell-to-cell communication. Using sniffer patch recordings, we show here that electrical stimulation of dorsal root ganglion (DRG) neurons elicits robust vesicular ATP release from their somata. The rate of release events increases with the frequency of nerve stimulation; external Ca2+ entry is required for the release. FM1–43 photoconversion analysis further reveals that small clear vesicles participate in exocytosis. In addition, the released ATP activates P2X7 receptors in satellite cells that enwrap each DRG neuron and triggers the communication between neuronal somata and glial cells. Blocking L-type Ca2+ channels completely eliminates the neuron–glia communication. We further show that activation of P2X7 receptors can lead to the release of tumor necrosis factor-α (TNFα) from satellite cells. TNFα in turn potentiates the P2X3 receptor-mediated responses and increases the excitability of DRG neurons. This study provides strong evidence that somata of DRG neurons actively release transmitters and play a crucial role in bidirectional communication between neurons and surrounding satellite glial cells. These results also suggest that, contrary to the conventional view, neuronal somata have a significant role in cell–cell signaling. PMID:17525149

  13. Epigenetic modification of DRG neuronal gene expression subsequent to nerve injury: etiological contribution to complex regional pain syndromes (Part I).

    PubMed

    Wang, Fuzhou; Stefano, George B; Kream, Richard M

    2014-06-25

    DRG is of importance in relaying painful stimulation to the higher pain centers and therefore could be a crucial target for early intervention aimed at suppressing primary afferent stimulation. Complex regional pain syndrome (CRPS) is a common pain condition with an unknown etiology. Recently added new information enriches our understanding of CRPS pathophysiology. Researches on genetics, biogenic amines, neurotransmitters, and mechanisms of pain modulation, central sensitization, and autonomic functions in CRPS revealed various abnormalities indicating that multiple factors and mechanisms are involved in the pathogenesis of CRPS. Epigenetics refers to mitotically and meiotically heritable changes in gene expression that do not affect the DNA sequence. As epigenetic modifications potentially play an important role in inflammatory cytokine metabolism, neurotransmitter responsiveness, and analgesic sensitivity, they are likely key factors in the development of chronic pain. In this dyad review series, we systematically examine the nerve injury-related changes in the neurological system and their contribution to CRPS. In this part, we first reviewed and summarized the role of neural sensitization in DRG neurons in performing function in the context of pain processing. Particular emphasis is placed on the cellular and molecular changes after nerve injury as well as different models of inflammatory and neuropathic pain. These were considered as the potential molecular bases that underlie nerve injury-associated pathogenesis of CRPS.

  14. Stimulatory effect of harmane and other beta-carbolines on locus coeruleus neurons in anaesthetized rats.

    PubMed

    Ruiz-Durántez, E; Ruiz-Ortega JA; Pineda, J; Ugedo, L

    2001-08-10

    Harmane, harmaline and norharmane are beta-carboline related compounds which have been proposed to be endogenous ligands for imidazoline receptors. The effect of these compounds on the activity of locus coeruleus (LC) neurons was studied by extracellular recordings techniques. Intracerebroventricular administration of harmane and harmaline increased the firing rate of LC neurons. Systemic administration of efaroxan, a mixed alpha(2)-adrenoceptor/I(1)-imidazoline antagonist or vagotomy failed to modify the harmane effect. Furthermore, local applications of harmane and harmaline increased the firing rate of LC neurons in a dose-related manner. Finally, intravenous administration of norharmane also increased the activity of LC neurons. Our results demonstrate that beta-carbolines stimulate LC neuron activity and indicate that this stimulation occurs directly in the LC by a mechanism independent of I(1)- and I(2)-imidazoline receptors.

  15. Augmentation of glycolytic metabolism by meclizine is indispensable for protection of dorsal root ganglion neurons from hypoxia-induced mitochondrial compromise.

    PubMed

    Zhuo, Ming; Gorgun, Murat F; Englander, Ella W

    2016-10-01

    To meet energy demands, dorsal root ganglion (DRG) neurons harbor high mitochondrial content, which renders them acutely vulnerable to disruptions of energy homeostasis. While neurons typically rely on mitochondrial energy production and have not been associated with metabolic plasticity, new studies reveal that meclizine, a drug, recently linked to modulations of energy metabolism, protects neurons from insults that disrupt energy homeostasis. We show that meclizine rapidly enhances glycolysis in DRG neurons and that glycolytic metabolism is indispensable for meclizine-exerted protection of DRG neurons from hypoxic stress. We report that supplementation of meclizine during hypoxic exposure prevents ATP depletion, preserves NADPH and glutathione stores, curbs reactive oxygen species (ROS) and attenuates mitochondrial clustering in DRG neurites. Using extracellular flux analyzer, we show that in cultured DRG neurons meclizine mitigates hypoxia-induced loss of mitochondrial respiratory capacity. Respiratory capacity is a measure of mitochondrial fitness and cell ability to meet fluctuating energy demands and therefore, a key determinant of cellular fate. While meclizine is an 'old' drug with long record of clinical use, its ability to modulate energy metabolism has been uncovered only recently. Our findings documenting neuroprotection by meclizine in a setting of hypoxic stress reveal previously unappreciated metabolic plasticity of DRG neurons as well as potential for pharmacological harnessing of the newly discovered metabolic plasticity for protection of peripheral nervous system under mitochondria compromising conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. A long noncoding RNA contributes to neuropathic pain by silencing Kcna2 in primary afferent neurons

    PubMed Central

    Zhao, Xiuli; Tang, Zongxiang; Zhang, Hongkang; Atianjoh, Fidelis E.; Zhao, Jian-Yuan; Liang, Lingli; Wang, Wei; Guan, Xiaowei; Kao, Sheng-Chin; Tiwari, Vinod; Gao, Yong-Jing; Hoffman, Paul N.; Cui, Hengmi; Li, Min; Dong, Xinzhong; Tao, Yuan-Xiang

    2013-01-01

    Neuropathic pain is a refractory disease characterized by maladaptive changes in gene transcription and translation within the sensory pathway. Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation, but how lncRNAs operate in the development of neuropathic pain is unclear. Here we identify a conserved lncRNA for Kcna2 (named Kcna2 antisense RNA) in first-order sensory neurons of rat dorsal root ganglion (DRG). Peripheral nerve injury increases Kcna2 antisense RNA expression in injured DRG through activation of myeloid zinc finger protein 1, a transcription factor that binds to Kcna2 antisense RNA gene promoter. Mimicking this increase downregulates Kcna2, reduces total Kv current, increases excitability in DRG neurons, and produces neuropathic pain symptoms. Blocking this increase reverses nerve injury-induced downregulation of DRG Kcna2 and attenuates development and maintenance of neuropathic pain. These findings suggest native Kcna2 antisense RNA as a new therapeutic target for the treatment of neuropathic pain. PMID:23792947

  17. Human Subthalamic Nucleus Theta and Beta Oscillations Entrain Neuronal Firing During Sensorimotor Conflict

    PubMed Central

    Zavala, Baltazar; Damera, Srikanth; Dong, Jian Wilson; Lungu, Codrin; Brown, Peter; Zaghloul, Kareem A.

    2017-01-01

    Recent evidence has suggested that prefrontal cortical structures may inhibit impulsive actions during conflict through activation of the subthalamic nucleus (STN). Consistent with this hypothesis, deep brain stimulation to the STN has been associated with altered prefrontal cortical activity and impaired response inhibition. The interactions between oscillatory activity in the STN and its presumably antikinetic neuronal spiking, however, remain poorly understood. Here, we simultaneously recorded intraoperative local field potential and spiking activity from the human STN as participants performed a sensorimotor action selection task involving conflict. We identified several STN neuronal response types that exhibited different temporal dynamics during the task. Some neurons showed early, cue-related firing rate increases that remained elevated longer during high conflict trials, whereas other neurons showed late, movement-related firing rate increases. Notably, the high conflict trials were associated with an entrainment of individual neurons by theta- and beta-band oscillations, both of which have been observed in cortical structures involved in response inhibition. Our data suggest that frequency-specific activity in the beta and theta bands influence STN firing to inhibit impulsivity during conflict. PMID:26494798

  18. Effect of beta-amyloid block of the fast-inactivating K+ channel on intracellular Ca2+ and excitability in a modeled neuron.

    PubMed

    Good, T A; Murphy, R M

    1996-12-24

    beta-Amyloid peptide (A beta), one of the primary protein components of senile plaques found in Alzheimer disease, is believed to be toxic to neurons by a mechanism that may involve loss of intracellular calcium regulation. We have previously shown that A beta blocks the fast-inactivating potassium (A) current. In this work, we show, through the use of a mathematical model, that the A beta-mediated block of the A current could result in increased intracellular calcium levels and increased membrane excitability, both of which have been observed in vitro upon acute exposure to A beta. Simulation results are compared with experimental data from the literature; the simulations quantitatively capture the observed concentration dependence of the neuronal response and the level of increase in intracellular calcium.

  19. Availability of neurotransmitter glutamate is diminished when beta-hydroxybutyrate replaces glucose in cultured neurons.

    PubMed

    Lund, Trine M; Risa, Oystein; Sonnewald, Ursula; Schousboe, Arne; Waagepetersen, Helle S

    2009-07-01

    Ketone bodies serve as alternative energy substrates for the brain in cases of low glucose availability such as during starvation or in patients treated with a ketogenic diet. The ketone bodies are metabolized via a distinct pathway confined to the mitochondria. We have compared metabolism of [2,4-(13)C]beta-hydroxybutyrate to that of [1,6-(13)C]glucose in cultured glutamatergic neurons and investigated the effect of neuronal activity focusing on the aspartate-glutamate homeostasis, an essential component of the excitatory activity in the brain. The amount of (13)C incorporation and cellular content was lower for glutamate and higher for aspartate in the presence of [2,4-(13)C]beta-hydroxybutyrate as opposed to [1,6-(13)C]glucose. Our results suggest that the change in aspartate-glutamate homeostasis is due to a decreased availability of NADH for cytosolic malate dehydrogenase and thus reduced malate-aspartate shuttle activity in neurons using beta-hydroxybutyrate. In the presence of glucose, the glutamate content decreased significantly upon activation of neurotransmitter release, whereas in the presence of only beta-hydroxybutyrate, no decrease in the glutamate content was observed. Thus, the fraction of the glutamate pool available for transmitter release was diminished when metabolizing beta-hydroxybutyrate, which is in line with the hypothesis of formation of transmitter glutamate via an obligatory involvement of the malate-aspartate shuttle.

  20. Reduction in voltage-gated K+ channel activity in primary sensory neurons in painful diabetic neuropathy: role of brain-derived neurotrophic factor.

    PubMed

    Cao, Xue-Hong; Byun, Hee-Sun; Chen, Shao-Rui; Cai, You-Qing; Pan, Hui-Lin

    2010-09-01

    Abnormal hyperexcitability of primary sensory neurons plays an important role in neuropathic pain. Voltage-gated potassium (Kv) channels regulate neuronal excitability by affecting the resting membrane potential and influencing the repolarization and frequency of the action potential. In this study, we determined changes in Kv channels in dorsal root ganglion (DRG) neurons in a rat model of diabetic neuropathic pain. The densities of total Kv, A-type (IA) and sustained delayed (IK) currents were markedly reduced in medium- and large-, but not in small-, diameter DRG neurons in diabetic rats. Quantitative RT-PCR analysis revealed that the mRNA levels of IA subunits, including Kv1.4, Kv3.4, Kv4.2, and Kv4.3, in the DRG were reduced approximately 50% in diabetic rats compared with those in control rats. However, there were no significant differences in the mRNA levels of IK subunits (Kv1.1, Kv1.2, Kv2.1, and Kv2.2) in the DRG between the two groups. Incubation with brain-derived neurotrophic factor (BDNF) caused a large reduction in Kv currents, especially IA currents, in medium and large DRG neurons from control rats. Furthermore, the reductions in Kv currents and mRNA levels of IA subunits in diabetic rats were normalized by pre-treatment with anti-BDNF antibody or K252a, a TrkB tyrosine kinase inhibitor. In addition, the number of medium and large DRG neurons with BDNF immunoreactivity was greater in diabetic than control rats. Collectively, our findings suggest that diabetes primarily reduces Kv channel activity in medium and large DRG neurons. Increased BDNF activity in these neurons likely contributes to the reduction in Kv channel function through TrkB receptor stimulation in painful diabetic neuropathy.

  1. TRPM8 is a neuronal osmosensor that regulates eye blinking in mice

    PubMed Central

    Quallo, Talisia; Vastani, Nisha; Horridge, Elisabeth; Gentry, Clive; Parra, Andres; Moss, Sian; Viana, Felix; Belmonte, Carlos; Andersson, David A.; Bevan, Stuart

    2015-01-01

    Specific peripheral sensory neurons respond to increases in extracellular osmolality but the mechanism responsible for excitation is unknown. Here we show that small increases in osmolality excite isolated mouse dorsal root ganglion (DRG) and trigeminal ganglion (TG) neurons expressing the cold-sensitive TRPM8 channel (transient receptor potential channel, subfamily M, member 8). Hyperosmotic responses were abolished by TRPM8 antagonists, and were absent in DRG and TG neurons isolated from Trpm8−/− mice. Heterologously expressed TRPM8 was activated by increased osmolality around physiological levels and inhibited by reduced osmolality. Electrophysiological studies in a mouse corneal preparation demonstrated that osmolality regulated the electrical activity of TRPM8-expressing corneal afferent neurons. Finally, the frequency of eye blinks was reduced in Trpm8−/− compared with wild-type mice and topical administration of a TRPM8 antagonist reduced blinking in wild-type mice. Our findings identify TRPM8 as a peripheral osmosensor responsible for the regulation of normal eye-blinking in mice. PMID:25998021

  2. Molecular and functional expression of cation-chloride cotransporters in dorsal root ganglion neurons during postnatal maturation

    PubMed Central

    Mao, Shihong; Garzon-Muvdi, Tomás; Di Fulvio, Mauricio; Chen, Yanfang; Delpire, Eric; Alvarez, Francisco J.

    2012-01-01

    GABA depolarizes and excites central neurons during early development, becoming inhibitory and hyperpolarizing with maturation. This “developmental shift” occurs abruptly, reflecting a decrease in intracellular Cl− concentration ([Cl−]i) and a hyperpolarizing shift in Cl− equilibrium potential due to upregulation of the K+-Cl− cotransporter KCC2b, a neuron-specific Cl− extruder. In contrast, primary afferent neurons (PANs) are depolarized by GABA throughout adulthood because of expression of NKCC1, a Na+-K+-2Cl− cotransporter that accumulates Cl− above equilibrium. The GABAA-mediated depolarization of PANs determines presynaptic inhibition in the spinal cord, a key mechanism gating somatosensory information. Little is known about developmental changes in Cl− transporter expression and Cl− homeostasis in PANs. Whether NKCC1 is expressed in PANs of all phenotypes or is restricted to subpopulations (e.g., nociceptors) is debatable. Likewise, whether PANs express KCC2s is controversial. We investigated NKCC1 and K+-Cl− cotransporter expression in rat and mouse dorsal root ganglion (DRG) neurons with molecular methods. Using fluorescence imaging microscopy, we measured [Cl−]i in acutely dissociated rat DRG neurons (P0–P21) loaded with N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide and classified with phenotypic markers. DRG neurons of all sizes express two NKCC1 mRNAs, one full-length and a shorter splice variant lacking exon 21. Immunolabeling with validated antibodies revealed ubiquitous expression of NKCC1 in DRG neurons irrespective of postnatal age and phenotype. As maturation progresses [Cl−]i decreases gradually, persisting above equilibrium in >95% mature neurons. DRG neurons express mRNAs for KCC1, KCC3s, and KCC4, but not for KCC2s. Mechanisms underlying PANs' developmental changes in Cl− homeostasis are discussed and compared with those of central neurons. PMID:22457464

  3. Fixative Composition Alters Distributions of Immunoreactivity for Glutaminase and Two Markers of Nociceptive Neurons, Nav1.8 and TRPV1, in the Rat Dorsal Root Ganglion

    PubMed Central

    Hoffman, E. Matthew; Schechter, Ruben; Miller, Kenneth E.

    2010-01-01

    Most, if not all, dorsal root ganglion (DRG) neurons use the neurotransmitter glutamate. There are, however, conflicting reports of the percentages of DRG neurons that express glutaminase (GLS), the enzyme that synthesizes glutamate, ranging from 30% to 100% of DRG neurons. Defining DRG neuron populations by the expression of proteins like GLS, which indicates function, is routinely accomplished with immunolabeling techniques. Proper characterization of DRG neuron populations relies on accurate detection of such antigens. It is known intuitively that fixation can alter immunoreactivity (IR). In this study, we compared the effects of five formaldehyde concentrations between 0.25% and 4.0% (w/v) and five picric acid concentrations between 0.0% and 0.8% (w/v) on the IR of GLS, the voltage-gated sodium channel 1.8 (Nav1.8), and the capsaicin receptor TRPV1. We also compared the effects of five incubation time lengths from 2 to 192 hr, in primary antiserum on IR. Lowering formaldehyde concentration elevated IR for all three antigens, while raising picric acid concentration increased Nav1.8 and TRPV1 IR. Increasing IR improved detection sensitivity, which led to higher percentages of labeled DRG neurons. By selecting fixation conditions that optimized IR, we found that all DRG neurons express GLS, 69% of neurons express Nav1.8, and 77% of neurons express TRPV1, indicating that some previous studies may have underestimated the percentages of DRG neurons expressing these proteins. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials. (J Histochem Cytochem 58:329–344, 2010) PMID:20026672

  4. Bidirectional communication between sensory neurons and osteoblasts in an in vitro coculture system.

    PubMed

    Kodama, Daisuke; Hirai, Takao; Kondo, Hisataka; Hamamura, Kazunori; Togari, Akifumi

    2017-02-01

    Recent studies have revealed that the sensory nervous system is involved in bone metabolism. However, the mechanism of communication between neurons and osteoblasts is yet to be elucidated. In this study, we investigated the signaling pathways between sensory neurons of the dorsal root ganglion (DRG) and the osteoblast-like MC3T3-E1 cells using an in vitro coculture system. Our findings indicate that signal transduction from DRG-derived neurons to MC3T3-E1 cells is suppressed by antagonists of the AMPA receptor and the NK 1 receptor. Conversely, signal transduction from MC3T3-E1 cells to DRG-derived neurons is suppressed by a P2X 7 receptor antagonist. Our results suggest that these cells communicate with each other by exocytosis of glutamate, substance P in the efferent signal, and ATP in the afferent signal. © 2017 Federation of European Biochemical Societies.

  5. Effects of Chemically Doped Bioactive Borate Glass on Neuron Regrowth and Regeneration.

    PubMed

    Gupta, Brinda; Papke, Jason B; Mohammadkhah, Ali; Day, Delbert E; Harkins, Amy B

    2016-12-01

    Peripheral nerve injuries present challenges to regeneration. Currently, the gold standard for nerve repair is an autograft that results in another region of the body suffering nerve damage. Previously, bioactive borate glass (BBG) has been studied in clinical trials to treat patients with non-healing wounds, and we have reported that BBG is conducive for soft tissue repair. BBG provides structural support, degrades in a non-cytotoxic manner, and can be chemically doped. Here, we tested a wide range of chemical compounds that are reported to have neuroprotective characteristics to promote regeneration of peripheral neurons after traumatic injury. We hypothesized that chemical dopants added in trace amounts to BBG would improve neuronal survival and neurite outgrowth from dorsal root ganglion (DRG) explants. We measured neurite outgrowth from whole DRG explants, and survival rates of dissociated neurons and support cells that comprise the DRG. Results show that chemically doped BBGs have differentially variable effects on neuronal survival and outgrowth, with iron, gallium, and zinc improving outgrowth of neurons, and iodine causing the most detriment to neurons. Because chemically doped BBGs support increased nerve regrowth and survival, they show promise for use in peripheral nerve regeneration.

  6. Glycogen synthase kinase-3beta and the p25 activator of cyclin dependent kinase 5 increase pausing of mitochondria in neurons.

    PubMed

    Morel, M; Authelet, M; Dedecker, R; Brion, J P

    2010-06-02

    The complex bi-directional axoplasmic transport of mitochondria is essential for proper metabolic functioning of neurons and is controlled by phosphorylation. We have investigated by time-lapse imaging the effects of increased expression of glycogen synthase kinase-3beta (GSK-3beta) and of the p25 activator of cyclin dependent kinase 5 on mitochondria movements in mammalian cortical neurons and in PC12 cells. Both GSK-3beta and p25 increased the stationary behaviour of mitochondria in PC12 and in neurons, decreased their anterograde transport but did not affect the intrinsic velocities of mitochondria. The microtubule-associated tau proteins were more phosphorylated in GSK-3beta and p25 transfected neurons, but ultrastructural observation showed that these cells still contained microtubules and nocodazole treatment further reduced residual mitochondria movements in GSK-3beta or p25 transfected neurons, indicating that microtubule disruption was not the primary cause of increased mitochondrial stationary behaviour in GSK-3beta or p25 transfected neurons. Our results suggest that increased expression of GSK-3beta and p25 acted rather by decreasing the frequency of mitochondrial movements driven by molecular motors and that GSK-3beta and p25 might regulate these transports by controlling the time that mitochondria spend pausing, rather than their velocities. Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Herpes Simplex Virus 1 Tropism for Human Sensory Ganglion Neurons in the Severe Combined Immunodeficiency Mouse Model of Neuropathogenesis

    PubMed Central

    Che, Xibing; Reichelt, Mike; Qiao, Yanli; Gu, Haidong; Arvin, Ann

    2013-01-01

    The tropism of herpes simplex virus (HSV-1) for human sensory neurons infected in vivo was examined using dorsal root ganglion (DRG) xenografts maintained in mice with severe combined immunodeficiency (SCID). In contrast to the HSV-1 lytic infectious cycle in vitro, replication of the HSV-1 F strain was restricted in human DRG neurons despite the absence of adaptive immune responses in SCID mice, allowing the establishment of neuronal latency. At 12 days after DRG inoculation, 26.2% of human neurons expressed HSV-1 protein and 13.1% expressed latency-associated transcripts (LAT). Some infected neurons showed cytopathic changes, but HSV-1, unlike varicella-zoster virus (VZV), only rarely infected satellite cells and did not induce fusion of neuronal and satellite cell plasma membranes. Cell-free enveloped HSV-1 virions were observed, indicating productive infection. A recombinant HSV-1-expressing luciferase exhibited less virulence than HSV-1 F in the SCID mouse host, enabling analysis of infection in human DRG xenografts for a 61-day interval. At 12 days after inoculation, 4.2% of neurons expressed HSV-1 proteins; frequencies increased to 32.1% at 33 days but declined to 20.8% by 61 days. Frequencies of LAT-positive neurons were 1.2% at 12 days and increased to 40.2% at 33 days. LAT expression remained at 37% at 61 days, in contrast to the decline in neurons expressing viral proteins. These observations show that the progression of HSV-1 infection is highly restricted in human DRG, and HSV-1 genome silencing occurs in human neurons infected in vivo as a consequence of virus-host cell interactions and does not require adaptive immune control. PMID:23269807

  8. Drug-Induced HSP90 Inhibition Alleviates Pain in Monoarthritic Rats and Alters the Expression of New Putative Pain Players at the DRG.

    PubMed

    Nascimento, Diana Sofia Marques; Potes, Catarina Soares; Soares, Miguel Luz; Ferreira, António Carlos; Malcangio, Marzia; Castro-Lopes, José Manuel; Neto, Fani Lourença Moreira

    2018-05-01

    Purinergic receptors (P2XRs) have been widely associated with pain states mostly due to their involvement in neuron-glia communication. Interestingly, we have previously shown that satellite glial cells (SGC), surrounding dorsal root ganglia (DRG) neurons, become activated and proliferate during monoarthritis (MA) in the rat. Here, we demonstrate that P2X7R expression increases in ipsilateral DRG after 1 week of disease, while P2X3R immunoreactivity decreases. We have also reported a significant induction of the activating transcriptional factor 3 (ATF3) in MA. In this study, we show that ATF3 knocked down in DRG cell cultures does not affect the expression of P2X7R, P2X3R, or glial fibrillary acidic protein (GFAP). We suggest that P2X7R negatively regulates P2X3R, which, however, is unlikely mediated by ATF3. Interestingly, we found that ATF3 knockdown in vitro induced significant decreases in the heat shock protein 90 (HSP90) expression. Thus, we evaluated in vivo the involvement of HSP90 in MA and demonstrated that the HSP90 messenger RNA levels increase in ipsilateral DRG of inflamed animals. We also show that HSP90 is mostly found in a cleaved form in this condition. Moreover, administration of a HSP90 inhibitor, 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), attenuated MA-induced mechanical allodynia in the first hours. The drug also reversed the HSP90 upregulation and cleavage. 17-DMAG seemed to attenuate glial activation and neuronal sensitization (as inferred by downregulation of GFAP and P2X3R in ipsilateral DRG) which might correlate with the observed pain alleviation. Our data indicate a role of HSP90 in MA pathophysiology, but further investigation is necessary to clarify the underlying mechanisms.

  9. Human Subthalamic Nucleus Theta and Beta Oscillations Entrain Neuronal Firing During Sensorimotor Conflict.

    PubMed

    Zavala, Baltazar; Damera, Srikanth; Dong, Jian Wilson; Lungu, Codrin; Brown, Peter; Zaghloul, Kareem A

    2017-01-01

    Recent evidence has suggested that prefrontal cortical structures may inhibit impulsive actions during conflict through activation of the subthalamic nucleus (STN). Consistent with this hypothesis, deep brain stimulation to the STN has been associated with altered prefrontal cortical activity and impaired response inhibition. The interactions between oscillatory activity in the STN and its presumably antikinetic neuronal spiking, however, remain poorly understood. Here, we simultaneously recorded intraoperative local field potential and spiking activity from the human STN as participants performed a sensorimotor action selection task involving conflict. We identified several STN neuronal response types that exhibited different temporal dynamics during the task. Some neurons showed early, cue-related firing rate increases that remained elevated longer during high conflict trials, whereas other neurons showed late, movement-related firing rate increases. Notably, the high conflict trials were associated with an entrainment of individual neurons by theta- and beta-band oscillations, both of which have been observed in cortical structures involved in response inhibition. Our data suggest that frequency-specific activity in the beta and theta bands influence STN firing to inhibit impulsivity during conflict. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  10. Characteristics of hyperpolarization-activated cyclic nucleotide-gated channels in dorsal root ganglion neurons at different ages and sizes.

    PubMed

    Hou, Baohua; Chen, Hengling; Qu, Xiangwei; Lin, Xianguang; Luo, Fang; Li, Chenhong

    2015-11-11

    In rat's sensory neurons, hyperpolarization-activated inward currents (Ih) play an essential role in mediating action potentials and contributing to neuronal excitability. Classified by the size of neurons and ages, we studied the Ih and transcription levels of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels using electrophysiology and the single-cell RT-PCR. In voltage-clamp studies, Ih and half-maximal activation voltage (V1/2) changed with age and size. An analysis of all HCN subtypes in dorsal root ganglion (DRG) neurons by single-cell RT-PCR was carried out. HCN1 and HCN3 in medium-small elderly neurons had a weak expression. HCN2 in newborns and HCN4 in elderly rats also had a weak expression. The aim of this study is to examine the age-related Ih and HCN channels subunits in different ages and sizes of DRG neurons. The results would be significant in understanding the physiological and pathophysiological function of different sizes of DRG neurons in different age periods.

  11. Expression of background potassium channels in rat DRG is cell-specific and down-regulated in a neuropathic pain model.

    PubMed

    Pollema-Mays, Sarah L; Centeno, Maria Virginia; Ashford, Crystle J; Apkarian, A Vania; Martina, Marco

    2013-11-01

    Neuropathic pain is associated with hyperexcitability of DRG neurons. Despite the importance of leakage potassium channels for neuronal excitability, little is known about their cell-specific expression in DRGs and possible modulation in neuropathic pain. Multiple leakage channels are expressed in DRG neurons, including TASK1, TASK3, TRESK, TRAAK, TWIK1, TREK1 and TREK2 but little is known about their distribution among different cell types. Our immunohistochemical studies show robust TWIK1 expression in large and medium size neurons, without overlap with TRPV1 or IB4 staining. TASK1 and TASK3, on the contrary, are selectively expressed in small cells; TASK1 expression closely overlaps TRPV1-positive cells, while TASK3 is expressed in TRPV1- and IB4-negative cells. We also studied mRNA expression of these channels in L4-L5 DRGs in control conditions and up to 4 weeks after spared nerve injury lesion. We found that TWIK1 expression is much higher than TASK1 and TASK3 and is strongly decreased 1, 2 and 4 weeks after neuropathic injury. TASK3 expression, on the other hand, decreases 1 week after surgery but reverts to baseline by 2weeks; TASK1 shows no significant change at any time point. These data suggest an involvement of TWIK1 in the maintenance of the pain condition. © 2013.

  12. A Population of Indirect Pathway Striatal Projection Neurons Is Selectively Entrained to Parkinsonian Beta Oscillations

    PubMed Central

    Vinciati, Federica

    2017-01-01

    Classical schemes of basal ganglia organization posit that parkinsonian movement difficulties presenting after striatal dopamine depletion stem from the disproportionate firing rates of spiny projection neurons (SPNs) therein. There remains, however, a pressing need to elucidate striatal SPN firing in the context of the synchronized network oscillations that are abnormally exaggerated in cortical–basal ganglia circuits in parkinsonism. To address this, we recorded unit activities in the dorsal striatum of dopamine-intact and dopamine-depleted rats during two brain states, respectively defined by cortical slow-wave activity (SWA) and activation. Dopamine depletion escalated striatal net output but had contrasting effects on “direct pathway” SPNs (dSPNs) and “indirect pathway” SPNs (iSPNs); their firing rates became imbalanced, and they disparately engaged in network oscillations. Disturbed striatal activity dynamics relating to the slow (∼1 Hz) oscillations prevalent during SWA partly generalized to the exaggerated beta-frequency (15–30 Hz) oscillations arising during cortical activation. In both cases, SPNs exhibited higher incidences of phase-locked firing to ongoing cortical oscillations, and SPN ensembles showed higher levels of rhythmic correlated firing, after dopamine depletion. Importantly, in dopamine-depleted striatum, a widespread population of iSPNs, which often displayed excessive firing rates and aberrant phase-locked firing to cortical beta oscillations, preferentially and excessively synchronized their firing at beta frequencies. Conversely, dSPNs were neither hyperactive nor synchronized to a large extent during cortical activation. These data collectively demonstrate a cell type-selective entrainment of SPN firing to parkinsonian beta oscillations. We conclude that a population of overactive, excessively synchronized iSPNs could orchestrate these pathological rhythms in basal ganglia circuits. SIGNIFICANCE STATEMENT Chronic depletion

  13. Peroxisome proliferator-activated receptor {gamma} is expressed in hippocampal neurons and its activation prevents {beta}-amyloid neurodegeneration: role of Wnt signaling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Inestrosa, Nibaldo C.; Godoy, Juan A.; MIFAB, Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de Chile, Santiago

    2005-03-10

    The molecular pathogenesis of Alzheimer's disease (AD) involves the participation of the amyloid-{beta}-peptide (A{beta}), which plays a critical role in the neurodegeneration that triggers the disease. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors, which are members of the nuclear receptor family. We report here that (1) PPAR{gamma} is present in rat hippocampal neurons in culture. (2) Activation of PPAR{gamma} by troglitazone and rosiglitazone protects rat hippocampal neurons against A{beta}-induced neurodegeneration, as shown by the 3-[4,5 -2yl]-2,5-diphenyltetrazolium bromide (MTT) reduction assay, immunofluorescence using an anti-heavy neurofilament antibody, and quantitative electron microscopy. (3) Hippocampal neurons treated with several PPAR{gamma} agonists, includingmore » troglitazone, rosiglitazone, and ciglitazone, prevent the excitotoxic A{beta}-induced rise in bulk-free Ca{sup 2+}. (4) PPAR{gamma} activation results in the modulation of Wnt signaling components, including the inhibition of glycogen synthase kinase-3{beta} (GSK-3{beta}) and an increase of the cytoplasmic and nuclear {beta}-catenin levels. We conclude that the activation of PPAR{gamma} prevents A{beta}-induced neurodegeneration by a mechanism that may involve a cross talk between neuronal PPAR{gamma} and the Wnt signaling pathway. More important, the fact that the activation of PPAR{gamma} attenuated A{beta}-dependent neurodegeneration opens the possibility to fight AD from a new therapeutic perspective.« less

  14. Paclitaxel-induced painful neuropathy is associated with changes in mitochondrial bioenergetics, glycolysis, and an energy deficit in dorsal root ganglia neurons

    PubMed Central

    Duggett, Natalie A.; Griffiths, Lisa A.; Flatters, Sarah J.L.

    2017-01-01

    Abstract Painful neuropathy is the major dose-limiting side effect of paclitaxel chemotherapy. Mitochondrial dysfunction and adenosine triphosphate (ATP) deficit have previously been shown in peripheral nerves of paclitaxel-treated rats, but the effects of paclitaxel in the dorsal root ganglia (DRGs) have not been explored. The aim of this study was to determine the bioenergetic status of DRG neurons following paclitaxel exposure in vitro and in vivo. Utilising isolated DRG neurons, we measured respiratory function under basal conditions and at maximal capacity, glycolytic function, and Adenosine diphosphate (ADP)/ATP levels at 3 key behavioural timepoints; prior to pain onset (day 7), peak pain severity and pain resolution. At day 7, maximal respiration and spare reserve capacity were significantly decreased in DRG neurons from paclitaxel-treated rats. This was accompanied by decreased basal ATP levels and unaltered ADP levels. At peak pain severity, respiratory function was unaltered, yet glycolytic function was significantly increased. Reduced ATP and unaltered ADP levels were also observed at the peak pain timepoint. All these effects in DRG neurons had dissipated by the pain resolution timepoint. None of these paclitaxel-evoked changes could be replicated from in vitro paclitaxel exposure to naive DRG neurons, demonstrating the impact of in vivo exposure and the importance of in vivo models. These data demonstrate the nature of mitochondrial dysfunction evoked by in vivo paclitaxel in the DRG for the first time. Furthermore, we have identified paclitaxel-evoked changes in the bioenergetics of DRG neurons, which result in a persistent energy deficit that is causal to the development and maintenance of paclitaxel-induced pain. PMID:28541258

  15. [Gastroenterology in the G-DRG-System 2004].

    PubMed

    Bunzemeier, H; Frühmorgen, P; Caspary, W F; Roeder, N

    2003-11-01

    After a year of preliminary voluntarily introduction of casemix funding in hospitals in 2003 nearly every German hospital will be confronted with lump sump payments on the basis of the G-DRG system for their inpatient care starting from January 2004. To analyse weaknesses referring to gastroenterology services within the G-DRG version 1.0 the German Association for Disorders of the Digestive System and Metabolism (DGVS) and the DRG-Research-Group from the University of Muenster conducted a DRG evaluation project. In the analysis patient data from 16 hospitals were included. As a result of the project recommendations for G-DRG adjustments were generated. Those recommendations were implemented in the advancement to G-DRG version 2004. Also the International Classification of Diseases (ICD-10) was modified to ICD-10 German Modification. The classification of procedures OPS-301 was revised. The main adjustments to the G-DRG system and both classifications will be presented in this paper.

  16. Comparative study of the distribution of the alpha-subunits of voltage-gated sodium channels in normal and axotomized rat dorsal root ganglion neurons.

    PubMed

    Fukuoka, Tetsuo; Kobayashi, Kimiko; Yamanaka, Hiroki; Obata, Koichi; Dai, Yi; Noguchi, Koichi

    2008-09-10

    We compared the distribution of the alpha-subunit mRNAs of voltage-gated sodium channels Nav1.1-1.3 and Nav1.6-1.9 and a related channel, Nax, in histochemically identified neuronal subpopulations of the rat dorsal root ganglia (DRG). In the naïve DRG, the expression of Nav1.1 and Nav1.6 was restricted to A-fiber neurons, and they were preferentially expressed by TrkC neurons, suggesting that proprioceptive neurons possess these channels. Nav1.7, -1.8, and -1.9 mRNAs were more abundant in C-fiber neurons compared with A-fiber ones. Nax was evenly expressed in both populations. Although Nav1.8 and -1.9 were preferentially expressed by TrkA neurons, other alpha-subunits were expressed independently of TrkA expression. Actually, all IB4(+) neurons expressed both Nav1.8 and -1.9, and relatively limited subpopulations of IB4(+) neurons (3% and 12%, respectively) expressed Nav1.1 and/or Nav1.6. These findings provide useful information in interpreting the electrophysiological characteristics of some neuronal subpopulations of naïve DRG. After L5 spinal nerve ligation, Nav1.3 mRNA was up-regulated mainly in A-fiber neurons in the ipsilateral L5 DRG. Although previous studies demonstrated that nerve growth factor (NGF) and glial cell-derived neurotrophic factor (GDNF) reversed this up-regulation, the Nav1.3 induction was independent of either TrkA or GFRalpha1 expression, suggesting that the induction of Nav1.3 may be one of the common responses of axotomized DRG neurons without a direct relationship to NGF/GDNF supply. (c) 2008 Wiley-Liss, Inc.

  17. Recombinant adeno-associated virus serotype 6 (rAAV2/6)-mediated gene transfer to nociceptive neurons through different routes of delivery

    PubMed Central

    Towne, Chris; Pertin, Marie; Beggah, Ahmed T; Aebischer, Patrick; Decosterd, Isabelle

    2009-01-01

    Background Gene transfer to nociceptive neurons of the dorsal root ganglia (DRG) is a promising approach to dissect mechanisms of pain in rodents and is a potential therapeutic strategy for the treatment of persistent pain disorders such as neuropathic pain. A number of studies have demonstrated transduction of DRG neurons using herpes simplex virus, adenovirus and more recently, adeno-associated virus (AAV). Recombinant AAV are currently the gene transfer vehicles of choice for the nervous system and have several advantages over other vectors, including stable and safe gene expression. We have explored the capacity of recombinant AAV serotype 6 (rAAV2/6) to deliver genes to DRG neurons and characterized the transduction of nociceptors through five different routes of administration in mice. Results Direct injection of rAAV2/6 expressing green fluorescent protein (eGFP) into the sciatic nerve resulted in transduction of up to 30% eGFP-positive cells of L4 DRG neurons in a dose dependant manner. More than 90% of transduced cells were small and medium sized neurons (< 700 μm2), predominantly colocalized with markers of nociceptive neurons, and had eGFP-positive central terminal fibers in the superficial lamina of the spinal cord dorsal horn. The efficiency and profile of transduction was independent of mouse genetic background. Intrathecal administration of rAAV2/6 gave the highest level of transduction (≈ 60%) and had a similar size profile and colocalization with nociceptive neurons. Intrathecal administration also transduced DRG neurons at cervical and thoracic levels and resulted in comparable levels of transduction in a mouse model for neuropathic pain. Subcutaneous and intramuscular delivery resulted in low levels of transduction in the L4 DRG. Likewise, delivery via tail vein injection resulted in relatively few eGFP-positive cells within the DRG, however, this transduction was observed at all vertebral levels and corresponded to large non-nociceptive cell

  18. Decreased voltage-gated potassium currents in rat dorsal root ganglion neurons after chronic constriction injury.

    PubMed

    Xiao, Yun; Wu, Yang; Zhao, Bo; Xia, Zhongyuan

    2016-01-20

    Voltage-gated potassium channels (KV) regulate pain transmission by controlling neuronal excitability. Changes in KV expression patterns may thus contribute toward hyperalgesia following nerve injury. The aim of this study was to characterize KV current density in dorsal root ganglion (DRG) neurons following chronic constriction injury (CCI) of the right sciatic nerve, a robust model of post-traumatic neuropathic pain. The study examined changes in small-diameter potassium ion currents (<30 µm) in neurons in the L4-L6 DRG following CCI by whole-cell patch-clamping and the association with post-CCI mechanical and thermal nociceptive thresholds. Compared with the control group, 7 days after CCI, the mechanical force and temperature required to elicit ipsilateral foot withdrawal decreased significantly, indicating tactile allodynia and thermal hyperalgesia. Post-CCI neurons had a significantly lower rheobase current and depolarized resting membrane potential than controls, suggesting KV current downregulation. Some ipsilateral DRG neurons also had spontaneous action potentials and repetitive firing. There was a 55% reduction in the total KV current density caused by a 55% decrease in the sustained delayed rectifier potassium ion current (IK) density and a 17% decrease in the transient A-type potassium ion current (IA) density. These results indicated that changes in DRG neuron IK and IA current density and concomitant afferent hyperexcitability may contribute toward neuropathic pain following injury. The rat CCI model may prove valuable for examining pathogenic mechanisms and potential therapies, such as KV channel modulators.

  19. Membrane potential oscillations are not essential for spontaneous firing generation in L4 Aβ-afferent neurons after L5-spinal nerve axotomy and are not mediated by HCN channels.

    PubMed

    Djouhri, L; Smith, T; Alotaibi, M; Weng, X

    2018-06-03

    What is the central question of this study? Is spontaneous activity (SA) in L4-DRG neurons induced by L5 spinal nerve axotomy is associated with membrane potentials oscillations in theses neurons, and are these membrane oscillations mediated by HCN channels? What is the main finding and its importance? Unlike injured L5 DRG neurons which have been shown to be incapable of firing spontaneously without membrane potentials oscillations, such membrane oscillations are not essential for SA generation in conducting "uninjured'' L4 neurons, and they are not mediated by HCN channels. These findings suggest that the underlying cellular mechanisms of SA in injured and "uninjured'' DRG neurons induced by spinal nerve injury are distinct. The underlying cellular and molecular mechanisms of peripheral neuropathic pain are not fully understood. However, preclinical studies using animal models of this debilitating condition suggest that it is driven partly by aberrant spontaneous activity (SA) in injured and uninjured dorsal root ganglion (DRG) neurons, and that SA in injured DRG neurons is triggered by subthreshold membrane potential oscillations (SMPOs). Here, using in vivo intracellular recording from control L4-DRG neurons, and ipsilateral L4-DRG neurons in female Wistar rats that had previously undergone L5-spinal nerve axotomy (SNA), we examined whether conducting 'uninjured' L4-DRG neurons in SNA rats exhibit SMPOs, and if so, whether such SMPOs are associated with SA in those L4-neurons, and whether they are mediated by hyperpolarization-activated cyclic nucleotide gated (HCN) channels. We found that 7-days after SNA: (a) none of control A- or C-fibre DRG neurons showed SMPOs or SA, but 50%, 43% and 0% of spontaneously active cutaneous L4 Aβ-low threshold mechanoreceptors, Aβ-nociceptors and C-nociceptors exhibited SMPOs respectively in SNA rats with established neuropathic pain behaviors, (b) neither SMPOs nor SA in L4 Aβ-neurons were suppressed by blocking HCN

  20. Inhibition of tetrodotoxin-resistant sodium current in dorsal root ganglia neurons mediated by D1/D5 dopamine receptors

    PubMed Central

    2013-01-01

    Background Dopaminergic fibers originating from area A11 of the hypothalamus project to different levels of the spinal cord and represent the major source of dopamine. In addition, tyrosine hydroxylase, the rate-limiting enzyme for the synthesis of catecholamines, is expressed in 8-10% of dorsal root ganglia (DRG) neurons, suggesting that dopamine may be released in the dorsal root ganglia. Dopamine has been shown to modulate calcium current in DRG neurons, but the effects of dopamine on sodium current and on the firing properties of small DRG neurons are poorly understood. Results The effects of dopamine and dopamine receptor agonists were tested on the tetrodotoxin-resistant (TTX-R) sodium current recorded from acutely dissociated small (diameter ≤ 25 μm) DRG neurons. Dopamine (20 μM) and SKF 81297 (10 μM) caused inhibition of TTX-R sodium current in small DRG neurons by 23% and 37%, respectively. In contrast, quinpirole (20 μM) had no effects on the TTX-R sodium current. Inhibition by SKF 81297 of the TTX-R sodium current was not affected when the protein kinase A (PKA) activity was blocked with the PKA inhibitory peptide (6–22), but was greatly reduced when the protein kinase C (PKC) activity was blocked with the PKC inhibitory peptide (19–36), suggesting that activation of D1/D5 dopamine receptors is linked to PKC activity. Expression of D1and D5 dopamine receptors in small DRG neurons, but not D2 dopamine receptors, was confirmed by Western blotting and immunofluorescence analysis. In current clamp experiments, the number of action potentials elicited in small DRG neurons by current injection was reduced by ~ 30% by SKF 81297. Conclusions We conclude that activation of D1/D5 dopamine receptors inhibits TTX-R sodium current in unmyelinated nociceptive neurons and dampens their intrinsic excitability by reducing the number of action potentials in response to stimulus. Increasing or decreasing levels of dopamine in the dorsal root ganglia

  1. [Hand surgery in the German DRG System 2007].

    PubMed

    Franz, D; Windolf, J; Kaufmann, M; Siebert, C H; Roeder, N

    2007-05-01

    Hand surgery often needs only a short length of stay in hospital. Patients' comorbidity is low. Many hand surgery procedures do not need inpatient structures. Up until 2006 special procedures of hand surgery could not be coded. The DRG structure did not separate very complex and less complex operations. Specialized hospitals needed a proper case allocation of their patients within the G-DRG system. The DRG structure concerning hand surgery increased in version 2007 of the G-DRG system. The main parameter of DRG splitting is the complexity of the operation. Furthermore additional criteria such as more than one significant OR procedure, the patients' age, or special diagnoses influence case allocation. A special OPS code for complex cases treated with hand surgery was implemented. The changes in the DRG structure and the implementation of the new OPS code for complex cases establish a strong basis for the identification of different patient costs. Different case allocation leads to different economic impacts on departments of hand surgery. Whether the new OPS code becomes a DRG splitting parameter has to be calculated by the German DRG Institute for further DRG versions.

  2. Ethanol Reversal of Oxycodone Tolerance in Dorsal Root Ganglia Neurons.

    PubMed

    Jacob, Joanna C; Sakakibara, Kensuke; Mischel, Ryan A; Henderson, Graeme; Dewey, William L; Akbarali, Hamid I

    2018-05-01

    Oxycodone is a semisynthetic opioid compound that is widely prescribed, used, and abused today, and has a well-established role in shaping the current opioid epidemic. Previously, we have shown that tolerance develops to the antinociceptive and respiratory depressive effects of oxycodone in mice, and that a moderate dose of acute ethanol or a protein kinase C (PKC) inhibitor reversed that tolerance. To investigate further if tolerance was occurring through neuronal mechanisms, our aims for this study were to assess the effects of acute and prolonged oxycodone in isolated dorsal root ganglia (DRG) neurons and to determine if this tolerance was reversed by either ethanol or a PKC inhibitor. We found that an acute exposure to 3 μ M oxycodone reduced neuronal excitability, as measured by increased threshold potentials and reduced action potential amplitude, without eliciting measurable changes in resting membrane potential. Exposure to 10 μ M oxycodone for 18-24 hours prevented oxycodone's effect on neuronal excitability, indicative of tolerance development. The development of opioid tolerance was mitigated in DRG neurons from β -arrestin 2 knockout mice. Oxycodone tolerance was reversed in isolated DRG neurons by the acute application of either ethanol (20 mM) or the PKC inhibitor, bisindolylmaleimide XI hydrochloride (Bis XI), when a challenge of 3 µ M oxycodone significantly reduced neuronal excitability following prolonged exposure. Through these studies, we concluded that oxycodone acutely reduced neuronal excitability, tolerance developed to this effect, and reversal of that tolerance occurred at the level of a single neuron, suggesting that reversal of oxycodone tolerance by either ethanol or Bis XI involves cellular mechanisms. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  3. Regulation of TRPV2 by axotomy in sympathetic, but not sensory neurons.

    PubMed

    Gaudet, Andrew D; Williams, Sarah J; Hwi, Lucy P-R; Ramer, Matt S

    2004-08-13

    Neuropathic pain results from traumatic or disease-related insults to the nervous system. Mechanisms that have been postulated to underlie peripheral neuropathy commonly implicate afferent neurons that have been damaged but still project centrally to the spinal cord, and/or intact neurons that interact with degenerating distal portions of the injured neurons. One pain state that is observed following peripheral nerve injury in the rat is thermal hyperalgesia. The noxious heat-gated ion channel TRPV1 may be responsible for this increased sensitivity, as it is up-regulated in L4 dorsal root ganglion (DRG) neurons following L5 spinal nerve lesion (SpNL). The TRPV1 homologue TRPV2 (or VRL-1) is another member of the TRPV subfamily of TRP ion channels. TRPV2 is a nonselective cation channel activated by high noxious temperatures (>52 degrees C) and is present in a subset of medium- to large-diameter DRG neurons. To establish whether TRPV2 is endogenous to the spinal cord, we examined its expression in the dorsal horn following rhizotomy. We found no significant decrease in TRPV2 immunoreactivity, suggesting that TRPV2 is endogenous to the spinal cord. In order to determine whether TRPV2, like TRPV1, is regulated by peripheral axotomy, we performed L5 SpNL and characterized TRPV2 distribution in the DRG, spinal cord, brainstem, and sympathetic ganglia. Our results show that peripheral axotomy did not regulate TRPV2 in the DRG, spinal cord, or brainstem; however, TRPV2 was up-regulated in sympathetic postganglionic neurons following injury, suggesting a potential role for TRPV2 in sympathetically mediated neuropathic pain.

  4. Redox modulation of A-type K+ currents in pain-sensing dorsal root ganglion neurons.

    PubMed

    Hsieh, Chi-Pan

    2008-06-06

    Redox modulation of fast inactivation has been described in certain cloned A-type voltage-gated K(+) (Kv) channels in expressing systems, but the effects remain to be demonstrated in native neurons. In this study, we examined the effects of cysteine-specific redox agents on the A-type K(+) currents in acutely dissociated small diameter dorsal root ganglion (DRG) neurons from rats. The fast inactivation of most A-type currents was markedly removed or slowed by the oxidizing agents 2,2'-dithio-bis(5-nitropyridine) (DTBNP) and chloramine-T. Dithiothreitol, a reducing agent for the disulfide bond, restored the inactivation. These results demonstrated that native A-type K(+) channels, probably Kv1.4, could switch the roles between inactivating and non-inactivating K(+) channels via redox regulation in pain-sensing DRG neurons. The A-type channels may play a role in adjusting pain sensitivity in response to peripheral redox conditions.

  5. Nociceptive neuronal Fc-gamma receptor I is involved in IgG immune complex induced pain in the rat.

    PubMed

    Jiang, Haowu; Shen, Xinhua; Chen, Zhiyong; Liu, Fan; Wang, Tao; Xie, Yikuan; Ma, Chao

    2017-05-01

    Antigen-specific immune diseases such as rheumatoid arthritis are often accompanied by pain and hyperalgesia. Our previous studies have demonstrated that Fc-gamma-receptor type I (FcγRI) is expressed in a subpopulation of rat dorsal root ganglion (DRG) neurons and can be directly activated by IgG immune complex (IgG-IC). In this study we investigated whether neuronal FcγRI contributes to antigen-specific pain in the naïve and rheumatoid arthritis model rats. In vitro calcium imaging and whole-cell patch clamp recordings in dissociated DRG neurons revealed that only the small-, but not medium- or large-sized DRG neurons responded to IgG-IC. Accordingly, in vivo electrophysiological recordings showed that intradermal injection of IgG-IC into the peripheral receptive field could sensitize only the C- (but not A-) type sensory neurons and evoke action potential discharges. Pain-related behavioral tests showed that intradermal injection of IgG-IC dose-dependently produced mechanical and thermal hyperalgesia in the hindpaw of rats. These behavioral effects could be alleviated by localized administration of non-specific IgG or an FcγRI antibody, but not by mast cell stabilizer or histamine antagonist. In a rat model of antigen-induced arthritis (AIA) produced by methylated bovine serum albumin, FcγRI were found upregulated exclusively in the small-sized DRG neurons. In vitro calcium imaging revealed that significantly more small-sized DRG neurons responded to IgG-IC in the AIA rats, although there was no significant difference between the AIA and control rats in the magnitude of calcium changes in the DRG neurons. Moreover, in vivo electrophysiological recordings showed that C-nociceptive neurons in the AIA rats exhibited a greater incidence of action potential discharges and stronger responses to mechanical stimuli after IgG-IC was injected to the receptive fields. These results suggest that FcγRI expressed in the peripheral nociceptors might be directly activated

  6. PKCepsilon-dependent potentiation of TTX-resistant Nav1.8 current by neurokinin-1 receptor activation in rat dorsal root ganglion neurons.

    PubMed

    Cang, Chun-Lei; Zhang, Hua; Zhang, Yu-Qiu; Zhao, Zhi-Qi

    2009-06-30

    Substance P (SP), which mainly exists in a subtype of small-diameter dorsal root ganglion (DRG) neurons, is an important signal molecule in pain processing in the spinal cord. Our previous results have proved the expression of SP receptor neurokinin-1 (NK-1) on DRG neurons and its interaction with transient receptor potential vanilloid 1 (TRPV1) receptor. In this study we investigated the effect of NK-1 receptor agonist on Na(v)1.8, a tetrodotoxin (TTX)-resistant sodium channel, in rat small-diameter DRG neurons employing whole-cell patch clamp recordings. NK-1 agonist [Sar(9), Met(O2)(11)]-substance P (Sar-SP) significantly enhanced the Na(v)1.8 currents in a subgroup of small-diameter DRG neurons under both the normal and inflammatory situation, and the enhancement was blocked by NK-1 antagonist Win51708 and protein kinase C (PKC) inhibitor bisindolylmaleimide (BIM), but not the protein kinase A (PKA) inhibitor H89. In particular, the inhibitor of PKCepsilon, a PKC isoform, completely blocked this effect. Under current clamp model, Sar-SP reduced the amount of current required to evoke action potentials and increased the firing rate in a subgroup of DRG neurons. These data suggest that activation of NK-1 receptor potentiates Na(v)1.8 sodium current via PKCepsilon-dependent signaling pathway, probably participating in the generation of inflammatory hyperalgesia.

  7. Merkel Cell-Driven BDNF Signaling Specifies SAI Neuron Molecular and Electrophysiological Phenotypes.

    PubMed

    Reed-Geaghan, Erin G; Wright, Margaret C; See, Lauren A; Adelman, Peter C; Lee, Kuan Hsien; Koerber, H Richard; Maricich, Stephen M

    2016-04-13

    The extent to which the skin instructs peripheral somatosensory neuron maturation is unknown. We studied this question in Merkel cell-neurite complexes, where slowly adapting type I (SAI) neurons innervate skin-derived Merkel cells. Transgenic mice lacking Merkel cells had normal dorsal root ganglion (DRG) neuron numbers, but fewer DRG neurons expressed the SAI markers TrkB, TrkC, and Ret. Merkel cell ablation also decreased downstream TrkB signaling in DRGs, and altered the expression of genes associated with SAI development and function. Skin- and Merkel cell-specific deletion of Bdnf during embryogenesis, but not postnatal Bdnf deletion or Ntf3 deletion, reproduced these results. Furthermore, prototypical SAI electrophysiological signatures were absent from skin regions where Bdnf was deleted in embryonic Merkel cells. We conclude that BDNF produced by Merkel cells during a precise embryonic period guides SAI neuron development, providing the first direct evidence that the skin instructs sensory neuron molecular and functional maturation. Peripheral sensory neurons show incredible phenotypic and functional diversity that is initiated early by cell-autonomous and local environmental factors found within the DRG. However, the contribution of target tissues to subsequent sensory neuron development remains unknown. We show that Merkel cells are required for the molecular and functional maturation of the SAI neurons that innervate them. We also show that this process is controlled by BDNF signaling. These findings provide new insights into the regulation of somatosensory neuron development and reveal a novel way in which Merkel cells participate in mechanosensation. Copyright © 2016 the authors 0270-6474/16/364362-15$15.00/0.

  8. An immunohistochemical study of neuropeptides and neuronal cytoskeletal proteins in the neuroepithelial component of a spontaneous murine ovarian teratoma. Primitive neuroepithelium displays immunoreactivity for neuropeptides and neuron-associated beta-tubulin isotype.

    PubMed Central

    Caccamo, D. V.; Herman, M. M.; Frankfurter, A.; Katsetos, C. D.; Collins, V. P.; Rubinstein, L. J.

    1989-01-01

    Approximately one third of the female mice of the LTXBO strain develop spontaneous ovarian teratomas. These tumors contain a large neuroepithelial component, which includes primitive neural structures resembling embryonic neural tubes (medulloepithelial rosettes), ependymoblastic and ependymal rosettes, neuroblasts, mature ganglionic neurons, myelinated neurites, and astrocytes. The purpose of this study was to characterize these tumors according to the immunohistochemical location of some well-characterized trophic and regulatory neuropeptides and neurotransmitters, several neuronal-associated cytoskeletal proteins, and other proteins indicative of neuronal and glial differentiation. Medulloepithelial rosettes showed focal serotonin-like, opioid peptide-like and gamma-amino butyric acid-like immunoreactivity, and displayed immunostaining for the neuron-associated class III beta-tubulin isotype. The mature ganglion cells were also immunoreactive for these markers, and, in addition, for somatostatin, cholecystokinin, bombesin, glucagon, vasoactive intestinal peptide, and neuropeptide Y. Mature ganglion cells were also immunoreactive for proteins associated with the neuronal cytoskeleton (including microtubule-associated proteins, MAP2 and tau, and higher molecular weight phosphorylated and non-phosphorylated neurofilament subunits), neuron-specific enolase, and synaptophysin. Undifferentiated stem cells, ependymoblastic and ependymal rosettes, and astroglia all stained with a monoclonal antibody that recognizes all mammalian beta-tubulin isotypes, but did not react with antibodies to neuronal-associated cytoskeletal proteins or neuropeptides. Neuropeptide-like immunoreactivity and demonstration of the class III beta-tubulin isotype indicate early neuronal commitment in neoplastic primitive neuroepithelium. These patterns of immunoreactivity closely follow those encountered in the normal neurocytogenesis of the mammalian and avian forebrain, and increase the

  9. DRG Voltage-Gated Sodium Channel 1.7 Is Upregulated in Paclitaxel-Induced Neuropathy in Rats and in Humans with Neuropathic Pain.

    PubMed

    Li, Yan; North, Robert Y; Rhines, Laurence D; Tatsui, Claudio Esteves; Rao, Ganesh; Edwards, Denaya D; Cassidy, Ryan M; Harrison, Daniel S; Johansson, Caj A; Zhang, Hongmei; Dougherty, Patrick M

    2018-01-31

    Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect experienced by cancer patients receiving treatment with paclitaxel. The voltage-gated sodium channel 1.7 (Na v 1.7) plays an important role in multiple preclinical models of neuropathic pain and in inherited human pain phenotypes, and its gene expression is increased in dorsal root ganglia (DRGs) of paclitaxel-treated rats. Hence, the potential of change in the expression and function of Na v 1.7 protein in DRGs from male rats with paclitaxel-related CIPN and from male and female humans with cancer-related neuropathic pain was tested here. Double immunofluorescence in CIPN rats showed that Na v 1.7 was upregulated in small DRG neuron somata, especially those also expressing calcitonin gene-related peptide (CGRP), and in central processes of these cells in the superficial spinal dorsal horn. Whole-cell patch-clamp recordings in rat DRG neurons revealed that paclitaxel induced an enhancement of ProTx II (a selective Na v 1.7 channel blocker)-sensitive sodium currents. Bath-applied ProTx II suppressed spontaneous action potentials in DRG neurons occurring in rats with CIPN, while intrathecal injection of ProTx II significantly attenuated behavioral signs of CIPN. Complementarily, DRG neurons isolated from segments where patients had a history of neuropathic pain also showed electrophysiological and immunofluorescence results indicating an increased expression of Na v 1.7 associated with spontaneous activity. Na v 1.7 was also colocalized in human cells expressing transient receptor potential vanilloid 1 and CGRP. Furthermore, ProTx II decreased firing frequency in human DRGs with spontaneous action potentials. This study suggests that Na v 1.7 may provide a potential new target for the treatment of neuropathic pain, including chemotherapy (paclitaxel)-induced neuropathic pain. SIGNIFICANCE STATEMENT This work demonstrates that the expression and function of the voltage-gated sodium channel Na

  10. Distinct cellular distributions of Kv4 pore-forming and auxiliary subunits in rat dorsal root ganglion neurons.

    PubMed

    Matsuyoshi, Hiroko; Takimoto, Koichi; Yunoki, Takakazu; Erickson, Vickie L; Tyagi, Pradeep; Hirao, Yoshihiko; Wanaka, Akio; Yoshimura, Naoki

    2012-09-17

    Dorsal root ganglia contain heterogeneous populations of primary afferent neurons that transmit various sensory stimuli. This functional diversity may be correlated with differential expression of voltage-gated K(+) (Kv) channels. Here, we examine cellular distributions of Kv4 pore-forming and ancillary subunits that are responsible for fast-inactivating A-type K(+) current. Expression pattern of Kv α-subunit, β-subunit and auxiliary subunit was investigated using immunohistochemistry, in situ hybridization and RT-PCR technique. The two pore-forming subunits Kv4.1 and Kv4.3 show distinct cellular distributions: Kv4.3 is predominantly in small-sized C-fiber neurons, whereas Kv4.1 is seen in DRG neurons in various sizes. Furthermore, the two classes of Kv4 channel auxiliary subunits are also distributed in different-sized cells. KChIP3 is the only significantly expressed Ca(2+)-binding cytosolic ancillary subunit in DRGs and present in medium to large-sized neurons. The membrane-spanning auxiliary subunit DPP6 is seen in a large number of DRG neurons in various sizes, whereas DPP10 is restricted in small-sized neurons. Distinct combinations of Kv4 pore-forming and auxiliary subunits may constitute A-type channels in DRG neurons with different physiological roles. Kv4.1 subunit, in combination with KChIP3 and/or DPP6, form A-type K(+) channels in medium to large-sized A-fiber DRG neurons. In contrast, Kv4.3 and DPP10 may contribute to A-type K(+) current in non-peptidergic, C-fiber somatic afferent neurons. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Demethylation regulation of BDNF gene expression in dorsal root ganglion neurons is implicated in opioid-induced pain hypersensitivity in rats.

    PubMed

    Chao, Yu-Chieh; Xie, Fang; Li, Xueyang; Guo, Ruijuan; Yang, Ning; Zhang, Chen; Shi, Rong; Guan, Yun; Yue, Yun; Wang, Yun

    2016-07-01

    Repeated administration of morphine may result in opioid-induced hypersensitivity (OIH), which involves altered expression of numerous genes, including brain-derived neurotrophic factor (BDNF) in dorsal root ganglion (DRG) neurons. Yet, it remains unclear how BDNF expression is increased in DRG neurons after repeated morphine treatment. DNA methylation is an important mechanism of epigenetic control of gene expression. In the current study, we hypothesized that the demethylation regulation of certain BDNF gene promoters in DRG neurons may contribute to the development of OIH. Real-time RT-PCR was used to assess changes in the mRNA transcription levels of major BDNF exons including exon I, II, IV, VI, as well as total BDNF mRNA in DRGs from rats after repeated morphine administration. The levels of exon IV and total BDNF mRNA were significantly upregulated by repeated morphine administration, as compared to that in saline control group. Further, ELISA array and immunocytochemistry study revealed a robust upregulation of BDNF protein expression in DRG neurons after repeated morphine exposure. Correspondingly, the methylation levels of BDNF exon IV promoter showed a significant downregulation by morphine treatment. Importantly, intrathecal administration of a BDNF antibody, but not control IgG, significantly inhibited mechanical hypersensitivity that developed in rats after repeated morphine treatment. Conversely, intrathecal administration of an inhibitor of DNA methylation, 5-aza-2'-deoxycytidine (5-aza-dC) markedly upregulated the BDNF protein expression in DRG neurons and enhanced the mechanical allodynia after repeated morphine exposure. Together, our findings suggest that demethylation regulation of BDNF gene promoter may be implicated in the development of OIH through epigenetic control of BDNF expression in DRG neurons. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. PGE2 released by primary sensory neurons modulates Toll-like receptor 4 activities through an EP4 receptor-dependent process.

    PubMed

    Tse, Kai-Hei; Chow, Kevin B S; Wise, Helen

    2016-04-15

    Exogenous prostaglandin E2 (PGE2) displays mixed regulatory properties with regard to inflammatory gene expression in dorsal root ganglion (DRG) cells. We show here that endogenously-produced nanomolar concentrations of PGE2, such as that generated in response to Toll-like receptor 4 (TLR4) stimulation, inhibits both cyclooxygenase-2 (COX-2) and tumour necrosis factor alpha (TNFα) mRNA expression in DRG cells in an EP4 receptor-dependent manner. DRG neurons appear to be the major source of PGE2 in the DRG and likely serve as both an autocrine and paracrine system for limiting over-activation of both DRG neurons and glial cells in response to TLR4 stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Insulin-like growth factor-1 prevents dorsal root ganglion neuronal tyrosine kinase receptor expression alterations induced by dideoxycytidine in vitro.

    PubMed

    Liu, Huaxiang; Lu, Jing; He, Yong; Yuan, Bin; Li, Yizhao; Li, Xingfu

    2014-03-01

    Dideoxycytidine (zalcitabine, ddC) produces neurotoxic effects. It is particularly important to understand the toxic effects of ddC on different subpopulations of dorsal root ganglion (DRG) neurons which express distinct tyrosine kinase receptor (Trk) and to find therapeutic factors for prevention and therapy for ddC-induced peripheral sensory neuropathy. Insulin-like growth factor-1 (IGF-1) has been shown to have neurotrophic effects on DRG sensory neurons. However, little is known about the effects of ddC on distinct Trk (TrkA, TrkB, and TrkC) expression in DRG neurons and the neuroprotective effects of IGF-1 on ddC-induced neurotoxicity. Here, we have tested the extent to which the expression of TrkA, TrkB, and TrkC receptors in primary cultured DRG neurons is affected by ddC in the presence or absence of IGF-1. In this experiment, we found that exposure of 5, 25, and 50 μmol/L ddC caused a dose-dependent decrease of the mRNA, protein, and the proportion of TrkA-, TrkB-, and TrkC-expressing neurons. IGF-1 (20 nmol/L) could partially reverse the decrease of TrkA and TrkB, but not TrkC, expression with ddC exposure. The phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 (10 μmol/L) blocked the effects of IGF-1. These results suggested that the subpopulations of DRG neurons which express distinct TrkA, TrkB, and TrkC receptors were affected by ddC exposure. IGF-1 might relieve the ddC-induced toxicity of TrkA- and TrkB-, but not TrkC-expressing DRG neurons. These data offer new clues for a better understanding of the association of ddC with distinct Trk receptor expression and provide new evidence of the potential therapeutic role of IGF-1 on ddC-induced neurotoxicity.

  14. Effects of 4-phenyl butyric acid on high glucose-induced alterations in dorsal root ganglion neurons.

    PubMed

    Sharma, Dilip; Singh, Jitendra Narain; Sharma, Shyam S

    2016-12-02

    Mechanisms and pathways involving in diabetic neuropathy are still not fully understood but can be unified by the process of overproduction of reactive oxygen species (ROS) such as superoxide, endoplasmic reticulum (ER) stress, downstream intracellular signaling pathways and their modulation. Susceptibility of dorsal root ganglion (DRG) to internal/external hyperglycemic environment stress contributes to the pathogenesis and progression of diabetic neuropathy. ER stress leads to abnormal ion channel function, gene expression, transcriptional regulation, metabolism and protein folding. 4-phenyl butyric acid (4-PBA) is a potent and selective chemical chaperone; which may inhibit ER stress. It may be hypothesized that 4-PBA could attenuate via channels in DRG in diabetic neuropathy. Effects of 4-PBA were determined by applying different parameters of oxidative stress, cell viability, apoptosis assays and channel expression in cultured DRG neurons. Hyperglycemia-induced apoptosis in the DRG neuron was inhibited by 4-PBA. Cell viability of DRG neurons was not altered by 4-PBA. Oxidative stress was significantly blocked by the 4-PBA. Sodium channel expression was not altered by the 4-PBA. Our data provide evidence that the hyperglycemia-induced alteration may be reduced by the 4-PBA without altering the sodium channel expression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Modulating nitric oxide levels in dorsal root ganglion neurons of rat with low-level laser therapy

    NASA Astrophysics Data System (ADS)

    Zheng, Li-qin; Wang, Yu-hua; He, Yi-peng; Zhou, Jie; Yang, Hong-qin; Zhang, Yan-ding; Xie, Shu-sen

    2015-05-01

    Nitric oxide (NO) and nitric oxide synthase (NOS) have an important role in pain signaling transmission in animal models. Low-level laser therapy (LLLT) is known to have an analgesic effect, but the mechanism is unclear. The aim of the study is to investigate the influence of LLLT on NO release and NOS synthesis in dorsal root ganglion (DRG) neurons, in order to find whether LLLI can ameliorate pain through modulating NO production at the cellular level. The results show that in stress conditions, the laser irradiation at 658 nm can modulate NO production in DRG neurons with soma diameter of about 20 μm in a short time after illumination, and affect NOS synthesis in a dose-dependent manner. It is demonstrated that LLLT might treat pain by altering NO release directly and indirectly in DRG neurons.

  16. [The possible drawbacks of applying the DRG classification].

    PubMed

    Huber, Zofia Swinarski

    2006-09-06

    The objective of this article is to present the difficulties linked to the measure and use of the Diagnosis Related Group (DRG) as part of a hospital's production and management accounting evaluation system. We will present here all the criticisms brought forth in management literature against DRG classifications. The article isn't intended to argue against and to push people to reconsider the tool but rather to attract the attention of politicians and hospital managers to all the possible difficulties and outcomes that could be generated by the DRG, this in terms of either the AP-DRG or the German-DRG, the latter being the classification that has been adopted in Switzerland as the basis for the construction of the future Swiss-DRG.

  17. Wogonin prevents rat dorsal root ganglion neurons death via inhibiting tunicamycin-induced ER stress in vitro.

    PubMed

    Xu, Shujuan; Zhao, Xin; Zhao, Quanlai; Zheng, Quan; Fang, Zhen; Yang, Xiaoming; Wang, Hong; Liu, Ping; Xu, Hongguang

    2015-04-01

    Wogonin is a natural flavonoid isolated from the root of Scutellaria baicalensis Georgi, which has been widely used in various research areas for its anti-oxidant, anti-inflammatory, and anti-cancer activities. It also presents a neuroprotective effect in the brain while encounters stress conditions, but the mechanisms controlling the neuroprotective effect of wogonin are not clear. In this study, we investigated the biomechanism underlying the neuroprotective effect of wogonin on rat dorsal root ganglion (DRG) neurons. Wogonin pre-treatment at 75 μM significantly increased the cell viability of DRG neurons and decreased the number of the propidium iodide-positive DRG neurons before the endoplasmic reticulum (ER) stress is being induced by tunicamycin (TUN) (0.75 μg/mL). In addition, Wogonin also inhibited the release of LDH and up-regulated the level of GSH. Furthermore, wogonin decreased the activation of ER stress-related molecules, including glucose-regulated protein 78 (GRP78), GRP94, C/EBP-homologous protein, active caspase12 and active caspase3, phosphorylation of pancreatic ER stress kinase, and eukaryotic initiation factor 2 alpha (eIF2α). In summary, our results indicated that wogonin could protect DRG neurons against TUN-induced ER stress.

  18. Increased neuronal beta-amyloid precursor protein expression in human temporal lobe epilepsy: association with interleukin-1 alpha immunoreactivity.

    PubMed

    Sheng, J G; Boop, F A; Mrak, R E; Griffin, W S

    1994-11-01

    Levels of immunoreactive beta-amyloid precursor protein and interleukin-1 alpha were found to be elevated in surgically resected human temporal lobe tissue from patients with intractable epilepsy compared with postmortem tissue from neurologically unaffected patients (controls). In tissue from epileptics, the levels of the 135-kDa beta-amyloid precursor protein isoform were elevated to fourfold (p < 0.05) those of controls and those of the 130-kDa isoform to threefold (p < 0.05), whereas those of the 120-kDa isoform (p > 0.05) were not different from control values. beta-Amyloid precursor protein-immunoreactive neurons were 16 times more numerous, and their cytoplasm and proximal processes were more intensely immunoreactive in tissue sections from epileptics than controls (133 +/- 12 vs. 8 +/- 3/mm2; p < 0.001). However, neither beta-amyloid precursor protein-immunoreactive dystrophic neurites nor beta-amyloid deposits were found in this tissue. Interleukin-1 alpha-immunoreactive cells (microglia) were three times more numerous in epileptics than in controls (80 +/- 8 vs. 25 +/- 5/mm2; p < 0.001), and these cells were often found adjacent to beta-amyloid precursor protein-immunoreactive neuronal cell bodies. Our findings, together with functions established in vitro for interleukin-1, suggest that increased expression of this protein contributes to the increased levels of beta-amyloid precursor protein in epileptics, thus indicating a potential role for both of these proteins in the neuronal dysfunctions, e.g., hyperexcitability, characteristic of epilepsy.

  19. DRG migration: A novel measure of inefficient surgical care in a value-based world.

    PubMed

    Hughes, Byron D; Mehta, Hemalkumar B; Sieloff, Eric; Shan, Yong; Senagore, Anthony J

    2018-03-01

    Diagnosis-Related Group (DRG) migration, DRG 331 to 330, is defined by the assignment to a higher cost DRG due only to post admission comorbidity or complications (CC). We assessed the 5% national Medicare data set (2011-2014) for colectomy (DRG's 331/330), excluding present on admission CC's and selecting patients with one or more CC's post-admission to define the impact on payments, cost, and length of stay (LOS). The incidence of DRG migration was 14.2%. This was associated with statistically significant increases in payments, hospital cost, and LOS compared to DRG 331 patients. When DRG migration rate was extrapolated to the entire at risk population, the results were an increase of Centers for Medicare and Medicaid Services (CMS) cost by $98 million, hospital cost by $418 million, and excess hospital days equaling 68,669 days. These negative outcomes represent potentially unnecessary variations in the processes of care, and therefore a unique economic concept defining inefficient surgical care. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. [Medical records, DRG and intensive care patients].

    PubMed

    Aardal, Sidsel; Berge, Kjersti; Breivik, Kjell; Flaatten, Hans K

    2005-04-07

    In order to control the quality of the medical report after a hospital stay with regards to the stay in the intensive care unit (ICU), and to cheque for correct DRG grouping, this study of 428 patients treated in our ICU in 2003 was conducted. All ICU patients from 2003 were found in our database, which includes specific ICD-10 diagnosis and specific ICU procedures. The medical record summarising the hospital stay (epicrisis) was retrieved for each patient from the hospital's electronic patient files and controlled for correct information regarding the ICU stay. DRG groups for each patient were retrieved from the hospital's administrative database. All stays were re-coded, with all information about the ICU stay was also included. The new DRG codes were compared with the old ones, and the difference in DRG points computed. The description of the stay in the ICU was missing or very insufficient in 46% of the records. In the DRG control we found that an additional 347.37 DRG points (18.4% of the original sum of all DRG points) were missing, corresponding to a loss to the hospital of 6.2 million NOK. In addition we discovered missing codes for tracheostomy corresponding to 2.8 million NOK, giving a total loss of 9 million NOK. This study confirms that an adequate description of the stay in the ICU is insufficient in a large number of medical records. This also leads to incorrect DRG grouping of many patients and significant financial losses to the hospital.

  1. Stimulation of neuronal neurite outgrowth using functionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Matsumoto, K.; Sato, C.; Naka, Y.; Whitby, R.; Shimizu, N.

    2010-03-01

    Low concentrations (0.11-1.7 µg ml - 1) of functionalized carbon nanotubes (CNTs), which are multi-walled CNTs modified by amino groups, when added with nerve growth factor (NGF), promoted outgrowth of neuronal neurites in dorsal root ganglion (DRG) neurons and rat pheochromocytoma cell line PC12h cells in culture media. The quantity of active extracellular signal-regulated kinase (ERK) was higher after the addition of both 0.85 µg ml - 1 CNTs and NGF than that with NGF alone. CNTs increased the number of cells with neurite outgrowth in DRG neurons and PC12h cells after the inhibition of the ERK signaling pathway using a mitogen-activated protein kinase (MAPK)/ERK kinase (MEK) inhibitor. Active ERK proteins were detected in MEK inhibitor-treated neurons after the addition of CNTs to the culture medium. These results demonstrate that CNTs may stimulate neurite outgrowth by activation of the ERK signaling pathway. Thus, CNTs are biocompatible and are promising candidates for biological applications and devices.

  2. [Adjustment of the German DRG system in 2009].

    PubMed

    Wenke, A; Franz, D; Pühse, G; Volkmer, B; Roeder, N

    2009-07-01

    The 2009 version of the German DRG system brought significant changes for urology concerning coding of diagnoses, medical procedures and the DRG structure. In view of the political situation and considerable economic pressure, a critical analysis of the 2009 German DRG system is warranted. Analysis of relevant diagnoses, medical procedures and G-DRGs in the versions 2008 and 2009 based on the publications of the German DRG-institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). The relevant diagnoses, medical procedures and German DRGs in the versions 2008 and 2009 were analysed based on the publications of the German DRG Institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). Changes for 2009 focus on the development of the DRG structure, DRG validation and codes for medical procedures to be used for very complex cases. The outcome of these changes for German hospitals may vary depending in the range of activities. The German DRG system again gained complexity. High demands are made on correct and complete coding of complex urology cases. The quality of case allocation in the German DRG system was improved. On the one hand some of the old problems (e.g. enterostomata) still persist, while on the other hand new problems evolved out of the attempt to improve the case allocation of highly complex and expensive cases. Time will tell whether the increase in highly specialized DRG with low case numbers will continue to endure and reach acceptable rates of annual fluctuations.

  3. Reactive species modify NaV1.8 channels and affect action potentials in murine dorsal root ganglia neurons

    PubMed Central

    Schink, Martin; Leipolcf, Enrico; Schirmeyer, Jana; Schönherr, Roland; Hoshi, Toshinori; Heinemann, Stefan H.

    2016-01-01

    Dorsal root ganglia (DRG) neurons are important relay stations between the periphery and the central nervous system and are essential for somatosensory signaling. Reactive species are produced in a variety of physiological and pathophysiological conditions and are known to alter electric signaling. Here we studied the influence of reactive species on the electrical properties of DRG neurons from mice with the whole-cell patch-clamp method. Even mild stress induced by either low concentrations of chloramine-T (10 µM) or low-intensity blue-light irradiation profoundly diminished action potential frequency but prolonged single action potentials in wild-type neurons. The impact on evoked action potentials was much smaller in neurons deficient of the tetrodotoxin (TTX)-resistant voltage-gated sodium channel NaV1.8 (NaV1.8−/−), the channel most important for the action potential upstroke in DRG neurons. Low concentrations of chloramine-T caused a significant reduction of NaV1.8 peak current and at higher concentrations progressively slowed down inactivation. Blue light had a smaller effect on amplitude but slowed down NaV1.8 channel inactivation. The observed effects were less apparent for TTX-sensitive NaV channels. NaV1.8 is an important reactive-species-sensitive component in the electrical signaling of DRG neurons, potentially giving rise to loss-of-function and gain-of-function phenomena depending on the type of reactive species and their effective concentration and time of exposure. PMID:26383867

  4. Reactive species modify NaV1.8 channels and affect action potentials in murine dorsal root ganglion neurons.

    PubMed

    Schink, Martin; Leipold, Enrico; Schirmeyer, Jana; Schönherr, Roland; Hoshi, Toshinori; Heinemann, Stefan H

    2016-01-01

    Dorsal root ganglion (DRG) neurons are important relay stations between the periphery and the central nervous system and are essential for somatosensory signaling. Reactive species are produced in a variety of physiological and pathophysiological conditions and are known to alter electric signaling. Here we studied the influence of reactive species on the electrical properties of DRG neurons from mice with the whole-cell patch-clamp method. Even mild stress induced by either low concentrations of chloramine-T (10 μM) or low-intensity blue light irradiation profoundly diminished action potential frequency but prolonged single action potentials in wild-type neurons. The impact on evoked action potentials was much smaller in neurons deficient of the tetrodotoxin (TTX)-resistant voltage-gated sodium channel NaV1.8 (NaV1.8(-/-)), the channel most important for the action potential upstroke in DRG neurons. Low concentrations of chloramine-T caused a significant reduction of NaV1.8 peak current and, at higher concentrations, progressively slowed down inactivation. Blue light had a smaller effect on amplitude but slowed down NaV1.8 channel inactivation. The observed effects were less apparent for TTX-sensitive NaV channels. NaV1.8 is an important reactive-species-sensitive component in the electrical signaling of DRG neurons, potentially giving rise to loss-of-function and gain-of-function phenomena depending on the type of reactive species and their effective concentration and time of exposure.

  5. The N-methyl-D-aspartate-evoked cytoplasmic calcium increase in adult rat dorsal root ganglion neuronal somata was potentiated by substance P pretreatment in a protein kinase C-dependent manner.

    PubMed

    Castillo, C; Norcini, M; Baquero-Buitrago, J; Levacic, D; Medina, R; Montoya-Gacharna, J V; Blanck, T J J; Dubois, M; Recio-Pinto, E

    2011-03-17

    The involvement of substance P (SP) in neuronal sensitization through the activation of the neurokinin-1-receptor (NK1r) in postsynaptic dorsal horn neurons has been well established. In contrast, the role of SP and NK1r in primary sensory dorsal root ganglion (DRG) neurons, in particular in the soma, is not well understood. In this study, we evaluated whether SP modulated the NMDA-evoked transient increase in cytoplasmic Ca2+ ([Ca2+]cyt) in the soma of dissociated adult DRG neurons. Cultures were treated with nerve growth factor (NGF), prostaglandin E2 (PGE2) or both NGF+PGE2. Treatment with NGF+PGE2 increased the percentage of N-methyl-D-aspartate (NMDA) responsive neurons. There was no correlation between the percentage of NMDA responsive neurons and the level of expression of the NR1 and NR2B subunits of the NMDA receptor or of the NK1r. Pretreatment with SP did not alter the percentage of NMDA responsive neurons; while it potentiated the NMDA-evoked [Ca2+]cyt transient by increasing its magnitude and by prolonging the period during which small- and some medium-sized neurons remained NMDA responsive. The SP-mediated potentiation was blocked by the SP-antagonist ([D-Pro4, D-Trp7,9]-SP (4-11)) and by the protein kinase C (PKC) blocker bisindolylmaleimide I (BIM); and correlated with the phosphorylation of PKCε. The Nk1r agonist [Sar9, Met(O2)11]-SP (SarMet-SP) also potentiated the NMDA-evoked [Ca2+]cyt transient. Exposure to SP or SarMet-SP produced a rapid increase in the labeling of phosphorylated-PKCε. In none of the conditions we detected phosphorylation of the NR2B subunit at Ser-1303. Phosphorylation of the NR2B subunit at Tyr1472 was enhanced to a similar extent in cells exposed to NMDA, SP or NMDA+SP, and that enhancement was blocked by BIM. Our findings suggest that NGF and PGE2 may contribute to the injury-evoked sensitization of DRG neurons in part by enhancing their NMDA-evoked [Ca2+]cyt transient in all sized DRG neurons; and that SP may further

  6. [Quality assessment of dermatology in the G-DRG system 2004].

    PubMed

    Fürstenberg, T; Hensen, P; Rompel, R; Roeder, N

    2004-11-01

    Since January 2004, all German hospitals have been obliged to operate with a new hospital funding system based on DRGs. For the DRG system to serve as a fair basis for reimbursement requires that the dermatologic services be adequately covered in the classification system. The German Dermatologic Society (DDG) in cooperation with the DRG-Research Group of the University Hospital Muenster carried out a DRG evaluation study. Based on these results, suggestions for the adjustment of the G-DRG system were proposed by the DDG in the G-DRG adaptation round for 2004. Based on data of the DRG evaluation project (14,555 dermatological cases from 19 hospitals) the homogeneity in the G-DRG system 2004 was examined and compared with the quality of depiction in the G-DRG version 1.0. The correlation between expenditure and case mix index in the hospitals improved in the G-DRG system 2004. Most proposals submitted by the German Dermatologic Society for the adaptation into the G-DRG system 2004 were accepted. Some fundamental problems such as reimbursement of high cost drugs and special services, as well as the reimbursement of high and low outliers, were only marginally addressed. The G-DRG system 2004 will need to be continuously adapted in the field of dermatology. Based on this work, the German Dermatologic Society has made suggestions to be adapted in the G-DRG system 2005 and submitted them to the German DRG Institute.

  7. The neurotrophins act synergistically with LIF and members of the TGF-beta superfamily to promote the survival of spiral ganglia neurons in vitro.

    PubMed

    Marzella, P L; Gillespie, L N; Clark, G M; Bartlett, P F; Kilpatrick, T J

    1999-12-01

    A number of growth factor families have been implicated in normal inner ear development, auditory neuron survival and protection. Several growth factors, including transforming growth factor-beta5 (TGF-beta5) and TGF-beta3, neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF) and leukemia inhibitory factor (LIF) were tested for their ability, individually or in combination, to promote auditory neuron survival in dissociated cell cultures of early rat post-natal spiral ganglion cells (SGCs). The results indicate that at discrete concentrations all growth factors act in an additive fashion and some in synergy when promoting neuronal survival. These findings support the hypothesis that growth factors from different families may be interdependent when sustaining neuronal integrity.

  8. Control of somatic membrane potential in nociceptive neurons and its implications for peripheral nociceptive transmission

    PubMed Central

    Du, Xiaona; Hao, Han; Gigout, Sylvain; Huang, Dongyang; Yang, Yuehui; Li, Li; Wang, Caixue; Sundt, Danielle; Jaffe, David B.; Zhang, Hailin; Gamper, Nikita

    2014-01-01

    Peripheral sensory ganglia contain somata of afferent fibres conveying somatosensory inputs to the central nervous system. Growing evidence suggests that the somatic/perisomatic region of sensory neurons can influence peripheral sensory transmission. Control of resting membrane potential (Erest) is an important mechanism regulating excitability, but surprisingly little is known about how Erest is regulated in sensory neuron somata or how changes in somatic/perisomatic Erest affect peripheral sensory transmission. We first evaluated the influence of several major ion channels on Erest in cultured small-diameter, mostly capsaicin-sensitive (presumed nociceptive) dorsal root ganglion (DRG) neurons. The strongest and most prevalent effect on Erest was achieved by modulating M channels, K2P and 4-aminopiridine-sensitive KV channels, while hyperpolarization-activated cyclic nucleotide-gated, voltage-gated Na+, and T-type Ca2+ channels to a lesser extent also contributed to Erest. Second, we investigated how varying somatic/perisomatic membrane potential, by manipulating ion channels of sensory neurons within the DRG, affected peripheral nociceptive transmission in vivo. Acute focal application of M or KATP channel enhancers or a hyperpolarization-activated cyclic nucleotide-gated channel blocker to L5 DRG in vivo significantly alleviated pain induced by hind paw injection of bradykinin. Finally, we show with computational modelling how somatic/perisomatic hyperpolarization, in concert with the low-pass filtering properties of the t-junction within the DRG, can interfere with action potential propagation. Our study deciphers a complement of ion channels that sets the somatic Erest of nociceptive neurons and provides strong evidence for a robust filtering role of the somatic and perisomatic compartments of peripheral nociceptive neuron. PMID:25168672

  9. AceDRG: a stereochemical description generator for ligands

    PubMed Central

    Emsley, Paul; Gražulis, Saulius; Merkys, Andrius; Vaitkus, Antanas

    2017-01-01

    The program AceDRG is designed for the derivation of stereochemical information about small molecules. It uses local chemical and topological environment-based atom typing to derive and organize bond lengths and angles from a small-molecule database: the Crystallography Open Database (COD). Information about the hybridization states of atoms, whether they belong to small rings (up to seven-membered rings), ring aromaticity and nearest-neighbour information is encoded in the atom types. All atoms from the COD have been classified according to the generated atom types. All bonds and angles have also been classified according to the atom types and, in a certain sense, bond types. Derived data are tabulated in a machine-readable form that is freely available from CCP4. AceDRG can also generate stereochemical information, provided that the basic bonding pattern of a ligand is known. The basic bonding pattern is perceived from one of the computational chemistry file formats, including SMILES, mmCIF, SDF MOL and SYBYL MOL2 files. Using the bonding chemistry, atom types, and bond and angle tables generated from the COD, AceDRG derives the ‘ideal’ bond lengths, angles, plane groups, aromatic rings and chirality information, and writes them to an mmCIF file that can be used by the refinement program REFMAC5 and the model-building program Coot. Other refinement and model-building programs such as PHENIX and BUSTER can also use these files. AceDRG also generates one or more coordinate sets corresponding to the most favourable conformation(s) of a given ligand. AceDRG employs RDKit for chemistry perception and for initial conformation generation, as well as for the interpretation of SMILES strings, SDF MOL and SYBYL MOL2 files. PMID:28177307

  10. Endomorphin-2 is Released from Newborn Rat Primary Sensory Neurons in a Frequency- and Calcium- Dependent Manner

    PubMed Central

    Scanlin, Heather L.; Carroll, Elizabeth A.; Jenkins, Victoria K.; Balkowiec, Agnieszka

    2008-01-01

    Recent evidence indicates that endomorphins, endogenous mu-opioid receptor (MOR) agonists, modulate synaptic transmission in both somatic and visceral sensory pathways. Here we show that endomorphin-2 (END-2) is expressed in newborn rat dorsal root ganglion (DRG) and nodose-petrosal ganglion complex (NPG) neurons, and rarely co-localizes with brain-derived neurotrophic factor (BDNF). In order to examine activity-dependent release of END-2 from neurons, we established a model using dispersed cultures of DRG and NPG cells activated by patterned electrical field stimulation. To detect release of END-2, we developed a novel rapid capture ELISA, in which END-2 capture antibody was added to neuronal cultures shortly before their electrical stimulation. The conventional assay was effective at reliably detecting END-2 only when the cells were stimulated in the presence of CTAP, a MOR-selective antagonist. This suggests that the strength of the novel assay is related primarily to rapid capture of released END-2 before it binds to endogenous MORs. Using the rapid capture ELISA, we found that stimulation protocols known to induce plastic changes at sensory synapses were highly effective at releasing END-2. Removal of extracellular calcium or blocking voltage-activated calcium channels significantly reduced the release. Together, our data provide the first evidence that END-2 is expressed by newborn DRG neurons of all sizes found in this age group, and can be released from these, as well as from NPG neurons, in an activity-dependent manner. These results point to END-2 as a likely mediator of activity-dependent plasticity in sensory pathways. PMID:18513316

  11. Nursing cost by DRG: nursing intensity weights.

    PubMed

    Knauf, Robert A; Ballard, Karen; Mossman, Philip N; Lichtig, Leo K

    2006-11-01

    Although diagnosis-related group (DRG) reimbursement is used for Medicare and many other payors, nursing--the largest portion of hospital costs--is not specifically identified and quantified in deriving payments in any of the DRG reimbursement systems except that of New York State. In New York, nursing costs are allocated to each DRG in payment rate formulation by means of nursing intensity weights (NIWs)--relative values reflecting the quantity and types of nursing services provided to patients in each DRG. In the absence of charges for nursing services, these NIWs are derived from scores for each DRG provided by a representative panel of nurses through a modified Delphi technique. NIWs have been shown to correlate with hospitals' nursing costs per day. They are used to set cost-based payment weights, thereby avoiding compression caused by using flat cost-to-charge or cost-per-day averages for all acute and intensive care patients.

  12. Tannic acid modulates excitability of sensory neurons and nociceptive behavior and the Ionic mechanism.

    PubMed

    Zhang, Xuan; Zhang, Huiran; Zhou, Najing; Xu, Jiaxi; Si, Man; Jia, Zhanfeng; Du, Xiaona; Zhang, Hailin

    2015-10-05

    M/Kv7 K(+) channels, Ca(2+)-activated Cl(-) channels (CaCCs) and voltage gated Na(+) channels expressed in dorsal root ganglia (DRG) play an important role in nociception. Tannic acid has been proposed to be involved in multiple beneficial health effects; tannic acid has also been described to be analgesic. However the underlying mechanism is unknown. In this study, we investigated the effects of tannic acid on M/Kv7 K(+), Na(+) currents and CaCCs, and the effects on bradykinin-induced nociceptive behavior. A perforated patch technique was used. The bradykinin-induced rat pain model was used to assess the analgesic effect of tannic acid. We demonstrated that tannic acid enhanced M/Kv7 K(+) currents but inhibited bradykinin-induced activation of CaCC/TMEM16A currents in rat small DRG neurons. Tannic acid potentiated Kv7.2/7.3 and Kv7.2 currents expressed in HEK293B cells, with an EC50 of 7.38 and 5.40 µM, respectively. Tannic acid inhibited TTX-sensitive and TTX-insensitive currents of small DRG neurons with IC50 of 5.25 and 8.43 µM, respectively. Tannic acid also potently suppressed the excitability of small DRG neurons. Furthermore, tannic acid greatly reduced bradykinin-induced pain behavior of rats. This study thus demonstrates that tannic acid is an activator of M/Kv7 K(+) and an inhibitor of voltage-gated Na(+) channels and CaCC/TMEM16A, which may underlie its inhibitory effects on excitability of DRG neurons and its analgesic effect. Tannic acid could be a useful agent in treatment of inflammatory pain conditions such as osteoarthritis, rheumatic arthritis and burn pain. Copyright © 2015. Published by Elsevier B.V.

  13. Glucagon-like peptide 1 receptor (GLP-1R) expression by nerve fibres in inflammatory bowel disease and functional effects in cultured neurons.

    PubMed

    Anand, Uma; Yiangou, Yiangos; Akbar, Ayesha; Quick, Tom; MacQuillan, Anthony; Fox, Mike; Sinisi, Marco; Korchev, Yuri E; Jones, Ben; Bloom, Steve R; Anand, Praveen

    2018-01-01

    Glucagon like-peptide 1 receptor (GLP-1R) agonists diminish appetite and may contribute to the weight loss in inflammatory bowel disease (IBD). The aim of this study was to determine, for the first time, the expression of GLP-1R by colon nerve fibres in patients with IBD, and functional effects of its agonists in cultured rat and human sensory neurons. GLP-1R and other nerve markers were studied by immunohistochemistry in colon biopsies from patients with IBD (n = 16) and controls (n = 8), human dorsal root ganglia (DRG) tissue, and in GLP-1R transfected HEK293 cells. The morphological effects of incretin hormones oxyntomodulin, exendin-4 and glucagon were studied on neurite extension in cultured DRG neurons, and their functional effects on capsaicin and ATP signalling, using calcium imaging. Significantly increased numbers of colonic mucosal nerve fibres were observed in IBD biopsies expressing GLP-1R (p = 0.0013), the pan-neuronal marker PGP9.5 (p = 0.0008), and sensory neuropeptide CGRP (p = 0.0014). An increase of GLP-1R positive nerve fibres in IBD colon was confirmed with a different antibody to GLP-1R (p = 0.016). GLP-1R immunostaining was intensely positive in small and medium-sized neurons in human DRG, and in human and rat DRG cultured neurons. Co-localization of GLP-1R expression with neuronal markers in colon and DRG confirmed the neural expression of GLP-1R, and antibody specificity was confirmed in HEK293 cells transfected with the GLP-1R. Treatment with oxyntomodulin, exendin-4 and GLP-1 increased neurite length in cultured neurons compared with controls, but did not stimulate calcium influx directly, or affect capsaicin responses. However, exendin-4 significantly enhanced ATP responses in human DRG neurons. Our results show that increased GLP-1R innervation in IBD bowel could mediate enhanced visceral afferent signalling, and provide a peripheral target for therapeutic intervention. The differential effect of GLP-1R agonists on capsaicin and ATP

  14. Glucagon-like peptide 1 receptor (GLP-1R) expression by nerve fibres in inflammatory bowel disease and functional effects in cultured neurons

    PubMed Central

    Yiangou, Yiangos; Akbar, Ayesha; Quick, Tom; MacQuillan, Anthony; Fox, Mike; Sinisi, Marco; Korchev, Yuri E.; Jones, Ben; Bloom, Steve R.; Anand, Praveen

    2018-01-01

    Introduction Glucagon like-peptide 1 receptor (GLP-1R) agonists diminish appetite and may contribute to the weight loss in inflammatory bowel disease (IBD). Objectives The aim of this study was to determine, for the first time, the expression of GLP-1R by colon nerve fibres in patients with IBD, and functional effects of its agonists in cultured rat and human sensory neurons. Methods GLP-1R and other nerve markers were studied by immunohistochemistry in colon biopsies from patients with IBD (n = 16) and controls (n = 8), human dorsal root ganglia (DRG) tissue, and in GLP-1R transfected HEK293 cells. The morphological effects of incretin hormones oxyntomodulin, exendin-4 and glucagon were studied on neurite extension in cultured DRG neurons, and their functional effects on capsaicin and ATP signalling, using calcium imaging. Results Significantly increased numbers of colonic mucosal nerve fibres were observed in IBD biopsies expressing GLP-1R (p = 0.0013), the pan-neuronal marker PGP9.5 (p = 0.0008), and sensory neuropeptide CGRP (p = 0.0014). An increase of GLP-1R positive nerve fibres in IBD colon was confirmed with a different antibody to GLP-1R (p = 0.016). GLP-1R immunostaining was intensely positive in small and medium-sized neurons in human DRG, and in human and rat DRG cultured neurons. Co-localization of GLP-1R expression with neuronal markers in colon and DRG confirmed the neural expression of GLP-1R, and antibody specificity was confirmed in HEK293 cells transfected with the GLP-1R. Treatment with oxyntomodulin, exendin-4 and GLP-1 increased neurite length in cultured neurons compared with controls, but did not stimulate calcium influx directly, or affect capsaicin responses. However, exendin-4 significantly enhanced ATP responses in human DRG neurons. Conclusion Our results show that increased GLP-1R innervation in IBD bowel could mediate enhanced visceral afferent signalling, and provide a peripheral target for therapeutic intervention. The differential

  15. Quercetin protects rat dorsal root ganglion neurons against high glucose-induced injury in vitro through Nrf-2/HO-1 activation and NF-κB inhibition.

    PubMed

    Shi, Yue; Liang, Xiao-chun; Zhang, Hong; Wu, Qun-li; Qu, Ling; Sun, Qing

    2013-09-01

    To examine the effects of quercetin, a natural antioxidant, on high glucose (HG)-induced apoptosis of cultured dorsal root ganglion (DRG) neurons of rats. DRG neurons exposed to HG (45 mmol/L) for 24 h were employed as an in vitro model of diabetic neuropathy. Cell viability, reactive oxygen species (ROS) level and apoptosis were determined. The expression of NF-кB, IкBα, phosphorylated IкBα and Nrf2 was examined using RT PCR and Western blot assay. The expression of hemeoxygenase-1 (HO-1), IL-6, TNF-α, iNOS, COX-2, and caspase-3 were also examined. HG treatment markedly increased DRG neuron apoptosis via increasing intracellular ROS level and activating the NF-κB signaling pathway. Co-treatment with quercetin (2.5, 5, and 10 mmol/L) dose-dependently decreased HG-induced caspase-3 activation and apoptosis. Quercetin could directly scavenge ROS and significantly increased the expression of Nrf-2 and HO-1 in DRG neurons. Quercetin also dose-dependently inhibited the NF-κB signaling pathway and suppressed the expression of iNOS, COX-2, and proinflammatory cytokines IL-6 and TNF-α. Quercetin protects rat DRG neurons against HG-induced injury in vitro through Nrf-2/HO-1 activation and NF-κB inhibition, thus may be beneficial for the treatment of diabetic neuropathy.

  16. NR2B Expression in Rat DRG Is Differentially Regulated Following Peripheral Nerve Injuries That Lead to Transient or Sustained Stimuli-Evoked Hypersensitivity

    PubMed Central

    Norcini, Monica; Sideris, Alexandra; Adler, Samantha M.; Hernandez, Lourdes A. M.; Zhang, Jin; Blanck, Thomas J. J.; Recio-Pinto, Esperanza

    2016-01-01

    Following injury, primary sensory neurons undergo changes that drive central sensitization and contribute to the maintenance of persistent hypersensitivity. NR2B expression in the dorsal root ganglia (DRG) has not been previously examined in neuropathic pain models. Here, we investigated if changes in NR2B expression within the DRG are associated with hypersensitivities that result from peripheral nerve injuries. This was done by comparing the NR2B expression in the DRG derived from two modalities of the spared nerve injury (SNI) model, since each variant produces different neuropathic pain phenotypes. Using the electronic von Frey to stimulate the spared and non-spared regions of the hindpaws, we demonstrated that sural-SNI animals develop sustained neuropathic pain in both regions while the tibial-SNI animals recover. NR2B expression was measured at Day 23 and Day 86 post-injury. At Day 23 and 86 post-injury, sural-SNI animals display strong hypersensitivity, whereas tibial-SNI animals display 50 and 100% recovery from post-injury-induced hypersensitivity, respectively. In tibial-SNI at Day 86, but not at Day 23 the perinuclear region of the neuronal somata displayed an increase in NR2B protein. This retention of NR2B protein within the perinuclear region, which will render them non-functional, correlates with the recovery observed in tibial-SNI. In sural-SNI at Day 86, DRG displayed an increase in NR2B mRNA which correlates with the development of sustained hypersensitivity in this model. The increase in NR2B mRNA was not associated with an increase in NR2B protein within the neuronal somata. The latter may result from a decrease in kinesin Kif17, since Kif17 mediates NR2B transport to the soma’s plasma membrane. In both SNIs, microglia/macrophages showed a transient increase in NR2B protein detected at Day 23 but not at Day 86, which correlates with the initial post-injury induced hypersensitivity in both SNIs. In tibial-SNI at Day 86, but not at Day 23

  17. NR2B Expression in Rat DRG Is Differentially Regulated Following Peripheral Nerve Injuries That Lead to Transient or Sustained Stimuli-Evoked Hypersensitivity.

    PubMed

    Norcini, Monica; Sideris, Alexandra; Adler, Samantha M; Hernandez, Lourdes A M; Zhang, Jin; Blanck, Thomas J J; Recio-Pinto, Esperanza

    2016-01-01

    Following injury, primary sensory neurons undergo changes that drive central sensitization and contribute to the maintenance of persistent hypersensitivity. NR2B expression in the dorsal root ganglia (DRG) has not been previously examined in neuropathic pain models. Here, we investigated if changes in NR2B expression within the DRG are associated with hypersensitivities that result from peripheral nerve injuries. This was done by comparing the NR2B expression in the DRG derived from two modalities of the spared nerve injury (SNI) model, since each variant produces different neuropathic pain phenotypes. Using the electronic von Frey to stimulate the spared and non-spared regions of the hindpaws, we demonstrated that sural-SNI animals develop sustained neuropathic pain in both regions while the tibial-SNI animals recover. NR2B expression was measured at Day 23 and Day 86 post-injury. At Day 23 and 86 post-injury, sural-SNI animals display strong hypersensitivity, whereas tibial-SNI animals display 50 and 100% recovery from post-injury-induced hypersensitivity, respectively. In tibial-SNI at Day 86, but not at Day 23 the perinuclear region of the neuronal somata displayed an increase in NR2B protein. This retention of NR2B protein within the perinuclear region, which will render them non-functional, correlates with the recovery observed in tibial-SNI. In sural-SNI at Day 86, DRG displayed an increase in NR2B mRNA which correlates with the development of sustained hypersensitivity in this model. The increase in NR2B mRNA was not associated with an increase in NR2B protein within the neuronal somata. The latter may result from a decrease in kinesin Kif17, since Kif17 mediates NR2B transport to the soma's plasma membrane. In both SNIs, microglia/macrophages showed a transient increase in NR2B protein detected at Day 23 but not at Day 86, which correlates with the initial post-injury induced hypersensitivity in both SNIs. In tibial-SNI at Day 86, but not at Day 23

  18. PKC regulates capsaicin-induced currents of dorsal root ganglion neurons in rats.

    PubMed

    Zhou, Y; Zhou, Z S; Zhao, Z Q

    2001-10-01

    Capsaicin activates a non-specific cation conductance in a subset of dorsal root ganglion (DRG) neurons. The inward current and membrane potential of acutely isolated DRG neurons were examined using whole-cell patch recording methods. We report here that the current and voltage responses activated by capsaicin were markedly increased by phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C (PKC). The mean current, after application of 0.3 microM PMA, was 153.5+/-5.7% of control (n=32) in Ca(2+)-free external solution and 181.6+/-6.8% of control (n=15) in standard external solution. Under current-clamp conditions, 0.3 microM PMA facilitated capsaicin-induced depolarization and action potential generation. Bindolylmaleimide I (BIM), a specific inhibitor of PKC activity, abolished the effect of PMA. In addition, capsaicin-evoked current was attenuated to 68.3+/-5.0% of control (n=13) by individual administration of 1 microM BIM in standard external solution, while 0.3 microM BIM did not have this effect. These data suggest that PKC can directly regulate the capsaicin response in DRG neurons, which could increase nociceptive sensory transmission and contribute to hyperalgesia.

  19. A New Regulatory Mechanism for Kv7.2 Protein During Neuropathy: Enhanced Transport from the Soma to Axonal Terminals of Injured Sensory Neurons.

    PubMed

    Cisneros, Elsa; Roza, Carolina; Jackson, Nieka; López-García, José Antonio

    2015-01-01

    Kv7.2 channel expression has been reported to decrease in dorsal root ganglia (DRG) following the induction of a peripheral neuropathy while other experiments show that Kv7.2 accumulates in peripheral neuromas. The mechanisms underlying these novel expression patterns are poorly understood. Here we use immunofluorescence methods to analyze Kv7.2 protein expression changes in sensory neurons following peripheral axotomy and the potential role of axonal transport. Results indicate that DRG neurons express Kv7.2 in ~16% of neurons and that this number decreases by about 65% after axotomy. Damaged neurons were identified in DRG by application of the tracer Fluoro-ruby at the site of injury during surgery. Reduction of Kv7.2 expression was particularly strong in damaged neurons although some loss was also found in putative uninjured neurons. In parallel to the decrease in the soma of axotomized sensory neurons, Kv7.2 accumulated at neuromatose fiber endings. Blockade of axonal transport with either vinblastine (VLB) or colchicine (COL) abolished Kv7.2 redistribution in neuropathic animals. Channel distribution rearrangements did not occur following induction of inflammation in the hind paw. Behavioral tests indicate that protein rearrangements within sensory afferents are essential to the development of allodynia under neuropathic conditions. These results suggest that axotomy enhances axonal transport in injured sensory neurons, leading to a decrease of somatic expression of Kv7.2 protein and a concomitant accumulation in damaged fiber endings. Localized changes in channel expression patterns under pathological conditions may create novel opportunities for Kv7.2 channel openers to act as analgesics.

  20. Erythropoietin's Beta Common Receptor Mediates Neuroprotection in Spinal Cord Neurons.

    PubMed

    Foley, Lisa S; Fullerton, David A; Mares, Joshua; Sungelo, Mitchell; Weyant, Michael J; Cleveland, Joseph C; Reece, T Brett

    2017-12-01

    Paraplegia from spinal cord ischemia-reperfusion (SCIR) remains an elusive and devastating complication of complex aortic operations. Erythropoietin (EPO) attenuates this injury in models of SCIR. Upregulation of the EPO beta common receptor (βcR) is associated with reduced damage in models of neural injury. The purpose of this study was to examine whether EPO-mediated neuroprotection was dependent on βcR expression. We hypothesized that spinal cord neurons subjected to oxygen-glucose deprivation would mimic SCIR injury in aortic surgery and EPO treatment attenuates this injury in a βcR-dependent fashion. Lentiviral vectors with βcR knockdown sequences were tested on neuron cell cultures. The virus with greatest βcR knockdown was selected. Spinal cord neurons from perinatal wild-type mice were harvested and cultured to maturity. They were treated with knockdown or nonsense virus and transduced cells were selected. Three groups (βcR knockdown virus, nonsense control virus, no virus control; n = 8 each) were subjected to 1 hour of oxygen-glucose deprivation. Viability was assessed. βcR expression was quantified by immunoblot. EPO preserved neuronal viability after oxygen-glucose deprivation (0.82 ± 0.04 versus 0.61 ± 0.01; p < 0.01). Additionally, EPO-mediated neuron preservation was similar in the nonsense virus and control mice (0.82 ± 0.04 versus 0.80 ± 0.05; p = 0.77). EPO neuron preservation was lost in βcR knockdown mice compared with nonsense control mice (0.46 ± 0.03 versus 0.80 ± 0.05; p < 0.01). EPO attenuates neuronal loss after oxygen-glucose deprivation in a βcR-dependent fashion. This receptor holds immense clinical promise as a target for pharmacotherapies treating spinal cord ischemic injury. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Regulate axon branching by the cyclic GMP pathway via inhibition of glycogen synthase kinase 3 in dorsal root ganglion sensory neurons.

    PubMed

    Zhao, Zhen; Wang, Zheng; Gu, Ying; Feil, Robert; Hofmann, Franz; Ma, Le

    2009-02-04

    Cyclic GMP has been proposed to regulate axonal development, but the molecular and cellular mechanisms underlying the formation of axon branches are not well understood. Here, we report the use of rodent embryonic sensory neurons from the dorsal root ganglion (DRG) to demonstrate the role of cGMP signaling in axon branching and to identify the downstream molecular pathway mediating this novel regulation. Pharmacologically, a specific cGMP analog promotes DRG axon branching in culture, and this activity can be achieved by activating the endogenous soluble guanylyl cyclase that produces cGMP. At the molecular level, the cGMP-dependent protein kinase 1 (PrkG1) mediates this activity, as DRG neurons isolated from the kinase-deficient mouse fail to respond to cGMP activation to make branches, whereas overexpression of a PrkG1 mutant with a higher-than-normal basal kinase activity is sufficient to induce branching. In addition, cGMP activation in DRG neurons leads to phosphorylation of glycogen synthase kinase 3 (GSK3), a protein that normally suppresses branching. This interaction is direct, because PrkG1 binds GSK3 in heterologous cells and the purified kinase can phosphorylate GSK3 in vitro. More importantly, overexpression of a dominant active form of GSK3 suppresses cGMP-dependent branching in DRG neurons. Thus, our study establishes an intrinsic signaling cascade that links cGMP activation to GSK3 inhibition in controlling axon branching during sensory axon development.

  2. HSV-1 interaction to 3-O-sulfated heparan sulfate in mouse-derived DRG explant and profiles of inflammatory markers during virus infection.

    PubMed

    Sharthiya, Harsh; Seng, Chanmoly; Van Kuppevelt, T H; Tiwari, Vaibhav; Fornaro, Michele

    2017-06-01

    The molecular mechanism of herpes simplex virus (HSV) entry and the associated inflammatory response in the nervous system remain poorly understood. Using mouse-derived ex vivo dorsal root ganglia (DRG) explant model and single cell neurons (SCNs), in this study, we provided a visual evidence for the expression of heparan sulfate (HS) and 3-O-sulfated heparan sulfate (3-OS HS) followed by their interactions with HSV-1 glycoprotein B (gB) and glycoprotein D (gD) during cell entry. Upon heparanase treatment of DRG-derived SCN, a significant inhibition of HSV-1 entry was observed suggesting the involvement of HS role during viral entry. Finally, a cytokine array profile generated during HSV-1 infection in DRG explant indicated an enhanced expression of chemokines (LIX, TIMP-2, and M-CSF)-known regulators of HS. Taken together, these results highlight the significance of HS during HSV-1 entry in DRG explant. Further investigation is needed to understand which isoforms of 3-O-sulfotransferase (3-OST)-generated HS contributed during HSV-1 infection and associated cell damage.

  3. The role of TRPV1 in different subtypes of dorsal root ganglion neurons in rat chronic inflammatory nociception induced by complete Freund's adjuvant

    PubMed Central

    Yu, Lu; Yang, Fei; Luo, Hao; Liu, Feng-Yu; Han, Ji-Sheng; Xing, Guo-Gang; Wan, You

    2008-01-01

    Background The present study aims to investigate the role of transient receptor potential vanilloid 1 (TRPV1) in dorsal root ganglion (DRG) neurons in chronic pain including thermal hyperalgesia and mechanical allodynia. Chronic inflammatory nociception of rats was produced by intraplantar injection of complete Freund's adjuvant (CFA) and data was collected until day 28 following injection. Results Thermal hyperalgesia was evident from day 1 to day 28 with peak at day 7, while mechanical allodynia persisted from day 1 to day 14 and was greatest at day 7. Intrathecal administration of AMG 9810 at day 7, a selective TRPV1 antagonist, significantly reduced thermal hyperalgesia and mechanical allodynia. TRPV1 expression in DRG detected by Western blotting was increased relative to baseline throughout the observation period. Double labeling of TRPV1 with neuronal marker neurofilament 200 (NF200), calcitonin gene-related peptide (CGRP) or isolectin B4 (IB4) was used to distinguish different subtypes of DRG neurons. TRPV1 expression was increased in the medium-sized myelinated A fiber (NF200 positive) neurons and in small non-peptidergic (IB4 positive) neurons from day 1 to day 14 and was increased in small peptidergic (CGRP positive) neurons from day 1 to day 28. Conclusion TRPV1 expression increases in all three types of DRG neurons after CFA injection and plays a role in CFA-induced chronic inflammatory pain including thermal hyperalgesia and mechanical allodynia. PMID:19055783

  4. In situ hybridization of nucleus basalis neurons shows increased. beta. -amyloid mRNA in Alzheimer disease

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cohen, M.L.; Golde, T.E.; Usiak, M.F.

    1988-02-01

    To determine which cells within the brain produce ..beta..-amyloid mRNA and to assess expression of the ..beta..-amyloid gene in Alzheimer disease, the authors analyzed brain tissue from Alzheimer and control patients by in situ hybridization. The results demonstrate that ..beta..-amyloid mRNA is produced by neurons in the nucleus basalis of Meynert and cerebral cortex and that nuclues basalis perikarya from Alzheimer patients consistently hybridize more ..beta..-amyloid probe than those from controls. These observations support the hypothesis that increased expression of the ..beta..-amyloid gene plays an important role in the deposition of amyloid in the brains of patients with Alzheimer disease.

  5. Immunoglobulinfree light chains reduce in an antigen-specific manner the rate of rise of action potentials of mouse non-nociceptive dorsal root ganglion neurons.

    PubMed

    Rijnierse, Anneke; Kraneveld, Aletta D; Salemi, Arezo; Zwaneveld, Sandra; Goumans, Aleida P H; Rychter, Jakub W; Thio, Marco; Redegeld, Frank A; Westerink, Remco H S; Kroese, Alfons B A

    2013-11-15

    Plasma B cells secrete immunoglobulinfree light chains (IgLC) which by binding to mast cells can mediate hypersensitivity responses and are involved in several immunological disorders. To investigate the effects of antigen-specific IgLC activation, intracellular recordings were made from cultured murine dorsal root ganglion (DRG) neurons, which can specifically bind IgLC. The neurons were sensitized with IgLC for 90min and subsequently activated by application of the corresponding antigen (DNP-HSA). Antigen application induced a decrease in the rate of rise of the action potentials of non-nociceptive neurons (MANOVA, p=2.10(-6)), without affecting the resting membrane potential or firing threshold. The action potentials of the nociceptive neurons (p=0.57) and the electrical excitability of both types of neurons (p>0.35) were not affected. We conclude that IgLC can mediate antigen-specific responses by reducing the rate of rise of action potentials in non-nociceptive murine DRG neurons. We suggest that antigen-specific activation of IgLC-sensitized non-nociceptive DRG neurons may contribute to immunological hypersensitivity responses and neuroinflammation. © 2013.

  6. Cytotoxic effect of commercially available methylprednisolone acetate with and without reduced preservatives on dorsal root ganglion sensory neurons in rats.

    PubMed

    Knezevic, Nebojsa Nick; Candido, Kenneth D; Cokic, Ivan; Krbanjevic, Aleksandar; Berth, Sarah L; Knezevic, Ivana

    2014-01-01

    Epidural and intrathecal injections of methylprednisolone acetate (MPA) have become the most commonly performed interventional procedures in the United States and worldwide in the last 2 decades. However neuraxial MPA injection has been dogged by controversy regarding the presence of different additives used in commercially prepared glucocorticoids. We previously showed that MPA could be rendered 85% free of polyethylene glycol (PEG) by a simple physical separation of elements in the suspension. The objective of the present study was to explore a possible cytotoxic effect of commercially available MPA (with intact or reduced preservatives) on rat sensory neurons. We exposed primary dissociated rat dorsal root ganglia (DRG) sensory neurons to commercially available MPA for 24 hours with either the standard (commercial) concentration of preservatives or to different fractions following separation (MPA suspension whose preservative concentration had been reduced, or fractions containing higher concentrations of preservatives). Cells were stained with the TUNEL assay kit to detect apoptotic cells and images were taken on the Bio-Rad Laser Sharp-2000 system. We also detected expression of caspase-3, as an indicator of apoptosis in cell lysates. We exposed sensory neurons from rat DRG to different concentrations of MPA from the original commercially prepared vial. TUNEL assay showed dose-related responses and increased percentages of apoptotic cells with increasing concentrations of MPA. Increased concentrations of MPA caused 1.5 - 2 times higher caspase-3 expression in DRG sensory neurons than in control cells (ANOVA, P = 0.001). Our results showed that MPA with reduced preservatives caused significantly less apoptosis observed with TUNEL assay labeling (P < 0.001) and caspase-3 immunoblotting (P = 0.001) than in neurons exposed to MPA from a commercially prepared vial or "clear phase" that contained higher concentrations of preservatives. Even though MPA with reduced

  7. Block of voltage-gated potassium channels by Pacific ciguatoxin-1 contributes to increased neuronal excitability in rat sensory neurons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Birinyi-Strachan, Liesl C.; Gunning, Simon J.; Lewis, Richard J.

    2005-04-15

    The present study investigated the actions of the polyether marine toxin Pacific ciguatoxin-1 (P-CTX-1) on neuronal excitability in rat dorsal root ganglion (DRG) neurons using patch-clamp recording techniques. Under current-clamp conditions, bath application of 2-20 nM P-CTX-1 caused a rapid, concentration-dependent depolarization of the resting membrane potential in neurons expressing tetrodotoxin (TTX)-sensitive voltage-gated sodium (Na{sub v}) channels. This action was completely suppressed by the addition of 200 nM TTX to the external solution, indicating that this effect was mediated through TTX-sensitive Na{sub v} channels. In addition, P-CTX-1 also prolonged action potential and afterhyperpolarization (AHP) duration. In a subpopulation of neurons,more » P-CTX-1 also produced tonic action potential firing, an effect that was not accompanied by significant oscillation of the resting membrane potential. Conversely, in neurons expressing TTX-resistant Na{sub v} currents, P-CTX-1 failed to alter any parameter of neuronal excitability examined in this study. Under voltage-clamp conditions in rat DRG neurons, P-CTX-1 inhibited both delayed-rectifier and 'A-type' potassium currents in a dose-dependent manner, actions that occurred in the absence of alterations to the voltage dependence of activation. These actions appear to underlie the prolongation of the action potential and AHP, and contribute to repetitive firing. These data indicate that a block of potassium channels contributes to the increase in neuronal excitability, associated with a modulation of Na{sub v} channel gating, observed clinically in response to ciguatera poisoning.« less

  8. Angiotensin II type 2 receptor (AT2R) localization and antagonist-mediated inhibition of capsaicin responses and neurite outgrowth in human and rat sensory neurons

    PubMed Central

    Anand, U; Facer, P; Yiangou, Y; Sinisi, M; Fox, M; McCarthy, T; Bountra, C; Korchev, YE; Anand, P

    2013-01-01

    Background The angiotensin II (AngII) receptor subtype 2 (AT2R) is expressed in sensory neurons and may play a role in nociception and neuronal regeneration. Methods We used immunostaining with characterized antibodies to study the localization of AT2R in cultured human and rat dorsal root ganglion (DRG) neurons and a range of human tissues. The effects of AngII and AT2R antagonist EMA401 on capsaicin responses in cultured human and rat (DRG) neurons were measured with calcium imaging, on neurite length and density with Gap43 immunostaining, and on cyclic adenosine monophosphate (cAMP) expression using immunofluorescence. Results AT2R expression was localized in small-/medium-sized cultured neurons of human and rat DRG. Treatment with the AT2R antagonist EMA401 resulted in dose-related functional inhibition of capsaicin responses (IC50 = 10 nmol/L), which was reversed by 8-bromo-cAMP, and reduced neurite length and density; AngII treatment significantly enhanced capsaicin responses, cAMP levels and neurite outgrowth. The AT1R antagonist losartan had no effect on capsaicin responses. AT2R was localized in sensory neurons of human DRG, and nerve fibres in peripheral nerves, skin, urinary bladder and bowel. A majority sub-population (60%) of small-/medium-diameter neuronal cells were immunopositive in both control post-mortem and avulsion-injured human DRG; some very small neurons appeared to be intensely immunoreactive, with TRPV1 co-localization. While AT2R levels were reduced in human limb peripheral nerve segments proximal to injury, they were preserved in painful neuromas. Conclusions AT2R antagonists could be particularly useful in the treatment of chronic pain and hypersensitivity associated with abnormal nerve sprouting. PMID:23255326

  9. 42 CFR 476.84 - Changes as a result of DRG validation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Changes as a result of DRG validation. 476.84... DRG validation. A provider or practitioner may obtain a review by a QIO under part 473 of this chapter... result of QIO validation activities. ...

  10. The implementation of DRG-based hospital reimbursement in Switzerland: A population-based perspective.

    PubMed

    Busato, André; von Below, Georg

    2010-10-16

    Switzerland introduces a DRG (Diagnosis Related Groups) based system for hospital financing in 2012 in order to increase efficiency and transparency of Swiss health care. DRG-based hospital reimbursement is not simultaneously realized in all Swiss cantons and several cantons already implemented DRG-based financing irrespective of the national agenda, a setting that provides an opportunity to compare the situation in different cantons. Effects of introducing DRGs anticipated for providers and insurers are relatively well known but it remains less clear what effects DRGs will have on served populations. The objective of the study is therefore to analyze differences of volume and major quality indicators of care between areas with or without DRG-based hospital reimbursement from a population based perspective. Small area analysis of all hospitalizations in acute care hospitals and of all consultations reimbursed by mandatory basic health insurance for physicians in own practice during 2003-2007. The results show fewer hospitalizations and a relocation of resources to outpatient care in areas with DRG reimbursement. Overall burden of disease expressed as per capita DRG cost weights was almost identical between the two types of hospital reimbursement and no distinct temporal differences were detected in this respect. But the results show considerably higher 90-day rehospitalization rates in DRG areas. The study provides evidence of both desired and harmful effects related to the implementation of DRGs. Systematic monitoring of outcomes and quality of care are therefore essential elements to maintain in the Swiss health system after DRG's are implemented on a nationwide basis in 2012.

  11. [DRG systems in Europe. Incentives, purposes and differences in 12 countries].

    PubMed

    Geissler, A; Scheller-Kreinsen, D; Quentin, W; Busse, R

    2012-05-01

    DRG systems were introduced across Europe based on expected transparency and efficiency gains. However, European DRG systems have not been systematically analysed so far. As a consequence little is known about the relative strengths and weaknesses of different DRG systems. The EuroDRG project closed this research and knowledge gap by systematically analysing and comparing the DRG systems of 12 countries with different health systems (Austria, the UK, Estonia, Finland, France, Germany, Ireland, The Netherlands, Poland, Portugal, Spain and Sweden).This article summarizes the results of this analysis illustrating how DRG systems across Europe differ with regard to policy goals, patient classification, data collection, price setting and actual reimbursement. Moreover, it outlines which main challenges arise within and across the different types of DRG systems. The results show that the European DRG systems are very heterogeneous. Even if the basic DRG approach of grouping similar patients remains the same across countries, the design of the main building blocks differs to a great extent.

  12. C5a Increases the Injury to Primary Neurons Elicited by Fibrillar Amyloid Beta.

    PubMed

    Hernandez, Michael X; Namiranian, Pouya; Nguyen, Eric; Fonseca, Maria I; Tenner, Andrea J

    2017-02-01

    C5aR1, the proinflammatory receptor for C5a, is expressed in the central nervous system on microglia, endothelial cells, and neurons. Previous work demonstrated that the C5aR1 antagonist, PMX205, decreased amyloid pathology and suppressed cognitive deficits in two Alzheimer's Disease (AD) mouse models. However, the cellular mechanisms of this protection have not been definitively demonstrated. Here, primary cultured mouse neurons treated with exogenous C5a show reproducible loss of MAP-2 staining in a dose-dependent manner within 24 hr of treatment, indicative of injury to neurons. This injury is prevented by the C5aR1 antagonist PMX53, a close analog of PMX205. Furthermore, primary neurons derived from C5aR1 null mice exhibited no MAP-2 loss after exposure to the highest concentration of C5a tested. Primary mouse neurons treated with both 100 nM C5a and 5 µM fibrillar amyloid beta (fAβ), to model what occurs in the AD brain, showed increased MAP-2 loss relative to either C5a or fAβ alone. Blocking C5aR1 with PMX53 (100 nM) blocked the loss of MAP2 in these primary neurons to the level seen with fAβ alone. Similar experiments with primary neurons derived from C5aR1 null mice showed a loss of MAP-2 due to fAβ treatment. However, the addition of C5a to the cultures did not enhance the loss of MAP-2 and the addition of PMX53 to the cultures did not change the MAP-2 loss in response to fAβ. Thus, at least part of the beneficial effects of C5aR1 antagonist in AD mouse models may be due to protection of neurons from the toxic effects of C5a.

  13. Dystonin/Bpag1 is a necessary endoplasmic reticulum/nuclear envelope protein in sensory neurons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Young, Kevin G.; University of Ottawa Center for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario; Kothary, Rashmi

    2008-09-10

    Dystonin/Bpag1 proteins are cytoskeletal linkers whose loss of function in mice results in a hereditary sensory neuropathy with a progressive loss of limb coordination starting in the second week of life. These mice, named dystonia musculorum (dt), succumb to the disease and die of unknown causes prior to sexual maturity. Previous evidence indicated that cytoskeletal defects in the axon are a primary cause of dt neurodegeneration. However, more recent data suggests that other factors may be equally important contributors to the disease process. In the present study, we demonstrate perikaryal defects in dorsal root ganglion (DRG) neurons at stages precedingmore » the onset of loss of limb coordination in dt mice. Abnormalities include alterations in endoplasmic reticulum (ER) chaperone protein expression, indicative of an ER stress response. Dystonin in sensory neurons localized in association with the ER and nuclear envelope (NE). A fusion protein ofthe dystonin-a2 isoform, which harbors an N-terminal transmembrane domain, associated with and reorganized the ER in cell culture. This isoform also interacts with the NE protein nesprin-3{alpha}, but not nesprin-3{beta}. Defects in dt mice, as demonstrated here, may ultimately result in pathogenesis involving ER dysfunction and contribute significantly to the dt phenotype.« less

  14. [Changes for rheumatology in the G-DRG system 2005].

    PubMed

    Fiori, W; Roeder, N; Lakomek, H-J; Liman, W; Köneke, N; Hülsemann, J L; Lehmann, H; Wenke, A

    2005-02-01

    The German prospective payment system G-DRG has been recently adapted and recalculated. Apart from the adjustments of the G-DRG classification system itself changes in the legal framework like the extension of the "convergence period" or the limitation of budget loss due to DRG introduction have to be considered. Especially the introduction of new procedure codes (OPS) describing the specialized and complex rheumatologic treatment of inpatients might be of significant importance. Even though these procedures will not yet develop influence on the grouping process in 2005, it will enable a more accurate description of the efforts of acute-rheumatologic treatment which can be used for further adaptations of the DRG algorithm. Numerous newly introduced additive payment components (ZE) result in a more adequate description of the "DRG-products". Although not increasing the individual hospital budget, these additive payments contribute to more transparency of high cost services and can be addressed separately from the DRG-budget. Furthermore a lot of other relevant changes to the G-DRG catalogue, the classification systems ICD-10-GM and OPS-301 and the German Coding Standards (DKR) are presented.

  15. Downregulation of ClC-3 in dorsal root ganglia neurons contributes to mechanical hypersensitivity following peripheral nerve injury.

    PubMed

    Pang, Rui-Ping; Xie, Man-Xiu; Yang, Jie; Shen, Kai-Feng; Chen, Xi; Su, Ying-Xue; Yang, Chao; Tao, Jing; Liang, Si-Jia; Zhou, Jia-Guo; Zhu, He-Quan; Wei, Xu-Hong; Li, Yong-Yong; Qin, Zhi-Hai; Liu, Xian-Guo

    2016-11-01

    ClC-3 chloride channel/antiporter has been demonstrated to play an important role in synaptic transmission in central nervous system. However, its expression and function in sensory neurons is poorly understood. In present work, we found that ClC-3 is expressed at high levels in dorsal root ganglia (DRG). Co-immunofluorescent data showed that ClC-3 is mainly distributed in A- and C-type nociceptive neurons. ClC-3 expression in DRG is decreased in the spared nerve injury (SNI) model of neuropathic pain. Knockdown of local ClC-3 in DRG neurons with siRNA increased mechanical sensitivity in naïve rats, while overexpression of ClC-3 reversed the hypersensitivity to mechanical stimuli after peripheral nerve injury. In addition, genetic deletion of ClC-3 enhances mouse mechanical sensitivity but did not affect thermal and cold threshold. Restoration of ClC-3 expression in ClC-3 deficient mice reversed the mechanical sensitivity. Mechanistically, loss of ClC-3 enhanced mechanical sensitivity through increasing the excitability of DRG neurons. These data indicate that ClC-3 is an endogenous inhibitor of neuropathic pain development. Downregulation of ClC-3 by peripheral nerve injury is critical for mechanical hypersensitivity. Our findings suggest that ClC-3 is a novel therapeutic target for treating neuropathic pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Advanced Oxidative Protein Products Cause Pain Hypersensitivity in Rats by Inducing Dorsal Root Ganglion Neurons Apoptosis via NADPH Oxidase 4/c-Jun N-terminal Kinase Pathways.

    PubMed

    Ding, Ruoting; Sun, Baihui; Liu, Zhongyuan; Yao, Xinqiang; Wang, Haiming; Shen, Xing; Jiang, Hui; Chen, Jianting

    2017-01-01

    Pain hypersensitivity is the most common category of chronic pain and is difficult to cure. Oxidative stress and certain cells apoptosis, such as dorsal root ganglion (DRG) neurons, play an essential role in the induction and development of pain hypersensitivity. The focus of this study is at a more specific molecular level. We investigated the role of advanced oxidative protein products (AOPPs) in inducing hypersensitivity and the cellular mechanism underlying the proapoptotic effect of AOPPs. Normal rats were injected by AOPPs-Rat serum albumin (AOPPs-RSA) to cause pain hypersensitivity. Primary cultured DRG neurons were treated with increasing concentrations of AOPPs-RSA or for increasing time durations. The MTT, flow cytometry and western blot analyses were performed in the DRG neurons. A loss of mitochondrial membrane potential (MMP) and an increase in intracellular reactive oxygen species (ROS) were observed. We found that AOPPs triggered DRG neurons apoptosis and MMP loss. After AOPPs treatment, intracellular ROS generation increased in a time- and dose-dependent manner, whereas, N -acetyl-L-cysteine (NAC), a specific ROS scavenger could inhibit the ROS generation. Proapoptotic proteins, such as Bax, caspase 9/caspase 3, and PARP-1 were activated, whereas anti-apoptotic Bcl-2 protein was down-regulated. AOPPs also increased Nox4 and JNK expression. Taken together, these findings suggest that AOPPs cause pain hypersensitivity in rats, and extracellular AOPPs accumulation triggered Nox4-dependent ROS production, which activated JNK, and induced DRG neurons apoptosis by activating caspase 3 and PARP-1.

  17. Neurotoxicity of cytarabine (Ara-C) in dorsal root ganglion neurons originates from impediment of mtDNA synthesis and compromise of mitochondrial function.

    PubMed

    Zhuo, Ming; Gorgun, Murat F; Englander, Ella W

    2018-06-01

    Peripheral Nervous System (PNS) neurotoxicity caused by cancer drugs hinders attainment of chemotherapy goals. Due to leakiness of the blood nerve barrier, circulating chemotherapeutic drugs reach PNS neurons and adversely affect their function. Chemotherapeutic drugs are designed to target dividing cancer cells and mechanisms underlying their toxicity in postmitotic neurons remain to be fully clarified. The objective of this work was to elucidate progression of events triggered by antimitotic drugs in postmitotic neurons. For proof of mechanism study, we chose cytarabine (ara-C), an antimetabolite used in treatment of hematological cancers. Ara-C is a cytosine analog that terminates DNA synthesis. To investigate how ara-C affects postmitotic neurons, which replicate mitochondrial but not genomic DNA, we adapted a model of Dorsal Root Ganglion (DRG) neurons. We showed that DNA polymerase γ, which is responsible for mtDNA synthesis, is inhibited by ara-C and that sublethal ara-C exposure of DRG neurons leads to reduction in mtDNA content, ROS generation, oxidative mtDNA damage formation, compromised mitochondrial respiration and diminution of NADPH and GSH stores, as well as, activation of the DNA damage response. Hence, it is plausible that in ara-C exposed DRG neurons, ROS amplified by the high mitochondrial content shifts from physiologic to pathologic levels signaling stress to the nucleus. Combined, the findings suggest that ara-C neurotoxicity in DRG neurons originates in mitochondria and that continuous mtDNA synthesis and reliance on oxidative phosphorylation for energy needs sensitize the highly metabolic neurons to injury by mtDNA synthesis terminating cancer drugs. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Distinct functional and temporal requirements for zebrafish Hdac1 during neural crest-derived craniofacial and peripheral neuron development.

    PubMed

    Ignatius, Myron S; Unal Eroglu, Arife; Malireddy, Smitha; Gallagher, Glen; Nambiar, Roopa M; Henion, Paul D

    2013-01-01

    The regulation of gene expression is accomplished by both genetic and epigenetic means and is required for the precise control of the development of the neural crest. In hdac1(b382) mutants, craniofacial cartilage development is defective in two distinct ways. First, fewer hoxb3a, dlx2 and dlx3-expressing posterior branchial arch precursors are specified and many of those that are consequently undergo apoptosis. Second, in contrast, normal numbers of progenitors are present in the anterior mandibular and hyoid arches, but chondrocyte precursors fail to terminally differentiate. In the peripheral nervous system, there is a disruption of enteric, DRG and sympathetic neuron differentiation in hdac1(b382) mutants compared to wildtype embryos. Specifically, enteric and DRG-precursors differentiate into neurons in the anterior gut and trunk respectively, while enteric and DRG neurons are rarely present in the posterior gut and tail. Sympathetic neuron precursors are specified in hdac1(b382) mutants and they undergo generic neuronal differentiation but fail to undergo noradrenergic differentiation. Using the HDAC inhibitor TSA, we isolated enzyme activity and temporal requirements for HDAC function that reproduce hdac1(b382) defects in craniofacial and sympathetic neuron development. Our study reveals distinct functional and temporal requirements for zebrafish hdac1 during neural crest-derived craniofacial and peripheral neuron development.

  19. Effects of Hindlimb Unweighting on MBP and GDNF Expression and Morphology in Rat Dorsal Root Ganglia Neurons.

    PubMed

    Zhang, Heng; Ren, Ning-Tao; Zhou, Fang-Qiang; Li, Jie; Lei, Wei; Liu, Ning; Bi, Long; Wu, Zi-Xiang; Zhang, Ran; Zhang, Yong-Gang; Cui, Geng

    2016-09-01

    With the development of technology and space exploration, studies on long-duration space flights have shown that microgravity induces damage to multiple organs, including the dorsal root ganglia (DRG). However, very little is known about the effects of long-term microgravity on DRG neurons. This study investigated the effects of microgravity on lumbar 5 (L5) DRG neurons in rats using the hindlimb unweighting (HU) model. Male (M) and female (F) Sprague-Dawley rats were randomly divided into M- and F-control (CON) groups and M- and F-HU groups, respectively (n = 10). At the end of HU treatment for 4 weeks, morphological changes were detected. Myelin basic protein (MBP) and degenerated myelin basic protein (dgen-MBP) expressions were analyzed by immunofluorescence and western blot assays. Glial cell line-derived neurotrophic factor (GDNF) protein and mRNA expressions were also analyzed by immunohistochemistry, western blot, and RT-PCR analysis, respectively. Compared with the corresponding CON groups, the HU groups exhibited slightly loose junctions between DRG neurons, some separated ganglion cells and satellite cells, and lightly stained Nissl bodies that were of smaller size and had a scattered distribution. High levels of dgen-MBP and low MBP expressions were appeared and GDNF expressions were significantly decreased in both HU groups. Changes were more pronounced in the F-HU group than in the M-HU group. In conclusion, HU treatment induced damage of L5 DRG neurons, which was correlated with decreased total MBP protein expression, increased dgen-MBP expression, and reduced GDNF protein and mRNA expression. Importantly, these changes were more severe in F-HU rats compared with M-HU rats.

  20. Expression of Vesicular Glutamate Transporters Type 1 and 2 in Sensory and Autonomic Neurons Innervating the Mouse Colorectum

    PubMed Central

    Brumovsky, Pablo R.; Robinson, David R.; La, Jun-Ho; Seroogy, Kim B.; Lundgren, Kerstin H.; Albers, Kathryn M.; Kiyatkin, Michael E.; Seal, Rebecca P.; Edwards, Robert H.; Watanabe, Masahiko; Hökfelt, Tomas; Gebhart, G.F.

    2013-01-01

    Vesicular glutamate transporters (VGLUTs) have been extensively studied in various neuronal systems, but their expression in visceral sensory and autonomic neurons remains to be analyzed in detail. Here we studied VGLUTs type 1 and 2 (VGLUT1 and VGLUT2, respectively) in neurons innervating the mouse colorectum. Lumbosacral and thoracolumbar dorsal root ganglion (DRG), lumbar sympathetic chain (LSC), and major pelvic ganglion (MPG) neurons innervating the colorectum of BALB/C mice were retrogradely traced with Fast Blue, dissected, and processed for immunohistochemistry. Tissue from additional naïve mice was included. Previously characterized antibodies against VGLUT1, VGLUT2, and calcitonin gene-related peptide (CGRP) were used. Riboprobe in situ hybridization, using probes against VGLUT1 and VGLUT2, was also performed. Most colorectal DRG neurons expressed VGLUT2 and often colocalized with CGRP. A smaller percentage of neurons expressed VGLUT1. VGLUT2-immunoreactive (IR) neurons in the MPG were rare. Abundant VGLUT2-IR nerves were detected in all layers of the colorectum; VGLUT1-IR nerves were sparse. A subpopulation of myenteric plexus neurons expressed VGLUT2 protein and mRNA, but VGLUT1 mRNA was undetectable. In conclusion, we show 1) that most colorectal DRG neurons express VGLUT2, and to a lesser extent, VGLUT1; 2) abundance of VGLUT2-IR fibers innervating colorectum; and 3) a subpopulation of myenteric plexus neurons expressing VGLUT2. Altogether, our data suggests a role for VGLUT2 in colorectal glutamatergic neurotransmission, potentially influencing colorectal sensitivity and motility. PMID:21800314

  1. Interaction of 3beta, 5alpha-tetrahydrodeoxycorticosterone in rat and guinea-pig neurons: a comparison of Ca2+ - and GABA(A)-CI- -channel current modulation.

    PubMed

    ffrench-Mullen, J M

    1999-01-01

    A comparison of the interaction of 3beta, 5alpha-tetrahydrodeoxycorticosterone (TDOC) on voltage-gated Ca2+ -and the gamma-aminobutyric receptor (GABA(A)) gated-Cl- -channels was examined in freshly dissociated guinea-pig (GP) and rat hippocampal CA1 neurons and rat hypothalamic ventromedial nucleus (VMN) neurons. The steady-state inhibition of the peak Ca2+ channel current evoked by depolarized steps from -80 to -10 mV by TDOC increased in concentration-dependent manner with IC50 values of 1 and 6 pM for rat and GP CA1 neurons, respectively and 3 nM for rat VMN neurons. TDOC rapidly and reversibly inhibited a fraction (up to 26%) of the total Ca2+ channel current in all neurons. Intracellular dialysis with GDP-beta-S (500 microM) significantly diminished the TDOC inhibition of the Ca2+ channel current, suggesting a G-protein involvement. In neurons isolated from pertussis-toxin-treated animals by chronic intracerebroventricular (1000 ng/24/48 h) infusion, the TDOC inhibition was also significantly diminished, suggesting modulation by the Galphai and/or Galphao G-protein subunits. The peak GABA-gated inward Cl- current was enhanced in both species from 0.1 to 10 microM with the greatest increase (48% at 10 microM) seen in the VMN. There was no difference in the enhancement of the GABA current in the CA1 region of both species. The results show that in contrast to the 3a-series, the 3beta-series weakly enhance the GABA-evoked Cl- current but potently inhibit the Ca2+ channel current. In addition, these results also suggest a common mode of action and a lack of interspecies difference for this steroid.

  2. 42 CFR 412.515 - LTC-DRG weighting factors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false LTC-DRG weighting factors. 412.515 Section 412.515 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE...-Term Care Hospitals § 412.515 LTC-DRG weighting factors. For each LTC-DRG, CMS assigns an appropriate...

  3. Determination of nitric oxide mediating intracellular Ca2+ release on neurons based on confocal microscopy imaging

    NASA Astrophysics Data System (ADS)

    Zheng, Liqin; Wang, Yuhua; He, Yipeng; Zeng, Yixiu; Zhang, Yanding; Xie, Shusen

    2014-09-01

    The gas NO is a ubiquitous intercellular messenger that modulates a wide range of physiological and pathophysiological functions. But few studies were made to study the role of NO in the Ca2+ release in dorsal root ganglion (DRG) neurons by confocal microscopy. Thus the objective of this study was to assess if NO has a role in Ca2+ signaling in DRG neurons using confocal microscopy combined with special fluorescence probe Fluo-3/AM. A 100 μM concentration of the NO donors (Sodium Nitroprusside, Dihydrate, SNP) and NO synthase inhibitor (NG-Monomethyl-L-arginine, Monoacetate salt, L-NMMA) was used in the study. Results showed that the fluorescence intensity increased rapidly after injecting SNP, which indicated that SNP could enhance intracellular Ca2+ release. And the fluorescence intensity shrank gradually with time and kept at a low level for quite a long period after loading with L-NMMA which indicated that L-NMMA could block intracellular Ca2+ release. All these results demonstrated that NO was involved in the regulation of intracellular Ca2+ release in the DRG neurons.

  4. Viral vector mediated continuous expression of interleukin-10 in DRG alleviates pain in type 1 diabetic animals.

    PubMed

    Thakur, Vikram; Gonzalez, Mayra; Pennington, Kristen; Chattopadhyay, Munmun

    2016-04-01

    Painful diabetic neuropathy is a common and difficult to treat complication of diabetes. A growing body of evidence implicates the role of inflammatory mediators in the damage to the peripheral axons and in the pathogenesis of neuropathic pain. Increased expression of pro-inflammatory cytokines such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α in the peripheral nervous system suggests the possibility of change in pain perception in diabetes. In this study we investigated that continuous delivery of IL10 in the nerve fibers achieved by HSV vector mediated transduction of dorsal root ganglion (DRG) in animals with Type 1 diabetes, blocks the nociceptive and stress responses in the DRG neurons by reducing IL1β expression along with inhibition of phosphorylation of p38 MAPK (mitogen-activated protein kinase) and protein kinase C (PKC). The continuous expression of IL10 also alters Toll like receptor (TLR)-4 expression in the DRG with increased expression of heat shock protein (HSP)-70 in conjunction with the reduction of pain. Taken together, this study suggests that macrophage activation in the peripheral nervous system may be involved in the pathogenesis of pain in Type 1 diabetes and therapeutic benefits of HSV mediated local expression of IL10 in the DRG with the reduction of a number of proinflammatory cytokines, subsequently inhibits the development of painful neuropathy along with a decrease in stress associated markers in the DRG. This basic and preclinical study provides an important evidence for a novel treatment strategy that could lead to a clinical trial for what is currently a treatment resistant complication of diabetes. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Bayesian logistic regression approaches to predict incorrect DRG assignment.

    PubMed

    Suleiman, Mani; Demirhan, Haydar; Boyd, Leanne; Girosi, Federico; Aksakalli, Vural

    2018-05-07

    Episodes of care involving similar diagnoses and treatments and requiring similar levels of resource utilisation are grouped to the same Diagnosis-Related Group (DRG). In jurisdictions which implement DRG based payment systems, DRGs are a major determinant of funding for inpatient care. Hence, service providers often dedicate auditing staff to the task of checking that episodes have been coded to the correct DRG. The use of statistical models to estimate an episode's probability of DRG error can significantly improve the efficiency of clinical coding audits. This study implements Bayesian logistic regression models with weakly informative prior distributions to estimate the likelihood that episodes require a DRG revision, comparing these models with each other and to classical maximum likelihood estimates. All Bayesian approaches had more stable model parameters than maximum likelihood. The best performing Bayesian model improved overall classification per- formance by 6% compared to maximum likelihood, with a 34% gain compared to random classification, respectively. We found that the original DRG, coder and the day of coding all have a significant effect on the likelihood of DRG error. Use of Bayesian approaches has improved model parameter stability and classification accuracy. This method has already lead to improved audit efficiency in an operational capacity.

  6. A New Regulatory Mechanism for Kv7.2 Protein During Neuropathy: Enhanced Transport from the Soma to Axonal Terminals of Injured Sensory Neurons

    PubMed Central

    Cisneros, Elsa; Roza, Carolina; Jackson, Nieka; López-García, José Antonio

    2015-01-01

    Kv7.2 channel expression has been reported to decrease in dorsal root ganglia (DRG) following the induction of a peripheral neuropathy while other experiments show that Kv7.2 accumulates in peripheral neuromas. The mechanisms underlying these novel expression patterns are poorly understood. Here we use immunofluorescence methods to analyze Kv7.2 protein expression changes in sensory neurons following peripheral axotomy and the potential role of axonal transport. Results indicate that DRG neurons express Kv7.2 in ~16% of neurons and that this number decreases by about 65% after axotomy. Damaged neurons were identified in DRG by application of the tracer Fluoro-ruby at the site of injury during surgery. Reduction of Kv7.2 expression was particularly strong in damaged neurons although some loss was also found in putative uninjured neurons. In parallel to the decrease in the soma of axotomized sensory neurons, Kv7.2 accumulated at neuromatose fiber endings. Blockade of axonal transport with either vinblastine (VLB) or colchicine (COL) abolished Kv7.2 redistribution in neuropathic animals. Channel distribution rearrangements did not occur following induction of inflammation in the hind paw. Behavioral tests indicate that protein rearrangements within sensory afferents are essential to the development of allodynia under neuropathic conditions. These results suggest that axotomy enhances axonal transport in injured sensory neurons, leading to a decrease of somatic expression of Kv7.2 protein and a concomitant accumulation in damaged fiber endings. Localized changes in channel expression patterns under pathological conditions may create novel opportunities for Kv7.2 channel openers to act as analgesics. PMID:26696829

  7. [Orthopedic and trauma surgery in the German-DRG-System 2009].

    PubMed

    Franz, D; Windolf, J; Siebert, C H; Roeder, N

    2009-01-01

    The German DRG-System was advanced into version 2009. For orthopedic and trauma surgery significant changes concerning coding of diagnoses, medical procedures and concerning the DRG-structure were made. Analysis of relevant diagnoses, medical procedures and G-DRGs in the versions 2008 and 2009 based on the publications of the German DRG-institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). Changes for 2009 focussed on the development of DRG-structure, DRG-validation and codes for medical procedures to be used for very complex cases. The outcome of these changes for German hospitals may vary depending in the range of activities. G-DRG-System gained complexity again. High demands are made on correct and complete coding of complex orthopedic and trauma surgery cases. Quality of case-allocation within the G-DRG-System was improved. Nevertheless, further adjustments of the G-DRG-System especially for cases with severe injuries are necessary.

  8. [The G-DRG system 2008. Relevant changes for rheumatology].

    PubMed

    Fiori, W; Lakomek, H-J; Buscham, K; Lehmann, H; Liman, W; Fuchs, A-K; Hülsemann, J L; Roeder, N

    2008-05-01

    The G-DRG system 2008 once again brings many changes to rheumatological departments in Germany. The following article presents the main general and specific changes in the G-DRG system, as well as in the classification systems for diagnoses and procedures and in invoicing for 2008. Since the G-DRG system is only a tool for the redistribution of resources, every hospital needs to analyze the economic effects of the system by applying the G-DRG transition grouper to its own cases. Depending on their clinical focus, rheumatological departments may experience positive or negative effects from the system's application. The strain placed on hospitals by the inadequate funding of increased costs needs to be assessed separately from the effects of redistribution by the G-DRG system.

  9. [Increasingly appropriate depiction of rheumatology for G-DRG reimbursement 2006].

    PubMed

    Lakomek, H J; Fiori, W; Buscham, K; Hülsemann, J; Köneke, N; Liman, W; Märker-Hermann, E; Roeder, N

    2006-02-01

    Starting with the second year of the so called "convergence period", specialized rheumatological treatment is now represented by a specific DRG (197Z) in the German G-DRG system. The definition of this DRG is based on the procedure codes for the complex and multimodal treatment of rheumatological inpatients (OPS 8-983 and 8-986). This will result in a more appropriate reimbursement of rheumatological treatment. The implementation of specialized rheumatological treatment can be regarded as exemplary for the incorporation of medical specializations into DRG systems. The first step is the definition of the characteristics by procedure codes, which can consequently be utilized within the grouping algorithm. After an inadequate representation of a medical specialization within the DRG system has been demonstrated, a new DRG will be established. As no cost data were available, the calculation of a cost weight for the new G-DRG 197Z is not yet possible for 2006. Hence, reimbursement has to be negotiated between the individual hospital and the budget commission of the health insurers. In this context, the use of clinical pathways is considered helpful.

  10. PKA-induced internalization of slack KNa channels produces dorsal root ganglion neuron hyperexcitability.

    PubMed

    Nuwer, Megan O; Picchione, Kelly E; Bhattacharjee, Arin

    2010-10-20

    Inflammatory mediators through the activation of the protein kinase A (PKA) pathway sensitize primary afferent nociceptors to mechanical, thermal, and osmotic stimuli. However, it is unclear which ion conductances are responsible for PKA-induced nociceptor hyperexcitability. We have previously shown the abundant expression of Slack sodium-activated potassium (K(Na)) channels in nociceptive dorsal root ganglion (DRG) neurons. Here we show using cultured DRG neurons, that of the total potassium current, I(K), the K(Na) current is predominantly inhibited by PKA. We demonstrate that PKA modulation of K(Na) channels does not happen at the level of channel gating but arises from the internal trafficking of Slack channels from DRG membranes. Furthermore, we found that knocking down the Slack subunit by RNA interference causes a loss of firing accommodation analogous to that observed during PKA activation. Our data suggest that the change in nociceptive firing occurring during inflammation is the result of PKA-induced Slack channel trafficking.

  11. Shp-1 dephosphorylates TRPV1 in dorsal root ganglion neurons and alleviates CFA-induced inflammatory pain in rats.

    PubMed

    Xiao, Xing; Zhao, Xiao-Tao; Xu, Ling-Chi; Yue, Lu-Peng; Liu, Feng-Yu; Cai, Jie; Liao, Fei-Fei; Kong, Jin-Ge; Xing, Guo-Gang; Yi, Ming; Wan, You

    2015-04-01

    Transient receptor potential vanilloid 1 (TRPV1) receptors are expressed in nociceptive neurons of rat dorsal root ganglions (DRGs) and mediate inflammatory pain. Nonspecific inhibition of protein-tyrosine phosphatases (PTPs) increases the tyrosine phosphorylation of TRPV1 and sensitizes TRPV1. However, less is known about tyrosine phosphorylation's implication in inflammatory pain, compared with that of serine/threonine phosphorylation. Src homology 2 domain-containing tyrosine phosphatase 1 (Shp-1) is a key phosphatase dephosphorylating TRPV1. In this study, we reported that Shp-1 colocalized with and bound to TRPV1 in nociceptive DRG neurons. Shp-1 inhibitors, including sodium stibogluconate and PTP inhibitor III, sensitized TRPV1 in cultured DRG neurons. In naive rats, intrathecal injection of Shp-1 inhibitors increased both TRPV1 and tyrosine-phosphorylated TRPV1 in DRGs and induced thermal hyperalgesia, which was abolished by pretreatment with TRPV1 antagonists capsazepine, BCTC, or AMG9810. Complete Freund's adjuvant (CFA)-induced inflammatory pain in rats significantly increased the expression of Shp-1, TRPV1, and tyrosine-phosphorylated TRPV1, as well as the colocalization of Shp-1 and TRPV1 in DRGs. Intrathecal injection of sodium stibogluconate aggravated CFA-induced inflammatory pain, whereas Shp-1 overexpression in DRG neurons alleviated it. These results suggested that Shp-1 dephosphorylated and inhibited TRPV1 in DRG neurons, contributing to maintain thermal nociceptive thresholds in normal rats, and as a compensatory mechanism, Shp-1 increased in DRGs of rats with CFA-induced inflammatory pain, which was involved in protecting against excessive thermal hyperalgesia.

  12. Activation of silent mechanoreceptive cat C and Aδ sensory neurons and their substance P expression following peripheral inflammation

    PubMed Central

    Xu, Guang-Yin; Huang, Li-Yen Mae; Zhao, Zhi-Qi

    2000-01-01

    The effect of inflammation on the excitability and the level of substance P (SP) in cat mechanoreceptive C and Aδ dorsal root ganglion (DRG) neurons were studied in vivo using intracellular recording and immunocytochemical techniques. Following injections of carrageenan (Carg) into the cat hindpaw, the percentage of C neurons exhibiting spontaneous activity increased from 7.2 to 20.7 % and the percentage of Aδ neurons increased from 6.9 to 18.6 %. In contrast to most cells from normal cats, which fired regularly below 10 Hz, many cells from Carg-treated cats fired at higher frequencies or in bursts. Inflammation (Carg treatment) also depolarized membrane potentials, increased membrane input resistance, caused the disappearance of inward rectifying currents and lowered the mean current thresholds of tibial nerve-evoked responses in DRG neurons. With inflammation, the percentage of C or Aδ neurons responding to low threshold mechanoreceptive stimuli increased (C neurons: normal, 13 %; inflamed, 41 %; Aδ neurons: normal, 13 %; inflamed, 39 %), while the percentage of C or Aδ neurons responding to high threshold mechanoreceptive stimuli remained unchanged. Some receptive field (RF)-responsive cells were injected with Lucifer Yellow and their SP immunoreactivity was determined. Following Carg treatment, substantially higher percentages of RF-responsive cells were SP positive (C neurons: normal, 35.7 %; inflamed, 60 %; Aδ neurons: normal, 18.2 %; inflamed, 66.7 %). These combined increases in the excitability of DRG neurons and SP-containing RF-responsive neurons could lead to sensitization of sensory neurons, thus contributing to the development of hyperalgesia. PMID:11034623

  13. [G-DRG system 2009: relevant changes for rheumatology].

    PubMed

    Fiori, W; Liedtke-Dyong, A; Lakomek, H-J; Buscham, K; Lehmann, H; Liman, W; Fuchs, A-K; Bessler, F; Roeder, N

    2009-08-01

    The following article presents the main general and specific changes in the G-DRG (German diagnosis-related groups) system in terms of the classification systems for diagnoses and procedures as well as the billing process for 2009. Of fundamental relevance is the national weighting of the G-DRG I97Z (complex rheumatologic treatment), which up to now had to be negotiated individually by each hospital. Emphasis is also put on case auditing by the health insurers. Being primarily a tool for redistribution of resources, every hospital has to analyze the economic effects of the 2009 G-DRG system by applying the G-DRG transition grouper to its own cases. Depending on their clinical focus rheumatological departments may experience positive or negative consequences from the development. The strain imposed on hospitals by inadequate refunding of rising costs has to be assessed separately from the effects of redistribution by the G-DRG system.

  14. Tumor necrosis factor-α inhibits angiotensin II receptor type 1 expression in dorsal root ganglion neurons via β-catenin signaling.

    PubMed

    Yang, Y; Wu, H; Yan, J-Q; Song, Z-B; Guo, Q-L

    2013-09-17

    Both tumor necrosis factor (TNF)-α and the angiotensin (Ang) II/angiotensin II receptor type 1 (AT1) axis play important roles in neuropathic pain and nociception. In the present study, we explored the interaction between the two systems by examining the mutual effects between TNF-α and the Ang II/AT1 receptor axis in dorsal root ganglion (DRG) neurons. Rat DRG neurons were treated with TNF-α in different concentrations for different lengths of time in the presence or absence of transcription inhibitor actinomycin D, TNF receptor 1 (TNFR1) inhibitor SPD304, β-catenin signaling inhibitor CCT031374, or different kinase inhibitors. TNF-α decreased the AT1 receptor mRNA level as well as the AT1a receptor promoter activity in a dose-dependent manner within 30 h, which led to dose-dependent inhibition of Ang II-binding AT1 receptor level on the cell membrane. Actinomycin D (1 mg/ml), SPD304 (50 μM), p38 mitogen-activated protein kinase (MAPK) inhibitor PD169316 (25 μM), and CCT031374 (50 μM) completely abolished the inhibitory effect of TNF-α on AT1 receptor expression. TNF-α dose-dependently increased soluble β-catenin and phosphorylated GSK-3β levels, which was blocked by SPD304 and PD169316. In DRG neurons treated with AT2 receptor agonist CGP421140, or Ang II with or without AT1 receptor antagonist losartan or AT2 receptor antagonist PD123319 for 30 h, we found that Ang II and Ang II+PD123319 significantly decreased TNF-α expression, whereas CPG421140 and Ang II+losartan increased TNF-α expression. In conclusion, we demonstrate that TNF-α inhibits AT1 receptor expression at the transcription level via TNFR1 in rat DRG neurons by increasing the soluble β-catenin level through the p38 MAPK/GSK-3β pathway. In addition, Ang II appears to inhibit and induce TNF-α expression via the AT1 receptor and the AT2 receptor in DRG neurons, respectively. This is the first evidence of crosstalk between TNF-α and the Ang II/AT receptor axis in DRG neurons

  15. Neuromedin U Type 1 Receptor Stimulation of A-type K+ Current Requires the βγ Subunits of Go Protein, Protein Kinase A, and Extracellular Signal-regulated Kinase 1/2 (ERK1/2) in Sensory Neurons*

    PubMed Central

    Zhang, Yiming; Jiang, Dongsheng; Zhang, Yuan; Jiang, Xinghong; Wang, Fen; Tao, Jin

    2012-01-01

    Although neuromedin U (NMU) has been implicated in analgesia, the detailed mechanisms still remain unclear. In this study, we identify a novel functional role of NMU type 1 receptor (NMUR1) in regulating the transient outward K+ currents (IA) in small dorsal root ganglion (DRG) neurons. We found that NMU reversibly increased IA in a dose-dependent manner, instead the sustained delayed rectifier K+ current (IDR) was not affected. This NMU-induced IA increase was pertussis toxin-sensitive and was totally reversed by NMUR1 knockdown. Intracellular application of GDPβS (guanosine 5′-O-(2-thiodiphosphate)), QEHA peptide, or a selective antibody raised against the Gαo or Gβ blocked the stimulatory effects of NMU. Pretreatment of the cells with the protein kinase A (PKA) inhibitor or ERK inhibitor abolished the NMU-induced IA response, whereas inhibition of phosphatidylinositol 3-kinase or PKC had no such effects. Exposure of DRG neurons to NMU markedly induced the phosphorylation of ERK (p-ERK), whereas p-JNK or p-p38 was not affected. Moreover, the NMU-induced p-ERK increase was attenuated by PKA inhibition and activation of PKA by foskolin would mimic the NMU-induced IA increase. Functionally, we observed a significant decrease of the firing rate of neuronal action potential induced by NMU and pretreatment of DRG neurons with 4-AP could abolish this effect. In summary, these results suggested that NMU increases IA via activation of NMUR1 that couples sequentially to the downstream activities of Gβγ of the Go protein, PKA, and ERK, which could contribute to its physiological functions including neuronal hypoexcitability in DRG neurons. PMID:22493291

  16. Purification and culture of adult rat dorsal root ganglia neurons.

    PubMed

    Delree, P; Leprince, P; Schoenen, J; Moonen, G

    1989-06-01

    To study the trophic requirements of adult rat dorsal root ganglia neurons (DRG) in vitro, we developed a purification procedure that yields highly enriched neuronal cultures. Forty to fifty ganglia are dissected from the spinal column of an adult rat. After enzymatic and mechanical dissociation of the ganglia, myelin debris are eliminated by centrifugation on a Percoll gradient. The resulting cell suspension is layered onto a nylon mesh with a pore size of 10 microns. Most of the neurons, the diameter of which ranged from 17 microns to greater than 100 microns, are retained on the upper surface of the sieve; most of the non-neuronal cells with a caliber of less than 10 microns after trypsinization go through it. Recovery of neurons is achieved by reversing the mesh onto a Petri dish containing culture medium. Neurons to non-neurons ratio is 1 to 10 in the initial cell suspension and 1 to 1 after separation. When these purified neurons are seeded at a density of 3,000 neurons/cm2 in 6 mm polyornithine-laminin (PORN-LAM) coated wells, neuronal survival (assessed by the ability to extend neurites), measured after 48 hr of culture, is very low (from 0 to 16%). Addition of nerve growth factor (NGF) does not improve neuronal survival. However, when neurons are cultured in the presence of medium conditioned (CM) by astrocytes or Schwann cells, 60-80% of the seeded, dye-excluding neurons survive. So, purified adult DRG neurons require for their short-term survival and regeneration in culture, a trophic support that is present in conditioned medium from PNS or CNS glia.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. RAGE-dependent potentiation of TRPV1 currents in sensory neurons exposed to high glucose.

    PubMed

    Lam, Doris; Momeni, Zeinab; Theaker, Michael; Jagadeeshan, Santosh; Yamamoto, Yasuhiko; Ianowski, Juan P; Campanucci, Verónica A

    2018-01-01

    Diabetes mellitus is associated with sensory abnormalities, including exacerbated responses to painful (hyperalgesia) or non-painful (allodynia) stimuli. These abnormalities are symptoms of diabetic peripheral neuropathy (DPN), which is the most common complication that affects approximately 50% of diabetic patients. Yet, the underlying mechanisms linking hyperglycemia and symptoms of DPN remain poorly understood. The transient receptor potential vanilloid 1 (TRPV1) channel plays a central role in such sensory abnormalities and shows elevated expression levels in animal models of diabetes. Here, we investigated the function of TRPV1 channels in sensory neurons cultured from the dorsal root ganglion (DRG) of neonatal mice, under control (5mM) and high glucose (25mM) conditions. After maintaining DRG neurons in high glucose for 1 week, we observed a significant increase in capsaicin (CAP)-evoked currents and CAP-evoked depolarizations, independent of TRPV1 channel expression. These functional changes were largely dependent on the expression of the receptor for Advanced Glycation End-products (RAGE), calcium influx, cytoplasmic ROS accumulation, PKC, and Src kinase activity. Like cultured neurons from neonates, mature neurons from adult mice also displayed a similar potentiation of CAP-evoked currents in the high glucose condition. Taken together, our data demonstrate that under the diabetic condition, DRG neurons are directly affected by elevated levels of glucose, independent of vascular or glial signals, and dependent on RAGE expression. These early cellular and molecular changes to sensory neurons in vitro are potential mechanisms that might contribute to sensory abnormalities that can occur in the very early stages of diabetes.

  18. RAGE-dependent potentiation of TRPV1 currents in sensory neurons exposed to high glucose

    PubMed Central

    Lam, Doris; Momeni, Zeinab; Theaker, Michael; Jagadeeshan, Santosh; Yamamoto, Yasuhiko; Ianowski, Juan P.

    2018-01-01

    Diabetes mellitus is associated with sensory abnormalities, including exacerbated responses to painful (hyperalgesia) or non-painful (allodynia) stimuli. These abnormalities are symptoms of diabetic peripheral neuropathy (DPN), which is the most common complication that affects approximately 50% of diabetic patients. Yet, the underlying mechanisms linking hyperglycemia and symptoms of DPN remain poorly understood. The transient receptor potential vanilloid 1 (TRPV1) channel plays a central role in such sensory abnormalities and shows elevated expression levels in animal models of diabetes. Here, we investigated the function of TRPV1 channels in sensory neurons cultured from the dorsal root ganglion (DRG) of neonatal mice, under control (5mM) and high glucose (25mM) conditions. After maintaining DRG neurons in high glucose for 1 week, we observed a significant increase in capsaicin (CAP)-evoked currents and CAP-evoked depolarizations, independent of TRPV1 channel expression. These functional changes were largely dependent on the expression of the receptor for Advanced Glycation End-products (RAGE), calcium influx, cytoplasmic ROS accumulation, PKC, and Src kinase activity. Like cultured neurons from neonates, mature neurons from adult mice also displayed a similar potentiation of CAP-evoked currents in the high glucose condition. Taken together, our data demonstrate that under the diabetic condition, DRG neurons are directly affected by elevated levels of glucose, independent of vascular or glial signals, and dependent on RAGE expression. These early cellular and molecular changes to sensory neurons in vitro are potential mechanisms that might contribute to sensory abnormalities that can occur in the very early stages of diabetes. PMID:29474476

  19. 42 CFR 476.84 - Changes as a result of DRG validation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Changes as a result of DRG validation. 476.84... § 476.84 Changes as a result of DRG validation. A provider or practitioner may obtain a review by a QIO under part 473 of this chapter for changes in diagnostic and procedural coding that resulted in a change...

  20. 42 CFR 476.84 - Changes as a result of DRG validation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Changes as a result of DRG validation. 476.84... § 476.84 Changes as a result of DRG validation. A provider or practitioner may obtain a review by a QIO under part 473 of this chapter for changes in diagnostic and procedural coding that resulted in a change...

  1. 42 CFR 476.84 - Changes as a result of DRG validation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Changes as a result of DRG validation. 476.84... § 476.84 Changes as a result of DRG validation. A provider or practitioner may obtain a review by a QIO under part 473 of this chapter for changes in diagnostic and procedural coding that resulted in a change...

  2. 42 CFR 476.84 - Changes as a result of DRG validation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Changes as a result of DRG validation. 476.84... § 476.84 Changes as a result of DRG validation. A provider or practitioner may obtain a review by a QIO under part 473 of this chapter for changes in diagnostic and procedural coding that resulted in a change...

  3. Advanced Oxidative Protein Products Cause Pain Hypersensitivity in Rats by Inducing Dorsal Root Ganglion Neurons Apoptosis via NADPH Oxidase 4/c-Jun N-terminal Kinase Pathways

    PubMed Central

    Ding, Ruoting; Sun, Baihui; Liu, Zhongyuan; Yao, Xinqiang; Wang, Haiming; Shen, Xing; Jiang, Hui; Chen, Jianting

    2017-01-01

    Pain hypersensitivity is the most common category of chronic pain and is difficult to cure. Oxidative stress and certain cells apoptosis, such as dorsal root ganglion (DRG) neurons, play an essential role in the induction and development of pain hypersensitivity. The focus of this study is at a more specific molecular level. We investigated the role of advanced oxidative protein products (AOPPs) in inducing hypersensitivity and the cellular mechanism underlying the proapoptotic effect of AOPPs. Normal rats were injected by AOPPs-Rat serum albumin (AOPPs–RSA) to cause pain hypersensitivity. Primary cultured DRG neurons were treated with increasing concentrations of AOPPs–RSA or for increasing time durations. The MTT, flow cytometry and western blot analyses were performed in the DRG neurons. A loss of mitochondrial membrane potential (MMP) and an increase in intracellular reactive oxygen species (ROS) were observed. We found that AOPPs triggered DRG neurons apoptosis and MMP loss. After AOPPs treatment, intracellular ROS generation increased in a time- and dose-dependent manner, whereas, N-acetyl-L-cysteine (NAC), a specific ROS scavenger could inhibit the ROS generation. Proapoptotic proteins, such as Bax, caspase 9/caspase 3, and PARP-1 were activated, whereas anti-apoptotic Bcl-2 protein was down-regulated. AOPPs also increased Nox4 and JNK expression. Taken together, these findings suggest that AOPPs cause pain hypersensitivity in rats, and extracellular AOPPs accumulation triggered Nox4-dependent ROS production, which activated JNK, and induced DRG neurons apoptosis by activating caspase 3 and PARP-1. PMID:28674486

  4. Amyloid-beta peptide oligomers disrupt axonal transport through an NMDA receptor-dependent mechanism that is mediated by glycogen synthase kinase 3beta in primary cultured hippocampal neurons.

    PubMed

    Decker, Helena; Lo, Karen Y; Unger, Sandra M; Ferreira, Sergio T; Silverman, Michael A

    2010-07-07

    Disruption of axonal transport is a hallmark of several neurodegenerative diseases, including Alzheimer's disease (AD). Even though defective transport is considered an early pathologic event, the mechanisms by which neurodegenerative insults impact transport are poorly understood. We show that soluble oligomers of the amyloid-beta peptide (AbetaOs), increasingly recognized as the proximal neurotoxins in AD pathology, induce disruption of organelle transport in primary hippocampal neurons in culture. Live imaging of fluorescent protein-tagged organelles revealed a marked decrease in axonal trafficking of dense-core vesicles and mitochondria in the presence of 0.5 microm AbetaOs. NMDA receptor (NMDAR) antagonists, including d-AP5, MK-801, and memantine, prevented the disruption of trafficking, thereby identifying signals for AbetaO action at the cell membrane. Significantly, both pharmacological inhibition of glycogen synthase kinase-3beta (GSK-3beta) and transfection of neurons with a kinase-dead form of GSK-3beta prevented the transport defect. Finally, we demonstrate by biochemical and immunocytochemical means that AbetaOs do not affect microtubule stability, indicating that disruption of transport involves a more subtle mechanism than microtubule destabilization, likely the dysregulation of intracellular signaling cascades. Results demonstrate that AbetaOs negatively impact axonal transport by a mechanism that is initiated by NMDARs and mediated by GSK-3beta and establish a new connection between toxic Abeta oligomers and AD pathology.

  5. Glycogen synthase kinase-3beta (GSK-3beta) inhibitors AR-A014418 and B6B3O prevent human immunodeficiency virus-mediated neurotoxicity in primary human neurons.

    PubMed

    Nguyen, Timothy B; Lucero, Ginger R; Chana, Gursharan; Hult, Britta J; Tatro, Erick T; Masliah, Eliezer; Grant, Igor; Achim, Cristian L; Everall, Ian P

    2009-09-01

    Glycogen synthase kinase-3beta (GSK3beta) role in human immunodeficiency virus(HIV)-associated neurodegeneration has been evidenced by previous investigations. In this study, we investigated the specificity of two GSK3beta-specific inhibitors, AR-A014418 (A) and B6B30 (B) to prevent direct neurotoxicity in primary human neurons exposed to HIV (BaL). Neurons were exposed to HIV (500 pg/ml) for 12-h and 6-day periods in the presence and absence of A (1 microM, 100 nM, 10 nM) and B (50 nM, 5 nM, 500 pM) to investigate acute and ongoing mechanisms of HIV neurotoxicity. Using an lactate dehydrogenase (LDH) assay to assess cytotoxicity, we observed a significant neurotoxic effect of HIV from control values (P < .01) that was not restored via coexposures of all concentrations of A and B. Additionally, no change in LDH levels were observed after 6 days. However, activity of the acute proapoptotic markers caspases 3 and 7 using a luminescence assay were measured and found to be increased by exposure to HIV (BaL) compared to controls (P = .022). This effect was ameliorated via coexposure to all concentrations of A and 50 nM B after 12 h (P < .01) and to all concentrations of A and B after 6 days (P < .01). Overall, the results from this study provide further evidence for the ability of GSK3beta inhibition to be neuroprotective against HIV-associated neurotoxicity by reducing HIV associated procaspase induction. These data support a role for GSK3beta as a potential therapeutic target and may have important clinical implications for treatment of HIV-associated neurocognitive disorder.

  6. [Orthopedic and trauma surgery in the German DRG system 2008].

    PubMed

    Franz, D; Kaufmann, M; Siebert, C H; Windolf, J; Roeder, N

    2008-04-01

    The German DRG (diagnosis-related groups) system has been modified and updated into version 2008. For orthopedic and trauma surgery significant changes concerning coding of diagnoses, medical procedures and the DRG structure were made. The modified version has been analyzed in order to ascertain whether the DRG system is suitably qualified to fulfill the demands of the reimbursement system or whether further improvements are necessary. Analysis of the severity of relevant side-effect diagnoses, medical procedures and G-DRGs in the versions 2007 and 2008 was carried out based on the publications of the German DRG institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). Changes for 2008 focused on the development of DRG structure, DRG validation and codes for medical procedures. The outcome of these changes for German hospitals may vary depending on the range of activities. G-DRG system has become even more complex and the new regulations have also resulted in new problems associated with complications.. High demands are made on correct and complete coding of complex orthopedic and trauma surgery cases. Quality of case allocation within the G-DRG system has been improved. Nevertheless, further improvements of the G-DRG system are necessary, especially for cases with severe injuries.

  7. Mechanical compression insults induce nanoscale changes of membrane-skeleton arrangement which could cause apoptosis and necrosis in dorsal root ganglion neurons.

    PubMed

    Quan, Xin; Guo, Kai; Wang, Yuqing; Huang, Liangliang; Chen, Beiyu; Ye, Zhengxu; Luo, Zhuojing

    2014-01-01

    In a primary spinal cord injury, the amount of mechanical compression insult that the neurons experience is one of the most critical factors in determining the extent of the injury. The ultrastructural changes that neurons undergo when subjected to mechanical compression are largely unknown. In the present study, using a compression-driven instrument that can simulate mechanical compression insult, we applied mechanical compression stimulation at 0.3, 0.5, and 0.7 MPa to dorsal root ganglion (DRG) neurons for 10 min. Combined with atomic force microscopy, we investigated nanoscale changes in the membrane-skeleton, cytoskeleton alterations, and apoptosis induced by mechanical compression injury. The results indicated that mechanical compression injury leads to rearrangement of the membrane-skeleton compared with the control group. In addition, mechanical compression stimulation induced apoptosis and necrosis and also changed the distribution of the cytoskeleton in DRG neurons. Thus, the membrane-skeleton may play an important role in the response to mechanical insults in DRG neurons. Moreover, sudden insults caused by high mechanical compression, which is most likely conducted by the membrane-skeleton, may induce necrosis, apoptosis, and cytoskeletal alterations.

  8. Biological constraints limit the use of rapamycin-inducible FKBP12-Inp54p for depleting PIP2 in dorsal root ganglia neurons.

    PubMed

    Coutinho-Budd, Jaeda C; Snider, Samuel B; Fitzpatrick, Brendan J; Rittiner, Joseph E; Zylka, Mark J

    2013-09-08

    Rapamycin-induced translocation systems can be used to manipulate biological processes with precise temporal control. These systems are based on rapamycin-induced dimerization of FK506 Binding Protein 12 (FKBP12) with the FKBP Rapamycin Binding (FRB) domain of mammalian target of rapamycin (mTOR). Here, we sought to adapt a rapamycin-inducible phosphatidylinositol 4,5-bisphosphate (PIP2)-specific phosphatase (Inp54p) system to deplete PIP2 in nociceptive dorsal root ganglia (DRG) neurons. We genetically targeted membrane-tethered CFP-FRBPLF (a destabilized FRB mutant) to the ubiquitously expressed Rosa26 locus, generating a Rosa26-FRBPLF knockin mouse. In a second knockin mouse line, we targeted Venus-FKBP12-Inp54p to the Calcitonin gene-related peptide-alpha (CGRPα) locus. We hypothesized that after intercrossing these mice, rapamycin treatment would induce translocation of Venus-FKBP12-Inp54p to the plasma membrane in CGRP+ DRG neurons. In control experiments with cell lines, rapamycin induced translocation of Venus-FKBP12-Inp54p to the plasma membrane, and subsequent depletion of PIP2, as measured with a PIP2 biosensor. However, rapamycin did not induce translocation of Venus-FKBP12-Inp54p to the plasma membrane in FRBPLF-expressing DRG neurons (in vitro or in vivo). Moreover, rapamycin treatment did not alter PIP2-dependent thermosensation in vivo. Instead, rapamycin treatment stabilized FRBPLF in cultured DRG neurons, suggesting that rapamycin promoted dimerization of FRBPLF with endogenous FKBP12. Taken together, our data indicate that these knockin mice cannot be used to inducibly deplete PIP2 in DRG neurons. Moreover, our data suggest that high levels of endogenous FKBP12 could compete for binding to FRBPLF, hence limiting the use of rapamycin-inducible systems to cells with low levels of endogenous FKBP12.

  9. Attenuated Response to Methamphetamine Sensitization and Deficits in Motor Learning and Memory after Selective Deletion of [beta]-Catenin in Dopamine Neurons

    ERIC Educational Resources Information Center

    Diaz-Ruiz, Oscar; Zhang, YaJun; Shan, Lufei; Malik, Nasir; Hoffman, Alexander F.; Ladenheim, Bruce; Cadet, Jean Lud; Lupica, Carl R.; Tagliaferro, Adriana; Brusco, Alicia; Backman, Cristina M.

    2012-01-01

    In the present study, we analyzed mice with a targeted deletion of [beta]-catenin in DA neurons (DA-[beta]cat KO mice) to address the functional significance of this molecule in the shaping of synaptic responses associated with motor learning and following exposure to drugs of abuse. Relative to controls, DA-[beta]cat KO mice showed significant…

  10. Isl-1 down-regulates DRG cell proliferation during chicken embryo development.

    PubMed

    Chen, Dawei; Wang, Guoxin; Luo, Haoshu; Liu, Jiali; Cui, Sheng

    2010-01-01

    Protein Isl-1 RNA interference and over expression in early chicken embryo dorsal root ganglia (DRG) were used to investigate the function of Isl-1 in DRG cell proliferation. Isl-1 targeted shRNA expression vector and Isl-1 over-expression vector were transfected into chicken embryo DRG by in ovo electroporation. Then, the DRG proliferation rate was detected by BrdU immunohistochemistry. The rate of DRG cell proliferation increased after Isl-1 knock-down and decreased after Isl-1 over-expression. In this study, we found that Isl-1 negatively modulates DRG cell proliferation.

  11. [Effects of Chinese herbal medicine Yiqi Huayu Recipe on apoptosis of dorsal root ganglion neurons and expression of caspase-3 in rats with lumbar nerve root compression].

    PubMed

    Xu, Le-qin; Li, Xiao-feng; Zhang, You-wei; Shu, Bing; Shi, Qi; Wang, Yong-jun; Zhou, Chong-jian

    2010-12-01

    To observe the effects of Yiqi Huayu Recipe, a Chinese compound herbal medicine, on apoptosis of dorsal root ganglion (DRG) neurons and expression of caspase-3 in rats after lumbar nerve root compression injury. A total of 40 male Sprague-Dawley rats were randomly allocated into 4 groups: control group, untreated group, Methylcobal group and Yiqi Huayu Recipe group. Surgery was performed on rats of untreated group, Methylcobal group and Yiqi Huayu Recipe group to place a micro-silica gel on right L₄ DRG, while control group received skin and paravertebral muscle incision only. Rats in Methylcobal group and Yiqi Huayu Recipe group were given Methylcobal by intramuscular injection and Yiqi Huayu Recipe intragastrically respectively. Rats in control group and untreated group received saline intragastrically as equal amount as Yiqi Huayu Recipe group. The compressed nerve roots were harvested at the 10th day after treatment. Apoptosis of DRG neurons was detected by terminal deoxynucleotidyl transferase-mediated nick-end labeling. Caspase-3 activity and mRNA expression in compressed nerve roots were detected with spectrophotography and real-time polymerase chain reaction respectively. Apoptosis of DRG neurons was significantly increased in the rat model. The apoptosis index of untreated group was higher than that of control group (P<0.01). Yiqi Huayu Recipe and Methylcobal could reduce the apoptosis of DRG neurons, and both groups showed a lower apoptosis index than untreated group (P<0.01). Caspase-3 activity and its gene expression were significantly increased in untreated group. The levels of caspase-3 activity and its gene expression in untreated group were higher than those in control group (P<0.05 or P<0.01). Yiqi Huayu Recipe and Methylcobal could reduce the overexpression of caspase-3 mRNA, and statistically significant differences were found between the untreated group and Yiqi Huayu Recipe group or Methylcobal group (P<0.01). Lumbar nerve root compression

  12. Characteristics of sensory neuronal groups in CGRP-cre-ER reporter mice: Comparison to Nav1.8-cre, TRPV1-cre and TRPV1-GFP mouse lines.

    PubMed

    Patil, Mayur J; Hovhannisyan, Anahit H; Akopian, Armen N

    2018-01-01

    Peptidergic sensory neurons play a critical role in nociceptive pathways. To precisely define the function and plasticity of sensory neurons in detail, new tools such as transgenic mouse models are needed. We employed electrophysiology and immunohistochemistry to characterize in detail dorsal root ganglion (DRG) neurons expressing an inducible CGRPcre-ER (CGRP-cre+); and compared them to DRG neurons expressing Nav1.8cre (Nav1.8-cre+), TRPV1cre (TRPV1-cre+) and TRPV1-GFP (V1-GFP+). Tamoxifen effectively induced CGRPcre-ER production in DRG. ≈87% of CGRPcre-ER-expressing neurons were co-labeled CGRP antibody. Three small and two medium-large-sized (5HT3a+/NPY2R- and NPY2R+) neuronal groups with unique electrophysiological profiles were CGRP-cre+. Nav1.8-cre+ neurons were detected in all CGRP-cre+ groups, as well as in 5 additional neuronal groups: MrgprD+/TRPA1-, MrgprD+/TRPA1+, TRPV1+/CGRP-, vGLUT3+ and ≈30% of trkC+ neurons. Differences between TRPV1cre and Nav1.8cre reporters were that unlike TRPV1-cre+, Nav1.8-cre+ expression was detected in non-nociceptive vGLUT3+ and trkC+ populations. Many TRPV1-cre+ neurons did not respond to capsaicin. In contrast, V1-GFP+ neurons were in 4 groups, each of which was capsaicin-sensitive. Finally, none of the analyzed reporter lines showed cre-recombination in trkB+, calbindin+, 70% of trkC+ or parvalbumin+ neurons, which together encompassed ≈20% of Nav1.8-cre- DRG neurons. The data presented here increases our knowledge of peptidergic sensory neuron characteristics, while showing the efficiency and specificity manipulation of peptidergic neurons by the CGRPcre-ER reporter. We also demonstrate that manipulation of all C- and A-nociceptors is better achieved with TRPV1-cre reporter. Finally, the described approach for detailed characterization of sensory neuronal groups can be applied to a variety of reporter mice.

  13. Targeting dorsal root ganglia and primary sensory neurons for the treatment of chronic pain

    PubMed Central

    Berta, Temugin; Qadri, Yawar; Tan, Ping-Heng; Ji, Ru-Rong

    2018-01-01

    Introduction Currently the treatment of chronic pain is inadequate and compromised by debilitating central nervous system side effects. Here we discuss new therapeutic strategies that target dorsal root ganglia (DRGs) in the peripheral nervous system for a better and safer treatment of chronic pain. Areas covered The DRGs contain the cell bodies of primary sensory neurons including nociceptive neurons. After painful injuries, primary sensory neurons demonstrate maladaptive molecular changes in DRG cell bodies and in their axons. These changes result in hypersensitivity and hyperexcitability of sensory neurons (peripheral sensitization) and are crucial for the onset and maintenance of chronic pain. We discuss the following new strategies to target DRGs and primary sensory neurons as a means of alleviating chronic pain and minimizing side effects: inhibition of sensory neuron-expressing ion channels such as TRPA1, TRPV1, and Nav1.7, selective blockade of C- and Aβ-afferent fibers, gene therapy, and implantation of bone marrow stem cells. Expert opinion These peripheral pharmacological treatments, as well as gene and cell therapies, aimed at DRG tissues and primary sensory neurons can offer better and safer treatments for inflammatory, neuropathic, cancer, and other chronic pain states. PMID:28480765

  14. Intrathecal administration of rapamycin inhibits the phosphorylation of DRG Nav1.8 and attenuates STZ-induced painful diabetic neuropathy in rats.

    PubMed

    He, Wan-You; Zhang, Bin; Xiong, Qing-Ming; Yang, Cheng-Xiang; Zhao, Wei-Cheng; He, Jian; Zhou, Jun; Wang, Han-Bing

    2016-04-21

    The mammalian target of rapamycin (mTOR) is a key regulator of mRNA translation and protein synthesis, and it is specifically inhibited by rapamycin. In chronic pain conditions, mTOR-mediated local protein synthesis is crucial for neuronal hyperexcitability and synaptic plasticity. The tetrodotoxin-resistant (TTX-R) sodium channel Nav1.8 plays a major role in action potential initiation and propagation and cellular excitability in DRG (dorsal root ganglion) neurons. In this study, we investigated if mTOR modulates the phosphorylation of Nav1.8 that is associated with neuronal hyperexcitability and behavioral hypersensitivity in STZ-induced diabetic rats. Painful diabetic neuropathy (PDN) was induced in Sprague-Dawley rats by intraperitoneal injection with streptozotocin (STZ) at 60mg/kg. After the onset of PDN, the rats received daily intrathecal administrations of rapamycin (1μg, 3μg, or 10μg/day) for 7 days; other diabetic rats received the same volumes of dimethyl sulfoxide (DMSO). Herein, we demonstrate a marked increase in protein expression of total mTOR and phospho-mTOR (p-mTOR) together with the up-regulation of phosphor-Nav1.8 (p-Nav1.8) prior to the mechanical withdrawal threshold reaching a significant reduction in dorsal root ganglions (DRGs). Furthermore, the intrathecal administration of rapamycin, inhibiting the activity of mTOR, suppressed the phosphorylation of DRG Nav1.8, reduced the TTX-R current density, heightened the voltage threshold for activation and lowered the voltage threshold for inactivation and relieved mechanical hypersensitivity in diabetic rats. An intrathecal injection (i.t.) of rapamycin inhibited the phosphorylation and enhanced the functional availability of DRG Nav1.8 attenuated STZ-induced hyperalgesia. These results suggest that rapamycin is a potential therapeutic intervention for clinical PDN. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Characteristics of dorsal root ganglia neurons sensitive to Substance P.

    PubMed

    Moraes, Eder Ricardo; Kushmerick, Christopher; Naves, Ligia Araujo

    2014-11-27

    Substance P modulates ion channels and the excitability of sensory neurons in pain pathways. Within the heterogeneous population of Dorsal Root Ganglia (DRG) primary sensory neurons, the properties of cells that are sensitive to Substance P are poorly characterized. To define this population better, dissociated rat DRG neurons were tested for their responsiveness to capsaicin, ATP and acid. Responses to ATP were classified according to the kinetics of current activation and desensitization. The same cells were then tested for modulation of action potential firing by Substance P. Acid and capsaicin currents were more frequently encountered in the largest diameter neurons. P2X3-like ATP currents were concentrated in small diameter neurons. Substance P modulated the excitability in 20 of 72 cells tested (28%). Of the Substance P sensitive cells, 10 exhibited an increase in excitability and 10 exhibited a decrease in excitability. There was no significant correlation between sensitivity to capsaicin and to Substance P. Excitatory effects of Substance P were strongly associated with cells that had large diameters, fired APs with large overshoots and slowly decaying after hyperpolarizations, and expressed acid currents at pH 7. No neurons that were excited by Substance P presented P2X3-like currents. In contrast, neurons that exhibited inhibitory effects of Substance P fired action potentials with rapidly decaying after hyperpolarizations. We conclude that excitatory effects of Substance P are restricted to a specific neuronal subpopulation with limited expression of putative nociceptive markers.

  16. [Possibilities and limitations for the representation of ENT medicine in the G-DRG reimbursement system. Results of the DRG evaluation project].

    PubMed

    Franz, D; Roeder, N; Hörmann, K; Alberty, J

    2006-03-01

    To improve the representation of ENT medicine in the German diagnosis related groups (G-DRG) reimbursement system, the German Association for ENT Medicine and the ENT Professional Medical Association, in cooperation with the DRG-Research Group of the University Hospital of Muenster, undertook a DRG evaluation project. A retrospective analysis was carried out of the DRG data records from 93,605 cases taken at 39 ENT institutions in 2003. A prospective collection of data from 25,666 cases, including defined expenditure data within a 4 month period in 2004, was also made. The number of cases per ENT institution ranged from 274 to 2,556. The mean case-mix was 792.0 and the mean case-mix index was 0.84. A total of 60.5% of the patients were male and 39.5% female, with an average age of 43.3 years. The mean patient clinical and complexity level (PCCL) was 0.72. Considerable adjustments have to be made, especially in oto-, rhino- and sinus-surgery. Allocation according to the complexity of the surgical procedure is mandatory and requires a revision of the German Catalogue of Medical Procedures. A DRG differentiation based on the PCCL should be implemented more frequently. Diagnostic endoscopies should be allocated via surgical partitioning. The adjustment proposals based on these results will gradually lead to an improved allocation of ENT medical procedures within the G-DRG system in 2006 and later.

  17. State-space decoding of primary afferent neuron firing rates

    NASA Astrophysics Data System (ADS)

    Wagenaar, J. B.; Ventura, V.; Weber, D. J.

    2011-02-01

    Kinematic state feedback is important for neuroprostheses to generate stable and adaptive movements of an extremity. State information, represented in the firing rates of populations of primary afferent (PA) neurons, can be recorded at the level of the dorsal root ganglia (DRG). Previous work in cats showed the feasibility of using DRG recordings to predict the kinematic state of the hind limb using reverse regression. Although accurate decoding results were attained, reverse regression does not make efficient use of the information embedded in the firing rates of the neural population. In this paper, we present decoding results based on state-space modeling, and show that it is a more principled and more efficient method for decoding the firing rates in an ensemble of PA neurons. In particular, we show that we can extract confounded information from neurons that respond to multiple kinematic parameters, and that including velocity components in the firing rate models significantly increases the accuracy of the decoded trajectory. We show that, on average, state-space decoding is twice as efficient as reverse regression for decoding joint and endpoint kinematics.

  18. [Effects of intrathecal administration of AM22-52 on mechanical allodynia and CCL2 expression in DRG in bone cancer rats].

    PubMed

    Chen, Ya-Juan; Huo, Yuan-Hui; Hong, Yanguo

    2017-02-25

    The pain peptide adrenomedullin (AM) plays a pivotal role in pathological pain. The present study was designed to investigate the effect of blockade of AM receptor on bone cancer pain (BCP) and its mechanism. BCP was developed by inoculation of Walker 256 mammary gland carcinoma cells in the tibia medullary cavity of Sprague Dawley rats. The selective AM receptor antagonist AM 22-52 was administered intrathecally on 15 d after the inoculation. Quantitative real-time PCR was used to detect mRNA level of CC chemokine ligand 2 (CCL2) in dorsal root ganglion (DRG). Double immunofluorescence staining was used to analyze the localizations of CCL2 and AM in DRG of normal rats. The results showed that, from 6 to15 d after the inoculation, the animals showed significant reduction in the mechanical pain threshold in the ipsilateral hindpaw, companied by the decline in bone density of tibia bone. The expression of CCL2 mRNA in DRG of BCP rats was increased by 3 folds (P < 0.001 vs saline group). Intrathecal administration of AM 22-52 abolished bone cancer-induced mechanical allodynia and increase of CCL2 mRNA level (P < 0.001). In normal rats, CCL2 was co-localized with AM in DRG neurons. These results suggest that AM may play a role in the pathogenesis of BCP. The increased AM bioactivity up-regulates CCL2 expression in DRG, which may contribute to the induction of pain hypersensitivity in bone cancer.

  19. 42 CFR 412.10 - Changes in the DRG classification system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Changes in the DRG classification system. 412.10... § 412.10 Changes in the DRG classification system. (a) General rule. CMS issues changes in the DRG classification system in a Federal Register notice at least annually. Except as specified in paragraphs (c) and...

  20. 42 CFR 412.10 - Changes in the DRG classification system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Changes in the DRG classification system. 412.10... § 412.10 Changes in the DRG classification system. (a) General rule. CMS issues changes in the DRG classification system in a Federal Register notice at least annually. Except as specified in paragraphs (c) and...

  1. [Orthopedic and trauma surgery in the German DRG System 2007].

    PubMed

    Franz, D; Kaufmann, M; Siebert, C H; Windolf, J; Roeder, N

    2007-03-01

    The German Diagnosis-Related Groups (DRG) System was further developed into its 2007 version. For orthopedic and trauma surgery, significant changes were made in terms of the coding of diagnoses and medical procedures, as well as in the DRG structure itself. The German Societies for Trauma Surgery and for Orthopedics and Orthopedic Surgery (Deutsch Gesellschaft für Unfallchirurgie, DGU; and Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie, DGOOC) once again cooperated constructively with the German DRG Institute InEK. Among other innovations, new International Classification of Diseases (ICD) codes for second-degree burns were implemented. Procedure codes for joint operations, endoprosthetic-surgery and spine surgery were restructured. Furthermore, a specific code for septic surgery was introduced in 2007. In addition, the DRG structure was improved. Case allocation of patients with more than one significant operation was established. Further DRG subdivisions were established according to the patients age and the Patient Clinical Complexity Level (PCCL). DRG developments for 2007 have improved appropriate case allocation, but once again increased the system's complexity. Clinicians need an ever growing amount of specific coding know-how. Still, further adjustments to the German DRG system are required to allow for a correct allocation of cases and funds.

  2. Dicer maintains the identity and function of proprioceptive sensory neurons

    PubMed Central

    O’Toole, Sean M.; Ferrer, Monica M.; Mekonnen, Jennifer; Zhang, Haihan; Shima, Yasuyuki; Ladle, David R.

    2017-01-01

    Neuronal cell identity is established during development and must be maintained throughout an animal’s life (Fishell G, Heintz N. Neuron 80: 602–612, 2013). Transcription factors critical for establishing neuronal identity can be required for maintaining it (Deneris ES, Hobert O. Nat Neurosci 17: 899–907, 2014). Posttranscriptional regulation also plays an important role in neuronal differentiation (Bian S, Sun T. Mol Neurobiol 44: 359–373, 2011), but its role in maintaining cell identity is less established. To better understand how posttranscriptional regulation might contribute to cell identity, we examined the proprioceptive neurons in the dorsal root ganglion (DRG), a highly specialized sensory neuron class, with well-established properties that distinguish them from other neurons in the ganglion. By conditionally ablating Dicer in mice, using parvalbumin (Pvalb)-driven Cre recombinase, we impaired posttranscriptional regulation in the proprioceptive sensory neuron population. Knockout (KO) animals display a progressive form of ataxia at the beginning of the fourth postnatal week that is accompanied by a cell death within the DRG. Before cell loss, expression profiling shows a reduction of proprioceptor specific genes and an increased expression of nonproprioceptive genes normally enriched in other ganglion neurons. Furthermore, although central connections of these neurons are intact, the peripheral connections to the muscle are functionally impaired. Posttranscriptional regulation is therefore necessary to retain the transcriptional identity and support functional specialization of the proprioceptive sensory neurons. NEW & NOTEWORTHY We have demonstrated that selectively impairing Dicer in parvalbumin-positive neurons, which include the proprioceptors, triggers behavioral changes, a lack of muscle connectivity, and a loss of transcriptional identity as observed through RNA sequencing. These results suggest that Dicer and, most likely by extension

  3. Dicer maintains the identity and function of proprioceptive sensory neurons.

    PubMed

    O'Toole, Sean M; Ferrer, Monica M; Mekonnen, Jennifer; Zhang, Haihan; Shima, Yasuyuki; Ladle, David R; Nelson, Sacha B

    2017-03-01

    Neuronal cell identity is established during development and must be maintained throughout an animal's life (Fishell G, Heintz N. Neuron 80: 602-612, 2013). Transcription factors critical for establishing neuronal identity can be required for maintaining it (Deneris ES, Hobert O. Nat Neurosci 17: 899-907, 2014). Posttranscriptional regulation also plays an important role in neuronal differentiation (Bian S, Sun T. Mol Neurobiol 44: 359-373, 2011), but its role in maintaining cell identity is less established. To better understand how posttranscriptional regulation might contribute to cell identity, we examined the proprioceptive neurons in the dorsal root ganglion (DRG), a highly specialized sensory neuron class, with well-established properties that distinguish them from other neurons in the ganglion. By conditionally ablating Dicer in mice, using parvalbumin (Pvalb)-driven Cre recombinase, we impaired posttranscriptional regulation in the proprioceptive sensory neuron population. Knockout (KO) animals display a progressive form of ataxia at the beginning of the fourth postnatal week that is accompanied by a cell death within the DRG. Before cell loss, expression profiling shows a reduction of proprioceptor specific genes and an increased expression of nonproprioceptive genes normally enriched in other ganglion neurons. Furthermore, although central connections of these neurons are intact, the peripheral connections to the muscle are functionally impaired. Posttranscriptional regulation is therefore necessary to retain the transcriptional identity and support functional specialization of the proprioceptive sensory neurons. NEW & NOTEWORTHY We have demonstrated that selectively impairing Dicer in parvalbumin-positive neurons, which include the proprioceptors, triggers behavioral changes, a lack of muscle connectivity, and a loss of transcriptional identity as observed through RNA sequencing. These results suggest that Dicer and, most likely by extension, micro

  4. VGLUTs and Glutamate Synthesis—Focus on DRG Neurons and Pain

    PubMed Central

    Malet, Mariana; Brumovsky, Pablo R.

    2015-01-01

    The amino acid glutamate is the principal excitatory transmitter in the nervous system, including in sensory neurons that convey pain sensation from the periphery to the brain. It is now well established that a family of membrane proteins, termed vesicular glutamate transporters (VGLUTs), serve a critical function in these neurons: they incorporate glutamate into synaptic vesicles. VGLUTs have a central role both under normal neurotransmission and pathological conditions, such as neuropathic or inflammatory pain. In the present short review, we will address VGLUTs in the context of primary afferent neurons. We will focus on the role of VGLUTs in pain triggered by noxious stimuli, peripheral nerve injury, and tissue inflammation, as mostly explored in transgenic mice. The possible interplay between glutamate biosynthesis and VGLUT-dependent packaging in synaptic vesicles, and its potential impact in various pain states will be presented. PMID:26633536

  5. The neuronal mechanisms underlying improvement of impulsivity in ADHD by theta/beta neurofeedback.

    PubMed

    Bluschke, Annet; Broschwitz, Felicia; Kohl, Simon; Roessner, Veit; Beste, Christian

    2016-08-12

    Neurofeedback is increasingly recognized as an intervention to treat core symptoms of attention deficit hyperactivity disorder (ADHD). Despite the large number of studies having been carried out to evaluate its effectiveness, it is widely elusive what neuronal mechanisms related to the core symptoms of ADHD are modulated by neurofeedback. 19 children with ADHD undergoing 8 weeks of theta/beta neurofeedback and 17 waiting list controls performed a Go/Nogo task in a pre-post design. We used neurophysiological measures combining high-density EEG recording with source localization analyses using sLORETA. Compared to the waiting list ADHD control group, impulsive behaviour measured was reduced after neurofeedback treatment. The effects of neurofeedback were very specific for situations requiring inhibitory control over responses. The neurophysiological data shows that processes of perceptual gating, attentional selection and resource allocation processes were not affected by neurofeedback. Rather, neurofeedback effects seem to be based on the modulation of response inhibition processes in medial frontal cortices. The study shows that specific neuronal mechanisms underlying impulsivity are modulated by theta/beta neurofeedback in ADHD. The applied neurofeedback protocol could be particularly suitable to address inhibitory control. The study validates assumed functional neuroanatomical target regions of an established neurofeedback protocol on a neurophysiological level.

  6. The neuronal mechanisms underlying improvement of impulsivity in ADHD by theta/beta neurofeedback

    PubMed Central

    Bluschke, Annet; Broschwitz, Felicia; Kohl, Simon; Roessner, Veit; Beste, Christian

    2016-01-01

    Neurofeedback is increasingly recognized as an intervention to treat core symptoms of attention deficit hyperactivity disorder (ADHD). Despite the large number of studies having been carried out to evaluate its effectiveness, it is widely elusive what neuronal mechanisms related to the core symptoms of ADHD are modulated by neurofeedback. 19 children with ADHD undergoing 8 weeks of theta/beta neurofeedback and 17 waiting list controls performed a Go/Nogo task in a pre-post design. We used neurophysiological measures combining high-density EEG recording with source localization analyses using sLORETA. Compared to the waiting list ADHD control group, impulsive behaviour measured was reduced after neurofeedback treatment. The effects of neurofeedback were very specific for situations requiring inhibitory control over responses. The neurophysiological data shows that processes of perceptual gating, attentional selection and resource allocation processes were not affected by neurofeedback. Rather, neurofeedback effects seem to be based on the modulation of response inhibition processes in medial frontal cortices. The study shows that specific neuronal mechanisms underlying impulsivity are modulated by theta/beta neurofeedback in ADHD. The applied neurofeedback protocol could be particularly suitable to address inhibitory control. The study validates assumed functional neuroanatomical target regions of an established neurofeedback protocol on a neurophysiological level. PMID:27514985

  7. Actions of bis(7)-tacrine and tacrine on transient potassium current in rat DRG neurons and potassium current mediated by K(V)4.2 expressed in Xenopus oocyte.

    PubMed

    Li, Xiang-Yuan; Zhang, Jian; Dai, Jia-Pei; Liu, Xiang-Ming; Li, Zhi-Wang

    2010-03-08

    Bis(7)-tacrine [bis(7)-tetrahydroaminacrine] is a dimeric AChE inhibitor derived from tacrine with a potential to treat Alzheimer's disease. Actions of bis(7)-tacrine on ligand-gated ion channels and voltage-gated cation channels have been identified on neurons of both central and peripheral nervous systems. In the present study, the effect of bis(7)-tacrine was investigated on the K(V)4.2 encoded potassium currents expressed in Xenopus oocytes and the transient A-type potassium current (I(K(A))) on rat DRG neurons. Bis(7)-tacrine suppressed recombinant Kv4.2 potassium channels in a concentration-dependent manner, with IC(50) value of 0.53+/-0.13 muM. Tacrine also inhibited Kv4.2 channels, but with a much lower potency (IC(50) 74+/-15 muM).The possible mechanisms underlying the inhibition on potassium currents by bis(7)-tacrine/tacrine could be that inactivation of the transient potassium currents was accelerated and recovery of the native or Kv4.2 expressed potassium currents was suppressed by bis(7)-tacrine/tacrine. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Reducing the Levels of Akt Activation by PDK1 Knock-in Mutation Protects Neuronal Cultures against Synthetic Amyloid-Beta Peptides.

    PubMed

    Yang, Shaobin; Pascual-Guiral, Sònia; Ponce, Rebeca; Giménez-Llort, Lydia; Baltrons, María A; Arancio, Ottavio; Palacio, Jose R; Clos, Victoria M; Yuste, Victor J; Bayascas, Jose R

    2017-01-01

    The Akt kinase has been widely assumed for years as a key downstream effector of the PI3K signaling pathway in promoting neuronal survival. This notion was however challenged by the finding that neuronal survival responses were still preserved in mice with reduced Akt activity. Moreover, here we show that the Akt signaling is elevated in the aged brain of two different mice models of Alzheimer Disease. We manipulate the rate of Akt stimulation by employing knock-in mice expressing a mutant form of PDK1 (phosphoinositide-dependent protein kinase 1) with reduced, but not abolished, ability to activate Akt. We found increased membrane localization and activity of the TACE/ADAM17 α-secretase in the brain of the PDK1 mutant mice with concomitant TNFR1 processing, which provided neurons with resistance against TNFα-induced neurotoxicity. Opposite to the Alzheimer Disease transgenic mice, the PDK1 knock-in mice exhibited an age-dependent attenuation of the unfolding protein response, which protected the mutant neurons against endoplasmic reticulum stressors. Moreover, these two mechanisms cooperatively provide the mutant neurons with resistance against amyloid-beta oligomers, and might singularly also contribute to protect these mice against amyloid-beta pathology.

  9. Transcriptional profiling at whole population and single cell levels reveals somatosensory neuron molecular diversity

    PubMed Central

    Chiu, Isaac M; Barrett, Lee B; Williams, Erika K; Strochlic, David E; Lee, Seungkyu; Weyer, Andy D; Lou, Shan; Bryman, Gregory S; Roberson, David P; Ghasemlou, Nader; Piccoli, Cara; Ahat, Ezgi; Wang, Victor; Cobos, Enrique J; Stucky, Cheryl L; Ma, Qiufu; Liberles, Stephen D; Woolf, Clifford J

    2014-01-01

    The somatosensory nervous system is critical for the organism's ability to respond to mechanical, thermal, and nociceptive stimuli. Somatosensory neurons are functionally and anatomically diverse but their molecular profiles are not well-defined. Here, we used transcriptional profiling to analyze the detailed molecular signatures of dorsal root ganglion (DRG) sensory neurons. We used two mouse reporter lines and surface IB4 labeling to purify three major non-overlapping classes of neurons: 1) IB4+SNS-Cre/TdTomato+, 2) IB4−SNS-Cre/TdTomato+, and 3) Parv-Cre/TdTomato+ cells, encompassing the majority of nociceptive, pruriceptive, and proprioceptive neurons. These neurons displayed distinct expression patterns of ion channels, transcription factors, and GPCRs. Highly parallel qRT-PCR analysis of 334 single neurons selected by membership of the three populations demonstrated further diversity, with unbiased clustering analysis identifying six distinct subgroups. These data significantly increase our knowledge of the molecular identities of known DRG populations and uncover potentially novel subsets, revealing the complexity and diversity of those neurons underlying somatosensation. DOI: http://dx.doi.org/10.7554/eLife.04660.001 PMID:25525749

  10. Tau Pathology is Present In Vivo and Develops In Vitro in Sensory Neurons from Human P301S Tau Transgenic Mice: A System for Screening Drugs against Tauopathies

    PubMed Central

    Mellone, Manuela; Kestoras, Dimitra; Andrews, Melissa R.; Dassie, Elisa; Crowther, R. Anthony; Stokin, Gorazd B.; Tinsley, Jon; Horne, Graeme; Goedert, Michel

    2013-01-01

    Intracellular tau aggregates are the neuropathological hallmark of several neurodegenerative diseases, including Alzheimer's disease, progressive supranuclear palsy, and cases of frontotemporal dementia, but the link between these aggregates and neurodegeneration remains unclear. Neuronal models recapitulating the main features of tau pathology are necessary to investigate the molecular mechanisms of tau malfunction, but current models show little and inconsistent spontaneous tau aggregation. We show that dorsal root ganglion (DRG) neurons in transgenic mice expressing human P301S tau (P301S-htau) develop tau pathology similar to that found in brain and spinal cord and a significant reduction in mechanosensation occurs before detectable fibrillar tau formation. DRG neuronal cultures established from adult P301S-htau mice at different ages retained the pattern of aberrant tau found in vivo. Moreover, htau became progressively hyperphosphorylated over 2 months in vitro beginning with nonsymptomatic neurons, while hyperphosphorylated P301S-htau-positive neurons from 5-month-old mice cultured for 2 months died preferentially. P301S-htau-positive neurons grew aberrant axons, including spheroids, typically found in human tauopathies. Neurons cultured at advanced stages of tau pathology showed a 60% decrease in the fraction of moving mitochondria. SEG28019, a novel O-GlcNAcase inhibitor, reduced steady-state pSer396/pSer404 phosphorylation over 7 weeks in a significant proportion of DRG neurons showing for the first time the possible beneficial effect of prolonged dosing of O-GlcNAcase inhibitor in vitro. Our system is unique in that fibrillar tau forms without external manipulation and provides an important new tool for understanding the mechanisms of tau dysfunction and for screening of compounds for treatment of tauopathies. PMID:24227726

  11. Thrombospondin-4 divergently regulates voltage-gated Ca2+ channel subtypes in sensory neurons after nerve injury.

    PubMed

    Pan, Bin; Guo, Yuan; Wu, Hsiang-En; Park, John; Trinh, Van Nancy; Luo, Z David; Hogan, Quinn H

    2016-09-01

    Loss of high-voltage-activated (HVA) calcium current (ICa) and gain of low-voltage-activated (LVA) ICa after painful peripheral nerve injury cause elevated excitability in sensory neurons. Nerve injury is also accompanied by increased expression of the extracellular matrix glycoprotein thrombospondin-4 (TSP4), and interruption of TSP4 function can reverse or prevent behavioral hypersensitivity after injury. We therefore investigated TSP4 regulation of ICa in dorsal root ganglion (DRG) neurons. During depolarization adequate to activate HVA ICa, TSP4 decreases both N- and L-type ICa and the associated intracellular calcium transient. In contrast, TSP4 increases ICa and the intracellular calcium signal after low-voltage depolarization, which we confirmed is due to ICa through T-type channels. These effects are blocked by gabapentin, which ameliorates neuropathic pain by targeting the α2δ1 calcium subunit. Injury-induced changes of HVA and LVA ICa are attenuated in TSP4 knockout mice. In the neuropathic pain model of spinal nerve ligation, TSP4 application did not further regulate ICa of injured DRG neurons. Taken together, these findings suggest that elevated TSP4 after peripheral nerve injury may contribute to hypersensitivity of peripheral sensory systems by decreasing HVA and increasing LVA in DRG neurons by targeting the α2δ1 calcium subunit. Controlling TSP4 overexpression in peripheral sensory neurons may be a target for analgesic drug development for neuropathic pain.

  12. Reimbursement of care for severe trauma under SwissDRG.

    PubMed

    Moos, Rudolf M; Sprengel, Kai; Jensen, Kai Oliver; Jentzsch, Thorsten; Simmen, Hans-Peter; Seifert, Burkhardt; Ciritsis, Bernhard; Neuhaus, Valentin; Volbracht, Jörk; Mehra, Tarun

    2016-01-01

    Treatment of patients with severe injuries is costly, with best results achieved in specialised care centres. However, diagnosis-related group (DRG)-based prospective payment systems have difficulties in depicting treatment costs for specialised care. We analysed reimbursement of care for severe trauma in the first 3 years after the introduction of the Swiss DRG reimbursement system (2012-2014). The study included all patients with solely basic insurance, hospital admission after 01.01.2011 and discharge in 2011 or 2012, who were admitted to the resuscitation room of the University Hospital of Zurich, aged ≥16 years and with an injury severity score (ISS) ≥16 (n = 364). Clinical, financial and administrative data were extracted from the electronic medical records. All cases were grouped into DRGs according to different SwissDRG versions. We considered results to be significant if p ≤0.002. The mean deficit decreased from 12 065 CHF under SwissDRG 1.0 (2012) to 2 902 CHF under SwissDRG 3.0 (2014). The main reason for the reduction of average deficits was a refinement of the DRG algorithm with a regrouping of 23 cases with an ISS ≥16 from MDC 01 to DRGs within MDC21A. Predictors of an increased total loss per case could be identified: for example, high total number of surgical interventions, surgeries on multiple anatomical regions or operations on the pelvis (p ≤0.002). Psychiatric diagnoses in general were also significant predictors of deficit per case (p<0.001). The reimbursement for care of severely injured patients needs further improvement. Cost neutral treatment was not possible under the first three versions of SwissDRG.

  13. Negative allosteric modulators that target human alpha4beta2 neuronal nicotinic receptors.

    PubMed

    Henderson, Brandon J; Pavlovicz, Ryan E; Allen, Jerad D; González-Cestari, Tatiana F; Orac, Crina M; Bonnell, Andrew B; Zhu, Michael X; Boyd, R Thomas; Li, Chenglong; Bergmeier, Stephen C; McKay, Dennis B

    2010-09-01

    Allosteric modulation of neuronal nicotinic acetylcholine receptors (nAChRs) is considered to be one of the most promising approaches for therapeutics. We have previously reported on the pharmacological activity of several compounds that act as negative allosteric modulators (NAMs) of nAChRs. In the following studies, the effects of 30 NAMs from our small chemical library on both human alpha4beta2 (Halpha4beta2) and human alpha3beta4 (Halpha3beta4) nAChRs expressed in human embryonic kidney ts201 cells were investigated. During calcium accumulation assays, these NAMs inhibited nAChR activation with IC(50) values ranging from 2.4 microM to more than 100 microM. Several NAMs showed relative selectivity for Halpha4beta2 nAChRs with IC(50) values in the low micromolar range. A lead molecule, KAB-18, was identified that shows relative selectivity for Halpha4beta2 nAChRs. This molecule contains three phenyl rings, one piperidine ring, and one ester bond linkage. Structure-activity relationship (SAR) analyses of our data revealed three regions of KAB-18 that contribute to its relative selectivity. Predictive three-dimensional quantitative SAR (comparative molecular field analysis and comparative molecular similarity indices analysis) models were generated from these data, and a pharmacophore model was constructed to determine the chemical features that are important for biological activity. Using docking approaches and molecular dynamics on a Halpha4beta2 nAChR homology model, a binding mode for KAB-18 at the alpha/beta subunit interface that corresponds to the predicted pharmacophore is described. This binding mode was supported by mutagenesis studies. In summary, these studies highlight the importance of SAR, computational, and molecular biology approaches for the design and synthesis of potent and selective antagonists targeting specific nAChR subtypes.

  14. [Treatment aspects of unstable angina. Costs and payments for DRG].

    PubMed

    Brunelli, C; Spallarossa, P; Pasdera, A; Bezante, G P; Zorzet, F; Rossettin, P

    1998-01-01

    Patients with unstable angina fall into a wide prognostic and therapeutic spectrum but, in general, have great access to specialty care and invasive procedures. In the modern era, in which admissions for unstable angina outnumber those for myocardial infarction, and growing economic pressures are placed on health care systems, cardiologists must re-examine clinical strategies for treating unstable angina in the light of health-cost accounting. The aims of the present study were to examine the current management of patients admitted to our cardiology department and to calculate the medical costs. A patient schedule was drawn up to prospectively register the number and type of cardiac processes carried out during hospitalization for all unstable angina patients in the period between March 1st and May 30th, 1995. Time (minutes) actually spent by both physicians and nurses for each cardiac process were carefully recorded in order to calculate the activity budget. The effective economic budget was built for each cardiac process taking into account salaries, consumable supplies, equipment service contracts, depreciation and indirect medical and non medical costs for CCU and ward. Based to the Diagnosis Related Groups (DRG) system, 53 out of 318 patients (16%) were admitted with documented or suspected unstable angina and allocated to discharge into four DRGs: DRG 140-medically treated unstable angina: 18 patients; DRG 124-unstable angina with angiography: 16 patients; DRG 122-unstable angina evolving in myocardial infarction: 6 patients; DRG 112-unstable angina with angioplasty: 13 patients. The mean cost for hospitalized patient with unstable angina was 5,574,958 Italian Liras (DRG 140 = 2,687,719; DRG 124 = 2,800,347; DRG 122 = 6,086,563; DRG 112 = 12,751,454). The difference in costs was essentially related to the procedures involved in medical care, DRGs with expensive cardiac processes having higher costs. Furthermore, these data show a deep discrepancy between

  15. Thy1.2 YFP-16 Transgenic Mouse Labels a Subset of Large-Diameter Sensory Neurons that Lack TRPV1 Expression

    PubMed Central

    Taylor-Clark, Thomas E.; Wu, Kevin Y.; Thompson, Julie-Ann; Yang, Kiseok; Bahia, Parmvir K.; Ajmo, Joanne M.

    2015-01-01

    The Thy1.2 YFP-16 mouse expresses yellow fluorescent protein (YFP) in specific subsets of peripheral and central neurons. The original characterization of this model suggested that YFP was expressed in all sensory neurons, and this model has been subsequently used to study sensory nerve structure and function. Here, we have characterized the expression of YFP in the sensory ganglia (DRG, trigeminal and vagal) of the Thy1.2 YFP-16 mouse, using biochemical, functional and anatomical analyses. Despite previous reports, we found that YFP was only expressed in approximately half of DRG and trigeminal neurons and less than 10% of vagal neurons. YFP-expression was only found in medium and large-diameter neurons that expressed neurofilament but not TRPV1. YFP-expressing neurons failed to respond to selective agonists for TRPV1, P2X2/3 and TRPM8 channels in Ca2+ imaging assays. Confocal analysis of glabrous skin, hairy skin of the back and ear and skeletal muscle indicated that YFP was expressed in some peripheral terminals with structures consistent with their presumed non-nociceptive nature. In summary, the Thy1.2 YFP-16 mouse expresses robust YFP expression in only a subset of sensory neurons. But this mouse model is not suitable for the study of nociceptive nerves or the function of such nerves in pain and neuropathies. PMID:25746468

  16. Modulation of neuronal oscillatory activity in the beta- and gamma-band is associated with current individual anxiety levels.

    PubMed

    Schneider, Till R; Hipp, Joerg F; Domnick, Claudia; Carl, Christine; Büchel, Christian; Engel, Andreas K

    2018-05-26

    Human faces are among the most salient visual stimuli and act both as socially and emotionally relevant signals. Faces and especially faces with emotional expression receive prioritized processing in the human brain and activate a distributed network of brain areas reflected, e.g., in enhanced oscillatory neuronal activity. However, an inconsistent picture emerged so far regarding neuronal oscillatory activity across different frequency-bands modulated by emotionally and socially relevant stimuli. The individual level of anxiety among healthy populations might be one explanation for these inconsistent findings. Therefore, we tested the hypothesis whether oscillatory neuronal activity is associated with individual anxiety levels during perception of faces with neutral and fearful facial expressions. We recorded neuronal activity using magnetoencephalography (MEG) in 27 healthy participants and determined their individual state anxiety levels. Images of human faces with neutral and fearful expressions, and physically matched visual control stimuli were presented while participants performed a simple color detection task. Spectral analyses revealed that face processing and in particular processing of fearful faces was characterized by enhanced neuronal activity in the theta- and gamma-band and decreased activity in the beta-band in early visual cortex and the fusiform gyrus (FFG). Moreover, the individuals' state anxiety levels correlated positively with the gamma-band response and negatively with the beta response in the FFG and the amygdala. Our results suggest that oscillatory neuronal activity plays an important role in affective face processing and is dependent on the individual level of state anxiety. Our work provides new insights on the role of oscillatory neuronal activity underlying processing of faces. Copyright © 2018. Published by Elsevier Inc.

  17. BKCa currents are enriched in a subpopulation of adult rat cutaneous nociceptive dorsal root ganglion neurons

    PubMed Central

    Zhang, Xiu-Lin; Mok, Lee-Peng; Katz, Elizabeth J; Gold, Michael S.

    2010-01-01

    The biophysical properties and distribution of voltage-dependent, Ca2+-modulated K+ (BKCa) currents among subpopulations of acutely dissociated DiI labeled cutaneous sensory neurons from the adult rat were characterized with whole cell patch clamp techniques. BKCa currents were isolated from total K+ current with iberiotoxin, charybdotoxin, or paxilline. There was considerable variability in biophysical properties of BKCa currents. There was also variability in the distribution of BKCa current among subpopulations of cutaneous DRG neurons. While present in each of the subpopulations defined by cell body size, IB4 binding or capsaicin sensitivity, BKCa current was present in vast majority (>90%) of small diameter IB4+ neurons but was present in only a minority of neurons in subpopulations defined by other criteria (i.e., small diameter IB4−). Current clamp analysis indicated that in IB4+ neurons, BKCa currents contribute to the repolarization of the action potential and adaptation in response to sustained membrane depolarization, while playing little role in the determination of action potential threshold. RT-PCR analysis of mRNA collected from whole DRG revealed the presence of multiple splice variants of the BKCa channel α-subunit, rslo and all 4 of the accessory β subunits, suggesting that heterogeneity in the biophysical and pharmacological properties of BKCa current in cutaneous neurons, reflects, at least in part, the differential distribution of splice variants and/or β subunits. Because even a small decrease in BKCa current appears to have a dramatic influence on excitability, modulation of this current may contribute to sensitization of nociceptive afferents observed following tissue injury. PMID:20105244

  18. The Mast Cell Degranulator Compound 48/80 Directly Activates Neurons

    PubMed Central

    Schemann, Michael; Kugler, Eva Maria; Buhner, Sabine; Eastwood, Christopher; Donovan, Jemma; Jiang, Wen; Grundy, David

    2012-01-01

    Background Compound 48/80 is widely used in animal and tissue models as a “selective” mast cell activator. With this study we demonstrate that compound 48/80 also directly activates enteric neurons and visceral afferents. Methodology/Principal Findings We used in vivo recordings from extrinsic intestinal afferents together with Ca++ imaging from primary cultures of DRG and nodose neurons. Enteric neuronal activation was examined by Ca++ and voltage sensitive dye imaging in isolated gut preparations and primary cultures of enteric neurons. Intraluminal application of compound 48/80 evoked marked afferent firing which desensitized on subsequent administration. In egg albumen-sensitized animals, intraluminal antigen evoked a similar pattern of afferent activation which also desensitized on subsequent exposure to antigen. In cross-desensitization experiments prior administration of compound 48/80 failed to influence the mast cell mediated response. Application of 1 and 10 µg/ml compound 48/80 evoked spike discharge and Ca++ transients in enteric neurons. The same nerve activating effect was observed in primary cultures of DRG and nodose ganglion cells. Enteric neuron cultures were devoid of mast cells confirmed by negative staining for c-kit or toluidine blue. In addition, in cultured enteric neurons the excitatory action of compound 48/80 was preserved in the presence of histamine H1 and H2 antagonists. The mast cell stabilizer cromolyn attenuated compound 48/80 and nicotine evoked Ca++ transients in mast cell-free enteric neuron cultures. Conclusions/Significance The results showed direct excitatory action of compound 48/80 on enteric neurons and visceral afferents. Therefore, functional changes measured in tissue or animal models may involve a mast cell independent effect of compound 48/80 and cromolyn. PMID:23272218

  19. 42 CFR 476.94 - Notice of QIO initial denial determination and changes as a result of a DRG validation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... changes as a result of a DRG validation. 476.94 Section 476.94 Public Health CENTERS FOR MEDICARE... DRG validation. (a) Notice of initial denial determination—(1) Parties to be notified. A QIO must... of identification; (vi) For retrospective review, (excluding DRG validation and post procedure review...

  20. Accumulation of misfolded SOD1 in dorsal root ganglion degenerating proprioceptive sensory neurons of transgenic mice with amyotrophic lateral sclerosis.

    PubMed

    Sábado, Javier; Casanovas, Anna; Tarabal, Olga; Hereu, Marta; Piedrafita, Lídia; Calderó, Jordi; Esquerda, Josep E

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is an adult-onset progressive neurodegenerative disease affecting upper and lower motoneurons (MNs). Although the motor phenotype is a hallmark for ALS, there is increasing evidence that systems other than the efferent MN system can be involved. Mutations of superoxide dismutase 1 (SOD1) gene cause a proportion of familial forms of this disease. Misfolding and aggregation of mutant SOD1 exert neurotoxicity in a noncell autonomous manner, as evidenced in studies using transgenic mouse models. Here, we used the SOD1(G93A) mouse model for ALS to detect, by means of conformational-specific anti-SOD1 antibodies, whether misfolded SOD1-mediated neurotoxicity extended to neuronal types other than MNs. We report that large dorsal root ganglion (DRG) proprioceptive neurons accumulate misfolded SOD1 and suffer a degenerative process involving the inflammatory recruitment of macrophagic cells. Degenerating sensory axons were also detected in association with activated microglial cells in the spinal cord dorsal horn of diseased animals. As large proprioceptive DRG neurons project monosynaptically to ventral horn MNs, we hypothesise that a prion-like mechanism may be responsible for the transsynaptic propagation of SOD1 misfolding from ventral horn MNs to DRG sensory neurons.

  1. Modelling the dorsal root ganglia using human pluripotent stem cells: A platform to study peripheral neuropathies.

    PubMed

    Viventi, Serena; Dottori, Mirella

    2018-07-01

    Sensory neurons of the dorsal root ganglia (DRG) are the primary responders to stimuli inducing feelings of touch, pain, temperature, vibration, pressure and muscle tension. They consist of multiple subpopulations based on their morphology, molecular and functional properties. Our understanding of DRG sensory neurons has been predominantly driven by rodent studies and using transformed cell lines, whereas less is known about human sensory DRG neurons simply because of limited availability of human tissue. Although these previous studies have been fundamental for our understanding of the sensory system, it is imperative to profile human DRG subpopulations as it is becoming evident that human sensory neurons do not share the identical molecular and functional properties found in other species. Furthermore, there are wide range of diseases and disorders that directly/indirectly cause sensory neuronal degeneration or dysfunctionality. Having an in vitro source of human DRG sensory neurons is paramount for studying their development, unique neuronal properties and for accelerating regenerative therapies to treat sensory neuropathies. Here we review the major studies describing generation of DRG sensory neurons from human pluripotent stem cells and fibroblasts and the gaps that need to be addressed for using in vitro-generated human DRG neurons to model human DRG tissue. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. 42 CFR 476.94 - Notice of QIO initial denial determination and changes as a result of a DRG validation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... changes as a result of a DRG validation. 476.94 Section 476.94 Public Health CENTERS FOR MEDICARE... changes as a result of a DRG validation. (a) Notice of initial denial determination—(1) Parties to be... working days of identification; (vi) For retrospective review, (excluding DRG validation and post...

  3. Multiscale Molecular Dynamics Simulations of Beta-Amyloid Interactions with Neurons

    NASA Astrophysics Data System (ADS)

    Qiu, Liming; Vaughn, Mark; Cheng, Kelvin

    2012-10-01

    Early events of human beta-amyloid protein interactions with cholesterol-containing membranes are critical to understanding the pathogenesis of Alzheimer's disease (AD) and to exploring new therapeutic interventions of AD. Atomistic molecular dynamics (AMD) simulations have been extensively used to study the protein-lipid interaction at high atomic resolutions. However, traditional MD simulations are not efficient in sampling the phase space of complex lipid/protein systems with rugged free energy landscapes. Meanwhile, coarse-grained MD (CGD) simulations are efficient in the phase space sampling but suffered from low spatial resolutions and from the fact that the energy landscapes are not identical to those of the AMD. Here, a multiscale approach was employed to simulate the protein-lipid interactions of beta-amyloid upon its release from proteolysis residing in the neuronal membranes. We utilized a forward (AMD to CGD) and reverse (CGD-AMD) strategy to explore new transmembrane and surface protein configuration and evaluate the stabilization mechanisms by measuring the residue-specific protein-lipid or protein conformations. The detailed molecular interactions revealed in this multiscale MD approach will provide new insights into understanding the early molecular events leading to the pathogenesis of AD.

  4. Resveratrol protects bupivacaine-induced neuro-apoptosis in dorsal root ganglion neurons via activation on tropomyosin receptor kinase A.

    PubMed

    Guo, Zhiliang; Liu, Yuanyuan; Cheng, Min

    2018-07-01

    General anesthesia in spinal cord may lead to unexpected but irreversible neurotoxicity. We investigated whether resveratrol (RSV) may protect bupivacaine (BUP)-induced neuro-apoptosis in spinal cord dorsal root ganglia (DRG). Mouse DRG cells were cultured in vitro, pre-treated with RSV and then 5 mM BUP. A concentration-dependent effect of RSV on reducing BUP-induced apoptosis of DRG neurons (DRGNs) was evaluated using a TUNEL assay. QRT-PCR and western blot assays were also conducted to evaluate gene and protein expressions of tropomyosin receptor kinase A/B/C (TrkA/B/C) and activated (phosphorylated) Trk receptors, phospho-TrkA/B/C. In addition, a functional TrkA blocking antibody MNAC13 was applied in DRG culture to further measure the functional role of Trk receptor in RSV-initiated apoptotic protection on BUP-damaged DRGNs. BUP promoted significant apoptosis in DRG. RSV exhibited protective effects against BUP-induced neuro-apoptosis in a concentration-dependent manner. qRT-PCR and western blot showed that RSV did not alter TrkA/B/C gene or protein expression, but significantly upregulated phospho-TrkA. Conversely, application of MNAC13 decreased phospho-TrkA and reversed RSV-initiated neuro-protection on BUP-induced DRGN apoptosis. Resveratrol may protect anesthesia-induced DRG neuro-apoptosis, and activation of TrkA signaling pathway may be the underlying mechanism in this process. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  5. [Orthopedic and trauma surgery in the German DRG system. Recent developments].

    PubMed

    Franz, D; Schemmann, F; Selter, D D; Wirtz, D C; Roeder, N; Siebert, H; Mahlke, L

    2012-07-01

    Orthopedics and trauma surgery are subject to continuous medical advancement. The correct and performance-based case allocation by German diagnosis-related groups (G-DRG) is a major challenge. This article analyzes and assesses current developments in orthopedics and trauma surgery in the areas of coding of diagnoses and medical procedures and the development of the 2012 G-DRG system. The relevant diagnoses, medical procedures and G-DRGs in the versions 2011 and 2012 were analyzed based on the publications of the German DRG Institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). Changes were made for the International Classification of Diseases (ICD) coding of complex cases with medical complications, the procedure coding for spinal surgery and for hand and foot surgery. The G-DRG structures were modified for endoprosthetic surgery on ankle, shoulder and elbow joints. The definition of modular structured endoprostheses was clarified. The G-DRG system for orthopedic and trauma surgery appears to be largely consolidated. The current phase of the evolution of the G-DRG system is primarily aimed at developing most exact descriptions and definitions of the content and mutual delimitation of operation and procedures coding (OPS). This is an essential prerequisite for a correct and performance-based case allocation in the G-DRG system.

  6. Charting a path forward: policy analysis of China's evolved DRG-based hospital payment system

    PubMed Central

    Liu, Rui; Shi, Jianwei; Yang, Beilei; Jin, Chunlin; Sun, Pengfei; Wu, Lingfang; Yu, Dehua; Xiong, Linping; Wang, Zhaoxin

    2017-01-01

    Abstract Background At present, the diagnosis-related groups-based prospective payment system (DRG-PPS) that has been implemented in China is merely a prototype called the simplified DRG-PPS, which is known as the ‘ceiling price for a single disease’. Given that studies on the effects of a simplified DRG-PPS in China have usually been controversial, we aim to synthesize evidence examining whether DRGs can reduce medical costs and length of stay (LOS) in China. Methods Data were searched from both Chinese [Wan Fang and China National Knowledge Infrastructure Database (CNKI)] and international databases (Web of Science and PubMed), as well as the official websites of Chinese health departments in the 2004–2016 period. Only studies with a design that included both experimental (with DRG-PPS implementation) and control groups (without DRG-PPS implementation) were included in the review. Results The studies were based on inpatient samples from public hospitals distributed in 12 provinces of mainland China. Among them, 80.95% (17/21) revealed that hospitalization costs could be reduced significantly, and 50.00% (8/16) indicated that length of stay could be decreased significantly. In addition, the government reports showed the enormous differences in pricing standards and LOS in various provinces, even for the same disease. Conclusions We conclude that the simplified DRGs are useful in controlling hospitalization costs, but they fail to reduce LOS. Much work remains to be done in China to improve the simplified DRG-PPS. PMID:28911128

  7. DRG coding practice: a nationwide hospital survey in Thailand

    PubMed Central

    2011-01-01

    Background Diagnosis Related Group (DRG) payment is preferred by healthcare reform in various countries but its implementation in resource-limited countries has not been fully explored. Objectives This study was aimed (1) to compare the characteristics of hospitals in Thailand that were audited with those that were not and (2) to develop a simplified scale to measure hospital coding practice. Methods A questionnaire survey was conducted of 920 hospitals in the Summary and Coding Audit Database (SCAD hospitals, all of which were audited in 2008 because of suspicious reports of possible DRG miscoding); the questionnaire also included 390 non-SCAD hospitals. The questionnaire asked about general demographics of the hospitals, hospital coding structure and process, and also included a set of 63 opinion-oriented items on the current hospital coding practice. Descriptive statistics and exploratory factor analysis (EFA) were used for data analysis. Results SCAD and Non-SCAD hospitals were different in many aspects, especially the number of medical statisticians, experience of medical statisticians and physicians, as well as number of certified coders. Factor analysis revealed a simplified 3-factor, 20-item model to assess hospital coding practice and classify hospital intention. Conclusion Hospital providers should not be assumed capable of producing high quality DRG codes, especially in resource-limited settings. PMID:22040256

  8. DRG coding practice: a nationwide hospital survey in Thailand.

    PubMed

    Pongpirul, Krit; Walker, Damian G; Rahman, Hafizur; Robinson, Courtland

    2011-10-31

    Diagnosis Related Group (DRG) payment is preferred by healthcare reform in various countries but its implementation in resource-limited countries has not been fully explored. This study was aimed (1) to compare the characteristics of hospitals in Thailand that were audited with those that were not and (2) to develop a simplified scale to measure hospital coding practice. A questionnaire survey was conducted of 920 hospitals in the Summary and Coding Audit Database (SCAD hospitals, all of which were audited in 2008 because of suspicious reports of possible DRG miscoding); the questionnaire also included 390 non-SCAD hospitals. The questionnaire asked about general demographics of the hospitals, hospital coding structure and process, and also included a set of 63 opinion-oriented items on the current hospital coding practice. Descriptive statistics and exploratory factor analysis (EFA) were used for data analysis. SCAD and Non-SCAD hospitals were different in many aspects, especially the number of medical statisticians, experience of medical statisticians and physicians, as well as number of certified coders. Factor analysis revealed a simplified 3-factor, 20-item model to assess hospital coding practice and classify hospital intention. Hospital providers should not be assumed capable of producing high quality DRG codes, especially in resource-limited settings.

  9. Modulation of A-type K+ channels by the short-chain cobrotoxin through the protein kinase C-delta isoform decreases membrane excitability in dorsal root ganglion neurons.

    PubMed

    Guo, Qiang; Jiang, You-Jing; Jin, Hong; Jiang, Xing-Hong; Gu, Bo; Zhang, Yi-Ming; Wang, Jian-Gong; Qin, Zheng-Hong; Tao, Jin

    2013-05-01

    A-type K(+) channels are crucial in controlling neuronal excitability, and their regulation in sensory neurons may alter pain sensation. In this study, we identified the functional role of cobrotoxin, the short-chain α-neurotoxin isolated from Naja atra venom, which acts in the regulation of the transient A-type K(+) currents (IA) and membrane excitability in dorsal root ganglion (DRG) neurons via the activation of the muscarinic M3 receptor (M3R). Our results showed that cobrotoxin increased IA in a concentration-dependent manner, whereas the sustained delayed rectifier K(+) currents (IDR) were not affected. Cobrotoxin did not affect the activation of IA markedly, however, it shifted the inactivation curve significantly in the depolarizing direction. The cobrotoxin-induced IA response was blocked by the M3R-selective antagonists DAU-5884 and 4-DAMP. An siRNA targeting the M3R in small DRG neurons abolished the cobrotoxin-induced IA increase. In addition, dialysis of the cells with the novel protein kinase C-delta isoform (PKC-δ) inhibitor δv1-1 or an siRNA targeting PKC-δ abolished the cobrotoxin-induced IA response, whereas inhibition of PKA or classic PKC activity elicited no such effects. Moreover, we observed a significant decrease in the firing rate of the neuronal action potential induced by M3R activation. Pretreatment of the cells with 4-aminopyridine, a selective blocker of IA, abolished this effect. Taken together, these results suggest that the short-chain cobrotoxin selectively enhances IA via a novel PKC-δ-dependent pathway. This effect occurred via the activation of M3R and might contribute to its neuronal hypoexcitability in small DRG neurons. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. [The G-DRG System 2009--relevant changes for rheumatology].

    PubMed

    Fiori, W; Liedtke-Dyong, A; Lakomek, H-J; Buscham, K; Lehmann, H; Liman, W; Fuchs, A-K; Bessler, F; Roeder, N

    2010-05-01

    The following article presents the major general and specific changes in the G-DRG system, in the classification systems for diagnoses and procedures as well as for the billing process for 2010. Since the G-DRG system is primarily a tool for the redistribution of resources, every hospital needs to analyze the economic effects of the changes by applying the G-DRG transition-grouper to its own cases. Depending on their clinical focus, rheumatological departments may experience positive or negative consequences from the adjustments. In addition, relevant current case law is considered.

  11. Genetic alteration of the metal/redox modulation of Cav3.2 T-type calcium channel reveals its role in neuronal excitability.

    PubMed

    Voisin, Tiphaine; Bourinet, Emmanuel; Lory, Philippe

    2016-07-01

    In this study, we describe a new knock-in (KI) mouse model that allows the study of the H191-dependent regulation of T-type Cav3.2 channels. Sensitivity to zinc, nickel and ascorbate of native Cav3.2 channels is significantly impeded in the dorsal root ganglion (DRG) neurons of this KI mouse. Importantly, we describe that this H191-dependent regulation has discrete but significant effects on the excitability properties of D-hair (down-hair) cells, a sub-population of DRG neurons in which Cav3.2 currents prominently regulate excitability. Overall, this study reveals that the native H191-dependent regulation of Cav3.2 channels plays a role in the excitability of Cav3.2-expressing neurons. This animal model will be valuable in addressing the potential in vivo roles of the trace metal and redox modulation of Cav3.2 T-type channels in a wide range of physiological and pathological conditions. Cav3.2 channels are T-type voltage-gated calcium channels that play important roles in controlling neuronal excitability, particularly in dorsal root ganglion (DRG) neurons where they are involved in touch and pain signalling. Cav3.2 channels are modulated by low concentrations of metal ions (nickel, zinc) and redox agents, which involves the histidine 191 (H191) in the channel's extracellular IS3-IS4 loop. It is hypothesized that this metal/redox modulation would contribute to the tuning of the excitability properties of DRG neurons. However, the precise role of this H191-dependent modulation of Cav3.2 channel remains unresolved. Towards this goal, we have generated a knock-in (KI) mouse carrying the mutation H191Q in the Cav3.2 protein. Electrophysiological studies were performed on a subpopulation of DRG neurons, the D-hair cells, which express large Cav3.2 currents. We describe an impaired sensitivity to zinc, nickel and ascorbate of the T-type current in D-hair neurons from KI mice. Analysis of the action potential and low-threshold calcium spike (LTCS) properties revealed

  12. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells

    PubMed Central

    Kiniwa, Yukiko; Li, Jiang; Wang, Mingjun; Sun, Chuang; Lee, Jeffrey E.; Wang, Rong-Fu; Wang, Helen Y.

    2015-01-01

    Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8+ T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4+ T helper (Th) cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4+ T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1) as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4+ Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4+ T cell-mediated immunotherapy in melanoma. PMID:25993655

  13. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells.

    PubMed

    Kiniwa, Yukiko; Li, Jiang; Wang, Mingjun; Sun, Chuang; Lee, Jeffrey E; Wang, Rong-Fu; Wang, Helen Y

    2015-01-01

    Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8(+) T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4(+) T helper (Th) cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4(+) T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1) as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4(+) Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4(+) T cell-mediated immunotherapy in melanoma.

  14. 42 CFR 476.94 - Notice of QIO initial denial determination and changes as a result of a DRG validation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... changes as a result of a DRG validation. 476.94 Section 476.94 Public Health CENTERS FOR MEDICARE... changes as a result of a DRG validation. (a) Notice of initial denial determination—(1) Parties to be... retrospective review, (excluding DRG validation and post procedure review), within 3 working days of the initial...

  15. 42 CFR 476.94 - Notice of QIO initial denial determination and changes as a result of a DRG validation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... changes as a result of a DRG validation. 476.94 Section 476.94 Public Health CENTERS FOR MEDICARE... changes as a result of a DRG validation. (a) Notice of initial denial determination—(1) Parties to be... retrospective review, (excluding DRG validation and post procedure review), within 3 working days of the initial...

  16. Millisecond infrared laser pulses depolarize and elicit action potentials on in-vitro dorsal root ganglion neurons

    PubMed Central

    Paris, Lambert; Marc, Isabelle; Charlot, Benoit; Dumas, Michel; Valmier, Jean; Bardin, Fabrice

    2017-01-01

    This work focuses on the optical stimulation of dorsal root ganglion (DRG) neurons through infrared laser light stimulation. We show that a few millisecond laser pulse at 1875 nm induces a membrane depolarization, which was observed by the patch-clamp technique. This stimulation led to action potentials firing on a minority of neurons beyond an energy threshold. A depolarization without action potential was observed for the majority of DRG neurons, even beyond the action potential energy threshold. The use of ruthenium red, a thermal channel blocker, stops the action potential generation, but has no effects on membrane depolarization. Local temperature measurements reveal that the depolarization amplitude is sensitive to the amplitude of the temperature rise as well as to the time rate of change of temperature, but in a way which may not fully follow a photothermal capacitive mechanism, suggesting that more complex mechanisms are involved. PMID:29082085

  17. Involvement of the Beta-Endorphin Neurons of the Hypothalamic Arcuate Nucleus in Ethanol-Induced Place Preference Conditioning in Mice

    PubMed Central

    Pastor, Raúl; Font, Laura; Miquel, Marta; Phillips, Tamara J.; Aragon, Carlos M.G.

    2014-01-01

    Background Increasing evidence indicates that mu- and delta-opioid receptors are decisively involved in the retrieval of memories underlying conditioned effects of ethanol. The precise mechanism by which these receptors participate in such effects remains unclear. Given the important role of the proopiomelanocortin (POMc)-derived opioid peptide beta-endorphin, an endogenous mu- and delta-opioid receptor agonist, in some of the behavioral effects of ethanol, we hypothesized that beta-endorphin would also be involved in ethanol conditioning. Methods In the present study we treated female Swiss mice with estradiol valerate (EV), which induces a neurotoxic lesion of the beta-endorphin neurons of the hypothalamic arcuate nucleus (ArcN). These mice were compared to saline-treated controls to investigate the role of beta-endorphin in the acquisition, extinction and reinstatement of ethanol (0 or 2 g/kg; i.p.)-induced conditioned place preference (CPP). Results Immunohistochemical analyses confirmed a decreased number of POMc-containing neurons of the ArcN with EV treatment. EV did not affect the acquisition or reinstatement of ethanol-induced CPP, but facilitated its extinction. Behavioral sensitization to ethanol, seen during the conditioning days, was not present in EV-treated animals. Conclusions The present data suggest that ArcN beta-endorphins are involved in the retrieval of conditioned memories of ethanol, and are implicated in the processes that underlie extinction of ethanol-cue associations. Results also reveal a dissociated neurobiology supporting behavioral sensitization to ethanol and its conditioning properties, as a beta-endorphin deficit affected sensitization to ethanol, while leaving acquisition and reinstatement of ethanol-induced CPP unaffected. PMID:22014186

  18. [Partial dorsal root rhizotomy increases the anterograde transportation of neunotrophic factors in primary sensory neuron].

    PubMed

    Long, Shuang-lian; Li, Yong-mei; Yuan, Yuan; Wang, Ting-hua; Wu, Lin-yan

    2005-05-01

    To investigate whether partial dorsal root rhizotomy promotes the anterograde Five adult cats were transportation of BDNF, NT-3 and GDNF in the primary sensory neuron. Subjected to unilateral spared root rhizotomy (the DRGs of L1-L5 and L7-S2 were removed, but L6 DRG was spared) and bilateral dorsal roots of L6 were ligated at the same time. Three days after operation, dorsal roots were taken out and made into frozen sections 20 microm in thickness. The sections were stained using specific BDNF, NT-3, GDNF antibody (1:1500) by ABC method. The immunoreactive density was observed in a site near DRG and a site near spinal cord. In the control group (with spared L6 DRG), there were no marked differences in NT-3 and GDNF immunoreactivity between the site near DRG and the site near spinal cord, while BDNF immunoreactivity was more intense in the site near DRG than that in the site near spinal cord. In the operation group, the immunoreactivity of each neurotrophin in the site near DRG was stronger than that in the site near spinal cord, and the immunoreactivities of BDNF, NT-3, GDNF in the site near DRG of the operation were stronger than those of the control group respectively. The increasing of immunoreactivities of neurotrophins near DRG following partial dorsal root rhizotomy suggests that partial dorsal root rhizotomy can promote their anterograde transportation from spared DRG to the spinal cord.

  19. Inhibition of Histone Deacetylases Attenuates Morphine Tolerance and Restores MOR Expression in the DRG of BCP Rats.

    PubMed

    He, Xiao-Tao; Zhou, Kai-Xiang; Zhao, Wen-Jun; Zhang, Chen; Deng, Jian-Ping; Chen, Fa-Ming; Gu, Ze-Xu; Li, Yun-Qing; Dong, Yu-Lin

    2018-01-01

    The easily developed morphine tolerance in bone cancer pain (BCP) significantly hindered its clinical use. Increasing evidence suggests that histone deacetylases (HDACs) regulate analgesic tolerance subsequent to continuous opioid exposure. However, whether HDACs contribute to morphine tolerance in the pathogenesis of BCP is still unknown. In the current study, we explored the possible engagement of HDACs in morphine tolerance during the pathogenesis of BCP. After intra-tibia tumor cell inoculation (TCI), we found that the increased expression of HDACs was negatively correlated with the decreased expression of MOR in the DRG following TCI. The paw withdrawal threshold (PWT) and percentage maximum possible effects (MPEs) decreased rapidly in TCI rats when morphine was used alone. In contrast, the concomitant use of SAHA and morphine significantly elevated the PWT and MPEs of TCI rats compared to morphine alone. Additionally, we found that SAHA administration significantly elevated MOR expression in the DRG of TCI rats with or without morphine treatment. Moreover, the TCI-induced increase in the co-expression of MOR and HDAC1 in neurons was significantly decreased after SAHA administration. These results suggest that HDACs are correlated with the downregulation of MOR in the DRG during the pathogenesis of BCP. Inhibition of HDACs using SAHA can be used to attenuate morphine tolerance in BCP.

  20. Peripheral nerve injury induces loss of nociceptive neuron-specific Gαi-interacting protein in neuropathic pain rat.

    PubMed

    Liu, Zhen; Wang, Fei; Fischer, Gregory; Hogan, Quinn H; Yu, Hongwei

    2016-01-01

    Gαi-interacting protein (GINIP) is expressed specifically in dorsal root ganglion (DRG) neurons and functions in modulation of peripheral gamma-aminobutyric acid B receptor (GBR). Genetic deletion of GINIP leads to impaired responsiveness to GBR agonist-mediated analgesia in rodent. It is, however, not defined whether nerve injury changes GINIP expression. Immunolabeling with validated antibody revealed GINIP expression in ~40% of total lumbar DRG neurons in normal adult rats. GINIP immunoreactivity was detected in ~80% of IB4-positive (nonpeptidergic) and ~30% of CGRP-positive (peptidergic) neurons. GINIP immunoreactivity in the spinal cord dorsal horn was colabeled with IB4 and partially with CGRP. In addition, GINIP was expressed in DRG neurons immunopositive for GBR1, GBR2, Gαi(s), and Gαo and was also extensively colabeled with multiple nociceptive neuronal markers, including Trpv1, NaV1.7, CaV2.2α1b, CaV3.2α1b, TrkA, and Trek2. Peripheral nerve injury by L5 spinal nerve ligation significantly decreased the proportion of GINIP immunoreactivity-positive neurons from 40 ± 8.4% to 0.8 ± 0.1% (p < 0.01, mean ± SD, four weeks after spinal nerve ligation) and the total GINIP protein to 1.3% ± 0.04% of its basal level (p < 0.01, n = 6 animals in each group, two weeks after spinal nerve ligation) in the ipsilateral L5 DRGs. Our results show that GINIP is predominantly expressed by small nonpeptidergic nociceptive neurons and that nerve injury triggers loss of GINIP expression. Signal transduction roles of GINIP may be diverse as it colabeled with various subgroups of nociceptive neurons. Future studies may investigate details of the signaling mechanism engaged by GINIP, as well as the pathophysiological significance of lost expression of GINIP in neuropathic pain. © The Author(s) 2016.

  1. Anti-oxidative and anti-inflammatory effects of cinnamaldehyde on protecting high glucose-induced damage in cultured dorsal root ganglion neurons of rats.

    PubMed

    Yang, Dan; Liang, Xiao-Chun; Shi, Yue; Sun, Qing; Liu, Di; Liu, Wei; Zhang, Hong

    2016-01-01

    To examine the mechanism underlying the beneficial role of cinnamaldehyde on oxidative damage and apoptosis in high glucose (HG)-induced dorsal root ganglion (DRG) neurons in vitro. HG-treated DRG neurons were developed as an in vitro model of diabetic neuropathy. The neurons were randomly divided into five groups: the control group, the HG group and the HG groups treated with 25, 50 and 100 nmol/L cinnamaldehyde, respectively. Cell viability was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and apoptosis rate was evaluated by the in situ TdT-mediated dUTP nick end labeling (TUNEL) assay. The intracellular level of reactive oxygen species (ROS) was measured with flow cytometry. Expression of nuclear factor-kappa B (NF-κB), inhibitor of κB (IκB), phosphorylated IκB (p-IκB), tumor necrosis factor (TNF)-α, interleukin-6 (IL-6) and caspase-3 were determined by western blotting and real-time quantitative reverse transcription polymerase chain reaction (RT-PCR). Expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1) were also measured by western blotting. Cinnamaldehyde reduced HG-induced loss of viability, apoptosis and intracellular generation of ROS in the DRG neurons via inhibiting NF-κB activity. The western blot assay results showed that the HG-induced elevated expressions of NF-κB, IκB and p-IκB were remarkably reduced by cinnamaldehyde treatment in a dose-dependent manner (P <0.01). The HG-induced over-expression of NF-κB p65 mRNA was remarkably attenuated after cinnamaldehyde treatment in a dose-dependent manner (P <0.01). However, the expressions of Nrf2 and HO-1 were not upregulated. Treatment with cinnamaldehyde not only attenuated caspase-3 activation and the caspase cleavage cascade in DRG neurons, but also lowered the elevated IL-6, TNF-α, cyclo-oxygenase and inducible nitric oxide synthase levels, indicating a reduction in inflammatory damage. Cinnamaldehyde protected

  2. [The German DRG system 2003-2010 from the perspective of intensive care medicine].

    PubMed

    Franz, Dominik; Bunzemeier, Holger; Roeder, Norbert; Reinecke, Holger

    2010-01-01

    Intensive care medicine is extremely heterogeneous, expensive and can only be partially planned and controlled. A correct and fair representation of intensive care medicine in the G-DRG system is an essential requirement for the use as a pricing system. From the perspective of intensive care medicine, pertinent changes of the DRG structure and differentiation of relevant parameters have been established within the G-DRG systems 2003-2010. Analysis of relevant diagnoses, medical procedures, co-payment structures and G-DRGs in the versions 2003-2010 based on the publications of the German DRG Institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). Since the first G-DRG system version 2003, numerous measures improved quality of case allocation of intensive care medicine. Highly relevant to the system version 2010 are duration of mechanical ventilation, the intensive care treatment complex and complicating constellations. The number of G-DRGs relevant to intensive medical care increased from n = 3 (2003) to n = 58 (2010). For standard cases, quality of case allocation and G-DRG reimbursement are adequate in 2010. The G-DRG system gained complexity again. High demands are made on correct and complete coding of complex cases. Nevertheless, further adjustments of the G-DRG system especially for cases with extremely high costs are necessary. Where the G-DRG system is unable to cover extremely high-cost cases, reimbursement solutions beyond the G-DRG structure should be taken into account.

  3. [Heterogeneity of costs and performance for penetrating eye injuries and suturing amniotic membranes under DRG conditions : Analysis of case constellations of the G-DRG C01B of the Regensburg University eye clinic].

    PubMed

    Franz, D; Mrosek, M; Mrosek, S; Helbig, H; Framme, C

    2012-01-01

    Patients with penetrating eye injuries are a very heterogeneous group both medically and economically. Since 2009, treatment involving sutures for open eye injuries and cases requiring amniotic membrane transplantation (AMT) were allocated to DRG C01B of the German diagnosis-related group system. However, given the significant clinical differences between these treatments, an inhomogeneity of costs to performance is postulated. This analysis describes case allocation problems within the G-DRG C01B category and presents solutions. A retrospective analysis was conducted from the standardized G-DRG data of 277 patients with open eye injuries and AMT between 2007 and 2008, grouped under the 2008 G-DRG system version to the G-DRG C01Z category. This data was provided by the Department of Ophthalmology at the University Hospital Regensburg. Additionally case-based data of the following were supplemented: length of surgery, time of anesthesia and intensity of patient care. Fixed and variable costs were determined for surgery and other inpatient treatment. Finally, an analysis of the heterogeneity of costs within the G-DRG C01B of the G-DRG system 2009 was implemented. Inhomogeneity was evident within the G-DRG C01B of the G-DRG system 2009 for the two groups suture of open eye injuries and AMT concerning the parameters length of stay, proportion of high outliers and cost per case. Multiple surgeries during an inpatient stay lead to an extended length of stay and increasing costs, especially within the AMT group. Intensity of patient care and the consideration of patient comorbidity did not yield relevant differences. The quality of the G-DRG system is measured by its ability to obtain adequate funding for highly complex and heterogeneous cases. Specific modifications of the G-DRG structures could increase the appropriateness of case allocation for patients with open eye injuries within the G-DRG C01B of the German DRG system 2009. As a result of the present study, cases

  4. 42 CFR 412.60 - DRG classification and weighting factors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false DRG classification and weighting factors. 412.60... Determining Prospective Payment Federal Rates for Inpatient Operating Costs § 412.60 DRG classification and weighting factors. (a) Diagnosis-related groups. CMS establishs a classification of inpatient hospital...

  5. 42 CFR 412.60 - DRG classification and weighting factors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false DRG classification and weighting factors. 412.60... Determining Prospective Payment Federal Rates for Inpatient Operating Costs § 412.60 DRG classification and weighting factors. (a) Diagnosis-related groups. CMS establishs a classification of inpatient hospital...

  6. 42 CFR 476.93 - Opportunity to discuss proposed initial denial determination and changes as a result of a DRG...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... determination and changes as a result of a DRG validation. 476.93 Section 476.93 Public Health CENTERS FOR... initial denial determination and changes as a result of a DRG validation. Before a QIO reaches an initial denial determination or makes a change as a result of a DRG validation, it must— (a) Promptly notify the...

  7. 42 CFR 476.93 - Opportunity to discuss proposed initial denial determination and changes as a result of a DRG...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... determination and changes as a result of a DRG validation. 476.93 Section 476.93 Public Health CENTERS FOR... initial denial determination and changes as a result of a DRG validation. Before a QIO reaches an initial denial determination or makes a change as a result of a DRG validation, it must— (a) Promptly notify the...

  8. 42 CFR 476.93 - Opportunity to discuss proposed initial denial determination and changes as a result of a DRG...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... determination and changes as a result of a DRG validation. 476.93 Section 476.93 Public Health CENTERS FOR... initial denial determination and changes as a result of a DRG validation. Before a QIO reaches an initial denial determination or makes a change as a result of a DRG validation, it must— (a) Promptly notify the...

  9. 42 CFR 476.93 - Opportunity to discuss proposed initial denial determination and changes as a result of a DRG...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... determination and changes as a result of a DRG validation. 476.93 Section 476.93 Public Health CENTERS FOR... and changes as a result of a DRG validation. Before a QIO reaches an initial denial determination or makes a change as a result of a DRG validation, it must— (a) Promptly notify the provider or supplier...

  10. [Neonatal septicemia in the G-DRG system].

    PubMed

    Mohrmann, M; Hentschel, R; Böhler, T; Dirschedl, P

    2006-12-01

    The introduction of Diagnosis Related Groups in Germany (G-DRG) has brought forward the obligation for physicians to take into account an intricate system of medical, economical and legal implementations. Mistakes in the process of encoding the principal diagnosis or procedures may have financial consequences. Problems to determine the correct ICD-code will be most prominent for diseases with poorly defined or even inconsistent diagnostic criteria as is the case for neonatal septicemia. We decided to evaluate whether the introduction of G-DRG resulted in a change of frequency of the diagnosis "neonatal septicemia". We analysed data derived from the quality assurance program "Neonatalerhebung" in the state of Baden-Württemberg during the years of 2001 through 2004, i. e., 2 years before and 2 years during the introduction of G-DRG. During this period an annual number of 12,316 up to 13,172 newborns were admitted to the participating hospitals. The mean number of diagnoses per patient increased from 2.2 to 3.8. The frequency of the diagnosis of septicemia remained constant. The percentage of newborns receiving antibiotic therapy did not change. The ratio of cases with "septicemia yes" over "antibiotics yes" did not change. Although it is difficult to determine the diagnosis of neonatal septicemia and in spite of the economic implications of this diagnosis, no change in the frequency of this diagnosis occurred during the introduction of DRG. Assuming that the participating hospitals used an identical database for the quality assurance program "Neonatalerhebung" and for accounting, we conclude that the DRG system is stable with respect to neonatal septicemia.

  11. Charting a path forward: policy analysis of China's evolved DRG-based hospital payment system.

    PubMed

    Liu, Rui; Shi, Jianwei; Yang, Beilei; Jin, Chunlin; Sun, Pengfei; Wu, Lingfang; Yu, Dehua; Xiong, Linping; Wang, Zhaoxin

    2017-09-01

    At present, the diagnosis-related groups-based prospective payment system (DRG-PPS) that has been implemented in China is merely a prototype called the simplified DRG-PPS, which is known as the 'ceiling price for a single disease'. Given that studies on the effects of a simplified DRG-PPS in China have usually been controversial, we aim to synthesize evidence examining whether DRGs can reduce medical costs and length of stay (LOS) in China. Data were searched from both Chinese [Wan Fang and China National Knowledge Infrastructure Database (CNKI)] and international databases (Web of Science and PubMed), as well as the official websites of Chinese health departments in the 2004-2016 period. Only studies with a design that included both experimental (with DRG-PPS implementation) and control groups (without DRG-PPS implementation) were included in the review. The studies were based on inpatient samples from public hospitals distributed in 12 provinces of mainland China. Among them, 80.95% (17/21) revealed that hospitalization costs could be reduced significantly, and 50.00% (8/16) indicated that length of stay could be decreased significantly. In addition, the government reports showed the enormous differences in pricing standards and LOS in various provinces, even for the same disease. We conclude that the simplified DRGs are useful in controlling hospitalization costs, but they fail to reduce LOS. Much work remains to be done in China to improve the simplified DRG-PPS. © The Author 2017. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.

  12. [Financing of inpatient orthopedics and trauma surgery in the G-DRG system 2010].

    PubMed

    Franz, D; Schemmann, F; Roeder, N; Mahlke, L

    2010-08-01

    The German DRG (diagnosis-related groups) system forms the basis for billing inpatient hospital services. It includes not only the case groups (G-DRGs), but also additional and innovation payments. This paper analyzes and evaluates the relevant developments of the G-DRG System 2010 for orthopedics and traumatology from the medical and classification perspectives. Analyses of relevant diagnoses, medical procedures and G-DRGs in the versions 2009 and 2010 based on the publications of the German DRG institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI) were carried out. The DRG catalog is has grown from 8 to 1,200 G-DRGs. A number of codes for surgical measures have been newly established or modified. Here, the identification and the correct and performance-based mapping of complex and elaborate scenarios was again the focus of the restructuring of the G-DRG system. The G-DRG structure in orthopedics and traumatology has been changed, especially in the areas of spinal surgery and surgery of the upper and lower extremities. The actual impact of the changes may vary depending on the individual hospital services. For the first time since the introduction of the G-DRG system, the pure numerical changes at the level of DRGs themselves are so marginal that only part of the DRG users in the hospitals will register them. The changes implemented not only a high selectivity between complex and less complex scenarios, but partly also unintended and unjustified revaluation of less complex measures. The G-DRG system has gained complexity again. Especially the G-DRG allocation of spinal surgery and multiple surgical interventions of the upper and/or lower extremities have reached such a complexity that only a few DRG users can follow them.

  13. G-DRG Version 2009: new developments.

    PubMed

    Müller, Marcel L; Forschner, Andrea; Wenke, Andreas; Luger, Thomas A; Rompel, Rainer; Roeder, Norbert; Hensen, Peter

    2009-04-01

    The update of the G-DRG system for the year 2009 has been successfully negotiated. Like in the past years, changes are minimal and not dramatic, but they significantly enhance the quality of the DRG system. Once again, the German DRG system demonstrates its versatility and reliability for clinical reimbursement purposes. In the field of dermatology, several improvements or enhancements can be identified; the average case mix index that declined in the past years should now rise by 0.5 percent for 2009. Oncology cases are affected especially by this increase. Some refinements advanced for several years by the German Dermatologic Society (DDG) have been recognized --complex therapies like vacuum wound therapy, isolation due to multi-resistant infections and multiple primary tumors now have better cost weights. Although there still remain some minor problems like reimbursement of cost-intensive treatments, German dermatology is in summary very well prepared for the year 2009.

  14. 42 CFR 478.15 - QIO review of changes resulting from DRG validation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false QIO review of changes resulting from DRG validation... review of changes resulting from DRG validation. (a) General rules. (1) A provider or practitioner dissatisfied with a change to the diagnostic or procedural coding information made by a QIO as a result of DRG...

  15. TRPA1 Is Functionally Expressed Primarily by IB4-Binding, Non-Peptidergic Mouse and Rat Sensory Neurons

    PubMed Central

    Stucky, Cheryl L.

    2012-01-01

    Subpopulations of somatosensory neurons are characterized by functional properties and expression of receptor proteins and surface markers. CGRP expression and IB4-binding are commonly used to define peptidergic and non-peptidergic subpopulations. TRPA1 is a polymodal, plasma membrane ion channel that contributes to mechanical and cold hypersensitivity during tissue injury, making it a key target for pain therapeutics. Some studies have shown that TRPA1 is predominantly expressed by peptidergic sensory neurons, but others indicate that TRPA1 is expressed extensively within non-peptidergic, IB4-binding neurons. We used FURA-2 calcium imaging to define the functional distribution of TRPA1 among peptidergic and non-peptidergic adult mouse (C57BL/6J) DRG neurons. Approximately 80% of all small-diameter (<27 µm) neurons from lumbar 1–6 DRGs that responded to TRPA1 agonists allyl isothiocyanate (AITC; 79%) or cinnamaldehyde (84%) were IB4-positive. Retrograde labeling via plantar hind paw injection of WGA-Alexafluor594 showed similarly that most (81%) cutaneous neurons responding to TRPA1 agonists were IB4-positive. Additionally, we cultured DRG neurons from a novel CGRP-GFP mouse where GFP expression is driven by the CGRPα promoter, enabling identification of CGRP-expressing live neurons. Interestingly, 78% of TRPA1-responsive neurons were CGRP-negative. Co-labeling with IB4 revealed that the majority (66%) of TRPA1 agonist responders were IB4-positive but CGRP-negative. Among TRPA1-null DRGs, few small neurons (2–4%) responded to either TRPA1 agonist, indicating that both cinnamaldehyde and AITC specifically target TRPA1. Additionally, few large neurons (≥27 µm diameter) responded to AITC (6%) or cinnamaldehyde (4%), confirming that most large-diameter somata lack functional TRPA1. Comparison of mouse and rat DRGs showed that the majority of TRPA1-responsive neurons in both species were IB4-positive. Together, these data demonstrate that TRPA1 is functionally

  16. Amyloid-beta aggregates cause alterations of astrocytic metabolic phenotype: impact on neuronal viability.

    PubMed

    Allaman, Igor; Gavillet, Mathilde; Bélanger, Mireille; Laroche, Thierry; Viertl, David; Lashuel, Hilal A; Magistretti, Pierre J

    2010-03-03

    Amyloid-beta (Abeta) peptides play a key role in the pathogenesis of Alzheimer's disease and exert various toxic effects on neurons; however, relatively little is known about their influence on glial cells. Astrocytes play a pivotal role in brain homeostasis, contributing to the regulation of local energy metabolism and oxidative stress defense, two aspects of importance for neuronal viability and function. In the present study, we explored the effects of Abeta peptides on glucose metabolism in cultured astrocytes. Following Abeta(25-35) exposure, we observed an increase in glucose uptake and its various metabolic fates, i.e., glycolysis (coupled to lactate release), tricarboxylic acid cycle, pentose phosphate pathway, and incorporation into glycogen. Abeta increased hydrogen peroxide production as well as glutathione release into the extracellular space without affecting intracellular glutathione content. A causal link between the effects of Abeta on glucose metabolism and its aggregation and internalization into astrocytes through binding to members of the class A scavenger receptor family could be demonstrated. Using astrocyte-neuron cocultures, we observed that the overall modifications of astrocyte metabolism induced by Abeta impair neuronal viability. The effects of the Abeta(25-35) fragment were reproduced by Abeta(1-42) but not by Abeta(1-40). Finally, the phosphoinositide 3-kinase (PI3-kinase) pathway appears to be crucial in these events since both the changes in glucose utilization and the decrease in neuronal viability are prevented by LY294002, a PI3-kinase inhibitor. This set of observations indicates that Abeta aggregation and internalization into astrocytes profoundly alter their metabolic phenotype with deleterious consequences for neuronal viability.

  17. Melatonin Suppresses Neuropathic Pain via MT2-Dependent and -Independent Pathways in Dorsal Root Ganglia Neurons of Mice

    PubMed Central

    Lin, Jia-Ji; Lin, Ye; Zhao, Tian-Zhi; Zhang, Chun-Kui; Zhang, Ting; Chen, Xiao-Li; Ding, Jia-Qi; Chang, Ting; Zhang, Zhuo; Sun, Chao; Zhao, Dai-Di; Zhu, Jun-Lin; Li, Zhu-Yi; Li, Jin-Lian

    2017-01-01

    Melatonin (Mel) and its receptors (MT1 and MT2) have a well-documented efficacy in treating different pain conditions. However, the anti-nociceptive effects of Mel and Mel receptors in neuropathic pain (NP) are poorly understood. To elucidate this process, pain behaviors were measured in a dorsal root ganglia (DRG)-friendly sciatic nerve cuffing model. We detected up-regulation of MT2 expression in the DRGs of cuff-implanted mice and its activation by the agonist 8-M-PDOT (8MP). Also, Mel attenuated the mechanical and thermal allodynia induced by cuff implantation. Immunohistochemical analysis demonstrated the expression of MT2 in the DRG neurons, while MT1 was expressed in the satellite cells. In cultured primary neurons, microarray analysis and gene knockdown experiments demonstrated that MT2 activation by 8MP or Mel suppressed calcium signaling pathways via MAPK1, which were blocked by RAR-related orphan receptor alpha (RORα) activation with a high dose of Mel. Furthermore, expression of nitric oxide synthase 1 (NOS1) was down-regulated upon Mel treatment regardless of MT2 or RORα. Application of Mel or 8MP in cuff-implanted models inhibited the activation of peptidergic neurons and neuro-inflammation in the DRGs by down-regulating c-fos, calcitonin gene-related peptide [CGRP], and tumor necrosis factor-1α [TNF-1α] and interleukin-1β [IL-1β]. Addition of the MT2 antagonist luzindole blocked the effects of 8MP but not those of Mel. In conclusion, only MT2 was expressed in the DRG neurons and up-regulated upon cuff implantation. The analgesic effects of Mel in cuff-implanted mice were closely associated with both MT2-dependent (MAPK-calcium channels) and MT2-independent (NOS1) pathways in the DRG. PMID:28656058

  18. Analgesic ineffectiveness of lacosamide after spinal nerve ligation and its sodium channel activity in injured neurons.

    PubMed

    Hagenacker, T; Schäfer, N; Büsselberg, D; Schäfers, M

    2013-07-01

    Lacosamide is a novel anti-epileptic drug that enhances the slow- and not fast-inactivating state of voltage-gated sodium channels. Lacosamide has demonstrated analgesic efficacy in several animal studies but preclinical studies on neuropathic pain models are rare, and recent clinical trials showed no superior analgesic effects. Here, we examine whether an acute or chronic administration of lacosamide (3-60 mg/kg, i.p.) attenuates pain behaviour induced by spinal nerve ligation (SNL). To validate the inhibitory efficacy of lacosamide on voltage-gated sodium channels, sodium currents in naïve and SNL-injured dorsal root ganglion (DRG) neurons were recorded using whole-cell patch clamping. Lacosamide only marginally attenuated thermal hyperalgesia, but not tactile allodynia when applied once 7 or 14 days after SNL and showed no analgesic effect when applied daily for 19 days. In naïve neurons, 100 μmol/L lacosamide inhibited sodium channel currents by 58% and enhanced the slow inactivation (87% for lacosamide vs. 47% for control). In contrast, lacosamide inhibited sodium currents in injured DRG neurons by only 15%, while the effects on slow inactivation were diminished. Isolated currents from the NaV 1.8 channel subtype were only marginally changed by lacosamide. The reduced effectiveness of lacosamide on voltage-gated sodium channel currents in injured DRG neurons may contribute to the reduced analgesic effect observed for the SNL model. © 2012 European Federation of International Association for the Study of Pain Chapters.

  19. [Proposals for adapting a DRG system in the fields of orthopedics and trauma surgery for 2004].

    PubMed

    Roeder, N; Franz, D; Siebert, H; Frank, D; Stücker, R; Meiners, A; Tempka, A; Siebert, C H

    2003-09-01

    The introduction of the DRG system in Germany-optional since 1 January 2003 and mandatory for all hospitals as of 1 January 2004-has resulted in great uncertainty, particularly on the part of hospitals, since apprehension prevails that the diagnostic and therapeutic measures practiced in Germany will not be appropriately represented and remunerated by a DRG system. The G-DRG version 1.0 prepared within the framework of substitutive execution is largely identical to the Australian AR-DRG version 4.1. Adjustments that do justice to the realities of German treatment modalities were at most insignificant. It is therefore essential that stock be taken for each medical specialty to determine to what extent treatment procedures commonly followed in Germany are adequately reflected in this G-DRG system or whether adjustments are necessary to make allowances for German realities. To be able to provide qualified statements on the problems involved, scientific analysis of possible problems is necessary utilizing German data. Thus, we undertook an evaluation of how the special fields of orthopedics and accident surgery are represented in the G-DRG system. The resultant data form the basis for evidence of presumable deficits in the representation of orthopedic and accident surgery cases in the G-DRG system. The German Association for Trauma Surgery and the German Association for Orthopedics and Orthopedic Surgery have undertaken a DRG evaluation project together with the Organization of Directors for Accident Surgery (chairperson: Professor Dr. Mischkowsky, Kempten), the Organization of Directors for Orthopedics (chairperson: Professor Dr. Puhl, Ulm), the DRG Working Group of the German Association for Accident Surgery, and the Joint Commission of the Professional Association of German Surgeons and the German Association for Surgery in cooperation with the DRG Research Group of the University Clinic Muenster, the German Hospital Association, and the German Medical Association

  20. miR-155 Deletion in Mice Overcomes Neuron-Intrinsic and Neuron-Extrinsic Barriers to Spinal Cord Repair.

    PubMed

    Gaudet, Andrew D; Mandrekar-Colucci, Shweta; Hall, Jodie C E; Sweet, David R; Schmitt, Philipp J; Xu, Xinyang; Guan, Zhen; Mo, Xiaokui; Guerau-de-Arellano, Mireia; Popovich, Phillip G

    2016-08-10

    Axon regeneration after spinal cord injury (SCI) fails due to neuron-intrinsic mechanisms and extracellular barriers including inflammation. microRNA (miR)-155-5p is a small, noncoding RNA that negatively regulates mRNA translation. In macrophages, miR-155-5p is induced by inflammatory stimuli and elicits a response that could be toxic after SCI. miR-155 may also independently alter expression of genes that regulate axon growth in neurons. Here, we hypothesized that miR-155 deletion would simultaneously improve axon growth and reduce neuroinflammation after SCI by acting on both neurons and macrophages. New data show that miR-155 deletion attenuates inflammatory signaling in macrophages, reduces macrophage-mediated neuron toxicity, and increases macrophage-elicited axon growth by ∼40% relative to control conditions. In addition, miR-155 deletion increases spontaneous axon growth from neurons; adult miR-155 KO dorsal root ganglion (DRG) neurons extend 44% longer neurites than WT neurons. In vivo, miR-155 deletion augments conditioning lesion-induced intraneuronal expression of SPRR1A, a regeneration-associated gene; ∼50% more injured KO DRG neurons expressed SPRR1A versus WT neurons. After dorsal column SCI, miR-155 KO mouse spinal cord has reduced neuroinflammation and increased peripheral conditioning-lesion-enhanced axon regeneration beyond the epicenter. Finally, in a model of spinal contusion injury, miR-155 deletion improves locomotor function at postinjury times corresponding with the arrival and maximal appearance of activated intraspinal macrophages. In miR-155 KO mice, improved locomotor function is associated with smaller contusion lesions and decreased accumulation of inflammatory macrophages. Collectively, these data indicate that miR-155 is a novel therapeutic target capable of simultaneously overcoming neuron-intrinsic and neuron-extrinsic barriers to repair after SCI. Axon regeneration after spinal cord injury (SCI) fails due to neuron

  1. Effective gene expression in the rat dorsal root ganglia with a non-viral vector delivered via spinal nerve injection

    PubMed Central

    Chang, Ming-Fong; Hsieh, Jung-Hsien; Chiang, Hao; Kan, Hung-Wei; Huang, Cho-Min; Chellis, Luke; Lin, Bo-Shiou; Miaw, Shi-Chuen; Pan, Chun-Liang; Chao, Chi-Chao; Hsieh, Sung-Tsang

    2016-01-01

    Delivering gene constructs into the dorsal root ganglia (DRG) is a powerful but challenging therapeutic strategy for sensory disorders affecting the DRG and their peripheral processes. The current delivery methods of direct intra-DRG injection and intrathecal injection have several disadvantages, including potential injury to DRG neurons and low transfection efficiency, respectively. This study aimed to develop a spinal nerve injection strategy to deliver polyethylenimine mixed with plasmid (PEI/DNA polyplexes) containing green fluorescent protein (GFP). Using this spinal nerve injection approach, PEI/DNA polyplexes were delivered to DRG neurons without nerve injury. Within one week of the delivery, GFP expression was detected in 82.8% ± 1.70% of DRG neurons, comparable to the levels obtained by intra-DRG injection (81.3% ± 5.1%, p = 0.82) but much higher than those obtained by intrathecal injection. The degree of GFP expression by neurofilament(+) and peripherin(+) DRG neurons was similar. The safety of this approach was documented by the absence of injury marker expression, including activation transcription factor 3 and ionized calcium binding adaptor molecule 1 for neurons and glia, respectively, as well as the absence of behavioral changes. These results demonstrated the efficacy and safety of delivering PEI/DNA polyplexes to DRG neurons via spinal nerve injection. PMID:27748450

  2. TRAF family member-associated NF-kappa B activator (TANK) expression increases in injured sensory neurons and is transcriptionally regulated by Sox11.

    PubMed

    Salerno, K M; Jing, X; Diges, C M; Davis, B M; Albers, K M

    2013-02-12

    Peripheral nerve injury evokes rapid and complex changes in gene transcription and cellular signaling pathways. Understanding how these changes are functionally related is essential for developing new approaches that accelerate and improve nerve regeneration. Toward this goal we found that nerve injury induces a rapid and significant up-regulation of the transcription factor Sox11 in dorsal root ganglia (DRG) neurons. Gain and loss of function studies have shown this increase is essential for normal axon regeneration. To determine how Sox11 impacts neuronal gene expression, DRG neurons were treated with Sox11 siRNA to identify potential transcriptional targets. One gene significantly reduced by Sox11 knockdown was TRAF (tumor necrosis factor (TNF) receptor-associated factor)-associated NF-κB activator (TANK). Here we show that TANK is expressed in DRG neurons, that TANK expression is increased in response to peripheral nerve injury and that Sox11 overexpression in vitro increases TANK expression. Injury and in vitro overexpression were also found to preferentially increase TANK transcript variant 3 and a larger TANK protein isoform. To determine if Sox11 regulates TANK transcription bioinformatic analysis was used to identify potential Sox-binding motifs within 5kbp of the TANK 5' untranslated region (UTR) across several mammalian genomes. Two sites in the mouse TANK gene were examined. Luciferase expression assays coupled with site-directed mutagenesis showed each site contributes to enhanced TANK promoter activity. In addition, chromatin immunoprecipitation assays showed direct Sox11 binding in regions containing the two identified Sox motifs in the mouse TANK 5'-UTR. These studies are the first to show that TANK is expressed in DRG neurons, that TANK is increased by peripheral nerve injury and that the regulation of TANK expression is, at least in part, controlled by the injury-associated transcription factor Sox11. Copyright © 2012 IBRO. Published by Elsevier

  3. TRAF family member-associated NF-kappa B activator (TANK) expression increases in injured sensory neurons and is transcriptionally regulated by Sox11

    PubMed Central

    Salerno, Kathleen M.; Jing, Xiaotang; Diges, Charlotte M.; Davis, Brian M.; Albers, Kathryn M.

    2013-01-01

    Peripheral nerve injury evokes rapid and complex changes in gene transcription and cellular signaling pathways. Understanding how these changes are functionally related is essential for developing new approaches that accelerate and improve nerve regeneration. Towards this goal we found that nerve injury induces a rapid and significant up-regulation of the transcription factor Sox11 in dorsal root ganglia (DRG) neurons. Gain and loss of function studies have shown this increase is essential for normal axon regeneration. To determine how Sox11 impacts neuronal gene expression, DRG neurons were treated with Sox11 siRNA to identify potential transcriptional targets. One gene significantly reduced by Sox11 knockdown was TRAF (tumor necrosis factor (TNF) receptor-associated factor)-associated NF-κB activator (TANK). Here we show that TANK is expressed in DRG neurons, that TANK expression is increased in response to peripheral nerve injury and that Sox11 overexpression in vitro increases TANK expression. Injury and in vitro overexpression were also found to preferentially increase TANK transcript variant 3 and a larger TANK protein isoform. To determine if Sox11 regulates TANK transcription bioinformatic analysis was used to identify potential Sox binding motifs within 5 kbp of the TANK 5’ untranslated region (UTR) across several mammalian genomes. Two sites in the mouse TANK gene were examined. Luciferase expression assays coupled with site-directed mutagenesis showed each site contributes to enhanced TANK promoter activity. In addition, chromatin immunoprecipitation assays showed direct Sox11 binding in regions containing the two identified Sox motifs in the mouse TANK 5’-UTR. These studies are the first to show that TANK is expressed in DRG neurons, that TANK is increased by peripheral nerve injury and that the regulation of TANK expression is, at least in part, controlled by the injury-associated transcription factor Sox11. PMID:23201825

  4. [ENT medicine and head and neck surgery in the G-DRG system 2008].

    PubMed

    Franz, D; Roeder, N; Hörmann, K; Alberty, J

    2008-09-01

    Further developments in the German DRG system have been incorporated into the 2008 version. For ENT medicine and head and neck surgery significant changes concerning coding of diagnoses, medical procedures and concerning the DRG-structure were made. Analysis of relevant diagnoses, medical procedures and G-DRGs in the versions 2007 and 2008 based on the publications of the German DRG institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). Changes for 2008 focussed on the development of DRG structure, DRG validation and codes for medical procedures. The outcome of these changes for German hospitals may vary depending on the range of activities. The G-DRG system has gained in complexity again. High demands are made on correct and complete coding of complex ENT and head and neck surgery cases. Quality of case allocation within the G-DRG system has been improved. For standard cases quality of case allocation is adequate. Nevertheless, further adjustments of the G-DRG system especially for cases with complex neck surgery are necessary.

  5. Mitochondria-targeted antioxidants protect against amyloid-beta toxicity in Alzheimer's disease neurons.

    PubMed

    Manczak, Maria; Mao, Peizhong; Calkins, Marcus J; Cornea, Anda; Reddy, Arubala P; Murphy, Michael P; Szeto, Hazel H; Park, Byung; Reddy, P Hemachandra

    2010-01-01

    The purpose of our study was to investigate the effects of the mitochondria-targeted antioxidants, MitoQ and SS31, and the anti-aging agent resveratrol on neurons from a mouse model (Tg2576 line) of Alzheimer's disease (AD) and on mouse neuroblastoma (N2a) cells incubated with the amyloid-beta (Abeta) peptide. Using electron and confocal microscopy, gene expression analysis, and biochemical methods, we studied mitochondrial structure and function and neurite outgrowth in N2a cells treated with MitoQ, SS31, and resveratrol, and then incubated with Abeta. In N2a cells only incubated with the Abeta, we found increased expressions of mitochondrial fission genes and decreased expression of fusion genes and also decreased expression of peroxiredoxins. Electron microscopy of the N2a cells incubated with Abeta revealed a significantly increased number of mitochondria, indicating that Abeta fragments mitochondria. Biochemical analysis revealed that function is defective in mitochondria. Neurite outgrowth was significantly decreased in Abeta-incubated N2a cells, indicating that Abeta affects neurite outgrowth. However, in N2a cells treated with MitoQ, SS31, and resveratrol, and then incubated with Abeta, abnormal expression of peroxiredoxins and mitochondrial structural genes were prevented and mitochondrial function was normal; intact mitochondria were present and neurite outgrowth was significantly increased. In primary neurons from amyloid-beta precursor protein transgenic mice that were treated with MitoQ and SS31, neurite outgrowth was significantly increased and cyclophilin D expression was significantly decreased. These findings suggest that MitoQ and SS31 prevent Abeta toxicity, which would warrant the study of MitoQ and SS31 as potential drugs to treat patients with AD.

  6. [ENT and head and neck surgery in the German DRG system 2007].

    PubMed

    Franz, D; Roeder, N; Hörmann, K; Alberty, J

    2007-07-01

    The German DRG system has been further developed into version 2007. For ENT and head and neck surgery, significant changes in the coding of diagnoses and medical operations as well as in the the DRG structure have been made. New ICD codes for sleep apnoea and acquired tracheal stenosis have been implemented. Surgery on the acoustic meatus, removal of auricle hyaline cartilage for transplantation (e. g. rhinosurgery) and tonsillotomy have been coded in the 2007 version. In addition, the DRG structure has been improved. Case allocation of more than one significant operation has been established. The G-DRG system has gained in complexity. High demands are made on the coding of complex cases, whereas standard cases require mostly only one specific diagnosis and one specific OPS code. The quality of case allocation for ENT patients within the G-DRG system has been improved. Nevertheless, further adjustments of the G-DRG system are necessary.

  7. Botulinum toxin decreases hyperalgesia and inhibits P2X3 receptor over-expression in sensory neurons induced by ventral root transection in rats.

    PubMed

    Xiao, Lizu; Cheng, Jianguo; Dai, Juanli; Zhang, Deren

    2011-09-01

    We aim to determine the effects of Botulinum toxin type A (BTX-A) on neuropathic pain behavior and the expression of P2X(3) receptor in dorsal root ganglion (DRG) in rats with neuropathic pain induced by L5 ventral root transection (L5 VRT). Neuropathic pain was induced by L5 VRT in male Sprague-Dawley rats. Either saline or BTX-A was administered to the plantar surface. Behavioral tests were conducted preoperatively and at predefined postoperative days. The expression of P2X(3) receptors in DRG neurons was detected by immunoreactivity at postoperative days 3, 7, 14, and 21. The number of positive P2X(3) neurons in the ipsilateral L5 DRG increased significantly after L5 VRT (P<0.001). This increase persisted for at least 3 weeks after the operation. No significant changes in P2X(3) expression were detected in the contralateral L5, or in the L4 DRGs bilaterally. Subcutaneous administration of BTX-A, performed on the left hindpaw at days 4, 8, or 16 post VRT surgery, significantly reduced mechanical allodynia bilaterally and inhibited P2X(3) over-expression induced by L5 VRT. L5 VRT led to over-expression of P2X(3) receptors in the L5 DRG and bilateral mechanical allodynia in rats. Subcutaneous injection of BTX-A significantly reversed the neuropathic pain behavior and the over-expression of P2X(3) receptor in nociceptive neurons. These data not only show over-expression of purinergic receptors in the VRT model of neuropathic pain but also reveal a novel mechanism of botulinum toxin action on nociceptive neurons. Wiley Periodicals, Inc.

  8. [What changes for rheumatologists in the G-DRG system 2006?].

    PubMed

    Liedtke-Dyong, A; Fiori, W; Lakomek, H-J; Hülsemann, J L; Köneke, N; Liman, W; Roeder, N

    2006-07-01

    Once more, the revision of the German DRG catalogue 2006 provides for more accurate reimbursement, particularly for specialised medical services. The newly established DRG I97Z (Rheumatologische Komplexbehandlung bei Krankheiten und Störungen an Muskel-Skelett-System und Bindegewebe) for the complex and multimodal treatment of rheumatic diseases allows an accurate picture of clinical practice in specialized rheumatologic departments and hospitals. Using this specific DRG-description, it will be possible to reduce the financial pressure which results from the redistribution of budgets in the second year of the period of convergence. A precondition for the affected hospitals is to deal with budget planning and calculation of G-DRGs without calculated cost weights for 2006. In addition, this article discusses the relevance of other modifications to the G-DRG system, additional payments, the conditions for payment, the coding standards, and the classification systems for diagnosis and procedures.

  9. Electrophysiological characteristics of IB4-negative TRPV1-expressing muscle afferent DRG neurons.

    PubMed

    Lin, Yi-Wen; Chen, Chih-Cheng

    2015-01-01

    Muscle afferent neurons that express transient receptor potential vanilloid type I (TRPV1) are responsible for muscle pain associated with tissue acidosis. We have previously found that TRPV1 of isolectin B4 (IB4)-negative muscle nociceptors plays an important role in the acid-induced hyperalgesic priming and the development of chronic hyperalgesia in a mouse model of fibromyalgia. To understand the electrophysiological properties of the TRPV1-expressing muscle afferent neurons, we used whole-cell patch clamp recording to study the acid responsiveness and action potential (AP) configuration of capsaicin-sensitive neurons innervating to gastrocnemius muscle. Here we showed that IB4-negative TRPV1-expressing muscle afferent neurons are heterogeneous in terms of cell size, resting membrane potential, AP configuration, tetrodotoxin (TTX)-resistance, and acid-induced current (I acid), as well as capsaicin-induced current (I cap). TRPV1-expressing neurons were all acid-sensitive and could be divided into two acid-sensitive groups depending on an acid-induced sustained current (type I) or an acid-induced biphasic ASIC3-like current (type II). Type I TRPV1-expressing neurons were distinguishable from type II TRPV1-expressing neurons in AP overshoot, after-hyperpolarization duration, and all I acid parameters, but not in AP threshold, TTX-resistance, resting membrane potential, and I cap parameters. These differential biophysical properties of TRPV1-expressing neurons might partially annotate their different roles involved in the development and maintenance of chronic muscle pain.

  10. Heterogeneity of European DRG systems and potentials for a common EuroDRG system Comment on "Cholecystectomy and Diagnosis-Related Groups (DRGs): patient classification and hospital reimbursement in 11 European countries".

    PubMed

    Geissler, Alexander; Quentin, Wilm; Busse, Reinhard

    2015-03-05

    Diagnosis-Related Group (DRG) systems across Europe are very heterogeneous, in particular because of different classification variables and algorithms as well as costing methodologies. But, given the challenge of increasing patient mobility within Europe, health systems are forced to incorporate a common patient classification language in order to compare and identify similar patients e.g. for reimbursement purposes. Beside the national adoption of DRGs for a wide range of purposes (measuring hospital activity vs. paying hospitals), a common DRG system can serve as an international communication basis among health administrators and can reduce the national development efforts as it is demonstrated by the NordDRG consortium. © 2015 by Kerman University of Medical Sciences.

  11. Administration of IL-1beta to the 4th ventricle causes anorexia that is blocked by agouti-related peptide and that coincides with activation of tyrosine-hydroxylase neurons in the nucleus of the solitary tract.

    PubMed

    DeBoer, Mark D; Scarlett, Jarrad M; Levasseur, Peter R; Grant, Wilmon F; Marks, Daniel L

    2009-02-01

    Inflammation-associated cachexia is associated with multiple chronic diseases and involves activation of appetite regulating centers in the arcuate nucleus of the hypothalamus (ARH). The nucleus of the solitary tract (NTS) in the brainstem has also been implicated as an important nucleus involved in appetite regulation. We set out to determine whether the NTS may be involved in inflammation-associated anorexia by injecting IL-1 beta into the 4th ventricle and assessing food intake and NTS neuronal activation. Injection of IL-1 beta produced a decrease in food intake at 3 and 12h after injection which was ameliorated at the 12h time point by a sub-threshold dose of agouti-related peptide (AgRP). Investigation into neuron types in the NTS revealed that IL-1 beta injection was associated with an increase in c-Fos activity in NTS neurons expressing tyrosine hydroxylase (TH). Additionally, injection of IL-1 beta into the 4th ventricle did not produce c-Fos activation of neurons expressing pro-opiomelanocortin (POMC) in the ARH, cells known to be involved in producing anorexia in response to systemic inflammation. Double-label in situ hybridization revealed that TH neurons did not express IL-1 receptor I (IL1-RI) transcript, demonstrating that c-Fos activation of TH neurons in this setting was not via direct stimulation of IL-1 beta on TH neurons themselves. We conclude that IL-1 beta injection into the 4th ventricle produces anorexia and is accompanied by an increase in activation in TH neurons in the NTS. This provides evidence that the brainstem may be an important mediator of anorexia in the setting of inflammation.

  12. Peripheral nerve injury induces loss of nociceptive neuron-specific Gαi-interacting protein in neuropathic pain rat

    PubMed Central

    Liu, Zhen; Wang, Fei; Fischer, Gregory; Hogan, Quinn H.

    2016-01-01

    Background Gαi-interacting protein (GINIP) is expressed specifically in dorsal root ganglion (DRG) neurons and functions in modulation of peripheral gamma-aminobutyric acid B receptor (GBR). Genetic deletion of GINIP leads to impaired responsiveness to GBR agonist-mediated analgesia in rodent. It is, however, not defined whether nerve injury changes GINIP expression. Results Immunolabeling with validated antibody revealed GINIP expression in ∼40% of total lumbar DRG neurons in normal adult rats. GINIP immunoreactivity was detected in ∼80% of IB4-positive (nonpeptidergic) and ∼30% of CGRP-positive (peptidergic) neurons. GINIP immunoreactivity in the spinal cord dorsal horn was colabeled with IB4 and partially with CGRP. In addition, GINIP was expressed in DRG neurons immunopositive for GBR1, GBR2, Gαi(s), and Gαo and was also extensively colabeled with multiple nociceptive neuronal markers, including Trpv1, NaV1.7, CaV2.2α1b, CaV3.2α1b, TrkA, and Trek2. Peripheral nerve injury by L5 spinal nerve ligation significantly decreased the proportion of GINIP immunoreactivity-positive neurons from 40 ± 8.4% to 0.8 ± 0.1% (p < 0.01, mean ± SD, four weeks after spinal nerve ligation) and the total GINIP protein to 1.3% ± 0.04% of its basal level (p < 0.01, n = 6 animals in each group, two weeks after spinal nerve ligation) in the ipsilateral L5 DRGs. Conclusion Our results show that GINIP is predominantly expressed by small nonpeptidergic nociceptive neurons and that nerve injury triggers loss of GINIP expression. Signal transduction roles of GINIP may be diverse as it colabeled with various subgroups of nociceptive neurons. Future studies may investigate details of the signaling mechanism engaged by GINIP, as well as the pathophysiological significance of lost expression of GINIP in neuropathic pain. PMID:27145804

  13. Inhibition of glycogen synthase kinase-3beta downregulates total tau proteins in cultured neurons and its reversal by the blockade of protein phosphatase-2A.

    PubMed

    Martin, Ludovic; Magnaudeix, Amandine; Esclaire, Françoise; Yardin, Catherine; Terro, Faraj

    2009-02-03

    In tauopathies such as Alzheimer's disease (AD), the molecular mechanisms of tau protein aggregation into neurofibrillary tangles (NFTs) and their contribution to neurodegeneration remain not understood. It was recently demonstrated that tau, regardless of its aggregation, might represent a key mediator of neurodegeneration. Therefore, reduction of tau levels might represent a mechanism of neuroprotection. Glycogen synthase kinase-3beta (GSK3beta) and protein phosphatase-2A (PP2A) are key enzymes involved in the regulation of tau phosphorylation, and have been suggested to be involved in the abnormal tau phosphorylation and aggregation in AD. Connections between PP2A and GSK3beta signaling have been reported. We have previously demonstrated that exposure of cultured cortical neurons to lithium decreased tau protein expression and provided neuroprotection against Abeta. Since lithium is not a specific inhibitor of GSK3beta (ID50=2.0 mM), whether or not the lithium-induced tau decrease involves GSK3beta remained to be determined. For that purpose, cultured cortical neurons were exposed to 6-bromo-indirubin-3'-oxime (6-BIO), a more selective and potent GSK3beta inhibitor (ID50=1.5 microM) or to lithium. Analysis of tau levels and phosphorylation by western-blot assays showed that lithium and 6-BIO dose-dependently decreased both tau protein levels and tau phosphorylation. Conversely, inhibition of cyclin-dependent kinase-5 (CDK5) by roscovitine decreased phosphorylated tau but failed to alter tau protein levels. These data indicate that GSK3beta might be selectively involved in the regulation of tau protein levels. Moreover, inhibition of PP2A by okadaic acid, but not that of PP2B (protein phosphatase-2B)/calcineurin by FK506, dose-dependently reversed lithium-induced tau decrease. These data indicate that GSK3beta regulates both tau phosphorylation and total tau levels through PP2A.

  14. Neuronal and glial expression of inward rectifier potassium channel subunits Kir2.x in rat dorsal root ganglion and spinal cord.

    PubMed

    Murata, Yuzo; Yasaka, Toshiharu; Takano, Makoto; Ishihara, Keiko

    2016-03-23

    Inward rectifier K(+) channels of the Kir2.x subfamily play important roles in controlling the neuronal excitability. Although their cellular localization in the brain has been extensively studied, only a few studies have examined their expression in the spinal cord and peripheral nervous system. In this study, immunohistochemical analyses of Kir2.1, Kir2.2, and Kir2.3 expression were performed in rat dorsal root ganglion (DRG) and spinal cord using bright-field and confocal microscopy. In DRG, most ganglionic neurons expressed Kir2.1, Kir2.2 and Kir2.3, whereas satellite glial cells chiefly expressed Kir2.3. In the spinal cord, Kir2.1, Kir2.2 and Kir2.3 were all expressed highly in the gray matter of dorsal and ventral horns and moderately in the white matter also. Within the gray matter, the expression was especially high in the substantia gelatinosa (lamina II). Confocal images obtained using markers for neuronal cells, NeuN, and astrocytes, Sox9, showed expression of all three Kir2 subunits in both neuronal somata and astrocytes in lamina I-III of the dorsal horn and the lateral spinal nucleus of the dorsolateral funiculus. Immunoreactive signals other than those in neuronal and glial somata were abundant in lamina I and II, which probably located mainly in nerve fibers or nerve terminals. Colocalization of Kir2.1 and 2.3 and that of Kir2.2 and 2.3 were present in neuronal and glial somata. In the ventral horn, motor neurons and interneurons were also immunoreactive with the three Kir2 subunits. Our study suggests that Kir2 channels composed of Kir2.1-2.3 subunits are expressed in neuronal and glial cells in the DRG and spinal cord, contributing to sensory transduction and motor control. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. 42 CFR 476.96 - Review period and reopening of initial denial determinations and changes as a result of DRG...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... determinations and changes as a result of DRG validations. 476.96 Section 476.96 Public Health CENTERS FOR... initial denial determinations and changes as a result of DRG validations. (a) General timeframe. A QIO or... initial denial determination or a change as a result of a DRG validation. (b) Extended timeframes. (1) An...

  16. 42 CFR 476.96 - Review period and reopening of initial denial determinations and changes as a result of DRG...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... determinations and changes as a result of DRG validations. 476.96 Section 476.96 Public Health CENTERS FOR... initial denial determinations and changes as a result of DRG validations. (a) General timeframe. A QIO or... initial denial determination or a change as a result of a DRG validation. (b) Extended timeframes. (1) An...

  17. 42 CFR 476.96 - Review period and reopening of initial denial determinations and changes as a result of DRG...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... determinations and changes as a result of DRG validations. 476.96 Section 476.96 Public Health CENTERS FOR... initial denial determinations and changes as a result of DRG validations. (a) General timeframe. A QIO or... initial denial determination or a change as a result of a DRG validation. (b) Extended timeframes. (1) An...

  18. Implementation of DRG Payment in France: issues and recent developments.

    PubMed

    Or, Zeynep

    2014-08-01

    In France, a DRG-based payment system was introduced in 2004/2005 for funding acute services in all hospitals with the objectives of improving hospital efficiency, transparency and fairness in payments to public and private hospitals. Despite the initial consensus on the necessity of the reform, providers have become increasingly critical of the system because of the problems encountered during the implementation. In 2012 the government announced its intention to modify the payment model to better deal with its adverse effects. The paper reports on the issues raised by the DRG-based payment in the French hospital sector and provides an overview of the main problems with the French DRG payment model. It also summarises the evidence on its impact and presents recent developments for reforming the current model. DRG-based payment addressed some of the chronic problems inherent in the French hospital market and improved accountability and productivity of health-care facilities. However, it has also created new problems for controlling hospital activity and ensuring that care provided is medically appropriate. In order to alter its adverse effects the French DRG model needs to better align greater efficiency with the objectives of better quality and effectiveness of care. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. 42 CFR 476.96 - Review period and reopening of initial denial determinations and changes as a result of DRG...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... determinations and changes as a result of DRG validations. 476.96 Section 476.96 Public Health CENTERS FOR... and changes as a result of DRG validations. (a) General timeframe. A QIO or its subcontractor— (1... change as a result of a DRG validation. (b) Extended timeframes. (1) An initial denial determination or...

  20. 42 CFR 476.85 - Conclusive effect of QIO initial denial determinations and changes as a result of DRG validations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... determinations and changes as a result of DRG validations. 476.85 Section 476.85 Public Health CENTERS FOR... denial determinations and changes as a result of DRG validations. A QIO initial denial determination or change as a result of DRG validation is final and binding unless, in accordance with the procedures in...

  1. 42 CFR 476.85 - Conclusive effect of QIO initial denial determinations and changes as a result of DRG validations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... determinations and changes as a result of DRG validations. 476.85 Section 476.85 Public Health CENTERS FOR... denial determinations and changes as a result of DRG validations. A QIO initial denial determination or change as a result of DRG validation is final and binding unless, in accordance with the procedures in...

  2. 42 CFR 476.85 - Conclusive effect of QIO initial denial determinations and changes as a result of DRG validations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... determinations and changes as a result of DRG validations. 476.85 Section 476.85 Public Health CENTERS FOR... denial determinations and changes as a result of DRG validations. A QIO initial denial determination or change as a result of DRG validation is final and binding unless, in accordance with the procedures in...

  3. Mitochondria-targeted antioxidant mitotempo protects mitochondrial function against amyloid beta toxicity in primary cultured mouse neurons.

    PubMed

    Hu, Hongtao; Li, Mo

    2016-09-09

    Mitochondrial defects including excess reactive oxygen species (ROS) production and compromised ATP generation are featured pathology in Alzheimer's disease (AD). Amyloid beta (Aβ)-mediated mitochondrial ROS overproduction disrupts intra-neuronal Redox balance, in turn exacerbating mitochondrial dysfunction leading to neuronal injury. Previous studies have found the beneficial effects of mitochondria-targeted antioxidants in preventing mitochondrial dysfunction and neuronal injury in AD animal and cell models, suggesting that mitochondrial ROS scavengers hold promise for the treatment of this neurological disorder. In this study, we have determined that mitotempo, a novel mitochondria-targeted antioxidant protects mitochondrial function from the toxicity of Aβ in primary cultured neurons. Our results showed that Aβ-promoted mitochondrial superoxide production and neuronal lipid oxidation were significantly suppressed by the application of mitotempo. Moreover, mitotempo also demonstrated protective effects on mitochondrial bioenergetics evidenced by preserved mitochondrial membrane potential, cytochrome c oxidase activity as well as ATP production. In addition, the Aβ-induced mitochondrial DNA (mtDNA) depletion and decreased expression levels of mtDNA replication-related DNA polymerase gamma (DNA pol γ) and Twinkle were substantially mitigated by mitotempo. Therefore, our study suggests that elimination of excess mitochondrial ROS rescues mitochondrial function in Aβ-insulted neruons; and mitotempo has the potential to be a promising therapeutic agent to protect mitochondrial and neuronal function in AD. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. [Classification of severely injured patients in the G-DRG System 2008].

    PubMed

    Juhra, C; Franz, D; Roeder, N; Vordemvenne, T; Raschke, M J

    2009-05-01

    Since the introduction of a per-case reimbursement system in Germany (German Diagnosis-Related Groups, G-DRG), the correct reimbursement for the treatment of severely injured patients has been much debated. While the classification of a patient in a polytrauma DRG follows different rules than the usual clinical definition, leading to a high number of patients not grouped as severely injured by the system, the system was also criticized in 2005 for its shortcomings in financing the treatment of severely injured patients. The development of financial reimbursement will be discussed in this paper. 167 patients treated in 2006 and 2007 due to a severe injury at the University-Hospital Münster and grouped into a polytrauma-DRG were included in this study. For each patient, cost-equivalents were estimated. For those patients treated in 2007 (n=110), exact costs were calculated following the InEK cost-calculation method. The reimbursement was calculated using the G-DRG-Systems of 2007, 2008 and 2009. Cost-equivalents/costs and clinical parameters were correlated. A total of 167 patients treated in 2006 and 2007 for a severe injury at the Münster University Hospital and grouped into a polytrauma DRG were included in this study. Cost equivalents were estimated for each patient. For those patients treated in 2007 (n=110), exact costs were calculated following the InEK (Institute for the Hospital Remuneration System) cost calculation method. Reimbursement was calculated using the G-DRG systems of 2007, 2008 and 2009. Cost equivalents/costs and clinical parameters were correlated. With the ongoing development of the G-DRG system, reimbursement for the treatment of severely injured patient has improved, but the amount of underfinancing remains substantial. As treatment of severely injured patients must be reimbursed using the G-DRG system, this system must be further adapted to better meet the needs of severely injured patients. Parameters such as total surgery time, injury

  5. Spike propagation through the dorsal root ganglia in an unmyelinated sensory neuron: a modeling study

    PubMed Central

    Sundt, Danielle; Gamper, Nikita

    2015-01-01

    Unmyelinated C-fibers are a major type of sensory neurons conveying pain information. Action potential conduction is regulated by the bifurcation (T-junction) of sensory neuron axons within the dorsal root ganglia (DRG). Understanding how C-fiber signaling is influenced by the morphology of the T-junction and the local expression of ion channels is important for understanding pain signaling. In this study we used biophysical computer modeling to investigate the influence of axon morphology within the DRG and various membrane conductances on the reliability of spike propagation. As expected, calculated input impedance and the amplitude of propagating action potentials were both lowest at the T-junction. Propagation reliability for single spikes was highly sensitive to the diameter of the stem axon and the density of voltage-gated Na+ channels. A model containing only fast voltage-gated Na+ and delayed-rectifier K+ channels conducted trains of spikes up to frequencies of 110 Hz. The addition of slowly activating KCNQ channels (i.e., KV7 or M-channels) to the model reduced the following frequency to 30 Hz. Hyperpolarization produced by addition of a much slower conductance, such as a Ca2+-dependent K+ current, was needed to reduce the following frequency to 6 Hz. Attenuation of driving force due to ion accumulation or hyperpolarization produced by a Na+-K+ pump had no effect on following frequency but could influence the reliability of spike propagation mutually with the voltage shift generated by a Ca2+-dependent K+ current. These simulations suggest how specific ion channels within the DRG may contribute toward therapeutic treatments for chronic pain. PMID:26334005

  6. [The challenge of adequate reimbursement for the seriously injured patient in the German DRG system].

    PubMed

    Franz, D; Lefering, R; Siebert, H; Windolf, J; Roeder, N; Mahlke, L

    2013-02-01

    Critically injured patients are a very heterogeneous group, medically and economically. Their treatment is a major challenge for both the medical care and the appropriate financial reimbursement. Systematic underfunding can have a significant impact on the quality of patient care. In 2009 the German Trauma Society and the DRG-Research Group of the University Hospital Muenster initialised a DRG evaluation project to analyse the validity of case allocation of critically injured patients within the German DRG system versions 2008 and 2011 with additional consideration of clinical data from the trauma registry of the German Trauma Society. Severe deficits within the G-DRG structure were identified and specific solutions were designed and realised. A retrospective analysis was undertaken of standardised G-DRG data (§ 21 KHEntgG) including case-related cost data from 3 362 critically injured patients in the periods 2007 and 2008 from 10 university hospitals and 7 large municipal hospitals. For 1 241 cases of the sample, complementary detailed information was available from the trauma registry of the German Trauma Society to monitor the case allocation of critically injured patients within the G-DRG system. Analyses of coding and grouping, performance of case allocation, and the homogeneity of costs in the G-DRG versions 2008 and 2011 were done. The following situations were found: (i) systematic underfunding of trauma patients in the G-DRG-Version 2008, especially trauma patients with acute paraplegia; (ii) participation in the official G-DRG development for 2011 with 13 proposals which were largely realised; (ii) the majority of cases with cost-covering in the G-DRG version 2011; (iv) significant improvements in the quality of statistical criteria; (v) overfunded trauma patients with high intensive care costs; (vi) underfunding for clinically relevant critically injured patients not identified in the G-DRG system. The quality of the G-DRG system is measured by the

  7. 42 CFR 476.85 - Conclusive effect of QIO initial denial determinations and changes as a result of DRG validations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... determinations and changes as a result of DRG validations. 476.85 Section 476.85 Public Health CENTERS FOR... changes as a result of DRG validations. A QIO initial denial determination or change as a result of DRG validation is final and binding unless, in accordance with the procedures in part 473— (a) The initial denial...

  8. Met receptor signaling is required for sensory nerve development and HGF promotes axonal growth and survival of sensory neurons

    PubMed Central

    Maina, Flavio; Hilton, Mark C.; Ponzetto, Carola; Davies, Alun M.; Klein, Rüdiger

    1997-01-01

    The development of the nervous system is a dynamic process during which factors act in an instructive fashion to direct the differentiation and survival of neurons, and to induce axonal outgrowth, guidance to, and terminal branching within the target tissue. Here we report that mice expressing signaling mutants of the hepatocyte growth factor (HGF) receptor, the Met tyrosine kinase, show a striking reduction of sensory nerves innervating the skin of the limbs and thorax, implicating the HGF/Met system in sensory neuron development. Using in vitro assays, we find that HGF cooperates with nerve growth factor (NGF) to enhance axonal outgrowth from cultured dorsal root ganglion (DRG) neurons. HGF also enhances the neurotrophic activities of NGF in vitro, and Met receptor signaling is required for the survival of a proportion of DRG neurons in vivo. This synergism is specific for NGF but not for the related neurotrophins BDNF and NT3. By using a mild signaling mutant of Met, we have demonstrated previously that Met requires signaling via the adapter molecule Grb2 to induce proliferation of myoblasts. In contrast, the actions of HGF on sensory neurons are mediated by Met effectors distinct from Grb2. Our findings demonstrate a requirement for Met signaling in neurons during development. PMID:9407027

  9. IL-33/ST2 signaling excites sensory neurons and mediates itch response in a mouse model of poison ivy contact allergy.

    PubMed

    Liu, Boyi; Tai, Yan; Achanta, Satyanarayana; Kaelberer, Melanie M; Caceres, Ana I; Shao, Xiaomei; Fang, Jianqiao; Jordt, Sven-Eric

    2016-11-22

    Poison ivy-induced allergic contact dermatitis (ACD) is the most common environmental allergic condition in the United States. Case numbers of poison ivy ACD are increasing due to growing biomass and geographical expansion of poison ivy and increasing content of the allergen, urushiol, likely attributable to rising atmospheric CO 2 Severe and treatment-resistant itch is the major complaint of affected patients. However, because of limited clinical data and poorly characterized models, the pruritic mechanisms in poison ivy ACD remain unknown. Here, we aim to identify the mechanisms of itch in a mouse model of poison ivy ACD by transcriptomics, neuronal imaging, and behavioral analysis. Using transcriptome microarray analysis, we identified IL-33 as a key cytokine up-regulated in the inflamed skin of urushiol-challenged mice. We further found that the IL-33 receptor, ST2, is expressed in small to medium-sized dorsal root ganglion (DRG) neurons, including neurons that innervate the skin. IL-33 induces Ca 2+ influx into a subset of DRG neurons through neuronal ST2. Neutralizing antibodies against IL-33 or ST2 reduced scratching behavior and skin inflammation in urushiol-challenged mice. Injection of IL-33 into urushiol-challenged skin rapidly exacerbated itch-related scratching via ST2, in a histamine-independent manner. Targeted silencing of neuronal ST2 expression by intrathecal ST2 siRNA delivery significantly attenuated pruritic responses caused by urushiol-induced ACD. These results indicate that IL-33/ST2 signaling is functionally present in primary sensory neurons and contributes to pruritus in poison ivy ACD. Blocking IL-33/ST2 signaling may represent a therapeutic approach to ameliorate itch and skin inflammation related to poison ivy ACD.

  10. Comprehensive Method for Culturing Embryonic Dorsal Root Ganglion Neurons for Seahorse Extracellular Flux XF24 Analysis

    PubMed Central

    Lange, Miranda; Zeng, Yan; Knight, Andrew; Windebank, Anthony; Trushina, Eugenia

    2012-01-01

    Changes in mitochondrial dynamics and function contribute to progression of multiple neurodegenerative diseases including peripheral neuropathies. The Seahorse Extracellular Flux XF24 analyzer provides a comprehensive assessment of the relative state of glycolytic and aerobic metabolism in live cells making this method instrumental in assessing mitochondrial function. One of the most important steps in the analysis of mitochondrial respiration using the Seahorse XF24 analyzer is plating a uniform monolayer of firmly attached cells. However, culturing of primary dorsal root ganglion (DRG) neurons is associated with multiple challenges, including their propensity to form clumps and detach from the culture plate. This could significantly interfere with proper analysis and interpretation of data. We have tested multiple cell culture parameters including coating substrates, culture medium, XF24 microplate plastics, and plating techniques in order to optimize plating conditions. Here we describe a highly reproducible method to obtain neuron-enriched monolayers of securely attached dissociated primary embryonic (E15) rat DRG neurons suitable for analysis with the Seahorse XF24 platform. PMID:23248613

  11. Comprehensive Method for Culturing Embryonic Dorsal Root Ganglion Neurons for Seahorse Extracellular Flux XF24 Analysis.

    PubMed

    Lange, Miranda; Zeng, Yan; Knight, Andrew; Windebank, Anthony; Trushina, Eugenia

    2012-01-01

    Changes in mitochondrial dynamics and function contribute to progression of multiple neurodegenerative diseases including peripheral neuropathies. The Seahorse Extracellular Flux XF24 analyzer provides a comprehensive assessment of the relative state of glycolytic and aerobic metabolism in live cells making this method instrumental in assessing mitochondrial function. One of the most important steps in the analysis of mitochondrial respiration using the Seahorse XF24 analyzer is plating a uniform monolayer of firmly attached cells. However, culturing of primary dorsal root ganglion (DRG) neurons is associated with multiple challenges, including their propensity to form clumps and detach from the culture plate. This could significantly interfere with proper analysis and interpretation of data. We have tested multiple cell culture parameters including coating substrates, culture medium, XF24 microplate plastics, and plating techniques in order to optimize plating conditions. Here we describe a highly reproducible method to obtain neuron-enriched monolayers of securely attached dissociated primary embryonic (E15) rat DRG neurons suitable for analysis with the Seahorse XF24 platform.

  12. [Definition of polytrauma in the German DRG system 2006. Up to 30% "incorrect classifications"].

    PubMed

    Flohé, S; Buschmann, C; Nabring, J; Merguet, P; Luetkes, P; Lefering, R; Nast-Kolb, D; Ruchholtz, S

    2007-07-01

    Severely injured patients represent a relevant financial cost factor in the health system especially for high level trauma centres. The introduction of a"diagnosis-related group" (DRG) system in Germany further revealed the potential negative economic impact of severely injured patients for trauma centres. In recent years several changes of the specific DRG for severely injured patients occurred with the aim of a convenient reimbursement for the trauma patient. The present study analysed 38 multiply injured patients admitted in the first half of the year 2004. These patients were analysed in terms of the respective DRG that was attributed to the patient on the basis of the definition criteria for 2004 and 2005. In addition for the same patient group the total inpatient treatment costs were calculated according to the algorithm developed by the Working Group on Polytrauma of the German Trauma Society. The analysis revealed three major problems in the reimbursement for severely injured patients according to the German DRG system: (1) In spite of the additional payment for blood compounds on top of the DRG reimbursement in 2005 a mean economic deficit of more than 4000 euro remains for each severely injured patient. (2) In 30% of the analysed trauma patients the combination of the diagnosis and operations did not lead to a specific polytrauma DRG or to an intensive care medicine DRG. (3) In the patients that could not be attributed to a polytrauma DRG, the economic deficit was with an average of more than 9000 euro even higher. This attribution aspect is also currently relevant, since the definition criteria for a polytrauma DRG were not changed in 2006 or 2007. We conclude that besides the recent changes in the reimbursement for polytrauma DRGs, which have been at least partly adapted to the real financial burden of these patients, the definition of a severely injured patient in the German DRG system may also need to be revised.

  13. Transfusion practice in Helsinki University Central Hospital: an analysis of diagnosis-related groups (DRG).

    PubMed

    Syrjälä, M T; Kytöniemi, I; Mikkolainen, K; Ranimo, J; Lauharanta, J

    2001-12-01

    Transfusion data combined with data automatically recorded in hospital databases provides an outstanding tool for blood utilization reporting. When the reporting is performed with an online analytical processing (OLAP) tool, real time reporting can be provided to blood subscribers. When this data is combined with a common patient classification system, Diagnosis-Related Groups (DRG), it is possible to produce statistical results, that are similar in different institutions and may provide a means for international transfusion bench-marking and cost comparison. We use a DRG classification to describe the transfusion practice in Helsinki University Central Hospital. The key indicators include the percentage of transfused patients, the number of transfused units and costs in different DRG groups, as well as transfusion rates per DRG weighted treatment episodes. Ninety-three per cent of all transfusions could be classified into different DRGs. The largest blood-using DRG group was acute adult leukaemia (DRG 473), which accounted for 10.4% of all transfusion costs. The 13 largest blood consuming DRGs accounted for half the total costs in 1998. Currently, there is a lack of an internationally accepted standardized way to report institutional or national transfusion practices. DRG-based transfusion reporting might serve as a means for transfusion benchmarking and thus aid studies of variations in transfusion practice.

  14. Investigating DRG cost weights for hospitals in middle income countries.

    PubMed

    Ghaffari, Shahram; Doran, Christopher; Wilson, Andrew; Aisbett, Chris; Jackson, Terri

    2009-01-01

    Identifying the cost of hospital outputs, particularly acute inpatients measured by Diagnosis Related Groups (DRGs), is an important component of casemix implementation. Measuring the relative costliness of specific DRGs is useful for a wide range of policy and planning applications. Estimating the relative use of resources per DRG can be done through different costing approaches depending on availability of information and time and budget. This study aims to guide costing efforts in Iran and other countries in the region that are pursuing casemix funding, through identifying the main issues facing cost finding approaches and introducing the costing models compatible with their hospitals accounting and management structures. The results show that inadequate financial and utilisation information at the patient's level, poorly computerized 'feeder systems'; and low quality data make it impossible to estimate reliable DRGs costs through clinical costing. A cost modelling approach estimates the average cost of 2.723 million Rials (Iranian Currency) per DRG. Using standard linear regression, a coefficient of 0.14 (CI = 0.12-0.16) suggests that the average cost weight increases by 14% for every one-day increase in average length of stay (LOS).We concluded that calculation of DRG cost weights (CWs) using Australian service weights provides a sensible starting place for DRG-based hospital management; but restructuring hospital accounting systems, designing computerized feeder systems, using appropriate software, and development of national service weights that reflect local practice patterns will enhance the accuracy of DRG CWs.

  15. [The DRG responsible physician in trauma and orthopedic surgery. Surgeon, encoder, and link to medical controlling].

    PubMed

    Ruffing, T; Huchzermeier, P; Muhm, M; Winkler, H

    2014-05-01

    Precise coding is an essential requirement in order to generate a valid DRG. The aim of our study was to evaluate the quality of the initial coding of surgical procedures, as well as to introduce our "hybrid model" of a surgical specialist supervising medical coding and a nonphysician for case auditing. The department's DRG responsible physician as a surgical specialist has profound knowledge both in surgery and in DRG coding. At a Level 1 hospital, 1000 coded cases of surgical procedures were checked. In our department, the DRG responsible physician who is both a surgeon and encoder has proven itself for many years. The initial surgical DRG coding had to be corrected by the DRG responsible physician in 42.2% of cases. On average, one hour per working day was necessary. The implementation of a DRG responsible physician is a simple, effective way to connect medical and business expertise without interface problems. Permanent feedback promotes both medical and economic sensitivity for the improvement of coding quality.

  16. Limb-state information encoded by peripheral and central somatosensory neurons: Implications for an afferent interface

    PubMed Central

    Weber, Douglas J.; London, Brian M.; Hokanson, James A.; Ayers, Christopher A.; Gaunt, Robert A.; Torres, Ricardo R.; Zaaimi, Boubker; Miller, Lee E.

    2013-01-01

    A major issue to be addressed in the development of neural interfaces for prosthetic control is the need for somatosensory feedback. Here, we investigate two possible strategies: electrical stimulation of either dorsal root ganglia (DRG) or primary somatosensory cortex (S1). In each approach, we must determine a model that reflects the representation of limb state in terms of neural discharge. This model can then be used to design stimuli that artificially activate the nervous system to convey information about limb state to the subject. Electrically activating DRG neurons using naturalistic stimulus patterns, modeled on recordings made during passive limb movement, evoked activity in S1 that was similar to that of the original movement. We also found that S1 neural populations could accurately discriminate different patterns of DRG stimulation across a wide range of stimulus pulse-rates. In studying the neural coding of limb-state in S1, we also decoded the kinematics of active limb movement using multi-electrode recordings in the monkey. Neurons having both proprioceptive and cutaneous receptive fields contributed equally to this decoding. Some neurons were most informative of limb state in the recent past, but many others appeared to signal upcoming movements suggesting that they also were modulated by an efference copy signal. Finally, we show that a monkey was able to detect stimulation through a large percentage of electrodes implanted in area 2. We discuss the design of appropriate stimulus paradigms for conveying time-varying limb state information, and the relative merits and limitations of central and peripheral approaches. PMID:21878419

  17. Axonal outgrowth, neuropeptides expression and receptors tyrosine kinase phosphorylation in 3D organotypic cultures of adult dorsal root ganglia

    PubMed Central

    Alves, Cecília J.; Leitão, Luís; Sousa, Daniela M.; Alencastre, Inês S.; Conceição, Francisco; Lamghari, Meriem

    2017-01-01

    Limited knowledge from mechanistic studies on adult sensory neuronal activity was generated, to some extent, in recapitulated adult in vivo 3D microenvironment. To fill this gap there is a real need to better characterize the adult dorsal root ganglia (aDRG) organotypic cultures to make these in vitro systems exploitable for different approaches, ranging from basic neurobiology to regenerative therapies, to address the sensory nervous system in adult stage. We conducted a direct head-to-head comparison of aDRG and embryonic DRG (eDRG) organotypic culture focusing on axonal growth, neuropeptides expression and receptors tyrosine kinase (RTK) activation associated with neuronal survival, proliferation and differentiation. To identify alterations related to culture conditions, these parameters were also addressed in retrieved aDRG and eDRG and compared with organotypic cultures. Under similar neurotrophic stimulation, aDRG organotypic cultures displayed lower axonal outgrowth rate supported by reduced expression of growth associated protein-43 and high levels of RhoA and glycogen synthase kinase 3 beta mRNA transcripts. In addition, differential alteration in sensory neuropeptides expression, namely calcitonin gene-related peptide and substance P, was detected and was mainly pronounced at gene expression levels. Among 39 different RTK, five receptors from three RTK families were emphasized: tropomyosin receptor kinase A (TrkA), epidermal growth factor receptors (EGFR, ErbB2 and ErbB3) and platelet-derived growth factor receptor (PDGFR). Of note, except for EGFR, the phosphorylation of these receptors was dependent on DRG developmental stage and/or culture condition. In addition, EGFR and PDGFR displayed alterations in their cellular expression pattern in cultured DRG. Overall we provided valuable information particularly important when addressing in vitro the molecular mechanisms associated with development, maturation and regeneration of the sensory nervous system

  18. Policy trends and reforms in the German DRG-based hospital payment system.

    PubMed

    Klein-Hitpaß, Uwe; Scheller-Kreinsen, David

    2015-03-01

    A central structural point in all DRG-based hospital payment systems is the conversion of relative weights into actual payments. In this context policy makers need to address (amongst other things) (a) how the price level of DRG-payments from one period to the following period is changed and (b) whether and how hospital payments based on DRGs are to be differentiated beyond patient characteristics, e.g. by organizational, regional or state-level factors. Both policy problems can be and in international comparison often are empirically addressed. In Germany relative weights are derived from a highly sophisticated empirical cost calculation, whereas the annual changes of DRG-based payments (base rates) as well as the differentiation of DRG-based hospital payments beyond patient characteristics are not empirically addressed. Rather a complex set of regulations and quasi-market negotiations are applied. There were over the last decade also timid attempts to foster the use of empirical data to address these points. However, these reforms failed to increase the fairness, transparency and rationality of the mechanism to convert relative weights into actual DRG-based hospital payments. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  19. Potentiation of transient receptor potential V1 functions by the activation of metabotropic 5-HT receptors in rat primary sensory neurons

    PubMed Central

    Ohta, Toshio; Ikemi, Yuki; Murakami, Matsuka; Imagawa, Toshiaki; Otsuguro, Ken-ichi; Ito, Shigeo

    2006-01-01

    5-Hydroxytryptamine (5-HT) is one of the major chemical mediators released in injured and inflamed tissue and is capable of inducing hyperalgesia in vivo. However, the cellular mechanisms of 5-HT-induced hyperalgesia remain unclear. Transient receptor potential V1 (TRPV1) plays a pivotal role in nociceptive receptors. In the present study, we determined whether 5-HT changes TRPV1 functions in cultured dorsal root ganglion (DRG) neurons isolated from neonatal rats, using Ca2+ imaging and whole-cell patch-clamp techniques. In more than 70% of DRG neurons, 5-HT potentiated the increases of [Ca2+]i induced by capsaicin, protons and noxious heat. Capsaicin-induced current and depolarizing responses, and proton-induced currents were also augmented by 5-HT. RT-PCR analysis revealed the expression of 5-HT2A and 5-HT7 receptors in rat DRG neurons. Agonists for 5-HT2A and 5-HT7 receptors mimicked the potentiating effect of 5-HT, and their antagonists decreased it. In DRG ipsilateral to the complete Freund's adjuvant-injected inflammation side, expression levels of 5-HT2A and 5-HT7 mRNAs increased, and the potentiating effect of 5-HT was more prominent than in the contralateral control side. These results suggest that the PKC- and PKA-mediated signalling pathways are involved in the potentiating effect of 5-HT on TRPV1 functions through the activation of 5-HT2A and 5-HT7 receptors, respectively. Under inflammatory conditions, the increases of the biosynthesis of these 5-HT receptors may lead to further potentiation of TRPV1 functions, resulting in the generation of inflammatory hyperalgesia in vivo. PMID:16901936

  20. Participation determinants in the DRG payment system of obstetrics and gynecology clinics in South Korea.

    PubMed

    Song, Jung-Kook; Kim, Chang-yup

    2010-03-01

    The Diagnosis Related Group (DRG) payment system, which has been implemented in Korea since 1997, is based on voluntary participation. Hence, the positive impact of this system depends on the participation of physicians. This study examined the factors determining participation of Korean obstetrics & gynecology (OBGYN) clinics in the DRG-based payment system. The demographic information, practice-related variables of OBGYN clinics and participation information in the DRG-based payment system were acquired from the nationwide data from 2002 to 2007 produced by the National Health Insurance Corporation and the Health Insurance Review & Assessment Service. The subjects were 336 OBGYN clinics consisting of 43 DRG clinics that had maintained their participation in 2003-2007 and 293 no-DRG (fee-for-service) clinics that had never been a DRG clinic during the same period. Logistic regression analysis was carried out to determine the factors associated with the participation of OBGYN clinics in the DRG-based payment system. The factors affecting participation of OBGYN clinics in the DRG-based payment system were as follows (p<0.05): (1) a larger number of caesarian section (c/sec) claims, (2) higher cost of a c/sec, (3) less variation in the price of a c/sec, (4) fewer days of admission for a c/sec, and (5) younger pregnant women undergoing a c/sec. These results suggest that OBGYN clinics with an economic practice pattern under a fee-for-service system are more likely to participate in the DRG-based payment system. Therefore, to ensure adequate participation of physicians, a payment system with a stronger financial incentive might be more suitable in Korea.

  1. DRG-based hospital payment systems and technological innovation in 12 European countries.

    PubMed

    Scheller-Kreinsen, David; Quentin, Wilm; Busse, Reinhard

    2011-12-01

    To assess how diagnosis-related group-based (DRG-based) hospital payment systems in 12 European countries participating in the EuroDRG project pay and incorporate technological innovation. A standardized questionnaire was used to guide comprehensive DRG system descriptions. Researchers from each country reviewed relevant materials to complete the questionnaire and drafted standardized country reports. Two characteristics of DRG-based hospital payment systems were identified as particularly important: the existence of short-term payment instruments encouraging technological innovation in different countries, and the characteristics of long-term updating mechanisms that assure technological innovation is ultimately incorporated into DRG-based hospital payment systems. Short-term payment instruments and long-term updating mechanisms differ greatly among the 12 European countries included in this study. Some countries operate generous short-term payment instruments that provide additional payments to hospitals for making use of technological innovation (e.g., France). Other countries update their DRG-based hospital payment systems very frequently and use more recent data for updates. Generous short-term payment instruments to promote technological innovation should be applied carefully as they may imply rapidly increasing health-care expenditures. In general, they should be granted only if rigorous analyses have demonstrated their benefits. If the evidence remains uncertain, coverage with evidence development frameworks or frequent updates of the DRG-based hospital systems may provide policy alternatives. Once the data and evidence base is substantially improved, future research should empirically investigate how different policy arrangements affect the adoption and use of technological innovation and health-care expenditures. Copyright © 2011 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  2. Diosgenin-3-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranoside obtained as a new anticancer agent from Dioscorea futschauensis induces apoptosis on human colon carcinoma HCT-15 cells via mitochondria-controlled apoptotic pathway.

    PubMed

    Wang, San-Long; Cai, Bing; Cui, Cheng-Bin; Liu, Hong-Wei; Wu, Chun-Fu; Yao, Xin-Sheng

    2004-06-01

    Diosgenin-3-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranoside (DRG) is a well-known pentacyclic triterpene glycoside newly isolated from the rhizomes of Dioscorea futschauensis R. Kunth (Dioscoreaceae) by our group. In the present work, the inhibitory effect of DRG on the cell proliferation of human cancer cell lines was examined to reveal for the first time that DRG shows stronger anticancer activity than that of the positive control cisplatin. DRG inhibited the proliferation of human cancer cells, A431, A2780, A549, K562, and HCT-15, with IC50 (micromol L(-1)) values of 9.33 +/- 0.22, 18.7 +/- 0.16, 9.98 +/- 0.38, 6.44 +/- 0.10, and 5.86 +/- 0.14 respectively. It was then found, by morphological observation, "DNA ladder" detection and flow cytometric analysis, that DRG exerts its anticancer effect through inducing apoptosis on HCT-15 cells. Furthermore, it has been demonstrated that DRG triggers a mitochondria-controlled apoptotic pathway to induce apoptosis on HCT-15 cells, which involves the reduction of the mitochondrial potential (deltapsim), the release of cytochrome c from mitochondria into the cytosol, and the down-regulation of the ratio of Bcl-2/Bax expression level. The present results reasonably suggest that regulating the balance of Bcl-2/Bax expression level plays a key role in the DRG-induced apoptosis. Such findings provide novel knowledge to elucidate the biological properties of DRG, even though DRG was discovered early in the late 1960s. These results suggest that DRG may be a good candidate as a chemotherapeutic agent to treat human colon carcinoma.

  3. [OR minute myth : Guidelines for calculation of DRG revenues per OR minute].

    PubMed

    Waeschle, R M; Hinz, J; Bleeker, F; Sliwa, B; Popov, A; Schmidt, C E; Bauer, M

    2016-02-01

    The economic situation in German Hospitals is tense and needs the implementation of differentiated controlling instruments. Accordingly, parameters of revenue development of different organizational units within a hospital are needed. This is particularly necessary in the revenue and cost-intensive operating theater field. So far there are only barely established productivity data for the control of operating room (OR) revenues during the year available. This article describes a valid method for the calculation of case-related revenues per OR minute conform to the diagnosis-related groups (DRG).For this purpose the relevant datasets from the OR information system and the § 21 productivity report (DRG grouping) of the University Medical Center Göttingen were combined. The revenues defined in the DRG browser of the Institute for Hospital Reimbursement (InEK) were assigned to the corresponding process times--incision-suture time (SNZ), operative preparation time and anesthesiology time--according to the InEK system. All full time stationary DRG cases treated within the OR were included and differentiated according to the surgical department responsible. The cost centers "OR section" and "anesthesia" were isolated to calculate the revenues of the operating theater. SNZ clusters and cost type groups were formed to demonstrate their impact on the revenues per OR minute. A surgical personal simultaneity factor (GZF) was calculated by division of the revenues for surgeons and anesthesiologists. This factor resembles the maximum DRG financed personnel deployment for surgeons in German hospitals.The revenue per OR minute including all cost types and DRG was 16.63 €/min. The revenues ranged from 10.45 to 24.34 €/min depending on the surgical field. The revenues were stable when SNZ clusters were analyzed. The differentiation of cost type groups revealed a revenue reduction especially after exclusion of revenues for implants and infrastructure. The calculated GZF over

  4. Quantitative Analysis of Rat Dorsal Root Ganglion Neurons Cultured on Microelectrode Arrays Based on Fluorescence Microscopy Image Processing.

    PubMed

    Mari, João Fernando; Saito, José Hiroki; Neves, Amanda Ferreira; Lotufo, Celina Monteiro da Cruz; Destro-Filho, João-Batista; Nicoletti, Maria do Carmo

    2015-12-01

    Microelectrode Arrays (MEA) are devices for long term electrophysiological recording of extracellular spontaneous or evocated activities on in vitro neuron culture. This work proposes and develops a framework for quantitative and morphological analysis of neuron cultures on MEAs, by processing their corresponding images, acquired by fluorescence microscopy. The neurons are segmented from the fluorescence channel images using a combination of segmentation by thresholding, watershed transform, and object classification. The positioning of microelectrodes is obtained from the transmitted light channel images using the circular Hough transform. The proposed method was applied to images of dissociated culture of rat dorsal root ganglion (DRG) neuronal cells. The morphological and topological quantitative analysis carried out produced information regarding the state of culture, such as population count, neuron-to-neuron and neuron-to-microelectrode distances, soma morphologies, neuron sizes, neuron and microelectrode spatial distributions. Most of the analysis of microscopy images taken from neuronal cultures on MEA only consider simple qualitative analysis. Also, the proposed framework aims to standardize the image processing and to compute quantitative useful measures for integrated image-signal studies and further computational simulations. As results show, the implemented microelectrode identification method is robust and so are the implemented neuron segmentation and classification one (with a correct segmentation rate up to 84%). The quantitative information retrieved by the method is highly relevant to assist the integrated signal-image study of recorded electrophysiological signals as well as the physical aspects of the neuron culture on MEA. Although the experiments deal with DRG cell images, cortical and hippocampal cell images could also be processed with small adjustments in the image processing parameter estimation.

  5. Short-term incubation of gabapentin or pregabalin does not affect chemically induced injury in neuronal cell models in vitro

    PubMed Central

    Baldewig, Malte; Goldbaum, Olaf; Richter-Landsberg, Christiane; Weyland, Andreas; Bantel, Carsten

    2018-01-01

    Purpose Gabapentinoids are currently the mainstay of pharmacological treatments for patients with neuropathic pain. Little is known about the effects of this therapy on the integrity of neuronal networks, especially in patients with an already-damaged nervous system. Since gabapentinoids can worsen cognitive functions and recent studies have shown alterations in the brains of patients with neuropathic pain, it may be possible that these drugs have neurotoxic effects. Methods Rat clonal PC12 pheochromocytoma (autonomic) and primary sensory dorsal-root ganglion (DRG) neurons from newborn Wistar rats were employed for this study. To mimic neuronal damage, cells were exposed to cytotoxins using either hydrogen peroxide (H2O2) or vincristine. Results No direct cytotoxic effects were observed after incubating PC12 cells for 24 hours with increasing concentrations of gabapentin or pregabalin using MTT cytotoxicity assays. Even a 7-day incubation did not cause cellular damage. Furthermore, in preinjured PC12 and DRG neurons, neither gabapentin nor pregabalin prevented or enhanced the cytotoxic effects of H2O2 or vincristine after incubation for 24 hours and 7 days, respectively. Cell morphology and integrity of the cytoskeleton assessed by employing immunostaining of cytoskeletal proteins (α-tubulin, neurofilament L) remained intact and were not altered by gabapentinoids. Conclusion Based on these results, gabapentinoids are unlikely to be neurotoxic in cultured autonomic (PC12) and sensory DRG cells, even when cells are preinjured. These results are of high clinical relevance, as it seems unlikely that the morphological changes recently observed in the brains of neuropathic pain patients are caused or worsened by gabapentinoids.

  6. [Description of the severely injured in the DRG system: is treatment of the severely injured still affordable?].

    PubMed

    Mahlke, L; Lefering, R; Siebert, H; Windolf, J; Roeder, N; Franz, D

    2013-11-01

    Due to the heterogeneity of severely injured patients (multiple trauma) it is difficult to assign them to homogeneic diagnosis-related groups (DRG). In recent years this has led to a systematic underfunding in the German reimbursement system (G-DRG) for cases of multiply injured patients. This project aimed to improve the reimbursement by modifying the case allocation algorithms of multiply injured patients within the G-DRG system. A retrospective analysis of standardized G-DRG data according to §21 of the Hospital Reimbursement Act (§ 21 KHEntgG) including case-related cost data from 3,362 critically injured patients from 2007 and 2008 from 10 university hospitals and 7 large municipal hospitals was carried out. For 1,241 cases complementary detailed information was available from the trauma registry of the German Trauma Society to monitor the case allocation of multiply injured patients within the G-DRG system. Analysis of coding and grouping, performance of case allocation and the homogeneity of costs in the G-DRG versions 2008-2012 was carried out. The results showed systematic underfunding of trauma patients in the G-DRG version 2008 but adequate cost covering in the majority of cases with the G-DRG versions 2011 and 2012. Cost coverage was foundfor multiply injured patients from the clinical viewpoint who were identified as multiple trauma by the G-DRG system. Some of the overfunded trauma patients had high intensive care costs. Also there was underfunding for multiple injured patients not identified as such in the G-DRG system. Specific modifications of the G-DRG allocation structures could increase the appropriateness of reimbursement of multiply injured patients. Data-based analysis is an essential prerequisite for a constructive development of the G-DRG system and a necessary tool for the active participation of medical specialist societies.

  7. Subdiaphragmatic vagotomy increases the sensitivity of lumbar Aδ primary afferent neurons along with voltage-dependent potassium channels in rats.

    PubMed

    Furuta, Sadayoshi; Watanabe, Lisa; Doi, Seira; Horiuchi, Hiroshi; Matsumoto, Kenjiro; Kuzumaki, Naoko; Suzuki, Tsutomu; Narita, Minoru

    2012-02-01

    Subdiaphragmatic vagal dysfunction causes chronic pain. To verify whether this chronic pain is accompanied by enhanced peripheral nociceptive sensitivity, we evaluated primary afferent neuronal excitability in subdiaphragmatic vagotomized (SDV) rats. SDV rats showed a decrease in the electrical stimuli-induced hind limb-flexion threshold at 250 Hz, but showed no similar effect at 5 or 2000 Hz, which indicated that lumbar primary afferent Aδ sensitivity was enhanced in SDV rats. The whole-cell patch-clamp technique also revealed the hyper-excitability of acutely dissociated medium-sized lumbar dorsal root ganglion (DRG) neurons isolated from SDV rats. The contribution of changes in voltage-dependent potassium (Kv) channels was assessed, and transient A-type K(+) (I(A) ) current density was apparently decreased. Moreover, Kv4.3 immunoreactivity in medium-sized DRG neurons was significantly reduced in SDV rats compared to sham. These results indicate that SDV causes hyper-excitability of lumbar primary Aδ afferent neurons, which may be induced along with suppressing I(A) currents via the decreased expression of Kv4.3. Thus, peripheral Aδ neuroplasticity may contribute to the chronic lower limb pain caused by SDV. Copyright © 2011 Wiley Periodicals, Inc.

  8. Secretagogin is expressed in sensory CGRP neurons and in spinal cord of mouse and complements other calcium-binding proteins, with a note on rat and human

    PubMed Central

    2012-01-01

    Background Secretagogin (Scgn), a member of the EF-hand calcium-binding protein (CaBP) superfamily, has recently been found in subsets of developing and adult neurons. Here, we have analyzed the expression of Scgn in dorsal root ganglia (DRGs) and trigeminal ganglia (TGs), and in spinal cord of mouse at the mRNA and protein levels, and in comparison to the well-known CaBPs, calbindin D-28k, parvalbumin and calretinin. Rat DRGs, TGs and spinal cord, as well as human DRGs and spinal cord were used to reveal phylogenetic variations. Results We found Scgn mRNA expressed in mouse and human DRGs and in mouse ventral spinal cord. Our immunohistochemical data showed a complementary distribution of Scgn and the three CaBPs in mouse DRG neurons and spinal cord. Scgn was expressed in ~7% of all mouse DRG neuron profiles, mainly small ones and almost exclusively co-localized with calcitonin gene-related peptide (CGRP). This co-localization was also seen in human, but not in rat DRGs. Scgn could be detected in the mouse sciatic nerve and accumulated proximal to its constriction. In mouse spinal cord, Scgn-positive neuronal cell bodies and fibers were found in gray matter, especially in the dorsal horn, with particularly high concentrations of fibers in the superficial laminae, as well as in cell bodies in inner lamina II and in some other laminae. A dense Scgn-positive fiber network and some small cell bodies were also found in the superficial dorsal horn of humans. In the ventral horn, a small number of neurons were Scgn-positive in mouse but not rat, confirming mRNA distribution. Both in mouse and rat, a subset of TG neurons contained Scgn. Dorsal rhizotomy strongly reduced Scgn fiber staining in the dorsal horn. Peripheral axotomy did not clearly affect Scgn expression in DRGs, dorsal horn or ventral horn neurons in mouse. Conclusions Scgn is a CaBP expressed in a subpopulation of nociceptive DRG neurons and their processes in the dorsal horn of mouse, human and rat, the

  9. IL-33/ST2 signaling excites sensory neurons and mediates itch response in a mouse model of poison ivy contact allergy

    PubMed Central

    Liu, Boyi; Tai, Yan; Achanta, Satyanarayana; Kaelberer, Melanie M.; Caceres, Ana I.; Shao, Xiaomei; Fang, Jianqiao; Jordt, Sven-Eric

    2016-01-01

    Poison ivy-induced allergic contact dermatitis (ACD) is the most common environmental allergic condition in the United States. Case numbers of poison ivy ACD are increasing due to growing biomass and geographical expansion of poison ivy and increasing content of the allergen, urushiol, likely attributable to rising atmospheric CO2. Severe and treatment-resistant itch is the major complaint of affected patients. However, because of limited clinical data and poorly characterized models, the pruritic mechanisms in poison ivy ACD remain unknown. Here, we aim to identify the mechanisms of itch in a mouse model of poison ivy ACD by transcriptomics, neuronal imaging, and behavioral analysis. Using transcriptome microarray analysis, we identified IL-33 as a key cytokine up-regulated in the inflamed skin of urushiol-challenged mice. We further found that the IL-33 receptor, ST2, is expressed in small to medium-sized dorsal root ganglion (DRG) neurons, including neurons that innervate the skin. IL-33 induces Ca2+ influx into a subset of DRG neurons through neuronal ST2. Neutralizing antibodies against IL-33 or ST2 reduced scratching behavior and skin inflammation in urushiol-challenged mice. Injection of IL-33 into urushiol-challenged skin rapidly exacerbated itch-related scratching via ST2, in a histamine-independent manner. Targeted silencing of neuronal ST2 expression by intrathecal ST2 siRNA delivery significantly attenuated pruritic responses caused by urushiol-induced ACD. These results indicate that IL-33/ST2 signaling is functionally present in primary sensory neurons and contributes to pruritus in poison ivy ACD. Blocking IL-33/ST2 signaling may represent a therapeutic approach to ameliorate itch and skin inflammation related to poison ivy ACD. PMID:27821781

  10. Experts' perspectives on SwissDRG: Second class care for vulnerable patient groups?

    PubMed

    Leu, A; Wepf, H; Elger, B; Wangmo, T

    2018-03-14

    On the 1st of January 2012, Switzerland introduced the diagnosis-related group hospital tariff structure (SwissDRG). It was recognised that healthcare provided to the most vulnerable patient groups would be a challenge for the new SwissDRG. Coincident with the implementation of SwissDRG, we explored hospital experts' perceptions of which patient groups are vulnerable under the SwissDRG system, what has changed for this group, as well as solutions to ensure adequate access to health care for them. We interviewed 43 experts from 40 Swiss hospitals. Participating experts named several vulnerable patient groups who share some common characteristics. These hospital experts were concerned about the patient groups that are not financially profitable and questioned the practicability of the current regulation. At the same time, they highlighted the complexity associated with caring for this group under the new SwissDRG and reported measures at the macro, meso, and micro levels to protect vulnerable patient groups from negative effects. To curb negative outcomes for vulnerable patient groups after the introduction of the SwissDRG, the Swiss legislation has introduced various instruments including the acute and transitional care (ATC) measures. We conclude that ATC measures do not produce the expected effect the legislators had hoped for. More health data is needed to identify situations where vulnerable patient groups are more susceptible to inadequate health care access in Switzerland. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. DRG benchmarking study establishes national coding norms.

    PubMed

    Vaul, J H

    1998-05-01

    With the increase in fraud and abuse investigations, healthcare financial managers should examine their organization's medical record coding procedures. The Federal government and third-party payers are looking specifically for improper billing of outpatient services, unbundling of procedures to increase payment, assigning higher-paying DRG codes for inpatient claims, and other abuses. A recent benchmarking study of Medicare Provider Analysis and Review (MEDPAR) data has established national norms for hospital coding and case mix based on DRGs and has revealed the majority of atypical coding cases fall into six DRG pairs. Organizations with a greater percentage of atypical cases--those more likely to be scrutinized by Federal investigators--will want to conduct suitable review and be sure appropriate documentation exists to justify the coding.

  12. [Financing of inpatient orthopaedics and trauma surgery in the 2011 G-DRG System].

    PubMed

    Franz, D; Schemmann, F; Roeder, N; Siebert, H; Mahlke, L

    2011-09-01

    The German DRG system forms the basis for billing inpatient hospital services. It includes not only the case groups (G-DRGs), but also copayments. This paper analyses and evaluates the relevant developments of the 2011 G-DRG system for orthopaedics and traumatology from the medical and classificatory perspective. An analysis was performed of relevant diagnoses, medical procedures and G-DRGs in the 2010 and 2011 versions based on the publications of the German DRG Institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). A number of codes for surgical measures have been newly established or modified - above all in foot surgery, arthroscopic surgery and wound surgery. Here, the identification and the correct and performance-based mapping of complex and elaborate scenarios was again the focus of the restructuring of the G-DRG system. The G-DRG structure in orthopaedics and traumatology is changed, especially for polytraumata. The allocation of common cases with a standardized treatment pattern appears to be appropriate and the reimbursement adequate. For the less common and more complex cases the 2011 G-DRG system still shows need for further modification (e.g. polytraumata, joint replacement, spine surgery). The proper integration of the modified OPS classification for foot surgery to the appropriate G-DRGs will be essential to maintain the high quality of the reimbursement structure for the future.

  13. [Beta-1 adrenoceptor blockade decreases the firing rate to painful stimuli in spinal wide-dynamic range neurons in rats].

    PubMed

    Lamothe-Molina, Paul J; Lamothe-Molina, Pedro A; López-Ávila, Alberto

    2014-01-01

    It is known that epinephrine/norepinephrine inhibit acute pain transmission. However, the role of ß-adrenoceptors is not clear. Thus, we analyzed if beta-1 and/or beta-2 adrenoceptors can modulate acute pain transmission by performing in vivo single unit recordings during painful and non-painful peripheral stimulation in rats. Longitudinal study in which we analyzed seven groups of male rats Wistar: control group (n = 11): saline (0.9 %); EPI group (n = 8): epinephrine 100 mcg; beta-1 agonist group (n = 8): dobutamine 125 mcg; beta-1-antagonist group (n = 9): metoprolol 100 mcg; beta-2-agonist group (n = 7): clenbuterol 100 mcg; beta-2-antagonist group (n = 8): butoxamine 100 mcg; beta-1-antagonist + EPI group (n = 10): metoprolol 100 mcg + epinephrine 100 mcg. For the statistical analysis we used ANOVA. Epinephrine significantly reduced the basal firing rate (BFR) in 34.1 % (p < 0.05) and also the evoked response by painful stimulation in 56 % (p < 0.05). No change was observed in the evoked response by non-painful stimulation. ANTß1 was the only beta-adrenoceptor acting drug that significantly reduced the evoked response by painful stimulation in 41 % (p < 0.05). None of the other drugs alone affected either the BFR or the evoked response to non-painful or painful stimulation. It is the first time that a beta-1-adrenoceptor antagonist (metoprolol) probes to be effective in reducing the response to painful stimulation in WDR neurons.

  14. TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chung, Eun Jee; Chun, Ji Na; Jung, Sun-Ah

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology inmore » pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful

  15. Development of lengths of stay and DRG cost weights in dermatology from 2003 to 2006.

    PubMed

    Wenke, Andreas; Müller, Marcel L; Babapirali, Judith; Rompel, Rainer; Hensen, Peter

    2009-08-01

    The G-DRG per case payments are calculated annually on the basis of present output and cost data provided from German hospitals. The economic valuation of dermatology-related DRGs depends largely on inpatients' length of stay. At present, longitudinal analyses of dermatologic hospital data considering the development of length of stay under DRG conditions are not available. A multicenter, longitudinal study of clinical data from hospitals with different care levels was performed (n = 23). Frequent and relevant dermatologic diagnoses were grouped and analyzed over a time period of four years (2003-2006). The development of lengths of stay and of G-DRG cost weights were studied in detail. Descriptive statistical methods were applied. After introduction of DRG, the data reveal a) reduction of length of stay in inpatient dermatology and b) after an initial abrupt rise, DRG valuation of dermatologic groups moderately decreased over time. Both trends changed most rapidly in the early years but reached a stable niveau in 2006. The study furthermore points out that not only length of stay, but also other type of costs influence DRG calculations. German dermatology reflects the international trend showing reductions of length of stay after introduction of a DRG-based hospital funding system. The DRG calculation and valuation of inpatient services depend on the duration of hospital stay. However, increasing per diem costs resulting from higher performances of every inpatient bed day are also taken into account. Further reduction of length of stay must not threaten the quality of inpatient care in dermatology.

  16. Diminished superoxide generation is associated with respiratory chain dysfunction and changes in the mitochondrial proteome of sensory neurons from diabetic rats.

    PubMed

    Akude, Eli; Zherebitskaya, Elena; Chowdhury, Subir K Roy; Smith, Darrell R; Dobrowsky, Rick T; Fernyhough, Paul

    2011-01-01

    Impairments in mitochondrial function have been proposed to play a role in the etiology of diabetic sensory neuropathy. We tested the hypothesis that mitochondrial dysfunction in axons of sensory neurons in type 1 diabetes is due to abnormal activity of the respiratory chain and an altered mitochondrial proteome. Proteomic analysis using stable isotope labeling with amino acids in cell culture (SILAC) determined expression of proteins in mitochondria from dorsal root ganglia (DRG) of control, 22-week-old streptozotocin (STZ)-diabetic rats, and diabetic rats treated with insulin. Rates of oxygen consumption and complex activities in mitochondria from DRG were measured. Fluorescence imaging of axons of cultured sensory neurons determined the effect of diabetes on mitochondrial polarization status, oxidative stress, and mitochondrial matrix-specific reactive oxygen species (ROS). Proteins associated with mitochondrial dysfunction, oxidative phosphorylation, ubiquinone biosynthesis, and the citric acid cycle were downregulated in diabetic samples. For example, cytochrome c oxidase subunit IV (COX IV; a complex IV protein) and NADH dehydrogenase Fe-S protein 3 (NDUFS3; a complex I protein) were reduced by 29 and 36% (P < 0.05), respectively, in diabetes and confirmed previous Western blot studies. Respiration and mitochondrial complex activity was significantly decreased by 15 to 32% compared with control. The axons of diabetic neurons exhibited oxidative stress and depolarized mitochondria, an aberrant adaption to oligomycin-induced mitochondrial membrane hyperpolarization, but reduced levels of intramitochondrial superoxide compared with control. Abnormal mitochondrial function correlated with a downregulation of mitochondrial proteins, with components of the respiratory chain targeted in lumbar DRG in diabetes. The reduced activity of the respiratory chain was associated with diminished superoxide generation within the mitochondrial matrix and did not contribute to

  17. Primary sensory neuron-specific interference of TRPV1 signaling by adeno-associated virus-encoded TRPV1 peptide aptamer attenuates neuropathic pain

    PubMed Central

    Xiang, Hongfei; Liu, Zhen; Wang, Fei; Xu, Hao; Roberts, Christopher; Fischer, Gregory; Stucky, Cheryl L; Dean, Caron; Pan, Bin; Hogan, Quinn H; Yu, Hongwei

    2017-01-01

    Background TRPV1 (transient receptor potential vanilloid subfamily member 1) is a pain signaling channel highly expressed in primary sensory neurons. Attempts for analgesia by systemic TRPV1 blockade produce undesirable side effects, such as hyperthermia and impaired heat pain sensation. One approach for TRPV1 analgesia is to target TRPV1 along the peripheral sensory pathway. Results For functional blockade of TRPV1 signaling, we constructed an adeno-associated virus (AAV) vector expressing a recombinant TRPV1 interfering peptide aptamer, derived from a 38mer tetrameric assembly domain (TAD), encompassing residues 735 to 772 of rat TRPV1, fused to the C-terminus of enhanced green fluorescent protein (EGFP). AAV-targeted sensory neurons expressing EGFP-TAD after vector injection into the dorsal root ganglia (DRG) revealed decreased inward calcium current and diminished intracellular calcium accumulation in response to capsaicin, compared to neurons of naïve or expressing EGFP alone. To examine the potential for treating neuropathic pain, AAV-EGFP-TAD was injected into fourth and fifth lumbar (L) DRGs of rats subjected to neuropathic pain by tibial nerve injury (TNI). Results showed that AAV-directed selective expression of EGFP-TAD in L4/L5 DRG neuron somata, and their peripheral and central axonal projections can limit TNI-induced neuropathic pain behavior, including hypersensitivity to heat and, to a less extent, mechanical stimulation. Conclusion Selective inhibition of TRPV1 activity in primary sensory neurons by DRG delivery of AAV-encoded analgesic interfering peptide aptamers is efficacious in attenuation of neuropathic pain. With further improvements of vector constructs and in vivo application, this approach might have the potential to develop as an alternative gene therapy strategy to treat chronic pain, especially heat hypersensitivity, without complications due to systemic TRPV1 blockade. PMID:28604222

  18. PD-L1 inhibits acute and chronic pain by suppressing nociceptive neuron activity via PD-1

    PubMed Central

    Chen, Gang; Kim, Yong Ho; Li, Hui; Luo, Hao; Liu, Da-Lu; Zhang, Zhi-Jun; Lay, Mark; Chang, Wonseok; Zhang, Yu-Qiu; Ji, Ru-Rong

    2018-01-01

    Programmed cell death ligand-1 (PD-L1) is typically produced by cancer cells and suppresses immunity through PD-1 receptor expressed on T cells. However, the role of PD-L1/PD-1 in regulating pain and neuronal function is unclear. Here we report that both melanoma and normal neural tissues including dorsal root ganglia (DRG) produce PD-L1 that can potently inhibit acute and chronic pain. Intraplantar injection of PD-L1 evokes analgesia in naïve mice via PD-1, whereas PD-L1 neutralization or PD-1 blockade induces mechanical allodynia. Mice lacking Pd1 exhibit thermal and mechanical hypersensitivity. PD-1 activation in DRG nociceptive neurons by PD-L1 induces SHP-1 phosphorylation, inhibits sodium channels, and causes hyperpolarization through activation of TREK2 K+ channels. PD-L1 also potently suppresses nociceptive neuron excitability of human DRGs. Remarkably, blocking PD-L1 or PD-1 elicits spontaneous pain and allodynia in melanoma-bearing mice. Our findings identify a previously unrecognized role of PD-L1 as an endogenous pain inhibitor and a neuromodulator. PMID:28530662

  19. Dynamics of beta-amyloid peptide in cholesterol superlattice domain

    NASA Astrophysics Data System (ADS)

    Smirnov, Anton; Zhu, Qing; Vaughn, Mark; Khare, Rajesh; Cheng, K.

    2006-10-01

    Presence of beta-amyloid peptide (beta-A) plagues in membranes of neuron cells is a clinical signature of Alzheimer disease. The onset of beta-A peptide aggregation occurs via a conformational transition from an alpha-helix state to a beta-sheet state. A gradual build-up of beta-A content in the neuronal extracellular space is another characteristic of the beta-A plague formation. Hypothetically, both the pathological conformation and the predominant localization of the beta-A can be a result of specific dynamic characteristics of the interphase between cellular membrane and extracellular milieu. In this study, the beta-A interphase problem has been investigated using a virtual membrane model implemented on the base of GROMACS molecular dynamics simulation package. The detailed folding pattern of beta-A has been examined using a novice interphase model comprised of a cholesterol supperlattice membrane and two water layers.

  20. On the use of administrative databases to support planning activities: the case of the evaluation of neonatal case-mix in the Emilia-Romagna region using DRG and APR-DRG classification systems.

    PubMed

    Fantini, M P; Cisbani, L; Manzoli, L; Vertrees, J; Lorenzoni, L

    2003-06-01

    There are several versions of the Diagnosis Related Group (DRG) classification systems that are used for case-mix analysis, utilization review, prospective payment, and planning applications. The objective of this study was to assess the adequacy of two of these DRG systems--Medicare DRG and All Patient Refined DRG--to classify neonatal patients. The first part of the paper contains a descriptive analysis that outlines the major differences between the two systems in terms of classification logic and variables used in the assignment process. The second part examines the statistical performance of each system on the basis of the administrative data collected in all public hospitals of the Emilia-Romagna region relating to neonates discharged in 1997 and 1998. The Medicare DRG are less developed in terms of classification structure and yield a poorer statistical performance in terms of reduction in variance for length of stay. This is important because, for specific areas, a more refined system can prove useful at regional level to remove systematic biases in the measurement of case-mix due to the structural characteristics of the Medicare DRGs classification system.

  1. Development of MY-DRG casemix pharmacy service weights in UKM Medical Centre in Malaysia.

    PubMed

    Ali Jadoo, Saad Ahmed; Aljunid, Syed Mohamed; Nur, Amrizal Muhammad; Ahmed, Zafar; Van Dort, Dexter

    2015-02-10

    The service weight is among several issues and challenges in the implementation of case-mix in developing countries, including Malaysia. The aim of this study is to develop the Malaysian Diagnosis Related Group (MY-DRG) case-mix pharmacy service weight in University Kebangsaan Malaysia-Medical Center (UKMMC) by identifying the actual cost of pharmacy services by MY-DRG groups in the hospital. All patients admitted to UKMMC in 2011 were recruited in this study. Combination of Step-down and Bottom-up costing methodology has been used in this study. The drug and supplies cost; the cost of staff; the overhead cost; and the equipment cost make up the four components of pharmacy. Direct costing approach has been employed to calculate Drugs and supplies cost from electronic-prescription system; and the inpatient pharmacy staff cost, while the overhead cost and the pharmacy equipments cost have been calculated indirectly from MY-DRG data base. The total pharmacy cost was obtained by summing the four pharmacy components' cost per each MY-DRG. The Pharmacy service weight of a MY-DRG was estimated by dividing the average pharmacy cost of the investigated MY-DRG on the average of a specified MY-DRG (which usually the average pharmacy cost of all MY-DRGs). Drugs and supplies were the main component (86.0%) of pharmacy cost compared o overhead cost centers (7.3%), staff cost (6.5%) and pharmacy equipments (0.2%) respectively. Out of 789 inpatient MY-DRGs case-mix groups, 450 (57.0%) groups were utilized by the UKMMC. Pharmacy service weight has been calculated for each of these 450 MY-DRGs groups. MY-DRG case-mix group of Lymphoma & Chronic Leukemia group with severity level three (C-4-11-III) has the highest pharmacy service weight of 11.8 equivalents to average pharmacy cost of RM 5383.90. While the MY-DRG case-mix group for Circumcision with severity level one (V-1-15-I) has the lowest pharmacy service weight of 0.04 equivalents to average pharmacy cost of RM 17.83. A mixed

  2. [How can the coding quality in the DRG system be determined?].

    PubMed

    Kahlmeyer, A; Volkmer, B

    2014-01-01

    The permanent adjustments ​​since 2003 to the G-DRG system have made the system even less understandable, so that many users have the feeling of feeding data into a black box which gives them a result without them being able to actively use the system itself. While chief physicians, senior physicians, and nursing managers are responsible to management for the results of the billing, they are in most cases not involved in the steps of DRG coding and billing. From this situation, a common question arises: "How well does my department code?" This uncertainty is exploited by many commercial vendors, who offer a wide variety of approaches for DRG optimization. The goal of this work is to provide advice as to how coding quality can be determined.

  3. Role of motoneuron-derived neurotrophin 3 in survival and axonal projection of sensory neurons during neural circuit formation.

    PubMed

    Usui, Noriyoshi; Watanabe, Keisuke; Ono, Katsuhiko; Tomita, Koichi; Tamamaki, Nobuaki; Ikenaka, Kazuhiro; Takebayashi, Hirohide

    2012-03-01

    Sensory neurons possess the central and peripheral branches and they form unique spinal neural circuits with motoneurons during development. Peripheral branches of sensory axons fasciculate with the motor axons that extend toward the peripheral muscles from the central nervous system (CNS), whereas the central branches of proprioceptive sensory neurons directly innervate motoneurons. Although anatomically well documented, the molecular mechanism underlying sensory-motor interaction during neural circuit formation is not fully understood. To investigate the role of motoneuron on sensory neuron development, we analyzed sensory neuron phenotypes in the dorsal root ganglia (DRG) of Olig2 knockout (KO) mouse embryos, which lack motoneurons. We found an increased number of apoptotic cells in the DRG of Olig2 KO embryos at embryonic day (E) 10.5. Furthermore, abnormal axonal projections of sensory neurons were observed in both the peripheral branches at E10.5 and central branches at E15.5. To understand the motoneuron-derived factor that regulates sensory neuron development, we focused on neurotrophin 3 (Ntf3; NT-3), because Ntf3 and its receptors (Trk) are strongly expressed in motoneurons and sensory neurons, respectively. The significance of motoneuron-derived Ntf3 was analyzed using Ntf3 conditional knockout (cKO) embryos, in which we observed increased apoptosis and abnormal projection of the central branch innervating motoneuron, the phenotypes being apparently comparable with that of Olig2 KO embryos. Taken together, we show that the motoneuron is a functional source of Ntf3 and motoneuron-derived Ntf3 is an essential pre-target neurotrophin for survival and axonal projection of sensory neurons.

  4. Neuro-fuzzy decoding of sensory information from ensembles of simultaneously recorded dorsal root ganglion neurons for functional electrical stimulation applications

    NASA Astrophysics Data System (ADS)

    Rigosa, J.; Weber, D. J.; Prochazka, A.; Stein, R. B.; Micera, S.

    2011-08-01

    Functional electrical stimulation (FES) is used to improve motor function after injury to the central nervous system. Some FES systems use artificial sensors to switch between finite control states. To optimize FES control of the complex behavior of the musculo-skeletal system in activities of daily life, it is highly desirable to implement feedback control. In theory, sensory neural signals could provide the required control signals. Recent studies have demonstrated the feasibility of deriving limb-state estimates from the firing rates of primary afferent neurons recorded in dorsal root ganglia (DRG). These studies used multiple linear regression (MLR) methods to generate estimates of limb position and velocity based on a weighted sum of firing rates in an ensemble of simultaneously recorded DRG neurons. The aim of this study was to test whether the use of a neuro-fuzzy (NF) algorithm (the generalized dynamic fuzzy neural networks (GD-FNN)) could improve the performance, robustness and ability to generalize from training to test sets compared to the MLR technique. NF and MLR decoding methods were applied to ensemble DRG recordings obtained during passive and active limb movements in anesthetized and freely moving cats. The GD-FNN model provided more accurate estimates of limb state and generalized better to novel movement patterns. Future efforts will focus on implementing these neural recording and decoding methods in real time to provide closed-loop control of FES using the information extracted from sensory neurons.

  5. The Effects of IGF-1 on TNF-α-Treated DRG Neurons by Modulating ATF3 and GAP-43 Expression via PI3K/Akt/S6K Signaling Pathway.

    PubMed

    Zhang, Lei; Yue, Yaping; Ouyang, Meishuo; Liu, Huaxiang; Li, Zhenzhong

    2017-05-01

    Upregulation of the pro-inflammatory cytokine tumor necrosis factor α (TNF-α) is involved in the development and progression of numerous neurological disorders. Recent reports have challenged the concept that TNF-α exhibits only deleterious effects of pro-inflammatory destruction, and have raised the awareness that it may play a beneficial role in neuronal growth and function in particular conditions, which prompts us to further investigate the role of this cytokine. Insulin-like growth factor-1 (IGF-1) is a cytokine possessing powerful neuroprotective effects in promoting neuronal survival, neuronal differentiation, neurite elongation, and neurite regeneration. The association of IGF-1 with TNF-α and the biological effects, produced by interaction of IGF-1 and TNF-α, on neuronal outgrowth status of primary sensory neurons are still to be clarified. In the present study, using an in vitro model of primary cultured rat dorsal root ganglion (DRG) neurons, we demonstrated that TNF-α challenge at different concentrations elicited diverse biological effects. Higher concentration of TNF-α (10 ng/mL) dampened neurite outgrowth, induced activating transcription factor 3 (ATF3) expression, reduced growth-associated protein 43 (GAP-43) expression, and promoted GAP-43 and ATF3 coexpression, which could be reversed by IGF-1 treatment; while lower concentration of TNF-α (1 ng/mL) promoted neurite sprouting, decreased ATF3 expression, increased GAP-43 expression, and inhibited GAP-43 and ATF3 coexpression, which could be potentiated by IGF-1 supplement. Moreover, IGF-1 administration restored the activation of Akt and p70 S6 kinase (S6K) suppressed by higher concentration of TNF-α (10 ng/mL) challenge. In contrast, lower concentration of TNF-α (1 ng/mL) had no significant effect on Akt or S6K activation, and IGF-1 administration activated these two kinases. The effects of IGF-1 were abrogated by phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. These data

  6. 42 CFR 478.15 - QIO review of changes resulting from DRG validation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false QIO review of changes resulting from DRG validation... review of changes resulting from DRG validation. (a) General rules. (1) A provider or practitioner... validation under section 1866(a)(1)(F) of the Act is entitled to a review of that change if— (i) The change...

  7. 42 CFR 478.15 - QIO review of changes resulting from DRG validation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false QIO review of changes resulting from DRG validation... review of changes resulting from DRG validation. (a) General rules. (1) A provider or practitioner... validation under section 1866(a)(1)(F) of the Act is entitled to a review of that change if— (i) The change...

  8. 42 CFR 478.15 - QIO review of changes resulting from DRG validation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false QIO review of changes resulting from DRG validation... review of changes resulting from DRG validation. (a) General rules. (1) A provider or practitioner... validation under section 1866(a)(1)(F) of the Act is entitled to a review of that change if— (i) The change...

  9. 42 CFR 478.15 - QIO review of changes resulting from DRG validation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false QIO review of changes resulting from DRG validation... review of changes resulting from DRG validation. (a) General rules. (1) A provider or practitioner... validation under section 1866(a)(1)(F) of the Act is entitled to a review of that change if— (i) The change...

  10. Potentiating role of interleukin-1beta (IL-1beta) and IL-1beta type 1 receptors in the medial hypothalamus in defensive rage behavior in the cat.

    PubMed

    Hassanain, M; Bhatt, S; Zalcman, S; Siegel, A

    2005-06-28

    Recently, this laboratory provided evidence that interleukin-1beta (IL-1beta), an immune and brain-derived cytokine, microinjected into the medial hypothalamus, potentiates defensive rage behavior in the cat elicited from the midbrain periaqueductal gray (PAG), and that such effects are blocked by a 5-HT2 receptor antagonist. Since this finding represents the first time that a brain cytokine has been shown to affect defensive rage behavior, the present study replicated and extended these findings by documenting the specific potentiating role played by IL-1beta Type 1 receptor (IL-1RI), and the anatomical relationship between IL-1beta and 5-HT2 receptors in the medial hypothalamus. IL-1beta (10 ng) microinjected into the medial hypothalamus induced two separate phases of facilitation, one at 60 min and another at 180 min, post-injection. In turn, these effects were blocked with pretreatment of the selective IL-1 Type I receptor antagonist (IL-1ra) (10 ng), demonstrating the selectivity of the effects of IL-1beta on medial hypothalamic neurons upon PAG-elicited defensive rage behavior. The next stage of the study utilized immunohistochemical methods to demonstrate that IL-1beta and 5-HT2 receptors were present on the same neurons within regions of the medial hypothalamus where IL-1beta and the IL-1beta receptor antagonists were administered. This provided anatomical evidence suggesting a relationship between IL-1RI and 5-HT2 receptors in the medial hypothalamus that is consistent with the previous pharmacological observations in our laboratory. The overall findings show that activation of IL-1RI in the medial hypothalamus potentiates defensive rage behavior in the cat and that these effects may also be linked to the presence of 5-HT2 receptors on the same groups of neurons in this region of hypothalamus.

  11. Implications of DRG Classification in a Bundled Payment Initiative for COPD.

    PubMed

    Parekh, Trisha M; Bhatt, Surya P; Westfall, Andrew O; Wells, James M; Kirkpatrick, Denay; Iyer, Anand S; Mugavero, Michael; Willig, James H; Dransfield, Mark T

    2017-12-01

    Institutions participating in the Medicare Bundled Payments for Care Improvement (BPCI) initiative invest significantly in efforts to reduce readmissions and costs for patients who are included in the program. Eligibility for the BPCI initiative is determined by diagnosis-related group (DRG) classification. The implications of this methodology for chronic diseases are not known. We hypothesized that patients included in a BPCI initiative for chronic obstructive pulmonary disease (COPD) would have less severe illness and decreased hospital utilization compared with those excluded from the bundled payment initiative. Retrospective observational study. We sought to determine the clinical characteristics and outcomes of Medicare patients admitted to the University of Alabama at Birmingham Hospital with acute exacerbations of COPD between 2012 and 2014 who were included and excluded in a BPCI initiative. Patients were included in the analysis if they were discharged with a COPD DRG or with a non-COPD DRG but with an International Classification of Diseases, Ninth Revision code for COPD exacerbation. Six hundred and ninety-eight unique patients were discharged for an acute exacerbation of COPD; 239 (34.2%) were not classified into a COPD DRG and thus were excluded from the BPCI initiative. These patients were more likely to have intensive care unit (ICU) admissions (63.2% vs 4.4%, respectively; P <.001) and require noninvasive (46.9% vs 6.5%; P <.001) and invasive mechanical ventilation (41.4% vs 0.7%; P <.001) during their hospitalization than those in the initiative. They also had a longer ICU length of stay (5.2 vs 1.8 days; P = .011), longer hospital length of stay (10.3 days vs 3.9 days; P <.001), higher in-hospital mortality (14.6% vs 0.7%; P <.001), and greater hospitalization costs (median = $13,677 [interquartile range = $7489-$23,054] vs $4281 [$2718-$6537]; P <.001). The use of DRGs to identify patients with COPD for inclusion in the BPCI initiative led to the

  12. Implications of DRG Classification in a Bundled Payment Initiative for COPD

    PubMed Central

    PAREKH, TRISHA M.; BHATT, SURYA P.; WESTFALL, ANDREW O.; WELLS, JAMES M.; KIRKPATRICK, DENAY; IYER, ANAND S.; MUGAVERO, MICHAEL; WILLIG, JAMES H.; DRANSFIELD, MARK T.

    2018-01-01

    OBJECTIVES Institutions participating in the Medicare Bundled Payments for Care Improvement (BPCI) initiative invest significantly in efforts to reduce readmissions and costs for patients who are included in the program. Eligibility for the BPCI initiative is determined by diagnosis-related group (DRG) classification. The implications of this methodology for chronic diseases are not known. We hypothesized that patients included in a BPCI initiative for chronic obstructive pulmonary disease (COPD) would have less severe illness and decreased hospital utilization compared with those excluded from the bundled payment initiative. STUDY DESIGN Retrospective observational study. METHODS We sought to determine the clinical characteristics and outcomes of Medicare patients admitted to the University of Alabama at Birmingham Hospital with acute exacerbations of COPD between 2012 and 2014 who were included and excluded in a BPCI initiative. Patients were included in the analysis if they were discharged with a COPD DRG or with a non-COPD DRG but with an International Classification of Diseases, Ninth Revision code for COPD exacerbation. RESULTS Six hundred and ninety-eight unique patients were discharged for an acute exacerbation of COPD; 239 (34.2%) were not classified into a COPD DRG and thus were excluded from the BPCI initiative. These patients were more likely to have intensive care unit (ICU) admissions (63.2% vs 4.4%, respectively; P <.001) and require noninvasive (46.9% vs 6.5%; P <.001) and invasive mechanical ventilation (41.4% vs 0.7%; P <.001) during their hospitalization than those in the initiative. They also had a longer ICU length of stay (5.2 vs 1.8 days; P = .011), longer hospital length of stay (10.3 days vs 3.9 days; P <.001), higher in-hospital mortality (14.6% vs 0.7%; P <.001), and greater hospitalization costs (median = $13,677 [interquartile range = $7489-$23,054] vs $4281 [$2718-$6537]; P <.001). CONCLUSIONS The use of DRGs to identify patients with

  13. Fragrant dioxane derivatives identify beta1-subunit-containing GABAA receptors.

    PubMed

    Sergeeva, Olga A; Kletke, Olaf; Kragler, Andrea; Poppek, Anja; Fleischer, Wiebke; Schubring, Stephan R; Görg, Boris; Haas, Helmut L; Zhu, Xin-Ran; Lübbert, Hermann; Gisselmann, Günter; Hatt, Hanns

    2010-07-30

    Nineteen GABA(A) receptor (GABA(A)R) subunits are known in mammals with only a restricted number of functionally identified native combinations. The physiological role of beta1-subunit-containing GABA(A)Rs is unknown. Here we report the discovery of a new structural class of GABA(A)R positive modulators with unique beta1-subunit selectivity: fragrant dioxane derivatives (FDD). At heterologously expressed alpha1betaxgamma2L (x-for 1,2,3) GABA(A)R FDD were 6 times more potent at beta1- versus beta2- and beta3-containing receptors. Serine at position 265 was essential for the high sensitivity of the beta1-subunit to FDD and the beta1N286W mutation nearly abolished modulation; vice versa the mutation beta3N265S shifted FDD sensitivity toward the beta1-type. In posterior hypothalamic neurons controlling wakefulness GABA-mediated whole-cell responses and GABAergic synaptic currents were highly sensitive to FDD, in contrast to beta1-negative cerebellar Purkinje neurons. Immunostaining for the beta1-subunit and the potency of FDD to modulate GABA responses in cultured hypothalamic neurons was drastically diminished by beta1-siRNA treatment. In conclusion, with the help of FDDs we reveal a functional expression of beta1-containing GABA(A)Rs in the hypothalamus, offering a new tool for studies on the functional diversity of native GABA(A)Rs.

  14. Identification of the Sensory Neuron Specific Regulatory Region for the Mouse Gene Encoding the Voltage Gated Sodium Channel Nav1.8

    PubMed Central

    Puhl, Henry L.; Ikeda, Stephen R.

    2008-01-01

    Voltage-gated sodium channels (VGSC) are critical membrane components that participate in the electrical activity of excitable cells. The type one VGSC family includes the tetrodotoxin insensitive sodium channel, Nav1.8, encoded by the Scn10a gene. Nav1.8 expression is restricted to small and medium diameter nociceptive sensory neurons of the dorsal root (DRG) and cranial sensory ganglia. In order to understand the stringent transcriptional regulation of the Scn10a gene, the sensory neuron specific promoter was functionally identified. While identifying the mRNA 5’ end, alternative splicing within the 5’ UTR was observed to create heterogeneity in the RNA transcript. Four kilobases of upstream genomic DNA was cloned and the presence of tissue specific promoter activity was tested by microinjection and adenoviral infection of fluorescent protein reporter constructs into primary mouse and rat neurons, and cell lines. The region contained many putative transcription factor binding sites and strong homology with the predicted rat ortholog. Homology to the predicted human ortholog was limited to the proximal end and several conserved cis elements were noted. Two regulatory modules were identified by microinjection of reporter constructs into DRG and superior cervical ganglia neurons: a neuron specific proximal promoter region between −1.6 and −0.2kb of the transcription start site cluster, and a distal sensory neuron switch region beyond −1.6kb that restricted fluorescent protein expression to a subset of primary sensory neurons. PMID:18466327

  15. 42 CFR 412.517 - Revision of LTC-DRG group classifications and weighting factors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Revision of LTC-DRG group classifications and... classifications and weighting factors. (a) CMS adjusts the classifications and weighting factors annually to... the LTC-DRG classifications and recalibration of the weighting factors described in paragraph (a) of...

  16. 42 CFR 412.517 - Revision of LTC-DRG group classifications and weighting factors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Revision of LTC-DRG group classifications and... classifications and weighting factors. (a) CMS adjusts the classifications and weighting factors annually to... the LTC-DRG classifications and recalibration of the weighting factors described in paragraph (a) of...

  17. Hysterectomy in Germany: a DRG-based nationwide analysis, 2005-2006.

    PubMed

    Stang, Andreas; Merrill, Ray M; Kuss, Oliver

    2011-07-01

    Hysterectomy is among the more common surgical procedures in gynecology. The aim of this study was to calculate population-wide rates of hysterectomy across Germany and to obtain information on the different modalities of hysterectomy currently performed in German hospitals. This was done on the basis of nationwide DRG statistics (DRG = diagnosis-related groups) covering the years 2005-2006. We analyzed the nationwide DRG statistics for 2005 and 2006, in which we found 305 015 hysterectomies. Based on these data we calculated hysterectomy rates for the female population. We determined the indications for each hysterectomy with an algorithm based on the ICD-10 codes, and we categorized the operations on the basis of their OPS codes (OPS = Operationen- und Prozedurenschlüssel [Classification of Operations and Procedures]). The overall rate of hysterectomy in Germany was 362 per 100 000 person-years. 55% of hysterectomies for benign diseases of the female genital tract were performed transvaginally. Bilateral ovariectomy was performed concomitantly in 23% of all hysterectomies, while 4% of all hysterectomies were subtotal. Hysterectomy rates varied considerably across federal states: the rate for benign disease was lowest in Hamburg (213.8 per 100 000 women per year) and highest in Mecklenburg-West Pomerania (361.9 per 100 000 women per year). Hysterectomy rates vary markedly from one region to another. Moreover, even though recent studies have shown that bilateral ovariectomy is harmful to women under 50 who undergo hysterectomy for benign disease, it is still performed in 4% of all hysterectomies for benign indications in Germany.

  18. Lifting the weight of a diagnosis-related groups family change: a comparison between refined and non-refined DRG systems for top-down cost accounting and efficiency indicators.

    PubMed

    Zlotnik, Alexander; Cuchi, Miguel Alfaro; Pérez Pérez, Maria Carmen

    Public healthcare providers in all Spanish Regions - Autonomous Communities (ACs) use All Patients Diagnosis-Related Groups (AP-DRGs) for billing non-insured patients, cost accounting and inpatient efficiency indicators. A national migration to All Patients Refined Diagnosis-Related Groups (APR-DRGs) has been scheduled for 2016. The analysis was performed on 202,912 inpatient care episodes ranging from 2005 to 2010. All episodes were grouped using AP-DRG v25.0 and APR-DRG v24.0. Normalised DRG weight variations for an AP-DRG to APR-DRG migration scenario were calculated and compared. Major differences exist between normalised weights for inpatient episodes depending on the DRGs family used. The usage of the APR-DRG system in Spain without any adjustments, as it was developed in the United States, should be approached with care. In order to avoid reverse incentives and provider financial risks, coding practices should be reviewed and structural differences between DRG families taken into account.

  19. Effects of 17beta-estradiol on glutamate synaptic transmission and neuronal excitability in the rat medial vestibular nuclei.

    PubMed

    Grassi, S; Frondaroli, A; Scarduzio, M; Dutia, M B; Dieni, C; Pettorossi, V E

    2010-02-17

    We investigated the effects of the neurosteroid 17beta-estradiol (E(2)) on the evoked and spontaneous activity of rat medial vestibular nucleus (MVN) neurons in brainstem slices. E(2) enhances the synaptic response to vestibular nerve stimulation in type B neurons and depresses the spontaneous discharge in both type A and B neurons. The amplitude of the field potential, as well as the excitatory post-synaptic potential (EPSP) and current (EPSC), in type B neurons, are enhanced by E(2). Both effects are long-term phenomena since they outlast the drug washout. The enhancement of synaptic response is mainly due to facilitation of glutamate release mediated by pre-synaptic N-methyl-D-aspartate receptors (NMDARs), since the reduction of paired pulse ratio (PPR) and the increase of miniature EPSC frequency after E(2) are abolished under D-(-)-2-amino-5-phosphonopentanoic acid (AP-5). E(2) also facilitates post-synaptic NMDARs, but it does not affect directly alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) and group I-metabotropic glutamate receptors (mGluRs-I). In contrast, the depression of the spontaneous discharge of type A and type B neurons appears to depend on E(2) modulation of intrinsic ion conductances, as the effect remains after blockade of glutamate, GABA and glycine receptors (GlyRs). The net effect of E(2) is to enhance the signal-to-noise ratio of the synaptic response in type B neurons, relative to resting activity of all MVN neurons. These findings provide evidence for a novel potential mechanism to modulate the responsiveness of vestibular neurons to afferent inputs, and so regulate vestibular function in vivo.

  20. [Development of the 2014 G-DRG system. Departure from coding of secondary diagnoses?].

    PubMed

    Volkmer, B G; Kahlmeyer, A; Petervari, M; Pechoel, M

    2014-01-01

    The objective of the German DRG (diagnosis-related groups) system is to adequately reimburse hospital costs using flat rate payments. The goal is to thereby achieve the most adequate representation of hospital costs in flat rate payments. The DRG for 2014 is based on the actual number of cases treated and the costs determined from 2012. For 2014, the current changes of the DRG system for the specialty urology concerning the coding and recording of secondary diagnoses are presented and discussed.

  1. Human Mas-Related G Protein-Coupled Receptors-X1 Induce Chemokine Receptor 2 Expression in Rat Dorsal Root Ganglia Neurons and Release of Chemokine Ligand 2 from the Human LAD-2 Mast Cell Line

    PubMed Central

    Solinski, Hans Jürgen; Petermann, Franziska; Rothe, Kathrin; Boekhoff, Ingrid; Gudermann, Thomas; Breit, Andreas

    2013-01-01

    Primate-specific Mas-related G protein-coupled receptors-X1 (MRGPR-X1) are highly enriched in dorsal root ganglia (DRG) neurons and induce acute pain. Herein, we analyzed effects of MRGPR-X1 on serum response factors (SRF) or nuclear factors of activated T cells (NFAT), which control expression of various markers of chronic pain. Using HEK293, DRG neuron-derived F11 cells and cultured rat DRG neurons recombinantly expressing human MRGPR-X1, we found activation of a SRF reporter gene construct and induction of the early growth response protein-1 via extracellular signal-regulated kinases-1/2 known to play a significant role in the development of inflammatory pain. Furthermore, we observed MRGPR-X1-induced up-regulation of the chemokine receptor 2 (CCR2) via NFAT, which is considered as a key event in the onset of neuropathic pain and, so far, has not yet been described for any endogenous neuropeptide. Up-regulation of CCR2 is often associated with increased release of its endogenous agonist chemokine ligand 2 (CCL2). We also found MRGPR-X1-promoted release of CCL2 in a human connective tissue mast cell line endogenously expressing MRGPR-X1. Thus, we provide first evidence to suggest that MRGPR-X1 induce expression of chronic pain markers in DRG neurons and propose a so far unidentified signaling circuit that enhances chemokine signaling by acting on two distinct yet functionally co-operating cell types. Given the important role of chemokine signaling in pain chronification, we propose that interruption of this signaling circuit might be a promising new strategy to alleviate chemokine-promoted pain. PMID:23505557

  2. Assessing DRG cost accounting with respect to resource allocation and tariff calculation: the case of Germany

    PubMed Central

    2012-01-01

    The purpose of this paper is to analyze the German diagnosis related groups (G-DRG) cost accounting scheme by assessing its resource allocation at hospital level and its tariff calculation at national level. First, the paper reviews and assesses the three steps in the G-DRG resource allocation scheme at hospital level: (1) the groundwork; (2) cost-center accounting; and (3) patient-level costing. Second, the paper reviews and assesses the three steps in G-DRG national tariff calculation: (1) plausibility checks; (2) inlier calculation; and (3) the “one hospital” approach. The assessment is based on the two main goals of G-DRG introduction: improving transparency and efficiency. A further empirical assessment attests high costing quality. The G-DRG cost accounting scheme shows high system quality in resource allocation at hospital level, with limitations concerning a managerially relevant full cost approach and limitations in terms of advanced activity-based costing at patient-level. However, the scheme has serious flaws in national tariff calculation: inlier calculation is normative, and the “one hospital” model causes cost bias, adjustment and representativeness issues. The G-DRG system was designed for reimbursement calculation, but developed to a standard with strategic management implications, generalized by the idea of adapting a hospital’s cost structures to DRG revenues. This combination causes problems in actual hospital financing, although resource allocation is advanced at hospital level. PMID:22935314

  3. Assessing DRG cost accounting with respect to resource allocation and tariff calculation: the case of Germany.

    PubMed

    Vogl, Matthias

    2012-08-30

    The purpose of this paper is to analyze the German diagnosis related groups (G-DRG) cost accounting scheme by assessing its resource allocation at hospital level and its tariff calculation at national level. First, the paper reviews and assesses the three steps in the G-DRG resource allocation scheme at hospital level: (1) the groundwork; (2) cost-center accounting; and (3) patient-level costing. Second, the paper reviews and assesses the three steps in G-DRG national tariff calculation: (1) plausibility checks; (2) inlier calculation; and (3) the "one hospital" approach. The assessment is based on the two main goals of G-DRG introduction: improving transparency and efficiency. A further empirical assessment attests high costing quality. The G-DRG cost accounting scheme shows high system quality in resource allocation at hospital level, with limitations concerning a managerially relevant full cost approach and limitations in terms of advanced activity-based costing at patient-level. However, the scheme has serious flaws in national tariff calculation: inlier calculation is normative, and the "one hospital" model causes cost bias, adjustment and representativeness issues. The G-DRG system was designed for reimbursement calculation, but developed to a standard with strategic management implications, generalized by the idea of adapting a hospital's cost structures to DRG revenues. This combination causes problems in actual hospital financing, although resource allocation is advanced at hospital level.

  4. Combination of quercetin, cinnamaldehyde and hirudin protects rat dorsal root ganglion neurons against high glucose-induced injury through Nrf-2/HO-1 activation and NF-κB inhibition.

    PubMed

    Shi, Yue; Liang, Xiao-Chun; Zhang, Hong; Sun, Qing; Wu, Qun-Li; Qu, Ling

    2017-09-01

    To examine the effects of the combination of quercetin (Q), cinnamaldehyde (C) and hirudin (H), a Chinese medicine formula on high glucose (HG)-induced apoptosis of cultured dorsal root ganglion (DRG) neurons. DRG neurons exposed to HG (45 mmol/L) for 24 h were employed as an in vitro model of diabetic neuropathy. Cell viability, reactive oxygen species (ROS) level and apoptosis were determined. The expression of nuclear factor of Kappa B (NF-κB), inhibitory kappa Bα(IκBα), phosphorylated IκBα and Nf-E2 related factor 2 (Nrf2) were examined using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot assay. The expression of hemeoxygenase-1 (HO-1), interleukin-6 (IL-6), tumor necrosis factor (TNF-α) and caspase-3 were also examined by RT-PCR and Western blot assay. HG treatment markedly increased DRG neuron apoptosis via increasing intracellular ROS level and activating the NF-κB signaling pathway (P<0.05). Co-treatment with Q, C, H and their combination decreased HG-induced caspase-3 activation and apoptosis (P<0.05 or P<0.01). The expressions of NF-κB, IL-6 and TNF-α were down-regulated, and Nrf2/HO-1 expression was up-regulated (P<0.05 or P<0.01). QCH has better effect in scavenging ROS, activating Nrf-2/HO-1, and down-regulating the NF-κB pathway than other treatment group. DRG neurons' apoptosis was increased in diabetic conditions, which was reduced by QCH formula treatment. The possible reason could be activating Nrf-2/HO-1 pathway, scavenging ROS, and inhibition of NF-κB activation. The effect of QCH combination was better than each monomer or the combination of the two monomers.

  5. Structure-activity relationships of N-beta-phenylpropionyl-L-tyrosine and its derivatives on the inhibition of an identifiable giant neurone of an African giant snail (Achatina fulica Férussac).

    PubMed Central

    Ariyoshi, Y.; Takeuchi, H.

    1982-01-01

    1 Inhibitory effects of N-beta-phenylpropionyl-L-tyrosine, N-beta-phenylpropionyl-L-tryptophan and their derivatives on an identifiable giant neurone, TAN (tonically autoactive neurone) of an African giant snail (Achatina fulica Férussac) were examined in an attempt to elucidate which structural features are necessary to produce the effect. 2 Of the compounds examined, N-beta-cyclohexylpropionyl-L-tyrosine showed the strongest effect. Its critical concentration (c.c.) was 3 X 10(-8)-10(-7)M, about ten times lower than that of N-beta-phenylpropionyl-L-tyrosine (c.c., 3 X 10(-7)-10(-6)M). N-beta-cyclohexylpropionyl-L-tryptophan (c.c., 10(-6)M) had an effect almost similar to that of N-beta-phenylpropionyl-L-tryptophan (c.c., 10(-6)M). 3 N-beta-Phenylpropionyl-N-methyl-L-tyrosine had no effect at a high concentration. 4 Effects of N-beta-phenylpropionyl-L-tyrosine amide (c.c., 3 X 10(-7)-10(-6)M) and N-beta-phenylpropionyl-L-tryptophan amide (c.c., 10(-6)M) were very similar to those of N-beta-phenylpropionyl-L-tyrosine and N-beta-phenylpropionyl-L-tryptophan respectively. 5 N-beta-Phenylpropionyl-p-amino-L-phenylalanine (c.c., 3 X 10(-5)-10(-4)M) and N-beta-phenylpropionyl-p-chloro-L-phenylalanine (c.c., 10(-4)M) had only a weak effect. 6 It is proposed that the structural features producing the effect are as follows: the active compound has a phenyl or a cyclohexyl group (hydrophobic binding group), after a suitable distance a peptide bond (proton donor and proton acceptor), adjacently a carbonyl group (proton acceptor), and a phenolic hydroxyl or an indolyl imino group (proton donor) in the molecule. PMID:7150871

  6. Adrenergic signaling mediates mechanical hyperalgesia through activation of P2X3 receptors in primary sensory neurons of rats with chronic pancreatitis.

    PubMed

    Wang, Shusheng; Zhu, Hong-Yan; Jin, Yi; Zhou, Youlang; Hu, Shufen; Liu, Tong; Jiang, Xinghong; Xu, Guang-Yin

    2015-04-15

    The mechanism of pain in chronic pancreatitis (CP) is poorly understood. The aim of this study was designed to investigate roles of norepinephrine (NE) and P2X receptor (P2XR) signaling pathway in the pathogenesis of hyperalgesia in a rat model of CP. CP was induced in male adult rats by intraductal injection of trinitrobenzene sulfonic acid (TNBS). Mechanical hyperalgesia was assessed by referred somatic behaviors to mechanical stimulation of rat abdomen. P2XR-mediated responses of pancreatic dorsal root ganglion (DRG) neurons were measured utilizing calcium imaging and whole cell patch-clamp-recording techniques. Western blot analysis and immunofluorescence were performed to examine protein expression. TNBS injection produced a significant upregulation of P2X3R expression and an increase in ATP-evoked responses of pancreatic DRG neurons. The sensitization of P2X3Rs was reversed by administration of β-adrenergic receptor antagonist propranolol. Incubation of DRG neurons with NE significantly enhanced ATP-induced intracellular calcium signals, which were abolished by propranolol, and partially blocked by protein kinase A inhibitor H-89. Interestingly, TNBS injection led to a significant elevation of NE concentration in DRGs and the pancreas, an upregulation of β2-adrenergic receptor expression in DRGs, and amplification of the NE-induced potentiation of ATP responses. Importantly, pancreatic hyperalgesia was markedly attenuated by administration of purinergic receptor antagonist suramin or A317491 or β2-adrenergic receptor antagonist butoxamine. Sensitization of P2X3Rs, which was likely mediated by adrenergic signaling in primary sensory neurons, contributes to pancreatic pain, thus identifying a potential target for treating pancreatic pain caused by inflammation. Copyright © 2015 the American Physiological Society.

  7. Transcription factor activating protein 2 beta (TFAP2B) mediates noradrenergic neuronal differentiation in neuroblastoma.

    PubMed

    Ikram, Fakhera; Ackermann, Sandra; Kahlert, Yvonne; Volland, Ruth; Roels, Frederik; Engesser, Anne; Hertwig, Falk; Kocak, Hayriye; Hero, Barbara; Dreidax, Daniel; Henrich, Kai-Oliver; Berthold, Frank; Nürnberg, Peter; Westermann, Frank; Fischer, Matthias

    2016-02-01

    Neuroblastoma is an embryonal pediatric tumor that originates from the developing sympathetic nervous system and shows a broad range of clinical behavior, ranging from fatal progression to differentiation into benign ganglioneuroma. In experimental neuroblastoma systems, retinoic acid (RA) effectively induces neuronal differentiation, and RA treatment has been therefore integrated in current therapies. However, the molecular mechanisms underlying differentiation are still poorly understood. We here investigated the role of transcription factor activating protein 2 beta (TFAP2B), a key factor in sympathetic nervous system development, in neuroblastoma pathogenesis and differentiation. Microarray analyses of primary neuroblastomas (n = 649) demonstrated that low TFAP2B expression was significantly associated with unfavorable prognostic markers as well as adverse patient outcome. We also found that low TFAP2B expression was strongly associated with CpG methylation of the TFAP2B locus in primary neuroblastomas (n = 105) and demethylation with 5-aza-2'-deoxycytidine resulted in induction of TFAP2B expression in vitro, suggesting that TFAP2B is silenced by genomic methylation. Tetracycline inducible re-expression of TFAP2B in IMR-32 and SH-EP neuroblastoma cells significantly impaired proliferation and cell cycle progression. In IMR-32 cells, TFAP2B induced neuronal differentiation, which was accompanied by up-regulation of the catecholamine biosynthesizing enzyme genes DBH and TH, and down-regulation of MYCN and REST, a master repressor of neuronal genes. By contrast, knockdown of TFAP2B by lentiviral transduction of shRNAs abrogated RA-induced neuronal differentiation of SH-SY5Y and SK-N-BE(2)c neuroblastoma cells almost completely. Taken together, our results suggest that TFAP2B is playing a vital role in retaining RA responsiveness and mediating noradrenergic neuronal differentiation in neuroblastoma. Copyright © 2015 Federation of European Biochemical Societies

  8. Noradrenergic lesioning with an anti-dopamine beta-hydroxylase immunotoxin

    NASA Technical Reports Server (NTRS)

    Picklo, M. J.; Wiley, R. G.; Lappi, D. A.; Robertson, D.

    1994-01-01

    Sympathectomy has been achieved by a variety of methods but each has its limitations. These include lack of tissue specificity, incomplete lesioning, and the age range of susceptibility to the lesioning. To circumvent these drawbacks, an immunotoxin was constructed using a monoclonal antibody against the noradrenergic specific enzyme dopamine beta-hydroxylase (D beta H) coupled via a disulfide bond to saporin, a ribosomal inactivating protein. Three days after intravenous injection of the anti-D beta H immunotoxin (50 micrograms) into adult Sprague-Dawley rats, 66% of neurons in the superior cervical ganglia were chromatolytic. Superior cervical ganglia neurons were poisoned in 1 day old and 1 week old (86% of neurons) neonatal rats following subcutaneous injection of 3.75 and 15 micrograms, respectively. The anti-D beta H immunotoxin will be a useful tool in the study of the peripheral noradrenergic system in adult and neonatal animals.

  9. TRPV1, but not TRPA1, in primary sensory neurons contributes to cutaneous incision-mediated hypersensitivity

    PubMed Central

    2013-01-01

    Background Mechanisms underlying postoperative pain remain poorly understood. In rodents, skin-only incisions induce mechanical and heat hypersensitivity similar to levels observed with skin plus deep incisions. Therefore, cutaneous injury might drive the majority of postoperative pain. TRPA1 and TRPV1 channels are known to mediate inflammatory and nerve injury pain, making them key targets for pain therapeutics. These channels are also expressed extensively in cutaneous nerve fibers. Therefore, we investigated whether TRPA1 and TRPV1 contribute to mechanical and heat hypersensitivity following skin-only surgical incision. Results Behavioral responses to mechanical and heat stimulation were compared between skin-incised and uninjured, sham control groups. Elevated mechanical responsiveness occurred 1 day post skin-incision regardless of genetic ablation or pharmacological inhibition of TRPA1. To determine whether functional changes in TRPA1 occur at the level of sensory neuron somata, we evaluated cytoplasmic calcium changes in sensory neurons isolated from ipsilateral lumbar 3–5 DRGs of skin-only incised and sham wild type (WT) mice during stimulation with the TRPA1 agonist cinnamaldehyde. There were no changes in the percentage of neurons responding to cinnamaldehyde or in their response amplitudes. Likewise, the subpopulation of DRG somata retrogradely labeled specifically from the incised region of the plantar hind paw showed no functional up-regulation of TRPA1 after skin-only incision. Next, we conducted behavior tests for heat sensitivity and found that heat hypersensitivity peaked at day 1 post skin-only incision. Skin incision-induced heat hypersensitivity was significantly decreased in TRPV1-deficient mice. In addition, we conducted calcium imaging with the TRPV1 agonist capsaicin. DRG neurons from WT mice exhibited sensitization to TRPV1 activation, as more neurons (66%) from skin-incised mice responded to capsaicin compared to controls (46%), and the

  10. [Expressional change of nitric oxide synthases in dorsal root ganglia of cats after selective dorsal rhizotomy].

    PubMed

    Qin, Hua-li; Zhou, Xue; Zhang, Wei; Chen, Si-xiu

    2004-01-01

    To examine the expressional change of nitric oxide synthase (NOS) in the injured dorsal root ganglia (DRG) and the ipsilateral adjacent uninjured DRG after selective dorsal rhizotomy. Immunochemical ABC method was used to detect the distribution of immunoreaction complex of NOS isoforms--nNOS and eNOS, and quantitative analysis was conducted to get the number of nNOS-immunoreactivity (nNOS-IR) neurons in normal DRG, dorsal rhizotomized DRG and spared DRG from adult cats on the 6th day after operation. This operating model was made by rhizotomizing unilateral L1-L5 dorsal roots and leaving L6 as a spared root. nNOS-immunoreactants were mainly distributed in the small-sized neurons in the DRG of cat. The percentage of nNOS-expressing small-sized neurons increased in the deafferentated L5 DRG (29.74%) when compared with the contralateral DRG (19.35%), and it also increased in the spared DRG (24.22%), compared with the contralateral DRG (18.61%). eNOS-IR was not observed in the DRG of adult cats. nNOS/NO up-regulated in DRG neurons is involved in a wide variety of biological functions under physiological and lesion-induced pathophysiological conditions in nerve system.

  11. FPGA platform for MEMS Disc Resonance Gyroscope (DRG) control

    NASA Astrophysics Data System (ADS)

    Keymeulen, Didier; Peay, Chris; Foor, David; Trung, Tran; Bakhshi, Alireza; Withington, Phil; Yee, Karl; Terrile, Rich

    2008-04-01

    Inertial navigation systems based upon optical gyroscopes tend to be expensive, large, power consumptive, and are not long lived. Micro-Electromechanical Systems (MEMS) based gyros do not have these shortcomings; however, until recently, the performance of MEMS based gyros had been below navigation grade. Boeing and JPL have been cooperating since 1997 to develop high performance MEMS gyroscopes for miniature, low power space Inertial Reference Unit applications. The efforts resulted in demonstration of a Post Resonator Gyroscope (PRG). This experience led to the more compact Disc Resonator Gyroscope (DRG) for further reduced size and power with potentially increased performance. Currently, the mass, volume and power of the DRG are dominated by the size of the electronics. This paper will detail the FPGA based digital electronics architecture and its implementation for the DRG which will allow reduction of size and power and will increase performance through a reduction in electronics noise. Using the digital control based on FPGA, we can program and modify in real-time the control loop to adapt to the specificity of each particular gyro and the change of the mechanical characteristic of the gyro during its life time.

  12. Selective Radiofrequency Stimulation of the Dorsal Root Ganglion (DRG) as a Method for Predicting Targets for Neuromodulation in Patients With Post Amputation Pain: A Case Series.

    PubMed

    Hunter, Corey W; Yang, Ajax; Davis, Tim

    2017-10-01

    While spinal cord stimulation (SCS) has established itself as an accepted and validated treatment for neuropathic pain, there are a number of conditions where it has experienced less, long-term success: post amputee pain (PAP) being one of them. Dorsal root ganglion (DRG) stimulation has shown great promise, particularly in conditions where traditional SCS has fallen short. One major difference between DRG stimulation and traditional SCS is the ability to provide focal stimulation over targeted areas. While this may be a contributing factor to its superiority, it can also be a limitation insofar stimulating the wrong DRG(s) can lead to failure. This is particularly relevant in conditions like PAP where neuroplastic maladaptation occurs causing the pain to deviate from expected patterns, thus creating uncertainty and variability in predicting targets for stimulation. We propose selective radiofrequency (RF) stimulation of the DRG as a method for preoperatively predicting targets for neuromodulation in patients with PAP. We present four patients with PAP of the lower extremities. RF stimulation was used to selectively stimulate individual DRG's, creating areas of paresthesias to see which most closely correlated/overlapped with the painful area(s). RF stimulation to the DRG's that resulted in the desirable paresthesia coverage in the residual or the missing limb(s) was recorded as "positive." Trial DRG leads were placed based on the positive RF stimulation findings. In each patient, stimulating one or more DRG(s) produced paresthesias patterns that were contradictory to know dermatomal patterns. Upon completion of a one-week trial all four patients reported 60-90% pain relief, with coverage over the painful areas, and opted for permanent implant. Mapping the DRG via RF stimulation appears to provide improved accuracy for determining lead placement in the setting of PAP where pain patterns are known to deviate from conventional dermatomal mapping. © 2017

  13. [DRG-based cost analysis of inpatient conservative treatment of stage III/IV peripheral arterial occlusive disease].

    PubMed

    Heidrich, H; Rogatti, W; Altmann, E; Bauersachs, R; Diehm, C; Fahrig, C; Lawall, H; Ranft, J; Schenker, M; Schweizer, H J; Stiegler, H; Wilke, M

    2003-11-01

    DRG-based cost analysis of inpatient conservative treatment of PAD stage III/IV BACKGROUND: In a prospective study carried out by the German Society of Angiology and the DRG Competence Center, Munich, the question was investigated whether the costs of conservative treatment of patients with PAOD stage III/IV (DRG F65) are adequately represented within the current G-DRG system. METHODS UND PATIENTS: Between September 1 and December 16, 2002, a total of 704 patients with DRG F65 (peripheral vascular diseases) were evaluated at 8 angiologic centers in Germany. Apart from the length of hospital stay, the total costs (cost equivalents) were calculated using a method developed by the DRG Research Group at the University of Münster. Moreover, the study population was compared with a German calculation sample for the DRGs F65A/B, as published by InEK. As it turned out, conservatively treated patients with PAOD stage III or IV (DRGs F65A/B) cause significantly (p < 0.001) higher costs and have significantly (p < 0.001) greater lengths of hospital stay than patients who were also assigned to DRG F65 because of other vascular diseases. At the same time it became clear that angiologic centers treat twice as many patients with critical limb ischemia in comparison with the German average. The reimbursement hitherto estimated by InEK covers not even half the cost actually produced by conservative treatment of PAD stage III/IV. To ensure a performance-related reimbursement, a new basis DRG for patients with PAD stage III/IV has to be created, as has ben proposed by the German Society of Angiology. Otherwise, adequate conservative therapy in accordance with existing guidelines, of patients who cannot be treated surgically or interventionally will not be possible any more in the future.

  14. Variability of nursing care by APR-DRG and by severity of illness in a sample of nine Belgian hospitals.

    PubMed

    Pirson, Magali; Delo, Caroline; Di Pierdomenico, Lionel; Laport, Nancy; Biloque, Veronique; Leclercq, Pol

    2013-10-10

    As soon as Diagnosis related Groups (DRG) were introduced in many hospital financing systems, most nursing research revealed that DRG were not very homogeneous with regard to nursing care. However, few studies are based on All Patient refined Diagnosis related Groups (APR-DRGs) and few of them use recent data. Objectives of this study are: (1) to evaluate if nursing activity is homogeneous by APR-DRG and by severity of illness (SOI) (2) to evaluate the outlier's rate associated with the nursing activity and (3) to compare nursing cost homogeneity per DRG and SOI. Study done in 9 Belgian hospitals on a selection of APR-DRG with more than 30 patients (7 638 inpatient stays). The evaluation of the homogeneity is based on coefficients of variation (CV). The 75th percentile + 1.5 × inter-quartile range was used to select high outliers. 25th percentile -1.5 × inter-quartile range was used to select low outliers. Nursing costs per ward were distributed on inpatient stays of each ward following two techniques (the LOS vs. the number of nursing care minutes per stay). The homogeneity of LOS by DRG and by SOI is relatively good (CV: 0.56). The homogeneity of the nursing activity by DRG is less good (CVs between 0.36 and 1.54) and is influenced by nursing activity outliers (high outliers' rate: 5.19%, low outliers' rate: 0.14%). The outlier's rate varies according to the studied variable. The high outliers' rate is higher for nursing activity than for LOS. The homogeneity of nursing costs is higher when costs are based on the LOS of patients than when based on minutes of nursing care (CVs between 0.26 and 1.46 for nursing costs based on LOS and between 0.49 and 2.04 for nursing costs based on minutes of nursing care). It is essential that the calculation of nursing cost by stay and by DRG for hospital financing purposes was based on nursing activity data, that more reflect resources used in wards, and not on LOS data. The only way to obtain this information is

  15. Variability of nursing care by APR-DRG and by severity of illness in a sample of nine Belgian hospitals

    PubMed Central

    2013-01-01

    Background As soon as Diagnosis related Groups (DRG) were introduced in many hospital financing systems, most nursing research revealed that DRG were not very homogeneous with regard to nursing care. However, few studies are based on All Patient refined Diagnosis related Groups (APR-DRGs) and few of them use recent data. Objectives of this study are: (1) to evaluate if nursing activity is homogeneous by APR-DRG and by severity of illness (SOI) (2) to evaluate the outlier’s rate associated with the nursing activity and (3) to compare nursing cost homogeneity per DRG and SOI. Methods Study done in 9 Belgian hospitals on a selection of APR-DRG with more than 30 patients (7 638 inpatient stays). The evaluation of the homogeneity is based on coefficients of variation (CV). The 75th percentile + 1.5 × inter-quartile range was used to select high outliers. 25th percentile −1.5 × inter-quartile range was used to select low outliers. Nursing costs per ward were distributed on inpatient stays of each ward following two techniques (the LOS vs. the number of nursing care minutes per stay). Results The homogeneity of LOS by DRG and by SOI is relatively good (CV: 0.56). The homogeneity of the nursing activity by DRG is less good (CVs between 0.36 and 1.54) and is influenced by nursing activity outliers (high outliers’ rate: 5.19%, low outliers’ rate: 0.14%). The outlier’s rate varies according to the studied variable. The high outliers’ rate is higher for nursing activity than for LOS. The homogeneity of nursing costs is higher when costs are based on the LOS of patients than when based on minutes of nursing care (CVs between 0.26 and 1.46 for nursing costs based on LOS and between 0.49 and 2.04 for nursing costs based on minutes of nursing care). Conclusions It is essential that the calculation of nursing cost by stay and by DRG for hospital financing purposes was based on nursing activity data, that more reflect resources used in wards, and not on LOS

  16. The Molecular Motor KIF1A Transports the TrkA Neurotrophin Receptor and Is Essential for Sensory Neuron Survival and Function.

    PubMed

    Tanaka, Yosuke; Niwa, Shinsuke; Dong, Ming; Farkhondeh, Atena; Wang, Li; Zhou, Ruyun; Hirokawa, Nobutaka

    2016-06-15

    KIF1A is a major axonal transport motor protein, but its functional significance remains elusive. Here we show that KIF1A-haploinsufficient mice developed sensory neuropathy. We found progressive loss of TrkA(+) sensory neurons in Kif1a(+/-) dorsal root ganglia (DRGs). Moreover, axonal transport of TrkA was significantly disrupted in Kif1a(+/-) neurons. Live imaging and immunoprecipitation assays revealed that KIF1A bound to TrkA-containing vesicles through the adaptor GTP-Rab3, suggesting that TrkA is a cargo of the KIF1A motor. Physiological measurements revealed a weaker capsaicin response in Kif1a(+/-) DRG neurons. Moreover, these neurons were hyposensitive to nerve growth factor, which could explain the reduced neuronal survival and the functional deficiency of the pain receptor TRPV1. Because phosphatidylinositol 3-kinase (PI3K) signaling significantly rescued these phenotypes and also increased Kif1a mRNA, we propose that KIF1A is essential for the survival and function of sensory neurons because of the TrkA transport and its synergistic support of the NGF/TrkA/PI3K signaling pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Low levels of citrin (SLC25A13) expression in adult mouse brain restricted to neuronal clusters.

    PubMed

    Contreras, Laura; Urbieta, Almudena; Kobayashi, Keiko; Saheki, Takeyori; Satrústegui, Jorgina

    2010-04-01

    The mitochondrial aspartate-glutamate carriers (AGC) aralar (SLC25A12) and citrin (SLC25A13) are components of the malate aspartate shuttle (MAS), a major intracellular pathway to transfer reducing equivalents from NADH to the mitochondrial matrix. Aralar is the main AGC isoform present in the adult brain, and it is expressed mainly in neurons. To search for the other AGC isoform, citrin, in brain glial cells, we used a citrin knockout mouse in which the lacZ gene was inserted into the citrin locus as reporter gene. In agreement with the low citrin levels known to be present in the adult mouse brain, beta-galactosidase expression was very low. Surprisingly, unlike the case with astroglial cultures that express citrin, no beta-galactosidase was found in brain glial cells. It was confined to neuronal cells within discrete neuronal clusters. Double-immunolabelling experiments showed that beta-galactosidase colocalized not with glial cell markers but with the pan-neuronal marker NeuN. The deep cerebellar nuclei and a few midbrain nuclei (reticular tegmental pontine nuclei; magnocellular red nuclei) were the regions where beta-galactosidase expression was highest, and it was up-regulated in fasted mice, as was also the case for liver beta-galactosidase. The results support the notion that glial cells have much lower AGC levels and MAS activity than neurons. (c) 2009 Wiley-Liss, Inc.

  18. [Is DRG Coding too Important to be Left to Physicians? - Evaluation of Economic Efficiency by Health Economists in a University Medical Centre].

    PubMed

    Burger, F; Walgenbach, M; Göbel, P; Parbs, S; Neugebauer, E

    2017-04-01

    Background: We investigated and evaluated the cost effectiveness of coding by health care economists in a centre for orthopaedics and trauma surgery in Germany, by quantifying and comparing the financial efficiency of physicians with basic knowledge of the DRG-system with the results of healthcare economists with in-depth knowledge (M.Sc.). In addition, a hospital survey was performed to establish how DRG-coding is being performed and the identity of the persons involved. Material and Methods: In a prospective and controlled study, 200 in-patients were coded by a healthcare economist (study group). Prior to that, the same cases were coded by physicians with basic training in the DRG-system, who made up the control group. All cases were picked randomly and blinded without informing the physicians coding the controls, in order to avoid any Hawthorne effect. We evaluated and measured the effective weighting within the G-DRG, the DRG returns per patient, the overall DRG return, and the additional time needed. For the survey, questionnaires were sent to 1200 German hospitals. The completed questionnaire was analysed using a statistical program. Results: The return difference per patient between controls and the study group was significantly greater (2472 ± 337 €; p < 0.05); the overall return was raised by 494,500 €. The mean additional time needed was 11.32 ± 0.8 min per case, resulting in an increase in proceeds of 218 ± 38 € per minute. 2.5 % of all cases had to be devaluated by the health economist after the initial coding by the control group. Returned sheets of 60 hospitals were evaluated. The median level of DRG case reports was 1277 (2500-62,300). Coding was performed in 69 % of cases by doctors, 19 % by skilled specialists for DRG coding and in 8 % together. Overall satisfaction with the DRG was described by 61 % of respondents as good or excellent. Conclusion: Our prospective and controlled study quantifies the cost

  19. Effect of knockout of α2δ-1 on action potentials in mouse sensory neurons.

    PubMed

    Margas, Wojciech; Ferron, Laurent; Nieto-Rostro, Manuela; Schwartz, Arnold; Dolphin, Annette C

    2016-08-05

    Gene deletion of the voltage-gated calcium channel auxiliary subunit α2δ-1 has been shown previously to have a cardiovascular phenotype, and a reduction in mechano- and cold sensitivity, coupled with delayed development of neuropathic allodynia. We have also previously shown that dorsal root ganglion (DRG) neuron calcium channel currents were significantly reduced in α2δ-1 knockout mice. To extend our findings in these sensory neurons, we have examined here the properties of action potentials (APs) in DRG neurons from α2δ-1 knockout mice in comparison to their wild-type (WT) littermates, in order to dissect how the calcium channels that are affected by α2δ-1 knockout are involved in setting the duration of individual APs and their firing frequency. Our main findings are that there is reduced Ca(2+) entry on single AP stimulation, particularly in the axon proximal segment, reduced AP duration and reduced firing frequency to a 400 ms stimulation in α2δ-1 knockout neurons, consistent with the expected role of voltage-gated calcium channels in these events. Furthermore, lower intracellular Ca(2+) buffering also resulted in reduced AP duration, and a lower frequency of AP firing in WT neurons, mimicking the effect of α2δ-1 knockout. By contrast, we did not obtain any consistent evidence for the involvement of Ca(2+)-activation of large conductance calcium-activated potassium (BK) and small conductance calcium-activated potassium (SK) channels in these events. In conclusion, the reduced Ca(2+) elevation as a result of single AP stimulation is likely to result from the reduced duration of the AP in α2δ-1 knockout sensory neurons.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'. © 2016 The Authors.

  20. [Is polytrauma affordable these days? G-DRG system vs per diem charge based on 1,030 patients with multiple injuries].

    PubMed

    Qvick, B; Buehren, V; Woltmann, A

    2012-10-01

    The introduction of diagnosis-related groups (DRG) in Germany comprises the risk of a non-cost-effective reimbursement in complex medical treatments. The aim of this study was to compare the reimbursement between the DRG system and the system of hospital per diem charge in effect until now. The G-DRG (Version 2004) reimbursement was calculated for 1,030 polytrauma patients (average ISS 26.4) treated at the BGU Murnau from 2000 to 2004, using a base value of 2900 euros, and compared to the reimbursement of hospital per diem charge. Just half of all polytrauma patients are classified as a polytrauma according to the DRG (18.7%) or as requiring artificial respiration based on the DRG (29.1%). The average G-DRG reimbursement was 27,157 euros vs 36,387 euros (74.6%). Patients with minor trauma, increasing age, high GCS, ICU stay without artificial respiration, trauma of the upper extremity and patients who survived show the greatest discrepancy. A revision of the G-DRG definition of polytrauma is necessary to ensure adequate reimbursement for management of patients with multiple injuries. The severity of a trauma has to be considered in the DRG system.

  1. 4α-phorbol 12,13-didecanoate activates cultured mouse dorsal root ganglia neurons independently of TRPV4

    PubMed Central

    Alexander, R; Kerby, A; Aubdool, AA; Power, AR; Grover, S; Gentry, C; Grant, AD

    2013-01-01

    Background and Purpose The Ca2+-permeable cation channel TRPV4 is activated by mechanical disturbance of the cell membrane and is implicated in mechanical hyperalgesia. Nerve growth factor (NGF) is increased during inflammation and causes mechanical hyperalgesia. 4α-phorbol 12,13-didecanoate (4αPDD) has been described as a selective TRPV4 agonist. We investigated NGF-induced hyperalgesia in TRPV4 wild-type (+/+) and knockout (–/–) mice, and the increases in [Ca2+]i produced by 4αPDD in cultured mouse dorsal root ganglia neurons following exposure to NGF. Experimental Approach Withdrawal thresholds to heat, von Frey hairs and pressure were measured in mice before and after systemic administration of NGF. Changes in intracellular Ca2+ concentration were measured by ratiometric imaging with Fura-2 in cultured DRG and trigeminal ganglia (TG) neurons during perfusion of TRPV4 agonists. Key Results Administration of NGF caused a significant sensitization to heat and von Frey stimuli in TRPV4 +/+ and –/– mice, but only TRPV4 +/+ mice showed sensitization to noxious pressure. 4αPDD stimulated a dose-dependent increase in [Ca2+]i in neurons from +/+ and –/– mice, with the proportion of responding neurons and magnitude of increase unaffected by the genotype. In contrast, the selective TRPV4 agonist GSK1016790A failed to stimulate an increase in intracellular Ca2+ in cultured neurons. Responses to 4αPDD were unaffected by pretreatment with NGF. Conclusions and Implications TRPV4 contributes to mechanosensation in vivo, but there is little evidence for functional TRPV4 in cultured DRG and TG neurons. We conclude that 4αPDD activates these neurons independently of TRPV4, so it is not appropriate to refer to 4αPDD as a selective TRPV4 agonist. PMID:22928864

  2. [Cardiovascular medicine in the German diagnosis-related group--(G-DRG) system 2005].

    PubMed

    Fürstenberg, T; Bunzemeier, H; Roeder, N; Reinecke, H

    2005-05-01

    The German diagnosis-related Group (G-DRG) System has recently been published in its third version. From 2005 on, this system will be the definite measure for the budgets of nearly all german hospitals. The preliminary phase with no budget reduction or redistribution being made and in which an inappropriate classification system had no negative impact on reimbursement has, thus, come to an end. At present, many hospitals are struggling in an economic competition about the independence or maintenance of the hospital or several sub-departments. The changes in the classification system with regard to a marked increase in the number of G DRGs, a modified grouping-logic, more properly determined reductions and extra charges for low and high outlier as well as the introduction of further additional charges contribute thereby to a better covering of services and treatments of cardiovascular patients. However, while many of the known problems have been eliminated, there are still weaknesses in the G-DRG System even concerning cardiovascular medicine. The G-DRG System has to be adapted continuously with consultation of the clinical expertise of the respective medical societies. The most important new aspects and changes in the G-DRG System 2005 and the accompanied execution regulations are explained with special view on cardiology.

  3. Non-fibrillar amyloid-{beta} peptide reduces NMDA-induced neurotoxicity, but not AMPA-induced neurotoxicity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Niidome, Tetsuhiro, E-mail: tniidome@pharm.kyoto-u.ac.jp; Goto, Yasuaki; Kato, Masaru

    2009-09-04

    Amyloid-{beta} peptide (A{beta}) is thought to be linked to the pathogenesis of Alzheimer's disease. Recent studies suggest that A{beta} has important physiological roles in addition to its pathological roles. We recently demonstrated that A{beta}42 protects hippocampal neurons from glutamate-induced neurotoxicity, but the relationship between A{beta}42 assemblies and their neuroprotective effects remains largely unknown. In this study, we prepared non-fibrillar and fibrillar A{beta}42 based on the results of the thioflavin T assay, Western blot analysis, and atomic force microscopy, and examined the effects of non-fibrillar and fibrillar A{beta}42 on glutamate-induced neurotoxicity. Non-fibrillar A{beta}42, but not fibrillar A{beta}42, protected hippocampal neurons frommore » glutamate-induced neurotoxicity. Furthermore, non-fibrillar A{beta}42 decreased both neurotoxicity and increases in the intracellular Ca{sup 2+} concentration induced by N-methyl-D-aspartate (NMDA), but not by {alpha}-amino-3-hydrozy-5-methyl-4-isoxazole propionic acid (AMPA). Our results suggest that non-fibrillar A{beta}42 protects hippocampal neurons from glutamate-induced neurotoxicity through regulation of the NMDA receptor.« less

  4. alpha 4 beta 2 subunit combination specific pharmacology of neuronal nicotinic acetylcholine receptors in N1E-115 neuroblastoma cells.

    PubMed

    Zwart, R; Abraham, D; Oortgiesen, M; Vijverberg, H P

    1994-08-22

    Pharmacological characteristics of native neuronal nicotinic acetylcholine receptor-mediated ion currents in mouse N1E-115 neuroblastoma cells have been investigated by superfusion of voltage clamped cells with known concentrations of the agonists acetylcholine, nicotine and cytisine, and the antagonists alpha-bungarotoxin and neuronal bungarotoxin. The sensitivity of the nicotinic acetylcholine receptor for agonists followed the agonist potency rank-order: nicotine approximately acetylcholine > cytisine. The EC50 values of acetylcholine and nicotine are 78 microM and 76 microM, respectively. Equal concentrations of acetylcholine and nicotine induce inward currents with approximately the same peak amplitude whereas cytisine induces much smaller inward currents. Acetylcholine-induced currents are unaffected by high concentrations of alpha-bungarotoxin. Conversely, at 10 and 90 nM neuronal bungarotoxin reduces the amplitude of the 1 mM acetylcholine-induced inward current to 47% and 11% of control values, respectively. Both the agonist potency rank-order and the differential sensitivity to snake toxins of nicotinic receptors in N1E-115 cells are consistent with the known pharmacological profile of alpha 4 beta 2 nicotinic receptors expressed in Xenopus oocytes and distinct from those of all other nicotinic acetylcholine receptors of known functional subunit compositions. All data indicate that the native nicotinic acetylcholine receptor in N1E-115 cells is an assembly of alpha 4 and beta 2 subunits, the putative major subtype of nicotinic acetylcholine receptor in the brain.

  5. Reimbursement of burns by DRG in four European countries: an analysis.

    PubMed

    Lotter, O; Jaminet, P; Amr, A; Chiarello, P; Schaller, H E; Rahmanian-Schwarz, A

    2011-11-01

    To analyze the German, Austrian, Italian and Spanish Diagnosis-Related Group (DRG)-systems regarding burns. We analyzed 78 cases of inpatients with burns which were processed by national DRG-groupers. DRGs were linked to thresholds concerning length of stay as well as reimbursement tables of the respective countries. Fifty-one % of cases showed higher reimbursement in Germany compared to Austria, 55% compared to Italy and 67% as against Spain. Total proceeds are highest in Austria with 1,577,000 €, followed by Italy with 1,569,000 €, Germany with 1,502,000 € and Spain with 902,596 €. No correlation was found between macroeconomic key figures and our data. International comparison of reimbursement of burns by DRG could be a useful instrument for benchmarking while not depending solely on political decisions or country-specific cost data. For better comparability, hospital indices based on healthcare baskets should be discussed. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

  6. Eugenol and carvacrol excite first- and second-order trigeminal neurons and enhance their heat-evoked responses

    PubMed Central

    Klein, Amanda H.; Joe, Christopher L.; Davoodi, Auva; Takechi, Kenichi; Carstens, Mirela Iodi; Carstens, E

    2014-01-01

    Eugenol and carvacrol from clove and oregano, respectively, are agonists of the warmth-sensitive transient receptor potential channel TRPV3 and the irritant-sensitive TRPA1. Eugenol and carvacrol induce oral irritation that rapidly desensitizes, accompanied by brief enhancement of innocuous warmth and heat pain in humans. We presently investigated if eugenol and carvacrol activate nociceptive primary afferent and higher-order trigeminal neurons and enhance their heat-evoked responses, using calcium imaging of cultured trigeminal ganglion (TG) and dorsal root ganglion (DRG) neurons, and in vivo single-unit recordings in trigeminal subnucleus caudalis (Vc) of rats. Eugenol and carvacrol activated 20-30% of TG and 7-20% of DRG cells, the majority of which additionally responded to menthol, mustard oil and/or capsaicin. TG cell responses to innocuous (39°) and noxious (42°C) heating were enhanced by eugenol and carvacrol. We identified dorsomedial Vc neurons responsive to noxious heating of the tongue in pentobarbital-anesthetized rats. Eugenol and carvacrol dose-dependently elicited desensitizing responses in 55% and 73% of heat-sensitive units, respectively. Responses to noxious heat were briefly enhanced by eugenol and carvacrol. Many eugenol- and carvacrol-responsive units also responded to menthol, cinnamaldehyde and capsaicin. These data support a peripheral site for eugenol and carvacrol to enhance warmth- and noxious heat-evoked responses of trigeminal neurons, and are consistent with the observation that these agonists briefly enhance warmth and heat pain on the human tongue. PMID:24759772

  7. The impacts of DRG-based payments on health care provider behaviors under a universal coverage system: a population-based study.

    PubMed

    Cheng, Shou-Hsia; Chen, Chi-Chen; Tsai, Shu-Ling

    2012-10-01

    To examine the impacts of diagnosis-related group (DRG) payments on health care provider's behavior under a universal coverage system in Taiwan. This study employed a population-based natural experiment study design. Patients who underwent coronary artery bypass graft surgery or percutaneous transluminal coronary angioplasty, which were incorporated in the Taiwan version of DRG payments in 2010, were defined as the intervention group. The comparison group consisted of patients who underwent cardiovascular procedures which were paid for by fee-for-services schemes and were selected by propensity score matching from patients treated by the same group of surgeons. The generalized estimating equations model and difference-in-difference analysis was used in this study. The introduction of DRG payment resulted in a 10% decrease (p<0.001) in patient's length of stay in the intervention group in relation to the comparison group. The intensity of care slightly declined with p<0.001. No significant changes were found concerning health care outcomes measured by emergency department visits, readmissions, and mortality after discharge. The DRG-based payment resulted in reduced intensity of care and shortened length of stay. The findings might be valuable to other countries that are developing or reforming their payment system under a universal coverage system. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. [Differential features of DRG 541 readmitting patients].

    PubMed

    López Pérez, J; López Álvarez, J; Montero Ruiz, E

    2015-01-01

    Hospital readmission is considered an adverse outcome, and the hospital readmission ratio is an indicator of health care quality. Published studies show a wide variability and heterogeneity, with large groups of patients with different diagnoses and prognoses. The aim of the study was to analyse the differences between patients readmitted and those who were not, in patients grouped into the diagnosis related group (DRG) 541. A retrospective observational study was conducted on DRG 541 patients discharged in 2010. Readmission is defined as any admission into any hospital department, and for any reason at ≤30 days from discharge. An analysis was performed that included age, sex, day of discharge, month of discharge, number of diagnoses and drugs at discharge, respiratory depressant drugs, length of stay, requests for consultations/referrals, Charlson comorbidity index, feeding method, hospitalisations in the previous 6 months, albumin and haemoglobin levels and medical examinations within 30 days after discharge. Of the 985 patients included in the study, 189 were readmitted. On multivariate analysis, significant variables were: Haemoglobin -0.6g/dl (95% confidence interval [95%CI] -0.9 to -0.3), gastrostomy feeding odds ratio (OR) 5.6 (95%CI: 1.5 to 21.6), hospitalisations in previous 6 months OR 1.9 (95%CI: 1.3 to 2.8), visits to emergency department OR 17.4 (95%CI: 11.3 to 26.8), medical checks after discharge OR 0.4 (95%CI: 0.2 to 0.8). DRG 541 readmitting patients have some distinctive features that could allow early detection and prevent hospital readmission. Copyright © 2015 SECA. Published by Elsevier Espana. All rights reserved.

  9. [Effects of self-adapting G-DRG system 2004 to 2006 on in-patient services payment in pediatric hematology and oncology patients of a university hospital].

    PubMed

    Christaras, A; Schaper, J; Strelow, H; Laws, H-J; Göbel, U

    2006-01-01

    Reimbursement of inpatient treatment by daily constant charges is replaced by diagnosis- and procedure-related group system (G-DRG) in German acute care hospitals excerpt for psychiatry since 2004. Re-designs of G-DRG system were undertaken in 2005 and 2006. Parallel to implementation requirement- and resource-based self-adjustment of this new reimbursement system has been established by law. Adjustments performed in 2005 and 2006 are examined with respect to their effect on reimbursements in treatments of children with oncological, hematological, and immunological diseases. An unchanged population of 349 patients associated with 1,731 inpatient stays of a Clinic of Pediatric Oncology, Hematology, and Immunology in 2004 was analyzed by methods and means of G-DRG systems 2004, 2005, and 2006. DRGs and additional payments for drugs and procedures eligible for all and/or individual hospitals were calculated. G-DRG system 2005 resulted in overall reimbursement loss of 3.77 % compared to G-DRG 2004. G-DRG 2006 leads to slightly improved overall reimbursements compared to G-DRG 2005 by increasing DRG-based revenues. G-DRG 2006 effects 2.40 % reduction in overall reimbursement compared to G-DRG 2004. This loss includes ameliorating effects of additional payments for drugs and blood products already. Despite introduction of additional payments especially designed for children and teenagers in 2006, additional payment volume is decreased by 21.71 % from 2005 to 2006. G-DRG 2006 yields over-all reimbursement losses of 1.45 % in comparison to G-DRG 2004. Overall reimbursements include introduced additional payments for drugs and blood products. (Reimbursements resulting out of DRG payment alone drop by 14.73 % from 2004 to 2005, and increase by 3.26 % from 2005 to 2006 (2004 vs. 2006 11.95 %). Introduction of additional payments for drugs and blood products on a Germany-wide basis introduced in 2005 dampens DRG-based reimbursement losses. Despite introduction of dosage

  10. The use of DRG for identifying clinical trials centers with high recruitment potential: a feasability study.

    PubMed

    Aegerter, Philippe; Bendersky, Noelle; Tran, Thi-Chien; Ropers, Jacques; Taright, Namik; Chatellier, Gilles

    2014-01-01

    Recruitment of large samples of patients is crucial for evidence level and efficacy of clinical trials (CT). Clinical Trial Recruitment Support Systems (CTRSS) used to estimate patient recruitment are generally specific to Hospital Information Systems and few were evaluated on a large number of trials. Our aim was to assess, on a large number of CT, the usefulness of commonly available data as Diagnosis Related Groups (DRG) databases in order to estimate potential recruitment. We used the DRG database of a large French multicenter medical institution (1.2 million inpatient stays and 400 new trials each year). Eligibility criteria of protocols were broken down into in atomic entities (diagnosis, procedures, treatments...) then translated into codes and operators recorded in a standardized form. A program parsed the forms and generated requests on the DRG database. A large majority of selection criteria could be coded and final estimations of number of eligible patients were close to observed ones (median difference = 25). Such a system could be part of the feasability evaluation and center selection process before the start of the clinical trial.

  11. Characterization of human dopamine responsive protein DRG-1 that binds to p75NTR-associated cell death executor NADE.

    PubMed

    Yu, Yao; Wang, Jiadong; Yuan, Hanying; Qin, Feng; Wang, Jing; Zhang, Nailing; Li, Yu-Yang; Liu, Jianping; Lu, Hong

    2006-07-19

    Expression of human dopamine responsive gene-1 (DRG-1) is up-regulated in response to treatment of dopamine in the rat astrocytes. However, its functions are not clear up to now. In the presented studies, DRG-1 was identified to be a conserved gene in the vertebrate and expressed abundantly in human testis, brain and skeletal muscle. DRG-1 was shown to interact with human p75NTR-associated cell death executor (NADE) in vivo and in vitro, and the interaction occurred in cytoplasm. The regions required for the interaction were subsequently mapped to the N-terminal of DRG-1 and the C-terminal of NADE. Furthermore, MTT assay showed that stable expression of DRG-1 in 293 cells could promote cell proliferation, and this promotion was suppressed by overexpression of NADE. In flow cytometry cell cycle analysis, overexpression of DRG-1 in 293 or PC12 cells increased the population of cells in the S phase with a concomitant decrease in G0/G1 population. These findings suggest that DRG-1 may contribute to the dopamine-induced cell growth, which is negatively regulated by NADE.

  12. [Insufficient funding of nursing service in paediatrics. The case of the DRG E77C].

    PubMed

    Herrmann, René; Fusch, Christoph; Flessa, Steffen

    2008-09-01

    For most of the existing German Diagnosis Related Groups (G-DRG) the German generalised compensation system for medical services in hospitals does not distinguish between children and adults. There is a risk of the cost of high-maintenance paediatric patients not being covered. This problem is tried to be solved by implementing a split based on the patient's age. Thus children under the age of one year will be classified to a different DRG than older patients with the same diagnosis. A study of working time combined with an analysis of the so-called "Pflegepersonalregelung-Minuten" carried out by the Ernst-Moritz-Arndt University of Greifswald exemplarily shows the different intenseness of care between paediatric and adult patients. Furthermore, the different intenseness of care correlates with the labour cost of the university hospital and shows the extensions of the shortfall for the most profitable DRG based on guidelines of the "Institut für das Entgeltsystem im Krankenhaus" (Institute for the compensation system in hospitals, InEK). Last but not least it discusses if the age-splitting planned for the 2008 DRG-Catalogue might improve the financial situation. Moreover the authors point out possibilities for a proper compensation for paediatrics in the G-DRG system.

  13. Physicians' Patient Load per DRG, the Consumption of Hospital Resources, and the Incentives of the DRG Prospective Payment System.

    ERIC Educational Resources Information Center

    Munoz, Eric; And Others

    1990-01-01

    The relationship between numbers (high or low) of patients per diagnosis-related group (DRG) treated by individual physicians and hospital resource consumption of the patients at a large academic medical center was studied for the period 1985-87. The findings, although a result of many varied factors, suggest a relationship between the two…

  14. [How does the German DRG system differentiate and reimburse vitreoretinal surgery in diabetic patients?].

    PubMed

    Krause, M; Goldschmidt, A J; Berg, M; Kropf, S; Sachs, A; Gatzioufas, Z; Brückner, K; Seitz, B

    2008-10-01

    The German DRG system (G-DRG system) is required to assign medical cases with similar costs correctly into a particular group, each case within the group receiving the same amount of reimbursement. At the same time the system should allow all-inclusive reimbursement, not necessarily reflecting the exact costs of each case. These opposite goals and the so far limited calculation basis raise the question of how the G-DRG system actually processes and reimburses empirically collected in-hospital treatment data. In 2005, 112 patients were admitted to the University Eye Hospital, University of the Saarland. All patients had diabetic retinopathy and required at least one vitreoretinal procedure. Demographic and clinical data were collected by using the hospital information system and the coding software KODIP. For statistic evaluation, principal diagnoses, ancillary diagnoses and procedures were each reassigned to particular groups. Reimbursement was calculated based on the case data of the year 2005. Also, the case data were reassigned with respect to calculation of reimbursement for the years 2006 and 2007. The results were compared with federal G-DRG calculation data. Mean age of the patients was 65.8 +/- 11.1 years, length of stay in-hospital was 9.3 +/- 3.2 days. In the 66 patients requiring general anaesthesia the cumulative length of stay in the operation room was 148.4 +/- 39.5 minutes, the cumulative duration of surgery was 86.3 +/- 34.1 minutes. In the 50 patients requiring local anaesthesia the cumulative length of stay in the operation room was 137.8 +/- 51.8 minutes, the cumulative duration of surgery was 81.6 +/- 43.6 minutes. The patients had 1.9 +/- 0.8 principal diagnoses, 14.4 +/- 5.8 ancillary diagnoses and 3.4 +/- 1.6 procedures. Twenty-five of 112 patients (22.3 %) were assigned to DRG C 03Z (1), 82 of 112 patients (73.2 %) were assigned to DRG C 17Z (2). Five patients were assigned to other DRG. Compared with the federal calculation data, our own

  15. DRG Spinal Cord Stimulation as Solution for Patients With Severe Pain Due to Anterior Cutaneous Nerve Entrapment Syndrome: A Case Series.

    PubMed

    Mol, Frédérique Mathilde Ulrike; Roumen, Rudi M H

    2018-04-01

    Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) is a debilitating neuropathic pain condition. A small portion of patients do not respond to any currently available treatment modalities. These patients, often young women, might benefit from targeted spinal cord stimulation of the dorsal root ganglion (DRG). This retrospective case series describes five ACNES patients who were referred from a Dutch dedicated tertiary referral center to collaborating sites with extensive experience in DRG stimulation to be implanted with a DRG Axium System (St. Jude/Abbott, IL, USA) in the period of 2013-2016. Numeric pain rating scores at routine 6- and 12-month follow-up visits were analyzed. Three patients experienced >50% pain reduction at 12 months follow-up. Four patients experienced device-related complications, such as lead dislocation, lead breakage, pain at the battery site, and overstimulation. This case series suggests DRG spinal cord stimulation can be safe and effective for some patients with persistent pain due to ACNES. © 2017 International Neuromodulation Society.

  16. Engineering PCL/lignin nanofibers as an antioxidant scaffold for the growth of neuron and Schwann cell.

    PubMed

    Wang, Jing; Tian, Lingling; Luo, Baiwen; Ramakrishna, Seeram; Kai, Dan; Loh, Xian Jun; Yang, In Hong; Deen, G Roshan; Mo, Xiumei

    2018-05-12

    Antioxidant is critical for the successful of nerve tissue regeneration, and biomaterials with antioxidant activity might be favorable for peripheral nerve repair. Lignin, a biopolymer from wood with excellent antioxidant properties, is still "unexplored" as biomaterials. To design an antioxidative bioscaffold for nerve regeneration, here we synthesized lignin-polycaprolactone (PCL) copolymers via solvent free ring-opening polymerization (ROP). Then such lignin-PCL copolymers were incorporated with PCL and engineered into nanofibrous scaffolds for supporting the growth of neuron and Schwann cell. Our results showed that the addition of lignin-PCL enhanced the mechanical properties of PCL nanofibers and endowed them with good antioxidant properties (up to 98.3 ± 1.9% free radical inhibition within 4 h). Cell proliferation assay showed that PCL/lignin-PCL nanofibers increased cell viability compared to PCL fibers, especially after an oxidative challenge. Moreover, Schwann cells and dorsal root ganglion (DRG) neurons cultured on the nanofibers to assess their potential for nerve regeneration. These results suggested that nanofibers with lignin copolymers promoted cell proliferation of both BMSCs and Schwann cells, enhanced myelin basic protein expressions of Schwann cells and stimulated neurite outgrowth of DRG neurons. In all, these sustainable, intrinsically antioxidant nanofibers may be a potential candidate for nerve TE applications. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. The Distributions of Voltage-Gated K+ current Subtypes in Different Cell Sizes from Adult Mouse Dorsal Root Ganglia.

    PubMed

    Sheng, Anqi; Hong, Jiangru; Zhang, Lulu; Zhang, Yan; Zhang, Guangqin

    2018-03-29

    Voltage-gated K + (K V ) currents play a crucial role in regulating pain by controlling neuronal excitability, and are divided into transient A-type currents (I A ) and delayed rectifier currents (I K ). The dorsal root ganglion (DRG) neurons are heterogeneous and the subtypes of K V currents display different levels in distinct cell sizes. To observe correlations of the subtypes of K V currents with DRG cell sizes, K V currents were recorded by whole-cell patch clamp in freshly isolated mouse DRG neurons. Results showed that I A occupied a high proportion in K V currents in medium- and large-diameter DRG neurons, whereas I K possessed a larger proportion of K V currents in small-diameter DRG neurons. A lower correlation was found between the proportion of I A or I K in K V currents and cell sizes. These data suggest that I A channels are mainly expressed in medium and large cells and I K channels are predominantly expressed in small cells.

  18. Regulation of voltage-gated Ca(2+) currents by Ca(2+)/calmodulin-dependent protein kinase II in resting sensory neurons.

    PubMed

    Kostic, Sandra; Pan, Bin; Guo, Yuan; Yu, Hongwei; Sapunar, Damir; Kwok, Wai-Meng; Hudmon, Andy; Wu, Hsiang-En; Hogan, Quinn H

    2014-09-01

    Calcium/calmodulin-dependent protein kinase II (CaMKII) is recognized as a key element in encoding depolarization activity of excitable cells into facilitated voltage-gated Ca(2+) channel (VGCC) function. Less is known about the participation of CaMKII in regulating VGCCs in resting cells. We examined constitutive CaMKII control of Ca(2+) currents in peripheral sensory neurons acutely isolated from dorsal root ganglia (DRGs) of adult rats. The small molecule CaMKII inhibitor KN-93 (1.0μM) reduced depolarization-induced ICa by 16-30% in excess of the effects produced by the inactive homolog KN-92. The specificity of CaMKII inhibition on VGCC function was shown by the efficacy of the selective CaMKII blocking peptide autocamtide-2-related inhibitory peptide in a membrane-permeable myristoylated form, which also reduced VGCC current in resting neurons. Loss of VGCC currents is primarily due to reduced N-type current, as application of mAIP selectively reduced N-type current by approximately 30%, and prior N-type current inhibition eliminated the effect of mAIP on VGCCs, while prior block of L-type channels did not reduce the effect of mAIP on total ICa. T-type currents were not affected by mAIP in resting DRG neurons. Transduction of sensory neurons in vivo by DRG injection of an adeno-associated virus expressing AIP also resulted in a loss of N-type currents. Together, these findings reveal a novel molecular adaptation whereby sensory neurons retain CaMKII support of VGCCs despite remaining quiescent. Published by Elsevier Inc.

  19. Dynamic Expression of Serotonin Receptor 5-HT3A in Developing Sensory Innervation of the Lower Urinary Tract

    PubMed Central

    Ritter, K. Elaine; Southard-Smith, E. Michelle

    2017-01-01

    Sensory afferent signaling is required for normal function of the lower urinary tract (LUT). Despite the wide prevalence of bladder dysfunction and pelvic pain syndromes, few effective treatment options are available. Serotonin receptor 5-HT3A is a known mediator of visceral afferent signaling and has been implicated in bladder function. However, basic expression patterns for this gene and others among developing bladder sensory afferents that could be used to inform regenerative efforts aimed at treating deficiencies in pelvic innervation are lacking. To gain greater insight into the molecular characteristics of bladder sensory innervation, we conducted a thorough characterization of Htr3a expression in developing and adult bladder-projecting lumbosacral dorsal root ganglia (DRG) neurons. Using a transgenic Htr3a-EGFP reporter mouse line, we identified 5-HT3A expression at 10 days post coitus (dpc) in neural crest derivatives and in 12 dpc lumbosacral DRG. Using immunohistochemical co-localization we observed Htr3a-EGFP expression in developing lumbosacral DRG that partially coincides with neuropeptides CGRP and Substance P and capsaicin receptor TRPV1. A majority of Htr3a-EGFP+ DRG neurons also express a marker of myelinated Aδ neurons, NF200. There was no co-localization of 5-HT3A with the TRPV4 receptor. We employed retrograde tracing in adult Htr3a-EGFP mice to quantify the contribution of 5-HT3A+ DRG neurons to bladder afferent innervation. We found that 5-HT3A is expressed in a substantial proportion of retrograde traced DRG neurons in both rostral (L1, L2) and caudal (L6, S1) axial levels that supply bladder innervation. Most bladder-projecting Htr3a-EGFP+ neurons that co-express CGRP, Substance P, or TRPV1 are found in L1, L2 DRG, whereas Htr3a-EGFP+, NF200+ bladder-projecting neurons are from the L6, S1 axial levels. Our findings contribute much needed information regarding the development of LUT innervation and highlight the 5-HT3A serotonin receptor as

  20. [Changes to diagnosis-related groups in urology in 2007. Urology in the G-DRG-System 2007].

    PubMed

    Wenke, A; Franz, D; Pühse, G; Hertle, L; Roeder, N

    2008-02-01

    The German DRG (dose-related groups) system is updated each year by the institution dealing with the remuneration in hospitals (InEK). Once again, the German Spcoety for Urology has supported the adjustment process in a constructive manner. Analysis of the changes and their implications is highly significant for urology. This article describes and discusses the main changes in the system for the specialty of urology insofar as they concern the structure of the DRG system and the catalogues of diagnoses (ICD) and of procedures (OPS). The 2007 edition of the DRG system leads to numerous changes for urology. There are new OPS codes for partial resection of the kidney, treatment of urinary incontinence and radical resection in the pelvis minor. Additional payment for implantation of a prosthetic penis is divided with reference to the type of prosthesis. At DRG level, new DRG splits are found depending on the PCCL and patient age. Combination operations on the bladder and bowel and on the male genitalia are assigned to newly established DRGs. The changes described enhance the professional accuracy of the representations of urological care provision. New strategies designed to solve problems in representation have been established (e.g. multi-step interventions). Various problems persist, e.g. those of operations on the penis (DRG M03Z) and the need for more finely defined representation of laser treatment in urology. In the short term practicable solutions to the problem of improving the quality of representation are needed.

  1. [Evaluation of the capacity of the APR-DRG classification system to predict hospital mortality].

    PubMed

    De Marco, Maria Francesca; Lorenzoni, Luca; Addari, Piero; Nante, Nicola

    2002-01-01

    Inpatient mortality has increasingly been used as an hospital outcome measure. Comparing mortality rates across hospitals requires adjustment for patient risks before making inferences about quality of care based on patient outcomes. Therefore it is essential to dispose of well performing severity measures. The aim of this study is to evaluate the ability of the All Patient Refined DRG system to predict inpatient mortality for congestive heart failure, myocardial infarction, pneumonia and ischemic stroke. Administrative records were used in this analysis. We used two statistics methods to assess the ability of the APR-DRG to predict mortality: the area under the receiver operating characteristics curve (referred to as the c-statistic) and the Hosmer-Lemeshow test. The database for the study included 19,212 discharges for stroke, pneumonia, myocardial infarction and congestive heart failure from fifteen hospital participating in the Italian APR-DRG Project. A multivariate analysis was performed to predict mortality for each condition in study using age, sex and APR-DRG risk mortality subclass as independent variables. Inpatient mortality rate ranges from 9.7% (pneumonia) to 16.7% (stroke). Model discrimination, calculated using the c-statistic, was 0.91 for myocardial infarction, 0.68 for stroke, 0.78 for pneumonia and 0.71 for congestive heart failure. The model calibration assessed using the Hosmer-Leme-show test was quite good. The performance of the APR-DRG scheme when used on Italian hospital activity records is similar to that reported in literature and it seems to improve by adding age and sex to the model. The APR-DRG system does not completely capture the effects of these variables. In some cases, the better performance might be due to the inclusion of specific complications in the risk-of-mortality subclass assignment.

  2. Knockdown of sodium channel NaV1.6 blocks mechanical pain and abnormal bursting activity of afferent neurons in inflamed sensory ganglia

    PubMed Central

    Xie, Wenrui; Strong, Judith A.; Ye, Ling; Mao, Ju-Xian; Zhang, Jun-Ming

    2013-01-01

    Inflammatory processes in the sensory ganglia contribute to many forms of chronic pain. We previously showed that local inflammation of the lumbar sensory ganglia rapidly leads to prolonged mechanical pain behaviors and high levels of spontaneous bursting activity in myelinated cells. Abnormal spontaneous activity of sensory neurons occurs early in many preclinical pain models, and initiates many other pathological changes, but its molecular basis is not well understood. The sodium channel isoform NaV1.6 can underlie repetitive firing and excitatory persistent and resurgent currents. We used in vivo knockdown of this channel via local injection of siRNA to examine its role in chronic pain following local inflammation of the rat lumbar sensory ganglia. In normal DRG, quantitative PCR showed that cells capable of firing repetitively had significantly higher relative expression of NaV1.6. In inflamed DRG, spontaneously active bursting cells expressed high levels of NaV1.6′ immunoreactivity. In vivo knockdown of NaV1.6 locally in the lumbar DRG at the time of DRG inflammation completely blocked development of pain behaviors and abnormal spontaneous activity, while having only minor effects on unmyelinated C-cells. Current research on isoform-specific sodium channel blockers for chronic pain is largely focused on NaV1.8, because it is present primarily in unmyelinated C fiber nociceptors, or on NaV1.7, because lack of this channel causes congenital indifference to pain. However, the results suggest that NaV1.6 may be a useful therapeutic target for chronic pain, and that some pain conditions may be primarily mediated by myelinated A-fiber sensory neurons. PMID:23622763

  3. Effects of harmane (1-methyl-beta-carboline) on neurons in the nucleus accumbens of the rat.

    PubMed

    Ergene, E; Schoener, E P

    1993-04-01

    Harmane, a beta-carboline alkaloid reported to exert locomotor and psychoactive effects, is found in certain plants and also has been shown to exist in the mammalian brain as an endogenous substance. In this study, the effects of locally perfused harmane were examined on spontaneous neuronal activity in the nucleus accumbens of urethane-anesthetized rats. Extracellular single-unit recording, coupled with push-pull perfusion, enabled the discrimination of specific, dose-related effects of harmane across a wide concentration range. At lower concentrations (10(-9)-10(-11) M), excitation prevailed, while at higher concentrations (10(-8)-10(-6) M) depression was most pronounced. These findings suggest a neuromodulatory role for harmane in the forebrain reward system.

  4. Glial cells isolated from dorsal root ganglia express prostaglandin E(2) (EP(4)) and prostacyclin (IP) receptors.

    PubMed

    Ng, Kai Yu; Wong, Yung Hou; Wise, Helen

    2011-07-01

    Isolated cells from adult rat dorsal root ganglia (DRG) are frequently used as a model system to study responses of primary sensory neurons to nociceptor sensitizing agents such as prostaglandin E(2) and prostacyclin, which are presumed to act only on the neurons in typical mixed cell cultures. In the present study, we evaluated the expression of prostaglandin E(2) (EP(4)) and prostacyclin (IP) receptors in cultures of mixed DRG cells and in purified DRG glia. We show here that EP(4) and IP receptor agonists stimulated adenylyl cyclase activity in both mixed DRG cells and in purified DRG glia, and that these responses were specifically inhibited by EP(4) and IP receptor antagonists, respectively. The presence of EP(4) and IP receptors in DRG glia was further confirmed by the expression of EP(4) and IP receptor immunoreactivity and mRNA. With the increasing awareness of neuron-glial interactions within intact DRG and the use of isolated DRG cells in the study of mechanisms underlying nociception, it will be essential to consider the role played by EP(4) and IP receptor-expressing glial cells when evaluating prostanoid-induced sensitization of DRG neurons. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. [Changing the internal cost allocation (ICA) on DRG shares : Example of computed tomography in a university radiology setting].

    PubMed

    Wirth, K; Zielinski, P; Trinter, T; Stahl, R; Mück, F; Reiser, M; Wirth, S

    2016-08-01

    In hospitals, the radiological services provided to non-privately insured in-house patients are mostly distributed to requesting disciplines through internal cost allocation (ICA). In many institutions, computed tomography (CT) is the modality with the largest amount of allocation credits. The aim of this work is to compare the ICA to respective DRG (Diagnosis Related Groups) shares for diagnostic CT services in a university hospital setting. The data from four CT scanners in a large university hospital were processed for the 2012 fiscal year. For each of the 50 DRG groups with the most case-mix points, all diagnostic CT services were documented including their respective amount of GOÄ allocation credits and invoiced ICA value. As the German Institute for Reimbursement of Hospitals (InEK) database groups the radiation disciplines (radiology, nuclear medicine and radiation therapy) together and also lacks any modality differentiation, the determination of the diagnostic CT component was based on the existing institutional distribution of ICA allocations. Within the included 24,854 cases, 63,062,060 GOÄ-based performance credits were counted. The ICA relieved these diagnostic CT services by € 819,029 (single credit value of 1.30 Eurocent), whereas accounting by using DRG shares would have resulted in € 1,127,591 (single credit value of 1.79 Eurocent). The GOÄ single credit value is 5.62 Eurocent. The diagnostic CT service was basically rendered as relatively inexpensive. In addition to a better financial result, changing the current ICA to DRG shares might also mean a chance for real revenues. However, the attractiveness considerably depends on how the DRG shares are distributed to the different radiation disciplines of one institution.

  6. [Consistency and Reliability of MDK Expertise Examining the Encoding in the German DRG System].

    PubMed

    Gaertner, T; Lehr, F; Blum, B; van Essen, J

    2015-09-01

    Hospital inpatient stays are reimbursed on the basis of German diagnosis-related groups (G-DRG). The G-DRG classification system is based on complex coding guidelines. The Medical Review Board of the Statutory Health Insurance Funds (MDK) examines the encoding by hospitals and delivers individual expertises on behalf of the German statutory health insurance companies in cases in which irregularities are suspected. A study was conducted on the inter-rater reliability of the MDK expertises regarding the scope of the assessment. A representative sample of 212 MDK expertises was taken from a selected pool of 1 392 MDK expertises in May 2013. This representative sample underwent a double-examination by 2 independent MDK experts using a special software based on the 3MTM G-DRG Grouper 2013 of 3M Medica, Germany. The following items encoded by the hospitals were examined: DRG, principal diagnosis, secondary diagnoses, procedures and additional payments. It was analysed whether the results of MDK expertises were consistent, reliable and correct. 202 expertises were eligible for evaluation, containing a total of 254 questions regarding one or more of the 5 items encoded by hospitals. The double-examination by 2 independent MDK experts showed matching results in 187 questions (73.6%) meaning they had been examined consistently and correctly. 59 questions (23.2%) did not show matching results, nevertheless they had been examined correctly regarding the scope of the assessment. None of the principal diagnoses was significantly affected by inconsistent or wrong judgment. A representative sample of MDK expertises examining the DRG encoding by hospitals showed a very high percentage of correct examination by the MDK experts. Identical MDK expertises cannot be achieved in all cases due to the scope of the assessment. Further improvement and simplification of codes and coding guidelines are required to reduce the scope of assessment with regard to correct DRG encoding and its

  7. Inhibition of acid-sensing ion channels by levo-tetrahydropalmatine in rat dorsal root ganglion neurons.

    PubMed

    Liu, Ting-Ting; Qu, Zu-Wei; Qiu, Chun-Yu; Qiu, Fang; Ren, Cuixia; Gan, Xiong; Peng, Fang; Hu, Wang-Ping

    2015-02-01

    Levo-tetrahydropalmatine (l-THP), a main bioactive Chinese herbal constituent from the genera Stephania and Corydalis, has been in use in clinical practice for years in China as a traditional analgesic agent. However, the mechanism underlying the analgesic action of l-THP is poorly understood. This study shows that l-THP can exert an inhibitory effect on the functional activity of native acid-sensing ion channels (ASICs), which are believed to mediate pain caused by extracellular acidification. l-THP dose dependently decreased the amplitude of proton-gated currents mediated by ASICs in rat dorsal root ganglion (DRG) neurons. l-THP shifted the proton concentration-response curve downward, with a decrease of 40.93% ± 8.45% in the maximum current response to protons, with no significant change in the pH0.5 value. Moreover, l-THP can alter the membrane excitability of rat DRG neurons to acid stimuli. It significantly decreased the number of action potentials and the amplitude of the depolarization induced by an extracellular pH drop. Finally, peripherally administered l-THP inhibited the nociceptive response to intraplantar injection of acetic acid in rats. These results indicate that l-THP can inhibit the functional activity of ASICs in dissociated primary sensory neurons and relieve acidosis-evoked pain in vivo, which for the first time provides a novel peripheral mechanism underlying the analgesic action of l-THP. © 2014 Wiley Periodicals, Inc.

  8. Role of sodium ferulate in the nociceptive sensory facilitation of neuropathic pain injury mediated by P2X(3) receptor.

    PubMed

    Zhang, Aixia; Xu, Changshui; Liang, Shangdong; Gao, Yun; Li, Guilin; Wei, Jie; Wan, Fang; Liu, Shuangmei; Lin, Jiari

    2008-12-01

    Neuropathic pain usually is persistent and no effective treatment. ATP plays an important role in the initiation of pain. P2X(3) receptors are localized in the dorsal root ganglion (DRG) neurons and activated by extracellular ATP. Sodium ferulate (SF) is an active principle from Chinese herbal medicine and has anti-inflammatory activities. This study observed the effects of SF on the nociceptive facilitation of the primary sensory afferent after chronic constriction injury (CCI) mediated by P2X(3) receptor. In this study, the content of ATP in DRG neurons was measured by high-performance liquid chromatography (HPLC). P2X(3) agonist-activated currents in DRG neurons was recorded by the whole-cell patch-clamp skill. The expression of P2X(3) mRNA in DRG neurons was analyzed by in situ hybridization. The ATP content of DRG was increased after CCI. In CCI rats treated with SF, the content of ATP in DRG neurons was reduced. SF decreased the increment of P2X(3) agonist-activated currents and P2X(3) mRNA expression in DRG neurons during CCI. SF may inhibit the initiation of pain and primary afferent sensitization mediated by P2X(3) receptor during CCI.

  9. The properties, distribution and function of Na+–Ca2+ exchanger isoforms in rat cutaneous sensory neurons

    PubMed Central

    Scheff, N N; Yilmaz, E; Gold, M S

    2014-01-01

    The Na+–Ca2+ exchanger (NCX) appears to play an important role in the regulation of the high K+-evoked Ca2+ transient in putative nociceptive dorsal root ganglion (DRG) neurons. The purpose of the present study was to (1) characterize the properties of NCX activity in subpopulations of DRG neurons, (2) identify the isoform(s) underlying NCX activity, and (3) begin to assess the function of the isoform(s) in vivo. In retrogradely labelled neurons from the glabrous skin of adult male Sprague–Dawley rats, NCX activity, as assessed with fura-2-based microfluorimetry, was only detected in putative nociceptive IB4+ neurons. There were two modes of NCX activity: one was evoked in response to relatively large and long lasting (∼325 nm for >12 s) increases in the concentration of intracellular Ca2+ ([Ca2+]i), and a second was active at resting [Ca2+]i > ∼150 nm. There also were two modes of evoked activity: one that decayed relatively rapidly (<5 min) and a second that persisted (>10 min). Whereas mRNA encoding all three NCX isoforms (NCX1–3) was detected in putative nociceptive cutaneous neurons with single cell PCR, pharmacological analysis and small interfering RNA (siRNA) knockdown of each isoform in vivo suggested that NCX2 and 3 were responsible for NCX activity. Western blot analyses suggested that NCX isoforms were differentially distributed within sensory neurons. Functional assays of excitability, action potential propagation, and nociceptive behaviour suggest NCX activity has little influence on excitability per se, but instead influences axonal conduction velocity, resting membrane potential, and nociceptive threshold. Together these results indicate that the function of NCX in the regulation of [Ca2+]i in putative nociceptive neurons may be unique relative to other cells in which these exchanger isoforms have been characterized and it has the potential to influence sensory neuron properties at multiple levels. PMID:25239455

  10. [The German DRG system and its effect on imaging quality in ENT, and head and neck surgery].

    PubMed

    Franz, D; Roeder, N; Hörmann, K; Alberty, J

    2006-04-01

    The new G-DRG system for 2006 was published in September 2005. This article presents, analyses, and comments essential changes in the G-DRG system for 2006 and their consequences for ENT-Medicine. The complexity of the G-DRG system has increased significantly. In 2006, the case allocation will be more differentiated for common surgical procedures on the middle ear, nose, paranasal sinuses, salivary glands, and for head and neck cancer. Furthermore, the patient's age and the clinical and complexity level (PCCL) will be of increased relevance in selected case constellations. However, diagnostic endoscopies with rigid instruments will still not be regarded as OR procedures. Essential adjustments proposed by the German Association for ENT Medicine (DGHNOKHC) and the ENT Medical Professional Association (HNO-Berufsverband) have been made, and the quality of case allocation of ENT-patients within the G-DRG system improved. Nevertheless, further adjustments to the G-DRG system are necessary.

  11. [Comparison of hand surgery in the German and Italian DRG systems].

    PubMed

    Lotter, O; Dolderer, J; Stahl, S; Atzei, A; Haerle, M; Schaller, H E

    2011-12-01

    Diagnosis-related groups (DRGs) are a patient classification system grouping related types of patients treated to the resources they consumed. In this analysis we compared the Italian and the German DRG systems regarding hand surgery with an emphasis on reimbursement of clinical cases. The 15 most common hand surgical diagnoses and their corresponding operative treatment in our clinic in 2009 were processed using a DRG grouper. The underlying data were transferred to the Italian system. Thus, the length of stay and the reimbursement of both countries could be obtained and compared. The latter was adjusted and corrected by the purchasing power of each country. The mean of the upper threshold of length of stay was 10 days in the German as well as the Italian system whereas the median was 2 times higher in Italy (6 vs. 12 days). Fifteen out of 19 cases showed higher reimbursement in Germany. The case mix index (CMI) of 0.917 in Germany represents a mean payment of 2,676 € per case. In Italy the hypothetical CMI of 0.635 resulted in a mean reimbursement of 1,853 € per case. The biggest difference in remuneration could be found for replantation of multiple fingers. For this service the German health-care system pays 12,320 € more than the Italian. Total proceeds of the top 15 diagnoses applying the number of cases treated in our clinic revealed 1.7 million € in the German and 1.2 million € in the Italian DRG system. Considering the purchasing power utilizing consumer prize parities, the difference of reimbursement between the countries decreased to 300,000 €. There is no mean length of stay per DRG in Italy, only the upper threshold of length of stay is determined. In most cases the latter is higher in Italy compared to Germany. The consumption of resources for finger replantation is not adequately represented in the Italian DRG system compared to finger amputation. Reimbursement of inpatient care is influenced by multiple factors not being subject

  12. Intracellular chloride regulation in amphibian dorsal root ganglion neurones studied with ion-selective microelectrodes.

    PubMed Central

    Alvarez-Leefmans, F J; Gamiño, S M; Giraldez, F; Noguerón, I

    1988-01-01

    1. Intracellular Cl- activity (aiCl) and membrane potential (Em) were measured in frog dorsal root ganglion neurones (DRG neurones) using double-barrelled Cl- -selective microelectrodes. In standard Ringer solution buffered with HEPES (5 mM), equilibrated with air or 100% O2, the resting membrane potential was -57.7 +/- 1.0 mV and aiCl was 23.6 +/- 1.0 mM (n = 53). The value of aiCl was 2.6 times the activity expected for an equilibrium distribution and the difference between Em and ECl was 25 mV. 2. Removal of external Cl- led to a reversible fall in aiCl. Initial rates of decay and recovery of aiCl were 4.1 and 3.3 mM min-1, respectively. During the recovery of aiCl following return to standard Ringer solution, most of the movement of Cl- occurred against the driving force for a passive distribution. Changes in aiCl were not associated with changes in Em. Chloride fluxes estimated from initial rates of change in aiCl when external Cl- was removed were too high to be accounted for by electrodiffusion. 3. The intracellular accumulation of Cl- was dependent on the extracellular Cl- activity (aoCl). The relationship between aiCl and aoCl had a sigmoidal shape with a half-maximal activation of about 50 mM-external Cl-. 4. The steady-state aiCl depended on the simultaneous presence of extracellular Na+ and K+. Similarly, the active reaccumulation of Cl- after intracellular Cl- depletion was abolished in the absence of either Na+ or K+ in the bathing solution. 5. The reaccumulation of Cl- was inhibited by furosemide (0.5-1 x 10(-3) M) or bumetanide (10(-5) M). The decrease in aiCl observed in Cl- -free solutions was also inhibited by bumetanide. 6. Cell volume changes were calculated from the observed changes in aiCl. Cells were estimated to shrink in Cl- -free solutions to about 75% their initial volume, at an initial rate of 6% min-1. 7. The present results provide direct evidence for the active accumulation of Cl- in DRG neurones. The mechanism of Cl- transport is

  13. Glycogen synthase kinase 3 beta alters anxiety-, depression-, and addiction-related behaviors and neuronal activity in the nucleus accumbens shell

    PubMed Central

    Crofton, Elizabeth J.; Nenov, Miroslav N.; Zhang, Yafang; Scala, Federico; Page, Sean A.; McCue, David L.; Li, Dingge; Hommel, Jonathan D.; Laezza, Fernanda; Green, Thomas A.

    2017-01-01

    Psychiatric disorders such as anxiety, depression and addiction are often comorbid brain pathologies thought to share common mechanistic biology. As part of the cortico-limbic circuit, the nucleus accumbens shell (NAcSh) plays a fundamental role in integrating information in the circuit, such that modulation of NAcSh circuitry alters anxiety, depression, and addiction-related behaviors. Intracellular kinase cascades in the NAcSh have proven important mediators of behavior. To investigate glycogen-synthase kinase 3 (GSK3) beta signaling in the NAcSh in vivo we knocked down GSK3beta expression with a novel adeno-associated viral vector (AAV2) and assessed changes in anxiety- and depression-like behavior and cocaine self-administration in GSK3beta knockdown rats. GSK3beta knockdown reduced anxiety-like behavior while increasing depression-like behavior and cocaine self-administration. Correlative electrophysiological recordings in acute brain slices were used to assess the effect of AAV-shGSK3beta on spontaneous firing and intrinsic excitability of tonically active interneurons (TANs), cells required for input and output signal integration in the NAcSh and for processing reward-related behaviors. Loose-patch recordings showed that TANs transduced by AAV-shGSK3beta exhibited reduction in tonic firing and increased spike half width. When assessed by whole-cell patch clamp recordings these changes were mirrored by reduction in action potential firing and accompanied by decreased hyperpolarization-induced depolarizing sag potentials, increased action potential current threshold, and decreased maximum rise time. These results suggest that silencing of GSK3beta in the NAcSh increases depression- and addiction-related behavior, possibly by decreasing intrinsic excitability of TANs. However, this study does not rule out contributions from other neuronal sub-types. PMID:28126496

  14. A neural mass model of basal ganglia nuclei simulates pathological beta rhythm in Parkinson's disease

    NASA Astrophysics Data System (ADS)

    Liu, Fei; Wang, Jiang; Liu, Chen; Li, Huiyan; Deng, Bin; Fietkiewicz, Chris; Loparo, Kenneth A.

    2016-12-01

    An increase in beta oscillations within the basal ganglia nuclei has been shown to be associated with movement disorder, such as Parkinson's disease. The motor cortex and an excitatory-inhibitory neuronal network composed of the subthalamic nucleus (STN) and the external globus pallidus (GPe) are thought to play an important role in the generation of these oscillations. In this paper, we propose a neuron mass model of the basal ganglia on the population level that reproduces the Parkinsonian oscillations in a reciprocal excitatory-inhibitory network. Moreover, it is shown that the generation and frequency of these pathological beta oscillations are varied by the coupling strength and the intrinsic characteristics of the basal ganglia. Simulation results reveal that increase of the coupling strength induces the generation of the beta oscillation, as well as enhances the oscillation frequency. However, for the intrinsic properties of each nucleus in the excitatory-inhibitory network, the STN primarily influences the generation of the beta oscillation while the GPe mainly determines its frequency. Interestingly, describing function analysis applied on this model theoretically explains the mechanism of pathological beta oscillations.

  15. Brain natriuretic peptide suppresses pain induced by BmK I, a sodium channel-specific modulator, in rats.

    PubMed

    Li, Zheng-Wei; Wu, Bin; Ye, Pin; Tan, Zhi-Yong; Ji, Yong-Hua

    2016-12-01

    A previous study found that brain natriuretic peptide (BNP) inhibited inflammatory pain via activating its receptor natriuretic peptide receptor A (NPRA) in nociceptive sensory neurons. A recent study found that functional NPRA is expressed in almost all the trigeminal ganglion (TG) neurons at membrane level suggesting a potentially important role for BNP in migraine pathophysiology. An inflammatory pain model was produced by subcutaneous injection of BmK I, a sodium channel-specific modulator from venom of Chinese scorpion Buthus martensi Karsch. Quantitative PCR, Western Blot, and immunohistochemistry were used to detect mRNA and protein expression of BNP and NPRA in dorsal root ganglion (DRG) and dorsal horn of spinal cord. Whole-cell patch clamping experiments were conducted to record large-conductance Ca 2+ -activated K + (BK Ca ) currents of membrane excitability of DRG neurons. Spontaneous and evoked pain behaviors were examined. The mRNA and protein expression of BNP and NPRA was up-regulated in DRG and dorsal horn of spinal cord after BmK I injection. The BNP and NPRA was preferentially expressed in small-sized DRG neurons among which BNP was expressed in both CGRP-positive and IB4-positive neurons while NPRA was preferentially expressed in CGRP-positive neurons. BNP increased the open probability of BK Ca channels and suppressed the membrane excitability of small-sized DRG neurons. Intrathecal injection of BNP significantly inhibited BmK-induced pain behaviors including both spontaneous and evoked pain behaviors. These results suggested that BNP might play an important role as an endogenous pain reliever in BmK I-induced inflammatory pain condition. It is also suggested that BNP might play a similar role in other pathophysiological pain conditions including migraine.

  16. Neuronal NLRP1 inflammasome activation of Caspase-1 coordinately regulates inflammatory interleukin-1-beta production and axonal degeneration-associated Caspase-6 activation

    PubMed Central

    Kaushal, V; Dye, R; Pakavathkumar, P; Foveau, B; Flores, J; Hyman, B; Ghetti, B; Koller, B H; LeBlanc, A C

    2015-01-01

    Neuronal active Caspase-6 (Casp6) is associated with Alzheimer disease (AD), cognitive impairment, and axonal degeneration. Caspase-1 (Casp1) can activate Casp6 but the expression and functionality of Casp1-activating inflammasomes has not been well-defined in human neurons. Here, we show that primary cultures of human CNS neurons expressed functional Nod-like receptor protein 1 (NLRP1), absent in melanoma 2, and ICE protease activating factor, but not the NLRP3, inflammasome receptor components. NLRP1 neutralizing antibodies in a cell-free system, and NLRP1 siRNAs in neurons hampered stress-induced Casp1 activation. NLRP1 and Casp1 siRNAs also abolished stress-induced Casp6 activation in neurons. The functionality of the NLRP1 inflammasome in serum-deprived neurons was also demonstrated by NLRP1 siRNA-mediated inhibition of speck formation of the apoptosis-associated speck-like protein containing a caspase recruitment domain conjugated to green fluorescent protein. These results indicated a novel stress-induced intraneuronal NLRP1/Casp1/Casp6 pathway. Lipopolysaccharide induced Casp1 and Casp6 activation in wild-type mice brain cortex, but not in that of Nlrp1−/− and Casp1−/− mice. NLRP1 immunopositive neurons were increased 25- to 30-fold in AD brains compared with non-AD brains. NLRP1 immunoreactivity in these neurons co-localized with Casp6 activity. Furthermore, the NLRP1/Casp1/Casp6 pathway increased amyloid beta peptide 42 ratio in serum-deprived neurons. Therefore, CNS human neurons express functional NLRP1 inflammasomes, which activate Casp1 and subsequently Casp6, thus revealing a fundamental mechanism linking intraneuronal inflammasome activation to Casp1-generated interleukin-1-β-mediated neuroinflammation and Casp6-mediated axonal degeneration. PMID:25744023

  17. Hypothermia blocks beta-catenin degradation after focal ischemia in rats.

    PubMed

    Zhang, Hanfeng; Ren, Chuancheng; Gao, Xuwen; Takahashi, Tetsuya; Sapolsky, Robert M; Steinberg, Gary K; Zhao, Heng

    2008-03-10

    Dephosphorylated and activated glycogen synthase kinase (GSK) 3beta hyperphosphorylates beta-catenin, leading to its ubiquitin-proteosome-mediated degradation. beta-catenin-knockdown increases while beta-catenin overexpression prevents neuronal death in vitro; in addition, protein levels of beta-catenin are reduced in the brain of Alzheimer's patients. However, whether beta-catenin degradation is involved in stroke-induced brain injury is unknown. Here we studied activities of GSK 3beta and beta-catenin, and the protective effect of moderate hypothermia (30 degrees C) on these activities after focal ischemia in rats. The results of Western blot showed that GSK 3beta was dephosphorylated at 5 and 24 h after stroke in the normothermic (37 degrees C) brain; hypothermia augmented GSK 3beta dephosphorylation. Because hypothermia reduces infarction, these results contradict with previous studies showing that GSK 3beta dephosphorylation worsens neuronal death. Nevertheless, hypothermia blocked degradation of total GSK 3beta protein. Corresponding to GSK 3beta activity in normothermic rats, beta-catenin phosphorylation transiently increased at 5 h in both the ischemic penumbra and core, and the total protein level of beta-catenin degraded after normothermic stroke. Hypothermia did not inhibit beta-catenin phosphorylation, but it blocked beta-catenin degradation in the ischemic penumbra. In conclusion, moderate hypothermia can stabilize beta-catenin, which may contribute to the protective effect of moderate hypothermia.

  18. Changes of cervical dorsal root ganglia induced by compression injury and decompression procedure: a novel rat model of cervical radiculoneuropathy.

    PubMed

    Tang, Zhan-Ying; Shu, Bing; Cui, Xue-Jun; Zhou, Chong-Jian; Shi, Qi; Holz, Jonathan; Wang, Yong-Jun

    2009-02-11

    Our study aimed to establish a model of compression injury of cervical dorsal root ganglia (DRG) in the rat and to investigate the pathological changes following compression injury and decompression procedures. Thirty rats were divided into three groups: control group receiving sham surgery, compression group undergoing surgery to place a micro-silica gel on C6 DRG, and decompression group with subsequent decompression procedure. The samples harvested from the different groups were examined with light microscopy, ultrastructural analysis, and horseradish peroxidase (HRP) retrograde tracing techniques. Apoptosis of DRG neurons was demonstrated with TUNEL staining. Changes in PGE2 and PLA2 in DRG neurons were detected with enzyme-linked immunosorbent assay (ELISA). Local expression of vascular endothelial growth factor (VEGF) was monitored with immunohistochemistry. DRG neurons in the compression group became swollen with vacuolar changes in cytoplasm. Decompression procedure partially ameliorated the resultant compression pathology. Ultrastructural examination showed a large number of swollen vacuoles, demyelinated nerve root fibers, absence of Schwann cells, and proliferation in the surrounding connective tissues in the compression group. Compared to the control group, the compression group showed a significant decrease in the number of the HRP-labeled cells and a significant increase in levels of PGE2 and PLA2, in the expression of VEGF protein, and in the number of apoptotic DRG neurons. These findings demonstrate that compression results in local inflammation, followed by increased apoptosis and upregulation of VEGF. We conclude that such a model provides a tool to study the pathogenesis and treatment of cervical radiculoneuropathy.

  19. Endosome-mediated retrograde axonal transport of P2X3 receptor signals in primary sensory neurons

    PubMed Central

    Chen, Xu-Qiao; Wang, Bin; Wu, Chengbiao; Pan, Jin; Yuan, Bo; Su, Yuan-Yuan; Jiang, Xing-Yu; Zhang, Xu; Bao, Lan

    2012-01-01

    Neurotrophins and their receptors adopt signaling endosomes to transmit retrograde signals. However, the mechanisms of retrograde signaling for other ligand/receptor systems are poorly understood. Here, we report that the signals of the purinergic (P)2X3 receptor, an ATP-gated ion channel, are retrogradely transported in dorsal root ganglion (DRG) neuron axons. We found that Rab5, a small GTPase, controls the early sorting of P2X3 receptors into endosomes, while Rab7 mediates the fast retrograde transport of P2X3 receptors. Intraplantar injection and axonal application into the microfluidic chamber of α, β-methylene-ATP (α, β-MeATP), a P2X selective agonist, enhanced the endocytosis and retrograde transport of P2X3 receptors. The α, β-MeATP-induced Ca2+ influx activated a pathway comprised of protein kinase C, rat sarcoma viral oncogene and extracellular signal-regulated protein kinase (ERK), which associated with endocytic P2X3 receptors to form signaling endosomes. Disruption of the lipid rafts abolished the α, β-MeATP-induced ERK phosphorylation, endocytosis and retrograde transport of P2X3 receptors. Furthermore, treatment of peripheral axons with α, β-MeATP increased the activation level of ERK and cAMP response element-binding protein in the cell bodies of DRG neurons and enhanced neuronal excitability. Impairment of either microtubule-based axonal transport in vivo or dynein function in vitro blocked α, β-MeATP-induced retrograde signals. These results indicate that P2X3 receptor-activated signals are transmitted via retrogradely transported endosomes in primary sensory neurons and provide a novel signaling mechanism for ligand-gated channels. PMID:22157653

  20. Endosome-mediated retrograde axonal transport of P2X3 receptor signals in primary sensory neurons.

    PubMed

    Chen, Xu-Qiao; Wang, Bin; Wu, Chengbiao; Pan, Jin; Yuan, Bo; Su, Yuan-Yuan; Jiang, Xing-Yu; Zhang, Xu; Bao, Lan

    2012-04-01

    Neurotrophins and their receptors adopt signaling endosomes to transmit retrograde signals. However, the mechanisms of retrograde signaling for other ligand/receptor systems are poorly understood. Here, we report that the signals of the purinergic (P)2X(3) receptor, an ATP-gated ion channel, are retrogradely transported in dorsal root ganglion (DRG) neuron axons. We found that Rab5, a small GTPase, controls the early sorting of P2X(3) receptors into endosomes, while Rab7 mediates the fast retrograde transport of P2X(3) receptors. Intraplantar injection and axonal application into the microfluidic chamber of α, β-methylene-ATP (α, β-MeATP), a P2X selective agonist, enhanced the endocytosis and retrograde transport of P2X(3) receptors. The α, β-MeATP-induced Ca(2+) influx activated a pathway comprised of protein kinase C, rat sarcoma viral oncogene and extracellular signal-regulated protein kinase (ERK), which associated with endocytic P2X(3) receptors to form signaling endosomes. Disruption of the lipid rafts abolished the α, β-MeATP-induced ERK phosphorylation, endocytosis and retrograde transport of P2X(3) receptors. Furthermore, treatment of peripheral axons with α, β-MeATP increased the activation level of ERK and cAMP response element-binding protein in the cell bodies of DRG neurons and enhanced neuronal excitability. Impairment of either microtubule-based axonal transport in vivo or dynein function in vitro blocked α, β-MeATP-induced retrograde signals. These results indicate that P2X(3) receptor-activated signals are transmitted via retrogradely transported endosomes in primary sensory neurons and provide a novel signaling mechanism for ligand-gated channels.

  1. [Experimental study on co-culture of salivary adenoid cystic carcinoma cells and ganglia].

    PubMed

    Gu, Ling; Bu, Rong-fa; Wang, Dong-sheng; E, Ling-ling; Zhu, Guo-xiong

    2012-01-01

    To construct the co-culture models of salivarya denoid cystic carcinoma (SACC) cells and dorsal root ganglia (DRG) of chickens and investigate the promotive effects of SACC on neural tissue. Glass-base culture dish was adopted to construct co-culture model of SACC-83 cells and DRG. SACC-83 cells were seeded in the medium pore with DRG around them. Outgrowth of neuronal processes was observed. Then DRG was cultured in the conditioned medium of SACC-83, with the groups of conditioned medium of MC3T3-E1 and HGF, the group of cell lysis buffer, the groups of serum-free medium and serum-plus medium as the controls. Outgrowth of neuronal processes was also recorded and compared with control groups. In the co-culture model of tumor and neuronal tissue, SACC-83 cells produced a suitable microenvironment in which neuronal processes remarkably grow. Neuronal processes of most DRG displayed growth tendency toward SACC. The group of conditioned medium from SACC-83 manifested obvious promotive effects on DRG. Co-culture model of tumor and neuronal tissue was successfully constructed, with which the promotive effects of tumor on outgrowth of neuronal processes could be observed. So hypothesized that SACC could secrete some neurotrophic factors to guide peripheral nerves gemmating and to trigger the cascade of the neural invasion in succession.

  2. Acetylsalicylic acid-induced changes in the chemical coding of extrinsic sensory neurons supplying the prepyloric area of the porcine stomach.

    PubMed

    Rytel, L; Calka, J

    2016-03-23

    Acetylsalicylic acid is a popular drug that is commonly used to treat fever and inflammation, but which can also negativity affect the mucosal layer of the stomach, although knowledge concerning its influence on gastric innervation is very scarce. Thus, the aim of the present study was to study the influence of prolonged acetylsalicylic acid supplementation on the extrinsic primary sensory neurons supplying the porcine stomach prepyloric region. Fast Blue (FB) was injected into the above-mentioned region of the stomach. Acetylsalicylic acid was then given orally to the experimental gilts from the seventh day after FB injection to the 27th day of the experiment. After euthanasia, the nodose ganglia (NG) and dorsal root ganglia (DRG) were collected. Sections of these ganglia were processed for routine double-labelling immunofluorescence technique for substance P (SP), calcitonine gene related peptide (CGRP), galanin (GAL), neuronal isoform of nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP). Under physiological conditions within the nodose ganglia, the percentage of the FB-labeled neurons immunoreactive to particular substances ranged between 17.9 ± 2.7% (VIP-like immunoreactive (LI) neurons in the right NG) and 60.4 ± 1.7% (SP-LI cells within the left NG). Acetylsalicylic acid supplementation caused a considerable increase in the expression of all active substances studied within both left and right NG and the percentage of neurons positive to particular substances fluctuated from 47.2 ± 3.6% (GAL-LI neurons in the right NG) to 67.2 ± 2.0% (cells immunoreactive to SP in the left NG). All studied substances were also observed in DRG neurons supplying the prepyloric region of the stomach, but the number of immunoreactive neurons was too small to conduct a statistical analysis. The obtained results show that ASA may influence chemical coding of the sensory neurons supplying the porcine stomach, but the exact mechanisms of this action still

  3. Overexpression of p35 in Min6 pancreatic beta cells induces a stressed neuron-like apoptosis.

    PubMed

    Zheng, Ya-Li; Hu, Ya-Fang; Zhang, Aiping; Wang, Wei; Li, Bo; Amin, Niranjana; Grant, Philip; Pant, Harish C

    2010-12-15

    Cdk5 activity has been implicated in brain development and the regulation of many neuronal processes. Recently, the expression of p35 and Cdk5 activity has been reported in pancreatic beta cells. Decreased Cdk5 activity enhanced glucose-stimulated insulin secretion. This suggests that Cdk5 may play an important role in the regulation of insulin secretion. To further understand how Cdk5 regulates insulin secretion in glucose-stimulated pancreatic β cells, we first confirmed the presence of a low level of p35 in pancreatic Min6 cells. Next, in a time-course experiment in high glucose (25 mM) we showed that endogenous p35 increased gradually accompanied by a 3-fold increase in Cdk5 activity by 16 h. Insulin secretion, however, doubled after 2 h followed by progressive downregulation, negatively correlated with Cdk5 activity. On the other hand, overexpression of p35 in these cells resulted in more than a three-fold increase in Cdk5 activity within 2 h coupled to a 50% reduction in insulin secretion in both high and low (3 mM) glucose. Most significantly, cells overexpressing p35, treated with high glucose for 4 h, showed induction of p25, the p35-derived truncated fragment which hyperactivates Cdk5 in neurons. As a result, insulin secretion was inhibited and cells became apoptotic. Roscovitine or co-infection of dominant negative Cdk5 (dnCdk5) with p35 increased insulin secretion and inhibited apoptosis. These results suggest that the model for deregulation and hyperactivation of Cdk5 in neurodegeneration may apply to the pathology seen in type 2 diabetes (T2DM). It is consistent with the view that Alzheimer's disease and T2DM are linked metabolically and pathologically by Cdk5 in a number of ways. Copyright © 2010. Published by Elsevier B.V.

  4. Hospital Coding Practice, Data Quality, and DRG-Based Reimbursement under the Thai Universal Coverage Scheme

    ERIC Educational Resources Information Center

    Pongpirul, Krit

    2011-01-01

    In the Thai Universal Coverage scheme, hospital providers are paid for their inpatient care using Diagnosis Related Group (DRG) reimbursement. Questionable quality of the submitted DRG codes has been of concern whereas knowledge about hospital coding practice has been lacking. The objectives of this thesis are (1) To explore hospital coding…

  5. ["Something humane has been lost". Re-evaluation of the attitudes of senior physicians towards the G-DRG System - a qualitative normative analysis].

    PubMed

    Knoll, Marco; Otte, Ina; Salloch, Sabine; Ruiner, Caroline; Kruppa, Esta; Vollmann, Jochen

    2018-04-01

    Only a few years after the implementation of the G-DRG (German Diagnosis Related Group) system physicians already began to complain of its negative effects on the quality of inpatient healthcare. The present study examines the recent experiences senior physicians have made with regard to the impact of the G-DRG system on the quality of healthcare and medical professionalism. Nine qualitative guided expert interviews were conducted focusing on the experiences of physicians in leading positions dealing with the G-DRG system in their everyday work. The interviewees report an intensification of work attributable to an increasing number of inpatient cases, a more lenient definition of medical indications and a reduction in patient retention time. The physicians interviewed have felt increasingly constrained by economic conditions. Additionally, they stated that the G-DRG system's incentive structure encourages the discrimination of older, care-dependent and multimorbid patients. Possible countermeasures include a political revision of incentive regulation as well as a strengthening of up-to-date professional ethical education and teaching. Copyright © 2018. Published by Elsevier GmbH.

  6. Recommendations for the classification of HIV associated neuromanifestations in the German DRG system.

    PubMed

    Evers, Stefan; Fiori, W; Brockmeyer, N; Arendt, G; Husstedt, I-W

    2005-09-12

    HIV associated neuromanifestations are of growing importance in the in-patient treatment of HIV infected patients. In Germany, all in-patients have to be coded according to the ICD-10 classification and the German DRG-system. We present recommendations how to code the different primary and secondary neuromanifestations of HIV infection. These recommendations are based on the commentary of the German DRG procedures and are aimed to establish uniform coding of neuromanifestations.

  7. Amyloid-beta oligomers impair fear conditioned memory in a calcineurin-dependent fashion in mice.

    PubMed

    Dineley, Kelly T; Kayed, Rakez; Neugebauer, Volker; Fu, Yu; Zhang, Wenru; Reese, Lindsay C; Taglialatela, Giulio

    2010-10-01

    Soluble oligomeric aggregates of the amyloid-beta (A beta) peptide are believed to be the most neurotoxic A beta species affecting the brain in Alzheimer disease (AD), a terminal neurodegenerative disorder involving severe cognitive decline underscored by initial synaptic dysfunction and later extensive neuronal death in the CNS. Recent evidence indicates that A beta oligomers are recruited at the synapse, oppose expression of long-term potentiation (LTP), perturb intracellular calcium balance, disrupt dendritic spines, and induce memory deficits. However, the molecular mechanisms behind these outcomes are only partially understood; achieving such insight is necessary for the comprehension of A beta-mediated neuronal dysfunction. We have investigated the role of the phosphatase calcineurin (CaN) in these pathological processes of AD. CaN is especially abundant in the CNS, where it is involved in synaptic activity, LTP, and memory function. Here, we describe how oligomeric A beta treatment causes memory deficits and depresses LTP expression in a CaN-dependent fashion. Mice given a single intracerebroventricular injection of A beta oligomers exhibited increased CaN activity and decreased pCREB, a transcription factor involved in proper synaptic function, accompanied by decreased memory in a fear conditioning task. These effects were reversed by treatment with the CaN inhibitor FK506. We further found that expression of hippocampal LTP in acutely cultured rodent brain slices was opposed by A beta oligomers and that this effect was also reversed by FK506. Collectively, these results indicate that CaN activation may play a central role in mediating synaptic and memory disruption induced by acute oligomeric A beta treatment in mice. (c) 2010 Wiley-Liss, Inc.

  8. Structure and performance of different DRG classification systems for neonatal medicine.

    PubMed

    Muldoon, J H

    1999-01-01

    There are a number of Diagnosis-Related Group (DRG) classification systems that have evolved over the past 2 decades, each with their own strengths and weaknesses. DRG systems are used for case-mix trending, utilization management and quality improvement, comparative reporting, prospective payment, and price negotiations. For any of these applications it is essential to know the accuracy with which the DRG system classifies patients, specifically for predicting resource use and also mortality. The objective of this study was to assess the adequacy of the three most commonly used DRG systems for neonatal patients-Medicare DRGs, All Patient Diagnosis-Related Groups (AP-DRGs), and All Patient Refined Diagnosis-Related Groups (APR-DRGs). A 2-part methodology is used to assess adequacy. The first part is a descriptive analysis that examines the structural characteristics of each system. This provides a framework for understanding the inherent strengths and weaknesses of each system and for interpreting their statistical performance. The second part examines the statistical performance of each system on a large nationally representative hospital database. The analysis identifies major differences in the structure and statistical performance of the three DRG systems for neonates. The Medicare DRGs are structurally the least developed and yield the poorest overall statistical performance (cost R2 = 0.292; mortality R2 = 0.083). The APR-DRGs are structurally the most developed and yield the best statistical performance (cost R2 = 0.627; mortality R2 = 0.416). The AP-DRGs are intermediate to Medicare DRGs and APR-DRGs, although closer to APR-DRGs (cost R2 = 0.507; mortality R2 = 0.304). An analysis of payment impacts and systematic effects identifies there are major systematic biases with the Medicare DRGs. At the patient level, there is substantial underpayment for surgical neonates, transferred-in neonates, neonates discharged to home health services, and neonates who die

  9. Financial impact of introducing the Swiss-DRG reimbursement system on potentially avoidable readmissions at a university hospital.

    PubMed

    Wasserfallen, Jean-Blaise; Zufferey, Jade

    2015-01-01

    Thirty-day readmissions can be classified as potentially avoidable (PARs) or not avoidable (NARs) by following a specific algorithm (SQLape®). We wanted to assess the financial impact of the Swiss-DRG system, which regroups some readmissions occurring within 18 days after discharge within the initial hospital stay, on PARs at our hospital. First, PARs were identified from all hospitalisations recorded in 2011 at our university hospital. Second, 2012 Swiss-DRG readmission rules were applied, regrouped readmissions (RR) were identified, and their financial impact computed. Third, RRs were classified as potentially avoidable (PARRs), not avoidable (NARRs), and others causes (OCRRs). Characteristics of PARR patients and stays were retrieved, and the financial impact of PARRS was computed. A total of 36,777 hospitalisations were recorded in 2011, of which 3,140 were considered as readmissions (8.5%): 1,470 PARs (46.8%) and 1,733 NARs (53.2%). The 2012 Swiss-DRG rules would have resulted in 910 RRs (2.5% of hospitalisations, 29% of readmissions): 395 PARRs (43% of RR), 181 NARRs (20%), and 334 OCRRs (37%). Loss in reimbursement would have amounted to CHF 3.157 million (0.6% of total reimbursement). As many as 95% of the 395 PARR patients lived at home. In total, 28% of PARRs occurred within 3 days after discharge, and 58% lasted less than 5 days; 79% of the patients were discharged home again. Loss in reimbursement would amount to CHF 1.771 million. PARs represent a sizeable number of 30-day readmissions, as do PARRs of 18-day RRs in the 2012 Swiss DRG system. They should be the focus of attention, as the PARRs represent an avoidable loss in reimbursement.

  10. Chemical Structure and Morphology of Dorsal Root Ganglion Neurons from Naive and Inflamed Mice*

    PubMed Central

    Barabas, Marie E.; Mattson, Eric C.; Aboualizadeh, Ebrahim; Hirschmugl, Carol J.; Stucky, Cheryl L.

    2014-01-01

    Fourier transform infrared spectromicroscopy provides label-free imaging to detect the spatial distribution of the characteristic functional groups in proteins, lipids, phosphates, and carbohydrates simultaneously in individual DRG neurons. We have identified ring-shaped distributions of lipid and/or carbohydrate enrichment in subpopulations of neurons which has never before been reported. These distributions are ring-shaped within the cytoplasm and are likely representative of the endoplasmic reticulum. The prevalence of chemical ring subtypes differs between large- and small-diameter neurons. Peripheral inflammation increased the relative lipid content specifically in small-diameter neurons, many of which are nociceptive. Because many small-diameter neurons express an ion channel involved in inflammatory pain, transient receptor potential ankyrin 1 (TRPA1), we asked whether this increase in lipid content occurs in TRPA1-deficient (knock-out) neurons. No statistically significant change in lipid content occurred in TRPA1-deficient neurons, indicating that the inflammation-mediated increase in lipid content is largely dependent on TRPA1. Because TRPA1 is known to mediate mechanical and cold sensitization that accompanies peripheral inflammation, our findings may have important implications for a potential role of lipids in inflammatory pain. PMID:25271163

  11. The trauma registry compared to All Patient Refined Diagnosis Groups (APR-DRG).

    PubMed

    Hackworth, Jodi; Askegard-Giesmann, Johanna; Rouse, Thomas; Benneyworth, Brian

    2017-05-01

    Literature has shown there are significant differences between administrative databases and clinical registry data. Our objective was to compare the identification of trauma patients using All Patient Refined Diagnosis Related Groups (APR-DRG) as compared to the Trauma Registry and estimate the effects of those discrepancies on utilization. Admitted pediatric patients from 1/2012-12/2013 were abstracted from the trauma registry. The patients were linked to corresponding administrative data using the Pediatric Health Information System database at a single children's hospital. APR-DRGs referencing trauma were used to identify trauma patients. We compared variables related to utilization and diagnosis to determine the level of agreement between the two datasets. There were 1942 trauma registry patients and 980 administrative records identified with trauma-specific APR-DRG during the study period. Forty-two percent (816/1942) of registry records had an associated trauma-specific APR-DRG; 69% of registry patients requiring ICU care had trauma APR-DRGs; 73% of registry patients with head injuries had trauma APR-DRGs. Only 21% of registry patients requiring surgical management had associated trauma APR-DRGs, and 12.5% of simple fractures had associated trauma APR-DRGs. APR-DRGs appeared to only capture a fraction of the entire trauma population and it tends to be the more severely ill patients. As a result, the administrative data was not able to accurately answer hospital or operating room utilization as well as specific information on diagnosis categories regarding trauma patients. APR-DRG administrative data should not be used as the only data source for evaluating the needs of a trauma program. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. 42 CFR 412.60 - DRG classification and weighting factors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... discharge is based, as appropriate, on the patient's age, sex, principal diagnosis (that is, the diagnosis... whether a change in the DRG assignment is appropriate. If the intermediary decides that a higher-weighted... (b) of this section at least annually to reflect changes in treatment patterns, technology, and other...

  13. In situ immunodetection of neuronal caspase-3 activation in Alzheimer disease.

    PubMed

    Selznick, L A; Holtzman, D M; Han, B H; Gökden, M; Srinivasan, A N; Johnson, E M; Roth, K A

    1999-09-01

    The mechanism by which cells die in Alzheimer disease (AD) is unknown. Several investigators speculate that much of the cell loss may be due to apoptosis, a highly regulated form of programmed cell death. Caspase-3 is a critical effector of neuronal apoptosis and may be inappropriately activated in AD. To address this possibility, we examined cortical and hippocampal brain sections from AD patients, as well as 2 animal models of AD, for in situ evidence of caspase-3 activation. We report here that senile plaques and neurofibrillary tangles in the AD brain are not associated with caspase-3 activation. Furthermore, amyloid beta (A beta) deposition in the APPsw transgenic mouse model of AD does not result in caspase-3 activation despite the ability of A beta to induce caspase-3 activation and neuronal apoptosis in vitro. AD brain sections do, however, exhibit caspase-3 activation in hippocampal neurons undergoing granulovacuolar degeneration. Our data suggests that caspase-3 does not have a significant role in the widespread neuronal cell death that occurs in AD, but may contribute to the specific loss of hippocampal neurons involved in learning and memory.

  14. DRG benchmarking: analysis of service structures and -differences in dermatology departments.

    PubMed

    Fürstenberg, Torsten; Gierling, Patrick; Irps, Sebastian; Gollnick, Harald; Kaufmann, Roland; Stadler, Rudolf; Rompel, Rainer; Hensen, Peter

    2014-07-01

    In the context of DRG-based hospital funding, the analysis of services provided in dermatologic inpatient care is highly relevant. We analyzed and compared clinical service structures and varieties in dermatologic hospitals through a benchmarking technique. For this multicenter cross-sectional study, routine data from 46 German dermatologic clinics and departments were collected, processed, and analyzed. In total, 95 257 data sets from 2011 were available. The data were grouped according to the G-DRG-system 2013 version. The average length of stay for all cases was 6.3 days (DRG "inliers": 5.7 days), and average patient age was 52 years. In total, 55 % of all cases were grouped to medical, 45 % to surgical DRGs. 71 % of all hospitals provide services within or close to this average value (± 10 %). No association was found between the number of hospital beds and the variety of clinical services provided in our sample. We found huge varieties in several parameters assessing the coding quality. The results reflect the heterogeneous reality in German inpatient dermatology. The varieties in dermatologic service range still depend on patient-related factors as well as infrastructural conditions and the resources available at each site. © 2014 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  15. Dorsal Root Ganglion (DRG) Stimulation in the Treatment of Phantom Limb Pain (PLP).

    PubMed

    Eldabe, Sam; Burger, Katja; Moser, Heinrich; Klase, Daniel; Schu, Stefan; Wahlstedt, Anders; Vanderick, Bernard; Francois, Eric; Kramer, Jeffery; Subbaroyan, Jeyakumar

    2015-10-01

    Phantom limb pain (PLP) is a neuropathic condition in which pain is perceived as arising from an amputated limb. PLP is distinct from, although associated with, pain in the residual limb and nonpainful phantom sensations of the missing limb. Its treatment is extremely challenging; pharmaceutical options, while commonly employed, may be insufficient or intolerable. Neuromodulatory interventions such as spinal cord stimulation have generated mixed results and may be limited by poor somatotopic specificity. It was theorized that dorsal root ganglion (DRG) neuromodulation may be more effective. Patients trialed a DRG neurostimulation system for their PLP and were subsequently implanted if results were positive. Retrospective chart review was completed, including pain ratings on a 100-mm visual analogue scale (VAS) and patient-reported outcomes. Across eight patients, the average baseline pain rating was 85.5 mm. At follow-up (mean of 14.4 months), pain was rated at 43.5 mm. Subjective ratings of quality of life and functional capacity improved. Some patients reduced or eliminated pain medications. Patients reported precise concordance of the paresthesia with painful regions, including in their phantom limbs; in one case, stimulation eliminated PLP as well as nonpainful phantom sensations. Three patients experienced a diminution of pain relief, despite good initial outcomes. DRG neuromodulation may be an effective tool in treating this pain etiology. Clinical outcomes in this report support recent converging evidence suggesting that the DRG may be the site of PLP generation and/or maintenance. Further research is warranted to elucidate mechanisms and optimal treatment pathways. © 2015 International Neuromodulation Society.

  16. [Complex surgical procedures in orthopedics and trauma surgery. A contribution to the proposal procedure for the DRG system in 2009].

    PubMed

    Flohé, S; Nabring, J; Luetkes, P; Nast-Kolb, D; Windolf, J

    2008-10-01

    Since the DRG system was introduced in 2003/2004 the system for remuneration has been continually modified in conjunction with input from specialized medical associations. As part of this development of the payment system, the criteria for classification of a diagnosis-related group were further expanded and new functions were added. This contribution addresses the importance of the complex surgical procedures as criteria for subdivision of the DRG case-based lump sums in orthopedics and trauma surgery.

  17. Artemin growth factor increases nicotinic cholinergic receptor subunit expression and activity in nociceptive sensory neurons.

    PubMed

    Albers, Kathryn M; Zhang, Xiu Lin; Diges, Charlotte M; Schwartz, Erica S; Yang, Charles I; Davis, Brian M; Gold, Michael S

    2014-05-22

    Artemin (Artn), a member of the glial cell line-derived growth factor (GDNF) family, supports the development and function of a subpopulation of peptidergic, TRPV1-positive sensory neurons. Artn (enovin, neublastin) is elevated in inflamed tissue and its injection in skin causes transient thermal hyperalgesia. A genome wide expression analysis of trigeminal ganglia of mice that overexpress Artn in the skin (ART-OE mice) showed elevation in nicotinic acetylcholine receptor (nAChR) subunits, suggesting these ion channels contribute to Artn-induced sensitivity. Here we have used gene expression, immunolabeling, patch clamp electrophysiology and behavioral testing assays to investigate the link between Artn, nicotinic subunit expression and thermal hypersensitivity. Reverse transcriptase-PCR validation showed increased levels of mRNAs encoding the nAChR subunits α3 (13.3-fold), β3 (4-fold) and β4 (7.7-fold) in trigeminal ganglia and α3 (4-fold) and β4 (2.8-fold) in dorsal root ganglia (DRG) of ART-OE mice. Sensory ganglia of ART-OE mice had increased immunoreactivity for nAChRα3 and exhibited increased overlap in labeling with GFRα3-positive neurons. Patch clamp analysis of back-labeled cutaneous afferents showed that while the majority of nicotine-evoked currents in DRG neurons had biophysical and pharmacological properties of α7-subunit containing nAChRs, the Artn-induced increase in α3 and β4 subunits resulted in functional channels. Behavioral analysis of ART-OE and wildtype mice showed that Artn-induced thermal hyperalgesia can be blocked by mecamylamine or hexamethonium. Complete Freund's adjuvant (CFA) inflammation of paw skin, which causes an increase in Artn in the skin, also increased the level of nAChR mRNAs in DRG. Finally, the increase in nAChRs transcription was not dependent on the Artn-induced increase in TRPV1 or TRPA1 in ART-OE mice since nAChRs were elevated in ganglia of TRPV1/TRPA1 double knockout mice. These findings suggest that Artn

  18. Autophagosome biogenesis in primary neurons follows an ordered and spatially regulated pathway.

    PubMed

    Maday, Sandra; Holzbaur, Erika L F

    2014-07-14

    Autophagy is an essential degradative pathway in neurons, yet little is known about mechanisms driving autophagy in highly polarized cells. Here, we use dual-color live-cell imaging to investigate the neuron-specific mechanisms of constitutive autophagosome biogenesis in primary dorsal root ganglion (DRG) and hippocampal cultures. Under basal conditions, autophagosomes are continuously generated in the axon tip. There is an ordered assembly of proteins recruited with stereotypical kinetics onto the developing autophagosome. Plasma- or mitochondrial-derived membranes were not incorporated into nascent autophagosomes in the distal axon. Rather, autophagosomes are generated at double FYVE-containing protein 1 (DFCP1)-positive subdomains of the endoplasmic reticulum (ER), distinct from ER exit sites. Biogenesis events are enriched distally; autophagosomes form infrequently in dendrites, the soma, or midaxon, consistent with a compartmentalized pathway for constitutive autophagy in primary neurons. Distal biogenesis may facilitate degradation of damaged mitochondria and long-lived cytoplasmic proteins reaching the axon tip via slow axonal transport. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Comparison of cost accounting methods from different DRG systems and their effect on health care quality.

    PubMed

    Leister, Jan Eric; Stausberg, Jürgen

    2005-09-28

    Diagnosis related groups (DRGs) are a well-established provider payment system. Because of their imminent potential of cost reduction, they have been widely introduced. In addition to cost cutting, several social objectives - e.g., improving overall health care quality - feed into the DRG system. The WHO compared different provider payment systems with regard to the following objectives: prevention of further health problems, providing services and solving health problems, and responsiveness to people's legitimate expectations. However, no study has been published which takes the impact of different cost accounting systems across the DRG systems into account. We compared the impact of different cost accounting methods within DRG-like systems by developing six criteria: integration of patients' health risk into pricing practice, incentives for quality improvement and innovation, availability of high class evidence based therapy, prohibition of economically founded exclusions, reduction of fragmentation incentives, and improvement of patient oriented treatment. We set up a first overview of potential and actual impacts of the pricing practices within Yale-DRGs, AR-DRGs, G-DRGs, Swiss AP-DRGs adoption and Swiss MIPP. It could be demonstrated that DRGs are not only a 'homogenous' group of similar provider payment systems but quite different by fulfilling major health care objectives connected with the used cost accounting methods. If not only the possible cost reduction is used to put in a good word for DRG-based provider payment systems, maximum accurateness concerning the method of cost accounting should prevail when implementing a new DRG-based provider payment system.

  20. Activation of TRPC channels contributes to OA-NO2-induced responses in guinea-pig dorsal root ganglion neurons

    PubMed Central

    Zhang, Xiulin; Beckel, Jonathan M; Daugherty, Stephanie L; Wang, Ting; Woodcock, Stephen R; Freeman, Bruce A; de Groat, William C

    2014-01-01

    Effects of nitro-oleic acid (OA-NO2) on TRP channels were examined in guinea-pig dissociated dorsal root ganglia (DRG) neurons using calcium imaging and patch clamp techniques. OA-NO2 increased intracellular Ca2+ in 60–80% DRG neurons. 1-Oleoyl-2acetyl-sn-glycerol (OAG), a TRPC agonist, elicited responses in 36% of OA-NO2-sensitive neurons while capsaicin (TRPV1 agonist) or allyl-isothiocyanate (AITC, TRPA1 agonist) elicited responses in only 16% and 10%, respectively, of these neurons. A TRPV1 antagonist (diarylpiperazine, 5 μm) in combination with a TRPA1 antagonist (HC-030031, 30 μm) did not change the amplitude of the Ca2+ transients or percentage of neurons responding to OA-NO2; however, a reducing agent DTT (50 mm) or La3+ (50 μm) completely abolished OA-NO2 responses. OA-NO2 also induced a transient inward current associated with a membrane depolarization followed by a prolonged outward current and hyperpolarization in 80% of neurons. The reversal potentials of inward and outward currents were approximately −20 mV and −60 mV, respectively. Inward current was reduced when extracellular Na+ was absent, but unchanged by niflumic acid (100 μm), a Cl− channel blocker. Outward current was abolished in the absence of extracellular Ca2+ or a combination of two Ca2+-activated K+ channel blockers (iberiotoxin, 100 nm and apamin, 1 μm). BTP2 (1 or 10 μm), a broad spectrum TRPC antagonist, or La3+ (50 μm) completely abolished OA-NO2 currents. RT-PCR performed on mRNA extracted from DRGs revealed the expression of all seven subtypes of TRPC channels. These results support the hypothesis that OA-NO2 activates TRPC channels other than the TRPV1 and TRPA1 channels already known to be targets in rat and mouse sensory neurons and challenge the prevailing view that electrophilic compounds act specifically on TRPA1 or TRPV1 channels. The modulation of sensory neuron excitability via actions on multiple TRP channels can contribute to the anti-inflammatory effect