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Sample records for sensory nerve desensitization

  1. Area of desensitization following mental nerve block in dogs.

    PubMed

    Krug, William; Losey, Jeannie

    2011-01-01

    Regional nerve blocks are commonly used to provide analgesia for dental and oral surgical procedures. The purpose of this study was to demarcate the areas of the mandible that would be desensitized by application of the mental nerve block. Seven healthy mixed-breed dogs were anesthetized for an annual dental examination and professional teeth cleaning procedure. Bupivacaine HCl (0.4 ml/ m2) was administered at one middle mental foramen based on previously described techniques for the mental nerve block. A noxious stimulus was applied at 23 predetermined ipsilateral mandibular locations using pressure from a mosquito hemostat on the mucocutaneous junction (MCJ) and a dental curette on the vestibular mucogingival line (MGL) at the incisor canine, and premolar teeth; and, the mesial and distal aspects of the first molar tooth. A thermal stimulus using a refrigerant spray on a cotton ball was applied to the ipsilateral canine, third premolar and fourth premolar teeth; and, the mesial and distal aspects of the first molar tooth. Demonstration of nociception or anesthesia was noted and the responses tabulated. The area of desensitized tissues was smaller than expected and highly variable within the study group. In conclusion, the unilateral mental nerve block does not reliably provide generalized desensitization to tissues of the incisive and rostral regions of the mandible. Although the mental nerve block is recommended, other modes of analgesia should be emphasized for surgical and dental procedures involving these areas. PMID:22206140

  2. Systemic Chemical Desensitization of Peptidergic Sensory Neurons with Resiniferatoxin Inhibits Experimental Periodontitis

    PubMed Central

    Breivik, Torbjørn; Gundersen, Yngvar; Gjermo, Per; Fristad, Inge; Opstad, Per Kristian

    2011-01-01

    Background and objective: The immune system is an important player in the pathophysiology of periodontitis. The brain controls immune responses via neural and hormonal pathways, and brain-neuro-endocrine dysregulation may be a central determinant for pathogenesis. Our current knowledge also emphasizes the central role of sensory nerves. In line with this, we wanted to investigate how desensitization of peptidergic sensory neurons influences the progression of ligature-induced periodontitis, and, furthermore, how selected cytokine and stress hormone responses to Gram-negative bacterial lipopolysaccharide (LPS) stimulation are affected. Material and methods: Resiniferatoxin (RTX; 50 μg/kg) or vehicle was injected subcutaneously on days 1, 2, and 3 in stress high responding and periodontitis-susceptible Fischer 344 rats. Periodontitis was induced 2 days thereafter. Progression of the disease was assessed after the ligatures had been in place for 20 days. Two h before decapitation all rats received LPS (150 μg/kg i.p.) to induce a robust immune and stress response. Results: Desensitization with RTX significantly reduced bone loss as measured by digital X-rays. LPS provoked a significantly higher increase in serum levels of the pro-inflammatory cytokine tumour necrosis factor (TNF)-α, but lower serum levels of the anti-inflammatory cytokine interleukin (IL)-10 and the stress hormone corticosterone. Conclusions: In this model RTX-induced chemical desensitization of sensory peptidergic neurons attenuated ligature-induced periodontitis and promoted a shift towards stronger pro-inflammatory cytokine and weaker stress hormone responses to LPS. The results may partly be explained by the attenuated transmission of immuno-inflammatory signals to the brain. In turn, this may weaken the anti-inflammatory brain-derived pathways. PMID:21339860

  3. Sensory Desensitization Training for Successful Net Application and EEG/ERP Acquisition in Difficult to Test Children

    ERIC Educational Resources Information Center

    Roesler, Cynthia P.; Flax, Judy; MacRoy-Higgins, Michelle; Fermano, Zena; Morgan-Byrne, Julie; Benasich, April A.

    2013-01-01

    This study examined the effectiveness of sensory desensitization training for 12 nonverbal children with autism to facilitate participation in an electrophysiological study assessing linguistic processing. Sensory desensitization was achieved for 10 of the 12 children and thus allowed collection of usable data in a passive linguistic paradigm.…

  4. Paclitaxel alters sensory nerve biomechanical properties.

    PubMed

    Bober, Brian G; Shah, Sameer B

    2015-10-15

    Paclitaxel is an effective chemotherapeutic that, despite its common use, frequently causes debilitating peripheral sensory neuropathy. Paclitaxel binds to and stabilizes microtubules, and through unknown mechanisms, causes abnormal microtubule aggregation. Given that microtubules contribute to the mechanical properties of cells, we tested the hypothesis that paclitaxel treatment would alter the stiffness of sensory nerves. Rat sural nerves were excised and soaked in Ringer's solution with or without paclitaxel. Nerves were secured between a force transducer and actuator, and linearly strained. Stress-strain curves were generated, from which elastic moduli were calculated. Paclitaxel treated nerves exhibited significantly higher moduli in both linear and transition regions of the curve. A composite-tissue model was then generated to estimate the stiffness increase in the cellular fraction of the nerve following paclitaxel treatment. This model was supported experimentally by data on mechanical properties of sural nerves stripped of their epineurium, and area fractions of the cellular and connective tissue components of the rat sural nerve, calculated from immunohistochemical images. Model results revealed that the cellular components of the nerve must stiffen 12x to 115x, depending on the initial axonal modulus assumed, in order to achieve the observed tissue level mechanical changes. Consistent with such an increase, electron microscopy showed increased microtubule aggregation and cytoskeletal packing, suggestive of a more cross-linked cytoskeleton. Overall, our data suggests that paclitaxel treatment induces increased microtubule bundling in axons, which leads to alterations in tissue-level mechanical properties. PMID:26321364

  5. Quantitative Sensory Testing of the Effect of Desensitizing Treatment After Dental Bleaching.

    PubMed

    Rahal, Vanessa; Gallinari, Marjorie O; Perdigão, Jorge; Cintra, Luciano T A; dos Santos, Paulo H; Briso, André L F

    2015-12-01

    The aim of this study was to quantify tooth sensitivity during bleaching and after a desensitizing treatment. Sensitivity was measured with a new device, TSA-II, which uses thermal stimuli for Quantitative Sensory Testing (QST). Ten patients underwent bleaching treatment using Whiteness HP Maxx (FGM Produtos Odontológicos Ltda) containing 35% hydrogen peroxide. After the bleaching session, the teeth were cleaned with air/water spray and the product Desensibilize KF 2% (FGM Produtos Odontológicos Ltda) was applied to the upper left teeth. Saline solution at room temperature was applied in the upper right teeth. QST was performed before bleaching, immediately after bleaching, and immediately after desensitizing treatment. In order to standardize tooth analysis, a 100% ethylene copolymer and vinyl acetate tray with circular perforations was used during measurements. Analysis of variance and the Student's t-test were used (a=0.05). Mean temperatures (SD) of cold sensation threshold for the upper right quadrant were: BB-13.898 (4.81), AB- 19.241 (3.68), AD-20.646 (3.72) and for the upper left quadrant they were: BB-14.102 (3.22), AB-19.646 (4.82), AD- 13.835 (3.63). Dental bleaching with highly concentrated peroxides changed dental cold sensation thresholds, but the topical desensitizer changed the immediate cold sensation thresholds produced by the cold stimulus. PMID:27095628

  6. Effect of nedocromil sodium on airway sensory nerves.

    PubMed

    Barnes, P J

    1993-07-01

    There is increasing evidence that the sensory nerves of the airway play a role in the asthmatic response. Nerve endings are exposed by the epithelial shedding that occurs with asthma. They may become sensitized and activated by inflammatory mediators and may release neuropeptides that then spread and amplify the inflammatory process in the airways. Nedocromil sodium may prevent the sensory nerves from becoming sensitized and inhibit their activation. This possibility is suggested because nedocromil is highly effective against several indirect challenges that involve sensory nerve stimulation. Nedocromil sodium was able to inhibit the bronchoconstriction induced in patients with asthma by exposure to bradykinin, sulfur dioxide, metabisulfite, and ultrasonically nebulized water. Cough, which is a prominent symptom of asthma, is believed to be a result of sensory nerve activation. In several long-term clinical studies, nedocromil sodium reduces the severity of cough among patients with asthma. Studies are needed to define how nedocromil sodium acts on the sensory nerves. PMID:8393025

  7. Palm to Finger Ulnar Sensory Nerve Conduction

    PubMed Central

    Davidowich, Eduardo; Orsini, Marco; Pupe, Camila; Pessoa, Bruno; Bittar, Caroline; Pires, Karina Lebeis; Bruno, Carlos; Coutinho, Bruno Mattos; de Souza, Olivia Gameiro; Ribeiro, Pedro; Velasques, Bruna; Bittencourt, Juliana; Teixeira, Silmar; Bastos, Victor Hugo

    2015-01-01

    Ulnar neuropathy at the wrist (UNW) is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN) in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC) of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way) and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV) ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW. PMID:26788268

  8. Sural nerve defects after nerve biopsy or nerve transfer as a sensory regeneration model for peripheral nerve conduit implantation.

    PubMed

    Radtke, C; Kocsis, J D; Reimers, K; Allmeling, C; Vogt, P M

    2013-09-01

    Nerve repair after injury can be effectively accomplished by direct suture approximation of the proximal and distal segments. This is more successful if coadaptation can be achieved without tension. Currently, the gold standard repair of larger deficits is the transplantation of an autologous sensory sural nerve graft. However, a significant disadvantage of this technique is the inevitable donor morbidity (sensory loss, neuroma and scar formation) after harvesting of the sural nerve. Moreover, limitation of autologous donor nerve length and fixed diameter of the available sural nerve are major drawbacks of current autograft treatment. Another approach that was introduced for nerve repair is the implantation of alloplastic nerve tubes made of, for example, poly-L-lactide. In these, nerve stumps of the transected nerves are surgically bridged using the biosynthetic conduit. A number of experimental studies, primarily in rodents, indicate axonal regeneration and remyelination after implantation of various conduits. However, only limited clinical studies with conduit implantation have been performed in acute peripheral nerve injuries particularly on digital nerves. Clinical transfer of animal studies, which can be carefully calibrated for site and extent of injury, to humans is difficult to interpret due to the intrinsic variability in human nerve injuries. This prevents effective quantification of improvement and induces bias in the study. Therefore, standardization of lesion/repair in human studies is warranted. Here we propose to use sural nerve defects, induced due to nerve graft harvesting or from diagnostic nerve biopsies as a model site to enable standardization of nerve conduit implantation. This would help better with the characterization of the implants and its effectiveness in axonal regeneration and remyelination. Nerve regeneration can be assessed, for example, by recovery of sensation, measured non-invasively by threshold to von Frey filaments and cold

  9. Role of renal sensory nerves in physiological and pathophysiological conditions

    PubMed Central

    2014-01-01

    Whether activation of afferent renal nerves contributes to the regulation of arterial pressure and sodium balance has been long overlooked. In normotensive rats, activating renal mechanosensory nerves decrease efferent renal sympathetic nerve activity (ERSNA) and increase urinary sodium excretion, an inhibitory renorenal reflex. There is an interaction between efferent and afferent renal nerves, whereby increases in ERSNA increase afferent renal nerve activity (ARNA), leading to decreases in ERSNA by activation of the renorenal reflexes to maintain low ERSNA to minimize sodium retention. High-sodium diet enhances the responsiveness of the renal sensory nerves, while low dietary sodium reduces the responsiveness of the renal sensory nerves, thus producing physiologically appropriate responses to maintain sodium balance. Increased renal ANG II reduces the responsiveness of the renal sensory nerves in physiological and pathophysiological conditions, including hypertension, congestive heart failure, and ischemia-induced acute renal failure. Impairment of inhibitory renorenal reflexes in these pathological states would contribute to the hypertension and sodium retention. When the inhibitory renorenal reflexes are suppressed, excitatory reflexes may prevail. Renal denervation reduces arterial pressure in experimental hypertension and in treatment-resistant hypertensive patients. The fall in arterial pressure is associated with a fall in muscle sympathetic nerve activity, suggesting that increased ARNA contributes to increased arterial pressure in these patients. Although removal of both renal sympathetic and afferent renal sensory nerves most likely contributes to the arterial pressure reduction initially, additional mechanisms may be involved in long-term arterial pressure reduction since sympathetic and sensory nerves reinnervate renal tissue in a similar time-dependent fashion following renal denervation. PMID:25411364

  10. Cobalt iontophoresis of sensory nerves in the rat lung.

    PubMed

    El-Bermani, A W; Chang, T L

    1979-02-01

    By iontophoretically introducing, first, cobalt and, subsequently, sulfide ions into the vagus nerve, it is possible to trace sensory nerves to their endings in the rat lung. Nerve fibers and terminals are found predominantly in the adventitia of the airways and blood vessels. Some nerves are found in the submucosa of the bronchi and bronchioles. Some are found in the cardiac muscle on the periphery of pulmonary veins, and a few nerves are seen to end among smooth muslces of the blood vessels and the airways. At least three types of nerve endings can be identified at the light microscopic level: (1) free nerve endings; (2) brush-like endings; (3) knob-like terminals. PMID:760496

  11. Transient Alterations of Cutaneous Sensory Nerve Function by Noninvasive Cryolipolysis.

    PubMed

    Garibyan, Lilit; Cornelissen, Laura; Sipprell, William; Pruessner, Joachim; Elmariah, Sarina; Luo, Tuan; Lerner, Ethan A; Jung, Yookyung; Evans, Conor; Zurakowski, David; Berde, Charles B; Rox Anderson, R

    2015-11-01

    Cryolipolysis is a noninvasive, skin cooling treatment for local fat reduction that causes prolonged hypoesthesia over the treated area. We tested the hypothesis that cryolipolysis can attenuate nociception of a range of sensory stimuli, including stimuli that evoke itch. The effects of cryolipolysis on sensory phenomena were evaluated by quantitative sensory testing (QST) in 11 healthy subjects over a period of 56 days. Mechanical and thermal pain thresholds were measured on treated and contralateral untreated (control) flanks. Itch duration was evaluated following histamine iontophoresis. Unmyelinated epidermal nerve fiber and myelinated dermal nerve fiber densities were quantified in skin biopsies from six subjects. Cryolipolysis produced a marked decrease in mechanical and thermal pain sensitivity. Hyposensitivity started between two to seven days after cryolipolysis and persisted for at least thirty-five days post treatment. Skin biopsies revealed that cryolipolysis decreased epidermal nerve fiber density, as well as dermal myelinated nerve fiber density, which persisted throughout the study. In conclusion, cryolipolysis causes significant and prolonged decreases in cutaneous sensitivity. Our data suggest that controlled skin cooling to specifically target cutaneous nerve fibers has the potential to be useful for prolonged relief of cutaneous pain and might have a use as a research tool to isolate and study cutaneous itch-sensing nerves in human skin. PMID:26099028

  12. Effects of motor and sensory nerve transplants on amount and specificity of sciatic nerve regeneration.

    PubMed

    Lago, Natalia; Rodríguez, Francisco J; Guzmán, Mónica S; Jaramillo, Jéssica; Navarro, Xavier

    2007-09-01

    Nerve regeneration after complete transection does not allow for adequate functional recovery mainly because of lack of selectivity of target reinnervation. We assessed if transplanting a nerve segment from either motor or sensory origin may improve specifically the accuracy of sensory and motor reinnervation. For this purpose, the rat sciatic nerve was transected and repaired with a silicone guide containing a predegenerated segment of ventral root (VR) or dorsal root (DR), compared to a silicone guide filled with saline. Nerve regeneration and reinnervation was assessed during 3 months by electrophysiologic and functional tests, and by nerve morphology and immunohistochemistry against choline acetyltransferase (ChAT) for labeling motor axons. Functional tests showed that reinnervation was successful in all the rats. However, the two groups with a root allotransplant reached higher degrees of reinnervation in comparison with the control group. Group VR showed the highest reinnervation of muscle targets, whereas Group DR had higher levels of sensory reinnervation than VR and saline groups. The total number of regenerated myelinated fibers was similar in the three groups, but the number of ChAT+ fibers was slightly lower in the VR group in comparison with DR and saline groups. These results indicate that a predegenerated root nerve allotransplant enhances axonal regeneration, leading to faster and higher levels of functional recovery. Although there is not clear preferential reinnervation, regeneration of motor axons is promoted at early times by a motor graft, whereas reinnervation of sensory pathways is increased by a sensory graft. PMID:17455293

  13. Nerve Growth Factor Decreases in Sympathetic and Sensory Nerves of Rats with Chronic Heart Failure

    PubMed Central

    Lu, Jian

    2014-01-01

    Nerve growth factor (NGF) plays a critical role in the maintenance and survival of both sympathetic and sensory nerves. Also, NGF can regulate receptor expression and neuronal activity in the sympathetic and sensory neurons. Abnormalities in NGF regulation are observed in patients and animals with heart failure (HF). Nevertheless, the effects of chronic HF on the levels of NGF within the sympathetic and sensory nerves are not known. Thus, the ELISA method was used to assess the levels of NGF in the stellate ganglion (SG) and dorsal root ganglion (DRG) neurons of control rats and rats with chronic HF induced by myocardial infarction. Our data show for the first time that the levels of NGF were significantly decreased (P < 0.05) in the SG and DRG neurons 6–20 weeks after ligation of the coronary artery. In addition, a close relation was observed between the NGF levels and the left ventricular function. In conclusion, chronic HF impairs the expression of NGF in the sympathetic and sensory nerves. Given that sensory afferent nerves are engaged in the sympathetic nervous responses to somatic stimulation (i.e. muscle activity during exercise) via a reflex mechanism, our data indicate that NGF is likely responsible for the development of muscle reflex-mediated abnormal sympathetic responsiveness observed in chronic HF. PMID:24913185

  14. Sensory nerve function and auto-mutilation after reconstruction of various gap lengths with nerve guides and autologous nerve grafts.

    PubMed

    den Dunnen, W F; Meek, M F

    2001-05-01

    The aim of this study was to evaluate sensory nerve recovery and auto-mutilation after reconstruction of various lengths of nerve gaps in the sciatic nerve of the rat, using different techniques. Group 4, in which the longest nerve gap (15 mm) was reconstructed with a thin-walled p(DL-lactide-gamma-caprolactone) nerve guide filled with modified denatured muscle tissue, showed the best results in the electro-stimulation tests and signs of severe auto-mutilation were not observed. Even in the control group, in which a 10 mm nerve gap was left open, in two of the five rats improvement of the sensory nerve function was observed, which was caused by re-innervation of the sciatic nerve and not by expansion of the neighboring saphenous nerve. It is hypothesized that a better quality of nerve reconstruction/guidance channel/support results in faster regeneration and hence re-innervation, thereby, preventing auto-mutilation. A thin red glabrous skin, anhydrosis (dryness of the skin), short nails and edema were interpreted as signs of autonomic dysfunction. PMID:11352096

  15. Tachykinins, sensory nerves, and asthma--an overview.

    PubMed

    Lundberg, J M

    1995-07-01

    Tachykinin peptides, substance P (SP) and neurokinin A (NKA), are released from airway sensory nerves upon exposure to irritant chemicals and endogenous agents including bradykinin, prostaglandins, histamine, and protons, The released neuropeptides are potent inducers of a cascade of responses, including vasodilatation, mucus secretion, plasma protein extravasation, leukocyte adhesion--activation, and bronchoconstriction. Neurokinin 1 receptors (preferably activated by SP) seem to be most important for inflammatory actions, while neurokinin 2 receptors (preferably activated by NKA) mediate bronchoconstriction. Species differences exist whereby rat and guinea-pig have a more developed neurogenic inflammation response than normal human airways. However, disease states such as inflammation or viral infections lead to enhanced peptide synthesis and (or) increased sensory nerve excitability. Together with increased neurokinin 1 receptor synthesis and loss of major tachykinin-degrading enzymes such as neutral endopeptidase in airway inflammation, this suggests that recently developed, orally active nonpeptide neurokinin receptor antagonists could have a therapeutic potential in asthmatic patients. PMID:8846429

  16. Sensory conduction in medial and lateral plantar nerves.

    PubMed Central

    Ponsford, S N

    1988-01-01

    A simple and reliable method of recording medial and lateral plantar nerve sensory action potentials is described. Potentials are recorded with surface electrodes at the ankle using surface electrodes stimulating orthodromically at the sole. The normal values obtained are higher in amplitude than those obtained by the method described by Guiloff and Sherratt and are detectable in older subjects aged over 80 years. The procedure is valuable in the diagnosis of early peripheral neuropathy, mononeuritis multiplex, tarsal tunnel syndrome and in differentiation between pre and post ganglionic L5 S1 lesions. PMID:2831304

  17. Vascularized Nerve Bypass Graft: A Case Report of an Additional Treatment for Poor Sensory Recovery.

    PubMed

    Usami, Satoshi; Tanaka, Kentaro; Ohkubo, Alisa; Okazaki, Mutsumi

    2016-04-01

    End-to-side neurorrhaphy has proven effective in basic research and in clinical application. One of the methods of end-to-side neurorrhaphy, nerve bypass technique, has been reported and axon regeneration has been proven. In clinical application, the utility of the nerve bypass technique has been revealed in some cases; however, these bypasses were performed using nonvascularized nerves. We initially used the vascularized nerve bypass graft technique with the sural nerve as a secondary clinical procedure after median nerve injury in a 61-year-old patient and achieved motor and sensory nerve regeneration, as supported by a nerve conduction study and clinical sensory test. This technique has the potential to become one of the choices for salvage procedure of severe nerve injury. PMID:27200248

  18. Vascularized Nerve Bypass Graft: A Case Report of an Additional Treatment for Poor Sensory Recovery

    PubMed Central

    Tanaka, Kentaro; Ohkubo, Alisa; Okazaki, Mutsumi

    2016-01-01

    Summary: End-to-side neurorrhaphy has proven effective in basic research and in clinical application. One of the methods of end-to-side neurorrhaphy, nerve bypass technique, has been reported and axon regeneration has been proven. In clinical application, the utility of the nerve bypass technique has been revealed in some cases; however, these bypasses were performed using nonvascularized nerves. We initially used the vascularized nerve bypass graft technique with the sural nerve as a secondary clinical procedure after median nerve injury in a 61-year-old patient and achieved motor and sensory nerve regeneration, as supported by a nerve conduction study and clinical sensory test. This technique has the potential to become one of the choices for salvage procedure of severe nerve injury. PMID:27200248

  19. Photostimulation of sensory neurons of the rat vagus nerve

    NASA Astrophysics Data System (ADS)

    Rhee, Albert Y.; Li, Gong; Wells, Jonathon; Kao, Joseph P. Y.

    2008-02-01

    We studied the effect of infrared (IR) stimulation on rat sensory neurons. Primary sensory neurons were prepared by enzymatic dissociation of the inferior (or "nodose") ganglia from the vagus nerves of rats. The 1.85-μm output of a diode laser, delivered through a 200-μm silica fiber, was used for photostimulation. Nodose neurons express the vanilloid receptor, TRPV1, which is a non-selective cation channel that opens in response to significant temperature jumps above 37 C. Opening TRPV1 channels allows entry of cations, including calcium (Ca 2+), into the cell to cause membrane depolarization. Therefore, to monitor TRPV1 activation consequent to photostimulation, we used fura-2, a fluorescent Ca 2+ indicator, to monitor the rise in intracellular Ca 2+ concentration ([Ca 2+]i). Brief trains of 2-msec IR pulses activated TRPV1 rapidly and reversibly, as evidenced by transient rises in [Ca 2+]i (referred to as Ca 2+ transients). Consistent with the Ca 2+ transients arising from influx of Ca 2+, identical photostimulation failed to evoke Ca 2+ responses in the absence of extracellular Ca 2+. Furthermore, the photo-induced Ca 2+ signals were abolished by capsazepine, a specific blocker of TRPV1, indicating that the responses were indeed mediated by TRPV1. We discuss the feasibility of using focal IR stimulation to probe neuronal circuit properties in intact neural tissue, and compare IR stimulation with another photostimulation technique-focal photolytic release of "caged" molecules.

  20. The Feline Dorsal Nerve of the Penis Arises from the Deep Perineal Nerve and Not the Sensory Afferent Branch

    PubMed Central

    Mariano, T. Y.; Boger, A. S.; Gustafson, K. J.

    2012-01-01

    Summary The cat has been used extensively as an animal model for urogenital studies involving the pudendal nerve. However, discrepancies persist in the literature regarding the origin of the dorsal nerve of the penis (DNP). This study used gross dissections and serial histological cross sections to demonstrate that the DNP arises from the deep perineal nerve and not the sensory afferent branch as previously reported. This finding indicates a better than previously appreciated neuroanatomical homology between the cat and human. PMID:18479311

  1. Arnold’s nerve cough reflex: evidence for chronic cough as a sensory vagal neuropathy

    PubMed Central

    Gibson, Peter G.; Birring, Surinder S.

    2014-01-01

    Arnold’s nerve ear-cough reflex is recognised to occur uncommonly in patients with chronic cough. In these patients, mechanical stimulation of the external auditory meatus can activate the auricular branch of the vagus nerve (Arnold’s nerve) and evoke reflex cough. This is an example of hypersensitivity of vagal afferent nerves, and there is now an increasing recognition that many cases of refractory or idiopathic cough may be due to a sensory neuropathy of the vagus nerve. We present two cases where the cause of refractory chronic cough was due to sensory neuropathy associated with ear-cough reflex hypersensitivity. In both cases, the cough as well as the Arnold’s nerve reflex hypersensitivity were successfully treated with gabapentin, a treatment that has previously been shown to be effective in the treatment of cough due to sensory laryngeal neuropathy (SLN). PMID:25383210

  2. Identification of Changes in Gene expression of rats after Sensory and Motor Nerves Injury

    PubMed Central

    Wang, Yu; Guo, Zhi-Yuan; Sun, Xun; Lu, Shi-bi; Xu, Wen-Jing; Zhao, Qing; Peng, Jiang

    2016-01-01

    Wallerian degeneration is a sequence of events in the distal stump of axotomized nerves. Despite large numbers of researches concentrating on WD, the biological mechanism still remains unclear. Hence we constructed a rat model with both motor and sensory nerves injury and then conducted a RNA-seq analysis. Here the rats were divided into the 4 following groups: normal motor nerves (NMN), injured motor nerves (IMN), normal sensory nerves (NSN) and injured sensory nerves (ISN). The transcriptomes of rats were sequenced by the Illumina HiSeq. The differentially expressed genes (DEGs) of 4 combinations including NMN vs. IMN, NSN vs. ISN, NMN vs. NSN and IMN vs. ISN were identified respectively. For the above 4 combinations, we identified 1666, 1514, 95 and 17 DEGs. We found that NMN vs. IMN shared the most common genes with NSN vs. ISN indicating common mechanisms between motor nerves injury and sensory nerves injury. At last, we performed an enrichment analysis and observed that the DEGs of NMN vs IMN and NSN vs. ISN were significantly associated with binding and activity, immune response, biosynthesis, metabolism and development. We hope our study may shed light on the molecular mechanisms of nerves degeneration and regeneration during WD. PMID:27253193

  3. Identification of Changes in Gene expression of rats after Sensory and Motor Nerves Injury.

    PubMed

    Wang, Yu; Guo, Zhi-Yuan; Sun, Xun; Lu, Shi-Bi; Xu, Wen-Jing; Zhao, Qing; Peng, Jiang

    2016-01-01

    Wallerian degeneration is a sequence of events in the distal stump of axotomized nerves. Despite large numbers of researches concentrating on WD, the biological mechanism still remains unclear. Hence we constructed a rat model with both motor and sensory nerves injury and then conducted a RNA-seq analysis. Here the rats were divided into the 4 following groups: normal motor nerves (NMN), injured motor nerves (IMN), normal sensory nerves (NSN) and injured sensory nerves (ISN). The transcriptomes of rats were sequenced by the Illumina HiSeq. The differentially expressed genes (DEGs) of 4 combinations including NMN vs. IMN, NSN vs. ISN, NMN vs. NSN and IMN vs. ISN were identified respectively. For the above 4 combinations, we identified 1666, 1514, 95 and 17 DEGs. We found that NMN vs. IMN shared the most common genes with NSN vs. ISN indicating common mechanisms between motor nerves injury and sensory nerves injury. At last, we performed an enrichment analysis and observed that the DEGs of NMN vs IMN and NSN vs. ISN were significantly associated with binding and activity, immune response, biosynthesis, metabolism and development. We hope our study may shed light on the molecular mechanisms of nerves degeneration and regeneration during WD. PMID:27253193

  4. Sensory nerve conduction deficit in experimental monoclonal gammopathy of undetermined significance (MGUS) neuropathy.

    PubMed

    Lawlor, M W; Richards, M P; Fisher, M A; Stubbs, E B

    2001-06-01

    An emerging body of evidence from in vitro studies and in vivo animal models supports a pathogenic role of antibodies in the development of peripheral neuropathy associated with monoclonal gammopathy of undetermined significance (MGUS). Although the assessment of motor and sensory nerve fiber function is of clinical importance, it is seldom applied experimentally. We describe the application of an electrophysiologic method for the evaluation of motor and sensory nerve fiber function using an experimental model of MGUS neuropathy. Supramaximal stimulation of the tibial nerve elicited an early motor response (M-wave, 1.7 +/- 0.1 ms, n = 10) and a late sensory (H-reflex, 7.8 +/- 0.1 ms, n = 10) response that was recorded from the hind foot of anesthetized rats. Intraneural injection of serum antibodies from a MGUS patient with sensorimotor polyneuropathy, but not from an age-matched control subject, produced a marked attenuation of the H-reflex (P < 0.01, n = 10) without affecting the M-wave. Light and electron microscopy of affected nerve showed myelinoaxonal degeneration with sparing of the smaller unmyelinated nerve fibers. The combined electrophysiologic and morphologic findings presented in this study are consistent with a selective sensory conduction deficit in MGUS neuropathy. Selective injury of afferent nerve fibers by this patient's serum antibodies may result from reactivity to neural antigens uniquely expressed by sensory neurons. PMID:11360265

  5. Neurilemmoma of Deep Peroneal Nerve Sensory Branch : Thermographic Findings with Compression Test.

    PubMed

    Ryu, Seung Jun; Zhang, Ho Yeol

    2015-09-01

    We report a case of neurilemmoma of deep peroneal nerve sensory branch that triggered sensory change with compression test on lower extremity. After resection of tumor, there are evoked thermal changes on pre- and post-operative infrared (IR) thermographic images. A 52-year-old female presented with low back pain, sciatica, and sensory change on the dorsal side of the right foot and big toe that has lasted for 9 months. She also presented with right tibial mass sized 1.2 cm by 1.4 cm. Ultrasonographic imaging revealed a peripheral nerve sheath tumor arising from the peroneal nerve. IR thermographic image showed hyperthermia when the neurilemoma induced sensory change with compression test on the fibular area, dorsum of foot, and big toe. After surgery, the symptoms and thermographic changes were relieved and disappeared. The clinical, surgical, radiographic, and thermographic perspectives regarding this case are discussed. PMID:26539275

  6. Neurilemmoma of Deep Peroneal Nerve Sensory Branch : Thermographic Findings with Compression Test

    PubMed Central

    Ryu, Seung Jun

    2015-01-01

    We report a case of neurilemmoma of deep peroneal nerve sensory branch that triggered sensory change with compression test on lower extremity. After resection of tumor, there are evoked thermal changes on pre- and post-operative infrared (IR) thermographic images. A 52-year-old female presented with low back pain, sciatica, and sensory change on the dorsal side of the right foot and big toe that has lasted for 9 months. She also presented with right tibial mass sized 1.2 cm by 1.4 cm. Ultrasonographic imaging revealed a peripheral nerve sheath tumor arising from the peroneal nerve. IR thermographic image showed hyperthermia when the neurilemoma induced sensory change with compression test on the fibular area, dorsum of foot, and big toe. After surgery, the symptoms and thermographic changes were relieved and disappeared. The clinical, surgical, radiographic, and thermographic perspectives regarding this case are discussed. PMID:26539275

  7. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas

    NASA Technical Reports Server (NTRS)

    Macias, M. Y.; Lehman, C. T.; Sanger, J. R.; Riley, D. A.

    1998-01-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies.

  8. Degeneration of proprioceptive sensory nerve endings in mice harboring amyotrophic lateral sclerosis-causing mutations.

    PubMed

    Vaughan, Sydney K; Kemp, Zachary; Hatzipetros, Theo; Vieira, Fernando; Valdez, Gregorio

    2015-12-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that primarily targets the motor system. Although much is known about the effects of ALS on motor neurons and glial cells, little is known about its effect on proprioceptive sensory neurons. This study examines proprioceptive sensory neurons in mice harboring mutations associated with ALS, in SOD1(G93A) and TDP43(A315T) transgenic mice. In both transgenic lines, we found fewer proprioceptive sensory neurons containing fluorescently tagged cholera toxin in their soma five days after injecting this retrograde tracer into the tibialis anterior muscle. We asked whether this is due to neuronal loss or selective degeneration of peripheral nerve endings. We found no difference in the total number and size of proprioceptive sensory neuron soma between symptomatic SOD1(G93A) and control mice. However, analysis of proprioceptive nerve endings in muscles revealed early and significant alterations at Ia/II proprioceptive nerve endings in muscle spindles before the symptomatic phase of the disease. Although these changes occur alongside those at α-motor axons in SOD1(G93A) mice, Ia/II sensory nerve endings degenerate in the absence of obvious alterations in α-motor axons in TDP43(A315T) transgenic mice. We next asked whether proprioceptive nerve endings are similarly affected in the spinal cord and found that nerve endings terminating on α-motor neurons are affected during the symptomatic phase and after peripheral nerve endings begin to degenerate. Overall, we show that Ia/II proprioceptive sensory neurons are affected by ALS-causing mutations, with pathological changes starting at their peripheral nerve endings. PMID:26136049

  9. Effect of long-term implanted nerve cuff electrodes on the electrophysiological properties of human sensory nerves.

    PubMed

    Slot, P J; Selmar, P; Rasmussen, A; Sinkjaer, T

    1997-03-01

    During a long-term implantation (307 days) of a tripolar split cuff electrode around the palmar digital nerve to the radial side of the left index finger, branching off the median nerve in a medullary lesioned C6 patient, the physiological state of the nerve was intensively monitored. The resulting sensory nerve action potential (SNAP) amplitude was recorded, using both near-nerve electrodes and the implanted cuff electrode. The SNAP amplitude declined within 10 days to approximately 50% of the first SNAP cuff amplitude measured on Day 2 after implantation and recovered to the initial amplitude within 3 months. The SNAP amplitude measurements made with near-nerve electrodes were consistent with the cuff results; the SNAP conduction velocity (CV) recorded by the near-nerve electrodes and the cuff electrode was constant during the whole implantation period. This is in agreement with the results from two other patients: one with a cuff implanted around the sural nerve, and the other with a cuff implanted around a branch of the tibial nerve. These results and animals studies show that the cuff electrode is an electrically stable neural-electrical transducer. PMID:9148706

  10. BREAST CANCER-INDUCED BONE REMODELING, SKELETAL PAIN AND SPROUTING OF SENSORY NERVE FIBERS

    PubMed Central

    Bloom, Aaron P.; Jimenez-Andrade, Juan M.; Taylor, Reid N.; Castañeda-Corral, Gabriela; Kaczmarska, Magdalena J.; Freeman, Katie T.; Coughlin, Kathleen A.; Ghilardi, Joseph R.; Kuskowski, Michael A.; Mantyh, Patrick W.

    2011-01-01

    Breast cancer metastasis to bone is frequently accompanied by pain. What remains unclear is why this pain tends to become more severe and difficult to control with disease progression. Here we test the hypothesis that with disease progression sensory nerve fibers that innervate the breast cancer bearing bone undergo a pathological sprouting and reorganization, which in other non-malignant pathologies has been shown to generate and maintain chronic pain. Injection of human breast cancer cells (MDA-MB-231-BO) into the femoral intramedullary space of female athymic nude mice induces sprouting of calcitonin gene-related peptide (CGRP+) sensory nerve fibers. Nearly all CGRP+ nerve fibers that undergo sprouting also co-express tropomyosin receptor kinase A (TrkA+) and growth associated protein-43 (GAP43+). This ectopic sprouting occurs in periosteal sensory nerve fibers that are in close proximity to breast cancer cells, tumor-associated stromal cells and remodeled cortical bone. Therapeutic treatment with an antibody that sequesters nerve growth factor (NGF), administered when the pain and bone remodeling were first observed, blocks this ectopic sprouting and attenuates cancer pain. The present data suggest that the breast cancer cells and tumor-associated stromal cells express and release NGF, which drives bone pain and the pathological reorganization of nearby CGRP+ / TrkA+ / GAP43+ sensory nerve fibers. PMID:21497141

  11. Evaluation of the Role of G Protein-Coupled Receptor Kinase 3 in Desensitization of Mouse Odorant Receptors in a Mammalian Cell Line and in Olfactory Sensory Neurons

    PubMed Central

    Kato, Aya; Reisert, Johannes; Ihara, Sayoko; Yoshikawa, Keiichi

    2014-01-01

    Thousands of odors are sensed and discriminated by G protein-coupled odorant receptors (ORs) expressed in olfactory sensory neurons (OSNs). G protein-coupled receptor kinases (GRKs) may have a role in desensitization of ORs. However, whether ORs are susceptible to agonist-dependent desensitization and whether GRKs affect odorant responsiveness of OSNs are currently unknown. Here we show that GRK3 attenuated the agonist responsiveness of a specific mouse odorant receptor for eugenol (mOR-EG) upon agonist pretreatment in HEK293 cells, but GRK3 did not affect the response amplitude or the recovery kinetics upon repeated agonist stimulation. We performed electrophysiological recordings of single OSNs which expressed mOR-EG and green fluorescent protein (GFP) in the presence or absence of GRK3. The kinetics and amplitude of agonist responsiveness of individual GFP-labeled mOR-EG neurons were not significantly affected by the absence of GRK3. These results indicate that the role of GRK3 in attenuating ORs responsiveness in OSNs may have been overestimated. PMID:25313015

  12. Sensory cutaneous nerve fine-needle aspiration in Hansen's disease: A retrospective analysis of our experience

    PubMed Central

    Prasoon, Dev; Mandal, Swapan Kumar; Agrawal, Parimal

    2015-01-01

    Background: Leprosy affects peripheral nerves. As Mycobacterium leprae has unique tropism for Schwann cells, thickened sensory cutaneous nerves provide an easy target for the detection of lepra bacilli and other changes associated with the disease. Materials and Methods: The data of patients with sensory cutaneous nerve involvement were retrieved from our record for the period January 2006 to December 2014. The hematoxylin and eosin (H and E)- and May-Grünwald-Giemsa (MGG)-stained slides were screened for Schwann cells, granuloma, and necrosis. Modified Ziehl-Neelsen (ZN)-stained smears were searched for lepra bacilli and globi. Morphological index was calculated in multibacillary lesions. Result: Twenty-nine sensory cutaneous nerves were aspirated in 23 patients. While 15 cases showed skin and nerve involvement, 8 cases showed only nerve involvement. Terminal cutaneous branch of the radial nerve was most often aspirated. No motor loss was observed after aspiration. Five cytologic pictures were seen — Epithelioid cell granuloma only in 6 cases, epithelioid cell granuloma with necrosis in 1 case, epithelioid cell granuloma with lepra bacilli in 3 cases, necrosis with lepra bacilli in 1 case, and only lepra bacilli in 12 cases. Morphological index ranged from 20% to 80%. Conclusion: Sensory cutaneous nerve fine-needle aspiration (FNA) is a feasible, viable, effective, and safe procedure. It adds to diagnostic FNA yield in patients with concomitant skin involvement and offers a way to evaluate patients with only nerve involvement. Calculation of morphological index allows prognostication and may have a role in assessing response to therapy and/or relapse. PMID:26729977

  13. Neuroplasticity of Sensory and Sympathetic Nerve Fibers in the Painful Arthritic Joint

    PubMed Central

    Ghilardi, Joseph R.; Freeman, Katie T.; Jimenez-Andrade, Juan M.; Coughlin, Kathleen; Kaczmarska, Magdalena J.; Castaneda-Corral, Gabriela; Bloom, Aaron P.; Kuskowski, Michael A.; Mantyh, Patrick W.

    2012-01-01

    Objective Many forms of arthritis are accompanied by significant chronic joint pain. Here we studied whether there is significant sprouting of sensory and sympathetic nerve fibers in the painful arthritic knee joint and whether nerve growth factor (NGF) drives this pathological reorganization. Methods A painful arthritic knee joint was produced by injection of complete Freund’s adjuvant (CFA) into the knee joint of young adult mice. CFA-injected mice were then treated systemically with vehicle or anti-NGF antibody. Pain behaviors were assessed and at 28 days following the initial CFA injection, the knee joints were processed for immunohistochemistry using antibodies raised against calcitonin gene-related peptide (CGRP; sensory nerve fibers), neurofilament 200 kDa (NF200; sensory nerve fibers), growth associated protein-43 (GAP43; sprouted nerve fibers), tyrosine hydroxylase (TH; sympathetic nerve fibers), CD31 (endothelial cells) or CD68 (monocytes/macrophages). Results In CFA-injected mice, but not vehicle-injected mice, there was a significant increase in the density of CD68+ macrophages, CD31+ blood vessels, CGRP+, NF200+, GAP43+, and TH+ nerve fibers in the synovium as well as joint pain-related behaviors. Administration of anti-NGF reduced these pain-related behaviors and the ectopic sprouting of nerve fibers, but had no significant effect on the increase in density of CD31+ blood vessels or CD68+ macrophages. Conclusions Ectopic sprouting of sensory and sympathetic nerve fibers occurs in the painful arthritic joint and may be involved in the generation and maintenance of arthritic pain. PMID:22246649

  14. Selectivity of distal reinnervation of regenerating mixed motor and sensory nerve fibres across muscle grafts in rats.

    PubMed

    Rath, S; Green, C J

    1991-04-01

    This study investigated target specificity during axonal regeneration of a mixed motor and sensory nerve towards respective targets. The femoral nerves in rats were divided and allowed to grow across a 6 mm gap interposed with frozen and thawed muscle grafts towards their distal motor and sensory nerve stumps. Fourteen weeks later the number of motoneurons projecting axons into the motor and sensory branches were determined by retrograde axonal tracing using horse-radish peroxidase. There were significantly higher numbers of motoneurons (p = 0.0034) projecting into the motor nerve than the sensory nerve. Efferent axons of a mixed nerve selectivity grew into motor branches when allowed to regenerate across a 6 mm gap interposed with muscle grafts. It is possible that a deliberately created 'structured gap' during repair of mixed nerves could improve axonal matching by allowing expression of neurotropism. PMID:2025759

  15. Intrafascicular stimulation of monkey arm nerves evokes coordinated grasp and sensory responses

    PubMed Central

    Ledbetter, Noah M.; Ethier, Christian; Oby, Emily R.; Hiatt, Scott D.; Wilder, Andrew M.; Ko, Jason H.; Agnew, Sonya P.; Miller, Lee E.

    2013-01-01

    High-count microelectrode arrays implanted in peripheral nerves could restore motor function after spinal cord injury or sensory function after limb loss. In this study, we implanted Utah Slanted Electrode Arrays (USEAs) intrafascicularly at the elbow or shoulder in arm nerves of rhesus monkeys (n = 4) under isoflurane anesthesia. Input-output curves indicated that pulse-width-modulated single-electrode stimulation in each arm nerve could recruit single muscles with little or no recruitment of other muscles. Stimulus trains evoked specific, natural, hand movements, which could be combined via multielectrode stimulation to elicit coordinated power or pinch grasp. Stimulation also elicited short-latency evoked potentials (EPs) in primary somatosensory cortex, which might be used to provide sensory feedback from a prosthetic limb. These results demonstrate a high-resolution, high-channel-count interface to the peripheral nervous system for restoring hand function after neural injury or disruption or for examining nerve structure. PMID:23076108

  16. Effect of helium-neon laser irradiation on peripheral sensory nerve latency

    SciTech Connect

    Snyder-Mackler, L.; Bork, C.E.

    1988-02-01

    The purpose of this randomized, double-blind study was to determine the effect of a helium-neon (He-Ne) laser on latency of peripheral sensory nerve. Forty healthy subjects with no history of right upper extremity pathological conditions were assigned to either a Laser or a Placebo Group. Six 1-cm2 blocks along a 12-cm segment of the subjects' right superficial radial nerve received 20-second applications of either the He-Ne laser or a placebo. We assessed differences between pretest and posttest latencies with t tests for correlated and independent samples. The Laser Group showed a statistically significant increase in latency that corresponded to a decrease in sensory nerve conduction velocity. Short-duration He-Ne laser application significantly increased the distal latency of the superficial radial nerve. This finding provides information about the mechanism of the reported pain-relieving effect of the He-Ne laser.

  17. Factors predicting sensory and motor recovery after the repair of upper limb peripheral nerve injuries

    PubMed Central

    He, Bo; Zhu, Zhaowei; Zhu, Qingtang; Zhou, Xiang; Zheng, Canbin; Li, Pengliang; Zhu, Shuang; Liu, Xiaolin; Zhu, Jiakai

    2014-01-01

    OBJECTIVE: To investigate the factors associated with sensory and motor recovery after the repair of upper limb peripheral nerve injuries. DATA SOURCES: The online PubMed database was searched for English articles describing outcomes after the repair of median, ulnar, radial, and digital nerve injuries in humans with a publication date between 1 January 1990 and 16 February 2011. STUDY SELECTION: The following types of article were selected: (1) clinical trials describing the repair of median, ulnar, radial, and digital nerve injuries published in English; and (2) studies that reported sufficient patient information, including age, mechanism of injury, nerve injured, injury location, defect length, repair time, repair method, and repair materials. SPSS 13.0 software was used to perform univariate and multivariate logistic regression analyses and to investigate the patient and intervention factors associated with outcomes. MAIN OUTCOME MEASURES: Sensory function was assessed using the Mackinnon-Dellon scale and motor function was assessed using the manual muscle test. Satisfactory motor recovery was defined as grade M4 or M5, and satisfactory sensory recovery was defined as grade S3+ or S4. RESULTS: Seventy-one articles were included in this study. Univariate and multivariate logistic regression analyses showed that repair time, repair materials, and nerve injured were independent predictors of outcome after the repair of nerve injuries (P < 0.05), and that the nerve injured was the main factor affecting the rate of good to excellent recovery. CONCLUSION: Predictors of outcome after the repair of peripheral nerve injuries include age, gender, repair time, repair materials, nerve injured, defect length, and duration of follow-up. PMID:25206870

  18. Acrolein depletes the neuropeptides CGRP and substance P in sensory nerves in rat respiratory tract.

    PubMed Central

    Springall, D R; Edginton, J A; Price, P N; Swanston, D W; Noel, C; Bloom, S R; Polak, J M

    1990-01-01

    The mammalian respiratory tract is densely innervated by autonomic and sensory nerves around airways and blood vessels. Subsets of these nerves contain a number of putative neurotransmitter peptides, such as substance P and calcitonin gene-related peptide (CGRP) in sensory nerves and vasoactive intestinal polypeptide (VIP), possibly serving autonomic functions. CGRP is also found in endocrine cells in rat airway epithelium. These peptides are all pharmacologically potent effectors of bronchial and vascular smooth muscle and bronchial secretion. Their functions in vivo are less well established. We have therefore examined the effects of inhaled acrolein, a sensory irritant, on three pulmonary neuropeptides: CGRP, substance P, and VIP. Groups of rats (n = 3 each) were exposed for 10 min to acrolein in air (Ct = 510, 1858, and 5693 mg.min/m3) or to air alone. Fifteen minutes later they were killed (pentabarbitone IP) and their respiratory tracts were dissected and fixed in 0.4% p-benzoquinone solution. Cryostat sections were stained by indirect immunofluorescence for a general nerve marker (PGP 9.5) and neuropeptides. The acrolein-treated animals had a dose-related decrease in tracheal substance P- and CGRP-immunoreactive nerve fibers compared with controls. No change was seen in total nerve fiber distribution and number (PGP 9.5) or VIP immunoreactivity, nor in CGRP-immunoreactive epithelial endocrine cells. It is concluded that the rat tracheal peptidergic nerves are a sensitive indicator of inhaled irritant substances. Their reduced immunoreactivity may be because of a release of sensory neuropeptides that could play a role in the physiological response to irritant or toxic compounds. Images FIGURE 4. a FIGURE 4. b FIGURE 5. a FIGURE 5. b FIGURE 6. a FIGURE 6. b FIGURE 7. a FIGURE 7. b FIGURE 7. c FIGURE 8. a FIGURE 8. b PMID:1696540

  19. Ca2+/calmodulin-mediated fast desensitization by the B1b subunit of the CNG channel affects response termination but not sensitivity to recurring stimulation in olfactory sensory neurons

    PubMed Central

    Song, Yijun; Cygnar, Katherine D.; Sagdullaev, Botir; Valley, Matthew; Hirsh, Sarah; Stephan, Aaron; Reisert, Johannes; Zhao, Haiqing

    2008-01-01

    Summary Ca2+/calmodulin-mediated negative feedback is a prototypical regulatory mechanism for Ca2+ permeable ion channels. In olfactory sensory neurons (OSNs) such regulation on the cyclic nucleotide-gated (CNG) channel is considered a major mechanism of OSN adaptation. To determine the role of Ca2+/calmodulin desensitization of the olfactory CNG channel, we introduced a mutation in the channel subunit CNGB1b in mice that rendered the channel resistant to fast desensitization by Ca2+/calmodulin. Contrary to expectations, mutant OSNs showed normal receptor current adaptation to repeated stimulation. Rather, they displayed slower response termination and consequently, a reduced ability to transmit olfactory information to the olfactory bulb. They also displayed reduced response decline during sustained odorant exposure. These results suggest that Ca2+/calmodulin-mediated CNG channel fast desensitization is less important in regulating the sensitivity to recurring stimulation than previously thought and instead functions primarily to terminate OSN responses. PMID:18466748

  20. Sensory nerve conduction in branches of common interdigital nerves: a new technique for normal controls and patients with morton's neuroma.

    PubMed

    Uludag, Burhanettin; Tataroglu, Cengiz; Bademkiran, Fikret; Uludag, Irem Fatma; Ertekin, Cumhur

    2010-06-01

    In this article, a new electrodiagnostic approach is described for patients with Morton's neuroma. The new method is based on the anatomic fact that the two branches of the common plantar interdigital nerves innervate the lateral side of one toe and the medial side the next one. This study included 20 normal subjects (aged 28-58 years, 10 men and 10 women) and 4 patients with Morton's neuroma (aged 44-52 years, 4 women). The branches of adjacent common plantar interdigital nerves that innerve one toe were stimulated superficially and separately with half of one toe covered with a piece of medical tape. The recordings were obtained on the posterior tibial nerve at the medial malleolus with needle electrodes. Thus, the difference in latencies of obtained sensory nerve action potentials on the posterior tibial nerve with needle electrode was measured. From normal subjects' data, it was determined that a latency difference value of above 0.17 milliseconds (mean +/- 2.5 SD) in one toe was abnormal. All of the patients with Morton's neuroma showed abnormal interlatency difference values. This new method, which we have developed, is more sensitive, simple to use, does not require extra equipment, and does not cause excessive pain. We suggest that interlatency difference between branches of the common plantar interdigital nerves is a useful and sensitive method for the diagnosis of Morton's neuroma. PMID:20479659

  1. Heightened motor and sensory (mirror-touch) referral induced by nerve block or topical anesthetic.

    PubMed

    Case, Laura K; Gosavi, Radhika; Ramachandran, Vilayanur S

    2013-08-01

    Mirror neurons allow us to covertly simulate the sensation and movement of others. If mirror neurons are sensory and motor neurons, why do we not actually feel this simulation- like "mirror-touch synesthetes"? Might afferent sensation normally inhibit mirror representations from reaching consciousness? We and others have reported heightened sensory referral to phantom limbs and temporarily anesthetized arms. These patients, however, had experienced illness or injury of the deafferented limb. In the current study we observe heightened sensory and motor referral to the face after unilateral nerve block for routine dental procedures. We also obtain double-blind, quantitative evidence of heightened sensory referral in healthy participants completing a mirror-touch confusion task after topical anesthetic cream is applied. We suggest that sensory and motor feedback exist in dynamic equilibrium with mirror representations; as feedback is reduced, the brain draws more upon visual information to determine- perhaps in a Bayesian manner- what to feel. PMID:23791606

  2. Phenotyping sensory nerve endings in vitro in the mouse

    PubMed Central

    Zimmermann, Katharina; Hein, Alexander; Hager, Ulrich; Kaczmarek, Jan Stefan; Turnquist, Brian P; Clapham, David E; Reeh, Peter W

    2014-01-01

    This protocol details methods to identify and record from cutaneous primary afferent axons in an isolated mammalian skin–saphenous nerve preparation. The method is based on extracellular recordings of propagated action potentials from single-fiber receptive fields. Cutaneous nerve endings show graded sensitivities to various stimulus modalities that are quantified by adequate and controlled stimulation of the superfused skin with heat, cold, touch, constant punctate pressure or chemicals. Responses recorded from single-fibers are comparable with those obtained in previous in vivo experiments on the same species. We describe the components and the setting-up of the basic equipment of a skin–nerve recording station (few days), the preparation of the skin and the adherent saphenous nerve in the mouse (15–45 min) and the isolation and recording of neurons (approximately 1–3 h per recording). In addition, stimulation techniques, protocols to achieve single-fiber recordings, issues of data acquisition and action potential discrimination are discussed in detail. PMID:19180088

  3. Early social isolation provokes electrophysiological and structural changes in cutaneous sensory nerves of adult male rats.

    PubMed

    Segura, Bertha; Melo, Angel I; Fleming, Alison S; Mendoza-Garrido, Maria Eugenia; González del Pliego, Margarita; Aguirre-Benitez, Elsa L; Hernández-Falcón, Jesús; Jiménez-Estrada, Ismael

    2014-12-01

    Sensory and social deprivation from the mother and littermates during early life disturbs the development of the central nervous system, but little is known about its effect on the development of the peripheral nervous system. To assess peripheral effects of early isolation, male rat pups were reared artificially in complete social isolation (AR); reared artificially with two same-age conspecifics (AR-Social); or reared by their mothers and with littermates (MR). As adults, the electrophysiological properties of the sensory sural (SU) nerve were recorded. We found that the amplitude and normalized area (with respect to body weight) of the compound action potential (CAP) response provoked by single electrical pulses of graded intensity in the SU nerves of AR animals were shorter than the CAP recorded in SU nerves from MR and AR-Social animals. The slope of the stimulus-response curve of AR SU nerves was smaller than that of the other nerves. The histological characterization of axons in the SU nerves was made and showed that the myelin thickness of axons in AR SU nerves was significant lower (2-7µm) than that of the axons in the other nerves. Furthermore, the area and axon diameter of SU nerves of both AR and AR-Social animals were significant lower than in MR animals. This is the first report to show that maternal and littermate deprivation by AR disturbs the development of the myelination and electrophysiological properties of axons in the SU nerve; the replacement of social cues prevents most of the effects. PMID:24897933

  4. Painful nerve injury increases plasma membrane Ca2+-ATPase activity in axotomized sensory neurons

    PubMed Central

    2012-01-01

    Background The plasma membrane Ca2+-ATPase (PMCA) is the principal means by which sensory neurons expel Ca2+ and thereby regulate the concentration of cytoplasmic Ca2+ and the processes controlled by this critical second messenger. We have previously found that painful nerve injury decreases resting cytoplasmic Ca2+ levels and activity-induced cytoplasmic Ca2+ accumulation in axotomized sensory neurons. Here we examine the contribution of PMCA after nerve injury in a rat model of neuropathic pain. Results PMCA function was isolated in dissociated sensory neurons by blocking intracellular Ca2+ sequestration with thapsigargin, and cytoplasmic Ca2+ concentration was recorded with Fura-2 fluorometry. Compared to control neurons, the rate at which depolarization-induced Ca2+ transients resolved was increased in axotomized neurons after spinal nerve ligation, indicating accelerated PMCA function. Electrophysiological recordings showed that blockade of PMCA by vanadate prolonged the action potential afterhyperpolarization, and also decreased the rate at which neurons could fire repetitively. Conclusion We found that PMCA function is elevated in axotomized sensory neurons, which contributes to neuronal hyperexcitability. Accelerated PMCA function in the primary sensory neuron may contribute to the generation of neuropathic pain, and thus its modulation could provide a new pathway for peripheral treatment of post-traumatic neuropathic pain. PMID:22713297

  5. Changes induced by peripheral nerve injury in the morphology and nanomechanics of sensory neurons

    NASA Astrophysics Data System (ADS)

    Benzina, Ouafa; Szabo, Vivien; Lucas, Olivier; Saab, Marie-belle; Cloitre, Thierry; Scamps, Frédérique; Gergely, Csilla; Martin, Marta

    2013-06-01

    Peripheral nerve injury in vivo promotes a regenerative growth in vitro characterized by an improved neurite regrowth. Knowledge of the conditioning injury effects on both morphology and mechanical properties of live sensory neurons could be instrumental to understand the cellular and molecular mechanisms leading to this regenerative growth. In the present study, we use differential interference contrast microscopy, fluorescence microscopy and atomic force microscopy (AFM) to show that conditioned axotomy, induced by sciatic nerve injury, does not increase somatic size of sensory neurons from adult mice lumbar dorsal root ganglia but promotes the appearance of longer and larger neurites and growth cones. AFM on live neurons is also employed to investigate changes in morphology and membrane mechanical properties of somas of conditioned neurons following sciatic nerve injury. Mechanical analysis of the soma allows distinguishing neurons having a regenerative growth from control ones, although they show similar shapes and sizes.

  6. Electrical neurostimulation for chronic pain: On selective relay of sensory neural activities in myelinated nerve fibers.

    PubMed

    Sacré, Pierre; Sarma, Sridevi V; Guan, Yun; Anderson, William S

    2015-08-01

    Chronic pain affects about 100 million adults in the US. Despite their great need, neuropharmacology and neurostimulation therapies for chronic pain have been associated with suboptimal efficacy and limited long-term success, as their mechanisms of action are unclear. Yet current computational models of pain transmission suffer from several limitations. In particular, dorsal column models do not include the fundamental underlying sensory activity traveling in these nerve fibers. We developed a (simple) simulation test bed of electrical neurostimulation of myelinated nerve fibers with underlying sensory activity. This paper reports our findings so far. Interactions between stimulation-evoked and underlying activities are mainly due to collisions of action potentials and losses of excitability due to the refractory period following an action potential. In addition, intuitively, the reliability of sensory activity decreases as the stimulation frequency increases. This first step opens the door to a better understanding of pain transmission and its modulation by neurostimulation therapies. PMID:26737344

  7. Precision pinch performance in patients with sensory deficits of the median nerve at the carpal tunnel.

    PubMed

    Yen, Wei-Jang; Kuo, Yao-Lung; Kuo, Li-Chieh; Chen, Shu-Min; Kuan, Ta-Shen; Hsu, Hsiu-Yun

    2014-01-01

    To investigate how sensory symptoms impact the motor control of hands, in this study we examined the differences in conventional sensibility assessments and pinch force control in the pinch-holding-up activity (PHUA) test between carpal tunnel syndrome (CTS) patients and healthy controls. CTS patients (n = 82) with 122 affected hands and an equal number of control subjects were recruited to participate in the threshold, discrimination, and PHUA tests. The patients showed significantly poorer hand sensibility and lower efficiency of force adjustment in the PHUA test as compared with the control subjects. Baseline pinch strength and the percentage of maximal pinch strength for the PHUA were significantly higher for the subgroup of sensory nerve action potential (SNAP) of <16 μV than for the subgroup of SNAP of 16 μV. Using a PHUA perspective to analyze the efficiency of force-adjustment could assist the clinical detection of sensory nerve dysfunction. PMID:24496877

  8. Sensory perturbations using suture and sutureless repair of transected median nerve in rats.

    PubMed

    Shaikh, Sumaiya; Shortland, Peter; Lauto, Antonio; Barton, Matthew; Morley, John W; Mahns, David A

    2016-03-01

    The effects of changes to cold, mechanical, and heat thresholds following median nerve transection with repair by sutures (Su) or Rose Bengal adhesion (RA) were compared to sham-operated animals. Both nerve-injured groups showed a transient, ipsilateral hyposensitivity to mechanical and heat stimuli followed by a robust and long-lasting hypersensitivity (6-7 weeks) with gradual recovery towards pre-injury levels by 90 days post-repair. Both tactile and thermal hypersensitivity were seen in the contralateral limb that was similar in onset but differed in magnitude and resolved more rapidly compared to the injured limb. Prior to injury, no animals showed any signs of aversion to cold plate temperatures of 4-16 °C. After injury, animals showed cold allodynia, lasting for 7 weeks in RA-repaired rats before recovering towards pre-injury levels, but were still present at 12 weeks in Su-repaired rats. Additionally, sensory recovery in the RA group was faster compared to the Su group in all behavioural tests. Surprisingly, sham-operated rats showed similar bilateral behavioural changes to all sensory stimuli that were comparable in onset and magnitude to the nerve-injured groups but resolved more quickly compared to nerve-injured rats. These results suggest that nerve repair using a sutureless approach produces an accelerated recovery with reduced sensorimotor disturbances compared to direct suturing. They also describe, for the first time, that unilateral forelimb nerve injury produces mirror-image-like sensory perturbations in the contralateral limb, suggesting that the contralateral side is not a true control for sensory testing. The potential mechanisms involved in this altered behaviour are discussed. PMID:26899181

  9. Recording sensory and motor information from peripheral nerves with Utah Slanted Electrode Arrays.

    PubMed

    Clark, Gregory A; Ledbetter, Noah M; Warren, David J; Harrison, Reid R

    2011-01-01

    Recording and stimulation via high-count penetrating microelectrode arrays implanted in peripheral nerves may help restore precise motor and sensory function after nervous system damage or disease. Although previous work has demonstrated safety and relatively successful stimulation for long-term implants of 100-electrode Utah Slanted Electrode Arrays (USEAs) in feline sciatic nerve [1], two major remaining challenges were 1) to maintain viable recordings of nerve action potentials long-term, and 2) to overcome contamination of unit recordings by myoelectric (EMG) activity in awake, moving animals. In conjunction with improvements to USEAs themselves, we have redesigned several aspects of our USEA containment and connector systems. Although further increases in unit yield and long-term stability remain desirable, here we report considerable progress toward meeting both of these goals: We have successfully recorded unit activity from USEAs implanted intrafascicularly in sciatic nerve for periods up to 4 months (the terminal experimental time point), and we have developed a containment system that effectively eliminates or substantially reduces EMG contamination of unit recordings in the moving animal. In addition, we used a 100-channel wireless recording integrated circuit attached to implanted USEAs to transmit broadband or spike-threshold data from nerve. Neural data thusly obtained during imposed limb movements were decoded blindly to drive a virtual prosthetic limb in real time. These results support the possibility of using USEAs in peripheral nerves to provide motor control and cutaneous or proprioceptive sensory feedback in individuals after limb loss or spinal cord injury. PMID:22255372

  10. Menthol Enhances the Desensitization of Human α3β4 Nicotinic Acetylcholine Receptors.

    PubMed

    Ton, Hoai T; Smart, Amanda E; Aguilar, Brittany L; Olson, Thao T; Kellar, Kenneth J; Ahern, Gerard P

    2015-08-01

    The α3β4 nicotinic acetylcholine receptor (nAChR) subtype is widely expressed in the peripheral and central nervous systems, including in airway sensory nerves. The nAChR subtype transduces the irritant effects of nicotine in tobacco smoke and, in certain brain areas, may be involved in nicotine addiction and/or withdrawal. Menthol, a widely used additive in cigarettes, is a potential analgesic and/or counterirritant at sensory nerves and may also influence nicotine's actions in the brain. We examined menthol's effects on recombinant human α3β4 nAChRs and native nAChRs in mouse sensory neurons. Menthol markedly decreased nAChR activity as assessed by Ca(2+) imaging, (86)Rb(+) efflux, and voltage-clamp measurements. Coapplication of menthol with acetylcholine or nicotine increased desensitization, demonstrated by an increase in the rate and magnitude of the current decay and a reduction of the current integral. These effects increased with agonist concentration. Pretreatment with menthol followed by its washout did not affect agonist-induced desensitization, suggesting that menthol must be present during the application of agonist to augment desensitization. Notably, menthol acted in a voltage-independent manner and reduced the mean open time of single channels without affecting their conductance, arguing against a simple channel-blocking effect. Further, menthol slowed or prevented the recovery of nAChRs from desensitization, indicating that it probably stabilizes a desensitized state. Moreover, menthol at concentrations up to 1 mM did not compete for the orthosteric nAChR binding site labeled by [(3)H]epibatidine. Taken together, these data indicate that menthol promotes desensitization of α3β4 nAChRs by an allosteric action. PMID:25964258

  11. Systemic labeling and visualization of dental sensory nerves by the novel fluorescent marker AM1-43.

    PubMed

    Nishikawa, Sumio

    2006-09-01

    Systemic labeling of sensory nerves was performed by injecting a small amount of the styryl dye AM1-43 subcutaneously to the back skin of 4-week-old mice in order to determine its ability to stain sensory nerves. One or 3 days later, dental tissues were fixed and cryosectioned. Molars showed bright nerve fibers in the periodontal ligament and pulp. Nerve fibers in dentinal tubules approximately 100 microm from the pulp were also labeled. In the incisor, there were only few labelings in the pulp, although free nerve endings and Ruffini-type mechanosensors in the periodontal ligament on the lingual side were brightly labeled. The AM1-43-positive fibers were also labeled by anti-PGP9.5. AM1-43 is an excellent marker for sensory nerves and it may be useful for further investigations of dental innervation and in exploring new analgesics for tooth pain. PMID:16955669

  12. Reappraisal of Supraorbital Sensory Nerve Conduction Recordings: Orthodromic and Antidromic Techniques

    PubMed Central

    Park, Hyeun Jun; Kim, Sung-Hoon; Lee, Se Kwang; Lee, Hang Jae

    2016-01-01

    Objective To establish a supraorbital nerve sensory conduction recording method and assess its usefulness. Methods Thirty-one healthy subjects without a history of trauma or neurological disease were recruited. For the orthodromic procedure, the recording electrode was attached immediately superior to the supraorbital notch. The stimulation electrode was placed on points along the hairline which evoked the largest sensory nerve action potentials (SNAPs). The antidromic sensory response was recorded after switching the recording and stimulating electrodes. The measured parameters were onset latency, peak latency, and baseline to peak amplitude of the SNAPs. The electrophysiological parameters of the bilateral supraorbital nerves were compared. We also recruited two patients who had sensory deficits on one side of their foreheads because of laceration injuries. Results The parameters of orthodromically recorded SNAPs were as follows: onset latency 1.21±0.22 ms (range, 0.9–1.6 ms), peak latency 1.54±0.23 ms (range, 1.2–2.2 ms), and baseline to peak amplitude 4.16±1.92 µV (range, 1.4–10 µV). Those of antidromically recorded SNAPs were onset latency 1.31±0.27 ms (range, 0.8–1.7 ms), peak latency 1.62±0.29 ms (range, 1.3–2.2 ms), and baseline to peak amplitude 4.00±1.89 µV (range, 1.5–9.0 µV). There was no statistical difference in onset latency, peak latency, or baseline to peak amplitude between the responses obtained using the orthodromic and antidromic methods, and the parameters also revealed no statistical difference between the supraorbital nerves on both sides. Conclusion We have successfully recorded supraorbital SNAPs. This conduction technique could be quite useful in evaluating patients with supraorbital nerve lesions. PMID:26949668

  13. Normal threshold values for a monofilament sensory test in sural and radial cutaneous nerves in Indian and Nepali volunteers.

    PubMed

    Wagenaar, Inge; Brandsma, Wim; Post, Erik; Richardus, Jan Hendrik

    2014-12-01

    The monofilament test (MFT) is a reliable method to assess sensory nerve function in leprosy and other neuropathies. Assessment of the radial cutaneous and sural nerves, in addition to nerves usually tested, can help improve diagnosis and monitoring of nerve function impairment (NFI). To enable the detection of impairments in leprosy patients, it is essential to know the monofilament threshold of these two nerves in normal subjects. The radial cutaneous, sural, ulnar, median and posterior tibial nerves of 245 volunteers were tested. All nerves were tested at three sites on both left and right sides. Normal monofilament thresholds were calculated per test-site and per nerve. We assessed 490 radial cutaneous and 482 sural nerves. The normal monofilament was 2 g (Filament Index Number (FIN) 4.31) for the radial cutaneous and 4 g (FIN 4.56) for the sural nerve, although heavy manual laborers demonstrated a threshold of 10 g (FIN 5.07) for the sural nerve. For median and ulnar nerves, the 200 mg (FIN 3.61) filament was confirmed as normal while the 4 g (FIN 4.56) filament was normal for the posterior tibial. Age and occupation have an effect on the mean touch sensitivity but do not affect the normal threshold for the radial cutaneous and sural nerves. The normal thresholds for the radial cutaneous and sural nerves are determined as the 2 g (FIN 4.31) and the 4 g (FIN 4.56) filaments, respectively. The addition of the radial cutaneous and sural nerve to sensory nerve assessment may improve the diagnosis of patients with impaired sensory nerve function. PMID:25675652

  14. Influence of immobilization and sensory re-education on the sensory recovery after reconstruction of digital nerves with direct suture or muscle-in-vein conduits

    PubMed Central

    Manoli, Theodora; Schiefer, Jennifer Lynn; Schulz, Lukas; Fuchsberger, Thomas; Schaller, Hans-Eberhard

    2016-01-01

    The influence of duration of immobilization and postoperative sensory re-education on the final outcome after reconstruction of digital nerves with direct suture or muscle-in-vein conduits was investigated. The final sensory outcome of 35 patients with 41 digital nerve injuries, who either underwent a direct suture (DS) or a nerve reconstruction with muscle-in-vein conduits (MVC), was assessed the earliest 12 months postoperatively using static and moving two-point discrimination as well as Semmes-Weinstein monofilaments. There was no significant difference in sensory recovery in cases with an immobilization of 3–7 days versus 10 days in the DS or MVC group. Moreover, no statistically significant difference in sensory recovery was found in cases receiving postoperative sensory re-education versus those not receiving in the DS or MVC group. An early mobilization does not seem to have a negative impact on the final outcome after digital nerve reconstruction. The effect of sensory re-education after digital nerve reconstruction should be reconsidered. PMID:27073390

  15. The relationship of nerve fibre pathology to sensory function in entrapment neuropathy.

    PubMed

    Schmid, Annina B; Bland, Jeremy D P; Bhat, Manzoor A; Bennett, David L H

    2014-12-01

    Surprisingly little is known about the impact of entrapment neuropathy on target innervation and the relationship of nerve fibre pathology to sensory symptoms and signs. Carpal tunnel syndrome is the most common entrapment neuropathy; the aim of this study was to investigate its effect on the morphology of small unmyelinated as well as myelinated sensory axons and relate such changes to somatosensory function and clinical symptoms. Thirty patients with a clinical and electrophysiological diagnosis of carpal tunnel syndrome [17 females, mean age (standard deviation) 56.4 (15.3)] and 26 age and gender matched healthy volunteers [18 females, mean age (standard deviation) 51.0 (17.3)] participated in the study. Small and large fibre function was examined with quantitative sensory testing in the median nerve territory of the hand. Vibration and mechanical detection thresholds were significantly elevated in patients with carpal tunnel syndrome (P<0.007) confirming large fibre dysfunction and patients also presented with increased thermal detection thresholds (P<0.0001) indicative of C and Aδ-fibre dysfunction. Mechanical and thermal pain thresholds were comparable between groups (P>0.13). A skin biopsy was taken from a median nerve innervated area of the proximal phalanx of the index finger. Immunohistochemical staining for protein gene product 9.5 and myelin basic protein was used to evaluate morphological features of unmyelinated and myelinated axons. Evaluation of intraepidermal nerve fibre density showed a striking loss in patients (P<0.0001) confirming a significant compromise of small fibres. The extent of Meissner corpuscles and dermal nerve bundles were comparable between groups (P>0.07). However, patients displayed a significant increase in the percentage of elongated nodes (P<0.0001), with altered architecture of voltage-gated sodium channel distribution. Whereas neither neurophysiology nor quantitative sensory testing correlated with patients' symptoms or

  16. Long-Standing Motor and Sensory Recovery following Acute Fibrin Sealant Based Neonatal Sciatic Nerve Repair.

    PubMed

    Perussi Biscola, Natalia; Politti Cartarozzi, Luciana; Ferreira Junior, Rui Seabra; Barraviera, Benedito; Leite Rodrigues de Oliveira, Alexandre

    2016-01-01

    Brachial plexus lesion results in loss of motor and sensory function, being more harmful in the neonate. Therefore, this study evaluated neuroprotection and regeneration after neonatal peripheral nerve coaptation with fibrin sealant. Thus, P2 neonatal Lewis rats were divided into three groups: AX: sciatic nerve axotomy (SNA) without treatment; AX+FS: SNA followed by end-to-end coaptation with fibrin sealant derived from snake venom; AX+CFS: SNA followed by end-to-end coaptation with commercial fibrin sealant. Results were analyzed 4, 8, and 12 weeks after lesion. Astrogliosis, microglial reaction, and synapse preservation were evaluated by immunohistochemistry. Neuronal survival, axonal regeneration, and ultrastructural changes at ventral spinal cord were also investigated. Sensory-motor recovery was behaviorally studied. Coaptation preserved synaptic covering on lesioned motoneurons and led to neuronal survival. Reactive gliosis and microglial reaction decreased in the same groups (AX+FS, AX+CFS) at 4 weeks. Regarding axonal regeneration, coaptation allowed recovery of greater number of myelinated fibers, with improved morphometric parameters. Preservation of inhibitory synaptic terminals was accompanied by significant improvement in the motor as well as in the nociceptive recovery. Overall, the present data suggest that acute repair of neonatal peripheral nerves with fibrin sealant results in neuroprotection and regeneration of motor and sensory axons. PMID:27446617

  17. Hyperglycemia- and neuropathy-induced changes in mitochondria within sensory nerves

    PubMed Central

    Hamid, Hussein S; Mervak, Colin M; Münch, Alexandra E; Robell, Nicholas J; Hayes, John M; Porzio, Michael T; Singleton, J Robinson; Smith, A Gordon; Feldman, Eva L; Lentz, Stephen I

    2014-01-01

    Objective This study focused on altered mitochondrial dynamics as a potential mechanism for diabetic peripheral neuropathy (DPN). We employed both an in vitro sensory neuron model and an in situ analysis of human intraepidermal nerve fibers (IENFs) from cutaneous biopsies to measure alterations in the size distribution of mitochondria as a result of hyperglycemia and diabetes, respectively. Methods Neurite- and nerve-specific mitochondrial signals within cultured rodent sensory neurons and human IENFs were measured by employing a three-dimensional visualization and quantification technique. Skin biopsies from distal thigh (DT) and distal leg (DL) were analyzed from three groups of patients; patients with diabetes and no DPN, patients with diabetes and confirmed DPN, and healthy controls. Results This analysis demonstrated an increase in mitochondria distributed within the neurites of cultured sensory neurons exposed to hyperglycemic conditions. Similar changes were observed within IENFs of the DT in DPN patients compared to controls. This change was represented by a significant shift in the size frequency distribution of mitochondria toward larger mitochondria volumes within DT nerves of DPN patients. There was a length-dependent difference in mitochondria within IENFs. Distal leg IENFs from control patients had a significant shift toward larger volumes of mitochondrial signal compared to DT IENFs. Interpretation The results of this study support the hypothesis that altered mitochondrial dynamics may contribute to DPN pathogenesis. Future studies will examine the potential mechanisms that are responsible for mitochondrial changes within IENFs and its effect on DPN pathogenesis. PMID:25493271

  18. Long-Standing Motor and Sensory Recovery following Acute Fibrin Sealant Based Neonatal Sciatic Nerve Repair

    PubMed Central

    Ferreira Junior, Rui Seabra

    2016-01-01

    Brachial plexus lesion results in loss of motor and sensory function, being more harmful in the neonate. Therefore, this study evaluated neuroprotection and regeneration after neonatal peripheral nerve coaptation with fibrin sealant. Thus, P2 neonatal Lewis rats were divided into three groups: AX: sciatic nerve axotomy (SNA) without treatment; AX+FS: SNA followed by end-to-end coaptation with fibrin sealant derived from snake venom; AX+CFS: SNA followed by end-to-end coaptation with commercial fibrin sealant. Results were analyzed 4, 8, and 12 weeks after lesion. Astrogliosis, microglial reaction, and synapse preservation were evaluated by immunohistochemistry. Neuronal survival, axonal regeneration, and ultrastructural changes at ventral spinal cord were also investigated. Sensory-motor recovery was behaviorally studied. Coaptation preserved synaptic covering on lesioned motoneurons and led to neuronal survival. Reactive gliosis and microglial reaction decreased in the same groups (AX+FS, AX+CFS) at 4 weeks. Regarding axonal regeneration, coaptation allowed recovery of greater number of myelinated fibers, with improved morphometric parameters. Preservation of inhibitory synaptic terminals was accompanied by significant improvement in the motor as well as in the nociceptive recovery. Overall, the present data suggest that acute repair of neonatal peripheral nerves with fibrin sealant results in neuroprotection and regeneration of motor and sensory axons. PMID:27446617

  19. Emerging Relationships between Exercise, Sensory Nerves, and Neuropathic Pain

    PubMed Central

    Cooper, Michael A.; Kluding, Patricia M.; Wright, Douglas E.

    2016-01-01

    The utilization of physical activity as a therapeutic tool is rapidly growing in the medical community and the role exercise may offer in the alleviation of painful disease states is an emerging research area. The development of neuropathic pain is a complex mechanism, which clinicians and researchers are continually working to better understand. The limited therapies available for alleviation of these pain states are still focused on pain abatement and as opposed to treating underlying mechanisms. The continued research into exercise and pain may address these underlying mechanisms, but the mechanisms which exercise acts through are still poorly understood. The objective of this review is to provide an overview of how the peripheral nervous system responds to exercise, the relationship of inflammation and exercise, and experimental and clinical use of exercise to treat pain. Although pain is associated with many conditions, this review highlights pain associated with diabetes as well as experimental studies on nerve damages-associated pain. Because of the global effects of exercise across multiple organ systems, exercise intervention can address multiple problems across the entire nervous system through a single intervention. This is a double-edged sword however, as the global interactions of exercise also require in depth investigations to include and identify the many changes that can occur after physical activity. A continued investment into research is necessary to advance the adoption of physical activity as a beneficial remedy for neuropathic pain. The following highlights our current understanding of how exercise alters pain, the varied pain models used to explore exercise intervention, and the molecular pathways leading to the physiological and pathological changes following exercise intervention. PMID:27601974

  20. Emerging Relationships between Exercise, Sensory Nerves, and Neuropathic Pain.

    PubMed

    Cooper, Michael A; Kluding, Patricia M; Wright, Douglas E

    2016-01-01

    The utilization of physical activity as a therapeutic tool is rapidly growing in the medical community and the role exercise may offer in the alleviation of painful disease states is an emerging research area. The development of neuropathic pain is a complex mechanism, which clinicians and researchers are continually working to better understand. The limited therapies available for alleviation of these pain states are still focused on pain abatement and as opposed to treating underlying mechanisms. The continued research into exercise and pain may address these underlying mechanisms, but the mechanisms which exercise acts through are still poorly understood. The objective of this review is to provide an overview of how the peripheral nervous system responds to exercise, the relationship of inflammation and exercise, and experimental and clinical use of exercise to treat pain. Although pain is associated with many conditions, this review highlights pain associated with diabetes as well as experimental studies on nerve damages-associated pain. Because of the global effects of exercise across multiple organ systems, exercise intervention can address multiple problems across the entire nervous system through a single intervention. This is a double-edged sword however, as the global interactions of exercise also require in depth investigations to include and identify the many changes that can occur after physical activity. A continued investment into research is necessary to advance the adoption of physical activity as a beneficial remedy for neuropathic pain. The following highlights our current understanding of how exercise alters pain, the varied pain models used to explore exercise intervention, and the molecular pathways leading to the physiological and pathological changes following exercise intervention. PMID:27601974

  1. Localization of NADPH Oxidase in Sympathetic and Sensory Ganglion Neurons and Perivascular Nerve Fibers

    PubMed Central

    Cao, Xian; Demel, Stacie L.; Quinn, Mark T.; Galligan, James J.; Kreulen, David L.

    2009-01-01

    Superoxide anion (O2−•) production was previously reported to be increased in celiac ganglia (CG) during DOCA-salt hypertension, possibly via activation of the reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase. This suggested a role for neuronal NADPH oxidase in autonomic neurovascular control. However, the expression and localization of NADPH oxidase in the peripheral neurons is not fully known. The purpose of this study was to examine the subcellular localization of NADPH oxidase in sympathetic and sensory ganglion neurons and perivascular nerve fibers. In rat CG, p22phox and neuropeptide Y (NPY) were colocalized in all neurons. P22phox was also localized to dorsal root ganglia (DRG) neurons that contain calcitonin gene related peptide (CGRP). In mesenteric arteries, p22phox and p47phox were colocalized with NPY or CGRP in perivascular nerve terminals. A similar pattern of nerve terminal staining of p22phox and p47phox was also found in cultured CG neurons and nerve growth factor (NGF)-differentiated PC12 cells. These data demonstrate a previously uncharacterized localization of NADPH oxidase in perivascular nerve fibers. The presence of a O2−• – generating enzyme in close vicinity to the sites of neurotransmitter handling in the nerve fibers suggests the possibility of novel redox-mediated mechanisms in peripheral neurovascular control. PMID:19716351

  2. Comparison of skin sensory thresholds using pre-programmed or single-frequency transcutaneous electrical nerve stimulation

    PubMed Central

    Kang, Jong Ho

    2015-01-01

    [Purpose] The purpose of the present study was to compare the sensory thresholds of healthy subjects using pre-programmed or single-frequency transcutaneous electrical nerve stimulation. [Subjects] Ninety healthy adult subjects were randomly assigned to pre-programmed or single-frequency stimulation groups, each consisting of 45 participants. [Methods] Sensory thresholds were measured in the participants’ forearms using von Frey filaments before and after pre-programmed or single-frequency transcutaneous electrical nerve stimulation, and the result in values were analyzed. [Results] Significant increases in sensory threshold after stimulation were observed in both groups. However, there were no significant differences between the two groups in sensory thresholds after stimulation or in the magnitude of threshold increases following stimulation. [Conclusion] Our results show that there are no differences between sensory threshold increases induced by pre-programmed and single-frequency transcutaneous electrical nerve stimulation. PMID:26834358

  3. Spontaneous pain in partial nerve injury models of neuropathy and the role of nociceptive sensory cover.

    PubMed

    Koplovitch, Pini; Minert, Anne; Devor, Marshall

    2012-07-01

    Spontaneous pain is difficult to measure in animals. One proposed biomarker of spontaneous pain is autotomy, a behavior frequently observed in rats with complete hindpaw denervation (the neuroma model of neuropathic pain). A large body of evidence suggests that this behavior reflects spontaneous dysesthesic sensations akin to phantom limb pain or anesthesia dolorosa. After partial paw denervation, such as in the spared nerve injury (SNI) model of neuropathic pain, autotomy is rare. Does this mean that spontaneous pain is absent? We denervated hindpaws in two stages: SNI surgery completed 7 or 28 days later by transection of the saphenous and sural nerves (SaSu). Minimal autotomy was evoked by the first stage. But it started rapidly after SaSu surgery rendered the limb numb, much more rapidly than after denervation in a single stage (neuroma model). The acceleration was proportional to the delay between the two surgeries. This "priming" effect of the first surgery indicates that the neural substrate of autotomy, spontaneous neuropathic pain, was not initiated by the onset of numbness, but rather by the first, SNI surgery. But the animal's pain experience was occult. The saphenous and sural nerves provided nociceptive sensory cover for the paw, preventing the behavioral expression of the spontaneous pain in the form of autotomy. The results support prior observations suggesting that partial nerve injury triggers spontaneous pain as well as allodynia, and illustrate the importance of nociceptive sensory cover in the prevention of self-inflicted limb injury. PMID:22548979

  4. NT-3 modulates NPY expression in primary sensory neurons following peripheral nerve injury

    PubMed Central

    STERNE, G. D.; BROWN, R. A.; GREEN, C. J.; TERENGHI, G.

    1998-01-01

    Peripheral nerve transection induces significant changes in neuropeptide expression and content in injured primary sensory neurons, possibly due to loss of target derived neurotrophic support. This study shows that neurotrophin-3 (NT-3) delivery to the injured nerve influences neuropeptide Y (NPY) expression within dorsal root ganglia (DRG) neurons. NT-3 was delivered by grafting impregnated fibronectin (500 ng/ml; NT group) in the axotomised sciatic nerve. Animals grafted with plain fibronectin mats (FN) or nerve grafts (NG) were used as controls. L4 and L5 DRG from operated and contralateral sides were harvested between 5 and 240 d. Using immunohistochemistry and computerised image analysis the percentage, diameter and optical density of neurons expressing calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP) and NPY were quantified. Sciatic nerve axotomy resulted in significant reduction in expression of CGRP and SP, and significant upregulation of VIP and NPY (P<0.05 for ipsilateral vs contralateral DRG). By d 30, exogenous NT-3 and nerve graft attenuated the upregulation of NPY (P<0.05 for NT and NG vs FN). However, NT-3 administration did not influence the expression of CGRP, SP or VIP. The mean cell diameter of NPY immunoreactive neurons was significantly smaller in the NT-3 group (P<0.05 for NT vs FN and NG) suggesting a differential influence of NT-3 on larger neurons. The optical densities of NPY immunoreactive neurons of equal size were the same in each group at any time point, indicating that the neurons responding to NT-3 downregulate NPY expression to levels not detectable by immunohistochemistry. These results demonstrate that targeted administration of NT-3 regulates the phenotype of a NPY-immunoreactive neuronal subpopulation in the dorsal root ganglia, a further evidence of the trophic role of neurotrophins on primary sensory neurons. PMID:9827642

  5. [Should biopsy be done on the sensory branch of the radial nerve in leprosy patients? Apropos of 112 cases].

    PubMed

    Grauwin, M Y; Dieye, M; Mane, I; Cartel, J L

    1997-01-01

    Biopsies of the superficial sensory branch of the radial nerve are contested. Some authors mention it to be simple and without harm, but others are formally against this procedure. At ILAD, 274 biopsies were made between 1986 to 1992. We present a review of 112 leprosy patients for whom biopsy was done. On 112 reexamined patients, we observed 2 benign neuroma, hence 2%. The comparison of nerve function before biopsy and after, of 63 of the 112 patients, reexamination shows no significant modification of the functional score. Given even the occurrence of benign neuroma in only 2% of the cases, the authors do not recommend the biopsy of the superficial sensory branch of the radial nerve. For research purposes on neuritis in leprosy, as well as to assure diagnosis in primary neuritic leprosy, we propose the biopsy of the sensory branch of the musculo cutaneous nerve at elbow level. PMID:9131938

  6. Intervertebral disc, sensory nerves and neurotrophins: who is who in discogenic pain?

    PubMed Central

    García-Cosamalón, José; del Valle, Miguel E; Calavia, Marta G; García-Suárez, Olivia; López-Muñiz, Alfonso; Otero, Jesús; Vega, José A

    2010-01-01

    The normal intervertebral disc (IVD) is a poorly innervated organ supplied only by sensory (mainly nociceptive) and postganglionic sympathetic (vasomotor efferents) nerve fibers. Interestingly, upon degeneration, the IVD becomes densely innervated even in regions that in normal conditions lack innervation. This increased innervation has been associated with pain of IVD origin. The mechanisms responsible for nerve growth and hyperinnervation of pathological IVDs have not been fully elucidated. Among the molecules that are presumably involved in this process are some members of the family of neurotrophins (NTs), which are known to have both neurotrophic and neurotropic properties and regulate the density and distribution of nerve fibers in peripheral tissues. NTs and their receptors are expressed in healthy IVDs but much higher levels have been observed in pathological IVDs, thus suggesting a correlation between levels of expression of NTs and density of innervation in IVDs. In addition, NTs also play a role in inflammatory responses and pain transmission by increasing the expression of pain-related peptides and modulating synapses of nociceptive neurons at the spinal cord. This article reviews current knowledge about the innervation of IVDs, NTs and NT receptors, expression of NTs and their receptors in IVDs as well as in the sensory neurons innervating the IVDs, the proinflammatory role of NTs, NTs as nociception regulators, and the potential network of discogenic pain involving NTs. PMID:20456524

  7. Activation of sensory nerves participates in stress-induced histamine release from mast cells in rats.

    PubMed

    Huang, Z L; Mochizuki, T; Watanabe, H; Maeyama, K

    1999-08-01

    To elucidate the mechanism by which stress induces rapid histamine release from mast cells, Wistar rats, pretreated as neonates with capsaicin, were subjected to immobilization stress for 2 h, and histamine release was measured in paws of anesthetized rats by using in vivo microdialysis after activation of sensory nerves by electrical or chemical stimulation. Immobilization stress studies indicated that in control rats stress induced a 2.7-fold increase in the level of plasma histamine compared to that in freely moving rats. Whereas pretreatment with capsaicin significantly decreased stress-induced elevation of plasma histamine. Microdialysis studies showed that electrical stimulation of the sciatic nerve resulted in a 4-fold increase of histamine release in rat paws. However, this increase was significantly inhibited in rats pretreated with capsaicin. Furthermore, injection of capsaicin into rat paw significantly increased histamine release in a dose-dependent manner. These results suggest that activation of sensory nerves participates in stress-induced histamine release from mast cells. PMID:10462124

  8. Secretion of Growth Hormone in Response to Muscle Sensory Nerve Stimulation

    NASA Technical Reports Server (NTRS)

    Grindeland, Richard E.; Roy, R. R.; Edgerton, V. R.; Gosselink, K. L.; Grossman, E. J.; Sawchenko, P. E.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    Growth hormone (GH) secretion is stimulated by aerobic and resistive exercise and inhibited by exposure to actual or simulated (bedrest, hindlimb suspension) microgravity. Moreover, hypothalamic growth hormone-releasing factor (GRF) and preproGRF mRNA are markedly decreased in spaceflight rats. These observations suggest that reduced sensory input from inactive muscles may contribute to the reduced secretion of GH seen in "0 G". Thus, the aim of this study was to determine the effect of muscle sensory nerve stimulation on secretion of GH. Fed male Wistar rats (304 +/- 23 g) were anesthetized (pentobarbital) and the right peroneal (Pe), tibial (T), and sural (S) nerves were cut. Electrical stimulation of the distal (D) or proximal (P) ends of the nerves was implemented for 15 min. to mimic the EMG activity patterns of ankle extensor muscles of a rat walking 1.5 mph. The rats were bled by cardiac puncture and their anterior pituitaries collected. Pituitary and plasma bioactive (BGH) and immunoactive (IGH) GH were measured by bioassay and RIA.

  9. Sensory and sympathetic nerve fibers undergo sprouting and neuroma formation in the painful arthritic joint of geriatric mice

    PubMed Central

    2012-01-01

    Introduction Although the prevalence of arthritis dramatically increases with age, the great majority of preclinical studies concerning the mechanisms that drive arthritic joint pain have been performed in young animals. One mechanism hypothesized to contribute to arthritic pain is ectopic nerve sprouting; however, neuroplasticity is generally thought to be greater in young versus old nerves. Here we explore whether sensory and sympathetic nerve fibers can undergo a significant ectopic nerve remodeling in the painful arthritic knee joint of geriatric mice. Methods Vehicle (saline) or complete Freund's adjuvant (CFA) was injected into the knee joint of 27- to 29-month-old female mice. Pain behaviors, macrophage infiltration, neovascularization, and the sprouting of sensory and sympathetic nerve fibers were then assessed 28 days later, when significant knee-joint pain was present. Knee joints were processed for immunohistochemistry by using antibodies raised against CD68 (monocytes/macrophages), PECAM (endothelial cells), calcitonin gene-related peptide (CGRP; sensory nerve fibers), neurofilament 200 kDa (NF200; sensory nerve fibers), tyrosine hydroxylase (TH; sympathetic nerve fibers), and growth-associated protein 43 (GAP43; nerve fibers undergoing sprouting). Results At 4 weeks after initial injection, CFA-injected mice displayed robust pain-related behaviors (which included flinching, guarding, impaired limb use, and reduced weight bearing), whereas animals injected with vehicle alone displayed no significant pain-related behaviors. Similarly, in the CFA-injected knee joint, but not in the vehicle-injected knee joint, a remarkable increase was noted in the number of CD68+ macrophages, density of PECAM+ blood vessels, and density and formation of neuroma-like structures by CGRP+, NF200+, and TH+ nerve fibers in the synovium and periosteum. Conclusions Sensory and sympathetic nerve fibers that innervate the aged knee joint clearly maintain the capacity for robust

  10. Collateral sprouting of sensory axons after end-to-side nerve coaptation--a longitudinal study in the rat.

    PubMed

    Kovacic, Uros; Tomsic, Martin; Sketelj, Janez; Bajrović, Fajko F

    2007-02-01

    The end-to-side nerve coaptation is able to induce collateral sprouting of axons from the donor nerve and to provide functional reinnervation of the target tissue. Sensory axon sprouting and its effects on the donor nerve up to 9 months after the end-to-side nerve coaptation were studied in the rat. Peroneal, tibial and saphenous nerves were transected and ligated, and the distal stump of the transected peroneal nerve was sutured to the side of the uninjured sural nerve. The average skin area of the residual sensitivity to pinch due to the axons sprouting through the recipient peroneal nerve did not change statistically significantly between 4 and 9 months after surgery. Axon counting, measurements of compound action potentials and retrograde neuron labeling indicate that the sprouting of the myelinated sensory axons and unmyelinated axons through the recipient nerve was largely completed by 2 months and 4 months after the end-to-side nerve coaptation, respectively, and remained stable thereafter for at least 9 months. A decrease in the amplitude and area of the CAP of myelinated fibers, observed in the donor nerve up to 4 months after surgery, was probably due to mild degeneration of nerve fibers and a tendency of the diameter of myelinated axons to decline. However, no significant changes in functional, electrophysiological or morphological properties of the donor nerve could be observed at the end of the observational period, indicating that end-to-side nerve coaptation has no detrimental effect on the donor nerve on a long-term scale. PMID:17045263

  11. Sensory disturbances of buccal and lingual nerve by muscle compression: A case report and review of the literature

    PubMed Central

    Alvira-González, Joaquín

    2016-01-01

    Introduction Several studies on cadavers dissection have shown that collateral branches of the trigeminal nerve cross muscle bundles on their way, being a possible etiological factor of some nerve disturbances. Case Report A 45-year-old man attended to the Temporomandibular Joint and Orofacial Pain Unit of the Master of Oral Surgery and Implantology in Hospital Odontològic of Barcelona University, referring tingling in the left hemifacial región and ipsilateral lingual side for one year, with discomfort when shaving or skin compression. Discussion Several branches of the trigeminal nerve follow a path through the masticatory muscles, being the lingual nerve and buccal nerve the most involved. The hyperactivity of the muscle bundles that are crossed by nerve structures generates a compression that could explain certain orofacial neuropathies (numbness and / or pain) in which a clear etiologic factor can not be identified. Key words:Buccal nerve, paresthesia, idiopathic trigeminal sensory neuropathy. PMID:26855715

  12. Mustard oils and cannabinoids excite sensory nerve fibres through the TRP channel ANKTM1.

    PubMed

    Jordt, Sven-Eric; Bautista, Diana M; Chuang, Huai-Hu; McKemy, David D; Zygmunt, Peter M; Högestätt, Edward D; Meng, Ian D; Julius, David

    2004-01-15

    Wasabi, horseradish and mustard owe their pungency to isothiocyanate compounds. Topical application of mustard oil (allyl isothiocyanate) to the skin activates underlying sensory nerve endings, thereby producing pain, inflammation and robust hypersensitivity to thermal and mechanical stimuli. Despite their widespread use in both the kitchen and the laboratory, the molecular mechanism through which isothiocyanates mediate their effects remains unknown. Here we show that mustard oil depolarizes a subpopulation of primary sensory neurons that are also activated by capsaicin, the pungent ingredient in chilli peppers, and by Delta(9)-tetrahydrocannabinol (THC), the psychoactive component of marijuana. Both allyl isothiocyanate and THC mediate their excitatory effects by activating ANKTM1, a member of the TRP ion channel family recently implicated in the detection of noxious cold. These findings identify a cellular and molecular target for the pungent action of mustard oils and support an emerging role for TRP channels as ionotropic cannabinoid receptors. PMID:14712238

  13. Cutaneous sensory nerve as a substitute for auditory nerve in solving deaf-mutes’ hearing problem: an innovation in multi-channel-array skin-hearing technology

    PubMed Central

    Li, Jianwen; Li, Yan; Zhang, Ming; Ma, Weifang; Ma, Xuezong

    2014-01-01

    The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice signals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequency analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to distinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes’ hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized. PMID:25317171

  14. Noninvasive peroneal sensory and motor nerve conduction recordings in the rabbit distal hindlimb: feasibility, variability and neuropathy measure.

    PubMed

    Hotson, John R

    2014-01-01

    The peroneal nerve anatomy of the rabbit distal hindlimb is similar to humans, but reports of distal peroneal nerve conduction studies were not identified with a literature search. Distal sensorimotor recordings may be useful for studying rabbit models of length-dependent peripheral neuropathy. Surface electrodes were adhered to the dorsal rabbit foot overlying the extensor digitorum brevis muscle and the superficial peroneal nerve. The deep and superficial peroneal nerves were stimulated above the ankle and the common peroneal nerve was stimulated at the knee. The nerve conduction studies were repeated twice with a one-week intertest interval to determine measurement variability. Intravenous vincristine was used to produce a peripheral neuropathy. Repeat recordings measured the response to vincristine. A compound muscle action potential and a sensory nerve action potential were evoked in all rabbits. The compound muscle action potential mean amplitude was 0.29 mV (SD ± 0.12) and the fibula head to ankle mean motor conduction velocity was 46.5 m/s (SD ± 2.9). The sensory nerve action potential mean amplitude was 22.8 μV (SD ± 2.8) and the distal sensory conduction velocity was 38.8 m/s (SD ± 2.2). Sensorimotor latencies and velocities were least variable between two test sessions (coefficient of variation  =  2.6-5.9%), sensory potential amplitudes were intermediate (coefficient of variation  =  11.1%) and compound potential amplitudes were the most variable (coefficient of variation  = 19.3%). Vincristine abolished compound muscle action potentials and reduced sensory nerve action potential amplitudes by 42-57% while having little effect on velocity. Rabbit distal hindlimb nerve conduction studies are feasible with surface recordings and stimulation. The evoked distal sensory potentials have amplitudes, configurations and recording techniques that are similar to humans and may be valuable for measuring large sensory fiber function in chronic

  15. Effects of colistin on the sensory nerve conduction velocity and F-wave in mice.

    PubMed

    Dai, Chongshan; Tang, Shusheng; Li, Jichang; Wang, Jiping; Xiao, Xilong

    2014-12-01

    The aim of this study was to examine the changes of sensory nerve conduction velocity (SNCV) and F-wave for colistin-induced peripheral neurotoxicity using a mouse model. Mice were administered with colistin 5, 7.5 and 15 mg/kg/day via a 3-min. intravenous infusion. The sensory nerve conduction velocity (SNCV) and F-wave were measured using the bipolar recording electrodes. The SNCV and F-wave latency changed in a dose- and time-dependent manner. The significant increase of F-wave latency and significant decrease of SNCV appeared on day 3 (p < 0.05 and 0.01, respectively) in the 15 mg/kg/day group, and they were markedly changed on day 7 in the 7.5 mg/kg/day (p < 0.01 and 0.05, respectively) and 15 mg/kg/day groups (both p < 0.01). In addition, F-wave latency also significantly increased on day 7 in the 5 mg/kg/day group (p < 0.05) without any clinical signs. These results indicate that SNCV and F-wave latency were more sensitive in colistin-induced neurotoxicity in mice, which highlights the early monitoring tool of polymyxins neurotoxicity in the clinic. PMID:24861773

  16. The functions of TRPA1 and TRPV1: moving away from sensory nerves

    PubMed Central

    Fernandes, ES; Fernandes, MA; Keeble, JE

    2012-01-01

    The transient receptor potential vanilloid 1 and ankyrin 1 (TRPV1 and TRPA1, respectively) channels are members of the TRP superfamily of structurally related, non-selective cation channels. It is rapidly becoming clear that the functions of TRPV1 and TRPA1 interlink with each other to a considerable extent. This is especially clear in relation to pain and neurogenic inflammation where TRPV1 is coexpressed on the vast majority of TRPA1-expressing sensory nerves and both integrate a variety of noxious stimuli. The more recent discovery that both TRPV1 and TRPA1 are expressed on a multitude of non-neuronal sites has led to a plethora of research into possible functions of these receptors. Non-neuronal cells on which TRPV1 and TRPA1 are expressed vary from vascular smooth muscle to keratinocytes and endothelium. This review will discuss the expression, functionality and roles of these non-neuronal TRP channels away from sensory nerves to demonstrate the diverse nature of TRPV1 and TRPA1 in addition to a direct role in pain and neurogenic inflammation. PMID:22233379

  17. Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Sanger, James R.; Matloub, Hani S.; Yousif, N. John; Bain, James L. W.

    1988-01-01

    Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myeliated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50 percent or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

  18. Motor and sensory ulnar nerve conduction velocities: effect of elbow position.

    PubMed

    Harding, C; Halar, E

    1983-05-01

    Ulnar motor and sensory nerve conduction velocities (NCV) were studied bilaterally in 20 able-bodied subjects for below elbow (BE) and across elbow (AE) segments to assess the effect of 4 different elbow positions on NCV (0 degrees, 45 degrees, 90 degrees, and 135 degrees). Although constant skin stimulation marker points were used, the AE segment length became progressively longer with increased elbow flexion. At 0 degrees flexion the AE segment motor NCV was found to be slower, and at 45 degrees it was found faster than the BE NCV. At each subsequent elbow flexion position (90 degrees and 135 degrees) there was an erroneous increase in motor and sensory NCV for the AE segments (p less than 0.01). This increase in AE NCV with elbow flexion was mostly due to stretching of skin over the flexed elbow. The nerve itself was observed in 4 cadaver specimens to slide distally with respect to the above elbow skin marker. Since 45 degrees elbow flexion was the position of least variation in motor NCV for AE and BE segments, this degree of elbow flexion appears to be optimum. From these measurements and from literature review neither short AE segment length (less than 10 cm) nor long AE segment length (greater than 15 cm) is optimum for measurement of AE NCV in the assessment of compressive neuropathy at the elbow. Short segments are subject to increased NCV variation while long segments may not detect pathological slowing of NCV only occurring over a short portion of the nerve. PMID:6847360

  19. Uptake of nerve growth factor along peripheral and spinal axons of primary sensory neurons

    SciTech Connect

    Richardson, P.M.; Riopelle, R.J.

    1984-07-01

    To investigate the distribution of nerve growth factor (NGF) receptors on peripheral and central axons, (/sup 125/I)NGF was injected into the sciatic nerve or spinal cord of adult rats. Accumulation of (/sup 125/I)NGF in lumbar dorsal root ganglia was monitored by gamma emission counting and radioautography. (/sup 125/I)NGF, injected endoneurially in small quantities, was taken into sensory axons by a saturable process and was transported retrogradely to their cell bodies at a maximal rate of 2.5 to 7.5 mm/hr. Because very little (/sup 125/I)NGF reached peripheral terminals, the results were interpreted to indicate that receptors for NGF are present on nonterminal segments of sensory axons. The specificity and high affinity of NGF uptake were illustrated by observations that negligible amounts of gamma activity accumulated in lumbar dorsal root ganglia after comparable intraneural injection of (/sup 125/I) cytochrome C or (/sup 125/I)oxidized NGF. Similar techniques were used to demonstrate avid internalization and retrograde transport of (/sup 125/I)NGF by intraspinal axons arising from dorsal root ganglia. Following injection of (/sup 125/I)NGF into lumbar or cervical regions of the spinal cord, neuronal perikarya were clearly labeled in radioautographs of lumbar dorsal root ganglia. Sites for NGF uptake on primary sensory neurons in the adult rat are not restricted to peripheral axon terminals but are extensively distributed along both peripheral and central axons. Receptors on axons provide a mechanism whereby NGF supplied by glia could influence neuronal maintenance or axonal regeneration.

  20. Sensory Recovery Outcome after Digital Nerve Repair in Relation to Different Reconstructive Techniques: Meta-Analysis and Systematic Review

    PubMed Central

    Wolf, Petra; Harder, Yves; Kern, Yasmin; Paprottka, Philipp M.; Machens, Hans-Günther; Lohmeyer, Jörn A.

    2013-01-01

    Good clinical outcome after digital nerve repair is highly relevant for proper hand function and has a significant socioeconomic impact. However, level of evidence for competing surgical techniques is low. The aim is to summarize and compare the outcomes of digital nerve repair with different methods (end-to-end and end-to-side coaptations, nerve grafts, artificial conduit-, vein-, muscle, and muscle-in-vein reconstructions, and replantations) to provide an aid for choosing an individual technique of nerve reconstruction and to create reference values of standard repair for nonrandomized clinical studies. 87 publications including 2,997 nerve repairs were suitable for a precise evaluation. For digital nerve repairs there was practically no particular technique superior to another. Only end-to-side coaptation had an inferior two-point discrimination in comparison to end-to-end coaptation or nerve grafting. Furthermore, this meta-analysis showed that youth was associated with an improved sensory recovery outcome in patients who underwent digital replantation. For end-to-end coaptations, recent publications had significantly better sensory recovery outcomes than older ones. Given minor differences in outcome, the main criteria in choosing an adequate surgical technique should be gap length and donor site morbidity caused by graft material harvesting. Our clinical experience was used to provide a decision tree for digital nerve repair. PMID:23984064

  1. Histochemistry of nerve fibres double labelled with anti-TRPV2 antibodies and sensory nerve marker AM1-43 in the dental pulp of rat molars.

    PubMed

    Nishikawa, Sumio

    2008-09-01

    AM1-43 can label sensory nerve fibres and sensory neurons. Permeation of non-selective cation channels of the nerve cell membrane is suggested to be the mechanism responsible for labelling. To identify these channels, two candidates, TRPV1 and TRPV2 were examined by immunocytochemistry in the dental pulp and trigeminal ganglion of rats injected with AM1-43. A part of AM1-43-labelled nerve fibres was also positive for anti-TRPV2 antibody but negative for anti-TRPV1 antibody in the dental pulp. In the trigeminal ganglion, a part of the neuron showed both bright AM1-43 labelling and anti-TRPV2 immunolabelling, but neurons double labelled with AM1-43 and TRPV1 were rare. These results suggest that TRPV2 channels, but not TRPV1 channels, contribute to the fluorescent labelling of AM1-43 in the dental pulp. PMID:18405879

  2. [A case of hereditary motor and sensory neuropathy with pyramidal tract sign, optic nerve atrophy and mental retardation].

    PubMed

    Adachi, T; Imaoka, K; Shirasawa, A; Yamaguchi, S; Kobayashi, S

    1998-12-01

    The patient was a 61-year-old man who suffered from gait disturbance since childhood. He also had mental retardation. Gait disturbance was slowly progressive. His mother, sister, brother and son of his sister suffered from gait disturbance. On neurological examination, he showed mental retardation, optic nerve atrophy and neural deafness. He also showed severe muscle atrophy and weakness of bilateral lower limbs associated with pes cavus. Muscle tonus of lower limbs and patellar tendon reflex were increased bilaterally. Achilles tendon reflex was absent. Babinski and Chaddock signs were positive. Superficial and deep sensations were almost normal. There were no cerebellar signs. Blood chemistry was normal. On nerve conduction studies, motor nerve conduction velocity of the upper limbs was normal and that of the posterior tibial nerve was decreased; right 36.0m/sec, left 29.7m/sec. Sensory nerve conduction velocity of the median nerve was slightly decreased; right 36.5m/sec, left 45.2m/sec and sural nerve did not respond to electric stimuli. On sural nerve biopsy, the density of myelinated fibers was severely decreased. Onion bulb formation was not observed. We classified this case as hereditary motor and sensory neuropathy (HMSN) type II based on nerve conduction studies and findings from sural nerve biopsy. HMSN with pyramidal tract sign has been classified as type V and HMSN with optic nerve atrophy as type VI. This case had characteristic symptoms as type V and VI. Histopathological findings of HMSN type V and VI have not been established yet. This case might provide an important clue for classification of HMSN. PMID:10349345

  3. TRPM8 function and expression in vagal sensory neurons and afferent nerves innervating guinea pig esophagus.

    PubMed

    Yu, Xiaoyun; Hu, Youtian; Ru, Fei; Kollarik, Marian; Undem, Bradley J; Yu, Shaoyong

    2015-03-15

    Sensory transduction in esophageal afferents requires specific ion channels and receptors. TRPM8 is a new member of the transient receptor potential (TRP) channel family and participates in cold- and menthol-induced sensory transduction, but its role in visceral sensory transduction is still less clear. This study aims to determine TRPM8 function and expression in esophageal vagal afferent subtypes. TRPM8 agonist WS-12-induced responses were first determined in nodose and jugular neurons by calcium imaging and then investigated by whole cell patch-clamp recordings in Dil-labeled esophageal nodose and jugular neurons. Extracellular single-unit recordings were performed in nodose and jugular C fiber neurons using ex vivo esophageal-vagal preparations with intact nerve endings in the esophagus. TRPM8 mRNA expression was determined by single neuron RT-PCR in Dil-labeled esophageal nodose and jugular neurons. The TRPM8 agonist WS-12 elicited calcium influx in a subpopulation of jugular but not nodose neurons. WS-12 activated outwardly rectifying currents in esophageal Dil-labeled jugular but not nodose neurons in a dose-dependent manner, which could be inhibited by the TRPM8 inhibitor AMTB. WS-12 selectively evoked action potential discharges in esophageal jugular but not nodose C fibers. Consistently, TRPM8 transcripts were highly expressed in esophageal Dil-labeled TRPV1-positive jugular neurons. In summary, the present study demonstrated a preferential expression and function of TRPM8 in esophageal vagal jugular but not nodose neurons and C fiber subtypes. This provides a distinctive role of TRPM8 in esophageal sensory transduction and may lead to a better understanding of the mechanisms of esophageal sensation and nociception. PMID:25591866

  4. Restoration of sensory and motor function in earthworm escape reflex pathways following ventral nerve cord transplantation.

    PubMed

    Vining, E P; Drewes, C D

    1985-07-01

    Twelve segments of earthworm ventral nerve cord (VNC) were excised from either segments 10-22 (i.e., within the MGF sensory field) or segments 75-87 (i.e., within the LGF sensory field) in donor worms and heterotopically, or homotopically, transplanted into recipient animals. Morphological evidence indicated that by four days after transplantation, peripheral connections were formed between the transplanted VNC and the body wall of the recipient, many of these connections involving novel pathways projecting ventrally from the transplant. Restoration of giant fiber touch sensitivity in the transplant occurred from 4-14 days after transplantation. Regardless of the site of transplantation, the restored sensitivity (i.e., MGF versus LGF sensory field) always reflected the origin of the donor VNC. Restoration of MGF-mediated motor activity in the transplant occurred approximately 17-22 days after transplantation. In the case of heterotopic transplants (i.e., anterior VNC into posterior segments), the restored MGF-mediated muscle potentials were facilitating, indicating at least some tendency for persistence of this feature after transplantation. Behavioral observations suggested that reconnections involving other reflex pathways (e.g., those controlling setal movements and peristaltic locomotion) were made within the transplant region and that properties of the restored reflexes reflected those of the donor VNC. The rapid restoration of sensory and motor connections, despite heterotopic placement, indicates a significant capacity for peripheral regeneration by the transplanted VNC. On the other hand, the maintenance of various properties of reflex function, despite heterotopic transplantation, suggests a limited capacity for rearrangement of established central connections in the transplanted VNC. PMID:4031850

  5. Somatosensory evoked potentials (SSEPs); sensory nerve conduction velocity (SNCV) and motor nerve conduction velocity (MNCV) in chronic renal failure.

    PubMed

    Makkar, R K; Kochar, D K

    1994-01-01

    Somatosensory evoked potentials, sensory and motor nerve conduction velocity were studied in 25 patients of chronic renal failure and the results were compared with 15 healthy persons. The values more than +/- 3 S.D. were considered abnormal. SNCV was reduced in 11/25 patients; average reduction being 18 m/s (highly significant, p < 0.001); MNCV was reduced in 11/25 patients, average reduction being 20 m/s (highly significant, p < 0.001). Both SNCV and MNCV in same person were reduced in 6/25 patients. In SSEP N9, N13 and N20 were delayed in almost all the patients (highly significant, p < 0.001). Amplitude of N20 and N13 were reduced in 1 and 4 patients respectively but amplitude of N9 was normal. Out of different IPLS, Ebw-N9 was delayed in 5/25 patients (p < 0.9, insignificant); N9-N13 was delayed in 8/25 patients (p < 0.001, highly significant); N13-N20 was delayed in 1/25 patients (p < 0.01, significant). The evidence of these neurophysiological abnormalities collectively suggest the presence of central-peripheral axonopathy in this disease. PMID:7956880

  6. Activation of EP4 receptors contributes to prostaglandin E2-mediated stimulation of renal sensory nerves.

    PubMed

    Kopp, Ulla C; Cicha, Michael Z; Nakamura, Kazuhiro; Nüsing, Rolf M; Smith, Lori A; Hökfelt, Tomas

    2004-12-01

    Induction of cyclooxygenase-2 (COX-2) in the renal pelvic wall increases prostaglandin E(2) (PGE(2)) leading to stimulation of cAMP production, which results in substance P (SP) release and activation of renal mechanosensory nerves. The subtype of PGE receptors involved, EP2 and/or EP4, was studied by immunohistochemistry and renal pelvic administration of agonists and antagonists of EP2 and EP4 receptors. EP4 receptor-like immunoreactivity (LI) was colocalized with calcitonin gene-related peptide (CGRP)-LI in dorsal root ganglia (DRGs) at Th(9)-L(1) and in nerve terminals in the renal pelvic wall. Th(9)-L(1) DRG neurons also contained EP3 receptor-LI and COX-2-LI, each of which was colocalized with CGRP-LI in some neurons. No renal pelvic nerves contained EP3 receptor-LI and only very few nerves COX-2-LI. The EP1/EP2 receptor antagonist AH-6809 (20 microM) had no effect on SP release produced by PGE(2) (0.14 microM) from an isolated rat renal pelvic wall preparation. However, the EP4 receptor antagonist L-161,982 (10 microM) blocked the SP release produced by the EP2/EP4 receptor agonist butaprost (10 microM) 12 +/- 2 vs. 2 +/- 1 and PGE(2), 9 +/- 1 vs. 1 +/- 0 pg/min. The SP release by butaprost and PGE(2) was similarly blocked by the EP4 receptor antagonist AH-23848 (30 microM). In anesthetized rats, the afferent renal nerve activity (ARNA) responses to butaprost 700 +/- 100 and PGE(2).780 +/- 100%.s (area under the curve of ARNA vs. time) were unaffected by renal pelvic perfusion with AH-6809. However, 1 microM L-161,982 and 10 microM AH-23848 blocked the ARNA responses to butaprost by 94 +/- 5 and 78 +/- 10%, respectively, and to PGE(2) by 74 +/- 16 and 74 +/- 11%, respectively. L-161,982 also blocked the ARNA response to increasing renal pelvic pressure 10 mmHg, 85 +/- 5%. In conclusion, PGE(2) increases renal pelvic release of SP and ARNA by activating EP4 receptors on renal sensory nerve fibers. PMID:15292051

  7. Self-powered sensory nerve system for civil structures using hybrid forisome actuators

    NASA Astrophysics Data System (ADS)

    Shoureshi, Rahmat A.; Shen, Amy

    2006-03-01

    In order to provide a true distributed sensor and control system for civil structures, we have developed a Structural Nervous System that mimics key attributes of a human nervous system. This nervous system is made up of building blocks that are designed based on mechanoreceptors as a fundamentally new approach for the development of a structural health monitoring and diagnostic system that utilizes the recently discovered plant-protein forisomes, a novel non-living biological material capable of sensing and actuation. In particular, our research has been focused on producing a sensory nervous system for civil structures by using forisomes as the mechanoreceptors, nerve fibers, neuronal pools, and spinocervical tract to the nodal and central processing units. This paper will present up to date results of our research, including the design and analysis of the structural nervous system.

  8. The effect of aging on the density of the sensory nerve fiber innervation of bone and acute skeletal pain

    PubMed Central

    Jimenez-Andrade, Juan M.; Mantyh, William G.; Bloom, Aaron P.; Freeman, Katie T.; Ghilardi, Joseph R.; Kuskowski, Michael A.; Mantyh, Patrick W.

    2010-01-01

    As humans age there is a decline in most sensory systems including vision, hearing, taste, smell, and tactile acuity. In contrast, the frequency and severity of musculoskeletal pain generally increases with age. To determine whether the density of sensory nerve fibers that transduce skeletal pain changes with age, calcitonin gene related peptide (CGRP) and neurofilament 200 kDa (NF200) sensory nerve fibers that innervate the femur were examined in the femurs of young (4 month old), middle-aged (13 month) and old (36 month) male F344/BNF1 rats. Whereas the bone quality showed a significant age-related decline, the density of CGRP+ and NF200+ nerve fibers that innervate the bone remained remarkably unchanged as well as the severity of acute skeletal fracture pain. Thus, while bone mass, quality and strength undergo a significant decline with age, the density of sensory nerve fibers that transduce noxious stimuli remain largely intact. These data may in part explain why musculoskeletal pain increases with age. PMID:20947214

  9. TRESK channel contribution to nociceptive sensory neurons excitability: modulation by nerve injury

    PubMed Central

    2011-01-01

    Background Neuronal hyperexcitability is a crucial phenomenon underlying spontaneous and evoked pain. In invertebrate nociceptors, the S-type leak K+ channel (analogous to TREK-1 in mammals) plays a critical role of in determining neuronal excitability following nerve injury. Few data are available on the role of leak K2P channels after peripheral axotomy in mammals. Results Here we describe that rat sciatic nerve axotomy induces hyperexcitability of L4-L5 DRG sensory neurons and decreases TRESK (K2P18.1) expression, a channel with a major contribution to total leak current in DRGs. While the expression of other channels from the same family did not significantly change, injury markers ATF3 and Cacna2d1 were highly upregulated. Similarly, acute sensory neuron dissociation (in vitro axotomy) produced marked hyperexcitability and similar total background currents compared with neurons injured in vivo. In addition, the sanshool derivative IBA, which blocked TRESK currents in transfected HEK293 cells and DRGs, increased intracellular calcium in 49% of DRG neurons in culture. Most IBA-responding neurons (71%) also responded to the TRPV1 agonist capsaicin, indicating that they were nociceptors. Additional evidence of a biological role of TRESK channels was provided by behavioral evidence of pain (flinching and licking), in vivo electrophysiological evidence of C-nociceptor activation following IBA injection in the rat hindpaw, and increased sensitivity to painful pressure after TRESK knockdown in vivo. Conclusions In summary, our results clearly support an important role of TRESK channels in determining neuronal excitability in specific DRG neurons subpopulations, and show that axonal injury down-regulates TRESK channels, therefore contributing to neuronal hyperexcitability. PMID:21527011

  10. Sensory nerve endings in the rat oro-facial region labeled by the anterograde and transganglionic transport of horseradish peroxidase: a new method for tracing peripheral nerve fibers.

    PubMed

    Marfurt, C F; Turner, D F

    1983-02-14

    The purpose of the present investigation is to introduce the enzyme horseradish peroxidase (HRP) for the study of the morphology and peripheral distribution of sensory nerve endings. HRP was injected into the trigeminal ganglion or trigeminal brainstem nuclear complex (TBNC) in separate adult rats. HRP injected into the trigeminal ganglion was taken up by the neuronal perikarya and transported anterogradely in massive amounts to sensory nerve endings in the cornea, vibrissal hair follicles, tooth pulps, and periodontal ligaments. HRP injected into the TBNC was taken up by trigeminal primary afferent fibers that terminated there and transported transganglionically, i.e., past or through the trigeminal ganglion, to peripheral sensory endings. The results of the present study demonstrate for the first time that: (1) anterograde HRP transport is a highly successful method of labeling with an intracellular marker trigeminal sensory endings in a variety of oro-facial tissues, and (2) trigeminal primary sensory neurons possess intra-axonal transport mechanisms by which HRP, and possibly other substances, taken up in the central nervous system may be transported to the periphery. PMID:6601506

  11. Implementation of linear sensory signaling via multiple coordinated mechanisms at central vestibular nerve synapses

    PubMed Central

    McElvain, Lauren E.; Faulstich, Michael; Jeanne, James M.; Moore, Jeffrey D.; du Lac, Sascha

    2015-01-01

    Summary Signal transfer in neural circuits is dynamically modified by the recent history of neuronal activity. Short-term plasticity endows synapses with nonlinear transmission properties, yet synapses in sensory and motor circuits are capable of signaling linearly over a wide range of presynaptic firing rates. How do such synapses achieve rate-invariant transmission despite history-dependent nonlinearities? Here, ultrastructural, biophysical, and computational analyses demonstrate that concerted molecular, anatomical, and physiological refinements are required for central vestibular nerve synapses to linearly transmit rate-coded sensory signals. Vestibular synapses operate in a physiological regime of steady-state depression imposed by tonic firing. Rate-invariant transmission relies on brief presynaptic action potentials that delimit calcium influx, large pools of rapidly mobilized vesicles, multiple low-probability release sites, robust postsynaptic receptor sensitivity, and efficient transmitter clearance. Broadband linear synaptic filtering of head motion signals is thus achieved by coordinately tuned synaptic machinery that maintains physiological operation within inherent cell biological limitations. PMID:25704949

  12. THE MAJORITY OF MYELINATED AND UNMYELINATED SENSORY NERVE FIBERS THAT INNERVATE BONE EXPRESS THE TROPOMYOSIN RECEPTOR KINASE A

    PubMed Central

    Castañeda-Corral, Gabriela; Jimenez-Andrade, Juan M.; Bloom, Aaron P.; Taylor, Reid N.; Mantyh, William G.; Kaczmarska, Magdalena J.; Ghilardi, Joseph R.; Mantyh, Patrick W.

    2011-01-01

    Although skeletal pain is a leading cause of chronic pain and disability, relatively little is known about the specific populations of nerve fibers that innervate the skeleton. Recent studies have reported that therapies blocking nerve growth factor (NGF) or its cognate receptor, tropomyosin receptor kinase A (TrkA) are efficacious in attenuating skeletal pain. A potential factor to consider when assessing the analgesic efficacy of targeting NGF-TrkA signaling in a pain state is the fraction of NGF-responsive TrkA+ nociceptors that innervate the tissue from which the pain is arising, as this innervation and the analgesic efficacy of targeting NGF-TrkA signaling may vary considerably from tissue to tissue. To explore this in the skeleton, tissue slices and whole mount preparations of the normal, adult mouse femur were analyzed using immunohistochemistry and confocal microscopy. Analysis of these preparations revealed that 80% of the unmyelinated/thinly myelinated sensory nerve fibers that express calcitonin gene-related peptide (CGRP) and innervate the periosteum, mineralized bone and bone marrow also express TrkA. Similarly, the majority of myelinated sensory nerve fibers that express neurofilament 200 kDa (NF200) which innervate the periosteum, mineralized bone and bone marrow also co-express TrkA. In the normal femur, the relative density of CGRP+, NF200+ and TrkA+ sensory nerve fibers per unit volume is: periosteum > bone marrow > mineralized bone > cartilage with the respective relative densities being 100: 2: 0.1: 0. The observation that the majority of sensory nerve fibers innervating the skeleton express TrkA+, may in part explain why therapies that block NGF/TrkA pathway are highly efficacious in attenuating skeletal pain. PMID:21277945

  13. Enhanced release of adenosine in rat hind paw following spinal nerve ligation: involvement of capsaicin-sensitive sensory afferents.

    PubMed

    Liu, X J; White, T D; Sawynok, J

    2002-01-01

    Modulation of endogenous adenosine levels by inhibition of adenosine metabolism produces a peripheral antinociceptive effect in a neuropathic pain model. The present study used microdialysis to investigate the neuronal mechanisms modulating extracellular adenosine levels in the rat hind paw following tight ligation of the L5 and L6 spinal nerves. Subcutaneous injection of 50 microl saline into the nerve-injured paw induced a rapid and short-lasting increase in extracellular adenosine levels in the subcutaneous tissues of the rat hind paw ipsilateral to the nerve injury. Saline injection did not increase adenosine levels in sham-operated rats or non-treated rats. The adenosine kinase inhibitor 5'-amino-5'-deoxyadenosine and the adenosine deaminase inhibitor 2'-deoxycoformycin, at doses producing a peripheral antinociceptive effect, did not further enhance subcutaneous adenosine levels in the nerve-injured paw. Systemic pretreatment with capsaicin, a neurotoxin selective for small-diameter sensory afferents, markedly reduced the saline-evoked release of adenosine in rat hind paw following spinal nerve ligation. Systemic pretreatment with 6-hydroxydopamine, a neurotoxin selective for sympathetic afferent nerves, did not affect release. These results suggest that following nerve injury, peripheral capsaicin-sensitive primary sensory afferent nerve terminals are hypersensitive, and are able to release adenosine following a stimulus that does not normally evoke release in sham-operated or intact rats. Sympathetic postganglionic afferents do not appear to be involved in such release. The lack of effect on such release by the inhibitors of adenosine metabolism suggests an altered peripheral adenosine system following spinal nerve ligation. PMID:12204207

  14. Roles of Sensory Nerves in the Regulation of Radiation-Induced Structural and Functional Changes in the Heart

    SciTech Connect

    Sridharan, Vijayalakshmi; Tripathi, Preeti; Sharma, Sunil; Moros, Eduardo G.; Zheng, Junying; Hauer-Jensen, Martin; Boerma, Marjan

    2014-01-01

    Purpose: Radiation-induced heart disease (RIHD) is a chronic severe side effect of radiation therapy of intrathoracic and chest wall tumors. The heart contains a dense network of sensory neurons that not only are involved in monitoring of cardiac events such as ischemia and reperfusion but also play a role in cardiac tissue homeostasis, preconditioning, and repair. The purpose of this study was to examine the role of sensory nerves in RIHD. Methods and Materials: Male Sprague-Dawley rats were administered capsaicin to permanently ablate sensory nerves, 2 weeks before local image-guided heart x-ray irradiation with a single dose of 21 Gy. During the 6 months of follow-up, heart function was assessed with high-resolution echocardiography. At 6 months after irradiation, cardiac structural and molecular changes were examined with histology, immunohistochemistry, and Western blot analysis. Results: Capsaicin pretreatment blunted the effects of radiation on myocardial fibrosis and mast cell infiltration and activity. By contrast, capsaicin pretreatment caused a small but significant reduction in cardiac output 6 months after irradiation. Capsaicin did not alter the effects of radiation on cardiac macrophage number or indicators of autophagy and apoptosis. Conclusions: These results suggest that sensory nerves, although they play a predominantly protective role in radiation-induced cardiac function changes, may eventually enhance radiation-induced myocardial fibrosis and mast cell activity.

  15. Sympathetic sprouting near sensory neurons after nerve injury occurs preferentially on spontaneously active cells and is reduced by early nerve block

    PubMed Central

    Xie, Wenrui; Strong, Judith Ann; Li, Huiqing; Zhang, Jun-Ming

    2006-01-01

    Some chronic pain conditions are maintained or enhanced by sympathetic activity. In animal models of pathological pain, abnormal sprouting of sympathetic fibers around large- and medium-size sensory neurons is observed in dorsal root ganglia (DRG). Large and medium size cells are also more likely to be spontaneously active, suggesting that sprouting may be related to neuron activity. We previously showed that sprouting could be reduced by systemic or locally applied lidocaine. In the complete sciatic nerve transection model in rats, spontaneous activity initially originates in the injury site; later, the DRG become the major source of spontaneous activity. In this study, spontaneous activity reaching the DRG soma was reduced by early nerve blockade (local perfusion of the transected nerve with TTX for the first 7 days after injury). This significantly reduced sympathetic sprouting. Conversely, increasing spontaneous activity by local nerve perfusion with K+ channel blockers increased sprouting. The hyperexcitability and spontaneous activity of DRG neurons observed in this model were also significantly reduced by early nerve blockade. These effects of early nerve blockade on sprouting, excitability, and spontaneous activity were all observed 4 to 5 weeks after the end of early nerve blockade, indicating that the early period of spontaneous activity in the injured nerve is critical for establishing the more long-lasting pathologies observed in the DRG. Individual spontaneously active neurons, labeled with fluorescent dye, were 5–6 times more likely than quiescent cells to be co-localized with sympathetic fibers, suggesting a highly localized correlation of activity and sprouting. PMID:17065247

  16. Sensory nerve fibres from lumbar intervertebral discs pass through rami communicantes. A possible pathway for discogenic low back pain.

    PubMed

    Suseki, K; Takahashi, Y; Takahashi, K; Chiba, T; Yamagata, M; Moriya, H

    1998-07-01

    It has been thought that lumbar intervertebral discs were innervated segmentally. We have previously shown that the L5-L6 intervertebral disc in the rat is innervated bilaterally from the L1 and L2 dorsal root ganglia through the paravertebral sympathetic trunks, but the pathways between the disc and the paravertebral sympathetic trunks were unknown. We have now studied the spines of 17 rats to elucidate the exact pathways. We examined serial sections of the lumbar spine using immunohistochemistry for calcitonin gene-related peptide, a sensory nerve marker. We showed that these nerve fibres from the intervertebral disc ran through the sinuvertebral nerve into the rami communicantes, not into the corresponding segmental spinal nerve. In the rat, sensory information from the lumbar intervertebral discs is conducted through rami communicantes. If this innervation pattern applies to man, simple decompression of the corresponding nerve root will not relieve discogenic pain. Anterior interbody fusion, with the denervation of rami communicantes, may be effective for such low back pain. PMID:9699846

  17. [Joint and sensory branch block of the obturator and femoral nerves in a case of femoral head osteonecrosis and arthritis].

    PubMed

    Cortiñas-Sáenz, M; Salmerón-Velez, G; Holgado-Macho, I A

    2014-01-01

    The sensory innervation of the hip joint is complex. The joint and sensory branch block of the obturator and femoral nerves is effective for treating the pain caused due to different hip diseases. This could be an option to be considered in certain circumstances such as, being a surgical-anaesthetic high risk, or if there is significant overweight, It could also be useful on other occasions if the traumatoligist considers that it is better to delay hip replacement for a limited period. PMID:24656423

  18. Alpha-Synuclein Pathology in Sensory Nerve Terminals of the Upper Aerodigestive Tract of Parkinson’s Disease Patients

    PubMed Central

    Mu, Liancai; Chen, Jingming; Sobotka, Stanislaw; Nyirenda, Themba; Benson, Brian; Gupta, Fiona; Sanders, Ira; Adler, Charles H.; Caviness, John N.; Shill, Holly A.; Sabbagh, Marwan; Samanta, Johan E.; Sue, Lucia I.; Beach, Thomas G.

    2015-01-01

    Dysphagia is common in Parkinson’s disease (PD) and causes significant morbidity and mortality. PD dysphagia has usually been explained as dysfunction of central motor control, much like other motor symptoms that are characteristic of the disease. However, PD dysphagia does not correlate with severity of motor symptoms nor does it respond to motor therapies. It is known that PD patients have sensory deficits in the pharynx, and that impaired sensation may contribute to dysphagia. However, the underlying cause of the pharyngeal sensory deficits in PD is not known. We hypothesized that PD dysphagia with sensory deficits may be due to degeneration of the sensory nerve terminals in the upper aerodigestive tract (UAT). We have previously shown that Lewy-type synucleinopathy (LTS) is present in the main pharyngeal sensory nerves of PD patients, but not in controls. In this study, the sensory terminals in UAT mucosa were studied to discern the presence and distribution of LTS. Whole-mount specimens (tongue-pharynx-larynx-upper esophagus) were obtained from 10 deceased human subjects with clinically diagnosed and neuropathologically confirmed PD (five with dysphagia and five without) and four age-matched healthy controls. Samples were taken from six sites and immunostained for phosphorylated α-synuclein (PAS). The results showed the presence of PAS-immunoreactive (PAS-ir) axons in all the PD subjects and in none of the controls. Notably, PD patients with dysphagia had more PAS-ir axons in the regions that are critical for initiating the swallowing reflex. These findings suggest that Lewy pathology affects mucosal sensory axons in specific regions of the UAT and may be related to PD dysphagia. PMID:26041249

  19. Sensory feedback by peripheral nerve stimulation improves task performance in individuals with upper limb loss using a myoelectric prosthesis

    NASA Astrophysics Data System (ADS)

    Schiefer, Matthew; Tan, Daniel; Sidek, Steven M.; Tyler, Dustin J.

    2016-02-01

    Objective. Tactile feedback is critical to grip and object manipulation. Its absence results in reliance on visual and auditory cues. Our objective was to assess the effect of sensory feedback on task performance in individuals with limb loss. Approach. Stimulation of the peripheral nerves using implanted cuff electrodes provided two subjects with sensory feedback with intensity proportional to forces on the thumb, index, and middle fingers of their prosthetic hand during object manipulation. Both subjects perceived the sensation on their phantom hand at locations corresponding to the locations of the forces on the prosthetic hand. A bend sensor measured prosthetic hand span. Hand span modulated the intensity of sensory feedback perceived on the thenar eminence for subject 1 and the middle finger for subject 2. We performed three functional tests with the blindfolded subjects. First, the subject tried to determine whether or not a wooden block had been placed in his prosthetic hand. Second, the subject had to locate and remove magnetic blocks from a metal table. Third, the subject performed the Southampton Hand Assessment Procedure (SHAP). We also measured the subject’s sense of embodiment with a survey and his self-confidence. Main results. Blindfolded performance with sensory feedback was similar to sighted performance in the wooden block and magnetic block tasks. Performance on the SHAP, a measure of hand mechanical function and control, was similar with and without sensory feedback. An embodiment survey showed an improved sense of integration of the prosthesis in self body image with sensory feedback. Significance. Sensory feedback by peripheral nerve stimulation improved object discrimination and manipulation, embodiment, and confidence. With both forms of feedback, the blindfolded subjects tended toward results obtained with visual feedback.

  20. Presence of sensory nerve corpuscles in the human corpus and cervix uteri during pregnancy and labor as revealed by immunohistochemistry

    PubMed Central

    Tingaker, Berith K; Ekman-Ordeberg, Gunvor; Forsgren, Sture

    2006-01-01

    Background The uterus is exposed to changes such as enlargement and distension during pregnancy and labor. In these processes and in the process of cervical ripening, proprioceptive information is likely to be of great importance. Therefore, we wanted to study the possible existence of sensory nerve corpuscles in uterine corpus and cervix during pregnancy and labor. Studies on this aspect have not previously been perfomed. Methods Biopsies were taken from the upper edge of the hysterotomy during caesarean section at term (n = 8), in labor (n = 5) and from the corresponding area in the non-pregnant uterus after hysterectomy (n = 7). Cervical biopsies were obtained transvaginally from the anterior cervical lip. Serial cryostat sections were prepared for immunohistochemistry using polyclonal antibodies against nerve growth factor receptor p75, protein gene product 9.5 and S-100. Results Structures with the characteristics of sensory nerve corpuscles were observed in several specimens after staining for p75, PGP 9.5 and S-100. They were observed in specimens of the non-pregnant corpus and cervix and also in specimens of the pregnant cervix before onset of labor. However, they were absent in all specimens during labor. Conclusion Sensory corpuscles have here for the first time been detected in the human corpus and cervix uteri. Studies on the importance of the corpuscles in relation to the protective reflex actions that occur in the uterus during pregnancy should be performed in the future. PMID:16938139

  1. Pharmacologic rescue of motor and sensory function by the neuroprotective compound P7C3 following neonatal nerve injury.

    PubMed

    Kemp, S W P; Szynkaruk, M; Stanoulis, K N; Wood, M D; Liu, E H; Willand, M P; Morlock, L; Naidoo, J; Williams, N S; Ready, J M; Mangano, T J; Beggs, S; Salter, M W; Gordon, T; Pieper, A A; Borschel, G H

    2015-01-22

    Nerve injuries cause pain, paralysis and numbness that can lead to major disability, and newborns often sustain nerve injuries during delivery that result in lifelong impairment. Without a pharmacologic agent to enhance functional recovery from these injuries, clinicians rely solely on surgery and rehabilitation to treat patients. Unfortunately, patient outcomes remain poor despite application of the most advanced microsurgical and rehabilitative techniques. We hypothesized that the detrimental effects of traumatic neonatal nerve injury could be mitigated with pharmacologic neuroprotection, and tested whether the novel neuroprotective agent P7C3 would block peripheral neuron cell death and enhance functional recovery in a rat neonatal nerve injury model. Administration of P7C3 after sciatic nerve crush injury doubled motor and sensory neuron survival, and also promoted axon regeneration in a dose-dependent manner. Treatment with P7C3 also enhanced behavioral and muscle functional recovery, and reversed pathological mobilization of spinal microglia after injury. Our findings suggest that the P7C3 family of neuroprotective compounds may provide a basis for the development of a new neuroprotective drug to enhance recovery following peripheral nerve injury. PMID:25313000

  2. A comparison of nerve conduction velocities and current perception thresholds as correlates of clinical severity of diabetic sensory neuropathy.

    PubMed Central

    Rendell, M S; Katims, J J; Richter, R; Rowland, F

    1989-01-01

    Nerve conduction velocities (NCVs) are the standard measurements used to confirm the presence or absence of diabetic neuropathy. NCVs were contrasted with the newer technique of measurement of alternating current perception thresholds (CPTs) in assessing the quantitative level of correlation with severity of diabetic sensory neuropathy. A very detailed, scored neurological history (symptoms) and physical examination, emphasising sensory assessment, was conducted on 71 individuals with diabetic neuropathy of varying degrees of severity. Sensory and motor NCVs and CPTs at 5, 250, and 2000 Hz of the upper and lower extremities were determined for these individuals. In addition, vibration thresholds (VTs) were measured as a third modality. Twenty eight individuals underwent repeated evaluations at 2, 6, 10 and 12 months after the initial procedures. Using the results of 169 complete evaluations, correlations were determined between physical scores (PS) and symptoms scores (SS) and NCVs. NCV correlations with the SS were weaker than with the PS. The strongest of the correlations were found between the PS and motor NCVs of the median nerve (rho = 0.29) and the tibial nerve (rho = 0.38). Normal NCVs were present in the face of very significant historical and physical abnormality. Correlations of the SS and PS with both VTs and CPTs were higher than with the NCVs. CPTs proved the more effective as predictors of both symptomatic and physical impairment. NCVs appear to lack the resolving power necessary to evaluate subtle differences in clinical state of diabetic sensory neuropathy. The supplementary use of current perception testing may improve the quantitative assessment of this condition. PMID:2738593

  3. Sensory nerves contribute to cutaneous vasodilator response to cathodal stimulation in healthy rats.

    PubMed

    Gohin, Stéphanie; Decorps, Johanna; Sigaudo-Roussel, Dominique; Fromy, Bérengère

    2015-09-01

    Cutaneous current-induced vasodilation (CIV) in response to galvanic current application is an integrative model of neurovascular interaction that relies on capsaicin-sensitive fiber activation. The upstream and downstream mechanisms related to the activation of the capsaicin-sensitive fibers involved in CIV are not elucidated. In particular, the activation of cutaneous transient receptor potential vanilloid type-1 (TRPV1) channels and/or acid-sensing ion channels (ASIC) (activators mechanisms) and the release of calcitonin gene-related peptide (CGRP) and substance P (SP) (effector mechanisms) have been tested. To assess cathodal CIV, we measured cutaneous blood flow using laser Doppler flowmetry for 20min following cathodal current application (240s, 100μA) on the skin of the thigh in anesthetized healthy rats for 20min. CIV was studied in rats treated with capsazepine and amiloride to inhibit TRPV1 and ASIC channels, respectively; CGRP8-37 and SR140333 to antagonize CGRP and neurokinin-1 (NK1) receptors, respectively; compared to their respective controls. Cathodal CIV was attenuated by capsazepine (12±2% vs 54±6%, P<0.001), amiloride (19±8% vs 61±6%, P<0.01), CGRP8-37 (15±6% vs 61±6%, P<0.001) and SR140333 (9±5% vs 54±6%, P<0.001) without changing local acidification. This is the first integrative study performed in healthy rats showing that cutaneous vasodilation in response to cathodal stimulation is initiated by activation of cutaneous TRPV1 and ASIC channels likely through local acidification. The involvement of CGRP and NK1 receptors suggests that cathodal CIV is the result of CGRP and SP released through activated capsaicin-sensitive fibers. Therefore cathodal CIV could be a valuable method to assess sensory neurovascular function in the skin, which would be particularly relevant to evaluate the presence of small nerve fiber disorders and the effectiveness of treatments. PMID:26205659

  4. Differential myelinated and unmyelinated sensory and autonomic skin nerve fiber involvement in patients with ophthalmic postherpetic neuralgia

    PubMed Central

    Truini, Andrea; Haanpaa, Maija; Provitera, Vincenzo; Biasiotta, Antonella; Stancanelli, Annamaria; Caporaso, Giuseppe; Santoro, Lucio; Cruccu, Giorgio; Nolano, Maria

    2015-01-01

    Postherpetic neuralgia (PHN) is a common and exceptionally drug-resistant neuropathic pain condition. In this cross-sectional skin biopsy study, seeking information on the responsible pathophysiological mechanisms we assessed how ophthalmic PHN affects sensory and autonomic skin innervation. We took 2-mm supraorbital punch skin biopsies from the affected and unaffected sides in 10 patients with ophthalmic PHN. Using indirect immunofluorescence and a large panel of antibodies including protein gene product (PGP) 9.5 we quantified epidermal unmyelinated, dermal myelinated and autonomic nerve fibers. Although skin biopsy showed reduced epidermal and dermal myelinated fiber density in specimens from the affected side, the epidermal/dermal myelinated nerve fiber ratio was lower in the affected than in the unaffected side (p < 0.001), thus suggesting a predominant epidermal unmyelinated nerve fiber loss. Conversely, autonomic skin innervation was spared. Our study showing that ophthalmic PHN predominantly affects unmyelinated nerve fiber and spares autonomic nerve fiber might help to understand the pathophysiological mechanisms underlying this difficult-to-treat condition. PMID:26300742

  5. Refining the Sensory and Motor Ratunculus of the Rat Upper Extremity Using fMRI and Direct Nerve Stimulation

    PubMed Central

    Cho, Younghoon R.; Pawela, Christopher P.; Li, Rupeng; Kao, Dennis; Schulte, Marie L.; Runquist, Matthew L.; Yan, Ji-Geng; Matloub, Hani S.; Jaradeh, Safwan S.; Hudetz, Anthony G.; Hyde, James S.

    2008-01-01

    It is well understood that the different regions of the body have cortical representations in proportion to the degree of innervation. Our current understanding of the rat upper extremity has been enhanced using functional MRI (fMRI), but these studies are often limited to the rat forepaw. The purpose of this study is to describe a new technique that allows us to refine the sensory and motor representations in the cerebral cortex by surgically implanting electrodes on the major nerves of the rat upper extremity and providing direct electrical nerve stimulation while acquiring fMRI images. This technique was used to stimulate the ulnar, median, radial, and musculocutaneous nerves in the rat upper extremity using four different stimulation sequences that varied in frequency (5 Hz vs. 10 Hz) and current (0.5 mA vs. 1.0 mA). A distinct pattern of cortical activation was found for each nerve. The higher stimulation current resulted in a dramatic increase in the level of cortical activation. The higher stimulation frequency resulted in both increases and attenuation of cortical activation in different regions of the brain, depending on which nerve was stimulated. PMID:17969116

  6. Low-level laser treatment improves longstanding sensory aberrations in the inferior alveolar nerve following surgical trauma

    NASA Astrophysics Data System (ADS)

    Khullar, Shelley M.; Brodin, P.; Barkvoll, P.; Haanoes, H. R.

    1996-01-01

    The incidence of inferior alveolar nerve (IAN) damage following removal of 3rd molar teeth or saggital split osteotomy has been reported as high as up to 5.5% and 100% respectively. Sensory aberrations in the IAN persisting for longer than 6 months leave some degree of permanent defect. Low level laser treatment (LLL) has a reported beneficial effect on regeneration of traumatically injured nerves. The purpose of this double blind clinical trial was to examine the effects of LLL using a GaAlAs laser (820 nm, Ronvig, Denmark) on touch and temperature sensory perception following a longstanding post surgical IAN injury. Thirteen patients were divided into two groups, one of which received real LLL (4 by 6 J per treatment along the distribution of the IAN to a total of 20 treatments during a time period between 36 - 69 days) and the other equivalent placebo LLL. The degree of mechanoreceptor injury as assessed by Semmes Weinstein Monofilaments (North Coast Medical, USA) were comparable in the two groups prior to treatment (p equals 0.9). Subsequent to LLL the real laser treatment group showed a significant improvement in mechanoreceptor sensory testing (p equals 0.01) as manifested by a decrease in load threshold (g) necessary to elicit a response from the most damaged area. The placebo LLL group showed no significant improvement, In addition, the real LLL group reported a subjective improvement in sensory function too. The degree of thermal sensitivity disability as assessed using a thermotester (Philips, Sweden) was comparable between the two groups prior to LLL p equals 0.5). However, there was no significant improvement in thermal sensitivity post LLL for either the real or placebo laser treated groups. In conclusion, GaAlAs LLL can improve mechanoreceptor perception in longstanding sensory aberration in the IAN.

  7. Early sensory re-education of the hand after peripheral nerve repair based on mirror therapy: a randomized controlled trial

    PubMed Central

    Paula, Mayara H.; Barbosa, Rafael I.; Marcolino, Alexandre M.; Elui, Valéria M. C.; Rosén, Birgitta; Fonseca, Marisa C. R.

    2016-01-01

    BACKGROUND: Mirror therapy has been used as an alternative stimulus to feed the somatosensory cortex in an attempt to preserve hand cortical representation with better functional results. OBJECTIVE: To analyze the short-term functional outcome of an early re-education program using mirror therapy compared to a late classic sensory program for hand nerve repair. METHOD: This is a randomized controlled trial. We assessed 20 patients with median and ulnar nerve and flexor tendon repair using the Rosen Score combined with the DASH questionnaire. The early phase group using mirror therapy began on the first postoperative week and lasted 5 months. The control group received classic sensory re-education when the protective sensation threshold was restored. All participants received a patient education booklet and were submitted to the modified Duran protocol for flexor tendon repair. The assessments were performed by the same investigator blinded to the allocated treatment. Mann-Whitney Test and Effect Size using Cohen's d score were used for inter-group comparisons at 3 and 6 months after intervention. RESULTS: The primary outcome (Rosen score) values for the Mirror Therapy group and classic therapy control group after 3 and 6 months were 1.68 (SD=0.5); 1.96 (SD=0.56) and 1.65 (SD=0.52); 1.51 (SD=0.62), respectively. No between-group differences were observed. CONCLUSION: Although some clinical improvement was observed, mirror therapy was not shown to be more effective than late sensory re-education in an intermediate phase of nerve repair in the hand. Replication is needed to confirm these findings. PMID:26786080

  8. Capsaicin-sensitive sensory nerves exert complex regulatory functions in the serum-transfer mouse model of autoimmune arthritis

    PubMed Central

    Borbély, Éva; Botz, Bálint; Bölcskei, Kata; Kenyér, Tibor; Kereskai, László; Kiss, Tamás; Szolcsányi, János; Pintér, Erika; Csepregi, Janka Zsófia; Mócsai, Attila; Helyes, Zsuzsanna

    2015-01-01

    Objective The K/BxN serum-transfer arthritis is a widely-used translational mouse model of rheumatoid arthritis, in which the immunological components have thoroughly been investigated. In contrast, little is known about the role of sensory neural factors and the complexity of neuro–immune interactions. Therefore, we analyzed the involvement of capsaicin-sensitive peptidergic sensory nerves in autoantibody-induced arthritis with integrative methodology. Methods Arthritogenic K/BxN or control serum was injected to non-pretreated mice or resiniferatoxin (RTX)-pretreated animals where capsaicin-sensitive nerves were inactivated. Edema, touch sensitivity, noxious heat threshold, joint function, body weight and clinical arthritis severity scores were determined repeatedly throughout two weeks. Micro-CT and in vivo optical imaging to determine matrix-metalloproteinase (MMP) and neutrophil-derived myeloperoxidase (MPO) activities, semiquantitative histopathological scoring and radioimmunoassay to measure somatostatin in the joint homogenates were also performed. Results In RTX-pretreated mice, the autoantibody-induced joint swelling, arthritis severity score, MMP and MPO activities, as well as histopathological alterations were significantly greater compared to non-pretreated animals. Self-control quantification of the bone mass revealed decreased values in intact female mice, but significantly greater arthritis-induced pathological bone formation after RTX-pretreatment. In contrast, mechanical hyperalgesia from day 10 was smaller after inactivating capsaicin-sensitive afferents. Although thermal hyperalgesia did not develop, noxious heat threshold was significantly higher following RTX pretreatment. Somatostatin-like immunoreactivity elevated in the tibiotarsal joints in non-pretreated, which was significantly less in RTX-pretreated mice. Conclusions Although capsaicin-sensitive sensory nerves mediate mechanical hyperalgesia in the later phase of autoantibody

  9. Differential motor and sensory functional recovery in male but not female adult rats is associated with remyelination rather than axon regeneration after sciatic nerve crush.

    PubMed

    Tong, Ling-Ling; Ding, You-Quan; Jing, Hong-Bo; Li, Xuan-Yang; Qi, Jian-Guo

    2015-05-01

    Peripheral nerve functional recovery after injuries relies on both axon regeneration and remyelination. Both axon regeneration and remyelination require intimate interactions between regenerating neurons and their accompanying Schwann cells. Previous studies have shown that motor and sensory neurons are intrinsically different in their regeneration potentials. Moreover, denervated Schwann cells accompanying myelinated motor and sensory axons have distinct gene expression profiles for regeneration-associated growth factors. However, it is unknown whether differential motor and sensory functional recovery exists. If so, the particular one among axon regeneration and remyelination responsible for this difference remains unclear. Here, we aimed to establish an adult rat sciatic nerve crush model with the nonserrated microneedle holders and measured rat motor and sensory functions during regeneration. Furthermore, axon regeneration and remyelination was evaluated by morphometric analysis of electron microscopic images on the basis of nerve fiber classification. Our results showed that Aα fiber-mediated motor function was successfully recovered in both male and female rats. Aδ fiber-mediated sensory function was partially restored in male rats, but completely recovered in female littermates. For both male and female rats, the numbers of regenerated motor and sensory axons were quite comparable. However, remyelination was diverse among myelinated motor and sensory nerve fibers. In detail, Aβ and Aδ fibers incompletely remyelinated in male, but not female rats, whereas Aα fibers fully remyelinated in both sexes. Our result indicated that differential motor and sensory functional recovery in male but not female adult rats is associated with remyelination rather than axon regeneration after sciatic nerve crush. PMID:25830493

  10. Regeneration of putative sensory and sympathetic cutaneous nerve endings in the rat foot after sciatic nerve injury.

    PubMed

    Stankovic, N; Johansson, O; Hildebrand, C

    1996-01-01

    The present study examines the occurrence of calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profiles in glabrous and hairy foot skin from normal and nerve-injured rats. After neurotomy/suture, glabrous skin samples contain few calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profies. The number of calcitonin gene-related peptide- and substance P-like immunoreacive profiles in the epidermis is significantly subnormal. Hairy skin from these rats does also contain few calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profiles. In addition, the presence of epidermal calcitonin gene-related peptide-like imunoreactive profiles in glabrous skin is subnormal on the contralateral side. After nerve crush injury, the occurrence of calcitonin gene-related peptide-like, but not substance P-like, immunoreactive profiles in th epidermis of the glabrous skin is significantly subnormal. The occurrence of tyrosine hylase-like immnunoreactive fibres in relation to the digital artery is also subnormal. The occurrence in hairy skin of calcitonin gene-related peptide-like immunoreactive, substance P-like immunoreactive and tyrosine hydroxylase-like immunoreactive profiles is subnormal. In both skin types, the contralateral occurrence of such profiles is subjectively normal. These results show that the occurrence of calcitonin gene-related peptide-, substance P-, and tyrosine hydroxylase-like immunoreactive profiles in glabrous and hairy foot skin is clearly subnormal after neurotomy and suture and less abnormal after nerve crush. After neurotomy and suture the contralateral side is also affected. PMID:10970110

  11. Genome-wide association study of sensory disturbances in the inferior alveolar nerve after bilateral sagittal split ramus osteotomy

    PubMed Central

    2013-01-01

    Background Bilateral sagittal split ramus osteotomy (BSSRO) is a common orthognatic surgical procedure. Sensory disturbances in the inferior alveolar nerve, including hypoesthesia and dysesthesia, are frequently observed after BSSRO, even without distinct nerve injury. The mechanisms that underlie individual differences in the vulnerability to sensory disturbances have not yet been elucidated. Methods The present study investigated the relationships between genetic polymorphisms and the vulnerability to sensory disturbances after BSSRO in a genome-wide association study (GWAS). A total of 304 and 303 patients who underwent BSSRO were included in the analyses of hypoesthesia and dysesthesia, respectively. Hypoesthesia was evaluated using the tactile test 1 week after surgery. Dysesthesia was evaluated by interview 4 weeks after surgery. Whole-genome genotyping was conducted using Illumina BeadChips including approximately 300,000 polymorphism markers. Results Hypoesthesia and dysesthesia occurred in 51 (16.8%) and 149 (49.2%) subjects, respectively. Significant associations were not observed between the clinical data (i.e., age, sex, body weight, body height, loss of blood volume, migration length of bone fragments, nerve exposure, duration of anesthesia, and duration of surgery) and the frequencies of hypoesthesia and dysesthesia. Significant associations were found between hypoesthesia and the rs502281 polymorphism (recessive model: combined χ2 = 24.72, nominal P = 6.633 × 10-7), between hypoesthesia and the rs2063640 polymorphism (recessive model: combined χ2 = 23.07, nominal P = 1.563 × 10-6), and between dysesthesia and the nonsynonymous rs2677879 polymorphism (trend model: combined χ2 = 16.56, nominal P = 4.722 × 10-5; dominant model: combined χ2 = 16.31, nominal P = 5.369 × 10-5). The rs502281 and rs2063640 polymorphisms were located in the flanking region of the ARID1B and ZPLD1 genes on chromosomes 6 and 3, whose official names are “AT rich

  12. Nerve conduction

    MedlinePlus Videos and Cool Tools

    ... the spinal cord to muscles and sensory receptors. A peripheral nerve is composed of nerve bundles (fascicles) ... two neurons, it must first be converted to a chemical signal, which then crosses a space of ...

  13. Sciatic nerve regeneration in mice and rats: recovery of sensory innervation is followed by a slowly retreating neuropathic pain-like syndrome.

    PubMed

    Vogelaar, Christina F; Vrinten, Dorien H; Hoekman, Marco F M; Brakkee, Jan H; Burbach, J Peter H; Hamers, Frank P T

    2004-11-19

    Peripheral nerve regeneration has been studied extensively in the sciatic nerve crush model, at the level of both function and gene expression. The crush injury allows full recovery of sensory and motor function in about 3 weeks as assessed by the foot reflex withdrawal test and De Medinacelli walking patterns. We used the recently developed CatWalk paradigm to study walking patterns in more detail in mice and rats. We found that, following the recovery of sensory function, the animals developed a state of mechanical allodynia, which retreated slowly over time. The motor function, although fully recovered with the conventional methods, was revealed to be still impaired because the animals did not put weight on their previously injured paw. The development of neuropathic pain following successful sensory recovery has not been described before in crush-lesioned animals and may provide an important new parameter to assess full sensory recovery. PMID:15494158

  14. Effect of Ranirestat on Sensory and Motor Nerve Function in Japanese Patients with Diabetic Polyneuropathy: A Randomized Double-Blind Placebo-Controlled Study

    PubMed Central

    Satoh, Jo; Kohara, Nobuo; Sekiguchi, Kenji; Yamaguchi, Yasuyuki

    2016-01-01

    We conducted a 26-week oral-administration study of ranirestat (an aldose reductase inhibitor) at a once-daily dose of 20 mg to evaluate its efficacy and safety in Japanese patients with diabetic polyneuropathy (DPN). The primary endpoint was summed change in sensory nerve conduction velocity (NCV) for the bilateral sural and proximal median sensory nerves. The sensory NCV was significantly (P = 0.006) improved by ranirestat. On clinical symptoms evaluated with the use of modified Toronto Clinical Neuropathy Score (mTCNS), obvious efficacy was not found in total score. However, improvement in the sensory test domain of the mTCNS was significant (P = 0.037) in a subgroup of patients diagnosed with neuropathy according to the TCNS severity classification. No clinically significant effects on safety parameters including hepatic and renal functions were observed. Our results indicate that ranirestat is effective on DPN (Japic CTI-121994). PMID:26881251

  15. Each Sensory Nerve Arising From the Geniculate Ganglion Expresses a Unique Fingerprint of Neurotrophin and Neurotrophin Receptor Genes

    PubMed Central

    Farbman, Albert I.; Guagliardo, Nick; Sollars, Suzanne I.; Hill, David L.

    2009-01-01

    Neurons in the geniculate ganglion, like those in other sensory ganglia, are dependent on neurotrophins for survival. Most geniculate ganglion neurons innervate taste buds in two regions of the tongue and two regions of the palate; the rest are cutaneous nerves to the skin of the ear. We investigated the expression of four neurotrophins, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), and NT-4, and five neurotrophin receptors, trkA, trkB, trkC, p75, and truncated trkB (Trn-B) in single sensory neurons of the adult rat geniculate ganglion associated with the five innervation fields. For fungiform papillae, a glass pipette containing biotinylated dextran was placed over the target papilla and the tracer was iontophoresed into the target papilla. For the other target fields, Fluoro-Gold was microinjected. After 3 days, geniculate ganglia were harvested, sectioned, and treated histochemically (for biotinylated dextran) or immunohistochemically (for Fluoro-Gold) to reveal the neurons containing the tracer. Single labeled neurons were harvested from the slides and subjected to RNA amplification and RT-PCR to reveal the neurotrophin or neurotrophin receptor genes that were expressed. Neurons projecting from the geniculate ganglion to each of the five target fields had a unique expression profile of neurotrophin and neurotrophic receptor genes. Several individual neurons expressed more than one neurotrophin receptor or more than one neurotrophin gene. Although BDNF is significantly expressed in taste buds, its primary high affinity receptor, trkB, was not prominently expressed in the neurons. The results are consistent with the interpretation that at least some, perhaps most, of the trophic influence on the sensory neurons is derived from the neuronal somata, and the trophic effect is paracrine or autocrine, rather than target derived. The BDNF in the taste bud may also act in a paracrine or autocrine manner on the trkB expressed

  16. Effects of short-term training on sensory and motor function in severed nerves of long-term human amputees.

    PubMed

    Dhillon, G S; Krüger, T B; Sandhu, J S; Horch, K W

    2005-05-01

    Much has been studied and written about plastic changes in the CNS of humans triggered by events such as limb amputation. However, little is known about the extent to which the original pathways retain residual function after peripheral amputation. Our earlier, acute study on long-term amputees indicated that central pathways associated with amputated peripheral nerves retain at least some sensory and motor function. The purpose of the present study was to determine if these functional connections would be strengthened or improved with experience and training over several days time. To do this, electrodes were implanted within fascicles of severed nerves of long-term human amputees to evaluate the changes in electrically evoked sensations and volitional motor neuron activity associated with attempted phantom limb movements. Nerve stimulation consistently resulted in discrete, unitary, graded sensations of touch/pressure and joint-position sense. There was no significant change in the values of stimulation parameters required to produce these sensations over time. Similarly, while the amputees were able to improve volitional control of motor neuron activity, the rate and pattern of change was similar to that seen with practice in normal individuals on motor tasks. We conclude that the central plasticity seen after amputation is most likely primarily due to unmasking, rather than replacement, of existing synaptic connections. These results also have implications for neural control of prosthetic limbs. PMID:15846000

  17. Characterization of Thoracic Motor and Sensory Neurons and Spinal Nerve Roots in Canine Degenerative Myelopathy, a Potential Disease Model of Amyotrophic Lateral Sclerosis

    PubMed Central

    Morgan, Brandie R.; Coates, Joan R.; Johnson, Gayle C.; Shelton, G. Diane; Katz, Martin L.

    2014-01-01

    Canine Degenerative Myelopathy (DM) is a progressive adult-onset multisystem degenerative disease with many features in common with amyotrophic lateral sclerosis (ALS). As with some forms of ALS, DM is associated with mutations in superoxide dismutase 1 (SOD1). Clinical signs include general proprioceptive ataxia and spastic upper motor neuron paresis in pelvic limbs, which progress to flaccid tetraplegia and dysphagia. The purpose of this study was to characterize DM as a potential disease model for ALS. We previously reported that intercostal muscle atrophy develops in dogs with advanced stage DM. To determine if other components of the thoracic motor unit (MU) also demonstrated morphological changes consistent with dysfunction, histopathologic and morphometric analyses were conducted on thoracic spinal motor neurons (MN) and dorsal root ganglia (DRG), and in motor and sensory nerve root axons from DM-affected Boxers and Pembroke Welsh Corgis (PWCs). No alterations in MNs, or motor root axons were observed in either breed. However, advanced stage PWCs exhibited significant losses of sensory root axons, and numerous DRG sensory neurons displayed evidence of degeneration. These results indicate that intercostal muscle atrophy in DM is not preceded by physical loss of the motor neurons innervating these muscles, or of their axons. Axonal loss in thoracic sensory roots and sensory nerve death suggest sensory involvement may play an important role in DM disease progression. Further analysis of the mechanisms responsible for these morphological findings would aid in the development of therapeutic intervention for DM and some forms of ALS. PMID:24375814

  18. Substitution of natural sensory input by artificial neurostimulation of an amputated trigeminal nerve does not prevent the degeneration of basal forebrain cholinergic circuits projecting to the somatosensory cortex

    PubMed Central

    Herrera-Rincon, Celia; Panetsos, Fivos

    2014-01-01

    Peripheral deafferentation downregulates acetylcholine (ACh) synthesis in sensory cortices. However, the responsible neural circuits and processes are not known. We irreversibly transected the rat infraorbital nerve and implanted neuroprosthetic microdevices for proximal stump stimulation, and assessed cytochrome-oxidase and choline- acetyl-transferase (ChAT) in somatosensory, auditory and visual cortices; estimated the number and density of ACh-neurons in the magnocellular basal nucleus (MBN); and localized down-regulated ACh-neurons in basal forebrain using retrograde labeling from deafferented cortices. Here we show that nerve transection, causes down regulation of MBN cholinergic neurons. Stimulation of the cut nerve reverses the metabolic decline but does not affect the decrease in cholinergic fibers in cortex or cholinergic neurons in basal forebrain. Artifical stimulation of the nerve also has no affect of ACh-innervation of other cortices. Cortical ChAT depletion is due to loss of corticopetal MBN ChAT-expressing neurons. MBN ChAT downregulation is not due to a decrease of afferent activity or to a failure of trophic support. Basalocortical ACh circuits are sensory specific, ACh is provided to each sensory cortex “on demand” by dedicated circuits. Our data support the existence of a modality-specific cortex-MBN-cortex circuit for cognitive information processing. PMID:25452715

  19. The exceptionally high reactivity of Cys 621 is critical for electrophilic activation of the sensory nerve ion channel TRPA1.

    PubMed

    Bahia, Parmvir K; Parks, Thomas A; Stanford, Katherine R; Mitchell, David A; Varma, Sameer; Stevens, Stanley M; Taylor-Clark, Thomas E

    2016-06-01

    Activation of the sensory nerve ion channel TRPA1 by electrophiles is the key mechanism that initiates nociceptive signaling, and leads to defensive reflexes and avoidance behaviors, during oxidative stress in mammals. TRPA1 is rapidly activated by subtoxic levels of electrophiles, but it is unclear how TRPA1 outcompetes cellular antioxidants that protect cytosolic proteins from electrophiles. Here, using physiologically relevant exposures, we demonstrate that electrophiles react with cysteine residues on mammalian TRPA1 at rates that exceed the reactivity of typical cysteines by 6,000-fold and that also exceed the reactivity of antioxidant enzymes. We show that TRPA1 possesses a complex reactive cysteine profile in which C621 is necessary for electrophile-induced binding and activation. Modeling of deprotonation energies suggests that K620 contributes to C621 reactivity and mutation of K620 alone greatly reduces the effect of electrophiles on TRPA1. Nevertheless, binding of electrophiles to C621 is not sufficient for activation, which also depends on the function of another reactive cysteine (C665). Together, our results demonstrate that TRPA1 acts as an effective electrophilic sensor because of the exceptionally high reactivity of C621. PMID:27241698

  20. Evidence for a role of capsaicin-sensitive sensory nerves in the lung oedema induced by Tityus serrulatus venom in rats.

    PubMed

    Andrade, Marcus V M; Souza, Danielle G; de A Castro, Maria Salete; Cunha-Melo, José R; Teixeira, Mauro M

    2002-03-01

    In the most severe cases of human envenoming by Tityus serrulatus, pulmonary oedema is a frequent finding and can be the cause of death. We have previously demonstrated a role for neuropeptides acting on tachykinin NK(1) receptors in the development of lung oedema following i.v. injection of T. serrulatus venom (TsV) in experimental animals. The present work was designed to investigate whether capsaicin-sensitive primary afferent neurons were a potential source of NK(1)-acting neuropeptides. To this end, sensory nerves were depleted of neuropeptides by neonatal treatment of rats with capsaicin. The effectiveness of this strategy at depleting sensory nerves was demonstrated by the inhibition of the neuropeptide-dependent response to intraplantar injection of formalin. Pulmonary oedema, as assessed by the levels of extravasation of Evans blue dye in the bronchoalveolar lavage and in the left lung, was markedly inhibited in capsaicin-treated animals. In contrast, capsaicin treatment failed to alter the increase in arterial blood pressure or the lethality following i.v. injection of TsV. Our results demonstrate an important role for capsaicin-sensitive sensory nerves in the cascade of events leading to lung injury following the i.v. administration of TsV. PMID:11711125

  1. Characterization of thoracic motor and sensory neurons and spinal nerve roots in canine degenerative myelopathy, a potential disease model of amyotrophic lateral sclerosis.

    PubMed

    Morgan, Brandie R; Coates, Joan R; Johnson, Gayle C; Shelton, G Diane; Katz, Martin L

    2014-04-01

    Canine degenerative myelopathy (DM) is a progressive, adult-onset, multisystem degenerative disease with many features in common with amyotrophic lateral sclerosis (ALS). As with some forms of ALS, DM is associated with mutations in superoxide dismutase 1 (SOD1). Clinical signs include general proprioceptive ataxia and spastic upper motor neuron paresis in pelvic limbs, which progress to flaccid tetraplegia and dysphagia. The purpose of this study was to characterize DM as a potential disease model for ALS. We previously reported that intercostal muscle atrophy develops in dogs with advanced-stage DM. To determine whether other components of the thoracic motor unit (MU) also demonstrated morphological changes consistent with dysfunction, histopathologic and morphometric analyses were conducted on thoracic spinal motor neurons (MNs) and dorsal root ganglia (DRG) and in motor and sensory nerve root axons from DM-affected boxers and Pembroke Welsh corgis (PWCs). No alterations in MNs or motor root axons were observed in either breed. However, advanced-stage PWCs exhibited significant losses of sensory root axons, and numerous DRG sensory neurons displayed evidence of degeneration. These results indicate that intercostal muscle atrophy in DM is not preceded by physical loss of the motor neurons innervating these muscles, nor of their axons. Axonal loss in thoracic sensory roots and sensory neuron death suggest that sensory involvement may play an important role in DM disease progression. Further analysis of the mechanisms responsible for these morphological findings would aid in the development of therapeutic intervention for DM and some forms of ALS. PMID:24375814

  2. Sensory recovery after primary repair of palmar digital nerves using a Revolnerv(®) collagen conduit: a prospective series of 27 cases.

    PubMed

    Arnaout, A; Fontaine, C; Chantelot, C

    2014-09-01

    Despite advances in microsurgery, digital nerve repair remains a challenge due to the lack of reproducible procedures with satisfactory functional results. The aim of this study was to compare the sensory and functional results of direct microsurgical sutures protected by a Revolnerv(®) nerve regeneration conduit, with results of a series of direct sutures without a protective conduit in the literature. From November 2009 to April 2010, 35 patients were treated by direct epiperineural suture for digital nerve injury, protected by a Revolnerv(®) nerve regeneration conduit at the FESUM centre "SOS-mains Lesquin/CHRU de Lille". Sensory recovery was assessed by the static two-point discrimination Weber test (WS) and the Semmes-Weinstein (SW) test at postoperative months 1, 3, and 6. The final evaluation was performed after a minimum follow-up of 6 months. Statistical analysis of sensory results (WS and SW) was mainly performed with non-parametric tests (Wilcoxon, Mann and Whitney). P<0.05 was considered to be statistically significant. One patient was excluded, six were lost to follow-up, and four could not be seen at the 6-month follow-up visit. Finally, 24 patients and 27 nerve sutures were included. Mean age was 38 years old and the ratio of women/men was 1/5. Eighty-five percent of the patients had useful (S3+) or normal (S4) discrimination at 6 months, and the average WS was 10.3 (±3.76). There was a tendency to better WS results in sharp transections compared to jagged lacerations (9.19 vs 11.82). The SW test was satisfactory in 15% of patients and acceptable in 30%. There were no complications from the Revolnerv(®) collagen tube. After 6 months follow-up this study shows that results with the Revolnerv(®) nerve regeneration conduit on direct palmar digital nerve sutures were comparable to but not better than those of uncoated direct sutures. A study including a larger population with longer follow-up is necessary to determine the value of this technique and

  3. Nerve Injury Diminishes Opioid Analgesia through Lysine Methyltransferase-mediated Transcriptional Repression of μ-Opioid Receptors in Primary Sensory Neurons.

    PubMed

    Zhang, Yuhao; Chen, Shao-Rui; Laumet, Geoffroy; Chen, Hong; Pan, Hui-Lin

    2016-04-15

    The μ-opioid receptor (MOR, encoded by Oprm1) agonists are the mainstay analgesics for treating moderate to severe pain. Nerve injury causes down-regulation of MORs in the dorsal root ganglion (DRG) and diminishes the opioid effect on neuropathic pain. However, the epigenetic mechanisms underlying the diminished MOR expression caused by nerve injury are not clear. G9a (encoded by Ehmt2), a histone 3 at lysine 9 methyltransferase, is a key chromatin regulator responsible for gene silencing. In this study, we determined the role of G9a in diminished MOR expression and opioid analgesic effects in animal models of neuropathic pain. We found that nerve injury in rats induced a long-lasting reduction in the expression level of MORs in the DRG but not in the spinal cord. Nerve injury consistently increased the enrichment of the G9a product histone 3 at lysine 9 dimethylation in the promoter of Oprm1 in the DRG. G9a inhibition or siRNA knockdown fully reversed MOR expression in the injured DRG and potentiated the morphine effect on pain hypersensitivity induced by nerve injury. In mice lacking Ehmt2 in DRG neurons, nerve injury failed to reduce the expression level of MORs and the morphine effect. In addition, G9a inhibition or Ehmt2 knockout in DRG neurons normalized nerve injury-induced reduction in the inhibitory effect of the opioid on synaptic glutamate release from primary afferent nerves. Our findings indicate that G9a contributes critically to transcriptional repression of MORs in primary sensory neurons in neuropathic pain. G9a inhibitors may be used to enhance the opioid analgesic effect in the treatment of chronic neuropathic pain. PMID:26917724

  4. Release of somatostatin and its role in the mediation of the anti-inflammatory effect induced by antidromic stimulation of sensory fibres of rat sciatic nerve.

    PubMed

    Szolcsányi, J; Helyes, Z; Oroszi, G; Németh, J; Pintér, E

    1998-03-01

    1. The effect of antidromic stimulation of the sensory fibres of the sciatic nerve on inflammatory plasma extravasation in various tissues and on cutaneous vasodilatation elicited in distant parts of the body was investigated in rats pretreated with guanethidine (8 mg kg(-1), i.p.) and pipecuronium (200 microg kg(-1), i.v.). 2. Antidromic sciatic nerve stimulation with C-fibre strength (20 V, 0.5 ms) at 5 Hz for 5 min elicited neurogenic inflammation in the innervated area and inhibited by 50.3 +/- 4.67% the development of a subsequent plasma extravasation in response to similar stimulation of the contralateral sciatic nerve. Stimulation at 0.5 Hz for 1 h also evoked local plasma extravasation and inhibited the carrageenin-induced (1%, 100 microl s.c.) cutaneous inflammation by 38.5 +/- 10.0% in the contralateral paw. Excitation at 0.1 Hz for 4 h elicited no local plasma extravasation in the stimulated hindleg but still reduced the carrageenin-induced oedema by 52.1 +/- 9.7% in the paw on the contralateral side. 3. Plasma extravasation in the knee joint in response to carrageenin (2%, 200 microl intra-articular injection) was diminished by 46.1 +/- 12.69% and 40.9 +/- 4.93% when the sciatic nerve was stimulated in the contralateral leg at 0.5 Hz for 1 h or 0.1 Hz for 4 h, respectively. 4. Stimulation of the peripheral stump of the left vagal nerve (20 V, 1 ms, 8 Hz, 10 min) elicited plasma extravasation in the trachea, oesophagus and mediastinal connective tissue in rats pretreated with atropine (2 mg kg(-1), i.v.), guanethidine (8 mg kg(-1), i.p.) and pipecuronium (200 microg kg(-1), i.v.). These responses were inhibited by 37.8 +/- 5.1%, 49.7 +/- 9.9% and 37.6 +/- 4.2%, respectively by antidromic sciatic nerve excitation (5 Hz, 5 min) applied 5 min earlier. 5. Pretreatment with polyclonal somatostatin antiserum (0.5 ml/rat, i.v.) or the selective somatostatin depleting agent cysteamine (280 mg kg(-1), s.c.) prevented the anti-inflammatory effect of sciatic nerve

  5. Exuberant sprouting of sensory and sympathetic nerve fibers in nonhealed bone fractures and the generation and maintenance of chronic skeletal pain

    PubMed Central

    Chartier, Stephane R.; Thompson, Michelle L.; Longo, Geraldine; Fealk, Michelle N.; Majuta, Lisa A.; Mantyh, Patrick W.

    2014-01-01

    Skeletal injury is a leading cause of chronic pain and long-term disability worldwide. While most acute skeletal pain can be effectively managed with nonsteroidal anti-inflammatory drugs and opiates, chronic skeletal pain is more difficult to control using these same therapy regimens. One possibility as to why chronic skeletal pain is more difficult to manage over time is that there may be nerve sprouting in non-healed areas of the skeleton that normally receive little (mineralized bone) to no (articular cartilage) innervation. If such ectopic sprouting did occur, it could result in normally nonnoxious loading of the skeleton being perceived as noxious and/or the generation of a neuropathic pain state. To explore this possibility, a mouse model of skeletal pain was generated by inducing a closed fracture of the femur. Examined animals had comminuted fractures and did not fully heal even at 90+ days post fracture. In all mice with nonhealed fractures, exuberant sensory and sympathetic nerve sprouting, an increase in the density of nerve fibers, and the formation of neuroma-like structures near the fracture site were observed. Additionally, all of these animals exhibited significant pain behaviors upon palpation of the nonhealed fracture site. In contrast, sprouting of sensory and sympathetic nerve fibers or significant palpation-induced pain behaviors was never observed in naïve animals. Understanding what drives this ectopic nerve sprouting and the role it plays in skeletal pain may allow a better understanding and treatment of this currently difficult-to-control pain state. PMID:25196264

  6. Nerve Growth Factor Mediates a Switch in Intracellular Signaling for PGE2-Induced Sensitization of Sensory Neurons from Protein Kinase A to Epac

    PubMed Central

    Vasko, Michael R.; Habashy Malty, Ramy; Guo, Chunlu; Duarte, Djane B.; Zhang, Yihong; Nicol, Grant D.

    2014-01-01

    We examined whether nerve growth factor (NGF), an inflammatory mediator that contributes to chronic hypersensitivity, alters the intracellular signaling that mediates the sensitizing actions of PGE2 from activation of protein kinase A (PKA) to exchange proteins directly activated by cAMP (Epacs). When isolated sensory neurons are grown in the absence of added NGF, but not in cultures grown with 30 ng/ml NGF, inhibiting protein kinase A (PKA) activity blocks the ability of PGE2 to augment capsaicin-evoked release of the neuropeptide CGRP and to increase the number of action potentials (APs) evoked by a ramp of current. Growing sensory neurons in culture in the presence of increasing concentrations of NGF increases the expression of Epac2, but not Epac1. An intradermal injection of complete Freund's adjuvant into the rat hindpaw also increases the expression of Epac2, but not Epac1 in the dorsal root ganglia and spinal cord: an effect blocked by intraplantar administration of NGF antibodies. Treating cultures grown in the presence of 30 ng/ml NGF with Epac1siRNA significantly reduced the expression of Epac1, but not Epac2, and did not block the ability of PGE2 to augment capsaicin-evoked release of CGRP from sensory neurons. Exposing neuronal cultures grown in NGF to Epac2siRNAreduced the expression of Epac2, but not Epac1 and prevented the PGE2-induced augmentation of capsaicin and potassium-evoked CGRP release in sensory neurons and the PGE2-induced increase in the number of APs generated by a ramp of current. In neurons grown with no added NGF, Epac siRNAs did not attenuate PGE2-induced sensitization. These results demonstrate that NGF, through increasing Epac2 expression, alters the signaling cascade that mediates PGE2-induced sensitization of sensory neurons, thus providing a novel mechanism for maintaining PGE2-induced hypersensitivity during inflammation. PMID:25126967

  7. Sensory nerve crush and regeneration and the receptive fields and response properties of neurons in the primary somatosensory cerebral cortex of cats.

    PubMed

    Brandenberg, G A; Mann, M D

    1989-03-01

    Extracellular recordings were made of activity evoked in neurons of the forepaw focus of somatosensory cerebral cortex by electrical stimulation of each paw in control cats and cats that had undergone crush injury of all cutaneous sensory nerves to the contralateral forepaw 31 to 63 days previously. Neurons responding only to stimulation of the contralateral forepaw were classified as sa; neurons responding to stimulation of both forepaws were classified as sb; neurons responding to stimulation of both contralateral paws were classified as sc; and neurons responding to stimulation of at least three paws were classified as m. The ratio sa:sb:sc:m neurons was 46:3:0:0 in control cats and 104:15:3:26 in cats that had undergone nerve crush 1-2 months prior to study. sa neurons from experimental cats had depth distributions similar to those in controls and responded to contralateral forepaw stimulation with more spikes per discharge, longer latency, and higher threshold than sa neurons in control cats. m neurons from experimental cats were distributed deeper in the cortex than sa neurons, and, when compared to experimental sa neurons, they responded with longer latency and poorer frequency-following ability; however, the number of spikes per discharge and threshold were not significantly different. The appearance of wide-field neurons in this tissue may be explained in terms of strengthening of previously sub-threshold inputs to neurons in the somatosensory system. If the neurons in sensory cortex play a requisite role in cutaneous sensations and if changes similar to those reported here occur and persist in human cortex after nerve crush, then "complete" recovery of sensation in such patients may occur against a background of changed cortical neuronal responsiveness. PMID:2920791

  8. Effect of high-frequency repetitive transcranial magnetic stimulation on motor cortical excitability and sensory nerve conduction velocity in subacute-stage incomplete spinal cord injury patients

    PubMed Central

    Cha, Hyun Gyu; Ji, Sang-Goo; Kim, Myoung-Kwon

    2016-01-01

    [Purpose] The aim of the present study was to determine whether repetitive transcranial magnetic stimulation can improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. [Subjects and Methods] This study was conducted on 20 subjects with diagnosed paraplegia due to spinal cord injury. These 20 subjects were allocated to an experimental group of 10 subjects that underwent active repetitive transcranial magnetic stimulation or to a control group of 10 subjects that underwent sham repetitive transcranial magnetic stimulation. The SCI patients in the experimental group underwent active repetitive transcranial magnetic stimulation and conventional rehabilitation therapy, whereas the spinal cord injury patients in the control group underwent sham repetitive transcranial magnetic stimulation and conventional rehabilitation therapy. Participants in both groups received therapy five days per week for six-weeks. Latency, amplitude, and sensory nerve conduction velocity were assessed before and after the six week therapy period. [Results] A significant intergroup difference was observed for posttreatment velocity gains, but no significant intergroup difference was observed for amplitude or latency. [Conclusion] repetitive transcranial magnetic stimulation may be improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. PMID:27512251

  9. Effect of high-frequency repetitive transcranial magnetic stimulation on motor cortical excitability and sensory nerve conduction velocity in subacute-stage incomplete spinal cord injury patients.

    PubMed

    Cha, Hyun Gyu; Ji, Sang-Goo; Kim, Myoung-Kwon

    2016-07-01

    [Purpose] The aim of the present study was to determine whether repetitive transcranial magnetic stimulation can improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. [Subjects and Methods] This study was conducted on 20 subjects with diagnosed paraplegia due to spinal cord injury. These 20 subjects were allocated to an experimental group of 10 subjects that underwent active repetitive transcranial magnetic stimulation or to a control group of 10 subjects that underwent sham repetitive transcranial magnetic stimulation. The SCI patients in the experimental group underwent active repetitive transcranial magnetic stimulation and conventional rehabilitation therapy, whereas the spinal cord injury patients in the control group underwent sham repetitive transcranial magnetic stimulation and conventional rehabilitation therapy. Participants in both groups received therapy five days per week for six-weeks. Latency, amplitude, and sensory nerve conduction velocity were assessed before and after the six week therapy period. [Results] A significant intergroup difference was observed for posttreatment velocity gains, but no significant intergroup difference was observed for amplitude or latency. [Conclusion] repetitive transcranial magnetic stimulation may be improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. PMID:27512251

  10. Genetics Home Reference: hereditary sensory and autonomic neuropathy type V

    MedlinePlus

    ... that primarily affects the sensory nerve cells (sensory neurons), which transmit information about sensations such as pain, ... in the development and survival of nerve cells (neurons), including sensory neurons. The NGFβ protein functions by ...

  11. Restoring motor control and sensory feedback in people with upper extremity amputations using arrays of 96 microelectrodes implanted in the median and ulnar nerves

    NASA Astrophysics Data System (ADS)

    Davis, T. S.; Wark, H. A. C.; Hutchinson, D. T.; Warren, D. J.; O'Neill, K.; Scheinblum, T.; Clark, G. A.; Normann, R. A.; Greger, B.

    2016-06-01

    Objective. An important goal of neuroprosthetic research is to establish bidirectional communication between the user and new prosthetic limbs that are capable of controlling >20 different movements. One strategy for achieving this goal is to interface the prosthetic limb directly with efferent and afferent fibres in the peripheral nervous system using an array of intrafascicular microelectrodes. This approach would provide access to a large number of independent neural pathways for controlling high degree-of-freedom prosthetic limbs, as well as evoking multiple-complex sensory percepts. Approach. Utah Slanted Electrode Arrays (USEAs, 96 recording/stimulating electrodes) were implanted for 30 days into the median (Subject 1-M, 31 years post-amputation) or ulnar (Subject 2-U, 1.5 years post-amputation) nerves of two amputees. Neural activity was recorded during intended movements of the subject’s phantom fingers and a linear Kalman filter was used to decode the neural data. Microelectrode stimulation of varying amplitudes and frequencies was delivered via single or multiple electrodes to investigate the number, size and quality of sensory percepts that could be evoked. Device performance over time was assessed by measuring: electrode impedances, signal-to-noise ratios (SNRs), stimulation thresholds, number and stability of evoked percepts. Main results. The subjects were able to proportionally, control individual fingers of a virtual robotic hand, with 13 different movements decoded offline (r = 0.48) and two movements decoded online. Electrical stimulation across one USEA evoked >80 sensory percepts. Varying the stimulation parameters modulated percept quality. Devices remained intrafascicularly implanted for the duration of the study with no significant changes in the SNRs or percept thresholds. Significance. This study demonstrated that an array of 96 microelectrodes can be implanted into the human peripheral nervous system for up to 1 month durations. Such an

  12. Dysregulation of the Descending Pain System in Temporomandibular Disorders Revealed by Low-Frequency Sensory Transcutaneous Electrical Nerve Stimulation: A Pupillometric Study

    PubMed Central

    Monaco, Annalisa; Cattaneo, Ruggero; Mesin, Luca; Ortu, Eleonora; Giannoni, Mario; Pietropaoli, Davide

    2015-01-01

    Using computerized pupillometry, our previous research established that the autonomic nervous system (ANS) is dysregulated in patients suffering from temporomandibular disorders (TMDs), suggesting a potential role for ANS dysfunction in pain modulation and the etiology of TMD. However, pain modulation hypotheses for TMD are still lacking. The periaqueductal gray (PAG) is involved in the descending modulation of defensive behavior and pain through μ, κ, and δ opioid receptors. Transcutaneous electrical nerve stimulation (TENS) has been extensively used for pain relief, as low-frequency stimulation can activate µ receptors. Our aim was to use pupillometry to evaluate the effect of low-frequency TENS stimulation of μ receptors on opioid descending pathways in TMD patients. In accordance with the Research Diagnostic Criteria for TMD, 18 females with myogenous TMD and 18 matched-controls were enrolled. All subjects underwent subsequent pupillometric evaluations under dark and light conditions before, soon after (end of stimulation) and long after (recovery period) sensorial TENS. The overall statistics derived from the darkness condition revealed no significant differences in pupil size between cases and controls; indeed, TENS stimulation significantly reduced pupil size in both groups. Controls, but not TMD patients, displayed significant differences in pupil size before compared with after TENS. Under light conditions, TMD patients presented a smaller pupil size compared with controls; the pupil size was reduced only in the controls. Pupil size differences were found before and during TENS and before and after TENS in the controls only. Pupillometry revealed that stimulating the descending opioid pathway with low-frequency sensory TENS of the fifth and seventh pairs of cranial nerves affects the peripheral target. The TMD patients exhibited a different pattern of response to TENS stimulation compared with the controls, suggesting that impaired modulation of the

  13. Dysregulation of the descending pain system in temporomandibular disorders revealed by low-frequency sensory transcutaneous electrical nerve stimulation: a pupillometric study.

    PubMed

    Monaco, Annalisa; Cattaneo, Ruggero; Mesin, Luca; Ortu, Eleonora; Giannoni, Mario; Pietropaoli, Davide

    2015-01-01

    Using computerized pupillometry, our previous research established that the autonomic nervous system (ANS) is dysregulated in patients suffering from temporomandibular disorders (TMDs), suggesting a potential role for ANS dysfunction in pain modulation and the etiology of TMD. However, pain modulation hypotheses for TMD are still lacking. The periaqueductal gray (PAG) is involved in the descending modulation of defensive behavior and pain through μ, κ, and δ opioid receptors. Transcutaneous electrical nerve stimulation (TENS) has been extensively used for pain relief, as low-frequency stimulation can activate µ receptors. Our aim was to use pupillometry to evaluate the effect of low-frequency TENS stimulation of μ receptors on opioid descending pathways in TMD patients. In accordance with the Research Diagnostic Criteria for TMD, 18 females with myogenous TMD and 18 matched-controls were enrolled. All subjects underwent subsequent pupillometric evaluations under dark and light conditions before, soon after (end of stimulation) and long after (recovery period) sensorial TENS. The overall statistics derived from the darkness condition revealed no significant differences in pupil size between cases and controls; indeed, TENS stimulation significantly reduced pupil size in both groups. Controls, but not TMD patients, displayed significant differences in pupil size before compared with after TENS. Under light conditions, TMD patients presented a smaller pupil size compared with controls; the pupil size was reduced only in the controls. Pupil size differences were found before and during TENS and before and after TENS in the controls only. Pupillometry revealed that stimulating the descending opioid pathway with low-frequency sensory TENS of the fifth and seventh pairs of cranial nerves affects the peripheral target. The TMD patients exhibited a different pattern of response to TENS stimulation compared with the controls, suggesting that impaired modulation of the

  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. A Rare Case of C2 Sensory Blockade with Preserved Phrenic Nerve Function in an Obstetric Patient.

    PubMed

    Coffman, John C; Fiorini, Kasey; Cook, Meghan; Small, Robert H

    2016-01-01

    High neuraxial blockade is a serious complication in obstetric patients and requires prompt recognition and management in order to optimize patient outcomes. In cases of high neuroblockade, patients may present with significant hypotension, dyspnea, agitation, difficulty speaking or inability to speak, or even loss of consciousness. We report the unusual presentation of an obstetric patient that remained hemodynamically stable and had the preserved ability to initiate breaths despite sensory blockade up to C2. The presence of differential motor and sensory block documented in this case helped enable the patient to be managed with noninvasive ventilatory support until the high blockade regressed and we are not aware of any other similar reports in literature. PMID:27559484

  16. A Rare Case of C2 Sensory Blockade with Preserved Phrenic Nerve Function in an Obstetric Patient

    PubMed Central

    Fiorini, Kasey; Cook, Meghan

    2016-01-01

    High neuraxial blockade is a serious complication in obstetric patients and requires prompt recognition and management in order to optimize patient outcomes. In cases of high neuroblockade, patients may present with significant hypotension, dyspnea, agitation, difficulty speaking or inability to speak, or even loss of consciousness. We report the unusual presentation of an obstetric patient that remained hemodynamically stable and had the preserved ability to initiate breaths despite sensory blockade up to C2. The presence of differential motor and sensory block documented in this case helped enable the patient to be managed with noninvasive ventilatory support until the high blockade regressed and we are not aware of any other similar reports in literature. PMID:27559484

  17. High Median Nerve Injuries.

    PubMed

    Isaacs, Jonathan; Ugwu-Oju, Obinna

    2016-08-01

    The median nerve serves a crucial role in extrinsic and intrinsic motor and sensory function to the radial half of the hand. High median nerve injuries, defined as injuries proximal to the anterior interosseous nerve origin, therefore typically result in significant functional loss prompting aggressive surgical management. Even with appropriate recognition and contemporary nerve reconstruction, however, motor and sensory recovery may be inadequate. With isolated persistent high median nerve palsies, a variety of available tendon transfers can improve key motor functions and salvage acceptable use of the hand. PMID:27387077

  18. Desensitization of metastable intermolecular composites

    DOEpatents

    Busse, James R.; Dye, Robert C.; Foley, Timothy J.; Higa, Kelvin T.; Jorgensen, Betty S.; Sanders, Victor E.; Son, Steven F.

    2011-04-26

    A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

  19. Adenosine receptor desensitization and trafficking.

    PubMed

    Mundell, Stuart; Kelly, Eamonn

    2011-05-01

    As with the majority of G-protein-coupled receptors, all four of the adenosine receptor subtypes are known to undergo agonist-induced regulation in the form of desensitization and trafficking. These processes can limit the ability of adenosine receptors to couple to intracellular signalling pathways and thus reduce the ability of adenosine receptor agonists as well as endogenous adenosine to produce cellular responses. In addition, since adenosine receptors couple to multiple signalling pathways, these pathways may desensitize differentially, while the desensitization of one pathway could even trigger signalling via another. Thus, the overall picture of adenosine receptor regulation can be complex. For all adenosine receptor subtypes, there is evidence to implicate arrestins in agonist-induced desensitization and trafficking, but there is also evidence for other possible forms of regulation, including second messenger-dependent kinase regulation, heterologous effects involving G proteins, and the involvement of non-clathrin trafficking pathways such as caveolae. In this review, the evidence implicating these mechanisms is summarized for each adenosine receptor subtype, and we also discuss those issues of adenosine receptor regulation that remain to be resolved as well as likely directions for future research in this field. PMID:20550943

  20. Improved gold chloride staining method for anatomical analysis of sensory nerve endings in the shoulder capsule and labrum as examples of loose and dense fibrous tissues

    PubMed Central

    Witherspoon, J W; Smirnova, IV; McIff, TE

    2014-01-01

    Consistency in gold chloride staining is essential for anatomical analysis of sensory nerve endings. The gold chloride stain for this purpose has been modified by many investigators, but often yields inconsistent staining, which makes it difficult to differentiate structures and to determine nerve ending distribution in large tissue samples. We introduce additional steps and major changes to the modified Gairns’ protocol. We controlled the temperature and mixing rate during tissue staining to achieve consistent staining and complete solution penetration. We subjected samples to sucrose dehydration to improve cutting efficiency. We then exposed samples to a solution containing lemon juice, formic acid and paraformaldehyde to produce optimal tissue transparency with minimal tissue deformity. We extended the time for gold chloride impregnation 1.5 fold. Gold chloride was reduced in the labrum using 25% formic acid in water for 18 h and in the capsule using 25% formic acid in citrate phosphate buffer for 2 h. Citrate binds gold nanoparticles, which minimizes aggregation in the tissue. We stored samples in fresh ultrapure water at 4° C to slow reduction and to maintain color contrast in the tissue. Tissue samples were embedded in Tissue Tek and sectioned at 80 and 100 μm instead of using glycerin and teasing the tissue apart as in Gairns’ modified gold chloride method. We attached sections directly to gelatin subbed slides after sectioning with a cryostat. The slides then were processed and coverslipped with Permount. Staining consistency was demonstrated throughout the tissue sections and neural structures were clearly identifiable. PMID:24476562

  1. Taurolidine and congeners activate hTRPA1 but not hTRPV1 channels and stimulate CGRP release from mouse tracheal sensory nerves.

    PubMed

    Kichko, Tatjana I; Pfirrmann, Rolf W; Reeh, Peter W

    2016-02-01

    Taurolidine has long been in clinical use as an antimicrobial irrigation that does not impede wound healing. It can even be administered intravenously (30 g/day) to treat sepsis or to exert newly recognized antineoplastic actions. Only one irritant effect is reported, that is, to temporarily induce burning pain of unknown origin when applied to body cavities or peripheral veins. The structure of the molecule suggested the chemoreceptor channel TRPA1 as a potential target, which was verified measuring stimulated CGRP release from sensory nerves of the isolated mouse trachea and calcium influx in hTRPA1-transfected HEK293 cells. With both methods, the concentration-response relationship of taurolidine exceeded the threshold value below 500 μmol/L and 100 μmol/L, respectively, and reached saturation at 1 mmol/L. The clinical 2% taurolidine solution did not evoke greater or longer lasting responses. The reversible tracheal response was abolished in TRPA1(-/-) but retained in TRPV1(-/-) mice. Consistently, hTRPV1-HEK showed no calcium influx as a response, likewise native HEK293 cells and hTRPA1-HEK deprived of extracellular calcium did not respond to taurolidine 1 mmol/L. The metabolite taurultam and its oxathiazine derivative, expected to cause less burning pain, showed weak tracheal irritancy only at 10 mmol/L, acting also through hTRPA1 but not hTRPV1. In conclusion, taurolidine, its metabolite, and a novel derivative showed no unspecific cellular effects but selectively, concentration-dependently and reversibly activated the irritant receptor TRPA1 in CGRP-expressing, thus nociceptive, neurons. The clinical solution of 2% taurolidine (~70 mmol/L) can, thus, rightly be expected to cause transient burning pain and neurogenic inflammation. PMID:26977296

  2. Bioenergetic deficits in peripheral nerve sensory axons during chemotherapy-induced neuropathic pain resulting from peroxynitrite-mediated post-translational nitration of mitochondrial superoxide dismutase

    PubMed Central

    Janes, Kali; Doyle, Timothy; Bryant, Leesa; Esposito, Emanuela; Cuzzocrea, Salvatore; Ryerse, Jan; Bennett, Gary J.; Salvemini, Daniela

    2016-01-01

    Many of the widely used anticancer drugs induce dose-limiting peripheral neuropathies that undermine their therapeutic efficacy. Animal models of chemotherapy-induced painful peripheral neuropathy (CIPN) evoked by a variety of drug classes, including taxanes, vinca alkaloids, platinum-complexes, and proteasome-inhibitors, suggest that the common underlying mechanism in the development of these neuropathies is mitotoxicity in primary nerve sensory axons (PNSAs) arising from reduced mitochondrial bioenergetics [eg adenosine triphosphate (ATP) production deficits due to compromised respiratory complex I and II activity]. The causative mechanisms of this mitotoxicity remain poorly defined. However, peroxynitrite, an important pro-nociceptive agent, has been linked to mitotoxicity in several disease states and may also drive the mitotoxicity associated with CIPN. Our findings reveal that the development of mechano-hypersensitivity induced by paclitaxel, oxaliplatin, and bortezomib was prevented by administration of the peroxynitrite decomposition catalyst Mn(III) 5,10,15,20-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (MnTE-2-PyP5+) without interfering with their anti-tumor effects. Peak CIPN was associated with the nitration and inactivation of superoxide dismutase in the mitochondria, but not in the cytosol, as well as a significant decrease in ATP production within the PNSAs; all of these events were attenuated by MnTE-2-PyP5+. Our results provide continued support for the role of mitotoxicity in the development of CIPN across chemotherapeutic drug classes, and identify peroxynitrite as a key mediator in these processes, thereby providing the rationale towards development of “peroxynitrite-targeted” therapeutics for CIPN. PMID:23891899

  3. Endogenous Opiate System and Systematic Desensitization.

    ERIC Educational Resources Information Center

    Egan, Kelly J.; And Others

    1988-01-01

    Administered intravenous infusions to phobic patients prior to systematic desensitization. Saline-infused subjects significantly demonstrated the predicted symptom decrease in response to systematic desensitization, whereas naloxone-infused subjects showed no change. Subject reports and psychophysiological measures of arousal indicated no…

  4. Potentiating potassium nitrate's desensitization with dimethyl isosorbide.

    PubMed

    Hodosh, M

    2001-01-01

    Desensitization of hypersensitive teeth by the combination of dimethyl isosorbide (DMI) and potassium nitrate (KNO3) is more effective than when KNO3 is used alone. KNO3/DMI work together to desensitize hypersensitive teeth at a higher, quicker, and more profound and lasting level. PMID:12017799

  5. [Desensitization of the nicotinic acetylcholine receptor].

    PubMed

    Quiñonez, M; Rojas, L

    1994-01-01

    In biological membranes, ionic channels act speeding up ion movements. Each ionic channel is excited by a specific stimulus (i.e. electric, mechanical, chemical, etc.). Chemically activated ionic channels (CAIC), such as the nicotinic acetylcholine receptor (nAChR), suffer desensitization when the receptor site is still occupied by the agonist molecule. The desensitized CAIC is a non functional channel state regarded as a particular case of receptors rundown. CAIC desensitization only involve reduced activity and not their membrane elimination. Desensitization is important to control synaptic transmission and the development of the nervous system. In this review we discuss results related to its production, modulation and some aspects associated to models that consider it. Finally, an approach combining molecular biology and electrophysiology techniques to understand desensitization and its importance in biological systems is presented. PMID:8525756

  6. Genetics Home Reference: hereditary sensory and autonomic neuropathy type II

    MedlinePlus

    ... that primarily affects the sensory nerve cells (sensory neurons), which transmit information about sensations such as pain, ... the sensations of pain, temperature, and touch (sensory neurons). The mutations involved in HSAN2A result in an ...

  7. Genetics Home Reference: hereditary sensory neuropathy type IA

    MedlinePlus

    ... Conditions hereditary sensory neuropathy type IA hereditary sensory neuropathy type IA Enable Javascript to view the expand/ ... PDF Open All Close All Description Hereditary sensory neuropathy type IA is a condition characterized by nerve ...

  8. Cross talk among tyrosine kinase receptors in PC12 cells: desensitization of mitogenic epidermal growth factor receptors by the neurotrophic factors, nerve growth factor and basic fibroblast growth factor.

    PubMed Central

    Mothe, I; Ballotti, R; Tartare, S; Kowalski-Chauvel, A; Van Obberghen, E

    1993-01-01

    We have studied the effects of nerve growth factor (NGF) and basic fibroblast growth factor (bFGF) on epidermal growth factor (EGF) binding to PC12 cells. We show that NGF and bFGF rapidly induce a reduction in 125I-EGF binding to PC12 cells in a dose-dependent manner. This decrease amounts to 50% for NGF and 35% for bFGF. Both factors appear to act through a protein kinase C(PKC)-independent pathway, because their effect persists in PKC-downregulated PC12 cells. Scatchard analysis indicates that NGF and bFGF decrease the number of high affinity EGF binding sites. In addition to their effect on EGF binding, NGF and bFGF activate in intact PC12 cells one or several serine/threonine kinases leading to EGF receptor threonine phosphorylation. Using an in vitro phosphorylation system, we show that NGF- or bFGF-activated extracellular regulated kinase 1 (ERK1) is able to phosphorylate a kinase-deficient EGF receptor. Phosphoamino acid analysis indicates that this phosphorylation occurs mainly on threonine residues. Furthermore, two comparable phosphopeptides are observed in the EGF receptor, phosphorylated either in vivo after NGF treatment or in a cell-free system by NGF-activated ERK1. Finally, a good correlation was found between the time courses of ERK1 activation and 125I-EGF binding inhibition after NGF or bFGF treatment. In conclusion, in PC12 cells the NGF- and bFGF-stimulated ERK1 appears to be involved in the induction of the threonine phosphorylation of the EGF receptor and the decrease in the number of high affinity EGF binding sites. Images PMID:8400459

  9. Shock desensitizing of solid explosives

    SciTech Connect

    Davis, William C

    2010-01-01

    Solid explosive can be desensitized by a shockwave too weak to initiate it promptly, and desensitized explosive does not react although its chemical composition is almost unchanged. A strong second shock does not cause reaction until it overtakes the first shock. The first shock, if it is strong enough, accelerates very slowly at first, and then more rapidly as detonation approaches. These facts suggest that there are two competing reactions. One is the usual explosive goes to products with the release of energy, and the other is explosive goes to dead explosive with no chemical change and no energy release. The first reaction rate is very sensitive to the local state, and the second is only weakly so. At low pressure very little energy is released and the change to dead explosive dominates. At high pressure, quite the other way, most of the explosive goes to products. Numerous experiments in both the initiation and the full detonation regimes are discussed and compared in support of these ideas.

  10. Shock desensitizing of solid explosive

    SciTech Connect

    Davis, William C

    2010-01-01

    Solid explosive can be desensitized by a shock wave too weak to initiate it promptly, and desensitized explosive does not react although its chemical composition is almost unchanged. A strong second shock does not cause reaction until it overtakes the first shock. The first shock, if it is strong enough, accelerates very slowly at first, and then more rapidly as detonation approaches. These facts suggest that there are two competing reactions. One is the usual explosive goes to products with the release of energy, and the other is explosive goes to dead explosive with no chemical change and no energy release. The first reaction rate is very sensitive to the local state, and the second is only weakly so. At low pressure very little energy is released and the change to dead explosive dominates. At high pressure, quite the other way, most of the explosive goes to products. Numerous experiments in both the initiation and the full detonation regimes are discussed and compared in testing these ideas.

  11. Assessing nerves in leprosy.

    PubMed

    Garbino, José Antonio; Heise, Carlos Otto; Marques, Wilson

    2016-01-01

    Leprosy neuropathy is dependent on the patient's immune response and expresses itself as a focal or multifocal neuropathy with asymmetric involvement. Leprosy neuropathy evolves chronically but recurrently develops periods of exacerbation during type 1 or type 2 reactions, leading to acute neuropathy. Nerve enlargement leading to entrapment syndromes is also a common manifestation. Pain may be either of inflammatory or neuropathic origin. A thorough and detailed evaluation is mandatory for adequate patient follow-up, including nerve palpation, pain assessment, graded sensory mapping, muscle power testing, and autonomic evaluation. Nerve conduction studies are a sensitive tool for nerve dysfunction, including new lesions during reaction periods or development of entrapment syndromes. Nerve ultrasonography is also a very promising method for nerve evaluation in leprosy. The authors propose a composite nerve clinical score for nerve function assessment that can be useful for longitudinal evaluation. PMID:26773623

  12. High-Resolution Ultrasonography of the Superficial Peroneal Motor and Sural Sensory Nerves May Be a Non-invasive Approach to the Diagnosis of Vasculitic Neuropathy

    PubMed Central

    Üçeyler, Nurcan; Schäfer, Kristina A.; Mackenrodt, Daniel; Sommer, Claudia; Müllges, Wolfgang

    2016-01-01

    High-resolution ultrasonography (HRUS) is an emerging new tool in the investigation of peripheral nerves. We set out to assess the utility of HRUS performed at lower extremity nerves in peripheral neuropathies. Nerves of 26 patients with polyneuropathies of different etiologies and 26 controls were investigated using HRUS. Patients underwent clinical, laboratory, electrophysiological assessment, and a diagnostic sural nerve biopsy as part of the routine work-up. HRUS was performed at the sural, tibial, and the common, superficial, and deep peroneal nerves. The superficial peroneal nerve longitudinal diameter (LD) distinguished best between the groups: patients with immune-mediated neuropathies (n = 13, including six with histology-proven vasculitic neuropathy) had larger LD compared to patients with non-immune-mediated neuropathies (p < 0.05) and to controls (p < 0.001). Among all subgroups, patients with vasculitic neuropathy showed the largest superficial peroneal nerve LD (p < 0.001) and had a larger sural nerve cross-sectional area when compared with disease controls (p < 0.001). Enlargement of the superficial peroneal and sural nerves as detected by HRUS may be a useful additional finding in the differential diagnosis of vasculitic and other immune-mediated neuropathies. PMID:27064457

  13. Antibiotic desensitization therapy in secondary syphilis and Listeria infection: case reports and review of desensitization therapy.

    PubMed

    Magpantay, Gil; Cardile, Anthony P; Madar, Cristian S; Hsue, Gunther; Belnap, Conrad

    2011-12-01

    Two adult cases, one of secondary syphilis and one of Listeria monocytogenes bacteremia, in which antibiotic desensitization therapy was utilized to assist treatment of active infection in the face of severe penicillin allergy. Clinical considerations are discussed that led to the decision to employ a formal desensitization procedure. Antibiotic desensitization protocols can facilitate optimal and safe antibiotic therapy in the appropriate clinical setting. PMID:22187514

  14. Systematic Desensitization: A Technique Worth Trying

    ERIC Educational Resources Information Center

    Bugg, Charles A.

    1972-01-01

    The author relates his experiences in using a modified form of systematic desensitization in a public school setting with counselees whose success and development are hampered by test anxiety and fear of public speaking. (Author)

  15. Homologous beta-adrenergic desensitization in isolated rat hepatocytes.

    PubMed Central

    García-Sáinz, J A; Michel, B

    1987-01-01

    Hepatocytes from hypothyroid rats have a marked beta-adrenergic responsiveness. Preincubation of these hepatocytes with isoprenaline induced a time-dependent and concentration-dependent desensitization of the beta-adrenergic responsiveness without altering that to glucagon (homologous desensitization). The desensitization was evidenced both in the cyclic AMP accumulation and in the stimulation of ureagenesis induced by the beta-adrenergic agonists. Under the same conditions, preincubation with glucagon induced no desensitization. Propranolol was also unable to induce desensitization, but blocked that induced by isoprenaline. Pertussis-toxin treatment did not alter the homologous beta-adrenergic desensitization induced by isoprenaline. PMID:2825633

  16. Profilin desensitization: A case series.

    PubMed

    Nucera, Eleonora; Aruanno, Arianna; Rizzi, Angela; Pecora, Valentina; Patriarca, Giampiero; Buonomo, Alessandro; Mezzacappa, Simona; Schiavino, Domenico

    2016-09-01

    The role of profilin as an allergen has long been questioned. The capacity of profilin to induce respiratory symptoms has recently been demonstrated; moreover, over 50% of patients sensitized to profilin experienced symptoms after the ingestion of plant-derived foods, suggesting that profilin should be considered as a clinically relevant food allergen.We describe the cases of seven allergic patients with oral allergy syndrome and other adverse reactions after eating plant-derived food, that have been undergone to profilin desensitization treatment.The protocol started with a drop of profilin solution (50 µg/mL) diluted 1:10(18) in water until the highest dose of 10 drops of undiluted solution three times a week. At the end of the treatment we observed a decreased mean diameter of profilin wheal in skin prick test (SPT) in five of the seven participants and in profilin specific IgE values in six patients that repeated the test. Regarding basophil activation test (BAT) and the detection of IgG4, we do not have significant results because the tests have to be repeated in some patients. Regarding the double-blind placebo-controlled challenges, after about 10 months of induction phase all the patients showed tolerance to several foods that they previously did not tolerate.Moreover, the immunotherapy with profilin has proved to be safe because no serious adverse events have been reported in our patients.In summary, the results of this exploratory study of sublingual immunotherapy (SLIT) for profilin allergy show that it can be a promising therapeutic option that could modify the clinical reactivity of the patients to the intake of plant-derived food. PMID:26684620

  17. Sciatic nerve injection injury.

    PubMed

    Jung Kim, Hyun; Hyun Park, Sang

    2014-06-11

    Nerve injury is a common complication following intramuscular injection and the sciatic nerve is the most frequently affected nerve, especially in children, the elderly and underweight patients. The neurological presentation may range from minor transient pain to severe sensory disturbance and motor loss with poor recovery. Management of nerve injection injury includes drug treatment of pain, physiotherapy, use of assistive devices and surgical exploration. Early recognition of nerve injection injury and appropriate management are crucial in order to reduce neurological deficit and to maximize recovery. Sciatic nerve injection injury is a preventable event. Total avoidance of intramuscular injection is recommended if other administration routes can be used. If the injection has to be administered into the gluteal muscle, the ventrogluteal region (gluteal triangle) has a more favourable safety profile than the dorsogluteal region (the upper outer quadrant of the buttock). PMID:24920643

  18. Playing violent video games and desensitization to violence.

    PubMed

    Brockmyer, Jeanne Funk

    2015-01-01

    This article examines current research linking exposure to violent video games and desensitization to violence. Data from questionnaire, behavioral, and psychophysiologic research are reviewed to determine if exposure to violent video games is a risk factor for desensitization to violence. Real-world implications of desensitization are discussed. PMID:25455576

  19. Nerve conduction and electromyography studies.

    PubMed

    Kane, N M; Oware, A

    2012-07-01

    Nerve conduction studies (NCS) and electromyography (EMG), often shortened to 'EMGs', are a useful adjunct to clinical examination of the peripheral nervous system and striated skeletal muscle. NCS provide an efficient and rapid method of quantifying nerve conduction velocity (CV) and the amplitude of both sensory nerve action potentials (SNAPs) and compound motor action potentials (cMAPs). The CV reflects speed of propagation of action potentials, by saltatory conduction, along large myelinated axons in a peripheral nerve. The amplitude of SNAPs is in part determined by the number of axons in a sensory nerve, whilst amplitude of cMAPs reflects integrated function of the motor axons, neuromuscular junction and striated muscle. Repetitive nerve stimulation (RNS) can identify defects of neuromuscular junction (NMJ) transmission, pre- or post-synaptic. Needle EMG examination can detect myopathic changes in muscle and signs of denervation. Combinations of these procedures can establish if motor and/or sensory nerve cell bodies or peripheral nerves are damaged (e.g. motor neuronopathy, sensory ganglionopathy or neuropathy), and also indicate if the primary target is the axon or the myelin sheath (i.e. axonal or demyelinating neuropathies). The distribution of nerve damage can be determined as either generalised, multifocal (mononeuropathy multiplex) or focal. The latter often due to compression at the common entrapment sites (such as the carpal tunnel, Guyon's canal, cubital tunnel, radial groove, fibular head and tarsal tunnel, to name but a few of the reported hundred or so 'entrapment neuropathies'). PMID:22614870

  20. Desensitizing nano powders to electrostatic discharge ignition

    SciTech Connect

    Steelman, Ryan; Clark, Billy; Pantoya, Michelle L.; Heaps, Ronald J.; Daniels, Michael A.

    2015-08-01

    Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.

  1. Rituximab Desensitization in Pediatric Patients: Results of a Case Series

    PubMed Central

    Lee, Joyce P.; Platt, Craig D.

    2016-01-01

    Rituximab is a monoclonal antibody (mAb) primarily used to treat oncologic and autoinflammatory conditions. Although hypersensitivity reactions (HSRs) and desensitization protocols to mAbs have been well described in adults, the experience in the pediatric population is very limited. We sought to determine the safety and efficacy of desensitization to rituximab in the pediatric population at our institution. We retrospectively reviewed the experience with HSRs and desensitization to rituximab during a 5-year period in our tertiary care pediatric center, including reaction evaluation, premedication regimens, and desensitization procedures and protocols. A total of 17 desensitizations to rituximab were performed in three patients. A 14-year-old patient underwent successful desensitization to rituximab using a published adult protocol without incident. Two younger patients (ages 7 years and 23 months) experienced significant reactions during initial desensitization attempts. Therefore, we designed a modified desensitization protocol to rituximab, with particular attention to the rate of infusion as mg/kg/h. This new patient weight-based protocol was successfully used in a total of 13 desensitizations in these two patients. Desensitization to rituximab was a safe and effective procedure in our pediatric population. We present a new patient weight-based desensitization protocol for pediatric patients who develop HSRs to rituximab, with particular usefulness for younger pediatric patients and potential utility in pediatric patients with HSRs to other mAbs.

  2. Desensitization and recovery of metastable intermolecular composites

    DOEpatents

    Busse, James R.; Dye, Robert C.; Foley, Timothy J.; Higa, Kelvin T.; Jorgensen, Betty S.; Sanders, Victor E.; Son, Steven F.

    2010-09-07

    A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

  3. Involvement of capsaicin-sensitive nerves in the bronchomotor effects of arachidonic acid and melittin: a possible role for lipoxin A4.

    PubMed Central

    Manzini, S.; Meini, S.

    1991-01-01

    1. Functional studies have been performed to evaluate the potential involvement of capsaicin-sensitive nerves in the bronchomotor responses evoked by lipid mediators produced from the metabolic breakdown of arachidonic acid (AA) in the guinea-pig bronchus. 2. In the presence of indomethacin, the exogenous administration of AA (0.01-1 mM) produced a concentration-dependent contractile response in guinea-pig isolated bronchial rings. AA-induced contractions were augmented by epithelium-removal and by thiorphan (10 microM), an inhibitor of tachykinin breakdown. A sustained downward and rightward displacement of the complete concentration-response curve to AA was observed after in vitro capsaicin desensitization. 3. BWA4C (1 microM), a selective inhibitor of 5-lipoxygenase, shifted the AA concentration-response curve to the right. In the presence of this inhibitor, capsaicin desensitization did not have any further inhibitory action. 4. A potent, concentration-dependent and capsaicin-sensitive bronchoconstrictor effect was also observed with the polypeptide, melittin (10 nM-1 microM), an activator of phospholipase A2, which therefore should generate endogenous AA. 5. In vitro capsaicin-desensitization produced a significant reduction of the bronchomotor responses evoked by lipoxin A4 (1-6 microM), but not of those elicited by other lipoxygenases products such as leukotriene D4 (1-100 nM) or by 15-hydroxyeicosatetraenoic acid (15-HETE, 1-6 microM). 6. These findings indicate that lipoxin A4 but not leukotriene D4 or 15-HETE, might be one of the lipoxygenase mediators of excitatory effects of AA on capsaicin-sensitive sensory nerves. PMID:1908731

  4. Genetics Home Reference: hereditary sensory and autonomic neuropathy type IE

    MedlinePlus

    ... by impaired function of nerve cells called sensory neurons, which transmit information about sensations such as pain, ... understood, the enzyme may help regulate nerve cell (neuron) maturation and specialization (differentiation), the ability of neurons ...

  5. Cutaneous tissue damage induces long-lasting nociceptive sensitization and regulation of cellular stress- and nerve injury-associated genes in sensory neurons.

    PubMed

    Rau, Kristofer K; Hill, Caitlin E; Harrison, Benjamin J; Venkat, Gayathri; Koenig, Heidi M; Cook, Sarah B; Rabchevsky, Alexander G; Taylor, Bradley K; Hai, Tsonwin; Petruska, Jeffrey C

    2016-09-01

    Tissue damage is one of the major etiological factors in the emergence of chronic/persistent pain, although mechanisms remain enigmatic. Using incision of the back skin of adult rats as a model for tissue damage, we observed sensitization in a nociceptive reflex enduring to 28days post-incision (DPI). To determine if the enduring behavioral changes corresponded with a long-term impact of tissue damage on sensory neurons, we examined the temporal expression profile of injury-regulated genes and the electrophysiological properties of traced dorsal root ganglion (DRG) sensory neurons. The mRNA for the injury/stress-hub gene Activating Transcription Factor 3 (ATF3) was upregulated and peaked within 4 DPI, after which levels declined but remained significantly elevated out to 28 DPI, a time when the initial incision appears healed and tissue-inflammation largely resolved. Accordingly, stereological image analysis indicated that some neurons expressed ATF3 only transiently (mostly medium-large neurons), while in others it was sustained (mostly small neurons), suggesting cell-type-specific responses. In retrogradely-traced ATF3-expressing neurons, Calcium/calmodulin-dependent protein kinase type IV (CAMK4) protein levels and isolectin-B4 (IB4)-binding were suppressed whereas Growth Associated Protein-43 (GAP-43) and Neuropeptide Y (NPY) protein levels were enhanced. Electrophysiological recordings from DiI-traced sensory neurons 28 DPI showed a significant sensitization limited to ATF3-expressing neurons. Thus, ATF3 expression is revealed as a strong predictor of single cells displaying enduring pain-related electrophysiological properties. The cellular injury/stress response induced in sensory neurons by tissue damage and indicated by ATF3 expression is positioned to contribute to pain which can occur after tissue damage. PMID:27264359

  6. Morphological studies of the vestibular nerve

    NASA Technical Reports Server (NTRS)

    Bergstroem, B.

    1973-01-01

    The anatomy of the intratemporal part of the vestibular nerve in man, and the possible age related degenerative changes in the nerve were studied. The form and structure of the vestibular ganglion was studied with the light microscope. A numerical analysis of the vestibular nerve, and caliber spectra of the myelinated fibers in the vestibular nerve branches were studied in individuals of varying ages. It was found that the peripheral endings of the vestibular nerve form a complicated pattern inside the vestibular sensory epithelia. A detailed description of the sensory cells and their surface organelles is included.

  7. The Diagnostic Value of Nerve Ultrasound in an Atypical Palmar Cutaneous Nerve Lesion.

    PubMed

    Zanette, Giampietro; Tamburin, Stefano

    2016-07-01

    Detailed knowledge of the fascicular anatomy of peripheral nerves is important for microsurgical repair and functional electrostimulation.We report a patient with a lesion on the left palmar cutaneous branch of the median nerve (PCBMN) and sensory signs expanding outside the PCBMN cutaneous innervation territory. Nerve conduction study showed the absence of left PCBMN sensory nerve action potential, but apparently, no median nerve (MN) involvement. Nerve ultrasound documented a neuroma of the left PCBMN and a coexistent lateral neuroma of the left MN in the carpal tunnel after the PCBMN left the main nerve trunk.Nerve ultrasound may offer important information in patients with peripheral nerve lesions and atypical clinical and/or nerve conduction study findings. The present case may shed some light on the somatotopy of MN fascicles at the wrist. PMID:26945219

  8. Sensory and motor neuropathy in a Border Collie.

    PubMed

    Harkin, Kenneth R; Cash, Walter C; Shelton, G Diane

    2005-10-15

    A 5-month-old female Border Collie was evaluated because of progressive hind limb ataxia. The predominant clinical findings suggested a sensory neuropathy. Sensory nerve conduction velocity was absent in the tibial, common peroneal, and radial nerves and was decreased in the ulnar nerve; motor nerve conduction velocity was decreased in the tibial, common peroneal, and ulnar nerves. Histologic examination of nerve biopsy specimens revealed considerable nerve fiber depletion; some tissue sections had myelin ovoids, foamy macrophages, and axonal degeneration in remaining fibers. Marked depletion of most myelinated fibers within the peroneal nerve (a mixed sensory and motor nerve) supported the electrodiagnostic findings indicative of sensorimotor neuropathy. Progressive deterioration in motor function occurred over the following 19 months until the dog was euthanatized. A hereditary link was not established, but a littermate was similarly affected. The hereditary characteristic of this disease requires further investigation. PMID:16266014

  9. Nerve injury induces a new profile of tactile and mechanical nociceptor input from undamaged peripheral afferents

    PubMed Central

    Gutierrez, Silvia; Aschenbrenner, Carol A.; Houle, Timothy T.; Hayashida, Ken-ichiro; Ririe, Douglas G.; Eisenach, James C.

    2014-01-01

    Chronic pain after nerve injury is often accompanied by hypersensitivity to mechanical stimuli, yet whether this reflects altered input, altered processing, or both remains unclear. Spinal nerve ligation or transection results in hypersensitivity to mechanical stimuli in skin innervated by adjacent dorsal root ganglia, but no previous study has quantified the changes in receptive field properties of these neurons in vivo. To address this, we recorded intracellularly from L4 dorsal root ganglion neurons of anesthetized young adult rats, 1 wk after L5 partial spinal nerve ligation (pSNL) or sham surgery. One week after pSNL, hindpaw mechanical withdrawal threshold in awake, freely behaving animals was decreased in the L4 distribution on the nerve-injured side compared with sham controls. Electrophysiology revealed that high-threshold mechanoreceptive cells of A-fiber conduction velocity in L4 were sensitized, with a seven-fold reduction in mechanical threshold, a seven-fold increase in receptive field area, and doubling of maximum instantaneous frequency in response to peripheral stimuli, accompanied by reductions in after-hyperpolarization amplitude and duration. Only a reduction in mechanical threshold (minimum von Frey hair producing neuronal activity) was observed in C-fiber conduction velocity high-threshold mechanoreceptive cells. In contrast, low-threshold mechanoreceptive cells were desensitized, with a 13-fold increase in mechanical threshold, a 60% reduction in receptive field area, and a 40% reduction in instantaneous frequency to stimulation. No spontaneous activity was observed in L4 ganglia, and the likelihood of recording from neurons without a mechanical receptive field was increased after pSNL. These data suggest massively altered input from undamaged sensory afferents innervating areas of hypersensitivity after nerve injury, with reduced tactile and increased nociceptive afferent response. These findings differ importantly from previous preclinical

  10. Defining the structural relationship between kainate receptor deactivation and desensitization

    PubMed Central

    Dawe, G. Brent; Musgaard, Maria; Andrews, Elizabeth D.; Daniels, Bryan A.; Aurousseau, Mark R.P.; Biggin, Philip C.; Bowie, Derek

    2016-01-01

    Desensitization is an important mechanism that curtails the activity of ligand-gated ion-channels (LGICs). Although the structural basis of desensitization is not fully resolved, it is thought to be governed by the physicochemical properties of the bound ligand. Here, we show the importance of an allosteric cation binding pocket in controlling transitions between activated and desensitized states of rat kainate-type (KAR) ionotropic glutamate receptors (iGluRs). Tethering a positive charge to this pocket sustains KAR activation, preventing desensitization, whereas mutations that disrupt cation binding eliminate channel gating. These different outcomes explain the structural distinction between deactivation and desensitization. Deactivation occurs when the ligand unbinds before the cation, whereas desensitization proceeds if a ligand is bound without cation pocket occupancy. This sequence of events is absent from AMPA-type iGluRs, identifying cations as gatekeepers of KAR gating, a role unique among even closely-related LGICs. PMID:23955023

  11. Desensitization and recovery of phototropic responsiveness in Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Janoudi, A. K.; Poff, K. L.

    1993-01-01

    Phototropism is induced by blue light, which also induces desensitization, a partial or total loss of phototropic responsiveness. The fluence and fluence-rate dependence of desensitization and recovery from desensitization have been measured for etiolated and red light (669-nm) preirradiated Arabidopsis thaliana seedlings. The extent of desensitization increased as the fluence of the desensitizing 450-nm light was increased from 0.3 to 60 micromoles m-2 s-1. At equal fluences, blue light caused more desensitization when given at a fluence rate of 1.0 micromole m-2 s-1 than at 0.3 micromole m-2 s-1. In addition, seedlings irradiated with blue light at the higher fluence rate required a longer recovery time than seedlings irradiated at the lower fluence rate. A red light preirradiation, probably mediated via phytochrome, decreased the time required for recovery from desensitization. The minimum time for detectable recovery was about 65 s, and the maximum time observed was about 10 min. It is proposed that the descending arm of the fluence-response relationship for first positive phototropism is a consequence of desensitization, and that the time threshold for second positive phototropism establishes a period during which recovery from desensitization occurs.

  12. Desensitization and recovery of phototropic responsiveness in Arabidopsis thaliana.

    PubMed Central

    Janoudi, A K; Poff, K L

    1993-01-01

    Phototropism is induced by blue light, which also induces desensitization, a partial or total loss of phototropic responsiveness. The fluence and fluence-rate dependence of desensitization and recovery from desensitization have been measured for etiolated and red light (669-nm) preirradiated Arabidopsis thaliana seedlings. The extent of desensitization increased as the fluence of the desensitizing 450-nm light was increased from 0.3 to 60 micromoles m-2 s-1. At equal fluences, blue light caused more desensitization when given at a fluence rate of 1.0 micromole m-2 s-1 than at 0.3 micromole m-2 s-1. In addition, seedlings irradiated with blue light at the higher fluence rate required a longer recovery time than seedlings irradiated at the lower fluence rate. A red light preirradiation, probably mediated via phytochrome, decreased the time required for recovery from desensitization. The minimum time for detectable recovery was about 65 s, and the maximum time observed was about 10 min. It is proposed that the descending arm of the fluence-response relationship for first positive phototropism is a consequence of desensitization, and that the time threshold for second positive phototropism establishes a period during which recovery from desensitization occurs. PMID:11537496

  13. Electrophysiological evaluation of nerve function in inferior alveolar nerve injury: relationship between nerve action potentials and histomorphometric observations.

    PubMed

    Murayama, M; Sasaki, K; Shibahara, T

    2015-12-01

    The objective of this study was to improve the accuracy of diagnosis of inferior alveolar nerve (IAN) injury by determining degrees of nerve disturbance using the sensory nerve action potential (SNAP) and sensory nerve conduction velocity (SCV). Crush and partial and complete nerve amputation injuries were applied to the IAN of rabbits, then SNAPs and histomorphometric observations were recorded at 1, 5, and 10 weeks. For crush injury, most nerves were smaller in diameter at 5 weeks than at 1 week, however after 10 weeks, extensive nerve regeneration was observed. The SNAP showed a decrease in SCV at weeks 1 and 5, followed by an increase at week 10. For partial nerve amputation, small to medium-sized nerve fibres were observed at weeks 1 and 5, then larger nerves were seen at week 10. Minimal changes in SCV were observed at weeks 1 and 5, however SCV increased at week 10. For complete nerve amputation, nerve fibres were sparse at week 1, but gradual nerve regeneration was observed at weeks 5 and 10. SNAPs were detectable from week 10, however the SCV was extremely low. This study showed SCV to be an effective factor in the evaluation of nerve injury and regeneration. PMID:26433750

  14. Rehabilitation of the trigeminal nerve

    PubMed Central

    Iro, Heinrich; Bumm, Klaus; Waldfahrer, Frank

    2005-01-01

    When it comes to restoring impaired neural function by means of surgical reconstruction, sensory nerves have always been in the role of the neglected child when compared with motor nerves. Especially in the head and neck area, with its either sensory, motor or mixed cranial nerves, an impaired sensory function can cause severe medical conditions. When performing surgery in the head and neck area, sustaining neural function must not only be highest priority for motor but also for sensory nerves. In cases with obvious neural damage to sensory nerves, an immediate neural repair, if necessary with neural interposition grafts, is desirable. Also in cases with traumatic trigeminal damage, an immediate neural repair ought to be considered, especially since reconstructive measures at a later time mostly require for interposition grafts. In terms of the trigeminal neuralgia, commonly thought to arise from neurovascular brainstem compression, a pharmaceutical treatment is considered as the state of the art in terms of conservative therapy. A neurovascular decompression of the trigeminal root can be an alternative in some cases when surgical treatment is sought after. Besides the above mentioned therapeutic options, alternative treatments are available. PMID:22073060

  15. Isolated median sensory neuropathy after acupuncture.

    PubMed

    Lee, Chang Ho; Hyun, Jung Keun; Lee, Seong Jae

    2008-12-01

    A 47-year-old left-handed man presented with pain and numbness in his left thumb and index finger after acupuncture treatment on an acupoint in his left wrist. A technique of herbal acupuncture, involving the use of a needle coated with apricot seed extract, was used. Median nerve conduction study showed an absence of sensory nerve action potential in the left index finger, whereas the results were normal in all other fingers. The radial and ulnar nerves in the left thumb and ring finger, respectively, showed no abnormality. Infrared thermography of the left index finger showed severe hypothermia. The patient was diagnosed as having an isolated injury to the sensory nerve fibers of the median nerve innervating the index finger. This is the first case report of complications from an herbal acupuncture treatment, and it highlights the possibility of focal peripheral nerve injury caused by acupuncture. PMID:19061751

  16. Sensory neuropathy in two Border collie puppies.

    PubMed

    Vermeersch, K; Van Ham, L; Braund, K G; Bhatti, S; Tshamala, M; Chiers, K; Schrauwen, E

    2005-06-01

    A peripheral sensory neuropathy was diagnosed in two Border collie puppies. Neurological, electrophysiological and histopathological examinations suggested a purely sensory neuropathy with mainly distal involvement. Urinary incontinence was observed in one of the puppies and histological examination of the vagus nerve revealed degenerative changes. An inherited disorder was suspected. PMID:15971901

  17. Nerve growth factor alters microtubule targeting agent-induced neurotransmitter release but not MTA-induced neurite retraction in sensory neurons.

    PubMed

    Pittman, Sherry K; Gracias, Neilia G; Fehrenbacher, Jill C

    2016-05-01

    Peripheral neuropathy is a dose-limiting side effect of anticancer treatment with the microtubule-targeted agents (MTAs), paclitaxel and epothilone B (EpoB); however, the mechanisms by which the MTAs alter neuronal function and morphology are unknown. We previously demonstrated that paclitaxel alters neuronal sensitivity, in vitro, in the presence of nerve growth factor (NGF). Evidence in the literature suggests that NGF may modulate the neurotoxic effects of paclitaxel. Here, we examine whether NGF modulates changes in neuronal sensitivity and morphology induced by paclitaxel and EpoB. Neuronal sensitivity was assessed using the stimulated release of calcitonin gene-related peptide (CGRP), whereas morphology of established neurites was evaluated using a high content screening system. Dorsal root ganglion cultures, maintained in the absence or presence of NGF, were treated from day 7 to day 12 in culture with paclitaxel (300nM) or EpoB (30nM). Following treatment, the release of CGRP was stimulated using capsaicin or high extracellular potassium. In the presence of NGF, EpoB mimicked the effects of paclitaxel: capsaicin-stimulated release was attenuated, potassium-stimulated release was slightly enhanced and the total peptide content was unchanged. In the absence of NGF, both paclitaxel and EpoB decreased capsaicin- and potassium-stimulated release and the total peptide content, suggesting that NGF may reverse MTA-induced hyposensitivity. Paclitaxel and EpoB both decreased neurite length and branching, and this attenuation was unaffected by NGF in the growth media. These differential effects of NGF on neuronal sensitivity and morphology suggest that neurite retraction is not a causative factor to alter neuronal sensitivity. PMID:26883566

  18. Internalization and desensitization of adenosine receptors

    PubMed Central

    Klaasse, Elisabeth C.; de Grip, Willem J.; Beukers, Margot W.

    2007-01-01

    Until now, more than 800 distinct G protein-coupled receptors (GPCRs) have been identified in the human genome. The four subtypes of the adenosine receptor (A1, A2A, A2B and A3 receptor) belong to this large family of GPCRs that represent the most widely targeted pharmacological protein class. Since adenosine receptors are widespread throughout the body and involved in a variety of physiological processes and diseases, there is great interest in understanding how the different subtypes are regulated, as a basis for designing therapeutic drugs that either avoid or make use of this regulation. The major GPCR regulatory pathway involves phosphorylation of activated receptors by G protein-coupled receptor kinases (GRKs), a process that is followed by binding of arrestin proteins. This prevents receptors from activating downstream heterotrimeric G protein pathways, but at the same time allows activation of arrestin-dependent signalling pathways. Upon agonist treatment, adenosine receptor subtypes are differently regulated. For instance, the A1Rs are not (readily) phosphorylated and internalize slowly, showing a typical half-life of several hours, whereas the A2AR and A2BR undergo much faster downregulation, usually shorter than 1 h. The A3R is subject to even faster downregulation, often a matter of minutes. The fast desensitization of the A3R after agonist exposure may be therapeutically equivalent to antagonist occupancy of the receptor. This review describes the process of desensitization and internalization of the different adenosine subtypes in cell systems, tissues and in vivo studies. In addition, molecular mechanisms involved in adenosine receptor desensitization are discussed. PMID:18368531

  19. Galvanic Skin Response and Reported Anxiety During Systematic Desensitization

    ERIC Educational Resources Information Center

    Hyman, Edward T.; Gale, Elliot N.

    1973-01-01

    The purpose of the present study was to investigate the GSR during systematic desensitization. Three groups of females each were preselected for high snake fear. Outcome measures indicated that the desensitization group reduced phobic behavior most, followed by the relaxation group, and then the exposure groups. (Author)

  20. Effects of Modeling and Desensitation in Reducing Dentist Phobia

    ERIC Educational Resources Information Center

    Shaw, David W.; Thoresen, Carl E.

    1974-01-01

    Many persons avoid dentists and dental work. The present study explored the effects of systematic desensitization and social-modeling treatments with placebo and assessment control groups. Modeling was more effective than desensitization as shown by the number of subjects who went to a dentist. (Author)

  1. EMG Biofeedback Training Versus Systematic Desensitization for Test Anxiety Reduction

    ERIC Educational Resources Information Center

    Romano, John L.; Cabianca, William A.

    1978-01-01

    Biofeedback training to reduce test anxiety among university students was investigated. Biofeedback training with systematic desensitization was compared to an automated systematic desensitization program not using EMG feedback. Biofeedback training is a useful technique for reducing test anxiety, but not necessarily more effective than systematic…

  2. Pinched Nerve

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Pinched Nerve Information Page Table of Contents (click to jump ... being done? Clinical Trials Organizations What is Pinched Nerve? The term "pinched nerve" is a colloquial term ...

  3. Nerve biopsy

    MedlinePlus

    Nerve biopsy may be done to help diagnose: Axon degeneration (destruction of the axon portion of the nerve cell) Damage to the ... Demyelination Inflammation of the nerve Leprosy Loss of axon tissue Metabolic neuropathies Necrotizing vasculitis Sarcoidosis

  4. The desensitization gate of inhibitory Cys-loop receptors

    NASA Astrophysics Data System (ADS)

    Gielen, Marc; Thomas, Philip; Smart, Trevor G.

    2015-04-01

    Cys-loop neurotransmitter-gated ion channels are vital for communication throughout the nervous system. Following activation, these receptors enter into a desensitized state in which the ion channel shuts even though the neurotransmitter molecules remain bound. To date, the molecular determinants underlying this most fundamental property of Cys-loop receptors have remained elusive. Here we present a generic mechanism for the desensitization of Cys-loop GABAA (GABAARs) and glycine receptors (GlyRs), which both mediate fast inhibitory synaptic transmission. Desensitization is regulated by interactions between the second and third transmembrane segments, which affect the ion channel lumen near its intracellular end. The GABAAR and GlyR pore blocker picrotoxin prevented desensitization, consistent with its deep channel-binding site overlapping a physical desensitization gate.

  5. Sensory neuropeptides and airway function.

    PubMed

    Solway, J; Leff, A R

    1991-12-01

    Sensory nerves synthesize tachykinins and calcitonin-gene related peptide and package these neuropeptides together in synaptic vesicles. Stimulation of these C-fibers by a range of chemical and physical factors results in afferent neuronal conduction that elicits central parasympathetic reflexes and in antidromic conduction that results in local release of neuropeptides through the axon reflex. In the airways, sensory neuropeptides act on bronchial smooth muscle, the mucosal vasculature, and submucosal glands to promote airflow obstruction, hyperemia, microvascular hyperpermeability, and mucus hypersecretion. In addition, tachykinins potentiate cholinergic neurotransmission. Proinflammatory effects of these peptides also promote the recruitment, adherence, and activation of granulocytes that may further exacerbate neurogenic inflammation (i.e., neuropeptide-induced plasma extravasation and vasodilation). Enzymatic degradation limits the physiological effects of tachykinins but may be impaired by respiratory infection or other factors. Given their sensitivity to noxious compounds and physical stimuli and their potent effects on airway function, it is possible that neuropeptide-containing sensory nerves play an important role in mediating airway responses in human disease. Supporting this view are the striking phenomenological similarities between hyperpnea-induced bronchoconstriction (HIB) in guinea pigs and HIB in patients with exercise-induced asthma. Endogenous tachykinins released from airway sensory nerves mediate HIB in guinea pigs and also cause hyperpnea-induced bronchovascular hyperpermeability in these animals. On the basis of these observations, it is reasonable to speculate that sensory neuropeptides participate in the pathogenesis of hyperpnea-induced airflow obstruction in human asthmatic subjects as well. PMID:1663932

  6. Dendritic cell dysfunction and diabetic sensory neuropathy in the cornea.

    PubMed

    Gao, Nan; Yan, Chenxi; Lee, Patrick; Sun, Haijing; Yu, Fu-Shin

    2016-05-01

    Diabetic peripheral neuropathy (DPN) often leads to neurotrophic ulcerations in the cornea and skin; however, the underlying cellular mechanisms of this complication are poorly understood. Here, we used post-wound corneal sensory degeneration and regeneration as a model and tested the hypothesis that diabetes adversely affects DC populations and infiltration, resulting in disrupted DC-nerve communication and DPN. In streptozotocin-induced type 1 diabetic mice, there was a substantial reduction in sensory nerve density and the number of intraepithelial DCs in unwounded (UW) corneas. In wounded corneas, diabetes markedly delayed sensory nerve regeneration and reduced the number of infiltrating DCs, which were a major source of ciliary neurotrophic factor (CNTF) in the cornea. While CNTF neutralization retarded reinnervation in normal corneas, exogenous CNTF accelerated nerve regeneration in the wounded corneas of diabetic mice and healthy animals, in which DCs had been locally depleted. Moreover, blockade of the CNTF-specific receptor CNTFRα induced sensory nerve degeneration and retarded regeneration in normal corneas. Soluble CNTFRα also partially restored the branching of diabetes-suppressed sensory nerve endings and regeneration in the diabetic corneas. Collectively, our data show that DCs mediate sensory nerve innervation and regeneration through CNTF and that diabetes reduces DC populations in UW and wounded corneas, resulting in decreased CNTF and impaired sensory nerve innervation and regeneration. PMID:27064280

  7. Dendritic cell dysfunction and diabetic sensory neuropathy in the cornea

    PubMed Central

    Gao, Nan; Yan, Chenxi; Lee, Patrick; Sun, Haijing

    2016-01-01

    Diabetic peripheral neuropathy (DPN) often leads to neurotrophic ulcerations in the cornea and skin; however, the underlying cellular mechanisms of this complication are poorly understood. Here, we used post-wound corneal sensory degeneration and regeneration as a model and tested the hypothesis that diabetes adversely affects DC populations and infiltration, resulting in disrupted DC-nerve communication and DPN. In streptozotocin-induced type 1 diabetic mice, there was a substantial reduction in sensory nerve density and the number of intraepithelial DCs in unwounded (UW) corneas. In wounded corneas, diabetes markedly delayed sensory nerve regeneration and reduced the number of infiltrating DCs, which were a major source of ciliary neurotrophic factor (CNTF) in the cornea. While CNTF neutralization retarded reinnervation in normal corneas, exogenous CNTF accelerated nerve regeneration in the wounded corneas of diabetic mice and healthy animals, in which DCs had been locally depleted. Moreover, blockade of the CNTF-specific receptor CNTFRα induced sensory nerve degeneration and retarded regeneration in normal corneas. Soluble CNTFRα also partially restored the branching of diabetes-suppressed sensory nerve endings and regeneration in the diabetic corneas. Collectively, our data show that DCs mediate sensory nerve innervation and regeneration through CNTF and that diabetes reduces DC populations in UW and wounded corneas, resulting in decreased CNTF and impaired sensory nerve innervation and regeneration. PMID:27064280

  8. Sensory mononeuropathies.

    PubMed

    Massey, E W

    1998-01-01

    The clinical neurologist frequently encounters patients with a variety of focal sensory symptoms and signs. This article reviews the clinical features, etiologies, laboratory findings, and management of the common sensory mononeuropathies including meralgia paresthetica, cheiralgia paresthetica, notalgia paresthetica, gonyalgia paresthetica, digitalgia paresthetica, intercostal neuropathy, and mental neuropathy. PMID:9608615

  9. Peripheral nerve conduits: technology update

    PubMed Central

    Arslantunali, D; Dursun, T; Yucel, D; Hasirci, N; Hasirci, V

    2014-01-01

    Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS) and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers) and designs (tubular, fibrous, and matrix type) are being presented. PMID:25489251

  10. A Group Desensitization Approach to Public Speaking Anxiety

    ERIC Educational Resources Information Center

    Akin, Clifford; Kunzman, Glen G.

    1974-01-01

    Program evaluation shows that a mixed behavioral format emphasizing practice situations produces results similar to traditionally operant or desensitization formats, with less attrition in attendance. Statistically significant changes on fear inventory scores is the measurable outcome of the program. (Author)

  11. Fascial entrapment of the sural nerve and its clinical relevance

    PubMed Central

    Natsis, Konstantinos; Tzika, Maria; Ioannidis, Orestis

    2014-01-01

    Sural nerve presents great topographic variability and it is responsible for sensory innervation of the posterolateral side of the distal third of the leg and lateral aspect of the foot. Entrapment of the nerve could be caused by compression due to fascial thickening, while the symptomatology includes sensory alterations and deficits at the nerve distribution area. We report a cadaveric case of a variant sural nerve that presented a distinct entrapment site. A supernumerary sensory branch was encountered originating from the common peroneal nerve, while the peroneal component of the sural nerve was observed to take a course within a fibrous fascial tunnel 3.1 cm in length that caused nerve fixation and flattening. The tension applied to the aforementioned branch was shown to worsen during passive forcible foot plantaflexion and inversion. The etiology, diagnosis and the treatment options are discussed comprehensively. PMID:24987554

  12. Injection nerve palsy

    PubMed Central

    Kakati, Arindhom; Bhat, Dhananjaya; Devi, Bhagavathula Indira; Shukla, Dhaval

    2013-01-01

    Objective: To study the clinical profile and outcome of surgery for injection nerve palsies. Materials and Methods: This is a retrospective study of patients with INP who were treated at our institute during May 2000 to May 2009. Clinical, electroneuromyography (ENMG), and operative findings were noted. Intraoperative nerve action potential monitoring was not used in any case. Outcome of patients who were followed was reviewed. Results: INP comprised 92 (11%) of 837 nerve injury patients. Seventy one patients were children less than 16 years. The nerves involved were sciatic in 80 patients, radial in 8, and others in four. Fifty seven patients had power, grade 0/5. ENMG studies revealed absent compound muscle action potential in 64 and absent sensory nerve action potential in 67 patients. Thirty nine (42.3%) of 92 patients underwent surgery. The mean duration since injury in these patients was 5.2 months (3 months to 11 months). All underwent neurolysis. Only 18 patients who underwent surgery had a follow up of more than 3 months. Ten (55.5%) patients had good or fair outcome after surgery. Except for grade of motor deficit prior to surgery, none of the variables were found to significantly affect the outcome. Conclusion: The outcome of INP is generally good and many patients recover spontaneously. The outcome of surgery is dependent on preoperative motor power. PMID:23546341

  13. Nerve biopsy

    MedlinePlus

    ... Loss of axon tissue Metabolic neuropathies Necrotizing vasculitis Sarcoidosis Risks Allergic reaction to the local anesthetic Discomfort ... Neurosarcoidosis Peripheral neuropathy Primary amyloidosis Radial nerve dysfunction Sarcoidosis Tibial nerve dysfunction Update Date 6/1/2015 ...

  14. Desensitizing and non-desensitizing subtypes of alpha-bungarotoxin-sensitive nicotinic acetylcholine receptors in cockroach neurons.

    PubMed

    Salgado, Vincent L; Saar, Raimund

    2004-10-01

    Two alpha-bungarotoxin-sensitive nicotinic receptor subtypes in cockroach neurons are identified as desensitizing (nAChD), selectively inhibitable with 100 nM imidacloprid, and non-desensitizing (nAChN), selectively inhibitable with 100 pM methyllycaconitine. Although the desensitization rate of nAChD receptors is highly variable, pharmacology is largely independent of desensitization rate. Because desensitized states tightly bind agonists, nAChD receptors are potently inhibited by neonicotinoids and specifically measured in radiolabeled imidacloprid binding assays. However, they are not usually detected in binding assays with radiolabeled alpha-bungarotoxin, which has a Kd for the resting state of 21 nM, but binds poorly to desensitized states often present in binding assays. In contrast, nAChN receptors are specifically measured in binding assays with radiolabeled alpha-bungarotoxin, which binds them with a Kd of 1.3 nM. nAChN receptors are activated by neonicotinoids at micromolar concentrations, and allosterically by spinosyn A, with an EC50 of 27 nM. Spinosyn A weakly antagonizes nAChD receptors -23% at 10 microM. The roles of the two nAChR subtypes in insecticide poisoning are discussed. PMID:15518655

  15. Therapy of vaginismus by hypnotic desensitization.

    PubMed

    Fuchs, K

    1980-05-01

    Fear and anxiety are of tremendous importance in the production and maintenance of a symptom. Vaginismus, as a reaction of avoidance of an anxiety-producing situation, is readily amenable to treatment by systematic desensitization. This may proceed mainly in two ways: "in vitro" or "in vivo." In order to strengthen and speed up the densensitization process, we used hypnotic techniques in a dynamic approach. The "in vitro" treatment proceeds with imagery, under hypnosis, of an "anxiety hierarchy" of increasingly erotic and sexually intimate situations which will be reproduced at home with the partner, until sexual intercourse is achieved. In the "in vivo" method the patient learns self-hypnosis and then inserts in the vagina first a finger, and then Hegar dilators of gradually increasing sizes. The partner, the patient, and the physician will then successively proceed to insertion, forming a team-referred work situation. This continues until the "female superior position," practiced first with the largest dilator, is reproduced at home by intercourse. Between 1965 and 1974 we treated 71 women with this method. Good results were obtained in 16 of 18 by the "in vitro" technique and in 53 of 54 by the "in vivo" technique. One patient was referred from the "in vitro" group to the "in vivo" group. In follow-up of 2 to 5 years there was no relapse or symptom substitution. PMID:6102843

  16. Autograft Substitutes: Conduits and Processed Nerve Allografts.

    PubMed

    Safa, Bauback; Buncke, Gregory

    2016-05-01

    Manufactured conduits and allografts are viable alternatives to direct suture repair and nerve autograft. Manufactured tubes should have gaps less than 10 mm, and ideally should be considered as an aid to the coaptation. Processed nerve allograft has utility as a substitute for either conduit or autograft in sensory nerve repairs. There is also a growing body of evidence supporting their utility in major peripheral nerve repairs, gap repairs up to 70 mm in length, as an alternative source of tissue to bolster the diameter of a cable graft, and for the management of neuromas in non-reconstructable injuries. PMID:27094886

  17. Imaging of the facial nerve.

    PubMed

    Veillona, F; Ramos-Taboada, L; Abu-Eid, M; Charpiot, A; Riehm, S

    2010-05-01

    The facial nerve is responsible for the motor innervation of the face. It has a visceral motor function (lacrimal, submandibular, sublingual glands and secretion of the nose); it conveys a great part of the taste fibers, participates to the general sensory of the auricle (skin of the concha) and the wall of the external auditory meatus. The facial mimic, production of tears, nasal flow and salivation all depend on the facial nerve. In order to image the facial nerve it is mandatory to be knowledgeable about its normal anatomy including the course of its efferent and afferent fibers and about relevant technical considerations regarding CT and MR to be able to achieve high-resolution images of the nerve. PMID:20456888

  18. Children's exposure to violent video games and desensitization to violence.

    PubMed

    Funk, Jeanne B

    2005-07-01

    Desensitization to violence is cited frequently as being an outcome of exposure to media violence and a condition that contributes to increased aggression. This article initiates the development of a conceptual model for describing possible relationships among violent video games, brain function, and desensitization by using empathy and attitudes toward violence as proxy measures of desensitization. More work is needed to understand how specific game content may affect brain activity, how brain development may be affected by heavy play at young ages, and how personality and lifestyle variables may moderate game influence. Given the current state of knowledge, recommendations are made for clinicians to help parents monitor and limit exposure to violent video games and encourage critical thinking about media violence. PMID:15936665

  19. [Metabolic changes in arachidonic acid during aspirin desensitization].

    PubMed

    Salazar Villa, R M; Zambrano Villa, S

    1996-01-01

    Aspirin sensitivity occurs in 10% of all asthmatics patients. In this subset of asthmatics, nasal congestion and bronchospasm occurs between 30-180 minutes after ingestion of aspirin. Following a respiratory reaction to aspirin, all patients can be desensitized to aspirin by repetitively introducing small and then larger doses of aspirin until the asthmatic subject can ingest 650 mg of aspirin without adverse effect. The mechanism of aspirin sensitivity are incompletely understood. And the reasons why ASA desensitization occurs universally are unknown. In this study, known ASA sensitive and control insensitive asthmatics were challenged with ASA. Urine was collected before, during induced bronchospasm, and after ingestion of 650 mg of ASA when the adverse effect (ie., acute desensitization) had subsided. Excretion levels of cyclo-oxygenase and lipoxygenase products in the urine were determined. PMID:8963642

  20. Achieving incompatible transplantation through desensitization: current perspectives and future directions.

    PubMed

    Jordan, Stanley C; Choi, Jua; Vo, Ashley

    2015-01-01

    The application of life-saving transplantation is severely limited by the shortage of organs, and histoincompatibility. To increase transplant rates in sensitized patients, new protocols for HLA and blood type incompatible (ABOi) desensitization have emerged. These approaches require significant desensitization using intravenous immunoglobulin, rituximab and plasma exchange. In addition, the development of donor-specific antibody responses post transplant is the major cause of allograft failure with return to dialysis. This increases patient morbidity/mortality and cost. Immunotherapeutic agents used for desensitization evolved from drug development in oncology and autoimmune diseases. Currently, there is a renaissance in development of novel drugs likely to improve antibody reduction in transplantation. These include agents that inactivate IgG molecules, anticytokine antibodies, costimulatory molecule blockade, anticomplement agents and therapies aimed at the plasma cell. PMID:25917629

  1. Sensory analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sensory evaluation can answer questions about a product that instruments cannot. The human subject is the instrument, and data can provide a wealth of information for a product developer, or results can be very variable and erroneous if all the precautions to minimize bias and external noise are no...

  2. Sensory Dysfunction

    MedlinePlus

    ... to Web version Sensory Dysfunction Overview Why are smell and taste important? Your senses of smell and taste let you fully enjoy the scents ... bitter and sour. Flavor involves both taste and smell. For example, because a person is able to ...

  3. Evaluation Of The Shear Bond Strength Between Dentin And Dental Luting Cement Following Dentin Surface Treatment By 980 Nm Diode Laser And Desensitizing Agent

    NASA Astrophysics Data System (ADS)

    Ibrahim, T.; Gheith, M.

    2011-09-01

    Dentin hypersensitivity is described clinically as an exaggerated response to non-noxious sensory stimuli. Current treatment is concentrating on two approaches; to occlude the dentinal tubules or to block neural transmission. This is achieved through using dentin desensitizers and low power lasers. Forty eight freshly extracted human molar teeth were used in this study and divided equally into three groups. Group 1) control group, group 2) laser treated dentin surface group, and group 3) desensitizing agent dentin surface group. Scanning electron microscopic analysis of laser treated group showed melted globules, no carbonization, recrystalization and crystal growth of the apatite in some areas. In diode laser dentin surface treated group showed the highest shear bond strength mean value.

  4. [Successful drug desensitization after vemurafenib-induced rash].

    PubMed

    Klossowski, N; Kislat, A; Homey, B; Gerber, P A; Meller, S

    2015-04-01

    The BRAF inhibitor vemurafenib was approved in 2011 for the treatment of inoperable or metastatic melanoma. Vemurafenib therapy is associated with several side effects, such as arthralgia, secondary skin tumors or inflammatory rashes. In particular cutaneous toxicities represent a serious threat to patients' adherence. Here, we present the case of a successful drug desensitization in a patient that presented with a vemurafenib-induced rash. Lymphocyte activation tests failed to detect drug-specific T cells, suggesting that the development of the rash was based upon a nonallergic drug hypersensitivity reaction. A program of slow desensitization was initiated and subsequently, vemurafenib was tolerated at the full effective and recommended dosage. PMID:25698338

  5. Opioid receptor desensitization: mechanisms and its link to tolerance

    PubMed Central

    Allouche, Stéphane; Noble, Florence; Marie, Nicolas

    2014-01-01

    Opioid receptors (OR) are part of the class A of G-protein coupled receptors and the target of the opiates, the most powerful analgesic molecules used in clinic. During a protracted use, a tolerance to analgesic effect develops resulting in a reduction of the effectiveness. So understanding mechanisms of tolerance is a great challenge and may help to find new strategies to tackle this side effect. This review will summarize receptor-related mechanisms that could underlie tolerance especially receptor desensitization. We will focus on the latest data obtained on molecular mechanisms involved in opioid receptor desensitization: phosphorylation, receptor uncoupling, internalization, and post-endocytic fate of the receptor. PMID:25566076

  6. Aspirin desensitization in aspirin-exacerbated respiratory disease.

    PubMed

    White, Andrew A; Stevenson, Donald D

    2013-05-01

    Although aspirin desensitization was discovered in 1922, it was not until 1979 that a therapeutic use for aspirin treatment, under the protection of desensitization, was discovered. In the last 33 years, details of aspirin treatment have been refined to the point where it is now recognized and accepted as a major therapeutic intervention in the treatment of aspirin-exacerbated respiratory disease, with therapeutic efficacy in approximately two-thirds of patients. It is only effective in patients who have aspirin-exacerbated respiratory disease and none of the other nonsteroidal anti-inflammatory drugs, despite their cross-reactive inhibition of cyclooxygenase-1, can effectively take the place of aspirin. PMID:23639709

  7. Neurophysiological approach to disorders of peripheral nerve.

    PubMed

    Crone, Clarissa; Krarup, Christian

    2013-01-01

    Disorders of the peripheral nerve system (PNS) are heterogeneous and may involve motor fibers, sensory fibers, small myelinated and unmyelinated fibers and autonomic nerve fibers, with variable anatomical distribution (single nerves, several different nerves, symmetrical affection of all nerves, plexus, or root lesions). Furthermore pathological processes may result in either demyelination, axonal degeneration or both. In order to reach an exact diagnosis of any neuropathy electrophysiological studies are crucial to obtain information about these variables. Conventional electrophysiological methods including nerve conduction studies and electromyography used in the study of patients suspected of having a neuropathy and the significance of the findings are discussed in detail and more novel and experimental methods are mentioned. Diagnostic considerations are based on a flow chart classifying neuropathies into eight categories based on mode of onset, distribution, and electrophysiological findings, and the electrophysiological characteristics in each type of neuropathy are discussed. PMID:23931776

  8. Three-dimensional Reconstruction of Peripheral Nerve Internal Fascicular Groups

    PubMed Central

    Zhong, Yingchun; Wang, Liping; Dong, Jianghui; Zhang, Yi; Luo, Peng; Qi, Jian; Liu, Xiaolin; Xian, Cory J.

    2015-01-01

    Peripheral nerves are important pathways for receiving afferent sensory impulses and sending out efferent motor instructions, as carried out by sensory nerve fibers and motor nerve fibers. It has remained a great challenge to functionally reconnect nerve internal fiber bundles (or fascicles) in nerve repair. One possible solution may be to establish a 3D nerve fascicle visualization system. This study described the key technology of 3D peripheral nerve fascicle reconstruction. Firstly, fixed nerve segments were embedded with position lines, cryostat-sectioned continuously, stained and imaged histologically. Position line cross-sections were identified using a trained support vector machine method, and the coordinates of their central pixels were obtained. Then, nerve section images were registered using the bilinear method, and edges of fascicles were extracted using an improved gradient vector flow snake method. Subsequently, fascicle types were identified automatically using the multi-directional gradient and second-order gradient method. Finally, a 3D virtual model of internal fascicles was obtained after section images were processed. This technique was successfully applied for 3D reconstruction for the median nerve of the hand-wrist and cubital fossa regions and the gastrocnemius nerve. This nerve internal fascicle 3D reconstruction technology would be helpful for aiding peripheral nerve repair and virtual surgery. PMID:26596642

  9. Compression Neuropathy of the Radial Nerve Due to Ganglion Cysts

    PubMed Central

    Lifchez, Scott D.; Dzwierzynski, William W.

    2008-01-01

    Ganglions of the upper extremity are common. Radial nerve dysfunction, particularly radial sensory dysfunction, is a rare finding in association with a ganglion. We present our experience with two such ganglia and a review of the literature. PMID:18780092

  10. Emotional Desensitization to Violence Contributes to Adolescents' Violent Behavior.

    PubMed

    Mrug, Sylvie; Madan, Anjana; Windle, Michael

    2016-01-01

    Many adolescents are exposed to violence in their schools, communities and homes. Exposure to violence at high levels or across multiple contexts has been linked with emotional desensitization, indicated by low levels of internalizing symptoms. However, the long-term consequences of such desensitization are unknown. This study examined emotional desensitization to violence, together with externalizing problems, as mediators of the relationship between exposure to violence in pre-adolescence and violent behavior in late adolescence. A community sample of youth (N = 704; 48% female; 76% African American, 22% Caucasian) reported on their exposure to violence in multiple settings at ages 11, 13 and 18. Internalizing and externalizing problems were assessed at ages 11 and 13; violent behavior was measured at age 18. Structural Equation Modeling showed that exposure to high levels of violence at age 11 was associated with lower levels of internalizing problems (quadratic effect) at age 13, as was exposure to violence across multiple contexts (linear effect). In turn, fewer internalizing problems and more externalizing problems at age 13 predicted more violent behavior at age 18. The results suggest that emotional desensitization to violence in early adolescence contributes to serious violence in late adolescence. PMID:25684447

  11. Desensitizing Children's Emotional Reactions to the Mass Media.

    ERIC Educational Resources Information Center

    Wilson, Barbara J.

    1989-01-01

    Assesses effectiveness of two desensitization strategies for reducing children's emotional reactions to mass media. Examines children having passive exposure, modeled exposure, or no exposure to lizards before watching a horror movie involving lizards. Finds that modeled exposure decreases emotional reactions and negative interpretations, whereas…

  12. Agonist mediated fetal muscle-type nicotinic acetylcholine receptor desensitization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The exposure of a developing embryo or fetus to teratogenic alkaloids from plants has the potential to cause developmental defects in livestock due to the inhibition of fetal movement by alkaloids. The mechanism behind the inhibition of fetal movement is the desensitization of fetal muscle-type nico...

  13. Emotionally Numb: Desensitization to Community Violence Exposure among Urban Youth

    ERIC Educational Resources Information Center

    Kennedy, Traci M.; Ceballo, Rosario

    2016-01-01

    Community violence exposure (CVE) is associated with numerous psychosocial outcomes among youth. Although linear, cumulative effects models have typically been used to describe these relations, emerging evidence suggests the presence of curvilinear associations that may represent a pattern of emotional desensitization among youth exposed to…

  14. Desensitization to media violence over a short period of time.

    PubMed

    Fanti, Kostas A; Vanman, Eric; Henrich, Christopher C; Avraamides, Marios N

    2009-01-01

    This study investigated the desensitization to violence over a short period of time. Participants watched nine violent movie scenes and nine comedy scenes, and reported whether they enjoyed the violent or comedy scenes and whether they felt sympathetic toward the victim of violence. Using latent growth modeling, analyses were carried out to investigate how participants responded to the different scenes across time. The findings of this study suggested that repeated exposure to media violence reduces the psychological impact of media violence in the short term, therefore desensitizing viewers to media violence. As a result, viewers tended to feel less sympathetic toward the victims of violence and actually enjoy more the violence portrayed in the media. Additionally, desensitization to media violence was better represented by a curvilinear pattern, whereas desensitization to comedy scenes was better represented by a linear pattern. Finally, trait aggression was not related to the pattern of change over time, although significant effects were found for initial reports of enjoyment and sympathy. PMID:19172659

  15. Effects of Systematic Desensitization in the Alleviation of Communication Apprehension.

    ERIC Educational Resources Information Center

    Watson, Arden K.

    A study examined stages and objectives of a systematic desensitization (SD) program and its effects on subject reported apprehension levels and perceived benefits and behavior changes toward public speaking. Subjects, 19 freshmen and sophomore university students, were administered the Personal Report of Communication Apprehension-24 (PRCA-24).…

  16. Localized interstitial granuloma annulare induced by subcutaneous injections for desensitization.

    PubMed

    Spring, Philipp; Vernez, Maxime; Maniu, Christa-Maria; Hohl, Daniel

    2013-06-01

    We describe a patient with interstitial granuloma annulare associated with subcutaneous injection therapy (SIT) for desensitization to a type I allergy. Asymptomatic, erythematous, violaceous annular patches were located at the injection sites on both her arms. Medical history revealed perennial rhinoconjonctivitis treated with SIT (Phostal Stallergen® cat 100% and D. pteronyssinus/D.farinae 50%:50%). PMID:24011321

  17. Eye Movement Desensitization and Reprocessing: A Critical Analysis.

    ERIC Educational Resources Information Center

    Erwin, Terry McVannel

    Since Shapiro's introduction of Eye Movement Desensitization and Reprocessing (EMDR) in 1989, it has been a highly controversial therapeutic technique. Critical reviews of Shapiro's initial study have highlighted many methodological shortcomings in her work. And early empirical research that followed Shapiro's original study has been criticized…

  18. The Thumb Domain Mediates Acid-sensing Ion Channel Desensitization.

    PubMed

    Krauson, Aram J; Carattino, Marcelo D

    2016-05-20

    Acid-sensing ion channels (ASICs) are cation-selective proton-gated channels expressed in neurons that participate in diverse physiological processes, including nociception, synaptic plasticity, learning, and memory. ASIC subunits contain intracellular N and C termini, two transmembrane domains that constitute the pore, and a large extracellular loop with defined domains termed the finger, β-ball, thumb, palm, and knuckle. Here we examined the contribution of the finger, β-ball, and thumb domains to activation and desensitization through the analysis of chimeras and the assessment of the effect of covalent modification of introduced Cys at the domain-domain interfaces. Our studies with ASIC1a-ASIC2a chimeras showed that swapping the thumb domain between subunits results in faster channel desensitization. Likewise, the covalent modification of Cys residues at selected positions in the β-ball-thumb interface accelerates the desensitization of the mutant channels. Studies of accessibility with thiol-reactive reagents revealed that the β-ball and thumb domains reside apart in the resting state but that they become closer to each other in response to extracellular acidification. We propose that the thumb domain moves upon continuous exposure to an acidic extracellular milieu, assisting with the closing of the pore during channel desensitization. PMID:27015804

  19. Stem cell salvage of injured peripheral nerve.

    PubMed

    Grimoldi, Nadia; Colleoni, Federica; Tiberio, Francesca; Vetrano, Ignazio G; Cappellari, Alberto; Costa, Antonella; Belicchi, Marzia; Razini, Paola; Giordano, Rosaria; Spagnoli, Diego; Pluderi, Mauro; Gatti, Stefano; Morbin, Michela; Gaini, Sergio M; Rebulla, Paolo; Bresolin, Nereo; Torrente, Yvan

    2015-01-01

    We previously developed a collagen tube filled with autologous skin-derived stem cells (SDSCs) for bridging long rat sciatic nerve gaps. Here we present a case report describing a compassionate use of this graft for repairing the polyinjured motor and sensory nerves of the upper arms of a patient. Preclinical assessment was performed with collagen/SDSC implantation in rats after sectioning the sciatic nerve. For the patient, during the 3-year follow-up period, functional recovery of injured median and ulnar nerves was assessed by pinch gauge test and static two-point discrimination and touch test with monofilaments, along with electrophysiological and MRI examinations. Preclinical experiments in rats revealed rescue of sciatic nerve and no side effects of patient-derived SDSC transplantation (30 and 180 days of treatment). In the patient treatment, motor and sensory functions of the median nerve demonstrated ongoing recovery postimplantation during the follow-up period. The results indicate that the collagen/SDSC artificial nerve graft could be used for surgical repair of larger defects in major lesions of peripheral nerves, increasing patient quality of life by saving the upper arms from amputation. PMID:24268028

  20. [Repair and revision 9. Peripheral trigeminal nerve injury].

    PubMed

    Vriens, J P M; van der Glas, H W; Koole, R

    2002-03-01

    A review is given about long-term incidence of sensory disturbance in the areas of innervation of the n. trigeminus for different types of trauma and/or treatment. Diagnosis, clinical course and possible types of treatment are in addition reviewed. Regarding diagnosis, the outcome of a test on sensory function is not always related to the degree of nerve damage because methods differ in the type of afferent nerve fibers of which function is tested, and some specificity might occur in nerve damage, i.e. either thick or thin afferent fibers might be predominantly affected at a particular time. An initial quick testing of sensory function is recommended. This testing includes examining two sensory modalities, which are related to functioning of thick and thin afferent fibers respectively and which have a dichotomous yes/no outcome on the incidence of a pronounced sensory disturbance. PMID:11933529

  1. Reduced evoked motor and sensory potential amplitudes in obstructive sleep apnea patients.

    PubMed

    Mihalj, Mario; Lušić, Linda; Đogaš, Zoran

    2016-06-01

    It is unknown to what extent chronic intermittent hypoxaemia in obstructive sleep apnea causes damage to the motor and sensory peripheral nerves. It was hypothesized that patients with obstructive sleep apnea would have bilaterally significantly impaired amplitudes of both motor and sensory peripheral nerve-evoked potentials of both lower and upper limbs. An observational study was conducted on 43 patients with obstructive sleep apnea confirmed by the whole-night polysomnography, and 40 controls to assess the relationship between obstructive sleep apnea and peripheral neuropathy. All obstructive sleep apnea subjects underwent standardized electroneurographic testing, with full assessment of amplitudes of evoked compound muscle action potentials, sensory neural action potentials, motor and sensory nerve conduction velocities, and distal motor and sensory latencies of the median, ulnar, peroneal and sural nerves, bilaterally. All nerve measurements were compared with reference values, as well as between the untreated patients with obstructive sleep apnea and control subjects. Averaged compound muscle action potential and sensory nerve action potential amplitudes were significantly reduced in the nerves of both upper and lower limbs in patients with obstructive sleep apnea compared with controls (P < 0.001). These results confirmed that patients with obstructive sleep apnea had significantly lower amplitudes of evoked action potentials of both motor and sensory peripheral nerves. Clinical/subclinical axonal damage exists in patients with obstructive sleep apnea to a greater extent than previously thought. PMID:26749257

  2. Pathological studies of spinal nerve ganglia in relation to intractable intercostal pain.

    PubMed

    Smith, F P

    1978-07-01

    Pathological examination, by light and electron microscopy, of spinal nerve ganglia surgically removed in treatment of intractable intercostal pain, has shown changes in sensory cells, whether the etiology of the pain has been trauma related to intercostal nerve, or infection by herpes zoster virus. The possible role of the sensory cell changes in accounting for causalgic type pain is discussed. PMID:684607

  3. Desensitizing Addiction: Using Eye Movements to Reduce the Intensity of Substance-Related Mental Imagery and Craving

    PubMed Central

    Littel, Marianne; van den Hout, Marcel A.; Engelhard, Iris M.

    2016-01-01

    Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. During this treatment, patients recall traumatic memories while making horizontal eye movements (EM). Studies have shown that EM not only desensitize negative memories but also positive memories and imagined events. Substance use behavior and craving are maintained by maladaptive memory associations and visual imagery. Preliminary findings have indicated that these mental images can be desensitized by EMDR techniques. We conducted two proof-of-principle studies to investigate whether EM can reduce the sensory richness of substance-related mental representations and accompanying craving levels. We investigated the effects of EM on (1) vividness of food-related mental imagery and food craving in dieting and non-dieting students and (2) vividness of recent smoking-related memories and cigarette craving in daily smokers. In both experiments, participants recalled the images while making EM or keeping eyes stationary. Image vividness and emotionality, image-specific craving and general craving were measured before and after the intervention. As a behavioral outcome measure, participants in study 1 were offered a snack choice at the end of the experiment. Results of both experiments showed that image vividness and craving increased in the control condition but remained stable or decreased after the EM intervention. EM additionally reduced image emotionality (experiment 2) and affected behavior (experiment 1): participants in the EM condition were more inclined to choose healthy over unhealthy snack options. In conclusion, these data suggest that EM can be used to reduce intensity of substance-related imagery and craving. Although long-term effects are yet to be demonstrated, the current studies suggest that EM might be a useful technique in addiction treatment. PMID:26903888

  4. Desensitizing Addiction: Using Eye Movements to Reduce the Intensity of Substance-Related Mental Imagery and Craving.

    PubMed

    Littel, Marianne; van den Hout, Marcel A; Engelhard, Iris M

    2016-01-01

    Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. During this treatment, patients recall traumatic memories while making horizontal eye movements (EM). Studies have shown that EM not only desensitize negative memories but also positive memories and imagined events. Substance use behavior and craving are maintained by maladaptive memory associations and visual imagery. Preliminary findings have indicated that these mental images can be desensitized by EMDR techniques. We conducted two proof-of-principle studies to investigate whether EM can reduce the sensory richness of substance-related mental representations and accompanying craving levels. We investigated the effects of EM on (1) vividness of food-related mental imagery and food craving in dieting and non-dieting students and (2) vividness of recent smoking-related memories and cigarette craving in daily smokers. In both experiments, participants recalled the images while making EM or keeping eyes stationary. Image vividness and emotionality, image-specific craving and general craving were measured before and after the intervention. As a behavioral outcome measure, participants in study 1 were offered a snack choice at the end of the experiment. Results of both experiments showed that image vividness and craving increased in the control condition but remained stable or decreased after the EM intervention. EM additionally reduced image emotionality (experiment 2) and affected behavior (experiment 1): participants in the EM condition were more inclined to choose healthy over unhealthy snack options. In conclusion, these data suggest that EM can be used to reduce intensity of substance-related imagery and craving. Although long-term effects are yet to be demonstrated, the current studies suggest that EM might be a useful technique in addiction treatment. PMID:26903888

  5. A reversible functional sensory neuropathy model.

    PubMed

    Danigo, Aurore; Magy, Laurent; Richard, Laurence; Sturtz, Franck; Funalot, Benoît; Demiot, Claire

    2014-06-13

    Small-fiber neuropathy was induced in young adult mice by intraperitoneal injection of resiniferatoxin (RTX), a TRPV1 agonist. At day 7, RTX induced significant thermal and mechanical hypoalgesia. At day 28, mechanical and thermal nociception were restored. No nerve degeneration in skin was observed and unmyelinated nerve fiber morphology and density in sciatic nerve were unchanged. At day 7, substance P (SP) was largely depleted in dorsal root ganglia (DRG) neurons, although calcitonin gene-related peptide (CGRP) was only moderately depleted. Three weeks after, SP and CGRP expression was restored in DRG neurons. At the same time, CGRP expression remained low in intraepidermal nerve fibers (IENFs) whereas SP expression had improved. In summary, RTX induced in our model a transient neuropeptide depletion in sensory neurons without nerve degeneration. We think this model is valuable as it brings the opportunity to study functional nerve changes in the very early phase of small fiber neuropathy. Moreover, it may represent a useful tool to study the mechanisms of action of therapeutic strategies to prevent sensory neuropathy of various origins. PMID:24792390

  6. Comparative evaluation of NovaMin desensitizer and Gluma desensitizer on dentinal tubule occlusion: a scanning electron microscopic study

    PubMed Central

    Joshi, Surabhi; Gowda, Ashwini Shivananje

    2013-01-01

    Purpose In this study, the effect of calcium sodium phosphosilicate (NovaMin) desensitizing agent, which is a powder-based system, and hydroxyethyl methacrylate and glutaraldehyde (Gluma desensitizer), which is liquid-based system, on dentinal tubule occlusion was analyzed by scanning electron microscope. The effects of the above two along with one control group were compared to determine the more effective method of sealing the dentinal tubules after initial application. Methods Twenty specimens were allocated to each of 3 groups: Control, Gluma desensitizer, and NovaMin. Two additional samples were also prepared and treated with Gluma and NovaMin; these samples were longitudinally fractured. The specimens were prepared from extracted sound human premolars and were stored in 10% formalin at room temperature. The teeth were cleaned of gross debris and then sectioned to provide one to two dentin specimens. The dentin specimens were etched with 6% citric acid for 2 minutes and rinsed in distilled water. Control discs were dried, and the test discs were treated with the desensitizing agents as per the manufacturer's instructions. The discs as well as longitudinal sections were later analyzed under the scanning electron microscope. The proportions of completely occluded, partially occluded, and open tubules within each group were calculated. The ratios of completely and partially occluded tubules to the total tubules for all the groups was determined, and the data was statistically analyzed using nonparametric tests and statistical significance was calculated. Results NovaMin showed more completely occluded tubules (0.545±0.051) while Gluma desensitizer showed more partially occluded tubules (0.532±0.075). The differences among all the groups were statistically significant (P≤ 0.05). Conclusion Both materials were effective in occluding dentinal tubules but NovaMin appeared more promising in occluding tubules completely after initial application. PMID:24455439

  7. Cholesterol modulates open probability and desensitization of NMDA receptors

    PubMed Central

    Korinek, Miloslav; Vyklicky, Vojtech; Borovska, Jirina; Lichnerova, Katarina; Kaniakova, Martina; Krausova, Barbora; Krusek, Jan; Balik, Ales; Smejkalova, Tereza; Horak, Martin; Vyklicky, Ladislav

    2015-01-01

    NMDA receptors (NMDARs) are glutamate-gated ion channels that mediate excitatory neurotransmission in the CNS. Although these receptors are in direct contact with plasma membrane, lipid–NMDAR interactions are little understood. In the present study, we aimed at characterizing the effect of cholesterol on the ionotropic glutamate receptors. Whole-cell current responses induced by fast application of NMDA in cultured rat cerebellar granule cells (CGCs) were almost abolished (reduced to 3%) and the relative degree of receptor desensitization was increased (by seven-fold) after acute cholesterol depletion by methyl-β-cyclodextrin. Both of these effects were fully reversible by cholesterol repletion. By contrast, the responses mediated by AMPA/kainate receptors were not affected by cholesterol depletion. Similar results were obtained in CGCs after chronic inhibition of cholesterol biosynthesis by simvastatin and acute enzymatic cholesterol degradation to 4-cholesten-3-one by cholesterol oxidase. Fluorescence anisotropy measurements showed that membrane fluidity increased after methyl-β-cyclodextrin pretreatment. However, no change in fluidity was observed after cholesterol enzymatic degradation, suggesting that the effect of cholesterol on NMDARs is not mediated by changes in membrane fluidity. Our data show that diminution of NMDAR responses by cholesterol depletion is the result of a reduction of the open probability, whereas the increase in receptor desensitization is the result of an increase in the rate constant of entry into the desensitized state. Surface NMDAR population, agonist affinity, single-channel conductance and open time were not altered in cholesterol-depleted CGCs. The results of our experiments show that cholesterol is a strong endogenous modulator of NMDARs. Key points NMDA receptors (NMDARs) are tetrameric cation channels permeable to calcium; they mediate excitatory synaptic transmission in the CNS and their excessive activation can lead to

  8. Nerve conduction velocity in hypertensive patients.

    PubMed

    Halar, E M; Stewart, D T; Venkatesh, B; Chrissian, S A

    1978-01-01

    Due to conflicting reports in the literature regarding nerve conduction velocities (NCVs) in hypertensives, peroneal and sural NCVs and facial nerve conduction latencies were studied in 30 hypertensives and in 30 controls. An improved technique of NCV measurement was used. Twenty-one of the hypertensives were retested after five weeks, and five of them were tested for motor and sensory NCVs of the median nerve during a short period of partial occlusion of blood flow in the arm. No changes were found that could be related to blood pressure, duration of hypertension, eyeground changes, or partial restriction of blood flow. PMID:619818

  9. A silk sericin/silicone nerve guidance conduit promotes regeneration of a transected sciatic nerve.

    PubMed

    Xie, Hongjian; Yang, Wen; Chen, Jianghai; Zhang, Jinxiang; Lu, Xiaochen; Zhao, Xiaobo; Huang, Kun; Li, Huili; Chang, Panpan; Wang, Zheng; Wang, Lin

    2015-10-28

    Peripheral nerve gap defects lead to significant loss of sensory or motor function. Tissue engineering has become an important alternative to nerve repair. Sericin, a major component of silk, is a natural protein whose value in tissue engineering has just begun to be explored. Here, the first time use of sericin in vivo is reported as a long-term implant for peripheral nerve regeneration. A sericin nerve guidance conduit is designed and fabricated. This conduit is highly porous with mechanical strength matching peripheral nerve tissue. It supports Schwann cell proliferation and is capable of up-regulating the transcription of glial cell derived neurotrophic factor and nerve growth factor in Schwann cells. The sericin conduit wrapped with a silicone conduit (sericin/silicone double conduits) is used for bridging repair of a 5 mm gap in a rat sciatic nerve transection model. The sericin/silicone double conduits achieve functional recovery comparable to that of autologous nerve grafting as evidenced by drastically improved nerve function and morphology. Importantly, this improvement is mainly attributed to the sericin conduit as the silicone conduit alone only produces marginal functional recovery. This sericin/silicone-double-conduit strategy offers an efficient and valuable alternative to autologous nerve grafting for repairing damaged peripheral nerve. PMID:26332703

  10. Emotionally numb: Desensitization to community violence exposure among urban youth.

    PubMed

    Kennedy, Traci M; Ceballo, Rosario

    2016-05-01

    Community violence exposure (CVE) is associated with numerous psychosocial outcomes among youth. Although linear, cumulative effects models have typically been used to describe these relations, emerging evidence suggests the presence of curvilinear associations that may represent a pattern of emotional desensitization among youth exposed to chronic community violence. This study uses longitudinal data to investigate relations between CVE and both internalizing and externalizing symptoms among 3,480 youth ages 3 to 12 at baseline and 9 to 18 at outcome. Results support desensitization models, as evidenced by longitudinal quadratic associations between Wave 2 CVE and Wave 3 anxiety/depressive symptoms, alongside cross-sectional linear associations between Wave 3 CVE and Wave 3 aggression. Neither age nor gender moderated the associations between CVE and well-being. (PsycINFO Database Record PMID:26986229

  11. Psychodynamic Emotional Regulation in View of Wolpe's Desensitization Model.

    PubMed

    Rabinovich, Merav

    2016-01-01

    The current research belongs to the stream of theoretical integration and establishes a theoretical platform for integrative psychotherapy in anxiety disorders. Qualitative metasynthesis procedures were applied to 40 peer-reviewed psychoanalytic articles involving emotional regulation. The concept of psychodynamic emotional regulation was found to be connected with the categories of desensitization, gradual exposure, containment, and transference. This article presents a model according to which psychoanalytic psychotherapy allows anxiety to be tolerated while following the core principles of systematic desensitization. It is shown that despite the antiresearch image of psychoanalytic psychotherapy, its foundations obey evidence-based principles. The findings imply that anxiety tolerance might be a key goal in which the cumulative wisdom of the different therapies can be used to optimize psychotherapy outcomes. PMID:27029107

  12. Brentuximab vedotin desensitization in a patient with refractory Hodgkin's lymphoma.

    PubMed

    Arora, Anubha; Bhatt, Vijaya Raj; Liewer, Susanne; Armitage, James O; Bociek, R Gregory

    2015-10-01

    Brentuximab vedotin has emerged as a useful treatment option for relapsed or refractory Hodgkin's lymphoma; however, uncommon cases of anaphylactic reactions may require its permanent discontinuation. We report a 29-yr-old woman with refractory Hodgkin's lymphoma, who developed an anaphylactic reaction during the second dose of brentuximab vedotin. A 12-step desensitization protocol was followed; after premedicating with antihistaminic agents, methylprednisolone and montelukast, a total dose of 156 mg of brentuximab vedotin (1.8 mg/kg) was given as three infusions with increasing rate and concentration. Such desensitization protocol can allow safe administration of brentuximab vedotin and may have a broader applicability in managing hypersensitivity reactions with other monoclonal antibodies. PMID:25892213

  13. Nonverbal patient with autism spectrum disorder and obstructive sleep apnea: use of desensitization to acclimatize to a dental appliance.

    PubMed

    Fetner, Maggie; Cascio, Carissa J; Essick, Gregory

    2014-01-01

    Patients with autism spectrum disorders (ASDs) may have difficulty tolerating conventional dental treatment due to aberrant sensory responsiveness. The purpose of this report was to describe the successful treatment of obstructive sleep apnea (OSA) in a nonverbal 20-year-old male patient with ASD using a dental appliance. A series of appointments prepared the patient for the required treatment procedures and desensitized him for use of the final appliance. The final appliance improved outcomes of a post-treatment sleep study, indicating successful treatment of OSA. Understanding the specific challenges of patients with ASD and the patience and foresight of providers in approaching these challenges, in collaboration with caregivers, can contribute to improved health outcomes for these patients. PMID:25514080

  14. Micromorphological Evaluation of Dentin Treated with Different Desensitizing Agents

    PubMed Central

    Osmari, Deise; de Oliveira Ferreira, Ana Carolina; de Carlo Bello, Mariana; Henrique Susin, Alexandre; Cecília Correa Aranha, Ana; Marquezan, Marcela; Lopes da Silveira, Bruno

    2013-01-01

    Introduction: The purpose of a desensitizing agent is a permanent coating or filling of dentin surface. Morphological analysis in vitro of this treated surface is essential to understand the interaction between desensitizing agent and hypersensitive dentin. The aim was to evaluate the morphology of four dentin surface treated with desensitizing agents. Methods: This was an in vitro laboratory study, where fifteen specimens from extracted human premolars were obtained. The enamel was removed to expose the dentin surface, polished with silicon carbide abrasive papers and etched with 6% citric acid for 2 min.The specimens were randomly divided into 5 groups: G1 - without treatment (control) (C), G2 - fluoride varnish (FV), G3 - potassium oxalate (PO), G4 - 2-step self-etching adhesive system (AS), G5 - diode laser (DL). The specimens were cleaved in the lingual buccaldirection, prepared for analysis by Scanning Electron Microscope and the surface and interior of the dentinal tubules were observed at 1500× magnification. Results: In the control group, the dentin etching promoted smear layer removal and exposure of dentinal tubules. In the group of fluoride varnish, a film was observed on the surface, with plugs of varnish into tubules. In the group of oxalate, partial obliteration of the tubular entrances was observed. In the group of the adhesive system, the tubules were obstructed through the formation of hybrid layer and a physical barrier on the surface. In the group of the diode laser, dentin melting and solidification with partial occlusion of dentinal tubules were observed. Conclusions: All desensitizing agents evaluated demonstrated ability to modify the surface of dentin, with partial or total occlusion of dentinal tubules. Thus, it is suggested to do more clinical studies to verify the effectiveness of the findings. PMID:25606322

  15. Explosives malfunction from sympathetic detonation to shock desensitization

    SciTech Connect

    Katsabanis, P.D.; Yeung, C.; Fitz, G.; Heater, R.

    1994-12-31

    Explosives malfunction due to shock waves is a serious concern for successful blasting results. Malfunction can range from sympathetic detonation to desensitization and modification of firing times of conventional pyrotechnic detonators. Decked charges consisting of commercial emulsion explosives having a detonator and a primer were placed in 10cm diameter blastholes and their performance was recorded. Due to the limited length of the holes the events were mainly sympathetic detonations although desensitization was also recorded. Pressure measurements along the stemming column showed that shock waves produced by an explosive have a significant amplitude even at relatively large distances away from the detonating explosive. It was found that 2m away from a detonating charge the pressures in the stemming material were above 0.1 GPa indicating that there is potential for primers and detonators to malfunction. Parallel charges consisting of a commercial emulsion explosive with a diameter of 32mm were confined in 2mm thick steel tubes and initiation was attempted using detonators having a delay interval of 25ms. The charges were placed in sand and the velocity of detonation of the acceptor charge was recorded using a continuous resistance probe system. Carbon resistors were also placed in the same position as the acceptor charge to examine the dynamic pressures that were applied to the charge. Sympathetic detonation, complete desensitization, partial desensitization and properly sequenced detonations were observed as the distance between charges was increased from 76 mm to 305 mm. Delay detonators were also tested in a similar to the last configuration. Modification of firing times was observed at distances between 150 and 360 mm.

  16. Fast desensitization of the response to InsP3 in Limulus ventral photoreceptors.

    PubMed Central

    Levitan, I; Hillman, P; Payne, R

    1993-01-01

    In Limulus ventral photoreceptor cells the time-course of the desensitization of InsP3 response was measured by an injection-pair paradigm. Pressure pulses of InsP3 were delivered into the cell with various interpulse intervals. The desensitization of the response to the second injection of each pair approached totality at 200 ms, which is the duration of the response to a single pressure pulse of InsP3. Lowering extracellular calcium did not affect the time-course of the desensitization. Lowering the temperature slowed down both the time-course of the response to InsP3 and the time-course of the desensitization to the same extent. These findings suggest that the desensitization is powerful enough and its onset fast enough to contribute to the transience of the InsP3 response. The time-course of the desensitization suggests it may influence light adaptation. PMID:8494989

  17. A bioengineered peripheral nerve construct using aligned peptide amphiphile nanofibers

    PubMed Central

    Yalom, Anisa; Berns, Eric J.; Stephanopoulos, Nicholas; McClendon, Mark T.; Segovia, Luis A.; Spigelman, Igor; Stupp, Samuel I.; Jarrahy, Reza

    2014-01-01

    Peripheral nerve injuries can result in lifelong disability. Primary coaptation is the treatment of choice when the gap between transected nerve ends is short. Long nerve gaps seen in more complex injuries often require autologous nerve grafts or nerve conduits implemented into the repair. Nerve grafts, however, cause morbidity and functional loss at donor sites, which are limited in number. Nerve conduits, in turn, lack an internal scaffold to support and guide axonal regeneration, resulting in decreased efficacy over longer nerve gap lengths. By comparison, peptide amphiphiles (PAs) are molecules that can self-assemble into nanofibers, which can be aligned to mimic the native architecture of peripheral nerve. As such, they represent a potential substrate for use in a bioengineered nerve graft substitute. To examine this, we cultured Schwann cells with bioactive PAs (RGDS-PA, IKVAV-PA) to determine their ability to attach to and proliferate within the biomaterial. Next, we devised a PA construct for use in a peripheral nerve critical sized defect model. Rat sciatic nerve defects were created and reconstructed with autologous nerve, PLGA conduits filled with various forms of aligned PAs, or left unrepaired. Motor and sensory recovery were determined and compared among groups. Our results demonstrate that Schwann cells are able to adhere to and proliferate in aligned PA gels, with greater efficacy in bioactive PAs compared to the backbone-PA alone. In vivo testing revealed recovery of motor and sensory function in animals treated with conduit/PA constructs comparable to animals treated with autologous nerve grafts. Functional recovery in conduit/PA and autologous graft groups was significantly faster than in animals treated with empty PLGA conduits. Histological examinations also demonstrated increased axonal and Schwann cell regeneration within the reconstructed nerve gap in animals treated with conduit/PA constructs. These results indicate that PA nanofibers may

  18. Spontaneous temporal changes and variability of peripheral nerve conduction analyzed using a random effects model.

    PubMed

    Krøigård, Thomas; Gaist, David; Otto, Marit; Højlund, Dorthe; Selmar, Peter E; Sindrup, Søren H

    2014-08-01

    The reproducibility of variables commonly included in studies of peripheral nerve conduction in healthy individuals has not previously been analyzed using a random effects regression model. We examined the temporal changes and variability of standard nerve conduction measures in the leg. Peroneal nerve distal motor latency, motor conduction velocity, and compound motor action potential amplitude; sural nerve sensory action potential amplitude and sensory conduction velocity; and tibial nerve minimal F-wave latency were examined in 51 healthy subjects, aged 40 to 67 years. They were reexamined after 2 and 26 weeks. There was no change in the variables except for a minor decrease in sural nerve sensory action potential amplitude and a minor increase in tibial nerve minimal F-wave latency. Reproducibility was best for peroneal nerve distal motor latency and motor conduction velocity, sural nerve sensory conduction velocity, and tibial nerve minimal F-wave latency. Between-subject variability was greater than within-subject variability. Sample sizes ranging from 21 to 128 would be required to show changes twice the magnitude of the spontaneous changes observed in this study. Nerve conduction studies have a high reproducibility, and variables are mainly unaltered during 6 months. This study provides a solid basis for the planning of future clinical trials assessing changes in nerve conduction. PMID:25083853

  19. Raman microspectroscopy for visualization of peripheral nerves

    NASA Astrophysics Data System (ADS)

    Minamikawa, Takeo; Harada, Yoshinori; Koizumi, Noriaki; Takamatsu, Tetsuro

    2013-02-01

    The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery is essential for improving quality of life of patients. To preserve peripheral nerves, detection of ne peripheral nerves that cannot be identi ed by human eye or under white light imaging is necessary. In this study, we sought to provide a proof-of-principle demonstration of a label-free detection technique of peripheral nerve tissues against adjacent tissues that employs spontaneous Raman microspectroscopy. A line-illumination confocal Raman microscope was used for the experiment. A laser operating at the wavelength of 532 nm was used as an excitation laser light. We obtained Raman spectra of peripheral nerve, brous connective tissue, skeletal muscle, blood vessel, and adipose tissue of Wistar rats, and extracted speci c spectral features of peripheral nerves and adjacent tissues. By applying multivariate image analysis, peripheral nerves were clearly detected against adjacent tissues without any preprocessing neither xation nor staining. These results suggest the potential of the Raman spectroscopic observation for noninvasive and label-free nerve detection, and we expect this method could be a key technique for nerve-sparing surgery.

  20. Intravenous linezolid administered orally: a novel desensitization strategy.

    PubMed

    Cawley, Michael J; Lipka, Ozana

    2006-04-01

    A 41-year-old woman with a history of myasthenia gravis was admitted to a local hospital because of severe muscle weakness, ptosis, shortness of breath, nausea and vomiting, and fever. Blood cultures revealed Enterococcus faecium resistant to several antimicrobial agents. The organism had minimum inhibitory concentrations above 16 microg/ml for vancomycin and above 2 microg/ml for quinupristin-dalfopristin. In the absence of therapeutic alternatives, treatment with linezolid was required (minimum inhibitory concentration 1.5 microg/ml). The first dose of linezolid resulted in a hypersensitivity reaction consistent with an immunoglobulin E-mediated response requiring medical intervention. Because of a lack of intravenous access and because of limited availability of the oral suspension from the manufacturer, a desensitization protocol was implemented in which the intravenous formulation of linezolid was given orally. The patient was successfully desensitized by using an escalating, 14-dose procedure. We believe this is the first case in the English language literature to describe successful desensitization with the oral administration of intravenous linezolid in a patient with E. faecium bacteremia who was allergic to oxazolidinone. PMID:16553517

  1. Desensitization of G protein-coupled receptors and neuronal functions.

    PubMed

    Gainetdinov, Raul R; Premont, Richard T; Bohn, Laura M; Lefkowitz, Robert J; Caron, Marc G

    2004-01-01

    G protein-coupled receptors (GPCRs) have proven to be the most highly favorable class of drug targets in modern pharmacology. Over 90% of nonsensory GPCRs are expressed in the brain, where they play important roles in numerous neuronal functions. GPCRs can be desensitized following activation by agonists by becoming phosphorylated by members of the family of G protein-coupled receptor kinases (GRKs). Phosphorylated receptors are then bound by arrestins, which prevent further stimulation of G proteins and downstream signaling pathways. Discussed in this review are recent progress in understanding basics of GPCR desensitization, novel functional roles, patterns of brain expression, and receptor specificity of GRKs and beta arrestins in major brain functions. In particular, screening of genetically modified mice lacking individual GRKs or beta arrestins for alterations in behavioral and biochemical responses to cocaine and morphine has revealed a functional specificity in dopamine and mu-opioid receptor regulation of locomotion and analgesia. An important and specific role of GRKs and beta arrestins in regulating physiological responsiveness to psychostimulants and morphine suggests potential involvement of these molecules in certain brain disorders, such as addiction, Parkinson's disease, mood disorders, and schizophrenia. Furthermore, the utility of a pharmacological strategy aimed at targeting this GPCR desensitization machinery to regulate brain functions can be envisaged. PMID:15217328

  2. [Acetylsalicylic acid desensitization in the new era of percutaneous coronary intervention].

    PubMed

    Fuertes Ferre, Georgina; Ferrer Gracia, Maria Cruz; Calvo Cebollero, Isabel

    2015-09-21

    Dual antiplatelet therapy is essential in patients undergoing percutaneous coronary intervention with stent implantation. Hypersensitivity to acetylsalicylic acid (ASA) limits treatment options. Desensitization to ASA has classically been studied in patients with respiratory tract disease. Over the last years, many protocols have been described about ASA desensitization in patients with ischemic heart disease, including acute coronary syndrome and the need for coronary stent implantation. It is important to know the efficacy and safety of ASA desensitization in these patients. PMID:25577589

  3. Optic nerve atrophy

    MedlinePlus

    Optic nerve atrophy is damage to the optic nerve. The optic nerve carries images of what the eye sees to ... problem most often affects older adults. The optic nerve can also be damaged by shock, toxins, radiation, ...

  4. Nerve biopsy (image)

    MedlinePlus

    Nerve biopsy is the removal of a small piece of nerve for examination. Through a small incision, a sample ... is removed and examined under a microscope. Nerve biopsy may be performed to identify nerve degeneration, identify ...

  5. Peripheral Nerve Disorders

    MedlinePlus

    ... spinal cord. Like static on a telephone line, peripheral nerve disorders distort or interrupt the messages between the brain ... body. There are more than 100 kinds of peripheral nerve disorders. They can affect one nerve or many nerves. ...

  6. Multiple Components of Ganglion Cell Desensitization in Response to Prosthetic Stimulation

    PubMed Central

    Freeman, Daniel K; Fried, Shelley I

    2011-01-01

    Retinal prostheses aim to restore functional vision to those blinded by outer retinal diseases using electric stimulation of surviving neurons. Previous work indicates that repetitive stimulation with stimuli that activate the synaptic network reduces the sensitivity of retinal neurons to further stimulation. Such desensitization may contribute to the fading of visual percepts over time reported by human subjects. Here, we show that desensitization may be more complex than previously considered. We recorded spike trains from rabbit retinal ganglion cells and found that desensitization persists in the presence of inhibitory blockers (strychnine and picrotoxin), indicating amacrine cell inhibition is not solely responsible for reducing sensitivity in response to electric stimulation. The threshold for direct activation of the ganglion cell changes little during the simultaneous desensitization of the synaptically mediated response, indicating that desensitization likely occurs upstream of the spike generator. In addition to the rapid desensitization acting over hundreds of milliseconds (τ = 176.4 ± 8.8ms), we report the presence of a slow acting desensitization with a time course of seconds (τ = 14.0 ± 1.1sec). The time course of the two components of desensitization that we found are similar to the two phases of brightness fading seen in human subjects. This suggests that the reduction in ganglion cell firing due to desensitization may be responsible for the fading of visual percepts over time in response to prosthetic stimulation. PMID:21248379

  7. Effect of different desensitizers on inhibition of bovine dentin demineralization: micro-computed tomography assessment.

    PubMed

    Lodha, Ena; Hamba, Hidenori; Nakashima, Syozi; Sadr, Alireza; Nikaido, Toru; Tagami, Junji

    2014-12-01

    This study evaluated the effect of two desensitizers on inhibition of dentin demineralization, after immersion in artificial saliva using micro-computed tomography (μCT). Dentin blocks cut from bovine incisors were treated with deionized water (DW, a negative control) or one of three desensitizers: a fluoride varnish (Duraphat, a positive control), a calcium phosphate desensitizer (Teethmate Desensitizer), and a fluoro-alumino-calcium silicate-based desensitizer (Nanoseal). After each treatment, the specimens in Duraphat, Nanoseal, and Teethmate Desensitizer groups were pre-immersed in artificial saliva (pH 6.5) for either 1 d or 1 wk. The mineral loss of the specimens after demineralization (pH 5.0, 3 h) was evaluated by μCT. The treated surface was investigated with scanning electron microscopy. Mineral loss in all treatment groups was significantly lower than that in DW. Duraphat was the most effective treatment against demineralization, followed by Nanoseal. Nanoseal showed significantly better reduction in mineral loss following immersion for 1 wk in artificial saliva than for 1 d. However, Teethmate Desensitizer and Duraphat did not exhibit enhanced inhibition of demineralization over a longer period of immersion in artificial saliva. Scanning electron microscopy images showed deposition of particles on the dentin in both Teethmate Desensitizer. The application of Teethmate Desensitizer and Nanoseal to the exposed dentin surface resulted in inhibition of demineralization, with Nanoseal resulting in improved inhibition after prolonged immersion in artificial saliva. PMID:25363830

  8. Mechanisms of alpha 1-adrenergic vascular desensitization in conscious dogs

    NASA Technical Reports Server (NTRS)

    Kiuchi, K.; Vatner, D. E.; Uemura, N.; Bigaud, M.; Hasebe, N.; Hempel, D. M.; Graham, R. M.; Vatner, S. F.

    1992-01-01

    To investigate the mechanisms of alpha 1-adrenergic vascular desensitization, osmotic minipumps containing either saline (n = 9) or amidephrine mesylate (AMD) (n = 9), a selective alpha 1-adrenergic receptor agonist, were implanted subcutaneously in dogs with chronically implanted arterial and right atrial pressure catheters and aortic flow probes. After chronic alpha 1-adrenergic receptor stimulation, significant physiological desensitization to acute AMD challenges was observed, i.e., pressor and vasoconstrictor responses to the alpha 1-adrenergic agonist were significantly depressed (p < 0.01) compared with responses in the same dogs studied in the conscious state before pump implantation. However, physiological desensitization to acute challenges of the neurotransmitter norepinephrine (NE) (0.1 micrograms/kg per minute) in the presence of beta-adrenergic receptor blockade was not observed for either mean arterial pressure (MAP) (30 +/- 7 versus 28 +/- 5 mm Hg) or total peripheral resistance (TPR) (29.8 +/- 4.9 versus 28.9 +/- 7.3 mm Hg/l per minute). In the presence of beta-adrenergic receptor plus ganglionic blockade after AMD pump implantation, physiological desensitization to NE was unmasked since the control responses to NE (0.1 micrograms/kg per minute) before the AMD pumps were now greater (p < 0.01) than after chronic AMD administration for both MAP (66 +/- 5 versus 32 +/- 2 mm Hg) and TPR (42.6 +/- 10.3 versus 23.9 +/- 4.4 mm Hg/l per minute). In the presence of beta-adrenergic receptor, ganglionic, plus NE-uptake blockade after AMD pump implantation, desensitization was even more apparent, since NE (0.1 micrograms/kg per minute) induced even greater differences in MAP (33 +/- 5 versus 109 +/- 6 mm Hg) and TPR (28.1 +/- 1.8 versus 111.8 +/- 14.7 mm Hg/l per minute). The maximal force of contraction induced by NE in the presence or absence of endothelium was significantly decreased (p < 0.05) in vitro in mesenteric artery rings from AMD pump dogs

  9. Ulnar nerve entrapment at the wrist.

    PubMed

    Earp, Brandon E; Floyd, W Emerson; Louie, Dexter; Koris, Mark; Protomastro, Paul

    2014-11-01

    Presentation of ulnar nerve entrapment at the wrist varies based on differential anatomy and the site or sites of compression. Therefore, an understanding of the anatomy of the Guyon canal is essential for diagnosis in patients presenting with motor and/or sensory deficits in the hand. The etiologies of ulnar nerve compression include soft-tissue tumors; repetitive or acute trauma; the presence of anomalous muscles and fibrous bands; arthritic, synovial, endocrine, and metabolic conditions; and iatrogenic injury. In addition to a thorough history and physical examination, which includes motor, sensory, and vascular assessments, imaging and electrodiagnostic studies facilitate the diagnosis of ulnar nerve lesions at the wrist. Nonsurgical management is appropriate for a distal compression lesion caused by repetitive activity, but surgical decompression is indicated if symptoms persist or worsen over 2 to 4 months. PMID:25344595

  10. Effect of concurrent mental nerve reconstruction at the same time as mandibular reconstruction using a fibula osteoseptocutaneous flap.

    PubMed

    Shimizu, Fumiaki; Ooatari, Miwako; Uehara, Miyuki; Takahashi, Yoshihiro; Kawano, Kenji

    2015-09-01

    The damage of inferior alveolar nerve causes some functional problem including numbness of lower lip and drooling. During segmental mandibulectomy, inferior alveolar nerve commonly resected, therefore, it is ideal to reconstruct the nerve to get better functional result. Sensory recovery was assessed after mandibular reconstruction using free fibula osteoseptocutaneous flap in thirteen cases. In six cases, the mental nerve reconstruction was performed simultaneously, and in seven cases, the mental nerve reconstruction was not performed. In the case that the mental nerve was reconstructed simultaneously, unilateral mental nerve reconstruction was performed in five cases, and bilateral mental nerve reconstruction was performed in one cases. More than one year after the reconstruction, sensory recovery was assessed and compared between the group that the mental nerve was reconstructed and the group that was not reconstructed. Our results showed almost a normal sensory recovery of the lips on the reconstructed side more than one year after the reconstruction in reconstructed group. In contrast, sensory recovery was poor in non-reconstructed group and non-reconstructed side. These results showed that mental nerve reconstruction at the same time as mandibular reconstruction affects the postoperative mandibular function. The sural nerve can be harvested from the same donor site of the free fibula osteoseptocutaneous flap and such mental nerve reconstruction with nerve grafting can be completed within an hour. Most cases of mandibular reconstruction using a free fibula osteoseptocutaneous flap transfer can therefore be candidates for mental nerve reconstruction at the time of mandibular reconstruction. PMID:26051850

  11. Visualization of nerve fibers and their relationship to peripheral nerve tumors by diffusion tensor imaging.

    PubMed

    Cage, Tene A; Yuh, Esther L; Hou, Stephanie W; Birk, Harjus; Simon, Neil G; Noss, Roger; Rao, Anuradha; Chin, Cynthia T; Kliot, Michel

    2015-09-01

    OBJECT The majority of growing and/or symptomatic peripheral nerve tumors are schwannomas and neurofibromas. They are almost always benign and can usually be resected while minimizing motor and sensory deficits if approached with the proper expertise and techniques. Intraoperative electrophysiological stimulation and recording techniques allow the surgeon to map the surface of the tumor in an effort to identify and thus avoid damaging functioning nerve fibers. Recently, MR diffusion tensor imaging (DTI) techniques have permitted the visualization of axons, because of their anisotropic properties, in peripheral nerves. The object of this study was to compare the distribution of nerve fibers as revealed by direct electrical stimulation with that seen on preoperative MR DTI. METHODS The authors conducted a retrospective chart review of patients with a peripheral nerve or nerve root tumor between March 2012 and January 2014. Diffusion tensor imaging and intraoperative data had been prospectively collected for patients with peripheral nerve tumors that were resected. Preoperative identification of the nerve fiber location in relation to the nerve tumor surface as seen on DTI studies was compared with the nerve fiber's intraoperative localization using electrophysiological stimulation and recordings. RESULTS In 23 patients eligible for study there was good correlation between nerve fiber location on DTI and its anatomical location seen intraoperatively. Diffusion tensor imaging demonstrated the relationship of nerve fibers relative to the tumor with 95.7% sensitivity, 66.7% specificity, 75% positive predictive value, and 93.8% negative predictive value. CONCLUSIONS Preoperative DTI techniques are useful in helping the peripheral nerve surgeon to both determine the risks involved in resecting a nerve tumor and plan the safest surgical approach. PMID:26323818

  12. Peripheral Nerve Repair in Rats Using Composite Hydrogel-Filled Aligned Nanofiber Conduits with Incorporated Nerve Growth Factor

    PubMed Central

    Jin, Jenny; Limburg, Sonja; Joshi, Sunil K.; Landman, Rebeccah; Park, Michelle; Zhang, Qia; Kim, Hubert T.

    2013-01-01

    Repair of peripheral nerve defects with current synthetic, tubular nerve conduits generally shows inferior recovery when compared with using nerve autografts, the current gold standard. We tested the ability of composite collagen and hyaluronan hydrogels, with and without the nerve growth factor (NGF), to stimulate neurite extension on a promising aligned, nanofiber poly-L-lactide-co-caprolactone (PLCL) scaffold. In vitro, the hydrogels significantly increased neurite extension from dorsal root ganglia explants. Consistent with these results, the addition of hydrogels as luminal fillers within aligned, nanofiber tubular PLCL conduits led to improved sensory function compared to autograft repair in a critical-size defect in the sciatic nerve in a rat model. Sensory recovery was assessed 3 and 12 weeks after repair using a withdrawal assay from thermal stimulation. The addition of hydrogel did not enhance recovery of motor function in the rat model. The NGF led to dose-dependent improvements in neurite out-growth in vitro, but did not have a significant effect in vivo. In summary, composite collagen/hyaluronan hydrogels enhanced sensory neurite outgrowth in vitro and sensory recovery in vivo. The use of such hydrogels as luminal fillers for tubular nerve conduits may therefore be useful in assisting restoration of protective sensation following peripheral nerve injury. PMID:23659607

  13. Agonist-selective mechanisms of mu-opioid receptor desensitization in human embryonic kidney 293 cells.

    PubMed

    Johnson, Elizabeth A; Oldfield, Sue; Braksator, Ellen; Gonzalez-Cuello, Ana; Couch, Daniel; Hall, Kellie J; Mundell, Stuart J; Bailey, Chris P; Kelly, Eamonn; Henderson, Graeme

    2006-08-01

    The ability of two opioid agonists, [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO) and morphine, to induce mu-opioid receptor (MOR) phosphorylation, desensitization, and internalization was examined in human embryonic kidney (HEK) 293 cells expressing rat MOR1 as well G protein-coupled inwardly rectifying potassium channel (GIRK) channel subunits. Both DAMGO and morphine activated GIRK currents, but the maximum response to DAMGO was greater than that of morphine, indicating that morphine is a partial agonist. The responses to DAMGO and morphine desensitized rapidly in the presence of either drug. Expression of a dominant negative mutant G protein-coupled receptor kinase 2 (GRK2), GRK2-K220R, markedly attenuated the DAMGO-induced desensitization of MOR1, but it had no effect on morphine-induced MOR1 desensitization. In contrast, inhibition of protein kinase C (PKC) either by the PKC inhibitory peptide PKC (19-31) or staurosporine reduced MOR1 desensitization by morphine but not that induced by DAMGO. Morphine and DAMGO enhanced MOR1 phosphorylation over basal. The PKC inhibitor bisindolylmaleimide 1 (GF109203X) inhibited MOR1 phosphorylation under basal conditions and in the presence of morphine, but it did not inhibit DAMGO-induced phosphorylation. DAMGO induced arrestin-2 translocation to the plasma membrane and considerable MOR1 internalization, whereas morphine did not induce arrestin-2 translocation and induced very little MOR1 internalization. Thus, DAMGO and morphine each induce desensitization of MOR1 signaling in HEK293 cells but by different molecular mechanisms; DAMGO-induced desensitization is GRK2-dependent, whereas morphine-induced desensitization is in part PKC-dependent. MORs desensitized by DAMGO activation are then readily internalized by an arrestin-dependent mechanism, whereas those desensitized by morphine are not. These data suggest that opioid agonists induce different conformations of the MOR that are susceptible to different

  14. Nerve Regeneration: Understanding Biology and Its Influence on Return of Function After Nerve Transfers.

    PubMed

    Gordon, Tessa

    2016-05-01

    Poor functional outcomes are frequent after peripheral nerve injuries despite the regenerative support of Schwann cells. Motoneurons and, to a lesser extent, sensory neurons survive the injuries but outgrowth of axons across the injury site is slow. The neuronal regenerative capacity and the support of regenerating axons by the chronically denervated Schwann cells progressively declines with time and distance of the injury from the denervated targets. Strategies, including brief low-frequency electrical stimulation that accelerates target reinnervation and functional recovery, and the insertion of cross-bridges between a donor nerve and a recipient denervated nerve stump, are effective in promoting functional outcomes after complete and incomplete injuries. PMID:27094884

  15. Bilateral oculomotor nerve palsy in Guillain-Barre syndrome.

    PubMed

    Burina, Adnan; Sinanović, Osman; Smajlović, Dzevdet; Vidović, Mirjana

    2008-01-01

    Guillain-Barre syndrome (GBS) is an acquired immune-mediated inflammatory disorder of the peripheral nervous system. GBS is also called acute idiopathic polyradiculoneuritis. Cranial nerves are affected in over 50% of all cases, with the facial nerves being affected the most. Otherwise, oculomotor nerves affection is rare and might occur in about 10% of cases. In this case report we present 61 years old female with GBS (acute motor and sensory axonal neuropathy subtype) associated with bilateral oculomotor nerve palsy. At the admittance in the neurological status were flaccid paraplegia, tendon reflexes absent at legs and reduced at arms, sensory disturbances in a distal (stocking-glove) distribution and bilateral ptosis. The disease was diagnosed on clinical features, nerve conduction velocity test (NCV), electromyogram (EMG) and cerebrospinal fluid (CSF) tests. After treatment with intravenous immunoglobulins and physical treatment the patient improved. She was able to walk by her own, mild semiptosis remained and she had no paresthesia. PMID:18669237

  16. Functional and topographic segregation of glomeruli revealed by local staining of antennal sensory neurons in the honeybee Apis mellifera.

    PubMed

    Nishino, Hiroshi; Nishikawa, Michiko; Mizunami, Makoto; Yokohari, Fumio

    2009-07-10

    In the primary olfactory center of animals, glomeruli are the relay stations where sensory neurons expressing cognate odorant receptors converge onto interneurons. In cockroaches, moths, and honeybees, sensory afferents from sensilla on the anterodorsal surface and the posteroventral surface of the flagellum form two nerves of almost equal thicknesses. In this study, double labeling of the two nerves, or proximal/distal regions of the nerves, with fluorescent dyes was used to investigate topographic organization of sensory afferents in the honeybee. The sensory neurons of ampullaceal sensilla responsive to CO2, coelocapitular sensilla responsive to hygrosensory, and thermosensory stimuli and coeloconic sensilla of unknown function were characterized with large somata and supplied thick axons exclusively to the ventral nerve. Correspondingly, all glomeruli innervated by sensory tract (T) 4 received thick axonal processes exclusively from the ventral nerve. Almost all T1-3 glomeruli received a similar number of sensory afferents from the two nerves. In the macroglomerular complexes of the drone, termination fields of afferents from the two nerves almost completely overlapped; this differs from moths and cockroaches, which show heterogeneous terminations in the glomerular complex. In T1-3 glomeruli, sensory neurons originating from more distal flagellar segments tended to terminate within the inner regions of the cortical layer. These results suggest that some degree of somatotopic organization of sensory afferents exist in T1-3 glomeruli, and part of T4 glomeruli serve for processing of hygro- and thermosensory signals. PMID:19412930

  17. Altered expression of the voltage-gated calcium channel subunit α2δ-1: A comparison between two experimental models of epilepsy and a sensory nerve ligation model of neuropathic pain

    PubMed Central

    Nieto-Rostro, M.; Sandhu, G.; Bauer, C.S.; Jiruska, P.; Jefferys, J.G.R.; Dolphin, A.C.

    2014-01-01

    The auxiliary α2δ-1 subunit of voltage-gated calcium channels is up-regulated in dorsal root ganglion neurons following peripheral somatosensory nerve damage, in several animal models of neuropathic pain. The α2δ-1 protein has a mainly presynaptic localization, where it is associated with the calcium channels involved in neurotransmitter release. Relevant to the present study, α2δ-1 has been shown to be the therapeutic target of the gabapentinoid drugs in their alleviation of neuropathic pain. These drugs are also used in the treatment of certain epilepsies. In this study we therefore examined whether the level or distribution of α2δ-1 was altered in the hippocampus following experimental induction of epileptic seizures in rats, using both the kainic acid model of human temporal lobe epilepsy, in which status epilepticus is induced, and the tetanus toxin model in which status epilepticus is not involved. The main finding of this study is that we did not identify somatic overexpression of α2δ-1 in hippocampal neurons in either of the epilepsy models, unlike the upregulation of α2δ-1 that occurs following peripheral nerve damage to both somatosensory and motor neurons. However, we did observe local reorganization of α2δ-1 immunostaining in the hippocampus only in the kainic acid model, where it was associated with areas of neuronal cell loss, as indicated by absence of NeuN immunostaining, dendritic loss, as identified by areas where microtubule-associated protein-2 immunostaining was missing, and reactive gliosis, determined by regions of strong OX42 staining. PMID:24641886

  18. Functional selectivity of kappa opioid receptor agonists in peripheral sensory neurons.

    PubMed

    Jamshidi, Raehannah J; Jacobs, Blaine A; Sullivan, Laura C; Chavera, Teresa A; Saylor, Rachel M; Prisinzano, Thomas E; Clarke, William P; Berg, Kelly A

    2015-11-01

    Activation of kappa opioid receptors (KORs) expressed by peripheral sensory neurons that respond to noxious stimuli (nociceptors) can reduce neurotransmission of pain stimuli from the periphery to the central nervous system. We have previously shown that the antinociception dose-response curve for peripherally restricted doses of the KOR agonist (-)-(trans)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]benzeneacetamide (U50488) has an inverted U shape. Here, we found that the downward phase of the U50488 dose-response curve was blocked by an inhibitor of extracellular signal-regulated kinase (ERK) activation U0126. Local administration of the selective KOR agonist salvinorin A (Sal-A), also resulted in an inverted U-shaped curve; however, the downward phase was insensitive to U0126. By contrast, inhibition of c-Jun N-terminal kinase (JNK) partially blocked the downward phase of the dose-response curve to Sal-A, suggesting a role for JNK. In cultures of peripheral sensory neurons, U50488 and Sal-A inhibited adenylyl cyclase activity with similar efficacies; however, their ability to activate ERK and JNK differed. Whereas U50488 activated ERK but not JNK, Sal-A activated JNK but not ERK. Moreover, although both U50488 and Sal-A produced homologous desensitization, desensitization to U50488 was blocked by inhibition of ERK activation, whereas desensitization to Sal-A was blocked by inhibition of JNK. Substitution of an ethoxymethyl ether for the C2 position acetyl group of Sal-A reduced stimulation of JNK, prevented desensitization by ethoxymethyl ether for the C2 position acetyl group of Sal-A, and resulted in a monotonic antinociception dose-response curve. Collectively, these data demonstrate the functional selectivity of KOR ligands for signaling in peripheral sensory neurons, which results in differential effects on behavioral responses in vivo. PMID:26297384

  19. Sensory testing of the human gastrointestinal tract

    PubMed Central

    Brock, Christina; Arendt-Nielsen, Lars; Wilder-Smith, Oliver; Drewes, Asbjørn Mohr

    2009-01-01

    The objective of this appraisal is to shed light on the various approaches to screen sensory information in the human gut. Understanding and characterization of sensory symptoms in gastrointestinal disorders is poor. Experimental methods allowing the investigator to control stimulus intensity and modality, as well as using validated methods for assessing sensory response have contributed to the understanding of pain mechanisms. Mechanical stimulation based on impedance planimetry allows direct recordings of luminal cross-sectional areas, and combined with ultrasound and magnetic resonance imaging, the contribution of different gut layers can be estimated. Electrical stimulation depolarizes free nerve endings non-selectively. Consequently, the stimulation paradigm (single, train, tetanic) influences the involved sensory nerves. Visual controlled electrical stimulation combines the probes with an endoscopic approach, which allows the investigator to inspect and obtain small biopsies from the stimulation site. Thermal stimulation (cold or warm) activates selectively mucosal receptors, and chemical substances such as acid and capsaicin (either alone or in combination) are used to evoke pain and sensitization. The possibility of multimodal (e.g. mechanical, electrical, thermal and chemical) stimulation in different gut segments has developed visceral pain research. The major advantage is involvement of distinctive receptors, various sensory nerves and different pain pathways mimicking clinical pain that favors investigation of central pain mechanisms involved in allodynia, hyperalgesia and referred pain. As impairment of descending control mechanisms partly underlies the pathogenesis in chronic pain, a cold pressor test that indirectly stimulates such control mechanisms can be added. Hence, the methods undoubtedly represent a major step forward in the future characterization and treatment of patients with various diseases of the gut, which provides knowledge to

  20. The Effect of Counselor Anxiety on the Systematic Desensitization of Test-Anxious College Students.

    ERIC Educational Resources Information Center

    Hudesman, John; Wiesner, Ezra

    1979-01-01

    Evaluates effect of the counselor's level of anxiety on students taking part in test anxiety desensitization workshops. Results indicate the number of sessions attended by students is inversely related to the counselor's level of anxiety. Implications for counselor screening in desensitization work are mentioned. (Author)

  1. Effectiveness of Structured Psychodrama and Systematic Desensitization in Reducing Test Anxiety.

    ERIC Educational Resources Information Center

    Kipper, David A.; Giladi, Daniel

    1978-01-01

    Students with examination anxiety took part in study of effectiveness of two kinds of treatment, structured psychodrama and systematic desensitization, in reducing test anxiety. Results showed that subjects in both treatment groups significantly reduced test-anxiety scores. Structured psychodrama is as effective as systematic desensitization in…

  2. Violence Exposure in Real-Life, Video Games, Television, Movies, and the Internet: Is There Desensitization?

    ERIC Educational Resources Information Center

    Funk, Jeanne B.; Baldacci, Heidi Bechtoldt; Pasold; Tracie; Baumgardner, Jennifer

    2004-01-01

    It is believed that repeated exposure to real-life and to entertainment violence may alter cognitive, affective, and behavioral processes, possibly leading to desensitization. The goal of the present study was to determine if there are relationships between real-life and media violence exposure and desensitization as reflected in related…

  3. Systematic Desensitization as a Method of Teaching a General Anxiety-Reducing Skill

    ERIC Educational Resources Information Center

    Zemore, Robert

    1975-01-01

    College students were treated with either a standard or modified version of systematic desensitization. Relative to a no-treatment control group, both treatment methods produced significant reductions in both the treated and untreated fears. The implications these findings have for two alternative conceptions of systematic desensitization are…

  4. Flooding and Systematic Desensitization: Efficacy in Subclinical Phobics as a Function of Arousal

    ERIC Educational Resources Information Center

    Suarez, Yolanda; And Others

    1976-01-01

    Flooding and systematic desensitization procedures were investigated for possible interactions with subject arousal level on reduction in phobic reactions. No such interaction was found. Behaviorally and on GSR response, both flooding and systematic desensitization were effective, but only the latter was effective on subjective reports. (NG)

  5. Clinical and electrophysiological assessment of inferior alveolar nerve function after lateral nerve transposition.

    PubMed

    Nocini, P F; De Santis, D; Fracasso, E; Zanette, G

    1999-04-01

    Inferior alveolar nerve (IAN) transposition surgery may cause some degree of sensory impairment. Accurate and reproducible tests are mandatory to assess IAN conduction capacity following nerve transposition. In this study subjective (heat, pain and tactile-discriminative tests) and objective (electrophysiological) assessments were performed in 10 patients receiving IAN transposition (bilaterally in 8 cases) in order to evaluate any impairment of the involved nerves one year post-operatively. All patients reported a tingling, well-tolerated sensation in the areas supplied by the mental nerve with no anaesthesia or burning paresthesia. Tactile discrimination was affected the most (all but 1 patient). No action potential was recorded in 4 patients' sides (23.5%); 12 sides showed a decreased nerve conduction velocity (NCV) (70.5%) and 1 side normal NCV values (6%). There was no significant difference in NCV decrease between partial and total transposition sides, if examined separately. Nerve conduction findings were related 2-point discrimination scores, but not to changes in pain and heat sensitivity. These findings show that lateral nerve transposition, though resulting in a high percentage of minor IAN injuries, as determined by electrophysiological testing, provides a viable surgical procedure to allow implant placement in the posterior mandible without causing severe sensory complaints. Considering ethical and forensic implications, patients should be fully informed that a certain degree of nerve injury might be expected to occur from the procedure. Electrophysiological evaluation is a reliable way to assess the degree of IAN dysfunction, especially if combined with a clinical examination. Intraoperative monitoring of IAN conduction might help identify the pathogenetic mechanisms of nerve injury and the surgical steps that are most likely to harm nerve integrity. PMID:10219131

  6. Desensitization by noradrenaline of responses to stimulation of pre- and postsynaptic adrenoceptors

    PubMed Central

    Ball, N.; Danks, J.L.; Dorudi, S.; Nasmyth, P.A.

    1982-01-01

    1 The effect of exposing isolated preparations of rat aortic strip, rat atria and mouse vas deferens to perfusions of Krebs solution containing various concentrations of noradrenaline on their sensitivity to the drug has been determined. 2 The responses evoked by stimulation of postsynaptic adrenoceptors in all the tissues and presynaptic α-adrenoceptors in the mouse vas deferens were diminished by the perfusion of noradrenaline through the organ bath for 30 min. 3 The concentration of noradrenaline required to produce desensitization was higher in the mouse vas deferens than in the other tissues and more was required to desensitize the chronotropic responses than the inotropic responses in rat isolated atria. 4 The inclusion of cocaine (10-5 M) in the bathing solution to block uptake1 increased the sensitivity of most tissues to noradrenaline. With the possible exception of the response to stimulation of presynaptic receptors in the mouse vas deferens, desensitization was somewhat increased in its presence. 5 When uptake2 was blocked by oestradiol (10-5 M), it was not possible to desensitize the contractor responses of the aortic strip and vas deferens to exogenous noradrenaline, nor the inotropic response of the atria to the drug. However, oestradiol failed to block the desensitization of chronotropic responses and responses to stimulation of presynaptic receptors in the vas deferens. 6 Blockade of monoamine oxidase (MAO) with iproniazid (7.2 × 10-4 M) or with pargyline (5 × 10-4 M) did not affect the desensitization process in the aortic strip. 7 Blockade of catechol-O-methyltransferase (COMT) with U-0521 (5.3 × 10-5 M) greatly increased desensitization in the aortic strip and desensitization of inotropic responses in the atria. It had no effect on desensitization of chronotropic responses. Its effect on responses in the mouse vas deferens was not determined. 8 The perfusion of methoxamine at concentrations about 1000 times higher than those of noradrenaline

  7. Pre-differentiation of mesenchymal stromal cells in combination with a microstructured nerve guide supports peripheral nerve regeneration in the rat sciatic nerve model.

    PubMed

    Boecker, Arne Hendrik; van Neerven, Sabien Geraldine Antonia; Scheffel, Juliane; Tank, Julian; Altinova, Haktan; Seidensticker, Katrin; Deumens, Ronald; Tolba, Rene; Weis, Joachim; Brook, Gary Anthony; Pallua, Norbert; Bozkurt, Ahmet

    2016-02-01

    Many bioartificial nerve guides have been investigated pre-clinically for their nerve regeneration-supporting function, often in comparison to autologous nerve transplantation, which is still regarded as the current clinical gold standard. Enrichment of these scaffolds with cells intended to support axonal regeneration has been explored as a strategy to boost axonal regeneration across these nerve guides Ansselin et al. (1998). In the present study, 20 mm rat sciatic nerve defects were implanted with a cell-seeded microstructured collagen nerve guide (Perimaix) or an autologous nerve graft. Under the influence of seeded, pre-differentiated mesenchymal stromal cells, axons regenerated well into the Perimaix nerve guide. Myelination-related parameters, like myelin sheath thickness, benefitted from an additional seeding with pre-differentiated mesenchymal stromal cells. Furthermore, both the number of retrogradely labelled sensory neurons and the axon density within the implant were elevated in the cell-seeded scaffold group with pre-differentiated mesenchymal stromal cells. However, a pre-differentiation had no influence on functional recovery. An additional cell seeding of the Perimaix nerve guide with mesenchymal stromal cells led to an extent of functional recovery, independent of the differentiation status, similar to autologous nerve transplantation. These findings encourage further investigations on pre-differentiated mesenchymal stromal cells as a cellular support for peripheral nerve regeneration. PMID:26296589

  8. Morphology of nerve endings in vocal fold of human newborn.

    PubMed

    Gonçalves da Silva Leite, Janaina; Costa Cavalcante, Maria Luzete; Fechine-Jamacaru, Francisco Vagnaldo; de Lima Pompeu, Margarida Maria; Leite, José Alberto Dias; Nascimento Coelho, Dulce Maria; Rabelo de Freitas, Marcos

    2016-10-01

    Sensory receptors are distributed throughout the oral cavity, pharynx, and larynx. Laryngeal sensitivity is crucial for maintaining safe swallowing, thus avoiding silent aspiration. Morphologic description of different receptor types present in larynx vary because of the study of many different species, from mouse to humans. The most commonly sensory structures described in laryngeal mucosa are free nerve endings, taste buds, muscle spindles, glomerular and corpuscular receptors. This study aimed at describing the morphology and the distribution of nerve endings in premature newborn glottic region. Transversal serial frozen sections of the whole vocal folds of three newborns were analyzed using an immuno-histochemical process with a pan-neuronal marker anti-protein gene product 9.5 (PGP 9.5). Imaging was done using a confocal laser microscope. Nerve fiber density in vocal cord was calculated using panoramic images in software Morphometric Analysis System v1.0. Some sensory structures, i.e. glomerular endings and intraepithelial free nerve endings were found in the vocal cord mucosa. Muscle spindles, complex nerve endings (Meissner-like, spherical, rectangular and growing) spiral-wharves nerve structures were identified in larynx intrinsic muscles. Nervous total mean density in vocal cord was similar in the three newborns, although they had different gestational age. The mean nerve fiber density was higher in the posterior region than anterior region of vocal cord. The present results demonstrate the occurrence of different morphotypes of sensory corpuscles and nerve endings premature newborn glottic region and provide information on their sensory systems. PMID:27619029

  9. Interaction of myenteric neurons and extrinsic nerves in the intestinal inhibitory response induced by mesenteric nerve stimulation.

    PubMed

    Yamasato, T; Nakayama, S

    1991-04-01

    Effects of the mesenteric nerve stimulation (MNS) on the twitch contraction induced by field stimulation were investigated regarding the relationship between myenteric neurons and extrinsic cholinergic nerves in the guinea-pig mesenteric nerve-ileal preparation. The twitch contraction was inhibited after MNS. The inhibition of the twitch contraction after MNS was induced twice, just after MNS (1st inhibition) and 2-3 min later (2nd inhibition) (type I), or once, just after MNS (1st inhibition) (type II), in recovery course of twitch contraction for 6-8 min. The 1st inhibition was slightly decreased by guanethidine and hexamethonium. The inhibitory response (1st inhibition) in both types I and II was recovered to the control level by pretreatment with naloxone (recovered twitch contraction), but the late inhibitory response (2nd inhibition) was markedly observed after 2-3 min in types I and II. Either the 1st or the 2nd inhibition was not altered by capsaicin, desensitization to calcitonin gene-related polypeptide (CGRP), vasoactive intestinal polypeptide (VIP), somatostatin, or galanin. The recovered twitch contraction in types I and II was decreased by CGRP-desensitization, or capsaicin. These results suggest that the first inhibitory response was induced by enteric opioid neurons connected with extrinsic cholinergic nerves, but the 2nd inhibition was induced by unknown substances other than CGRP, VIP, somatostatin, and galanin. The twitch contraction may partly be induced by endogenous neurokinin-like substances. And, some CGRP containing neurons, which connect with extrinsic cholinergic nerves, probably activate the intrinsic excitatory neurons. PMID:1678243

  10. Median and ulnar nerve injuries; what causes different repair outcomes?

    PubMed Central

    Nouraei, Mohammad Hadi; Hosseini, Alireza; Salek, Shadi; Nouraei, Farhad; Bina, Roya

    2015-01-01

    Background: Peripheral nerve injuries have significant effects on patients’ life quality. To make patients’ therapeutic expectations more realistic, prediction of repair outcome has significant importance. Materials and Methods: Totally, 74 patients with 94 nerve injuries (44 median and 50 ulnar nerves) were evaluated and followed up for 5 years between 2008 and 2013 in two main university hospitals of Isfahan. Patients’ age was 6–64 years. 24 nerves were excluded from the study and among the remaining; 53 nerves were repaired primarily and 17 nerves secondarily. 42 nerves were injured at a low-level, 17 nerves at intermediate and 11 at a high one. Medical Research Council Scale used for sensory and motor assessment. S3+ and S4 scores for sensory recovery and M4 and M5 scores for motor recovery were considered as favorable results. The follow-up time was between 8 and 24 months. Results: There was no significant difference between favorable sensory outcomes of median and ulnar nerves. The difference between favorable motor outcomes of the median nerve was higher than ulnar nerve (P = 0.03, odds ratio = 2.9). More favorable results were seen in high-level injuries repair than low ones (P = 0.035), and also cases followed more than 18 months compared to less than 12 months (P = 0.041), respectively. The favorable outcomes for patients younger than 16 were more than 40 and older, however, their difference was not significant (P = 0.059). The difference between primary and secondary repair favorable outcomes was not significant (P = 0.37). Conclusion: In patients older than 40 or injured at a high-level, there is a high possibility of repetitive operations and reconstructive measures. The necessity for long-term follow-up and careful attentions during a postoperative period should be pointed to all patients. PMID:26605244

  11. Case report: Double nerve transfer of the anterior and posterior interosseous nerves to treat a high ulnar nerve defect at the elbow.

    PubMed

    Delclaux, S; Aprédoaei, C; Mansat, P; Rongières, M; Bonnevialle, P

    2014-10-01

    Double neurotization of the deep branch of ulnar nerve (DBUN) and superficial branch of ulnar nerve using the anterior interosseous nerve (AIN) and the recurrent (thenar) branch of the median nerve was first described by Battiston and Lanzetta. This article details the postoperative results after 18 months of a patient who underwent this technique using the posterior interosseous nerve (PIN) instead of the recurrent branch of the median nerve for sensory reconstruction. A 35-year-old, right-handed man suffered major trauma to his right upper limb following a serious motor vehicle accident. One year later, a pseudocystic neuroma of the ulnar nerve was evident on ultrasound examination and MRI. After the neuroma had been resected, the nerve defect was estimated at 8 cm. One and a half years after the initial trauma, with the patient still at M0/S0, we transferred the AIN and PIN onto the deep and superficial branches of the ulnar nerve respectively. Nerve recovery was monitored clinically every month and by electromyography (EMG) every three months initially and then every six months. At 18 months postoperative, 5th digit abduction/adduction was 28 mm. Sensation was present at the base of the 5th digit. The patient was graded M3/S2. Clear re-innervation of the abductor digiti minimi was demonstrated by EMG (motor conduction velocity 50 m/s). Given that the ulnar nerve could not be excited at the elbow, this re-innervation had to be the result of the double nerve transfer. Neurotization of the DBUN using the AIN produces functional results as early as 1 year after surgery. Using PIN for sensory neurotization is easy to perform, has no negative consequences for the donor site, and leads to good recovery of sensation (graded as S2) after 18 months. PMID:25260763

  12. Electrophysiology and nerve biopsy in men exposed to lead

    PubMed Central

    Buchthal, F.; Behse, F.

    1979-01-01

    ABSTRACT Twenty lead-exposed men were selected on the basis of a maximum level of lead in the blood of 70-140 μg/100 ml within the past year. There was no clinical evidence of neuropathy attributable to lead and haemoglobin levels were normal. In individuals, maximum motor and sensory conduction and the amplitude of the evoked potentials were normal or borderline in the median, peroneal and sural nerves, except in the distal portion of the deep peroneal nerve. In this nerve, motor conduction was slowed because of compression by metal-lined safety shoes; changes in this segment are not included in the findings. When the average conduction velocity in lead-exposed men was compared with the average in nerves of controls matched for age, distal motor latency was slightly prolonged in the median nerve. The average latency for proximal muscle supplied by the peroneal nerve was prolonged, and the maximum motor conduction velocity was slowed in the median nerve from elbow to wrist (0·01 > p <0·001). In addition, the average maximum sensory conduction was slightly slowed along the distal and intermediate portion of the superficial peroneal and sural nerves (p <0·001). The average minimum sensory conduction velocities were normal, as were the average amplitudes of the evoked muscle action potentials and the average ratio of amplitude of the muscle action potential evoked by stimuli at a proximal and a distal nerve site. The average amplitude of the sensory potentials recorded in the median and the superficial peroneal nerves tended to be increased. Electromyography of the abductor pollicis brevis and anterior tibial muscles showed that the only abnormality was an increased incidence of polyphasic potentials in the anterior tibial muscle of seven men. Neither the slowing in conduction nor the histological findings in the sural nerves of eight men were related to the level of lead in the blood. The slight slowing in conduction suggests a minor defect in the excitable

  13. Structural mechanism of glutamate receptor activation and desensitization.

    PubMed

    Meyerson, Joel R; Kumar, Janesh; Chittori, Sagar; Rao, Prashant; Pierson, Jason; Bartesaghi, Alberto; Mayer, Mark L; Subramaniam, Sriram

    2014-10-16

    Ionotropic glutamate receptors are ligand-gated ion channels that mediate excitatory synaptic transmission in the vertebrate brain. To gain a better understanding of how structural changes gate ion flux across the membrane, we trapped rat AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) and kainate receptor subtypes in their major functional states and analysed the resulting structures using cryo-electron microscopy. We show that transition to the active state involves a 'corkscrew' motion of the receptor assembly, driven by closure of the ligand-binding domain. Desensitization is accompanied by disruption of the amino-terminal domain tetramer in AMPA, but not kainate, receptors with a two-fold to four-fold symmetry transition in the ligand-binding domains in both subtypes. The 7.6 Å structure of a desensitized kainate receptor shows how these changes accommodate channel closing. These findings integrate previous physiological, biochemical and structural analyses of glutamate receptors and provide a molecular explanation for key steps in receptor gating. PMID:25119039

  14. The distribution of nerves in human deciduous and permanent teeth.

    PubMed

    Itoh, K

    1976-11-01

    Human permanent teeth without caries, obtained from 10-16 year old males and females and noncarious human deciduous teeth in which roots remained intact or were only poorly resorbed, were studied histologically. The distribution of sensory nerves in deciduous teeth were compared with that in permanent teeth by means of the silver-nitrate technique. 1. In radicular pulp, the sensory nerve fiber bundles accompany blood vessels in the axial area and several nerve single-fibers occur in the peripheral area of the pulp. 2. The subodontoblastic nerve plexus is formed in or beneath the cell-rich zone of the coronal pulp, and further, the marginal nerve plexus is built up near the pulpo-predentinal border. 3. The nerve fibers entering the predentin can be classified into 3 types by their courses. In the first type, nerve fibers pass directly toward the calcification front along the dentinal tubules in the predentin. In the second type, nerve fibers run obliquely or transversely in the predentin. The transversal fibers form a plexus-like structure by dividing and interlacing at various levels of predentin. The third type nerve fibers pass along the dentinal tubules in the predentin and, after reaching the predentino-dentinal border, reverse the odontoblast layer, thus forming a looped course. 4. There is no essential difference between the nerve supply in the deciduous and in the permanent teeth, but the nerves in the deciduous teeth are less dense in distribution and lower in amount than in the permanent teeth. Moreover, a typical marginal nerve plexus, which occurs constantly in the permanent teeth, is only occasionally found in the deciduous teeth; and no nerve fiber was observed to penetrate into the calcified dentin in the deciduous teeth. This finding seems to account for the fact that the deciduous teeth are less sensitive than their permanent successors. PMID:798562

  15. Infraorbital nerve transpositioning into orbital floor: a modified technique to minimize nerve injury following zygomaticomaxillary complex fractures

    PubMed Central

    Kotrashetti, Sharadindu Mahadevappa; Kale, Tejraj Pundalik; Bhandage, Supriya

    2015-01-01

    Objectives Transpositioning of the inferior alveolar nerve to prevent injury in lower jaw has been advocated for orthognathic, pre-prosthetic and for implant placement procedures. However, the concept of infra-orbital nerve repositioning in cases of mid-face fractures remains unexplored. The infraorbital nerve may be involved in trauma to the zygomatic complex which often results in sensory disturbance of the area innervated by it. Ten patients with infraorbital nerve entrapment were treated in similar way at our maxillofacial surgery centre. Materials and Methods In this article we are reporting three cases of zygomatico-maxillary complex fracture in which intra-operative repositioning of infra-orbital nerve into the orbital floor was done. This was done to release the nerve from fractured segments and to reduce the postoperative neural complications, to gain better access to fracture site and ease in plate fixation. This procedure also decompresses the nerve which releases it off the soft tissue entrapment caused due to trauma and the organized clot at the fractured site. Results There was no evidence of sensory disturbance during their three month follow-up in any of the patient. Conclusion Infraorbital nerve transposition is very effective in preventing paresthesia in patients which fracture line involving the infraorbital nerve. PMID:25922818

  16. Nerve conduction velocity

    MedlinePlus

    Nerve conduction velocity (NCV) is a test to see how fast electrical signals move through a nerve. ... normal body temperature. Being too cold slows nerve conduction. Tell your doctor if you have a cardiac ...

  17. Femoral nerve damage (image)

    MedlinePlus

    The femoral nerve is located in the leg and supplies the muscles that assist help straighten the leg. It supplies sensation ... leg. One risk of damage to the femoral nerve is pelvic fracture. Symptoms of femoral nerve damage ...

  18. Ulnar nerve damage (image)

    MedlinePlus

    The ulnar nerve originates from the brachial plexus and travels down arm. The nerve is commonly injured at the elbow because of elbow fracture or dislocation. The ulnar nerve is near the surface of the body where ...

  19. Diabetes and nerve damage

    MedlinePlus

    ... hot or cold When the nerves that control digestion are affected, you may have trouble digesting food. ... harder to control. Damage to nerves that control digestion almost always occurs in people with severe nerve ...

  20. Tendon Transfers for Combined Peripheral Nerve Injuries.

    PubMed

    Makarewich, Christopher A; Hutchinson, Douglas T

    2016-08-01

    Combined peripheral nerve injuries present a unique set of challenges to the hand surgeon when considering tendon transfers. They are often associated with severe soft tissue trauma, including lacerations to remaining innervated muscles and tendons, significant scar formation, and substantial sensory loss. In the case of combined nerve injuries, there are typically fewer options for tendon transfers due to fewer tendons of shared function that are expendable as well as associated injuries to tendon or muscle bellies. As such, careful preoperative planning must be performed to make the most of remaining muscle tendon units. PMID:27387081

  1. Peripheral Nerve Reconstruction after Injury: A Review of Clinical and Experimental Therapies

    PubMed Central

    Grinsell, D.; Keating, C. P.

    2014-01-01

    Unlike other tissues in the body, peripheral nerve regeneration is slow and usually incomplete. Less than half of patients who undergo nerve repair after injury regain good to excellent motor or sensory function and current surgical techniques are similar to those described by Sunderland more than 60 years ago. Our increasing knowledge about nerve physiology and regeneration far outweighs our surgical abilities to reconstruct damaged nerves and successfully regenerate motor and sensory function. It is technically possible to reconstruct nerves at the fascicular level but not at the level of individual axons. Recent surgical options including nerve transfers demonstrate promise in improving outcomes for proximal nerve injuries and experimental molecular and bioengineering strategies are being developed to overcome biological roadblocks limiting patient recovery. PMID:25276813

  2. Internal tobacco industry research on olfactory and trigeminal nerve response to nicotine and other smoke components.

    PubMed

    Megerdichian, Christine L; Rees, Vaughan W; Wayne, Geoffrey Ferris; Connolly, Gregory N

    2007-11-01

    Evidence has shown that factors other than the central pharmacological effects of nicotine are important in promoting smoking behavior. One such non-nicotine effect includes sensory stimulation, which may promote smoking by developing learned associations with nicotine's rewarding effects, or by constituting a rewarding experience independent of nicotine. The present study used internal tobacco industry documents to examine industry efforts to understand and manipulate stimulation of the sensory nerves by tobacco smoke, and the influence of sensory stimulation on smoker behavior. Research focused on sensory nerves of the head and neck, including the olfactory nerve, which carries flavor and odor, and the trigeminal nerve, which carries irritant information. The tobacco industry maintained a systematic research program designed to elucidate an understanding of responses of sensory nerves to nicotine and other components of tobacco smoke, and attempted to develop nicotine-like compounds that would enhance sensory responses in smokers. Industry research appeared intended to aid in the development of new products with greater consumer appeal. The potential influence of sensory response in enhancing nicotine dependence through an associative mechanism was acknowledged by the tobacco industry, but evidence for research in this area was limited. These findings add to evidence of industry manipulation of sensory factors to enhance smoking behavior and may have implications for development of more effective treatment strategies, including more "acceptable" nicotine replacement therapies. PMID:17978985

  3. Histochemical discrimination of fibers in regenerating rat infraorbital nerve

    NASA Technical Reports Server (NTRS)

    Wilke, R. A.; Riley, D. A.; Sanger, J. R.

    1992-01-01

    In rat dorsal root ganglia, histochemical staining of carbonic anhydrase (CA) and cholinesterase (CE) yields a reciprocal pattern of activity: Sensory processes are CA positive and CE negative, whereas motor processes are CA negative and CE positive. In rat infraorbital nerve (a sensory peripheral nerve), we saw extensive CA staining of nearly 100% of the myelinated axons. Although CE reactivity in myelinated axons was extremely rare, we did observe CE staining of unmyelinated autonomic fibers. Four weeks after transection of infraorbital nerves, CA-stained longitudinal sections of the proximal stump demonstrated 3 distinct morphological zones. A fraction of the viable axons retained CA activity to within 2 mm of the distal extent of the stump, and the stain is capable of resolving growth sprouts being regenerated from these fibers. Staining of unmyelinated autonomic fibers in serial sections shows that CE activity was not retained as far distally as is the CA sensory staining.

  4. Sensory functions in chronic neuralgia.

    PubMed Central

    Lindblom, U; Verrillo, R T

    1979-01-01

    Eleven patients with sustained neuralgia, in most cases after traumatic nerve lesion, were subjected to quantitative sensory testing with thermal and non-noxious mechanical stimuli. Measurements were made in the pain area and at a homologous site on the contralateral normal side. All patients were hypoaesthetic with raised thresholds for warm and cold or touch, or both. Thermal pain thresholds were also raised in some patients but lowered in others indicating hypersensitivity of the nociceptor system or dysaesthesia for thermal input. In six patients single mechanical stimuli produced a painful response above the touch detection threshold. Reaction time measurements indicated that this painful response to suprathreshold mechanical pulses was measured by magnitude estimation as a function of stimulus amplitude. The results were fitted by power functions, as in normal skin, but with steeper slopes on the abnormal side. Suprathreshold hyperaesthesia (recruitment) may exist in the presence of normal threshold functioning. PMID:448382

  5. Use of Vein Conduit and Isolated Nerve Graft in Peripheral Nerve Repair: A Comparative Study

    PubMed Central

    Ahmad, Imran; Akhtar, Md. Sohaib

    2014-01-01

    Aims and Objectives. The aim of this study was to evaluate the effectiveness of vein conduit in nerve repair compared with isolated nerve graft. Materials and Methods. This retrospective study was conducted at author's centre and included a total of 40 patients. All the patients had nerve defect of more than 3 cm and underwent nerve repair using nerve graft from sural nerve. In 20 cases, vein conduit (study group) was used whereas no conduit was used in other 20 cases. Patients were followed up for 2 years at the intervals of 3 months. Results. Patients had varying degree of recovery. Sensations reached to all the digits at 1 year in study groups compared to 18 months in control group. At the end of second year, 84% patients of the study group achieved 2-point discrimination of <10 mm compared to 60% only in control group. In terms of motor recovery, 82% patients achieved satisfactory hand function in study group compared to 56% in control group (P < .05). Conclusions. It was concluded that the use of vein conduit in peripheral nerve repair is more effective method than isolated nerve graft providing good sensory and motor recovery. PMID:25405029

  6. Quantitative evaluation of human delta opioid receptor desensitization using the operational model of drug action.

    PubMed

    Navratilova, Edita; Waite, Sue; Stropova, Dagmar; Eaton, Miriam C; Alves, Isabel D; Hruby, Victor J; Roeske, William R; Yamamura, Henry I; Varga, Eva V

    2007-05-01

    Agonist-mediated desensitization of the opioid receptors is thought to function as a protective mechanism against sustained opioid signaling and therefore may prevent the development of opioid tolerance. However, the exact molecular mechanism of opioid receptor desensitization remains unresolved because of difficulties in measuring and interpreting receptor desensitization. In the present study, we investigated deltorphin II-mediated rapid desensitization of the human delta opioid receptors (hDOR) by measuring guanosine 5'-O-(3-[(35)S]thio)-triphosphate binding and inhibition of cAMP accumulation. We developed a mathematical analysis based on the operational model of agonist action (Black et al., 1985) to calculate the proportion of desensitized receptors. This approach permits a correct analysis of the complex process of functional desensitization by taking into account receptor-effector coupling and the time dependence of agonist pretreatment. Finally, we compared hDOR desensitization with receptor phosphorylation at Ser363, the translocation of beta-arrestin2, and hDOR internalization. We found that in Chinese hamster ovary cells expressing the hDOR, deltorphin II treatment leads to phosphorylation of Ser363, translocation of beta-arrestin2 to the plasma membrane, receptor internalization, and uncoupling from G proteins. It is noteworthy that mutation of the primary phosphorylation site Ser363 to alanine had virtually no effect on agonist-induced beta-arrestin2 translocation and receptor internalization yet significantly attenuated receptor desensitization. These results strongly indicate that phosphorylation of Ser363 is the primary mechanism of hDOR desensitization. PMID:17322005

  7. Fast Synaptic Inhibition in Spinal Sensory Processing and Pain Control

    PubMed Central

    Zeilhofer, Hanns Ulrich; Wildner, Hendrik; Yevenes, Gonzalo E.

    2013-01-01

    The two amino acids γ-amino butyric acid (GABA) and glycine mediate fast inhibitory neurotransmission in different CNS areas and serve pivotal roles in the spinal sensory processing. Under healthy conditions, they limit the excitability of spinal terminals of primary sensory nerve fibers and of intrinsic dorsal horn neurons through pre- and postsynaptic mechanisms, and thereby facilitate the spatial and temporal discrimination of sensory stimuli. Removal of fast inhibition not only reduces the fidelity of normal sensory processing but also provokes symptoms very much reminiscent of pathological and chronic pain syndromes. This review summarizes our knowledge of the molecular bases of spinal inhibitory neurotransmission and its organization in dorsal horn sensory circuits. Particular emphasis is placed on the role and mechanisms of spinal inhibitory malfunction in inflammatory and neuropathic chronic pain syndromes. PMID:22298656

  8. Contingency contracting and systematic desensitization for heroin addicts in methadone maintenance programs.

    PubMed

    Piane, G

    2000-01-01

    The use and effectiveness of contingency contracting and systematic desensitization with heroin addicts being treated in methadone maintenance programs are discussed. Both behavior therapies can be practically implemented in methadone maintenance programs to supplement methadone pharmacotherapy. Contingency contracting has been effectively employed to reduce illicit drug use and to manage patients in the clinic. Systematic desensitization has less effect on actual heroin usage yet effectively reduces the fear of withdrawal and general anxiety, while improving self-image, assertiveness, and adjustment in the community. A clinic protocol that incorporates all three therapies-methadone maintenance, contingency contracting, and systematic desensitization-is proposed. PMID:11061683

  9. Monoclonal antibody desensitization in a patient with a generalized urticarial reaction following denosumab administration.

    PubMed

    Gutiérrez-Fernández, D; Cruz, María-Jesús; Foncubierta-Fernández, A; Moreno-Ancillo, A; Fernández-Anguita, M J; Medina-Varo, F; Andres-García, J A

    2015-01-01

    Denosumab is a human monoclonal antibody indicated for the treatment of osteoporosis in postmenopausal women with a high risk of fractures. To our knowledge, no cases of desensitization to this drug have been described in the literature. We report the first case of generalized urticarial reaction and facial angioedema after therapy with denosumab. A subcutaneous desensitization protocol was successfully completed in this patient. Rapid desensitization is a promising method for the delivery of denosumab after a hypersensitivity reaction, and should be considered in osteoporosis treatment when no acceptable therapeutic alternatives are available. PMID:26504466

  10. Clinical characteristics of trigeminal nerve injury referrals to a university centre.

    PubMed

    Tay, A B G; Zuniga, J R

    2007-10-01

    The aim of this retrospective study was to determine the aetiology and characteristics of trigeminal nerve injuries referred to a university centre with nerve injury care. Fifty-nine patients with 73 injured trigeminal nerves were referred in 10 months. The most common aetiologies were odontectomy (third molar surgery) (52.1% of nerves), local anaesthetic (LA) injections (12.3%), orthognathic surgery (12.3%) and implant surgery (11.0%). The inferior alveolar nerve (IAN) was most commonly injured nerve (64.4%), followed by the lingual nerve (LN) (28.8%). About a quarter of IAN injuries (27.3%) and half of LN injuries (57.1%) from odontectomy had severe sensory impairment. There were twice as many LN than IAN injuries from local anaesthetic injections, but all had mild or no sensory impairment. Nerve injuries from implant surgery occurred only in IAN injuries; none had severe sensory impairment. Neuropathic pain occurred in 14.9% of IAN injuries and only in those with mild or no sensory impairment. Nerve surgery was offered to 45.8% of patients; a third underwent surgery. PMID:17875382

  11. Communications Between the Trigeminal Nerve and the Facial Nerve in the Face: A Systematic Review.

    PubMed

    Hwang, Kun; Yang, Su Cheol; Song, Ju Sung

    2015-07-01

    The aim of the article is to elucidate the communications between the trigeminal nerve and facial nerve in the face. In a PubMed search, 328 studies were found using the terms 'trigeminal nerve, facial nerve, and communication.' The abstracts were read and 39 full-text articles were reviewed. Among them, 11 articles were analyzed. In the studies using dissection, the maxillary branch (V2) had the highest frequency (95.0% ± 8.0%) of communication with the facial nerve, followed by the mandibular branch (V3) (76.7% ± 38.5%). The ophthalmic branch (V1) had the lowest frequency of communication (33.8% ± 19.5%). In a Sihler stain, all of the maxillary branches and mandibular branches had communications with the facial nerve and 85.7% (12/14 hemifaces) of the ophthalmic branches had communications. The frequency of communications between the trigeminal nerve and facial nerve were significantly higher (P = 0.00, t-test) in the studies using a Sihler stain (94.7% ± 1.1%) than the studies using dissection (76.9 ± 35.8). The reason for the significantly higher frequency of trigeminal-facial communication in the studies using a Sihler stain is because of the limitation of the Sihler stain itself. This technique cannot differentiate the motor nerves from sensory nerves at the periphery, and a crossover can be misinterpreted as communication near to nerve terminal. PMID:26114519

  12. Electrical stimulation accelerates nerve regeneration and functional recovery in delayed peripheral nerve injury in rats.

    PubMed

    Huang, Jinghui; Zhang, Yongguang; Lu, Lei; Hu, Xueyu; Luo, Zhuojing

    2013-12-01

    The present study aims to investigate the potential of brief electrical stimulation (ES; 3 V, 20 Hz, 20 min) in improving functional recovery in delayed nerve injury repair (DNIR). The sciatic nerve of Sprague Dawley rats was transected, and the repair of nerve injury was delayed for different time durations (2, 4, 12 and 24 weeks). Brief depolarizing ES was applied to the proximal nerve stump when the transected nerve stumps were bridged with a hollow nerve conduit (5 mm in length) after delayed periods. We found that the diameter and number of regenerated axons, the thickness of myelin sheath, as well as the number of Fluoro-Gold retrograde-labeled motoneurons and sensory neurons were significantly increased by ES, suggesting that brief ES to proximal nerve stumps is capable of promoting nerve regeneration in DNIR with different delayed durations, with the longest duration of 24 weeks. In addition, the amplitude of compound muscle action potential (gastrocnemius muscle) and nerve conduction velocity were also enhanced, and gastrocnemius muscle atrophy was partially reversed by brief ES, indicating that brief ES to proximal nerve stump was able to improve functional recovery in DNIR. Furthermore, brief ES was capable of increasing brain-derived neurotrophic factor (BDNF) expression in the spinal cord in DNIR, suggesting that BDNF-mediated neurotrophin signaling might be one of the contributing factors to the beneficial effect of brief ES on DNIR. In conclusion, the present findings indicate the potential of using brief ES as a useful method to improve functional recovery for delayed repair of peripheral nerve lesions. PMID:24118464

  13. Early Interfaced Neural Activity from Chronic Amputated Nerves

    PubMed Central

    Garde, Kshitija; Keefer, Edward; Botterman, Barry; Galvan, Pedro; Romero, Mario I.

    2009-01-01

    Direct interfacing of transected peripheral nerves with advanced robotic prosthetic devices has been proposed as a strategy for achieving natural motor control and sensory perception of such bionic substitutes, thus fully functionally replacing missing limbs in amputees. Multi-electrode arrays placed in the brain and peripheral nerves have been used successfully to convey neural control of prosthetic devices to the user. However, reactive gliosis, micro hemorrhages, axonopathy and excessive inflammation currently limit their long-term use. Here we demonstrate that enticement of peripheral nerve regeneration through a non-obstructive multi-electrode array, after either acute or chronic nerve amputation, offers a viable alternative to obtain early neural recordings and to enhance long-term interfacing of nerve activity. Non-restrictive electrode arrays placed in the path of regenerating nerve fibers allowed the recording of action potentials as early as 8 days post-implantation with high signal-to-noise ratio, as long as 3 months in some animals, and with minimal inflammation at the nerve tissue-metal electrode interface. Our findings suggest that regenerative multi-electrode arrays of open design allow early and stable interfacing of neural activity from amputated peripheral nerves and might contribute towards conveying full neural control and sensory feedback to users of robotic prosthetic devices. PMID:19506704

  14. Novel Roles for Osteopontin and Clusterin in Peripheral Motor and Sensory Axon Regeneration

    PubMed Central

    Mi, Ruifa; Connor, Emmalynn; Reed, Nicole; Vyas, Alka; Alspalter, Manula; Coppola, Giovanni; Geschwind, Daniel H.; Brushart, Thomas M.

    2014-01-01

    Previous studies demonstrated that Schwann cells (SCs) express distinct motor and sensory phenotypes, which impact the ability of these pathways to selectively support regenerating neurons. In the present study, unbiased microarray analysis was used to examine differential gene expression in denervated motor and sensory pathways in rats. Several genes that were significantly upregulated in either denervated sensory or motor pathways were identified and two secreted factors were selected for further analysis: osteopontin (OPN) and clusterin (CLU) which were upregulated in denervated motor and sensory pathways, respectively. Sciatic nerve transection induced upregulation of OPN and CLU and expression of both returned to baseline levels with ensuing regeneration. In vitro analysis using exogenously applied OPN induced outgrowth of motor but not sensory neurons. CLU, however, induced outgrowth of sensory neurons, but not motor neurons. To assess the functional importance of OPN and CLU, peripheral nerve regeneration was examined in OPN and CLU−/− mice. When compared with OPN+/+ mice, motor neuron regeneration was reduced in OPN−/− mice. Impaired regeneration through OPN−/− peripheral nerves grafted into OPN+/+ mice indicated that loss of OPN in SCs was responsible for reduced motor regeneration. Sensory neuron regeneration was impaired in CLU−/− mice following sciatic nerve crush and impaired regeneration nerve fibers through CLU−/− nerve grafts transplanted into CLU+/+ mice indicated that reduced sensory regeneration is likely due to SC-derived CLU. Together, these studies suggest unique roles for SC-derived OPN and CLU in regeneration of peripheral motor and sensory axons. PMID:24478351

  15. Systematic desensitization to reduce dream-induced anxiety.

    PubMed

    Cavior, N; Deutsch, A M

    1975-12-01

    A modified version of systematic desensitization was used to reduce the anxiety and negative interpersonal consequences produced by a recurrent aversive dream resulting from events in the real world. The subject, a 16-year-old incarcerated male, was first taught a standard relaxation technique. The subject's dream was divided into 12 hierarchical imaginal scenes. Following initial relaxation, each scene was sequentially introduced and followed by the therapist's suggestion that the subject was still very relaxed. After three sessions with the therapists and several practice sessions by himself, the subject reported no further anxiety to the dream (which continued to occur) and improved relations with the institutional staff. Six months of follow-up showed no recurrence of the anxiety or the subsequent irritability which the subject had initially reported as leading to negative interpersonal relations with the staff. PMID:468

  16. In vivo desensitization in the treatment of recurrent nightmares.

    PubMed

    Eccles, A; Wilde, A; Marshall, W L

    1988-12-01

    The literature, although sparse, suggests that behavioral interventions targeting the overt waking manifestations of the fear content of nightmares, can effectively reduce the frequency and intensity of these dreams. A 20-year-old female with recurrent nightmares centering on a fear of snakes, was treated by in vivo desensitization in which she approached a live, harmless snake. During treatment the client displayed habituation of fear of the snake and this corresponded to reductions in her nightmares. By the end of treatment and at 3-month and 1-year follow-up evaluations, she was free of fear and her nightmares had been eliminated. It is suggested that in vivo behavioral treatment of the content of nightmares may be a very effective way to eliminate these distressing dreams. PMID:2906945

  17. Repair of peripheral nerve with vein wrapping*

    PubMed Central

    LEUZZI, S.; ARMENIO, A.; LEONE, L.; DE SANTIS, V.; DI TURI, A.; ANNOSCIA, P.; BUFANO, L.; PASCONE, M.

    2014-01-01

    Objective The post–traumatic neuro-anastomosis must be protected from the surrounding environment. This barrier must be biologically inert, biodegradable, not compressing but protecting the nerve. Formation of painful neuroma is one of the major issues with neuro-anastomosis; currently there is no consensus on post-repair neuroma prevention. Aim of this study is to evaluate the efficacy of neuroanastomosis performed with venous sheath to reduce painful neuromas formation, improve the electrical conductivity of the repaired nerve, and reduce the discrepancies of the sectioned nerve stumps. Patients and methods From a trauma population of 320 patients treated in a single centre between January 2008 and December 2011, twenty-six patients were identified as having an injury to at least one of the peripheral nerves of the arm and enrolled in the study. Patients were divided into two groups. In the group A (16 patients) the end-to-end nerve suture was wrapped in a vein sheath and compared with the group B (10 patients) in which a simple end-to-end neurorrhaphy was performed. The venous segment used to cover the nerve micro-suture was harvested from the superficial veins of the forearm. The parameters analyzed were: functional recovery of motor nerves, sensitivity and pain. Results Average follow-up was 14 months (range: 12–24 months). The group A showed a more rapid motor and sensory recovery and a reduction of the painful symptoms compared to the control group (B). Conclusions The Authors demonstrated that, in their experience, the venous sheath provides a valid solution to avoid the dispersion of the nerve fibres, to prevent adherent scars and painful neuromas formation. Moreover it can compensate the different size of two nerve stumps, allowing, thereby, a more rapid functional and sensitive recovery without expensive devices. PMID:24841688

  18. Putative lateral inhibition in sensory processing for directional turns

    PubMed Central

    Yafremava, Liudmila S.

    2011-01-01

    Computing targeted responses is a general problem in goal-directed behaviors. We sought the sensory template for directional turning in the predatory sea slug Pleurobranchaea californica, which calculates precise turn angles by averaging multiple stimulus sites on its chemotactile oral veil (Yafremava LS, Anthony CW, Lane L, Campbell JK, Gillette R. J Exp Biol 210: 561–569, 2007). Spiking responses to appetitive chemotactile stimulation were recorded in the two bilateral pairs of oral veil nerves, the large oral veil nerve (LOVN) and the tentacle nerve (TN). The integrative abilities of the peripheral nervous system were significant. Nerve spiking responses to punctate, one-site stimulation of the oral veil followed sigmoid relations as stimuli moved between lateral tentacle and the midline. Receptive fields of LOVN and TN were unilateral, overlapping, and oppositely weighted for responsiveness across the length of oral veil. Simultaneous two-site stimulation caused responses of amplitudes markedly smaller than the sum of corresponding one-site responses. Plots of two-site nerve responses against the summed approximate distances from midline of each site were markedly linear. Thus the sensory paths in the peripheral nervous system show reciprocal occlusion similar to lateral inhibition. This outcome suggests a novel neural function for lateral inhibitory mechanisms, distinct from simple contrast enhancement, in computation of both sensory maps and targeted motor actions. PMID:21490281

  19. Some pathologies of sensory and neural hearing loss.

    PubMed

    Bergstrom, L

    1975-01-01

    Recently surgical implantation of devices to stimulate the auditory nerve in man makes it apparent that sensory and neural pathologies of deafness need to be differentiated from each other. In this paper 10 exemplary cases are presented. In addition, an attempt is made to compile the information now available about sensory and neural pathologies in the various diseases that cause deafness. Superficially, it would appear that most such entities are sensory in nature and thus theoretically might be amenable to auditory nerve stimulation. However, loss of supporting cells seems to be associated with cochlear nerve fibre degeneration. Many individuals may, therefore, eventually develop combined pathology. The paucity of knowledge of pathology of the auditory pathways and their radiations in deaf persons is recognized as a limiting factor in attempts to predict which patients might benefit from auditory nerve stimulation. It is not within the scope of this paper to delineate the possible deleterious effects that cochlear implants might have on the auditory nerve. PMID:1148918

  20. Burning mouth syndrome and other oral sensory disorders: a unifying hypothesis.

    PubMed

    Grushka, Miriam; Epstein, Joel B; Gorsky, Meir

    2003-01-01

    Burning Mouth Syndrome (BMS) is a sensory disorder which results in constant, bilateral burning pain of the tongue, lips, and other oral mucous membranes. Atypical odontalgia (AO) is another sensory disorder, usually defined as a toothache-like pain for which no dental cause can be identified. Previous literature has suggested that AO is often associated with a concomitant temporomandibular disorder (TMD). This hypothesis paper explores the possibility that BMS, AO and TMD can be related through hyperactivity of both the sensory and motor components of the trigeminal nerve following loss of central inhibition as a result of taste damage in the chorda tympani and/or the glossopharyngeal nerves. PMID:14657979

  1. Sensory Guillain-Barré syndrome: A case report.

    PubMed

    Zhang, Jing; Liu, Na; Zhang, Zhe-Cheng; Zheng, Rui-Zhi; Li, Qian

    2014-12-01

    A 58-year-old female exhibited the onset of symmetrical sensory abnormalities of the face and extremities. The neurological examination revealed normal muscle strength with abated or absent tendon reflexes. The patient experienced symmetrical glove- and stocking-type pinprick sensations in the distal extremities and a loss of temperature sensation, but had normal proprioception and vibration senses and joint topesthesia. The lumbar puncture showed protein cell separation at the fifth week after the onset of symptoms. At the same time-point, the electrophysiological examination showed demyelination changes involving the trigeminal nerve and the somatic motor nerve. Needle electromyography revealed normal results. The clinical symptoms ceased progression at the fourth week after symptom onset, and began to improve from the sixth. This case was considered to be sensory Guillain-Barré syndrome, which was characterized by its cranial nerve involvement. PMID:25371720

  2. Transcriptomic analyses of genes and tissues in inherited sensory neuropathies.

    PubMed

    Sapio, Matthew R; Goswami, Samridhi C; Gross, Jacklyn R; Mannes, Andrew J; Iadarola, Michael J

    2016-09-01

    Inherited sensory neuropathies are caused by mutations in genes affecting either primary afferent neurons, or the Schwann cells that myelinate them. Using RNA-Seq, we analyzed the transcriptome of human and rat DRG and peripheral nerve, which contain sensory neurons and Schwann cells, respectively. We subdivide inherited sensory neuropathies based on expression of the mutated gene in these tissues, as well as in mouse TRPV1 lineage DRG nociceptive neurons, and across 32 human tissues from the Human Protein Atlas. We propose that this comprehensive approach to neuropathy gene expression leads to better understanding of the involved cell types in patients with these disorders. We also characterize the genetic "fingerprint" of both tissues, and present the highly tissue-specific genes in DRG and sciatic nerve that may aid in the development of gene panels to improve diagnostics for genetic neuropathies, and may represent specific drug targets for diseases of these tissues. PMID:27343803

  3. Applications of Desensitization Procedures for School-Related Problems; A Review.

    ERIC Educational Resources Information Center

    Prout, H. Thompson; Harvey, John R.

    1978-01-01

    A variety of desensitization and counterconditioning procedures have been utilized to deal with school-related problems. These procedures are reviewed with respect to applications for treating school phobia, test anxiety, and other academic anxieties. (Author)

  4. Quantifying Hierarchy Stimuli in Systematic Desensitization Via GSR: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Barabasz, Arreed F.

    1974-01-01

    The aim of the method for quantifying hierarchy stimuli by Galvanic Skin Resistance recordings is to improve the results of systematic desensitization by attenuating the subjective influences in hierarchy construction which are common in traditional procedures. (Author/CS)

  5. Mechanisms of desensitization of the adrenocorticotropin response to arginine vasopressin in ovine anterior pituitary cells.

    PubMed

    Hassan, A; Mason, D

    2005-01-01

    Arginine vasopressin (AVP) stimulates adrenocorticotropin (ACTH) secretion from corticotroph cells of the anterior pituitary via activation of the V1b vasopressin receptor, a member of the G protein-coupled receptor (GPCR) family. Recently, we have shown that treatment of ovine anterior pituitary cells with AVP for short periods results in reduced responsiveness to subsequent stimulation with AVP. The aim of this study was to investigate mechanisms involved in this desensitization process. Among the GPCR family, rapid desensitization is commonly mediated by receptor phosphorylation, with resensitization being mediated by internalization and subsequent dephosphorylation of the receptors by protein phosphatases. Since desensitization of V1a vasopressin receptors is mediated by protein kinase C-mediated receptor phosphorylation, we investigated the involvement of this enzyme in desensitization of the ACTH response to AVP. Treatment of perifused ovine anterior pituitary cells with the specific protein kinase C (PKC) activator 1,2-dioctanoyl-sn-glycerol (300 microM) did not induce any reduction in response to a subsequent 5-min stimulation with 100 nM AVP, despite potently stimulating ACTH secretion. Likewise, the results obtained using the PKC inhibitor Ro 31-8220 were not consistent with involvement of PKC in AVP desensitization: 2 microM Ro 31-8220 did not reduce the ability of a 10 nM AVP pretreatment to induce desensitization to a subsequent stimulation with 100 nM AVP. Pharmacologic blockade of receptor internalization by treatment with 0.25 mg/ml concanavalin A significantly impaired the ability of a 15-min pretreatment with 10 nM AVP to induce desensitization, rather than affecting resensitization. Treatment with 10 nM okadaic acid, an inhibitor of protein phosphatase 1 and 2A, had no effect on either resensitization or desensitization. In contrast, inhibition of protein phosphatase 2B (PP2B) with 1 microM FK506 decreased the rate of resensitization: complete

  6. Immune Profiles to Predict Response to Desensitization Therapy in Highly HLA-Sensitized Kidney Transplant Candidates

    PubMed Central

    Yabu, Julie M.; Siebert, Janet C.; Maecker, Holden T.

    2016-01-01

    Background Kidney transplantation is the most effective treatment for end-stage kidney disease. Sensitization, the formation of human leukocyte antigen (HLA) antibodies, remains a major barrier to successful kidney transplantation. Despite the implementation of desensitization strategies, many candidates fail to respond. Current progress is hindered by the lack of biomarkers to predict response and to guide therapy. Our objective was to determine whether differences in immune and gene profiles may help identify which candidates will respond to desensitization therapy. Methods and Findings Single-cell mass cytometry by time-of-flight (CyTOF) phenotyping, gene arrays, and phosphoepitope flow cytometry were performed in a study of 20 highly sensitized kidney transplant candidates undergoing desensitization therapy. Responders to desensitization therapy were defined as 5% or greater decrease in cumulative calculated panel reactive antibody (cPRA) levels, and non-responders had 0% decrease in cPRA. Using a decision tree analysis, we found that a combination of transitional B cell and regulatory T cell (Treg) frequencies at baseline before initiation of desensitization therapy could distinguish responders from non-responders. Using a support vector machine (SVM) and longitudinal data, TRAF3IP3 transcripts and HLA-DR-CD38+CD4+ T cells could also distinguish responders from non-responders. Combining all assays in a multivariate analysis and elastic net regression model with 72 analytes, we identified seven that were highly interrelated and eleven that predicted response to desensitization therapy. Conclusions Measuring baseline and longitudinal immune and gene profiles could provide a useful strategy to distinguish responders from non-responders to desensitization therapy. This study presents the integration of novel translational studies including CyTOF immunophenotyping in a multivariate analysis model that has potential applications to predict response to

  7. Candida albicans-Derived β-1,2-Linked Mannooligosaccharides Induce Desensitization of Macrophages

    PubMed Central

    Jouault, Thierry; Fradin, Chantal; Trinel, Pierre-André; Poulain, Daniel

    2000-01-01

    Candida albicans β-1,2-oligomannosides stimulate macrophage tumor necrosis factor alpha (TNF-α) but not NO release. This stimulation desensitized macrophages by altering β-1,2-oligomannoside-dependent TNF-α production and lipopolysaccharide-dependent TNF-α and NO secretion. Desensitization was not related to tyrosine phosphorylation signal transduction but was transferred by culture supernatants in which arachidonic acid derivatives were evidenced. PMID:10639473

  8. Opposite Effects of KCTD Subunit Domains on GABAB Receptor-mediated Desensitization*

    PubMed Central

    Seddik, Riad; Jungblut, Stefan P.; Silander, Olin K.; Rajalu, Mathieu; Fritzius, Thorsten; Besseyrias, Valérie; Jacquier, Valérie; Fakler, Bernd; Gassmann, Martin; Bettler, Bernhard

    2012-01-01

    GABAB receptors assemble from principle and auxiliary subunits. The principle subunits GABAB1 and GABAB2 form functional heteromeric GABAB(1,2) receptors that associate with homotetramers of auxiliary KCTD8, -12, -12b, or -16 (named after their K+ channel tetramerization domain) subunits. These auxiliary subunits constitute receptor subtypes with distinct functional properties. KCTD12 and -12b generate desensitizing receptor responses while KCTD8 and -16 generate largely non-desensitizing receptor responses. The structural elements of the KCTDs underlying these differences in desensitization are unknown. KCTDs are modular proteins comprising a T1 tetramerization domain, which binds to GABAB2, and a H1 homology domain. KCTD8 and -16 contain an additional C-terminal H2 homology domain that is not sequence-related to the H1 domains. No functions are known for the H1 and H2 domains. Here we addressed which domains and sequence motifs in KCTD proteins regulate desensitization of the receptor response. We found that the H1 domains in KCTD12 and -12b mediate desensitization through a particular sequence motif, T/NFLEQ, which is not present in the H1 domains of KCTD8 and -16. In addition, the H2 domains in KCTD8 and -16 inhibit desensitization when expressed C-terminal to the H1 domains but not when expressed as a separate protein in trans. Intriguingly, the inhibitory effect of the H2 domain is sequence-independent, suggesting that the H2 domain sterically hinders desensitization by the H1 domain. Evolutionary analysis supports that KCTD12 and -12b evolved desensitizing properties by liberating their H1 domains from antagonistic H2 domains and acquisition of the T/NFLEQ motif. PMID:23035119

  9. Lateralization Technique and Inferior Alveolar Nerve Transposition

    PubMed Central

    Sanches, Marco Antonio; Ramalho, Gabriel Cardoso; Manzi, Marcello Roberto

    2016-01-01

    Bone resorption of the posterior mandible can result in diminished bone edge and, therefore, the installation of implants in these regions becomes a challenge, especially in the presence of the mandibular canal and its contents, the inferior alveolar nerve. Several treatment alternatives are suggested: the use of short implants, guided bone regeneration, appositional bone grafting, distraction osteogenesis, inclined implants tangential to the mandibular canal, and the lateralization of the inferior alveolar nerve. The aim was to elucidate the success rate of implants in the lateralization technique and in inferior alveolar nerve transposition and to determine the most effective sensory test. We conclude that the success rate is linked to the possibility of installing implants with long bicortical anchor which favors primary stability and biomechanics. PMID:27433360

  10. Retinal ganglion cell axons regenerate in the presence of intact sensory fibres.

    PubMed

    King, Carolyn; Bartlett, Carole; Sauvé, Yves; Lund, Ray; Dunlop, Sarah; Beazley, Lyn

    2006-02-01

    A novel allograft paradigm was used to test whether adult mammalian central axons regenerate within a peripheral nerve environment containing intact sensory axons. Retinal ganglion cell axon regeneration was compared following anastomosis of dorsal root ganglia grafts or conventional peripheral nerve grafts to the adult rat optic nerve. Dorsal root ganglia grafts comprised intact sensory and degenerate motor axons, whereas conventional grafts comprised both degenerating sensory and motor axons. Retinal ganglion cell axons were traced after 2 months. Dorsal root ganglia survived with their axons persisting throughout the graft. Comparable numbers of retinal ganglion cells regenerated axons into both dorsal root ganglia (1053+/-223) and conventional grafts (1323+/-881; P>0.05). The results indicate that an intact sensory environment supports central axon regeneration. PMID:16407770

  11. The effect of three desensitizing agents on dentin hypersensitivity: a randomized, split-mouth clinical trial.

    PubMed

    Torres, C R G; Silva, T M; Fonseca, B M; Sales, A L L S; Holleben, P; Di Nicolo, R; Borges, A B

    2014-01-01

    The aim of this study was to evaluate the efficacy of three desensitizing agents to provide relief to dentin hypersensitivity after one session in a four-week follow-up. Forty selected patients participated in a double-blind study following a split-mouth model. One application of the desensitizing agents (A, Admira Protect [Voco]; B, Bifluorid 12 [Voco]; and C, Colgate Pro-Relief in office [Colgate Palmolive]) was performed in three different quadrants for each patient. Each tooth was evaluated by tactile and evaporative stimuli, and the sensitivity response was measured using the Visual Analogue Scale. Evaluations were performed at baseline, immediately after treatment, and after one, two, three, and four weeks. The application of Kruskal-Wallis and Dunn multiple comparisons tests (5%) for both tactile and evaporative stimuli showed that all agents presented a significant desensitizing effect. In groups A and B this relief was maintained for four and three weeks, respectively, as measured by tactile stimulus and for four weeks with evaporative stimulus. The desensitizing effect for group C was maintained for two weeks for both tactile and evaporative stimuli. It is concluded that all desensitizing agents tested were effective in reducing sensitivity compared to baseline values. One application of Admira Protect and Bifluorid 12 presented a longer-lasting desensitizing effect than did Colgate Pro-Relief (applied in the office) on both tactile and evaporative stimuli. PMID:24720265

  12. Effect of low frequency transcutaneous magnetic stimulation on sensory and motor transmission.

    PubMed

    Leung, Albert; Shukla, Shivshil; Lee, Jacquelyn; Metzger-Smith, Valerie; He, Yifan; Chen, Jeffrey; Golshan, Shahrokh

    2015-09-01

    Peripheral nerve injury diminishes fast conducting large myelinated afferent fibers transmission but enhances smaller pain transmitting fibers firing. This aberrant afferent neuronal behavior contributes to development of chronic post-traumatic peripheral neuropathic pain (PTP-NP). Non-invasive dynamic magnetic flux stimulation has been implicated in treating PTP-NP, a condition currently not adequately addressed by other therapies including transcutaneous electrical nerve stimulation (TENS). The current study assessed the effect of low frequency transcutaneous magnetic stimulation (LFTMS) on peripheral sensory thresholds, nerve conduction properties, and TENS induced fast afferent slowing effect as measured by motor and sensory conduction studies in the ulnar nerve. Results indicated sham LFTMS with TENS (Sham + TENS) significantly (P = 0.02 and 0.007, respectively) reduces sensory conduction velocity (CV) and increases sensory onset latency (OL), and motor peak latency (PL) whereas, real LFTMS with TENS (Real + TENS) reverses effects of TENS on sensory CV and OL, and significantly (P = 0.036) increases the sensory PL. LFTMS alone significantly (P < 0.05) elevates sensory PL and onset-to-peak latency. LFTMS appears to reverse TENS slowing effect on fast conducting fibers and casts a selective peripheral modulatory effect on slow conducting pain afferent fibers. PMID:25989482

  13. Corneal confocal microscopy reveals trigeminal small sensory fiber neuropathy in amyotrophic lateral sclerosis

    PubMed Central

    Ferrari, Giulio; Grisan, Enrico; Scarpa, Fabio; Fazio, Raffaella; Comola, Mauro; Quattrini, Angelo; Comi, Giancarlo; Rama, Paolo; Riva, Nilo

    2014-01-01

    Although subclinical involvement of sensory neurons in amyotrophic lateral sclerosis (ALS) has been previously demonstrated, corneal small fiber sensory neuropathy has not been reported to-date. We examined a group of sporadic ALS patients with corneal confocal microscopy, a recently developed imaging technique allowing in vivo observation of corneal small sensory fibers. Corneal confocal microscopy (CCM) examination revealed a reduction of corneal small fiber sensory nerve number and branching in ALS patients. Quantitative analysis demonstrated an increase in tortuosity and reduction in length and fractal dimension of ALS patients’ corneal nerve fibers compared to age-matched controls. Moreover, bulbar function disability scores were significantly related to measures of corneal nerve fibers anatomical damage. Our study demonstrates for the first time a corneal small fiber sensory neuropathy in ALS patients. This finding further suggests a link between sporadic ALS and facial-onset sensory and motor neuronopathy (FOSMN) syndrome, a rare condition characterized by early sensory symptoms (with trigeminal nerve distribution), followed by wasting and weakness of bulbar and upper limb muscles. In addition, the finding supports a model of neurodegeneration in ALS as a focally advancing process. PMID:25360111

  14. The Relationship between Nerve Conduction Study and Clinical Grading of Carpal Tunnel Syndrome

    PubMed Central

    Cheluvaiah, Janardhan D.; Agadi, Jagadish B.; Nagaraj, Karthik

    2016-01-01

    Introduction Carpal Tunnel Syndrome (CTS) is the most common nerve entrapment. Subjective sensory symptoms are common place in patients with CTS, but sometimes they are not supported by objective findings in the neurological examination. Electrodiagnostic (EDx) studies are a valid and reliable means of confirming the diagnosis. The amplitudes along with the conduction velocities of the sensory nerve action potential and motor nerve action potential reflect the functional state of axons, and are useful parameters and complement the clinical grading in the assessment of severity of CTS. Aim To conduct median nerve sensory and motor conduction studies on patients with carpal tunnel syndrome and correlate the relationship between nerve conduction study parameters and the clinical severity grading. Materials and Methods Based on clinical assessment, the study patients were divided into 03 groups with mild CTS, moderate CTS and severe CTS respectively as per Mackinnson’s classification. Median and ulnar nerve conduction studies were performed on bilateral upper limbs of 50 patients with symptoms of CTS and 50 age and sex matched healthy control subjects. The relationship between the clinical severity grade and various nerve conduction study parameters were correlated. Results In this prospective case control study, 50 patients with symptoms consistent with CTS and 50 age and sex matched healthy control subjects were examined over a 10 month period. A total of 30 patients had unilateral CTS (right upper limb in 19 and left upper limb in 11) and 20 patients had bilateral CTS. Female to male ratio was 3.54 to 1. Age ranged from 25 to 81 years. The mean age at presentation was 49.68±11.7 years. Tingling paresthesias of hand and first three fingers were the most frequent symptoms 48 (98%). Tinel’s and Phalen’s sign were positive in 36 (72%) and 44 (88%) patients respectively. The mean duration of symptoms at presentation was 52.68±99.81 weeks. 16 patients (32%) had

  15. Significant Differences in Sympathetic Nerve Fiber Density Among the Facial Skin Nerves: A Histologic Study Using Human Cadaveric Specimens.

    PubMed

    Matsubayashi, Tadatoshi; Cho, Kwang Ho; Jang, Hyung Suk; Murakami, Gen; Yamamoto, Masahito; Abe, Shin-Ichi

    2016-08-01

    Sympathetic nerve fibers in the skin nerves are connected with vasomotor, thermoregulatory, sensory input modulatory, and immunologic events; however, to our knowledge, no histological information is available for skin nerves in the human face. Using specimens from 17 donated cadavers (mean age, 86 years), we measured a sectional area of tyrosine hydroxylase (TH)-positive fibers in (1) the frontal nerve (V1), (2) the infraorbital nerve (V2), (3) the mental nerve (V3), (4) the greater auricular nerve (C2), (5) the auriculotemporal nerve (ATN), and (6) the zygomatic branch of the facial nerve (VII). The V1, V2, and V3 were obtained at their entrances to the subcutaneous tissue from the bony canal or notch. The V1, C2, ATN, and/or VII usually contained abundant TH-positive fibers (almost 3%-8% of the nerve sectional area), whereas the V2 and V3 consistently carried few TH-positive fibers (<1%). The difference between these two groups was quite significant (P < 0.001). Thus, from the superior cervical ganglion, the sympathetic nerve fibers reached the forehead through the frontal nerve trunk, whereas artery-bounded fibers came to the cheek, nose, and mouth. The sympathetic palsy caused by trigeminal nerve involvement is mainly characterized by the symptoms seen in the distribution of the ophthalmic division of the trigeminal nerve, such as in Horner's syndrome. It suggests that the forehead and the other facial areas are representative parts of those different sympathetic innervations that could be useful for evaluating the sympathetic function of the face in various diseases. Anat Rec, 299:1054-1059, 2016. © 2016 Wiley Periodicals, Inc. PMID:27072367

  16. Sensory Conversion Devices

    NASA Astrophysics Data System (ADS)

    Medelius, Pedro

    The human body has five basic sensory functions: touch, vision, hearing, taste, and smell. The effectiveness of one or more of these human sensory functions can be impaired as a result of trauma, congenital defects, or the normal ageing process. Converting one type of function into another, or translating a function to a different part of the body, could result in a better quality of life for a person with diminished sensorial capabilities.

  17. Signaling by Sensory Receptors

    PubMed Central

    Julius, David; Nathans, Jeremy

    2012-01-01

    Sensory systems detect small molecules, mechanical perturbations, or radiation via the activation of receptor proteins and downstream signaling cascades in specialized sensory cells. In vertebrates, the two principal categories of sensory receptors are ion channels, which mediate mechanosensation, thermosensation, and acid and salt taste; and G-protein-coupled receptors (GPCRs), which mediate vision, olfaction, and sweet, bitter, and umami tastes. GPCR-based signaling in rods and cones illustrates the fundamental principles of rapid activation and inactivation, signal amplification, and gain control. Channel-based sensory systems illustrate the integration of diverse modulatory signals at the receptor, as seen in the thermosensory/pain system, and the rapid response kinetics that are possible with direct mechanical gating of a channel. Comparisons of sensory receptor gene sequences reveal numerous examples in which gene duplication and sequence divergence have created novel sensory specificities. This is the evolutionary basis for the observed diversity in temperature- and ligand-dependent gating among thermosensory channels, spectral tuning among visual pigments, and odorant binding among olfactory receptors. The coding of complex external stimuli by a limited number of sensory receptor types has led to the evolution of modality-specific and species-specific patterns of retention or loss of sensory information, a filtering operation that selectively emphasizes features in the stimulus that enhance survival in a particular ecological niche. The many specialized anatomic structures, such as the eye and ear, that house primary sensory neurons further enhance the detection of relevant stimuli. PMID:22110046

  18. Transgenic BDNF induces nerve fiber regrowth into the auditory epithelium in deaf cochleae.

    PubMed

    Shibata, Seiji B; Cortez, Sarah R; Beyer, Lisa A; Wiler, James A; Di Polo, Adriana; Pfingst, Bryan E; Raphael, Yehoash

    2010-06-01

    Sensory organs typically use receptor cells and afferent neurons to transduce environmental signals and transmit them to the CNS. When sensory cells are lost, nerves often regress from the sensory area. Therapeutic and regenerative approaches would benefit from the presence of nerve fibers in the tissue. In the hearing system, retraction of afferent innervation may accompany the degeneration of auditory hair cells that is associated with permanent hearing loss. The only therapy currently available for cases with severe or complete loss of hair cells is the cochlear implant auditory prosthesis. To enhance the therapeutic benefits of a cochlear implant, it is necessary to attract nerve fibers back into the cochlear epithelium. Here we show that forced expression of the neurotrophin gene BDNF in epithelial or mesothelial cells that remain in the deaf ear induces robust regrowth of nerve fibers towards the cells that secrete the neurotrophin, and results in re-innervation of the sensory area. The process of neurotrophin-induced neuronal regeneration is accompanied by significant preservation of the spiral ganglion cells. The ability to regrow nerve fibers into the basilar membrane area and protect the auditory nerve will enhance performance of cochlear implants and augment future cell replacement therapies such as stem cell implantation or induced transdifferentiation. This model also provides a general experimental stage for drawing nerve fibers into a tissue devoid of neurons, and studying the interaction between the nerve fibers and the tissue. PMID:20109446

  19. Transgenic BDNF induces nerve fiber regrowth into the auditory epithelium in deaf cochleae

    PubMed Central

    Shibata, Seiji B.; Cortez, Sarah R.; Beyer, Lisa A.; Wiler, Jim A.; Di Polo, Adriana; Pfingst, Bryan E.; Raphael, Yehoash

    2010-01-01

    Sensory organs typically use receptor cells and afferent neurons to transduce environmental signals and transmit them to the CNS. When sensory cells are lost, nerves often regress from the sensory area. Therapeutic and regenerative approaches would benefit from the presence of nerve fibers in the tissue. In the hearing system, retraction of afferent innervation may accompany the degeneration of auditory hair cells that is associated with permanent hearing loss. The only therapy currently available for cases with severe or complete loss of hair cells is the cochlear implant auditory prosthesis. To enhance the therapeutic benefits of a cochlear implant, it is necessary to attract nerve fibers back into the cochlear epithelium. Here we show that forced expression of the neurotrophin gene BDNF in epithelial or mesothelial cells that remain in the deaf ear, induces robust regrowth of nerve fibers towards the cells that secrete the neurotrophin, and results in re-innervation of the sensory area. The process of neurotrophin-induced neuronal regeneration is accompanied by significant preservation of the spiral ganglion cells. The ability to regrow nerve fibers into the basilar membrane area and protect the auditory nerve will enhance performance of cochlear implants and augment future cell replacement therapies such as stem cell implantation or induced transdifferentiation. This model also provides a general experimental stage for drawing nerve fibers into a tissue devoid of neurons, and studying the interaction between the nerve fibers and the tissue. PMID:20109446

  20. IL-17 and VEGF are necessary for efficient corneal nerve regeneration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contribution of acute inflammation to sensory nerve regeneration was investigated in the murine cornea using a model of corneal abrasion that removes the stratified epithelium and subbasal nerve plexus. Abrasion induced accumulation of IL-17(+) CCR6(+) yo T cells, neutrophils, and platelets in t...

  1. Postherniotomy dysejaculation: successful treatment with mesh removal and nerve transection.

    PubMed

    Aasvang, E K; Kehlet, H

    2008-12-01

    Dysejaculation following groin hernia repair can occur in about 1-2% of patients, resulting in impairment of sexual function. We report a case of chronic postherniotomy dysejaculation treated with transection of the ilioinguinal and iliohypogastric nerves and decompression of vas deferens that was embedded and twisted in shrunken mesh and scar tissue. At three months follow-up, there was reduced overall pain and no dysejaculation, and quantitative sensory testing showed reversal of sensory abnormalities, except for sensory loss, compared with preoperative values. PMID:18437287

  2. Effects of Polysialic Acid on Sensory Innervation of the Cornea

    PubMed Central

    Mao, Xiuli; Zhang, Yuntao; Schwend, Tyler; Conrad, Gary W.

    2014-01-01

    Sensory trigeminal growth cones innervate the cornea in a coordinated fashion during embryonic development. Polysialic acid (polySia) is known for its important roles during nerve development and regeneration. The purpose of this work is to determine whether polySia, present in developing eyefronts and on the surface of sensory nerves, may provide guidance cues to nerves during corneal innervation. Expression and localization of polySia in embryonic day (E)5-14 chick eyefronts and E9 trigeminal ganglia were identified using Western blotting and immunostaining. Effects of polySia removal on trigeminal nerve growth behavior were determined in vivo, using exogenous endoneuraminidase (endoN) treatments to remove polySia substrates during chick cornea development, and in vitro, using neuronal explant cultures. PolySia substrates, made by the physical adsorption of colominic acid to a surface coated with poly-D-lysine (PDL), were used as a model to investigate functions of the polySia expressed in axonal environments. PolySia was localized within developing eyefronts and on trigeminal sensory nerves. Distributions of PolySia in corneas and pericorneal regions are developmentally regulated. PolySia removal caused defasciculation of the limbal nerve trunk in vivo from E7 to E10. Removal of polySia on trigeminal neurites inhibited neurite outgrowth and caused axon defasciculation, but did not affect Neural Cell Adhesion Molecule (NCAM) expression or Schwann cell migration in vitro. PolySia substrates in vitro inhibited outgrowth of trigeminal neurites and promoted their fasciculation. In conclusion, polySia is localized on corneal nerves and in their targeting environment during early developing stages of chick embryos. PolySias promote fasciculation of trigeminal axons in vivo and in vitro, whereas, in contrast, their removal promotes defasciculation. PMID:25478909

  3. Hereditary sensory neuropathy type I

    PubMed Central

    Auer-Grumbach, Michaela

    2008-01-01

    Hereditary sensory neuropathy type I (HSN I) is a slowly progressive neurological disorder characterised by prominent predominantly distal sensory loss, autonomic disturbances, autosomal dominant inheritance, and juvenile or adulthood disease onset. The exact prevalence is unknown, but is estimated as very low. Disease onset varies between the 2nd and 5th decade of life. The main clinical feature of HSN I is the reduction of sensation sense mainly distributed to the distal parts of the upper and lower limbs. Variable distal muscle weakness and wasting, and chronic skin ulcers are characteristic. Autonomic features (usually sweating disturbances) are invariably observed. Serious and common complications are spontaneous fractures, osteomyelitis and necrosis, as well as neuropathic arthropathy which may even necessitate amputations. Some patients suffer from severe pain attacks. Hypacusis or deafness, or cough and gastrooesophageal reflux have been observed in rare cases. HSN I is a genetically heterogenous condition with three loci and mutations in two genes (SPTLC1 and RAB7) identified so far. Diagnosis is based on the clinical observation and is supported by a family history. Nerve conduction studies confirm a sensory and motor neuropathy predominantly affecting the lower limbs. Radiological studies, including magnetic resonance imaging, are useful when bone infections or necrosis are suspected. Definitive diagnosis is based on the detection of mutations by direct sequencing of the SPTLC1 and RAB7 genes. Correct clinical assessment and genetic confirmation of the diagnosis are important for appropriate genetic counselling and prognosis. Differential diagnosis includes the other hereditary sensory and autonomic neuropathies (HSAN), especially HSAN II, as well as diabetic foot syndrome, alcoholic neuropathy, neuropathies caused by other neurotoxins/drugs, immune mediated neuropathy, amyloidosis, spinal cord diseases, tabes dorsalis, lepra neuropathy, or decaying skin

  4. Role of cyclic GMP and calcineurin in homologous and heterologous desensitization of natriuretic peptide receptor-A.

    PubMed

    Fortin, Yann; De Léan, André

    2006-05-01

    The natriuretic peptide receptor-A (NPR-A) mediates natriuretic, hypotensive, and antihypertrophic effects of natriuretic peptides through the production of cGMP. In pathological conditions such as heart failure, these effects are attenuated by homologous and heterologous desensitization mechanisms resulting in the dephosphorylation of the cytosolic portion of the receptor. In contrast with natriuretic peptide-induced desensitization, pressor hormone-induced desensitization is dependent on protein kinase C (PKC) stimulation and (or) cytosolic calcium elevation. Mechanisms by which PKC and Ca(2+) promote NPR-A desensitization are not known. The role of cGMP and of the cytosolic Ca(2+) pathways in NPR-A desensitization were therefore studied. In contrast with the activation of NPR-A by its agonist, activation of soluble guanylyl cyclases of LLC-PK1 cells by sodium nitroprusside also leads to a production of cGMP but without altering NPR-A activation. Consequently, cGMP elevation per se does not appear to mediate homologous desensitization of NPR-A. In addition, cytosolic calcium increase is required only for the heterologous desensitization pathway since the calcium chelator BAPTA-AM blocks only PMA or ionomycin-induced desensitization. Calcineurin inhibitors block the NPR-A guanylyl cyclase heterologous desensitization induced by ionomycin, suggesting an essential role for this Ca(2+)-stimulated phosphatase in NPR-A desensitization. In summary, the present report demonstrates that neither cGMP nor Ca(2+) cytosolic elevation cause NPR-A homologous desensitization. Our results also indicate for the first time a role for calcineurin in NPR-A heterologous desensitization. PMID:16902599

  5. Pseudoradial Nerve Palsy Caused by Acute Ischemic Stroke.

    PubMed

    Tahir, Hassan; Daruwalla, Vistasp; Meisel, Jeremy; Kodsi, Samir E

    2016-01-01

    Pseudoperipheral palsy has been used to characterize isolated monoparesis secondary to stroke. Isolated hand nerve palsy is a rare presentation for acute cerebral stroke. Our patient presented with clinical features of typical peripheral radial nerve palsy and a normal computed tomography scan of the head, which, without a detailed history and neurological examination, could have been easily misdiagnosed as a peripheral nerve lesion deferring further investigation for a stroke. We stress the importance of including cerebral infarction as a critical differential diagnosis in patients presenting with sensory-motor deficit in an isolated peripheral nerve pattern. A good history and physical exam can differentiate stroke from peripheral neuropathy as the cause of radial nerve palsy. PMID:27493976

  6. Pseudoradial Nerve Palsy Caused by Acute Ischemic Stroke

    PubMed Central

    Tahir, Hassan; Daruwalla, Vistasp; Meisel, Jeremy; Kodsi, Samir E.

    2016-01-01

    Pseudoperipheral palsy has been used to characterize isolated monoparesis secondary to stroke. Isolated hand nerve palsy is a rare presentation for acute cerebral stroke. Our patient presented with clinical features of typical peripheral radial nerve palsy and a normal computed tomography scan of the head, which, without a detailed history and neurological examination, could have been easily misdiagnosed as a peripheral nerve lesion deferring further investigation for a stroke. We stress the importance of including cerebral infarction as a critical differential diagnosis in patients presenting with sensory-motor deficit in an isolated peripheral nerve pattern. A good history and physical exam can differentiate stroke from peripheral neuropathy as the cause of radial nerve palsy. PMID:27493976

  7. Neurology: an ancient sensory organ in crocodilians.

    PubMed

    Soares, Daphne

    2002-05-16

    Crocodilians hunt at night, waiting half-submerged for land-bound prey to disturb the water surface. Here I show that crocodilians have specialized sensory organs on their faces that can detect small disruptions in the surface of the surrounding water, and which are linked to a dedicated, hypertrophied nerve system. Such 'dome' pressure receptors are also evident in fossils from the Jurassic period, indicating that these semi-aquatic predators solved the problem of combining armour with tactile sensitivity many millions of years ago. PMID:12015589

  8. Termino-lateral nerve suture in lesions of the digital nerves: clinical experience and literature review.

    PubMed

    Artiaco, S; Tos, P; Conforti, L G; Geuna, S; Battiston, B

    2010-02-01

    Documented experience of treatment of digital nerve lesions with the termino-lateral (end-to-side) nerve suture is limited. Our clinical experience of this technique is detailed here alongside a systematic review of the previous literature. We performed, from 2002 to 2008, seven termino-lateral sutures with epineural window opening for digital nerve lesions. Functional outcome was analysed using the two-point discrimination test and the Semmes-Weinstein monofilament test. The results showed a sensory recovery of S3+ in six cases and S3 in one case. The mean distance found in the two-point discrimination test was 12.7 mm (range 8-18 mm). After a review of the literature, we were able to obtain homogeneous data from 17 additional patients operated by termino-lateral coaptation. The overall number of cases included in our review was 24. A sensory recovery was observed in 23 out of 24 patients. The functional results were S0 in one case, S3 in one case, S3+ in twenty cases and S4 in two cases. Excluding the one unfavourable case, the mean distance in the two-point discrimination test was 9.7 mm (range 3-18 mm). It can thus be concluded that the treatment of digital nerve lesions with termino-lateral suture showed encouraging results. Based on the results obtained in this current study we believe that in case of loss of substance, end-to-side nerve coaptation may be an alternative to biological and synthetic tubulisation when a digital nerve reconstruction by means of nerve autograft is declined by the patient. PMID:19687081

  9. Differential fiber-specific block of nerve conduction in mammalian peripheral nerves using kilohertz electrical stimulation

    PubMed Central

    Patel, Yogi A.

    2015-01-01

    Kilohertz electrical stimulation (KES) has been shown to induce repeatable and reversible nerve conduction block in animal models. In this study, we characterized the ability of KES stimuli to selectively block specific components of stimulated nerve activity using in vivo preparations of the rat sciatic and vagus nerves. KES stimuli in the frequency range of 5–70 kHz and amplitudes of 0.1–3.0 mA were applied. Compound action potentials were evoked using either electrical or sensory stimulation, and block of components was assessed through direct nerve recordings and muscle force measurements. Distinct observable components of the compound action potential had unique conduction block thresholds as a function of frequency of KES. The fast component, which includes motor activity, had a monotonically increasing block threshold as a function of the KES frequency. The slow component, which includes sensory activity, showed a nonmonotonic block threshold relationship with increasing KES frequency. The distinct trends with frequency of the two components enabled selective block of one component with an appropriate choice of frequency and amplitude. These trends in threshold of the two components were similar when studying electrical stimulation and responses of the sciatic nerve, electrical stimulation and responses of the vagus nerve, and sensorimotor stimulation and responses of the sciatic nerve. This differential blocking effect of KES on specific fibers can extend the applications of KES conduction block to selective block and stimulation of neural signals for neuromodulation as well as selective control of neural circuits underlying sensorimotor function. PMID:25878155

  10. Involvement of AMPA receptor desensitization in short-term synaptic depression at the calyx of Held in developing rats

    PubMed Central

    Koike-Tani, Maki; Kanda, Takeshi; Saitoh, Naoto; Yamashita, Takayuki; Takahashi, Tomoyuki

    2008-01-01

    Paired-pulse facilitation (PPF) and depression (PPD) are forms of short-term plasticity that are generally thought to reflect changes in transmitter release probability. However, desensitization of postsynaptic AMPA receptors (AMPARs) significantly contributes to PPD at many glutamatergic synapses. To clarify the involvement of AMPAR desensitization in synaptic PPD, we compared PPD with AMPAR desensitization, induced by paired-pulse glutamate application in patches excised from postsynaptic cells at the calyx of Held synapse of developing rats. We found that AMPAR desensitization contributed significantly to PPD before the onset of hearing (P10–12), but that its contribution became negligible after hearing onset. During postnatal development (P7–21) the recovery of AMPARs from desensitization became faster. Concomitantly, glutamate sensitivity of AMPAR desensitization declined. Single-cell reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated a developmental decline of GluR1 expression that correlated with speeding of the recovery of AMPARs from desensitization. Transmitter release probability declined during the second postnatal week (P7–14). Manipulation of the extracellular Ca2+/Mg2+ ratio, to match release probability at P7–8 and P13–15 synapses, revealed that the release probability is also an important factor determining the involvement of AMPAR desensitization in PPD. We conclude that the extent of involvement of AMPAR desensitization in short-term synaptic depression is determined by both pre- and postsynaptic mechanisms. PMID:18339695

  11. Sensory Correlations in Autism

    ERIC Educational Resources Information Center

    Kern, Janet K.; Trivedi, Madhukar H.; Grannemann, Bruce D.; Garver, Carolyn R.; Johnson, Danny G.; Andrews, Alonzo A.; Savla, Jayshree S.; Mehta, Jyutika A.; Schroeder, Jennifer L.

    2007-01-01

    This study examined the relationship between auditory, visual, touch, and oral sensory dysfunction in autism and their relationship to multisensory dysfunction and severity of autism. The Sensory Profile was completed on 104 persons with a diagnosis of autism, 3 to 56 years of age. Analysis showed a significant correlation between the different…

  12. Intraoperative nerve monitoring during total shoulder arthroplasty surgery

    PubMed Central

    Aresti, Nick; Plumb, Karen; Cowan, Joseph; Higgs, Deborah; Lambert, Simon; Falworth, Mark

    2014-01-01

    Background Nerve injury is an acknowledged complication of total shoulder arthroplasty (TSA). Although the incidence of postoperative neurological deficit has been reported to be between 1% and 16%, the true incidence of nerve damage is considered to be higher. The present study aimed to identify the rate of intraoperative nerve injury during total shoulder arthroplasty and to determine potential risk factors. Methods A prospective study of nerve conduction in 21 patients who underwent primary or revision TSA was carried out over a 12-month period. Nerve conduction was monitored by measuring intraoperative sensory evoked potentials (SEP). A significant neurophysiological signal change was defined as either a unilateral or bilateral decrease in SEP signal of ≥50%, a latency increase of ≥10% or a change in waveform morphology, not caused by operative or anaesthetic technique. Results Seven (33%) patients had a SEP signal change. The only significant risk factor identified for signal change was male sex (odds ratio 15.00, 95% confidence interval). The median nerve was the most affected nerve in the operated arm. All but one signal change returned to normal before completion of the operation and no patient had a persisting postoperative clinical neurological deficit. Conclusions The incidence of intraoperative nerve damage may be more common than previously reported. However, the loss of SEP signal is reversible and does not correlate with persisting clinical neurological deficits. The median nerve appears to be most at risk. Monitoring SEPs in the operated limb during TSA may be a valuable tool during TSA.

  13. Aldose reductase inhibition improves nerve conduction velocity in diabetic patients.

    PubMed

    Judzewitsch, R G; Jaspan, J B; Polonsky, K S; Weinberg, C R; Halter, J B; Halar, E; Pfeifer, M A; Vukadinovic, C; Bernstein, L; Schneider, M; Liang, K Y; Gabbay, K H; Rubenstein, A H; Porte, D

    1983-01-20

    To assess the potential role of polyol-pathway activity in diabetic neuropathy, we measured the effects of sorbinil--a potent inhibitor of the key polyol-pathway enzyme aldose reductase--on nerve conduction velocity in 39 stable diabetics in a randomized, double-blind, cross-over trial. During nine weeks of treatment with sorbinil (250 mg per day), nerve conduction velocity was greater than during a nine-week placebo period for all three nerves tested: the peroneal motor nerve (mean increase [+/- S.E.M.], 0.70 +/- 0.24 m per second, P less than 0.008), the median motor nerve (mean increase, 0.66 +/- 0.27, P less than 0.005), and the median sensory nerve (mean increase, 1.16 +/- 0.50, P less than 0.035). Conduction velocity for all three nerves declined significantly within three weeks after cessation of the drug. These effects of sorbinil were not related to glycemic control, which was constant during the study. Although the effect of sorbinil in improving nerve conduction velocity in diabetics was small, the findings suggest that polyol-pathway activity contributes to slowed nerve conduction in diabetics. The clinical applicability of these observations remains to be determined, but they encourage further exploration of this approach to the treatment or prevention of diabetic neuropathy. PMID:6401351

  14. NMDA receptor desensitization regulated by direct binding to PDZ1-2 domains of PSD-95

    PubMed Central

    Sornarajah, Lavan; Vasuta, Oana Cristina; Zhang, Lily; Sutton, Christine; Li, Bo; El-Husseini, Alaa; Raymond, Lynn A.

    2010-01-01

    Regulation of NMDA receptor (NMDAR) activity by desensitization is important in physiological and pathological states; NMDAR desensitization contributes in shaping synaptic responses and may be protective by limiting calcium influx during sustained glutamate insults. We previously reported that glycine-independent desensitization decreases during hippocampal neuronal development, correlating with NMDAR synaptic localization and association with post-synaptic density 95 (PSD-95). PSD-95/Discs large/zona occludens (PDZ)-1,2 domains of PSD-95 bind to the C-terminus of NMDAR NR2 subunits. The role of PSD-95 in anchoring signaling proteins near NMDARs is well documented. To determine if PSD-95-induced changes in NMDAR desensitization occur because of direct binding to NR2 or due to recruitment of regulatory proteins, we tested the effects of various PSD-95 constructs on NMDAR currents in human embryonic kidney 293 (HEK293) cells and neurons. In HEK cells, wild-type PSD-95 significantly reduced wild-type NMDAR desensitization without altering currents of NMDARs containing NR2A-S1462A, a mutation that abolishes PSD-95 binding. The PSD-95 N-terminus truncated after the PDZ1-2 domains was sufficient for this effect in neurons with low endogenous PSD-95 levels; in NMDAR-expressing HEK cells, the effect persisted when PSD-95 multimerization was eliminated. Moreover, other PSD-95 family members with highly homologous PDZ1-2 domains significantly reduced NMDAR desensitization. In mature neurons, disruption of PSD-95/NMDAR interaction through protein kinase C (PKC) activation increased desensitization to levels found in immature neurons, and this effect was not due to PKC direct regulation of NMDAR activity. We conclude that direct binding of PSD-95 increases stability of NMDAR responses to agonist exposure in neuronal and non-neuronal cells. PMID:18400955

  15. A new desensitizing dentifrice--an 8-week clinical investigation.

    PubMed

    Sowinski, J A; Battista, G W; Petrone, M E; Chaknis, P; Zhang, Y P; DeVizio, W; Volpe, A R; Proskin, H M

    2000-01-01

    An 8-week, double-blind, three-way clinical trial compared the dentinal hypersensitivity-reducing effectiveness of a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength Toothpaste, Colgate-Palmolive Co.) with a commercially available desensitizing dentifrice containing 5.0% potassium nitrate and 0.243% sodium fluoride in a silica base (Sensodyne Fresh Mint Toothpaste, Block Drug Company, Inc.) and a nondesensitizing dentifrice containing 0.243% sodium fluoride in a silica base (Colgate Winterfresh Gel, Colgate-Palmolive Co.). One hundred nine subjects were stratified into three balanced groups according to gender, age, mean baseline tactile (Yeaple Probe), and thermal (air blast) scores. The test products were randomly assigned to each group with instructions to brush twice daily. Oral examinations with tactile and thermal assessments were repeated after 4 and 8 weeks. The new dentifrice group demonstrated statistically significant improvements in tactile and thermal sensitivity over the two control groups. PMID:11908355

  16. Endothelin-1 induced desensitization in primary afferent neurons

    PubMed Central

    Smith, Terika P.; Smith, Sherika N.; Sweitzer, Sarah M.

    2014-01-01

    Endothelin-1 (ET-1) is a known algogen that causes acute pain and sensitization in humans and spontaneous nociceptive behaviors when injected into the periphery in rats, and is elevated during vaso-occlusive episodes (VOEs) in sickle cell disease (SCD) patients. Previously, our lab has shown that a priming dose of ET-1 produces sensitization to capsaicin-induce secondary hyperalgesia. The goal of this study was to determine if the sensitization induced by ET-1 priming is occurring at the level of the primary afferent neuron. Calcium imaging in cultured dorsal root ganglion (DRG) neurons was utilized to examine the effects of ET-1 on primary afferent neurons. ET-1 induces [Ca2+]i transients in unprimed cells. ET-1 induced [Ca2+]i transients are attenuated by priming with ET-1. This priming effect occurs whether the priming dose is given 0-4 days prior to the challenge dose. Similarly, ET-1 priming decreases capsaicin-induced [Ca2+]i transients. At the level of the primary afferent neuron, ET-1 priming has a desensitizing effect on challenge exposures to ET-1 and capsaicin. PMID:25220703

  17. Phosphorylation and desensitization of alpha1d-adrenergic receptors.

    PubMed Central

    García-Sáinz, J A; Vázquez-Cuevas, F G; Romero-Avila, M T

    2001-01-01

    In rat-1 fibroblasts stably expressing rat alpha(1d)-adrenoceptors, noradrenaline and PMA markedly decreased alpha(1d)-adrenoceptor function (noradrenaline-elicited increases in calcium in whole cells and [(35)S]guanosine 5'-[gamma-thio]triphosphate binding in membranes), suggesting homologous and heterologous desensitizations. Photoaffinity labelling, Western blotting and immunoprecipitation identified alpha(1d)-adrenoceptors as a broad band of 70-80 kDa. alpha(1d)-Adrenoceptors were phosphorylated in the basal state and noradrenaline and PMA increased it. The effect of noradrenaline was concentration-dependent (EC(50) 75 nM), rapid (maximum at 1 min) and transient. Phorbol ester-induced phosphorylation was concentration-dependent (EC(50) 25 nM), slightly slower (maximum at 5 min) and stable for at least 60 min. Inhibitors of protein kinase C decreased the effect of phorbol esters but not that of noradrenaline. Evidence of cross-talk of alpha(1d)-adrenoceptors with receptors endogenously expressed in rat-1 fibroblasts was given by the ability of endothelin, lysophosphatidic acid and bradykinin to induce alpha(1d)-adrenoceptor phosphorylation. In summary, it is shown for the first time here that alpha(1d)-adrenoceptors are phosphoproteins and that receptor phosphorylation is increased by the natural ligand, noradrenaline, by direct activation of protein kinase C and via cross-talk with other receptors endogenously expressed in rat-1 fibroblasts. Receptor phosphorylation has functional repercussions. PMID:11171057

  18. The Efficacy of Selected Desensitizing OTC Products: A Systematic Review

    PubMed Central

    Talioti, E.; Hill, R.; Gillam, D. G.

    2014-01-01

    Objectives. The aim of the present study was to review the published literature in order to identify relevant studies for inclusion and to determine whether there was any evidence on the clinical effectiveness of selected desensitizing toothpastes, calcium sodium phosphosilicate (CSPS), amorphous calcium phosphate (ACP), nanohydroxyapatite, and casein phosphopeptide-amorphous calcium phosphate (tooth mousse) on reducing dentine hypersensitivity (DH). Materials and Methods. Following a review of 593 papers identified from searching both electronic databases (PUBMED) and hand searching of relevant written journals, only 5 papers were accepted for inclusion. Results. Analysis of the included studies (3 CSPS and 2 ACP) would suggest that there may be some benefit for patients using these products for reducing DH. No direct comparative studies were available to assess all these products under the same conditions neither were there any comparative randomised controlled studies that compared at least two of these products in determining their effectiveness in treating DH. Conclusions. Due to the small number of included studies, there are limited clinical data to support any claims of clinical efficacy of these OTC products. Further studies are therefore required to determine the efficacy of these products in well-controlled RCT studies with a larger sample size. PMID:25006466

  19. Hypersensitivity to antineoplastic agents: mechanisms and treatment with rapid desensitization.

    PubMed

    Castells, Mariana; Sancho-Serra, Maria del Carmen; Simarro, Maria

    2012-09-01

    Hypersensitivity reactions (HSRs) to chemotherapy drugs, such as taxanes and platins, and to monoclonal antibodies limit their therapeutic use due to the severity of some reactions and the fear of inducing a potentially lethal reaction in highly sensitized patients. Patients who experience hypersensitivity reactions face the prospect of abandoning first-line treatment and switching to a second-line, less effective therapy. Some of these reactions are mast cell-mediated hypersensitivity reactions, a subset of which occur through an immunoglobulin (IgE)-dependent mechanism, and are thus true allergies. Others involve mast cells without a demonstrable IgE mechanism. Whether basophils can participate in these reactions has not been demonstrated. Rapid drug desensitization (RDD) is a procedure that induces temporary tolerance to a drug, allowing a medication allergic patient to receive the optimal agent for his or her disease. Through RDD, patients with IgE and non-IgE HSRs can safely be administered important medications while minimizing or completely inhibiting adverse reactions. Due to the clinical expansion and success of RDD, the molecular mechanisms inducing the temporary tolerization have been investigated and are partially understood, allowing for safer and more effective protocols. This article reviews the current literature on molecular mechanisms of RDD with an emphasis in our recent contributions to this field as well as the indications, methods and outcomes of RDD for taxanes, platins, and monoclonal antibodies. PMID:22576054

  20. Normalization of sonographical multifocal nerve enlargements in a MADSAM patient following a good clinical response to intravenous immunoglobulin.

    PubMed

    Tanaka, Kanta; Ota, Natsuko; Harada, Yuzuru; Wada, Ikko; Suenaga, Toshihiko

    2016-09-01

    Focal nerve enlargements at sites of conduction blocks can be visualized sonographically in patients with multifocal acquired demyelinating sensory and motor neuropathy (MADSAM). However, little is known about association between nerve morphological changes and treatment responses. Here we present a 73-year-old female MADSAM patient whose sonographical multifocal nerve enlargements normalized following a good treatment response. She was admitted to our department with progressive asymmetrical muscle weakness and sensory disturbances for 6 months. Ultrasonography revealed multifocal nerve enlargements at sites of electrophysiological demyelination. Intravenous immunoglobulin improved her symptoms and electrophysiological abnormalities. Six months later, ultrasonography revealed normalization of multifocal nerve enlargements. Contrary to our observations, one previous report described a MADSAM patient with persistent nerve enlargements at the sites of resolved conduction blocks. In this earlier patient, however, the time from onset to remission was approximately 30 months. Morphological changes of nerve enlargements in MADSAM may vary with treatment response. PMID:27460345

  1. NEUROPHYSIOLOGICAL EVALUATION OF SENSORY SYSTEMS'

    EPA Science Inventory

    Exposure to many neurotoxic compounds has been shown to produce a sensory system dysfunction. Neurophysiological assessment of sensory function in humans and animal models often uses techniques known as sensory evoked potentials. Because both humans and animals show analogous res...

  2. Human periodontal ligament stem cells repair mental nerve injury

    PubMed Central

    Li, Bohan; Jung, Hun-Jong; Kim, Soung-Min; Kim, Myung-Jin; Jahng, Jeong Won; Lee, Jong-Ho

    2013-01-01

    Human periodontal ligament stem cells are easily accessible and can differentiate into Schwann cells. We hypothesized that human periodontal ligament stem cells can be used as an alternative source for the autologous Schwann cells in promoting the regeneration of injured peripheral nerve. To validate this hypothesis, human periodontal ligament stem cells (1 × 106) were injected into the crush-injured left mental nerve in rats. Simultaneously, autologous Schwann cells (1 × 106) and PBS were also injected as controls. Real-time reverse transcriptase polymerase chain reaction showed that at 5 days after injection, mRNA expression of low affinity nerve growth factor receptor was significantaly increased in the left trigeminal ganglion of rats with mental nerve injury. Sensory tests, histomorphometric evaluation and retrograde labeling demonstrated that at 2 and 4 weeks after injection, sensory function was significantly improved, the numbers of retrograde labeled sensory neurons and myelinated axons were significantly increased, and human periodontal ligament stem cells and autologous Schwann cells exhibited similar therapeutic effects. These findings suggest that transplantation of human periodontal ligament stem cells show a potential value in repair of mental nerve injury. PMID:25206604

  3. Peripheral nerve regeneration and neurotrophic factors

    PubMed Central

    TERENGHI, GIORGIO

    1999-01-01

    The role of neurotrophic factors in the maintenance and survival of peripheral neuronal cells has been the subject of numerous studies. Administration of exogenous neurotrophic factors after nerve injury has been shown to mimic the effect of target organ-derived trophic factors on neuronal cells. After axotomy and during peripheral nerve regeneration, the neurotrophins NGF, NT-3 and BDNF show a well defined and selective beneficial effect on the survival and phenotypic expression of primary sensory neurons in dorsal root ganglia and of motoneurons in spinal cord. Other neurotrophic factors such as CNTF, GDNF and LIF also exert a variety of actions on neuronal cells, which appear to overlap and complement those of the neurotrophins. In addition, there is an indirect contribution of GGF to nerve regeneration. GGF is produced by neurons and stimulates proliferation of Schwann cells, underlining the close interaction between neuronal and glial cells during peripheral nerve regeneration. Different possibilities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. The studies reviewed in this article show the therapeutic potential of neurotrophic factors for the treatment of peripheral nerve injury and for neuropathies. PMID:10227662

  4. Ulnar nerve damage (image)

    MedlinePlus

    ... arm. The nerve is commonly injured at the elbow because of elbow fracture or dislocation. The ulnar nerve is near ... surface of the body where it crosses the elbow, so prolonged pressure on the elbow or entrapment ...

  5. Nerve Injuries in Athletes.

    ERIC Educational Resources Information Center

    Collins, Kathryn; And Others

    1988-01-01

    Over a two-year period this study evaluated the condition of 65 athletes with nerve injuries. These injuries represent the spectrum of nerve injuries likely to be encountered in sports medicine clinics. (Author/MT)

  6. Radial nerve dysfunction (image)

    MedlinePlus

    The radial nerve travels down the arm and supplies movement to the triceps muscle at the back of the upper arm. ... the wrist and hand. The usual causes of nerve dysfunction are direct trauma, prolonged pressure on the ...

  7. Tibial nerve dysfunction

    MedlinePlus

    ... a loss of movement or sensation in the foot from damage to the tibial nerve. ... Tibial nerve dysfunction is an unusual form of peripheral ... the calf and foot muscles. A problem in function with a single ...

  8. Nerve conduction velocity

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003927.htm Nerve conduction velocity To use the sharing features on this page, please enable JavaScript. Nerve conduction velocity (NCV) is a test to see how ...

  9. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  10. Radial nerve dysfunction

    MedlinePlus

    ... nerve leads to problems with movement in the arm and wrist and with sensation in the back of the arm or hand. ... to the radial nerve, which travels down the arm and controls movement of the triceps muscle at ...

  11. Degenerative Nerve Diseases

    MedlinePlus

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many ... viruses. Sometimes the cause is not known. Degenerative nerve diseases include Alzheimer's disease Amyotrophic lateral sclerosis Friedreich's ...

  12. Engineering a multimodal nerve conduit for repair of injured peripheral nerve.

    PubMed

    Quigley, A F; Bulluss, K J; Kyratzis, I L B; Gilmore, K; Mysore, T; Schirmer, K S U; Kennedy, E L; O'Shea, M; Truong, Y B; Edwards, S L; Peeters, G; Herwig, P; Razal, J M; Campbell, T E; Lowes, K N; Higgins, M J; Moulton, S E; Murphy, M A; Cook, M J; Clark, G M; Wallace, G G; Kapsa, R M I

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate

  13. Engineering a multimodal nerve conduit for repair of injured peripheral nerve

    NASA Astrophysics Data System (ADS)

    Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate

  14. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.

    PubMed

    Ince, Hülya; Taşdemir, Haydar Ali; Aydin, Murat; Ozyürek, Hamit; Tilki, Hacer Erdem

    2015-07-01

    The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test. PMID:25342307

  15. The non-linear relationship between nerve conduction velocity and skin temperature.

    PubMed Central

    Todnem, K; Knudsen, G; Riise, T; Nyland, H; Aarli, J A

    1989-01-01

    Median motor and sensory nerves were examined in 20 healthy subjects. Superficial stimulating and recording electrodes were used, and the nerves were examined at natural skin temperature, after cooling and after heating of the arm. The conduction velocity for the fastest and slow conducting sensory fibres (temperature range 17-37 degrees C), and for the fastest conducting motor fibres (temperature range 19-38 degrees C) increased non-linearly with increase in skin temperature. Similarly, distal motor latencies increased non-linearly with decrease in skin temperature. The effect of temperature was most pronounced in the low temperature range, and change in conduction velocity per degree centigrade was reduced toward higher skin temperature. Sensory nerve response duration increased linearly with decline in skin temperature. Sensory and motor amplitude did not show any significant relation to skin temperature. PMID:2738592

  16. Nerve and muscle involvement in mitochondrial disorders: an electrophysiological study.

    PubMed

    Mancuso, Michelangelo; Piazza, Selina; Volpi, Leda; Orsucci, Daniele; Calsolaro, Valeria; Caldarazzo Ienco, Elena; Carlesi, Cecilia; Rocchi, Anna; Petrozzi, Lucia; Calabrese, Rosanna; Siciliano, Gabriele

    2012-04-01

    Involvement of the peripheral nervous system in mitochondrial disorders (MD) has been previously reported. However, the exact prevalence of peripheral neuropathy and/or myopathy in MD is still unclear. In order to evaluate the prevalence of neuropathy and myopathy in MD, we performed sensory and motor nerve conduction studies (NCS) and concentric needle electromyography (EMG) in 44 unselected MD patients. NCS were abnormal in 36.4% of cases, and were consistent with a sensori-motor axonal multineuropathy (multifocal neuropathy), mainly affecting the lower limbs. EMG evidence of myopathy was present in 54.5% of patients, again mainly affecting the lower limbs. Nerve and muscle involvement was frequently subclinical. Peripheral nerve and muscle involvement is common in MD patients. Our study supports the variability of the clinical expression of MD. Further studies are needed to better understand the molecular basis underlying the phenotypic variability among MD patients. PMID:21751099

  17. Central changes in primary afferent fibers following peripheral nerve lesions.

    PubMed

    Coggeshall, R E; Lekan, H A; Doubell, T P; Allchorne, A; Woolf, C J

    1997-04-01

    Cutting or crushing rat sciatic nerve does not significantly reduce the number of central myelinated sensory axons in the dorsal roots entering the fourth and fifth lumbar segments even over very extended periods of time. Unmyelinated axons were reduced by approximately 50%, but only long after sciatic nerve lesions (four to eight months), and reinnervation of the peripheral target did not rescue these axons. This indicates that a peripheral nerve lesion sets up a slowly developing but major shift towards large afferent fiber domination of primary afferent input into the spinal cord. In addition, since myelinated axons are never lost, this is good evidence that the cells that give rise to these fibers are also not lost. If this is the case, this would indicate that adult primary sensory neurons with myelinated axons do not depend on peripheral target innervation for survival. PMID:9130791

  18. Laryngeal nerve damage

    MedlinePlus

    Laryngeal nerve damage is injury to one or both of the nerves that are attached to the voice box. ... Injury to the laryngeal nerves is uncommon. When it does occur, it can be from: A complication of neck or chest surgery (especially thyroid, lung, ...

  19. Molecular signaling and pulpal nerve development.

    PubMed

    Fried, K; Nosrat, C; Lillesaar, C; Hildebrand, C

    2000-01-01

    The purpose of this review is to discuss molecular factors influencing nerve growth to teeth. The establishment of a sensory pulpal innervation occurs concurrently with tooth development. Epithelial/mesenchymal interactions initiate the tooth primordium and change it into a complex organ. The initial events seem to be controlled by the epithelium, and subsequently, the mesenchyme acquires odontogenic properties. As yet, no single initiating epithelial or mesenchymal factor has been identified. Axons reach the jaws before tooth formation and form terminals near odontogenic sites. In some species, local axons have an initiating function in odontogenesis, but it is not known if this is also the case with mammals. In diphyodont mammals, the primary dentition is replaced by a permanent dentition, which involves a profound remodeling of terminal pulpal axons. The molecular signals underlying this remodeling remain unknown. Due to the senescent deterioration of the dentition, the target area of tooth nerves shrinks with age, and these nerves show marked pathological-like changes. Nerve growth factor and possibly also brain-derived neurotrophic factor seem to be important in the formation of a sensory pulpal innervation. Neurotrophin-3 and -4/5 are probably not involved. In addition, glial cell line-derived neurotrophic factor, but not neurturin, seems to be involved in the control of pulpal axon growth. A variety of other growth factors may also influence developing tooth nerves. Many major extracellular matrix molecules, which can influence growing axons, are present in developing teeth. It is likely that these molecules influence the growing pulpal axons. PMID:11021633

  20. Desensitization Using Bortezomib and High-dose Immunoglobulin Increases Rate of Deceased Donor Kidney Transplantation.

    PubMed

    Jeong, Jong Cheol; Jambaldorj, Enkthuya; Kwon, Hyuk Yong; Kim, Myung-Gyu; Im, Hye Jin; Jeon, Hee Jung; In, Ji Won; Han, Miyeun; Koo, Tai Yeon; Chung, Junho; Song, Eun Young; Ahn, Curie; Yang, Jaeseok

    2016-02-01

    Combination therapy of intravenous immunoglobulin (IVIG) and rituximab showed a good transplant rate in highly sensitized wait-listed patients for deceased donor kidney transplantation (DDKT), but carried the risk of antibody-mediated rejection. The authors investigated the impact of a new combination therapy of bortezomib, IVIG, and rituximab on transplantation rate.This study was a prospective, open-labeled clinical trial. The desensitization regimen consisted of 2 doses of IVIG (2  g/kg), a single dose of rituximab (375  mg/m), and 4 doses of bortezomib (1.3  mg/m). The transplant rate was analyzed. Anti-Human leukocyte antigen (HLA) DRB antibodies were determined by a Luminex solid-phase bead assay at baseline and after 2, 3, and 6 months in the desensitized patients.There were 19 highly sensitized patients who received desensitization and 17 patients in the control group. Baseline values of class I and II panel reactive antibody (%, peak mean fluorescence intensity) were 83  ±  16.0 (14952  ±  5820) and 63  ±  36.0 (10321  ±  7421), respectively. Deceased donor kidney transplantation was successfully performed in 8 patients (42.1%) in the desensitization group versus 4 (23.5%) in the control group. Multivariate time-varying covariate Cox regression analysis showed that desensitization increased the probability of DDKT (hazard ratio, 46.895; 95% confidence interval, 3.468-634.132; P = 0.004). Desensitization decreased mean fluorescence intensity values of class I panel reactive antibody by 15.5% (20.8%) at 2 months. In addition, a liberal mismatch strategy in post hoc analysis increased the benefit of desensitization in donor-specific antibody reduction. Desensitization was well tolerated, and acute rejection occurred only in the control group.In conclusion, a desensitization protocol using bortezomib, high-dose IVIG, and rituximab increased the DDKT rate in highly sensitized, wait-listed patients. PMID:26844479

  1. Desensitization Using Bortezomib and High-dose Immunoglobulin Increases Rate of Deceased Donor Kidney Transplantation

    PubMed Central

    Jeong, Jong Cheol; Jambaldorj, Enkthuya; Kwon, Hyuk Yong; Kim, Myung-Gyu; Im, Hye Jin; Jeon, Hee Jung; In, Ji Won; Han, Miyeun; Koo, Tai Yeon; Chung, Junho; Song, Eun Young; Ahn, Curie; Yang, Jaeseok

    2016-01-01

    Abstract Combination therapy of intravenous immunoglobulin (IVIG) and rituximab showed a good transplant rate in highly sensitized wait-listed patients for deceased donor kidney transplantation (DDKT), but carried the risk of antibody-mediated rejection. The authors investigated the impact of a new combination therapy of bortezomib, IVIG, and rituximab on transplantation rate. This study was a prospective, open-labeled clinical trial. The desensitization regimen consisted of 2 doses of IVIG (2 g/kg), a single dose of rituximab (375 mg/m2), and 4 doses of bortezomib (1.3 mg/m2). The transplant rate was analyzed. Anti-Human leukocyte antigen (HLA) DRB antibodies were determined by a Luminex solid-phase bead assay at baseline and after 2, 3, and 6 months in the desensitized patients. There were 19 highly sensitized patients who received desensitization and 17 patients in the control group. Baseline values of class I and II panel reactive antibody (%, peak mean fluorescence intensity) were 83 ± 16.0 (14952 ± 5820) and 63 ± 36.0 (10321 ± 7421), respectively. Deceased donor kidney transplantation was successfully performed in 8 patients (42.1%) in the desensitization group versus 4 (23.5%) in the control group. Multivariate time-varying covariate Cox regression analysis showed that desensitization increased the probability of DDKT (hazard ratio, 46.895; 95% confidence interval, 3.468–634.132; P = 0.004). Desensitization decreased mean fluorescence intensity values of class I panel reactive antibody by 15.5% (20.8%) at 2 months. In addition, a liberal mismatch strategy in post hoc analysis increased the benefit of desensitization in donor-specific antibody reduction. Desensitization was well tolerated, and acute rejection occurred only in the control group. In conclusion, a desensitization protocol using bortezomib, high-dose IVIG, and rituximab increased the DDKT rate in highly sensitized, wait-listed patients. PMID:26844479

  2. Competitive antagonists facilitate the recovery from desensitization of α1β2γ2 GABAA receptors expressed in Xenopus oocytes

    PubMed Central

    Xu, Xiao-jun; Roberts, Diane; Zhu, Guo-nian; Chang, Yong-chang

    2016-01-01

    Aim: The continuous presence of an agonist drives its receptor into a refractory state, termed desensitization. In this study, we tested the hypothesis that a competitive antagonist, SR95531, could facilitate the recovery of α1β2γ2 GABAA receptor from functional desensitization. Methods: α1β2γ2 GABAA receptors were expressed in Xenopus oocytes. GABA-evoked currents were recorded using two-electrode voltage-clamp technique. Drugs were applied through perfusion. Results: Long application of GABA (100 μmol/L) evoked a large peak current followed by a small amplitude steady-state current (desensitization). Co-application of SR95531 during the desensitization caused a larger rebound of GABA current after removal of SR95531. Furthermore, application of SR95531 after removal of GABA increased the rate of receptor recovery from desensitization, and the recovery time constant was decreased from 59±3.2 s to 33±1.6 s. SR95531-facilitated receptor recovery from desensitization was dependent on the perfusion duration of SR95531. It was also dependent on the concentration of SR95531, and the curve fitting with Hill equation revealed two potency components, which were similar to the two potency components in inhibition of the steady-state current by SR95531. Bicuculline caused similar facilitation of desensitization recovery. Conclusion: SR95531 facilitates α1β2γ2 GABAA receptor recovery from desensitization, possibly through two mechanisms: binding to the desensitized receptor and converting it to the non-desensitized state, and binding to the resting state receptor and preventing re-desensitization. PMID:27374488

  3. Sensory perception threshold measurement: an evaluation of semiobjective testing devices.

    PubMed

    Halar, E M; Hammond, M C; LaCava, E C; Camann, C; Ward, J

    1987-08-01

    Five semiobjective devices for testing sensory perception thresholds were concomitantly used on 36 normal subjects to determine normal threshold values, intersubject variability, and their correlation with age. The five devices include the Semmes-Weinstein monofilament (touch); three-point esthesiometer (two-point discrimination); Pfizer thermal tester (temperature); biothesiometer (vibration); and Optacon tactile tester (vibration). Each subject was tested at 12 upper extremity (UE) and ten lower extremity (LE) sites. The threshold was determined by the two-alternative forced choice method. Results showed that the mean threshold for each sensory perception modality in the UE sites was significantly lower than in the LE sites. The means of distally located sites for two-point discrimination and vibration thresholds were significantly lower than the means of the proximal sites in the UE. In the LE, touch perception threshold was significantly higher distally than proximally. Distally located nerves (median and ulnar) showed lower mean threshold values than proximally located nerves for two-point discrimination. There were also similar findings for the other sensory modalities in the UE and LE. The mean threshold of dermatomes showed significant variation across the trials for two-point discrimination and vibration sensation. Distally located dermatomes showed lower threshold values than those located proximally. The means of most sites tested for each sensory modality (except vibration tested by the Optacon) showed correlation with age. There was no difference in threshold values between men and women for any sensory modality. The mean values of standard deviation were provided for each peripheral sensory nerve and dermatome.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3619613

  4. Mutations in the channel domain alter desensitization of a neuronal nicotinic receptor.

    PubMed

    Revah, F; Bertrand, D; Galzi, J L; Devillers-Thiéry, A; Mulle, C; Hussy, N; Bertrand, S; Ballivet, M; Changeux, J P

    1991-10-31

    A variety of ligand-gated ion channels undergo a fast activation process after the rapid application of agonist and also a slower transition towards desensitized or inactivated closed channel states when exposure to agonist is prolonged. Desensitization involves at least two distinct closed states in the acetylcholine receptor, each with an affinity for agonists higher than those of the resting or active conformations. Here we investigate how structural elements could be involved in the desensitization of the acetylcholine-gated ion channel from the chick brain alpha-bungarotoxin sensitive homo-oligomeric alpha 7 receptor, using site-directed mutagenesis and expression in Xenopus oocytes. Mutations of the highly conserved leucine 247 residue from the uncharged MII segment of alpha 7 suppress inhibition by the open-channel blocker QX-222, indicating that this residue, like others from MII, faces the lumen of the channel. But, unexpectedly, the same mutations decrease the rate of desensitization of the response, increase the apparent affinity for acetylcholine and abolish current rectification. Moreover, unlike wild-type alpha 7, which has channels with a single conductance level, the leucine-to-threonine mutant has an additional conducting state active at low acetylcholine concentrations. It is possible that mutation of Leu 247 renders conductive one of the high-affinity desensitized states of the receptor. PMID:1719423

  5. Short-Term Desensitization of Muscarinic K+ Current in the Heart

    PubMed Central

    Murakami, Shingo; Inanobe, Atsushi; Kurachi, Yoshihisa

    2013-01-01

    Acetylcholine (ACh) rapidly increases cardiac K+ currents (IKACh) by activating muscarinic K+ (KACh) channels followed by a gradual amplitude decrease within seconds. This phenomenon is called short-term desensitization and its precise mechanism and physiological role are still unclear. We constructed a mathematical model for IKACh to examine the conditions required to reconstitute short-term desensitization. Two conditions were crucial: two distinct muscarinic receptors (m2Rs) with different affinities for ACh, which conferred an IKACh response over a wide range of ACh concentrations, and two distinct KACh channels with different affinities for the G-protein βγ subunits, which contributed to reconstitution of the temporal behavior of IKACh. Under these conditions, the model quantitatively reproduced several unique properties of short-term desensitization observed in myocytes: 1), the peak and quasi-steady states with 0.01–100 μM [ACh]; 2), effects of ACh preperfusion; and 3), recovery from short-term desensitization. In the presence of 10 μM ACh, the IKACh model conferred recurring spontaneous firing after asystole of 8.9 s and 10.7 s for the Demir and Kurata sinoatrial node models, respectively. Therefore, two different populations of KACh channels and m2Rs may participate in short-term desensitization of IKACh in native myocytes, and may be responsible for vagal escape at nodal cells. PMID:24048003

  6. An in vitro evaluation of the effects of desensitizing agents on microleakage of Class V cavities

    PubMed Central

    Yikilgan, İhsan; Özcan, Suat; Bala, Oya; Ömürlü, Hüma

    2016-01-01

    Background The aim of this study was to evaluate the effect of a desensitizing agent on microleakage of Class V cavities. Material and Methods 72 premolar teeth were used. There were 6 groups. Class V restorations were prepared with two different restorative materials (Equia fil, GC, America and Grandio, VOCO, Germany) and two adhesive systems (Clearfil SE Bond, Kuraray, Japan and S3 Bond Plus, Kuraray, Japan) with and without desensitizing agent (Gluma Desensitizer, Heraeus Kulzer, Germany). Restorations were polished with aluminum oxide abrasive discs. Then a range of 5 - 55C thermocycling was performed 10.000 times. The microleakage of restorations was examined with dye penetration method (Basic fuchsine). Bonferroni corrections and Kruskal-Wallis test were used to determine the significance of differences in occlusal and gingival dye penetration scores between groups. Results There was no stastistical significance between the occlusal and gingival microleakage scores within the groups were shown. Conclusions It can be concluded that use of desensitizing agent under both high viscosity glass ionomer restorative materials and resin composites doesn’t affect the microleakage. Key words:High viscosity glass ionomer cement, composite resin, desensitizing agent, microleakage. PMID:26855707

  7. Lentiviral-mediated transfer of CDNF promotes nerve regeneration and functional recovery after sciatic nerve injury in adult rats

    SciTech Connect

    Cheng, Lei; Liu, Yi; Zhao, Hua; Zhang, Wen; Guo, Ying-Jun; Nie, Lin

    2013-10-18

    Highlights: •CDNF was successfully transfected by a lentiviral vector into the distal sciatic nerve. •CDNF improved S-100, NF200 expression and nerve regeneration after sciatic injury. •CDNF improved the remyelination and thickness of the regenerated sciatic nerve. •CDNF improved gastrocnemius muscle weight and sciatic functional recovery. -- Abstract: Peripheral nerve injury is often followed by incomplete and unsatisfactory functional recovery and may be associated with sensory and motor impairment of the affected limb. Therefore, a novel method is needed to improve the speed of recovery and the final functional outcome after peripheral nerve injuries. This report investigates the effect of lentiviral-mediated transfer of conserved dopamine neurotrophic factor (CDNF) on regeneration of the rat peripheral nerve in a transection model in vivo. We observed notable overexpression of CDNF protein in the distal sciatic nerve after recombinant CDNF lentiviral vector application. We evaluated sciatic nerve regeneration after surgery using light and electron microscopy and the functional recovery using the sciatic functional index and target muscle weight. HE staining revealed better ordered structured in the CDNF-treated group at 8 weeks post-surgery. Quantitative analysis of immunohistochemistry of NF200 and S-100 in the CDNF group revealed significant improvement of axonal and Schwann cell regeneration compared with the control groups at 4 weeks and 8 weeks after injury. The thickness of the myelination around the axons in the CDNF group was significantly higher than in the control groups at 8 weeks post-surgery. The CDNF group displayed higher muscle weights and significantly increased sciatic nerve index values. Our findings suggest that CDNF gene therapy could provide durable and stable CDNF protein concentration and has the potential to enhance peripheral nerve regeneration, morphological and functional recovery following nerve injury, which suggests a

  8. Mitotoxicity in distal symmetrical sensory peripheral neuropathies

    PubMed Central

    Bennett, Gary J.; Doyle, Timothy; Salvemini, Daniela

    2016-01-01

    Chronic distal symmetrical sensory peripheral neuropathy is a common neurological complication of cancer chemotherapy, HIV treatment and diabetes. Although aetiology-specific differences in presentation are evident, the clinical signs and symptoms of these neuropathies are clearly similar. Data from animal models of neuropathic pain suggest that the similarities have a common cause: mitochondrial dysfunction in primary afferent sensory neurons. Mitochondrial dysfunction is caused by mitotoxic effects of cancer chemotherapeutic drugs of several chemical classes, HIV-associated viral proteins, and nucleoside reverse transcriptase inhibitor treatment, as well as the (possibly both direct and indirect) effects of excess glucose. The mitochondrial injury results in a chronic neuronal energy deficit, which gives rise to spontaneous nerve impulses and a compartmental neuronal degeneration that is first apparent in the terminal receptor arbor—that is, intraepidermal nerve fibres—of cutaneous afferent neurons. Preliminary data suggest that drugs that prevent mitochondrial injury or improve mitochondrial function could be useful in the treatment of these conditions. PMID:24840972

  9. Lentivirus vector-mediated Rho guanine nucleotide dissociation inhibitor 2 induces beta-2 adrenergic receptor desensitization in β2AR desensitization mice model

    PubMed Central

    Ni, Songshi; Zhao, Jing; Fu, Zhenxue

    2014-01-01

    Background It is well-known that chronic administration of β2AR agonists can induce β2AR desensitization. Our previous study showed that Rho guanine nucleotide dissociation inhibitor 2 (RhoGDI2) overexpression induced beta-2 adrenergic receptor (β2AR) desensitization in airway smooth muscle cells. The purpose of this study was to further study the function of RhoGDI2 in β2AR desensitization by β2AR desensitization mouse model. Methods Studies were performed using a β2AR desensitization mice model induced by salbutamol. The mice were randomly divided into five groups (n=45): RhoGDI2 overexpression group (n=10); RhoGDI2 siRNA group (n=10); empty viral vector group (n=10); experimental control group (n=10); blank control group—without any drug treatment (n=5). The first four groups were used the same methods and the same dose to establish β2AR desensitization mice model by salbutamol. The first three groups that salbutamol-treated were used for intratracheal delivery of lentiviral vectors. Airway hyperreactivity was measured through a whole-body plethysmograph system. RhoGDI2, β2AR, GRK2 mRNA and protein expression levels were then detected by RT-PCR and western blot analyses in fresh lung tissues. As well as the activity of GRK was assessed by light-dependent phosphorylation of rhodopsin. Results We successfully constructed β2AR desensitization mouse model. As expected, airway responsiveness after inhaling acetylcholine chloride (Ach) was markedly increased in the RhoGDI2 overexpression group compared to experimental control group and blank control group when concentrations of Ach was 45 mg/mL (all P<0.05), while, it was markedly decreased in the RhoGDI2 siRNA group compared to experimental control group (P<0.05). RhoGDI2, GRK2 expressions and GRK enzymatic activity were significantly increased in RhoGDI2 overexpression group compared to experimental control group and blank control group (all P<0.05). RhoGDI2, GRK2 expressions and GRK enzymatic activity

  10. [Ganglia of peripheral nerves].

    PubMed

    Tatagiba, M; Penkert, G; Samii, M

    1993-01-01

    The authors present two different types of ganglion affecting the peripheral nerves: extraneural and intraneural ganglion. Compression of peripheral nerves by articular ganglions is well known. The surgical management involves the complete removal of the lesion with preservation of most nerve fascicles. Intraneural ganglion is an uncommon lesion which affects the nerve diffusely. The nerve fascicles are usually intimately involved between the cysts, making complete removal of all cysts impossible. There is no agreement about the best surgical management to be applied in these cases. Two possibilities are available: opening of the epineural sheath lengthwise and pressing out the lesion; or resection of the affected part of the nerve and performing a nerve reconstruction. While in case of extraneural ganglion the postoperative clinical evolution is very favourable, only long follow up studies will reveal in case of intraneural ganglion the best surgical approach. PMID:8128785

  11. Activation and Desensitization of Peripheral Muscle and Neuronal Nicotinic Acetylcholine Receptors by Selected, Naturally-Occurring Pyridine Alkaloids.

    PubMed

    Green, Benedict T; Lee, Stephen T; Welch, Kevin D; Cook, Daniel; Kem, William R

    2016-01-01

    Teratogenic alkaloids can cause developmental defects due to the inhibition of fetal movement that results from desensitization of fetal muscle-type nicotinic acetylcholine receptors (nAChRs). We investigated the ability of two known teratogens, the piperidinyl-pyridine anabasine and its 1,2-dehydropiperidinyl analog anabaseine, to activate and desensitize peripheral nAChRs expressed in TE-671 and SH-SY5Y cells. Activation-concentration response curves for each alkaloid were obtained in the same multi-well plate. To measure rapid desensitization, cells were first exposed to five potentially-desensitizing concentrations of each alkaloid in log10 molar increments from 10 nM to 100 µM and then to a fixed concentration of acetylcholine (ACh), which alone produces near-maximal activation. The fifty percent desensitization concentration (DC50) was calculated from the alkaloid concentration-ACh response curve. Agonist fast desensitization potency was predicted by the agonist potency measured in the initial response. Anabaseine was a more potent desensitizer than anabasine. Relative to anabaseine, nicotine was more potent to autonomic nAChRs, but less potent to the fetal neuromuscular nAChRs. Our experiments have demonstrated that anabaseine is more effective at desensitizing fetal muscle-type nAChRs than anabasine or nicotine and, thus, it is predicted to be more teratogenic. PMID:27384586

  12. The Effects of Systematic Desensitization on Test-Anxious Students in an Urban Community College: Learning Theory and Applications.

    ERIC Educational Resources Information Center

    Woods, Nathaniel A.

    A study involving 97 students (79 females and 18 males) at New York City Technical College was undertaken to determine the effectiveness of desensitization in reducing test anxiety and improving grade point averages (GPAs). The study compared the GPAs of students who completed workshops using the desensitization hierarchy developed by R. Strieby…

  13. Activation and Desensitization of Peripheral Muscle and Neuronal Nicotinic Acetylcholine Receptors by Selected, Naturally-Occurring Pyridine Alkaloids

    PubMed Central

    Green, Benedict T.; Lee, Stephen T.; Welch, Kevin D.; Cook, Daniel; Kem, William R.

    2016-01-01

    Teratogenic alkaloids can cause developmental defects due to the inhibition of fetal movement that results from desensitization of fetal muscle-type nicotinic acetylcholine receptors (nAChRs). We investigated the ability of two known teratogens, the piperidinyl-pyridine anabasine and its 1,2-dehydropiperidinyl analog anabaseine, to activate and desensitize peripheral nAChRs expressed in TE-671 and SH-SY5Y cells. Activation-concentration response curves for each alkaloid were obtained in the same multi-well plate. To measure rapid desensitization, cells were first exposed to five potentially-desensitizing concentrations of each alkaloid in log10 molar increments from 10 nM to 100 µM and then to a fixed concentration of acetylcholine (ACh), which alone produces near-maximal activation. The fifty percent desensitization concentration (DC50) was calculated from the alkaloid concentration-ACh response curve. Agonist fast desensitization potency was predicted by the agonist potency measured in the initial response. Anabaseine was a more potent desensitizer than anabasine. Relative to anabaseine, nicotine was more potent to autonomic nAChRs, but less potent to the fetal neuromuscular nAChRs. Our experiments have demonstrated that anabaseine is more effective at desensitizing fetal muscle-type nAChRs than anabasine or nicotine and, thus, it is predicted to be more teratogenic. PMID:27384586

  14. Desensitization of GABAergic receptors as a mechanism of zolpidem-induced somnambulism.

    PubMed

    Juszczak, Grzegorz R

    2011-08-01

    Sleepwalking is a frequently reported side effect of zolpidem which is a short-acting hypnotic drug potentiating activity of GABA(A) receptors. Paradoxically, the most commonly used medications for somnambulism are benzodiazepines, especially clonazepam, which also potentiate activity of GABA(A) receptors. It is proposed that zolpidem-induced sleepwalking can be explained by the desensitization of GABAergic receptors located on serotonergic neurons. According to the proposed model, the delay between desensitization of GABA receptors and a compensatory decrease in serotonin release constitutes the time window for parasomnias. The occurrence of sleepwalking depends on individual differences in receptor desensitization, autoregulation of serotonin release and drug pharmacokinetics. The proposed mechanism of interaction between GABAergic and serotonergic systems can be also relevant for zolpidem abuse and zolpidem-induced hallucinations. It is therefore suggested that special care should be taken when zolpidem is used in patients taking at the same time selective serotonin reuptake inhibitors. PMID:21565448

  15. Effect of combined nicotine and shrapnel exposure on pain measures and gait after nerve injury.

    PubMed

    Rittenhouse, Bradley; Hill-Pryor, Crystal D; McConathy, Adam; Parker, Peter; Franco, Nelson; Toussaint, Esra; Barker, Darrell; Prasad, Balakrishna; Pizarro, Jose M

    2011-11-01

    A significant fraction of military soldiers sustain nerve injury and use tobacco or nicotine containing products. Healing of nerve injuries is influenced by many factors, such as degree of original injury, healing potential of the nerve, and general health of patient. However, recently, it has been demonstrated that the presence of retained insoluble metal fragments decreases healing. The effects of systemic nicotine administration, with or without metal fragments at the site of nerve injury, were evaluated. Both the nicotine-administered groups (nicotine, nicotine + shrapnel) showed significant increase in the peroneal function compared with untreated controls, as assessed by paw area (p < 0.05). Furthermore, to test possible role of altered sensory function, we used the hot plate assay. Latency to withdraw paw from a hot plate was significantly shorter in nicotine groups (p < 0.05). These data indicate that nicotine improves sensory and motor aspects of nerve function, in the presence or absence of shrapnel. PMID:22165666

  16. Glycemic control and nerve conduction abnormalities in non-insulin-dependent diabetic subjects.

    PubMed

    Graf, R J; Halter, J B; Pfeifer, M A; Halar, E; Brozovich, F; Porte, D

    1981-03-01

    The influence of therapy of hyperglycemia on the progression of diabetic neuropathy is unclear. We studied variables of glycemia and motor and sensory nerve conduction velocity in a group of 18 non-insulin-dependent diabetic subjects before and after institution of diabetes therapy. Diabetes therapy significantly reduced variables of glycemia after 1, 3, 6, and 12 months. Conduction velocity of the median motor nerve was improved from baseline at each time tested during treatment. In addition, peroneal and tibial motor nerve conduction velocities improved in patients whose levels of hyperglycemia were lowered. Moreover, extent of improvement of conduction velocity of some motor nerves was related to the degree of reduction of hyperglycemia. Sensory nerve conduction velocity was not altered by diabetes therapy. These findings support the hypothesis of a metabolic component to diabetic neuropathy and suggest that optimal glycemic control may be beneficial to patients with this disorder. PMID:7013592

  17. [Development of Researches on Acupuncture Treatment of Peripheral Nerve Injury].

    PubMed

    Tao, Xing; Ma, Tie-ming

    2016-02-01

    Peripheral nerve injury is a common clinical disease. Acupuncture therapy has been demonstrated to be effective in improving nerve injury in clinical practice, but its underlying mechanisms in prompting tissue repair basically remain unknown. In the present paper, the authors reviewed some descriptions of traditional Chinese medicine on peripheral nerve injury and treatment, and recent development of researches on acupuncture treatment of it in both clinical practice and animal studies. Clinical trials demonstrated that acupuncture treatment can relieve nerve injury induced pain, ameliorate both sensory and motor functions. Experimental studies showed that acupuncture stimulation may promote nerve repair by reducing desquamation of medullary sheath of nerve fibers, inhibiting apoptosis of nerve cells, and up-regulating expression of myelin basic protein, Slit-1 protein and gene, etc. In addition, acupuncture intervention may also improve the microenvironment of neural regeneration including increase of the proliferation and differentiation of Schwann cells and release of various types of neurotrophic factors. However, its mechanisms underlying accelerating rehabilitation of peripheral nerve injury need being researched further. PMID:27141630

  18. Assessment of nerve morphology in nerve activation during electrical stimulation

    NASA Astrophysics Data System (ADS)

    Gomez-Tames, Jose; Yu, Wenwei

    2013-10-01

    The distance between nerve and stimulation electrode is fundamental for nerve activation in Transcutaneous Electrical Stimulation (TES). However, it is not clear the need to have an approximate representation of the morphology of peripheral nerves in simulation models and its influence in the nerve activation. In this work, depth and curvature of a nerve are investigated around the middle thigh. As preliminary result, the curvature of the nerve helps to reduce the simulation amplitude necessary for nerve activation from far field stimulation.

  19. Effects of lead acetate on guinea pig - cochear microphonics, action potential, and motor nerve conduction velocity

    SciTech Connect

    Yamamura, K.; Maehara, N.; Terayama, K.; Ueno, N.; Kohyama, A.; Sawada, Y.; Kishi, R.

    1987-04-01

    Segmental demyelination and axonal degeneration of motor nerves induced by lead exposure is well known in man, and animals. The effect of lead acetate exposure to man may involve the cranial nerves, since vertigo and sensory neuronal deafness have been reported among lead workers. However, there are few reports concerning the dose-effects of lead acetate both to the peripheral nerve and the cranial VII nerve with measurement of blood lead concentration. The authors investigated the effects of lead acetate to the cochlea and the VIII nerve using CM (cochlear microphonics) and AP (action potential) of the guinea pigs. The effects of lead acetate to the sciatic nerve were measured by MCV of the sciatic nerve with measurement of blood lead concentration.

  20. Neural stem/progenitor cell properties of glial cells in the adult mouse auditory nerve

    PubMed Central

    Lang, Hainan; Xing, Yazhi; Brown, LaShardai N.; Samuvel, Devadoss J.; Panganiban, Clarisse H.; Havens, Luke T.; Balasubramanian, Sundaravadivel; Wegner, Michael; Krug, Edward L.; Barth, Jeremy L.

    2015-01-01

    The auditory nerve is the primary conveyor of hearing information from sensory hair cells to the brain. It has been believed that loss of the auditory nerve is irreversible in the adult mammalian ear, resulting in sensorineural hearing loss. We examined the regenerative potential of the auditory nerve in a mouse model of auditory neuropathy. Following neuronal degeneration, quiescent glial cells converted to an activated state showing a decrease in nuclear chromatin condensation, altered histone deacetylase expression and up-regulation of numerous genes associated with neurogenesis or development. Neurosphere formation assays showed that adult auditory nerves contain neural stem/progenitor cells (NSPs) that were within a Sox2-positive glial population. Production of neurospheres from auditory nerve cells was stimulated by acute neuronal injury and hypoxic conditioning. These results demonstrate that a subset of glial cells in the adult auditory nerve exhibit several characteristics of NSPs and are therefore potential targets for promoting auditory nerve regeneration. PMID:26307538

  1. The Proximal Medial Sural Nerve Biopsy Model: A Standardised and Reproducible Baseline Clinical Model for the Translational Evaluation of Bioengineered Nerve Guides

    PubMed Central

    van Neerven, Sabien G. A.; Claeys, Kristl G.; O'Dey, Dan mon; Brook, Gary A.; Sellhaus, Bernd; Schulz, Jörg B.; Weis, Joachim; Pallua, Norbert

    2014-01-01

    Autologous nerve transplantation (ANT) is the clinical gold standard for the reconstruction of peripheral nerve defects. A large number of bioengineered nerve guides have been tested under laboratory conditions as an alternative to the ANT. The step from experimental studies to the implementation of the device in the clinical setting is often substantial and the outcome is unpredictable. This is mainly linked to the heterogeneity of clinical peripheral nerve injuries, which is very different from standardized animal studies. In search of a reproducible human model for the implantation of bioengineered nerve guides, we propose the reconstruction of sural nerve defects after routine nerve biopsy as a first or baseline study. Our concept uses the medial sural nerve of patients undergoing diagnostic nerve biopsy (≥2 cm). The biopsy-induced nerve gap was immediately reconstructed by implantation of the novel microstructured nerve guide, Neuromaix, as part of an ongoing first-in-human study. Here we present (i) a detailed list of inclusion and exclusion criteria, (ii) a detailed description of the surgical procedure, and (iii) a follow-up concept with multimodal sensory evaluation techniques. The proximal medial sural nerve biopsy model can serve as a preliminarynature of the injuries or baseline nerve lesion model. In a subsequent step, newly developed nerve guides could be tested in more unpredictable and challenging clinical peripheral nerve lesions (e.g., following trauma) which have reduced comparability due to the different nature of the injuries (e.g., site of injury and length of nerve gap). PMID:25006574

  2. Neurocontrol in sensory cortex

    NASA Astrophysics Data System (ADS)

    Ritt, Jason; Nandi, Anirban; Schroeder, Joseph; Ching, Shinung

    Technology to control neural ensembles is rapidly advancing, but many important challenges remain in applications, such as design of controls (e.g. stimulation patterns) with specificity comparable to natural sensory encoding. We use the rodent whisker tactile system as a model for active touch, in which sensory information is acquired in a closed loop between feedforward encoding of sensory information and feedback guidance of sensing motions. Motivated by this system, we present optimal control strategies that are tailored for underactuation (a large ratio of neurons or degrees of freedom to stimulation channels) and limited observability (absence of direct measurement of the system state), common in available stimulation technologies for freely behaving animals. Using a control framework, we have begun to elucidate the feedback effect of sensory cortex activity on sensing in behaving animals. For example, by optogenetically perturbing primary sensory cortex (SI) activity at varied timing relative to individual whisker motions, we find that SI modulates future sensing behavior within 15 msec, on a whisk by whisk basis, changing the flow of incoming sensory information based on past experience. J.T.R. and S.C. hold Career Awards at the Scientific Interface from the Burroughs Wellcome Fund.

  3. Examining Sensory Quadrants in Autism

    ERIC Educational Resources Information Center

    Kern, Janet K.; Garver, Carolyn R.; Carmody, Thomas; Andrews, Alonzo A.; Trivedi, Madhukar H.; Mehta, Jyutika A.

    2007-01-01

    The purpose of this study was to examine sensory quadrants in autism based on Dunn's Theory of Sensory Processing. The data for this study was collected as part of a cross-sectional study that examined sensory processing (using the Sensory Profile) in 103 persons with autism, 3-43 years of age, compared to 103 age- and gender-matched community…

  4. Engineered G protein coupled receptors reveal independent regulation of internalization, desensitization and acute signaling

    PubMed Central

    Scearce-Levie, Kimberly; Lieberman, Michael D; Elliott, Heather H; Conklin, Bruce R

    2005-01-01

    Background The physiological regulation of G protein-coupled receptors, through desensitization and internalization, modulates the length of the receptor signal and may influence the development of tolerance and dependence in response to chronic drug treatment. To explore the importance of receptor regulation, we engineered a series of Gi-coupled receptors that differ in signal length, degree of agonist-induced internalization, and ability to induce adenylyl cyclase superactivation. All of these receptors, based on the kappa opioid receptor, were modified to be receptors activated solely by synthetic ligands (RASSLs). This modification allows us to compare receptors that have the same ligands and effectors, but differ only in desensitization and internalization. Results Removal of phosphorylation sites in the C-terminus of the RASSL resulted in a mutant that was resistant to internalization and less prone to desensitization. Replacement of the C-terminus of the RASSL with the corresponding portion of the mu opioid receptor eliminated the induction of AC superactivation, without disrupting agonist-induced desensitization or internalization. Surprisingly, removal of phosphorylation sites from this chimera resulted in a receptor that is constitutively internalized, even in the absence of agonist. However, the receptor still signals and desensitizes in response to agonist, indicating normal G-protein coupling and partial membrane expression. Conclusions These studies reveal that internalization, desensitization and adenylyl cyclase superactivation, all processes that decrease chronic Gi-receptor signals, are independently regulated. Furthermore, specific mutations can radically alter superactivation or internalization without affecting the efficacy of acute Gi signaling. These mutant RASSLs will be useful for further elucidating the temporal dynamics of the signaling of G protein-coupled receptors in vitro and in vivo. PMID:15707483

  5. Receptor downregulation and desensitization enhance the information processing ability of signaling receptors

    SciTech Connect

    Shankaran, Harish; Wiley, H. S.; Resat, Haluk

    2007-11-09

    The activation of cell surface receptors in addition to initiating signaling events also triggers regulatory processes that restrict the duration of signaling. Acute attenuation of signaling can be accomplished either via ligand-induced internalization of receptors (receptor downregulation) or via ligand-induced receptor desensitization. These phenomena have traditionally been viewed in the context of “adaptation” wherein the receptor system enters a refractory state in the presence of sustained ligand stimuli and thereby prevents the cell from “over-responding” to the ligand. Here we use the epidermal growth factor receptor (EGFR) and G-protein coupled receptors (GPCR) as model systems to respectively examine the effects of downregulation and desensitization on the ability of signaling receptors to decode time-varying ligand stimuli. We show that downregulation and desensitization mechanisms can lead to tight and efficient input-output coupling thereby ensuring synchronous processing of ligand inputs. Frequency response analysis indicates that upstream elements of the EGFR and GPCR networks behave like low-pass filters. Receptor downregulation and desensitization increase the filter bandwidth thereby enabling the receptor systems to decode inputs in a wider frequency range. Further, system-theoretic analysis reveals that the receptor systems are analogous to classical mechanical over-damped oscillators. This analogy enables us to describe downregulation and desensitization as phenomena that make the systems more resilient in responding to ligand perturbations thereby improving the stability of the system resting state. We hypothesize that, in addition to serving as mechanisms for adaptation, receptor downregulation and desensitization play a critical role in temporal information processing.

  6. Desensitization of Functional µ-Opioid Receptors Increases Agonist Off-Rate

    PubMed Central

    2014-01-01

    Desensitization of µ-opioid receptors (MORs) develops over 5–15 minutes after the application of some, but not all, opioid agonists and lasts for tens of minutes after agonist removal. The decrease in function is receptor selective (homologous) and could result from 1) a reduction in receptor number or 2) a decrease in receptor coupling. The present investigation used photolysis of two caged opioid ligands to examine the kinetics of MOR-induced potassium conductance before and after MOR desensitization. Photolysis of a caged antagonist, carboxynitroveratryl-naloxone (caged naloxone), blocked the current induced by a series of agonists, and the time constant of decline was significantly decreased after desensitization. The increase in the rate of current decay was not observed after partial blockade of receptors with the irreversible antagonist, β-chlornaltrexamine (β-CNA). The time constant of current decay after desensitization was never more rapid than 1 second, suggesting an increased agonist off-rate rather than an increase in the rate of channel closure downstream of the receptor. The rate of G protein–coupled K+ channel (GIRK) current activation was examined using photolysis of a caged agonist, carboxynitrobenzyl-tyrosine-[Leu5]-enkephalin. After acute desensitization or partial irreversible block of MORs with β-CNA, there was an increase in the time it took to reach a peak current. The decrease in the rate of agonist-induced GIRK conductance was receptor selective and dependent on receptor number. The results indicate that opioid receptor desensitization reduced the number of functional receptor and that the remaining active receptors have a reduced agonist affinity. PMID:24748657

  7. Receptor downregulation and desensitization enhance the information processing ability of signalling receptors

    PubMed Central

    Shankaran, Harish; Wiley, H Steven; Resat, Haluk

    2007-01-01

    Background In addition to initiating signaling events, the activation of cell surface receptors also triggers regulatory processes that restrict the duration of signaling. Acute attenuation of signaling can be accomplished either via ligand-induced internalization of receptors (endocytic downregulation) or via ligand-induced receptor desensitization. These phenomena have traditionally been viewed in the context of adaptation wherein the receptor system enters a refractory state in the presence of sustained ligand stimuli and thereby prevents the cell from over-responding to the ligand. Here we use the epidermal growth factor receptor (EGFR) and G-protein coupled receptors (GPCR) as model systems to respectively examine the effects of downregulation and desensitization on the ability of signaling receptors to decode time-varying ligand stimuli. Results Using a mathematical model, we show that downregulation and desensitization mechanisms can lead to tight and efficient input-output coupling thereby ensuring synchronous processing of ligand inputs. Frequency response analysis indicates that upstream elements of the EGFR and GPCR networks behave like low-pass filters with the system being able to faithfully transduce inputs below a critical frequency. Receptor downregulation and desensitization increase the filter bandwidth thereby enabling the receptor systems to decode inputs in a wider frequency range. Further, system-theoretic analysis reveals that the receptor systems are analogous to classical mechanical over-damped systems. This analogy enables us to metaphorically describe downregulation and desensitization as phenomena that make the systems more resilient in responding to ligand perturbations thereby improving the stability of the system resting state. Conclusion Our findings suggest that in addition to serving as mechanisms for adaptation, receptor downregulation and desensitization can play a critical role in temporal information processing. Furthermore

  8. Primary repair of crush nerve injuries by means of biological tubulization with muscle-vein-combined grafts.

    PubMed

    Tos, Pierluigi; Battiston, Bruno; Ciclamini, Davide; Geuna, Stefano; Artiaco, Stefano

    2012-07-01

    Despite extensive research and surgical innovation, the treatment of peripheral nerve injuries remains a complex issue, particularly in nonsharp lesions. The aim of this study was to assess the clinical outcome in a group of 16 patients who underwent, in emergency, a primary repair for crush injury of sensory and mixed nerves of the upper limb with biological tubulization, namely, the muscle-vein-combined graft. The segments involved were sensory digital nerves in eight cases and mixed nerves in another eight cases (four median nerves and four ulnar nerves). The length of nerve defect ranged from 0.5 to 4 cm (mean 1.9 cm). Fifteen of 16 patients showed some degree of functional recovery. Six patients showed diminished light touch (3.61), six had protective sensation (4.31), and three showed loss of protective sensation (4.56) using Semmes-Weinstein monofilament test. All the patients who underwent digital nerve repair had favorable results graded as S4 in one case, S3+ in six cases, and S3 in one case. With respect to mixed nerve repair, we observed two S4, two S3+, two S3, one S2, and one S0 sensory recovery. Less favorable results were observed for motor function with three M4, one M3, two M2, and two M0 recoveries. Altogether, the results of this retrospective study demonstrates that tubulization nerve repair in emergency, in case of short nerve gaps, may restore the continuity of the nerve avoiding secondary nerve grafting. This technique preserves donor nerve and, in case of failure, does not preclude a delayed repair with a nerve graft. PMID:22422438

  9. [Subacute sensory neuronopathy associated with squamous cell carcinoma of the lung: a case report].

    PubMed

    Noto, Yuichi; Shiga, Kensuke; Fujinami, Jun; Mizuno, Toshiki; Nakagawa, Masanori; Tanaka, Keiko

    2009-08-01

    We report a 59-year-old man who developed dysesthesia in all extremities with severe loss of deep sensation over three months. A radiating radicular pain was also noted in the extremities. The nerve conduction study barely elicited sensory nerve action potentials both in the median and in the sural nerve. An extensive search for anti-neuronal antibodies including anti-Hu and anti-CV2 antibody was negetive. The biopsy specimen of an enlarged tracheobronchial lymph node revealed squamous cell carcinoma. The subsequent chemotherapy and radiation therapy for the neoplasm improved the radicular pain and the deep sensation to a moderate extent, leading to the diagnosis of paraneoplastic subacute sensory neuropathy (SSN). In general, cases with paraneoplastic SSN are associated mostly with small cell lung cancer, and quite rarely with squamous cell lung cancer. The early detection and the treatment of the primary tumor are crucial in a patient with subacute progression of sensory-dominant neuropathy. PMID:19827601

  10. High-resolution magnetic resonance imaging of the lower extremity nerves.

    PubMed

    Burge, Alissa J; Gold, Stephanie L; Kuong, Sharon; Potter, Hollis G

    2014-02-01

    Magnetic resonance (MR) imaging of the nerves, commonly known as MR neurography is increasingly being used as noninvasive means of diagnosing peripheral nerve disease. High-resolution imaging protocols aimed at imaging the nerves of the hip, thigh, knee, leg, ankle, and foot can demonstrate traumatic or iatrogenic injury, tumorlike lesions, or entrapment of the nerves, causing a potential loss of motor and sensory function in the affected area. A thorough understanding of normal MR imaging and gross anatomy, as well as MR findings in the presence of peripheral neuropathies will aid in accurate diagnosis and ultimately help guide clinical management. PMID:24210318

  11. Biological and Electrophysiologic Effects of Poly(3,4-ethylenedioxythiophene) on Regenerating Peripheral Nerve Fibers

    PubMed Central

    Baghmanli, Ziya; Sugg, Kristoffer B.; Wei, Benjamin; Shim, Bong S.; Martin, David C.; Cederna, Paul S.; Urbanchek, Melanie G.

    2014-01-01

    Background Uninjured peripheral nerves in upper-limb amputees represent attractive sites for connectivity with neuroprostheses because their predictable internal topography allows for precise sorting of motor and sensory signals. The inclusion of poly(3,4-ethylenedioxythiophene) reduces impedance and improves charge transfer at the biotic-abiotic interface. This study evaluates the in vivo performance of poly(3,4-ethylenedioxythiophene)–coated interpositional decellularized nerve grafts across a critical nerve conduction gap, and examines the long-term effects of two different poly(3,4-ethylenedioxythiophene) formulations on regenerating peripheral nerve fibers. Methods In 48 rats, a 15-mm gap in the common peroneal nerve was repaired using a nerve graft of equivalent length, including (1) decellularized nerve chemically polymerized with poly(3,4-ethylenedioxythiophene) (dry); (2) decellularized nerve electrochemically polymerized with poly(3,4-ethylenedioxythiophene) (wet); (3) intact nerve; (4) autogenous nerve graft; (5) decellularized nerve alone; and (6) unrepaired nerve gap controls. All groups underwent electrophysiologic characterization at 3 months, and nerves were harvested for histomorphometric analysis. Results Conduction velocity was significantly faster in the dry poly(3,4-ethylenedioxythiophene) group compared with the sham, decellularized nerve, and wet poly(3,4-ethylenedioxythiophene) groups. Maximum specific force for the dry poly(3,4-ethylenedioxythiophene) group was more similar to sham than were decellularized nerve controls. Evident neural regeneration was demonstrated in both dry and wet poly(3,4-ethylenedioxythiophene) groups by the presence of normal regenerating axons on histologic cross-section. Conclusions Both poly(3,4-ethylenedioxythiophene) formulations were compatible with peripheral nerve regeneration at 3 months. This study supports poly(3,4-ethylenedioxythiophene) as a promising adjunct for peripheral nerve interfaces for

  12. Processing of nerve biopsies: A practical guide for neuropathologists

    PubMed Central

    Weis, Joachim; Brandner, Sebastian; Lammens, Martin; Sommer, Claudia; Vallat, Jean-Michel

    2012-01-01

    Nerve biopsy is a valuable tool in the diagnostic work-up of peripheral neuropathies. Currently, major indications include interstitial pathologies such as suspected vasculitis and amyloidosis, atypical cases of inflammatory neuropathy and the differential diagnosis of hereditary neuropathies that cannot be specified otherwise. However, surgical removal of a piece of nerve causes a sensory deficit and – in some cases – chronic pain. Therefore, a nerve biopsy is usually performed only when other clinical, laboratory and electrophysiological methods have failed to clarify the cause of disease. The neuropathological work-up should include at least paraffin and resin semithin histology using a panel of conventional and immunohistochemical stains. Cryostat section staining, teased fiber preparations, electron microscopy and molecular genetic analyses are potentially useful additional methods in a subset of cases. Being performed, processed and read by experienced physicians and technicians nerve biopsies can provide important information relevant for clinical management. PMID:22192700

  13. Cross-face nerve transfer for established trigeminal branch II palsy.

    PubMed

    Koshima, Isao; Narushima, Mitsunaga; Mihara, Makoto; Uchida, Gentaro; Nakagawa, Masahiro

    2009-12-01

    Reconstruction for trigeminal nerve II palsy is challenging. Cross-face nerve transfer from the contralateral trigeminal nerve facilitates this reconstruction. However, the microanatomy and techniques required for nerve sutures cause problems for many surgeons. Following the recent development of supramicrosurgical techniques appropriate for the microanatomy of peripheral nerves, a new method of intraoral "cross-face nerve transfer" was successfully used for repairing trigeminal nerve II palsy. Two cases of trigeminal nerve II palsy were repaired with contralateral trigeminal nerve transfer without any nerve graft. Affected upper labial sensory recovery was 1.65 to 2.44 (Semmes-Weinstein values) and 15 to 30 mm (moving 2-point discriminations) at 1 to 1 1/2 years after surgery. The advantages of this method are excellent nerve regeneration and the lack of donor site morbidity. It is a brief and simple operation in comparison to free nerve grafts. The disadvantage is a need for a supramicrosurgical technique, using a needle less than 80 microm wide. PMID:19934846

  14. Neurotoxicity of perineural vs intraneural-extrafascicular injection of liposomal bupivacaine in the porcine model of sciatic nerve block.

    PubMed

    Damjanovska, M; Cvetko, E; Hadzic, A; Seliskar, A; Plavec, T; Mis, K; Vuckovic Hasanbegovic, I; Stopar Pintaric, T

    2015-12-01

    Liposomal bupivacaine is a prolonged-release local anaesthetic, the neurotoxicity of which has not yet been determined. We used quantitative histomorphometric and immunohistochemical analyses to evaluate the neurotoxic effect of liposomal bupivacaine after perineural and intraneural (extrafascicular) injection of the sciatic nerve in pigs. In this double-blind prospective randomised trial, 4 ml liposomal bupivacaine 1.3% was injected either perineurally (n = 5) or intraneurally extrafascicularly (n = 5). Intraneural-extrafascicular injection of saline (n = 5) was used as a control. After emergence from anaesthesia, neurological examinations were conducted over two weeks. After harvesting the sciatic nerves, no changes in nerve fibre density or myelin width indicative of nerve injury were observed in any of the groups. Intraneural injections resulted in longer sensory blockade than perineural (p < 0.003) without persistent motor or sensory deficit. Sciatic nerve block with liposomal bupivacaine in pigs did not result in histological evidence of nerve injury. PMID:26338496

  15. Nerve conduction abnormalities in untreated maturity-onset diabetes: relation to levels of fasting plasma glucose and glycosylated hemoglobin.

    PubMed

    Graf, R J; Halter, J B; Halar, E; Porte, D

    1979-03-01

    The role of metabolic abnormalities in the development of diabetic neuropathy is controversial. To investigate the influence of hyperglycemia on nerve conduction, we studied 20 untreated maturity-onset diabetic patients and 23 normal control subjects of similar age. Nerve conduction velocity of motor (median, peroneal, and tibial) and sensory (median and sural) nerves in diabetic patients was significantly slowed and H-reflex latency time prolonged. Levels of fasting plasma glucose in diabetic subjects were correlated with slowed motor conduction velocity of the median, peroneal, and tibial nerves but not with sensory nerve conduction velocities. Levels of glycosylated hemoglobin, an index of long-term glycemia, were correlated with slowing of peroneal motor conduction velocity in diabetic patients. These associations could not be explained by patient age or duration of diabetes. These findings suggest that the degree of hyperglycemia of untreated maturity-onset diabetes contributes to the motor nerve conduction abnormalities in this disease. PMID:426398

  16. Fiber components of the recurrent laryngeal nerve in the cat.

    PubMed

    Gacek, R R; Lyon, M J

    1976-01-01

    Experimental neuroanatomical methods were employed in 21 adult cats to determine 1) the number and size of myelinated motor and sensory fibers in the recurrent laryngeal nerve (RLN), and 2) the fiber components originating in the nucleus ambiguus (NA) and retrofacial nucleus (RFN) of the brain stem. Intracranial transection of the X and XI cranial nerves and selective destruction of the NA or RFN were the experimental lesions inflicted in order to obtain the following results. About 55% (312) of the right RLN (565 fibers) is composed of myelinated motor nerve fibers which measure 4 mu - 9 mu in diameter. Nine percent come from the RFN and are smaller (4-6 mu) than the 46% which emanate from the NA and measure 6-9 mu in diameter. The remaining 45% of the RLN is made up of sensory neurons which can be divided into three groups. 1) The largest numerical group (32%) is very small in caliber (1-3 mu) and supplies extralaryngeal regions (trachea, esophagus). 2) The intermediate size fiber group (4-9 mu) comprises 11% of the RLN and probably supplies the subglottic mucosa. 3) The smallest group (2%) of sensory fibers is the largest in diameter (10-15 mu) and may represent either the innervation of muscle spindles or afferents from the superior laryngeal nerve coursing down into the chest. PMID:949153

  17. Effects of Topical Nasal Anesthetic on Fiberoptic Endoscopic Examination of Swallowing with Sensory Testing (FEESST)

    PubMed Central

    McCullough, Gary H.; Guidry, Tiffany J.; Mennemeier, Mark; Schluterman, Keith

    2013-01-01

    Objections to the use of topical nasal anesthesia (TNA) during fiberoptic endoscopic evaluation of swallowing (FEES) with sensory testing (FEESST) have been raised, primarily because of the possibility of desensitizing the pharyngeal and laryngeal mucosa and affecting both the sensory and motor aspects of the swallow. Furthermore, it has been suggested that TNA is not necessary during FEES as it does not improve patient comfort or make the procedure easier for the endoscopist. The purpose of this double-blind, randomized, controlled, crossover clinical trial was to determine how gel TNA during flexible endoscopic evaluation of swallowing with sensory testing affects sensation, swallowing, and comfort rating scores in healthy nondysphagic participants. Laryngopharyngeal sensory thresholds and swallowing durations were compared between two conditions: TNA and sham. Transition duration decreased statistically significantly during the TNA condition compared to the sham for 10 ml only (p < 0.05). All other swallowing measures did not change between the conditions. Laryngopharyngeal sensory thresholds and perceptions did not change between conditions. No change was observed for subject comfort scores, ease of exam, or quality of view. Future studies should evaluate TNA administration variables, including concentration, dosage amount, and method of application, to determine the optimal strategy for providing comfort while avoiding altered swallowing. PMID:23828313

  18. The Furcal Nerve Revisited

    PubMed Central

    Dabke, Harshad V.

    2014-01-01

    Atypical sciatica and discrepancy between clinical presentation and imaging findings is a dilemma for treating surgeon in management of lumbar disc herniation. It also constitutes ground for failed back surgery and potential litigations thereof. Furcal nerve (Furcal = forked) is an independent nerve with its own ventral and dorsal branches (rootlets) and forms a link nerve that connects lumbar and sacral plexus. Its fibers branch out to be part of femoral and obturator nerves in-addition to the lumbosacral trunk. It is most commonly found at L4 level and is the most common cause of atypical presentation of radiculopathy/sciatica. Very little is published about the furcal nerve and many are unaware of its existence. This article summarizes all the existing evidence about furcal nerve in English literature in an attempt to create awareness and offer insight about this unique entity to fellow colleagues/professionals involved in spine care. PMID:25317309

  19. Neuroepithelial circuit formed by innervation of sensory enteroendocrine cells

    PubMed Central

    Bohórquez, Diego V.; Shahid, Rafiq A.; Erdmann, Alan; Kreger, Alex M.; Wang, Yu; Calakos, Nicole; Wang, Fan; Liddle, Rodger A.

    2015-01-01

    Satiety and other core physiological functions are modulated by sensory signals arising from the surface of the gut. Luminal nutrients and bacteria stimulate epithelial biosensors called enteroendocrine cells. Despite being electrically excitable, enteroendocrine cells are generally thought to communicate indirectly with nerves through hormone secretion and not through direct cell-nerve contact. However, we recently uncovered in intestinal enteroendocrine cells a cytoplasmic process that we named neuropod. Here, we determined that neuropods provide a direct connection between enteroendocrine cells and neurons innervating the small intestine and colon. Using cell-specific transgenic mice to study neural circuits, we found that enteroendocrine cells have the necessary elements for neurotransmission, including expression of genes that encode pre-, post-, and transsynaptic proteins. This neuroepithelial circuit was reconstituted in vitro by coculturing single enteroendocrine cells with sensory neurons. We used a monosynaptic rabies virus to define the circuit’s functional connectivity in vivo and determined that delivery of this neurotropic virus into the colon lumen resulted in the infection of mucosal nerves through enteroendocrine cells. This neuroepithelial circuit can serve as both a sensory conduit for food and gut microbes to interact with the nervous system and a portal for viruses to enter the enteric and central nervous systems. PMID:25555217

  20. Neuroepithelial circuit formed by innervation of sensory enteroendocrine cells.

    PubMed

    Bohórquez, Diego V; Shahid, Rafiq A; Erdmann, Alan; Kreger, Alex M; Wang, Yu; Calakos, Nicole; Wang, Fan; Liddle, Rodger A

    2015-02-01

    Satiety and other core physiological functions are modulated by sensory signals arising from the surface of the gut. Luminal nutrients and bacteria stimulate epithelial biosensors called enteroendocrine cells. Despite being electrically excitable, enteroendocrine cells are generally thought to communicate indirectly with nerves through hormone secretion and not through direct cell-nerve contact. However, we recently uncovered in intestinal enteroendocrine cells a cytoplasmic process that we named neuropod. Here, we determined that neuropods provide a direct connection between enteroendocrine cells and neurons innervating the small intestine and colon. Using cell-specific transgenic mice to study neural circuits, we found that enteroendocrine cells have the necessary elements for neurotransmission, including expression of genes that encode pre-, post-, and transsynaptic proteins. This neuroepithelial circuit was reconstituted in vitro by coculturing single enteroendocrine cells with sensory neurons. We used a monosynaptic rabies virus to define the circuit's functional connectivity in vivo and determined that delivery of this neurotropic virus into the colon lumen resulted in the infection of mucosal nerves through enteroendocrine cells. This neuroepithelial circuit can serve as both a sensory conduit for food and gut microbes to interact with the nervous system and a portal for viruses to enter the enteric and central nervous systems. PMID:25555217

  1. Afferent neurons of the hypoglossal nerve of the rat as demonstrated by horseradish peroxidase tracing.

    PubMed

    Neuhuber, W; Mysicka, A

    1980-01-01

    Cell bodies of sensory neurons of the rat's hypoglossal nerve were demonstrated by the somatopetal horseradish peroxidase (HRP) transport technique. Labelled perikarya were found within the second and third cervical spinal ganglia and in the vagal sensory ganglia. After application of HRP to the cut peripheral trunk of the hypoglossal nerve about 200 labelled cell bodies were counted in each animal. The vast majority of the axons from cervical spinal ganglion cells reach the hypoglossal nerve via the descending ramus (N. descendens hypoglossi). However, there may exist an additional pathway, probably via the cervical sympathetic trunk. Application of HPR to the medial and lateral end branches led to a labelling of much fewer spinal ganglion cells while the number of labelled vegal sensory neurons remained unchanged. Thus, it is suggested that the majority of the cervical afferents of the hypoglossal nerve originates within the extrinsic tongue musculature and the geniohyoid muscle, whereas the vagal afferents may perhaps derive exclusively from the intrinsic muslces. Histograms of the mean diameters of labelled cell bodies show a predominance of very small perikarya. This contrasts with the diameter distribution of sensory perikarya labelled after HRP application to nerves supplying other skeletal muscles. It is therefore assumed that the afferent component of the hypoglossal nerve is composed mainly of small-calibre axons. PMID:7356184

  2. Extrinsic Sensory Innervation of the Gut: Structure and Function.

    PubMed

    Brookes, Simon; Chen, Nan; Humenick, Adam; Spencer, Nick J; Costa, Marcello

    2016-01-01

    Extrinsic sensory neurons play a key role in the function of the gastrointestinal tract. They are responsible for the sensations that arise in the gut and can initiate automatic reflexes. In some cases, disordered sensation is clinically problematic-pain, bloating, excessive urgency and nausea are well-known examples. Major advances have been made in understanding the function of somatic sensory neurons in the last 50 years. However, the sensory neurons that mediate sensations from the viscera remain less well understood. This is partly because viscera receive a dense autonomic innervation that can be difficult to separate from extrinsic sensory neurons. A key requirement to understand the genesis of sensation is to distinguish the different classes of sensory neurons and the types of stimuli which they encode. The aim of this short paper is to summarise what was known about these matters 30 years ago and highlight some of the major advances in the understanding of the types of extrinsic sensory neurons to the gut. Necessarily, the choice of papers is somewhat idiosyncratic, but they illustrate the range of advances that have been made in distinguishing the different classes of gastrointestinal afferent nerves. PMID:27379635

  3. Endoscopic Facial Nerve Surgery.

    PubMed

    Marchioni, Daniele; Soloperto, Davide; Rubini, Alessia; Nogueira, João Flávio; Badr-El-Dine, Mohamed; Presutti, Livio

    2016-10-01

    Tympanic facial nerve segment surgery has been traditionally performed using microscopic approaches, but currently, exclusive endoscopic approaches have been performed for traumatic, neoplastic, or inflammatory diseases, specially located at the geniculate ganglion, greater petrosal nerve, and second tract of the facial nerve, until the second genu. The tympanic segment of the facial nerve can be reached and visualized using an exclusive transcanal endoscopic approach, even in poorly accessible regions such as the second genu and geniculate ganglion, avoiding mastoidectomy, bony demolition, and meningeal or cerebral lobe tractions, with low complication rates using a minimally invasive surgical route. PMID:27468633

  4. Distinct signaling of Drosophila chemoreceptors in olfactory sensory neurons

    PubMed Central

    Cao, Li-Hui; Jing, Bi-Yang; Yang, Dong; Zeng, Xiankun; Shen, Ying; Tu, Yuhai; Luo, Dong-Gen

    2016-01-01

    In Drosophila, olfactory sensory neurons (OSNs) rely primarily on two types of chemoreceptors, odorant receptors (Ors) and ionotropic receptors (Irs), to convert odor stimuli into neural activity. The cellular signaling of these receptors in their native OSNs remains unclear because of the difficulty of obtaining intracellular recordings from Drosophila OSNs. Here, we developed an antennal preparation that enabled the first recordings (to our knowledge) from targeted Drosophila OSNs through a patch-clamp technique. We found that brief odor pulses triggered graded inward receptor currents with distinct response kinetics and current–voltage relationships between Or- and Ir-driven responses. When stimulated with long-step odors, the receptor current of Ir-expressing OSNs did not adapt. In contrast, Or-expressing OSNs showed a strong Ca2+-dependent adaptation. The adaptation-induced changes in odor sensitivity obeyed the Weber–Fechner relation; however, surprisingly, the incremental sensitivity was reduced at low odor backgrounds but increased at high odor backgrounds. Our model for odor adaptation revealed two opposing effects of adaptation, desensitization and prevention of saturation, in dynamically adjusting odor sensitivity and extending the sensory operating range. PMID:26831094

  5. Diagnosis of Severe Carpal Tunnel Syndrome Using Nerve Conduction Study and Ultrasonography.

    PubMed

    Fujimoto, Kazuhiro; Kanchiku, Tsukasa; Kido, Kenji; Imajo, Yasuaki; Funaba, Masahiro; Taguchi, Toshihiko

    2015-10-01

    This study investigated the correlation between nerve conduction study and ultrasonographic findings for assessment of the usefulness of ultrasonography in determining carpal tunnel syndrome severity. Hands of adults with carpal tunnel syndrome were assessed using ultrasound and nerve conduction studies and grouped according to median nerve cross-sectional area (CSA). There were significant differences (p < 0.01) in mean median nerve CSA between controls, patients with median sensory nerve conduction velocity ≤40 m/s and patients with absent sensory nerve action potential and between controls, patients with median nerve distal motor latency ≥4.5 ms and patients with absent compound muscle action potentials of the abductor pollicis brevis. This is the first report to define median nerve CSA cutoff values (18 mm(2)) for determining carpal tunnel syndrome severity in patients with absent compound muscle action potentials of the abductor pollicis brevis. Median nerve CSA values below the cutoff values should prompt clinicians to consider other disorders, such as cervical compressive myelopathy. PMID:26111913

  6. Efficacy of lidocaine hydrochloride for laryngeal desensitization: a clinical comparison of techniques in the cat.

    PubMed

    Dyson, D H

    1988-05-01

    Assessment of laryngeal relaxation and ease of intubation in cats was made after preanesthetic medication with acepromazine/meperidine/atropine (IM) and induction of anesthesia 20 minutes later by thiopental administration (IV). Healthy cats (n = 32) scheduled for elective surgery were randomly assigned to 1 of 4 treatment groups to be provided with laryngeal desensitization: group 1, 2% lidocaine HCl (2 mg/kg of body weight) given IV 30 seconds before thiopental induction; group 2, 2% lidocaine HCl (2 mg/kg) topically applied to the larynx; group 3, 10% lidocaine HCl (10 mg) as a topical aerosol; and group 4, no treatment before intubation. A significant (P less than 0.05; ANOVA) difference between groups in the reaction to intubation attempts was apparent. Cats receiving 2% lidocaine IV or no treatment for desensitization had a greater response to intubation than did those receiving 2% or 10% lidocaine topically. The number of attempts required to intubate cats was significantly (P less than 0.05) greater in cats with no treatment than in cats treated topically with 2% or 10% lidocaine. Response to IV administration of 2% lidocaine HCl was not significantly different from the response to other treatments, indicating little advantage over no laryngeal desensitization. It was concluded that topical application of 2% lidocaine (2 mg/kg) or 10% lidocaine aerosol 1 1/2 minutes before intubation provides effective laryngeal desensitization in the cat. PMID:3391852

  7. Ceftaroline desensitization procedure in a pregnant patient with multiple drug allergies.

    PubMed

    Kuhlen, James L; Blumenthal, Kimberly G; Sokol, Caroline L; Balekian, Diana S; Weil, Ana A; Varughese, Christy A; Shenoy, Erica S; Banerji, Aleena

    2015-01-01

    Validated skin testing is lacking for many drugs, including ceftaroline. The cross-reactivity between ceftaroline and other β-lactam antibiotics is unknown. We report a case of a pregnant patient with cystic fibrosis and multiple drug allergies who required ceftaroline for methicillin-resistant Staphylococcus aureus pneumonia and underwent an uncomplicated empiric desensitization procedure. PMID:26034776

  8. Preshock Desensitization Phenomena during Initiation of Covered Heterogeneous Explosives by Shaped Charge Jets

    NASA Astrophysics Data System (ADS)

    Hussain, Tariq; Liu, Yan; Huang, Fenglei; Tanver, Abbas

    2016-04-01

    The initiation of heterogeneous explosives by shaped charge jets is discussed. A reactive flow model, specially modified to account for the desensitization effects due to preshocking in heterogeneous explosives, is used to investigate the initiation of explosives by a shaped charge jet. Previously reported shaped charge jet initiation experimental setups are simulated using hydrodynamic software LS-DYNA with the desensitization model implemented as a user-defined equation of state. The simulation results indicate that the desensitization effects caused by the shocks preceding the jet play a significant role in determination of the run to detonation distance for covered explosives initiated by jets. The failure in initiation in the first explosive sample that is in contact with the steel plate and initiation of the second sample separated further by an air gap during penetration of the jet can be explained on the basis of desensitization phenomena. The simulation qualitatively reproduces various shock interaction phenomenon occurring in explosives during penetration by a shaped charge jet.

  9. Desensitization of Test-Anxious Urban Community College Students and Resulting Changes in Grade Point Average.

    ERIC Educational Resources Information Center

    Hudesman, John; Wiesner, Ezra

    1979-01-01

    Examines a nine-session behavior modification program to relieve test anxiety in which instruction in muscle relaxation techniques was followed by desensitization to 25 test-related anxiety-producing items. An experimental group showed a significant increase in grade point average compared to a control group. (MB)

  10. Eye movement desensitization treatment of a child's nightmares: a case report.

    PubMed

    Pellicer, X

    1993-03-01

    A new therapeutic method (eye movement desensitization), described in 1989 by Shapiro, was applied to the treatment of recurrent nightmares in a 10-year-old girl. The technique, in a single session, resulted in the complete remission of the nightmares. There was no relapse during a 6 month follow-up. PMID:8103777

  11. Accelerated Desensitization and Adaptive Attitudes Interventions and Test Gains with Academic Probation Students

    ERIC Educational Resources Information Center

    Driscoll, Richard; Holt, Bruce; Hunter, Lori

    2005-01-01

    The study evaluates the test-gain benefits of an accelerated desensitization and adaptive attitudes intervention for test-anxious students. College students were screened for high test anxiety. Twenty anxious students, half of them on academic probation, were assigned to an Intervention or to a minimal treatment Control group. The Intervention was…

  12. A Review of Eye Movement Desensitization and Reprocessing (EMDR): Research Findings and Implications for Counsellors.

    ERIC Educational Resources Information Center

    MacCluskie, Kathryn C.

    1998-01-01

    States that within the last six years a new therapeutic technique for the treatment of posttraumatic stress disorder, Eye Movement Desensitization and Reprocessing (EMDR), has emerged. Examines the strengths and weaknesses of published studies concerning EMDR, describes the nature of the debate about the efficacy of EMDR, and reviews implications…

  13. Using Eye Movement Desensitization and Reprocessing To Enhance Treatment of Couples.

    ERIC Educational Resources Information Center

    Protinsky, Howard; Sparks, Jennifer; Flemke, Kimberly

    2001-01-01

    Eye Movement Desensitization and Reprocessing (EMDR) as a clinical technique may enhance treatment effectiveness when applied in couple therapy that is emotionally and experientially oriented. Clinical experience indicates EMDR-based interventions are useful for accessing and reprocessing intense emotions in couple interactions. EMDR can amplify…

  14. Eye Movement Desensitization and Reprocessing (EMDR) Treatment for Psychologically Traumatized Individuals.

    ERIC Educational Resources Information Center

    Wilson, Sandra A.; And Others

    1995-01-01

    Studies the effects of 3 90-minute Eye Movement Desensitization and Reprocessing (EMDR) treatment sessions on traumatic memories of 80 participants. Participants receiving EMDR showed decreases in complaints and anxiety, and increases in positive cognition. Participants in the delayed-treatment condition showed no improvement in any measures in…

  15. Facilitating and Debilitating Test Anxiety Among College Students and Volunteers for Desensitization Workshops

    ERIC Educational Resources Information Center

    Hudesman, John; Wiesner, Ezra

    1978-01-01

    Examines whether the degree of facilitating and debilitating test anxiety is different for students who volunteer for test anxiety desensitization workshops than it is for the general college population, whether test anxiety in urban community college students is correlated, and whether either or both of the AAT scales are predictive of student…

  16. Sensory axon regeneration: rebuilding functional connections in the spinal cord

    PubMed Central

    Smith, George M.; Falone, Anthony E.; Frank, Eric

    2011-01-01

    Functional regeneration within the adult spinal cord remains a formidable task. A major barrier to regeneration of sensory axons into the spinal cord is the dorsal root entry zone. This region displays many of the inhibitory features characteristic of other central nervous system injuries. Several experimental treatments, including inactivation of inhibitory molecules (such as Nogo and chondroitin sulfate proteoglycans) or administration of neurotrophic factors (such as nerve growth factor, neurotrophin3, glial derived neurotrophic factor and artemin), have been found to promote anatomical and functional regeneration across this barrier. There have been relatively few experiments, however, to determine if regenerating axons project back to their appropriate target areas within the spinal cord. This review focuses on recent advances in sensory axon regeneration, including studies assessing the ability of sensory axons to reconnect with their original synaptic targets. PMID:22137336

  17. Alkaline phosphatase relieves desensitization of adenylate cyclase-coupled beta-adrenergic receptors in avian erythrocyte membranes

    SciTech Connect

    Stadel, J.M.; Rebar, R.; Crooke, S.T.

    1987-05-01

    Desensitization of adenylate cyclase-coupled ..beta..-adrenergic receptors in avian erythrocytes results in 40-65% decrease in agonist-stimulated adenylate cyclase activity and correlates with increased phosphorylation of ..beta..-adrenergic receptors. To assess the role of phosphorylation in desensitization, membranes from isoproterenol- and cAMP-desensitized turkey erythrocytes were incubated with alkaline phosphatase for 30 min at 37/sup 0/C, pH = 8.0. In both cases alkaline phosphatase treatment significantly reduced desensitization of agonist-stimulated adenylate cyclase activity by 40-60%. Similar results were obtained following alkaline phosphatase treatment of membranes from isoproterenol- and cAMP-desensitized duck erythrocytes. In addition, alkaline phosphatase treatment of membranes from duck erythrocytes desensitized with phorbol 12-mystrate 13-acetate returned adenylate cyclase activity to near control values. In all experiments inclusion of 20 mM NaPO/sub 4/ to inhibit alkaline phosphatase during treatment of membranes blocked the enzyme's effect on agonist-stimulated adenylate cyclase activity. These results demonstrate a role for phosphorylation in desensitization of adenylate cyclase-coupled ..beta..-adrenergic receptors in avian erythrocytes.

  18. Change in desensitization of cat muscle acetylcholine receptor caused by coexpression of Torpedo acetylcholine receptor subunits in Xenopus oocytes.

    PubMed Central

    Sumikawa, K; Miledi, R

    1989-01-01

    Cat muscle acetylcholine receptors (AcChoR) expressed in Xenopus oocytes desensitized more slowly than Torpedo electric organ AcChoRs, also expressed in oocytes. To examine the bases for the different degrees of desensitization, cat-Torpedo AcChoR hybrids were formed by injecting oocytes with cat denervated muscle mRNA mixed with a large excess of cloned Torpedo AcChoR subunit mRNAs. Hybrid AcChoRs formed by coinjection of cat muscle mRNA with the Torpedo beta or delta subunit mRNAs desensitized as slowly as cat AcChoR. In contrast, the hybrid AcChoRs expressed by coinjection with the Torpedo gamma subunit mRNA desensitized much more rapidly than cat AcChoR. The AcChoRs expressed in oocytes injected with cat muscle mRNA together with the Torpedo beta, gamma, and delta subunit mRNAs desensitized as rapidly as Torpedo AcChoR, indicating that the cat alpha subunit does not play an important role in determining the slow rate of desensitization. It is concluded that the difference in the rates of desensitization of cat and Torpedo AcChoRs is determined mainly by differences in their respective gamma subunits. Images PMID:2536157

  19. Motor nerve conduction velocity is affected in segmental vitiligo lesional limbs.

    PubMed

    Zhou, Jun; Zhong, Zhenyu; Li, Jian; Fu, Wenwen

    2016-06-01

    To evaluate the effects of segmental vitiligo (SV) on nerve conduction velocity (NCV) in different nerves, we compared the patient's lesional side of their body to the contralateral normal side. The 106 participants were selected from outpatients visiting the dermatological clinics of Huashan Hospital, Fudan University, from November 2011 to March 2014. NCVs were measured on the limbs and the face, including both motor and sensory nerves. The parameters for NCVs included motor nerve conduction velocity (MCV) and its distal conduction latency, sensory nerve conduction velocity, sensory nerve action potentials amplitude, and compound muscle action potential amplitude. MCV on the limbs was compromised by SV state, which was significantly slower on the lesional side of the body compared with the normal contralateral side (P = 0.006). Furthermore, SV at the stable stage significantly impaired MCV compared with the SV at progressive stage. There was no significant difference in the other parameters of NCV between lesional and normal sides of the body. Compound muscle action potentials in the face did not differ between lesional and healthy sides. Motor nerves in the limbs were compromised by SV, particularly when the disease was at the stable stage. PMID:26916936

  20. Spatial and Functional Selectivity of Peripheral Nerve Signal Recording With the Transversal Intrafascicular Multichannel Electrode (TIME).

    PubMed

    Badia, Jordi; Raspopovic, Stanisa; Carpaneto, Jacopo; Micera, Silvestro; Navarro, Xavier

    2016-01-01

    The selection of suitable peripheral nerve electrodes for biomedical applications implies a trade-off between invasiveness and selectivity. The optimal design should provide the highest selectivity for targeting a large number of nerve fascicles with the least invasiveness and potential damage to the nerve. The transverse intrafascicular multichannel electrode (TIME), transversally inserted in the peripheral nerve, has been shown to be useful for the selective activation of subsets of axons, both at inter- and intra-fascicular levels, in the small sciatic nerve of the rat. In this study we assessed the capabilities of TIME for the selective recording of neural activity, considering the topographical selectivity and the distinction of neural signals corresponding to different sensory types. Topographical recording selectivity was proved by the differential recording of CNAPs from different subsets of nerve fibers, such as those innervating toes 2 and 4 of the hindpaw of the rat. Neural signals elicited by sensory stimuli applied to the rat paw were successfully recorded. Signal processing allowed distinguishing three different types of sensory stimuli such as tactile, proprioceptive and nociceptive ones with high performance. These findings further support the suitability of TIMEs for neuroprosthetic applications, by exploiting the transversal topographical structure of the peripheral nerves. PMID:26087496

  1. Comparative study of peripheral neuropathy and nerve regeneration in NOD and ICR diabetic mice.

    PubMed

    Homs, Judit; Ariza, Lorena; Pagès, Gemma; Verdú, Enrique; Casals, Laura; Udina, Esther; Chillón, Miguel; Bosch, Assumpció; Navarro, Xavier

    2011-09-01

    The non-obese diabetic (NOD) mouse was suggested as an adequate model for diabetic autonomic neuropathy. We evaluated sensory-motor neuropathy and nerve regeneration following sciatic nerve crush in NOD males rendered diabetic by multiple low doses of streptozotocin, in comparison with similarly treated Institute for Cancer Research (ICR) mice, a widely used model for type I diabetes. Neurophysiological values for both strains showed a decline in motor and sensory nerve conduction velocity at 7 and 8 weeks after induction of diabetes in the intact hindlimb. However, amplitudes of compound muscle and sensory action potentials (CMAPs and CNAPs) were significantly reduced in NOD but not in ICR diabetic mice. Morphometrical analysis showed myelinated fiber loss in highly hyperglycemic NOD mice, but no significant changes in fiber size. There was a reduction of intraepidermal nerve fibers, more pronounced in NOD than in ICR diabetic mice. Interestingly, aldose reductase and poly(ADP-ribose) polymerase (PARP) activities were increased already at 1 week of hyperglycemia, persisting until the end of the experiment in both strains. Muscle and nerve reinnervation was delayed in diabetic mice following sciatic nerve crush, being more marked in NOD mice. Thus, diabetes of mid-duration induces more severe peripheral neuropathy and slower nerve regeneration in NOD than in ICR mice. PMID:22003936

  2. Bladder emptying by intermittent electrical stimulation of the pudendal nerve

    NASA Astrophysics Data System (ADS)

    Boggs, Joseph W.; Wenzel, Brian J.; Gustafson, Kenneth J.; Grill, Warren M.

    2006-03-01

    Persons with a suprasacral spinal cord injury cannot empty their bladder voluntarily. Bladder emptying can be restored by intermittent electrical stimulation of the sacral nerve roots (SR) to cause bladder contraction. However, this therapy requires sensory nerve transection to prevent dyssynergic contraction of the external urethral sphincter (EUS). Stimulation of the compound pudendal nerve trunk (PN) activates spinal micturition circuitry, leading to a reflex bladder contraction without a reflex EUS contraction. The present study determined if PN stimulation could produce bladder emptying without nerve transection in cats anesthetized with α-chloralose. With all nerves intact, intermittent PN stimulation emptied the bladder (64 ± 14% of initial volume, n = 37 across six cats) more effectively than either distention-evoked micturition (40 ± 19%, p < 0.001, n = 27 across six cats) or bilateral intermittent SR stimulation (25 ± 23%, p < 0.005, n = 4 across two cats). After bilateral transection of the nerves innervating the urethral sphincter, intermittent SR stimulation voided 79 ± 17% (n = 12 across three cats), comparable to clinical results obtained with SR stimulation. Voiding via intermittent PN stimulation did not increase after neurotomy (p > 0.10), indicating that PN stimulation was not limited by bladder-sphincter dyssynergia. Intermittent PN stimulation holds promise for restoring bladder emptying following spinal injury without requiring nerve transection.

  3. Histopathological effects of radiosurgery on a human trigeminal nerve

    PubMed Central

    Al-Otaibi, Faisal; Alhindi, Hindi; Alhebshi, Adnan; Albloushi, Monirah; Baeesa, Saleh; Hodaie, Mojgan

    2013-01-01

    Background: Radiosurgery is a well-established treatment modality for medically refractory trigeminal neuralgia. The exact mechanism of pain relief after radiosurgery is not clearly understood. Histopathology examination of the trigeminal nerve in humans after radiosurgery is rarely performed and has produced controversial results. Case Description: We report on a 45-year-old female who received radiosurgery treatment for trigeminal neuralgia by Cyberknife. A 6-mm portion of the cisternal segment of trigeminal nerve received a dose of 60 Gy. The clinical benefit started 10 days after therapy and continued for 8 months prior to a recurrence of her previous symptoms associated with mild background pain. She underwent microvascular decompression and partial sensory root sectioning. Atrophied trigeminal nerve rootlets were grossly noted intraoperatively under surgical microscope associated with changes in trigeminal nerve color to gray. A biopsy from the inferolateral surface of the nerve proximal to the midcisternal segment showed histological changes in the form of fibrosis and axonal degeneration. Conclusion: This case study supports the evidence of histological damage of the trigeminal nerve fibers after radiosurgery therapy. Whether or not the presence and degree of nerve damage correlate with the degree of clinical benefit and side effects are not revealed by this study and need to be explored in future studies. PMID:24605252

  4. The spinal accessory nerve plexus, the trapezius muscle, and shoulder stabilization after radical neck cancer surgery.

    PubMed Central

    Brown, H; Burns, S; Kaiser, C W

    1988-01-01

    A clinical and anatomic study of the spinal accessory, the eleventh cranial nerve, and trapezius muscle function of patients who had radical neck cancer surgery was conducted. This study was done not only to document the indispensibility of the trapezius muscle to shoulder-girdle stability, but also to clarify the role of the eleventh cranial nerve in the variable motor and sensory changes occurring after the loss of this muscle. Seventeen male patients, 49-69 years of age, (average of 60 years of age) undergoing a total of 23 radical neck dissections were examined for upper extremity function, particularly in regard to the trapezius muscle, and for subjective signs of pain. The eleventh nerve, usually regarded as the sole motor innervation to the trapezius, was cut in 17 instances because of tumor involvement. Dissection of four fresh and 30 preserved adult cadavers helped to reconcile the motor and sensory differences in patients who had undergone loss of the eleventh nerve. The dissections and clinical observations corroborate that the trapezius is a key part of a "muscle continuum" that stabilizes the shoulder. Variations in origins and insertions of the trapezius may influence its function in different individuals. As regards the spinal accessory nerve, it is concluded that varying motor and sensory connections form a plexus with the eleventh nerve, accounting, in part, for the variations in motor innervation and function of the trapezius, as well as for a variable spectrum of sensory changes when the eleventh nerve is cut. For this reason, it is suggested that the term "spinal accessory nerve plexus" be used to refer to the eleventh nerve when it is considered in the context of radical neck cancer surgery. Images Fig. 4. Fig. 6. Fig. 7. Fig. 8. PMID:3056289

  5. Sensory activity affects sensory axon development in C. elegans.

    PubMed

    Peckol, E L; Zallen, J A; Yarrow, J C; Bargmann, C I

    1999-05-01

    The simple nervous system of the nematode C. elegans consists of 302 neurons with highly reproducible morphologies, suggesting a hard-wired program of axon guidance. Surprisingly, we show here that sensory activity shapes sensory axon morphology in C. elegans. A class of mutants with deformed sensory cilia at their dendrite endings have extra axon branches, suggesting that sensory deprivation disrupts axon outgrowth. Mutations that alter calcium channels or membrane potential cause similar defects. Cell-specific perturbations of sensory activity can cause cell-autonomous changes in axon morphology. Although the sensory axons initially reach their targets in the embryo, the mutations that alter sensory activity cause extra axon growth late in development. Thus, perturbations of activity affect the maintenance of sensory axon morphology after an initial pattern of innervation is established. This system provides a genetically tractable model for identifying molecular mechanisms linking neuronal activity to nervous system structure. PMID:10101123

  6. Vascular smooth muscle desensitization in rabbit epigastric and mesenteric arteries during hemorrhagic shock.

    PubMed

    Ratz, P H; Miner, A S; Huang, Y; Smith, C A; Barbee, R W

    2016-07-01

    The decompensatory phase of hemorrhage (shock) is caused by a poorly defined phenomenon termed vascular hyporeactivity (VHR). VHR may reflect an acute in vivo imbalance in levels of contractile and relaxant stimuli favoring net vascular smooth muscle (VSM) relaxation. Alternatively, VHR may be caused by intrinsic VSM desensitization of contraction resulting from prior exposure to high levels of stimuli that temporarily adjusts cell signaling systems. Net relaxation, but not desensitization, would be expected to resolve rapidly in an artery segment removed from the in vivo shock environment and examined in vitro in a fresh solution. Our aim was to 1) induce shock in rabbits and apply an in vitro mechanical analysis on muscular arteries isolated pre- and postshock to determine whether VHR involves intrinsic VSM desensitization, and 2) identify whether net VSM relaxation induced by nitric oxide and cyclic nucleotide-dependent protein kinase activation in vitro can be sustained for some time after relaxant stimulus washout. The potencies of phenylephrine- and histamine-induced contractions in in vitro epigastric artery removed from rabbits posthemorrhage were decreased by ∼0.3 log units compared with the control contralateral epigastric artery removed prehemorrhage. Moreover, a decrease in KCl-induced tonic, relative to phasic, tension of in vitro mesenteric artery correlated with the degree of shock severity as assessed by rates of lactate and K(+) accumulation. VSM desensitization was also caused by tyramine in vivo and PE in vitro, but not by relaxant agents in vitro. Together, these results support the hypothesis that VHR during hemorrhagic decompensation involves contractile stimulus-induced long-lasting, intrinsic VSM desensitization. PMID:27199133

  7. Effects of a Dicalcium and Tetracalcium Phosphate-Based Desensitizer on In Vitro Dentin Permeability

    PubMed Central

    Zhou, Jianfeng; Chiba, Ayaka; Scheffel, Debora L. S.; Hebling, Josimeri; Agee, Kelli; Niu, Li-na; Tay, Franklin R.; Pashley, David H.

    2016-01-01

    The present study evaluated the effectiveness of a dicalcium and tetracalcium phosphate-based desensitizer in reducing dentin permeability in vitro. Dentin fluid flow was measured before and after treatment of dentin with patent dentinal tubules using 1 or 3 applications of the dicalcium and tetracalcium phosphate containing agent TeethmateTM (TM) and comparing the results with two sodium fluoride varnishes VellaTM (VLA) and VanishTM (VAN), after storage in artificial saliva for 24 h, 48 h and 7 days. Significant differences were observed among the 4 methods employed for reducing dentin permeability (p < 0.001) and the 3 post-treatment times (p < 0.001). VLA and VAN never achieved 50% permeability reductions consistently in any of the 3 time periods. Only the calcium phosphate-based desensitizer applied for 3 times consistently reduced dentin permeability by 50% after 24 h. When applied once, the permeability reduction of TM increased progressively over the 3 time periods. After 7 days, only one and three applications of the calcium phosphate-based desensitizer consistently reduced dentin permeability by more than 50%. Permeability reductions corresponded well with scanning electron microscopy examination of dentinal tubule orifice occlusion in dentin specimens treated with the agents. Overall, the dicalcium and tetracalcium phosphate-based desensitizer is effective in reducing dentin permeability via a tubule occlusion mechanism. The ability of the agent to reduce dentin permeability renders it to be potentially useful as a clinical dentin desensitizing agent, which has to be confirmed in future clinical studies. By contrast, the two sodium fluoride varnishes are not effective in dentin permeability reduction and should be considered as topical fluoride delivering agents rather than tubular orifice-blocking agents. PMID:27359118

  8. Outcome after Desensitization in HLA or ABO-Incompatible Kidney Transplant Recipients: A Single Center Experience

    PubMed Central

    Kauke, Teresa; Klimaschewski, Sandra; Schoenermarck, Ulf; Fischereder, Michael; Dick, Andrea; Guba, Markus; Stangl, Manfred; Werner, Jens; Meiser, Bruno; Habicht, Antje

    2016-01-01

    Background The shortage of deceased donors led to an increase of living donor kidney (LDK) transplantations performed in the presence of donor-specific antibodies (DSA) or ABO incompatibility (ABOi) using various desensitization protocols. Methods We herein analyzed 26 ABOi and 8 Luminex positive DSA patients who were successfully desensitized by anti-CD20, antigen-specific immunoadsorption and/or plasmapheresis to receive an LDK transplant. Twenty LDK recipients with non-donor-specific HLA-antibodies (low risk) and 32 without anti-HLA antibodies (no risk) served as control groups. Results 1-year graft survival rate and renal function was similar in all 4 groups (creatinine: 1.63 ± 0.5 vs 1.78 ± 0.6 vs 1.64 ± 0.5 vs 1.6 ± 0.3 mg/dl in ABOi, DSA, low risk and no risk group). The incidence of acute T-cell mediated rejections did not differ between the 4 groups (15% vs 12, 5% vs 15% vs 22% in ABOi, DSA, low risk and no risk), while antibody-mediated rejections were only found in the DSA (25%) and ABOi (7.5%) groups. Incidence of BK nephropathy (BKVN) was significantly more frequent after desensitization as compared to controls (5/34 vs 0/52, p = 0.03). Conclusion We demonstrate favorable short-term allograft outcome in LDK transplant recipients after desensitization. However, the desensitization was associated with an increased risk of BKVN. PMID:26730981

  9. Low-intensity pulsed ultrasound accelerates nerve regeneration following inferior alveolar nerve transection in rats.

    PubMed

    Sato, Mai; Motoyoshi, Mitsuru; Shinoda, Masamichi; Iwata, Koichi; Shimizu, Noriyoshi

    2016-06-01

    Inferior alveolar nerve (IAN) injury, which is frequently caused by orofacial surgery or trauma, induces sensory loss in orofacial regions innervated by the IAN. However, no effective treatment for orofacial sensory loss currently exists. We determined whether sensory loss in facial skin above the mental foramen following IAN transection was recovered by exposure of the transected IAN to low-intensity pulsed ultrasound (LIPUS). Inferior alveolar nerve transection (IANX) was performed in 7-wk-old male Sprague-Dawley rats. On day 7 after IANX, the effect of daily LIPUS (from day 0) on the transected IAN, in terms of sensitivity to mechanical stimulation of the facial skin above the mental foramen, was examined. Moreover, the number of trigeminal ganglion (TG) neurons innervating the facial skin above the mental foramen of rats with IANX treated daily with LIPUS was counted using the retrograde neurotracing technique. Daily exposure of the transected IAN to LIPUS significantly promoted recovery of the head-withdrawal threshold in response to mechanical stimulation of the facial skin above the mental foramen, and the number of TG neurons innervating the facial skin above mental foramen was significantly increased in rats with IANX treated daily with LIPUS compared with sham or LIPUS-unexposed rats. Daily treatment of stumps of the transected IAN with LIPUS facilitated morphological and functional regeneration, suggesting that LIPUS is an effective and novel therapy for IAN injury. PMID:27058986

  10. Nerve Growth Factor: A Focus on Neuroscience and Therapy

    PubMed Central

    Aloe, Luigi; Rocco, Maria Luisa; Omar Balzamino, Bijorn; Micera, Alessandra

    2015-01-01

    Nerve growth factor (NGF) is the firstly discovered and best characterized neurotrophic factor, known to play a critical protective role in the development and survival of sympathetic, sensory and forebrain cholinergic neurons. NGF promotes neuritis outgrowth both in vivo and in vitro and nerve cell recovery after ischemic, surgical or chemical injuries. Recently, the therapeutic property of NGF has been demonstrated on human cutaneous and corneal ulcers, pressure ulcer, glaucoma, maculopathy and retinitis pigmentosa. NGF eye drops administration is well tolerated, with no detectable clinical evidence of systemic or local adverse effects. The aim of this review is to summarize these biological properties and the potential clinical development of NGF. PMID:26411962

  11. A new type of functional chemical sensitizer MgH2 for improving pressure desensitization resistance of emulsion explosives

    NASA Astrophysics Data System (ADS)

    Cheng, Y. F.; Yan, S. L.; Ma, H. H.; Shen, Z. W.; Liu, R.

    2016-03-01

    In millisecond-delay blasting and deep water blasting projects, traditional emulsion explosives sensitized by the chemical sensitizer NaNO2 often encounter incomplete explosion or misfire problems because of the "pressure desensitization" phenomenon, which seriously affects blasting safety and construction progress. A MgH2-sensitized emulsion explosive was invented to solve these problems. Experimental results show that MgH2 can effectively reduce the problem of pressure desensitization. In this paper, the factors which influence the pressure desensitization of two types of emulsion explosives are studied, and resistance to this phenomenon of MgH2-sensitized emulsion explosives is discussed.

  12. Sensory loss in multifocal motor neuropathy: a clinical and electrophysiological study.

    PubMed

    Lambrecq, Virginie; Krim, Elsa; Rouanet-Larrivière, Marie; Lagueny, Alain

    2009-02-01

    Some patients fulfilling the criteria for the diagnosis of multifocal motor neuropathy with conduction block (MMN-CB) at the onset of disease may subsequently develop a sensory loss associated with electrophysiological sensory abnormalities. The latter could represent an overlap between MMN-CB and multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy. The objective was to specify the features of MMN-CB with sensory loss (MMN-CB-Se). Five patients in a series of 11 consecutive patients who fulfilled the criteria of the American Association of Neuromuscular and Electrodiagnostic Medicine for MMN-CB at the first examination and were treated periodically with intravenous immunoglobulin (IVIg) developed sensory loss in the course of the disease. In these five patients we compared the clinical, laboratory, and electrophysiological features found after the development of sensory loss with those at the first examination. The mean time to appearance of objective sensory signs was 7.2 years. In three of the five patients the sensory loss was preceded by intermittent paresthesias in the same nerve territories as the motor involvement. The most frequent electrophysiological abnormality was amplitude reduction of sensory nerve action potentials. There were no bilateral or symmetrical clinical and electrophysiological sensory abnormalities. Anti-GM1 IgM antibodies were positive in four patients. MMN-CB-Se could be an overlap between MMN-CB and MADSAM. It shares the distribution of the sensory disorders encountered in MADSAM, but it is closer to MMN-CB on clinical and therapeutic levels. Study of more patients would be useful to classify this subgroup more accurately. PMID:19127532

  13. Dynamics of the sensory response to urethral flow over multiple time scales in rat

    PubMed Central

    Danziger, Zachary C; Grill, Warren M

    2015-01-01

    The pudendal nerve carries sensory information from the urethra that controls spinal reflexes necessary to maintain continence and achieve efficient micturition. Despite the key role urethral sensory feedback plays in regulation of the lower urinary tract, there is little information about the characteristics of urethral sensory responses to physiological stimuli, and the quantitative relationship between physiological stimuli and the evoked sensory activation is unknown. Such a relation is critical to understanding the neural control of the lower urinary tract and how dysfunction arises in disease states. We systematically quantified pudendal afferent responses to fluid flow in the urethra in vivo in the rat. We characterized the sensory response across a range of stimuli, and describe a previously unreported long-term neural accommodation phenomenon. We developed and validated a compact mechanistic mathematical model capable of reproducing the pudendal sensory activity in response to arbitrary profiles of urethral flows. These results describe the properties and function of urethral afferents that are necessary to understand how sensory disruption manifests in lower urinary tract pathophysiology. Key points Sensory information from the urethra is essential to maintain continence and to achieve efficient micturition and when compromised by disease or injury can lead to substantial loss of function. Despite the key role urethral sensory information plays in the lower urinary tract, the relationship between physiological urethral stimuli, such as fluid flow, and the neural sensory response is poorly understood. This work systematically quantifies pudendal afferent responses to a range of fluid flows in the urethra in vivo and describes a previously unknown long-term neural accommodation phenomenon in these afferents. We present a compact mechanistic mathematical model that reproduces the pudendal sensory activity in response to urethral flow. These results have

  14. Approaches to Peripheral Nerve Repair: Generations of Biomaterial Conduits Yielding to Replacing Autologous Nerve Grafts in Craniomaxillofacial Surgery.

    PubMed

    Gaudin, Robert; Knipfer, Christian; Henningsen, Anders; Smeets, Ralf; Heiland, Max; Hadlock, Tessa

    2016-01-01

    Peripheral nerve injury is a common clinical entity, which may arise due to traumatic, tumorous, or even iatrogenic injury in craniomaxillofacial surgery. Despite advances in biomaterials and techniques over the past several decades, reconstruction of nerve gaps remains a challenge. Autografts are the gold standard for nerve reconstruction. Using autografts, there is donor site morbidity, subsequent sensory deficit, and potential for neuroma development and infection. Moreover, the need for a second surgical site and limited availability of donor nerves remain a challenge. Thus, increasing efforts have been directed to develop artificial nerve guidance conduits (ANCs) as new methods to replace autografts in the future. Various synthetic conduit materials have been tested in vitro and in vivo, and several first- and second-generation conduits are FDA approved and available for purchase, while third-generation conduits still remain in experimental stages. This paper reviews the current treatment options, summarizes the published literature, and assesses future prospects for the repair of peripheral nerve injury in craniomaxillofacial surgery with a particular focus on facial nerve regeneration. PMID:27556032

  15. Approaches to Peripheral Nerve Repair: Generations of Biomaterial Conduits Yielding to Replacing Autologous Nerve Grafts in Craniomaxillofacial Surgery

    PubMed Central

    Knipfer, Christian; Hadlock, Tessa

    2016-01-01

    Peripheral nerve injury is a common clinical entity, which may arise due to traumatic, tumorous, or even iatrogenic injury in craniomaxillofacial surgery. Despite advances in biomaterials and techniques over the past several decades, reconstruction of nerve gaps remains a challenge. Autografts are the gold standard for nerve reconstruction. Using autografts, there is donor site morbidity, subsequent sensory deficit, and potential for neuroma development and infection. Moreover, the need for a second surgical site and limited availability of donor nerves remain a challenge. Thus, increasing efforts have been directed to develop artificial nerve guidance conduits (ANCs) as new methods to replace autografts in the future. Various synthetic conduit materials have been tested in vitro and in vivo, and several first- and second-generation conduits are FDA approved and available for purchase, while third-generation conduits still remain in experimental stages. This paper reviews the current treatment options, summarizes the published literature, and assesses future prospects for the repair of peripheral nerve injury in craniomaxillofacial surgery with a particular focus on facial nerve regeneration. PMID:27556032

  16. Intraoperative vagal nerve monitoring.

    PubMed

    Leonetti, J P; Jellish, W S; Warf, P; Hudson, E

    1996-08-01

    A variety of benign and malignant neoplasms occur in the superior cervical neck, parapharyngeal space or the infratemporal fossa. The surgical resection of these lesions may result in postoperative iatrogenic injury to the vagus nerve with associated dysfunctional swallowing and airway protection. Anatomic and functional preservation of this critical cranial nerve will contribute to a favorable surgical outcome. Fourteen patients with tumors of the cervical neck or adjacent skull base underwent intraoperative vagal nerve monitoring in an attempt to preserve neural integrity following tumor removal. Of the 11 patients with anatomically preserved vagal nerves in this group, seven patients had normal vocal cord mobility following surgery and all 11 patients demonstrated normal vocal cord movement by six months. In an earlier series of 23 patients with tumors in the same region who underwent tumor resection without vagal nerve monitoring, 18 patients had anatomically preserved vagal nerves. Within this group, five patients had normal vocal cord movement at one month and 13 patients demonstrated normal vocal cord movement at six months. This paper will outline a technique for intraoperative vagal nerve monitoring utilizing transcricothyroid membrane placement of bipolar hook-wire electrodes in the vocalis muscle. Our results with the surgical treatment of cervical neck and lateral skull base tumors for patients with unmonitored and monitored vagal nerves will be outlined. PMID:8828272

  17. Inferior alveolar nerve repositioning.

    PubMed

    Louis, P J

    2001-09-01

    Nerve repositioning is a viable alternative for patients with an atrophic edentulous posterior mandible. Patients, however, should be informed of the potential risks of neurosensory disturbance. Documentation of the patient's baseline neurosensory function should be performed with a two-point discrimination test or directional brush stroke test preoperatively and postoperatively. Recovery of nerve function should be expected in 3 to 6 months. The potential for mandibular fracture when combining nerve repositioning with implant placement also should be discussed with the patient. This can be avoided by minimizing the amount of buccal cortical plate removal during localization of the nerve and maintaining the integrity of the inferior cortex of the mandible. Additionally, avoid overseating the implant, thus avoiding stress along the inferior border of the mandible. The procedure does allow for the placement of longer implants, which should improve implant longevity. Patients undergoing this procedure have expressed overall satisfaction with the results. Nerve repositioning also can be used to preserve the inferior alveolar nerve during resection of benign tumors or cysts of the mandible. This procedure allows the surgeon to maintain nerve function in situations in which the nerve would otherwise have to be resected. PMID:11665379

  18. Distal median nerve dysfunction

    MedlinePlus

    ... Names Neuropathy - distal median nerve Images Central nervous system and peripheral nervous system References Jarvik JG, Comstock BA, Kliot M, et al. Surgery versus non-surgical therapy for carpal tunnel syndrome: a randomized ... D. Disorders of peripheral nerves. In: Daroff RB, Fenichel GM, Jankovic J, ...

  19. Optic Nerve Decompression

    MedlinePlus

    ... canals). The optic nerve is the “nerve of vision” and extends from the brain, through your skull, and into your eye. A ... limited to, the following: loss of vision, double vision, inadequate ... leakage of brain fluid (CSF), meningitis, nasal bleeding, infection of the ...

  20. Recording Sensory Words

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2007-01-01

    From children's viewpoints, what they experience in the world is what the world is like--for everyone. "What do others experience with their senses when they are in the same situation?" is a question that young children can explore by collecting data as they use a "feely box," or take a "sensory walk." There are many ways to focus the children's…

  1. Studying Sensory Perception.

    ERIC Educational Resources Information Center

    Ackerly, Spafford C.

    2001-01-01

    Explains the vestibular organ's role in balancing the body and stabilizing the visual world using the example of a hunter. Describes the relationship between sensory perception and learning. Recommends using optical illusions to illustrate the distinctions between external realities and internal perceptions. (Contains 13 references.) (YDS)

  2. Structured Sensory Trauma Interventions

    ERIC Educational Resources Information Center

    Steele, William; Kuban, Caelan

    2010-01-01

    This article features the National Institute of Trauma and Loss in Children (TLC), a program that has demonstrated via field testing, exploratory research, time series studies, and evidence-based research studies that its Structured Sensory Intervention for Traumatized Children, Adolescents, and Parents (SITCAP[R]) produces statistically…

  3. Prevention of iatrogenic inferior alveolar nerve injuries in relation to dental procedures.

    PubMed

    Renton, T

    2010-09-01

    This article aims to review current hypotheses on the aetiology and prevention of inferior alveolar nerve (IAN) injuries in relation to dental procedures. The inferior alveolar nerve can be damaged during many dental procedures, including administration of local anaesthetic, implant bed preparation and placement, endodontics, third molar surgery and other surgical interventions. Damage to sensory nerves can result in anaesthesia, paraesthesia, pain, or a combination of the three. Pain is common in inferior alveolar nerve injuries, resulting in significant functional problems. The significant disability associated with these nerve injuries may also result in increasing numbers of medico-legal claims. Many of these iatrogenic nerve injuries can be avoided with careful patient assessment and planning. Furthermore, if the injury occurs there are emerging strategies that may facilitate recovery. The emphasis of this review is on how we may prevent these injuries and facilitate resolution in the early post surgical phase. PMID:21133047

  4. In Vivo Two-Photon Microscopy of Single Nerve Endings in Skin

    PubMed Central

    Yuryev, Mikhail; Molotkov, Dmitry

    2014-01-01

    Nerve endings in skin are involved in physiological processes such as sensing1 as well as in pathological processes such as neuropathic pain2. Their close-to-surface positioning facilitates microscopic imaging of skin nerve endings in living intact animal. Using multiphoton microscopy, it is possible to obtain fine images overcoming the problem of strong light scattering of the skin tissue. Reporter transgenic mice that express EYFP under the control of Thy-1 promoter in neurons (including periphery sensory neurons) are well suited for the longitudinal studies of individual nerve endings over extended periods of time up to several months or even life-long. Furthermore, using the same femtosecond laser as for the imaging, it is possible to produce highly selective lesions of nerve fibers for the studies of the nerve fiber restructuring. Here, we present a simple and reliable protocol for longitudinal multiphoton in vivo imaging and laser-based microsurgery on mouse skin nerve endings. PMID:25178088

  5. Diabetic neuropathy: structural analysis of nerve hydration by Magnetic Resonance Spectroscopy

    SciTech Connect

    Griffey, R.H.; Eaton, P.; Sibbitt, R.R.; Sibbitt, W.L. Jr.; Bicknell, J.M.

    1988-11-18

    The water content of the sural nerve of diabetic patients was quantitatively defined by magnetic resonance proton imaging as a putative reflection of activity of the aldose-reductase pathway. Thirty-nine patients were evaluated, comparing group A, symptomatic diabetic men with sensory neuropathy; group B, similarly symptomatic diabetic men treated aldose-reductase inhibition; group C, neurologically asymptomatic diabetic men; and group D, control nondiabetic men. Marked increase in hydration of the sural nerve was seen in more than half of the symptomatic diabetic patients. Two of 11 neurologically asymptomatic diabetics had increased nerve hydration, suggesting a presymptomatic alteration of the nerve. Symptomatic diabetics treated with aldose-reductase inhibitors had normal nerve water levels. Increased level of peripheral nerve water represents a new finding in diabetes mellitus. It seems to be related to aldose-reductase activity, involved in the development of neuropathy, and similar to events that occur in other target tissue in human diabetes.

  6. Peripheral nerve injuries resulting from common surgical procedures in the lower portion of the abdomen.

    PubMed

    Stulz, P; Pfeiffer, K M

    1982-03-01

    Twenty-three patients had a painful ilioinguinal and/or iliohypogastric nerve entrapment syndrome following common surgical procedures in the lower portion of the abdomen (appendectomy, repair of inguinal hernia, and gynecologic procedures through transverse incision). The diagnostic triad of nerve entrapment after operation comprises (1) typical burning or lancinating pain near the incision that radiates to the area supplied by the nerve, (2) clear evidence of impaired sensory perception of the nerve, and (3) pain relieved by infiltration with anesthetic for local effects at the site where the two nerves leave the internal oblique muscle. Surgical repair of the scar with resection of the compromised nerve is the most effective treatment. Sixteen patients became symptom free after neurectomy, seven still suffer chronic pain in the scar. PMID:7065874

  7. Peripheral nerve: from the microscopic functional unit of the axon to the biomechanically loaded macroscopic structure.

    PubMed

    Topp, Kimberly S; Boyd, Benjamin S

    2012-01-01

    Peripheral nerves are composed of motor and sensory axons, associated ensheathing Schwann cells, and organized layers of connective tissues that are in continuity with the tissues of the central nervous system. Nerve fiber anatomy facilitates conduction of electrical impulses to convey information over a distance, and the length of these polarized cells necessitates regulated axonal transport of organelles and structural proteins for normal cell function. Nerve connective tissues serve a protective function as the limb is subjected to the stresses of myriad limb positions and postures. Thus, the tissues are uniquely arranged to control the local nerve fiber environment and modulate physical stresses. In this brief review, we describe the microscopic anatomy and physiology of peripheral nerve and the biomechanical properties that enable nerve to withstand the physical stresses of everyday life. PMID:22133662

  8. Sensory analysis of lipstick.

    PubMed

    Yap, K C S; Aminah, A

    2011-06-01

    Sensory analysis of lipstick product by trained panellists started with recruiting female panels who are lipstick users, in good health condition and willing to be a part of sensory members. This group of people was further scrutinized with duo-trio method using commercial lipstick samples that are commonly used among them. About 40% of the 15 panels recruited were unable to differentiate the lipstick samples they usually use better than chance. The balance of nine panels that were corrected at least with 65% across all trials in panels screening process was formed a working group to develop sensory languages as a means of describing product similarities and differences and a scoring system. Five sessions with each session took about 90 min were carried out using 10 types of lipsticks with different waxes mixture ratio in the formulation together with six commercial lipsticks that are the most common to the panels. First session was focus on listing out the panels' perception towards the characteristic of the lipstick samples after normal application on their lips. Second session was focus on the refining and categorizing the responses gathered from the first session and translated into sensory attributes with its definition. Third session was focus on the scoring system. Fourth and fifth sessions were repetition of the third session to ensure consistency. In a collective effort of the panels, sensory attributes developed for lipstick were Spreadability, Off flavour, Hardness, Smoothness, Moist, Not messy, Glossy and Greasy. Analysis of variance was able to provide ample evidence on gauging the panel performance. A proper panels selecting and training was able to produce a reliable and sensitive trained panel for evaluating the product based on the procedures being trained. PMID:21272038

  9. Preoperative transcutaneous electrical nerve stimulation for localizing superficial nerve paths.

    PubMed

    Natori, Yuhei; Yoshizawa, Hidekazu; Mizuno, Hiroshi; Hayashi, Ayato

    2015-12-01

    During surgery, peripheral nerves are often seen to follow unpredictable paths because of previous surgeries and/or compression caused by a tumor. Iatrogenic nerve injury is a serious complication that must be avoided, and preoperative evaluation of nerve paths is important for preventing it. In this study, transcutaneous electrical nerve stimulation (TENS) was used for an in-depth analysis of peripheral nerve paths. This study included 27 patients who underwent the TENS procedure to evaluate the peripheral nerve path (17 males and 10 females; mean age: 59.9 years, range: 18-83 years) of each patient preoperatively. An electrode pen coupled to an electrical nerve stimulator was used for superficial nerve mapping. The TENS procedure was performed on patients' major peripheral nerves that passed close to the surgical field of tumor resection or trauma surgery, and intraoperative damage to those nerves was apprehensive. The paths of the target nerve were detected in most patients preoperatively. The nerve paths of 26 patients were precisely under the markings drawn preoperatively. The nerve path of one patient substantially differed from the preoperative markings with numbness at the surgical region. During surgery, the nerve paths could be accurately mapped preoperatively using the TENS procedure as confirmed by direct visualization of the nerve. This stimulation device is easy to use and offers highly accurate mapping of nerves for surgical planning without major complications. The authors conclude that TENS is a useful tool for noninvasive nerve localization and makes tumor resection a safe and smooth procedure. PMID:26420473

  10. A phenotypically restricted set of primary afferent nerve fibers innervate the bone versus skin: therapeutic opportunity for treating skeletal pain

    PubMed Central

    Jimenez-Andrade, Juan Miguel; Mantyh, William G.; Bloom, Aaron P.; Xu, Kevin Haili; Ferng, Alice S.; Dussor, Gregory; Vanderah, Todd W.; Mantyh, Patrick W.

    2009-01-01

    Although musculoskeletal pain is one of the most common causes of chronic pain and physical disability in both developed as well as developing countries, relatively little is known about the nerve fibers and mechanisms that drive skeletal pain. Small diameter sensory nerve fibers, most of which are C-fiber nociceptors, can be separated into two broad populations: the peptide-rich and peptide-poor nerve fibers. Peptide-rich nerve fibers express substance P (SP) and calcitonin gene related peptide (CGRP). In contrast, the peptide-poor nerve fibers bind to isolectin B4 (IB4) and express the purinergic receptor P2X3 and Mas-related G protein-coupled receptor member d (Mrgprd). In the present report, we used mice in which the Mrgprd+ nerve fibers express genetically encoded axonal tracers to determine the peptide-rich and peptide-poor sensory nerve fibers that innervate the glabrous skin of the hindpaw as compared to the bone marrow, mineralized bone and periosteum of the femur. Whereas the skin is richly innervated by CGRP+, SP+, P2X3+ and Mrgprd+ sensory nerve fibers, the bone marrow, mineralized bone and periosteum receive a significant innervation by SP+ and CGRP+, but not Mrgprd+ and P2X3+ nerve fibers. This lack of redundancy in the populations of C-fibers that innervate the bone may present a unique therapeutic opportunity for targeting skeletal pain, as the peptide-rich and peptide-poor sensory nerve fibers generally express a different repertoire of receptors and channels to detect noxious stimuli. Thus, therapies that target the specific types of C-nerve fibers that innervate the bone may be uniquely effective in attenuating skeletal pain as compared to skin pain. PMID:19766746

  11. Acid-sensing by airway afferent nerves

    PubMed Central

    Lee, Lu-Yuan; Gu, Qihai; Xu, Fadi; Hong, Ju-Lun

    2013-01-01

    Inhalation of acid aerosol or aspiration of acid solution evokes a stimulatory effect on airway C-fiber and Aδ afferents, which in turn causes airway irritation and triggers an array of defense reflex responses (e.g., cough, reflex bronchoconstriction, etc.). Tissue acidosis can also occur locally in the respiratory tract as a result of ischemia or inflammation, such as in the airways of asthmatic patients during exacerbation. The action of proton on the airway sensory neurons is generated by activation of two different current species: a transient (rapidly activating and inactivating) current mediated through the acid-sensing ion channels, and a slowly activating and sustained current mediated through the transient receptor potential vanilloid type 1 (TRPV1) receptor. In view of the recent findings that the expression and/or sensitivity of TRPV1 are up-regulated in the airway sensory nerves during chronic inflammatory reaction, the proton-evoked irritant effects on these nerves may play an important part in the manifestation of various symptoms associated with airway inflammatory diseases. PMID:23524016

  12. Tolerance of cranial nerves of the cavernous sinus to radiosurgery

    SciTech Connect

    Tishler, R.B.; Loeffler, J.S.; Alexander, E. III; Kooy, H.M. ); Lunsford, L.D.; Duma, C.; Flickinger, J.C. )

    1993-09-20

    Stereotactic radiosurgery is becoming a more accepted treatment option for benign, deep seated intracranial lesions. However, little is known about the effects of large single fractions of radiation on cranial nerves. This study was undertaken to assess the effect of radiosurgery on the cranial nerves of the cavernous sinus. The authors examined the tolerance of cranial nerves (II-VI) following radiosurgery for 62 patients (42/62 with meningiomas) treated for lesions within or near the cavernous sinus. Twenty-nine patients were treated with a modified 6 MV linear accelerator (Joint Center for Radiation Therapy) and 33 were treated with the Gamma Knife (University of Pittsburgh). Three-dimensional treatment plans were retrospectively reviewed and maximum doses were calculated for the cavernous sinus and the optic nerve and chiasm. Median follow-up was 19 months (range 3-49). New cranial neuropathies developed in 12 patients from 3-41 months following radiosurgery. Four of these complications involved injury to the optic system and 8 (3/8 transient) were the result of injury to the sensory or motor nerves of the cavernous sinus. There was no clear relationship between the maximum dose to the cavernous sinus and the development of complications for cranial nerves III-VI over the dose range used (1000-4000 cGy). For the optic apparatus, there was a significantly increased incidence of complications with dose. Four of 17 patients (24%) receiving greater than 800 cGy to any part of the optic apparatus developed visual complications compared with 0/35 who received less than 800 cGy (p = 0.009). Radiosurgery using tumor-controlling doses of up to 4000 cGy appears to be a relatively safe technique in treating lesions within or near the sensory and motor nerves (III-VI) of the cavernous sinus. The dose to the optic apparatus should be limited to under 800 cGy. 21 refs., 4 tabs.

  13. Understanding Sensory Integration. ERIC Digest.

    ERIC Educational Resources Information Center

    DiMatties, Marie E.; Sammons, Jennifer H.

    This brief paper summarizes what is known about sensory integration and sensory integration dysfunction (DSI). It outlines evaluation of DSI, treatment approaches, and implications for parents and teachers, including compensatory strategies for minimizing the impact of DSI on a child's life. Review of origins of sensory integration theory in the…

  14. Extending the understanding of sensory neuropeptides.

    PubMed

    De Swert, Katelijne O; Joos, Guy F

    2006-03-01

    The tachykinins substance P and neurokinin A are present in human airways, in sensory nerves and immune cells. Tachykinins can be recovered from the airways after inhalation of ozone, cigarette smoke or allergen. They interact in the airways with tachykinin NK1, NK2 and NK3 receptors to cause bronchoconstriction, plasma protein extravasation, and mucus secretion and to attract and activate immune cells. In preclinical studies they have been implicated in the pathophysiology of asthma and chronic obstructive pulmonary disease, including allergen- and cigarette smoke induced airway inflammation and bronchial hyperresponsiveness and mucus secretion. Dual NK1/NK2 or triple NK1/NK2/NK3 tachykinin receptor antagonists offer therapeutic potential in airway diseases such as asthma and chronic obstructive pulmonary disease. PMID:16464447

  15. Sympathetic and sensory innervation of small intensely fluorescent (SIF) cells in rat superior cervical ganglion.

    PubMed

    Takaki, Fumiya; Nakamuta, Nobuaki; Kusakabe, Tatsumi; Yamamoto, Yoshio

    2015-02-01

    The sympathetic ganglion contains small intensely fluorescent (SIF) cells derived from the neural crest. We morphologically characterize SIF cells and focus on their relationship with ganglionic cells, preganglionic nerve fibers and sensory nerve endings. SIF cells stained intensely for tyrosine hydroxylase (TH), with a few cells also being immunoreactive for dopamine β-hydroxylase (DBH). Vesicular acetylcholine transporter (VAChT)-immunoreactive puncta were distributed around some clusters of SIF cells, whereas some SIF cells closely abutted DBH-immunoreactive ganglionic cells. SIF cells contained bassoon-immunoreactive products beneath the cell membrane at the attachments and on opposite sites to the ganglionic cells. Ganglion neurons and SIF cells were immunoreactive to dopamine D2 receptors. Immunohistochemistry for P2X3 revealed ramified nerve endings with P2X3 immunoreactivity around SIF cells. Triple-labeling for P2X3, TH and VAChT allowed the classification of SIF cells into three types based on their innervation: (1) with only VAChT-immunoreactive puncta, (2) with only P2X3-immunoreactive nerve endings, (3) with both P2X3-immunoreactive nerve endings and VAChT-immunoreactive puncta. The results of retrograde tracing with fast blue dye indicated that most of these nerve endings originated from the petrosal ganglion. Thus, SIF cells in the superior cervical ganglion are innervated by preganglionic fibers and glossopharyngeal sensory nerve endings and can be classified into three types. SIF cells might modulate sympathetic activity in the superior cervical ganglion. PMID:25416508

  16. Nerve Growth Factor Inhibits Sympathetic Neurons' Response to an Injury Cytokine

    NASA Astrophysics Data System (ADS)

    Shadiack, Annette M.; Vaccariello, Stacey A.; Sun, Yi; Zigmond, Richard E.

    1998-06-01

    Axonal damage to adult peripheral neurons causes changes in neuronal gene expression. For example, axotomized sympathetic, sensory, and motor neurons begin to express galanin mRNA and protein, and recent evidence suggests that galanin plays a role in peripheral nerve regeneration. Previous studies in sympathetic and sensory neurons have established that galanin expression is triggered by two consequences of nerve transection: the induction of leukemia inhibitory factor (LIF) and the reduction in the availability of the target-derived factor, nerve growth factor. It is shown in the present study that no stimulation of galanin expression occurs following direct application of LIF to intact neurons in the superior cervical sympathetic ganglion. Injection of animals with an antiserum to nerve growth factor concomitant with the application of LIF, on the other hand, does stimulate galanin expression. The data suggest that the response of neurons to an injury factor, LIF, is affected by whether the neurons still receive trophic signals from their targets.

  17. The effects of sensory denervation on the responses of the rabbit eye to prostaglandin E1, bradykinin and substance P.

    PubMed Central

    Butler, J. M.; Hammond, B. R.

    1980-01-01

    1 Six to eight days after diathermic destruction of the fifth cranial nerve in the rabbit, the ocular hypertensive and miotic responses to intracameral administration of capsaicin, bradykinin, and prostaglandin E1 were greatly reduced or completely abolished. The response to substance P was not abolished. 2 A response could still be obtained to chemical irritants 36 h after coagulation of the nerve and it is deduced that manifestation of the response is dependent upon functional sensory nerve terminals, and is independent of central connections. 3 It is suggested that prostaglandin E1 and bradykinin act directly upon the sensory nerve endings and that propagation of the response is augmented by axon reflex. 4 In view of the ability of substance P to induce miosis in the denervated eyes, it is presumed that its actions are not mediated via sensory nerves. 5 It is considered possible that the mediator(s) released from sensory nerve endings after chemical irritation or antidromic stimulation may act in the same way as substance P with regard to the miotic effect. 6 Synthetic substance P will only produce ocular hypertension in doses which induce a maximal miotic response. This may either be a question of access or a partial resemblance to the endogenous mediator. PMID:6156734

  18. Dermatological and immunological conditions due to nerve lesions

    PubMed Central

    Bove, Domenico; Lupoli, Amalia; Caccavale, Stefano; Piccolo, Vincenzo; Ruocco, Eleonora

    2013-01-01

    Summary Some syndromes are of interest to both neurologists and dermatologists, because cutaneous involvement may harbinger symptoms of a neurological disease. The aim of this review is to clarify this aspect. The skin, because of its relationships with the peripheral sensory nervous system, autonomic nervous system and central nervous system, constitutes a neuroimmunoendocrine organ. The skin contains numerous neuropeptides released from sensory nerves. Neuropeptides play a precise role in cutaneous physiology and pathophysiology, and in certain skin diseases. A complex dysregulation of neuropeptides is a feature of some diseases of both dermatological and neurological interest (e.g. cutaneous and nerve lesions following herpes zoster infection, cutaneous manifestations of carpal tunnel syndrome, trigeminal trophic syndrome). Dermatologists need to know when a patient should be referred to a neurologist and should consider this option in those presenting with syndromes of unclear etiology. PMID:24125557

  19. Morphology and Intrinsic Excitability of Regenerating Sensory and Motor Neurons Grown on a Line Micropattern

    PubMed Central

    Benzina, Ouafa; Cloitre, Thierry; Martin, Marta; Raoul, Cédric; Gergely, Csilla; Scamps, Frédérique

    2014-01-01

    Axonal regeneration is one of the greatest challenges in severe injuries of peripheral nerve. To provide the bridge needed for regeneration, biological or synthetic tubular nerve constructs with aligned architecture have been developed. A key point for improving axonal regeneration is assessing the effects of substrate geometry on neuronal behavior. In the present study, we used an extracellular matrix-micropatterned substrate comprising 3 µm wide lines aimed to physically mimic the in vivo longitudinal axonal growth of mice peripheral sensory and motor neurons. Adult sensory neurons or embryonic motoneurons were seeded and processed for morphological and electrical activity analyses after two days in vitro. We show that micropattern-guided sensory neurons grow one or two axons without secondary branching. Motoneurons polarity was kept on micropattern with a long axon and small dendrites. The micro-patterned substrate maintains the growth promoting effects of conditioning injury and demonstrates, for the first time, that neurite initiation and extension could be differentially regulated by conditioning injury among DRG sensory neuron subpopulations. The micro-patterned substrate impacts the excitability of sensory neurons and promotes the apparition of firing action potentials characteristic for a subclass of mechanosensitive neurons. The line pattern is quite relevant for assessing the regenerative and developmental growth of sensory and motoneurons and offers a unique model for the analysis of the impact of geometry on the expression and the activity of mechanosensitive channels in DRG sensory neurons. PMID:25329060

  20. Accelerating axonal growth promotes motor recovery after peripheral nerve injury in mice

    PubMed Central

    Ma, Chi Him Eddie; Omura, Takao; Cobos, Enrique J.; Latrémolière, Alban; Ghasemlou, Nader; Brenner, Gary J.; van Veen, Ed; Barrett, Lee; Sawada, Tomokazu; Gao, Fuying; Coppola, Giovanni; Gertler, Frank; Costigan, Michael; Geschwind, Dan; Woolf, Clifford J.

    2011-01-01

    Although peripheral nerves can regenerate after injury, proximal nerve injury in humans results in minimal restoration of motor function. One possible explanation for this is that injury-induced axonal growth is too slow. Heat shock protein 27 (Hsp27) is a regeneration-associated protein that accelerates axonal growth in vitro. Here, we have shown that it can also do this in mice after peripheral nerve injury. While rapid motor and sensory recovery occurred in mice after a sciatic nerve crush injury, there was little return of motor function after sciatic nerve transection, because of the delay in motor axons reaching their target. This was not due to a failure of axonal growth, because injured motor axons eventually fully re-extended into muscles and sensory function returned; rather, it resulted from a lack of motor end plate reinnervation. Tg mice expressing high levels of Hsp27 demonstrated enhanced restoration of motor function after nerve transection/resuture by enabling motor synapse reinnervation, but only within 5 weeks of injury. In humans with peripheral nerve injuries, shorter wait times to decompression surgery led to improved functional recovery, and, while a return of sensation occurred in all patients, motor recovery was limited. Thus, absence of motor recovery after nerve damage may result from a failure of synapse reformation after prolonged denervation rather than a failure of axonal growth. PMID:21965333

  1. A case of hydrocortisone desensitization in a patient with radiocontrast-induced anaphylactoid reaction and corticosteroid allergy.

    PubMed

    Lee-Wong, Mary; McClelland, Suzanne; Chong, Kaman; Fernandez-Perez, Evans R; Fernandez, Evans

    2006-01-01

    Allergic reactions and systemic desensitization to corticosteroids have been documented rarely in English language literature. These reactions appear more often when the agent is applied topically and may lead to dangerous complications in patients if administered i.v. Therefore, the safety and efficacy of using an i.v. corticosteroid for desensitization in a patient who has a history of allergy to corticosteroid must be weighed carefully, especially when the aim of its use is to prevent an allergic reaction from a second drug. We report a case of successful systemic hydrocortisone desensitization in a patient with radiocontrast-induced anaphylactoid reaction and corticosteroid allergy. Sensitization to corticosteroids was determined through skin testing. The patient was desensitized to hydrocortisone and premedicated with hydrocortisone and diphenhydramine and subsequently underwent cardiac catheterization with radiocontrast without adverse reaction. PMID:16913271

  2. Differential desensitization of mu- and delta- opioid receptors in selected neural pathways following chronic morphine treatment.

    PubMed Central

    Noble, F.; Cox, B. M.

    1996-01-01

    1. Morphine produces a plethora of pharmacological effects and its chronic administration induces several side-effects. The cellular mechanisms by which opiates induce these side-effects are not fully understood. Several studies suggest that regulation of adenylyl cyclase activity by opioids and other transmitters plays an important role in the control of neural function. 2. The aim of this study was to evaluate desensitization of mu- and delta- opioid receptors, defined as a reduced ability of opioid agonists to inhibit adenylyl cyclase activity, in four different brain structures known to be involved in opiate drug actions: caudate putamen, nucleus accumbens, thalamus and periaqueductal gray (PAG). Opiate regulation of adenylyl cyclase in these regions has been studied in control and morphine-dependent rats. 3. The chronic morphine treatment used in the present study (subcutaneous administration of 15.4 mg morphine/rat/day for 6 days via osmotic pump) induced significant physical dependence as indicated by naloxone-precipitated withdrawal symptoms. 4. Basal adenylyl cyclase in the four brain regions was not modified by this chronic morphine treatment. In the PAG and the thalamus, a desensitization of mu- and delta-opioid receptors was observed, characterized by a reduced ability of Tyr-D-Ala-Gly-(NMe)Phe-Gly-ol (DAMGO; mu), Tyr-D-Pen-Gly-Phe-D-Pen (DPDPE; delta) and [D-Ala2]-deltorphin-II (DT-II; delta) to inhibit adenylyl cyclase, activity following chronic morphine treatment. 5. The opioid receptor desensitization in PAG and thalamus appeared to be heterologous since the metabotropic glutamate receptor agonists, L-AP4 and glutamate, and the 5-hydroxytryptamine (5-HT)1A receptor agonist, R(+)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT), also showed reduced inhibition of adenylyl cyclase activity following chronic morphine treatment. 6. In the nucleus accumbens and the caudate putamen, desensitization of delta-opioid receptor

  3. Hydrophilic Polymers Enhance Early Functional Outcomes after Nerve Autografting

    PubMed Central

    Sexton, Kevin W.; Pollins, Alonda C.; Cardwell, Nancy L.; Del Corral, Gabriel A.; Bittner, George D.; Shack, R. Bruce; Nanney, Lillian B.; Thayer, Wesley P.

    2014-01-01

    Background Approximately 12% of operations for traumatic neuropathy are for patients with segmental nerve loss and less than 50% of these injuries obtain meaningful functional recovery. Polyethylene glycol (PEG) therapy has been shown to improve functional outcomes after nerve severance and we hypothesized this therapy could also benefit nerve autografting. Methods A segmental rat sciatic nerve injury model was used, whereby a 0.5 cm defect was repaired with an autograft using microsurgery. Experimental animals were treated with solutions containing methylene blue (MB) and PEG; control animals did not receive PEG. Compound Actions Potentials (CAPs) were recorded before nerve transection, after solution therapy, and at 72 hours postoperatively. The animals underwent behavioral testing at 24 and 72 hours postoperatively. After sacrifice, nerves were fixed, sectioned, and immunostained to allow for quantitative morphometric analysis. Results The introduction of hydrophilic polymers greatly improved morphological and functional recovery of rat sciatic axons at 1–3 days following nerve autografting. PEG therapy restored CAPs in all animals and CAPs were still present 72 hours postoperatively. No CAPS were detectable in control animals. Footfall asymmetry scores and sciatic functional index scores were significantly improved for PEG therapy group at all time points (p <0.05 and p<0.001; p <0.001 and p <0.01). Sensory and motor axon counts were increased distally in nerves treated with PEG compared to control (p = 0.0189 and p = 0.0032). Conclusions PEG therapy improves early physiologic function, behavioral outcomes, and distal axonal density after nerve autografting. PMID:22521220

  4. Peripheral Sensory Neurons Expressing Melanopsin Respond to Light.

    PubMed

    Matynia, Anna; Nguyen, Eileen; Sun, Xiaoping; Blixt, Frank W; Parikh, Sachin; Kessler, Jason; Pérez de Sevilla Müller, Luis; Habib, Samer; Kim, Paul; Wang, Zhe Z; Rodriguez, Allen; Charles, Andrew; Nusinowitz, Steven; Edvinsson, Lars; Barnes, Steven; Brecha, Nicholas C; Gorin, Michael B

    2016-01-01

    The ability of light to cause pain is paradoxical. The retina detects light but is devoid of nociceptors while the trigeminal sensory ganglia (TG) contain nociceptors but not photoreceptors. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) are thought to mediate light-induced pain but recent evidence raises the possibility of an alternative light responsive pathway independent of the retina and optic nerve. Here, we show that melanopsin is expressed in both human and mouse TG neurons. In mice, they represent 3% of small TG neurons that are preferentially localized in the ophthalmic branch of the trigeminal nerve and are likely nociceptive C fibers and high-threshold mechanoreceptor Aδ fibers based on a strong size-function association. These isolated neurons respond to blue light stimuli with a delayed onset and sustained firing, similar to the melanopsin-dependent intrinsic photosensitivity observed in ipRGCs. Mice with severe bilateral optic nerve crush exhibit no light-induced responses including behavioral light aversion until treated with nitroglycerin, an inducer of migraine in people and migraine-like symptoms in mice. With nitroglycerin, these same mice with optic nerve crush exhibit significant light aversion. Furthermore, this retained light aversion remains dependent on melanopsin-expressing neurons. Our results demonstrate a novel light-responsive neural function independent of the optic nerve that may originate in the peripheral nervous system to provide the first direct mechanism for an alternative light detection pathway that influences motivated behavior. PMID:27559310

  5. Somatomotor and sensory urethral control of micturition in female rats

    PubMed Central

    Cruz, Yolanda; Pastelín, César; Balog, Brian M.; Zaszczurynski, Paul J.

    2014-01-01

    In rats, axons of external urethral sphincter (EUS) motoneurons travel through the anastomotic branch of the pudendal nerve (ABPD) and anastomotic branch of the lumbosacral trunk (ABLT) and converge in the motor branch of the sacral plexus (MBSP). The aim of the present study was to determine in female rats the contribution of these somatomotor pathways and urethral sensory innervation from the dorsal nerve of the clitoris on urinary continence and voiding. EUS electromyographic (EMG) activity during cystometry, leak point pressure (LPP), and voiding efficiency (VE) were assessed in anesthetized virgin Sprague-Dawley female rats before and after transection of the above nerve branches. Transection of the MBSP eliminated EUS EMG, decreased LPP by 50%, and significantly reduced bladder contraction duration, peak pressure, intercontraction interval, and VE. Transection of the ABPD or ABLT decreased EUS EMG discharge and LPP by 25% but did not affect VE. Transection of the dorsal nerve of the clitoris did not affect LPP but reduced contraction duration, peak pressure, intercontraction interval, and VE. We conclude that somatomotor control of micturition is provided by the MBSP with axons travelling through the ABPD and ABLT. Partial somatomotor urethral denervation induces mild urinary incontinence, whereas partial afferent denervation induces voiding dysfunction. ABPD and ABLT pathways could represent a safeguard ensuring innervation to the EUS in case of upper nerve damage. Detailed knowledge of neuroanatomy and functional innervation of the urethra will enable more accurate animal models of neural development, disease, and dysfunction in the future. PMID:25339694

  6. Peripheral Sensory Neurons Expressing Melanopsin Respond to Light

    PubMed Central

    Matynia, Anna; Nguyen, Eileen; Sun, Xiaoping; Blixt, Frank W.; Parikh, Sachin; Kessler, Jason; Pérez de Sevilla Müller, Luis; Habib, Samer; Kim, Paul; Wang, Zhe Z.; Rodriguez, Allen; Charles, Andrew; Nusinowitz, Steven; Edvinsson, Lars; Barnes, Steven; Brecha, Nicholas C.; Gorin, Michael B.

    2016-01-01

    The ability of light to cause pain is paradoxical. The retina detects light but is devoid of nociceptors while the trigeminal sensory ganglia (TG) contain nociceptors but not photoreceptors. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) are thought to mediate light-induced pain but recent evidence raises the possibility of an alternative light responsive pathway independent of the retina and optic nerve. Here, we show that melanopsin is expressed in both human and mouse TG neurons. In mice, they represent 3% of small TG neurons that are preferentially localized in the ophthalmic branch of the trigeminal nerve and are likely nociceptive C fibers and high-threshold mechanoreceptor Aδ fibers based on a strong size-function association. These isolated neurons respond to blue light stimuli with a delayed onset and sustained firing, similar to the melanopsin-dependent intrinsic photosensitivity observed in ipRGCs. Mice with severe bilateral optic nerve crush exhibit no light-induced responses including behavioral light aversion until treated with nitroglycerin, an inducer of migraine in people and migraine-like symptoms in mice. With nitroglycerin, these same mice with optic nerve crush exhibit significant light aversion. Furthermore, this retained light aversion remains dependent on melanopsin-expressing neurons. Our results demonstrate a novel light-responsive neural function independent of the optic nerve that may originate in the peripheral nervous system to provide the first direct mechanism for an alternative light detection pathway that influences motivated behavior. PMID:27559310

  7. Radial Nerve Tendon Transfers.

    PubMed

    Cheah, Andre Eu-Jin; Etcheson, Jennifer; Yao, Jeffrey

    2016-08-01

    Radial nerve palsy typically occurs as a result of trauma or iatrogenic injury and leads to the loss of wrist extension, finger extension, thumb extension, and a reduction in grip strength. In the absence of nerve recovery, reconstruction of motor function involves tendon transfer surgery. The most common donor tendons include the pronator teres, wrist flexors, and finger flexors. The type of tendon transfer is classified based on the donor for the extensor digitorum communis. Good outcomes have been reported for most methods of radial nerve tendon transfers as is typical for positional tendon transfers not requiring significant power. PMID:27387076

  8. Morphine-induced μ-Opioid Receptor Rapid Desensitization is independent of Receptor Phosphorylation and β-Arrestins

    PubMed Central

    Chu, Ji; Zheng, Hui; Loh, Horace H.; Law, Ping-Yee

    2008-01-01

    Receptor desensitization involving receptor phosphorylation and subsequent βArrestin (βArr) recruitment has been implicated in the tolerance development mediated by μ-opioid receptor (OPRM1). However, the roles of receptor phosphorylation and βArr on morphine-induced OPRM1 desensitization remain to be demonstrated. Using OPRM1-induced intracellular Ca2+ ([Ca2+]i )release to monitor receptor activation, as predicted, [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO), induced OPRM1 desensitization in a receptor phosphorylation- and βArr-dependent manner. The DAMGO-induced OPRM1 desensitization was attenuated significantly when phosphorylation deficient OPRM1 mutants or Mouse Embryonic Fibroblast (MEF) cells from βArr1 and 2 knockout mice were used in the studies. Specifically, DAMGO-induced desensitization was blunted in HEK293 cells expressing the OPRM1S375A mutant and was eliminated in MEF cells isolated from βArr2 knockout mice expressing the wild type OPRM1. However, although morphine also could induce a rapid desensitization on [Ca2+]i release to a greater extent than that of DAMGO and could induce the phosphorylation of Ser375 residue, morphine-induced desensitization was not influenced by mutating the phosphorylation sites or in MEF cells lacking βArr1 and 2. Hence, morphine could induce OPRM1 desensitization via pathway independent of βArr, thus suggesting the in vivo tolerance development to morphine can occur in the absence of βArr. PMID:18558479

  9. CRYPTOGENIC SENSORY POLYNEUROPATHY

    PubMed Central

    Pasnoor, Mamatha; Dimachkie, Mazen M.; Barohn, Richard J.

    2014-01-01

    Chronic sensory or sensorimotor polyneuropathy is a common cause for referral to neurologists. Despite extensive diagnostic testing, up to one-third of these patients remain without a known cause. They are referred to as having cryptogenic sensory peripheral neuropathy (CSPN). The age of onset is variable but usually in the sixth to seventh decade of life, affecting men and women equally. CSPN symptoms progress slowly, most patients present with distal leg paresthesias or pain that progressed over years to involve the hands. On examination, there may be additional mild toe flexion and extension weakness. Electrophysiologic testing and histology reveals axonal neuropathy. Prognosis is usually favorable as most patients maintain independent ambulation. Besides patient education and reassurance, management is focused on pharmacotherapy of neuropathic pain (see Treatment of Painful Peripheral Neuropathy chapter) and physical therapy for balance training and occasionally assistive devices. PMID:23642719

  10. Stretch-induced nerve injury: a proposed technique for the study of nerve regeneration and evaluation of the influence of gabapentin on this model

    PubMed Central

    Machado, J.A.; Ghizoni, M.F.; Bertelli, J.; Teske, Gabriel C.; Teske, Guilherme C.; Martins, D.F.; Mazzardo-Martins, L.; Cargnin-Ferreira, E.; Santos, A.R.S.; Piovezan, A.P.

    2013-01-01

    The rat models currently employed for studies of nerve regeneration present distinct disadvantages. We propose a new technique of stretch-induced nerve injury, used here to evaluate the influence of gabapentin (GBP) on nerve regeneration. Male Wistar rats (300 g; n=36) underwent surgery and exposure of the median nerve in the right forelimbs, either with or without nerve injury. The technique was performed using distal and proximal clamps separated by a distance of 2 cm and a sliding distance of 3 mm. The nerve was compressed and stretched for 5 s until the bands of Fontana disappeared. The animals were evaluated in relation to functional, biochemical and histological parameters. Stretching of the median nerve led to complete loss of motor function up to 12 days after the lesion (P<0.001), compared to non-injured nerves, as assessed in the grasping test. Grasping force in the nerve-injured animals did not return to control values up to 30 days after surgery (P<0.05). Nerve injury also caused an increase in the time of sensory recovery, as well as in the electrical and mechanical stimulation tests. Treatment of the animals with GBP promoted an improvement in the morphometric analysis of median nerve cross-sections compared with the operated vehicle group, as observed in the area of myelinated fibers or connective tissue (P<0.001), in the density of myelinated fibers/mm2 (P<0.05) and in the degeneration fragments (P<0.01). Stretch-induced nerve injury seems to be a simple and relevant model for evaluating nerve regeneration. PMID:24270909

  11. Sensory axons excitability changes in carpal tunnel syndrome after neural mobilization.

    PubMed

    Ginanneschi, Federica; Cioncoloni, David; Bigliazzi, Jacopo; Bonifazi, Marco; Lorè, Cosimo; Rossi, Alessandro

    2015-09-01

    Increased mechanosensitivity of the median nerve in carpal tunnel syndrome (CTS) has been demonstrated during upper limb tension test 1 (ULTT1) when the nerve is passively elongated. However, the neurophysiological changes of the sensory axons during stressing activities are unknown. The aim of present study was to verify possible changes in the excitability of median nerve afferent axons following nerve stress in elongation, in subjects with and without CTS. Eight CTS hands and eight controls were selected. Recruitment properties of the median nerve were studied by analyzing the relationship between the intensity of electrical stimulation and the size of motor response, before and after intermittent-repetitive neural mobilization. Only in CTS hands, after the intervention, the stimulus-response curve was strikingly abnormal: both plateau and slope values were significantly lower. During anatomical stress across the median nerve in elongation, compressive forces may exert mechanical traction on the median nerve, since it is 'tethered' at the carpal tunnel, resulting inactivation of Na(+) channels at the wrist, or impairment of energy-dependent processes which affect axonal conduction block. We conclude that in entrapment neuropathies, neural mobilization during nerve elongation may generate conduction failure in peripheral nerve. Our study supports specific considerations for patient education and therapeutic approaches. PMID:25896622

  12. Electrophysiological characterisation of motor and sensory tracts in patients with hereditary spastic paraplegia (HSP)

    PubMed Central

    2013-01-01

    Background Hereditary spastic paraplegias (HSPs) are characterised by lower limb spasticity due to degeneration of the corticospinal tract. We set out for an electrophysiological characterisation of motor and sensory tracts in patients with HSP. Methods We clinically and electrophysiologically examined a cohort of 128 patients with genetically confirmed or clinically probable HSP. Motor evoked potentials (MEPs) to arms and legs, somato-sensory evoked potentials of median and tibial nerves, and nerve conduction studies of tibial, ulnar, sural, and radial nerves were assessed. Results Whereas all patients showed clinical signs of spastic paraparesis, MEPs were normal in 27% of patients and revealed a broad spectrum with axonal or demyelinating features in the others. This heterogeneity can at least in part be explained by different underlying genotypes, hinting for distinct pathomechanisms in HSP subtypes. In the largest subgroup, SPG4, an axonal type of damage was evident. Comprehensive electrophysiological testing disclosed a more widespread affection of long fibre tracts involving peripheral nerves and the sensory system in 40%, respectively. Electrophysiological abnormalities correlated with the severity of clinical symptoms. Conclusions Whereas HSP is primarily considered as an upper motoneuron disorder, our data suggest a more widespread affection of motor and sensory tracts in the central and peripheral nervous system as a common finding in HSP. The distribution patterns of electrophysiological abnormalities were associated with distinct HSP genotypes and could reflect different underlying pathomechanisms. Electrophysiological measures are independent of symptomatic treatment and may therefore serve as a reliable biomarker in upcoming HSP trials. PMID:24107482

  13. Effects of methylmercury on the motor and sensory innervation of the rat extensor digitorum longus muscle

    SciTech Connect

    Yip, R.K.; Riley, D.A.

    1987-06-01

    The histochemical study examined the effects of chronic methylmercury (MeHg) intoxication on the motor and sensory innervation of extensor digitorum longus muscles. Light microscopic examination of silver-stained axons in the intramuscular nerve bundles of MeHg-treated rats showed Wallerian-like degeneration and a reduction in the number of nerve fibers. Disrupted axons were predominantly sensory because 22.2% of spindle afferents (I/sub a/) and 90.0% of Golgi tendon organ (I/sub b/) sensory fibers were completely degenerated whereas less than 1% of motor ending were totally destroyed. Partial disruption occurred in the cholinesterase and motor terminals of 13.7% of endplates. Their results demonstrated greater vulnerability of sensory nerves than of motor nerves to MeHg-induced degeneration. Thus, the abnormal reflexes, ataxia, and muscle weakness following MeHg poisoning appear related to reduction of proprioceptive feedback from muscles and tendons irradiation to the documented lesions in the central nervous system.

  14. High Ulnar Nerve Injuries: Nerve Transfers to Restore Function.

    PubMed

    Patterson, Jennifer Megan M

    2016-05-01

    Peripheral nerve injuries are challenging problems. Nerve transfers are one of many options available to surgeons caring for these patients, although they do not replace tendon transfers, nerve graft, or primary repair in all patients. Distal nerve transfers for the treatment of high ulnar nerve injuries allow for a shorter reinnervation period and improved ulnar intrinsic recovery, which are critical to function of the hand. PMID:27094893

  15. Effect of Collateral Sprouting on Donor Nerve Function After Nerve Coaptation: A Study of the Brachial Plexus

    PubMed Central

    Reichert, Paweł; Kiełbowicz, Zdzisław; Dzięgiel, Piotr; Puła, Bartosz; Wrzosek, Marcin; Bocheńska, Aneta; Gosk, Jerzy

    2016-01-01

    Background The aim of the present study was to evaluate the donor nerve from the C7 spinal nerve of the rabbit brachial plexus after a coaptation procedure. Assessment was performed of avulsion of the C5 and C6 spinal nerves treated by coaptation of these nerves to the C7 spinal nerve. Material/Methods After nerve injury, fourteen rabbits were treated by end-to-side coaptation (ETS), and fourteen animals were treated by side-to-side coaptation (STS) on the right brachial plexus. Electrophysiological and histomorphometric analyses and the skin pinch test were used to evaluate the outcomes. Results There was no statistically significant difference in the G-ratio proximal and distal to the coaptation in the ETS group, but the differences in the axon, myelin sheath and fiber diameters were statistically significant. The comparison of the ETS and STS groups distal to the coaptation with the controls demonstrated statistically significant differences in the fiber, axon, and myelin sheath diameters. With respect to the G-ratio, the ETS group exhibited no significant differences relative to the control, whereas the G-ratio in the STS group and the controls differed significantly. In the electrophysiological study, the ETS and STS groups exhibited major changes in the biceps and subscapularis muscles. Conclusions The coaptation procedure affects the histological structure of the nerve donor, but it does not translate into changes in nerve conduction or the sensory function of the limb. The donor nerve lesion in the ETS group is transient and has minimal clinical relevance. PMID:26848925

  16. Effect of Collateral Sprouting on Donor Nerve Function After Nerve Coaptation: A Study of the Brachial Plexus.

    PubMed

    Reichert, Pawel; Kiełbowicz, Zdzisław; Dzięgiel, Piotr; Puła, Bartosz; Wrzosek, Marcin; Bocheńska, Aneta; Gosk, Jerzy

    2016-01-01

    BACKGROUND The aim of the present study was to evaluate the donor nerve from the C7 spinal nerve of the rabbit brachial plexus after a coaptation procedure. Assessment was performed of avulsion of the C5 and C6 spinal nerves treated by coaptation of these nerves to the C7 spinal nerve. MATERIAL AND METHODS After nerve injury, fourteen rabbits were treated by end-to-side coaptation (ETS), and fourteen animals were treated by side-to-side coaptation (STS) on the right brachial plexus. Electrophysiological and histomorphometric analyses and the skin pinch test were used to evaluate the outcomes. RESULTS There was no statistically significant difference in the G-ratio proximal and distal to the coaptation in the ETS group, but the differences in the axon, myelin sheath and fiber diameters were statistically significant. The comparison of the ETS and STS groups distal to the coaptation with the controls demonstrated statistically significant differences in the fiber, axon, and myelin sheath diameters. With respect to the G-ratio, the ETS group exhibited no significant differences relative to the control, whereas the G-ratio in the STS group and the controls differed significantly. In the electrophysiological study, the ETS and STS groups exhibited major changes in the biceps and subscapularis muscles. CONCLUSIONS The coaptation procedure affects the histological structure of the nerve donor, but it does not translate into changes in nerve conduction or the sensory function of the limb. The donor nerve lesion in the ETS group is transient and has minimal clinical relevance. PMID:26848925

  17. P2Y1 and P2Y12 receptors for ADP desensitize by distinct kinase-dependent mechanisms.

    PubMed

    Hardy, Adam R; Conley, Pamela B; Luo, Jiansong; Benovic, Jeffrey L; Poole, Alastair W; Mundell, Stuart J

    2005-05-01

    Adenosine 5'-diphosphate (ADP) plays a central role in regulating platelet function by the activation of the G protein-coupled receptors P2Y(1) and P2Y(12). Although it is well established that aggregation responses of platelets to ADP desensitize, the underlying mechanisms involved remain unclear. In this study we demonstrate that P2Y(1)- and P2Y(12)-mediated platelet responses desensitize rapidly. Furthermore, we have established that these receptors desensitize by different kinase-dependent mechanisms. G protein-coupled receptor kinase (GRK) 2 and GRK6 are both endogenously expressed in platelets. Transient overexpression of dominant-negative mutants of these kinases or reductions in endogenous GRK expression by the use of specific siRNAs in 1321N1 cells showed that P2Y(12), but not P2Y(1), desensitization is mediated by GRKs. In contrast, desensitization of P2Y(1), but not P2Y(12), is largely dependent on protein kinase C activity. This study is the first to show that both P2Y(1) and P2Y(12) desensitize in human platelets, and it reveals ways in which their sensitivity to ADP may be differentially and independently altered. PMID:15665114

  18. Blockade of Nerve Sprouting and Neuroma Formation Markedly Attenuates the Development of Late Stage Cancer Pain

    PubMed Central

    Mantyh, William G.; Jimenez-Andrade, Juan M.; Stake, James I.; Bloom, Aaron P.; Kaczmarska, Magdalena J.; Taylor, Reid N.; Freeman, Katie T.; Ghilardi, Joseph R.; Kuskowski, Michael A.; Mantyh, Patrick W.

    2010-01-01

    For many patients, pain is the first sign of cancer and, while pain can be present at any time, the frequency and intensity of pain tend to increase with advancing stages of the disease. Thus, between 75 and 90% of patients with metastatic or advanced-stage cancer will experience significant cancer-induced pain. One major unanswered question is why cancer pain increases and frequently becomes more difficult to fully control with disease progression. To gain insight into this question we used a mouse model of bone cancer pain to demonstrate that as tumor growth progresses within bone, Tropomyosin receptor kinase A (TrkA)-expressing sensory and sympathetic nerve fibers undergo profuse sprouting and form neuroma-like structures. To address what is driving the pathological nerve reorganization we administered an antibody to nerve growth factor (anti-NGF). Early sustained administration of anti-NGF, whose cognate receptor is TrkA, blocks the pathological sprouting of sensory and sympathetic nerve fibers, the formation of neuroma-like structures, and inhibits the development of cancer pain. These results suggest that cancer cells and their associated stromal cells release NGF, which induces a pathological remodeling of sensory and sympathetic nerve fibers. This pathological remodeling of the peripheral nervous system then participates in driving cancer pain. Similar to therapies that target the cancer itself, the data presented here suggest that the earlier that therapies blocking this pathological nerve remodeling are initiated, the more effective the control of cancer pain. PMID:20851743

  19. Cortical Brain Mapping of Peripheral Nerves Using Functional Magnetic Resonance Imaging in a Rodent Model

    PubMed Central

    Cho, Younghoon R.; Jones, Seth R.; Pawela, Christopher P.; Li, Rupeng; Kao, Dennis S.; Schulte, Marie L.; Runquist, Matthew L.; Yan, Ji-Geng; Hudetz, Anthony G.; Jaradeh, Safwan S.; Hyde, James S.; Matloub, Hani S.

    2008-01-01

    The regions of the body have cortical and subcortical representation in proportion to their degree of innervation. The rat forepaw has been studied extensively in recent years using functional magnetic resonance imaging (fMRI)—typically by stimulation using electrodes directly inserted into the skin of the forepaw. Here, we stimulate using surgically implanted electrodes. A major distinction is that stimulation of the skin of the forepaw is mostly sensory, whereas direct nerve stimulation reveals not only the sensory system but also deep brain structures associated with motor activity. In this paper, we seek to define both the motor and sensory cortical and subcortical representations associated with the four major nerves of the rodent upper extremity. We electrically stimulated each nerve (median, ulnar, radial, and musculocutaneous) during fMRI acquisition using a 9.4T Bruker scanner. A current level of 0.5-1.0 mA and a frequency of 5 Hz were used while keeping the duration constant. A distinct pattern of cortical activation was found for each nerve that can be correlated with known sensorimotor afferent and efferent pathways to the rat forepaw. This direct nerve stimulation rat model can provide insight into peripheral nerve injury. PMID:18924070

  20. Delayed Presentation of Sciatic Nerve Injury after Total Hip Arthroplasty: Neurosurgical Considerations, Diagnosis, and Management

    PubMed Central

    Xu, Linda W.; Veeravagu, Anand; Azad, Tej D.; Harraher, Ciara; Ratliff, John K.

    2016-01-01

    Background  Total hip arthroplasty (THA) is an established treatment for end-stage arthritis, congenital deformity, and trauma with good long-term clinical and functional outcomes. Delayed sciatic nerve injury is a rare complication after THA that requires prompt diagnosis and management. Methods  We present a case of sciatic nerve motor and sensory deficit in a 52-year-old patient 2 years after index left THA. Electromyography (EMG) results and imaging with radiographs and CT of the affected hip demonstrated an aberrant acetabular cup screw in the posterior-inferior quadrant adjacent to the sciatic nerve. Case Description  The patient underwent surgical exploration that revealed injury to the peroneal division of the sciatic nerve due to direct injury from screw impingement. A literature review identified 11 patients with late-onset neuropathy after THA. Ten patients underwent surgical exploration and pain often resolved after surgery with 56% of patients recovering sensory function and 25% experiencing full recovery of motor function. Conclusions  Delayed neuropathy of the sciatic nerve is a rare complication after THA that is most often due to hardware irritation, component failure, or wear-related pseudotumor formation. Operative intervention is often pursued to explore and directly visualize the nerve with limited results in the literature showing modest relief of pain and sensory symptoms and poor restoration of motor function. PMID:27602309

  1. Brain Mass and Cranial Nerve Size in Shrews and Moles

    PubMed Central

    Leitch, Duncan B.; Sarko, Diana K.; Catania, Kenneth C.

    2014-01-01

    We investigated the relationship between body size, brain size, and fibers in selected cranial nerves in shrews and moles. Species include tiny masked shrews (S. cinereus) weighing only a few grams and much larger mole species weighing up to 90 grams. It also includes closely related species with very different sensory specializations – such as the star-nosed mole and the common, eastern mole. We found that moles and shrews have tiny optic nerves with fiber counts not correlated with body or brain size. Auditory nerves were similarly small but increased in fiber number with increasing brain and body size. Trigeminal nerve number was by far the largest and also increased with increasing brain and body size. The star-nosed mole was an outlier, with more than twice the number of trigeminal nerve fibers than any other species. Despite this hypertrophied cranial nerve, star-nosed mole brains were not larger than predicted from body size, suggesting that magnification of their somatosensory systems does not result in greater overall CNS size. PMID:25174995

  2. Acute motor and sensory polyganglioradiculoneuritis in a cat: clinical and histopathological findings.

    PubMed

    Gutierrez-Quintana, Rodrigo; Cuesta-Garcia, Nerea; Wessmann, Annette; Johnston, Pamela; Penderis, Jacques

    2015-02-01

    Polyneuropathies can have a variety of clinical presentations and tend to be rare in cats. In this report we describe a 6-year-old domestic shorthair cat with an acute and rapidly progressive onset of lower motor neuron and sensory signs affecting the spinal and cranial nerves. Histopathological examination revealed moderate-to-severe multifocal inflammatory infiltrates at the ventral and dorsal nerve roots, and dorsal spinal ganglia at the level of the L4 and cauda equina. The type and severity of inflammation varied between nerve roots, being composed of mainly neutrophils in some and mainly lymphocytes and macrophages in others. Immunohistochemistry showed a combination of neutrophils, macrophages and lymphocytes infiltrating the nerve roots and ganglia. The majority of the lymphocytes were T lymphocytes; only a few B lymphocytes were seen. Neurons within the affected ganglia showed central chromatolysis and necrosis. Wallerian-like degeneration and demyelination were observed in the nerve roots. A sensory and motor polyganglioradiculoneuritis was diagnosed. An autoimmune process similar to the acute motor and sensory neuropathy subtype of Guillain-Barré syndrome in humans or an infection by an unidentified agent were considered most likely. PMID:24782456

  3. Injured sensory neuron-derived CSF1 induces microglia proliferation and DAP12-dependent pain

    PubMed Central

    Guan, Zhonghui; Kuhn, Julia A.; Wang, Xidao; Colquitt, Bradley; Solorzano, Carlos; Vaman, Smitha; Guan, Andrew K.; Evans-Reinsch, Zoe; Braz, Joao; Devor, Marshall; Abboud-Werner, Sherry L.; Lanier, Lewis L.; Lomvardas, Stavros; Basbaum, Allan I.

    2015-01-01

    SUMMARY Although microglia are implicated in nerve injury-induced neuropathic pain, how injured sensory neurons engage microglia is unclear. Here we demonstrate that peripheral nerve injury induces de novo expression of colony-stimulating factor 1 (CSF1) in injured sensory neurons. The CSF1 is transported to the spinal cord where it targets the microglial CSF1 receptor (CSF1R). Cre-mediated sensory neuron deletion of Csf1 completely prevented nerve injury-induced mechanical hypersensitivity and reduced microglia activation and proliferation. In contrast, intrathecal injection of CSF1 induces mechanical hypersensitivity and microglial proliferation. Nerve injury also upregulated CSF1 in motoneurons, where it is required for ventral horn microglial activation and proliferation. Downstream of CSF1R, we found that the microglial membrane adapter protein DAP12 is required for both nerve injury- and intrathecal CSF1-induced upregulation of pain-related microglial genes and the ensuing pain, but not for microglia proliferation. Thus, both CSF1 and DAP12 are potential targets for the pharmacotherapy of neuropathic pain. PMID:26642091

  4. Novel targeted sensory reinnervation technique to restore functional hand sensation after transhumeral amputation.

    PubMed

    Hebert, Jacqueline S; Olson, Jaret L; Morhart, Michael J; Dawson, Michael R; Marasco, Paul D; Kuiken, Todd A; Chan, K Ming

    2014-07-01

    We present a case study of a novel variation of the targeted sensory reinnervation technique that provides additional control over sensory restoration after transhumeral amputation. The use of intraoperative somatosensory evoked potentials on individual fascicles of the median and ulnar nerves allowed us to specifically target sensory fascicles to reroute to target cutaneous nerves at a distance away from anticipated motor sites in a transhumeral amputee. This resulted in restored hand maps of the median and ulnar nerve in discrete spatially separated areas. In addition, the subject was able to use native and reinnervated muscle sites to control a robotic arm while simultaneously sensing touch and force feedback from the robotic gripper in a physiologically correct manner. This proof of principle study is the first to demonstrate the ability to have simultaneous dual flow of information (motor and sensory) within the residual limb. In working towards clinical deployment of a sensory integrated prosthetic device, this surgical method addresses the important issue of restoring a usable access point to provide natural hand sensation after upper limb amputation. PMID:24760915

  5. Ulnar nerve dysfunction

    MedlinePlus

    ... pressure on the elbow An elbow fracture or dislocation Temporary pain and tingling of this nerve can ... Saunders; 2011:chap 428. Read More Broken bone Dislocation Mononeuritis multiplex Mononeuropathy Myelin Peripheral neuropathy Systemic Update ...

  6. Diabetic Nerve Problems

    MedlinePlus

    ... at the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get ... you change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. ...

  7. Ulnar nerve dysfunction

    MedlinePlus

    ... surface of the body where it crosses the elbow. The damage destroys the nerve covering ( myelin sheath) ... be caused by: Long-term pressure on the elbow An elbow fracture or dislocation Temporary pain and ...

  8. Degenerative Nerve Diseases

    MedlinePlus

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical ...

  9. Common peroneal nerve dysfunction

    MedlinePlus

    ... people: Who are very thin (for example, from anorexia nervosa ) Who have certain autoimmune conditions, such as ... Elsevier; 2013:chap 22. Read More Alertness - decreased Anorexia Broken bone Diabetes and nerve damage Mononeuritis multiplex ...

  10. Femoral nerve dysfunction

    MedlinePlus

    ... An abnormal knee reflex Smaller than normal quadriceps muscles on the front of the thigh Tests that may be done include: Electromyography ( EMG ) Nerve conduction tests ( NCV ), usually done at ...

  11. Femoral nerve dysfunction

    MedlinePlus

    Neuropathy - femoral nerve; Femoral neuropathy ... Craig EJ, Clinchot DM. Femoral neuropathy. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, Pain, and Rehabilitation . 3rd ...

  12. Diabetic Nerve Problems

    MedlinePlus

    ... the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get it. ... change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. Controlling ...

  13. Treatment of Chronic Plantar Heel Pain With Radiofrequency Neural Ablation of the First Branch of the Lateral Plantar Nerve and Medial Calcaneal Nerve Branches.

    PubMed

    Arslan, Aydın; Koca, Tuba Tulay; Utkan, Ali; Sevimli, Resit; Akel, İbrahim

    2016-01-01

    From March 2012 to February 2013, 37 patients experiencing plantar heel pain for ≥6 months despite treatment with physical therapy and other conservative treatment modalities were followed up. If neurogenic heel pain originating from the first branch of the lateral plantar nerve was present, with or without the medial calcaneal nerve, diagnostic nerve blocks to these nerves were performed for confirmation. If the pain was determined to be of neurogenic origin, radiofrequency neural ablation (RFNA) was applied to the corresponding sensory nerve endings. Pain was evaluated using the visual analog scale, and patients were followed for at least one year. A total of 41 feet from 37 patients (30 [81.1%] females, 7 [18.9%] males; mean age, 50.7 ± 1.6 years; mean body mass index, 30.6 ± 0.7 kg/m(2)) were included. The mean visual analog scale scores improved significantly from 1 to 6 to 12 months after the procedure relative to before the procedure, with 88% of all patients rating the treatment as either very successful or successful at 12 months postoperatively. RFNA applied to both the first branch of the lateral plantar nerve and the medial calcaneal nerve sensory branches (16 [39%] feet) and only the first branch of the lateral plantar nerve sensory branches (25 [61%] feet) showed similarly high levels of success. Of the 41 feet, 28 [68.3%] had received extracorporeal shockwave therapy, 35 [85.4%] had received steroid injections, and 22 [53.7%] had received both extracorporeal shockwave therapy and steroid injections before RFNA as an index procedure. All were unresponsive to these previous treatments. In contrast, almost all (88%) were treated successfully with RFNA. Despite a high incidence of neurologic variations, with a precise diagnosis and good application of the technique using the painful points, chronic plantar heel pain can be treated successfully with RFNA. PMID:27073185

  14. Desensitization of Triggers and Urge Reduction for Paruresis: A Case Report

    PubMed Central

    Park, Hyoin; Jang, Eun Young; Bae, Hwallip

    2016-01-01

    Paruresis is a special type of non-generalized social phobia that involves fear and avoidance of urination in public restrooms. We administered eight 60-minute sessions of desensitization of triggers and urge reduction (DeTUR), an addiction protocol of eye movement desensitization and reprocessing (EMDR) therapy, to a 29-year old man with paruresis of 10 year duration. Because phobic avoidance is the hallmark of any anxiety disorder, we applied DeTUR targeting the urge to avoid each anxiety-provoking situation in succession. After treatment, the participant no longer met the requirements for a diagnosis of social anxiety disorder, and the self-reported symptoms of social anxiety had decreased to non-clinical levels; furthermore, these treatment gains were maintained at the one-year follow-up. Further clinical studies are needed to generalize this finding. PMID:26766960

  15. Desensitization of Triggers and Urge Reduction for Paruresis: A Case Report.

    PubMed

    Park, Hyoin; Kim, Daeho; Jang, Eun Young; Bae, Hwallip

    2016-01-01

    Paruresis is a special type of non-generalized social phobia that involves fear and avoidance of urination in public restrooms. We administered eight 60-minute sessions of desensitization of triggers and urge reduction (DeTUR), an addiction protocol of eye movement desensitization and reprocessing (EMDR) therapy, to a 29-year old man with paruresis of 10 year duration. Because phobic avoidance is the hallmark of any anxiety disorder, we applied DeTUR targeting the urge to avoid each anxiety-provoking situation in succession. After treatment, the participant no longer met the requirements for a diagnosis of social anxiety disorder, and the self-reported symptoms of social anxiety had decreased to non-clinical levels; furthermore, these treatment gains were maintained at the one-year follow-up. Further clinical studies are needed to generalize this finding. PMID:26766960

  16. I-95 phobia treated with hypnotic systematic desensitization: a case report.

    PubMed

    Iglesias, Alex; Iglesias, Alex; Iglesias, Adam

    2013-10-01

    Systematic desensitization and hypnosis mediated therapy share empirical evidence of efficacy in the treatment of specific phobias. However, a review of the literature indicated there is limited documentation in the employment of these modalities for treating driving related phobias (DRP). This article reports on the use of hypnosis aided systematic desensitization (HASD) in the successful treatment of a case of non-accident related driving phobia, specifically manifested on Interstate 95 (I-95). The treatment consisted of 6 office sessions of HASD along with 14 in-vivo sessions where the patient performed multiple exposures/rehearsals of the behaviors that had been successfully mastered at the office visits. The results indicated that this patient with case of (DRP) was able to resume travel on I-95 at conclusion of treatment. The patient was symptom free at follow up 6 months later. PMID:24665816

  17. Desensitization of sulphonylurea- and nutrient-induced insulin secretion following prolonged treatment with glibenclamide.

    PubMed

    Ball, A J; Flatt, P R; McClenaghan, N H

    2000-11-24

    Functional effects of prolonged exposure to the sulphonylurea glibenclamide were examined in a popular clonal pancreatic beta-cell line, denoted as BRIN-BD11. In acute 20-min incubations, 200 microM of tolbutamide or glibenclamide stimulated insulin release from non-depolarized and depolarized cells, which was dramatically reduced following 18-h culture with 100 microM glibenclamide. Sulphonylurea desensitization in non-depolarized cells was reversed following 6-36-h subsequent culture in the absence of glibenclamide. However, desensitization of insulinotropic effects of sulphonylureas in depolarized cells following glibenclamide culture and associated decline in cellular insulin content was not fully reversible. Culture with 100 microM glibenclamide also markedly reduced the acute insulinotropic actions of glucose, L-alanine, L-arginine, 2-ketoisocaproic acid (KIC) and KCl. These effects were almost completely reversed following 18-h culture in the absence of the sulphonylurea. PMID:11090651

  18. Desensitization of triggers and urge reprocessing for pathological gambling: a case series.

    PubMed

    Bae, Hwallip; Han, Changwoo; Kim, Daeho

    2015-03-01

    This case series introduces the desensitization of triggers and urge reprocessing (DeTUR), as a promising adjunctive therapy in addition to comprehensive treatment package for pathological gambling. This addiction protocol of eye movement desensitization and reprocessing was delivered to four male inpatients admitted to a 10-week inpatient program for pathological gambling. The therapist gave three 60-min weekly sessions of the DeTUR using bilateral stimulation (horizontal eye movements or alternative tactile stimuli) focusing on the hierarchy of triggering situations and the urge to initiate gambling behaviors. After treatment, self-reported gambling symptoms, depression, anxiety, and impulsiveness were all improved, and all the participants reported satisfaction with the therapy. They were followed up for 6 months and all maintained their abstinence from gambling and their symptomatic improvements. Given the efficiency (i.e., brevity and efficacy) of the treatment, a controlled study to confirm the effects of the DeTUR on pathological gambling would be justified. PMID:24293014

  19. Laminin-based Nanomaterials for Peripheral Nerve Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Neal, Rebekah Anne

    Peripheral nerve transection occurs commonly in traumatic injury, causing motor and sensory deficits distal to the site of injury. One option for surgical repair is the nerve conduit. Conduits currently on the market are hollow tubes into which the nerve ends are sutured. Although these conduits fill the gap, they often fail due to the slow rate of regeneration over long gaps. To facilitate increased speed of regeneration and greater potential for functional recovery, the ideal conduit should provide biochemically relevant signals and physical guidance cues, thus playing an active role in peripheral nerve regeneration. In this dissertation, I fabricated laminin-1 and laminin-polycaprolactone (PCL) blend nanofibers that mimic the geometry and functionality of the peripheral nerve basement membrane. These fibers resist hydration in aqueous media and require no harsh chemical crosslinkers. Adhesion and differentiation of both neuron-like and neuroprogenitor cells is improved on laminin nanofibrous meshes over two-dimensional laminin substrates. Blend meshes with varying laminin content were characterized for composition, tensile properties, degradation rates, and bioactivity in terms of cell attachment and axonal elongation. I have established that 10% (wt) laminin content is sufficient to retain the significant neurite-promoting effects of laminin critical in peripheral nerve repair. In addition, I utilized modified collector plate design to manipulate electric field gradients during electrospinning for the fabrication of aligned nanofibers. These aligned substrates provide enhanced directional guidance cues to the regenerating axons. Finally, I replicated the clinical problem of peripheral nerve transection using a rat tibial nerve defect model for conduit implantation. When the lumens of conduits were filled with nanofiber meshes of varying laminin content and alignment, I observed significant recovery of sensory and motor function over six weeks. This recovery was

  20. Schwannoma of Extraocular Nerves

    PubMed Central

    Niazi, Wasim; Boggan, James E.

    1994-01-01

    An unusual case of schwannoma arising from the third cranial nerve in a thirteen year old male is reported. The patient presented with paresis of the right oculomotor nerve and ipsilateral hemiparesis. The clinical features of this case are discussed and the pertinent medical literature reviewed. ImagesFigure 1p220-bFigure 2Figure 3Figure 4Figure 5Figure 6 PMID:17171175