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1

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

ERIC Educational Resources Information Center

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.…

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

2013-01-01

2

Sensory nerve conduction of the plantar nerve compared with other nerve conduction tests in rats  

Microsoft Academic Search

ObjectiveIn rats the available techniques for evaluation of sensory nerve conduction are limited. We report a new method of sensory nerve conduction of the plantar nerve using needle electrodes as the recording electrodes behind the medial malleolus and ring electrodes as the stimulating electrodes around the three middle toes.

Katsumi Kurokawa; Diogo F de Almeida; Yun Zhang; Charles D Hébert; John G Page; Karen M Schweikart; Shin J Oh

2004-01-01

3

Prolonged sensory-selective nerve blockade.  

PubMed

Sensory-selective local anesthesia has long been a key goal in local anesthetic development. For example, it allows women to be pain-free during labor without compromising their ability to push. Here we show that prolonged sensory-selective nerve block can be produced by specific concentrations of surfactants-such as are used to enhance drug flux across skin-in combination with QX-314, a lidocaine derivative that has relative difficulty penetrating nerves. For example, injection of 25 mM QX-314 in 30 mM octyltrimethylammonium bromide (OTAB) lasted up to 7 h. Sensory selectivity was imparted to varying degrees by cationic, neutral, and anionic surfactants, and also was achieved with another lidocaine derivative, QX-222. Simultaneous injection of OTAB at a s.c. injection site remote from the sciatic nerve did not result in prolonged sensory-specific nerve blockade from QX-314, suggesting that the observed effect is due to a local interaction between the surfactant and the lidocaine derivative, not a systemic effect. PMID:20133669

Sagie, Itay; Kohane, Daniel S

2010-02-23

4

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

PubMed Central

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

Lu, Jian

2014-01-01

5

Substance P enhances cholinergic receptor desensitization in a clonal nerve cell line.  

PubMed

Substance P inhibits carbamylcholine-induced 22Na+ uptake in the clonal cell line PC12. This inhibition is noncompetitive with agonist but competitive with Na+. Octahydrohistrionicotoxin (H8-HTX) also exhibits this same pattern of inhibition. Moreover, both substance P and H8-HTX are very effective in enhancing agonist-induced receptor desensitization. Local anesthetics, such as QX222, also cause inhibition that is competitive with Na+, but they have only marginal effects on desensitization. Because substance P and H8-HTX cannot by themselves cause desensitization, their action is dependent on and synergistic with the action of agonist. Furthermore, substance P and H8-HTX do not appear to compete for the same site as QX222, which is thought to bind to the ion channel. Finally, substance P can stabilize the desensitized state of the receptor even when added subsequent to the actual desensitization and removal of agonist. Thus, substance P does not require open ion channels for binding and may modulate the activity of the receptor-ionophore complex by binding to a distinct regulatory site. PMID:6153798

Stallcup, W B; Patrick, J

1980-01-01

6

Uses of Skin Biopsy for Sensory and Autonomic Nerve Assessment  

PubMed Central

Skin biopsy is a valuable diagnostic tool for small-fiber-predominant neuropathy by the quantification of intra-epidermal nerve fiber density (IENFD). It has the unique advantage of being a minimally invasive procedure with the potential for longitudinal evaluation of both sensory and autonomic fibers. Unmyelinated small fibers are not otherwise quantified objectively with such a level of sensitivity as has been reported with IENFD. Recent advances include an expansion of the skin punch biopsy technique to evaluate larger myelinated fibers and mechanoreceptors, and recent work has also focused on additional methods of quantifying dermal fibers and densely innervated autonomic structures. This review discusses current work using skin biopsy for the pathologic analysis of peripheral nerve fibers in neuropathy of various causes as well as its use in clinical trials. PMID:23250768

Myers, M. Iliza; Peltier, Amanda C.

2013-01-01

7

Ulnar nerve palsy-like motor and sensory loss caused by a small cortical infarct.  

PubMed

A 56-year-old man with a small infarct in the left precentral knob area induced both motor and sensory impairments that were similar to right ulnar nerve palsy. The only difference from ulnar nerve palsy was that the patient showed sensory disturbance not only on the ulnar side but also on the radial side of the right ring finger. PMID:21440458

Ueno, Tatsuya; Tomiyama, Masahiko; Haga, Rie; Nishijima, Haruo; Kon, Tomoya; Funamizu, Yukihisa; Miki, Yasuo; Arai, Akira; Suzuki, Chieko; Baba, Masayuki

2012-11-01

8

Photostimulation of sensory neurons of the rat vagus nerve  

NASA Astrophysics Data System (ADS)

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-?m output of a diode laser, delivered through a 200-?m 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.

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

2008-02-01

9

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

PubMed Central

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

Gibson, Peter G.; Birring, Surinder S.

2014-01-01

10

Changes in sensory activity of ocular surface sensory nerves during allergic keratoconjunctivitis.  

PubMed

Peripheral neural mechanisms underlying the sensations of irritation, discomfort, and itch accompanying the eye allergic response have not been hitherto analyzed. We explored this question recording the changes in the electrical activity of corneoconjunctival sensory nerve fibers of the guinea pig after an ocular allergic challenge. Sensitization was produced by i.p. ovalbumin followed by repeated application in the eye of 10% ovalbumin on days 14 to 18. Blinking and tearing rate were measured. Spontaneous and stimulus-evoked (mechanical, thermal, chemical) impulse activity was recorded from mechanonociceptor, polymodal nociceptor and cold corneoscleral sensory afferent fibers. After a single (day 14) or repeated daily exposures to the allergen during the following 3 to 4days, tearing and blinking rate increased significantly. Also, sensitization was observed in mechanonociceptors (transient reduction of mechanical threshold only on day 14) and in polymodal nociceptors (sustained enhancement of the impulse response to acidic stimulation). In contrast, cold thermoreceptors showed a significant decrease in basal ongoing activity and in the response to cooling. Treatment with the TRPV1 and TRPA1 blockers capsazepine and HC-030031 reversed the augmented blinking. Only capsazepine attenuated tearing rate increase and sensitization of the polymodal nociceptors response to CO2. Capsazepine also prevented the decrease in cold thermoreceptor activity caused by the allergic challenge. We conclude that changes in nerve impulse activity accompanying the ocular allergic response, primarily mediated by activation of nociceptor's TRPV1 and to a lesser degree by activation of TRPA1 channels, explain the eye discomfort sensations accompanying allergic episodes. PMID:23867735

Acosta, M Carmen; Luna, Carolina; Quirce, Susana; Belmonte, Carlos; Gallar, Juana

2013-11-01

11

Effects of Ozone on Epithelium and Sensory Nerves in the Bronchial Mucosa of Healthy Humans  

Microsoft Academic Search

Neuropeptides released from sensory nerves during inflammation have potent effects on broncho- motor tone, airway secretion, and inflammatory cells. We investigated the effects of ozone on sen- sory nerves by exposing 12 healthy, nonsmoking subjects to 0.2 ppm ozone and filtered air (FA) for 2 h on separate occasions, with intermittent exercise and rest. Spirometry was performed at baseline and

MAMIDIPUDI THIRUMALA KRISHNA; DAVID SPRINGALL; QING-HAI MENG; NICHOLAS WITHERS; DOMINIC MACLEOD; GIANLUCA BISCIONE; ANTHONY FREW; JULIA POLAK; STEPHEN HOLGATE

12

Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas  

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

13

THE ABSENCE OF ENDOGENOUS ?-ENDORPHIN SELECTIVELY BLOCKS PHOSPHORYLATION AND DESENSITIZATION OF MU OPIOID RECEPTORS FOLLOWING PARTIAL SCIATIC NERVE LIGATION  

PubMed Central

Phosphorylation of specific sites in the 2nd intracellular loop and in the C-terminal domain have previously been suggested to cause desensitization and internalization of the mu-opioid receptor (MOP-R). To assess sites of MOP-R phosphorylation in vivo, affinity-purified, phosphoselective antibodies were raised against either phosphothreonine-180 in the 2nd intracellular loop (MOR-P1) or the C-terminal domain of MOP-R containing phosphothreonine-370 and phosphoserine-375 (MOR-P2). We found that MOR-P2-immunoreactivity (IR) was significantly increased within the striatum of wild-type C57BL/6 mice after injection of the agonist fentanyl. Pretreatment with the antagonist naloxone blocked the fentanyl-induced increase. Furthermore, mutant mice lacking MOP-R showed only non-specific nuclear MOR-P2-IR before or after fentanyl treatment, confirming the specificity of the MOR-P2 antibodies. To assess whether MOP-R phosphorylation occurs following endogenous opioid release, we induced chronic neuropathic pain by partial sciatic nerve ligation (pSNL), which caused a significant increase in MOR-P2-IR in the striatum. pSNL also induced signs of mu opioid receptor tolerance demonstrated by a rightward shift in the morphine dose response in the tail withdrawal assay and by a reduction in morphine conditioned place preference (CPP). Mutant mice selectively lacking all forms of the ?-endorphin peptides derived from the Pomc gene did not show increased MOR-P2-IR, decreased morphine antinociception, or reduced morphine CPP following pSNL. In contrast gene deletion of either proenkephalin or prodynorphin opioids did not block the effects of pSNL. These results suggest that neuropathic pain caused by pSNL in wild-type mice activates the release of the endogenous opioid ?-endorphin, which subsequently induces MOP-R phosphorylation and opiate tolerance. PMID:17467916

Petraschka, Michael; Li, Shuang; Gilbert, Terri L.; Westenbroek, Ruth E.; Bruchas, Michael R.; Schreiber, Selena; Lowe, Janet; Low, Malcolm J.; Pintar, John E.; Chavkin, Charles

2007-01-01

14

Sensory nerve-mediated nasal vasodilatory response to inspired ethyl acrylate.  

PubMed

The irritants acrolein, acetaldehyde, and acetic acid induce a rapid sensory nerve-mediated nasal vasodilatory response in the rat. The aim of the current study was to examine acute nasal sensory nerve-mediated acute responses to an irritant ester vapor, ethyl acrylate. For this purpose, the upper respiratory tract of the urethane-anesthetized male F344 rat was isolated by insertion of an endotracheal cannula, and ethyl acrylate-laden air was drawn continuously through that site at a flow rate of 100 ml/min for 50 min. Vascular function was monitored by measuring inert vapor (acetone) uptake throughout the exposure. Nasal flow resistance was also monitored during exposure, and plasma protein extravasation was measured by Evans blue dye leakage. At exposure concentrations of 100 to 400 ppm, ethyl acrylate induced a rapid nasal vasodilatory response, as indicated by increased acetone uptake rates. This response was maintained throughout the exposure. Changes in nasal flow resistance or in Evans blue dye leakage were not observed at these exposure concentrations. The vasodilatory response was diminished in animals pretreated with the sensory nerve toxin capsaicin, providing strong evidence that this response was sensory nerve mediated. Pretreatment with the carboxylesterase inhibitor bis-para-nitro-phenolphospahte at a dose sufficient to inhibit nasal carboxylesterase did not alter the response, suggesting that the parent ester, not the carboxylesterase metabolites, is primarily responsible for the sensory-nerve-mediated vasodilatory responses to this ester. PMID:12119070

Morris, John B

2002-06-01

15

Sensory reinnervation of muscle spindles after repair of tibial nerve defects using autogenous vein grafts  

PubMed Central

Motor reinnervation after repair of tibial nerve defects using autologous vein grafts in rats has previously been reported, but sensory reinnervation after the same repair has not been fully investigated. In this study, partial sensory reinnervation of muscle spindles was observed after repair of 10-mm left tibial nerve defects using autologous vein grafts with end-to-end anastomosis in rats, and functional recovery was confirmed by electrophysiological studies. There were no significant differences in the number, size, or electrophysiological function of reinnervated muscle spindles between the two experimental groups. These findings suggest that repair of short nerve defects with autologous vein grafts provides comparable results to immediate end-to-end anastomosis in terms of sensory reinnervation of muscle spindles. PMID:25206863

Pang, Youwang; Hong, Qingnan; Zheng, Jinan

2014-01-01

16

Sensory nerve conduction and nociception in the equine lower forelimb during perineural bupivacaine infusion along the palmar nerves  

PubMed Central

The purpose of this investigation was to study lateral palmar nerve (LPN) and medial palmar nerve (MPN) morphology and determine nociception and sensory nerve conduction velocity (SNCV) following placement of continuous peripheral nerve block (CPNB) catheters along LPN and MPN with subsequent bupivacaine (BUP) infusion. Myelinated nerve fiber distribution in LPN and MPN was examined after harvesting nerve specimens in 3 anesthetized horses and processing them for morphometric analysis. In 5 sedated horses, CPNB catheters were placed along each PN in both forelimbs. Horses then received in one forelimb 3 mL 0.125% BUP containing epinephrine 1:200 000 and 0.04% NaHCO3 per catheter site followed by 2 mL/h infusion over a 6-day period, while in the other forelimb equal amounts of saline (SAL) solution were administered. The hoof withdrawal response (HWR) threshold during pressure loading of the area above the dorsal coronary band was determined daily in both forelimbs. On day 6 SNCV was measured under general anesthesia of horses in each limb’s LPN and MPN to detect nerve injury, followed by CPNB catheter removal. The SNCV was also recorded in 2 anesthetized non-instrumented horses (sham controls). In both LPN and MPN myelinated fiber distributions were bimodal. The fraction of large fibers (>7 ?m) was greater in the MPN than LPN (P < 0.05). Presence of CPNB catheters and SAL administration did neither affect measured HWR thresholds nor SNCVs, whereas BUP infusion suppressed HWRs. In conclusion, CPNB with 0.125% BUP provides pronounced analgesia by inhibiting sensory nerve conduction in the distal equine forelimb. PMID:21197231

Zarucco, Laura; Driessen, Bernd; Scandella, Massimiliano; Cozzi, Francesca; Cantile, Carlo

2010-01-01

17

TRPA1 induced in sensory neurons contributes to cold hyperalgesia after inflammation and nerve injury  

PubMed Central

Cold hyperalgesia is a well-documented symptom of inflammatory and neuropathic pain; however, the underlying mechanisms of this enhanced sensitivity to cold are poorly understood. A subset of transient receptor potential (TRP) channels mediates thermosensation and is expressed in sensory tissues, such as nociceptors and skin. Here we report that the pharmacological blockade of TRPA1 in primary sensory neurons reversed cold hyperalgesia caused by inflammation and nerve injury. Inflammation and nerve injury increased TRPA1, but not TRPM8, expression in tyrosine kinase A–expressing dorsal root ganglion (DRG) neurons. Intrathecal administration of anti–nerve growth factor (anti-NGF), p38 MAPK inhibitor, or TRPA1 antisense oligodeoxynucleotide decreased the induction of TRPA1 and suppressed inflammation- and nerve injury–induced cold hyperalgesia. Conversely, intrathecal injection of NGF, but not glial cell line–derived neurotrophic factor, increased TRPA1 in DRG neurons through the p38 MAPK pathway. Together, these results demonstrate that an NGF-induced TRPA1 increase in sensory neurons via p38 activation is necessary for cold hyperalgesia. Thus, blocking TRPA1 in sensory neurons might provide a fruitful strategy for treating cold hyperalgesia caused by inflammation and nerve damage. PMID:16110328

Obata, Koichi; Katsura, Hirokazu; Mizushima, Toshiyuki; Yamanaka, Hiroki; Kobayashi, Kimiko; Dai, Yi; Fukuoka, Tetsuo; Tokunaga, Atsushi; Tominaga, Makoto; Noguchi, Koichi

2005-01-01

18

Roles of mast cells and sensory nerves in cutaneous vascular hyperpermeability and scratching behavior induced by poly-L-arginine in rats.  

PubMed

We investigated whether the polycation poly-L-arginine elicited cutaneous vascular hyperpermeability and scratching behavior and, if so, whether these responses involved mast cells and sensory nerves in rats. Intradermal injections of poly-L-arginine induced vascular hyperpermeability and scratching behavior. Combined treatment with chlorpheniramine and methysergide almost completely suppressed the poly-L-arginine (50 microg/site)-induced plasma leakage. Capsaicin desensitization and the tachykinin NK(1) receptor antagonist LY303870, (R)-1-[N-(2-methoxybenzyl)acetylamino]-3-(1H-indol-3-yl)-2-[N-(2-(4-(piperidin-1-yl)piperidin-1-yl)acetyl)amino]propane, partially inhibited the leakage. In mast cell-deficient rats, poly-L-arginine only minimally induced plasma leakage. On the other hand, capsaicin desensitization and LY303870, but not chlorpheniramine or methysergide, suppressed the poly-L-arginine (200 microg/site)-induced scratching. Moreover, poly-L-arginine elicited the scratching even in mast cell-deficient rats. These results suggest that substance P is at least partly involved in both the cutaneous plasma leakage and the scratching behavior induced by poly-L-arginine. Moreover, mast cell-derived amines are suggested to be involved in the plasma extravasation but scarcely, if any, in the scratching behavior. PMID:11513841

Hayashi, K; Sato, H; Kaise, T; Ohmori, K; Ishii, A; Sano, J; Karasawa, A

2001-08-17

19

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

PubMed Central

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

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

2014-01-01

20

Sensory Nerve Innervation of Epineurial Arterioles of the Sciatic Nerve Containing Calcitonin Gene–Related Peptide: Effect of Streptozotocin-Induced Diabetes  

PubMed Central

The authors have determined that epineurial arterioles of the sciatic nerve are innervated by nonadrenergic, noncholinergic nerves that contribute to the regulation of vasodilation. Using immunohistochemistry, the authors determined that nerves innervating epineurial arterioles contain the neuropeptide calcitonin gene–related peptide (CGRP). Using streptozotocin-induced diabetic rats, the authors demonstrated that CGRP content in sensory nerves innervating epineurial arterioles and vasodilation in response to exogenous CGRP was decreased. In summary, epineurial arterioles of the sciatic nerve are innervated by sensory nerves containing the neuropeptide CGRP. The diabetes-like condition induced by streptozotocin reduces the content of CGRP in these nerves and exogenous CGRPmediated vasodilation. CGRP is likely an important regulator of vascular tone and compromising its function could contribute to nerve ischemia and diabetic neuropathy. PMID:15512786

Coppey, L. J.; Gellett, J. S.; Davidson, E. P.

2004-01-01

21

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

PubMed

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

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

2013-08-01

22

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

Microsoft Academic Search

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

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

2004-01-01

23

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

PubMed

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 ?V than for the subgroup of SNAP of ?16 ?V. Using a PHUA perspective to analyze the efficiency of force-adjustment could assist the clinical detection of sensory nerve dysfunction. PMID:24496877

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

2014-01-01

24

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

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

25

Photodamage to the cutaneous sensory nerves: role in photoaging and carcinogenesis of the skin?  

PubMed

Chronic exposure to ultraviolet radiation (UVR) plays a significant role in aging and carcinogenesis of the skin. Sensory nerve fibers densely innervate all layers of the skin and get in close anatomical as well as functional contact with cellular components of the epidermis and dermis. In this review, we address the impact of acute and chronic UVR exposure on the cutaneous sensory nervous system and its mediators. We suggest that skin cell-derived nerve growth factor (NGF) and skin nerve-derived neuropeptides such as substance P (SP) and calcitonin gene-related peptide (CGRP) may play a central role in intrinsic aging as well as extrinsic (photo-) aging of the skin. In addition, we discuss the possible role of these mediators in photocarcinogenesis. PMID:16465302

Legat, Franz J; Wolf, Peter

2006-02-01

26

CAPSAICIN-SENSITIVE SENSORY NERVE FIBERS CONTRIBUTE TO THE GENERATION AND MAINTENANCE OF SKELETAL FRACTURE PAIN  

PubMed Central

Although skeletal pain can have a marked impact on a patient’s functional status and quality of life, relatively little is known about the specific populations of peripheral nerve fibers that drive non-malignant bone pain. In the present report, neonatal male Sprague Dawley rats were treated with capsaicin or vehicle and femoral fracture was produced when the animals were young adults (15–16 weeks old). Capsaicin treatment, but not vehicle, resulted in a significant (>70%) depletion in the density of calcitonin-gene related peptide positive (CGRP+) sensory nerve fibers, but not 200 kD neurofilament H positive (NF200+) sensory nerve fibers in the periosteum. The periosteum is a thin, cellular and fibrous tissue that tightly adheres to the outer surface of all but the articulated surface of bone and appears to play a pivotal role in driving fracture pain. In animals treated with capsaicin, but not vehicle, there was a 50% reduction in the severity, but no change in the time course, of fracture-induced skeletal pain related behaviors as measured by spontaneous flinching, guarding and weight bearing. These results suggest that both capsaicin-sensitive (primarily CGRP+ C-fibers) and capsaicin-insensitive (primarily NF200+ A-delta fibers) sensory nerve fibers participate in driving skeletal fracture pain. Skeletal pain can be a significant impediment to functional recovery following trauma-induced fracture, osteoporosis-induced fracture and orthopedic surgery procedures such as knee and hip replacement. Understanding the specific populations of sensory nerve fibers that need to be targeted to inhibit the generation and maintenance of skeletal pain may allow the development of more specific mechanism-based therapies that can effectively attenuate acute and chronic skeletal pain. PMID:19486928

Jimenez-Andrade, Juan Miguel; Bloom, Aaron P.; Mantyh, William G.; Koewler, Nathan J.; Freeman, Katie T.; Delong, David; Ghilardi, Joseph R.; Kuskowski, Michael A.; Mantyh, Patrick W.

2009-01-01

27

Sickle cell disease in mice is associated with sensitization of sensory nerve fibers.  

PubMed

The pain phenotype in sickle cell disease (SCD) patients is highly variable. A small percentage of SCD patients experience many vaso-occlusive crises/year, 5% of patients account for over 30% of pain episodes, while 39% report few episodes of severe pain. Clearly, a better understanding of the pathobiology of SCD is needed to improve its therapy. Humanized sickle cell mice recapitulate several phenotypes of SCD patients and provide a model for the study of SCD pain. Researchers have shown that one strain of humanized SCD mice, the BERK strain, has abnormal pain phenotype. However, the nociception phenotype of another humanized SCD mouse strain, the Townes strain, has not been described. In a large cross-sectional study of BERK and Townes SCD mice, we examined thermosensory response and sensory nerve fiber function using sine-wave electrical stimulation at 2000, 250, and 5?Hz to stimulate preferentially A?, A?, and C sensory nerve fibers, respectively. We found that BERK and Townes mice, compared to respective controls, had decreases in 2000, 250, and 5?Hz current vocalization thresholds in patterns that suggest sensitization of a broad spectrum of sensory nerve fibers. In addition, the pattern of sensitization of sensory fibers varied according to strain, sex, age, and mouse genotype. In a similarly variable pattern, Townes and BERKs also had significantly altered sensitivity to noxious thermal stimuli in agreement with what has been shown by others. In summary, the analysis of somatosensory function using sine-wave electrical stimulation in humanized sickle cell mice suggests that in SCD, both myelinated and unmyelinated, fibers are sensitized. The pattern of sensory fiber sensitization is distinct from that observed in pain models of neuropathic and inflammatory pain. These findings raise the possibility that sensitization of a broad spectrum of sensory fibers might contribute to the altered and variable nociception phenotype in SCD. PMID:25070860

Kenyon, Nicholas; Wang, Li; Spornick, Nicholas; Khaibullina, Alfia; Almeida, Luis Ef; Cheng, Yao; Wang, Jichuan; Guptill, Virginia; Finkel, Julia C; Quezado, Zenaide Mn

2015-01-01

28

Noninvasive Peroneal Sensory and Motor Nerve Conduction Recordings in the Rabbit Distal Hindlimb: Feasibility, Variability and Neuropathy Measure  

PubMed Central

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 ?V (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 models of peripheral neuropathies. PMID:24658286

Hotson, John R.

2014-01-01

29

Amplitude of sensory nerve action potential in early stage diabetic peripheral neuropathy: an analysis of 500 cases  

PubMed Central

Early diagnosis of diabetic peripheral neuropathy is important for the successful treatment of diabetes mellitus. In the present study, we recruited 500 diabetic patients from the Fourth Affiliated Hospital of Kunming Medical University in China from June 2008 to September 2013: 221 cases showed symptoms of peripheral neuropathy (symptomatic group) and 279 cases had no symptoms of peripheral impairment (asymptomatic group). One hundred healthy control subjects were also recruited. Nerve conduction studies revealed that distal motor latency was longer, sensory nerve conduction velocity was slower, and sensory nerve action potential and amplitude of compound muscle action potential were significantly lower in the median, ulnar, posterior tibial and common peroneal nerve in the diabetic groups compared with control subjects. Moreover, the alterations were more obvious in patients with symptoms of peripheral neuropathy. Of the 500 diabetic patients, neural conduction abnormalities were detected in 358 cases (71.6%), among which impairment of the common peroneal nerve was most prominent. Sensory nerve abnormality was more obvious than motor nerve abnormality in the diabetic groups. The amplitude of sensory nerve action potential was the most sensitive measure of peripheral neuropathy. Our results reveal that varying degrees of nerve conduction changes are present in the early, asymptomatic stage of diabetic peripheral neuropathy. PMID:25221597

Zhang, Yunqian; Li, Jintao; Wang, Tingjuan; Wang, Jianlin

2014-01-01

30

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

PubMed Central

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 A?-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 function deficits, the presence of elongated nodes was inversely correlated with a number of functional and symptom related scores (P < 0.023). Our findings suggest that carpal tunnel syndrome does not exclusively affect large fibres but is associated with loss of function in modalities mediated by both unmyelinated and myelinated sensory axons. We also document for the first time that entrapment neuropathies lead to a clear reduction in intraepidermal nerve fibre density, which was independent of electrodiagnostic test severity. The presence of elongated nodes in the target tissue further suggests that entrapment neuropathies affect nodal structure/myelin well beyond the focal compression site. Interestingly, nodal lengthening may be an adaptive phenomenon as it inversely correlates with symptom severity. PMID:25348629

Schmid, Annina B.; Bland, Jeremy D. P.; Bhat, Manzoor A.

2014-01-01

31

Cough Sensors. III. Opioid and Cannabinoid Receptors on Vagal Sensory Nerves  

Microsoft Academic Search

Cough is a persistent symptom of many inflammatory airways' diseases. Cough is mediated by receptors sited on sensory nerves\\u000a and then through vagal afferent pathways, which terminate in the brainstem respiratory centre. Cough is often described as\\u000a an unmet clinical need. Opioids are the only prescription-based anti-tussives currently available in the UK. They possess\\u000a limited efficacy and exhibit serious unwanted

M. G. Belvisi; D. J. Hele

32

?? T cells infiltrating sensory nerve biopsies from patients with inflammatory neuropathy  

Microsoft Academic Search

Sensory nerve biopsy specimens from patients with Guillain Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy\\u000a (CIDP), and controls consisting of other neuropathies, were examined in order to characterise the nature and intensity of\\u000a any inflammatory infiltrate. In order to establish whether ?? T cells were present in these infiltrates we examined the expression\\u000a of ?? and ?? T cell receptors

John Winer; Sharon Hughes; Joanne Cooper; Anne Ben-Smith; Caroline Savage

2002-01-01

33

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

PubMed Central

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

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

34

The effect of treatment with BRX-220, a co-inducer of heat shock proteins, on sensory fibers of the rat following peripheral nerve injury  

E-print Network

of the rat following peripheral nerve injury B. Kalmar,a,b,* L. Greensmith,a M. Malcangio,c S.B. McMahon,c P sciatic nerve injury in adult rats and treatment with BRX-220, the following features of the sensory and functional properties in the sensory system following peripheral nerve injury. D 2003 Elsevier Inc. All

Burnstock, Geoffrey

35

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

PubMed Central

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 nerve sprouting and formation of neuroma-like structures after inflammation/injury. Understanding the factors that drive this neuroplasticity, whether this pathologic reorganization of nerve fibers contributes to chronic joint pain, and how the phenotype of sensory and sympathetic nerves changes with age may provide pharmacologic insight and targets for better controlling aging-related joint pain. PMID:22548760

2012-01-01

36

Secretion of Growth Hormone in Response to Muscle Sensory Nerve Stimulation  

NASA Technical Reports Server (NTRS)

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.

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

37

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

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

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

2014-01-01

38

Renal sensory and sympathetic nerves reinnervate the kidney in a similar time-dependent fashion after renal denervation in rats  

PubMed Central

Efferent renal sympathetic nerves reinnervate the kidney after renal denervation in animals and humans. Therefore, the long-term reduction in arterial pressure following renal denervation in drug-resistant hypertensive patients has been attributed to lack of afferent renal sensory reinnervation. However, afferent sensory reinnervation of any organ, including the kidney, is an understudied question. Therefore, we analyzed the time course of sympathetic and sensory reinnervation at multiple time points (1, 4, and 5 days and 1, 2, 3, 4, 6, 9, and 12 wk) after renal denervation in normal Sprague-Dawley rats. Sympathetic and sensory innervation in the innervated and contralateral denervated kidney was determined as optical density (ImageJ) of the sympathetic and sensory nerves identified by immunohistochemistry using antibodies against markers for sympathetic nerves [neuropeptide Y (NPY) and tyrosine hydroxylase (TH)] and sensory nerves [substance P and calcitonin gene-related peptide (CGRP)]. In denervated kidneys, the optical density of NPY-immunoreactive (ir) fibers in the renal cortex and substance P-ir fibers in the pelvic wall was 6, 39, and 100% and 8, 47, and 100%, respectively, of that in the contralateral innervated kidney at 4 days, 4 wk, and 12 wk after denervation. Linear regression analysis of the optical density of the ratio of the denervated/innervated kidney versus time yielded similar intercept and slope values for NPY-ir, TH-ir, substance P-ir, and CGRP-ir fibers (all R2 > 0.76). In conclusion, in normotensive rats, reinnervation of the renal sensory nerves occurs over the same time course as reinnervation of the renal sympathetic nerves, both being complete at 9 to 12 wk following renal denervation. PMID:23408032

Mulder, Jan; Hökfelt, Tomas; Knuepfer, Mark M.

2013-01-01

39

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

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

40

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

PubMed Central

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

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

41

Endogenous NGF and Nerve Impulses Regulate the Collateral Sprouting of Sensory Axons in the Skin of the Adult Rat  

Microsoft Academic Search

We have investigated the co-involvement of enclogenous NGF and impulses in the collateral sprouting of cutaneous sensory nerves in adult rats, specifically the A&axons in- volved in mechanonociception and the C-fibers that mediate heat nociception. Their collateral sprouting was measured by the progressive expansion, respectively, of the behav- iorally defined \\

Jack Diamond; Michael Holmes; Michael Coughlin

1992-01-01

42

Nerve Growth Factors (NGF, BDNF) Enhance Axonal Regeneration but Are not Required for Survival of Adult Sensory Neurons  

Microsoft Academic Search

Largely on the basis of studies with nerve growth factor (NGF), it is now widely accepted that development of the peripheral nervous system of vertebrates is dependent in part on the interaction of immature sensory and autonomic neurons with specific survival factors that are derived from peripheral target fields. I have found, in marked contrast to an absolute requirement for

Ronald M. Lindsay

1988-01-01

43

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

PubMed Central

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

2011-01-01

44

Capsaicin Combined with Local Anesthetics Preferentially Prolongs Sensory/Nociceptive Block in Rat Sciatic Nerve  

PubMed Central

Background Transient receptor potential vanilloid 1 channels integrate nociceptive stimuli and are predominantly expressed by unmyelinated C-fiber nociceptors, but not low-threshold mechanoreceptive sensory or motor fibers. A recent report showed that the transient receptor potential vanilloid 1 channel agonist capsaicin allows a hydrophilic quaternary ammonium derivative of lidocaine, QX-314, to selectively block C fibers without motor block. The authors tested whether a similar differential block would be produced using amphipathicN-methyl amitriptyline, amitriptyline, bupivacaine, or lidocaine, either alone or together with 0.05% capsaicin, in a rat sciatic nerve block model. Methods Rats (n = 8/group) were anesthetized with sevoflurane, and 0.2 ml of drug was injected either alone or with capsaicin (simultaneously or 10 min later) next to the sciatic nerve in the sciatic notch. Motor function was assessed by the extensor postural thrust. Nociception was evaluated by the nocifensive withdrawal reflex and vocalization evoked by pinch of a skin fold over the lateral metatarsus (cutaneous pain) with a serrated forceps. Results N-Methyl amitriptyline, amitriptyline, bupivacaine, or lidocaine, followed by injection of capsaicin 10 min later, each elicited a predominantly nociceptive-specific blockade. In comparison, simultaneous application of each local anesthetic with capsaicin did not elicit a clinically significant differential block, with the exception of N-methyl amitriptyline. Conclusions Both tertiary amine local anesthetics and their quaternary ammonium derivatives can elicit a predominantly sensory/nociceptor selective block when followed by injection of capsaicin. The combined application of transient receptor potential vanilloid 1 channel agonists and various local anesthetics or their quaternary ammonium derivatives is an appealing strategy to achieve a long-lasting differential block in regional analgesia. PMID:18946300

Binshtok, Alexander M.; Wang, Chi-Fei; Hevelone, Nathanael D.; Bean, Bruce P.; Woolf, Clifford J.; Wang, Ging Kuo

2009-01-01

45

Sensory nerve terminal mitochondrial dysfunction induces hyperexcitability in airway nociceptors via protein kinase C.  

PubMed

Airway sensory nerve excitability is a key determinant of respiratory disease-associated reflexes and sensations such as cough and dyspnea. Inflammatory signaling modulates mitochondrial function and produces reactive oxygen species (ROS). Peripheral terminals of sensory nerves are densely packed with mitochondria; thus, we hypothesized that mitochondrial modulation would alter neuronal excitability. We recorded action potential firing from the terminals of individual bronchopulmonary C-fibers using a mouse ex vivo lung-vagal ganglia preparation. C-fibers were characterized as nociceptors or non-nociceptors based upon conduction velocity and response to transient receptor potential (TRP) channel agonists. Antimycin A (mitochondrial complex III Qi site inhibitor) had no effect on the excitability of non-nociceptors. However, antimycin A increased excitability in nociceptive C-fibers, decreasing the mechanical threshold by 50% and increasing the action potential firing elicited by a P2X2/3 agonist to 270% of control. Antimycin A-induced nociceptor hyperexcitability was independent of TRP ankyrin 1 or TRP vanilloid 1 channels. Blocking mitochondrial ATP production with oligomycin or myxothiazol had no effect on excitability. Antimycin A-induced hyperexcitability was dependent on mitochondrial ROS and was blocked by intracellular antioxidants. ROS are known to activate protein kinase C (PKC). Antimycin A-induced hyperexcitability was inhibited by the PKC inhibitor bisindolylmaleimide (BIM) I, but not by its inactive analog BIM V. In dissociated vagal neurons, antimycin A caused ROS-dependent PKC translocation to the membrane. Finally, H2O2 also induced PKC-dependent nociceptive C-fiber hyperexcitability and PKC translocation. In conclusion, ROS evoked by mitochondrial dysfunction caused nociceptor hyperexcitability via the translocation and activation of PKC. PMID:24642367

Hadley, Stephen H; Bahia, Parmvir K; Taylor-Clark, Thomas E

2014-06-01

46

Roles of sensory nerves in the regulation of radiation-induced structural and functional changes in the heart  

PubMed Central

Purpose Radiation-induced heart disease (RIHD) is a chronic severe side effect of radiotherapy of intrathoracic and chest wall tumors. The heart contains a dense network of sensory neurons that are not only involved in monitoring of cardiac events such as ischemia/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, two weeks before local image-guided heart X-ray irradiation with a single dose of 21 Gy. During the 6-months follow up time, 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-Blots. Results Capsaicin-pretreatment blunted the effects of radiation on myocardial fibrosis and mast cell infiltration and activity. On the other hand, capsaicin-pretreatment caused a small but significant reduction in cardiac output at 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, while playing a predominantly protective role in radiation-induced cardiac function changes, may eventually enhance radiation-induced myocardial fibrosis and mast cell activity. PMID:24331664

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

2013-01-01

47

A pilot study of sensory feedback by transcutaneous electrical nerve stimulation to improve manipulation deficit caused by severe sensory loss after stroke  

PubMed Central

Background Sensory disturbance is common following stroke and can exacerbate functional deficits, even in patients with relatively good motor function. In particular, loss of appropriate sensory feedback in severe sensory loss impairs manipulation capability. We hypothesized that task-oriented training with sensory feedback assistance would improve manipulation capability even without sensory pathway recovery. Methods We developed a system that provides sensory feedback by transcutaneous electrical nerve stimulation (SENS) for patients with sensory loss, and investigated the feasibility of the system in a stroke patient with severe sensory impairment and mild motor deficit. The electrical current was modulated by the force exerted by the fingertips so as to allow the patient to identify the intensity. The patient had severe sensory loss due to a right thalamic hemorrhage suffered 27 months prior to participation in the study. The patient first practiced a cylindrical grasp task with SENS for 1 hour daily over 29 days. Pressure information from the affected thumb was fed back to the unaffected shoulder. The same patient practiced a tip pinch task with SENS for 1 hour daily over 4 days. Pressure information from the affected thumb and index finger was fed back to the unaffected and affected shoulders, respectively. We assessed the feasibility of SENS and examined the improvement of manipulation capability after training with SENS. Results The fluctuation in fingertip force during the cylindrical grasp task gradually decreased as the training progressed. The patient was able to maintain a stable grip force after training, even without SENS. Pressure exerted by the tip pinch of the affected hand was unstable before intervention with SENS compared with that of the unaffected hand. However, they were similar to each other immediately after SENS was initiated, suggesting that the somatosensory information improved tip pinch performance. The patient’s manipulation capability assessed by the Box and Block Test score improved through SENS intervention and was partly maintained after SENS was removed, until at least 7 months after the intervention. The sensory test score, however, showed no recovery after intervention. Conclusions We conclude that the proposed system would be useful in the rehabilitation of patients with sensory loss. PMID:23764012

2013-01-01

48

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

PubMed

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

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

2014-01-01

49

Sigma-1 receptor expression in sensory neurons and the effect of painful peripheral nerve injury  

PubMed Central

Background The sigma-1 receptor (?1R), an endoplasmic reticulum chaperone protein, is widely distributed and regulates numerous intracellular processes in neurons. Nerve injury alters the structure and function of axotomized dorsal root ganglion (DRG) neurons, contributing to the development of pain. The ?1R is enriched in the spinal cord and modulates pain after peripheral nerve injury. However, ?1R expression in the DRG has not been studied. We therefore characterized ?1R expression in DRGs at baseline and following spinal nerve ligation (SNL) in rats. Results Immunohistochemical (IHC) studies in DRG sections show ?1R in both neuronal somata and satellite glial cells. The punctate distribution of ?1R in the neuronal cytoplasm suggests expression in the endoplasmic reticulum. When classified by neuronal size, large neurons (>1300 ?m) showed higher levels of ?1R staining than other groups (700-1300 ?m, <700 ?m). Comparing ?1R expression in neuronal groups characterized by expression of calcitonin gene-related peptide (CGRP), isolectin-B4 (IB4) and neurofilament-200 (NF-200), we found ?1R expression in all three neuronal subpopulations, with highest levels of ?1R expression in the NF-200 group. After SNL, lysates from L5 DRGs that contains axotomized neurons showed decreased ?1R protein but unaffected transcript level, compared with Control DRGs. IHC images also showed decreased ?1R protein expression, in SNL L5 DRGs, and to a lesser extent in the neighboring SNL L4 DRGs. Neurons labeled by CGRP and NF-200 showed decreased ?1R expression in L5 and, to a lesser extent, L4 DRGs. In IB4-labeled neurons, ?1R expression decreased only in axotomized L5 DRGs. Satellite cells also showed decreased ?1R expression in L5 DRGs after SNL. Conclusions Our data show that ?1R is present in both sensory neurons and satellite cells in rat DRGs. Expression of ?1R is down-regulated in axotomized neurons as well as in their accompanying satellite glial cells, while neighboring uninjured neurons show a lesser down-regulation. Therefore, elevated ?1R expression in neuropathic pain is not an explanation for pain relief after ?1R blockade. This implies that increased levels of endogenous ?1R agonists may play a role, and diminished neuroprotection from loss of glial ?1R may be a contributing factor. PMID:24015960

2013-01-01

50

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

PubMed

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

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

51

Inhibitory activity of the novel CB2 receptor agonist, GW833972A, on guinea-pig and human sensory nerve function in the airways  

PubMed Central

Background and purpose: Sensory nerves regulate central and local reflexes such as airway plasma protein leakage, bronchoconstriction and cough. Sensory nerve activity may be enhanced during inflammation such that these protective effects become exacerbated and deleterious. Cannabinoids are known to inhibit airway sensory nerve function. However, there is still controversy surrounding which receptor is involved in eliciting these effects. Experimental approach: We have adopted a pharmacological approach, including using a novel, more selective CB2 receptor agonist, GW 833972A (1000-fold selective CB2/CB1), and receptor selective antagonists to investigate the inhibitory activity of cannabinoids on sensory nerve activity in vitro and in vivo in guinea-pig models of cough and plasma extravasation. Key results: GW 833972A inhibited capsaicin-induced depolarization of the human and guinea-pig and prostaglandin E2 (PGE2) and hypertonic saline-induced depolarization of the guinea-pig isolated vagus nerve in vitro. GW 833972A also inhibited citric acid-induced cough but not plasma extravasation in the guinea-pig and this effect was blocked by a CB2 receptor antagonist. Conclusions and implications: This confirms and extends previous studies highlighting the role of CB2 receptors in the modulation of sensory nerve activity elicited both by the exogenous ligands capsaicin and hypertonic saline but also by endogenous modulators such as PGE2 and low pH stimuli. These data establish the CB2 receptor as an interesting target for the treatment of chronic cough. PMID:18695648

Belvisi, M G; Patel, H J; Freund-Michel, V; Hele, D J; Crispino, N; Birrell, M A

2008-01-01

52

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

NASA Astrophysics Data System (ADS)

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.

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

1996-01-01

53

A comparison between complete immobilisation and protected active mobilisation in sensory nerve recovery following isolated digital nerve injury.  

PubMed

Post-operative immobilisation following isolated digital nerve repair remains a controversial issue amongst the microsurgical community. Protocols differ from unit to unit and even, as evidenced in our unit, may differ from consultant to consultant. We undertook a retrospective review of 46 patients who underwent isolated digital nerve repair over a 6-month period. Follow-up ranged from 6 to 18 months. Twenty-four were managed with protected active mobilisation over a 4-week period while 22 were immobilised over the same period. Outcomes such as return to work, cold intolerance, two-point discrimination and temperature differentiation were used as indicators of clinical recovery. Our results showed that there was no significant difference noted in either clinical assessment of recovery or return to work following either post-operative protocol, suggesting that either regime may be adopted, tailored to the patient's needs and resources of the unit. PMID:22147643

Henry, F P; Farkhad, R I; Butt, F S; O'Shaughnessy, M; O'Sullivan, S T

2012-06-01

54

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

PubMed

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

Stankovic, N; Johansson, O; Hildebrand, C

1996-01-01

55

Influence of Breaching the Connective Sheaths of the Donor Nerve on Its Myelinated Sensory Axons and on Their Sprouting into the End-to-Side Coapted Nerve in the Rat  

PubMed Central

Abstract The influence of breaching the connective sheaths of the donor sural nerve on axonal sprouting into the end-to-side coapted peroneal nerve was examined in the rat. In parallel, the effect of these procedures on the donor nerve was assessed. The sheaths of the donor nerve at the coaptation site were either left completely intact (group A) or they were breached by epineurial sutures (group B), an epineurial window (group C), or a perineurial window (group D). In group A, the compound action potential (CAP) of sensory axons was detected in ?10% and 40% of the recipient nerves at 4 and 8 weeks, respectively, which was significantly less frequently than in group D at both recovery periods. In addition, the number of myelinated axons in the recipient nerve was significantly larger in group D than in other groups at 4 weeks. At 8 weeks, the number of axons in group A was only ?15% of the axon numbers in other groups (p<0.05). Focal subepineurial degenerative changes in the donor nerves were only seen after 4 weeks, but not later. The average CAP area and the total number of myelinated axons in the donor nerves were not different among the experimental groups. In conclusion, myelinated sensory axons are able to penetrate the epiperineurium of donor nerves after end-to-side nerve coaption; however, their ingrowth into recipient nerves is significantly enhanced by breaching the epiperineurial sheets at the coaptation site. Breaching does not cause permanent injury to the donor nerve. PMID:22873667

Žele, Tilen; Tomši?, Martin; Sketelj, Janez; Bajrovi?, Fajko F.

2012-01-01

56

Systemic acetyl- l -carnitine eliminates sensory neuronal loss after peripheral axotomy: a new clinical approach in the management of peripheral nerve trauma  

Microsoft Academic Search

Several hundred thousand peripheral nerve injuries occur each year in Europe alone. Largely due to the death of around 40%\\u000a of primary sensory neurons, sensory outcome remains disappointingly poor despite considerable advances in surgical technique;\\u000a yet no clinical therapies currently exist to prevent this neuronal death. Acetyl-l-carnitine (ALCAR) is a physiological peptide with roles in mitochondrial bioenergetic function, which may

Andrew McKay Hart; Mikael Wiberg; Mike Youle; Giorgio Terenghi

2002-01-01

57

Sciatic nerve injury induces apoptosis of dorsal root ganglion satellite glial cells and selectively modifies neurosteroidogenesis in sensory neurons.  

PubMed

Neurosteroids are synthesized either by glial cells, by neurons, or within the context of neuron-glia cross-talk. Various studies suggested neurosteroid involvement in the control of neurodegeneration but there is no evidence showing that the natural protection of nerve cells against apoptosis directly depends on their own capacity to produce neuroprotective neurosteroids. Here, we investigated the interactions between neurosteroidogenesis and apoptosis occurring in sensory structures of rats subjected to neuropathic pain generated by sciatic nerve chronic constriction injury (CCI). Using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), we observed no apoptotic cells in the spinal cord up to 30 days after CCI although pain symptoms such as mechano-allodynia, thermal and mechanical hyperalgesia were evidenced with the Hargreaves's behavioral and von Frey filament tests. In contrast, double-labeling experiments combining TUNEL and immunostaining with antibodies against glutamine synthetase or neuronal nuclei protein revealed apoptosis occurrence in satellite glial cells (SGC) (not in neurons) of CCI rat ipsilateral dorsal root ganglia (DRG) at day 30 after injury. Pulse-chase experiments coupled with high performance liquid chromatography and flow scintillation detection showed that, among numerous biosynthetic pathways converting [(3)H]pregnenolone into various [(3)H]neurosteroids, only [(3)H]estradiol formation was selectively modified and upregulated in DRG of CCI rats. Consistently, immunohistochemical investigations localized aromatase (estradiol-synthesizing enzyme) in DRG neurons but not in SGC. Pharmacological inhibition of aromatase caused apoptosis of CCI rat DRG neurons. Altogether, our results suggest that endogenously produced neurosteroids such as estradiol may be pivotal for the protection of DRG sensory neurons against sciatic nerve CCI-induced apoptosis. PMID:19565659

Schaeffer, Véronique; Meyer, Laurence; Patte-Mensah, Christine; Eckert, Anne; Mensah-Nyagan, Ayikoe G

2010-01-15

58

Deceased expression of prostatic acid phosphatase in primary sensory neurons after peripheral nerve injury  

PubMed Central

Prostatic acid phosphatase (PAP) is expressed in nociceptive dorsal root ganglion (DRG) neurons and functions as an ectonucleotidase that dephosphorylates extracellular adenosine monophosphate (AMP) to adenosine to suppress pain via activating A1-adenosine receptor (A1R) in dorsal spinal cord. However, the effect of peripheral nerve injury on the expression of PAP has not been reported until now. In the present study we found that PAP expression in DRG neurons is significantly decreased from the 2nd day after peripheral nerve injury and reaches the bottom at the 14th. In addition, intrathecal PAP injection can reduce mechanical allodynia induced by spared nerve injury. Our findings suggest that the decrease of PAP is involved in pathophysiological mechanisms of neuropathic pain.

Huang, Bo; Li, Xia; Zhu, Xiao-Chun; Lu, Yi-Sheng

2014-01-01

59

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

Microsoft Academic Search

Background  Neuronal hyperexcitability is a crucial phenomenon underlying spontaneous and evoked pain. In invertebrate nociceptors, the\\u000a S-type leak K+ channel (analogous to TREK-1 in mammals) plays a critical role of in determining neuronal excitability following nerve injury.\\u000a Few data are available on the role of leak K2P channels after peripheral axotomy in mammals.\\u000a \\u000a \\u000a \\u000a \\u000a Results  Here we describe that rat sciatic nerve axotomy

Astrid Tulleuda; Barbara Cokic; Gerard Callejo; Barbara Saiani; Jordi Serra; Xavier Gasull

2011-01-01

60

Tiotropium modulates transient receptor potential V1 (TRPV1) in airway sensory nerves: A beneficial off-target effect???  

PubMed Central

Background Recent studies have suggested that the long-acting muscarinic receptor antagonist tiotropium, a drug widely prescribed for its bronchodilator activity in patients with chronic obstructive pulmonary disease and asthma, improves symptoms and attenuates cough in preclinical and clinical tussive agent challenge studies. The mechanism by which tiotropium modifies tussive responses is not clear, but an inhibition of vagal tone and a consequent reduction in mucus production from submucosal glands and bronchodilation have been proposed. Objective The aim of this study was to investigate whether tiotropium can directly modulate airway sensory nerve activity and thereby the cough reflex. Methods We used a conscious cough model in guinea pigs, isolated vagal sensory nerve and isolated airway neuron tissue– and cell-based assays, and in vivo single-fiber recording electrophysiologic techniques. Results Inhaled tiotropium blocked cough and single C-fiber firing in the guinea pig to the transient receptor potential (TRP) V1 agonist capsaicin, a clinically relevant tussive stimulant. Tiotropium and ipratropium, a structurally similar muscarinic antagonist, inhibited capsaicin responses in isolated guinea pig vagal tissue, but glycopyrrolate and atropine did not. Tiotropium failed to modulate other TRP channel–mediated responses. Complementary data were generated in airway-specific primary ganglion neurons, demonstrating that tiotropium inhibited capsaicin-induced, but not TRPA1-induced, calcium movement and voltage changes. Conclusion For the first time, we have shown that tiotropium inhibits neuronal TRPV1-mediated effects through a mechanism unrelated to its anticholinergic activity. We speculate that some of the clinical benefit associated with taking tiotropium (eg, in symptom control) could be explained through this proposed mechanism of action. PMID:24506933

Birrell, Mark A.; Bonvini, Sara J.; Dubuis, Eric; Maher, Sarah A.; Wortley, Michael A.; Grace, Megan S.; Raemdonck, Kristof; Adcock, John J.; Belvisi, Maria G.

2014-01-01

61

Sensory Neuron Signaling to the Brain: Properties of Transmitter Release from Olfactory Nerve Terminals  

Microsoft Academic Search

olfactory bulb glomeruli. To better understand the process by which information contained in the odorant-evoked firing of ORNs is transmitted to the brain, we examined the properties of glutamate release from olfactory nerve (ON) terminals in slices of the rat olfactory bulb. We show that marked paired pulse depression is the same in simultaneously recorded periglomerular and tufted neurons, and

Gabe J. Murphy; Lindsey L. Glickfeld; Zev Balsen; Jeffry S. Isaacson

2004-01-01

62

The impact and specificity of nerve perturbation on novel vibrotactile sensory letter learning.  

PubMed

The purposes of this study were to determine if induced radiating paresthesia interferes with (a) acquisition and/or (b) utilization of complex tactile information, and (c) identify whether interference reflects tactile masking or response competition. Radiating ulnar (experiment 1) and median (experiment 2) nerve paresthesia was quantified on ulnar innervated vibrotactile Morse code letter acquisition and recollection tasks. Induced paresthesia differentially impacted letter acquisition and recollection, but only when presented to the same anatomical spatial location. PMID:24844345

Passmore, Steven R; Bosse, Jessica; Murphy, Bernadette; Lee, Timothy D

2014-12-01

63

Regulating cough through modulation of sensory nerve function in the airways.  

PubMed

Whilst local anaesthetics when applied directly to laryngeal nerves or topically to the lung can suppress cough, their chronic use is constrained because of dose limiting side effects. However, the effectiveness of local anaesthetics suggests that selectivity targeting nerves in the airway may provide novel approaches for the treatment of cough in the future. There is a considerable wealth of evidence showing that there are different afferent nerve subtypes in the airways. Traditionally C-fibres have been the focus of much research in the cough field since the stimulation of these afferents by capsaicin is able to elicit cough in guinea-pigs and in man, and drugs targeting various proteins expressed in these nerves (e.g. mu-opioid, NOP1, TRPV1, sodium channels) have been shown to be anti-tussive in preclinical models of cough. However, interest in A? fibres has increased recently in light of the discovery of a specific cough receptor in the guinea-pig that is provoked by citric acid and punctate stimulation, but not capsaicin and which has been anatomically linked to A? fibres. There is also some evidence that as a result of inflammation in the airways, A? fibres can begin to express neuropeptides and TRPV1 receptors so that they can become responsive to endogenous activators of this ion channel and to irritants like capsaicin. Consequently, there is considerable interest in targeting either one or both afferent nerve types for the treatment of chronic cough. However, to date the translation of preclinical studies into man has largely been disappointing and certainly there is a need for better preclinical models in this field. There also remain many challenges to overcome at a clinical level, such as what patient group(s) should be used to assess anti-tussive drugs and whether the use of irritants that induce cough in healthy volunteers (such as citric acid or capsaicin) is of any value in the assessment of novel anti-tussive drugs. The development of several continuous monitoring methodologies for measuring cough will hopefully allow better evaluation of treatments in patients with chronic cough. Nonetheless, cough remains a major unmet clinical need in respiratory medicine where new drugs are urgently required. PMID:23524012

Spina, D; Page, C P

2013-10-01

64

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

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

Herrera-Rincon, Celia; Panetsos, Fivos

2014-01-01

65

Different effects of blocked potassium channels on action potentials, accommodation, adaptation and anode break excitation in human motor and sensory myelinated nerve fibres: computer simulations  

Microsoft Academic Search

.  ?Action potentials and electrotonic responses to 300-ms depolarizing and hyperpolarizing currents for human motor and sensory\\u000a myelinated nerve fibres have been simulated on the basis of double cable models. The effects of blocked nodal or internodal\\u000a potassium (fast or slow) channels on the fibre action potentials, early and late adaptations to 30-ms suprathreshold slowly\\u000a increasing depolarizing stimuli have been examined.

D. I. Stephanova; K. Mileva

2000-01-01

66

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

PubMed

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

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

2002-03-01

67

Acceleration of ulcer healing by cholecystokinin (CCK): role of CCK-A receptors, somatostatin, nitric oxide and sensory nerves.  

PubMed

CCK exhibits a potent cytoprotective activity against acute gastric lesions, but its role in ulcer healing has been little examined. In this study we determined whether exogenous CCK or endogenously released CCK by camostate, an inhibitor of luminal proteases, or by the diversion of pancreatico-biliary secretion from the duodenum, could affect ulcer healing. In addition, the effects of antagonism of CCK-A receptors (by loxiglumide, LOX) or CCK-B receptors (by L-365,260), an inhibition of NO-synthase by N(G)-nitro-L-arginine (L-NNA), or sensory denervation by large neurotoxic dose of capsaicin on CCK-induced ulcer healing were examined. Gastric ulcers were produced by serosal application of acetic acid and animals were sacrificed 9 days after ulcer induction. The area of ulcers and blood flow at the ulcer area were determined. Plasma levels of gastrin and CCK and luminal somatostatin were measured by RIA and mucosal biopsy samples were taken for histological evaluation and measurement of DNA synthesis. CCK given s.c. reduced dose dependently the ulcer area; the threshold dose of CCK being 1 nmol/kg and the dose inhibiting this area by 50% being 5 nmol/kg. This healing effect of CCK was accompanied by a significant increase in the GBF at ulcer margin and the rise in luminal NO production, plasma gastrin level and DNA synthesis. Concurrent treatment with LOX, completely abolished the CCK-8-induced acceleration of the ulcer healing and the rise in the GBF at the ulcer margin, whereas L-365,260 remained without any influence. Treatment with camostate or diversion of pancreatic juice that raised plasma CCK level to that observed with administration of CCK-8, also accelerated ulcer healing and this effect was also attenuated by LOX but not by L-365,260. Inhibition of NO-synthase by L-NNA significantly delayed ulcer healing and reversed the CCK-8 induced acceleration of ulcer healing, hyperemia at the ulcer margin and luminal NO release, and these effects were restored by the addition to L-NNA of L-arginine but not D-arginine. Capsaicin denervation attenuated CCK-induced ulcer healing, and the accompanying rise in the GBF at the ulcer margin and decreased plasma gastrin and luminal release of somatostatin when compared to those in rats with intact sensory nerves. Detectable signals for CCK-A and B receptor mRNAs as well as for cNOS mRNA expression were recorded by RT-PCR in the vehicle control gastric mucosa. The expression of CCK-A receptor mRNA and cNOS mRNA was significantly increased in rats treated with CCK-8 and camostate, whereas CCK-B receptor mRNA remained unaffected. We conclude that CCK accelerates ulcer healing by the mechanism involving upregulation of specific CCK-A receptors, enhancement of somatostatin release, stimulation of sensory nerves and hyperemia in the ulcer area, possibly mediated by NO. PMID:10458643

Brzozowski, T; Konturek, P C; Konturek, S J; Pajdo, R; Drozdowicz, D; Kwiecie?, S; Hahn, E G

1999-06-30

68

Mechanisms of aspirin desensitization.  

PubMed

Aspirin-exacerbated respiratory disease is a clinical syndrome characterized by severe, persistent asthma, hyperplastic eosinophilic sinusitis with nasal polyps, and reactions to aspirin and other nonsteroidal antiinflammatory drugs that preferentially inhibit cyclooxygenase 1. The mechanisms behind the therapeutic effects of aspirin desensitization remain poorly understood. Recent studies suggest that the clinical benefits may occur through direct inhibition of tyrosine kinases and the signal transducer and activator of transcription 6 signaling pathway, which results in inhibition of interleukin 4 production. In this article, the current understanding of the mechanisms of aspirin desensitization is reviewed and future areas of investigation are discussed. PMID:23639710

Burnett, Trever; Katial, Rohit; Alam, Rafeul

2013-05-01

69

CAN SENSORY AND MOTOR COLLATERAL SPROUTING BE INDUCED FROM INTACT PERIPHERAL NERVE BY END-TO-SIDE ANASTOMOSIS?  

Microsoft Academic Search

The possibility that collateral sprouting could occur from intact axons in an undamaged sciatic nerve was studied in the rat by suturing either a 7-day predegenerated or a fresh nerve segment in an end-to-side fashion to the sciatic nerve proper. Following a 14- or 35-day recovery period, the pinch reflex test was performed on the transplanted segment to demonstrate the

G. LUNDBORG; Q. ZHAO; M. KANJE; N. DANIELSEN; J. M. KERNS

1994-01-01

70

Ipsilateral facial sensory and motor responses to basal fronto-temporal cortical stimulation: Evidence suggesting direct activation of cranial nerves  

Microsoft Academic Search

To clarify the generator mechanism of sensory and motor facial responses ipsilateral to electrical stimulation of the inferior fronto-temporal cortex in epilepsy patients. Out of 30 patients who have been evaluated with chronically implanted subdural electrodes for medically intractable partial seizure or brain tumor involving the basal frontal or temporal cortex, 4 patients (age ranging 24–57 years) showed sensory and

Tahamina Begum; Akio Ikeda; Masao Matsuhashi; Nobuhiro Mikuni; Susumu Miyamoto; Nobuo Hashimoto; Takashi Nagamine; Hidenao Fukuyama; Hiroshi Shibasaki

2006-01-01

71

A Silicon Model of Auditory-Nerve Response Nonlinear signal processing is an integral part of sensory transduction in  

E-print Network

intensities to a manageable excursion of signal level. Spiral-ganglion neurons connect to each inner hair cell of an auditory-nerve fiber can encode only about 25 dB of sound intensity. Humans can sense binaural time5 Chapter 2 A Silicon Model of Auditory-Nerve Response Nonlinear signal processing is an integral

Lazzaro, John

72

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

PubMed Central

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

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

2014-01-01

73

The method of isolation of the crayfish abdominal stretch receptor maintaining a connection of the sensory neuron to the ventral nerve cord ganglion.  

PubMed

The crayfish stretch receptor consisting of the single mechanoreceptor neurons enveloped by satellite glial cells is the simplest functioning neuroglial preparation. However, during isolation, its axons are usually transected that eliminates afferent regulation and induces complex axotomy-related signaling responses in neurons and satellite glia. We developed new microsurgical method of crayfish stretch receptor isolation, which preserves connections of sensory neurons to the ventral nerve cord ganglion. The stretch receptor may either remain on the abdominal carapace, or be completely isolated. In both cases, it may be either intact, or axotomized. The integrity of axons was confirmed by firing recording from proximal and distal axon points. Normal, necrotic and apoptotic cells were visualized using double fluorochroming with Hoechst 33342 and propidium iodide. The isolated mechanoreceptor neurons maintain regular firing during 8-10 or more hours. Glial cells surrounding non-axotomized neurons demonstrate lower necrosis and apoptosis levels than the axotomized ones. Unlike the existing method, in which the sensory neurons were axotomized, the present method preserves links between the sensory neurons and the ganglion and makes possible to avoid consequences of axotomy in neurons and satellite glia. The present neuroglial preparation may be used as a simple but informative model object in studies of axotomy-induced degeneration and survival of peripheral neurons, the role of glia in neuron injury, the signaling mechanisms of neuroglial interactions, and the effects of diverse physical and chemical factors on neuronal and glial cells. PMID:25374161

Khaitin, Andrej M; Rudkovskii, Mikhail V; Uzdensky, Anatoly B

2015-03-01

74

Genetic inactivation and pharmacological blockade of sigma-1 receptors prevent paclitaxel-induced sensory-nerve mitochondrial abnormalities and neuropathic pain in mice  

PubMed Central

Background Paclitaxel, a widely-used antineoplastic drug, produces a painful peripheral neuropathy that in rodents is associated with peripheral-nerve mitochondrial alterations. The sigma-1 receptor (?1R) is a ligand-regulated molecular chaperone involved in mitochondrial calcium homeostasis and pain hypersensitivity. This receptor plays a key role in paclitaxel-induced neuropathic pain, but it is not known whether it also modulates mitochondrial abnormalities. In this study, we used a mouse model of paclitaxel-induced neuropathic pain to test the involvement of the ?1R in the mitochondrial abnormalities associated with paclitaxel, by using genetic (?1R knockout mice) and pharmacological (?1R antagonist) approaches. Results Paclitaxel administration to wild-type (WT) mice produced cold- and mechanical-allodynia, and an increase in the frequency of swollen and vacuolated mitochondria in myelinated A-fibers, but not in C-fibers, of the saphenous nerve. Behavioral and mitochondrial alterations were marked at 10 days after paclitaxel-administration and had resolved at day 28. In contrast, paclitaxel treatment did not induce allodynia or mitochondrial abnormalities in ?1R knockout mice. Moreover, the prophylactic treatment of WT mice with BD-1063 also prevented the neuropathic pain and mitochondrial abnormalities induced by paclitaxel. Conclusions These results suggest that activation of the ?1R is necessary for development of the sensory nerve mitochondrial damage and neuropathic pain produced by paclitaxel. Therefore, ?1R antagonists might have therapeutic value for the prevention of paclitaxel-induced neuropathy. PMID:24517272

2014-01-01

75

Sciatic nerve injury in adult rats causes distinct changes in the central projections of sensory neurons expressing different glial cell line-derived neurotrophic factor family receptors.  

PubMed

Most small unmyelinated neurons in adult rat dorsal root ganglia (DRG) express one or more of the coreceptors targeted by glial cell line-derived neurotrophic factor (GDNF), neurturin, and artemin (GFRalpha1, GFRalpha2, and GFRalpha3, respectively). The function of these GDNF family ligands (GFLs) is not fully elucidated but recent evidence suggests GFLs could function in sensory neuron regeneration after nerve injury and peripheral nociceptor sensitization. In this study we used immunohistochemistry to determine if the DRG neurons targeted by each GFL change after sciatic nerve injury. We compared complete sciatic nerve transection and the chronic constriction model and found that the pattern of changes incurred by each injury was broadly similar. In lumbar spinal cord there was a widespread increase in neuronal GFRalpha1 immunoreactivity (IR) in the L1-6 dorsal horn. GFRalpha3-IR also increased but in a more restricted area. In contrast, GFRalpha2-IR decreased in patches of superficial dorsal horn and this loss was more extensive after transection injury. No change in calcitonin gene-related peptide-IR was detected after either injury. Analysis of double-immunolabeled L5 DRG sections suggested the main effect of injury on GFRalpha1- and GFRalpha3-IR was to increase expression in both myelinated and unmyelinated neurons. In contrast, no change in basal expression of GFRalpha2-IR was detected in DRG by analysis of fluorescence intensity and there was a small but significant reduction in GFRalpha2-IR neurons. Our results suggest that the DRG neuronal populations targeted by GDNF, neurturin, or artemin and the effect of exogenous GFLs could change significantly after a peripheral nerve injury. PMID:20533358

Keast, Janet R; Forrest, Shelley L; Osborne, Peregrine B

2010-08-01

76

Modified oral metronidazole desensitization protocol  

PubMed Central

The Center for Disease Control guidelines recommend desensitization to metronidazole in patients with trichomoniasis and hypersensitivity to metronidazole. There is only one published oral metronidazole desensitization protocol. The purpose of this study was to design a new, more gradual oral desensitization protocol to decrease systemic reactions that may occur when using the previously published protocol. We present two patients with presumed IgE-mediated allergy to metronidazole who underwent oral desensitization using our modified protocol. Case 1 was a 65-year-old woman with trichomoniasis who presented for metronidazole desensitization with a history of intraoperative anaphylaxis and positive skin tests to metronidazole. The patient tolerated six doses of the modified desensitization but developed systemic symptoms of nasal congestion and diffuse pruritus after the 25- and 100-mg doses. Both reactions were treated with intravenous (i.v.) antihistamines. Because of gastrointestinal irritation, the desensitization was completed at a dose of 250 mg orally every 6 hours. Case 2 was a 42-year-old woman with trichomoniasis and a history of hives immediately after administration of i.v. metronidazole who presented for desensitization. The patient had negative skin-prick and intradermal testing to metronidazole. She developed lip tingling and pruritus on her arms 15 minutes after the 10-mg dose. Fexofenadine at 180 mg was given orally and symptoms resolved. She tolerated the rest of the protocol without reaction and received a total dose of 2 g of metronidazole. Our oral metronidazole desensitization for presumed IgE-mediated reactions offers a second option for physicians wishing to use a more gradual escalation in dose. PMID:24612959

Pien, Lily C.; Gutta, Ravi C.; Abouhassan, Susan R.

2014-01-01

77

Desensitization properties of P2X3 receptors shaping pain signaling  

PubMed Central

ATP-gated P2X3 receptors are mostly expressed by nociceptive sensory neurons and participate in transduction of pain signals. P2X3 receptors show a combination of fast desensitization onset and slow recovery. Moreover, even low nanomolar agonist concentrations unable to evoke a response, can induce desensitization via a phenomenon called “high affinity desensitization.” We have also observed that recovery from desensitization is agonist-specific and can range from seconds to minutes. The recovery process displays unusually high temperature dependence. Likewise, recycling of P2X3 receptors in peri-membrane regions shows unexpectedly large temperature sensitivity. By applying kinetic modeling, we have previously shown that desensitization characteristics of P2X3 receptor are best explained with a cyclic model of receptor operation involving three agonist molecules binding a single receptor and that desensitization is primarily developing from the open receptor state. Mutagenesis experiments suggested that desensitization depends on a certain conformation of the ATP binding pocket and on the structure of the transmembrane domains forming the ion pore. Further molecular determinants of desensitization have been identified by mutating the intracellular N- and C-termini of P2X3 receptor. Unlike other P2X receptors, the P2X3 subtype is facilitated by extracellular calcium that acts via specific sites in the ectodomain neighboring the ATP binding pocket. Thus, substitution of serine275 in this region (called “left flipper”) converts the natural facilitation induced by extracellular calcium to receptor inhibition. Given their strategic location in nociceptive neurons and unique desensitization properties, P2X3 receptors represent an attractive target for development of new analgesic drugs via promotion of desensitization aimed at suppressing chronic pain. PMID:24367291

Giniatullin, Rashid; Nistri, Andrea

2013-01-01

78

Differential upregulation in DRG neurons of an ?2?-1 splice variant with a lower affinity for gabapentin after peripheral sensory nerve injury  

PubMed Central

The ?2?-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. ?2?-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 ?2?-1 splice variants in DRG neurons, and have found that although the main ?2?-1 splice variant in DRG is the same as that in brain (?2?-1 ?A+B+C), there is also another ?2?-1 splice variant (?A+B?C), which is expressed in DRG neurons and is differentially upregulated compared to the main DRG splice variant ?2?-1 ?A+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 ?2?-1 ?A+B?C splice variant supports CaV2 calcium currents with unaltered properties compared to ?2?-1 ?A+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

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

79

Extensive Sprouting of Sensory Afferents and Hyperalgesia Induced by Conditional Expression of Nerve Growth Factor in the Adult Spinal Cord  

Microsoft Academic Search

Genetic transfer of growth-promoting molecules was proposed as a potential strategy to modify the nonpermissive nature of the adult CNS to induce axonal regeneration. To evaluate whether overexpression of neurotrophins or cellular adhesion molecules would effect axonal plasticity, adenoviruses encod- ing fibroblast growth factor-2 (FGF-2\\/Adts), nerve growth factor (NGF\\/Adts), neurotrophin-3, and the cell adhesion molecules N-cadherin and L1 were injected

Mario I. Romero; Nagarathnamma Rangappa; Li Li; Ellis Lightfoot; Mary G. Garry; George M. Smith

2000-01-01

80

Upregulation of Bradykinin B2 Receptor Expression by Neurotrophic Factors and Nerve Injury in Mouse Sensory Neurons  

Microsoft Academic Search

Bradykinin B2 receptor mRNA was detected at low levels, both by RT-PCR and by in situ hybridization, in freshly isolated dorsal root ganglia (DRG) and in ganglia cultured in the absence of neurotrophic factors, but was strongly upregulated by culture in the presence of nerve growth factor (NGF). The effect of NGF is mediated via TrkA receptors. The related neurotrophins,

Yih-Jing Lee; Olof Zachrisson; David A. Tonge; Peter A. McNaughton

2002-01-01

81

Use of ultrasound and fluoroscopy guidance in percutaneous radiofrequency lesioning of the sensory branches of the femoral and obturator nerves.  

PubMed

Hip pain is a common condition that is often seen in patients with multiple comorbidities. Often surgery is not an option due to these comorbidities. Percutaneous radiofrequency lesioning of the articular branches of the obturator and femoral nerves is an alternative treatment for hip pain. Traditionally, fluoroscopy is used to guide needle placement. We report a case where a novel approach was used with ultrasound guidance to visualize vascular and soft tissue structures in real time. The use of ultrasound might help to guide the needle to avoid vascular complications due to anatomical variation between patients. PMID:23656575

Chaiban, Gassan; Paradis, Tyler; Atallah, Joseph

2014-04-01

82

Synaptic Desensitization of NMDA Receptors by Calcineurin  

Microsoft Academic Search

Desensitization is a phenomenon that is common to many ligand-gated ion channels but has been demonstrated only rarely with physiological stimulation. Numerous studies describe desensitization of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor by exogenous agonists, but whether synaptic stimulation causes desensitization has been unknown. Synaptic stimulation of NMDA receptors on rat hippocampal neurons resulted in desensitization that was prevented

Gang Tong; Dawn Shepherd; Craig E. Jahr

1995-01-01

83

[Dermatopolymyositis during desensitization with candidin].  

PubMed

A dermatopolymyositis observation is reported. An urticaria has preceded the dermatopolymyositis and has been treated by a desensitivity procedure. The possible connection between this treatment and the dermatopolymyositis occurring is debated. This observation gives the opportunity to point out the importance of a thorough knowledge of the phenomena involved by such a treatment. PMID:4048686

Pradalier, A; Dry, J; Artigou, C; Chateau, M

1985-06-01

84

Desensitization protocols and their outcome.  

PubMed

In the last decade, transplantation across previously incompatible barriers has increasingly become popular because of organ donor shortage, availability of better methods of detecting and characterizing anti-HLA antibodies, ease of diagnosis, better understanding of antibody-mediated rejection, and the availability of effective regimens. This review summarizes all manuscripts published since the first publication in 2000 on desensitized patients and discusses clinical outcomes including acute and chronic antibody-mediated rejection rate, the new agents available, kidney paired exchange programs, and the future directions in sensitized patients. There were 21 studies published between 2000 and 2010, involving 725 patients with donor-specific anti-HLA antibodies (DSAs) who underwent kidney transplantation with different desensitization protocols. All studies were single center and retrospective. The patient and graft survival were 95% and 86%, respectively, at a 2-year median follow-up. Despite acceptable short-term patient and graft survivals, acute rejection rate was 36% and acute antibody-mediated rejection rate was 28%, which is significantly higher than in nonsensitized patients. Recent studies with longer follow-up of those patients raised concerns about long-term success of desensitization protocols. The studies utilizing protocol biopsies in desensitized patients also reported higher subclinical and chronic antibody-mediated rejection. An association between the strength of DSAs determined by median fluorescence intensity values of Luminex single-antigen beads and risk of rejection was observed. Two new agents, bortezomib, a proteasome inhibitor, and eculizumab, an anti-complement C5 antibody, were recently introduced to desensitization protocols. An alternative intervention is kidney paired exchange, which should be considered first for sensitized patients. PMID:21441131

Marfo, Kwaku; Lu, Amy; Ling, Min; Akalin, Enver

2011-04-01

85

PROCESSES OF EXCITATION IN THE DENDRITES AND IN THE SOMA OF SINGLE ISOLATED SENSORY NERVE CELLS OF THE LOBSTER AND CRAYFISH  

PubMed Central

The stretch receptor organs of Alexandrowicz in lobster and crayfish possess sensory neurons which have their cell bodies in the periphery. The cell bodies send dendrites into a fine nearby muscle strand and at the opposite pole they give rise to an axon running to the central nervous system. Mechanisms of excitation between dendrites, cell soma, and axon have been studied in completely isolated receptor structures with the cell components under visual observation. Two sensory neuron types were investigated, those which adapt rapidly to stretch, the fast cells, and those which adapt slowly, the slow cells. 1. Potentials recorded from the cell body of the neurons with intracellular leads gave resting potentials of 70 to 80 mv. and action potentials which in fresh preparations exceeded the resting potentials by about 10 to 20 mv. In some experiments chymotrypsin or trypsin was used to make cell impalement easier. They did not appreciably alter resting or action potentials. 2. It has been shown that normally excitation starts in the distal portion of dendrites which are depolarized by stretch deformation. The changed potential within the dendritic terminals can persist for the duration of stretch and is called the generator potential. Secondarily, by electrotonic spread, the generator potential reduces the resting potential of the nearby cell soma. This excitation spread between dendrites and soma is seen best during subthreshold excitation by relatively small stretches of normal cells. It is also seen during the whole range of receptor stretch in neurons in which nerve conduction has been blocked by an anesthetic. The electrotonic changes in the cells are graded, reflecting the magnitude and rate of rise of stretch, and presumably the changing levels of the generator potential. Thus in the present neurons the resting potential and the excitability level of the cell soma can be set and controlled over a wide range by local events within the dendrites. 3. Whenever stretch reduces the resting membrane potential, measured in the relaxed state in the cell body, by 8 to 12 mv. in slow cells and by 17 to 22 mv. in fast cells, conducted impulses are initiated. It is thought that in slow cells conducted impulses are initiated in the dendrites while in fast cells they arise in the cell body or near to it. In fresh preparations the speed of stretch does not appreciably influence the membrane threshold for discharges, while during developing fatigue the firing level is higher when extension is gradual. 4. Some of the specific neuron characteristics are: Fast receptor cells have a relatively high threshold to stretch. During prolonged stretch the depolarization of the cell soma is not well maintained, presumably due to a decline in the generator potential, resulting in cessation of discharges in less than a minute. This appears to be the basis of the relatively rapid adaptation. A residual subthreshold depolarization can persist for many minutes of stretch. Slow cells which resemble the sensory fibers of vertebrate spindles are excited by weak stretch. Their discharge rate remains remarkably constant for long periods. It is concluded that, once threshold excitation is reached, the generator potential within slow cell dendrites is well maintained for the duration of stretch. Possible reasons for differences in discharge properties between fast and slow cells are discussed. 5. If stretch of receptor cells is gradually continued above threshold, the discharge frequency first increases over a considerable range without an appreciable change in the firing level for discharges. Beyond that range the membrane threshold for conducted responses of the cell soma rises, the impulses become smaller, and partial conduction in the soma-axon boundary region occurs. At a critical depolarization level which may be maintained for many minutes, all conduction ceases. These overstretch phenomena are reversible and resemble cathodal block. 6. The following general scheme of excitation is proposed: stretch deformation of dendritic terminals ? generat

Eyzaguirre, Carlos; Kuffler, Stephen W.

1955-01-01

86

Camphor Activates and Strongly Desensitizes the Transient Receptor Potential Vanilloid Subtype 1 Channel in a Vanilloid-Independent Mechanism  

Microsoft Academic Search

Camphor is a naturally occurring compound that is used as a major active ingredient of balms and liniments supplied as topical analgesics. Despite its long history of common medical use, the underlying molecular mechanism of camphor action is not understood. Capsaicin and menthol, two other topically applied agents widely used for similar purposes, are known to excite and desensitize sensory

Haoxing Xu; Nathaniel T. Blair; David E. Clapham

2005-01-01

87

The Role of Cutaneous Innervation in the Sensory Abnormalities Associated with Diabetic Neuropathy  

E-print Network

Diabetes-induced nerve damage results in cutaneous denervation, nerve conduction slowing, suppressed regenerative responses, and debilitating painful or insensate sensory symptoms. The increasing prevalence of diabetic ...

Johnson, Megan Sarah

2008-05-05

88

Shock desensitizing of solid explosive  

SciTech Connect

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.

Davis, William C [Los Alamos National Laboratory

2010-01-01

89

?-Opioid receptor desensitization: homologous or heterologous?  

PubMed Central

There is considerable controversy over whether ?-opioid receptor (MOPr) desensitization is homologous or heterologous and over the mechanisms underlying such desensitization. In different cell types MOPr desensitization has been reported to involve receptor phosphorylation by various kinases, including G-protein-coupled receptor kinases (GRKs), second messenger and other kinases as well as perturbation of the MOPr effector pathway by GRK sequestration of G protein ?? subunits or ion channel modulation. Here we report that in brainstem locus coeruleus (LC) neurons prepared from relatively mature rats (5–8 weeks old) rapid MOPr desensitization induced by the high-efficacy opioid peptides methionine enkephalin and DAMGO was homologous and not heterologous to ?2-adrenoceptors and somatostatin SST2 receptors. Given that these receptors all couple through G proteins to the same set of G-protein inwardly rectifying (GIRK) channels it is unlikely therefore that in mature neurons MOPr desensitization involves G protein ?? subunit sequestration or ion channel modulation. In contrast, in slices from immature animals (less than postnatal day 20), MOPr desensitization was observed to be heterologous and could be downstream of the receptor. Heterologous MOPr desensitization was not dependent on protein kinase C or c-Jun N-terminal kinase activity, but the change from heterologous to homologous desensitization with age was correlated with a decrease in the expression levels of GRK2 in the LC and other brain regions. The observation that the mechanisms underlying MOPr desensitization change with neuronal development is important when extrapolating to the mature brain results obtained from experiments on expression systems, cell lines and immature neuronal preparations. PMID:23002724

Llorente, Javier; Lowe, Janet D; Sanderson, Helen S; Tsisanova, Elena; Kelly, Eamonn; Henderson, Graeme; Bailey, Chris P

2012-01-01

90

Low concentrations of nicotine differentially desensitize nicotinic acetylcholine receptors that include ?5 or ?6 subunits and that mediate synaptosomal neurotransmitter release  

PubMed Central

Desensitization is a complex property of nicotinic acetylcholine receptors (nAChR). Several subtypes of nAChR have high sensitivity to nicotine and mediate effects of nicotine at concentrations found in blood of tobacco smokers. Desensitization of some of these receptor subtypes has been studied in model systems, however, other subtypes have been difficult to express heterologously in native forms. In addition, model systems may not have the same accessory molecules and post-translational modifications found in native populations. We have used wild-type and subunit null mutant mice to study desensitization properties of the high sensitivity ?4?2-nAChRs including those that have ?5 subunits at both GABAergic and dopaminergic nerve terminals. In addition, we have studied the desensitization of one subtype of ?6?2-nAChRs at dopaminergic terminals using ?4 subunit null mutant mice. Exposure to low nicotine concentrations, leads to rapid, but partial desensitization of activity mediated by these receptors. ?4?2-nAChRs including ?5 subunits show faster rates of recovery from desensitization than ?4?2-nAChRs without ?5. Inclusion of the ?5 subunit significantly shifts the concentration response for desensitization to higher values, indicating that receptors with ?5 subunits are less desensitized by a 10-min exposure to low concentrations of nicotine. Receptors with ?6 subunits appear to desensitize to a lesser degree than those with ?4 subunits, indicating that ?6?2-nAChRs are somewhat resistant to desensitization by nicotine. These results highlight the importance of studying various receptor subtypes in native systems and how they may differentially respond to nicotine and to nicotinic drugs. PMID:22239849

Grady, Sharon R.; Wageman, Charles R.; Patzlaff, Natalie E.; Marks, Michael J.

2012-01-01

91

Peripheral nerve lengthening as a regenerative strategy  

PubMed Central

Peripheral nerve injury impairs motor, sensory, and autonomic function, incurring substantial financial costs and diminished quality of life. For large nerve gaps, proximal lesions, or chronic nerve injury, the prognosis for recovery is particularly poor, even with autografts, the current gold standard for treating small to moderate nerve gaps. In vivo elongation of intact proximal stumps towards the injured distal stumps of severed peripheral nerves may offer a promising new strategy to treat nerve injury. This review describes several nerve lengthening strategies, including a novel internal fixator device that enables rapid and distal reconnection of proximal and distal nerve stumps. PMID:25317163

Vaz, Kenneth M.; Brown, Justin M.; Shah, Sameer B.

2014-01-01

92

Reinnervation after nerve suture in rat groin flaps.  

PubMed

Regeneration of sensory and adrenergic nerves in the skin was studied in rats. The aim was to investigate the effect of reanastomosing the cut nerve ends of the nerve trunk leading to the microvascular groin flap. Reinnervation was demonstrated immunohistochemically using calcitonin gene-related peptide (CGRP) as marker for sensory nerves, neuropeptide Y (NPY) and tyrosine hydroxylase (TH) as markers for adrenergic nerves and Protein Gene Product 9.5 (PGP 9.5) as general neuronal marker. It was demonstrated that reanastomosing of the nerve trunk was favourable for both the sensory and sympathetic reinnervation of microsurgical flaps. PMID:9635785

Ranne, J O; Lähteenmäki, P T; Vaalasti, A; Waris, T H; Lindholm, T S

1998-01-01

93

Genetics Home Reference: Hereditary sensory and autonomic neuropathy type V  

MedlinePLUS

... to feel pain, heat, and cold. Deep pain perception, the feeling of pain from injuries to bones, ... gene ; growth factor ; hereditary ; inherited ; joint ; mutation ; neuropathy ; perception ; protein ; receptor ; recessive ; sensory nerve ; sensory neuropathy ; tissue ; ...

94

Localization of a Passively Transferred Human Recombinant Monoclonal Antibody to Herpes Simplex Virus Glycoprotein D to Infected Nerve Fibers and Sensory Neurons In Vivo  

Microsoft Academic Search

A human recombinant monoclonal antibody to herpes simplex virus (HSV) glycoprotein D labeled with the fluorescent dye Cy5 was administered to mice infected in the cornea with HSV type 1 (HSV-1). The distribution of such antibody in the corneas and trigeminal ganglia of the mice was then investigated by confocal micros- copy. The antibody was detected on HSV-infected nerve fibers

PIETRO PAOLO SANNA; THOMAS J. DEERINCK; MARK H. ELLISMAN

1999-01-01

95

Playing Violent Video Games and Desensitization to Violence.  

PubMed

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

Brockmyer, Jeanne Funk

2015-01-01

96

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

PubMed

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 studies, but are consistent with clinical findings in most patients with chronic neuropathic pain. PMID:25274350

Boada, M Danilo; Gutierrez, Silvia; Aschenbrenner, Carol A; Houle, Timothy T; Hayashida, Ken-Ichiro; Ririe, Douglas G; Eisenach, James C

2015-01-01

97

Activation of the 5-HT1B/D receptor reduces hindlimb neurogenic inflammation caused by sensory nerve stimulation and capsaicin.  

PubMed

Activation of the 5-HT(1B/D) receptor inhibits cerebrovascular neurogenic inflammation (NI). The aim of this study was to determine if the 5-HT(1B/D) receptor agonist sumatriptan can also inhibit NI in other regions of the body. NI was assessed by measuring plasma extravasation (PE) and changes in blood flow in the rat hindpaw. Sumatriptan was administered locally (20 microl, 50 or 100 nM, s.c.) into the dorso-medial region of one hindpaw. The other paw was pre-treated with vehicle (20 microl of 0.9% saline) and served as a control. NI was induced after treatment with sumatriptan/vehicle by injecting capsaicin (15 microl, 1%, s.c.) into each paw or by electrically stimulating the saphenous nerve (4 Hz, 30s). Sumatriptan administered locally or systemically (300 microg/kg, i.v.) significantly reduced saphenous nerve and capsaicin-induced PE and vasodilation. The systemic and local inhibitory actions of sumatriptan are mediated by the 5-HT(1B/D) receptor as pre-treatment with the 5-HT(1B/D) antagonist GR127935 (GR; 15 microl, 1 microM, s.c. or 0.2 micromol/kg, i.v.) completely blocked the inhibitory effect of sumatriptan on capsaicin-induced vasodilation and reduced the inhibitory effect of sumatriptan on capsaicin and electrically induced-PE. Neither PE induced by local injection of substance P (SP) (20 pmol, 20 microl, s.c.) nor vasodilation induced by local CGRP injection was affected by pre-treatment with sumatriptan. These findings indicate that both local and systemic activation of the 5-HT(1B/D) receptor by sumatriptan reduce NI induced by nerve stimulation or capsaicin presumably by inhibiting neuropeptide release. 5-HT(1B/D) receptor agonists may be useful for the treatment of non-trigeminal pain conditions involving NI. PMID:17499925

Carmichael, Nicole M E; Charlton, Milton P; Dostrovsky, Jonathan O

2008-01-01

98

Nerve allografts and conduits in peripheral nerve repair.  

PubMed

Since the last update on nerve conduits and allograft in 2000, investigations have established the efficacy of these alternatives to autograft in the repair of small sensory neural gaps. However, limited insights into the biology of the regenerating nerve continue to preclude intelligent conduit design. Ongoing discoveries in neuroscience and biomaterial engineering hold promise for the eventual development of allograft and conduits with potential of surpassing nerve autografts in clinical efficacy. In this review, we summarize the history, recent advances, and emerging developments in nerve conduits and allograft. PMID:23895714

Lin, Michael Y; Manzano, Givenchy; Gupta, Ranjan

2013-08-01

99

Aspirin desensitization/challenge in 3 patients with unstable angina.  

PubMed

Aspirin sensitivity is relatively frequent and can be a major problem in patients who need percutaneous coronary intervention and stenting with subsequent dual antiplatelet therapy. Desensitization is often the therapy in these patients, but this can prolong the time to revascularization significantly. Rapid oral aspirin desensitization protocols have been described since 2000. However, data are lacking on the optimal strategy for aspirin desensitization and determining which patients are mostly benefited from this desensitization. The authors describe the use of a Wong-modified protocol in 3 patients who had known aspirin sensitivity and who had unstable angina and an indication for percutaneous coronary intervention. PMID:20739873

Ortega-Loayza, Alex G; Raza, Syed; Minisi, Anthony J; Topaz, On; Heller, Andrew; Jovin, Ion S

2010-11-01

100

Histrionicotoxin enhances agonist-induced desensitization of acetylcholine receptor.  

PubMed Central

Dihydroisohistrionicotoxin inhibits acetylcholine receptor-dependent 22Na+ uptake of cultured chick muscle cells with a KI of 0.2 micrometer. The inhibition is noncompetitive with respect to agonists. The toxin enhances desensitization of the receptor by agonists which is accompanied by a 10-fold increase in receptor affinity for agonists. Dihydroisohistrionicotoxin increases the affinity of the desensitized form of the receptor for agonists but not antagonists. The results suggest that dihydroisohistrionicotoxin inhibits the acetylcholine receptor by causing an increase in the affinity of the desensitized form of the receptor for agonists and thereby stabilizing the desensitized state. PMID:272000

Burgermeister, W; Catterall, W A; Witkop, B

1977-01-01

101

Esophagoprotective activity of angiotensin-(1-7) in experimental model of acute reflux esophagitis. Evidence for the role of nitric oxide, sensory nerves, hypoxia-inducible factor-1alpha and proinflammatory cytokines.  

PubMed

Gastroesophageal reflux disease (GERD) is a global disease rapidly increasing among world population. The pathogenesis of reflux esophagitis which is considered as the early stage of GERD is complex, resulting from an imbalance between aggressive factors damaging the esophagus and a number of the natural defense mechanisms. The esophageal mucosa is in a state of continuous exposure to potentially damaging endogenous and exogenous factors. Important aggressive components of gastric refluxate include acid and pepsin and also pancreatic enzymes and bile. Among aggressive factors of exogenous origin, cigarette smoking, non-steroidal anti-inflammatory drugs (NSAID), and steroids are of the utmost importance. The basic level of esophageal defense against acid-pepsin damage consists of the anti-reflux mechanisms such as the luminal acid clearance and removal of the esophageal contents and neutralization of luminal acidity. In addition the esophageal mucosal protection includes the presence of pre-epithelial, epithelial and post-epithelial cellular and functional components. Recently, the progress have been made in the understanding of role of the heptapeptide member of the renin-angiotensin system (RAS), angiotensin-(1-7) (Ang-(1-7)) in the control of gastrointestinal functions. It has been shown that all components of local RAS including Ang-(1-7) are detectable in the gastrointestinal wall including not only the stomach but also the esophagus. Previous studies revealed that Ang-(1-7), which is an important component of the RAS, exerts vasodilatory, anti-inflammatory and antioxidant activities in the stomach. Ang-(1-7) was recently implicated in gastroprotection, but its effects on esophageal mucosa in a rodent model of reflux esophagitis and in human subjects presenting GERD symptoms have not been explored. The present study was aimed to evaluate the possible protective effects of Ang-(1-7) and Mas-receptors upon esophageal mucosal damage in acute reflux esophagitis (RE) induced in anesthetized rats by ligating the pylorus and the limiting ridge (a transitional region between the forestomach and the corpus of stomach). Consequently, the total gastric reservoir to store gastric juice was greatly diminished, resulting in the reflux of this juice into the esophagus. Because Mas receptors are functionally linked to nitric oxide (NO) formation, we also studied involvement of endogenous NO in the mediation of protective and circulatory effects of exogenous Ang-(1-7). Moreover, an attempt was made to assess the possible role of sensory neurons in the modulation of the protective effects exerted by Ang-(1-7)/Mas receptor system. Six series of rats were pretreated 30 min before induction of RE with 1) vehicle (saline), 2) Ang-(1-7) (5-50 ?g/kg i.p.), 3) A779 (50 ?g/kg i.p.), the selective Mas receptor antagonist applied alone, 4) Ang-(1-7) (50 ?g/kg i.p.) combined with A779, 5) L-NNA (20 mg/kg i.p.) administered alone, and 6) Ang-(1-7) (50 ?g/kg i.p.) combined with L-NNA. In separate group of rats, capsaicin (total dosage of 125 mg/kg within three days) was administered s.c. 2 weeks before the induction of RE to induce functional ablation of sensory nerves. Rats with intact sensory nerves and those with capsaicin-induced sensory denervation received vehicle (saline) or Ang-(1-7) (50 ?g/kg i.p.) to determine whether this vasoactive metabolite of angiotensin I could be also effective in rats with capsaicin-induced impairment of the synthesis and release of sensory neuropeptides such as CGRP. Four hours after induction of RE, the mucosal damage was graded with mucosal lesion index (LI) from 0 to 6, the esophageal microcirculatory blood flow (EBF) was determined by H2-gas clearance technique and plasma level of pro-inflammatory cytokines interleukin-1b (IL-1?), and tumor necrosis factor-? (TNF-?) was determined by ELISA. The expression of proinflammatory factors including COX-2, cytokine IL-1? and hypoxia inducible factor 1alpha (Hif1?) was analyzed in the esophageal mucosal biopsies. In rats with RE, the esophageal LI was signi

Pawlik, M W; Kwiecien, S; Pajdo, R; Ptak-Belowska, A; Brzozowski, B; Krzysiek-Maczka, G; Strzalka, M; Konturek, S J; Brzozowski, T

2014-12-01

102

Pharmacological enhancement of peripheral nerve regeneration in the rat by systemic acetyl- L-carnitine treatment  

Microsoft Academic Search

Peripheral nerve trauma remains a major cause of morbidity, largely due to the death of ?40% of innervating sensory neurons, and to slow regeneration after repair. Acetyl-L-carnitine (ALCAR) is a physiological peptide that virtually eliminates sensory neuronal death, and may improve regeneration after primary nerve repair. This study determines the effect of ALCAR upon regeneration after secondary nerve repair, thereby

Andrew McKay Hart; Mikael Wiberg; Giorgio Terenghi

2002-01-01

103

Biochem. J. (2010) 432, 549556 (Printed in Great Britain) doi:10.1042/BJ20100936 549 PP2B/calcineurin-mediated desensitization of TRPV1 does not require  

E-print Network

/calcineurin-mediated desensitization of TRPV1 does not require AKAP150 Elaine D. POR*, Bret K. SAMELSON, Sergei BELUGIN, Armen N at the plasma membrane often initiates agonist-dependent signalling events. In sensory neurons, AKAP150 (A. Recent evidence indicates that AKAP150-anchored PKA and PKC phosphorylate and sensitize the TRPV1

Scott, John D.

104

Evaluation of Antibacterial Effectiveness of Desensitizers against Oral Bacteria  

PubMed Central

Objectives Desensitizers contribute to better clinical results by reducing the rate of cervical dentin sensitivity. However, information on their antibacterial effect is limited. This study examined the antibacterial activities of a triclosan containing (Seal & Protect), a benzalconium containing desensitizer (Micro Prime), a fluoride containing prophilaxy paste (Sultan Desensitizer), two fluoride containing varnishes (Cavity Shealth and Ultra EZ), and a dentin bonding primer (All Bond). Methods The test materials were inserted in the wells of Muller Hinton agar plates inoculated with Streptococcus mutans, Streptococcus salivarious, Staphylococcus aureus, Streptococcus faecalis and Pseudomonas aeruginosa. The diameters of the inhibition zones produced around the materials were measured after 24 h of incubation. The results were analyzed by the Kruskal Wallis one way ANOVA and the Mann-Whitney tests at a significance level of P<.05. Results Micro Prime Desensitizer containing benzalkonium chloride had the highest antibacterial effectiveness compared to other desensitizers used in this study. In addition, triclosan containing Seal & Protect and acidic components containing All Bond showed very high antibacterial efficacy. On the other hand, fluoride within both varnishes had little antibacterial effectiveness. However a fluoride component in a paste (Sultan Desensitizer) showed very high bactericidal effect. Conclusions All desensitizers except fluoride varnishes showed various degrees of antibacterial effect against the bacteria tested in this study. If antibacterial effect is also required from the desensitizers’ clinicians should avoid use of varnishes. PMID:19212508

Duran, Ismet; Sengun, Abdulkadir; Hadimli, Hasan Huseyin; Ulker, Mustafa

2008-01-01

105

EMG Biofeedback Training Versus Systematic Desensitization for Test Anxiety Reduction  

ERIC Educational Resources Information Center

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…

Romano, John L.; Cabianca, William A.

1978-01-01

106

Galvanic Skin Response and Reported Anxiety During Systematic Desensitization  

ERIC Educational Resources Information Center

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)

Hyman, Edward T.; Gale, Elliot N.

1973-01-01

107

Peripheral nerve conduits: technology update  

PubMed Central

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

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

2014-01-01

108

Investigation of shock initiation of desensitized RDX  

SciTech Connect

The process of initiation of detonation of pressed desensitized RDX is considered. Pressure profiles were recorded by manganin gauges in different cross sections of a charge and processed by the Lagrange analysis for a reacting flow. The analysis has shown that the decomposition rate immediately behind the initiating wave front is low and increases with increase of pressure in it. A maximum in the dependence of the decomposition rate on the reaction coordinate can be observed when the values of the reaction coordinate are 0.4-0.6.

Bordzilovskii, S.A.; Karakhanov, S.M.

1995-11-01

109

Nerve conduction studies in early tuberculoid leprosy  

PubMed Central

Context: Hansen's disease is a chronic illness; besides involving skin and peripheral nerves, it affects multiple organs. Nerve involvement is always present in leprosy, and it may be present much before the patient manifests clinically. Aims: To assess nerve conduction parameters in thickened and contralateral non-thickened nerves in early tuberculoid leprosy Materials and Methods: Fifty new untreated male patients with tuberculoid and borderline tuberculoid leprosy in the age group of 15-50 years with thickened peripheral nerves on one side were included in the study. Nerve conduction studies consisting of sensory and motor velocity (NCV), distal latencies, and amplitude were carried out on thickened ulnar, common peroneal, and posterior tibial nerves and contralateral normal nerves. Statistical Analysis Used: Mean values along with coefficient of variation were obtained for various parameters. These were compared with normal values of the control population. P value was used to verify statistical significance. Results: Nerve conduction parameters were deranged in most of the thickened nerves. Sensory parameters were affected early in the disease process. Conclusion: Additional parameters are required to assess nerve damage in early cases, where it is more in slow conducting fibers (average velocity fibers). Change in conduction velocity may not be marked; this calls for the measurement of fast fibers separately because potentials recorded are mainly from myelinated fibers. PMID:25593812

Vashisht, Deepak; Das, Arjun Lal; Vaishampayan, Sanjeev S; Vashisht, Surbhi; Joshi, Rajneesh

2014-01-01

110

Habituation and desensitization of the Hering-Breuer reflex in rat  

PubMed Central

Many processes in mammalian and invertebrate central nervous systems exhibit habituation and/or sensitization of their responses to repetitive stimuli. Here, we studied the adaptive behaviours of the respiratory pattern generator in rat on repetitive vagal-afferent stimulation and compared these behaviours obtained in vivo with the reported effects of such stimuli on synaptic transmission in the corresponding signal pathway in vitro. Sustained (1 min) electrical pulsed stimulation of the vagus nerve elicited the classic Hering-Breuer (HB) reflex slowing of the respiratory rhythm followed by a bi-exponential recovery, and a post-stimulus rebound (PR). The recovery from the HB reflex satisfied the classic criteria of habituation. The fast component of the recovery and the PR were abolished by systemic administration of an NMDA receptor antagonist or electrolytic lesioning of the pontine Kölliker-Fuse nucleus. The characteristics of the fast recovery and PR suggest a vagally induced desensitization of the NMDA receptor-dependent pontine input to the respiratory pattern generator. The slow component of recovery persisted after both experimental interventions and accounted for the habituation to the vagal input. The characteristics of the slow recovery in vivo were reminiscent of the reported synaptic accommodation in vitro in the medullary region where vagal afferents terminate. The habituation of vagal input and desensitization of pontine input act in concert to offset the HB reflex. Such simultaneous habituation-desensitization in parallel neural pathways with differing sensitivities to NMDA receptor activation represent a hitherto unknown pairing of dual non-associative learning processes in the mammalian brain. PMID:10699090

Siniaia, Marina S; Young, Daniel L; Poon, Chi-Sang

2000-01-01

111

Endogenous NGF and CNTF levels in human peripheral nerve injury.  

PubMed

Nerve growth factor (NGF) is trophic to sensory and sympathetic fibres, and ciliary neurotrophic factor (CNTF) to motoneurones, in animal models of peripheral nerve injury: NGF excess produces hyperalgesia. In this first study of injured human nerves and sensory ganglia, we quantified and localized endogenous NGF and CNTF in 59 neonate and adult patients with brachial plexus and peripheral nerve injury. NGF levels were generally depleted in injured nerves, but relatively preserved acutely in nerve segments distal to injury. NGF immunostaining was observed in Schwann cells in distal nerve segments with pockets of high levels in some neuromas. CNTF levels and immunostaining in Schwann cells were markedly decreased distally within days of injury. We propose that early local administration of NGF and CNTF-like agents may help prevent degenerative changes in injured nerves, while at later stages local anti-NGF treatment (e.g. of some neuromas) may ameliorate chronic pain. PMID:9223080

Anand, P; Terenghi, G; Birch, R; Wellmer, A; Cedarbaum, J M; Lindsay, R M; Williams-Chestnut, R E; Sinicropi, D V

1997-05-27

112

Successful Desensitization of a Patient with Rituximab Hypersensitivity  

PubMed Central

Rituximab is a monoclonal antibody which targets CD20 in B cells that is used for the treatment of CD20 positive oncologic and hematologic malignancies. Rituximab causes hypersensitivity reactions during infusions. The delay of treatment or loss of a highly efficient drug can be prevented by rapid drug desensitization method in patients who are allergic to rituximab. We report a low grade B cell non-Hodgkin lymphoma patient with rituximab hypersensitivity successfully treated with rapid drug desensitization. In experienced centers, drug desensitization is a novel modality to break through in case of hypersensitivity that should be considered.

Ataca, Pinar; Atilla, Erden; Kendir, Resat; Bavbek, Sevim; Ozcan, Muhit

2015-01-01

113

Theobromine inhibits sensory nerve activation and cough  

Microsoft Academic Search

Cough is a common and protective reflex, but persistent coughing is debilitating and impairs quality of life. Antitussive treatment using opioids is limited by unacceptable side effects, and there is a great need for more effective remedies. The present study demonstrates that theobromine, a methylxanthine derivative present in cocoa, effectively inhibits citric acid- induced cough in guinea-pigs in vivo. Furthermore,

Omar S. Usmani; Maria G. Belvisi; Hema J. Patel; Natascia Crispino; Mark A. Birrell; Márta Korbonits; Peter J. Barnes

2004-01-01

114

THE ROLE OF GLYOXALASE I IN HYPERGLYCEMIA-INDUCED SENSORY NEURON DAMAGE AND DEVELOPMENT OF DIABETIC SENSORY NEUROPATHY SYMPTOMS  

E-print Network

Diabetic neuropathy is the most common and debilitating complication of diabetes mellitus with over half of all patients developing altered sensation as a result of damage to peripheral sensory neurons. Hyperglycemia results in altered nerve...

Jack, Megan Marie

2011-08-31

115

Contribution of Pretesting to Several Measures of Semantic Desensitization Effectiveness  

ERIC Educational Resources Information Center

Snake- or spider-phobic subjects (N=32) were randomly assigned to one of four groups. Subjects receiving semantic desensitization therapy showed less posttest anxiety on the semantic differential than control subjects regardless of testing condition. (Author)

Israel, Allen C.; And Others

1977-01-01

116

Phosphorylation-Independent Desensitization of G Protein-Coupled Receptors?  

NSDL National Science Digital Library

G protein-coupled receptors (GPCRs) are involved in a multitude of signaling processes and respond to a wide range of ligands. The activity of GPCRs is subject to three principal modes of regulation: desensitization, trafficking, and down-regulation. Desensitization is defined as a loss in the responsiveness of a signaling system. The generally established paradigm for GPCR desensitization involves receptor phosphorylation by GPCR kinases (GRKs), initiated by agonist-induced conformational changes in the receptor or by kinases activated by specific signaling pathways. GRKs have several interaction domains and may be able to contribute to receptor desensitization through mechanisms that do not involve the kinase activity of GRK. Pao and Benovic discuss some of these interactions and their relevance for the regulation of GPCR signaling.

Christina S. Pao (Thomas Jefferson University;The Kimmel Cancer Center, Department of Microbiology and Immunology REV); Jeffrey L. Benovic (Thomas Jefferson University;The Kimmel Cancer Center, Department of Microbiology and Immunology REV)

2002-10-08

117

Palmar cutaneous nerve conduction in patients with carpal tunnel syndrome.  

PubMed

Objective: This study aimed to assess palmar cutaneous branch of the median nerve (PCBm) conduction in patients with clinically diagnosed carpal tunnel syndrome (CTS), to compare PCBm conduction with that of the median and ulnar nerves, and to determine the PCBm conduction abnormality rate in patients with CTS. Materials and Methods: The study included 99 hands of 60 patients with clinical CTS and 38 hands of 38 healthy controls. Sensory nerve conduction study (NCS) was performed on the median nerve, ulnar nerve, and PCBm, and onset latency, conduction velocity and amplitude were recorded. Additionally, differences in latency and velocity between the median nerve and PCBm, and the difference in latency between the median and ulnar nerves were calculated. Results: In all, 56% of the patients with CTS had abnormal PCBm conduction. Additionally, in 7 of 8 hands with abnormal sensation -both in the thenar eminence and abnormal sensory distribution along the main branch -NCS of the PCBm was also abnormal. Conclusions: The PCBm is not ideal as a comparator nerve for the neurophysiological diagnosis of CTS. The frequency of PCBm abnormality in CTS patients may be related to the concomitant damage in both of these nerves. Additionally, the present findings may help explain, at least in part, why patients with CTS often exhibit sensory involvement beyond the classical median nerve sensory borders. PMID:25271802

Uluc, Kayihan; Aktas, Ilknur; Sunter, Gulin; Kahraman Koytak, Pinar; Akyuz, Gulseren; Isak, Baris; Tanridag, Tulin; Us, Onder

2014-11-01

118

Warmth suppresses and desensitizes damage-sensing ion channel TRPA1  

PubMed Central

Background Acute or chronic tissue damage induces an inflammatory response accompanied by pain and alterations in local tissue temperature. Recent studies revealed that the transient receptor potential A1 (TRPA1) channel is activated by a wide variety of substances that are released following tissue damage to evoke nociception and neurogenic inflammation. Although the effects of a noxious range of cold temperatures on TRPA1 have been rigorously studied, it is not known how agonist-induced activation of TRPA1 is regulated by temperature over an innocuous range centred on the normal skin surface temperature. This study investigated the effect of temperature on agonist-induced currents in human embryonic kidney (HEK) 293 cells transfected with rat or human TRPA1 and in rat sensory neurons. Results Agonist-induced TRPA1 currents in HEK293 cells were strongly suppressed by warm temperatures, and almost abolished at 39°C. Such inhibition occurred when TRPA1 was activated by either electrophilic or non-electrophilic agonists. Warming not only decreased the apparent affinity of TRPA1 for mustard oil (MO), but also greatly enhanced the desensitization and tachyphylaxis of TRPA1. Warming also attenuated MO-induced ionic currents in sensory neurons. These results suggest that the extent of agonist-induced activity of TRPA1 may depend on surrounding tissue temperature, and local hyperthermia during acute inflammation could be an endogenous negative regulatory mechanism to attenuate persistent pain at the site of injury. Conclusion These results indicate that warmth suppresses and desensitizes damage-sensing ion channel TRPA1. Such warmth-induced suppression of TRPA1 may also explain, at least in part, the mechanistic basis of heat therapy that has been widely used as a supplemental anti-nociceptive approach. PMID:22458587

2012-01-01

119

Sensory ability in the narwhal tooth organ system.  

PubMed

The erupted tusk of the narwhal exhibits sensory ability. The hypothesized sensory pathway begins with ocean water entering through cementum channels to a network of patent dentinal tubules extending from the dentinocementum junction to the inner pulpal wall. Circumpulpal sensory structures then signal pulpal nerves terminating near the base of the tusk. The maxillary division of the fifth cranial nerve then transmits this sensory information to the brain. This sensory pathway was first described in published results of patent dentinal tubules, and evidence from dissection of tusk nerve connection via the maxillary division of the fifth cranial nerve to the brain. New evidence presented here indicates that the patent dentinal tubules communicate with open channels through a porous cementum from the ocean environment. The ability of pulpal tissue to react to external stimuli is supported by immunohistochemical detection of neuronal markers in the pulp and gene expression of pulpal sensory nerve tissue. Final confirmation of sensory ability is demonstrated by significant changes in heart rate when alternating solutions of high-salt and fresh water are exposed to the external tusk surface. Additional supporting information for function includes new observations of dentinal tubule networks evident in unerupted tusks, female erupted tusks, and vestigial teeth. New findings of sexual foraging divergence documented by stable isotope and fatty acid results add to the discussion of the functional significance of the narwhal tusk. The combined evidence suggests multiple tusk functions may have driven the tooth organ system's evolutionary development and persistence. PMID:24639076

Nweeia, Martin T; Eichmiller, Frederick C; Hauschka, Peter V; Donahue, Gretchen A; Orr, Jack R; Ferguson, Steven H; Watt, Cortney A; Mead, James G; Potter, Charles W; Dietz, Rune; Giuseppetti, Anthony A; Black, Sandie R; Trachtenberg, Alexander J; Kuo, Winston P

2014-04-01

120

Implications of Sensory Stimulation in Self-Destructive Behavior.  

ERIC Educational Resources Information Center

The author extends the self stimulatory theory of self destructive behavior in autistic, schizophrenic, and mentally retarded individuals to suggest that damage of the skin's nerve structure lowers the tactile sensory threshold for physical input and enables individuals to obtain sensory stimulation by repeatedly depressing the damaged area. (CL)

Edelson, Stephen M.

1984-01-01

121

Spontaneous intraneural hematoma of the sural nerve.  

PubMed

Symptomatic intraneural hemorrhage occurs rarely. It presents with pain and/or weakness in the distribution following the anatomic innervation pattern of the involved nerve. When a purely sensory nerve is affected, the symptoms can be subtle. We present a previously healthy 36-year-old female who developed an atraumatic, spontaneous intraneural hematoma of her sural nerve. Sural dysfunction was elicited from the patient's history and physical examination. The diagnosis was confirmed with magnetic resonance imaging, and surgical decompression provided successful resolution of her preoperative symptoms. To our knowledge, this entity has not been reported previously. Our case highlights the importance of having a high index of suspicion for nerve injury or compression in patients whose complaints follow a typical peripheral nerve distribution. Prior studies have shown that the formation of intraneural hematoma and associated compression of nerve fibers result in axonal degeneration, and surgical decompression decreases axonal degeneration and aids functional recovery. PMID:25311865

Richardson, Shawn S; McLawhorn, Alexander S; Mintz, Douglas N; DiCarlo, Edward F; Weiland, Andrew J

2015-04-01

122

An unusual cause of radial nerve palsy.  

PubMed

Neurapraxia frequently occurs following traction injury to the nerve intraoperatively, leading to radial nerve palsy which usually recovers in 5-30 weeks. In our case, we had operated a distal one-third of humeral shaft fracture and fixed it with 4.5 mm limited contact dynamic compression plate. The distal neurovascular status of the limb was assessed postoperatively in the recovery room and was found to be intact and all the sensory-motor functions of the radial nerve were normal. On the second postoperative day, following the suction drain removal and dressing, patient developed immediate radial nerve palsy along with wrist drop. We reviewed the literature and found no obvious cause for the nerve palsy and concluded that it was due to traction injury to the radial nerve while removing the suction drain in negative pressure. PMID:24889983

Agrawal, Hemendra Kumar; Khatkar, Vipin; Garg, Mohit; Singh, Balvinder; Jaiman, Ashish; Sharma, Vinod Kumar

2014-06-01

123

Increased substance P content in nerve fibers associated with mesenteric veins from deoxycorticosterone acetate (DOCA)-salt hypertensive rats  

Microsoft Academic Search

This study examined sensory nerves associated with mesenteric arteries and veins in sham and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Reactivity of arteries and veins to substances released from sensory nerves was also studied in vitro using computer-assisted video microscopy. Co-localization of substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactivity (ir) was used to evaluate perivascular sensory nerves. Radioimmunoassay was

James J. Galligan; Sara B. Miller; Khurshed Katki; Scott Supowit; Donald DiPette; Gregory D. Fink

2006-01-01

124

Plasma somatostatin-like immunoreactivity increases in the plasma of septic patients and rats with systemic inflammatory reaction: experimental evidence for its sensory origin and protective role.  

PubMed

Alterations of somatostatin-like immunoreactivity (SST-LI) in the plasma of 11 systemic inflammatory response syndrome (SIRS) patients were investigated in correlation with cytokines, adhesion molecules and coagulation markers repeatedly during 4 days. The origin and role of SST were studied in the cecum ligation and puncture (CLP) rat SIRS model. Capsaicin-sensitive peptidergic sensory nerves were defunctionalized by resiniferatoxin (RTX) pretreatment 2 weeks earlier, in a separate group animals were treated with the somatostatin receptor antagonist cyclo-somatostatin (C-SOM). Plasma SST-LI significantly elevated in septic patients compared to healthy volunteers during the whole 4-day period. Significantly decreased Horowitz score showed severe lung injury, increased plasma C-reactive protein and procalcitonin confirmed SIRS. Soluble P-selectin, tissue plasminogen activator and the interleukin 8 and monocyte chemotactic protein-1 significantly increased, interleukin 6 and soluble CD40 ligand did not change, and soluble Vascular Adhesion Molecule-1 decreased. SST-LI significantly increased in rats both in the plasma and the lung 6h after CLP compared to sham-operation. After RTX pretreatment SST-LI was not altered in intact animals, but the SIRS-induced elevation was absent. Lung MPO activity significantly increased 6h following CLP compared to sham operation, which was significantly higher both after RTX-desensitization and C-SOM-treatment. Most non-pretreated operated rats survived the 6h, but 60% of the RTX-pretreated ones died showing a significantly worse survival. This is the first comprehensive study in humans and animal experiments providing evidence that SST is released from the activated peptidergic sensory nerves. It gets into the bloodstream and mediates a potent endogenous protective mechanism. PMID:24457113

Suto, Balazs; Szitter, Istvan; Bagoly, Terez; Pinter, Erika; Szolcsányi, Janos; Loibl, Csaba; Nemeth, Timea; Tanczos, Krisztian; Molnar, Tihamer; Leiner, Tamas; Varnai, Bianka; Bardonicsek, Zsofia; Helyes, Zsuzsanna

2014-04-01

125

Poisoning by organophosphorus insecticides and sensory neuropathy  

PubMed Central

OBJECTIVES—Poisoning by organophosphate insecticides causes cholinergic toxicity. Organophosphate induced delayed polyneuropathy (OPIDP) is a sensory-motor distal axonopathy which usually occurs after ingestion of large doses of certain organophosphate insecticides and has so far only been reported in patients with preceding cholinergic toxicity. Surprisingly, it was recently reported by other authors that an exclusively sensory neuropathy developed in eight patients after repeated unquantified exposures to chlorpyrifos, which did not cause clear-cut cholinergic toxicity. The objective was to assess whether an exclusively sensory neuropathy develops in patients severely poisoned by various OPs.?METHODS—Toxicological studies and electrophysiological measurements were performed in peripheral motor and sensory nerves in 11 patients after acute organophosphate poisoning among which two subjects were poisoned with chlorpyrifos.?RESULTS—Three patients developed OPIDP, including one poisoned by chlorpyrifos. Exclusively sensory neuropathy was never seen after either single or repeated acute organophosphate poisoning. A mild sensory component was associated with a severe motor component in two of the three cases of OPIDP, the other was an exclusively motor polyneuropathy.?CONCLUSION—A sensory-motor polyneuropathy caused by organophosphate insecticides might occur after a severe poisoning and the sensory component, if present, is milder than the motor one. Bearing in mind the toxicological characteristics of these organophosphate insecticides, other causes should be sought for sensory peripheral neuropathies in patients who did not display severe cholinergic toxicity a few weeks before the onset of symptoms and signs.?? PMID:9576536

Moretto, A.; Lotti, M.

1998-01-01

126

?-Opioid receptor desensitization: Is morphine different?  

PubMed Central

Opioid tolerance and dependence are important phenomena. The contribution of acute ?-opioid receptor regulatory mechanisms to the development of analgesic tolerance or physical dependence are unknown, and even the mechanisms underlying relatively rapid receptor desensitization in single cells are unresolved. To a large degree, the uncertainty surrounding the mechanisms and consequences of short-term regulation of ?-opioid receptors in single cells arises from the limitations in the experimental design in many of the studies that have investigated these events. Receptor overexpression and use of assays in which regulatory mechanisms are likely to blunt control determinations have led to measurements of opioid receptor activity that are likely to be insensitive to receptor uncoupling. Together with uncertainties concerning molecular details of ?-opioid receptor interactions with potential regulatory molecules such as G protein-coupled receptor kinases and arrestins, we are left with an incomplete picture crudely copied from the well-worked-out regulatory schema for ?2-adrenoceptors. As a consequence, suggestions that clinically relevant ?-opioid receptor agonists may have different propensities to produce tolerance and dependence that arise from their differential recruitment of regulatory mechanisms are premature, and have not yet been appropriately assessed, nor explained in the context of a thoroughly established regulatory scheme. In this commentary, we outline the experimental limitations that have given rise to conflicting ideas about how ?-opioid receptors are regulated, and identify the issues we feel still need to be addressed before we can understand why morphine promotes receptor trafficking differently to other opioids. PMID:15504746

Connor, Mark; Osborne, Peregrine B; Christie, MacDonald J

2004-01-01

127

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)

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.

Ibrahim, T.; Gheith, M.

2011-09-01

128

The consistent presence of the human accessory deep peroneal nerve  

PubMed Central

Twenty-four human legs were dissected macroscopically to study the morphological details of the accessory deep peroneal nerve. This nerve arose from the superficial peroneal nerve and descended in the lateral compartment of the leg, deep to peroneus longus along the posterior border of peroneus brevis. Approaching the ankle joint, this nerve passed through the peroneal tunnels to wind around the lateral malleolus; it then crossed beneath the peroneus brevis tendon anteriorly to reach the dorsum of the foot. The accessory deep peroneal nerve was found in every case examined and constantly gave off muscular branches to peroneus brevis and sensory branches to the ankle region. In addition, this nerve occasionally had muscular branches to peroneus longus and extensor digitorum brevis, and sensory branches to the fibula and the foot. The anomalous muscles around the lateral malleolus were also innervated by this nerve. Neither cutaneous branches nor communicating branches with other nerves were found. The present study reveals that the accessory deep peroneal nerve is consistently present and possesses a proper motor and sensory distribution in the lateral region of the leg and ankle. It is not an anomalous nerve as has previously been suggested. PMID:10227671

KUDOH, HIROYUKI; SAKAI, TATSUO; HORIGUCHI, MASAHARU

1999-01-01

129

Clinical Strategies to Enhance Nerve Regeneration in Composite Tissue Allotransplantation  

PubMed Central

Synopsis Reinnervation of a hand transplant ultimately dictates functional recovery but provides a significant regenerative challenge. The authors present a review highlighting interventions to enhance nerve regeneration through acceleration of axonal regeneration or augmentation of Schwann cell supportand discuss their relevance to composite tissue allotransplantation. Surgical techniques that may be performed at the time of transplantation to optimize intrinsic muscle recovery—including appropriate alignment of ulnar nerve motor and sensory components, transfer of the distal anterior interosseous nerve to the recurrent motor branch of the median nerve, and prophylactic release of potential nerve entrapment points—are also presented. PMID:22051390

Glaus, Simone W.; Johnson, Philip J.; Mackinnon, Susan E.

2011-01-01

130

The Trigeminal (V) and Facial (VII) Cranial Nerves  

PubMed Central

There are close functional and anatomical relationships between cranial nerves V and VII in both their sensory and motor divisions. Sensation on the face is innervated by the trigeminal nerves (V) as are the muscles of mastication, but the muscles of facial expression are innervated mainly by the facial nerve (VII) as is the sensation of taste. This article briefly reviews the anatomy of these cranial nerves, disorders of these nerves that are of particular importance to psychiatry, and some considerations for differential diagnosis. PMID:20386632

Sanders, Richard D.

2010-01-01

131

A reversible functional sensory neuropathy model.  

PubMed

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

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

2014-06-13

132

Nanofibrous nerve conduit-enhanced peripheral nerve regeneration.  

PubMed

Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15-mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (?-caprolactone) (PCL) microfibers (981?±?83 nm, Microfiber) or nanofibers (251?±?32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non-porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10(3) vs. 0.98 ± 0.30 × 10(3) in Microfiber, p?nerve regeneration. These results could provide useful insights for future nerve guide designs. PMID:22700359

Jiang, Xu; Mi, Ruifa; Hoke, Ahmet; Chew, Sing Yian

2014-05-01

133

Nerve conduction  

MedlinePLUS Videos and Cool Tools

... fibers (neurons). Neurons consist of dendrites, axon, and cell body. The dendrites are the tree-like structures ... signals from other neurons and from special sensory cells that sense the body’s surrounding environment. The cell ...

134

Eye Movement Desensitization and Reprocessing: A Conceptual Framework  

PubMed Central

Eye movement desensitization and reprocessing (EMDR) is a method which was initially used for the treatment of post-traumatic stress disorder. But it is now being used in different therapeutic situations. EMDR is an eight-phase treatment method. History taking, client preparation, assessment, desensitization, installation, body scan, closure and reevaluation of treatment effect are the eight phases of this treatment which are briefly described. A case report is also depicted which indicates the efficacy of EMDR. The areas where EMDR is used and the possible ways through which it is working are also described. PMID:21716864

Menon, Sukanya B.; Jayan, C.

2010-01-01

135

Opioid receptor desensitization: mechanisms and its link to tolerance  

PubMed Central

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

Allouche, Stéphane; Noble, Florence; Marie, Nicolas

2014-01-01

136

A bioengineered peripheral nerve construct using aligned peptide amphiphile nanofibers.  

PubMed

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 represent a promising biomaterial for use in bioengineered peripheral nerve repair. PMID:25064803

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

2014-10-01

137

Lazzaro and Mead --Circuit Models of Sensory Transduction in the Cochlea CIRCUIT MODELS OF SENSORY TRANSDUCTION  

E-print Network

intensities to a manageable excursion of signal level. Spiral-ganglion neurons connect-nerve fiber can encode only about 25 dB of sound intensity. Humans can sense binaural time differences of Technology Pasadena, California, 91125 Nonlinear signal processing is an integral part of sensory

Lazzaro, John

138

Raman microspectroscopy for visualization of peripheral nerves  

NASA Astrophysics Data System (ADS)

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.

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

2013-02-01

139

Analysis of trigeminal nerve disorders after oral and maxillofacial intervention  

PubMed Central

Background Quantitative sensory testing (QST) is applied to evaluate somatosensory nerve fiber function in the spinal system. This study uses QST in patients with sensory dysfunctions after oral and maxillofacial surgery. Methods Orofacial sensory functions were investigated by psychophysical means in 60 volunteers (30 patients with sensory disturbances and 30 control subjects) in innervation areas of the infraorbital, mental and lingual nerves. The patients were tested 1 week, 4 weeks, 7 weeks and 10 weeks following oral and maxillofacial surgery. Results QST monitored somatosensory deficits and recovery of trigeminal nerve functions in all patients. Significant differences (p < 0.05) between control group and patients were shown for cold, warm and mechanical detection thresholds and for cold, heat and mechanical pain thresholds. Additionally, QST monitored recovery of nerve functions in all patients. Conclusion QST can be applied for non-invasive assessment of sensory nerve function (A?-, A?- and C-fiber) in the orofacial region and is useful in the diagnosis of trigeminal nerve disorders in patients. PMID:20977760

2010-01-01

140

Eye Movement Desensitization and Reprocessing: A Critical Analysis.  

ERIC Educational Resources Information Center

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…

Erwin, Terry McVannel

141

DESENSITIZATION OF HERPESVIRUS-ENCODED G PROTEIN-COUPLED RECEPTORS  

PubMed Central

Members of the herpesvirus family, including human cytomegalovirus (HCMV) and Kaposi’s Sarcoma-associated herpesvirus (KSHV/HHV-8), encode G protein-coupled receptor (GPCR) homologs, which strongly activate classical G-protein signal transduction networks within the cell. In animal models of herpesvirus infection, the viral GPCRs appear to play physiologically important roles by enabling viral replication within tropic tissues and by promoting reactivation from latency. While a number of studies have defined intracellular signaling pathways activated by herpesviral GPCRs, it remains unclear if their physiological function is subjected to the process of desensitization as observed for cellular GPCRs. G protein-coupled receptor kinases (GRK) and arrestin proteins have been recently implicated in regulating viral GPCR signaling; however, the role that these desensitization proteins play in viral GPCR function in vivo remains unknown. Here, we review what is currently known regarding viral GPCR desensitization and discuss potential biological ramifications of viral GPCR regulation by the host cell desensitization machinery. PMID:18054964

Sherrill, Joseph D.; Miller, William E.

2008-01-01

142

Desensitizing Children's Emotional Reactions to the Mass Media.  

ERIC Educational Resources Information Center

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…

Wilson, Barbara J.

1989-01-01

143

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

PubMed Central

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

Joshi, Surabhi; Gowda, Ashwini Shivananje

2013-01-01

144

Pure sensory Guillain-Barré syndrome: A case report and review of the literature.  

PubMed

Sensory Guillain-Barré syndrome (GBS) is an acute demyelinating neuropathy that presents clinically with involvement of the sensory peripheral nerve only. To date, <10 cases of pure sensory GBS have been reported; thus, the clinical and pathological features of sensory variant GBS are yet to be well characterized. The current study reports the case of a 43-year-old female that presented with acute, symmetric and monophasic sensory neuropathy, without motor weakness. Patient history, clinical examination, routine nerve conduction studies and sural nerve biopsy were reviewed. All the observations were consistent with a diagnosis of pure sensory GBS. In particular, the pathological features of the sural nerve biopsy revealed that the form of regenerated nerve fibers have complete structure of myelinated nerve fascicles, and these myelinated nerve fibers are thicker than other parts of the biopsy. The patient received small-dose (20 mg/day) prednisone initially, but without any benefit. Satisfactory improvements were observed with one course of intravenous immunoglobulin. PMID:25289029

Yang, Jingjing; Huan, Mingming; Jiang, Huajun; Song, Chunli; Zhong, Lin; Liang, Zhanhua

2014-11-01

145

Nerves of the hand beyond the carpal tunnel.  

PubMed

Imaging studies including ultrasound (US) and magnetic resonance imaging may be required to evaluate the median nerve in patients with suspected carpal tunnel syndrome. However, the radial and ulnar nerves contribute to sensory and motor innervations to the hand as well. Compressive, traumatic, and iatrogenic events may damage the small terminal branches of these nerves. In the hand, US is able to identify injuries of the median, ulnar, radial nerve, and terminal branches. This article presents the role of imaging to evaluate the nerves of the hand with an emphasis on US. Due to its high-resolution capabilities, US is useful to determine the location, extent, and type of nerve lesion. Moreover, US is useful for a postsurgical assessment. The anterior interosseous nerve, Guyon's tunnel syndrome, and Wartenberg's syndrome are also described. PMID:22648428

Tagliafico, Alberto; Cadoni, Angela; Fisci, Erica; Gennaro, Sergio; Molfetta, Luigi; Perez, Maribel Miguel; Klauser, Andrea S; Martinoli, Carlo

2012-04-01

146

Sensory receptors in monotremes.  

PubMed Central

This is a summary of the current knowledge of sensory receptors in skin of the bill of the platypus, Ornithorhynchus anatinus, and the snout of the echidna, Tachyglossus aculeatus. Brief mention is also made of the third living member of the monotremes, the long-nosed echidna, Zaglossus bruijnii. The monotremes are the only group of mammals known to have evolved electroreception. The structures in the skin responsible for the electric sense have been identified as sensory mucous glands with an expanded epidermal portion that is innervated by large-diameter nerve fibres. Afferent recordings have shown that in both platypuses and echidnas the receptors excited by cathodal (negative) pulses and inhibited by anodal (positive) pulses. Estimates give a total of 40,000 mucous sensory glands in the upper and lower bill of the platypus, whereas there are only about 100 in the tip of the echidna snout. Recording of electroreceptor-evoked activity from the brain of the platypus have shown that the largest area dedicated to somatosensory input from the bill, S1, shows alternating rows of mechanosensory and bimodal neurons. The bimodal neurons respond to both electrosensory and mechanical inputs. In skin of the platypus bill and echidna snout, apart from the electroreceptors, there are structures called push rods, which consist of a column of compacted cells that is able to move relatively independently of adjacent regions of skin. At the base of the column are Merkel cell complexes, known to be type I slowly adapting mechanoreceptors, and lamellated corpuscles, probably vibration receptors. It has been speculated that the platypus uses its electric sense to detect the electromyographic activity from moving prey in the water and for obstacle avoidance. Mechanoreceptors signal contact with the prey. For the echidna, a role for the electrosensory system has not yet been established during normal foraging behaviour, although it has been shown that it is able to detect the presence of weak electric fields in water. Perhaps the electric sense is used to detect moving prey in moist soil. PMID:9720114

Proske, U; Gregory, J E; Iggo, A

1998-01-01

147

Adult Peripheral Nerve Disorders—Nerve Entrapment, Repair, Transfer and Brachial Plexus Disorders  

PubMed Central

Learning Objectives After reviewing this article the reader should be able to: 1. Describe the pathophysiologic bases for nerve injury and how it applies to patient evaluation and management. 2. Realize the wide variety of injury patterns and associated patient complaint and physical findings associated with peripheral nerve pathology. 3. Evaluate and recommend further tests to aid in defining the diagnosis. 4. Specify treatment options and potential risks and benefits. Summary Peripheral nerve disorders comprise a gamut of problems ranging from entrapment neuropathy, to direct open traumatic injury and closed brachial plexus injury. The pathophysiology of injury defines the patient symptoms, exam findings and treatment options and is critical to accurate diagnosis and treatment. Goals of treatment include management of often associated pain and improvement of sensory and motor function. Understanding peripheral nerve anatomy is critical to adopting novel nerve transfer procedures, which may provide superior options for a variety of injury patterns. PMID:21532404

Fox, Ida K.; Mackinnon, Susan E.

2011-01-01

148

CHARACTERIZATION & TREATMENT OF LARGE SENSORY FIBER PERIPHERAL NEUROPATHY IN DIABETIC MICE  

E-print Network

Patients with large-fiber diabetic sensorimotor polyneuropathy (DPN) can develop altered sensorimotor function. Gait and balance control are regulated, in part, through large sensory nerves innervating muscle spindles. The overall goal...

Muller, Karra

2008-11-17

149

Control of hair cell excitability by vestibular primary sensory neurons Journal: Journal of Neuroscience  

E-print Network

Control of hair cell excitability by vestibular primary sensory neurons Journal: Journal, Neurosciences Keywords: Excitotoxicity, Development, Excitability, Hair Cell, repair, synapse impairement, utricle, voltage-gated sodium channel Themes & Topics: a. Hair celss, endorgans, and nerve

Paris-Sud XI, Université de

150

Electrical and mechanical responses of guinea-pig bladder muscle to nerve stimulation.  

PubMed

1 The electrical and mechanical responses to transmural stimulation of intrinsic nerves have been recorded from smooth muscle strips dissected from the dome of the guinea-pig bladder, by use of intracellular microelectrodes, and conventional tension recording techniques. 2 Stimulation of intrinsic nerves evoked action potentials in all cells studied. Hyperpolarization of the cells by extracellular current injection revealed subthreshold excitatory junction potentials (e.j.ps) in about a quarter of the cells studied. 3 Action potentials could still be evoked in the presence of atropine and neostigmine, but were abolished after desensitization of the cells to alpha, beta-methylene ATP, a stable analogue of ATP. 4 In the presence of neostigmine, the evoked action potential was followed by a slow depolarization of the membrane. The mechanical response increased in amplitude and duration. 5 The contractile response to transmural nerve stimulation was reduced but not abolished in the presence of either atropine or desensitizing doses of alpha, beta-methylene ATP. Atropine was more effective at high frequencies of stimulation (greater than or equal to 30 Hz), and alpha, beta-methylene ATP at low frequencies (less than or equal to 15 Hz). In combination the drugs abolished the response. 6 The results suggest that the mechanical response to excitatory nerve stimulation is biphasic. The early transient response is elicited by e.j.ps and evoked spikes, is resistant to atropine, but sensitive to desensitization of purinoceptors. The late response is mediated through muscarinic receptors, involves little membrane depolarization, and is unaffected by desensitization of purinoceptors. These responses are analogous to the responses seen in rabbit bladder, and in the sympathetically innervated rat tail artery and guinea-pig vas deferens. PMID:2611483

Brading, A F; Mostwin, J L

1989-12-01

151

The Proximal Medial Sural Nerve Biopsy Model: A Standardised and Reproducible Baseline Clinical Model for the Translational Evaluation of Bioengineered Nerve Guides  

PubMed Central

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

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

152

Micromorphological Evaluation of Dentin Treated with Different Desensitizing Agents  

PubMed Central

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.

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

153

Playing violent video games, desensitization, and moral evaluation in children  

Microsoft Academic Search

Relationships between short- and long-term exposure to violent video games and desensitization, as measured through components of moral evaluation, were examined. Sixty-six children aged 5–12 years old completed questionnaires assessing video game experience and preferences and empathy and attitudes toward violence. The children played a violent or nonviolent video game and then responded to vignettes about everyday occurrences. Vignette responses

Jeanne B. Funk; Debra D. Buchman; Jennifer Jenks; Heidi Bechtoldt

2003-01-01

154

Neuromodulation of the suprascapular nerve.  

PubMed

The shoulder joint is an enarthrodial or ball-and-socket joint. A complex network of anatomic structures endows the human shoulder with tremendous mobility, greater than any other joint in the body. Many pathologies can been found in those patients with chronic shoulder pain. The painful limitation of shoulder motion affects hand and arm motion as well; therefore, it significantly influences work performance and everyday activities as well as the quality of life. Therefore, the treatment of patients with chronic shoulder pain has major social and health economic implications. In this article we present a patient with a complex history of shoulder pathology including 7 surgeries that left the patient with chronic debilitating shoulder pain. She was suffering from chronic pain and limited mobility of the shoulder joint due to adhesive shoulder capsulitis. She was treated with a multimodality approach with the goals of increasing shoulder range of motion and decreasing her pain. This did not provide significant improvement. The suprascapular nerve supplies motor and sensory innervation to the shoulder, and can be easily accessible in the supraspinatus fossa. A suprascapular nerve block dramatically decreased her pain. This clinical observation along with confirmatory nerve block play an important role during the decision-making process for a trial period of electrical neuromodulation. She was followed for 3 months after the permanent implantation of a suprascapular nerve stimulator. Her pain and shoulder range of motion in all planes improved dramatically. Peripheral nerve stimulation (PNS) of the suprascapular nerve, in addition to multimodality pain management, is one approach to the difficult task of treating adhesive capsulitis with accompanying pain and the inability to move the shoulder. We conducted a literature review on PubMed and found no case describing a similar patient to our knowledge. PMID:25415792

Elahi, Foad; Reddy, Chandan G

2014-12-01

155

Prospective iterative trial of proteasome inhibitor-based desensitization.  

PubMed

A prospective iterative trial of proteasome inhibitor (PI)-based therapy for reducing HLA antibody (Ab) levels was conducted in five phases differing in bortezomib dosing density and plasmapheresis timing. Phases included 1 or 2 bortezomib cycles (1.3?mg/m(2) ?×?6-8 doses), one rituximab dose and plasmapheresis. HLA Abs were measured by solid phase and flow cytometry (FCM) assays. Immunodominant Ab (iAb) was defined as highest HLA Ab level. Forty-four patients received 52 desensitization courses (7 patients enrolled in multiple phases): Phase 1 (n?=?20), Phase 2 (n?=?12), Phase 3 (n?=?10), Phase 4 (n?=?5), Phase 5 (n?=?5). iAb reductions were observed in 38 of 44 (86%) patients and persisted up to 10 months. In Phase 1, a 51.5% iAb reduction was observed at 28 days with bortezomib alone. iAb reductions increased with higher bortezomib dosing densities and included class I, II, and public antigens (HLA DR?3, HLA DR?4 and HLA DR?5). FCM median channel shifts decreased in 11/11 (100%) patients by a mean of 103?±?54 mean channel shifts (log scale). Nineteen out of 44 patients (43.2%) were transplanted with low acute rejection rates (18.8%) and de novo DSA formation (12.5%). In conclusion, PI-based desensitization consistently and durably reduces HLA Ab levels providing an alternative to intravenous immune globulin-based desensitization. PMID:25534446

Woodle, E S; Shields, A R; Ejaz, N S; Sadaka, B; Girnita, A; Walsh, R C; Alloway, R R; Brailey, P; Cardi, M A; Abu Jawdeh, B G; Roy-Chaudhury, P; Govil, A; Mogilishetty, G

2015-01-01

156

Reversible acute axonal polyneuropathy associated with Wernicke-Korsakoff syndrome: impaired physiological nerve conduction due to thiamine deficiency?  

Microsoft Academic Search

Acute axonal polyneuropathy and Wernicke-Korsakoff encephalopathy developed simultaneously in three patients. Nerve conduction studies (NCS) detected markedly decreased compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs) with minimal conduction slowing; sympathetic skin responses (SSRs) were also notably decreased. Sural nerve biopsies showed only mild axonal degeneration with scattered myelin ovoid formation. The symptoms of neuropathy lessened within

S Ishibashi; T Yokota; T Shiojiri; T Matunaga; H Tanaka; K Nishina; H Hirota; A Inaba; M Yamada; T Kanda; H Mizusawa

2003-01-01

157

Altered expression of the voltage-gated calcium channel subunit ?2?-1: A comparison between two experimental models of epilepsy and a sensory nerve ligation model of neuropathic pain  

PubMed Central

The auxiliary ?2?-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 ?2?-1 protein has a mainly presynaptic localization, where it is associated with the calcium channels involved in neurotransmitter release. Relevant to the present study, ?2?-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 ?2?-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 ?2?-1 in hippocampal neurons in either of the epilepsy models, unlike the upregulation of ?2?-1 that occurs following peripheral nerve damage to both somatosensory and motor neurons. However, we did observe local reorganization of ?2?-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

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

2014-01-01

158

The sensory innervation of the pineal organ in the lizard, Lacerta viridis , with remarks on its position in the trend of pineal phylogenetic structural and functional evolution  

Microsoft Academic Search

The sensory innervation of the pineal organ of adult Lacerta viridis has been investigated. Some specimens of Lacerta muralis lillfordi were also used. In the pineal epithelium, a small number of nerve cell pericarya of a sensory type are present. They lie either solitary or in small clusters close to the basement membrane. The axons originating from the nerve cell

J. Ariëns Kappers

1967-01-01

159

[Autoimmune autonomic ganglionopathy and acute autonomic and sensory neuropathy].  

PubMed

Autonomic neuropathies may occur primarily or secondarily to various underlying diseases. Primary autonomic neuropathies are divided into pure autonomic neuropathy, autonomic neuropathy with sensory impairment, and autonomic neuropathy with sensory and motor impairment based on the concomitance or absence of sensory or motor dysfunctions. Autoimmune autonomic ganglionopathy refers to a pure autonomic neuropathy, which typically affects both cholinergic and adrenergic functions. About a half of the patients with autoimmune autonomic ganglionopathy are positive for anti-ganglionic acetylcholine receptor antibodies. The mode of progression widely ranges from acute to chronic, including that mimicking pure autonomic failure. The number of unmyelinated fibers in the sural nerve biopsy specimens tends to decrease with the duration of disease become longer. Immunomodulatory treatments are suggested to be effective for autoimmune autonomic ganglionopathy. Acute autonomic and sensory neuropathy is characterized by autonomic and sensory impairment without motor dysfunction that reaches its nadir within a short period of time mimicking the progression of Guillain-Barré syndrome. The monophasic clinical course and frequent presence of a history of antecedent infections suggests a participation of immune mechanisms. The initial symptoms are those related to autonomic disturbance or superficial sensory impairment, while deep sensory impairment accompanied by sensory ataxia subsequently appears in some patients. Sural nerve biopsy specimens reveal small-fiber predominant axonal loss, and autopsy cases show neuronal loss in the thoracic sympathetic and dorsal root ganglia. Hence, small neurons in the autonomic and sensory ganglia may be affected in the initial phase and, subsequently, large neurons in the sensory ganglia are damaged in acute autonomic and sensory neuropathy. PMID:24291976

Koike, Haruki; Sobue, Gen

2013-01-01

160

Mechanisms of alpha 1-adrenergic vascular desensitization in conscious dogs  

NASA Technical Reports Server (NTRS)

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 compared with saline control dogs. Furthermore, alpha 1-adrenergic receptor density, as determined by [3H]prazosin binding in membrane preparations from vessels in the mesentery, was decreased (8.2 +/- 1.0 versus 18.4 +/- 1.4 fmol/mg protein, p < 0.001) without any change in Kd in the AMD pump dogs compared with the saline pump dogs.(ABSTRACT TRUNCATED AT 400 WORDS).

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

1992-01-01

161

The catecholaminergic nerve plexus of Holothuroidea  

PubMed Central

Catecholamines have been extensively reported to be present in most animal groups, including members of Echinodermata. In this study, we investigated the presence and distribution of catecholaminergic nerves in two members of the Holothuroidea, Holothuria glaberrima (Selenka, 1867) (Aspidochirotida, Holothuroidea) and Holothuria mexicana (Ludwig, 1875) (Aspidochirotida, Holothuroidea), by using induced fluorescence for catecholamines on tissue sections and immunohistochemistry with an antibody that recognizes tyrosine hydroxylase. The presence of a catecholaminergic nerve plexus similar in distribution and extension to those previously reported in other members of Echinodermata was observed. This plexus, composed of cells and fibers, is found in the ectoneural component of the echinoderm nervous system and is continuous with the circumoral nerve ring and the radial nerves, tentacular nerves, and esophageal plexus. In addition, fluorescent nerves in the tube feet are continuous with the catecholaminergic components of the radial nerve cords. This is the first comprehensive report on the presence and distribution of catecholamines in the nervous system of Holothuroidea. The continuity and distribution of the catecholaminergic plexus strengthen the notion that the catecholaminergic cells are interneurons, since these do not form part of the known sensory or motor circuits and the fluorescence is confined to organized nervous tissue. PMID:20827375

Díaz-Balzac, Carlos A.; Mejías, Wigberto; Jiménez, Luis B.

2010-01-01

162

Fiber composition of the rat sciatic nerve.  

PubMed

The rat sciatic nerve originates from the spinal segments L4-L6. It is unifascicular at the trochanter; 5-7 mm distally, the nerve splits into two and then into four fascicles. The tibial portion gives rise to the tibial and the sural nerves, and the peroneal portion gives rise to the peroneal nerve and a cutaneous branch that perforates the lateral hamstring muscles to innervate the proximolateral face of the calf. The number and type of the axons in these branches were determined in light and electron micrographs of normal nerves, and after de-efferentation or sympathectomy. Deafferentation was technically not feasible because spinal ganglia and ventral roots were supplied by the same vascular plexus. The tibial nerve contained 1,000 motor and 3,500 myelinated afferent axons, 3,700 sympathetic axons, and 5,400 unmyelinated afferent axons. The peroneal nerve contained 600 motor and 1,300 myelinated afferent axons, 1,100 sympathetic axons and 3,000 unmyelinated afferent axons. The sural nerve contained 1,100 myelinated and 2,800 unmyelinated afferent axons; in addition, there were 1,500 unmyelinated sympathetic axons. The cutaneous branch consisted of 400 myelinated and 1,800 unmyelinated afferent axons. Thus, the entire sciatic nerve at midthigh is composed of about 27,000 axons; 6% are myelinated motor axons, 23% and 48% are myelinated and unmyelinated sensory axons, respectively, and 23% are unmyelinated sympathetic axons. The techniques used did not demonstrate sympathetic axons in the cutaneous branch and did not reveal the few motor axons contained in the sural nerve. PMID:3706794

Schmalbruch, H

1986-05-01

163

Histochemical discrimination of fibers in regenerating rat infraorbital nerve  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

164

Sensoric Protection after Median Nerve Injury: Babysitter-Procedure Prevents Muscular Atrophy and Improves Neuronal Recovery  

PubMed Central

The babysitter-procedure might offer an alternative when nerve reconstruction is delayed in order to overcome muscular atrophy due to denervation. In this study we aimed to show that a sensomotoric babysitter-procedure after median nerve injury is capable of preserving irreversible muscular atrophy. The median nerve of 20 female Wistar rats was denervated. 10 animals received a sensory protection with the N. cutaneous brachii. After six weeks the median nerve was reconstructed by autologous nerve grafting from the contralateral median nerve in the babysitter and the control groups. Grasping tests measured functional recovery over 15 weeks. At the end of the observation period the weight of the flexor digitorum sublimis muscle was determined. The median nerve was excised for histological examinations. Muscle weight (P < 0.0001) was significantly superior in the babysitter group compared to the control group at the end of the study. The histological evaluation revealed a significantly higher diameter of axons (P = 0.0194), nerve fiber (P = 0.0409), and nerve surface (P = 0.0184) in the babysitter group. We conclude that sensory protection of a motor nerve is capable of preserving muscule weight and we may presume that metabolism of the sensory nerve was sufficient to keep the target muscle's weight and vitality. PMID:25133176

Beck-Broichsitter, Benedicta E.; Becker, Stephan T.; Lamia, Androniki; Fregnan, Federica; Sinis, Nektarios

2014-01-01

165

Sensory innervation of normal and hypospadiac prepuce: possible implications in hypospadiology  

Microsoft Academic Search

Sensory innervation of the skin influences wound healing through the release of neuropeptides from the nerve endings. The purpose of this study was to investigate the differences in the sensory innervation of the normal and the hypospadiac prepuce. The prepuce from 10 healthy children undergoing routine circumcision and 10 age-matched children undergoing hypospadias repair were submitted for immunohistochemistry, using antibodies against protein

Zafar Nazir; Rehan Masood; Resham Rehman

2004-01-01

166

Injury of the Inferior Alveolar Nerve during Implant Placement: a Literature Review  

PubMed Central

ABSTRACT Objectives The purpose of present article was to review aetiological factors, mechanism, clinical symptoms, and diagnostic methods as well as to create treatment guidelines for the management of inferior alveolar nerve injury during dental implant placement. Material and Methods Literature was selected through a search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were inferior alveolar nerve injury, inferior alveolar nerve injuries, inferior alveolar nerve injury implant, inferior alveolar nerve damage, inferior alveolar nerve paresthesia and inferior alveolar nerve repair. The search was restricted to English language articles, published from 1972 to November 2010. Additionally, a manual search in the major anatomy, dental implant, periodontal and oral surgery journals and books were performed. The publications there selected by including clinical, human anatomy and physiology studies. Results In total 136 literature sources were obtained and reviewed. Aetiological factors of inferior alveolar nerve injury, risk factors, mechanism, clinical sensory nerve examination methods, clinical symptoms and treatment were discussed. Guidelines were created to illustrate the methods used to prevent and manage inferior alveolar nerve injury before or after dental implant placement. Conclusions The damage of inferior alveolar nerve during the dental implant placement can be a serious complication. Clinician should recognise and exclude aetiological factors leading to nerve injury. Proper presurgery planning, timely diagnosis and treatment are the key to avoid nerve sensory disturbances management. PMID:24421983

Wang, Hom-Lay; Sabalys, Gintautas

2011-01-01

167

Peripheral nerve regeneration through collagen devices with different in vivo degradation characteristics  

E-print Network

In the United States more than 200,000 people are treated each year for peripheral nerve injuries that require surgery. Functional recovery of motor and sensory capability is limited following autograft, the most common ...

Harley, Brendan A. (Brendan Andrew), 1978-

2002-01-01

168

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

PubMed Central

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

Ahmad, Imran; Akhtar, Md. Sohaib

2014-01-01

169

Fast Synaptic Inhibition in Spinal Sensory Processing and Pain Control  

PubMed Central

The two amino acids ?-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

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

2013-01-01

170

The pattern and diagnostic criteria of sensory neuronopathy: a case–control study  

PubMed Central

Acquired sensory neuronopathies encompass a group of paraneoplastic, dysimmune, toxic or idiopathic disorders characterized by degeneration of peripheral sensory neurons in dorsal root ganglia. As dorsal root ganglia cannot easily be explored, the clinical diagnosis of these disorders may be difficult. The question as to whether there exists a common clinical pattern of sensory neuronopathies, allowing the establishment of validated and easy-to-use diagnostic criteria, has not yet been addressed. In this study, logistic regression was used to construct diagnostic criteria on a retrospective study population of 78 patients with sensory neuronopathies and 56 with other sensory neuropathies. For this, sensory neuronopathy was provisionally considered as unambiguous in 44 patients with paraneoplastic disorder or cisplatin treatment and likely in 34 with a dysimmune or idiopathic setting who may theoretically have another form of neuropathy. To test the homogeneity of the sensory neuronopathy population, likely candidates were compared with unambiguous cases and then the whole population was compared with the other sensory neuropathies population. Criteria accuracy was checked on 37 prospective patients referred for diagnosis of sensory neuropathy. In the study population, sensory neuronopathy showed a common clinical and electrophysiological pattern that was independent of the underlying cause, including unusual forms with only patchy sensory loss, mild electrical motor nerve abnormalities and predominant small fibre or isolated lower limb involvement. Logistic regression allowed the construction of a set of criteria that gave fair results with the following combination: ataxia in the lower or upper limbs + asymmetrical distribution + sensory loss not restricted to the lower limbs + at least one sensory action potential absent or three sensory action potentials <30% of the lower limit of normal in the upper limbs + less than two nerves with abnormal motor nerve conduction study in the lower limbs. PMID:19506068

Camdessanché, Jean-Philippe; Jousserand, Guillemette; Ferraud, Karine; Vial, Christophe; Petiot, Philippe; Honnorat, Jérôme

2009-01-01

171

Applying eye movement desensitization and reprocessing (EMDR) to the treatment of traumatized children: Five case studies  

Microsoft Academic Search

Citation: Greenwald, R. (1994). Applying eye movement desensitization and reprocessing (EMDR) to the treatment of traumatized children: Fi ve case studies. Anxiety Disorders Practice Journal, 1, 83-97. Abstract Eye movement desensitization and reprocessing (EMDR) is a recently developed psychotherapy method which appears to increase efficiency in treating trauma-based psychological disturbance. Applications to child tr eatment were explored in five case

RICKY GREENWALD

172

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

ERIC Educational Resources Information Center

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…

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

2004-01-01

173

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

ERIC Educational Resources Information Center

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)

Suarez, Yolanda; And Others

1976-01-01

174

Nerve Impulses in Plants  

ERIC Educational Resources Information Center

Summarizes research done on the resting and action potential of nerve impulses, electrical excitation of nerve cells, electrical properties of Nitella, and temperature effects on action potential. (GS)

Blatt, F. J.

1974-01-01

175

Short-term cholinergic desensitization of rat pancreatic secretory response  

SciTech Connect

Dispersed pancreatic acini were first exposed to carbamylcholine (10/sup -7/-10/sup -4/ M) for 60 min, washed, and reexposed to this same agonist (10/sup -8/-10/sup -3/ M) for 15 min. During this second incubation, the functional secretory capacity of these acini was evaluated by measuring amylase release. Acini preexposed to concentrations of carbamylcholine of 10/sup -6/ M or greater showed shifts to the right in the subsequent carbamylcholine dose-response curves of amylase release. A 3-h recovery period (without carbamylcholine) did not restore the altered carbamylcholine dose-response curve. Ca/sup 2 +/ concentrations of 10/sup -7/ M or 2.5 x 10/sup -3/ M instead of 0.5 x 10/sup -3/ M during the 60-min preincubation did not affect the desensitization process. With use of N-(/sup 3/H)methylscopolamine to evaluate muscarinic receptors, the only changes observed after desensitization were a significant decrease in the high-affinity and an equivalent increase in that of the low-affinity receptors. After cholinergic exposure amylase release stimulated by caerulein was only slightly modified, whereas amylase release in response to a phorbol ester 12-O-tetradecanoylphorbol-13-acetate and to the ionophore A23187 was not altered. These data indicate that short-term desensitization with a cholinergic agent is relatively specific to muscarinic agonists, causes changes in the muscarinic receptor high-and low-affinity concentration but does not alter intracellular steps after calcium mobilization or protein kinase C activation known to be involved in the secretion process.

Asselin, J.; Larose, L.; Morisset, J.

1987-03-01

176

Repair of peripheral nerve with vein wrapping*  

PubMed Central

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

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

2014-01-01

177

Successful desensitization to brentuximab vedotin after hypersensitivity reaction.  

PubMed

Monoclonal antibodies (mAb) have become the standard of care for numerous diseases. However, side effects including infusion and hypersensitivity reactions experienced by patients continue to be a limiting factor in their use. In the therapy of cancer, treatment choices are frequently limited and minimizing side effects of a life-saving or life-prolonging therapy becomes of the utmost importance. We report the successful use of a rapid desensitization protocol in a patient with NHL, treated with a novel antibody-drug conjugate, chimeric monoclonal antibody linked to the antimitotic agent monomethyl auristatin E (MMAE) Brentuximab vedotin, who had previously developed a hypersensitivity reaction. PMID:24918568

Story, Sara K; Petrov, Andrej A; Geskin, Larisa J

2014-06-01

178

Subunit-specific desensitization of heteromeric kainate receptors  

PubMed Central

Kainate receptor subunits can form functional channels as homomers of GluK1, GluK2 or GluK3, or as heteromeric combinations with each other or incorporating GluK4 or GluK5 subunits. However, GluK4 and GluK5 cannot form functional channels by themselves. Incorporation of GluK4 or GluK5 into a heteromeric complex increases glutamate apparent affinity and also enables receptor activation by the agonist AMPA. Utilizing two-electrode voltage clamp of Xenopus oocytes injected with cRNA encoding kainate receptor subunits, we have observed that heteromeric channels composed of GluK2/GluK4 and GluK2/GluK5 have steady state concentration–response curves that were bell-shaped in response to either glutamate or AMPA. By contrast, homomeric GluK2 channels exhibited a monophasic steady state concentration–response curve that simply plateaued at high glutamate concentrations. By fitting several specific Markov models to GluK2/GluK4 heteromeric and GluK2 homomeric concentration–response data, we have determined that: (a) two strikingly different agonist binding affinities exist; (b) the high-affinity binding site leads to channel opening; and (c) the low-affinity agonist binding site leads to strong desensitization after agonist binding. Model parameters also approximate the onset and recovery kinetics of desensitization observed for macroscopic currents measured from HEK-293 cells expressing GluK2 and GluK4 subunits. The GluK2(E738D) mutation lowers the steady state apparent affinity for glutamate by 9000-fold in comparison to GluK2 homomeric wildtype receptors. When this mutant subunit was expressed with GluK4, the rising phase of the glutamate steady state concentration–response curve overlapped with the wildtype curve, whereas the declining phase was right-shifted toward lower affinity. Taken together, these data are consistent with a scheme whereby high-affinity agonist binding to a non-desensitizing GluK4 subunit opens the heteromeric channel, whereas low-affinity agonist binding to GluK2 desensitizes the whole channel complex. PMID:20026616

Mott, David D; Rojas, Asheebo; Fisher, Janet L; Dingledine, Raymond J; Benveniste, Morris

2010-01-01

179

Sensory response following knee joint damage in rabbits  

PubMed Central

Background Altered sensory information arising from damaged knee joint structures has been hypothesized as a contributing factor to persistent muscle dysfunction following injury. Methods Composite femoral nerve sensory signal was measured in 24 rabbits randomly allocated (8 per group) to receive surgical anterior cruciate ligament (ACL) transection with or without autograft reconstruction or nothing (control). Two-weeks after the intervention composite afferent signals were recorded from the femoral nerve. Side-to-side ratios (surgical side vs contralateral healthy side) for peak femoral nerve afferent composite signal were used for comparison. Results Femoral nerve afferent signal ratios were significantly higher in the ACL-R (2.21?±?0.74) group when compared to the ACL-T (1.28?±?0.61, P?=?0.02) group and Control group (1.31?±?0.78, P?=?0.03). Conclusion The magnitude of sensory information recorded on the femoral nerve is increased following ACL injury and reconstruction surgery, but not after an isolated ACL injury in rabbits. PMID:24766654

2014-01-01

180

Endoscopically assisted sural nerve harvest in infants.  

PubMed

A technique of endoscopic sural nerve harvest was devised to minimize the donor site scarring in infants requiring peripheral nerve grafting procedures. The harvests were performed under tourniquet control using three 2-cm incisions for access at the lateral malleolus, midcalf, and popliteal fossa. Endoscopic visualization and blunt dissection of the nerve was achieved with a 4-mm-diameter, 18-cm-long telescope with a 0-degree angle lens, stabilized in an Emory retractor and attached to a video camera. The medial sural nerve was divided in the popliteal fossa proximally under direct vision. The lateral sural nerve was identified and harvested when present. This technique has been in use since 1994 and has been undertaken in more than 200 patients. The most common indication for surgery was obstetrical brachial plexus palsy. No nerve graft injury was noted upon examination under the operating microscope. Postoperative pain, swelling, and ecchymosis were minimal. Most patients have a detectable area of sensory loss at long-term follow-up but are unaware of this finding. Donor site scarring has been aesthetically satisfactory. PMID:20567685

Capek, Lucie; Clarke, Howard M

2008-02-01

181

Sensory Guillain-Barré syndrome: A case report  

PubMed Central

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

ZHANG, JING; LIU, NA; ZHANG, ZHE-CHENG; ZHENG, RUI-ZHI; LI, QIAN

2014-01-01

182

Sensory Guillain-Barré syndrome: A case report.  

PubMed

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

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

2014-12-01

183

L2 Spinal Nerve–Block Effects on Acute Low Back Pain From Osteoporotic Vertebral Fracture  

Microsoft Academic Search

Elderly patients with osteoporosis sometimes experience lumbar vertebral fracture and may feel diffuse nonlocalized pain in the back, the lateral portion of the trunk, and the area surrounding the iliac crest. The pattern of sensory innervation of vertebral bodies remains unclear. Some sensory nerves from the L2 and L5 vertebral bodies may enter the paravertebral sympathetic trunks and reach the

Seiji Ohtori; Masaomi Yamashita; Gen Inoue; Kazuyo Yamauchi; Munetaka Suzuki; Sumihisa Orita; Yawara Eguchi; Nobuyasu Ochiai; Shunji Kishida; Masashi Takaso; Kazuhisa Takahashi

2009-01-01

184

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

PubMed Central

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

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

2010-01-01

185

Do nerve growth factor-related mechanisms contribute to loss of cutaneous nociception in leprosy?  

Microsoft Academic Search

While sensory loss in leprosy skin is the consequence of invasion by M. leprae of Schwann cells related to unmyelinated fibres, early loss of cutaneous pain sensation, even in the presence of nerve fibres and inflammation, is a hallmark of leprosy, and requires explanation. In normal skin, nerve growth factor (NGF) is produced by basal keratinocytes, and acts via its

Paul Facer; Dawn Mann; Rajeev Mathur; Shubha Pandya; Uma Ladiwala; Bhim Singhal; Jo-Anne Hongo; Dominick V Sinicropi; Giorgio Terenghi; Praveen Anand

2000-01-01

186

Directed nerve regeneration enabled by wirelessly powered electrodes printed on a biodegradable polymer.  

PubMed

Wirelessly directed nerve regeneration: inductively powered electrical stimulation circuits on the biodegradable polymer polycaprolactone demonstrate directed regeneration of sensory neurons from a dorsal root ganglion. These circuits, produced using a unique transfer printing process, illustrate progress towards the use of electrical stimulation systems on biodegradable materials to improve peripheral nerve repair functional outcomes. PMID:24376117

Martin, Christopher; Dejardin, Théophile; Hart, Andrew; Riehle, Mathis O; Cumming, David R S

2014-07-01

187

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

PubMed Central

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

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

2014-01-01

188

Fibrolipomatous hamartoma of nerve.  

PubMed

Fibrolipomatous hamartomas of nerve are rare, benign, fibrofatty malformations of peripheral nerves, most commonly affecting the median nerve. Lower extremity cases are extremely rare. The authors present a very rare case of a fibrolipomatous hamartoma involving the superficial peroneal nerve, and review the literature regarding its clinical presentation and surgical management. PMID:8161996

Bibbo, C; Warren, A M

1994-01-01

189

[Regeneration of the facial nerve in comparison to other peripheral nerves : from bench to bedside].  

PubMed

Despite increasing knowledge of cellular and molecular mechanisms determining the success or failure of peripheral nerve regeneration, no effective treatments for peripheral nerve injury exist. Newly developed and validated approaches for precise numerical assessment of motor deficits have recently allowed testing of novel strategies in experimental animals. One of these approaches is the daily manual stimulation of the denervated musculature. This treatment is effective in cases of cranial nerve lesions with preservation of the sensory input (facial or hypoglossal nerve) and has the potential of direct translation in clinical settings. However, manual stimulation appears to be ineffective for the treatment of mixed peripheral nerve injuries. Generally, no long-term improvement of functional recovery is achieved by electrical stimulation in rodents. While short-term post-traumatic stimulation of the proximal nerve stump has no negative effects, direct electrical stimulation of the muscle during the period of de- and reinnervation appears to hinder muscle fibre reinnervation. Finally, experimental evidence suggests that application of peptides known as glycomimetics, which mimic functional properties of carbohydrate molecules, may provide significant benefits after injuries of mixed peripheral nerves. PMID:20454881

Irintchev, A; Angelov, D N; Guntinas-Lichius, O

2010-05-01

190

Assessing Decreased Sensation and Increased Sensory Phenomena in Diabetic Polyneuropathies  

PubMed Central

Loss of sensation and increased sensory phenomena are major expressions of varieties of diabetic polyneuropathies needing improved assessments for clinical and research purposes. We provide a neurobiological explanation for the apparent paradox between decreased sensation and increased sensory phenomena. Strongly endorsed is the use of the 10-g monofilaments for screening of feet to detect sensation loss, with the goal of improving diabetic management and prevention of foot ulcers and neurogenic arthropathy. We describe improved methods to assess for the kind, severity, and distribution of both large- and small-fiber sensory loss and which approaches and techniques may be useful for conducting therapeutic trials. The abnormality of attributes of nerve conduction may be used to validate the dysfunction of large sensory fibers. The abnormality of epidermal nerve fibers/1 mm may be used as a surrogate measure of small-fiber sensory loss but appear not to correlate closely with severity of pain. Increased sensory phenomena are recognized by the characteristic words patients use to describe them and by the severity and persistence of these symptoms. Tests of tactile and thermal hyperalgesia are additional markers of neural hyperactivity that are useful for diagnosis and disease management. PMID:24158999

Herrmann, David N.; Staff, Nathan P.; Dyck, P. James B.

2013-01-01

191

Fibrolipomatous hamartoma of sural nerve: a new site of an unusual lesion.  

PubMed

Neural fibrolipomatous hamartoma is a rare benign tumour commonly involving the median nerve. Other less frequently involved nerves include the ulnar, radial, brachial plexus, superficial peroneal nerve, inferior calcaneal nerve and median plantar nerve. Involvement of sural nerve has not been reported in the available literature so far. A three-year-old female child presented with a painless swelling over the posterolateral aspect of left leg with no associated motor or sensory deficits. Radiological investigations revealed a fat density lesion with interspersed neural element in the subcutaneous plane of the left leg. Histopathological examination of the excised specimen showed features of a fibrolipomatous hamartoma of the nerve. This report describes the occurrence of fibrolipomatous hamartoma in the sural nerve for the first time in the literature. This rare tumour should be considered in the differential diagnosis of such lesions. PMID:24763237

Parihar, Asmita; Verma, Sarika; Senger, Mamta; Agarwal, Anil; Bansal, Kalpana; Gupta, Ruchika

2014-04-01

192

Schwann Cells Seeded in Acellular Nerve Grafts Improve Functional Recovery  

PubMed Central

Introduction This study evaluated whether Schwann cells (SCs) from different nerve sources transplanted into cold-preserved acellular nerve grafts (CP-ANGs) would improve functional regeneration compared to nerve isografts. Methods SCs isolated and expanded from motor and sensory branches of rat femoral and sciatic nerves were seeded into 14mm CP-ANGs. Growth factor expression, axonal regeneration, and functional recovery were evaluated in a14 mm rat sciatic injury model and compared to isografts. Results At 14 days, motor or sensory-derived SCs increased expression of growth factors in CP-ANGs versus isografts. After 42 days, histomorphometric analysis found CP-ANGs with SCs and isografts had similar numbers of regenerating nerve fibers. At 84 days, muscle force generation was similar for CP-ANGs with SCs and isografts. SC source did not affect nerve fiber counts or muscle force generation. Discussion SCs transplanted into CP-ANGs increase functional regeneration to isograft levels; however SC nerve source did not have an effect. PMID:23625513

Jesuraj, Nithya J.; Santosa, Katherine B.; MacEwan, Matthew R.; Moore, Amy M.; Kasukurthi, Rahul; Ray, Wilson Z.; Flagg, Eric R.; Hunter, Daniel A.; Borschel, Gregory H.; Johnson, Philip J.; Mackinnon, Susan E.; Sakiyama-Elbert, Shelly E.

2014-01-01

193

Effects of polysialic acid on sensory innervation of the cornea.  

PubMed

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

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

2015-02-15

194

Characterising the mechanism of airway smooth muscle ?2 adrenoceptor desensitization by rhinovirus infected bronchial epithelial cells.  

PubMed

Rhinovirus (RV) infections account for approximately two thirds of all virus-induced asthma exacerbations and often result in an impaired response to ?2 agonist therapy. Using an in vitro model of RV infection, we investigated the mechanisms underlying RV-induced ?2 adrenoceptor desensitization in primary human airway smooth muscle cells (ASMC). RV infection of primary human bronchial epithelial cells (HBEC) for 24 hours produced conditioned medium that caused ?2 adrenoceptor desensitization on ASMCs without an effect on ASMCs viability. Less than 3 kDa size fractionation together with trypsin digestion of RV-induced conditioned medium did not prevent ?2 adrenoceptor desensitization, suggesting it could potentially be mediated by a small peptide or lipid. RV infection of BECs, ASMCs and fibroblasts produced prostaglandins, of which PGE2, PGF2? and PGI2 had the ability to cause ?2 adrenoceptor desensitization on ASMCs. RV-induced conditioned medium from HBECs depleted of PGE2 did not prevent ASMC ?2 adrenoceptor desensitization; however this medium induced PGE2 from ASMCs, suggesting that autocrine prostaglandin production may be responsible. Using inhibitors of cyclooxygenase and prostaglandin receptor antagonists, we found that ?2 adrenoceptor desensitization was mediated through ASMC derived COX-2 induced prostaglandins. Since ASMC prostaglandin production is unlikely to be caused by RV-induced epithelial derived proteins or lipids we next investigated activation of toll-like receptors (TLR) by viral RNA. The combination of TLR agonists poly I:C and imiquimod induced PGE2 and ?2 adrenoceptor desensitization on ASMC as did the RNA extracted from RV-induced conditioned medium. Viral RNA but not epithelial RNA caused ?2 adrenoceptor desensitization confirming that viral RNA and not endogenous human RNA was responsible. It was deduced that the mechanism by which ?2 adrenoceptor desensitization occurs was by pattern recognition receptor activation of COX-2 induced prostaglandins. PMID:23457497

Van Ly, David; Faiz, Alen; Jenkins, Christine; Crossett, Ben; Black, Judith L; McParland, Brent; Burgess, Janette K; Oliver, Brian G G

2013-01-01

195

Desensitization in interferon-beta1a allergy: a case report.  

PubMed

We report a 41-year-old patient with multiple sclerosis (MS) who was successfully desensitized after she developed non-injection-site urticaria and angioedema due to interferon (IFN)-beta1a. Although a few cases of urticaria and anaphylaxis have been reported in the literature, to our knowledge this is the first report of a successful desensitization with IFN-beta1a. Desensitization with IFN-beta1a allowed us to continue with the administration of interferon-beta, which is a mainstay in treatment for MS. PMID:19127077

Fusun Kalpaklioglu, Ayse; Baccioglu Kavut, Ayse; Erdemoglu, Ali Kemal

2009-01-01

196

Extra-adrenal paraganglioma of the median nerve.  

PubMed

An extra-adrenal paraganglioma is an uncommon tumour that arises from the paraganglia associated with the autonomous nervous system. A paraganglioma arising in the sensory-somatic nervous system is extremely rare and clinically is easily confused with other neurogenic tumours. We describe a paraganglioma that arose in the median nerve of a 22-year-old woman. PMID:23750845

Chong, Yosep; Park, Minjong; Ko, Young-Hyeh

2014-12-01

197

Sudden peroneal nerve palsy in a varus arthritic knee.  

PubMed

Peroneal nerve palsy has been reported in association with traumatic and nontraumatic causes. We encountered a 75-year-old man whose peroneal nerve palsy developed suddenly following varus deformity of the arthritic knee. A review of the literature found 1 other report describing a progressive peroneal nerve palsy associated with a varus deformity of the knee due to arthritis. Our patient had progressive intractable knee pain; 3-compartment, severe degenerative changes in the knees; varus knee malalignment and laxity; right peroneal nerve palsy; and decreased sensation to light touch and pinprick on the dorsum of the right foot. The preoperative WOMAC score was 36. Nerve conduction studies confirmed acute peroneal neuropathy with conduction block at the fibular neck and secondary axonal degeneration. Magnetic resonance imaging of the knee showed osteophytes and cysts surrounding the fibular neck. Although their compression could be responsible for the nerve palsy, the sudden process made this less possible. Thus, the patient underwent total knee arthroplasty of both knees without exploration of the nerve. At 5-month follow-up, the WOMAC score was 78. The patient walked with a cane with no varus thrust, and his right knee had no varus laxity in full extension. The peroneal nerve did not retain its function. Sensory examination and postoperative nerve conduction studies showed no improvement. PMID:19968227

Seyyed Hosseinzadeh, Hamid Reza; Eajazi, Alireza; Kazemi, Seyyed Morteza; Daftari Besheli, Laleh; Hassas Yeganeh, Mehrnoush; Aydanloo, Ali

2009-12-01

198

Nerve conduction studies of upper extremities in tennis players  

PubMed Central

Objectives: The influence of regular and intense practice of an asymmetric sport such as tennis on nerves in the elbow region was examined. Methods: The study included 21 male elite tennis players with a mean (SD) age of 27.5 (1.7) years and 21 male non-active controls aged 26.4 (1.9) years. Anthropometric measurements (height, weight, limb length, and perimeters of arm and forearm) were determined for each subject, and range of motion assessment and radiographic examination carried out. Standard nerve conduction techniques using constant measured distances were applied to evaluate the median, ulnar, and radial nerves in the dominant and non-dominant limb of each individual. Results: The sensory and motor conduction velocities of the radial nerve and the sensory conduction velocity of the ulnar nerve were significantly delayed in the dominant arms of tennis players compared with their non-dominant arms and normal subjects. There were no statistical differences in the latencies, conduction velocities, or amplitudes of the median motor and sensory nerves between controls and tennis players in either the dominant or non-dominant arms. However, the range of motion of the upper extremity was significantly increased in tennis players when compared with control subjects. Tennis players were taller and heavier than control subjects and their dominant upper limb lengths were longer, and arm and forearm circumferences greater, than those of the control subjects. Conclusions: Many of the asymptomatic tennis players with abnormal nerve conduction tests in the present study may have presymptomatic or asymptomatic neuropathy similar to subclinical entrapment nerve neuropathy. PMID:15388554

Colak, T; Bamac, B; Ozbek, A; Budak, F; Bamac, Y

2004-01-01

199

Signaling by Sensory Receptors  

PubMed Central

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

Julius, David; Nathans, Jeremy

2012-01-01

200

Neurology: an ancient sensory organ in crocodilians.  

PubMed

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

Soares, Daphne

2002-05-16

201

Human periodontal ligament stem cells repair mental nerve injury  

PubMed Central

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

Li, Bohan; Jung, Hun-Jong; Kim, Soung-Min; Kim, Myung-Jin; Jahng, Jeong Won; Lee, Jong-Ho

2013-01-01

202

Peripheral nerve regeneration and neurotrophic factors  

PubMed Central

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

TERENGHI, GIORGIO

1999-01-01

203

Peroneal nerve dysfunction after total knee arthroplasty: characterization and treatment.  

PubMed

The purpose of this study was to report on the presentation, evaluation, treatment, and outcome of patients who had a peroneal nerve dysfunction after total knee arthroplasty. Six patients were unable to achieve adequate range of motion after physical therapy, and the remaining 5 patients had sensory symptoms that interfered with daily activities despite adequate range of motion. All 11 patients had abnormal electrodiagnostic testing but had intact motor strength and were treated with surgical decompression of the nerve. The patients with motion problems had a mean increase in range of motion of 40 ° (range, 20 °-70 °) at final follow-up. All patients with dominant sensory symptoms had a resolution of leg and foot pain after treatment. Orthopedic surgeons should be aware of peroneal nerve dysfunction as a possible cause of unsatisfactory rehabilitation and/or persistent atypical lateral leg pain after total knee arthroplasty. PMID:20570090

Zywiel, Michael G; Mont, Michael A; McGrath, Mike S; Ulrich, Slif D; Bonutti, Peter M; Bhave, Anil

2011-04-01

204

Primary sensory neuronal rescue with systemic acetyl- l-carnitine following peripheral axotomy. A dose-response analysis  

Microsoft Academic Search

The loss of a large proportion of primary sensory neurons after peripheral nerve axotomy is well documented. As a consequence of this loss, the innervation density attained on completion of regeneration will never be normal, regardless of how well the individual surviving neurons regenerate. Acetyl-l-carnitine (ALCAR), an endogenous peptide in man, has been demonstrated to protect sensory neurons, thereby avoiding

Andrew D. H Wilson; Andrew Hart; Thomas Brannstrom; Mikael Wiberg; Giorgio Terenghi

2003-01-01

205

Anaphylactic reaction to polyethylene-glycol conjugated-asparaginase: premedication and desensitization may not be sufficient.  

PubMed

In hypersensitive reactions to native L-asparaginase, either premedication and desensitization or substitution with polyethylene glycol conjugated asparaginase (PEG-ASP) is preferred. Anaphylaxis with PEG-ASP is rare. An 8-year-old girl and a 2.5-year-old boy, both diagnosed as having acute lymphoblastic leukemia, presented with native L-asparaginase hypersensitivity and substitution with PEG-ASP was preferred. They received a premedication (methylprednisolone, hydroxyzine and ranitidine) followed by desensitization with PEG-ASP infusion. Both patients developed anaphylaxis with peg-asparaginase. These are the first reported cases of anaphylactic reaction to PEG-ASP, despite the application of both premedication and desensitization. Anaphylaxis with PEG-ASP is very rare and premedication and desensitization protocols may not prevent these hypersensitive reactions. PMID:23910807

Sahiner, Umit M; Yavuz, S Tolga; Gökce, Muge; Buyuktiryaki, Betul; Altan, Ilhan; Aytac, Selin; Tuncer, Murat; Tuncer, Ayfer; Sackesen, Cansin

2013-08-01

206

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

ERIC Educational Resources Information Center

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)

Barabasz, Arreed F.

1974-01-01

207

Atomistic Mechanism for the Activation and Desensitization of an AMPA-Subtype Glutamate Receptor  

PubMed Central

Ionotropic glutamate receptors (iGluRs) mediate fast excitatory synaptic transmission in the central nervous system. Upon agonist binding, an iGluR opens to allow the flow of cations and subsequently enters into a desensitized state. It remains unclear how agonist binding to the ligand-binding domain is transmitted to the transmembrane domain for channel activation and desensitization. Here we report molecular dynamics simulations of an AMPA-subtype iGluR in explicit water and membrane. Channel opening and closing were observed in simulations of the activation and desensitization processes, respectively. The motions of the LBD-TMD linkers along the central axis of the receptor and in the lateral plane contributed cooperatively to channel opening and closing. The detailed mechanism of channel activation and desensitization suggested by the simulations here is consistent with existing data and may serve as a guide for new experiments and for the design of pharmacological agents. PMID:21673675

Dong, Hao; Zhou, Huan-Xiang

2012-01-01

208

Engineering a multimodal nerve conduit for repair of injured peripheral nerve  

NASA Astrophysics Data System (ADS)

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 hydrogel. This indicates return of some feeling to the limb via the fully-configured conduit. Immunohistochemical analysis of the implanted conduits removed from the rats after the four-week implantation period confirmed the presence of myelinated axons within the conduit and distal to the site of implantation, further supporting that the conduit promoted nerve repair over this period of time. This study describes the design considerations and fabrication of a novel multicomponent, multimodal bio-engineered synthetic conduit for peripheral nerve repair.

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

209

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...

210

Violence exposure in real-life, video games, television, movies, and the internet: is there desensitization?  

Microsoft Academic Search

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 characteristics. One hundred fifty fourth and fifth graders completed measures of real-life

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

2004-01-01

211

Uncontrollable, but not controllable, stress desensitizes 5-HT1A receptors in the dorsal raphe nucleus  

PubMed Central

Uncontrollable stressors produce behavioral changes that do not occur if the organism can exercise behavioral control over the stressor. Previous studies suggest that the behavioral consequences of uncontrollable stress depend on hypersensitivity of serotonergic neurons in the dorsal raphe nucleus (DRN), but the mechanisms involved have not been determined. We used ex vivo single unit recording in rats to test the hypothesis that the effects of uncontrollable stress are produced by desensitization of DRN 5-HT1A autoreceptors. These studies revealed that uncontrollable, but not controllable, tailshock impaired 5-HT1A receptor-mediated inhibition of DRN neuronal firing. Moreover, this effect was observed only at timepoints when the behavioral effects of uncontrollable stress are present. Furthermore, temporary inactivation of the medial prefrontal cortex with the GABAA receptor agonist muscimol, which eliminates the protective effects of control on behavior, led even controllable stress to now produce functional desensitization of DRN 5-HT1A receptors. Additionally, behavioral immunization, an experience with controllable stress before uncontrollable stress that prevents the behavioral outcomes of uncontrollable stress, also blocked functional desensitization of DRN 5-HT1A receptors by uncontrollable stress. Lastly, western blot analysis revealed that uncontrollable stress leads to desensitization rather than downregulation of DRN 5-HT1A receptors. Thus, treatments that prevent controllable stress from being protective led to desensitization of 5-HT1A receptors, while treatments that block the behavioral effects of uncontrollable stress also blocked 5-HT1A receptor desensitization. These data suggest that uncontrollable stressors produce a desensitization of DRN 5-HT1A autoreceptors, and that this desensitization is responsible for the behavioral consequences of uncontrollable stress. PMID:21976495

Rozeske, RR; Evans, AK; Frank, MG; Watkins, LR; Lowry, CA; Maier, SF

2011-01-01

212

Nerve conduction velocity  

MedlinePLUS

... to determine the speed of the nerve signals. Electromyography (recording from needles placed into the muscles) is ... Often, the nerve conduction test is followed by electromyography (EMG). In this test, needles are placed into ...

213

Electromechanical Nerve Stimulator  

NASA Technical Reports Server (NTRS)

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.

Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

1993-01-01

214

Evidence for Glutamate as a Neuroglial Transmitter within Sensory Ganglia  

PubMed Central

This study examines key elements of glutamatergic transmission within sensory ganglia of the rat. We show that the soma of primary sensory neurons release glutamate when depolarized. Using acute dissociated mixed neuronal/glia cultures of dorsal root ganglia (DRG) or trigeminal ganglia and a colorimetric assay, we show that when glutamate uptake by satellite glial cells (SGCs) is inhibited, KCl stimulation leads to simultaneous increase of glutamate in the culture medium. With calcium imaging we see that the soma of primary sensory neurons and SGCs respond to AMPA, NMDA, kainate and mGluR agonists, and selective antagonists block this response. Using whole cell patch-clamp technique, inward currents were recorded from small diameter (<30 µm) DRG neurons from intact DRGs (ex-vivo whole ganglion preparation) in response to local application of the above glutamate receptor agonists. Following a chronic constriction injury (CCI) of either the inferior orbital nerve or the sciatic nerve, glutamate expression increases in the trigeminal ganglia and DRG respectively. This increase occurs in neurons of all diameters and is present in the somata of neurons with injured axons as well as in somata of neighboring uninjured neurons. These data provides additional evidence that glutamate can be released within the sensory ganglion, and that the somata of primary sensory neurons as well as SGCs express functional glutamate receptors at their surface. These findings, together with our previous gene knockdown data, suggest that glutamatergic transmission within the ganglion could impact nociceptive threshold. PMID:23844184

Kung, Ling-Hsuan; Gong, Kerui; Adedoyin, Mary; Ng, Johnson; Bhargava, Aditi; Ohara, Peter T.; Jasmin, Luc

2013-01-01

215

Surveillance of the gastrointestinal mucosa by sensory neurons.  

PubMed

A dense network of extrinsic and intrinsic sensory neurons supplies the gastrointestinal tract. Intrinsic sensory neurons provide the enteric nervous system with the kind of information that this brain of the gut requires for its autonomic control of digestion, whereas extrinsic afferents notify the brain about processes that are relevant to energy and fluid homeostasis and the sensation of discomfort and pain. The sensory repertoire of afferent neurons is extended by their responsiveness to mediators released from enteroendocrine and immune cells, which act like "taste buds" of the gut and serve as interface between the gastrointestinal lumen and the sensory nerve terminals in the lamina propria of the mucosa. Functional bowel disorders such as non-ulcer dyspepsia and irritable bowel syndrome are characterized by abdominal discomfort or pain in the absence of an identifiable organic cause. It is hypothesized with good reason that infection, inflammation or trauma causes sensory pathways to undergo profound phenotypic and functional alterations that outlast the acute insult. The pertinent changes involve an exaggerated sensitivity of the peripheral afferent nerve fibres as well as a distorted processing and representation of the incoming information in the brain. This concept identifies a number of receptors and ion channels that are selectively expressed by primary afferent neurons as important molecular targets at which to aim novel therapies for functional bowel disorders. PMID:11787755

Holzer, P; Michl, T; Danzer, M; Jocic, M; Schicho, R; Lippe, I T

2001-12-01

216

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

PubMed

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

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

217

Postsynaptic nicotinic receptor desensitized by non-contractile Ca2+ mobilization via protein kinase-C activation at the mouse neuromuscular junction.  

PubMed Central

1. Non-contractile Ca2+ mobilization (unaccompanied by muscle contraction) was initiated by nerve stimulation in the presence of neostigmine (more than 0.03 microM) at the endplate region of mouse diaphragm muscles. In the process of nicotinic receptor desensitization, the depressant effect of non-contractile Ca2+ on contractile Ca2+ mobilization was investigated by measurement of Ca(2+)-aequorin luminescence. 2. When the phrenic nerve was stimulated with paired pulses having intervals of 150, 300, 600, 1000 and 2000 ms, contractile Ca2+ transients were elicited during the generation of non-contractile Ca2+ mobilization. The amplitude of the contractile Ca2+ transients elicited by the second pulse (S2) was depressed at the shorter pulse intervals, but recovered to the initial contractile response (S1) at longer pulse intervals. 3. The extent of depression of S2 was enhanced by increasing the concentration of neostigmine (0.03 to 0.3 microM). When a low concentration (0.05 microM) of pancuronium, a competitive nicotinic antagonist, completely blocked non-contractile Ca2+ mobilization, the depression of S2 was diminished. 4. The depression of S2 was enhanced when the peak amplitude of non-contractile Ca2+ mobilization was raised by increasing the external Ca2+ concentration from 1.3 to 5 mM. 5. Staurosporine (10 nM), a protein kinase-C inhibitor, diminished the depression of S2 despite large amounts of non-contractile Ca2+ mobilization. The diminishing effect of staurosporine was counteracted by TPA (0.1 microM), a protein kinase-C activator. 6. These findings suggest that non-contractile Ca2+ mobilization may enhance the desensitization of the postsynaptic nicotinic receptor via activation of protein kinase-C at the neuromuscular junction. PMID:7881745

Kimura, I; Dezaki, K; Tsuneki, H; Kimura, M

1995-01-01

218

Lentiviral-mediated transfer of CDNF promotes nerve regeneration and functional recovery after sciatic nerve injury in adult rats  

SciTech Connect

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 promising strategy for peripheral nerve repair.

Cheng, Lei; Liu, Yi; Zhao, Hua; Zhang, Wen; Guo, Ying-Jun; Nie, Lin, E-mail: chengleiyx@126.com

2013-10-18

219

Effect of combined nicotine and shrapnel exposure on pain measures and gait after nerve injury.  

PubMed

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

Rittenhouse, Bradley; Hill-Pryor, Crystal D; McConathy, Adam; Parker, Peter; Franco, Nelson; Toussaint, Esra; Barker, Darrell; Prasad, Balakrishna; Pizarro, Jose M

2011-11-01

220

Various types of total laparoscopic nerve-sparing radical hysterectomies and their effects on bladder function  

PubMed Central

Objective This study was conducted to ascertain the correlation between preserved pelvic nerve networks and bladder function after laparoscopic nerve-sparing radical hysterectomy. Methods Between 2009 and 2011, 53 patients underwent total laparoscopic radical hysterectomies. They were categorized into groups A, B, and C based on the status of preserved pelvic nerve networks: complete preservation of the pelvic nerve plexus (group A, 27 cases); partial preservation (group B, 13 cases); and complete sacrifice (group C, 13 cases). To evaluate bladder function, urodynamic studies were conducted preoperatively and postoperatively at 1, 3, 6, and 12 months after surgery. Results No significant difference in sensory function was found between groups A and B. However, the sensory function of group C was significantly lower than that of the other groups. Group A had significantly better motor function than groups B and C. No significant difference in motor function was found between groups B and C. Results showed that the sensory nerve is distributed predominantly at the dorsal half of the pelvic nerve networks, but the motor nerve is predominantly distributed at the ventral half. Conclusion Various types of total laparoscopic nerve-sparing radical hysterectomies can be tailored to patients with cervical carcinomas. PMID:25045432

Fujiwara, Kazuko; Ebisawa, Keiko; Hada, Tomonori; Ota, Yoshiaki; Andou, Masaaki

2014-01-01

221

Temporal mismatch between pain behaviour, skin Nerve Growth Factor and intra-epidermal nerve fibre density in trigeminal neuropathic pain  

PubMed Central

Background The neurotrophin Nerve Growth factor (NGF) is known to influence the phenotype of mature nociceptors, for example by altering synthesis of neuropeptides, and changes in NGF levels have been implicated in the pathophysiology of chronic pain conditions such as neuropathic pain. We have tested the hypothesis that after partial nerve injury, NGF accumulates within the skin and causes ‘pro-nociceptive’ phenotypic changes in the remaining population of sensory nerve fibres, which could underpin the development of neuropathic pain. Results Eleven days after chronic constriction injury of the rat mental nerve the intra-epidermal nerve fibre density of the chin skin from had reduced from 11.6?±?4.9 fibres/mm to 1.0?±?0.4 fibres/mm; this slowly recovered to 2.4?±?2.0 fibres/mm on day 14 and 4.0?±?0.8 fibres/mm on day 21. Cold hyperalgesia in the ipsilateral lower lip was detectable 11 days after chronic constriction injury, although at this time skin [NGF] did not differ between sides. At 14 days post-injury, there was a significantly greater [NGF] ipsilaterally compared to contralaterally (ipsilateral?=?111?±?23 pg/mg, contralateral?=?69?±?13 pg/mg), but there was no behavioural evidence of neuropathic pain at this time-point. By 21 days post-injury, skin [NGF] was elevated bilaterally and there was a significant increase in the proportion of TrkA-positive (the high-affinity NGF receptor) intra-epidermal nerve fibres that were immunolabelled for the neuropeptide Calcitonin Gene-related peptide. Conclusions The temporal mismatch in behaviour, skin [NGF] and phenotypic changes in sensory nerve fibres indicate that increased [NGF] does not cause hyperalgesia after partial mental nerve injury, although it may contribute to the altered neurochemistry of cutaneous nerve fibres. PMID:24380503

2014-01-01

222

Limitations of nerve repair of segmental defects using acellular conduits.  

PubMed

The authors present the case of a 20-year-old man who, 3 months after his initial injury, underwent repair of a 1.7-cm defect of the ulnar nerve at the wrist; repair was performed with an acellular nerve allograft. Given the absence of clinical or electrophysiological recovery at 8 months postrepair, the patient underwent reexploration, excision of the "regenerated cable," and rerepair of the ulnar nerve with sural nerve autografts. Histology of the cable demonstrated minimal axonal regeneration at the midpoint of the repair. At the 6- and 12-month follow-ups of the sural nerve graft repair, clinical and electrophysiological evidence of both sensory and motor reinnervation of the ulnar nerve and associated hand muscles was demonstrated. In this report, the authors describe a single case of failed acellular nerve allograft and correlate the results with basic science and human studies reporting length and diameter limitations in human nerve repair utilizing grafts or conduits devoid of viable Schwann cells. PMID:23746100

Berrocal, Yerko A; Almeida, Vania W; Levi, Allan D

2013-09-01

223

Case of fibrolipomatous hamartoma of the digital nerve without macrodactyly.  

PubMed

Fibrolipomatous hamartoma of nerves without macrodactyly is a rare lesion characterized by fibrofatty proliferation causing epineural and perineural fibrosis with fatty infiltration around the nerve bundles. We report an unusual case of fibromatous hamartoma of the ulnar digital nerve of the thumb in a 43-year-old woman. Magnetic resonance imaging revealed a large fusiform mass along the nerve. The findings were unusual and pathognomonic and included a coaxial cable-like appearance on axial sections and a spaghettilike appearance on coronal sections on both T1- and T2-weighted images; these findings were useful for the diagnosis and preoperative evaluation of this lesion. Surgical exploration revealed a yellow, cordlike mass of the digital nerve enlarged by fat. Gross excision could not be done without extensive damage to the nerve. Therefore, a limited excision with biopsy of the fibrolipomatous tissue around the nerve bundles was performed. The histological appearance was consistent with fibrolipomatous hamartoma. There was no recurrence of the mass and no neurological deficit 3 years after surgery. Some authors have suggested that invasive excision can cause catastrophic sensory or motor deficits because of the extensive fatty infiltration of the nerve fascicles. In conclusion, the recommended treatment for this lesion is limited excision with only biopsy to confirm the diagnosis. PMID:22197873

Nanno, Mitsuhiko; Sawaizumi, Takuya; Takai, Shinro

2011-01-01

224

Human sensory subsystems emulator.  

PubMed

Last year this author presented his design for a computerized human nervous system function emulator for use in an android robot. This paper describes that emulator's sensory subsystems in more detail and adds new functions. Topics covered include sensor types, signal conditioning, data handling in the afferent pathways and interpretation of sensory information. Physiological sensory modalities (including: temperature, pressure, acceleration, humidity, sound and light stimuli) as well as nonphysiological (including: magnetic, radio, infrared, ultrasound and satellite GPS) are elucidated. The relationship of a primitive stimulus (i.e.: heat) to a high level sensation (i.e.: pain) is explored. PMID:11347421

Frenger, P

2001-01-01

225

Sensory Characteristics in ASD  

PubMed Central

In this paper, we review evidence regarding differences in the types of sensory experiences of persons with ASD with respect to both unisensory and multisensory processing. We discuss selfreports, carer questionnaires as well as perceptual processing differences found in the laboratory. Incoming information is processed through one or more of our senses and fundamental differences in the processing of information from any sensory modality or combination of sensory modalities are likely to have cascading effects on the way individuals with ASD experience the world around them, effects that can have both positive and negative impact on a individual with ASD’s quality of life. PMID:21264053

Stewart, Mary E.; Russo, Natalie; Banks, Jennifer; Miller, Louisa; Burack, Jacob A.

2009-01-01

226

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

PubMed Central

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

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

2008-01-01

227

Effects of dental trauma on pulpal and periodontal nerve morphology.  

PubMed

Regeneration and morphological changes in sensory peptidergic nerves in pulp and periodontium were studied after general dental trauma by means of immunohistochemistry. In control teeth also the total nerve supply was demonstrated by using antibody to the general neuronal marker, protein gene product (PGP)9.5. Two experimental rat models were used, i.e. tooth replantation and induced traumatic occlusion. Results from these studies are reviewed here. In the controls, the PGP9.5-immunoreactive(IR) nerve supply in pulp and periodontium was generally denser compared to CGRP-IR and SP-IR nerves. In the replanted teeth, regeneration of CGRP-IR nerves closely followed the pulp cell renewal. Density and distribution of the regenerated nerves showed two different patterns which seemed to depend on the capacity of the renewed pulp to form postoperative dentine. The nerve density never reached the same level as the controls. In teeth not able to form irregular dentine, the pulp was sparsely innervated and the pulp cavity was filled with innervated bone. Nerve responses in CGRP-IR and SP-IR nerves after unilateral induced traumatic occlusion in the first maxillary molar were studied at different observation periods up to 30 days. After 5 days, localized morphological nerve changes were found both in the pulp and periodontium within the total rat molar dentition. With increasing observation periods, the pulpal neural changes progressed and were extended to all pulpal areas compared to the periodontium, where the nerve responses remained localized to cervical and apical tissues throughout the experiment. PMID:1380713

Kvinnsland, I; Heyeraas, K J; Byers, M R

1992-01-01

228

A tingling sanshool derivative excites primary sensory neurons and elicits nocifensive behavior in rats  

PubMed Central

Szechuan peppers contain hydroxy-?-sanshool that imparts desirable tingling, cooling, and numbing sensations. Hydroxy-?-sanshool activates a subset of sensory dorsal root ganglion (DRG) neurons by inhibiting two-pore potassium channels. We presently investigated if a tingle-evoking sanshool analog, isobutylalkenyl amide (IBA), excites rat DRG neurons and, if so, if these neurons are also activated by agonists of TRPM8, TRPA1, and/or TRPV1. Thirty-four percent of DRG neurons tested responded to IBA, with 29% of them also responding to menthol, 29% to cinnamic aldehyde, 66% to capsaicin, and subsets responding to two or more transient receptor potential (TRP) agonists. IBA-responsive cells had similar size distributions regardless of whether they responded to capsaicin or not; cells only responsive to IBA were larger. Responses to repeated application of IBA at a 5-min interstimulus interval exhibited self-desensitization (tachyphylaxis). Capsaicin did not cross-desensitize responses to IBA to any greater extent than the tachyphylaxis observed with repeated IBA applications. These findings are consistent with psychophysical observations that IBA elicits tingle sensation accompanied by pungency and cooling, with self-desensitization but little cross-desensitization by capsaicin. Intraplantar injection of IBA elicited nocifensive responses (paw licking, shaking-flinching, and guarding) in a dose-related manner similar to the effects of intraplantar capsaicin and serotonin. IBA had no effect on thermal sensitivity but enhanced mechanical sensitivity at the highest dose tested. These observations suggest that IBA elicits an unfamiliar aversive sensation that is expressed behaviorally by the limited response repertoire available to the animal. PMID:21273322

Klein, Amanda H.; Sawyer, Carolyn M.; Zanotto, Karen L.; Ivanov, Margaret A.; Cheung, Susan; Carstens, Mirela Iodi; Furrer, Stephan; Simons, Christopher T.; Slack, Jay P.

2011-01-01

229

A tingling sanshool derivative excites primary sensory neurons and elicits nocifensive behavior in rats.  

PubMed

Szechuan peppers contain hydroxy-?-sanshool that imparts desirable tingling, cooling, and numbing sensations. Hydroxy-?-sanshool activates a subset of sensory dorsal root ganglion (DRG) neurons by inhibiting two-pore potassium channels. We presently investigated if a tingle-evoking sanshool analog, isobutylalkenyl amide (IBA), excites rat DRG neurons and, if so, if these neurons are also activated by agonists of TRPM8, TRPA1, and/or TRPV1. Thirty-four percent of DRG neurons tested responded to IBA, with 29% of them also responding to menthol, 29% to cinnamic aldehyde, 66% to capsaicin, and subsets responding to two or more transient receptor potential (TRP) agonists. IBA-responsive cells had similar size distributions regardless of whether they responded to capsaicin or not; cells only responsive to IBA were larger. Responses to repeated application of IBA at a 5-min interstimulus interval exhibited self-desensitization (tachyphylaxis). Capsaicin did not cross-desensitize responses to IBA to any greater extent than the tachyphylaxis observed with repeated IBA applications. These findings are consistent with psychophysical observations that IBA elicits tingle sensation accompanied by pungency and cooling, with self-desensitization but little cross-desensitization by capsaicin. Intraplantar injection of IBA elicited nocifensive responses (paw licking, shaking-flinching, and guarding) in a dose-related manner similar to the effects of intraplantar capsaicin and serotonin. IBA had no effect on thermal sensitivity but enhanced mechanical sensitivity at the highest dose tested. These observations suggest that IBA elicits an unfamiliar aversive sensation that is expressed behaviorally by the limited response repertoire available to the animal. PMID:21273322

Klein, Amanda H; Sawyer, Carolyn M; Zanotto, Karen L; Ivanov, Margaret A; Cheung, Susan; Carstens, Mirela Iodi; Furrer, Stephan; Simons, Christopher T; Slack, Jay P; Carstens, E

2011-04-01

230

Understanding Sensory Nerve Mechanotransduction through Localized Elastomeric Matrix Control  

Microsoft Academic Search

BackgroundWhile neural systems are known to respond to chemical and electrical stimulation, the effect of mechanics on these highly sensitive cells is still not well understood. The ability to examine the effects of mechanics on these cells is limited by existing approaches, although their overall response is intimately tied to cell-matrix interactions. Here, we offer a novel method, which we

Yi-Wen Lin; Chao-Min Cheng; Philip R. Leduc; Chih-Cheng Chen; Damien Keating

2009-01-01

231

Electromechanical tactile stimulation system for sensory vision substitution  

NASA Astrophysics Data System (ADS)

A sensory substitution device is developed in which nonretinal stimulus is used to generate input to the brain of blind people to substitute for damage or loss of retinal input. Although the final realization of this technology (direct stimulation of the corneal nerve endings) was not addressed, a device consisting of a contact lens delivering point mechanical or electrical stimulating of the corneal nerves and a camera mounted on a spectacles frame which wirelessly transmit processed image to the contact lens, translating the visual information into tactile sensation is expected to be constructed. In order to improve the spatial resolution of the constructed image, the camera will also time multiplex, compress and encode the captured image before transmitting it to the stimulating contact lens. Preliminary devices performing tactile stimulation of the fingers and of the tongue by applying point electrical stimulations, were constructed and tested. Subjects were taught to "see" using the mechanical and the electrical tactile sensory.

Zalevsky, Zeev; Elani, Gal; Azoulay, Eli; Ilani, Dan; Beiderman, Yevgeny; Belkin, Michael

2013-02-01

232

Do nerve growth factor-related mechanisms contribute to loss of cutaneous nociception in leprosy?  

PubMed

While sensory loss in leprosy skin is the consequence of invasion by M. leprae of Schwann cells related to unmyelinated fibres, early loss of cutaneous pain sensation, even in the presence of nerve fibres and inflammation, is a hallmark of leprosy, and requires explanation. In normal skin, nerve growth factor (NGF) is produced by basal keratinocytes, and acts via its high affinity receptor (trk A) on nociceptor nerve fibres to increase their sensitivity, particularly in inflammation. We have therefore studied NGF- and trk A-like immunoreactivity in affected skin and mirror-site clinically-unaffected skin from patients with leprosy, and compared these with non-leprosy, control skin, following quantitative sensory testing at each site. Sensory tests were within normal limits in clinically-unaffected leprosy skin, but markedly abnormal in affected skin. Sub-epidermal PGP 9.5- and trk A- positive nerve fibres were reduced only in affected leprosy skin, with fewer fibres contacting keratinocytes. However, NGF-immunoreactivity in basal keratinocytes, and intra-epidermal PGP 9.5-positive nerve fibres, were reduced in both sites compared to non-leprosy controls, as were nerve fibres positive for the sensory neurone specific sodium channel SNS/PN3, which is regulated by NGF, and may mediate inflammation-induced hypersensitivity. Keratinocyte trk A expression (which mediates an autocrine role for NGF) was increased in clinically affected and unaffected skin, suggesting a compensatory mechanism secondary to reduced NGF secretion at both sites. We conclude that decreased NGF- and SNS/PN3-immunoreactivity, and loss of intra-epidermal innervation, may be found without sensory loss on quantitative testing in clinically-unaffected skin in leprosy; this appears to be a sub-clinical change, and may explain the lack of cutaneous pain with inflammation. Sensory loss occurred with reduced sub-epidermal nerve fibres in affected skin, but these still showed trk A-staining, suggesting NGF treatment may restore pain sensation. PMID:10692623

Facer, P; Mann, D; Mathur, R; Pandya, S; Ladiwala, U; Singhal, B; Hongo, J; Sinicropi, D V; Terenghi, G; Anand, P

2000-03-01

233

Processing of nerve biopsies: A practical guide for neuropathologists  

PubMed Central

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

Weis, Joachim; Brandner, Sebastian; Lammens, Martin; Sommer, Claudia; Vallat, Jean-Michel

2012-01-01

234

Three-dimensional reconstruction and visualization of the median nerve from serial tissue sections.  

PubMed

The purpose of this study was to definitively implement the three-dimensional visualization of sensory and motor fascicles in the human median nerve by means of acetylcholinesterase (AChe) histochemical staining and under the assistance of the computer technology. One fresh human median nerve was harvested from a male adult cadaver. The median nerve was fixed at a special holder. Then, the whole holder was embedded and rapidly frozen in the liquid nitrogen. The processed median nerve was then cut coronally every 100 microm at a 20 microm thickness along its long axis in a sliding freezing microtome. The total number of sections was 4,650 slices. All sections were stained with the AChe histochemical method. The stained sections were scanned and saved as Joint Photographic Experts Group files. These images with positively and negatively stained sections were acquired to an Intel dual Pentium computer. The Adobe Photoshop CS2 software was used to compare the reference points of images before and after staining. The two-dimensional intraneural microstructure database of median nerve was then acquired. A software of 3D nerve visualization system was developed. With the 3D nerve visualization system, the 3D visualization result of intraneural microstructure of median nerve was created. The findings may provide more accurate and detailed anatomic information for nerve repairs, specifically for the fascicular nerve repairs. The 3D nerve visualization technique may have potential for future studies of topography of peripheral nerve. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009. PMID:19308949

Sun, Kuo; Zhang, Jian; Chen, Tongyi; Chen, Zhongwei; Chen, Zenggan; Li, Zhi; Li, Hua; Hu, Ping

2009-01-01

235

Block of AMPA receptor desensitization by a point mutation outside the ligand-binding domain.  

PubMed

Desensitization of ionotropic glutamate receptors (GluRs), specifically the AMPA receptor subtype, shapes the postsynaptic response at certain synapses in the brain. All known mechanisms that alter desensitization, either pharmacological or mutational, are associated with the ligand-binding domain. Here we report that substitution of a conserved positively charged arginine (R) with a negatively charged glutamate in the linker between the pore-forming M3 segment and the S2 lobe, a region outside the ligand-binding domain, blocks desensitization in homomeric AMPA receptors composed of GluR-B(i) subunits. A charge-reversing substitution of a glutamate adjacent to this conserved R enhanced desensitization, consistent with these effects attributable to electrostatics. Homologous substitutions of the conserved R in GluR-B(o), GluR-A(i) and the kainate receptor GluR-6 subunits produced comparable but less visible effects on desensitization. Subunit specificity was also apparent for accessibility of substituted cysteines in the M3-S2 linker, suggesting that this part of the channel is not structurally identical in different GluRs. Additionally, reactivity with a sulfhydryl-specific reagent was state dependent, suggesting that the conformations of the nonconducting closed and desensitized states are different at the level of the M3-S2 linker. Our results therefore represent the first identification of elements outside the ligand-binding domain affecting desensitization in non-NMDA receptor channels and suggest that electrostatic interactions involving charged residues in the M3-S2 linker influence channel gating in a subunit- and subtype-specific manner. PMID:15152033

Yelshansky, Maria V; Sobolevsky, Alexander I; Jatzke, Claudia; Wollmuth, Lonnie P

2004-05-19

236

Neuromorphic sensory systems.  

PubMed

Biology provides examples of efficient machines which greatly outperform conventional technology. Designers in neuromorphic engineering aim to construct electronic systems with the same efficient style of computation. This task requires a melding of novel engineering principles with knowledge gleaned from neuroscience. We discuss recent progress in realizing neuromorphic sensory systems which mimic the biological retina and cochlea, and subsequent sensor processing. The main trends are the increasing number of sensors and sensory systems that communicate through asynchronous digital signals analogous to neural spikes; the improved performance and usability of these sensors; and novel sensory processing methods which capitalize on the timing of spikes from these sensors. Experiments using these sensors can impact how we think the brain processes sensory information. PMID:20493680

Liu, Shih-Chii; Delbruck, Tobi

2010-06-01

237

Phosphorylation and desensitization of alpha1d-adrenergic receptors.  

PubMed Central

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

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

2001-01-01

238

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

PubMed

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

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

2014-01-01

239

Survival in sensitized lung transplant recipients with perioperative desensitization.  

PubMed

Donor-specific HLA antibodies (DSA) have an adverse effect on short-term and long-term lung transplant outcomes. We implemented a perioperative strategy to treat DSA-positive recipients, leading to equivalent rejection and graft survival outcomes. Pretransplant DSA were identified to HLA-A, B, C, DR and DQ antigens. DSA-positive patients were transplanted if panel reactive antibody (PRA) ?30% or medically urgent and desensitized with perioperative plasma exchange, intravenous immune globulin, antithymocyte globulin (ATG), and mycophenolic acid (MPA). PRA-positive/DSA-negative recipients received MPA. Unsensitized patients received routine cyclosporine, azathioprine and prednisone without ATG. From 2008-2011, 340 lung-only first transplants were performed: 53 DSA-positive, 93 PRA-positive/DSA-negative and 194 unsensitized. Thirty-day survival was 96 %/99%/96% in the three groups, respectively. One-year graft survival was 89%/88%/86% (p?=?0.47). DSA-positive and PRA-positive/DSA-negative patients were less likely to experience any ? grade 2 acute rejection (9% and 9% vs. 18% unsensitized p?=?0.04). Maximum predicted forced expiratory volume (1 s) (81%/74%/76%, p?=?NS) and predicted forced vital capacity (81%/77%/78%, respectively, p?=?NS) were equivalent between groups. With the application of this perioperative treatment protocol, lung transplantation can be safely performed in DSA/PRA-positive patients, with similar outcomes to unsensitized recipients. PMID:25612494

Tinckam, K J; Keshavjee, S; Chaparro, C; Barth, D; Azad, S; Binnie, M; Chow, C W; de Perrot, M; Pierre, A F; Waddell, T K; Yasufuku, K; Cypel, M; Singer, L G

2015-02-01

240

Effects of Acute Organophosphorus Poisoning on Function of Peripheral Nerves: A Cohort Study  

PubMed Central

Background Following acute organophosphorus (OP) poisoning patients complain of numbness without objective sensory abnormalities or other features of OP induced delayed polyneuropathy. The aim of this study was to measure peripheral nerve function after acute exposure to OP. Methods A cohort study was conducted with age, gender and occupation matched controls. Motor nerve conduction velocity (MNCV), amplitude and area of compound muscle action potential (CMAP), sensory nerve conduction velocity (SNCV), F- waves and electromyography (EMG) on the deltoid and the first dorsal interosseous muscles on the dominant side were performed, following acute OP poisoning. All neurophysiological assessments except EMG were performed on the controls. Assessments were performed on the day of discharge from the hospital (the first assessment) and six weeks (the second assessment) after the exposure. The controls were assessed only once. Results There were 70 patients (50 males) and 70 controls. Fifty-three patients attended for the second assessment. In the first assessment MNCV of all the motor nerves examined, CMAP amplitude and SNCV of ulnar nerve, median and ulnar F-wave occurrence in the patients were significantly reduced compared to the controls. In the second assessment significant reduction was found in SNCV of both sensory nerves examined, MNCV of ulnar nerve, CMAP amplitude of common peroneal nerve, F-wave occurrence of median and ulnar nerves. No abnormalities were detected in the patients when compared to the standard cut-off values of nerve conduction studies except F-wave occurrence. EMG studies did not show any abnormality. Conclusion There was no strong evidence of irreversible peripheral nerve damage following acute OP poisoning, however further studies are required. PMID:23185328

Jayasinghe, Sudheera S.; Pathirana, Kithsiri D.; Buckley, Nick A.

2012-01-01

241

Neuroepithelial circuit formed by innervation of sensory enteroendocrine cells.  

PubMed

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

Bohórquez, Diego V; Shahid, Rafiq A; Erdmann, Alan; Kreger, Alex M; Wang, Yu; Calakos, Nicole; Wang, Fan; Liddle, Rodger A

2015-02-01

242

Endothelium-dependent and NO-mediated desensitization to vasopressin in rat aorta.  

PubMed Central

1. The present study was performed to characterize the tachyphylaxis of rat aortae to vasopressin. Isometric tension generated by rat thoracic aorta sliced in 4 mm rings, was recorded. 2. Tension generated by intact rings increased with cumulative additions of vasopressin up to 10 nM (1.51 +/- 0.15 g). After this concentration, most rings lost their tension and relaxed to 1.09 +/- 0.17 g (P < 0.001) despite further addition of vasopressin. This tachyphylaxis was not observed in endothelium-denuded rings (from 2.87 +/- 0.12 g to 2.68 +/- 0.17 g). 3. Repeated administrations of supramaximal concentration (100 nM) of vasopressin confirmed an enhanced desensitization in intact rings, compared to endothelium-denuded rings. No desensitization to phenylephrine was observed in intact or in endothelium-denuded rings. 4. Dose-response curves to a V1 receptor agonist, [Phe2, Ile3, Orn8]-vasopressin, and to a V2 receptor agonist, [deamino-Cys1,D-Arg8]-vasopressin, were performed in intact preparations. An increase in tension, followed by a desensitization was observed with the V1 receptor agonist. In contrast, the V2 receptor agonist did not induce any response. 5. Pretreatment of intact aortic rings with the cyclo-oxygenase inhibitor, diclofenac (1 microM), did not prevent the desensitization to vasopressin. In contrast, NO synthase inhibition with NG-nitro-L-arginine (30 microM) resulted in an attenuated desensitization to vasopressin in intact rings (from 2.46 +/- 0.17 to 2.25 +/- 0.22 g, NS). 6. To confirm the involvement of NO, endothelium-denuded rings were pretreated with sodium nitroprusside (SNP). At a concentration of 10 nM, SNP induced a desensitization to vasopressin comparable with that observed in intact rings. 7. Pretreatment of endothelium-denuded rings with 8-bromo-cyclic GMP (100 microM) reduced maximum contraction to vasopressin without producing any desensitization. In contrast, guanylate cyclase inhibition with either LY 83,583 (10 microM) or methylene blue (10 microM) blocked completely the desensitization of intact rings to vasopressin. 8. The results suggest that the endothelium-dependent tachyphylaxis to vasopressin is due to rapid desensitization and is mediated by NO. However, it is unclear whether this effect of NO involves cyclic GMP. PMID:8922738

Millette, E.; Lamontagne, D.

1996-01-01

243

Characterization of the thrombin-induced desensitization of platelet activation by thrombin.  

PubMed

Brief exposure of platelets to thrombin makes them less sensitive to subsequent activation by thrombin, a phenomenon demonstrated by Shuman, Botney, and Fenton [J. Clin. Invest., 63, 1211-1218, 1979] by incubating prostacyclin-inhibited platelets with thrombin; after removal of thrombin and prostacyclin, the platelets were selectively desensitized to subsequent activation by thrombin. The conditions for this desensitization have been further defined. Inhibition of thrombin-induced platelet activation by prostacyclin was not absolute, it was only temporary, it could be overcome with higher thrombin concentrations, and it varied with platelet concentration and temperature. With low enough thrombin concentrations, high enough prostacyclin concentrations and short enough times of exposure, platelets could be pretreated with thrombin with no evidence of activation. After addition of hirudin to inhibit thrombin, the platelets were washed and tested for thrombin-induced secretion of ATP. Desensitization to thrombin depended on the concentration of thrombin during pretreatment and on the length of pretreatment, consistent with a catalytic modification of a receptor. A less extensive desensitization was observed when platelets without inhibitor were incubated with a sub-threshold level of thrombin before addition of an activating concentration of thrombin. This desensitization also varied with the time of pretreatment and the concentration of sub-threshold thrombin. PMID:6356458

McGowan, E B; Detwiler, T C

1983-07-15

244

Correlating efficacy and desensitization with GluK2 ligand-binding domain movements  

PubMed Central

Gating of AMPA- and kainate-selective ionotropic glutamate receptors can be defined in terms of ligand affinity, efficacy and the rate and extent of desensitization. Crucial insights into all three elements have come from structural studies of the ligand-binding domain (LBD). In particular, binding-cleft closure is associated with efficacy, whereas dissociation of the dimer formed by neighbouring LBDs is linked with desensitization. We have explored these relationships in the kainate-selective subunit GluK2 by studying the effects of mutating two residues (K531 and R775) that form key contacts within the LBD dimer interface, but whose truncation unexpectedly attenuates desensitization. One mutation (K531A) also switches the relative efficacies of glutamate and kainate. LBD crystal structures incorporating these mutations revealed several conformational changes that together explain their phenotypes. K531 truncation results in new dimer contacts, consistent with slower desensitization and sideways movement in the ligand-binding cleft correlating with efficacy. The tested mutants also disrupted anion binding; no chloride was detected in the dimer-interface site, including in R775A where absence of chloride was the only structural change evident. From this, we propose that the charge balance in the GluK2 LBD dimer interface maintains a degree of instability, necessary for rapid and complete desensitization. PMID:23720540

Nayeem, Naushaba; Mayans, Olga; Green, Tim

2013-01-01

245

Desensitization of enucleated cells to hormones and role of cytoskeleton in control of normal hormonal response.  

PubMed Central

Prostaglandin E1 and the beta-adrenergic hormone l-isoproterenol stimulated cyclic AMP formation in both nucleated and enucleated myeloid leukemic cells that could be induced to differentiate normally to mature cells by the macrophage- and granulocyte-inducing protein MGI (MGI+D+ cells). Enucleated as well as nucleated MGI+D+ cells also desensitized to these hormones, indicating that this desensitization is an extranuclear process. Nucleated or enucleated mutant myeloid leukemic cells that are not induced to differentiate (MGI-D- cells) were not desensitized to these hormones. The antitubulin alkaloids colchicine and vinblastine, but not the antimicrofilament compound cytochalasin B, increased the maximal hormone-induced formation of cyclic AMP in nucleated MGI+D+ cells but not in the MGI-D- cells. These alkaloids also inhibited the development of desensitization to l-isoproterenol and prostaglandin E1 in enucleated MGI+D+ cells. The results indicate that in MGI+D+ cells the cytoskeletal system puts constraints on the cells' ability to respond to these hormones and that these constraints are absent in the mutant MGI-D- cells. Because MGI+D+ but not MGI-D- cells can be induced to differentiate by the macrophage- and granulocyte-inducing protein, cytoskeletal constraints, which are also found in normal myeloid cells, may be necessary for cell competence to differentiate. The results support the suggestion that membrane cytoskeletal constraints generate may control the normal response and desensitization to membrane-mediated cell inducers. PMID:6254040

Simantov, R; Shkolnik, T; Sachs, L

1980-01-01

246

The furcal nerve revisited.  

PubMed

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

Harshavardhana, Nanjundappa S; Dabke, Harshad V

2014-08-01

247

Sensory input is required for callosal axon targeting in the somatosensory cortex  

PubMed Central

Background Sensory input is generally thought to be necessary for refining and consolidating neuronal connections during brain development. We here report that cortical callosal axons in somatosensory cortex require sensory input for their target selection in contralateral cortex. Results Eliminating sensory input to either hemisphere by unilateral transection of infraorbital nerve (ION) prevents target selection of callosal axons in contralateral cortex. Strikingly, blocking sensory input bilaterally, by simultaneously transecting both IONs, results in rescued callosal projection. In contrast, non-simultaneous bilateral ION transection has the same effect as unilateral transection. Similar results are obtained by lesion of whisker hair follicles. c-Fos-positive neurons in brain slices treated with KCl is decreased more in contralateral cortex with unilateral removal of sensory input, but decreased similarly in both cortices in mice with simultaneous bilateral removal of sensory input. Frequency of sEPSC of cortical neurons is also reduced in contralateral cortex with the unilateral removal of sensory input, but equally reduced on both sides with the bilateral removal of sensory input, suggesting that unbalanced bilateral sensory input might lead to mismatched neuronal activity between the two cortices and contribute to the formation of callosal projection. Conclusion Our data demonstrate a critical role of balanced bilateral somatosensory input in the formation of callosal connections, and thus reveal a new role of sensory input in wiring brain circuits. PMID:24305168

2013-01-01

248

Histopathological effects of radiosurgery on a human trigeminal nerve  

PubMed Central

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

Al-Otaibi, Faisal; Alhindi, Hindi; Alhebshi, Adnan; Albloushi, Monirah; Baeesa, Saleh; Hodaie, Mojgan

2013-01-01

249

Nerve and Blood Vessels  

Microsoft Academic Search

From the histologic point of view, nerves are round or flattened cords, with a complex internal structure made of myelinated\\u000a and unmyelinated nerve fibers, containing axons and Schwann cells grouped in fascicles (Fig. 4.1a) (Erickson 1997). Along the course of the nerve, fibers can traverse from one fascicle to another and fascicles can split and merge. Based\\u000a on the fascicular

Maura Valle; Maria Pia Zamorani

250

Interest of telemicrosurgery in peripheral nerve tumors: about a series of seven cases.  

PubMed

Surgery of the chronic peripheral nerve lesion should not only limit recurrence after excision, but it should also limit the sensory and motor sequelae. The aim of this work was to study the interest of telemicrosurgery to improve this result. Our series included 7 patients with peripheral nerve neuroma and tumors including two cases of hereditary neurofibromatosis. A Da Vinci S(®) robot equipped with microsurgical instruments was used for intraneural dissection. One case was performed with minimally invasive approach. At last follow-up, the pain decreased from 6/10 preoperatively to 3/10 postoperatively. The sensory deficit was stable except for two patients, whose sensory function was improved. No recurrence was noted. Telemicrosurgery seems to have two interests in the treatment of chronic peripheral nerve lesions: it reduces the size of incisions and increases the accuracy of surgery. These preliminary results suggest that surgical robots could play an essential role in microsurgery. PMID:24290701

Tigan, L; Miyamoto, H; Hendriks, S; Facca, S; Liverneaux, P

2014-02-01

251

An Evaluation of in Vivo Desensitization and Video Modeling to Increase Compliance with Dental Procedures in Persons with Mental Retardation  

ERIC Educational Resources Information Center

Fear of dental procedures deters many individuals with mental retardation from accepting dental treatment. This study was conducted to assess the effectiveness of two procedures, in vivo desensitization and video modeling, for increasing compliance with dental procedures in participants with severe or profound mental retardation. Desensitization

Conyers, Carole; Miltenberger, Raymond G.; Peterson, Blake; Gubin, Amber; Jurgens, Mandy; Selders, Andrew; Dickinson, Jessica; Barenz, Rebecca

2004-01-01

252

The Effects of Systematic Desensitization on Test-Anxious Students in an Urban Community College: Learning Theory and Applications.  

ERIC Educational Resources Information Center

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…

Woods, Nathaniel A.

253

Diabetic neuropathy: structural analysis of nerve hydration by Magnetic Resonance Spectroscopy  

SciTech Connect

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.

Griffey, R.H.; Eaton, P.; Sibbitt, R.R.; Sibbitt, W.L. Jr.; Bicknell, J.M.

1988-11-18

254

Cholecystokinin-induced desensitization of enzyme secretion in dispersed acini from guinea pig pancreas.  

PubMed

Incubating dispersed acini from guinea pig pancreas with cholecystokinin and then washing the cells to remove cholecystokinin reduced the subsequent stimulation of amylase secretion caused by pancreatic secretagogues, whose actions are mediated by release of cellular calcium (i.e., cholecystokinin, carbamylcholine, bombesin, litorin, physalaemin, and A23187), but did not alter the stimulation caused by secretagogues whose actions are mediated by cAMP (i.e., vasoactive intestinal peptide and secretin). This cholecystokinin-induced desensitization was reversible, and the onset of the process as well as its reversal were time- and temperature-dependent changes. The concentrations of cholecystokinin required to cause desensitization were greater than those required to cause maximal stimulation of amylase secretion, and this finding suggests that the submaximal stimulation of enzyme secretion seen with supramaximal concentrations of cholecystokinin may be caused by cholecystokinin-induced desensitization. PMID:6158873

Abdelmoumene, S; Gardner, J D

1980-10-01

255

Communication between neuronal somata and satellite glial cells in sensory ganglia.  

PubMed

Studies of the structural organization and functions of the cell body of a neuron (soma) and its surrounding satellite glial cells (SGCs) in sensory ganglia have led to the realization that SGCs actively participate in the information processing of sensory signals from afferent terminals to the spinal cord. SGCs use a variety ways to communicate with each other and with their enwrapped soma. Changes in this communication under injurious conditions often lead to abnormal pain conditions. "What are the mechanisms underlying the neuronal soma and SGC communication in sensory ganglia?" and "how do tissue or nerve injuries affect the communication?" are the main questions addressed in this review. PMID:23918214

Huang, Li-Yen M; Gu, Yanping; Chen, Yong

2013-10-01

256

Receptor downregulation and desensitization enhance the information processing ability of signalling receptors  

PubMed Central

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, engineering metaphors such as the ones described here could prove to be invaluable in understanding the design principles of biological systems. PMID:17996096

Shankaran, Harish; Wiley, H Steven; Resat, Haluk

2007-01-01

257

Capsaicin and sensory neurones: a historical perspective.  

PubMed

Capsaicin, the pungent ingredient of red pepper has become not only a "hot" topic in neuroscience but its new target-related unique actions have opened the door for the drug industry to introduce a new chapter of analgesics. After several lines of translational efforts with over 1,000 patents and clinical trials, the 8% capsaicin dermal patch reached the market and its long-lasting local analgesic effect in some severe neuropathic pain states is now well established. This introductory chapter outlines on one hand the historical background based on the author's 50 years of experience in this field and on the other hand emphasizes new scopes, fascinating perspectives in pharmaco-physiology, and molecular pharmacology of nociceptive sensory neurons. Evidence for the effect of capsaicin on C-polymodal nociceptors (CMH), C-mechanoinsensitive (CHMi), and silent C-nociceptors are listed and the features of the capsaicin-induced blocking effects of nociceptors are demonstrated. Common and different characteristics of nociceptor-blocking actions after systemic, perineural, local, intrathecal, and in vitro treatments are summarized. Evidence for the misleading conclusions drawn from neonatal capsaicin pretreatment is presented. Perspectives opened from cloning the capsaicin receptor "Transient Receptor Potential Vanilloid 1" (TRPV1) are outlined and potential molecular mechanisms behind the long-lasting functional, ultrastructural, and nerve terminal-damaging effects of capsaicin and other TRPV1 agonists are summarized. Neurogenic inflammation and the long-list of "capsaicin-sensitive" tissue responses are mediated by an unorthodox dual sensory-efferent function of peptidergic TRPV1-expressing nerve terminals which differ from the classical efferent and sensory nerve endings that have a unidirectional role in neuroregulation. Thermoregulatory effects of capsaicin are discussed in detail. It is suggested that since hyperthermia and burn risk due to enhanced noxious heat threshold are the major obstacles of some TRPV1 antagonists, they could be overcome. The special "multisteric" gating function of the TRPV1 cation channel provides the structural ground for blocking chemical activation of TRPV1 without affecting its responsiveness to physical stimuli. A new chapter of potential analgesics targeting nociceptors is now already supported for pain relief in persistent pathological pain states. PMID:24941663

Szolcsányi, János

2014-01-01

258

Nerve conduction velocity study of the upper limb in Raynaud's phenomenon.  

PubMed

A prospective study of upper limb nerve conduction velocity was performed in 39 subjects (9 males, 30 females, mean age 46.8 years) with idiopathic Raynaud's phenomenon (RP) and 18 patients (3 males, 15 females, mean age 49.9 years) with RP secondary to systemic sclerosis (SS). Five subjects with idiopathic RP (13%) showed slowing of sensory conduction velocity (SCV) of the distal median nerve, associated with delayed distal motor latency (DML) of the same nerve in three patients, without clinical signs or symptoms of carpal tunnel syndrome (CTS). Three patients with secondary RP (17%) had reduction of SCV of the distal median nerve, associated with increased DML of the same nerve in one and with clinically silent slowing of SCV of the ulnar nerve in two (11%). Mean distal SCVs of the median nerve were significantly lower and mean DMLs were significantly higher in both groups with respect to a control group. Mean distal conduction of the ulnar nerve was significantly slower only in the group with secondary RP. No slowing was observed in the proximal part of any nerve. It seems likely that patients with idiopathic RP have slowing of conduction in the distal part of the median nerve, along the carpal tunnel. Since slowing does not occur in all parts of the nerves of the hand, it cannot be related to acral vasomotor disturbances, but to local or systemic factors. In contrast, patients with secondary RP had slowing of median and ulnar nerve conduction velocity, presumably related to subclinical distal peripheral neuropathy. A nerve conduction study of the hand could be useful in cases of suspected secondary origin of RP. In idiopathic RP, slowing of conduction may only affect the median nerve, whereas in secondary RP it may affect other nerves of the hand. PMID:10984133

Mondelli, M; Romano, C; De Stefano, R; Cioni, R

2000-01-01

259

AAEM case report #25: anterior interosseous nerve syndrome.  

PubMed

A case study is reported regarding a 57-year-old woman, chose chief complaint was weakness in her thumb that she had noted while gardening. The patient described difficulty pulling weeds out because of an inability to get a firm grip when using the thumb. Physical examination showed weakness of the flexor pollicis longus and flexor digitorum profundus to the index finger. There was no other weakness and no clinical sensory deficit. Electrodiagnostic studies revealed normal median motor and sensory nerve conduction studies with needle examination abnormalities noted only in the flexor pollicis longus, flexor digitorum profundus, and pronator quadratus. The literature on anterior interosseous nerve syndrome (AINS) is reviewed. It is important to differentiate those with idiopathic AINS as part of a neuralgic amyotrophy picture from those with an anatomic cause such as a fibrous band or anomalous muscle. Electrodiagnostic examination can be useful to help make this distinction. PMID:1518518

Wertsch, J J

1992-09-01

260

GLIAL RESPONSES AFTER CHORDA TYMPANI NERVE INJURY  

PubMed Central

The chorda tympani (CT) nerve innervates lingual taste buds and is susceptible to damage during dental and inner ear procedures. Interruption of the CT results in a disappearance of taste buds, which can be accompanied by taste disturbances. Because the CT usually regenerates to reinnervate taste buds successfully in a few weeks, a persistence of taste disturbances may indicate alterations in central nervous function. Peripheral injury to other sensory nerves leads to glial responses at central terminals, which actively contribute to abnormal sensations arising from nerve damage. Therefore, the current study examined microglial and astrocytic responses in the first central gustatory relay -the nucleus of the solitary tract (nTS)- after transection of the CT. Damage to the CT resulted in significant microglial responses in terms of morphological reactivity and an increased density of microglial cells from 2-20 days after injury. This increased microglial population primarily resulted from microglial proliferation from 1.5-3 days, which was supplemented by microglial migration within sub-divisions of the nTS between days 2-3. Unlike other nerve injuries, CT injury did not result in recruitment of bone marrow-derived precursors. Astrocytes also reacted in the nTS with increased levels of GFAP by 3 days, although none showed evidence of cell division. GFAP levels remained increased at 30 days by which time microglial responses had resolved. These results show that nerve damage to the CT results in central glial responses, which may participate in long lasting taste alterations following CT lesion. PMID:22315167

Bartel, Dianna L.

2013-01-01

261

Morphology and Intrinsic Excitability of Regenerating Sensory and Motor Neurons Grown on a Line Micropattern  

PubMed Central

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

Benzina, Ouafa; Cloitre, Thierry; Martin, Marta; Raoul, Cédric; Gergely, Csilla; Scamps, Frédérique

2014-01-01

262

[Nerve sheath tumours].  

PubMed

Peripheral nerve sheath tumors are common neoplasms in daily practice. Diagnosis and classification of most conventional peripheral nerve sheath tumors are relatively straightforward for the experienced observer; but on occasion, they are diagnostically challenging (especially with locally aggressive and malignant tumors). This article aims to provide an update of the data (clinical, histological, immunohistochemistry and genomic) of benign, intermediate and malignant peripheral nerve sheath tumors, thanks to the latest WHO "Classification of Tumors of Soft Tissue and Bone", published in 2013, which includes a new chapter on "Nerve Sheath Tumors". Advances in molecular biology have provided new insights into the nature of the various peripheral nerve sheath tumors, and have begun to suggest novel targeted therapeutic approaches. PMID:25541115

Le Guellec, Sophie

2015-01-01

263

Biological Actions of Nerve Growth Factor in the Peripheral Nervous System  

Microsoft Academic Search

Since the discovery of nerve growth factor (NGF), its role in the physiology\\/pathophysiology of nerve function has been under intense investigation. More recently, the potential of recombinant human NGF (rhNGF) as a putative treatment for peripheral neuropathies, in particular diabetic polyneuropathy and HIV-associated sensory neuropathy, is being explored. In animal models of diabetes, depletion of endogenous NGF levels has been

Cynthia A. Rask

1999-01-01

264

Detecting acute neurotoxicity during platinum chemotherapy by neurophysiological assessment of motor nerve hyperexcitability  

Microsoft Academic Search

BACKGROUND: Platinum-based drugs, such as cisplatin and oxaliplatin, are well-known for inducing chronic sensory neuropathies but their acute and motor neurotoxicities are less well characterised. Use was made of nerve conduction studies and needle electromyography (EMG) to assess motor nerve excitability in cancer patients during their first treatment cycle with platinum-based chemotherapy in this study. METHODS: Twenty-nine adult cancer patients

Andrew Hill; Peter Bergin; Fritha Hanning; Paul Thompson; Michael Findlay; Dragan Damianovich; Mark J McKeage

2010-01-01

265

Distribution of galanin-immunoreactive nerve fibers in the rat nasal mucosa.  

PubMed

Galanin-like immunoreactivity was found in nerve fibers beneath and within the epithelium of the rat mucosa by the use of immunohistochemical techniques. Immunoreactive fibers were also noted close to blood vessels and seromucous glands in the lamina propria. Fast blue applied to the nasal mucosa underwent retrograde transport to some immunoreactive neurons of the trigeminal ganglion. Thus, the rat nasal mucosa was shown to be innervated by galanin-containing sensory nerves. PMID:1707721

Matsuda, Y; Inagaki, S; Nakai, Y; Takagi, H

1990-12-17

266

Hydrophilic Polymers Enhance Early Functional Outcomes after Nerve Autografting  

PubMed Central

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

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

267

Why Are Sensory Axons More Vulnerable for Ischemia than Motor Axons?  

PubMed Central

Objective In common peripheral neuropathies, sensory symptoms usually prevail over motor symptoms. This predominance of sensory symptoms may result from higher sensitivity of sensory axons to ischemia. Methods We measured median nerve compound sensory action potentials (CSAPs), compound muscle action potentials (CMAPs), and excitability indices in five healthy subjects during forearm ischemia lasting up to disappearance of both CSAPs and CMAPs. Results Ischemia induced: (1) earlier disappearance of CSAPs than CMAPs (mean ± standard deviation 30±5 vs. 46±6 minutes), (2) initial changes compatible with axonal depolarization on excitability testing (decrease in threshold, increase in strength duration time constant (SDTC) and refractory period, and decrease in absolute superexcitability) which were all more prominent in sensory than in motor axons, and (3) a subsequent decrease of SDTC reflecting a decrease in persistent Na+ conductance during continuing depolarisation. Interpretation Our study shows that peripheral sensory axons are more vulnerable for ischemia than motor axons, with faster inexcitability during ischemia. Excitability studies during ischemia showed that this was associated with faster depolarization and faster persistent Na+ channel inactivation in sensory than in motor axons. These findings might be attributed to differences in ion channel composition between sensory and motor axons and may contribute to the predominance of sensory over motor symptoms in common peripheral neuropathies. PMID:23840596

Hofmeijer, Jeannette; Franssen, Hessel; van Schelven, Leonard J.; van Putten, Michel J. A. M.

2013-01-01

268

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

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

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

269

Stretch-induced nerve injury: a proposed technique for the study of nerve regeneration and evaluation of the influence of gabapentin on this model.  

PubMed

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

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

2013-11-01

270

Environmental Awareness (Sensory Awareness).  

ERIC Educational Resources Information Center

Capitalizing on the resources available within a city block, this resource guide for the emotionally handicapped (K-6) describes methods and procedures for developing sensory awareness in the urban out-of-doors. Conceptual focus is on interdependency ("living things are interdependent"). Involvement in the environment (observing, thinking, doing)…

Carpenter, Marian

271

Recording Sensory Words  

ERIC Educational Resources Information Center

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…

Ashbrook, Peggy

2007-01-01

272

Structured Sensory Trauma Interventions  

ERIC Educational Resources Information Center

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…

Steele, William; Kuban, Caelan

2010-01-01

273

Blockade of Nerve Sprouting and Neuroma Formation Markedly Attenuates the Development of Late Stage Cancer Pain  

PubMed Central

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

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

274

Effect of sensory stimulation (acupuncture) on sympathetic and parasympathetic activities in healthy subjects  

Microsoft Academic Search

It has been postulated that sensory stimulation (acupuncture) affects the cardiovascular system via the autonomic nervous system. Previously, skin temperature, thermography, plethysmography and blood pressure changes have been used in evaluation of sympathetic nerve activity following acupuncture. By using power spectral analysis, the low frequency and high frequency components of heart rate variability can be calculated reflecting the sympathetic and

Eva Haker; Henrik Egekvist; Peter Bjerring

2000-01-01

275

Electrophysiological characterisation of motor and sensory tracts in patients with hereditary spastic paraplegia (HSP)  

PubMed Central

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

2013-01-01

276

Understanding Sensory Integration. ERIC Digest.  

ERIC Educational Resources Information Center

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…

DiMatties, Marie E.; Sammons, Jennifer H.

277

Sensory Integration in Mental Health  

Microsoft Academic Search

Lorna Jean King is interviewed concerning the present status of sensory integration as a treatment modality in the area of mental health. Topics covered are: use of sensory integration techniques with adults and adolescents in both chronic and acute mental health settings; goals and expected outcomes of using sensory integration techniques; cost-effectiveness of these techniques; differences between occupational therapy and

Barbara W. Posthuma

1983-01-01

278

Sensory analysis of lipstick.  

PubMed

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

Yap, K C S; Aminah, A

2011-06-01

279

Spontaneous nerve torsion: unusual cause of radial nerve palsy.  

PubMed

Spontaneous nerve torsion is a rare cause of nerve palsy. We describe a case of nerve torsion affecting the radial nerve in order to inform radiologists of the existence of this condition and subtle features on cross-sectional imaging that can suggest the diagnosis preoperatively. PMID:25244923

Endo, Yoshimi; Miller, Theodore T; Carlson, Erik; Wolfe, Scott W

2015-03-01

280

Somatomotor and sensory urethral control of micturition in female rats.  

PubMed

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

Cruz, Yolanda; Pastelín, César; Balog, Brian M; Zaszczurynski, Paul J; Damaser, Margot S

2014-12-01

281

Advances in nerve repair.  

PubMed

Patients with peripheral nerve injuries face unpredictable and often suboptimal functional outcome, even following standard microsurgical nerve repair. The challenge of improving such outcomes following nerve surgical procedures has interested many research teams, in both clinical and fundamental fields. Some innovative treatments are presently being applied to a widening range of patients, whereas others will require further development before translation to human subjects. This article presents several recent advances in emerging therapies at various stages of clinical application. Nerve transfers have been successfully used in clinical settings, but new indications are being described, enlarging the range of patients who might benefit from them. Brief direct nerve electrical stimulation has been shown to improve nerve regeneration and outcome in animal models and in a small cohort of patients. Further clinical trials are warranted to prove the efficacy of this exciting and easily applicable approach. Animal studies also suggest a tremendous potential for stem and precursor cell therapy. Further studies will lead to a better understanding of their mechanisms of action in nerve repair and potential applications for human patients. PMID:23250767

Khuong, Helene T; Midha, Rajiv

2013-01-01

282

Changes in nerve microcirculation following peripheral nerve compression?  

PubMed Central

Following peripheral nerve compression, peripheral nerve microcirculation plays important roles in regulating the nerve microenvironment and neurotrophic substances, supplying blood and oxygen and maintaining neural conduction and axonal transport. This paper has retrospectively analyzed the articles published in the past 10 years that addressed the relationship between peripheral nerve compression and changes in intraneural microcirculation. In addition, we describe changes in different peripheral nerves, with the aim of providing help for further studies in peripheral nerve microcirculation and understanding its protective mechanism, and exploring new clinical methods for treating peripheral nerve compression from the perspective of neural microcirculation. PMID:25206398

Gao, Yueming; Weng, Changshui; Wang, Xinglin

2013-01-01

283

Anterior interosseous nerve syndrome  

PubMed Central

Objective: We sought to determine lesion sites and spatial lesion patterns in spontaneous anterior interosseous nerve syndrome (AINS) with high-resolution magnetic resonance neurography (MRN). Methods: In 20 patients with AINS and 20 age- and sex-matched controls, MRN of median nerve fascicles was performed at 3T with large longitudinal anatomical coverage (upper arm/elbow/forearm): 135 contiguous axial slices (T2-weighted: echo time/repetition time 52/7,020 ms, time of acquisition: 15 minutes 48 seconds, in-plane resolution: 0.25 × 0.25 mm). Lesion classification was performed by visual inspection and by quantitative analysis of normalized T2 signal after segmentation of median nerve voxels. Results: In all patients and no controls, T2 lesions of individual fascicles were observed within upper arm median nerve trunk and strictly followed a somatotopic/internal topography: affected were those motor fascicles that will form the anterior interosseous nerve further distally while other fascicles were spared. Predominant lesion focus was at a mean distance of 14.6 ± 5.4 cm proximal to the humeroradial joint. Discriminative power of quantitative T2 signal analysis and of qualitative lesion rating was high, with 100% sensitivity and 100% specificity (p < 0.0001). Fascicular T2 lesion patterns were rated as multifocal (n = 17), monofocal (n = 2), or indeterminate (n = 1) by 2 independent observers with strong agreement (kappa = 0.83). Conclusion: It has been difficult to prove the existence of fascicular/partial nerve lesions in spontaneous neuropathies using clinical and electrophysiologic findings. With MRN, fascicular lesions with strict somatotopic organization were observed in upper arm median nerve trunks of patients with AINS. Our data strongly support that AINS in the majority of cases is not a surgically treatable entrapment neuropathy but a multifocal mononeuropathy selectively involving, within the main trunk of the median nerve, the motor fascicles that continue distally to form the anterior interosseous nerve. PMID:24415574

Bäumer, Philipp; Meinck, Hans-Michael; Schiefer, Johannes; Weiler, Markus; Bendszus, Martin; Kele, Henrich

2014-01-01

284

Acute motor and sensory polyganglioradiculoneuritis in a cat: clinical and histopathological findings.  

PubMed

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

Gutierrez-Quintana, Rodrigo; Cuesta-Garcia, Nerea; Wessmann, Annette; Johnston, Pamela; Penderis, Jacques

2015-02-01

285

Reversible acute axonal polyneuropathy associated with Wernicke-Korsakoff syndrome: impaired physiological nerve conduction due to thiamine deficiency?  

PubMed

Acute axonal polyneuropathy and Wernicke-Korsakoff encephalopathy developed simultaneously in three patients. Nerve conduction studies (NCS) detected markedly decreased compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs) with minimal conduction slowing; sympathetic skin responses (SSRs) were also notably decreased. Sural nerve biopsies showed only mild axonal degeneration with scattered myelin ovoid formation. The symptoms of neuropathy lessened within two weeks after an intravenous thiamine infusion. CMAPs, SNAPs, and SSRs also increased considerably. We suggest that this is a new type of peripheral nerve impairment: physiological conduction failure with minimal conduction delay due to thiamine deficiency. PMID:12700319

Ishibashi, S; Yokota, T; Shiojiri, T; Matunaga, T; Tanaka, H; Nishina, K; Hirota, H; Inaba, A; Yamada, M; Kanda, T; Mizusawa, H

2003-05-01

286

The Systematic Desensitization of High Debilitating Test Anxious College Students by Relaxation and Assertion.  

ERIC Educational Resources Information Center

The present study compared the effects of assertion with that of progressive relaxation training in systematic desensitization. Nineteen Ss were selected on the basis of exemplifying high debilitating test anxiety according to Alpert and Haber's (1960) Achievement Anxiety Test. Results showed that test anxious Ss who received either relaxation or…

Parker, Paul J.

287

Desensitization and Modeling Treatments of Spider Fear Using Two Types of Scenes  

ERIC Educational Resources Information Center

Three types of therapy were combined with two types of scenes. Spider-phobic subjects were assigned to one of the six treatment conditions or to an untreated control group. In general, (a) Desensitization and modeling therapies were equally effective; (b) modeling alone was more effective than mere exposure to the phobic object. (Author)

Denney, Douglas R.; Sullivan, Bernard J.

1976-01-01

288

Mood Regulation, Dreaming and Nightmares: Evaluation of a Desensitization Function for REM Sleep  

Microsoft Academic Search

This paper is an evaluation of the hypothesis that REM sleep and dreaming serve a mood regulatory function, in particular, that they desensitize affect. There is presently experimental evidence that daytime mood influences REM sleep and dreaming and that the latter, in turn, influence daytime mood. It is suggested that these interrelationships may be better understood using a modified behavioral

Michael L. Perlis; Tore A. Nielsen

1993-01-01

289

Accelerated Desensitization and Adaptive Attitudes Interventions and Test Gains with Academic Probation Students  

ERIC Educational Resources Information Center

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…

Driscoll, Richard; Holt, Bruce; Hunter, Lori

2005-01-01

290

Eye Movement Desensitization and Reprocessing in Addiction Continuing Care: A Phenomenological Study of Women in Recovery  

Microsoft Academic Search

Traditional models of addiction treatment and relapse prevention fail to consider the role that unresolved trauma plays in an addicted woman's recovery experience. Implementing Eye Movement Desensitization and Reprocessing (EMDR) into the treatment process offers a potential solution to this problem. Ten women (alumnae of an extended-care treatment facility) participated in a semistandardized interview to share their experiences with active

Jamie Marich

2010-01-01

291

A Review of Eye Movement Desensitization and Reprocessing (EMDR): Research Findings and Implications for Counsellors.  

ERIC Educational Resources Information Center

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…

MacCluskie, Kathryn C.

1998-01-01

292

Using Eye Movement Desensitization and Reprocessing To Enhance Treatment of Couples.  

ERIC Educational Resources Information Center

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…

Protinsky, Howard; Sparks, Jennifer; Flemke, Kimberly

2001-01-01

293

Science and pseudoscience in the development of eye movement desensitization and reprocessing  

Microsoft Academic Search

The enormous popularity recently achieved by Eye Movement Desensitization and Reprocessing (EMDR) as a treatment for anxiety disorders appears to have greatly outstripped the evidence for its efficacy from controlled research studies. The disparity raises disturbing questions concerning EMDR's aggressive commercial promotion and its rapid acceptance among practitioners. In this article, we: (1) summarize the evidence concerning EMDR's efficacy; (2)

James D. Herbert; Scott O. Lilienfeld; Jeffrey M. Lohr; Robert W Montgomery; William T O'Donohue; Gerald M Rosen; David F Tolin

2000-01-01

294

Efficacy of the eye movement desensitization procedure in the treatment of traumatic memories  

Microsoft Academic Search

The aim of the study was to determine the effectiveness of the recently developed Eye Movement Desensitization (EMD) procedure on traumatic memory symptomatology. Twenty-two subjects suffering from symptoms related to traumatic memories were used in the study. All had been victims of traumatic incidents concerning the Vietnam War, childhood sexual molestation, sexual or physical assault, or emotional abuse. Memories of

Francine Shapiro

1989-01-01

295

Modified desensitization protocols for a pediatric patient with anaphylactic reaction to deferoxamine.  

PubMed

Thalassemia major is an inherited form of chronic hemolytic anemia that results in iron overload due to regular blood transfusions. Deferoxamine is used as chelating agentfor treatment ofpatients with chronic iron overload worldwide. Anaphylactic reaction to deferoxamine is rare, and the mechanism ofdeferoxamine-induced anaphylaxis is not well understood. Only afewpediatric cases ofsuccessful desensitization for deferoxamine hypersensitivity have been described, and a different protocol has been used in each report. We report a case ofanaphylaxis to deferoxamine in a thirteen-years-old Thai boy with Hemoglobin E/?-thalassemia disease who underwent successful desensitization. He had been receiving blood transfusions since the age often months. At age eleven, the patient began treatment with deferoxamine. Treatment was interrupted after the occurrence ofanaphylaxis, with urticaria, wheezing and gastrointestinal symptoms. A skin prick test was positive, indicating a type 1 hypersensitivity reaction. Deferoxamine desensitization was attempted with various differentprotocols. Finally, the patient could tolerate deferoxamine therapy at the dose previously administered. We proposed this modified subcutaneous desensitization protocolforpediatric cases that develop allergic reactions to deferoxamine. PMID:25518318

Surapolchai, Pacharapan; Poachanukoon, Orapan; Satayasai, Wallee; Silapamongkonkul, Pakatip

2014-08-01

296

Exposure to Violent Video Games and Desensitization to Violence in Children and Adolescents  

Microsoft Academic Search

Entertainment computing is central to the leisure activities of many Americans, with a remarkable array of choices now available to the average person. Video and computer games, in particular violent games, are especially popular, even with relatively young children. With this popularity, concern has been raised about possible unintended consequences of participation in interactive violence. Desensitization to violence has been

Jeanne B. Funk

2006-01-01

297

The effect of video game violence on physiological desensitization to real-life violence  

Microsoft Academic Search

Past research shows that violent video game exposure increases aggressive thoughts, angry feelings, physiological arousal, aggressive behaviors, and decreases helpful behaviors. However, no research has experimentally examined violent video game effects on physiological desensitization, defined as showing less physiological arousal to violence in the real world after exposure to video game violence in the virtual world. This experiment attempts to

Nicholas L. Carnagey; Craig A. Anderson; Brad J. Bushman

2007-01-01

298

The eVect of video game violence on physiological desensitization to real-life violence  

Microsoft Academic Search

Past research shows that violent video game exposure increases aggressive thoughts, angry feelings, physiological arousal, aggressive behaviors, and decreases helpful behaviors. However, no research has experimentally examined violent video game eVects on physiologi- cal desensitization, deWned as showing less physiological arousal to violence in the real world after exposure to video game violence in the virtual world. This experiment attempts

Nicholas L. Carnagey; Craig A. Anderson; Brad J. Bushman

2006-01-01

299

Treatment of Specific Phobias with Eye Movement Desensitization and Reprocessing (EMDR)  

Microsoft Academic Search

This paper considers the current empirical status of Eye Movement Desensitization and Reprocessing (EMDR) as a treatment method for specific phobias, along with some conceptual and practical issues in relation to its use. Both uncontrolled and controlled studies on the application of EMDR with specific phobias demonstrate that EMDR can produce significant improvements within a limited number of sessions. With

A. De Jongh; E. Ten Broeke; M. R. Renssen

1999-01-01

300

Prolonged Exposure versus Eye Movement Desensitization and Reprocessing (EMDR) for PTSD rape victims  

Microsoft Academic Search

This controlled study evaluated the relative efficacy of Prolonged Exposure (PE) and Eye Movement Desensitization and Reprocessing (EMDR) compared to a no-treatment waitlist control (WAIT) in the treatment of PTSD in adult female rape victims (n = 74). Improvement in PTSD as assessed by blind independent assessors, depression, dissociation, and state anxiety was significantly greater in both the PE and

Barbara Olasov Rothbaum; Millie C. Astin; Fred Marsteller

2005-01-01

301

Nicotinic acetylcholine receptor desensitization is regulated by activation-induced extracellular adenosine accumulation.  

PubMed

Adenosine modulation of nicotinic ACh receptor (nAChR) function was studied in primary cultures of rat skeletal muscle. Activation of the nAChR by carbachol increased extracellular adenosine concentration in a dose-dependent manner. Furthermore, carbachol activation of the nicotinic receptor resulted in a twofold increase in cAMP levels in the muscle cells. The carbachol-dependent increase in cAMP levels was inhibited by adenosine receptor antagonists as well as by nicotinic receptor antagonists. These results suggest that the increased cAMP levels were due to adenosine receptor activation by the extracellular adenosine accumulated on nAChR activation. Others have shown that desensitization of the nAChR by agonist is mediated, in part, by phosphorylation. Since we found that nicotinic cholinergic agonists also cause adenosine accumulation with concomitant cAMP increases, we determined whether the accumulated adenosine has a role in desensitization. We found that the adenosine receptor antagonist, BW1434U, significantly inhibited carbachol-induced nAChR desensitization, indicating that extracellular adenosine is involved in nAChR desensitization. Our data suggest that nAChR function is regulated via a feedback mechanism mediated by adenosine released from muscle on activation of the nAChR. PMID:1331363

Pitchford, S; Day, J W; Gordon, A; Mochly-Rosen, D

1992-11-01

302

The Use of In Vivo Desensitization as Part of a Total Therapeutic Intervention  

ERIC Educational Resources Information Center

The use of in vivo and imaginal desensitization procedures for treatment of a fear of flying in airplanes is described. The direct benefits of the program, along with the positive effects it had upon progress on a series of other, equally troublesome presenting problems is discussed. (Author)

Bernstein, Douglas A.; Beaty, William E.

1971-01-01

303

Laminin-based Nanomaterials for Peripheral Nerve Tissue Engineering  

NASA Astrophysics Data System (ADS)

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 supported by nerve conduction studies and electromyography which described impulse transmission, muscle stimulation, and foot twitch through the region of regeneration. These studies provide a firm foundation for the use of natural-synthetic blend electrospun nanofibers to enhance existing hollow nerve guidance conduits. The similarity in surgical technique and obvious benefit to the patient should lead to rapid translation into clinical application.

Neal, Rebekah Anne

304

[Transplantation of nerve tissue].  

PubMed

The results of transplantation of various parts of the central and peripheral nervous system are considered. Transplantation of nerve trunks is used clinically, and heterogenous regeneration of the nerves results in reinnervation of tissues and organs. The spinal ganglion transplantation is successfully used in experiments with both embryonic and mature differentiated neurons. Transplantation of different parts of the cortex, some subcortical structures, hyppocampus, hypothalamus, cerebellum and the spinal cord is made using immature neurons. Some attempts have been made to transplant the nerve tissue grown in vitro into a host. PMID:6998434

Chumasov, E I; Chalisova, N I

1980-01-01

305

Suprascapular nerve entrapment.  

PubMed

It is important to be aware of neuropathy involving the suprascapular nerve. While direct trauma to the suprascapular nerve is the usual cause (direct blow to the base of the neck or posterior shoulder, shoulder dislocation or fracture), the problem may result from overuse injuries (such as repetitive tennis serving or spiking of a volley ball), excessive horizontal adduction, weight lifting, backpacking or no apparent reason. These last three years we have operated 8 cases of suprascapular nerve neurolysis at the level of suprascapular incision, and section of the transverse scapular ligament through the back supraspinal approach. PMID:15830964

Corò, L; Azuelos, A; Alexandre, A

2005-01-01

306

Carboxyl-terminal Domain of Transient Receptor Potential Vanilloid 1 Contains Distinct Segments Differentially Involved in Capsaicin- and Heat-induced Desensitization*  

PubMed Central

Multiple Ca2+-dependent processes are involved in capsaicin-induced desensitization of transient receptor potential vanilloid 1 (TRPV1), but desensitization of TRPV1 by heat occurs even in the absence of extracellular Ca2+, although the mechanisms are unknown. In this study, we tested the hypothesis that capsaicin and heat desensitize TRPV1 through distinct mechanisms involving distinct structural segments of TRPV1. In HEK293 cells that heterologously express TRPV1, we found that heat-induced desensitization was not affected by the inclusion of intracellular ATP or alanine mutation of Lys155, both of which attenuate capsaicin-induced desensitization, suggesting that heat-induced desensitization occurs through mechanisms distinct from capsaicin-induced desensitization. To determine protein domains involved in heat-induced desensitization, we generated chimeric proteins between TRPV1 and TRPV3, a heat-gated channel lacking heat-induced desensitization. We found that TRPV1 with the carboxyl-terminal domain (CTD) of TRPV3 retained heat activation but was impaired in heat-induced desensitization. Further experiments using chimeric or deletion mutants within TRPV1 CTD indicated that the distal half of CTD regulates the activation and desensitization of TRPV1 in modality-specific manners. Within the distal CTD, we identified two segments that distinctly regulated capsaicin- and heat-induced desensitization. The results suggest that the activation and desensitization of TRPV1 by capsaicin and heat can be modulated differentially and disproportionally through different regions of TRPV1 CTD. Identifying the domains involved in thermal regulation of TRPV1 may facilitate the development of novel anti-hyperalgesic approaches aimed at attenuating activation and enhancing desensitization of TRPV1 by thermal stimuli. PMID:24174527

Joseph, John; Wang, Sen; Lee, Jongseok; Ro, Jin Y.; Chung, Man-Kyo

2013-01-01

307

The Sciatic Nerve Cuffing Model of Neuropathic Pain in Mice  

PubMed Central

Neuropathic pain arises as a consequence of a lesion or a disease affecting the somatosensory system. This syndrome results from maladaptive changes in injured sensory neurons and along the entire nociceptive pathway within the central nervous system. It is usually chronic and challenging to treat. In order to study neuropathic pain and its treatments, different models have been developed in rodents. These models derive from known etiologies, thus reproducing peripheral nerve injuries, central injuries, and metabolic-, infectious- or chemotherapy-related neuropathies. Murine models of peripheral nerve injury often target the sciatic nerve which is easy to access and allows nociceptive tests on the hind paw. These models rely on a compression and/or a section. Here, the detailed surgery procedure for the "cuff model" of neuropathic pain in mice is described. In this model, a cuff of PE-20 polyethylene tubing of standardized length (2 mm) is unilaterally implanted around the main branch of the sciatic nerve. It induces a long-lasting mechanical allodynia, i.e., a nociceptive response to a normally non-nociceptive stimulus that can be evaluated by using von Frey filaments. Besides the detailed surgery and testing procedures, the interest of this model for the study of neuropathic pain mechanism, for the study of neuropathic pain sensory and anxiodepressive aspects, and for the study of neuropathic pain treatments are also discussed. PMID:25078668

Yalcin, Ipek; Megat, Salim; Barthas, Florent; Waltisperger, Elisabeth; Kremer, Mélanie; Salvat, Eric; Barrot, Michel

2014-01-01

308

Median Nerve Injuries Caused by Carpal Tunnel Injections  

PubMed Central

Local steroid injections are widely used for diagnostic and therapeutic purposes in the management of carpal tunnel syndrome. The median nerve injury is the most serious complication in association with carpal tunnel injections although the incidence is low. A median nerve injury will be presented with shooting pain at the injection time along with other sensory distortion, motor weakness and muscle atrophy. The management includes a conservative treatment and a surgical exploration. Carpal tunnel injections should be used at a minimum only. If such steroid injection is required, an appropriate needle positioning is vital for the nerve injury prevention. The patient should not be heavily sedated and should be encouraged to inform experiences of numbness/paresthesia during the procedure immediately. PMID:24748938

Kim, Hyun Jung

2014-01-01

309

Desensitization of vascular response in vivo: Contribution of genetic variation in the alpha2B-adrenergic receptor subtype  

PubMed Central

OBJECTIVES Vascular alpha2B adrenergic receptors (?2B-ARs) mediate vasoconstriction and contribute to peripheral regulation of vascular tone. In vitro, a common 301-303 deletion in the ?2B-AR gene, ADRA2B, results in loss of ?2B-AR desensitization. We examined the hypothesis that ADRA2B del301-303 or other common ADRA2B variants alter vascular desensitization in vivo. METHODS We measured sensitivity to a highly selective ?2-AR agonist, dexmedetomidine, (0.01–1000 ng/min) in the dorsal hand vein in 41 healthy subjects. To induce desensitization a dose of dexmedetomidine that resulted in submaximal constriction was infused for 180 minutes and dorsal hand vein responses measured. Desensitization was defined as the ratio between the area-under-the-effect curve for each individual’s response, and the hypothetical area-under-the-effect curve assuming that the initial response had been maintained for 180 minutes (ratio below 1 reflecting desensitization). The relationship between six ADRA2B variants (1 promoter, 3 coding, and 2 in the 3? UTR) with an allele frequency > 5% and desensitization was determined. RESULTS Forty-one subjects (22 men, 21 whites, age 18-45 years) were studied. The ADRA2B 301-303 deletion allele (ins/del and del/del, n=18) was associated with resistance to desensitization [1.01 (IQR 0.90-1.06)] compared to ins/ins homozygous subjects (n=23) [0.91 (IQR 0.73-0.99)], p=0.026. In addition, the ?98 GG, 1182 CC, and 1776 CC genotypes were associated with significantly less desensitization than GC or CC, and CA or AA genotypes, respectively. CONCLUSION Common ADRA2B variants contribute to the interindividual variability in vascular desensitization to an ?2-AR agonist in vivo. PMID:20051907

Muszkat, Mordechai; Kurnik, Daniel; Sofowora, Gbenga G.; Solus, Joseph; Xie, Hong-Guang; Harris, Paul A.; Williams, Scott M.; Wood, Alastair J.J.; Stein, C. Michael

2010-01-01

310

Fibrolipomatous hamartoma of median nerve.  

PubMed

Fibrolipomaous hamartoma is a benign neoplasm of nerves, resulting from anomalous growth of fibroadipose tissue of the nerve sheath. The median nerve is the most commonly involved nerve. Magnetic resonance imaging (MRI) features are pathognomonic, showing a coaxial cable-like appearance on axial images and spaghetti-like appearance on coronal images. Preferred management of the lesion is conservative. PMID:17875173

Jain, T P; Srivastava, D N; Mittal, R; Gamanagatti, S

2007-10-01

311

Regulation of early and delayed radiation responses in rat small intestine by capsaicin-sensitive nerves  

SciTech Connect

Purpose: Mast cells protect against the early manifestations of intestinal radiation toxicity, but promote chronic intestinal wall fibrosis. Intestinal sensory nerves are closely associated with mast cells, both anatomically and functionally, and serve an important role in the regulation of mucosal homeostasis. This study examined the effect of sensory nerve ablation on the intestinal radiation response in an established rat model. Methods and Materials: Rats underwent sensory nerve ablation with capsaicin or sham ablation. Two weeks later, a localized segment of ileum was X-irradiated or sham irradiated. Structural, cellular, and molecular changes were examined 2 weeks (early injury) and 26 weeks (chronic injury) after irradiation. The mast cell dependence of the effect of sensory nerve ablation on intestinal radiation injury was assessed using c-kit mutant (Ws/Ws) mast cell-deficient rats. Results: Capsaicin treatment caused a baseline reduction in mucosal mast cell density, crypt cell proliferation, and expression of substance P and calcitonin gene-related peptide, two neuropeptides released by sensory neurons. Sensory nerve ablation strikingly exacerbated early intestinal radiation toxicity (loss of mucosal surface area, inflammation, intestinal wall thickening), but attenuated the development of chronic intestinal radiation fibrosis (collagen I accumulation and transforming growth factor {beta} immunoreactivity). In mast cell-deficient rats, capsaicin treatment exacerbated postradiation epithelial injury (loss of mucosal surface area), but none of the other aspects of radiation injury were affected by capsaicin treatment. Conclusions: Ablation of capsaicin-sensitive enteric neurons exacerbates early intestinal radiation toxicity, but attenuates development of chronic fibroproliferative changes. The effect of capsaicin treatment on the intestinal radiation response is partly mast cell dependent.

Wang Junru [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States); Zheng Huaien [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States); Kulkarni, Ashwini [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States); Ou Xuemei [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States); Hauer-Jensen, Martin [Department of Surgery, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States) and Department of Pathology, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR (United States)]. E-mail: mhjensen@life.uams.edu

2006-04-01

312

Sensory Perception: Lessons from Synesthesia  

PubMed Central

Synesthesia, the conscious, idiosyncratic, repeatable, and involuntary sensation of one sensory modality in response to another, is a condition that has puzzled both researchers and philosophers for centuries. Much time has been spent proving the condition’s existence as well as investigating its etiology, but what can be learned from synesthesia remains a poorly discussed topic. Here, synaesthesia is presented as a possible answer rather than a question to the current gaps in our understanding of sensory perception. By first appreciating the similarities between normal sensory perception and synesthesia, one can use what is known about synaesthesia, from behavioral and imaging studies, to inform our understanding of “normal” sensory perception. In particular, in considering synesthesia, one can better understand how and where the different sensory modalities interact in the brain, how different sensory modalities can interact without confusion ? the binding problem ? as well as how sensory perception develops. PMID:23766741

Harvey, Joshua Paul

2013-01-01

313

Benzoquinone reveals a cysteine-dependent desensitization mechanism of TRPA1.  

PubMed

The transient receptor potential ankyrin 1 (TRPA1) nonselective cation channel has a conserved function as a noxious chemical sensor throughout much of Metazoa. Electrophilic chemicals activate both insect and vertebrate TRPA1 via covalent modification of cysteine residues in the amino-terminal region. Although naturally occurring electrophilic plant compounds, such as mustard oil and cinnamaldehyde, are TRPA1 agonists, it is unknown whether arthropod-produced electrophiles activate mammalian TRPA1. We characterized the effects of the electrophilic arthropod defensive compound para-benzoquinone (pBQN) on the human TRPA1 channel. We used whole-cell recordings of human embryonic kidney cells heterologously expressing either wild-type TRPA1 or TRPA1 with three serine-substituted cysteines crucial for electrophile activation (C621S, C641S, C665S). We found that pBQN activates TRPA1 starting at 10 nM and peaking at 300 nM; higher concentrations caused rapid activation followed by a fast decline. Activation by pBQN required reactivity with cysteine residues, but ones that are distinct from those previously reported to be the key targets of electrophiles. The current reduction we found at higher pBQN concentrations was a cysteine-dependent desensitization of TRPA1, and did not require prior activation. The cysteines required for desensitization are not accessible to all electrophiles as iodoacetamide and internally applied 2-(trimethylammonium)ethyl methanesulfonate failed to cause desensitization (despite large activation). Interestingly, following pBQN desensitization, wild-type TRPA1 had dramatically reduced response to the nonelectrophile agonist carvacrol, whereas the triple cysteine mutant TRPA1 retained its full response. Our results suggest that modification of multiple cysteine residues by electrophilic compounds can generate both activation and desensitization of the TRPA1 channel. PMID:23478802

Ibarra, Yessenia; Blair, Nathaniel T

2013-05-01

314

Protein kinase C potentiates homologous desensitization of the beta2-adrenoceptor in bovine tracheal smooth muscle.  

PubMed

Preincubation (30 min) of bovine tracheal smooth muscle with various concentrations (0.1, 1 and 10 microM) of fenoterol decreased isoprenaline-induced maximal relaxation (E(max)) of methacholine-contracted preparations in a concentration dependent fashion, indicating desensitization of the beta(2)-adrenoceptor. Preincubation with 1 microM of the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) caused a small but significant decrease in isoprenaline-induced E(max), indicating activated PKC-mediated heterologous beta(2)-adrenoceptor desensitization. To investigate the capacity of activated PKC to regulate homologous desensitization, we incubated the smooth muscle strips with the combination of both 1 microM PMA and 1 microM fenoterol. This combined treatment synergistically decreased the isoprenaline-induced maximal relaxation, as compared to the individual effects of PMA and fenoterol alone, indicating a common pathway for heterologous and homologous desensitization. Moreover, the specific PKC-inhibitor 2-[1-(3-dimethylaminopropyl)-1H-indol-3-yl]-3-(1H-indol-3-yl) maleimide (GF 109203X) markedly increased the potency and E(max) of isoprenaline for all conditions used, including control conditions, and the synergistic effects of PMA and fenoterol were completely prevented. In conclusion, the present study demonstrates that homologous desensitization of the beta(2)-adrenergic receptor can be enhanced by PKC activation. For the first time we have provided evidence that this concept is functionally operative in airway smooth muscle, and it may explain the reduced bronchodilator response to beta(2)-adrenoceptor agonists in patients with asthma during a severe exacerbation. PMID:16324695

Boterman, Mark; Smits, Steven R J G; Meurs, Herman; Zaagsma, Johan

2006-01-01

315

Desensitization of nicotinic acetylcholine receptors as a strategy for drug development.  

PubMed

The specific pharmacological response evoked by a nicotinic acetylcholine receptor (nAChR) agonist is governed by the anatomical distribution and expression of each receptor subtype and by the stoichiometry of subunits comprising each subtype. Contributing to this complexity is the ability of agonists that bind to the orthosteric site of the receptor to alter the affinity state of the receptor and induce desensitization and the observation that, at low doses, some nAChR antagonists evoke agonist-like nicotinic responses. Brain concentrations of nicotine rarely increase to the low-mid micromolar concentrations that have been reported to evoke direct agonist-like responses, such as calcium influx or neurotransmitter release. Low microgram per kilogram doses of nicotine administered to humans or to nonhuman primates to improve cognition and working memory probably result only in low nanomolar brain concentrations--more in line with the ability of nicotine to induce receptor desensitization. Here we review data illustrating that nicotine, its major metabolite cotinine, and two novel analogs of choline, JWB1-84-1 [2-(4-(pyridin-3-ylmethyl)piperazin-1-yl)ethanol] and JAY2-22-33, JWB1-84-1 [2-(methyl(pyridine-3-ylmethyl)amino)-ethanol], improve working memory in macaques. The effectiveness of these four compounds in the task was linearly related to their effectiveness in producing desensitization of the pressor response to ganglionic stimulation evoked by a nAChR agonist in rats. Only nicotine evoked an agonist-like action (increased resting blood pressure). Therefore, it is possible to develop new chemical entities that have the ability to desensitize nAChRs without an antecedent agonist action. Because these "silent desensitizers" are probably acting allosterically, an additional degree of subtype specificity could be attained. PMID:19023041

Buccafusco, Jerry J; Beach, J Warren; Terry, Alvin V

2009-02-01

316

Benzoquinone Reveals a Cysteine-Dependent Desensitization Mechanism of TRPA1  

PubMed Central

The transient receptor potential ankyrin 1 (TRPA1) nonselective cation channel has a conserved function as a noxious chemical sensor throughout much of Metazoa. Electrophilic chemicals activate both insect and vertebrate TRPA1 via covalent modification of cysteine residues in the amino-terminal region. Although naturally occurring electrophilic plant compounds, such as mustard oil and cinnamaldehyde, are TRPA1 agonists, it is unknown whether arthropod-produced electrophiles activate mammalian TRPA1. We characterized the effects of the electrophilic arthropod defensive compound para-benzoquinone (pBQN) on the human TRPA1 channel. We used whole-cell recordings of human embryonic kidney cells heterologously expressing either wild-type TRPA1 or TRPA1 with three serine-substituted cysteines crucial for electrophile activation (C621S, C641S, C665S). We found that pBQN activates TRPA1 starting at 10 nM and peaking at 300 nM; higher concentrations caused rapid activation followed by a fast decline. Activation by pBQN required reactivity with cysteine residues, but ones that are distinct from those previously reported to be the key targets of electrophiles. The current reduction we found at higher pBQN concentrations was a cysteine-dependent desensitization of TRPA1, and did not require prior activation. The cysteines required for desensitization are not accessible to all electrophiles as iodoacetamide and internally applied 2-(trimethylammonium)ethyl methanesulfonate failed to cause desensitization (despite large activation). Interestingly, following pBQN desensitization, wild-type TRPA1 had dramatically reduced response to the nonelectrophile agonist carvacrol, whereas the triple cysteine mutant TRPA1 retained its full response. Our results suggest that modification of multiple cysteine residues by electrophilic compounds can generate both activation and desensitization of the TRPA1 channel. PMID:23478802

Ibarra, Yessenia

2013-01-01

317

Repair of ruptured spinal nerve roots in a brachial plexus lesion. Case report.  

PubMed

A 22-year-old woman sustained a brachial plexus injury with supraganglionic rupture of the C-8 and T-1 nerve roots as a result of a traffic accident. She was operated on approximately 1 week following the accident. After a hemilaminectomy, the intradural defects in the ruptured roots were bridged with sural nerve grafts. Within 3 years she recovered function in all muscles supplied from the lower roots in the plexus except for the intrinsic hand muscles, but she had a persisting, complete sensory loss in the ulnar nerve distribution. The possibility for functional gain after repair of spinal root lesions in brachial plexus patients is discussed. PMID:7897534

Carlstedt, T; Norén, G

1995-04-01

318

Cervical Radiculopathy (Pinched Nerve)  

MedlinePLUS

... nerve. The medical term for this condition is cervical radiculopathy. Understanding your spine and how it works can help you better understand cervical radiculopathy. Learn more about your spine online at Spine Basics: http://orthoinfo. org/topic. ...

319

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. ...

320

Nerve reconstruction in lumbosacral plexopathy. Case report and review of the literature.  

PubMed

Neurological injury to the lumbosacral plexus associated with pelvic and sacral fractures has traditionally been treated conservatively, despite significant and often debilitating functional deficits of the lower extremities. The authors report a case of reconstruction of the lumbosacral plexus, including nerve grafting to restore lower-extremity function caused by severe trauma to the pelvis. A 16-year-old boy sustained pelvic and sacral fractures in a motor vehicle accident. After stabilization of his orthopedic injuries, he suffered from paresis of his right gluteal and hamstring muscles and had no motor or sensory function below his knee. Two months later, he underwent reconstruction of his lumbosacral plexus performed using a nerve graft from his L-5 and S-1 nerve roots proximal to the inferior gluteal nerve and distal to a branch to the hamstring muscles. After another 2 months, his recovering saphenous nerve was transferred to the sensory component of the posterior tibial nerve by using cabled sural nerve grafts to restore sensation to the sole of his foot. After 2.5 years, he experienced reinnervation of his gluteal and hamstring muscles and could perceive vibration on the sole of his foot. With the assistance of a foot-drop splint, the patient ambulates well and is able to ski. Operative details and the relevant literature are reviewed. PMID:16206740

Tung, Thomas H; Martin, D Zachary; Novak, Christine B; Lauryssen, Carl; Mackinnon, Susan E

2005-01-01

321

Medial Antebrachial Cutaneous Nerve Injury After Brachial Plexus Block: Two Case Reports  

PubMed Central

Medial antebrachial cutaneous (MABC) nerve injury associated with iatrogenic causes has been rarely reported. Local anesthesia may be implicated in the etiology of such injury, but has not been reported. Two patients with numbness and painful paresthesia over the medial aspect of the unilateral forearm were referred for electrodiagnostic study, which revealed MABC nerve lesion in each case. The highly selective nature of the MABC nerve injuries strongly suggested that they were the result of direct nerve injury by an injection needle during previous brachial plexus block procedures. Electrodiagnostic studies can be helpful in evaluating cases of sensory disturbance after local anesthesia. To our knowledge, these are the first documented cases of isolated MABC nerve injury following ultrasound-guided axillary brachial plexus block. PMID:24466530

Jung, Mi Jin; Byun, Ha Young; Lee, Chang Hee; Moon, Seung Won; Oh, Min-Kyun

2013-01-01

322

Microscopic characteristics of the acoustic tumor in relationship of its nerve of origin.  

PubMed

The microscopic characteristics of a 0.9 cm vestibular schwannoma en bloc resected with its nerve of origin which occurred in a 54-year-old white woman presenting with a two-year history of a unilateral progressive sensori-neural hearing loss is described. The tumor originated in the inferior vestibular portion of the vestibular division of the VIIIth cranial nerve just medial to the internal auditory canal meatus at approximately the level of the glial-non-glial junction. The tumor demonstrated two distinctly different, yet simultaneous, modes of involvement with its nerve of origin: 1. inseparable cellular continuity; and 2. peripheral compression of the remainder of the nerve within the tumor capsule. Despite only slight microscopic continuity of the nerve histologically, electronystagmography showed no unilateral weakness on bithermal caloric testing, and pure tone and speech audiometry was only moderately depressed. PMID:933694

Neely, J G; Britton, B H; Greenberg, S D

1976-07-01

323

Heterophilic Binding of L1 on Unmyelinated Sensory Axons Mediates Schwann Cell Adhesion and Is Required for Axonal Survival  

Microsoft Academic Search

This study investigated the function of the adhesion molecule L1 in unmyelinated fibers of the pe- ripheral nervous system (PNS) by analysis of L1- deficient mice. We demonstrate that L1 is present on axons and Schwann cells of sensory unmyelinated fi- bers, but only on Schwann cells of sympathetic unmy- elinated fibers. In L1-deficient sensory nerves, Schwann cells formed but

C. A. Haney; Z. Sahenk; C. Li; V. P. Lemmon; J. Roder; B. D. Trapp

1999-01-01

324

Measurement in Sensory Modulation: The Sensory Processing Scale Assessment  

PubMed Central

OBJECTIVE. Sensory modulation issues have a significant impact on participation in daily life. Moreover, understanding phenotypic variation in sensory modulation dysfunction is crucial for research related to defining homogeneous groups and for clinical work in guiding treatment planning. We thus evaluated the new Sensory Processing Scale (SPS) Assessment. METHOD. Research included item development, behavioral scoring system development, test administration, and item analyses to evaluate reliability and validity across sensory domains. RESULTS. Items with adequate reliability (internal reliability >.4) and discriminant validity (p < .01) were retained. Feedback from the expert panel also contributed to decisions about retaining items in the scale. CONCLUSION. The SPS Assessment appears to be a reliable and valid measure of sensory modulation (scale reliability >.90; discrimination between group effect sizes >1.00). This scale has the potential to aid in differential diagnosis of sensory modulation issues. PMID:25184464

Miller, Lucy J.; Sullivan, Jillian C.

2014-01-01

325

Biomedical engineering strategies for peripheral nerve repair: surgical applications, state of the art, and future challenges.  

PubMed

Damage to the peripheral nervous system is surprisingly common and occurs primarily from trauma or a complication of surgery. Although recovery of nerve function occurs in many mild injuries, outcomes are often unsatisfactory following severe trauma. Nerve repair and regeneration presents unique clinical challenges and opportunities, and substantial contributions can be made through the informed application of biomedical engineering strategies. This article reviews the clinical presentations and classification of nerve injuries, in addition to the state of the art for surgical decision-making and repair strategies. This discussion presents specific challenges that must be addressed to realistically improve the treatment of nerve injuries and promote widespread recovery. In particular, nerve defects a few centimeters in length use a sensory nerve autograft as the standard technique; however, this approach is limited by the availability of donor nerve and comorbidity associated with additional surgery. Moreover, we currently have an inadequate ability to noninvasively assess the degree of nerve injury and to track axonal regeneration. As a result, wait-and-see surgical decisions can lead to undesirable and less successful "delayed" repair procedures. In this fight for time, degeneration of the distal nerve support structure and target progresses, ultimately blunting complete functional recovery. Thus, the most pressing challenges in peripheral nerve repair include the development of tissue-engineered nerve grafts that match or exceed the performance of autografts, the ability to noninvasively assess nerve damage and track axonal regeneration, and approaches to maintain the efficacy of the distal pathway and targets during the regenerative process. Biomedical engineering strategies can address these issues to substantially contribute at both the basic and applied levels, improving surgical management and functional recovery following severe peripheral nerve injury. PMID:21488817

Pfister, Bryan J; Gordon, Tessa; Loverde, Joseph R; Kochar, Arshneel S; Mackinnon, Susan E; Cullen, D Kacy

2011-01-01

326

Electrophysiological aspects of sensory conduction velocity in healthy adults. 1. Conduction velocity from digit to palm, from palm to wrist, and across the elbow, as a function of age.  

PubMed Central

The sensory conduction velocity from digit to palm and from palm to wrist was determined in median (digit 3) and ulnar (digit 5) nerves in 47 healthy subjects with age range from 21 to 77 years. The decrement of the sensory conduction as a function of age was more marked in the palm to wrist than in the digit to palm segment. Sensory conduction velocity of the ulnar nerve across the elbow was also studied. Irregularities in the shape of the sensory evoked potential recorded above the cubital sulcus were found in 12.76% of cases, especially in subjects over 50 years of age. These results suggest that aging causes decrement in sensory conduction and changes in the shape of the evoked potentials, especially at points where the nerves are more frequently compressed. Images PMID:731254

Cruz Martínez, A; Barrio, M; Pérez Conde, M C; Gutiérrez, A M

1978-01-01

327

Cardiovascular responses to sciatic nerve stimulation are blocked by paratrigeminal nucleus lesion  

Microsoft Academic Search

The paratrigeminal nucleus (Pa5) receives primary sensory inputs from the vagus, glossopharyngeal, and trigeminal nerves and has efferent projections to the nucleus of the solitary tract (NTS), rostroventrolateral reticular nucleus (RVL), as well as to the nucleus ambiguus (Amb), lateral reticular (LRt), parabrachial (PB) and ventral posteromedial thalamic (VPM) nuclei, suggesting that it may play a significant role in cardiovascular

Yun-Guo Yu; Cristofer A Caous; Antonio C Balan; Giles A Rae; Charles J Lindsey

2002-01-01

328

Shock wave over hand muscles: a neurophysiological study on peripheral conduction nerves in normal subjects  

PubMed Central

Summary Background and purpose: shock waves are defined as a sequence of single sonic pulses largely used in the treatment of bone and tendon diseases and recently on muscular hypertonia in stroke patients. Our purpose is to investigate the short and long term effect of extra-corporeal shock wave therapy (ESWT) on the peripheral nerve conduction and central conductions from the treated muscles in normal human subjects in order to define safety criteria. Methods: we studied 10 patients normal subjects. Motor and sensory nerve conduction velocity and F response from right ipothenar eminence (abductor digiti minimi) of the hand was recorded. Furthermore MEP latency and amplitude and central conduction from the same muscles by transcranial magnetic stimulation was evaluated. In all subjects each neurophysiological measures were monitored before, immediately after, 15 minutes and after 30 minutes from the active ESWT treatment (1600 shots with an energy applied of 0.030 mj/mm2). Results: no significant short or long term changes were noted in sensory and motor peripheral nerve conduction and in central motor conduction in all the subjects evaluated after ESWT. Conclusions: the ESWT has no effect on sensory and motor peripheral nerve conduction and in central motor conduction. The ESWT using low level of energy represent a safety method for treating the muscles in human subjects without involvement of motor or sensory nervous trunks. Different mechanisms of action of ESWT are discussed. PMID:23738282

Manganotti, Paolo; Amelio, Ernesto; Guerra, Claudio

2012-01-01

329

The mechanism of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor desensitization after removal of glutamate.  

PubMed Central

We have examined responses of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate) receptors in the chick nucleus magnocellularis to pairs of pulses of glutamate and determined the extent of desensitization and the rate of recovery. Receptors recovered from desensitization with a time constant of 16 ms, regardless of the concentration or duration of the conditioning pulse. Even with very brief conditioning pulses, evoking submaximal currents, desensitization occurred at a consistent rate after the removal of free ligand. A quantitative kinetic model based on these data shows that receptors must desensitize from a closed state. The results provide evidence that very brief exposure to glutamate, on the time scale of uniquantal synaptic transmission, will result in a significant reduction in sensitivity of postsynaptic receptors. Images FIGURE 4 PMID:7711235

Raman, I M; Trussell, L O

1995-01-01

330

Use of axonal projection patterns for the homologisation of cerebral nerves in Opisthobranchia, Mollusca and Gastropoda  

PubMed Central

Introduction Gastropoda are guided by several sensory organs in the head region, referred to as cephalic sensory organs (CSOs). These CSOs are innervated by distinct nerves. This study proposes a unified terminology for the cerebral nerves and the categories of CSOs and then investigates the neuroanatomy and cellular innervation patterns of these cerebral nerves, in order to homologise them. The homologisation of the cerebral nerves in conjunction with other data, e.g. ontogenetic development or functional morphology, may then provide insights into the homology of the CSOs themselves. Results Nickel-lysine axonal tracing (“backfilling”) was used to stain the somata projecting into specific nerves in representatives of opisthobranch Gastropoda. Tracing patterns revealed the occurrence, size and relative position of somata and their axons and enabled these somata to be mapped to specific cell clusters. Assignment of cells to clusters followed a conservative approach based primarily on relative location of the cells. Each of the four investigated cerebral nerves could be uniquely identified due to a characteristic set of soma clusters projecting into the respective nerves via their axonal pathways. Conclusions As the described tracing patterns are highly conserved morphological characters, they can be used to homologise nerves within the investigated group of gastropods. The combination of adequate number of replicates and a comparative approach allows us to provide preliminary hypotheses on homologies for the cerebral nerves. Based on the hypotheses regarding cerebral nerve homology together with further data on ultrastructure and immunohistochemistry of CSOs published elsewhere, we can propose preliminary hypotheses regarding homology for the CSOs of the Opisthobranchia themselves. PMID:23597272

2013-01-01

331

Schwann cells reposition a peripheral nerve to isolate it from postembryonic remodeling of its targets  

PubMed Central

Although much is known about the initial construction of the peripheral nervous system (PNS), less well understood are the processes that maintain the position and connections of nerves during postembryonic growth. Here, we show that the posterior lateral line nerve in zebrafish initially grows in the epidermis and then rapidly transitions across the epidermal basement membrane into the subepidermal space. Our experiments indicate that Schwann cells, which myelinate axons in the PNS, are required to reposition the nerve. In mutants lacking Schwann cells, the nerve is mislocalized and the axons remain in the epidermis. Transplanting wild-type Schwann cells into these mutants rescues the position of the nerve. Analysis of chimeric embryos suggests that the process of nerve relocalization involves two discrete steps – the degradation and recreation of the epidermal basement membrane. Although the outgrowth of axons is normal in mutants lacking Schwann cells, the nerve becomes severely disorganized at later stages. In wild-type embryos, exclusion of the nerve from the epidermis isolates axons from migration of their targets (sensory neuromasts) within the epidermis. Without Schwann cells, axons remain within the epidermis and are dragged along with the migrating neuromasts. Our analysis of the posterior lateral line system defines a new process in which Schwann cells relocate a nerve beneath the epidermal basement membrane to insulate axons from the postembryonic remodeling of their targets. PMID:20876648

Raphael, Alya R.; Perlin, Julie R.; Talbot, William S.

2010-01-01

332

The effects of 5-HT on sensory, central and motor neurons driving the abdominal superficial flexor muscles in the crayfish.  

PubMed

Serotonin (5-HT) induces a variety of physiological and behavioral effects in crustaceans. However, the mechanisms employed by 5-HT to effect behavioral changes are not fully understood. Among the mechanisms by which these changes might occur are alterations in synaptic drive and efficacy of sensory, interneurons and motor neurons, as well as direct effects on muscles. We investigated these aspects with the use of a defined sensory-motor system, which is entirely contained within a single abdominal segment and consists of a 'cuticular sensory neurons segmental ganglia abdominal superficial flexor motor neurons-muscles' circuit. Our studies address the role of 5-HT in altering (1) the activity of motor neurons induced by sensory stimulation; (2) the inherent excitability of superficial flexor motor neurons; (3) transmitter release properties of the motor nerve terminal and (4) input resistance of the muscle. Using en passant recordings from the motor nerve, with and without sensory stimulation, and intracellular recordings from the muscle, we show that 5-HT enhances sensory drive and output from the ventral nerve cord resulting in an increase in the firing frequency of the motor neurons. Also, 5-HT increases transmitter release at the neuromuscular junction, and alters input resistance of the muscle fibers. PMID:11281271

Strawn, J R; Neckameyer, W S; Cooper, R L

2000-12-01

333

Spatial spread of activation and background desensitization in toad rod outer segments  

PubMed Central

1. The spread of activation and background desensitization in rods was studied by recording membrane current from single outer segments in pieces of isolated toad retina. 2. Flash sensitivity changed slightly along the outer segment, falling by about 30% from base to tip. 3. When only the distal half of an outer segment was in the recording pipette, illumination of the unrecorded part elicited little or no photocurrent at the recorded part, indicating that a photoisomerization does not cause activation of the entire outer segment. 4. With diffuse illumination of an outer segment fully drawn into the pipette, the intensity—response relations at fixed times were invariant in form for most of the rising phase of the flash response and were considerably steeper than the Michaelis relation. The observed relation was consistent with a model in which a photoisomerization blocks all channels over a short region of the outer segment. 5. With illumination restricted to a narrow transverse slit, the intensity—response relations at fixed times were much less steep, as would be expected for a very limited longitudinal spread of activation. An upper limit for the effective longitudinal diffusion coefficient of the internal transmitter was estimated to be about 3 × 10-7 cm2 sec-1. This corresponds to a space constant for longitudinal spread of transmitter of about 3 ?m at the time of the dim response peak. 6. The time course of flash responses elicited with light positioned either on the edge or on the centre of the outer segment was very similar. 7. Desensitization resulting from steady illumination by a transverse slit was also localized longitudinally. A linear desensitization parameter T, defined in Results, decayed approximately exponentially along the outer segment, on either side of the site of photoisomerization, with a space constant of about 6 ?m. 8. Transverse spread of desensitization was more effective than longitudinal spread. 9. After turning off a dim diffuse background light, the decay of T was roughly exponential with a time constant of several seconds. From this, and the steady state space constant of 6 ?m, it is estimated that the effective longitudinal diffusion coefficient for a `desensitizing substance' would also be about 10-7 cm2 sec-1. 10. The restricted longitudinal spread of activation and desensitization may be explained by the barrier to diffusion presented by the stacked membranous disks in the outer segment. This baffling reduces the effective longitudinal diffusion coefficient to about 1/50 that of ordinary aqueous diffusion, but it does not significantly affect transverse spread. PMID:6798202

Lamb, T. D.; McNaughton, P. A.; Yau, K.-W.

1981-01-01

334

Clinical evaluation of low-power laser and a desensitizing agent on dentin hypersensitivity.  

PubMed

The aim of this randomized, longitudinal clinical study was to evaluate different protocols for dentin hypersensitivity treatment with low-power laser at different dosages, desensitizing agent, and associations, for a period of 6 months. After analysis of the inclusion and exclusion criteria of volunteer participants, those who present pain resulting from non-carious cervical lesions were selected. Twenty-seven patients participated in the study, and 55 lesions were recorded. The lesions were divided into five groups (n?=?11), treated, and evaluated: G1: Gluma Desensitizer (Heraeus); G2: low-power laser (Photon Lase, DMC) at low dose (three vestibular points and one apical point of irradiation: 30 mW, 10 J/cm(2), 9 s per point with wavelength of 810 nm), three sessions were performed with an interval of 72 h between them; G3: low-power laser at high dose (application at one cervical and one apical point: 100 mW, 90 J/cm(2), 11 s per point with wavelength of 810 nm), three sessions were performed with an interval of 72 h between irradiations; G4: low-power laser at low dose + Gluma Desensitizer; and G5: low-power laser at high dose + Gluma Desensitizer, the level of sensitivity of each volunteer was evaluated with a visual analog scale of pain (VAS) with the use of air from a triple syringe and exploration with a probe after time intervals of 5 min, 1 week, and 1, 3, and 6 months after treatment. Data were collected and subjected to statistical analysis. Kolmogorov-Smirnov test was used to verify the distribution of the data, and nonparametric Kruskal-Wallis and Friedman tests were performed for comparison among the experimental groups and time intervals studied, respectively. Statistically significant differences between the studied time intervals (p?desensitizing agent presented immediate effects of pain reduction. For low-level lasers, it was observed that there were distinct effects for the different doses; however, both were efficient in reducing pain up to the 6 months of clinical follow-up. Therefore, it could be concluded that all the desensitizing protocols were effective in reducing dentin hypersensitivity, but with different effects. The combination of protocols is an interesting alternative in the treatment of cervical dentin hypersensitivity. PMID:24197517

Lopes, Anely Oliveira; de Paula Eduardo, Carlos; Aranha, Ana Cecília Correa

2013-10-01

335

Repair of sciatic nerve defects using tissue engineered nerves  

PubMed Central

In this study, we constructed tissue-engineered nerves with acellular nerve allografts in Sprague-Dawley rats, which were prepared using chemical detergents-enzymatic digestion and mechanical methods, in combination with bone marrow mesenchymal stem cells of Wistar rats cultured in vitro, to repair 15 mm sciatic bone defects in Wistar rats. At postoperative 12 weeks, electrophysiological detection results showed that the conduction velocity of regenerated nerve after repair with tissue-engineered nerves was similar to that after autologous nerve grafting, and was higher than that after repair with acellular nerve allografts. Immunohistochemical staining revealed that motor endplates with acetylcholinesterase-positive nerve fibers were orderly arranged in the middle and superior parts of the gastrocnemius muscle; regenerated nerve tracts and sprouted branches were connected with motor endplates, as shown by acetylcholinesterase histochemistry combined with silver staining. The wet weight ratio of the tibialis anterior muscle at the affected contralateral hind limb was similar to the sciatic nerve after repair with autologous nerve grafts, and higher than that after repair with acellular nerve allografts. The hind limb motor function at the affected side was significantly improved, indicating that acellular nerve allografts combined with bone marrow mesenchymal stem cell bridging could promote functional recovery of rats with sciatic nerve defects. PMID:25206507

Zhang, Caishun; Lv, Gang

2013-01-01

336

Ca2+-dependent Desensitization of TRPV2 Channels is Mediated by Hydrolysis of Phosphatidylinositol 4,5-Bisphosphate  

PubMed Central

TRPV2 is a member of the transient receptor potential family of ion channels involved in chemical and thermal pain transduction. Unlike the related TRPV1 channel, TRPV2 does not appear to bind either calmodulin or ATP in its N-terminal ankyrin repeat domain. In addition, it does not contain a calmodulin-binding site in the distal C-terminal region, as has been proposed for TRPV1. We have found that TRPV2 channels transiently expressed in F-11 cells undergo Ca2+-dependent desensitization, similar to the other TRPV’s, suggesting that the mechanism of desensitization may be conserved in the subfamily of TRPV’s channels. TRPV2 desensitization was not altered in whole-cell recordings in the presence of calmodulin inhibitors or upon coexpression of mutant calmodulin but was sensitive to changes in membrane phosphatidylinositol (4,5)-bisphosphate (PIP2) suggesting a role of membrane PIP2 in TRPV2 desensitization. Simultaneous confocal imaging and electrophysiological recording of cells expressing TRPV2 and a fluorescent PIP2-binding probe demonstrated that TRPV2 desensitization was concomitant with depletion of PIP2. We conclude that the decrease in PIP2 levels upon channel activation underlies a major component of Ca2+-dependent desensitization of TRPV2 and may play a similar role in other TRP channels. PMID:20926660

Mercado, Jose; Gordon-Shaag, Ariela; Zagotta, William N.; Gordon, Sharona E.

2010-01-01

337

Conformational Changes in the Lower Palm Domain of ASIC1a Contribute to Desensitization and RFamide Modulation  

PubMed Central

Acid-sensing ion channel 1a (ASIC1a) is a proton-gated cation channel that contributes to fear and pain as well as neuronal damage following persistent cerebral acidosis. Neuropeptides can affect acid-induced neuronal injury by altering ASIC1a inactivation and/or steady-state desensitization. Yet, exactly how ASIC1a inactivation and desensitization occur or are modulated by peptides is not completely understood. We found that regions of the extracellular palm domain and the ?11-12 linker are important for inactivation and steady-state desensitization of ASIC1a. The single amino acid substitutions L280C and L415C dramatically enhanced the rate of inactivation and altered the pH-dependence of steady-state desensitization. Further, the use of methanethiosulfonate (MTS) reagents suggests that the lower palm region (L280C) undergoes a conformational change when ASIC1a transitions from closed to desensitized. We determined that L280C also displays an altered response to the RFamide peptide, FRRFamide. Further, the presence of FRRFamide limited MTS modification of L280C. Together, these results indicate a potential role of the lower palm domain in peptide modulation and suggest RFamide-related peptides promote conformational changes within this region. These data provide empirical support for the idea that L280, and likely this region of the central vestibule, is intimately involved in channel inactivation and desensitization. PMID:23977127

Frey, Erin N.; Pavlovicz, Ryan E.; Wegman, Clem John; Li, Chenglong; Askwith, Candice C.

2013-01-01

338

Cortical oscillations and sensory predictions.  

PubMed

Many theories of perception are anchored in the central notion that the brain continuously updates an internal model of the world to infer the probable causes of sensory events. In this framework, the brain needs not only to predict the causes of sensory input, but also when they are most likely to happen. In this article, we review the neurophysiological bases of sensory predictions of "what' (predictive coding) and 'when' (predictive timing), with an emphasis on low-level oscillatory mechanisms. We argue that neural rhythms offer distinct and adapted computational solutions to predicting 'what' is going to happen in the sensory environment and 'when'. PMID:22682813

Arnal, Luc H; Giraud, Anne-Lise

2012-07-01

339

Fiber diameter distributions in the chinchilla's ampullary nerves  

NASA Technical Reports Server (NTRS)

A morphometric study of the chinchilla's ampullary nerves was conducted to produce an unbiased accounting of the diameter distribution of their constituent fibers. Diameter analyses were determined from 1 microm plastic-embedded nerve sections taken at a plane immediately proximal to the sensory epithelium. We found these nerves to be composed of 2094+/-573 fibers, having diameters that ranged from 0.5 to 8 microm. The distributions of diameters were positively skewed, where approximately 75% of the fibers were found to have diameters less than 3.5 microm. An analysis of the spatial distribution of diameters within the nerve section revealed that the lateralmost areas of the nerve contained larger fractions of fibers within the smallest diameter quintiles, and the central area harbored greater proportions of the larger diameter quintiles. However, significant fractions of all quintiles were found in all areas. These data were integrated with available data of Fernandez et al. (1998) to produce diameter estimates of calyx, dimorphic, and bouton morphology subpopulations. In view of a general relationship between diameter, innervation locus, and an afferent's physiologic characteristics, these data provide the basis for developing a perspective for the in situ distribution of afferent response dynamics.

Hoffman, Larry F.; Honrubia, Vicente

2002-01-01

340

Cyclic sciatica from extrapelvic endometriosis affecting the sciatic nerve.  

PubMed

Sciatic (catamenial) radiculopathy, waxing and waning with the menstrual cycle, is an uncommon condition typically caused by pelvic endometriosis affecting the lumbosacral plexus or proximal sciatic nerve. The authors describe a woman with catamenial sciatica caused by endometriosis affecting the sciatic nerve trunk in the upper thigh. Symptomatic with leg pain for 5 years, this patient developed gluteal atrophy and sensory loss and decreased strength in the L-5 dermatomyotome, a distribution confirmed by electromyography. Magnetic resonance imaging suggested thickening of the sciatic nerve at and distal to the sciatic notch. At operation the nerve showed extrinsic and intrinsic abnormality, proven to be endometriosis. Her symptoms improved, and she began gonadotropin-releasing hormone agonist therapy for further suppression. This very unusual case shows that endometriosis can affect the sciatic nerve over a range of territory inside and outside the pelvis, and that surgery must be appropriately directed to avoid negative exploration. Surgical decompression achieves good relief of symptoms, and medical therapy also allows sustained suppression of this disease. PMID:21184633

Floyd, John R; Keeler, Elizabeth R; Euscher, Elizabeth D; McCutcheon, Ian E

2011-02-01

341

Biofabrication and testing of a fully cellular nerve graft.  

PubMed

Rupture of a nerve is a debilitating injury with devastating consequences for the individual's quality of life. The gold standard of repair is the use of an autologous graft to bridge the severed nerve ends. Such repair however involves risks due to secondary surgery at the donor site and may result in morbidity and infection. Thus the clinical approach to repair often involves non-cellular solutions, grafts composed of synthetic or natural materials. Here we report on a novel approach to biofabricate fully biological grafts composed exclusively of cells and cell secreted material. To reproducibly and reliably build such grafts of composite geometry we use bioprinting. We test our grafts in a rat sciatic nerve injury model for both motor and sensory function. In particular we compare the regenerative capacity of the biofabricated grafts with that of autologous grafts and grafts made of hollow collagen tubes by measuring the compound action potential (for motor function) and the change in mean arterial blood pressure as consequence of electrically eliciting the somatic pressor reflex. Our results provide evidence that bioprinting is a promising approach to nerve graft fabrication and as a consequence to nerve regeneration. PMID:24192236

Owens, Christopher M; Marga, Francoise; Forgacs, Gabor; Heesch, Cheryl M

2013-12-01

342

Fibrolipomatous hamartoma of the inferior calcaneal nerve (Baxter nerve).  

PubMed

Fibrolipomatous hamartoma (FLH) is a rare, benign lesion of the peripheral nerves most frequently involving the median nerve and its digital branches (80 %). Pathognomonic MR features of FLH such as coaxial-cable-like appearance on axial planes and a spaghetti-like appearance on coronal planes have been described by Marom and Helms, obviating the need for diagnostic biopsy. We present a case of fibrolipomatous hamartoma of the inferior calcaneal nerve (Baxter nerve) with associated subcutaneous fat proliferation. PMID:22526881

Zeng, Rong; Frederick-Dyer, Katherine; Ferguson, N Lynn; Lewis, James; Fu, Yitong

2012-09-01

343

Sensory reinnervation of free flaps in reconstruction of the breast and the upper and lower extremities?  

PubMed Central

There is long-standing debate about sensate versus non-sensate free microvascular flaps among microsurgeons. The principle of connecting not only the vascular supply, but also sensitive nerves, in free tissue transfer is attractive. However, increased operating time and partial spontaneous innervation led to the common decision to restrict microsurgical tissue transfer to the vascular anastomosis and to leave the nerves “untreated”. Nevertheless, in special cases such as breast reconstruction or extremity reconstruction, the question about sensory nerve coaptation of the flaps remains open. We present our experience with free microvascular tissue transfer for breast and extremity reconstruction and compare the data with previous literature and conclude that most free flap surgeries do not benefit from nerve coaptation.

Sinis, Nektarios; Lamia, Androniki; Gudrun, Helml; Schoeller, Thomas; Werdin, Frank

2012-01-01

344

Potentiation, desensitization, and inversion of response in bacterial sensing of chemical stimuli.  

PubMed Central

Behavior patterns of chemotactic mutants of Salmonella typhimurium were compared to those of the wild type by using the quantitative tumble frequency assay. Some cheU mutants were completely inverted in their responses--e.g., attractants produce responses expected for repellents and repellents produce responses expected for attractants. Still others swam smoothly and did not respond to any stimuli. Mutants of other complementation groups were found to exhibit exact additivity or potentiation in response to multiple stimuli whereas the wild type showed desensitization. The results suggest that the cheU gene product acts as a switch at the interface between the sensing system and the motor response. The system is finely tuned so that changes in individual proteins can produce potentiation, desensitization, exact additivity, or inversion of responses. Images PMID:351616

Rubik, B A; Koshland, D E

1978-01-01

345

Influence of desensitizing agents on the microshear bond strength of adhesive systems to dentin.  

PubMed

The aim of this study was to evaluate the effect of desensitizing agents on the micro-shear bond strength of adhesive systems to dentin. Forty bovine teeth were divided into 8 groups (n=5): G1--Single Bond (SB); G2--GH.F + SB; G3-- Desensibilize + SB; G4--essensiv + SB; G5 --ingle Bond 2 (SB2); G6--H.E + SB2; G7--esensibilize + SB2; G8--Dessensiv + SB2. In all of the groups, the desensitizing agents were applied after phosphoric acid etching and before the dentin adhesive application. Z250 composite resin tubes were bonded on the treated surface. After 24 hours, the teeth were tested in a universal machine. Data were submitted to ANOVA and Tukey's test (5%). The results showed that the groups where Desensibilize and Dessensiv were applied exhibited smaller bond strength values. PMID:19601495

Maeda, Fernando A; Guedes, Ana P A; Catelan, Anderson; Pavan, Sabrina; Briso, André L F; Sundfeld, Renato H; dos Santos, Paulo H

2009-01-01

346

Analysis and Measurement of the Sympathetic and Sensory Innervation of White and Brown Adipose Tissue  

PubMed Central

Here, we provide a detailed account of how to denervate white and brown adipose tissue (WAT and BAT) and how to measure sympathetic nervous system (SNS) activity to these and other tissues neurochemically. The brain controls many of the functions of WAT and BAT via the SNS innervation of the tissues, especially lipolysis and thermogenesis, respectively. There is no clearly demonstrated parasympathetic innervation of WAT or the major interscapular BAT (IBAT) depot. WAT and BAT communicate with the brain neurally via sensory nerves. We detail the surgical denervation (eliminating both innervations) of several WAT pads and IBAT. We also detail more selective chemical denervation of the SNS innervation via intra-WAT/IBAT 6-hydroxy-dopamine (a catecholaminergic neurotoxin) injections and selective chemical sensory denervation via intra-WAT/IBAT capsaicin (a sensory nerve neurotoxin) injections. Verifications of the denervations are provided (HPLC-EC detection for SNS, ELIA for calcitonin gene-related peptide (proven sensory nerve marker)). Finally, assessment of the SNS drive to WAT/BAT or other tissues is described using the alpha-methyl-para-tyrosine method combined with HPLC-EC, a direct neurochemical measure of SNS activity. These methods have proven useful for us and for other investigators interested in innervation of adipose tissues. The chemical denervation approach has been extended to nonadipose tissues as well. PMID:24480348

Vaughan, Cheryl H.; Zarebidaki, Eleen; Ehlen, J. Christopher; Bartness, Timothy J.

2014-01-01

347

Reductions in External Divalent Cations Evoke Novel Voltage-Gated Currents in Sensory Neurons  

PubMed Central

It has long been recognized that divalent cations modulate cell excitability. Sensory nerve excitability is of critical importance to peripheral diseases associated with pain, sensory dysfunction and evoked reflexes. Thus we have studied the role these cations play on dissociated sensory nerve activity. Withdrawal of both Mg2+ and Ca2+ from external solutions activates over 90% of dissociated mouse sensory neurons. Imaging studies demonstrate a Na+ influx that then causes depolarization-mediated activation of voltage-gated Ca2+ channels (CaV), which allows Ca2+ influx upon divalent re-introduction. Inhibition of CaV (?-conotoxin, nifedipine) or NaV (tetrodotoxin, lidocaine) fails to reduce the Na+ influx. The Ca2+ influx is inhibited by CaV inhibitors but not by TRPM7 inhibition (spermine) or store-operated channel inhibition (SKF96365). Withdrawal of either Mg2+ or Ca2+ alone fails to evoke cation influxes in vagal sensory neurons. In electrophysiological studies of dissociated mouse vagal sensory neurons, withdrawal of both Mg2+ and Ca2+ from external solutions evokes a large slowly-inactivating voltage-gated current (IDF) that cannot be accounted for by an increased negative surface potential. Withdrawal of Ca2+ alone fails to evoke IDF. Evidence suggests IDF is a non-selective cation current. The IDF is not reduced by inhibition of NaV (lidocaine, riluzole), CaV (cilnidipine, nifedipine), KV (tetraethylammonium, 4-aminopyridine) or TRPM7 channels (spermine). In summary, sensory neurons express a novel voltage-gated cation channel that is inhibited by external Ca2+ (IC50?0.5 µM) or Mg2+ (IC50?3 µM). Activation of this putative channel evokes substantial cation fluxes in sensory neurons. PMID:22328938

Bahia, Parmvir K.; Bennett, Eric S.; Taylor-Clark, Thomas E.

2012-01-01

348

Summary report on desensitizing CP explosive to electrostatic discharge via additives  

Microsoft Academic Search

The purpose of this study was to experimentally investigate the possibility of desensitizing pressed CP (2-(5-cyanotetrazolato)pentaamminecobalt (III) perchlorate) explosive to electrostatic discharge through the incorporation of small percentages of additives. It was subsequently shown that graphite, calcium stearate and aluminum flake in the amounts of 3 to 5 weight percent were effective in reducing the electrostatic spark sensitivity of CP

J. W. Fronabarger; A. A. Heckes

1978-01-01

349

The Cognitive Dismantling of Eye Movement Desensitization and Reprocessing (EMDR) Treatment of Posttraumatic Stress Disorder (PTSD)  

Microsoft Academic Search

Twenty-seven subjects were exposed to standard Eye Movement Desensitization and Reprocessing (EMDR) treatment or a similar treatment without the explicit cognitive elements found in EMDR. Standardized psychometric assessments were administered (Structured Interview for Post Traumatic Stress Disorder, Impact of Event Scale, Revised Symptom Checklist-90) by independent assessors at pretest, posttest and two separate follow-up periods. Potential subjects met specific inclusion\\/exclusion

Karen Cusack; C. Richard Spates

1999-01-01

350

Telokin mediates Ca 2+ desensitization through activation of myosin phosphatase in phasic and tonic smooth muscle  

Microsoft Academic Search

Telokin, a 17 kDa smooth muscle specific protein, consists of the C-terminal domain of MLCK, is phosphorylated by PKA and PKG at Ser13 in vivo (Wu et al. (1998) J Biol Chem 273: 11362–11369; Walker et al. (2001) J. Biol Chem 276: 24519–24524) and is proposed to induce Ca2+-desensitization through activation of myosin phosphatase (Wu et al. (1998) J. Biol

Nandini Choudhury; Alexander S. Khromov; Andrew P. Somlyo; Avril V. Somlyo

2004-01-01

351

CXCL9 causes heterologous desensitization of CXCL12-mediated memory T lymphocyte activation.  

PubMed

The chemokine receptors CXCR3 and CXCR4 are primarily involved in memory Th1 cell-driven autoimmune diseases. Although recent studies in chronic inflammatory disease showed therapeutic success using combined blockade, details of CXCR3 and CXCR4 synergism are not understood. In this investigation, we intended to unravel the interaction of these chemokine receptors in static and dynamic cell-migration assays at both the cellular and molecular levels. Effects of combined stimulation by murine CXCL9 and CXCL12, ligands of CXCR3 and CXCR4, respectively, were analyzed using a murine central memory Th1 cell clone. Costimulation with CXCL9 desensitized the chemotaxis of Th1 cells toward CXCL12 by up to 54%. This effect was found in murine EL-4 cells, as well as in primary human T cells. Furthermore, under dynamic flow conditions CXCL12-induced crawling and endothelial transmigration of Th1 cells was desensitized by CXCL9. Subsequent experiments uncovered several molecular mechanisms underlying the heterologous cross-regulation of CXCR4 signaling by the CXCR3 ligand. CXCR4 surface expression was reduced, whereas CXCL12-induced Akt phosphorylation and intracellular Ca(2+) signals were modulated. Moreover, blockade of Rac by NSC23766 revealed differential effects on CXCL12 and CXCL9 chemotaxis and abolished the desensitizing effect of CXCL9. The desensitization of CXCR4 via CXCR3 in memory Th1 cells suggests that their in vivo homeostasis, widely regulated by CXCL12, seemed to be significantly altered by CXCR3 ligands. Our data provide a more detailed understanding for the continuing extravasation and recruitment of Th1 lymphocytes into sites of persistent inflammation. PMID:23447686

Giegold, Oliver; Ogrissek, Nadine; Richter, Cornelia; Schröder, Matthias; Herrero San Juan, Martina; Pfeilschifter, Josef M; Radeke, Heinfried H

2013-04-01

352

Matrix metalloproteinase-2 is downregulated in sciatic nerve by streptozotocin induced diabetes and/or treatment with minocycline: Implications for nerve regeneration.  

PubMed

Minocycline is an inhibitor of matrix metalloproteinases (MMPs) and has been shown to have analgesic effects. Whilst increased expression of MMPs is associated with neuropathic pain, MMPs also play crucial roles in Wallerian degeneration and nerve regeneration. In this study we examined the expression of MMP-2, MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1/-2 in the sciatic nerve of control and streptozotocin-induced diabetic rats treated with either vehicle or minocycline by quantitative PCR and gelatin zymography. We assessed the effects of minocycline on nerve conduction velocity and intraepidermal nerve fibre (IENF) deficits in diabetic neuropathy and investigated the effects of minocycline or MMP-2 on neurite outgrowth from primary cultures of dissociated adult rat sensory neurons. We show that MMP-2 is expressed constitutively in the sciatic nerve in vivo and treatment with minocycline or diabetes leads to downregulation of MMP-2 expression and activity. The functional consequence of this is IENF deficits in minocycline-treated nondiabetic rats and an unsupportive microenvironment for regeneration in diabetes. Minocycline reduces levels of MMP-2 mRNA and nerve growth factor-induced neurite outgrowth. Furthermore, in vivo minocycline treatment reduces preconditioning-induced in vitro neurite outgrowth following a sciatic nerve crush. In contrast, the addition of active MMP-2 facilitates neurite outgrowth in the absence of neurotrophic support and pre-treatment of diabetic sciatic nerve substrata with active MMP-2 promotes a permissive environment for neurite outgrowth. In conclusion we suggest that MMP-2 downregulation may contribute to the regenerative deficits in diabetes. Minocycline treatment also downregulates MMP-2 activity and is associated with inhibitory effects on sensory neurons. Thus, caution should be exhibited with its use as the balance between beneficial and detrimental outcomes may be critical in assessing the benefits of using minocycline to treat diabetic neuropathy. PMID:25158309

Ali, Sumia; Driscoll, Heather E; Newton, Victoria L; Gardiner, Natalie J

2014-11-01

353

Functional desensitization of the ?2 adrenoceptor is not dependent on agonist efficacy  

PubMed Central

Chronic treatment with ?2 adrenoceptor agonists is recommended as a first-line maintenance therapy for chronic obstructive pulmonary disease (COPD). However, a potential consequence of long-term treatment may be the loss of functional response (tachyphylaxis) over time. In this study, we have investigated the tendency of such agonists, with a range of efficacies, to develop functional desensitization to cAMP responses in primary human bronchial smooth muscle cells following prolonged agonist exposure. The data show that upon repeat exposure, all agonists produced functional desensitization to the same degree and rate. In addition, ?2 adrenoceptor internalization and ?-arrestin-2 recruitment were monitored using ?2·eGFP visualization and the PathHunter™ ?-arrestin-2 assay, respectively. All agonists were capable of causing robust receptor internalization and ?-arrestin-2 recruitment, the rate of which was influenced by agonist efficacy, as measured in those assays. In summary, although a relationship exists between agonist efficacy and the rate of both receptor internalization and ?-arrestin-2 recruitment, there is no correlation between agonist efficacy and the rate or extent of functional desensitization.

Rosethorne, Elizabeth M; Bradley, Michelle E; Kent, Toby C; Charlton, Steven J

2015-01-01

354

Multiple successful desensitizations to brentuximab vedotin: a case report and literature review.  

PubMed

Brentuximab vedotin is an antibody-drug conjugate FDA-approved for the treatment of systemic anaplastic large-cell lymphoma (ALCL) that has relapsed after multiagent chemotherapy. At least 2 cases of hypersensitivity reactions to brentuximab vedotin have been reported, without attempted desensitization. This report describes a morbidly obese 32-year-old woman with ALCL that relapsed after autologous stem cell transplantation, who was treated on a phase II clinical study with brentuximab vedotin. After 1 dose, she experienced near-complete remission, but therapy was stopped because of severe drug-related toxicity. She then received 5 cytotoxic treatments and radiation, and ultimately experienced disease progression. The patient was rechallenged with brentuximab vedotin approximately 28 months after initial exposure and tolerated the dose well, but experienced a significant allergic reaction with the next dose. High-dose steroid and antihistamine prophylaxis administered 50 minutes before the subsequent brentuximab vedotin infusion was unsuccessful in mitigating this reaction. Brentuximab vedotin was successfully infused according to a rapid desensitization protocol. With progressive dose titration and supportive care, the patient tolerated this therapy. She received 11 doses through a rapid desensitization protocol and experienced a durable disease remission. PMID:24717566

DeVita, Michael D; Evens, Andrew M; Rosen, Steven T; Greenberger, Paul A; Petrich, Adam M

2014-04-01

355

Peripheral site of action of levodropropizine in experimentally-induced cough: role of sensory neuropeptides.  

PubMed

The mechanism of action of levodropropizine has been investigated in different models of experimentally-induced cough in guinea-pigs. In particular it has been demonstrated that the antitussive drug has a peripheral site of action by injecting the drug intracerebroventricularly (i.c.v.). In these experiments levodropropizine (40 micrograms/50 microliters i.c.v.) did not prevent electrically-induced cough. On the other hand, codeine (5 micrograms/50 microliters i.c.v.) markedly prevented coughing. A difference in the potency ratio of levodropropizine and codeine has been demonstrated in capsaicin-induced cough; after oral administration, codeine was about two to three times more potent than levodropropizine. However, after aerosol administration the two compounds were equipotent. These data might suggest a peripheral site of action for levodropropizine which is related to sensory neuropeptides. Further support for the role of sensory neuropeptides in the mechanism of action of levodropropizine comes from the results obtained in capsaicin-desensitized animals. In this experimental model levodropropizine failed to prevent the vagally elicited cough in neuropeptide-depleted animals, whereas codeine did not differentiate between control and capsaicin-treated animals. In conclusion, our results support the suggestion that levodropropizine has a peripheral site of action. In addition, the interference with the sensory neuropeptide system may explain, at least in part, its activity in experimentally-induced cough. PMID:1611233

Lavezzo, A; Melillo, G; Clavenna, G; Omini, C

1992-06-01

356

Optic nerve hypoplasia in children.  

PubMed Central

Optic nerve hypoplasia (ONH) is characterised by a diminished number of optic nerve fibres in the optic nerve(s) and until recently was thought to be rare. It may be associated with a wide range of other congenital abnormalities. Its pathology, clinical features, and the conditions associated with it are reviewed. Neuroendocrine disorders should be actively sought in any infant or child with bilateral ONH. Early recognition of the disorder may in some cases be life saving. Images PMID:2191713

Zeki, S. M.; Dutton, G. N.

1990-01-01

357

Aging profoundly delays functional recovery from gustatory nerve injury  

PubMed Central

The peripheral taste system remains plastic during adulthood. Sectioning the chorda tympani (CT) nerve, which sends sensory information from the anterior tongue to the CNS, causes degeneration of distal fibers and target taste buds. However, taste function is restored after about 40 days in young adult rodents. We tested whether aging impacts the reappearance of neural responses after unilateral CT nerve injury. Taste bud regeneration was minimal at day 50–65 after denervation, and most aged animals died before functional recovery could be assessed. A subset (n=3/5) of old rats exhibited normal CT responses at day 85 post-sectioning, suggesting the potential for efficient recovery. The aged taste system is fairly resilient to sensory receptor loss and major functional changes in normal aging. However, injury to the taste system reveals a surprising vulnerability in old rodents. The gustatory system provides an excellent model to study mechanisms underlying delayed recovery from peripheral nerve injury. Strategies to accelerate recovery and restore normal function will be of interest as the elderly population continues to grow. PMID:22387273

He, Lianying; Yadgarov, Arkadiy; Sharif, Shan; McCluskey, Lynnette Phillips

2012-01-01

358

Sensory properties of fruit skins  

Microsoft Academic Search

The sensory characteristics of fruit skins were determined for a range of produce including large fruit (apples, pears, and tomatoes) and small fruit (grapes, strawberries, blueberries, and cherry tomatoes). These results provided a context within which to study the sensory properties of skins from novel kiwifruit (Actinidia). The kiwifruit skins ranged from the edible skins of grape-sized Actinidia arguta through

Rachel L. Amos

2007-01-01

359

Peroneal nerve entrapment in runners  

Microsoft Academic Search

In a practice involving large groups of athletes, seven runners and one soccer player with peroneal nerve compression neuropathy secondary to exercise have been found. Running incited pain, numbness and tin gling to varying degrees in all patients, and examination after running revealed muscle weakness and a positive percussion test as the nerve winds around the fibular neck. Nerve conduction

Robert E. Leach; Michael B. Purnell; Akiyoshi Saito

1989-01-01

360

Fibrolipoma of the median nerve  

Microsoft Academic Search

Neural fibrolipoma or fibrolipomatous hamartoma is an uncommon benign tumor that usually arises in the median nerve. Fibrofatty tissue proliferates around the nerve and infiltrates the epineurium and perineurium. We report a case of fibrolipomatous hamartoma of the left median nerve in an 18-year-old woman. Our objective was to describe the pathognomonic magnetic resonance imaging features, whose presence obviates the

Kais Nouira; Hend Belhiba; Sofiène Baccar; Anissa Miaaoui; Monia Ben Messaoud; Imène Turki; Ilhem Cheour; Emna Menif

2007-01-01

361

Prostanoid receptor EP1 and Cox-2 in injured human nerves and a rat model of nerve injury: a time-course study  

PubMed Central

Background Recent studies show that inflammatory processes may contribute to neuropathic pain. Cyclooxygenase-2 (Cox-2) is an inducible enzyme responsible for production of prostanoids, which may sensitise sensory neurones via the EP1 receptor. We have recently reported that while macrophages infiltrate injured nerves within days of injury, they express increased Cox-2-immunoreactivity (Cox-2-IR) from 2 to 3 weeks after injury. We have now investigated the time course of EP1 and Cox-2 changes in injured human nerves and dorsal root ganglia (DRG), and the chronic constriction nerve injury (CCI) model in the rat. Methods Tissue sections were immunostained with specific antibodies to EP1, Cox-2, CD68 (human macrophage marker) or OX42 (rat microglial marker), and neurofilaments (NF), prior to image analysis, from the following: human brachial plexus nerves (21 to 196 days post-injury), painful neuromas (9 days to 12 years post-injury), avulsion injured DRG, control nerves and DRG, and rat CCI model tissues. EP1 and NF-immunoreactive nerve fibres were quantified by image analysis. Results EP1:NF ratio was significantly increased in human brachial plexus nerve fibres, both proximal and distal to injury, in comparison with uninjured nerves. Sensory neurones in injured human DRG showed a significant acute increase of EP1-IR intensity. While there was a rapid increase in EP1-fibres and CD-68 positive macrophages, Cox-2 increase was apparent later, but was persistent in human painful neuromas for years. A similar time-course of changes was found in the rat CCI model with the above markers, both in the injured nerves and ipsilateral dorsal spinal cord. Conclusion Different stages of infiltration and activation of macrophages may be observed in the peripheral and central nervous system following peripheral nerve injury. EP1 receptor level increase in sensory neurones, and macrophage infiltration, appears to precede increased Cox-2 expression by macrophages. However, other methods for detecting Cox-2 levels and activity are required. EP1 antagonists may show therapeutic effects in acute and chronic neuropathic pain, in addition to inflammatory pain. PMID:16393343

Durrenberger, Pascal F; Facer, Paul; Casula, Maria A; Yiangou, Yiangos; Gray, Roy A; Chessell, Iain P; Day, Nicola C; Collins, Sue D; Bingham, Sharon; Wilson, Alex W; Elliot, David; Birch, Rolfe; Anand, Praveen

2006-01-01

362

Vagus Nerve Stimulation  

Microsoft Academic Search

Vagus nerve stimulation (VNS) is a safe and reliable treatment adjunct for patients with medically intractable epilepsy. It is both a preventive and an abortive form of therapy, potentially effective against both partial and generalized seizures in adults and children. VNS also has a number of serendipitous effects on mood, memory, and attention and has been approved for the treatment

Arun Paul Amar; Michael L. Levy; Charles Y. Liu; Michael L. J. Apuzzo

2008-01-01

363

Ischemic Nerve Block.  

ERIC Educational Resources Information Center

This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…

Williams, Ian D.

364

Segmental thoracic lipomatosis of nerve with nerve territory overgrowth.  

PubMed

Lipomatosis of nerve (LN), or fibrolipomatous hamartoma, is a rare condition of fibrofatty enlargement of the peripheral nerves. It is associated with bony and soft tissue overgrowth in approximately one-third to two-thirds of cases. It most commonly affects the median nerve at the carpal tunnel or digital nerves in the hands and feet. The authors describe a patient with previously diagnosed hemihypertrophy of the trunk who had a history of large thoracic lipomas resected during infancy, a thoracic hump due to adipose proliferation within the thoracic paraspinal musculature, and scoliotic deformity. She had fatty infiltration in the thoracic spinal nerves on MRI, identical to findings pathognomonic of LN at better-known sites. Enlargement of the transverse processes at those levels and thickened ribs were also found. This case appears to be directly analogous to other instances of LN with overgrowth, except that this case involved axial nerves rather than the typical appendicular nerves. PMID:24506247

Mahan, Mark A; Amrami, Kimberly K; Howe, B Matthew; Spinner, Robert J

2014-05-01

365

Facial and glossal distribution of anaesthesia after inferior alveolar nerve block.  

PubMed

The aim of this study was to subjectively determine the distribution of anaesthesia by mapping areas of sensory loss following inferior alveolar nerve block. Fifty healthy dental students were the subjects of this study (men 32, women 18). They were asked to draw the anaesthetized area on a diagram of the face and tongue 20 min after inferior alveolar nerve block. They evaluated the degree of anaesthesia by touching their faces and moving their tongues. All of the 50 subjects reported anaesthesia in the facial area. Of these, 21 (42%) reported the cutaneous distribution of anaesthesia on mental nerve territory only. Seventeen subjects (34%) reported anaesthesia on mental and buccal nerve territory. Nine subjects (18%) reported anaesthesia on mental, buccal, and auriculotemporal nerve territory. Two subjects (4%) reported anaesthesia on mental and auriculotemporal nerve territory and one subject (2%) on mental, buccal and infra-orbital nerve territory. Forty-seven of the 50 subjects (94%) reported anaesthesia of the tongue with the various degree of anaesthesia according to the area. Of these, 17 subjects (34%) reported strong anaesthesia on the anterior area and weak anaesthesia on the middle part of the tongue. Nineteen subjects (38%) reported strong anaesthesia of the lateral area and weak anaesthesia on the medial area, and 11 subjects (22%) reported anaesthesia on only the lateral side of the tongue. Three subjects (6%) reported no anaesthesia of the tongue. The distribution of anaesthesia of the facial and glossal regions determined subjectively after inferior alveolar nerve block, varies significantly between individuals. PMID:12535147

Kim, H-K; Lee, Y-S; Kho, H-S; Yum, K-W; Chung, S-C

2003-02-01

366

Salinibacter Sensory Rhodopsin  

PubMed Central

Halobacterium salinarum sensory rhodopsin I (HsSRI), a dual receptor regulating both negative and positive phototaxis in haloarchaea, transmits light signals through changes in protein-protein interactions with its transducer, halobacterial transducer protein I (HtrI). Haloarchaea also have another sensor pigment, sensory rhodopsin II (SRII), which functions as a receptor regulating negative phototaxis. Compared with HsSRI, the signal relay mechanism of SRII is well characterized because SRII from Natronomonus pharaonis (NpSRII) is much more stable than HsSRI and HsSRII, especially in dilute salt solutions and is much more resistant to detergents. Two genes encoding SRI homologs were identified from the genome sequence of the eubacterium Salinibacter ruber. Those sequences are distantly related to HsSRI (?40% identity) and contain most of the amino acid residues identified as necessary for its function. To determine whether those genes encode functional protein(s), we cloned and expressed them in Escherichia coli. One of them (SrSRI) was expressed well as a recombinant protein having all-trans retinal as a chromophore. UV-Vis, low-temperature UV-Vis, pH-titration, and flash photolysis experiments revealed that the photochemical properties of SrSRI are similar to those of HsSRI. In addition to the expression system, the high stability of SrSRI makes it possible to prepare large amounts of protein and enables studies of mutant proteins that will allow new approaches to investigate the photosignaling process of SRI-HtrI. PMID:18566451

Kitajima-Ihara, Tomomi; Furutani, Yuji; Suzuki, Daisuke; Ihara, Kunio; Kandori, Hideki; Homma, Michio; Sudo, Yuki

2008-01-01

367

Diagnostic challenges in movement disorders: Sensory Ataxia Neuropathy Dysarthria and Ophthalmoplegia (SANDO) syndrome.  

PubMed

A woman in her early 60s presented to our Movement Disorders Centre with a 5-year history of progressive peripheral neuropathy, gait instability with falls, blurred vision, cognitive impairment and tremors. The patient was found to have profound sensory ataxia, chronic ophthalmoplegia, dementia with significant deficits in registration and construction and bilateral resting tremor of the hands. Investigations revealed an unremarkable MRI of the brain, negative cerebrospinal fluid studies, and unremarkable chemistries. Nerve conduction studies found a severe sensorimotor axonal polyneuropathy. Genetic testing revealed a compound heterozygous mutation in the POLG1 gene consistent with the diagnosis of Sensory Ataxia Neuropathy Dysarthria and Ophthalmoplegia (SANDO) syndrome. PMID:23997076

Lovan, Alyson; Ihtsham ul Haq; Balakrishnan, Nikhil

2013-01-01

368

Capsaicin-sensitive sensory neurons regulate myocardial function and gene expression pattern of rat hearts: a DNA microarray study  

Microsoft Academic Search

We have previously shown that capsaicin-sensitive sensory nerves contribute to the regulation of normal cardiac function and to the development of cardiac adaptation to ischemic stress; however, the underlying molecular mechanisms remain unknown. Therefore, here we assessed cardiac functional alterations and relative gene expression changes by DNA microarray analysis of 6400 genes in rat hearts 7 days after the end

A. Zvara; Péter Bencsik; Gabriella Fodor; Tamás Csont; László Hackler; Mária Dux; Susanna Fürst; Gábor Jancsó; László G. Puskás; Péter Ferdinandy

2005-01-01

369

Topohistology of sympathetic and parasympathetic nerve fibers in branches of the pelvic plexus: an immunohistochemical study using donated elderly cadavers  

PubMed Central

Although the pelvic autonomic plexus may be considered a mixture of sympathetic and parasympathetic nerves, little information on its composite fibers is available. Using 10 donated elderly cadavers, we investigated in detail the topohistology of nerve fibers in the posterior part of the periprostatic region in males and the infero-anterior part of the paracolpium in females. Neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP) were used as parasympathetic nerve markers, and tyrosine hydroxylase (TH) was used as a marker of sympathetic nerves. In the region examined, nNOS-positive nerves (containing nNOS-positive fibers) were consistently predominant numerically. All fibers positive for these markers appeared to be thin, unmyelinated fibers. Accordingly, the pelvic plexus branches were classified into 5 types: triple-positive mixed nerves (nNOS+, VIP+, TH+, thick myelinated fibers + or -); double-positive mixed nerves (nNOS+, VIP-, TH+, thick myelinated fibers + or -); nerves in arterial walls (nNOS-, VIP+, TH+, thick myelinated fibers-); non-parasympathetic nerves (nNOS-, VIP-, TH+, thick myelinated fibers + or -); (although rare) pure sensory nerve candidates (nNOS-, VIP-, TH-, thick myelinated fibers+). Triple-positive nerves were 5-6 times more numerous in the paracolpium than in the periprostatic region. Usually, the parasympathetic nerve fibers did not occupy a specific site in a nerve, and were intermingled with sympathetic fibers. This morphology might be the result of an "incidentally" adopted nerve fiber route, rather than a target-specific pathway. PMID:24693483

Hieda, Keisuke; Sasaki, Hiromasa; Murakami, Gen; Abe, Shinichi; Matsubara, Akio; Miyake, Hideaki; Fujisawa, Masato

2014-01-01

370

Laryngopharyngeal sensory discrimination testing and the laryngeal adductor reflex.  

PubMed

Laryngopharyngeal sensory capacity has been determined by endoscopically administering air pulse stimuli to the mucosa innervated by the superior laryngeal nerve and asking the patient if he or she feels the stimulus. A potential shortcoming of this psychophysical testing (PT) procedure is that it is a subjective test, and patients with impaired cognition may not be able to perform the required task. In the search for an objective measure of laryngeal sensory function, we have observed that the laryngeal adductor reflex (LAR) is evoked at stimulus intensities similar to those capable of eliciting the psychophysical, or perceptual, response. The purpose of this study is to determine if the threshold for eliciting the LAR is the same as that of the sensory threshold. A specially designed endoscope was used to present air pulse stimuli (range 0.0 to 10 mm Hg) to the laryngopharynx in 20 healthy subjects and in 80 patients with dysphagia, using both PT and the LAR. The patients had a variety of underlying diagnoses, with stroke and chronic neurologic disease predominating (n = 65). In the control group and in the group of patients with dysphagia, there was no statistically significant difference between the median laryngopharyngeal sensory thresholds whether we used PT or the LAR (p>.05, Wilcoxon signed-rank test). The intraclass correlation for the total sample was .999 (U = .999, L = .998). Since psychophysical and sensorimotor reflex thresholds were not statistically significantly different and the intraclass correlation was close to a perfect correlation, we conclude that the LAR can be used as an objective and accurate clinical method of endoscopically assessing laryngopharyngeal sensory capacity. PMID:10453777

Aviv, J E; Martin, J H; Kim, T; Sacco, R L; Thomson, J E; Diamond, B; Close, L G

1999-08-01

371

Reversible Nerve Damage and Corneal Pathology in Murine Herpes Simplex Stromal Keratitis  

PubMed Central

ABSTRACT Herpes simplex virus type 1 (HSV-1) shedding from sensory neurons can trigger recurrent bouts of herpes stromal keratitis (HSK), an inflammatory response that leads to progressive corneal scarring and blindness. A mouse model of HSK is often used to delineate immunopathogenic mechanisms and bears many of the characteristics of human disease, but it tends to be more chronic and severe than human HSK. Loss of blink reflex (BR) in human HSK is common and due to a dramatic retraction of corneal sensory nerve termini in the epithelium and the nerve plexus at the epithelial/stromal interface. However, the relationship between loss of BR due to nerve damage and corneal pathology associated with HSK remains largely unexplored. Here, we show a similar retraction of corneal nerves in mice with HSK. Indeed, we show that much of the HSK-associated corneal inflammation in mice is actually attributable to damage to the corneal nerves and accompanying loss of BR and can be prevented or ameliorated by tarsorrhaphy (suturing eyelids closed), a clinical procedure commonly used to prevent corneal exposure and desiccation. In addition, we show that HSK-associated nerve retraction, loss of BR, and severe pathology all are reversible and regulated by CD4+ T cells. Thus, defining immunopathogenic mechanisms of HSK in the mouse model will necessitate distinguishing mechanisms associated with the immunopathologic response to the virus from those associated with loss of corneal sensation. Based on our findings, investigation of a possible contribution of nerve damage and BR loss to human HSK also appears warranted. IMPORTANCE HSK in humans is a potentially blinding disease characterized by recurrent inflammation and progressive scarring triggered by viral release from corneal nerves. Corneal nerve damage is a known component of HSK, but the causes and consequences of HSK-associated nerve damage remain obscure. We show that desiccation of the corneal surface due to nerve damage and associated loss of BR severely exacerbates and prolongs inflammation-induced pathology in mice. Preventing corneal desiccation results in a milder and more transient HSK with variable scarring that mirrors HSK seen in most humans. We further show that nerve damage is reversible and regulated by CD4+ T cells. Thus, we provide a mouse model that more closely resembles typical human HSK and suggest nerve damage is an important but largely overlooked factor in human disease. PMID:24789786

Yun, Hongmin; Rowe, Alexander M.; Lathrop, Kira L.; Harvey, Stephen A. K.

2014-01-01

372

Enhancement by calcitonin gene-related peptide of non-contractile Ca2(+)-induced nicotinic receptor desensitization at the mouse neuromuscular junction.  

PubMed Central

1. Nicotinic acetylcholine receptor (AChR)-operated non-contractile Ca2+ mobilization (unaccompanied by muscle contraction) depressed contractile Ca2+ mobilization (accompanied by muscle contraction) in mouse diaphragm muscles. In the process of nicotinic AChR desensitization, the enhancing role of calcitonin gene-related peptide (CGRP) on the non-contractile Ca2(+)-induced depression of contractile Ca2+ mobilization was investigated by measurement of Ca2(+)-aequorin luminescence in the presence of neostigmine (0.1 microM). 2. When the phrenic nerve was stimulated with paired pulses at intervals of 150, 300, 600, 1000 and 2000 ms, contractile Ca2+ transients were elicited during the generation of non-contractile Ca2+ mobilization. The amplitude of the contractile Ca2 transients elicited by the second pulse (S2) was depressed at the shorter pulse intervals, but not at the longer pulse intervals. 3. The extent of depression of S2 was enhanced when the duration of non-contractile Ca2+ mobilization was prolonged by CGRP (10 nM). However, CGRP failed to enhance the depression of S2 when non-contractile Ca2+ mobilization was not observed at the low external Ca2+ concentration (1.3 mM). 4. The enhancing effect by CGRP on the depression of S2 was counteracted by staurosporine (3 nM), a protein kinase-C inhibitor, despite prolongation of the duration of non-contractile Ca2+ mobilization. 5. When H-89 (1 microM), a protein kinase-A inhibitor, completely blocked non-contractile Ca2+ mobilization, the depression of S2 was diminished. The prolongation of the duration of non-contractile Ca2+ mobilization by AA373 (300 microM), a protein kinase-A activator, enhanced the depression of S2. The enhancing effect was observed neither with CGRP nor with AA373, in the presence of H-89 (0.1 microM). 6. These findings suggest that the CGRP mobilizes non-contractile Ca2+ through activation of protein kinase-A, which in turn may activate protein kinase-C, then enhance the desensitization of postsynaptic nicotinic AChRs at the neuromuscular junction. Images Figure 4 PMID:8864531

Dezaki, K.; Kimura, I.; Tsuneki, H.; Kimura, M.

1996-01-01

373

The central projections of the laryngeal nerves in the rat  

PubMed Central

The larynx serves respiratory, protective, and phonatory functions. The motor and sensory innervation to the larynx controlling these functions is provided by the superior laryngeal nerve (SLN) and the recurrent laryngeal nerve (RLN). Classical studies state that the SLN innervates the cricothyroid muscle and provides sensory innervation to the supraglottic cavity, whereas the RLN supplies motor innervation to the remaining intrinsic laryngeal muscles and sensory innervation to the infraglottic cavity, but recent data suggest a more complex anatomical and functional organisation. The current neuroanatomical tracing study was undertaken to provide a comprehensive description of the central brainstem connections of the axons within the SLN and the RLN, including those neurons that innervate the larynx. The study has been carried out in 41 adult male Sprague–Dawley rats. The central projections of the laryngeal nerves were labelled following application of biotinylated dextran amines onto the SLN, the RLN or both. The most remarkable result of the study is that in the rat the RLN does not contain any afferent axons from the larynx, in contrast to the pattern observed in many other species including man. The RLN supplied only special visceromotor innervation to the intrinsic muscles of the larynx from motoneurons in the nucleus ambiguus (Amb). All the afferent axons innervating the larynx are contained within the SLN, and reach the nucleus of the solitary tract. The SLN also contained secretomotor efferents originating from motoneurons in the dorsal motor nucleus of the vagus, and special visceral efferent fibres from the Amb. In conclusion, the present study shows that in the rat the innervation of the larynx differs in significant ways from that described in other species. PMID:21599662

Pascual-Font, Arán; Hernández-Morato, Ignacio; McHanwell, Stephen; Vázquez, Teresa; Maranillo, Eva; Sañudo, Jose; Valderrama-Canales, Francisco J

2011-01-01

374

Ultrasound of Peripheral Nerves  

PubMed Central

Over the last decade, neuromuscular ultrasound has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent papers outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasound is well suited for use in electrodiagnostic laboratories where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management. PMID:23314937

Suk, Jung Im; Walker, Francis O.; Cartwright, Michael S.

2013-01-01

375

A Case of Acute Motor and Sensory Axonal Neuropathy Following Hepatitis A Infection  

PubMed Central

Acute motor and sensory axonal neuropathy (AMSAN) are recently described subtypes of Guillain-Barre syndrome characterized by acute onset of distal weakness, loss of deep tendon reflexes, and sensory symptoms. A 21-yr-old male was transferred to our hospital due to respiration difficulties and progressive weakness. In laboratory findings, immunoglobulin M antibodies against hepatitis A were detected in blood and cerebrospinal fluid. The findings of motor nerve conduction studies showed markedly reduced amplitudes of compound muscle action potentials in bilateral peroneal, and posterior tibial nerves, without evidence of demyelination. Based on clinical features, laboratory findings, and electrophysiologic investigation, the patient was diagnosed the AMSAN following acute hepatitis A viral infection. The patient was treated with intravenous immunoglobulin and recovered slowly. Clinicians should consider this rare but a serious case of AMSAN following acute hepatitis A infection. PMID:24339719

Jo, Yoon-Sik; Han, Sang-Don; Choi, Jin-Yong; Kim, Ick Hee; Kim, Yong-Duk

2013-01-01

376

Neurological Complications in Thyroid Surgery: A Surgical Point of View on Laryngeal Nerves  

PubMed Central

The cervical branches of the vagus nerve that are pertinent to endocrine surgery are the superior and the inferior laryngeal nerves: their anatomical course in the neck places them at risk during thyroid surgery. The external branch of the superior laryngeal nerve (EB) is at risk during thyroid surgery because of its close anatomical relationship with the superior thyroid vessels and the superior thyroid pole region. The rate of EB injury (which leads to the paralysis of the cricothyroid muscle) varies from 0 to 58%. The identification of the EB during surgery helps avoiding both an accidental transection and an excessive stretching. When the nerve is not identified, the ligation of superior thyroid artery branches close to the thyroid gland is suggested, as well as the abstention from an indiscriminate use of energy-based devices that might damage it. The inferior laryngeal nerve (RLN) runs in the tracheoesophageal groove toward the larynx, close to the posterior aspect of the thyroid. It is the main motor nerve of the intrinsic laryngeal muscles, and also provides sensory innervation to the larynx. Its injury finally causes the paralysis of the omolateral vocal cord and various sensory alterations: the symptoms range from mild to severe hoarseness, to acute airway obstruction, and swallowing impairment. Permanent lesions of the RNL occur from 0.3 to 7% of cases, according to different factors. The surgeon must be aware of the possible anatomical variations of the nerve, which should be actively searched for and identified. Visual control and gentle dissection of RLN are imperative. The use of intraoperative nerve monitoring has been safely applied but, at the moment, its impact in the incidence of RLN injuries has not been clarified. In conclusion, despite a thorough surgical technique and the use of intraoperative neuromonitoring, the incidence of neurological complications after thyroid surgery cannot be suppressed, but should be maintained in a low range. PMID:25076936

Varaldo, Emanuela; Ansaldo, Gian Luca; Mascherini, Matteo; Cafiero, Ferdinando; Minuto, Michele N.

2014-01-01

377

Posttraumatic osseous tunnel formation causing sciatic nerve entrapment.  

PubMed

Sciatic nerve entrapment in an osseous tunnel has only been reported twice previously. We describe a 19-year-old man evaluated for left lower limb pain and weakness that began one and one half years after sustaining stab wounds to the left buttock and midline back near the T11 vertebrae. The patient had sciatica and demonstrated motor and sensory deficits on physical exam. Electrodiagnostic studies demonstrated a localized injury to the sciatic nerve in the proximal thigh. Radiographic studies of the left pelvis and femur showed an 8 to 10cm linear opacification overshadowing the left femoral head and anatomic neck. An arteriogram of the left leg demonstrated a 3 x 4cm lobulated aneurysm arising from the distal portion of the inferior gluteal artery. Surgical exploration revealed the sciatic nerve to be encased in cylindrical bone. The ectopic bone was removed and the sciatic nerve released. The patient had gradual improvement with a nearly complete neurological recovery by three months after surgery. PMID:8489370

Kaplan, J L; Challenor, Y

1993-05-01

378

Dysfunctional penile cholinergic nerves in diabetic impotent men  

SciTech Connect

Impotence in the diabetic man may be secondary to a neuropathic condition of the autonomic penile nerves. The relationship between autonomic neuropathy and impotence in diabetes was studied in human corporeal tissue obtained during implantation of a penile prosthesis in 19 impotent diabetic and 15 nondiabetic patients. The functional status of penile cholinergic nerves was assessed by determining their ability to accumulate tritiated choline (34), and synthesize (34) and release (19) tritiated-acetylcholine after incubation of corporeal tissue with tritiated-choline (34). Tritiated-choline accumulation, and tritiated-acetylcholine synthesis and release were significantly reduced in the corporeal tissue from diabetic patients compared to that from nondiabetic patients (p less than 0.05). The impairment in acetylcholine synthesis worsened with the duration of diabetes (p less than 0.025). No differences in the parameters measured were found between insulin-dependent (11) and noninsulin-dependent (8) diabetic patients. The ability of the cholinergic nerves to synthesize acetylcholine could not be predicted clinically with sensory vibration perception threshold testing. It is concluded that there is a functional penile neuropathic condition of the cholinergic nerves in the corpus cavernosum of diabetic impotent patients that may be responsible for the erectile dysfunction.

Blanco, R.; Saenz de Tejada, I.; Goldstein, I.; Krane, R.J.; Wotiz, H.H.; Cohen, R.A. (Boston Univ. School of Medicine, MA (USA))

1990-08-01

379

Localization and control of activity in peripheral nerves.  

PubMed

Interest in the field of the natural control of human limb using physiological signals has risen dramatically in the past 20 years due to the success of the brain machine interface. Cortical signals carry significant information but are difficult to access. The peripheral nerves of the body carry both command and sensory signals and are far more accessible. While numerous studies have documented the selective stimulation properties of, conventionally round, nerve cuff electrodes (i.e., transverse geometry) and even self-sizing electrodes, recording the activity levels from individual fascicles using these electrodes is still an unsolved problem. Moreover, the control algorithms for the control of joint movement with multiple contact electrodes such as the flat interface nerve electrode (FINE) have been difficult to implement. We propose solutions to both these problems by using beam forming techniques to detect the location and the activity in various fascicles. We also developed a control algorithm that separates the dynamic from the passive properties to solve the redundancy problem in multiple joint problems. This techniques could find application in the natural control of artificial limbs from peripheral nerve signals for patients with amputated limbs or to restore function in patients with stroke or paralyzed limbs. PMID:19163426

Durand, D M; Park, H J; Wodlinger, B

2008-01-01

380

Sensory functions in the foot soles in victims of generalized torture, in victims also beaten under the feet (falanga) and in healthy controls – A blinded study using quantitative sensory testing  

PubMed Central

Background Falanga torture (beatings on the foot soles) produces local chronic pain and severe walking difficulties. We have previously reported signs of neuropathic pain in the feet of falanga victims. The objective here was to clarify underlying pain mechanisms by quantifying sensory impairments in the feet of torture victims who had experienced both generalized torture and those who had been exposed to falanga in addition. An ethnically matched control group was available. Methods We employed quantitative sensory testing (QST) by investigators blinded to whether the patients, 32 male torture victims from the Middle East, had (n=15), or had not (n=17) been exposed to falanga. Pain intensity, area and stimulus dependence were used to characterize the pain as were interview data on sensory symptoms. QST included thresholds for touch, cold, warmth, cold-pain, heat-pain, deep pressure pain and wind-up to cutaneous noxious stimuli in the foot soles. Clinical data on anxiety and depression were retrieved. Results Almost all falanga victims had moderate or strong pain in their feet and in twice as large an area of their foot soles as other torture victims. One-third of the latter had no pain in their feet and many reported slight pain; in spite of this, there were no differences in foot sole QST data between the tortured groups. A comparison with normal data indicated that both tortured groups had hypoesthesia for all cutaneous sensory fibre groups except those transmitting cold and heat pain, in addition to deep mechano-nociceptive hyperalgesia. Conclusion A comparison of the QST data between victims having been exposed to generalized torture and victims who in addition had been exposed to falanga, showed no differences on the group level. The sensory disturbances in relation to our control group are compatible with central sensitization and de-sensitization, pointing to a core role of central mechanisms. A further analysis to create individual sensory profiles from our measurements is in progress. PMID:23272808

2012-01-01

381

Sensory Ecology, Winter 2011 Stuart Thompson  

E-print Network

vision in mate selection in fishes Adaptations for seeing at very low light levels The role of visual on the adaptations of sensory systems to aquatic life and on the importance of sensory systems to the ecology will study the role of sensory adaptations in behavior and ecology. TOPICS The sensory world The kinds

382

The Efficacy of Sensory Integration Procedures  

Microsoft Academic Search

The purpose of this paper is to report on the status of research which has been de- signed to determine the effectiveness of occupational and physical therapy using sensory integration (SI) procedures. Sensory integration efficacy is the extent to which sensory integra- tion procedures have proven to be beneficial. (A reference list of sensory integration efficacy studies is available from

Sharon A. Cermak; Anne Henderson

383

Nociceptive Sensory Neurons Drive Interleukin-23 Mediated Psoriasiform Skin Inflammation  

PubMed Central

The skin has a dual function as a barrier and a sensory interface between the body and the environment. To protect against invading pathogens, the skin harbors specialized immune cells, including dermal dendritic cells (DDCs) and interleukin (IL)-17 producing ?? T cells (??T17), whose aberrant activation by IL-23 can provoke psoriasis-like inflammation1–4. The skin is also innervated by a meshwork of peripheral nerves consisting of relatively sparse autonomic and abundant sensory fibers. Interactions between the autonomic nervous system and immune cells in lymphoid organs are known to contribute to systemic immunity, but how peripheral nerves regulate cutaneous immune responses remains unclear5,6. Here, we have exposed the skin of mice to imiquimod (IMQ), which induces IL-23 dependent psoriasis-like inflammation7,8. We show that a subset of sensory neurons expressing the ion channels TRPV1 and NaV1.8 is essential to drive this inflammatory response. Imaging of intact skin revealed that a large fraction of DDCs, the principal source of IL-23, is in close contact with these nociceptors. Upon selective pharmacological or genetic ablation of nociceptors9–11, DDCs failed to produce IL-23 in IMQ exposed skin. Consequently, the local production of IL-23 dependent inflammatory cytokines by dermal ??T17 cells and the subsequent recruitment of inflammatory cells to the skin were dramatically reduced. Intradermal injection of IL-23 bypassed the requirement for nociceptor communication with DDCs and restored the inflammatory response12. These findings indicate that TRPV1+NaV1.8+ nociceptors, by interacting with DDCs, regulate the IL-23/IL-17 pathway and control cutaneous immune responses. PMID:24759321

Riol-Blanco, Lorena; Ordovas-Montanes, Jose; Perro, Mario; Naval, Elena; Thiriot, Aude; Alvarez, David; Wood, John N.; von Andrian, Ulrich H.

2014-01-01

384

Sensory neuronopathy complicating systemic lupus erythematosus: a case report  

PubMed Central

Introduction Systemic lupus erythematosus is a multi-system connective tissue disorder. Peripheral neuropathy is a known and underestimated complication in systemic lupus erythematosus. Ganglionopathy manifests when neuronal cell bodies in the dorsal root ganglion are involved. Autoimmune disorders are a known etiology, with systemic lupus erythematosus being a rare cause. Case presentation A 32-year-old South Asian woman presented with oral ulceration involving her lips following initiation of treatment for a febrile illness associated with dysuria. She had a history of progressively worsening numbness over a period of 4 months involving both the upper and lower limbs symmetrically while sparing the trunk. Her vibration sense was impaired, and her reflexes were diminished. For the past 4 years, she had had a bilateral, symmetrical, non-deforming arthritis involving the upper and lower limbs. Her anti-nuclear antibody and anti-double-stranded deoxyribonucleic acid status were positive. Although her anti-Ro antibodies were positive, she did not have clinical features suggestive of Sjögren syndrome. Nerve conduction studies revealed sensory neuronopathy. A diagnosis of systemic lupus erythematosus complicated by sensory neuronopathy was made. Treatment with intravenous immunoglobulin resulted in clinical and electrophysiological improvement. Conclusion Peripheral neuropathy in systemic lupus erythematosus can, by itself, be a disabling feature. Nerve conduction studies should be considered when relevant. Neuropathy in systemic lupus erythematosus should be given greater recognition, and rarer forms of presentation should be entertained in the differential diagnosis when the clinical picture is atypical. Intravenous immunoglobulin may have role in treatment of sensory neuronopathy in systemic lupus erythematosus. PMID:24884917

2014-01-01

385

Prostanoid receptor EP1 and Cox2 in injured human nerves and a rat model of nerve injury: a time-course study  

Microsoft Academic Search

BACKGROUND: Recent studies show that inflammatory processes may contribute to neuropathic pain. Cyclooxygenase-2 (Cox-2) is an inducible enzyme responsible for production of prostanoids, which may sensitise sensory neurones via the EP1 receptor. We have recently reported that while macrophages infiltrate injured nerves within days of injury, they express increased Cox-2-immunoreactivity (Cox-2-IR) from 2 to 3 weeks after injury. We have

Pascal F Durrenberger; Paul Facer; Maria A Casula; Yiangos Yiangou; Roy A Gray; Iain P Chessell; Nicola C Day; Sue D Collins; Sharon Bingham; Alex W Wilson; David Elliot; Rolfe Birch; Praveen Anand

2006-01-01

386

Treatment of Diabetic Sensory Polyneuropathy  

Microsoft Academic Search

Opinion statement  No current disease-modifying treatments have been shown definitively in randomized clinical trials to reduce or reverse diabetic\\u000a sensory polyneuropathy (DSP). It is increasingly recognized that individuals with “prediabetes” or impaired glucose regulation\\u000a can already have a “small-fiber” neuropathy, or mild DSP, in which sensory axons of both small and larger diameter are damaged.\\u000a Small-fiber neuropathy is frequently associated with

Lindsay Zilliox; James W. Russell

2011-01-01

387

Neurotrophin3 Administration Attenuates Deficits of Pyridoxine-Induced Large-Fiber Sensory Neuropathy  

Microsoft Academic Search

Chronic treatment of adult rats for 2-3 weeks with high doses of pyridoxine (vitamin B6) produced a profound proprioceptive loss, similar to that found in humans overdosed with this vita- min or treated with the chemotherapeutic agent cisplatin. Pyr- idoxine toxicity was manifest as deficits in simple and precise locomotion and sensory nerve function and as degeneration of large-diameter\\/large-fiber spinal

Maureen E. Helgren; Kenneth D. Cliffer; Kim Torrento; Chris Cavnor; Rory Curtis; Peter S. DiStefano; Stanley J. Wiegand; Ronald M. Lindsay

1997-01-01

388

Sensory peptides as neuromodulators of wound healing in aged rats.  

PubMed

An intact nociceptor system of primary afferent sensory nerves is important for the initiation of the inflammatory process and successful tissue repair. Dysfunction of this system with age could be a contributing factor for delayed wound healing in the elderly. This study was designed to examine the role of sensory nerves (using capsaicin-pretreated rats) and the effect of aging on the healing of a thermal wound induced on the interscapular region (using a CO2 laser). The healing endpoint was the time when full wound contraction had occurred. The ability of the sensory peptides, substance P (SP) and calcitonin gene-related peptide (CGRP), in modulating wound healing in aged rats was examined by taking into account the modulatory interaction effects between these peptides. A blister model in the rat hind footpad combined with a laser Doppler flowmeter was used initially to establish these vascular interaction effects. The results showed a significant delay in thermal wound healing in both the capsaicin-treated and aged rats. Using the blister model, we demonstrated the ability of SP and CGRP to induce a limited and a prolonged vasodilator response, respectively. When tested together, SP attenuated the vascular effect of CGRP, an effect that was reversed using the tachykinin antagonist spantide II. When injected at the wound site, SP and CGRP were equally potent in promoting wound healing in aged rats. The beneficial effect of taking the interaction effects into account was most evident in a group of rats that received the tachykinin antagonist as part of their initial treatment with CGRP and 6 h later, an injection of SP; the time to complete wound closure was 11.3 +/- 0.6 days compared to 21.0 +/- 0.9 days in aged controls. We contend that would healing in aged rats can be accelerated by exogenous administration of sensory peptides. Furthermore, modulatory interaction effects between sensory peptides should be taken into consideration when designing any treatment protocol that purports to accelerate wound healing. PMID:8808984

Khalil, Z; Helme, R

1996-09-01

389

Evaluation and use of regenerative multi electrode interfaces in peripheral nerves  

NASA Astrophysics Data System (ADS)

Peripheral nerves offer unique accessibility to the innate motor and sensory pathways that can be interfaced with high degree of selectivity for intuitive and bidirectional control of advanced upper extremity prosthetic limbs. Several peripheral nerve interfaces have been proposed and investigated over the last few decades with significant progress made in the area of sensory feedback. However, clinical translation still remains a formidable challenge due to the lack of long term recordings. Prominent causes include signal degradation, eventual interface failures, and lack of specificity in the low amplitude nerve signals. This dissertation evaluates the capabilities of the newly developed Regenerative Multi-electrode Interface (REMI) by the characterization of signal quality progression, the identification of interfaced axon types, and the demonstration of "functional linkage" between acquired signals and target organs. Chapter 2 details the chronic recording of high quality signals from REMI in sciatic nerve which remained stable over a 120 day implantation period indicative of minimal ongoing tissue response with no detrimental effects on the recording ability. The dominant cause of failures was attributable to abiotic factors pertaining to the connector/wire breakage, observed in 76% of REMI implants. Also, the REMI implants had 20% higher success rate and significantly larger Signal to Noise Ratio (SNR) in comparison to the Utah Slanted Electrode Array (USEA). Chapter 3 describes the successful feasibility of interfacing with motor and sensory axons by REMI implantation in the tibial and sural fascicles of the sciatic nerve. A characteristic sampling bias towards recording signals from medium-to-large diameter axons that are primarily involved in mechanoception and proprioception sensory functions was uncovered. Specific bursting units (Inter Spike Interval of 30-70ms) were observed most frequently from the tibial fascicle during bipedal locomotion. Chapter 4 explores the discrimination between motor and proprioceptive origin of this bursting activity and reports the identified efferent motor nature, as well as the demonstration of a significant and stable correlation with the activity of distal muscle involved in locomotion. In summary, sensory-motor neural activity was recorded chronically by REMI electrodes with high SNR which serves as a tool for evaluating firing patterns of specific axon types during voluntary movement or sensory stimulation. In turn, this interface can be used to improve motor control and sensory feedback in closed loop systems for robotic prosthesis.

Desai, Vidhi

390

Pathological features of ganglioradiculitis (sensory neuropathy) in two dogs.  

PubMed

Canine ganglioradiculitis (sensory neuropathy) was examined pathologically in two dogs (dog Nos. 1 and 2). The affected dogs had 1 and 2 years clinical courses from the onset, respectively. As common clinical signs, both cases showed progressive ataxia, difficulty in prehending food, visual deficit, and several sensory abnormalities. Gross observation after tissue fixation revealed whitish discoloration in the dorsal column of the spinal cords. The histological lesions were mainly distributed in the spinal dorsal roots, ganglions, and dorsal columns. In the spinal dorsal roots and ganglions, there were striking myelin loss, mild infiltration of mononuclear cells, and proliferation of small spindle cells. In the dorsal funiculus, there were moderate to severe diffuse myelin-loss and axonal degeneration. Immunohistochemistry for substance P (SP) revealed marked reduction of SP-immunopositive granules in the spinal substantia gelatinosa of affected dogs. By immunohistochemistry, CD3-positive cells were observed in the dorsal roots of dog No. 2, while CD3-positive cells were rare in those of dog No. 1. In the spinal ganglion of dog No. 1 there were many CD3- and MHC class II-positive cells. By indirect immunofluorescence assay using sera from affected dogs, no autoantibodies against canine nerve tissues were detected. The clinicopathological features of the present cases are almost consistent with those in previous reports of canine sensory neuropathies, while the etiology remains unclear. PMID:18176020

Funamoto, Miwako; Nibe, Kazumi; Morozumi, Motoji; Edamura, Kazuya; Uchida, Kazuyuki

2007-12-01

391

Preventive effect of commercial desensitizing toothpastes on bovine enamel erosion in vitro.  

PubMed

This study evaluated in vitro commercial desensitizing toothpastes with respect to the prevention of erosion and explored the effect of their agents alone or in combination with fluoride. Bovine enamel blocks were randomly allocated to five groups of 20 and exposed to: Sensodyne ProNamel (1,425 ppm F as NaF, 5% KNO(3)), Sensodyne Original (no fluoride, 10% SrCl(2)), Colgate Sensitive (1,450 ppm F as sodium monofluorophosphate, 5% K citrate), Crest (fluoride-only toothpaste, 1,100 ppm F as NaF) and water (negative control). A second experiment was conducted with experimental dentifrices containing fluoride (NaF, 1,100 ppm F), 10% SrCl(2), 5% KNO(3 )or 5% K citrate alone or the latter three combined with F. The samples were submitted to four cycles, alternating demineralization (cola, 10 min) and remineralization (artificial saliva, 1 h). Before and between cyclic de- and remineralization, blocks were treated with slurries of the respective toothpastes or water (1 min). Erosive tissue loss was analyzed by profilometry. Data were analyzed by Kruskal-Wallis and Dunn's tests (p < 0.05). The mean erosion depth (+/- SE, mum) was significantly less for Colgate Sensitive (0.04 +/- 0.00), Sensodyne Original (0.06 +/- 0.01) and Crest (0.07 +/- 0.01) than for Sensodyne ProNamel (2.36 +/- 0.25) or water (2.92 +/- 0.24), which did not significantly differ from each other. Both F and the desensitizing agents alone reduced erosion, but no additive effect was found. In addition, the combination of F and KNO(3) did not reduce erosion. These in vitro results suggest that the presence of fluoride or desensitizing substances in toothpastes, alone or in combination, can reduce erosion of enamel, but this is not valid for all the formulations. PMID:20145397

Kato, M T; Lancia, M; Sales-Peres, S H C; Buzalaf, M A R

2010-01-01

392

Renal artery nerve distribution and density in the porcine model: biologic implications for the development of radiofrequency ablation therapies.  

PubMed

Catheter-based renal artery denervation has demonstrated to be effective in decreasing blood pressure among patients with refractory hypertension. The anatomic distribution of renal artery nerves may influence the safety and efficacy profile of this procedure. We aimed to describe the anatomic distribution and density of periarterial renal nerves in the porcine model. Thirty arterial renal sections were included in the analysis by harvesting a tissue block containing the renal arteries and perirenal tissue from each animal. Each artery was divided into 3 segments (proximal, mid, and distal) and assessed for total number, size, and depth of the nerves according to the location. Nerve counts were greatest proximally (45.62% of the total nerves) and decreased gradually distally (mid, 24.58%; distal, 29.79%). The distribution in nerve size was similar across all 3 sections (?40% of the nerves, 50-100 ?m; ?30%, 0-50 ?m; ?20%, 100-200 ?m; and ?10%, 200-500 ?m). In the arterial segments ?45% of the nerves were located within 2 mm from the arterial wall whereas ?52% of all nerves were located within 2.5 mm from the arterial wall. Sympathetic efferent fibers outnumbered sensory afferent fibers overwhelmingly, intermixed within the nerve bundle. In the porcine model, renal artery nerves are seen more frequently in the proximal segment of the artery. Nerve size distribution appears to be homogeneous throughout the artery length. Nerve bundles progress closer to the arterial wall in the distal segments of the artery. This anatomic distribution may have implications for the future development of renal denervation therapies. PMID:23911638

Tellez, Armando; Rousselle, Serge; Palmieri, Taylor; Rate, William R; Wicks, Joan; Degrange, Ashley; Hyon, Chelsea M; Gongora, Carlos A; Hart, Randy; Grundy, Will; Kaluza, Greg L; Granada, Juan F

2013-12-01

393

Acetylcholine and lobster sensory neurones  

PubMed Central

Experiments are presented in support of the hypothesis that acetylcholine functions as a sensory transmitter in the lobster nervous system. 1. Several different peripheral sensory structures incorporate radioactive choline into acetylcholine. The preparation most enriched in sensory as opposed to other nervous elements (the antennular sense organs of the distal outer flagellum) does not incorporate significant amounts of glutamate, tyrosine or tryptophan into any of the other major transmitter candidates. 2. There is a parallel between the distribution of the enzyme choline acetyltransferase and the proportion of sensory fibres in nervous tissue from many parts of the lobster nervous system. 3. Isolated sensory axons contain at least 500 times as much choline acetyltransferase per cm of axon as do efferent excitatory and inhibitory fibres. 4. Abdominal ganglia and root stumps show a decline in the rate of incorporation of choline into acetylcholine 2 to 8 weeks after severing the first and second roots bilaterally (leaving the connectives and third roots intact). Extracts of the root stumps exhibit a significantly lower level of choline acetyltransferase 2 weeks after this operation. 5. Curare and atropine partially block an identified sensory synapse in the lobster abdominal ganglion. ImagesText-fig. 4Text-fig. 5Plate 1 PMID:4343316

Barker, David L.; Herbert, Edward; Hildebrand, John G.; Kravitz, Edward A.

1972-01-01

394

A role for inflammatory mediators in heterologous desensitization of CysLT1 receptor in human monocytes  

PubMed Central

Cysteinyl-leukotrienes (cysteinyl-LT) are rapidly generated at sites of inflammation and, in addition to their role in asthma, rhinitis, and other immune disorders, are increasingly regarded as significant inflammatory factors in cancer, gastrointestinal, cardiovascular diseases. We recently demonstrated that in monocyte/macrophage–like U937 cells, extracellular nucleotides heterologously desensitize CysLT1 receptor (CysLT1R)-induced Ca2+ transients. Given that monocytes express a number of other inflammatory and chemoattractant receptors, this study was aimed at characterizing transregulation between these different stimuli. We demonstrate that in U937 cells and in primary human monocytes, a series of inflammatory mediators activating Gi-coupled receptor (FPR1, BLT1) desensitize CysLT1R-induced Ca2+ response unidirectionally through activation of PKC. Conversely, PAF-R, exclusively coupled to Gq, cross-desensitizes CysLT1R without the apparent involvement of any kinase. Interestingly, Gs-coupled receptors (?2AR, H1/2R, EP2/4R) are also able to desensitize CysLT1R response through activation of PKA. Heterologous desensitization seems to affect mostly the Gi-mediated signaling of the CysLT1R. The hierarchy of desensitization among agonists may be important for leukocyte signal processing at the site of inflammation. Considering that monocytes/macrophages are likely to be the major source of cysteinyl-LT in many immunological and inflammatory processes, shedding light on how their receptors are regulated will certainly help to better understand the role of these cells in orchestrating this complex network of integrated signals. PMID:19965602

Capra, Valérie; Accomazzo, Maria Rosa; Gardoni, Fabrizio; Barbieri, Silvia; Rovati, G. Enrico

2010-01-01

395

Mitogen-activated protein kinase is required for the behavioral desensitization that occurs after repeated injections of angiotensin II  

PubMed Central

Angiotensin II (AngII) acts on central angiotensin type 1 (AT1) receptors to increase water and saline intake. Prolonged exposure to AngII in cell culture models results in a desensitization of the AT1 receptor that is thought to involve receptor internalization, and a behavioral correlate of this desensitization has been shown in rats after repeated central injections of AngII. Specifically, rats given repeated injections of AngII drink less water than controls after a subsequent test injection of AngII. Under the same conditions, however, repeated injections of AngII have no effect on AngII-induced saline intake. Given earlier studies indicating that separate intracellular signaling pathways mediate AngII-induced water and saline intake, we hypothesized that the desensitization observed in rats may be incomplete, leaving the receptor able to activate mitogen-activated protein (MAP) kinases (ERK1/2), which play a role in AngII-induced saline intake without affecting water intake. In support of this hypothesis, we found no difference in MAP kinase phosphorylation after an AngII test injection in rats given prior treatment with repeated injections of vehicle, AngII, or Sar1,Ile4,Ile8-AngII (SII), an AngII analog that activates MAP kinase without G protein coupling. In addition, we found that pretreatment with the MAP kinase inhibitor U0126 completely blocked the desensitizing effect of repeated AngII injections on water intake. Furthermore, AngII-induced water intake was reduced similarly by repeated injections of AngII or SII. The results suggest that G protein-independent signaling is sufficient to produce behavioral desensitization of the angiotensin system and that the desensitization requires MAP kinase activation. PMID:22581747

Vento, Peter J.; Daniels, Derek

2013-01-01

396

Desensitization of pressed RDX/paraffin and HMX/paraffin compounds by multiple shock waves  

SciTech Connect

Multiple shock initiation of detonation in pressed RDX/paraffin and HMX/paraffin compounds is studied. If the explosive is preshocked by a weak shock wave, the effect of desensitization is observed, which is detectable by two features. First, a weak reaction appears behind the second shock wave. Second, the run to detonation increases by 100% for pressed RDX. Experiments with the samples of pressed RDX show that the run to detonation in preloaded explosive can be estimated from the distance at which the second wave overtakes the first weak shock; the run to detonation expected for the second shock wave, from Pop-plot data.

Bordzilovskii, S.A.; Karakhanov, S.M.

1995-09-01

397

Evidence of cellular nicotinic receptor desensitization in rats exhibiting nicotine-induced acute tolerance  

Microsoft Academic Search

Rationale  Individuals vary in their susceptibility to nicotine addiction. However, there is little evidence that behavioral sensitivity\\u000a to nicotine is dependent upon the functional state of nicotinic cholinergic receptors (nAChRs).\\u000a \\u000a \\u000a \\u000a Objective  To determine the relationship between in vivo pharmacological desensitization (in other words, acute tolerance) and brain\\u000a regional nAChR function.\\u000a \\u000a \\u000a \\u000a Methods  Male Sprague–Dawley rats, trained to discriminate nicotine (0.4 mg\\/kg free base) from saline

Susan E. Robinson; John R. James; Laura N. Lapp; Robert E. Vann; Daniel F. Gross; Scott D. Philibin; John A. Rosecrans

2006-01-01

398

Prolonged Exposure versus Eye Movement Desensitization and Reprocessing (EMDR) for PTSD rape victims.  

PubMed

This controlled study evaluated the relative efficacy of Prolonged Exposure (PE) and Eye Movement Desensitization and Reprocessing (EMDR) compared to a no-treatment wait-list control (WAIT) in the treatment of PTSD in adult female rape victims (n = 74). Improvement in PTSD as assessed by blind independent assessors, depression, dissociation, and state anxiety was significantly greater in both the PE and EMDR group than the WAIT group (n = 20 completers per group). PE and EMDR did not differ significantly for change from baseline to either posttreatment or 6-month follow-up measurement for any quantitative scale. PMID:16382428

Rothbaum, Barbara Olasov; Astin, Millie C; Marsteller, Fred

2005-12-01

399

The innervation pattern of the human Achilles tendon: studies of the normal and tendinosis tendon with markers for general and sensory innervation  

Microsoft Academic Search

Pain-free normal Achilles tendons and chronic painful Achilles tendons were examined by the use of antibodies against a general nerve marker (protein gene-product 9.5, PGP9.5), sensory markers (substance P, SP; calcitonin gene-related peptide, CGRP), and immunohistochemistry. In the normal tendons, immunoreactions against PGP9.5 and against SP\\/CGRP were encountered in the paratendinous loose connective tissue, being confined to nerve fascicles and

Dennis Bjur; Håkan Alfredson; Sture Forsgren

2005-01-01

400

Sensory Neuron Development in Mouse Coccygeal Vertebrae and Its Relationship to Tail Biopsies for Genotyping  

PubMed Central

A common method of genotyping mice is via tissue obtained from tail biopsies. However, there is no available information on the temporal development of sensory neurons in the tail and how their presence or absence might affect the age for performing tail biopsies. The goals of this study were to determine if afferent sensory neurons, and in particular nociceptive neurons, are present in the coccygeal vertebrae at or near the time of birth and if not, when they first can be visualized on or in those vertebrae. Using toluidine blue neuronal staining, transmission electron microscopy, and calcitonin-related gene peptide immunostaining, we found proximal to distal maturation of coccygeal nerve growth in the C57BL/6J mouse. Single nerve bundles were first seen on postpartum day (PPD) 0. On PPD 3 presumptive nociceptive sensory nerve fibers were seen entering the vertebral perichondrium. Neural development continued through the last time point (PPD 7) but at no time were neural fibers seen entering the body of the vertebrae. The effect of age on the development of pain perception in the neonatal mouse is discussed. PMID:24505409

Silverman, Jerald; Hendricks, Gregory

2014-01-01