Sample records for sensory nerve desensitization

  1. Sensory nerves and pancreatitis

    PubMed Central

    Li, Qingfu

    2014-01-01

    Sensory nerves are a kind of nerve that conduct afferent impulses from the periphery receptors to the central nervous system (CNS) and are able to release neuromediators from the activated peripheral endings. Sensory nerves are particularly important for microcirculatory response, and stimulation of pancreatic sensory nerves releases a variety of neuropeptides such as substance P (SP), calcitonin gene-related peptide (CGRP), etc., leading to neurogenic inflammation characterized as the local vasodilatation and plasma extravasation. Deactivation of sensory nerves often leads to the disturbances of pancreatic microcirculation. Pancreatitis is a common digestive disease that can lead to severe complications and even death if it goes untreated. Experimental studies in animals and tissue analysis in patients with pancreatitis have shown significant changes in sensory nerves supplying the pancreatic gland. Thus making clear the whole mechanism of pancreatitis is essential to treat and cure it. Sensory nerves may have a close correlation with the development of pancreatitis, and knowing more about the role of sensory nerve in pancreatitis is important for the treatment for pancreatitis. This review is aimed to summarize the relationship between sensory nerves and pancreatitis. PMID:25493260

  2. Bladder sensory desensitization decreases urinary urgency

    Microsoft Academic Search

    Carlos Silva; Joăo Silva; Helder Castro; Frederico Reis; Paulo Dinis; António Avelino; Francisco Cruz

    2007-01-01

    BACKGROUND: Bladder desensitization has been investigated as an alternative treatment for refractory detrusor overactivity. Most open and controlled clinical trials conducted with intravesical RTX showed that desensitization delays the appearance of involuntary detrusor contractions during bladder filling and decreases the number of episodes of urgency incontinence. Urgency is being recognised as the fundamental symptom of overactive bladder (OAB), a symptomatic

  3. Nerve Conduction Velocity of Small Components in Human Sensory Nerves

    Microsoft Academic Search

    W. Tackmann; R. Minkenberg

    1977-01-01

    Slow conducted components of sensory nerve action potentials were investigated in median and in sural nerves of controls and in patients with peripheral nerve diseases. In the normal group the slow components showed no relation to age which is in contrast to the maximum velocity. In both the median nerve and sural nerve of about 20% of the patients with

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  5. Functional selectivity and time-dependence of ?-opioid receptor desensitization at nerve terminals in the mouse ventral tegmental area

    PubMed Central

    Lowe, J D; Bailey, C P

    2015-01-01

    BACKGROUND AND PURPOSE The majority of studies examining desensitization of the ?-opioid receptor (MOR) have examined those located at cell bodies. However, MORs are extensively expressed at nerve terminals throughout the mammalian nervous system. This study is designed to investigate agonist-induced MOR desensitization at nerve terminals in the mouse ventral tegmental area (VTA). EXPERIMENTAL APPROACH MOR function was measured in mature mouse brain slices containing the VTA using whole-cell patch-clamp electrophysiology. Presynaptic MOR function was isolated from postsynaptic function and the functional selectivity, time-dependence and mechanisms of agonist-induced MOR desensitization were examined. KEY RESULTS MORs located at GABAergic nerve terminals in the VTA were completely resistant to rapid desensitization induced by the high-efficacy agonists DAMGO and Met-enkephalin. MORs located postsynaptically on GABAergic cell bodies readily underwent rapid desensitization in response to DAMGO. However, after prolonged (>7 h) treatment with Met-enkephalin, profound homologous MOR desensitization was observed. Morphine could induce rapid MOR desensitization at nerve terminals when PKC was activated. CONCLUSIONS AND IMPLICATIONS Agonist-induced MOR desensitization in GABAergic neurons in the VTA is compartment-selective as well as agonist-selective. When MORs are located at cell bodies, higher-efficacy agonists induce greater levels of rapid desensitization than lower-efficacy agonists. However, the converse is true at nerve terminals where agonists that induce MOR desensitization via PKC are capable of rapid agonist-induced desensitization while higher-efficacy agonists are not. MOR desensitization induced by higher-efficacy agonists at nerve terminals only takes place after prolonged receptor activation. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2 PMID:24467517

  6. The near-nerve sensory nerve conduction in tarsal tunnel syndrome

    Microsoft Academic Search

    S J Oh; H S Kim; B K Ahmad

    1985-01-01

    The near-nerve sensory nerve conduction in the medial and lateral plantar nerves was studied in 25 cases of tarsal tunnel syndrome. Sensory nerve conduction was abnormal in 24 cases (96%) The most common abnormalities were slow nerve conduction velocities and dispersion phenomenon (prolonged duration of compound nerve action potentials). These two electrophysiological abnormalities are indicative of a focal segmental demyelination

  7. Sensory effects of capsaicin congeners. Part II: Importance of chemical structure and pungency in desensitizing activity of capsaicin-type compounds.

    PubMed

    Szolcsányi, J; Jancsó-Gábor, A

    1976-01-01

    The characteristic insensitivity of sensory nerve endings to chemically induced pain brought about by capsaicin could be reproduced on the rat's eye by pungent vanillylamides, homovanilloyl-alkylamides and piperine, while homovanilloyl-cycloalkylamides, -azacycloalkylamides, - alkylesters, -alkyl-homovanillylamides, undecenoyl-3-aminopropranololand zingerone were practically ineffective in this respect. Desensitizing potency was not parallel with the stimulating effect of the compounds, e.g. the strongly pungent homovanilloyl-octylester failed to desensitize the receptors, while the less pungent homovanilloyl-dodecylamide proved to be a more potent desensitizing agent than capsaicin itself. It is concluded that the inverse position of the acylamide linkage does not modify, while its replacement by an esteric group completely abolishes the desensitizing activity. In contrast to the stimulating effect, in desensitizing action the presence of an alkyl chain is essential and its optimal length corresponds to 10-12 C atoms. On the basis of these results the possible molecular interactions at the site of action are discussed. PMID:947170

  8. Somatosensory evoked potentials, sensory nerve potentials and sensory nerve conduction in hereditary motor and sensory neuropathy type I

    Microsoft Academic Search

    M. Aramideh; J. E. Hoogendijk; C. M. Aalfs; F. E. Posthumus Meyjes; M. Visser; B. W. Ongerboer De Visser

    1992-01-01

    Thirty-nine patients from six families with hereditary motor and sensory neuropathy type I and control subjects were included in this study. A neurological deficit score (NDS) was derived from a neurological examination and compared with neurophysiological test findings. Further, sensory nerve conduction velocities (SNCV) were compared with the motor nerve conduction velocities (MNCV). Five patients whom peaks of N11\\/N13 complex

  9. Theobromine inhibits sensory nerve activation and cough.

    PubMed

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

    2005-02-01

    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, in a randomized, double-blind, placebo-controlled study in man, theobromine suppresses capsaicin-induced cough with no adverse effects. We also demonstrate that theobromine directly inhibits capsaicin-induced sensory nerve depolarization of guinea-pig and human vagus nerve suggestive of an inhibitory effect on afferent nerve activation. These data indicate the actions of theobromine appear to be peripherally mediated. We conclude theobromine is a novel and promising treatment, which may form the basis for a new class of antitussive drugs. PMID:15548587

  10. Sensory ReEducation after Median Nerve Lesions

    Microsoft Academic Search

    C. B. WYNN PARRY; M. SALTER

    1976-01-01

    Technique for re-educating sensory function after median nerve lesions at the wrist is described.Results of re-education of Twenty-three patients are presented. The functional results are good and belie the traditional view of sensory function after nerve suture.Recent advances in sensory neuro-physiology-are discussed which may explain the successes of this technique.

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

    PubMed

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

    2013-09-01

    Nerve repair after injury can be effectively accomplished by direct suture approximation of the proximal and distal segments. This is more successful if coadaptation can be achieved without tension. Currently, the gold standard repair of larger deficits is the transplantation of an autologous sensory sural nerve graft. However, a significant disadvantage of this technique is the inevitable donor morbidity (sensory loss, neuroma and scar formation) after harvesting of the sural nerve. Moreover, limitation of autologous donor nerve length and fixed diameter of the available sural nerve are major drawbacks of current autograft treatment. Another approach that was introduced for nerve repair is the implantation of alloplastic nerve tubes made of, for example, poly-L-lactide. In these, nerve stumps of the transected nerves are surgically bridged using the biosynthetic conduit. A number of experimental studies, primarily in rodents, indicate axonal regeneration and remyelination after implantation of various conduits. However, only limited clinical studies with conduit implantation have been performed in acute peripheral nerve injuries particularly on digital nerves. Clinical transfer of animal studies, which can be carefully calibrated for site and extent of injury, to humans is difficult to interpret due to the intrinsic variability in human nerve injuries. This prevents effective quantification of improvement and induces bias in the study. Therefore, standardization of lesion/repair in human studies is warranted. Here we propose to use sural nerve defects, induced due to nerve graft harvesting or from diagnostic nerve biopsies as a model site to enable standardization of nerve conduit implantation. This would help better with the characterization of the implants and its effectiveness in axonal regeneration and remyelination. Nerve regeneration can be assessed, for example, by recovery of sensation, measured non-invasively by threshold to von Frey filaments and cold allodynia. Moreover, the implantation of nerve conduits may not only serve as a model to examine nerve repair, but it could also prevent neuroma formation, which is a major morbidity of sural nerve extraction. PMID:23867139

  12. Sensory Nerves Promote Ozone-induced Lung Inflammation in Mice

    Microsoft Academic Search

    REGINA M. GRAHAM; MITCHELL FRIEDMAN; GARY W. HOYLE

    Genetically manipulated mice exhibiting altered innervation of the airways were used to examine the role of sensory nerves in ozone-induced lung inflammation. Transgenic mice expressing nerve growth factor (NGF) from the lung-specific Clara cell secre- tory protein (CCSP) promoter exhibit hyperinnervation of the air- ways by sympathetic and tachykinin-containing sensory nerve fi- bers. Mice carrying a mutation in the low-affinity

  13. A Randomized, Controlled, Open-Label Study of the Long-Term Effects of NGX-4010, a High-Concentration Capsaicin Patch, on Epidermal Nerve Fiber Density and Sensory Function in Healthy Volunteers

    Microsoft Academic Search

    William R. Kennedy; Geertrui F. Vanhove; Shiao-ping Lu; Jeffrey Tobias; Keith R. Bley; David Walk; Gwen Wendelschafer-Crabb; Donald A. Simone; Mona M. Selim

    2010-01-01

    Desensitization of nociceptive sensory nerve endings is the basis for the therapeutic use of capsaicin in neuropathic pain syndromes. This study evaluated the pharmacodynamic effects of a single 60-minute application of NGX-4010, a high-concentration (8% w\\/w) capsaicin patch, on both thighs of healthy volunteers. Epidermal nerve fiber (ENF) density and quantitative sensory testing (QST) using thermal, tactile, and sharp mechanical-pain

  14. Sensory conduction of the sural nerve in polyneuropathy.

    PubMed

    Burke, D; Skuse, N F; Lethlean, A K

    1974-06-01

    Using surface electrodes, sensory nerve action potentials (SAP) have been recorded in the proximal segment (mid-calf to lateral malleolus) and the distal segment (lateral malleolus to toe 5) of the sural nerve and in the median nerve in 79 control subjects. The values obtained for the distal segment of the sural nerve varied widely and in seven apparently normal subjects no SAP could be distinguished. In the proximal segment conduction velocities were over 40 m/s and there was no significant change with age, unlike the median nerve in which a highly significant slowing occurred with age. Comparison of the results of sural and median sensory conduction studies in 300 consecutive patients screened for sensory polyneuropathy confirms the value of sural nerve sensory studies as a routine screening test, and confirms the belief that the changes in polyneuropathy are usually more prominent in lower limb nerves. It is therefore suggested that studies of sural sensory conduction form the single most useful test in the diagnosis of sensory polyneuropathy. PMID:4367408

  15. Natural history of sensory nerve recovery after cutaneous nerve injury following foot and ankle surgery

    PubMed Central

    Bai, Lu; Han, Yan-ni; Zhang, Wen-tao; Huang, Wei; Zhang, Hong-lei

    2015-01-01

    Cutaneous nerve injury is the most common complication following foot and ankle surgery. However, clinical studies including long-term follow-up data after cutaneous nerve injury of the foot and ankle are lacking. In the current retrospective study, we analyzed the clinical data of 279 patients who underwent foot and ankle surgery. Subjects who suffered from apparent paresthesia in the cutaneous sensory nerve area after surgery were included in the study. Patients received oral vitamin B12 and methylcobalamin. We examined final follow-up data of 17 patients, including seven with sural nerve injury, five with superficial peroneal nerve injury, and five with plantar medial cutaneous nerve injury. We assessed nerve sensory function using the Medical Research Council Scale. Follow-up immediately, at 6 weeks, 3, 6 and 9 months, and 1 year after surgery demonstrated that sensory function was gradually restored in most patients within 6 months. However, recovery was slow at 9 months. There was no significant difference in sensory function between 9 months and 1 year after surgery. Painful neuromas occurred in four patients at 9 months to 1 year. The results demonstrated that the recovery of sensory function in patients with various cutaneous nerve injuries after foot and ankle surgery required at least 6 months. PMID:25788928

  16. Leptin-sensitive sensory nerves innervate white fat

    PubMed Central

    Murphy, Keegan T.; Schwartz, Gary J.; Nguyen, Ngoc Ly T.; Mendez, Jennifer M.; Ryu, Vitaly

    2013-01-01

    Leptin, the primary white adipose tissue (WAT) adipokine, is thought to convey lipid reserve information to the brain via the circulation. Because WAT responds to environmental/internal signals in a fat pad-specific (FPS) manner, systemic signals such as leptin would fail to communicate such distinctive information. Saturation of brain leptin transport systems also would fail to convey increased lipid levels beyond that point. WAT possesses sensory innervation exemplified by proven sensory-associated peptides in nerves within the tissue and by viral sensory nerve-specific transneuronal tract tracer, H129 strain of herpes simplex virus 1 labeling of dorsal root ganglia (DRG) pseudounipolar neurons, spinal cord and central sensory circuits. Leptin as a paracrine factor activating WAT sensory innervation could supply the brain with FPS information. Therefore, we tested for and found the presence of the long form of the leptin receptor (Ob-Rb) on DRG pseudounipolar neurons immunohistochemically labeled after injections of Fluorogold, a retrograde tract tracer, into inguinal WAT (IWAT). Intra-IWAT leptin injections (300 ng) significantly elevated IWAT nerve spike rate within 5 min and persisted for at least 30 min. Intra-IWAT leptin injections also induced significant c-Fos immunoreactivity (ir), indicating neural activation across DRG pseudounipolar sensory neurons labeled with Fluorogold IWAT injections. Intraperitoneal leptin injection did not increase c-Fos-ir in DRG or the arcuate nucleus, nor did it increase arcuate signal transducer and activator of transcription 3 phosphorylation-ir. Collectively, these results strongly suggest that endogenous leptin secreted from white adipocytes functions as a paracrine factor to activate spinal sensory nerves innervating the tissue. PMID:23612999

  17. Reduced intraepidermal nerve fiber density in HIV-associated sensory

    E-print Network

    Steinbach, Joe Henry

    severity and progression of HIV disease. Background: SN affects 30% of individuals with AIDS, and treatment in a substudy examining epidermal nerve fibers. IENF density was compared with neuropathic pain intensity (measured with the Gracely Pain Scale), patient and physician global pain assessments, quantitative sensory

  18. Transient receptor potential channels on sensory nerves.

    PubMed

    Eid, S R; Cortright, D N

    2009-01-01

    The somatosensory effects of natural products such as capsaicin, mustard oil, and menthol have been long recognized. Over the last decade, the identification of transient receptor potential (TRP) channels in primary sensory neurons as the targets for these agents has led to an explosion of research into the roles of "thermoTRPs" TRPV1, TRPV2, TRPV3, TRPV4, TRPA1, and TRPM8 in nociception. In concert, through the efforts of many industrial and academic teams, a number of agonists and antagonists of these channels have been discovered, paving the way for a better understanding of sensory biology and, potentially, for novel treatments for diseases. PMID:19655110

  19. The distal sensory nerve action potential as a diagnostic tool for the differentiation of lesions in dorsal roots and peripheral nerves

    Microsoft Academic Search

    R. Benecke; B. Conrad

    1980-01-01

    On the basis of the conception that, in preganglionic lesions, peripheral sensory nerve fibers should remain intact, the question arises whether evaluation of distal sensory nerve action potentials can be helpful in differentiating between cervical dorsal root and peripheral nerve lesions. Amplitudes of sensory nerve action potentials (SNAP) and corresponding distal sensory conduction velocities (SCV) of the median and ulnar

  20. Nerve growth factor decreases in sympathetic and sensory nerves of rats with chronic heart failure.

    PubMed

    Xing, Jihong; Lu, Jian; Li, Jianhua

    2014-08-01

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

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

    PubMed Central

    Lu, Jian

    2014-01-01

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

  2. Transient Receptor Potential Channels on Sensory Nerves

    Microsoft Academic Search

    S. R. Eid; D. N. Cortright

    \\u000a The somatosensory effects of natural products such as capsaicin, mustard oil, and menthol have been long recognized. Over\\u000a the last decade, the identification of transient receptor potential (TRP) channels in primary sensory neurons as the targets\\u000a for these agents has led to an explosion of research into the roles of “thermoTRPs” TRPV1, TRPV2, TRPV3, TRPV4, TRPA1, and\\u000a TRPM8 in nociception.

  3. Motor and sensory nerve conduction velocities in Yucatan minipigs

    Microsoft Academic Search

    C Hort-Legrand; L Noah; E Mériguet; D Mésangeau

    2006-01-01

    Summary Motor and\\/or sensory conduction velocities are used to assess peripheral nervous system disorders. Although the miniature pig represents a model of choice for long-term pharmacological experimentation, no study has so far been reported on this model in relation to the measurement of nerve conduction velocities. We developed the present technique and applied it to 34 3-18-month-old Yucatan minipigs. Motor

  4. Sensory Nerve Conduction in Demyelinating and Axonal Guillain-Barré Syndromes

    Microsoft Academic Search

    Satoshi Kuwabara; Kazue Ogawara; Sonoko Misawa; Keiko Mizobuchi; Jia-Ying Sung; Yukiko Kitano; Masahiro Mori; Takamichi Hattori

    2004-01-01

    Guillain-Barré syndrome is divided into acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN) based on motor nerve conduction studies. We investigated whether sensory nerve conduction studies contribute to the electrodiagnosis of AIDP and AMAN. In consecutive 59 patients with AIDP (n = 26) or AMAN (n = 33), results of sensory nerve conduction studies in the median,

  5. Tissue Preparation and Immunostaining of Mouse Sensory Nerve Fibers Innervating Skin and Limb Bones

    PubMed Central

    Shepherd, Andrew J.; Mohapatra, Durga P.

    2012-01-01

    Detection and primary processing of physical, chemical and thermal sensory stimuli by peripheral sensory nerve fibers is key to sensory perception in animals and humans. These peripheral sensory nerve fibers express a plethora of receptors and ion channel proteins which detect and initiate specific sensory stimuli. Methods are available to characterize the electrical properties of peripheral sensory nerve fibers innervating the skin, which can also be utilized to identify the functional expression of specific ion channel proteins in these fibers. However, similar electrophysiological methods are not available (and are also difficult to develop) for the detection of the functional expression of receptors and ion channel proteins in peripheral sensory nerve fibers innervating other visceral organs, including the most challenging tissues such as bone. Moreover, such electrophysiological methods cannot be utilized to determine the expression of non-excitable proteins in peripheral sensory nerve fibers. Therefore, immunostaining of peripheral/visceral tissue samples for sensory nerve fivers provides the best possible way to determine the expression of specific proteins of interest in these nerve fibers. So far, most of the protein expression studies in sensory neurons have utilized immunostaining procedures in sensory ganglia, where the information is limited to the expression of specific proteins in the cell body of specific types or subsets of sensory neurons. Here we report detailed methods/protocols for the preparation of peripheral/visceral tissue samples for immunostaining of peripheral sensory nerve fibers. We specifically detail methods for the preparation of skin or plantar punch biopsy and bone (femur) sections from mice for immunostaining of peripheral sensory nerve fibers. These methods are not only key to the qualitative determination of protein expression in peripheral sensory neurons, but also provide a quantitative assay method for determining changes in protein expression levels in specific types or subsets of sensory fibers, as well as for determining the morphological and/or anatomical changes in the number and density of sensory fibers during various pathological states. Further, these methods are not confined to the staining of only sensory nerve fibers, but can also be used for staining any types of nerve fibers in the skin, bones and other visceral tissue. PMID:22314687

  6. Bladder reinnervation using a primarily motor donor nerve (femoral nerve branches) is functionally superior to using a primarily sensory donor nerve (genitofemoral nerve)

    PubMed Central

    Gomez-Amaya, Sandra M.; Barbe, Mary F.; Brown, Justin M.; Lamarre, Neil S.; Braverman, Alan S.; Massicotte, Vicky S.; Ruggieri, Michael R.

    2014-01-01

    Purpose To determine whether transfer of a primarily motor nerve (Femoral, F) to the anterior vesicle branch of the pelvic nerve (PN) allows more effective bladder reinnervation than a primarily sensory nerve (genitofemoral, GF). Methods Forty-one female mongrel hounds underwent bladder decentralization, decentralization and then bilateral nerve transfer (GFNT and FNT) or were sham/unoperated controls. Decentralization was achieved by bilateral transection of all sacral roots that induce bladder contractions upon electrical stimulation. The retrograde neuronal labeling dye fluorogold was injected into the bladder 3 weeks prior to euthanasia. Results Increased detrusor pressure after direct stimulation of the transferred nerve, lumbar spinal cord or spinal roots was observed in 12/17 GFNT dogs (mean detrusor pressure = 7.6±1.4 cmH2O) and in 9/10 FNT-V dogs (mean detrusor pressure = 11.7±3.1 cm H2O). The mean detrusor pressures after direct electrical stimulation of transferred femoral nerves were statistically significantly greater than after stimulation of the transferred genitofemoral nerves. Retrogradely labeled neurons from the bladder observed in upper lumbar cord segments after GFNT and FNT confirmed bladder reinnervation as did labeled axons at the nerve transfer site. Conclusions While transfer of either a mixed sensory and motor nerve (GFN) or a primarily motor nerve (FN) can reinnervate the bladder, using a primarily motor nerve provides greater return of nerve-evoked detrusor contraction. This surgical approach may be useful for patients with lower motor spinal cord injury to accomplish bladder emptying. PMID:25066874

  7. Functional Recovery of Denervated Skeletal Muscle with Sensory or Mixed Nerve Protection: A Pilot Study

    PubMed Central

    Li, Qing Tian; Zhang, Pei Xun; Yin, Xiao Feng; Han, Na; Kou, Yu Hui; Deng, Jiu Xu; Jiang, Bao Guo

    2013-01-01

    Functional recovery is usually poor following peripheral nerve injury when reinnervation is delayed. Early innervation by sensory nerve has been indicated to prevent atrophy of the denervated muscle. It is hypothesized that early protection with sensory axons is adequate to improve functional recovery of skeletal muscle following prolonged denervation of mixed nerve injury. In this study, four groups of rats received surgical denervation of the tibial nerve. The proximal and distal stumps of the tibial nerve were ligated in all animals except for those in the immediate repair group. The experimental groups underwent denervation with nerve protection of peroneal nerve (mixed protection) or sural nerve (sensory protection). The experimental and unprotected groups had a stage II surgery in which the trimmed proximal and distal tibial nerve stumps were sutured together. After 3 months of recovery, electrophysiological, histological and morphometric parameters were assessed. It was detected that the significant muscle atrophy and a good preserved structure of the muscle were observed in the unprotected and protective experimental groups, respectively. Significantly fewer numbers of regenerated myelinated axons were observed in the sensory-protected group. Enhanced recovery in the mixed protection group was indicated by the results of the muscle contraction force tests, regenerated myelinated fiber, and the results of the histological analysis. Our results suggest that early axons protection by mixed nerve may complement sensory axons which are required for promoting functional recovery of the denervated muscle natively innervated by mixed nerve. PMID:24244555

  8. Sensory nerve conduction in the upper limbs at various stages of diabetic neuropathy 1

    Microsoft Academic Search

    P. Noël

    1973-01-01

    In 59 diabetic patients, sensory nerve potentials were recorded at various sites along the course of the median nerve. Pathological responses were characterized by reduced amplitude, desynchronization and decreased conduction velocity (CV). Four groups of patients with increasingly severe nerve dysfunction were distinguished. The presence and severity of clinical neuropathy in the upper limbs could be related to decreased maximal

  9. Efferent desensitization of auditory nerve fibre responses in the cochlea of the turtle Pseudemys scripta elegans.

    PubMed Central

    Art, J J; Fettiplace, R

    1984-01-01

    Extracellular recordings were made from single auditory afferents in the isolated half-head of the turtle, and changes in their acoustic sensitivity were examined following electrical stimulation of the efferent fibres to the basilar papilla. Short trains of efferent shocks caused a prolonged elevation of the pure tone thresholds of the auditory afferents and an abolition of their spontaneous activity. These changes could be demonstrated in a majority of recordings and without antidromic firing of the afferent. The amount of desensitization increased steeply with shock number and a train of ten closely spaced shocks could elevate the threshold at the most sensitive or characteristic frequency by four orders of magnitude. Desensitization also occurred with single efferent shocks at repetition frequencies exceeding 25/s. Discharge rate versus sound pressure functions were constructed for a number of afferents. The maximum slope of the functions, and the saturated firing rates were both reduced by efferent stimulation; there was also an over-all shift of the rate-intensity function to higher stimulus levels. Such effects would enable the afferent to signal a wider range of sound pressures. Efferent stimulation caused a broadening of the afferent frequency-threshold curves by removal of the narrowly-tuned region around the characteristic frequency. We suggest that the loss in tuning and concomitant improvement in temporal resolution may be a functionally important consequence of efferent action. Images Plate 1 PMID:6520796

  10. Photostimulation of sensory neurons of the rat vagus nerve

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    We studied the effect of infrared (IR) stimulation on rat sensory neurons. Primary sensory neurons were prepared by enzymatic dissociation of the inferior (or "nodose") ganglia from the vagus nerves of rats. The 1.85-?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.

  11. Retrograde changes in motor and sensory conduction velocity after nerve injury.

    PubMed

    Stöhr, M; Schumm, F; Reill, P

    1977-03-21

    Nerve section is followed by a reduction of motor and sensory conduction velocity in the proximal segment of the injured nerve. This reduction of velocity is associated with retrograde changes in fiber size. If reinnervation does not occur within the next 1 1/2--2 years, retrograde degeneration of nerve fibers results, and the amplitude of the evoked nerve potential in the proximal segment of the injured nerve decreases. This retrograde degeneration is probably significant in view of the poor results frequently obtained after nerve transplantation which is carried out too late. PMID:67191

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

    PubMed

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

    2013-11-01

    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

  13. Sensory outcomes of the anterior tongue after lingual nerve repair in oropharyngeal cancer.

    PubMed

    Elfring, T T; Boliek, C A; Seikaly, H; Harris, J; Rieger, J M

    2012-03-01

    Primary treatment of oropharyngeal cancer often involves surgical resection and reconstruction of the affected area. However, during base of tongue reconstruction the lingual nerve is often severed on one or both sides, affecting sensation in the preserved tissue of the anterior tongue. The loss of specific tongue sensations could negatively affect a person's oral function and quality of life. The aim of this study was to explore the effects of different types of lingual nerve intervention on sensory function for patients with base of tongue cancer as compared to healthy, age-matched adults. Subjects included 30 patients who had undergone primary oropharyngeal reconstruction with a radial forearm free-flap and 30 matched controls. Sensations tested were temperature, two-point discrimination, light touch, taste, oral stereognosis and texture on the anterior two-thirds of the tongue. Results indicated that type of surgical nerve repair may not have a significant impact on overall sensory outcomes, providing mixed results for either nerve repair technique. Sensations for the nonoperated tongue side and operated side with lingual nerve intact were comparable to matched controls, with mixed outcomes for nerve repair. The poorest sensory outcomes were observed in patients with the lingual nerve severed, while all patients with lingual nerve intervention exhibited deteriorated taste sensation on the affected tongue side. Overall, patients in this study who had undergone oropharyngeal reconstruction with lingual nerve intervention exhibited decreased levels of sensation on the operated tongue side, with minimal differences between types of lingual nerve repair. PMID:21923892

  14. Sensory nerve conduction velocities in the cutaneous afferents of the ulnar and peroneal nerves of the dog: Tissue temperature-dependent reference ranges

    Microsoft Academic Search

    A. Miyamoto; A. Sumi; Y. Ishido; T. Nakano; M. Yahagi; S. Inada

    1990-01-01

    Sensory nerve conduction velocities in the cutaneous afferents of the ulnar and peroneal nerves of the neurologically normal adult dog were determined by stimulation at stimulus intensities of 15, 20 and 25 V through subcutaneously placed electrodes and by the averaged evoked response technique. Stimulus intensities of 15 V for the ulnar nerve and 20 V for the peroneal nerve

  15. Sensory and motor maximum nerve conduction velocity in the peripheral and central nervous system of the beagle dog

    Microsoft Academic Search

    U. Schaeppi; M. Teste; U. Siegenthaler

    1982-01-01

    Sensory maximum nerve conduction velocity (MNCV) and motor MNCV were monitored in altogether 14 beagle dogs anaesthetized with pentobarbital. Sensory MNCV was determined by averaging cortically evoked potentials from somatosensory area I (SS I) in response to repeated electrical stimulation of digital paw pads, tibial nerve at calcaneus or sciatic nerve at trochanter.

  16. Peripheral motor and sensory nerve conduction studies in normal infants and children

    Microsoft Academic Search

    Antonio Garc??a; Jesús Calleja; Francisco M. Antol??n; José Berciano

    2000-01-01

    Objective: There are few data on electrophysiological data of motor and sensory fibres during nerve maturation. The aim of this study is to investigate the evolution of nerve conduction in the upper and lower limbs during the first years of life.Methods: The study comprised 92 normal infants and children aged from 1 week to 6 years. Using surface electrodes, the

  17. Comparison of orthodromic and antidromic sensory nerve conduction velocity measurements in the carpal tunnel syndrome

    Microsoft Academic Search

    W. Tackmann; H. E. Kaeser; H. G. Magun

    1981-01-01

    Orthodromic and antidromic nerve conduction velocities were determined in sensory median nerve fibres from digit to palm and from palm to wrist in patients with the carpal tunnel syndrome. In a large number of subjects the carpal tunnel syndrome could be detected only when the palm-to-wrist segment was investigated.

  18. Plasticity in developing rat uterine sensory nerves: the role of NGF and TrkA

    Microsoft Academic Search

    C. Chalar; A. Richeri; L. Viettro; R. Chávez-Genaro; P. Bianchimano; N. M. Marmol; K. Crutcher; G. Burnstock; T. Cowen; M. M. Brauer

    2003-01-01

    In the present study we investigated the effects of infantile\\/prepubertal chronic oestrogen treatment, chemical sympathectomy with guanethidine and combined sympathectomy and chronic oestrogen treatment on developing sensory nerves of the rat uterus. Changes in sensory innervation were assessed quantitatively on uterine cryostat tissue sections stained for calcitonin gene-related peptide (CGRP). Uterine levels of NGF protein, using immunohistochemistry and ELISA, and

  19. Outcomes of short-gap sensory nerve injuries reconstructed with processed nerve allografts from a multicenter registry study.

    PubMed

    Rinker, Brian D; Ingari, John V; Greenberg, Jeffrey A; Thayer, Wesley P; Safa, Bauback; Buncke, Gregory M

    2015-06-01

    Background?Short-gap digital nerve injuries are a common surgical problem, but the optimal treatment modality is unknown. A multicenter database was queried and analyzed to determine the outcomes of nerve gap reconstructions between 5 and 15?mm with processed nerve allograft. Methods?The current RANGER registry is designed to continuously monitor and compile injury, repair, safety, and outcomes data. Centers followed their own standard of care for treatment and follow-up. The database was queried for digital nerve injuries with a gap between 5 and 15?mm reporting sufficient follow-up data to complete outcomes analysis. Available quantitative outcome measures were reviewed and reported. Meaningful recovery was defined by the Medical Research Council Classification (MRCC) scale at S3-S4 for sensory function. Results?Sufficient follow-up data were available for 24 subjects (37 repairs) in the prescribed gap range. Mean age was 43 years (range, 23-81). Mean gap was 11?±?3 (5-15) mm. Time to repair was 13?±?42 (0-215) days. There were 25 lacerations, 8 avulsion/amputations, 2 gunshots, 1 crush injury, and 1 injury of unknown mechanism. Meaningful recovery, defined as S3-S4 on the MRCC scales, was reported in 92% of repairs. Sensory recovery of S3+ or S4 was observed in 84% of repairs. Static 2PD was 7.1?±?2.9?mm (n?=?19). Return to light touch was observed in 23 out of 32 repairs reporting Semmes-Weinstein monofilament outcomes (SWMF). There were no reported nerve adverse events. Conclusion?Sensory outcomes for processed nerve allografts were equivalent to historical controls for nerve autograft and exceed those of conduit. Processed nerve allografts provide an effective solution for short-gap digital nerve reconstructions. PMID:25893633

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

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

    PubMed

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

    1998-12-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies. PMID:9843078

  2. Prevalence of subclinical neuropathy in diabetic patients: assessment by study of conduction velocity distribution within motor and sensory nerve fibres

    Microsoft Academic Search

    Pierluigi Bertora; Pierluigi Valla; Elisabetta Dezuanni; Maurizio Osio; Davide Mantica; Maurizio Bevilacqua; Guido Norbiato; Mario Riccardo Caccia; Alfonso Mangoni

    1998-01-01

    Nerve conduction velocity distribution (CVD) study is a newly-developed electrodiagnostic method for detecting alterations\\u000a in the composition of nerve fibres according to their conduction velocity. The presence of subclinical neuropathy was evaluated\\u000a in 138 diabetic patients by CVD study of four motor nerves (external popliteal and ulnar nerves bilaterally) and two sensory\\u000a nerves (median nerve bilaterally), and the data obtained

  3. Ultrasound of radial, ulnar, median, and sciatic nerves in healthy subjects and patients with hereditary motor and sensory neuropathies

    Microsoft Academic Search

    Oliver Heinemeyer; Carl D Reimers

    1999-01-01

    This study was conducted to evaluate the capability of ultrasonography to visualize extremity nerves. Fifty healthy women and men and 10 patients suffering with hereditary motor and sensory neuropathy (HMSN) were examined. The radial nerve lateral to the humerus, ulnar nerve distal to the cubital tunnel, median nerve in the middle of the forearm and proximal to the palmar crease,

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2010-10-01

    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% NaHCO(3) 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

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

    SciTech Connect

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

    1988-02-01

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

  7. Nerve injury induces the expression of syndecan-1 heparan sulfate proteoglycan in primary sensory neurons.

    PubMed

    Murakami, K; Tanaka, T; Bando, Y; Yoshida, S

    2015-08-01

    Heparan sulfate proteoglycans (HSPGs) have important functions in development of the central nervous system; however, their functions in nerve injury are not yet fully understood. We previously reported the expression of syndecan-1, a type of HSPG, in cranial motor neurons after nerve injury, suggesting the importance of syndecan-1 in the pathology of motor nerve injury. In this study, we examined the expression of syndecan-1, a type of HSPG, in primary sensory neurons after nerve injury in mice. Sciatic nerve axotomy strongly induced the expression of syndecan-1 in a subpopulation of injured dorsal root ganglion (DRG) neurons, which were small in size and had CGRP- or isolectin B4-positive fibers. Syndecan-1 was also distributed in the dorsal horn of the spinal cord ipsilateral to the axotomy, and located on the membrane of axons in lamina II of the dorsal horn. Not only sciatic nerve axotomy, infraorbital nerve axotomy also induced the expression of syndecan-1 in trigeminal ganglion neurons. Moreover, syndecan-1 knockdown in cultured DRG neurons induced a shorter neurite extension. These results suggest that syndecan-1 expression in injured primary sensory neurons may have functional roles in nerve regeneration and synaptic plasticity, resulting in the development of neuropathic pain. PMID:26002314

  8. The correlation between sensory nerve conduction velocities and three metabolic indices in rats treated with streptozotocin

    Microsoft Academic Search

    P. O. O. Julu

    1988-01-01

    Summary  The fastest conduction velocities of the myelinated (A) and unmyelinated (C) sensory nerve fibres were measured in the saphenous nerves of rats made diabetic up to 5 weeks previously by injection of streptozotocin. The conduction velocity of the fastest A-alpha fibres in treated rats fell by 25% compared to control rats. The effect on the slow A-delta fibres was small

  9. Sensory nerve conduction studies of the L-1\\/L-2 dorsal rami

    Microsoft Academic Search

    Amrit P. Singh; Hillel M. Sommer

    1996-01-01

    Objective: This report describes a technique for performing sensory nerve conduction studies of the lateral cutaneous branches of the dorsal rami of the L-1\\/L-2 nerve roots for use in the evaluation of unilateral low back pain without lower limb referral.Subjects: Eleven healthy adult volunteers (9 men and 2 women) ranging in age from 25 to 36 years with no current

  10. Assessment of Sensory Nerve Conduction in Carpal Tunnel Syndrome before, during and after Operation

    Microsoft Academic Search

    R. LUCHETTI; R. SCHOENHUBER; A. LANDI

    1988-01-01

    Sensory conduction velocities of the median nerve before, during and after operation were compared in nine patients with carpal tunnel syndrome and four controls, in order to evaluate the prognostic value of the pre-operative and intra-operative findings.Sensory conduction velocity was higher after operation than before in all patients (mean difference 31.33%), but not in control subjects. One patient showed a

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

    PubMed Central

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

    2014-01-01

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

  12. Characteristics of patients with sensory neuropathy diagnosed with abnormal small nerve fibres on skin biopsy.

    PubMed

    De Sousa, E A; Hays, A P; Chin, R L; Sander, H W; Brannagan, T H

    2006-08-01

    Clinical, laboratory and electrodiagnostic (EDX) characteristics of 62 patients with sensory neuropathy with abnormal skin biopsies were reviewed. Reduced epidermal nerve fibre density (ENFD) was seen in 71% and morphological changes with normal ENFD were seen in 29% of the patients. Patients with small fibre sensory neuropathy may have associated large fibre loss undetected by routine EDX. Identified associations included abnormal glucose metabolism, Lyme vaccination, monoclonal gammopathy, vitamin B12 deficiency, coeliac disease, and diseases of the connective tissue, inflammatory bowel and thyroid. Sensory neuropathy remained undetermined in 50% of the patients. PMID:16844956

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

    PubMed

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

    2010-06-01

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

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

    PubMed Central

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

    1990-01-01

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

  15. Regeneration of sensory but not motor axons following visceral nerve injury.

    PubMed

    Payne, Sophie C; Belleville, Philip J; Keast, Janet R

    2015-04-01

    Following peripheral nerve injury, restoration of function may occur via the regeneration of injured axons or compensatory sprouting of spared axons. Injury to visceral nerves that control urogenital organs is a common consequence of pelvic surgery, however their capacity to reinnervate organs is poorly understood. To determine if and how sensory and motor connections to the bladder are re-established, a novel surgical model of visceral nerve injury was performed unilaterally in adult male Wistar rats. Bladder-projecting motor and sensory neurons in pelvic ganglia and lumbosacral dorsal root ganglia, respectively, were identified and characterised by retrograde tracing and immunofluorescence. Application of tracers ipsi- and contralateral to injury distinguished the projection pathways of new connections in the bladder. In naive animals, the majority of sensory and motor neurons project ipsilaterally to the bladder, while ~20 % project contralaterally and ~5 % bilaterally. Injured axons of motor neurons were unable to regenerate by 4weeks after transection. In contrast, by this time many injured sensory neurons regrew axons to reform a substantial plexus within the detrusor and suburothelial tissues. These regeneration responses were also indicated by upregulation of activating transcription factor-3 (ATF-3), which was sustained in motor neurons but transient in sensory bladder-projecting neurons. Axotomy had little or no effect on the survival of bladder-projecting sensory and motor neurons. We also found evidence that uninjured motor and sensory neurons develop additional projections to the denervated bladder tissue and return connectivity, likely by undergoing compensatory growth. In conclusion, our results show that visceral sensory and motor neurons have a different capacity to regenerate axons following axotomy, however in both components of the circuit uninjured bladder neurons spontaneously grow new axon collaterals to replace the lost terminal field within the organ. For a full functional recovery, understanding the environmental and cellular mechanisms that reduce the ability of pelvic ganglion cells to undergo axonal regeneration is needed. PMID:25725351

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

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

    PubMed

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

    2014-01-01

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

  18. Phenotyping sensory nerve endings in vitro in the mouse

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2008-01-01

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

  20. Menthol Enhances the Desensitization of Human ?3?4 Nicotinic Acetylcholine Receptors.

    PubMed

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

    2015-08-01

    The ?3?4 nicotinic acetylcholine receptor (nAChR) subtype is widely expressed in the peripheral and central nervous systems, including in airway sensory nerves. The nAChR subtype transduces the irritant effects of nicotine in tobacco smoke and, in certain brain areas, may be involved in nicotine addiction and/or withdrawal. Menthol, a widely used additive in cigarettes, is a potential analgesic and/or counterirritant at sensory nerves and may also influence nicotine's actions in the brain. We examined menthol's effects on recombinant human ?3?4 nAChRs and native nAChRs in mouse sensory neurons. Menthol markedly decreased nAChR activity as assessed by Ca(2+) imaging, (86)Rb(+) efflux, and voltage-clamp measurements. Coapplication of menthol with acetylcholine or nicotine increased desensitization, demonstrated by an increase in the rate and magnitude of the current decay and a reduction of the current integral. These effects increased with agonist concentration. Pretreatment with menthol followed by its washout did not affect agonist-induced desensitization, suggesting that menthol must be present during the application of agonist to augment desensitization. Notably, menthol acted in a voltage-independent manner and reduced the mean open time of single channels without affecting their conductance, arguing against a simple channel-blocking effect. Further, menthol slowed or prevented the recovery of nAChRs from desensitization, indicating that it probably stabilizes a desensitized state. Moreover, menthol at concentrations up to 1 mM did not compete for the orthosteric nAChR binding site labeled by [(3)H]epibatidine. Taken together, these data indicate that menthol promotes desensitization of ?3?4 nAChRs by an allosteric action. PMID:25964258

  1. Modelled temperature-dependent excitability behaviour of a generalised human peripheral sensory nerve fibre.

    PubMed

    Smit, Jacoba E; Hanekom, Tania; Hanekom, Johan J

    2009-08-01

    The objective of this study was to determine if a recently developed human Ranvier node model, which is based on a modified version of the Hodgkin-Huxley model, could predict the excitability behaviour in human peripheral sensory nerve fibres with diameters ranging from 5.0 to 15.0 microm. The Ranvier node model was extended to include a persistent sodium current and was incorporated into a generalised single cable nerve fibre model. Parameter temperature dependence was included. All calculations were performed in Matlab. Sensory nerve fibre excitability behaviour characteristics predicted by the new nerve fibre model at different temperatures and fibre diameters compared well with measured data. Absolute refractory periods deviated from measured data, while relative refractory periods were similar to measured data. Conduction velocities showed both fibre diameter and temperature dependence and were underestimated in fibres thinner than 12.5 microm. Calculated strength-duration time constants ranged from 128.5 to 183.0 micros at 37 degrees C over the studied nerve fibre diameter range, with chronaxie times about 30% shorter than strength-duration time constants. Chronaxie times exhibited temperature dependence, with values overestimated by a factor 5 at temperatures lower than body temperature. Possible explanations include the deviated absolute refractory period trend and inclusion of a nodal strangulation relationship. PMID:19579032

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

    PubMed Central

    Hotson, John R.

    2014-01-01

    The peroneal nerve anatomy of the rabbit distal hindlimb is similar to humans, but reports of distal peroneal nerve conduction studies were not identified with a literature search. Distal sensorimotor recordings may be useful for studying rabbit models of length-dependent peripheral neuropathy. Surface electrodes were adhered to the dorsal rabbit foot overlying the extensor digitorum brevis muscle and the superficial peroneal nerve. The deep and superficial peroneal nerves were stimulated above the ankle and the common peroneal nerve was stimulated at the knee. The nerve conduction studies were repeated twice with a one-week intertest interval to determine measurement variability. Intravenous vincristine was used to produce a peripheral neuropathy. Repeat recordings measured the response to vincristine. A compound muscle action potential and a sensory nerve action potential were evoked in all rabbits. The compound muscle action potential mean amplitude was 0.29 mV (SD ± 0.12) and the fibula head to ankle mean motor conduction velocity was 46.5 m/s (SD ± 2.9). The sensory nerve action potential mean amplitude was 22.8 ?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

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

    PubMed Central

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

    2014-01-01

    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

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

    Microsoft Academic Search

    M. G. Belvisi; D. J. Hele

    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

  5. Effects of ozone on epithelium and sensory nerves in the bronchial mucosa of healthy humans.

    PubMed

    Krishna, M T; Springall, D; Meng, Q H; Withers, N; Macleod, D; Biscione, G; Frew, A; Polak, J; Holgate, S

    1997-09-01

    Neuropeptides released from sensory nerves during inflammation have potent effects on bronchomotor tone, airway secretion, and inflammatory cells. We investigated the effects of ozone on sensory 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 15 min after exposures, and bronchoscopy (bronchial biopsy and bronchoalveolar lavage [BAL]) was done 6 h after exposure. Frozen sections were immunostained for the anatomic neural marker protein gene peptide (PGP) 9.5 and the sensory neutropeptides substance P (SP) and calcitonin-gene-related peptide (CGRP). Nerves in the submucosa were quantified by image analysis. A trend toward an increase in the levels of polymorphonuclear leukocytes (PMNs) (air versus ozone, median [interquartile range]: 3.5 [2 to 5.3%] versus 9.8 [4.2 to 16.3%], p = 0.07) and ciliated epithelial cells (median [interquartile range]: 1.6 [1.3 to 3.4%] versus 5 [2.2 to 9.8%], p = 0.05) was observed in the BAL fluid (BALF). There was a significant decrease in SP immunoreactivity following ozone exposure (median [interquartile range]: 0.6 [0.05 to 1.2] versus 0.15 [0.08 to 0.18], p < 0.05). A significant inverse correlation was observed between SP immunoreactivity and: (1) percent PMNs and ciliated epithelial cells in the BALF; and (2) percent change in FEV1 following exposure to ozone. These findings indicate that short-term exposure to 0.2 ppm ozone causes epithelial shedding and stimulates subepithelial sensory nerves to release SP into the airways. The release of SP could contribute to bronchoconstriction and subsequent neutrophil infiltration into the airways. PMID:9310018

  6. Sensory nerves and nitric oxide contribute to reflex cutaneous vasodilation in humans.

    PubMed

    Wong, Brett J

    2013-04-15

    We tested the hypothesis that inhibition of cutaneous sensory nerves would attenuate reflex cutaneous vasodilation in response to an increase in core temperature. Nine subjects were equipped with four microdialysis fibers on the forearm. Two sites were treated with topical anesthetic EMLA cream for 120 min. Sensory nerve inhibition was verified by lack of sensation to a pinprick. Microdialysis fibers were randomly assigned as 1) lactated Ringer (control); 2) 10 mM nitro-L-arginine methyl ester (L-NAME) to inhibit nitric oxide synthase; 3) EMLA + lactated Ringer; and 4) EMLA + L-NAME. Laser-Doppler flowmetry was used as an index of skin blood flow, and blood pressure was measured via brachial auscultation. Subjects wore a water-perfused suit, and oral temperature was monitored as an index of core temperature. The suit was perfused with 50°C water to initiate whole body heat stress to raise oral temperature 0.8°C above baseline. Cutaneous vascular conductance (CVC) was calculated and normalized to maximal vasodilation (%CVC(max)). There was no difference in CVC between control and EMLA sites (67 ± 5 vs. 69 ± 6% CVC(max)), but the onset of vasodilation was delayed at EMLA compared with control sites. The L-NAME site was significantly attenuated compared with control and EMLA sites (45 ± 5% CVC(max); P < 0.01). Combined EMLA + L-NAME site (25 ± 6% CVC(max)) was attenuated compared with control and EMLA (P < 0.001) and L-NAME only (P < 0.01). These data suggest cutaneous sensory nerves contribute to reflex cutaneous vasodilation during the early, but not latter, stages of heat stress, and full expression of reflex cutaneous vasodilation requires functional sensory nerves and NOS. PMID:23408029

  7. Electrical stimulation of sensory nerves with skin electrodes for research, diagnosis, communication and behavioral conditioning: A survey

    Microsoft Academic Search

    ERICH A. PFEIFFERt

    1968-01-01

    When electrical current is passed through the body by means of electrodes applied to the skin, sensory nerves can be stimulated.\\u000a This results in sensations that vary from barely perceivable to highly unpleasant. Such electrocutaneous stimulation of sensory\\u000a nerves has been studied by engineers, neurologists, physiologists and psychologists, who have investigated the interrelationship\\u000a between the physical parameters of the electrical

  8. Role of sensory nerves in the cutaneous vasoconstrictor response to local cooling in humans.

    PubMed

    Hodges, Gary J; Traeger, J Andrew; Tang, Tri; Kosiba, Wojciech A; Zhao, Kun; Johnson, John M

    2007-07-01

    Local cooling (LC) causes a cutaneous vasoconstriction (VC). In this study, we tested whether there is a mechanism that links LC to VC nerve function via sensory nerves. Six subjects participated. Local skin and body temperatures were controlled with Peltier probe holders and water-perfused suits, respectively. Skin blood flow at four forearm sites was monitored by laser-Doppler flowmetry with the following treatments: untreated control, pretreatment with local anesthesia (LA) blocking sensory nerve function, pretreatment with bretylium tosylate (BT) blocking VC nerve function, and pretreatment with both LA and BT. Local skin temperature was slowly reduced from 34 to 29 degrees C at all four sites. Both sites treated with LA produced an increase in cutaneous vascular conductance (CVC) early in the LC process (64 +/- 55%, LA only; 42 +/- 14% LA plus BT; P < 0.05), which was absent at the control and BT-only sites (5 +/- 8 and 6 +/- 8%, respectively; P > 0.05). As cooling continued, there were significant reductions in CVC at all sites (P < 0.05). At control and LA-only sites, CVC decreased by 39 +/- 4 and 46 +/- 8% of the original baseline values, which were significantly (P < 0.05) more than the reductions in CVC at the sites treated with BT and BT plus LA (-26 +/- 8 and -22 +/- 6%). Because LA affected only the short-term response to LC, either alone or in the presence of BT, we conclude that sensory nerves are involved early in the VC response to LC, but not for either adrenergic or nonadrenergic VC with longer term LC. PMID:17468334

  9. On the identification of sensory information from mixed nerves by using single-channel cuff electrodes

    PubMed Central

    2010-01-01

    Background Several groups have shown that the performance of motor neuroprostheses can be significantly improved by detecting specific sensory events related to the ongoing motor task (e.g., the slippage of an object during grasping). Algorithms have been developed to achieve this goal by processing electroneurographic (ENG) afferent signals recorded by using single-channel cuff electrodes. However, no efforts have been made so far to understand the number and type of detectable sensory events that can be differentiated from whole nerve recordings using this approach. Methods To this aim, ENG afferent signals, evoked by different sensory stimuli were recorded using single-channel cuff electrodes placed around the sciatic nerve of anesthetized rats. The ENG signals were digitally processed and several features were extracted and used as inputs for the classification. The work was performed on integral datasets, without eliminating any noisy parts, in order to be as close as possible to real application. Results The results obtained showed that single-channel cuff electrodes are able to provide information on two to three different afferent (proprioceptive, mechanical and nociceptive) stimuli, with reasonably good discrimination ability. The classification performances are affected by the SNR of the signal, which in turn is related to the diameter of the fibers encoding a particular type of neurophysiological stimulus. Conclusions Our findings indicate that signals of acceptable SNR and corresponding to different physiological modalities (e.g. mediated by different types of nerve fibers) may be distinguished. PMID:20423488

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

    PubMed Central

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

    2014-01-01

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

  11. Orbital pain and unruptured carotid-posterior communicating artery aneurysms: the role of sensory fibers of the third cranial nerve.

    PubMed

    Lanzino, G; Andreoli, A; Tognetti, F; Limoni, P; Calbucci, F; Bortolami, R; Lucchi, M L; Callegari, E; Testa, C

    1993-01-01

    Intact aneurysms of the carotid siphon at the point of take-off of the posterior communicating artery may exhibit orbital pain, whether associated with oculomotor palsy or not as a warning symptom prior to rupture. In order to explain this symptom the hypothesis of a sensory pathway within the third cranial nerve, which is liable to compression by the enlarging aneurysm sac, has been investigated. Data from human autopsy material show evidence of sensory ganglion cells within the rootlets of the oculomotor nerve; furthermore, studies in animals prove that the third nerve contains sensory fibers which run proximally along the nerve bundles, enter the brainstem and reach the spinal trigeminal nucleus. These fibers come from the ophthalmic division of the fifth nerve and join the third nerve at the level of the lateral wall of the cavernous sinus. Although a number of questions remain to be solved, the presence of a sensory pattern within the third nerve could account for fronto-orbital pain from enlarging aneurysms impinging on the third nerve itself. PMID:8434520

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

    Microsoft Academic Search

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

    1989-01-01

    Nerve conduction velocities (NCVs) are the standard measurements used to confirm the presence or absence of diabetic neuropathy. NCVs were contrasted with the newer technique of measurement of alternating current perception thresholds (CPTs) in assessing the quantitative level of correlation with severity of diabetic sensory neuropathy. A very detailed, scored neurological history (symptoms) and physical examination, emphasising sensory assessment, was

  13. Serial changes of sensory nerve conduction velocity and minimal F-wave latency in streptozotocin-induced diabetic rats

    Microsoft Academic Search

    Noriaki Kato; Mitsuhiro Makino; Kuniharu Mizuno; Tsunemasa Suzuki; Masaomi Shindo

    1998-01-01

    We studied the serial changes of sensory nerve conduction velocity (SNCV) in the caudal nerve of streptozotocin (STZ)-induced diabetic rats using a new technical method. Minimal F-wave latency was also studied by stimulating the tibial nerve. The SNCV in the diabetic rats was slower than that in the normal rats 2 weeks after STZ injection, and minimal F-wave latency was

  14. Ultrasound-guided Selective Sensory Nerve Block for Wide-awake Forearm Tendon Reconstruction

    PubMed Central

    Nakanishi, Yasuaki; Kobata, Yasunori; Shimizu, Takamasa; Kira, Tsutomu; Onishi, Tadanobu; Hayami, Naoki; Tanaka, Yasuhito

    2015-01-01

    Background: Wide-awake hand surgery is useful for tendon reconstruction because surgeons can observe the actual movement of the reconstructed tendons during the surgery. We hypothesized that accurate ultrasound-guided injection of local anesthetics into the sensory nerves contributes to reliable analgesia with a relatively small amount of anesthetic. Methods: We enrolled 8 patients who underwent forearm tendon transfer. Three patients underwent reconstruction of flexor tendon ruptures in zones 4 and 5, 3 underwent opponensplasty, and 2 underwent multiple tendon transfers according to Brand’s procedure. All patients underwent ultrasound-guided injection of ropivacaine to each sensory nerve branch of the upper arm and forearm and into the subfascial layer of the forearm. The mean amount of total ropivacaine was 193?mg. Results: In 7 of the 8 patients, we confirmed adequate active contraction of the flexor or extensor muscles during surgery. The expected active motion of the flexor pollicis longus was not found in 1 patient during surgery because the effect of the anesthetic had spread too widely, involving the motor branch of the median nerve. Two patients required additional infiltration of 2–3?mL of local anesthetic because of local wound pain. All patients gained satisfactory function of the transferred tendons after the surgery, and no remarkable perioperative complications related to local anesthetic systemic toxicity occurred. Conclusions: Selective administration of an anesthetic to the sensory nerve branches and subfascial layer enables the performance of wide-awake forearm tendon surgery. The ultrasound-guided injection technique provides safe and effective regional anesthesia for wide-awake surgery.

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

    PubMed Central

    2012-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  17. 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

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

    2014-08-15

    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

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

    PubMed

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

    2004-01-15

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

  19. Sensory fibers of the pelvic nerve innervating the Rat's urinary bladder.

    PubMed

    Shea, V K; Cai, R; Crepps, B; Mason, J L; Perl, E R

    2000-10-01

    Much attention has been given to the pelvic nerve afferent innervation of the urinary bladder; however, reports differ considerably in descriptions of afferent receptor types, their conduction velocities, and their potential roles in bladder reflexes and sensation. The present study was undertaken to do a relatively unbiased sampling of bladder afferent fibers of the pelvic nerve in adult female rats. The search stimulus for units to be studied was electrical stimulation of both the bladder nerves and the pelvic nerve. Single-unit activity of 100 L(6) dorsal root fibers, activated by both pelvic and bladder nerve stimulation, was analyzed. Sixty-five units had C-fiber and 35 units had Adelta-fiber conduction velocities. Receptive characteristics were established by direct mechanical stimulation, filling of the bladder with 0.9% NaCl at a physiological speed and by filling the bladder with solutions containing capsaicin, potassium, or turpentine oil. The majority (61) of these fibers were unambiguously excited by bladder filling with 0.9% NaCl and were classified as mechanoreceptors. All mechanoreceptors with receptive fields on the body of the bladder had low pressure thresholds (nerve sensory innervation of the rat bladder is complex, may be sensitive to hormonal status, and that the properties of individual sensory receptors are not related in an obvious manner to the conduction velocity of their fibers. PMID:11024085

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  1. INCREASED CARDIAC SYMPATHETIC NERVE ACTIVITY IN HEART FAILURE IS NOT DUE TO DESENSITIZATION OF THE ARTERIAL BAROREFLEX

    PubMed Central

    Watson, A.M.D.; Hood, S.G.; Ramchandra, R.; McAllen, R.M.; May, C.N.

    2007-01-01

    Increased sympathetic drive to the heart worsens prognosis in heart failure, but the level of cardiac sympathetic nerve activity (CSNA) has been assessed only by indirect methods, which do not permit testing whether its control by arterial baroreceptors is defective. To do this, CSNA was measured directly in 16 female sheep, 8 of which had been ventricularly paced at 200–220 beats/min for 4–6 weeks, until their ejection fraction fell to between 35 and 40%. Recording electrodes were surgically implanted in the cardiac sympathetic nerves and after 3 days’ recovery, responses to intravenous phenylephrine and nitroprusside infusions were measured in conscious sheep. Electrophysiological recordings showed that resting CSNA (bursts/100 heart beats) was significantly elevated in heart failure sheep (89±3) compared with normal animals (46±6, P<0.001). This increased CSNA was not accompanied by any increase in the low frequency power of heart rate variability. The baroreceptor- heart rate reflex was significantly depressed in heart failure (maximum gain ?3.29±0.56 vs. ?5.34±0.66 beats/min/mmHg in normal animals), confirming published findings. In contrast, the baroreflex control of CSNA was undiminished (maximum gain in heart failure ?6.33±1.06, vs. ?6.03±0.95 %/mmHg in normal sheep). Direct recordings in a sheep model of heart failure thus show that resting CSNA is strikingly increased, but this is not due to defective control by arterial baroreceptors. PMID:17434976

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

    SciTech Connect

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

    1984-07-01

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

  3. Nitro-oleic acid desensitizes TRPA1 and TRPV1 agonist responses in adult rat DRG neurons.

    PubMed

    Zhang, Xiulin; Koronowski, Kevin B; Li, Lu; Freeman, Bruce A; Woodcock, Stephen; de Groat, William C

    2014-01-01

    Nitro-oleic acid (OA-NO2), an electrophilic fatty acid nitroalkene byproduct of redox reactions, activates transient receptor potential ion channels (TRPA1 and TRPV1) in primary sensory neurons. To test the possibility that signaling actions of OA-NO2 might modulate TRP channels, we examined: (1) interactions between OA-NO2 and other agonists for TRPA1 (allyl-isothiocyanate, AITC) and TRPV1 (capsaicin) in rat dissociated dorsal root ganglion cells using Ca(2+) imaging and patch clamp techniques and (2) interactions between these agents on sensory nerves in the rat hindpaw. Ca(2+) imaging revealed that brief application (15-30 s) of each of the three agonists induced homologous desensitization. Heterologous desensitization also occurred when one agonist was applied prior to another agonist. OA-NO2 was more effective in desensitizing the response to AITC than the response to capsaicin. Prolonged exposure to OA-NO2 (20 min) had a similar desensitizing effect on AITC or capsaicin. Homologous and heterologous desensitizations were also demonstrated with patch clamp recording. Deltamethrin, a phosphatase inhibitor, reduced the capsaicin or AITC induced desensitization of OA-NO2 but did not suppress the OA-NO2 induced desensitization of AITC or capsaicin, indicating that heterologous desensitization induced by either capsaicin or AITC occurs by a different mechanism than the desensitization produced by OA-NO2. Subcutaneous injection of OA-NO2 (2.5mM, 35 ?l) into a rat hindpaw induced delayed and prolonged nociceptive behavior. Homologous desensitization occurred with AITC and capsaicin when applied at 15 minute intervals, but did not occur with OA-NO2 when applied at a 30 min interval. Pretreatment with OA-NO2 reduced AITC-evoked nociceptive behaviors but did not alter capsaicin responses. These results raise the possibility that OA-NO2 might be useful clinically to reduce neurogenic inflammation and certain types of painful sensations by desensitizing TRPA1 expressing nociceptive afferents. PMID:24212047

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

    PubMed

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

    2015-03-15

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

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

    PubMed

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

    2004-12-01

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

  6. Nerve Growth Factor-Dependence of Herpes Simplex Virus Latency in Peripheral Sympathetic and Sensory Neurons in vitro

    Microsoft Academic Search

    C. L. Wilcox; L. Smith; C. R. Freed; E. M. Johnson

    1990-01-01

    Previously, we reported that nerve growth factor (NGF) is required to maintain herpes simplex virus (HSV) latency in cultures of rat sympathetic neurons (Wilcox and Johnson, 1987, 1988). Here, we extend these results by showing that NGF was also required to maintain HSV latency in cultures of sensory neurons obtained from dorsal root ganglia of rats, monkeys, and humans. The

  7. Selective Targeting of TRPV1 Expressing Sensory Nerve Terminals in the Spinal Cord for Long Lasting Analgesia

    PubMed Central

    Sikand, Parul; Parihar, Arti; Evans, M. Steven; Premkumar, Louis S.

    2009-01-01

    Chronic pain is a major clinical problem and opiates are often the only treatment, but they cause significant problems ranging from sedation to deadly respiratory depression. Resiniferatoxin (RTX), a potent agonist of Transient Receptor Potential Vanilloid 1 (TRPV1), causes a slow, sustained and irreversible activation of TRPV1 and increases the frequency of spontaneous excitatory postsynaptic currents, but causes significant depression of evoked EPSCs due to nerve terminal depolarization block. Intrathecal administration of RTX to rats in the short-term inhibits nociceptive synaptic transmission, and in the long-term causes a localized, selective ablation of TRPV1-expressing central sensory nerve terminals leading to long lasting analgesia in behavioral models. Since RTX actions are selective for central sensory nerve terminals, other efferent functions of dorsal root ganglion neurons can be preserved. Preventing nociceptive transmission at the level of the spinal cord can be a useful strategy to treat chronic, debilitating and intractable pain. PMID:19753113

  8. Sensory Nerve Terminal Mitochondrial Dysfunction Induces Hyperexcitability in Airway Nociceptors via Protein Kinase C

    PubMed Central

    Hadley, Stephen H.; Bahia, Parmvir K.

    2014-01-01

    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

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

    PubMed

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

    2014-06-01

    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

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

    PubMed Central

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

    2009-01-01

    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

  11. Thyroid hormone reduces the loss of axotomized sensory neurons in dorsal root ganglia after sciatic nerve transection in adult rat.

    PubMed

    Schenker, Michel; Kraftsik, Rudolf; Glauser, Liliane; Kuntzer, Thierry; Bogousslavsky, Julien; Barakat-Walter, Ibtissam

    2003-11-01

    We have shown that a local administration of thyroid hormones (T3) at the level of transected rat sciatic nerve induced a significant increase in the number of regenerated axons. To address the question of whether local administration of T3 rescues the axotomized sensory neurons from death, in the present study we estimated the total number of surviving neurons per dorsal root ganglion (DRG) in three experimental group animals. Forty-five days following rat sciatic nerve transection, the lumbar (L4 and L5) DRG were removed from PBS-control, T3-treated as well as from unoperated rats, and serial sections (1 microm) were cut. The physical dissector method was used to estimate the total number of sensory neurons in the DRGs. Our results revealed that in PBS-control rats transection of sciatic nerve leads to a significant (P < 0.001) decrease in the mean number of sensory neurons (8743.8 +/- 748.6) compared with the number of neurons in nontransected ganglion (mean 13,293.7 +/- 1368.4). However, administration of T3 immediately after sciatic nerve transection rescues a great number of axotomized neurons so that their mean neuron number (12,045.8 +/- 929.8) is not significantly different from the mean number of neurons in the nontransected ganglion. In addition, the volume of ganglia showed a similar tendency. These results suggest that T3 rescues a high number of axotomized sensory neurons from death and allows these cells to grow new axons. We believe that the relative preservation of neurons is important in considering future therapeutic approaches of human peripheral nerve lesion and sensory neuropathy. PMID:14637094

  12. Identification of the sensory nerve fiber responsible for lysophosphatidic acid-induced allodynia in mice.

    PubMed

    Ohsawa, M; Miyabe, Y; Katsu, H; Yamamoto, S; Ono, H

    2013-09-01

    Lysophosphatidic acid (LPA) has been considered one of the molecular culprits for neuropathic pain. Understanding how LPA changes the function of primary afferent fibers might be an essential step for clarifying the pathogenesis of neuropathic pain. The present study was designed to identify the primary afferent fibers (A?, A?, or C) participating in LPA-induced allodynia in ddY mice. Mechanical allodynia and thermal hyperalgesia were evaluated by the von Frey filament test and thermal paw withdrawal test, respectively. Sensory nerve fiber responsiveness was measured using a Neurometer. Daily repeated intrathecal treatment with LPA led to a decrease in the mechanical, but not thermal nociceptive threshold, and a reduction in the threshold for paw withdrawal induced by 2000-Hz (A? fiber) and 250-Hz (A? fiber), but not 5-Hz (C fiber) sine-wave electrical stimulation. When the transient receptor potential cation channel subfamily V member 1 (TRPV1) receptor agonist resiniferatoxin (RTX) was administered subcutaneously before the start of LPA treatment, LPA-induced mechanical allodynia and A? and A? fiber hypersensitivity demonstrated by neurometry were not affected, indicating that TRPV1-expressing nerve fibers (possibly C fibers) might not be essential for LPA-induced allodynia. LPA-induced allodynia was reversed by treatment with RTX at 7 days after the start of LPA treatment. Expression of TRPV1 on myelinated nerve fibers after repeated intrathecal LPA treatment was observed in the dorsal root ganglion. These results suggest that sensitization of A? and A? fibers, but not C fibers, contributes to the development of intrathecally administered LPA-induced mechanical allodynia. Moreover, increased or newly expressed TRPV1 receptors in A? and A? fibers are considered to be involved in the maintenance of LPA-induced allodynia. PMID:23685168

  13. Desensitization of bladder sensory fibers by intravesical capsaicin or capsaicin analogs. A new strategy for treatment of urge incontinence in patients with spinal detrusor hyperreflexia or bladder hypersensitivity disorders

    Microsoft Academic Search

    F. Cruz

    1998-01-01

    Recent experimental studies have identified a category of unmyelinated type C bladder afferent fibers in the pelvic nerves which are extremely sensitive to capsaicin. Sensory input conveyed by these fibers triggers a spinal reflex which, in chronic spinalized animals, facilitates and controls micturition. In addition, bladder C fibers were also shown to have a role in bladder pain perception. In

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

    PubMed

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

    2015-08-01

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

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

    PubMed Central

    2013-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    1996-01-01

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

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

    PubMed Central

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

    2015-01-01

    Objective The K/BxN serum-transfer arthritis is a widely-used translational mouse model of rheumatoid arthritis, in which the immunological components have thoroughly been investigated. In contrast, little is known about the role of sensory neural factors and the complexity of neuro–immune interactions. Therefore, we analyzed the involvement of capsaicin-sensitive peptidergic sensory nerves in autoantibody-induced arthritis with integrative methodology. Methods Arthritogenic K/BxN or control serum was injected to non-pretreated mice or resiniferatoxin (RTX)-pretreated animals where capsaicin-sensitive nerves were inactivated. Edema, touch sensitivity, noxious heat threshold, joint function, body weight and clinical arthritis severity scores were determined repeatedly throughout two weeks. Micro-CT and in vivo optical imaging to determine matrix-metalloproteinase (MMP) and neutrophil-derived myeloperoxidase (MPO) activities, semiquantitative histopathological scoring and radioimmunoassay to measure somatostatin in the joint homogenates were also performed. Results In RTX-pretreated mice, the autoantibody-induced joint swelling, arthritis severity score, MMP and MPO activities, as well as histopathological alterations were significantly greater compared to non-pretreated animals. Self-control quantification of the bone mass revealed decreased values in intact female mice, but significantly greater arthritis-induced pathological bone formation after RTX-pretreatment. In contrast, mechanical hyperalgesia from day 10 was smaller after inactivating capsaicin-sensitive afferents. Although thermal hyperalgesia did not develop, noxious heat threshold was significantly higher following RTX pretreatment. Somatostatin-like immunoreactivity elevated in the tibiotarsal joints in non-pretreated, which was significantly less in RTX-pretreated mice. Conclusions Although capsaicin-sensitive sensory nerves mediate mechanical hyperalgesia in the later phase of autoantibody-induced chronic arthritis, they play important anti-inflammatory roles at least partially through somatostatin release. PMID:25524130

  18. Motor and sensory nerve conduction velocity in the baboon: normal values and changes during acrylamide neuropathy

    Microsoft Academic Search

    A. P. Hopkins; R. W. Gilliatt

    1971-01-01

    Nerve conduction velocity and the amplitude of nerve and muscle action potentials have been measured in the median and anterior tibial nerves of normal adult and infant baboons. The effect of altered temperature on velocity has also been investigated. Seven adult baboons were intoxicated with acrylamide. In animals given 10-15 mg\\/kg\\/day, the gradual development of a peripheral neuropathy was accompanied

  19. The effect of different warming methods on sensory nerve conduction velocity in shipyard workers occupationally exposed to hand–arm vibration

    Microsoft Academic Search

    Martin Cherniack; Anthony J. Brammer; Ronnie Lundstrom; Tim F. Morse; Greg Neely; Tohr Nilsson; Donald Peterson; Esko Toppila; Nicholas Warren; Ulysses Diva; Marc Croteau; Jeffrey Dussetschleger

    2008-01-01

    Objectives  Segmental sensory nerve conduction velocity (SNCV) was measured from the wrists to the hands and digits in a population of\\u000a 134 (126 men and 8 women) vibration-exposed shipyard workers following systemic warming using a bicycle ergometer. Results\\u000a were compared to earlier nerve conduction tests, identical in execution, except that the warming process was segmental and\\u000a cutaneous. The study was designed

  20. The effects of juvenile capsaicin desensitization in rats: behavioral impairments.

    PubMed

    Petrovszki, Zita; Adam, Gábor; Kekesi, Gabriella; Tuboly, Gábor; Morvay, Zita; Nagy, Endre; Benedek, György; Horvath, Gyöngyi

    2014-02-10

    Capsaicin desensitization leads to behavioral changes, some of which are related to schizophrenia, but investigations into these effects have been scarce. The goal of this study was to characterize the consequences of juvenile capsaicin desensitization on different functions: acute and inflammation-induced thermal and mechanical sensitivity, urinary bladder capacity and thermoregulation, and also on the potentially schizophrenia-related impairments in sensory-motor gating, motor activity and cognitive functioning. Male Wistar rats desensitized with increasing doses of subcutaneous capsaicin after weaning were investigated. Heat and mechanical pain sensitivity did not change significantly; however, morphine produced a prolonged decrease in the nociceptive response to inflammation in desensitized animals. Ultrasound examination of the bladder revealed enhanced bladder volume in treated animals. Capsaicin-treated animals had higher body temperature at 22 °C in both dark and light periods, and they also showed prolonged hyperthermia in new environmental circumstances. Warm environment induced a profound impairment of thermoregulation in desensitized animals. The treated animals also showed higher levels of activity during the active phase and at both cool and warm temperatures. The amplitude of the responses to auditory stimuli and prepulse inhibition did not differ between the two groups, but the desensitized animals showed learning impairments in the novel object recognition test. These results suggest that juvenile capsaicin desensitization leads to sustained changes in several functions that may be related to schizophrenia. We propose that capsaicin desensitization, together with other interventions, may lead to an improved chronic animal model of schizophrenia. PMID:24291382

  1. Topography and ultrastructure of sensory nerve endings in the joint capsules of the Kowari (Dasyuroides byrnei), an Australian marsupial.

    PubMed

    Strasmann, T; Halata, Z; Loo, S K

    1987-01-01

    The present investigation in concerned with the topography and ultrastructure of sensory nerve endings in the joint capsules of the Kowari (Dasyuroides byrnei), an Australian marsupial. Material for light and electron microscopy was obtained from shoulder, elbow and knee joint capsules. On the basis of differences in the organization of the connective tissue belonging to the fibrous layer, 3 variants of capsule structure have been distinguished: a rigid, a flaccid and an intermediate type. Whilst the rigid type is characterized by dense connective tissue in the clearly demarcated fibrous layer, the flaccid type shows loose, irregularly arranged connective tissue in the fibrous layer which merges into the synovial layer of the joint capsule. The morphology of the intermediate type corresponds to an intermediate stage between the former two types. In the fibrous layer of the joint capsules three different types of sensory nerve endings were observed: free nerve endings, Ruffini corpuscles and lamellated corpuscles. The free nerve endings are supplied by myelinated afferent axons (1-2 microns in diameter); the terminal thickenings of which are incompletely surrounded by a terminal Schwann cell. Ruffini corpuscles are present in three different varieties: small corpuscles without a perineural capsule predominantly within the flaccid part of the capsule; slightly larger corpuscles with an incomplete perineural capsule and large corpuscles resembling Golgi tendon organs which predominantly occur in the rigid parts of the capsule. The afferent myelinated axons measure 2-4 microns in diameter. The lamellated corpuscles show two variants: small corpuscles with a 2 to 4-layered perineural capsule in the rigid parts of the joint capsules and large corpuscles with two longitudinal clefts of the inner core in the flaccid parts. Both types are supplied by myelinated axons of 3-5 microns in diameter. Thus, in the fibrous layer of the rigid type of joint capsules large Ruffini and small lamellated corpuscles predominate, whereas the fibrous layer of the flaccid type coincides with small Ruffini and large lamellated corpuscles. The present data, therefore, corroborate the concept that the morphology of mechanoreceptors depends upon the texture of the surrounding connective tissue. PMID:3605642

  2. Quantitative analysis of contact sites between mast cells and sensory nerves in cutaneous psoriasis and lichen planus based on a histochemical double staining technique

    Microsoft Academic Search

    A. Naukkarinen; I. T. Harvima; M. L. Aalto; R. J. Harvima; M. Horsmanheimo

    1991-01-01

    The aim of the present study was to test further our previous hypothesis that the inflammatory reaction in psoriasis is neurogenic. For this purpose, contact sites between mast cells and sensory nerves were morphometrically analysed in the basement membrane zone, papillary dermis and three dermal zones of lesional\\/non-lesional psoriatic and lichen planus skin as well as in healthy control skin.

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

    Microsoft Academic Search

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

    2011-01-01

    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

  4. Tachykinin receptors mediating responses to sensory nerve stimulation and exogenous tachykinins and analogues in the rabbit isolated iris sphincter.

    PubMed Central

    Hall, J. M.; Mitchell, D.; Morton, I. K.

    1993-01-01

    1. We have used selective tachykinin receptor agonists and antagonists to investigate the nature of the receptors mediating responses to endogenous and exogenous tachykinins in the rabbit iris sphincter preparation in vitro. 2. The NK1-selective agonist, substance P methyl ester, induced contraction with a pD2 of 9.16 indicating the presence of NK1 receptors. In confirmation, the NK1-selective antagonist, GR82334, competitively antagonized responses to substance P methyl ester with high affinity (pKB 7.46). 3. NK3 receptors also mediate contraction since NK3-selective agonists exhibited high potency, e.g. the pD2 of [Me-Phe7]-neurokinin B was 9.67, and their responses were not inhibited by GR82334 (10 microM). 4. NK2 receptor activation does not seem to contribute to contraction since the NK2-selective agonist [beta-Ala8]-neurokinin A(4-10) had relatively low potency (pD2 6.43), and the NK2-selective antagonists MEN10207 (1 microM) and L-659,877 (10 microM) were inactive or had low affinity, respectively. 5. GR82334 (1 microM) significantly inhibited responses to electrical field-stimulation of non-adrenergic non-cholinergic sensory nerves (3, 10 and 30 Hz), and caused a rightward shift of the log concentration-response curve to bradykinin (lateral shift ca. 1000 fold). Higher concentrations of GR82334 (10 microM) significantly attenuated responses to capsaicin (1-60 microM) whilst completely abolishing responses to field-stimulation (3, 10 and 30 Hz) and bradykinin (1 nM- 3 microM). 6. In conclusion, NK1 and NK3 receptor activation results in contraction of the rabbit iris sphincter. The contractile response following sensory nerve stimulation by bradykinin, capsaicin and electrical field stimulation results from NK1 receptor activation. PMID:8401912

  5. Neural Control of Blood Pressure: Focusing on Capsaicin-Sensitive Sensory Nerves

    Microsoft Academic Search

    Youping Wang; Donna H. Wang

    Hypertension is a major risk factor leading to devastating cardiovascular events such as myocardial infarction, stroke, heart failure, and renal failure. Despite intensive research in this area, mechanisms underlying essential hyperten- sion remain to be defined. Accumulating evidence indicates that neural components including both sympathetic and sen- sory nerves innervating the cardiovascular and renal tissues play a key role in

  6. On the identification of sensory information from mixed nerves by using single-channel cuff electrodes

    Microsoft Academic Search

    Stanisa Raspopovic; Jacopo Carpaneto; Esther Udina; Xavier Navarro; Silvestro Micera

    2010-01-01

    BACKGROUND: Several groups have shown that the performance of motor neuroprostheses can be significantly improved by detecting specific sensory events related to the ongoing motor task (e.g., the slippage of an object during grasping). Algorithms have been developed to achieve this goal by processing electroneurographic (ENG) afferent signals recorded by using single-channel cuff electrodes. However, no efforts have been made

  7. Modelled temperature-dependent excitability behaviour of a single ranvier node for a human peripheral sensory nerve fibre.

    PubMed

    Smit, Jacoba E; Hanekom, Tania; Hanekom, Johan J

    2009-01-01

    The objective of this study was to determine whether the Hodgkin-Huxley model for unmyelinated nerve fibres could be modified to predict excitability behaviour at Ranvier nodes. Only the model parameters were modified to those of human, with the equations left unaltered. A model of a single Ranvier node has been developed as part of a larger model to describe excitation behaviour in a generalised human peripheral sensory nerve fibre. Parameter values describing the ionic and leakage conductances, corresponding equilibrium potentials, resting membrane potential and membrane capacitance of the original Hodgkin-Huxley model were modified to reflect the corresponding parameter values for human. Parameter temperature dependence was included. The fast activating potassium current kinetics were slowed down to represent those of a slow activating and deactivating potassium current, which do not inactivate. All calculations were performed in MATLAB. Action potential shape and amplitude were satisfactorily predicted at 20, 25 and 37 degrees C, and were not influenced by activation or deactivation of the slow potassium current. The calculated chronaxie time constant was 65.5 micros at 37 degrees C. However, chronaxie times were overestimated at temperatures lower than body temperature. PMID:19066936

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

    PubMed Central

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

    2014-01-01

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

  9. Peripheral nerve regeneration and NGF-dependent neurite outgrowth of adult sensory neurons converge on STAT3 phosphorylation downstream of neuropoietic cytokine receptor gp130.

    PubMed

    Quarta, Serena; Baeumer, Bastian E; Scherbakov, Nadja; Andratsch, Manfred; Rose-John, Stefan; Dechant, Georg; Bandtlow, Christine E; Kress, Michaela

    2014-09-24

    After nerve injury, adult sensory neurons can regenerate peripheral axons and reconnect with their target tissue. Initiation of outgrowth, as well as elongation of neurites over long distances, depends on the signaling of receptors for neurotrophic growth factors. Here, we investigated the importance of gp130, the signaling subunit of neuropoietic cytokine receptors in peripheral nerve regeneration. After sciatic nerve crush, functional recovery in vivo was retarded in SNS-gp130(-/-) mice, which specifically lack gp130 in sensory neurons. Correspondingly, a significantly reduced number of free nerve endings was detected in glabrous skin from SNS-gp130(-/-) compared with control mice after nerve crush. Neurite outgrowth and STAT3 activation in vitro were severely reduced in cultures in gp130-deficient cultured neurons. Surprisingly, in neurons obtained from SNS-gp130(-/-) mice the increase in neurite length was reduced not only in response to neuropoietic cytokine ligands of gp130 but also to nerve growth factor (NGF), which does not bind to gp130-containing receptors. Neurite outgrowth in the absence of neurotrophic factors was partially rescued in gp130-deficient neurons by leptin, which activates STAT3 downstream of leptic receptor and independent of gp130. The neurite outgrowth response of gp130-deficient neurons to NGF was fully restored in the presence of leptin. Based on these findings, gp130 signaling via STAT3 activation is suggested not only to be an important regulator of peripheral nerve regeneration in vitro and in vivo, but as determining factor for the growth promoting action of NGF in adult sensory neurons. PMID:25253866

  10. Sensory nerves, vascular endothelium and neurogenic relaxation of the guinea-pig isolated pulmonary artery

    Microsoft Academic Search

    Carlo Alberto Maggi; Riccardo Patacchini; Francesca Perretti; Manuela Tramontana; Stefano Manzini; Pierangelo Geppetti; Paolo Santicioli

    1990-01-01

    1. In the presence of atropine and guanethidine (3 µmol\\/l each), electrical field stimulation (1–20 Hz) produced frequency-dependent relaxations of the histamine-(3 µmol\\/l) induced vascular tone in isolated rings from the guinea-pig pulmonary artery. The electrically-evoked relaxations were abolished by tetrodotoxin (1 µmol\\/l). The amplitude of these nerve-mediated, nonadrenergic non-cholinergic (NANC) relaxations was unaffected by removal of the vascular endothelium

  11. Anti-inflammatory effects of limb ischaemic preconditioning are mediated by sensory nerve activation in rats

    Microsoft Academic Search

    Petra Hartmann; Renáta Varga; Zsuzsanna Zobolyák; Júlia Héger; Blanka Cs?sz; István Németh; Zsolt Rázga; Csaba Vízler; Dénes Garab; Péter Sántha; Gábor Jancsó; Mihály Boros; Andrea Szabó

    2011-01-01

    We have shown that ischaemic preconditioning ameliorates both the local periosteal and the systemic leukocyte activation evoked\\u000a by limb ischaemia–reperfusion. We hypothesized that the activation of chemosensitive afferent nerves by transient ischaemia\\u000a contributes to the protective mechanisms of ischaemic preconditioning via a calcitonin gene-related peptide (CGRP)-dependent\\u000a mechanism. In Sprague–Dawley rats, 60-min complete limb ischaemia was followed by 180 min of reperfusion.

  12. Successful oral acyclovir desensitization.

    PubMed

    Henry, R E; Wegmann, J A; Hartle, J E; Christopher, G W

    1993-05-01

    A 65-year-old woman with the acquired immunodeficiency syndrome (AIDS) complicated by recurrent mucocutaneous herpes simplex virus (HSV) infection developed angioedema on the initiation of her second course of oral acyclovir therapy. Oral rechallenge in hospital three days later confirmed acyclovir hypersensitivity. Vidarabine and foscarnet therapies were abandoned after treatment failure and unacceptable toxicity. Acyclovir desensitization was accomplished using a protocol derived from oral penicillin desensitization regimens. Mucocutaneous HSV infection responded to intravenous acyclovir followed by chronic oral suppression without recurrences of HSV or hypersensitivity. This report is an example of acyclovir hypersensitivity and successful oral desensitization. PMID:8498729

  13. The role of reactive oxygen species and capsaicin-sensitive sensory nerves in the pathomechanisms of gastric ulcers induced by stress.

    PubMed

    Kwiecie?, S; Brzozowski, T; Konturek, P C; Pawlik, M W; Pawlik, W W; Kwiecie?, N; Konturek, S J

    2003-09-01

    Gastric microcirculation plays an important role in the maintenance of the gastric mucosal barrier and mucosal integrity. Sensory nerves are involved in the regulation of mucosal blood circulation and mucosal defense. Therefore, the ablation of these nerves by neurotoxic doses of capsaicin provides the possibility of determination of their role in gastric mucosal integrity. Stress ulceration represents a serious gastric lesions. Results of our previous experiments have indicated that water immersion and restraint stress (WRS) led to increased oxidative metabolism. Ablation of sensory nerves by high doses of capsaicin retards healing of gastric ulcers, but the role of reactive oxygen species (ROS) in the healing process has been little studied. Therefore, the aim of our present investigations was to determine the participation of ROS in sensory nerve activity during WRS. Experiments were carried out on 90 male Wistar rats and the area of gastric lesions was measured by planimetry. Colorimetric assays were used to determine gastric mucosal levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), as well as superoxide dismutase (SOD) activity. We demonstrated that inactivation of sensory nerves resulted in magnification of gastric mucosal damage induced by the WRS. In this process, oxidative stress, as reflected by an increase of MDA and 4-HNE tissue concentrations (an index of lipid peroxidation), as well as decrease of SOD activity, could play an important role. Aspirin, applied in a low dose, exerts a protective activity, possibly due to its metabolites, which possess the anti-oxidant and ROS scavanging properties. Pentoxyfilline-induced gastroprotection and hyperemia depends upon attenuation of the oxidative stress. This protection and hyperemia were, at least in part, attenuated by ASA. PMID:14566080

  14. Targeted Expression of a Multifunctional Chimeric Neurotrophin in the Lesioned Sciatic Nerve Accelerates Regeneration of Sensory and Motor Axons

    Microsoft Academic Search

    Hiroshi Funakoshi; Marten Risling; Thomas Carlstedt; Urban Lendahl; Tonis Timmusk; Madis Metsis; Yuji Yamamoto; Carlos F. Ibanez

    1998-01-01

    Peripheral nerve injury markedly regulates expression of neurotrophins and their receptors in the lesioned nerve. However, the role of endogenously produced neurotrophins in the process of nerve regeneration is unclear. Expression of a multifunctional neurotrophin, panneurotrophin-1 (PNT-1), was targeted to the peripheral nerves of transgenic mice by using a gene promoter that is specifically activated after nerve lesion but that

  15. Identity of Myelinated Cutaneous Sensory Neurons Projecting to Nocireceptive Laminae Following Nerve Injury in Adult Mice

    PubMed Central

    WOODBURY, C. JEFFERY; KULLMANN, FLORENTA A.; McILWRATH, SABRINA L.; KOERBER, H. RICHARD

    2009-01-01

    It is widely thought that, after peripheral injury, some low-threshold mechanoreceptive (LTMR) afferents “sprout” into pain-specific laminae (I–II) of the dorsal horn and are responsible for chronic pain states such as mechanical allodynia. Although recent studies have questioned this hypothesis, they fail to account for a series of compelling results from single-fiber analyses showing extensive projections from large-diameter myelinated afferents into nocireceptive layers after nerve injury. Here we show that, in the thoracic spinal cord of naďve adult mouse, all myelinated nociceptors gave rise to terminal projections throughout the superficial dorsal horn laminae (I–II). Most (70%) of these fibers had large-diameter axons with recurving flame-shaped central arbors that projected throughout the dorsal horn laminae I–V. This morphology was reminiscent of that attributed to sprouted LTMRs described in previous studies. After peripheral nerve axotomy, we found that LTMR afferents with narrow, uninflected somal action potentials did not sprout into superficial laminae of the dorsal horn. Only myelinated noiceptive afferents with broad, inflected somal action potentials were found to give rise to recurving collaterals and project into superficial “pain-specific” laminae after axotomy. We conclude that the previously undocumented central morphology of large, myelinated cutaneous nociceptors may very well account for the morphological findings previously thought to require sprouting of LTMRs. PMID:18335545

  16. Endogenous prostaglandins and afferent sensory nerves in gastroprotective effect of hydrogen sulfide against stress-induced gastric lesions.

    PubMed

    Magierowski, Marcin; Jasnos, Katarzyna; Kwiecien, Slawomir; Drozdowicz, Danuta; Surmiak, Marcin; Strzalka, Malgorzata; Ptak-Belowska, Agata; Wallace, John L; Brzozowski, Tomasz

    2015-01-01

    Hydrogen sulfide (H2S) plays an important role in human physiology, exerting vasodilatory, neuromodulatory and anti-inflammatory effects. H2S has been implicated in the mechanism of gastrointestinal integrity but whether this gaseous mediator can affect hemorrhagic lesions induced by stress has been little elucidated. We studied the effect of the H2S precursor L-cysteine, H2S-donor NaHS, the H2S synthesizing enzyme (CSE) activity inhibitor- D,L-propargylglycine (PAG) and the gastric H2S production by CSE/CBS/3-MST activity in water immersion and restraint stress (WRS) ulcerogenesis and the accompanying changes in gastric blood flow (GBF). The role of endogenous prostaglandins (PGs) and sensory afferent nerves releasing calcitonin gene-related peptide (CGRP) in the mechanism of gastroprotection induced by H2S was examined in capsaicin-denervated rats and those pretreated with capsazepine to inhibit activity of vanilloid receptors (VR-1). Rats were pretreated with vehicle, NaHS, the donor of H2S and or L-cysteine, the H2S precursor, with or without the concurrent treatment with 1) nonselective (indomethacin) and selective cyclooxygenase (COX)-1 (SC-560) or COX-2 (rofecoxib) inhibitors. The expression of mRNA and protein for COX-1 and COX-2 were analyzed in gastric mucosa pretreated with NaHS with or without PAG. Both NaHS and L-cysteine dose-dependently attenuated severity of WRS-induced gastric lesions and significantly increased GBF. These effects were significantly reduced by pretreatment with PAG and capsaicin denervation. NaHS increased gastric H2S production via CSE/CBS but not 3-MST activity. Inhibition of COX-1 and COX-2 activity significantly diminished NaHS- and L-cysteine-induced protection and hyperemia. NaHS increased expression of COX-1, COX-2 mRNAs and proteins and raised CGRP mRNA expression. These effects of NaHS on COX-1 and COX-2 protein contents were reversed by PAG and capsaicin denervation. We conclude that H2S exerts gastroprotection against WRS-induced gastric lesions by the mechanism involving enhancement in gastric microcirculation mediated by endogenous PGs, sensory afferent nerves releasing CGRP and the activation of VR-1 receptors. PMID:25774496

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

    Microsoft Academic Search

    B. Kalmar; L. Greensmith; M. Malcangio; S. B. McMahon; P. Csermely; G. Burnstocke

    2003-01-01

    In this study, we examined the effect BRX-220, a co-inducer of heat shock proteins, in injury-induced peripheral neuropathy. Following sciatic nerve injury in adult rats and treatment with BRX-220, the following features of the sensory system were studied: (a) expression of calcitonin gene-related peptide (CGRP); (b) binding of isolectin B4 (IB4) in dorsal root ganglia (DRG) and spinal cord; (c)

  18. Displacement of the contents of dentinal tubules and sensory transduction in intradental nerves of the cat.

    PubMed

    Andrew, D; Matthews, B

    2000-12-15

    Experiments were performed on anaesthetized cats to test the hypothesis that fluid flow through dentinal tubules is part of the mechanism involved in the transduction of pain-producing stimuli in teeth. In 11 animals, fluid flow through dentine and single- and multi-unit activity in intradental nerves were recorded simultaneously during the application of changes in hydrostatic pressure (-500 to +500 mm Hg) to exposed dentine. Seventeen A-fibres (conduction velocity (CV), 10.6-55.1 m s(-1)) were isolated that were pressure sensitive. The thresholds of these units in terms of dentinal fluid flow were in the range 0.3-2.1 nl s(-1) mm(-2) during outward flow from the pulp and 2.0-3.5 nl s(-1) mm(-2) during inward flow. All the units were more sensitive to outward than inward flow. Twenty-eight units (CV, 0.6-48.8 m s-1) were not pressure sensitive, and 12 of these had conduction velocities in the C-fibre range (< 2.5 m s(-1)). The velocities of the tubular contents were calculated by estimating the number and diameters of dentinal tubules exposed. At the threshold of single-fibre responses these velocities were in the range 31.7-222.9 microm s(-1) during outward flow 211.4-369.6 microm s-1 during inward flow. Repetitive pressure stimulation of dentine resulted in a progressive reduction in the evoked discharge, which was probably due to pulp damage. In seven animals, 10 single intradental nerve fibres were selected that responded to hydrostatic pressure stimuli and their responses to the application of hot, cold, osmotic, mechanical and drying stimuli to exposed dentine were investigated. With these stimuli dentinal fluid flow could not be recorded in vivo for technical reasons and was therefore recorded in vitro after completion of the electrophysiological recordings. With each form of stimulus, the discharge evoked in vivo was closely related to the flow predicted from the in vitro measurements. The results were therefore consistent with the hypothesis that the stimuli act through a common transduction mechanism that involves fluid flow through dentine. PMID:11118506

  19. Cellular/Molecular Camphor Activates and Strongly Desensitizes the Transient

    E-print Network

    Clapham, David E.

    , including ankyrin-repeat TRP 1 (TRPA1). The camphor-induced desensitization of TRPV1 and block of TRPA1 may) as well as TRPM8 and ankyrin-repeat TRP 1 (TRPA1) are expressed in sensory cells, particularly; Pata- poutian et al., 2003), although the cold temperature activation of TRPA1 is unclear (Story et al

  20. Structural determinant of TRPV1 desensitization interacts with calmodulin

    Microsoft Academic Search

    Mitsuko Numazaki; Tomoko Tominaga; Kumiko Takeuchi; Namie Murayama; Hidenori Toyooka; Makoto Tominaga

    2003-01-01

    The capsaicin receptor, TRPV1 (VR1), is a sensory neuron-specific ion channel that serves as a polymodal detector of pain-producing chemical and physical stimuli. Extracellular Ca2+-dependent desensitization of TRPV1 observed in patch-clamp experiments when using both heterologous expression systems and native sensory ganglia is thought to be one mechanism underlying the paradoxical effectiveness of capsaicin as an analgesic therapy. Here, we

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

    E-print Network

    Lazzaro, John

    part of sensory transduction in the nervous system. Sensory inputs are analog, continuous-time signals the sound energy present at the eardrum into the first neural representation of the auditory system

  2. Sympathetic sprouting and changes in nociceptive sensory innervation in the glabrous skin of the rat hind paw following partial peripheral nerve injury.

    PubMed

    Yen, Laurene D; Bennett, Gary J; Ribeiro-da-Silva, Alfredo

    2006-04-20

    Previous studies have suggested that sympathetic sprouting in the periphery may contribute to the development and persistence of sympathetically maintained pain in animal models of neuropathic pain. In the present study, we examined changes in the cutaneous innervation in rats with a chronic constriction injury to the sciatic nerve. At several periods postinjury, hind paw skin was harvested and processed by using a monoclonal antibody against dopamine-beta-hydroxylase to detect sympathetic fibers and a polyclonal antibody against calcitonin gene-related peptide to identify peptidergic sensory fibers. We observed migration and branching of sympathetic fibers into the upper dermis of the hind paw skin, where they were normally absent. This migration was first detected at 2 weeks, peaked at 4-6 weeks, and lasted for at least 20 weeks postlesion. At 8 weeks postlesion, there was a dramatic increase in the density of peptidergic fibers in the upper dermis. Quantification revealed that densities of peptidergic fibers 8 weeks postlesion were significantly above levels in sham animals. The ectopic sympathetic fibers did not innervate blood vessels but formed a novel association and wrapped around sprouted peptidergic nociceptive fibers. Our data show a long-term sympathetic and sensory innervation change in the rat hind paw skin after the chronic constriction injury. This novel fiber arrangement after nerve lesion may play an important role in the development and persistence of sympathetically maintained neuropathic pain after partial nerve lesions. PMID:16506190

  3. Interaction between selective cyclooxygenase inhibitors and capsaicin-sensitive afferent sensory nerves in pathogenesis of stress-induced gastric lesions. Role of oxidative stress.

    PubMed

    Kwiecien, S; Konturek, P C; Sliwowski, Z; Mitis-Musiol, M; Pawlik, M W; Brzozowski, B; Jasnos, K; Magierowski, M; Konturek, S J; Brzozowski, T

    2012-04-01

    Gastric microcirculation plays an important role in the maintenance of the mucosal gastric integrity and the mechanism of injury as well as providing protection to the gastric mucosa. Disturbances in the blood perfusion, through the microcapillaries within the gastric mucosa may result in the formation of mucosal damage. Acute gastric mucosal lesions constitute an important clinical problem. Originally, one of the essential component of maintaining the gastric mucosal integrity was the biosynthesis of prostaglandins (PGs), an issue that has captured the attention of numerous investigations. PGs form due to the activity of cyclooxygenase (COX), an enzyme which is divided into 2 isoforms: constitutive (COX-1) and inducible (COX-2) ones. The inhibition of COX-1 by SC-560, or COX-2 by rofecoxib, reduces gastric blood flow (GBF) and impairs gastric mucosal integrity. Another detrimental effect on the gastric mucosal barrier results from the ablation of sensory afferent nerves by neurotoxic doses of capsaicin. Functional ablation of the sensory afferent nerves by capsaicin attenuates GBF and also renders the gastric mucosa more susceptible to gastric mucosal damage induced by ethanol, aspirin and stress. However, the role of reactive oxygen species (ROS) in the interaction between COX specific inhibitors and afferent sensory nerves has not been extensively studied. The aim of our present study was to determine the participation of ROS in pathogenesis of stress-induced gastric lesions in rats administered with SC-560 or rofecoxib, with or without ablation of the sensory afferent nerves. ROS were estimated by measuring the gastric mucosal tissue level of MDA and 4-HNE, the products of lipid peroxidation by ROS as well as the SOD activity and reduced glutathione (GSH) levels, both considered to be scavengers of ROS. It was demonstrated that exposure to 3.5 h of WRS resulted in gastric lesions, causing a significant increase of MDA and 4-HNE in the gastric mucosa, accompanied by a decrease of SOD activity and mucosal GSH level. Pretreatment with COX-1 and COX-2 inhibitors (SC-560 and rofecoxib, respectively) aggravated the number of gastric lesions, decreased GBF, attenuated GSH level without further significant changes in MDA and 4-HNE tissue levels and SOD activity. Furthermore, the capsaicin--nactivation of sensory nerves resulted in exaggeration of gastric mucosal damage induced by WRS and this was further augmented by rofecoxib. We conclude that oxidative stress, as reflected by an increase of MDA and 4-HNE tissue concentrations (an index of lipid peroxidation), as well as decrease of SOD activity and the fall in GSH tissue level, may play an important role in the mechanism of interaction between the inhibition of COX activity and afferent sensory nerves releasing vasoactive neuropeptides. This is supported by the fact that the addition of specific COX-1 or COX-2 inhibitors to animals with capsaicin denervation led to exacerbation of gastric lesions, and further fall in the antioxidizing status of gastric mucosa exposed to stress. PMID:22653901

  4. Vanilloid receptors in the urinary bladder: regional distribution, localization on sensory nerves, and species-related differences

    Microsoft Academic Search

    Arpad Szallasi; Bruno Conte; Cristina Goso; Peter M. Blumberg; Stefano Manzini

    1993-01-01

    Using selective surgical ablations we have investigated the localization of vanilloid receptors (specific [3H]resiniferatoxin binding sites) on terminals of the pelvic, hypogastric, and pudendal nerves in the rat urinary bladder. Pelvic and hypogastric nerve resections resulted in 90%6 and 25% loss of specific [3H]resiniferatoxin (RTX) binding sites, respectively, whilst pudendic nerve resection had no measurable effect on the binding. In

  5. Vascularization of the dorsal root ganglia and peripheral nerve of the mouse: Implications for chemical-induced peripheral sensory neuropathies

    Microsoft Academic Search

    Juan M Jimenez-Andrade; Monica B Herrera; Joseph R Ghilardi; Marina Vardanyan; Ohannes K Melemedjian; Patrick W Mantyh

    2008-01-01

    Although a variety of industrial chemicals, as well as several chemotherapeutic agents used to treat cancer or HIV, preferentially induce a peripheral sensory neuropathy what remains unclear is why these agents induce a sensory vs. a motor or mixed neuropathy. Previous studies have shown that the endothelial cells that vascularize the dorsal root ganglion (DRG), which houses the primary afferent

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

    PubMed Central

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

    2014-01-01

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

  7. The vestibulocochlear nerve (VIII).

    PubMed

    Benoudiba, F; Toulgoat, F; Sarrazin, J-L

    2013-10-01

    The vestibulocochlear nerve (8th cranial nerve) is a sensory nerve. It is made up of two nerves, the cochlear, which transmits sound and the vestibular which controls balance. It is an intracranial nerve which runs from the sensory receptors in the internal ear to the brain stem nuclei and finally to the auditory areas: the post-central gyrus and superior temporal auditory cortex. The most common lesions responsible for damage to VIII are vestibular Schwannomas. This report reviews the anatomy and various investigations of the nerve. PMID:24095603

  8. Enhanced early sensory outcome after nerve repair as a result of immediate post-operative re-learning: a randomized controlled trial.

    PubMed

    Rosén, B; Vikström, P; Turner, S; McGrouther, D A; Selles, R W; Schreuders, T A R; Björkman, A

    2015-07-01

    We assessed the use of guided plasticity training to improve the outcome in the first 6 months after nerve repair. In a multicentre randomized controlled trial, 37 adults with median or ulnar nerve repair at the distal forearm were randomized to intervention, starting the first week after surgery with sensory and motor re-learning using mirror visual feedback and observation of touch, or to a control group with re-learning starting when reinnervation could be detected. The primary outcome at 3 and 6 months post-operatively was discriminative touch (shape texture identification test, part of the Rosen score). At 6 months, discriminative touch was significantly better in the early intervention group. Improvement of discriminative touch between 3 and 6 months was also significantly greater in that group. There were no significant differences in motor function, pain or in the total score. We conclude that early re-learning using guided plasticity may have a potential to improve the outcomes after nerve repair. LEVEL OF EVIDENCE II. PMID:25294735

  9. Observations on the function of nuclear factor kappa B (NF-kappaB) in the survival of adult primary sensory neurons after nerve injury.

    PubMed

    Gushchina, Svetlana; Leinster, Veronica; Wu, Dongsheng; Jasim, Avin; Demestre, Maria; Lopez de Heredia, Luis; Michael, Gregory J; Barker, Philip A; Richardson, Peter M; Magoulas, Charalambos

    2009-02-01

    Peripheral nerve transections cause much more neuronal death in embryonic and neonatal dorsal root ganglia (DRG) than in adult DRG. Here we used transgenic approaches to examine the hypothesis that NF-kappaB is an important intrinsic factor of adult DRG neurons for their in vivo capacity to survive after nerve injury. We generated transgenic mice expressing the NF-kappaB super-inhibitor (IkappaBalpha-SI), a multi-mutant form of IkappaBalpha, specifically in adult neurons. Adult DRG neurons in these transgenic animals are not abnormally susceptible to apoptosis after peripheral nerve injury, although there is a significant inhibition in the ability of NF-kappaB to translocate into their nucleus. We investigated the observed lack of NF-kappaB neuroprotective function at the level of NF-kappaB transcriptional activity using transgenic NF-kappaB/LacZ reporter mice. We show that the expression of the NF-kappaB reporter transgene is restricted in naďve and injured DRG neurons. However, NF-kappaB transcriptional activity in adult DRG neurons is evident upon exposure to Trichostatin A (TSA) which is a specific inhibitor of histone deacetylases. Taken together our results illustrate that the functions of NF-kappaB are limited in adult primary sensory neurons due to a transcriptional repression mechanism mediated by histone deacetylases, and that intrinsic neuroprotective factors other than NF-kappaB are responsible for the resistance of adult DRG neurons to apoptosis in response to nerve injury. PMID:19049877

  10. Comparison of the sensory threshold in healthy human volunteers with the sensory nerve response of the rat in vitro hindlimb skin and saphenous nerve preparation on cutaneous electrical stimulation

    Microsoft Academic Search

    R. M. R. McAllister; L. A. Urban; A. Dray; P. J. Smith

    1995-01-01

    We report a comparative study of stimulation thresholds of cutaneous fibres of the rat in vitro skin and saphenous nerve preparation with psychophysical measurements of sensibility to cutaneous electrical stimulation in human volunteers. The same clinical diagnostic stimulator and modified skin electrodes were used in both animal and human experiments. Axons were recruited by increasing the stimulus strength, and correlation

  11. Modified oral metronidazole desensitization protocol.

    PubMed

    Gendelman, Samantha R; Pien, Lily C; Gutta, Ravi C; Abouhassan, Susan R

    2014-03-01

    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

  12. Concordance between epidermal nerve fiber density and sensory examination in patients with symptoms of idiopathic small fiber neuropathy

    Microsoft Academic Search

    David Walk; Gwen Wendelschafer-Crabb; Cynthia Davey; William R. Kennedy

    2007-01-01

    Quantitation of epidermal nerve fiber (ENF) density is an objective diagnostic test of small fiber neuropathy (SFN). For a diagnostic test to be clinically useful it should correspond well with clinically meaningful physical findings. We performed a retrospective analysis of the concordance between foot ENF density and clinical findings in all patients seen at our institution with possible idiopathic SFN

  13. Nerve growth factor acts through the TrkA receptor to protect sensory neurons from the damaging effects of the HIV-1 viral protein, Vpr

    PubMed Central

    Webber, Christine A.; Salame, Jihan; Luu, Gia-Linh S.; Acharjee, Shaona; Ruangkittisakul, Araya; Martinez, Jose A.; Jalali, Hanieh; Watts, Russell; Ballanyi, Klaus; Guo, Gui Fang; Zochodne, Douglas W.; Power, Christopher

    2013-01-01

    Distal sensory polyneuropathy (DSP) with associated neuropathic pain is the most common neurological disorder affecting patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Viral protein R (Vpr) is a neurotoxic protein encoded by HIV-1 and secreted by infected macrophages. Vpr reduces neuronal viability, increases cytosolic calcium and membrane excitability of cultured dorsal root ganglion (DRG) sensory neurons, and is associated with mechanical allodynia in vivo. A clinical trial with HIV/AIDS patients demonstrated that nerve growth factor (NGF) reduced the severity of DSP-associated neuropathic pain, a problem linked to damage to small diameter, potentially NGF responsive fibers. Herein, the actions of NGF were investigated in our Vpr model of DSP and we demonstrated that NGF significantly protected sensory neurons from the effects of Vpr. Footpads of immunodeficient Vpr transgenic (vpr/RAG1?/?) mice displayed allodynia (p<0.05), diminished epidermal innervation (p<0.01) and reduced NGF mRNA expression (p<0.001) compared to immunodeficient (wildtype/RAG1?/?) littermate control mice. Compartmented cultures confirmed recombinant Vpr exposure to the DRG neuronal perikarya decreased distal neurite extension (p<0.01), whereas NGF exposure at these distal axons protected the DRG neurons from the Vpr-induced effect on their cell bodies. NGF prevented Vpr-induced attenuation of the phosphorylated glycogen synthase-3 axon extension pathway and tropomyosin related kinase A (TrkA) receptor expression in DRG neurons (p<0.05) and it directly counteracted the cytosolic calcium burst caused by Vpr exposure to DRG neurons (p<0.01). TrkA receptor antagonists indicated that NGF acted through the TrkA receptor to block the Vpr-mediated decrease in axon outgrowth in neonatal and adult rat and fetal human DRG neurons (p<0.05). Similarly, inhibiting the lower affinity NGF receptor, p75, blocked Vpr’s effect on DRG neurons. Overall, NGF/TrkA signalling or p75 receptor inhibition protects somatic sensory neurons exposed to Vpr, thus laying the groundwork for potential therapeutic options for HIV/AIDS patients suffering from DSP. PMID:23912036

  14. Augmented mechanical response of muscle thin-fiber sensory receptors recorded from rat muscle-nerve preparations in vitro after eccentric contraction.

    PubMed

    Taguchi, Toru; Sato, Jun; Mizumura, Kazue

    2005-10-01

    Unaccustomed strenuous exercise, especially that from eccentric muscular work, often causes muscle tenderness, which is a kind of mechanical hyperalgesia. We developed an animal model of delayed-onset muscle soreness (DOMS) from eccentric muscular contraction (ECC) in rats and demonstrated the existence of muscle tenderness by means of behavioral pain tests and c-Fos protein expression in the spinal dorsal horn. The purpose of the present study was to examine whether the sensitivities of muscle thin-fiber sensory receptors to mechanical, chemical, and thermal stimuli were altered after repetitive ECC in a rat model of DOMS. ECC was caused in the animals by electrical stimulation of the common peroneal nerve innervating the extensor digitorum longus muscle (EDL) while the muscle was being stretched. Activities of single thin-fiber receptors (sensitive to pressure but insensitive to stretch, with conduction velocity slower than 2.0 m/s) were recorded from muscle (EDL)-nerve preparations in vitro 2 days after ECC when mechanical hyperalgesia was at its peak. The mechanical threshold of thin-fiber receptors was found to be very much lower in the ECC preparations than in the nontreated control (CTR) [median 65.4 mN (interquartile range [IQR]; 46.6-122.0 mN) in the CTR preparation vs. 38.2 mN (IQR; 26.8-55.8 mN) in the ECC, P < 0.001]. In addition, the total number of evoked discharges during a ramp mechanical stimulus, taken as an index of the magnitude of the mechanical response, nearly doubled in the ECC preparations compared with the CTR [24.7 spikes (IQR; 14.2-37.1 spikes) in the CTR preparation vs. 54.2 spikes (IQR; 24.3-89.0 spikes) in the ECC, P < 0.001]. In contrast, the numbers of discharges induced by chemical (pH 5.5, lactic acid, adenosine triphosphate, and bradykinin) and thermal (cold and heat) stimuli were not different between the two preparations. These results suggest that augmentation of the mechanical response in muscle thin-fiber sensory receptors might be related to the muscle tenderness in DOMS after ECC. PMID:16160095

  15. Grapefruit-seed extract attenuates ethanol-and stress-induced gastric lesions via activation of prostaglandin, nitric oxide and sensory nerve pathways

    PubMed Central

    Brzozowski, Tomasz; Konturek, Peter C; Drozdowicz, Danuta; Konturek, Stanislaw J; Zayachivska, Oxana; Pajdo, Robert; Kwiecien, Slawomir; Pawlik, Wieslaw W; Hahn, Eckhart G

    2005-01-01

    AIM: Grapefruit-seed extract (GSE) containing flavonoids, possesses antibacterial and antioxidative properties but whether it influences the gastric defense mechanism and gastroprotection against ethanol- and stress-induced gastric lesions remains unknown. METHODS: We compared the effects of GSE on gastric mucosal lesions induced in rats by topical application of 100% ethanol or 3.5 h of water immersion and restraint stress (WRS) with or without (A) inhibition of cyclooxygenase (COX)-1 activity by indomethacin and rofecoxib, the selective COX-2 inhibitor, (B) suppression of NO-synthase with L-NNA (20 mg/kg ip), and (C) inactivation by capsaicin (125 mg/kg sc) of sensory nerves with or without intragastric (ig) pretreatment with GSE applied 30 min prior to ethanol or WRS. One hour after ethanol and 3.5 h after the end of WRS, the number and area of gastric lesions were measured by planimetry, the gastric blood flow (GBF) was assessed by H2-gas clearance technique and plasma gastrin levels and the gastric mucosal generation of PGE2, superoxide dismutase (SOD) activity and malonyldialdehyde (MDA) concentration, as an index of lipid peroxidation were determined. RESULTS: Ethanol and WRS caused gastric lesions accompanied by the significant fall in the GBF and SOD activity and the rise in the mucosal MDA content. Pretreatment with GSE (8-64 mg/kg i g) dose-dependently attenuated gastric lesions induced by 100% ethanol and WRS; the dose reducing these lesions by 50% (ID50) was 25 and 36 mg/kg, respectively, and this protective effect was similar to that obtained with methyl PGE2 analog (5 ?g/kg i g). GSE significantly raised the GBF, mucosal generation of PGE2, SOD activity and plasma gastrin levels while attenuating MDA content. Inhibition of PGE2 generation with indomethacin or rofecoxib and suppression of NO synthase by L-NNA or capsaicin denervation reversed the GSE-induced protection and the accompanying hyperemia. Co-treatment of exogenous calcitonine gene-related peptide (CGRP) with GSE restored the protection and accompanying hyperemic effects of GSE in rats with capsaicin denervation. CONCLUSION: GSE exerts a potent gastroprotective activity against ethanol and WRS-induced gastric lesions via an increase in endogenous PG generation, suppression of lipid peroxidation and hyperemia possibly mediated by NO and CGRP released from sensory nerves. PMID:16425415

  16. Asymptomatic small fiber neuropathy in diabetes mellitus: investigations with intraepidermal nerve fiber density, quantitative sensory testing and laser-evoked potentials.

    PubMed

    Ragé, Michael; Van Acker, Nathalie; Knaapen, Michiel W M; Timmers, Maarten; Streffer, Johannes; Hermans, Michel P; Sindic, Christian; Meert, Theo; Plaghki, Léon

    2011-10-01

    This study aimed at evaluating the performance of a battery of morphological and functional tests for the assessment of small nerve fiber loss in asymptomatic diabetic neuropathy (DNP). Patients diagnosed for ?10 years with type 1 (n = 10) or type 2 (n = 13) diabetes mellitus (DM) without conventional symptoms or signs of DNP were recruited and compared with healthy controls (n = 18) and patients with overt DNP (n = 5). Intraepidermal nerve fiber density (IENFd) was measured with PGP9.5 immunostaining on punch skin biopsies performed at the distal leg. Functional tests consisted of quantitative sensory testing (QST) for light-touch, cool, warm and heat pain detection thresholds and brain-evoked potentials with electrical (SEPs) and CO(2) laser stimulation [laser-evoked potentials (LEPs)] of hand dorsum and distal leg using small (0.8 mm(2)) and large (20 mm(2)) beam sizes. Results confirmed a state of asymptomatic DNP in DM, but only at the distal leg. Defining a critical small fiber loss as a reduction of IENFd ?-2 z scores of healthy controls, this state prevailed in type 2 (30%) over type 1 DM (10%) patients despite similar disease duration and current glycemic control. LEPs with the small laser beam performed best in terms of sensitivity (91%), specificity (83%) and area-under-the ROC curve (0.924). Although this performance was not statically different from that of warm and cold detection threshold, LEPs offer an advantage over QST given that they bypass the subjective report and are therefore unbiased by perceptual factors. PMID:21472496

  17. Changes in expression of sensory organ-specific microRNAs in rat dorsal root ganglia in association with mechanical hypersensitivity induced by spinal nerve ligation

    PubMed Central

    Aldrich, Benjamin T.; Frakes, Eli P.; Kasuya, Junko; Hammond, Donna L.; Kitamoto, Toshihiro

    2009-01-01

    Chronic neuropathic pain caused by peripheral nerve injury is associated with global changes in gene expression in damaged neurons. To understand the molecular mechanisms underlying neuropathic pain, it is essential to elucidate how nerve injury alters gene expression and how the change contributes to the development and maintenance of chronic pain. MicroRNAs are non-protein-coding RNA molecules that regulate gene expression in a wide variety of biological processes mainly at the level of translation. This study investigated the possible involvement of microRNAs in gene regulation relevant to neuropathic pain. The analyses focused on a sensory organ-specific cluster of microRNAs that includes miR-96, -182, and -183. RT-PCR analyses confirmed that these microRNAs were highly enriched in the dorsal root ganglion (DRG) of adult rats. Using the L5 spinal nerve ligation (SNL) model of chronic neuropathic pain, we observed a significant reduction in expression of these microRNAs in injured DRG neurons compared to controls. In situ hybridization and immunohistochemical analyses revealed that these microRNAs are expressed in both myelinated (N52 positive) and unmyelinated (IB4 positive) primary afferent neurons. They also revealed that the intracellular distributions of the microRNAs in DRG neurons were dramatically altered in animals with mechanical hypersensitivity. Whereas microRNAs were uniformly distributed within the DRG soma of non-allodynic animals, they were preferentially localized to the periphery of neurons in allodynic animals. The redistribution of microRNAs was associated with changes in the distribution of the stress granule protein TIA-1. These data demonstrate that SNL induces changes in expression levels and patterns of miR-96, -182, and -183, implying their possible contribution to chronic neuropathic pain through translational regulation of pain-relevant genes. Moreover, stress granules were suggested to be assembled and associated with microRNAs after SNL, which may play a role in modification of microRNA-mediated gene regulation in DRG neurons. PMID:19699278

  18. Cadaveric nerve allotransplantation in the treatment of persistent thoracic neuralgia.

    PubMed

    Barbour, John R; Yee, Andrew; Moore, Amy M; Trulock, Elbert P; Buchowski, Jacob M; Mackinnon, Susan E

    2015-04-01

    When relief from neuralgia cannot be achieved with traditional methods, neurectomy may be considered to abate the stimulus, and primary opposition of the terminal nerve ending is recommended to prevent neuroma. Nerve repair with autograft is limited by autologous nerves available for large nerve defects. Cadaveric allografts provide an unlimited graft source without donor-site morbidities, but are rapidly rejected unless appropriate immunosuppression is achieved. An optimal treatment method for nerve allograft transplantation would minimize rejection while simultaneously permitting nerve regeneration. This report details a novel experience of nerve allograft transplantation using cadaveric nerve grafts to desensitize persistent postoperative thoracic neuralgia. PMID:25841822

  19. Desensitization of metastable intermolecular composites

    DOEpatents

    Busse, James R. (South Fork, CO); Dye, Robert C. (Los Alamos, NM); Foley, Timothy J. (Los Alamos, NM); Higa, Kelvin T. (Ridgecrest, CA); Jorgensen, Betty S. (Jemez Springs, NM); Sanders, Victor E. (White Rock, NM); Son, Steven F. (Los Alamos, NM)

    2011-04-26

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

  20. NERVE INJURY AFTER LAPAROSCOPIC VARICOCELECTOMY

    Microsoft Academic Search

    KRISTIN CHROUSER; DAVID VANDERSTEEN; JULIE CROCKER; YURI REINBERG

    2004-01-01

    Purpose:Laparoscopic varicocelectomy is a minimally invasive option for varicoceles in children. Occasional reports of nerve injury after inguinal laparoscopic procedures have been published. There is anatomical variation in the sensory innervation of the anterior thigh and variable branching patterns of the nerves involved. We report a retrospective analysis of our patients, focusing on the incidence of sensory changes on the

  1. Processes of excitation in the dendrites and in the soma of single isolated sensory nerve cells of the lobster and crayfish.

    PubMed

    EYZAGUIRRE, C; KUFFLER, S W

    1955-09-20

    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 --> generator

  2. Specialized Nerve Tests: EMG, NCV and SSEP

    MedlinePLUS

    ... spinal cord are able to send and receive sensory information like pain, temperature and touch. When ordering ... SSEP is used to double check whether the sensory part of the nerve is working correctly. What ...

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

    Microsoft Academic Search

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

    2005-01-01

    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

  4. Peripheral nerve lengthening as a regenerative strategy

    PubMed Central

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

    2014-01-01

    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

  5. Nerve conduction and electromyography studies.

    PubMed

    Kane, N M; Oware, A

    2012-07-01

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

  6. Sensory interaction with central ‘generators’ during respiration in the dogfish

    Microsoft Academic Search

    B. L. Roberts; C. M. Ballintijn

    1988-01-01

    Summary The activity in sensory and motor nerves of the gills was recorded from selected branches of the vagus nerve in decerebrate dogfish,Scyliorhinus canicula. Vagal motoneuronal activity was observed at the start of the rapid pharyngeal contraction and was followed by sensory nerve activity which preceded the slow expansion phase. Rhythmical vagal motoneuronal activity was still present after all movements

  7. DECREASED SENSORY RECEPTORS P2X 3 AND TRPV1 IN SUBUROTHELIAL NERVE FIBERS FOLLOWING INTRADETRUSOR INJECTIONS OF BOTULINUM TOXIN FOR HUMAN DETRUSOR OVERACTIVITY

    Microsoft Academic Search

    A. APOSTOLIDIS; R. POPAT; Y. YIANGOU; D. COCKAYNE; A. P. D. W. FORD; J. B. DAVIS; P. DASGUPTA; C. J. FOWLER; P. ANAND

    2005-01-01

    PurposeBotulinum neurotoxin type A (BoNT\\/A) is effective in the treatment of intractable detrusor overactivity (DO). In addition to its known inhibitory effect on presynaptic release of acetylcholine by motor terminals, there is increasing evidence that BoNT\\/A may affect sensory fibers. We investigated a possible effect of BoNT\\/A on human bladder afferent mechanisms by studying the sensory receptors P2X3 and TRPV1

  8. Blocking and desensitization in RF amplifiers

    Microsoft Academic Search

    Robert G. Meyer; Alvin K. Wong

    1995-01-01

    Blocking and desensitization in RF amplifiers is analyzed and related to second and third order intermodulation performance. Methods of predicting blocking behavior are described and used to improve the performance of an existing amplifier. Measurements are compared with theoretical predictions

  9. Nerve Regeneration After Radiofrequency Application

    Microsoft Academic Search

    Nobuyasu Ochiai; James P. Tasto; Seiji Ohtori; Norimasa Takahashi; Hideshige Moriya; David Amiel

    Background: Many patients with chronic tendinosis have experienced early pain relief after application of bipolar radiofrequency treatment. It is hypothesized that the mechanism of action may be the acute degeneration and\\/or ablation of sensory nerve fibers. Hypothesis: After ablation or degeneration by bipolar radiofrequency, nerve fibers will have the ability to regenerate with time. Study Design: Controlled laboratory study. Methods:

  10. 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 ; ...

  11. Hereditary motor and sensory neuropathy--Lom, a novel demyelinating neuropathy associated with deafness in gypsies. Clinical, electrophysiological and nerve biopsy findings

    Microsoft Academic Search

    Luba Kalaydjieva; Amelia Nikolova; Ivo Turnev; Julia Petrova; Anna Hristova; Boryana Ishpekova; Iva Petkova; Alexander Shmarov; Stella Stancheva; L. Middleton; Luciano Merlini; A. Trogu; J. R. Muddle; R. H. M. King; P. K. Thomas

    1998-01-01

    Summary A previously unrecognized neuropathy was identified in Bulgarian gypsies, and was designated hereditary motor and sensory neuropathy-Lom (HMSNL) after the town where the initial cases were found. It was subsequently identified in other gypsy communities. The disorder, which is of autosomal recessive inheritance, was mapped to chromosome 8q24. It begins consistently in the first decade of life with gait

  12. Prevention of NKCC1 phosphorylation avoids downregulation of KCC2 in central sensory pathways and reduces neuropathic pain after peripheral nerve injury.

    PubMed

    Mňdol, Laura; Cobianchi, Stefano; Navarro, Xavier

    2014-08-01

    Neuropathic pain after peripheral nerve injury is characterized by loss of inhibition in both peripheral and central pain pathways. In the adult nervous system, the Na(+)-K(+)-2Cl(-) (NKCC1) and neuron-specific K(+)-Cl(-) (KCC2) cotransporters are involved in setting the strength and polarity of GABAergic/glycinergic transmission. After nerve injury, the balance between these cotransporters changes, leading to a decrease in the inhibitory tone. However, the role that NKCC1 and KCC2 play in pain-processing brain areas is unknown. Our goal was to study the effects of peripheral nerve injury on NKCC1 and KCC2 expression in dorsal root ganglia (DRG), spinal cord, ventral posterolateral (VPL) nucleus of the thalamus, and primary somatosensory (S1) cortex. After sciatic nerve section and suture in adult rats, assessment of mechanical and thermal pain thresholds showed evidence of hyperalgesia during the following 2 months. We also found an increase in NKCC1 expression in the DRG and a downregulation of KCC2 in spinal cord after injury, accompanied by later decrease of KCC2 levels in higher projection areas (VPL and S1) from 2 weeks postinjury, correlating with neuropathic pain signs. Administration of bumetanide (30 mg/kg) during 2 weeks following sciatic nerve lesion prevented the previously observed changes in the spinothalamic tract projecting areas and the appearance of hyperalgesia. In conclusion, the present results indicate that changes in NKCC1 and KCC2 in DRG, spinal cord, and central pain areas may contribute to development of neuropathic pain. PMID:24813295

  13. Cranial and Spinal Nerve Organization in Amphioxus and Lampreys: Evidence for an Ancestral Craniate Pattern

    Microsoft Academic Search

    B. Fritzsch; Glenn Northcutt

    1993-01-01

    The spinal nerves in amphioxus are compared with the spinal and cranial nerves in lampreys. The dorsal spinal roots in amphioxus are similar to the mixed sensory and motor dorsal roots of many cranial nerves in lampreys but not to the purely sensory dorsal spinal roots in lampreys and gnathostomes. Likewise, cranial nerves V, VII, IX and X in lampreys,

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

    PubMed

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

    2015-01-01

    Chronic pain after nerve injury is often accompanied by hypersensitivity to mechanical stimuli, yet whether this reflects altered input, altered processing, or both remains unclear. Spinal nerve ligation or transection results in hypersensitivity to mechanical stimuli in skin innervated by adjacent dorsal root ganglia, but no previous study has quantified the changes in receptive field properties of these neurons in vivo. To address this, we recorded intracellularly from L4 dorsal root ganglion neurons of anesthetized young adult rats, 1 wk after L5 partial spinal nerve ligation (pSNL) or sham surgery. One week after pSNL, hindpaw mechanical withdrawal threshold in awake, freely behaving animals was decreased in the L4 distribution on the nerve-injured side compared with sham controls. Electrophysiology revealed that high-threshold mechanoreceptive cells of A-fiber conduction velocity in L4 were sensitized, with a seven-fold reduction in mechanical threshold, a seven-fold increase in receptive field area, and doubling of maximum instantaneous frequency in response to peripheral stimuli, accompanied by reductions in after-hyperpolarization amplitude and duration. Only a reduction in mechanical threshold (minimum von Frey hair producing neuronal activity) was observed in C-fiber conduction velocity high-threshold mechanoreceptive cells. In contrast, low-threshold mechanoreceptive cells were desensitized, with a 13-fold increase in mechanical threshold, a 60% reduction in receptive field area, and a 40% reduction in instantaneous frequency to stimulation. No spontaneous activity was observed in L4 ganglia, and the likelihood of recording from neurons without a mechanical receptive field was increased after pSNL. These data suggest massively altered input from undamaged sensory afferents innervating areas of hypersensitivity after nerve injury, with reduced tactile and increased nociceptive afferent response. These findings differ importantly from previous preclinical studies, but are consistent with clinical findings in most patients with chronic neuropathic pain. PMID:25274350

  15. Prevention and reversal of motor and sensory peripheral nerve conduction abnormalities in streptozotocin-diabetic rats by the prostacyclin analogue iloprost

    Microsoft Academic Search

    M. A. Cotter; K. C. Dines; N. E. Cameron

    1993-01-01

    The effects of the prostacyclin analogue iloprost on nerve function were examined in streptozotocin-diabetic rats. Rats were treated either with iloprost from induction of diabetes over 2 months in a preventive experiment, or for 1 month following a 1 month untreated period of diabetes in a reversal experiment. One and 2 months untreated diabetic control, non-diabetic control, and iloprost-treated non-diabetic

  16. Asymptomatic small fiber neuropathy in diabetes mellitus: investigations with intraepidermal nerve fiber density, quantitative sensory testing and laser-evoked potentials

    Microsoft Academic Search

    Michael Ragé; Nathalie Van Acker; Michiel W. M. Knaapen; Maarten Timmers; Johannes Streffer; Michel P. Hermans; Christian Sindic; Theo Meert; Léon Plaghki

    This study aimed at evaluating the performance of a battery of morphological and functional tests for the assessment of small\\u000a nerve fiber loss in asymptomatic diabetic neuropathy (DNP). Patients diagnosed for ?10 years with type 1 (n = 10) or type 2 (n = 13) diabetes mellitus (DM) without conventional symptoms or signs of DNP were recruited and compared with healthy controls\\u000a (n = 18) and patients

  17. Compound nerve conduction velocity – A reflection of proprioceptive afferents?

    Microsoft Academic Search

    Antti J. Metso; Kirsi Palmu; Juhani V. Partanen

    2008-01-01

    ObjectiveTo gather the required sample size to compare compound nerve conduction velocities (CV) to cutaneous sensory CVs and motor CVs to find out if there are statistically significant differences between these nerve fibre populations.

  18. Modeling Shock Desensitization of Composition B Explosive

    NASA Astrophysics Data System (ADS)

    Mader, Charles

    2014-03-01

    The NOBEL multimaterial adaptive grid Eulerian hydrodynamic code was used to model a shaped charge jet formation, its interaction with a steel plate, and shock formation of a bow shock in front of the jet that shocks and desensitizes a cylinder of Composition B (60/40 RDX/TNT at 1.715 g/cc) explosive so that when the jet arrives it fails to initiate detonation in the desensitized explosive. The jet passes through the Composition B explosive cylinder, an air gap, and then initiates propagating detonation in a second Composition B explosive cylinder that has not been desensitized by a preshock. The experimental arrangement was studied using X-ray radiography at the Material Research Laboratory in Melbourne, Australia.

  19. Monkey median nerve repaired by nerve graft or collagen nerve guide tube.

    PubMed

    Archibald, S J; Shefner, J; Krarup, C; Madison, R D

    1995-05-01

    Nerve regeneration was followed in 15 median and 1 ulnar nerve of eight Macaca fascicularis monkeys by serial electrophysiological assessments over a period of three and a half years. Nerve gaps of 5 mm at the wrist were bridged by collagen-based nerve guides, nerve autografts, or direct suture repairs. Thenar muscle reinnervation occurred between 50 and 70 d for all groups, indicating axonal elongation rates of approximately 1 mm/d. The recovery rates of the compound muscle action potential (CMAP) and the compound sensory action potential (CSAP) amplitudes were significantly slower after direct suture repair compared to the other two procedures, although the final levels of recovery were all comparable. Similar results were achieved in one median and one ulnar nerve following nerve guide repair of a 15 mm nerve gap. The functional reinnervation of Pacinian corpuscles was detected in all cases following either nerve graft or nerve guide repair, with similar amplitudes and latencies of the tactile evoked CSAP for both types of repair. Histological analysis demonstrated a significant increase in the number of myelinated axons in the median nerve distal to the nerve lesions following both nerve graft and nerve guide repairs compared to proximal and normal controls, with significant reductions of fiber diameter and corresponding increases in g-ratio. The return of a bimodal frequency distribution of myelinated axon fiber diameter was confirmed by three-dimensional surface plots which illustrate the frequency distribution of the relationship between fiber diameter and g-ratio. These combined results demonstrate that nerve regeneration after repair of a 5 mm nerve gap with a collagen nerve guide in the nonhuman primate is similar to that after graft repair, and the final level of physiological recovery for both repair procedures is comparable to direct suture repair of the median nerve. PMID:7751969

  20. Origins, actions and dynamic expression patterns of the neuropeptide VGF in rat peripheral and central sensory neurones following peripheral nerve injury

    PubMed Central

    Moss, Andrew; Ingram, Rachel; Koch, Stephanie; Theodorou, Andria; Low, Lucie; Baccei, Mark; Hathway, Gareth J; Costigan, Michael; Salton, Stephen R; Fitzgerald, Maria

    2008-01-01

    Background The role of the neurotrophin regulated polypeptide, VGF, has been investigated in a rat spared injury model of neuropathic pain. This peptide has been shown to be associated with synaptic strengthening and learning in the hippocampus and while it is known that VGFmRNA is upregulated in dorsal root ganglia following peripheral nerve injury, the role of this VGF peptide in neuropathic pain has yet to be investigated. Results Prolonged upregulation of VGF mRNA and protein was observed in injured dorsal root ganglion neurons, central terminals and their target dorsal horn neurons. Intrathecal application of TLQP-62, the C-terminal active portion of VGF (5–50 nmol) to naďve rats caused a long-lasting mechanical and cold behavioral allodynia. Direct actions of 50 nM TLQP-62 upon dorsal horn neuron excitability was demonstrated in whole cell patch recordings in spinal cord slices and in receptive field analysis in intact, anesthetized rats where significant actions of VGF were upon spontaneous activity and cold evoked responses. Conclusion VGF expression is therefore highly modulated in nociceptive pathways following peripheral nerve injury and can cause dorsal horn cell excitation and behavioral hypersensitivity in naďve animals. Together the results point to a novel and powerful role for VGF in neuropathic pain. PMID:19077191

  1. Morphine Induces Desensitization of Insulin Receptor Signaling

    Microsoft Academic Search

    Yu Li; Shoshana Eitan; Jiong Wu; Christopher J. Evans; Brigitte Kieffer; Xiaojian Sun; Roberto D. Polakiewicz

    2003-01-01

    between the MOR and the insulin receptor (IR) signaling cascades. We show that prolonged morphine exposure of cell lines expressing endogenous or transfected MOR, IR, and the insulin substrate 1 (IRS-1) protein specifically desensitizes IR signaling to Akt and ERK cascades. Morphine caused serine phosphory- lation of the IR and impaired the formation of the signaling complex among the IR,

  2. Systematic Desensitization as an Instructional Module

    ERIC Educational Resources Information Center

    Horan, John J.; And Others

    1976-01-01

    This article reports on the development and evaluation of an instructional module for teaching systematic desensitization. Physiological and self-report data reflecting changes in client fear levels were gathered in an attempt to determine whether the instructional module is effective. (Author)

  3. Neonatal desensitization allows long-term

    E-print Network

    Cai, Long

    for long-term immune protection of human fetal and stem cell­derived neural cells transplanted into the adult rat brain, by desensitizing the host rat to similar cells in the neonatal period, without the need appropriate immunosuppression, neural xenografts in the adult rat or mouse brain are rejected within 2­4 weeks

  4. Desensitization and recovery of metastable intermolecular composites

    DOEpatents

    Busse, James R. (South Fork, CO); Dye, Robert C. (Los Alamos, NM); Foley, Timothy J. (Los Alamos, NM); Higa, Kelvin T. (Ridgecrest, CA); Jorgensen, Betty S. (Jemez Springs, NM); Sanders, Victor E. (White Rock, NM); Son, Steven F. (Los Alamos, NM)

    2010-09-07

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

  5. TIP DESENSITIZATION OF AN AXIAL TURBINE ROTOR

    E-print Network

    Camci, Cengiz

    the leakage jet orientation between the outer casing and the tip surface. This scenario is typical of bladesCC-42 TIP DESENSITIZATION OF AN AXIAL TURBINE ROTOR USING TIP PLATFORM EXTENSIONS Debashis Dey1/ Abstract Aerodynamic losses due to the formation of a leakage vortex near the tip section of rotor blades

  6. Depolarization-induced Intracellular Free Calcium Concentration Increases Show No Desensitizing Effect in Rat Odontoblasts.

    PubMed

    Kojima, Yuki; Higashikawa, Asuka; Kimura, Maki; Sato, Masaki; Mochizuki, Hiroyuki; Ogura, Kazuhiro; Sase, Toshiyuki; Shinya, Akinori; Kobune, Kunio; Furuya, Tadashi; Sato, Toru; Shibukawa, Yoshiyuki; Tazaki, Masakazu

    2015-01-01

    Odontoblasts play an important role in the transduction of the sensory signals underlying dentinal pain. Transmembrane voltage-independent Ca(2+) influx in odontoblasts has been well described. Voltage-dependent Ca(2+) influx has also been reported, but its biophysical properties remain unclear. The aim of the present study was to investigate the desensitizing effect of voltage-dependent Ca(2+) influx in rat odontoblasts by measuring depolarization-induced intracellular free Ca(2+) concentrations ([Ca(2+) ]i ). Odontoblasts on dental pulp slices from newborn rats were acutely isolated and [Ca(2+) ]i measured by using fura-2 fluorescence. Repeated application of extracellular high-K(+) solution (50 mM), which induces membrane depolarization-elicited repeated and transient increases in [Ca(2+) ]i in the presence of extracellular Ca(2+). Increases in depolarization-induced [Ca(2+) ]i showed no significant desensitizing effect (p >0.05; Friedman test). These results suggest that odontoblasts express a voltage-dependent Ca(2+) influx pathway with no desensitizing properties. PMID:26085001

  7. The value of skin biopsy with recording of intraepidermal nerve fiber density and quantitative sensory testing in the assessment of small fiber involvement in patients with different causes of polyneuropathy.

    PubMed

    Nebuchennykh, Maria; Lřseth, Sissel; Lindal, Sigurd; Mellgren, Svein Ivar

    2009-07-01

    The primary aim of our study was to demonstrate how the diagnostic characteristics of skin biopsy used to evaluate small fiber involvement in patients with different causes of polyneuropathy are intrinsically related to the method used to establish the reference values (cut-off values). We also investigated intraepidermal nerve fiber (IENF) density and abnormalities in quantitative sensory testing (QST) in patients with different causes of polyneuropathy and signs of small fiber involvement. A total of 210 patients with symptoms and signs of polyneuropathy were entered into the study. All patients underwent neurological examination, nerve conduction studies, QST on the thigh and distal part of the calf with detection of warm and cold perception thresholds, and skin biopsy with assessment of IENF density. Cut-off values for IENF density were established from our reference material using Z-scores (calculated from multiple regression analysis), fifth percentile, and receiver operating characteristic (ROC) analysis. Of the patients participating in the study, 65 had an established diagnosis of diabetes mellitus, 70 were classified with idiopathic polyneuropathy, and 75 had other possible causes of polyneuropathy. Forty-five patients met the criteria for small fiber polyneuropathy (SFN), and the remaining 165 had also involvement of large nerve fibers. Of the total patient cohort, 84 (40%) had reduced IENF density based on the Z-score, and 106 patients (50%) had at least one abnormality based on QST. In the SFN group, skin biopsy showed a sensitivity of 31% and a specificity of 98% when reference values were presented with Z-scores. When the fifth percentile was used as the cut-off value (6.7 fibers/mm), sensitivity was 35% and specificity 95%. Applying the ROC analysis with a chosen sensitivity of 78% and specificity of 64%, we had a cut-off point of 10.3 fibers/mm. We conclude that skin biopsy with assessment of IENF is a useful method for investigating patients with SFN. The diagnostic value of the test, however, depends upon on the approach used to estimate the reference values. PMID:19252773

  8. Clinical disease severity and axonal dysfunction in hereditary motor and sensory neuropathy Ia

    Microsoft Academic Search

    Camiel Verhamme; Ivo N. van Schaik; Johannes H. T. M. Koelman; Rob J. de Haan; Marinus Vermeulen; Marianne de Visser

    2004-01-01

    Background Hereditary motor and sensory neuropathy type Ia (HMSN Ia) is known as a primarily demyelinating peripheral nerve disease. Evidence is accumulating that axonal involvement determines the course of the disease process. Methods Fifty-one patients were investigated. Physical disability and impairments were scored. Nerve conduction velocities (NCVs) were used as indirect measures for myelination status and compound muscle\\/sensory nerve action

  9. [Sensory sensitization, part II: Pathophysiology in dysfunctional disorders. Understanding the inner life of the nerve pathways may explain hitherto unexplainable symptoms].

    PubMed

    Levander, Hans

    2003-04-30

    This article is based on a vast clinical experience from patients presenting with widespread pain syndromes as well as dysfunctional symptoms from inner organs. A literature survey has been performed. Allodynia and hyperalgesia that partly explain the fibromyalgia and local myalgia syndromes seem to arise from a pathophysiological process of nociceptive sensitisation. It is proposed that the concept of "sensory sensitisation dysfunctional disorders" be applied to conditions like bronchial hyperreactivity, Da Costas syndrome, Dercum's disease (Adipositas dolorosa), dry eyes and mouth syndrome, fibromyalgia, gastralgia, globus hystericus, interstitial cystitis, chronic prostatitis, irritable bowel syndrome, photo- and phonosensitivity, rhinitis, tension headache, tinnitus, vestibulitis syndrome. These dysfunctional disorders cannot be satisfactorily explained by presently known pathophysiological models like ongoing inflammatory process, tissue degeneration, fibrosis, blood vessel diseases, tumours, immune reactions, toxic or deficiency conditions, metabolic disturbances. Neurogenic mechanisms also seem to play an important role in the pathophysiology of arthritic conditions, and might be worthwhile to include in forthcoming discussions concerning the aetiology of chronic inflammatory disease. PMID:12789809

  10. Nerve Regeneration After Radiofrequency Application

    Microsoft Academic Search

    Nobuyasu Ochiai; James P. Tasto; Seiji Ohtori; Norimasa Takahashi; Hideshige Moriya; David Amiel

    2007-01-01

    Background: Many patients with chronic tendinosis have experienced early pain relief after application of bipolar radiofrequency treatment. It is hypothesized that the mechanism of action may be the acute degeneration and\\/or ablation of sensory nerve fibers.Hypothesis: After ablation or degeneration by bipolar radiofrequency, nerve fibers will have the ability to regenerate with time.Study Design: Controlled laboratory study.Methods: Eighteen Sprague-Dawley rats

  11. GABAB receptor phosphorylation regulates KCTD12-induced K+ current desensitization

    PubMed Central

    Adelfinger, Lisa; Turecek, Rostislav; Ivankova, Klara; Jensen, Anders A.; Moss, Stephen J.; Gassmann, Martin; Bettler, Bernhard

    2015-01-01

    GABAB receptors assemble from GABAB1 and GABAB2 subunits. GABAB2 additionally associates with auxiliary KCTD subunits (named after their K+ channel tetramerization-domain). GABAB receptors couple to heterotrimeric G–proteins and activate inwardly-rectifying K+ channels through the ?? subunits released from the G-protein. Receptor-activated K+ currents desensitize in the sustained presence of agonist to avoid excessive effects on neuronal activity. Desensitization of K+ currents integrates distinct mechanistic underpinnings. GABAB receptor activity reduces protein kinase-A activity, which reduces phosphorylation of serine-892 in GABAB2 and promotes receptor degradation. This form of desensitization operates on the time scale of several minutes to hours. A faster form of desensitization is induced by the auxiliary subunit KCTD12, which interferes with channel activation by binding to the G-protein ?? subunits. Here we show that the two mechanisms of desensitization influence each other. Serine-892 phosphorylation in heterologous cells rearranges KCTD12 at the receptor and slows KCTD12-induced desensitization. Likewise, protein kinase-A activation in hippocampal neurons slows fast desensitization of GABAB receptor-activated K+ currents while protein kinase-A inhibition accelerates fast desensitization. Protein kinase-A fails to regulate fast desensitization in KCTD12 knock-out mice or knock-in mice with a serine-892 to alanine mutation, thus demonstrating that serine-892 phosphorylation regulates KCTD12-induced desensitization in vivo. Fast current desensitization is accelerated in hippocampal neurons carrying the serine-892 to alanine mutation, showing that tonic serine-892 phosphorylation normally limits KCTD12-induced desensitization. Tonic serine-892 phosphorylation is in turn promoted by assembly of receptors with KCTD12. This cross-regulation of serine-892 phosphorylation and KCTD12 activity sharpens the response during repeated receptor activation. PMID:25065880

  12. Desensitization of parathyroid hormone receptors on cultured bone cells

    SciTech Connect

    Pun, K.K.; Ho, P.W.; Nissenson, R.A.; Arnaud, C.D. (Univ. of Hong Kong (Hong Kong))

    1990-12-01

    Administration of excessive amounts of parathyroid hormone (PTH) in the treatment of osteoporosis can reverse the beneficial effects of a low-dose, intermittent regime. To investigate the direct actions and the possible cellular mechanisms of PTH in inducing desensitization of PTH receptors, we studied the effects of desensitization on rat osteoblastic UMR-106 cells. When the osteoblasts were preincubated with bPTH-(1-34), complete refractoriness to a subsequent challenge with the hormone developed within 1 h and at hormone concentrations as low as 5 nM. When osteoblasts thus desensitized were incubated in hormone-free medium, recovery of the cAMP responses began within 2 h and reached maximum after 16 h. Cycloheximide did not affect the process of desensitization. (Nle8,Nle18,Tyr34)bPTH-(3-34)amide significantly impaired the desensitization process by PTH-(1-34) but did not have stimulatory effect on cAMP responses. No significant heterologous desensitization was obvious after preincubation with isoprenaline (50 microM), prostaglandin E1 (50 microM), or prostaglandin E2 (50 microM) for 2 h. Binding experiments with (125I)PLP-(1-36)amide after desensitization revealed that there was an approximate twofold decrease in receptor affinities as analyzed by Scatchard analysis, showing that the decrease in affinity was prominent in the process of desensitization. When the cells were treated with monensin during desensitization, PTH challenge after desensitization produced significantly lower cyclic AMP responses. Recovery after desensitization occurred over a period of 16 h. Inclusion of monensin, but not cycloheximide, impaired the recovery. The results show that homologous desensitization of rat osteoblasts to PTH is brought about by the occupancy of receptors by PTH-(1-34) but not by cAMP generation itself.

  13. Histrionicotoxin enhances agonist-induced desensitization of acetylcholine receptor.

    PubMed Central

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

    1977-01-01

    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

  14. Influence of human skin injury on regeneration of sensory neurons

    Microsoft Academic Search

    O. Taherzadeh; W. R. Otto; U. Anand; J. Nanchahal; P. Anand

    2003-01-01

    The regeneration of sensory nerve fibres is regulated by trophic factors released from their target tissue, particularly the basal epidermis, and matrix molecules. Means to modulate this response may be useful for the treatment of neuromas and painful hypertrophic scars and of sensory deficits in skin grafts and flaps. We have developed an in vitro model of sensory neuron regeneration

  15. Delayed decrement of the nerve impulse propagation during induced limb ischaemia in chronic hepatic failure

    Microsoft Academic Search

    V K Nielsen; T Kardel

    1975-01-01

    Sensory thresholds for vibrations and electrical shocks and the sensory nerve conduction velocity (median nerve) were measured during 30 minutes of induced limb ischaemia in 10 normal subjects and 15 patients with chronic hepatic failure. Sensory action potentials were recorded simultaneously at the wrist and elbow. Seven patients (group A) had a normal perception time for vibrations. As in normal

  16. Sensory Impairment

    Microsoft Academic Search

    Elizabeth Keating; R. Neill Hadder

    Anthropological studies of sensory impairment address biological conditions and cultural disablement while contributing to theoretical discussions of cultural competence, communicative practices, the role of narrative, and features of identity, ideologies, and technology. As boundary cases, impairments can disclose essential aspects of the senses in human life. Sensory impairment studies navigate the complexities of comparing dominant sensory discourses with individual sense

  17. Sensory Impairment

    Microsoft Academic Search

    Elizabeth Keating; R. Neill Hadder

    2010-01-01

    Anthropological studies of sensory impairment address biological conditions and cultural disablement while contributing to theoretical discussions of cultural competence, communicative practices, the role of narrative, and features of identity, ideologies, and technology. As boundary cases, impairments can disclose essential aspects of the senses in human life. Sensory impairment studies navigate the complexities of comparing dominant sensory discourses with individual sense

  18. 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

    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

    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

  19. Hyperalgesic actions of cytokines on peripheral nerves

    Microsoft Academic Search

    Robert R. Myers; Rochelle Wagner; Linda S. Sorkin

    \\u000a The relationship between nerve injury and pain is pervasive in medicine, being both a simple, common experience and an important\\u000a diagnostic tool. Acute trauma to a nerve is almost always painful and has been experienced by many people in association with\\u000a sports and workplace activities. In these cases, injuries occur usually because of nerve stretching or compression, damaging\\u000a sensory axons

  20. Quantitative sensory testing.

    PubMed

    Siao, Peter; Cros, Didier P

    2003-05-01

    Quantitative sensory testing is a reliable way of assessing large and small sensory nerve fiber function. Sensory deficits may be quantified and the data used in parametric statistical analysis in research studies and drug trials. It is an important addition to the neurophysiologic armamentarium, because conventional sensory nerve conduction tests only the large fibers. QST is a psychophysical test and lacks the objectivity of NCS. The results are subject to changes owing to distraction, boredom, mental fatigue, drowsiness, or confusion. When patients are consciously or unconsciously biased toward an abnormal QST result, no psychophysical testing can reliably distinguish these patients from those with organic disease. QST tests the integrity of the entire sensory neuraxis and is of no localizing value. Dysfunction of the peripheral nerves or central nervous system may give rise to abnormalities in QST. As is true for other neurophysiologic tests, QST results should always be interpreted in light of the patient's clinical presentation. Quantitative sensory testing has been shown to be reasonably reproducible over a period of days or weeks in normal subjects. Because longitudinal QST studies of patients in drug trials are usually performed over a period of several months to a few years, reproducibility studies on the placebo-control group should be included. For individual patients, more studies are needed to determine the maximum allowable difference between two QSTs that can be attributed to experimental error. The reproducibility of thermal thresholds may not be as good as that of vibration threshold. Different commercially available QST instruments have different specifications (thermode size, stimulus characteristics), testing protocols, algorithms, and normal values. Only QST instruments and their corresponding methodologies that have been shown to be reproducible should be used for research and patient care. The data in the literature do not allow conclusions regarding the superiority of any QST instruments. The future of QST is promising; however, many factors can affect QST results. As is true for other neurophysiologic tests, QST is susceptible to many extraneous factors and to misuse when not properly interpreted by the clinician. PMID:12795516

  1. Entrapment of the superficial peroneal nerve: an anatomical insight.

    PubMed

    Tzika, Maria; Paraskevas, George; Natsis, Konstantinos

    2015-03-01

    Entrapment of the superficial peroneal nerve is an uncommon neuropathy that may occur because of mechanical compression of the nerve, usually at its exit from the crural fascia. The symptoms include sensory alterations over the distribution area of the superficial peroneal nerve. Clinical examination, electrophysiologic findings, and imaging techniques can establish the diagnosis. Variations in the superficial peroneal sensory innervation over the dorsum of the foot may lead to variable results during neurologic examination and variable symptomatology in patients with nerve entrapment or lesions. Knowledge of the nerve's anatomy at the lower leg, foot, and ankle is of essential significance for the neurologist and surgeon intervening in the area. PMID:25815655

  2. Systematic desensitization of erectile impotence: A controlled study

    Microsoft Academic Search

    G. Kockott; F. Dittmar; L. Nusselt

    1975-01-01

    Results of a study conducted to assess the therapeutic effectiveness of systematic desensitization of erectile impotence are described. Three groups of eight patients each were formed. They were treated with systematic desensitization or conventional medication and general advice, or put on a waiting list. Therapeutic effects were investigated on the behavioral, subjective, and physiological levels. There were no significant differences

  3. Nerve Cross-Bridging to Enhance Nerve Regeneration in a Rat Model of Delayed Nerve Repair

    PubMed Central

    2015-01-01

    There are currently no available options to promote nerve regeneration through chronically denervated distal nerve stumps. Here we used a rat model of delayed nerve repair asking of prior insertion of side-to-side cross-bridges between a donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) nerve stump ameliorates poor nerve regeneration. First, numbers of retrogradely-labelled TIB neurons that grew axons into the nerve stump within three months, increased with the size of the perineurial windows opened in the TIB and CP nerves. Equal numbers of donor TIB axons regenerated into CP stumps either side of the cross-bridges, not being affected by target neurotrophic effects, or by removing the perineurium to insert 5-9 cross-bridges. Second, CP nerve stumps were coapted three months after inserting 0-9 cross-bridges and the number of 1) CP neurons that regenerated their axons within three months or 2) CP motor nerves that reinnervated the extensor digitorum longus (EDL) muscle within five months was determined by counting and motor unit number estimation (MUNE), respectively. We found that three but not more cross-bridges promoted the regeneration of axons and reinnervation of EDL muscle by all the CP motoneurons as compared to only 33% regenerating their axons when no cross-bridges were inserted. The same 3-fold increase in sensory nerve regeneration was found. In conclusion, side-to-side cross-bridges ameliorate poor regeneration after delayed nerve repair possibly by sustaining the growth-permissive state of denervated nerve stumps. Such autografts may be used in human repair surgery to improve outcomes after unavoidable delays. PMID:26016986

  4. The desensitization gate of inhibitory Cys-loop receptors

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  5. Desensitization and Internalization of Endothelin Receptor A

    PubMed Central

    Gärtner, Florian; Seidel, Thorsten; Schulz, Uwe; Gummert, Jan; Milting, Hendrik

    2013-01-01

    Endothelin receptor A (ETA), a G protein-coupled receptor, mediates endothelin signaling, which is regulated by GRK2. Three Ser and seven Thr residues recently proven to be phosphoacceptor sites are located in the C-terminal extremity (CTE) of the receptor following its palmitoylation site. We created various phosphorylation-deficient ETA mutants. The phospholipase C activity of mutant receptors in HEK-293 cells was analyzed during continuous endothelin stimulation to investigate the impact of phosphorylation sites on ETA desensitization. Total deletion of phosphoacceptor sites in the CTE affected proper receptor regulation. However, proximal and distal phosphoacceptor sites both turned out to be sufficient to induce WT-like desensitization. Overexpression of the G?q coupling-deficient mutant GRK2-D110A suppressed ETA-WT signaling but failed to decrease phospholipase C activity mediated by the phosphorylation-deficient mutant ETA-6PD. In contrast, GRK2-WT acted on both receptors, whereas the kinase-inactive mutant GRK2-D110A/K220R failed to inhibit signaling of ETA-WT and ETA-6PD. This demonstrates that ETA desensitization involves at least two autonomous GRK2-mediated components: 1) a phosphorylation-independent signal decrease mediated by blocking of G?q and 2) a mechanism involving phosphorylation of Ser and Thr residues in the CTE of the receptor in a redundant fashion, able to incorporate either proximal or distal phosphoacceptor sites. High level transfection of GRK2 variants influenced signaling of ETA-WT and ETA-6PD and hints at an additional phosphorylation-independent regulatory mechanism. Furthermore, internalization of mRuby-tagged receptors was observed with ETA-WT and the phosphorylation-deficient mutant ETA-14PD (lacking 14 phosphoacceptor sites) and turned out to be based on a phosphorylation-independent mechanism. PMID:24064210

  6. Sensory deficit in Parkinson's disease: evidence of a cutaneous denervation.

    PubMed

    Nolano, Maria; Provitera, Vincenzo; Estraneo, Anna; Selim, Mona M; Caporaso, Giuseppe; Stancanelli, Annamaria; Saltalamacchia, Anna Maria; Lanzillo, Bernardo; Santoro, Lucio

    2008-07-01

    Sensory disturbances are part of the clinical picture of Parkinson's disease. Abnormalities in sensory processing, through a basal ganglia involvement, are thought to be responsible for the sensory dysfunction since sensory nerve conduction velocity (NCV) is usually normal. However, NCV does not examine small fibres or terminal endings of large sensory fibres, whereas skin biopsy is more suitable for these purposes. To evaluate peripheral sensory nerves in Parkinson's disease, we studied cutaneous free and encapsulated sensory nerve endings in 18 patients and 30 healthy controls using 3-mm punch biopsies from glabrous and hairy skin. Ten patients had additional skin biopsies from the contralateral side. Further evaluation included NCV and Quantitative Sensory Testing. Parkinson's disease patients showed a significant increase in tactile and thermal thresholds (P < 0.01), a significant reduction in mechanical pain perception (P < 0.01) and significant loss of epidermal nerve fibres (ENFs) and Meissner corpuscles (MCs) (P < 0.01). In patients with bilateral biopsies, loss of pain perception and ENFs was higher on the more affected side (P < 0.01). We found evidence suggesting attempts at counteracting degenerative processes as increased branching, sprouting of nerves and enlargement of the vascular bed. Morphological and functional findings did not correlate with age or disease duration. Disease severity correlated with loss of MCs and reduction in cold perception and pain perception. We demonstrated a peripheral deafferentation in Parkinson's disease that could play a major role in the pathogenesis of the sensory dysfunction. PMID:18515869

  7. Suprascapular Nerve Block for Postoperative Pain Relief in Arthroscopic Shoulder Surgery: A New Modality?

    Microsoft Academic Search

    DENISE J. WEDEL; Ewan D. Ritchie; Doris Tong; Frances Chung; Andrew M. Norris; Anthony Miniaci

    1998-01-01

    effects, and intraarticular local anesthetic has been shown to be ineffective when used for postoperative pain relief. The suprascapular nerve supplies 70% of the sensory nerve supply to the shoulder joint, and local anesthetic block of this nerve is effective in cer- tain shoulder pain disorders. To determine the effi- cacy of a suprascapular nerve block, subcutaneous saline was compared

  8. Nerve and Nerve Root Biomechanics

    Microsoft Academic Search

    Kristen J. Nicholson; Beth A. Winkelstein

    \\u000a Together, the relationship between the mechanical response of neural tissues and the related mechanisms of injury provide\\u000a a foundation for defining relevant thresholds for injury. The nerves and nerve roots are biologic structures with specific\\u000a and important functions, and whose response to mechanical loading can have immediate, long-lasting and widespread consequences.\\u000a In particular, when nerves or nerve roots are mechanically

  9. Ulnar nerve reconstruction with an expanded polytetrafluoroethylene conduit.

    PubMed

    Stanec, S; Stanec, Z

    1998-12-01

    The ulnar nerve of a 22-year-old woman was reconstructed by expanded polytetrafluoroethylene (ePTFE) conduit, 141 days after nerve transection at the distal forearm level. A 2.9 cm nerve gap was bridged by a corrugated, 3.9 cm long, 6 mm diameter ePTFE tube. At final evaluation 3 years later the patient achieved excellent motor and sensory recovery. Exploration of the tube, at that time, showed macroscopically normal nerve inside the conduit. PMID:10209470

  10. Rapid recovery from capsaicin desensitization during recurrent stimulation.

    PubMed

    Green, B G

    1996-12-01

    Topical desensitization of the tongue was assessed during multiple bouts of exposure to capsaicin. In the first experiment subjects rated perceived irritation as 30 capsaicin stimuli (33 microM) were applied to the tongue tip in three blocks of 10, with 15 min breaks between blocks. Significant desensitization was measured at the beginning of the second and third blocks within each session. However, as stimulation continued within those blocks sensations of irritation grew toward undesensitized levels ('stimulus-induced recovery' (SIR)). Desensitization did not extend across days. The second experiment employed a 10-fold higher concentration of capsaicin (330 microM) to determine if SIR was limited to low levels of desensitization. SIR occurred as before within sessions, and the higher concentration produced desensitization across days that also exhibited recovery during the first block of stimuli on days 2 and 3. The third experiment included piperine, zingerone and citric acid as stimuli to determine if SIR was specific to capsaicin. Piperine produced SIR under conditions of both self- and cross-desensitization with capsaicin, whereas recovery failed to materialize with zingerone. Citric acid was not significantly cross-desensitized by capsaicin, so recovery could not be measured. Overall the results demonstrate that desensitization of the tongue produced by either capsaicin or piperine can be temporarily reversed if stimulation with either chemical is resumed for only a few minutes. The implications these findings may have for hypotheses about the mechanisms of capsaicin desensitization and sensitization as well as for clinical applications of capsaicin as a topical analgesic are discussed. PMID:9121811

  11. Topical capsaicin in humans: parallel loss of epidermal nerve fibers and pain sensation

    Microsoft Academic Search

    Maria Nolano; Donald A Simone; Gwen Wendelschafer-Crabb; Timothy Johnson; Eric Hazen; William R Kennedy

    1999-01-01

    Capsaicin applied topically to human skin produces itching, pricking and burning sensations due to excitation of nociceptors. With repeated application, these positive sensory responses are followed by a prolonged period of hypalgesia that is usually referred to as desensitization, or nociceptor inactivation. Consequently, capsaicin has been recommended as a treatment for a variety of painful syndromes. The precise mechanisms that

  12. A collagen-based nerve guide conduit for peripheral nerve repair: an electrophysiological study of nerve regeneration in rodents and nonhuman primates.

    PubMed

    Archibald, S J; Krarup, C; Shefner, J; Li, S T; Madison, R D

    1991-04-22

    When a peripheral nerve is severed and left untreated, the most likely result is the formation of an endbulb neuroma; this tangled mass of disorganized nerve fibers blocks functional recovery following nerve injury. Although there are several different approaches for promoting nerve repair, which have been greatly refined over recent years, the clinical results of peripheral nerve repair remain very disappointing. In this paper we compare the results of a collagen nerve guide conduit to the more standard clinical procedure of nerve autografting to promote repair of transected peripheral nerves in rats and nonhuman primates. In rats, we tested recovery from sciatic nerve transection and repair by 1) direct microsurgical suture, 2) 4 mm autograft, or 3) entubulation repair with collagen-based nerve guide conduits. Evoked muscle action potentials (MAP) were recorded from the gastrocnemius muscle at 4 and 12 weeks following sciatic nerve transection. At 4 weeks the repair group of direct suture demonstrated a significantly greater MAP, compared to the other surgical repair groups. However, at 12 weeks all four surgical repair groups displayed similar levels of recovery of the motor response. In six adult male Macaca fascicularis monkeys the median nerve was transected 2 cm above the wrist and repaired by either a 4 mm nerve autograft or a collagen-based nerve guide conduit leaving a 4 mm gap between nerve ends. Serial studies of motor and sensory fibers were performed by recording the evoked MAP from the abductor pollicis brevis muscle (APB) and the sensory action potential (SAP) evoked by stimulation of digital nerves (digit II), respectively, up to 760 days following surgery. Evoked muscle responses returned to normal baseline levels in all cases. Statistical analysis of the motor responses, as judged by the slope of the recovery curves, indicated a significantly more rapid rate of recovery for the nerve guide repair group. The final level of recovery of the MAP amplitudes was not significantly different between the groups. In contrast, the SAP amplitude only recovered to the low normal range and there were no statistically significant differences between the two groups in terms of sensory recovery rates. The rodent and primate studies suggest that in terms of recovery of physiological responses from target muscle and sensory nerves, entubulation repair of peripheral nerves with a collagen-based nerve guide conduit over a short nerve gap (4 mm) is as effective as a standard nerve autograft.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2071700

  13. Theobromine inhibits sensory nerve activation and cough

    Microsoft Academic Search

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

    2004-01-01

    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,

  14. Spinal root origins and innervations of the suprascapular nerve.

    PubMed

    Shin, Chuog; Lee, Seo-Eun; Yu, Kee-Hyun; Chae, Han-Kyo; Lee, Kyu-Seok

    2010-03-01

    The suprascapular nerve branches provide efferent innervation to the supraspinatus and infraspinatus muscles as well as sensory innervation to the shoulder joint. This study was carried out to verify the spinal root origins and innervations of the suprascapular nerve. Fifty samples of the suprascapular nerve taken from 37 adult Korean cadavers were used in this study. The suprascapular nerve was found to comprise the ventral rami of the C5 and C6 in 76.0% of the fifty samples; C4, C5, and C6 nerves in 18.0%; and C5 nerve in only 6.0%. The C5 nerve was consistently shown to be the largest in mean diameter and was found to be a major contributor of nerve fibers leading to the suprascapular nerve. This study shows that the main spinal component of the suprascapular nerve is C5 nerve. In most cases, the rate of the involvement of the C4 and C6 nerves (18.0 and 94.0%, respectively) with the suprascapular nerve was less than that of C5 nerve. C4 and C5 nerves were shown to contribute nerve fibers to the supraspinatus and infraspinatus muscles and to both shoulder joints, whereas C6 nerve displayed variable patterns of innervation. PMID:19937327

  15. Phosphorylation-Independent Desensitization of G Protein-Coupled Receptors?

    NSDL National Science Digital Library

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

    2002-10-08

    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.

  16. New Concepts Receptor Desensitization by Neurotransmitters in Membranes: Are

    E-print Network

    Cantor, Robert S.

    New Concepts Receptor Desensitization by Neurotransmitters in Membranes: Are Neurotransmitters of a neurotransmitter to its receptor that results in activation, the neurotransmitter also acts indirectly is nonspecific: each neurotransmitter will, in principle, affect all receptors in the membrane. For proteins

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

    E-print Network

    Jack, Megan Marie

    2011-08-31

    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...

  18. Sensory neuropathies including painful and toxic neuropathies

    Microsoft Academic Search

    John H. J. Wokke; Gert W. van Dijk

    1997-01-01

    In most peripheral neuropathies, dysfunction of motor and sensory nerve fibres is present. However, in some of them either\\u000a pattern may predominate or be exclusively present. In this review we describe the clinical characteristics of sensory neuropathies,\\u000a with emphasis on their possible causes. Guidelines are given for the diagnostic approach in these patients and, where possible,\\u000a suggestions are given for

  19. Mechanism of action of a desensitizing fluoride toothpaste delivering calcium and phosphate ingredients in the treatment of dental hypersensitivity. Part II: comparison with a professional treatment for tooth hypersensitivity.

    PubMed

    Charig, Andrew J; Thong, Stephen; Flores, Florita; Gupta, Shivank; Major, Elizabeth; Winston, Anthony E

    2009-01-01

    Tooth hypersensitivity can occur when gum recession causes exposure of dentin. Tiny tubules, which permeate dentin, provide open passageways from the mouth to the intradental nerve in the pulpal cavity. Under such circumstances, stimuli in the mouth can cause pressure on the intradental nerve, leading to pain. Sealing the outside of the tubules with an impermeable substance can effectively treat hypersensitivity. One such clinically proven composition is a professionally applied tooth desensitizer, which has been shown to initially produce a layer of amorphous calcium phosphate (ACP) on the surface of dentin. Under the influence of fluoride, ACP reforms as hydroxyapatite (HAP), which has essentially the same composition as tooth mineral. Three fluoride toothpastes that deliver calcium and phosphate salts to the teeth also have been demonstrated in clinical trials to relieve hypersensitivity. This study compared the mechanism of action of these toothpastes to that of the professional desensitizer. A single application of the professional desensitizer or multiple applications of any of the three toothpastes was shown to reduce dentin permeability. A conventional fluoride toothpaste also was found to inhibit fluid flow through the dentin but to a lesser degree than the other toothpastes. The desensitizer and the three toothpastes were found to occlude the dentinal tubules with a layer of calcium phosphate that had a calcium-to-phosphate ratio consistent with the formation of ACP or HAP. The morphology of the coherent mineral layer formed by Arm & Hammer Enamel Care Sensitive was similar, especially to that produced by the desensitizer. In contrast, the conventional toothpaste left localized areas of surface residue composed of silica particles. The mechanism of action of the three toothpastes that deliver calcium and phosphate salts is the same as that of the professional desensitizer. PMID:19998729

  20. Stem cell salvage of injured peripheral nerve.

    PubMed

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

    2015-01-01

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

  1. Implications of Sensory Stimulation in Self-Destructive Behavior.

    ERIC Educational Resources Information Center

    Edelson, Stephen M.

    1984-01-01

    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)

  2. Regenerating sensory neurones of diabetic rats express reduced levels of mRNA for GAP43, ?-preprotachykinin and the nerve growth factor receptors, trkA and p75 NGFR

    Microsoft Academic Search

    Kengo Maeda; Paul Fernyhough; David R. Tomlinson

    1996-01-01

    Nerve growth factor (NGF) is considered to play a role in neurite outgrowth of small fibres which express its high-affinity receptor, trkA. Nerve regeneration is delayed in diabetes mellitus following an experimental crush injury. In steady-state (i.e., in the absence of axotomy) diabetic rats also show reduced expression of NGF in certain target tissues. This study was designed to measure

  3. Mechanism of action of a desensitizing fluoride toothpaste delivering calcium and phosphate ingredients in the treatment of dental hypersensitivity. Part III: Prevention of dye penetration through dentin vs a calcium- and phosphate-free control.

    PubMed

    Winston, Anthony E; Charig, Andrew J; Thong, Stephen

    2010-01-01

    It is generally accepted that the pain of dental hypersensitivity resulting from gum recession is from the movement of fluid within the exposed tubules of dentin, causing changes in pressure on the nerve within the pulpal cavity. One method of treating hypersensitivity is to occlude the tubules, preventing fluid movement. This article discusses the use of a dye penetration technique, which establishes this mechanism of action for a desensitizing fluoride toothpaste containing calcium and phosphate. Two groups of intact teeth were perfectly sealed with enamel paint. Windows 100-micro to 200-micro deep were opened on opposite sides of each tooth at the dentin-enamel junction and briefly etched using 20% polyacrylic acid. One batch of teeth was treated eight times for 30 mins each with a 1:3 slurry of the desensitizing toothpaste and another set with a similar slurry prepared from a calcium- and phosphate-free control. A 0.85% aqueous solution of acid red fuchsin dye was applied to each window and allowed to dry. After a brief rinse, the teeth were sectioned across the windows. Almost no dye penetration was seen in teeth treated with the desensitizing toothpaste; however, extensive penetration through the dentin was visible in the control-treated teeth. The differences in dye penetration for the two sets of teeth were significant by both subjective (P < .001) and objective (P < .01) measures. Tubule occlusion because of calcium and phosphate ions from the desensitizing toothpaste accounts for its tooth desensitizing efficacy. PMID:20158016

  4. Reactive Oxygen Species (ROS) and the Sensory Neurovascular Component

    Microsoft Academic Search

    Rabea Graepel; Jennifer Victoria Bodkin; Susan Diana Brain

    \\u000a A dense perivascular network of C- and A?-sensory nerve fibers innervate the vascular system and are ideally situated to influence\\u000a vascular events. The nerves release potent vasodilator neuropeptides including substances P, CGRP and a range of other agents,\\u000a depending on their location and the nature of nerve activation. A number of interactions between neuropeptides and ROS have\\u000a been described and

  5. Mechanical stimulation increases intracellular calcium concentration in nodose sensory neurons

    Microsoft Academic Search

    R. V. Sharma; M. W. Chapleau; G. Hajduczok; R. E. Wachtel; L. J. Waite; R. C. Bhalla; F. M. Abboud

    1995-01-01

    The cellular mechanisms involved in activation of mechanosensitive visceral sensory nerves are poorly understood. The major goal of this study was to determine the effect of mechanical stimulation on intracellular calcium concentration ([Ca2+]i) using nodose sensory neurons grown in culture. Primary cultures of nodose sensory neurons were prepared by enzymatic dispersion from nodose ganglia of 4–8 week old Sprague-Dawley rats.

  6. The consistent presence of the human accessory deep peroneal nerve.

    PubMed

    Kudoh, H; Sakai, T; Horiguchi, M

    1999-01-01

    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

  7. Acute small fibre sensory neuropathy: another variant of Guillain-Barré syndrome?

    PubMed Central

    Seneviratne, U; Gunasekera, S

    2002-01-01

    The clinical features and normal routine nerve conduction studies, which assess large diameter nerve fibre function, indicate small sensory fibre dysfunction in the group. Their presentation and CSF findings would fit into the diagnosis of sensory Guillain-Barré syndrome. The current study suggests that acute small fibre sensory neuropathy (ASFSN) is another clinical entity which could perhaps be included in the heterogeneous range of Guillain-Barré syndrome. PMID:11909922

  8. Aerodynamic tip desensitization in axial flow turbines

    NASA Astrophysics Data System (ADS)

    Dey, Debashis

    The leakage flow near the tip of unshrouded rotor blades in axial turbines imposes significant thermal loads on the blade. It is also responsible for up to a third of aerodynamic losses in a turbine stage. The leakage flow, mainly induced by the pressure differential across the rotor tip section, usually rolls into a stream-wise vertical structure near the suction side part of the blade tip. The current study uses several concepts to reduce the severity of losses introduced by the leakage vortex. Three tip desensitization techniques, both active and passive, are examined. Coolant flow from a tip trench is used to counter the momentum of the leakage jet. Next, a very short winglet obtained by slightly extending the tip platform in the tangential direction is investigated. Lastly, the widely used concept of squealer tip is studied. The current investigation is performed in the Axial Flow Turbine Research Facility (AFTRF) of the Pennsylvania State University. Rotating frame five hole probe measurements as well as stationary frame phase averaged total pressure measurements downstream of a single stage turbine facility were taken. The study enables one to draw conclusions about the nature of the flowfield in the rotor tip region. It also shows that significant efficiency gains could be obtained by using some of these techniques.

  9. Free vascularized deep peroneal nerve grafts.

    PubMed

    Koshima, I; Okumoto, K; Umeda, N; Moriguchi, T; Ishii, R; Nakayama, Y

    1996-04-01

    An ideal donor site for vascularized nerve grafts should have a constant anatomy, minimal functional loss after the nerve has been sacrificed, and a dependable blood supply parallel to the nerve over a relatively long distance. Creating a pedicle for a free vascularized deep peroneal nerve graft with the anterior tibial vessels seems to be a most suitable method for repairing long nerve gaps of over 20 cm and digital nerve defects with severe finger damage. Applications of this nerve graft to digital nerve losses with severely scarred beds created by avulsion injury, and two-stage reconstruction in some partial brachial plexus palsies (free vascularized nerve graft in the first stage and free vascularized muscle graft in the second stage) are well indicated. Advantages of this technique are: (1) A long nerve graft (up to 25 cm) can be obtained, and anomalies are rare (the nerve is absent in only 4 percent of cases). (2) The caliber of the vascular pedicle is large (approximately equal to 3 mm). (3) The nerve has a sufficient blood supply from the collateral blood vessels. (4) The graft can be easily obtained in the supine position. (5) A monitoring skin flap, based on the inferior lateral peroneal artery, can be attached to the nerve graft. (6) Sensory loss resulting from the sacrifice of the nerve covers a minimal area. (7) A donor scar on the anterior aspect of the lower leg is more acceptable than one on the posterior aspect because of less movement in walking. Disadvantages of this technique are: (1) Sacrifice of the large vessels in the lower leg may result in circulatory complications in the donor foot; to avoid this problem, preoperative angiography is recommended. (2) The donor scar is in an exposed area in female patients. (3) There may be temporary postoperative edema and disability in the donor leg. PMID:8726331

  10. Opioid receptors on peripheral sensory axons

    Microsoft Academic Search

    Richard E Coggeshall; Shengtai Zhou; Susan M Carlton

    1997-01-01

    Opioid receptors have been demonstrated by light microscopic techniques in fine cutaneous nerves in naive animals. The present study extends these findings by showing that 29 and 38% of unmyelinated cutaneous sensory axons can be immunostained for ?- or ?-opioid receptors respectively. Local cutaneous injection of DAMGO, a ?-opioid ligand, ameliorates the nociceptive behaviors caused by local cutaneous injection of

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

    NASA Astrophysics Data System (ADS)

    Ibrahim, T.; Gheith, M.

    2011-09-01

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

  12. The effect of surgical medicaments on peripheral nerve function

    Microsoft Academic Search

    A. R. Loescher; P. P. Robinson

    1998-01-01

    Surgical medicaments are often placed in close proximity to peripheral nerves and maybe responsible for some postoperative sensory disturbances. In this study we investigated the effect of four medicaments - BIPP, (bismuth iodoform paraffin paste), Whitehead's varnish (compound iodoform paint), Surgicel (oxidized regenerated cellulose) and Carnoy's solution (ethanol, chloroform and acetic acid) - on peripheral nerve function. The experiments were

  13. Central changes in primary afferent fibers following peripheral nerve lesions

    Microsoft Academic Search

    R. E Coggeshall; H. A Lekan; T. P Doubell; A Allchorne; C. J Woolf

    1997-01-01

    Cutting or crushing rat sciatic nerve does not significantly reduce the number of central myelinated sensory axons in the dorsal roots entering the fourth and fifth lumbar segments even over very extended periods of time. Unmyelinated axons were reduced by ?50%, but only long after sciatic nerve lesions (four to eight months), and reinnervation of the peripheral target did not

  14. A Controlled Study to Assess the Clinical Efficacy of Totally Self-Administered Systematic Desensitization

    ERIC Educational Resources Information Center

    Rosen, Gerald M.; And Others

    1976-01-01

    Highly anxious self-referred snake phobics received either (a) therapist-administered desensitization, (b) self-administered desensitization with weekly therapist phone calls, (c) totally self-administered desensitization, (d) self-administered double-blind placebo control, or (e) no treatment. Pretreatment to posttreatment measures revealed…

  15. Desensitization Mechanism of GABA Receptors Revealed by Single Oocyte Binding and Receptor Function

    Microsoft Academic Search

    YongChang Chang; Emmanuel Ghansah; Yonghui Chen; Jiawei Ye; David S. Weiss

    2002-01-01

    Prolonged exposure of most fast neurotransmitter-operated ion channels to agonist drives the receptors into a nonfunctional, or desensitized, state. Despite extensive investigation, desensiti- zation remains a thoroughly characterized, yet poorly under- stood, process. Part of the difficulty in elucidating the mecha- nism of desensitization has been an inability to resolve the kinetics of both agonist binding and functional desensitization in

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

    PubMed

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

    2015-07-01

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

  17. Ulnar nerve repair by the silicone chamber technique. Case report.

    PubMed

    Lundborg, G; Dahlin, L B; Danielsen, N

    1991-01-01

    The ulnar nerve of a 21-year old man was repaired at the wrist by a silicone chamber technique 10 days after a traumatic transection. A 3 mm gap was left between the nerve ends inside the chamber. At follow-up three years later, motor and sensory recovery was excellent. At exploration at that time a macroscopically normal nerve was found in the tube. PMID:2052913

  18. C-peptide improves autonomic nerve function in IDDM patients

    Microsoft Academic Search

    B. L. Johansson; K. Borg; E. Fernqvist-Forbes; T. Odergren; S. Remahl; J. Wahren

    1996-01-01

    Summary  In order to determine the possible influence of C-peptide on nerve function, 12 insulin-dependent diabetic (IDDM) patients with symptoms of diabetic polyneuropathy were studied twice under euglycaemic conditions. Tests of autonomic nerve function (respiratory heart rate variability, acceleration and brake index during tilting), quantitative sensory threshold determinations, nerve conduction studies and clinical neurological examination were carried out before and during

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

    PubMed

    Funk, Jeanne B

    2005-07-01

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

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

    PubMed

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

    2015-04-01

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

  1. Extraction of significant nerve conduction predictors in early diagnosis of leprosy

    Microsoft Academic Search

    A. G. Ramakrishnan; T. M. Srinivasan

    1992-01-01

    Compound nerve action potentials were obtained from 25 normal subjects and 21 leprosy patients after electrical stimulation of median nerves. Parameters such as sensory nerve conduction velocity, motor threshold of stimulation and peak to peak amplitudes were measured. Responses were recorded from two orthodromal locations and one antidromal site. Multivariate analysis was applied on the data to determine the discriminating

  2. Nerve conduction tests in patients with fibromyalgia: comparison with normal controls

    Microsoft Academic Search

    Murat Ersoz

    2003-01-01

    The purpose of this study was to evaluate nerve conduction in fibromyalgia (FM) patients and normal subjects. Testing of F waves and motor, sensory, and mixed nerve conduction was performed in 33 consecutive female FM patients complaining of paresthesias in the extremities and in 17 age- and sex-matched healthy volunteers. The nerve conduction results in FM patients were no different

  3. n-Hexane-induced changes in nerve conduction velocities and somatosensory evoked potentials

    Microsoft Academic Search

    A. Mutti; F. Ferri; G. Lommi; S. Lotta; S. Lucertini; I. Franchini

    1982-01-01

    Fifteen women from a shoe factory were examined clinically and their cerebral evoked responses to 256 electrical stimulations of the median nerve were averaged. Neurophysiological investigations included maximal motor (MCV) and distal sensory (dSCV) nerve conduction velocity measurement on ulnar, median, and peroneal nerves. A referent group was composed of 15 age-matched women without exposure to neurotoxic chemicals. MCVs and

  4. Nerve conduction velocities in the lower extremity in patients with Raynaud's phenomenon and clinical applications

    Microsoft Academic Search

    Dimitrios Kostopoulos; Konstantine Rizopoulos; Nikolaos Vartholomeos

    2008-01-01

    Summary Background and purpose: The purpose of the study is to study the nerve conductivity of the tibial motor, peroneal motor, peroneal sensory, and sural nerves in patients with primary and secondary Raynaud's phenomenon (RP). Subjects: Twenty each: primary RP, secondary RP, and normal controls. Methods: Electromyography using distal latency (DL) and nerve conduction velocity (NCV) as dependent variables. Results:

  5. Optic Nerve Drusen

    MedlinePLUS

    ... Conditions Frequently Asked Questions Espańol Condiciones Chinese Conditions Optic Nerve Drusen En Espańol Read in Chinese What are optic nerve drusen? Optic nerve drusen are abnormal globular ...

  6. A reversible functional sensory neuropathy model.

    PubMed

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

    2014-06-13

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

  7. Neuropeptides in insect sensory neurones: tachykinin-, FMRFamide- and allatotropin-related peptides in terminals of locust thoracic sensory afferents.

    PubMed

    Persson, M G; Nässel, D R

    1999-01-16

    Sensory afferents in the thoracic ganglia of the locust Locusta migratoria were labelled with antisera to different neuropeptides: locustatachykinins, FMRFamide and allatotropin. The locustatachykinin-immunoreactive (LTKIR) sensory fibres were derived from the legs and entered the ventral sensory neuropil of each of the thoracic ganglia via nerve 5. In the thoracic neuropil, the LTKIR sensory fibres formed a distinct plexus of terminations ventrally in the ipsilateral hemisphere. The peripheral cell bodies of the sensory neurones could not be revealed, but lesion experiments indicated that origin of the LTKIR fibres was the tarsus of each leg. Possibly the thin fibres are from tarsal chemoreceptors. Double labelling immunocytochemistry revealed that all the LTKIR sensory fibres contained colocalized FMRFamide immunoreactivity. A larger population of sensory fibres reacted with antiserum to moth (Manduca sexta) allatotropin. By means of double labelling immunocytochemistry, we could show that the LTKIR fibres constituted a subpopulation of the larger set of allatotropin-like immunoreactive fibres. Thus some sensory fibres may contain colocalized peptides related to locustatachykinins, FMRFamide-related peptide(s) and allatotropin-like peptide. A separate non-overlapping small set of sensory fibres in nerve 5 reacted with an antiserum to serotonin. Sensory fibres of the other nerves of the ventral nerve cord, including the abdominal ganglia, did not react with the peptide antisera. Since acetylcholine is the likely primary neurotransmitter of insect sensory fibres, it is possible that the peptides and serotonin are colocalized with this transmitter and serve modulatory functions in a subset of the leg afferents. PMID:9878709

  8. Eye movement desensitization and reprocessing: a conceptual framework.

    PubMed

    Menon, Sukanya B; Jayan, C

    2010-07-01

    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

  9. Raman microspectroscopy for visualization of peripheral nerves

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

  10. A (heat) shock to the system promotes peripheral nerve regeneration

    PubMed Central

    Höke, Ahmet

    2011-01-01

    Peripheral nerves are easily damaged, resulting in loss of motor and sensory function. Recovery of motor and sensory function after peripheral nerve injury is suboptimal, even after appropriate surgical repair. This is due to the slow rate of axonal elongation during regeneration and atrophic changes that occur in denervated Schwann cells and target muscle with proximal lesions. One way to solve this problem is to accelerate the rate at which the axons regenerate. In this issue of the JCI, Ma and colleagues show that this can be achieved in mice by overexpression of heat shock protein 27, providing hope for enhanced functional recovery in patients after peripheral nerve damage. PMID:21965324

  11. Peripheral Nerve Disorders

    MedlinePLUS

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

  12. Positive Attentional Cues as Cognitive Factors in Desensitization.

    ERIC Educational Resources Information Center

    Carrico, Kenneth L.; Riggs, Ronald C.

    The purpose of this study was to investigate the function of positive attentional cues as cognitive factors in the modification of fear responses in a desensitization-like treatment procedure. Positive attentional cues are defined as positively-valenced descriptors of the feared stimulus. Two groups of two subjects each were assessed as to the…

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

    PubMed

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

    2009-01-01

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

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

    ERIC Educational Resources Information Center

    Erwin, Terry McVannel

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

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

    ERIC Educational Resources Information Center

    Wilson, Barbara J.

    1989-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  17. Increased risk of median nerve dysfunction in floor cleaners: a controlled clinical and neurophysiological study.

    PubMed

    Bekkelund, S I; Torbergsen, T; Rom, A K; Mellgren, S I

    2001-09-01

    We studied median nerve involvement in a group of asymptomatic handworkers at risk for carpal tunnel syndrome, and we evaluated damage to thin and thick nerve fibres in the distribution area of the median nerve. Considering floor cleaners as workers at high risk of developing cumulative traumatic disorders in the wrist, we included 42 cleaners and 41 controls. We assessed nerve conduction studies, vibration threshold, and temperature and pain thresholds of the median nerve. The cleaners had significantly impaired motor nerve conduction velocity (p = 0.006), longer sensory distal latency (p = 0.01), lower sensory amplitude (p = 0.0005), and increased difference in heat and cold threshold of the median nerve (p = 0.0002). Increased temperature threshold was associated with prolonged sensory distal latency of the median nerve in the cleaners. In conclusion, impaired neurophysiological variables in the median nerve in floor cleaners compared with controls confirm the hypothesis that those workers are at risk of developing median nerve dysfunction. Sensory nerves seem to be more susceptible to injury than motor branches. PMID:11680403

  18. Desensitization of the neutrophil aggregation response to chemotactic factors.

    PubMed Central

    O'Flaherty, J. T.; Kreutzer, D. L.; Showell, H. S.; Becker, E. L.; Ward, P. A.

    1978-01-01

    In the presence of Ca2+ and Mg2+, the chemotactic fragment of C5, the synthetic chemotactic oligopeptide formyl-methionyl-leucyl-phenyl-alanine, and the ionophore A23187 aggregated human neutrophils. Aggregation induced by the two chemotactic factors was transient and reversed within 2 to 4 minutes after exposure; aggregation induced by A23187 was sustained and continued to increase over 15 minutes. In the absence of the bivalent cations, none of these three agents aggregated the cells. If bivalent cations were added after cell contact with a chemotactic factor, aggregation was detected after, but not before, addition of the cations. Under these conditions, the magnitude of the aggregation response was sharply reduced: cells preincubated with a chemotactic factor for longer than 2 to 4 minutes aggregated minimally after addition of bivalent cations. Moreover, cells preincubated with a chemotactic factor for 4 minutes, exposed to bivalent cations, and then rechallenged with the same chemotactic factor also showed a minimal aggregation response, ie, the cells were "desensitized" to the original stimulus. However, cells desensitized to one of the chemotactic factors still aggregated prominently when exposed to the other chemotactic factor or to A23187. Cells could not be desensitized to the ionophore A23187. Desensitization of the neutrophil aggregation response closely resembles desensitization of mast cell and leukocyte degranulation. Degranulation and aggregation appear to be closely related cellular responses to immunologic stimuli. Both responses may reflect alterations in surface membrane permeability to bivalent cations and/or changes in surface membrane adhesiveness to other biologic membranes. PMID:717543

  19. Acute Activation, Desensitization and Smoldering Activation of Human Acetylcholine Receptors

    PubMed Central

    Campling, Barbara G.; Kuryatov, Alexander; Lindstrom, Jon

    2013-01-01

    The behavioral effects of nicotine and other nicotinic agonists are mediated by AChRs in the brain. The relative contribution of acute activation versus chronic desensitization of AChRs is unknown. Sustained “smoldering activation” occurs over a range of agonist concentrations at which activated and desensitized AChRs are present in equilibrium. We used a fluorescent dye sensitive to changes in membrane potential to examine the effects of acute activation and chronic desensitization by nicotinic AChR agonists on cell lines expressing human ?4?2, ?3?4 and ?7 AChRs. We examined the effects of acute and prolonged application of nicotine and the partial agonists varenicline, cytisine and sazetidine-A on these AChRs. The range of concentrations over which nicotine causes smoldering activation of ?4?2 AChRs was centered at 0.13 µM, a level found in smokers. However, nicotine produced smoldering activation of ?3?4 and ?7 AChRs at concentrations well above levels found in smokers. The ?4?2 expressing cell line contains a mixture of two stoichiometries, namely (?4?2)2?2 and (?4?2)2?4. The (?4?2)2?2 stoichiometry is more sensitive to activation by nicotine. Sazetidine-A activates and desensitizes only this stoichiometry. Varenicline, cytisine and sazetidine-A were partial agonists on this mixture of ?4?2 AChRs, but full agonists on ?3?4 and ?7 AChRs. It has been reported that cytisine and varenicline are most efficacious on the (?4?2)2?4 stoichiometry. In this study, we distinguish the dual effects of activation and desensitization of AChRs by these nicotinic agonists and define the range of concentrations over which smoldering activation can be sustained. PMID:24244538

  20. Acute activation, desensitization and smoldering activation of human acetylcholine receptors.

    PubMed

    Campling, Barbara G; Kuryatov, Alexander; Lindstrom, Jon

    2013-01-01

    The behavioral effects of nicotine and other nicotinic agonists are mediated by AChRs in the brain. The relative contribution of acute activation versus chronic desensitization of AChRs is unknown. Sustained "smoldering activation" occurs over a range of agonist concentrations at which activated and desensitized AChRs are present in equilibrium. We used a fluorescent dye sensitive to changes in membrane potential to examine the effects of acute activation and chronic desensitization by nicotinic AChR agonists on cell lines expressing human ?4?2, ?3?4 and ?7 AChRs. We examined the effects of acute and prolonged application of nicotine and the partial agonists varenicline, cytisine and sazetidine-A on these AChRs. The range of concentrations over which nicotine causes smoldering activation of ?4?2 AChRs was centered at 0.13 µM, a level found in smokers. However, nicotine produced smoldering activation of ?3?4 and ?7 AChRs at concentrations well above levels found in smokers. The ?4?2 expressing cell line contains a mixture of two stoichiometries, namely (?4?2)2?2 and (?4?2)2?4. The (?4?2)2?2 stoichiometry is more sensitive to activation by nicotine. Sazetidine-A activates and desensitizes only this stoichiometry. Varenicline, cytisine and sazetidine-A were partial agonists on this mixture of ?4?2 AChRs, but full agonists on ?3?4 and ?7 AChRs. It has been reported that cytisine and varenicline are most efficacious on the (?4?2)2?4 stoichiometry. In this study, we distinguish the dual effects of activation and desensitization of AChRs by these nicotinic agonists and define the range of concentrations over which smoldering activation can be sustained. PMID:24244538

  1. Agonist- and Ca2+-dependent Desensitization of TRPV1 Channel Targets the Receptor to Lysosomes for Degradation*

    PubMed Central

    Sanz-Salvador, Lucía; Andrés-Borderia, Amparo; Ferrer-Montiel, Antonio; Planells-Cases, Rosa

    2012-01-01

    TRPV1 receptor agonists such as the vanilloid capsaicin and the potent analog resiniferatoxin are well known potent analgesics. Depending on the vanilloid, dose, and administration site, nociceptor refractoriness may last from minutes up to months, suggesting the contribution of different cellular mechanisms ranging from channel receptor desensitization to Ca2+ cytotoxicity of TRPV1-expressing neurons. The molecular mechanisms underlying agonist-induced TRPV1 desensitization and/or tachyphylaxis are still incompletely understood. Here, we report that prolonged exposure of TRPV1 to agonists induces rapid receptor endocytosis and lysosomal degradation in both sensory neurons and recombinant systems. Agonist-induced receptor internalization followed a clathrin- and dynamin-independent endocytic route, triggered by TRPV1 channel activation and Ca2+ influx through the receptor. This process appears strongly modulated by PKA-dependent phosphorylation. Taken together, these findings indicate that TRPV1 agonists induce long-term receptor down-regulation by modulating the expression level of the channel through a mechanism that promotes receptor endocytosis and degradation and lend support to the notion that cAMP signaling sensitizes nociceptors through several mechanisms. PMID:22493457

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

    PubMed

    Patel, Yogi A; Butera, Robert J

    2015-06-01

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

  3. Identification of a Ca 2+ Sensing Receptor in Rat Trigeminal Ganglia, Sensory Axons, and Tooth Dental Pulp

    Microsoft Academic Search

    Karin J. Heyeraas; Sivakami R. Haug; Richard D. Bukoski; Emmanuel M. Awumey

    2008-01-01

    Extracellular Ca2+ regulates dentin formation, but little information is available on this regulatory mechanism. We have previously reported\\u000a that sensory denervation reduces dentin formation, suggesting a role for sensory nerves in tooth mineralization. The G protein-coupled\\u000a Ca2+-sensing receptor (CaR) is expressed in dorsal root ganglia and perivascular sensory nerves in mesenteric arterioles, and\\u000a activation of these receptors by Ca2+ has

  4. Role of domain calcium in purinergic P2X2 receptor channel desensitization.

    PubMed

    Coddou, Claudio; Yan, Zonghe; Stojilkovic, Stanko S

    2015-05-01

    Activation of P2X2 receptor channels (P2X2Rs) is characterized by a rapid current growth accompanied by a decay of current during sustained ATP application, a phenomenon known as receptor desensitization. Using rat, mouse, and human receptors, we show here that two processes contribute to receptor desensitization: bath calcium-independent desensitization and calcium-dependent desensitization. Calcium-independent desensitization is minor and comparable during repetitive agonist application in cells expressing the full size of the receptor but is pronounced in cells expressing shorter versions of receptors, indicating a role of the COOH terminus in control of receptor desensitization. Calcium-dependent desensitization is substantial during initial agonist application and progressively increases during repetitive agonist application in bath ATP and calcium concentration-dependent manners. Experiments with substitution of bath Na(+) with N-methyl-d-glucamine (NMDG(+)), a large organic cation, indicate that receptor pore dilation is a calcium-independent process in contrast to receptor desensitization. A decrease in the driving force for calcium by changing the holding potential from -60 to +120 mV further indicates that calcium influx through the channel pores at least partially accounts for receptor desensitization. Experiments with various receptor chimeras also indicate that the transmembrane and/or intracellular domains of P2X2R are required for development of calcium-dependent desensitization and that a decrease in the amplitude of current slows receptor desensitization. Simultaneous calcium and current recording shows development of calcium-dependent desensitization without an increase in global intracellular calcium concentrations. Combined with experiments with clamping intrapipette concentrations of calcium at various levels, these experiments indicate that domain calcium is sufficient to establish calcium-dependent receptor desensitization in experiments with whole-cell recordings. PMID:25673774

  5. A Novel Internal Fixator Device for Peripheral Nerve Regeneration

    PubMed Central

    Chuang, Ting-Hsien; Wilson, Robin E.; Love, James M.; Fisher, John P.

    2013-01-01

    Recovery from peripheral nerve damage, especially for a transected nerve, is rarely complete, resulting in impaired motor function, sensory loss, and chronic pain with inappropriate autonomic responses that seriously impair quality of life. In consequence, strategies for enhancing peripheral nerve repair are of high clinical importance. Tension is a key determinant of neuronal growth and function. In vitro and in vivo experiments have shown that moderate levels of imposed tension (strain) can encourage axonal outgrowth; however, few strategies of peripheral nerve repair emphasize the mechanical environment of the injured nerve. Toward the development of more effective nerve regeneration strategies, we demonstrate the design, fabrication, and implementation of a novel, modular nerve-lengthening device, which allows the imposition of moderate tensile loads in parallel with existing scaffold-based tissue engineering strategies for nerve repair. This concept would enable nerve regeneration in two superposed regimes of nerve extension—traditional extension through axonal outgrowth into a scaffold and extension in intact regions of the proximal nerve, such as that occurring during growth or limb-lengthening. Self-sizing silicone nerve cuffs were fabricated to grip nerve stumps without slippage, and nerves were deformed by actuating a telescoping internal fixator. Poly(lactic co-glycolic) acid (PLGA) constructs mounted on the telescoping rods were apposed to the nerve stumps to guide axonal outgrowth. Neuronal cells were exposed to PLGA using direct contact and extract methods, and they exhibited no signs of cytotoxic effects in terms of cell morphology and viability. We confirmed the feasibility of implanting and actuating our device within a sciatic nerve gap and observed axonal outgrowth following device implantation. The successful fabrication and implementation of our device provides a novel method for examining mechanical influences on nerve regeneration. PMID:23102114

  6. Peripherin and ATF3 genes are differentially regulated in regenerating and non-regenerating primary sensory neurons

    Microsoft Academic Search

    Adam J. Reid; Dag Welin; Mikael Wiberg; Giorgio Terenghi; Lev N. Novikov

    2010-01-01

    Peripheral nerve injury leads to deficient recovery of sensation and a causative factor may be that only 50–60% of primary sensory neurons succeed in regenerating axons after primary nerve repair. In this study, an in vivo rat sciatic nerve injury and regeneration model was combined with laser microdissection and quantitative real-time polymerase chain reaction with the aim of examining the

  7. DACTYL SENSORY INFLUENCES ON ROCK LOBSTER LOCOMOTION I. INTRASEGMENTAL AND INTERSEGMENTAL LEG REFLEXES DURING STANDING AND WALKING

    Microsoft Academic Search

    UWE MULLER; FRANCOIS CLARACt

    Summary 1. Recordings of activity of the rock lobster dactyl sensory nerve during walking on a driven belt showed that the receptors of this nerve were mainly active during the power stroke when the leg was loaded. This nerve contains in particular the afferent fibres of the funnel canal organ (FCO) which are bimodal sensillae located in the cuticle of

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

    PubMed Central

    YANG, JINGJING; HUAN, MINGMING; JIANG, HUAJUN; SONG, CHUNLI; ZHONG, LIN; LIANG, ZHANHUA

    2014-01-01

    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

  9. Anterograde transneuronal viral tract tracing reveals central sensory circuits from brown fat and sensory denervation alters its thermogenic responses

    PubMed Central

    Vaughan, Cheryl H.

    2012-01-01

    Brown adipose tissue (BAT) thermogenic activity and growth are controlled by its sympathetic nervous system (SNS) innervation, but nerve fibers containing sensory-associated neuropeptides [substance P, calcitonin gene-related peptide (CGRP)] also suggest sensory innervation. The central nervous system (CNS) projections of BAT afferents are unknown. Therefore, we used the H129 strain of the herpes simplex virus-1 (HSV-1), an anterograde transneuronal viral tract tracer used to delineate sensory nerve circuits, to define these projections. HSV-1 was injected into interscapular BAT (IBAT) of Siberian hamsters and HSV-1 immunoreactivity (ir) was assessed 24, 48, 72, 96, and 114 h postinjection. The 96- and 114-h groups had the most HSV-1-ir neurons with marked infections in the hypothalamic paraventricular nucleus, periaqueductal gray, olivary areas, parabrachial nuclei, raphe nuclei, and reticular areas. These sites also are involved in sympathetic outflow to BAT suggesting possible BAT sensory-SNS thermogenesis feedback circuits. We tested the functional contribution of IBAT sensory innervation on thermogenic responses to an acute (24 h) cold exposure test by injecting the specific sensory nerve toxin capsaicin directly into IBAT pads and then measuring core (Tc) and IBAT (TIBAT) temperature responses. CGRP content was significantly decreased in capsaicin-treated IBAT demonstrating successful sensory nerve destruction. TIBAT and Tc were significantly decreased in capsaicin-treated hamsters compared with the saline controls at 2 h of cold exposure. Thus the central sensory circuits from IBAT have been delineated for the first time, and impairment of sensory feedback from BAT appears necessary for the appropriate, initial thermogenic response to acute cold exposure. PMID:22378771

  10. Neuromodulation of the suprascapular nerve.

    PubMed

    Elahi, Foad; Reddy, Chandan G

    2014-01-01

    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

  11. Nerve biopsy in children with severe Guillain-Barré syndrome and inexcitable motor nerves.

    PubMed

    Massaro, M E; Rodriguez, E C; Pociecha, J; Arroyo, H A; Sacolitti, M; Taratuto, A L; Fejerman, N; Reisin, R C

    1998-08-01

    The presence of inexcitable motor nerves early in the course of Guillain-Barré syndrome (GBS) identifies a subgroup of patients with more severe disease and delayed recovery. How frequently these electrodiagnostic findings reflect a primary axonal attack ("axonal" GBS) is controversial. We present two children with severe acute GBS, delayed recovery, and residual disability despite early treatment with human immunoglobulin. They had inexcitable motor nerves at days 6 and 7, and profuse fibrillations and positive waves on subsequent studies. Clinically and electrodiagnostically, both children's disease resembled the acute motor-sensory axonal variant of GBS (AMSAN). Sensory and motor nerve biopsies revealed severe macrophage-associated demyelination with axonal degeneration of variable severity. We conclude that clinical and electrodiagnostic features cannot discriminate between the "axonal" and demyelinating GBS. Early and severe demyelination with secondary axonal damage may mimic clinically and electrophysiologically the AMSAN variant of GBS. PMID:9710009

  12. `L'acropathie ulcéro-mutilante familiale' with involvement of the distal mixed nerves and long bones fractures

    Microsoft Academic Search

    A. Juši?; Z. Radoševi?; N. Gr?evi?; V. Hlavka; R. Petri?evi?-Migi?; V. Hartl-Prpi?

    1973-01-01

    Two siblings are described with mutilating lesions of the feet and hands, with sensory disturbances and muscle amyotrophy. The motor and afferent nerve conduction velocities were at the lower limit of normal. The nerve action potentials disappeared, first with percutaneous stimulation of the fingers and later with more proximal direct nerve stimulation. Early in the course of the illness indolent

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

    E-print Network

    Muller, Karra

    2008-11-17

    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...

  14. Sparsity and Compressed Coding in Sensory Systems Victor J. Barranca1,2

    E-print Network

    Kovacic, Gregor

    by a significantly smaller network of ganglion cells before entering the optic nerve. How then is sensory information and transmitted through a wide array of neuronal networks of various sizes and functionalities. Despite

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

    PubMed Central

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

    2015-01-01

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

  16. Micromorphological Evaluation of Dentin Treated with Different Desensitizing Agents

    PubMed Central

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

    2013-01-01

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

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

    Microsoft Academic Search

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

    2003-01-01

    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

  18. Sensory interaction with central 'generators' during respiration in the dogfish.

    PubMed

    Roberts, B L; Ballintijn, C M

    1988-04-01

    The activity in sensory and motor nerves of the gills was recorded from selected branches of the vagus nerve in decerebrate dogfish, Scyliorhinus canicula. Vagal motoneuronal activity was observed at the start of the rapid pharyngeal contraction and was followed by sensory nerve activity which preceded the slow expansion phase. Rhythmical vagal motoneuronal activity was still present after all movements had been prevented by curare paralysis although the frequency of the rhythm was higher than in the ventilating fish. Electrical stimulation of vagal sensory fibres had 3 effects on the ventilatory movements. (1) It evoked a reflex contraction of several gill muscles after a latency of about 11 ms. (2) It could reset the respiratory cycle because a stimulus given during expansion delayed the onset of the subsequent contraction. (3) The stimulus could entrain the rhythm if it was given continuously at a frequency close to that of ventilation. The vagal motor rhythm was disrupted by trigeminal nerve stimulation in the paralyzed fish but not if the motor rhythm was being entrained by vagal nerve stimulation. Vagal sensory activity may be important, therefore, in maintaining the stability of the generating circuits. PMID:3373457

  19. The catecholaminergic nerve plexus of Holothuroidea

    PubMed Central

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

    2010-01-01

    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

  20. The catecholaminergic nerve plexus of Holothuroidea.

    PubMed

    Díaz-Balzac, Carlos A; Mejías, Wigberto; Jiménez, Luis B; García-Arrarás, José E

    2010-05-01

    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

  1. Superior laryngeal nerve block: an anatomical study.

    PubMed

    Stockwell, M; Lozanoff, S; Lang, S A; Nyssen, J

    1995-01-01

    Superior laryngeal nerve anaesthesia is frequently used to facilitate endotracheal intubation in the awake patient. We have modified the transcutaneous approach to this nerve block to employ a short bevel needle. This improves tactile perception in performing the procedure thus simplifying identification of the correct depth of injection. This study was designed to determine the anatomical basis of superior laryngeal nerve anaesthesia and to estimate the success rate using our modified technique. At autopsy, 20 cadavers had nerve block performed substituting 0.02% methylene blue for local anaesthetic. Dissection was then performed to identify the anatomical structures stained by the simulated local anaesthetic. Additional dissections were performed in formalin-fixed cadavers. We found that the dye was injected into the paraglottic space bounded laterally by the thyrohyoid membrane and thyroid cartilage, medially by the laryngeal submucosa, caudad by the conus elasticus, cephalad by the hyoid bone, and anteriorly and posteriorly by the anterior and posterior thyrohyoid ligaments, respectively. The internal laryngeal nerve, the sensory branch of the superior laryngeal nerve, passed through this compartment and was heavily stained with simulated local anaesthetic. Resistance to the passage of the short bevel needle was provided by the lateral glossoepiglottic fold, not the thyrohyoid membrane as we had expected. Of 40 injections, 39 were deemed successful for a success rate of 97.5%. We conclude that this is a simple and highly successful technique for performing superior laryngeal nerve anaesthesia. PMID:7712327

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

    PubMed Central

    Grinsell, D.; Keating, C. P.

    2014-01-01

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

  3. Morphometry of endoneurial capillaries in diabetic sensory and autonomic neuropathy

    Microsoft Academic Search

    J. Bradley; P. K. Thomas; R. H. M. King; J. G. Llewelyn; J. R. Muddle; P. J. Watkins

    1990-01-01

    Summary  Nerve biopsies were obtained from 27 patients with diabetic neuropathy. All had a symmetric distal sensory and autonomic neuropathy or a purely sensory neuropathy. Mean age was 39.8 years (range 23–57 years). Two patients had Type 2 (non-insulin-dependent) diabetes mellitus and the remainder Type 1 (insulin-dependent) diabetes. Morphometric observations on endoneurial capillaries were compared with results from organ donor control

  4. Agonist-induced desensitization of adenylyl cyclase in Y1 adrenocortical tumor cells

    SciTech Connect

    Olson, M.F.; Tsao, J.; Pon, D.J.; Schimmer, B.P. (Banting and Best Department of Medical Research, University of Toronto, Ontario (Canada))

    1991-01-01

    Y1 adrenocortical tumor cells (Y1DS) and Y1 mutants resistant to ACTH-induced desensitization of adenylyl cyclase (Y1DR) were transfected with a gene encoding the mouse beta 2-adrenergic receptor (beta 2-AR). Transfectants expressed beta 2-ARs that were able to stimulate adenylyl cyclase activity and steroid biosynthesis. These transfectants were used to explore the basis for the DR mutation in Y1 cells. The authors demonstrate that beta-adrenergic agonists desensitize the adenylyl cyclase system in transfected Y1DS cells whereas transfected Y1DR cells are resistant to desensitization by beta-adrenergic agonists. The fate of the beta 2-ARs during desensitization was evaluated by photoaffinity labelling with (125I)iodocyanopindolol diazerine. Desensitization of Y1DS transfectants was accompanied by a modest loss in receptor density that was insufficient to account for the complete loss of responsiveness to beta-adrenergic agonists. The extent of receptor loss induced by beta-adrenergic agonists in Y1DR transfectants exceeded that in the Y1DS transfectants indicating that the mutation which protects Y1DR cells from agonist-induced desensitization is prior to receptor down-regulation in the desensitization pathway. From these results we infer that ACTH and isoproterenol desensitize adenylyl cyclase by a common pathway and that receptor loss is not a major component of the desensitization process in these cells.

  5. Multiple components of ganglion cell desensitization in response to prosthetic stimulation

    NASA Astrophysics Data System (ADS)

    Freeman, Daniel K.; Fried, Shelley I.

    2011-02-01

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

  6. Sensory testing of the human gastrointestinal tract

    PubMed Central

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

    2009-01-01

    The objective of this appraisal is to shed light on the various approaches to screen sensory information in the human gut. Understanding and characterization of sensory symptoms in gastrointestinal disorders is poor. Experimental methods allowing the investigator to control stimulus intensity and modality, as well as using validated methods for assessing sensory response have contributed to the understanding of pain mechanisms. Mechanical stimulation based on impedance planimetry allows direct recordings of luminal cross-sectional areas, and combined with ultrasound and magnetic resonance imaging, the contribution of different gut layers can be estimated. Electrical stimulation depolarizes free nerve endings non-selectively. Consequently, the stimulation paradigm (single, train, tetanic) influences the involved sensory nerves. Visual controlled electrical stimulation combines the probes with an endoscopic approach, which allows the investigator to inspect and obtain small biopsies from the stimulation site. Thermal stimulation (cold or warm) activates selectively mucosal receptors, and chemical substances such as acid and capsaicin (either alone or in combination) are used to evoke pain and sensitization. The possibility of multimodal (e.g. mechanical, electrical, thermal and chemical) stimulation in different gut segments has developed visceral pain research. The major advantage is involvement of distinctive receptors, various sensory nerves and different pain pathways mimicking clinical pain that favors investigation of central pain mechanisms involved in allodynia, hyperalgesia and referred pain. As impairment of descending control mechanisms partly underlies the pathogenesis in chronic pain, a cold pressor test that indirectly stimulates such control mechanisms can be added. Hence, the methods undoubtedly represent a major step forward in the future characterization and treatment of patients with various diseases of the gut, which provides knowledge to clinicians about the underlying symptoms and treatment of these patients. PMID:19132764

  7. Chronic dexamethasone treatment and its effects on sensory neuropeptides, pulpal injury reactions and reparative dentin

    Microsoft Academic Search

    A. M. Ferrari; M. R. Byers

    1996-01-01

    Initial sensory nerve reactions to dental injuries include terminal sprouting and intensified immunoreactivity for calcitonin gene-related peptide (CGRP) and substance P (SP); those reactions are reduced at 4 days after injury when rats are treated daily with dexamethasone (DEX) [17]. Here we have analyzed long-term effects of DEX (daily, 0.2 mg\\/kg) on wound healing, sensory nerve sprouting, and CGRP\\/SP intensity

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

    PubMed Central

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

    2014-01-01

    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

  9. Histochemical discrimination of fibers in regenerating rat infraorbital nerve

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  10. Damage and regeneration of peripheral nerves in advanced treated leprosy.

    PubMed

    Miko, T L; Le Maitre, C; Kinfu, Y

    1993-08-28

    Despite the rapidly falling prevalence of leprosy, the disability and handicap resulting from loss of protective sensation, due to irreversible nerve damage, will remain a huge medical problem for many years. To elucidate the location and consequences of permanent nerve damage in treated leprosy, a prospective study involving nine patients who underwent leg amputation was conducted. Full-length nerves dissected from amputated legs were studied with histological and immunohistochemical methods. Our main findings were that: in both lepromatous and tuberculoid leprosy nerve damage increased distally, culminating in total destruction of dermal nerves and sensory nerve endings; after the therapy-related decrease of inflammation large-scale nerve regeneration took place; and that regenerating axons persisted for decades and in tuberculoid leprosy they might reach the subcutaneous fat of the plantar skin. We conclude that nerve regeneration was blocked by fibrous replacement of the distal-most nerves and nerve endings, and that the theoretical basis of nerve grafting in leprosy is in need of further clarification. In some patients, autologous transplantation of skin flaps, probably irrespective of the duration of loss of sensation, might help in regaining protective sensation. PMID:8102668

  11. 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

    J. Ariëns Kappers

    1967-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

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

    E-print Network

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

    2002-01-01

    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 ...

  14. Femoral nerve dysfunction

    MedlinePLUS

    Neuropathy - femoral nerve; Femoral neuropathy ... Felice, KJ. Focal neuropathies of the femoral, obturator, lateral femoral cutaneous and other nerves of the thigh and pelvis. In: Bromberg MB, Smith ...

  15. Uncoupling of the beta-adrenergic receptor as a mechanism of in vitro neutrophil desensitization

    SciTech Connect

    Galant, S.P.; Britt, S.

    1984-02-01

    Human leukocytes have been useful in studying desensitization phenomena to beta-adrenergic agonists in a number of clinical conditions. In the present in vitro study the authors have explored the mechanism for beta-adrenergic desensitization and have compared conditions for homologous and heterologous desensitization, using the intact PMN model. PMN preincubated with isoproterenol (10/sup -4/M), washed thoroughly, then restimulated, desensitized rapidly so that within 10 min 80% of control isoproterenol-induced cyclic AMP stimulation is lost. Cells washed free of isoproterenol recover full responsiveness in 1 to 2 hr. The estimated isoproterenol desensitization EC/sub 50/ in cells washed and then restimulated is 1 x 10/sup -5/M, and EC/sub 50/ in unwashed cells that are restimulated is 9 x 10/sup -8/M. Rank-order potency studies of catecholamine desensitization show isoproterenol > epinephrine > norepinephrine, a beta-2 pattern. Isoproterenol-induced desensitization results in a small reduction in (/sup 3/H)DHA binding sites, which becomes statistically significant (p < 0.05) from control values at 1 hr (67% of control) and 3 hr (64%). In the absence of GTP, isoproterenol binding is characterized by an EC/sub 50/ of 6.6 +/- 2.6 x 10/sup -/(M, which is significantly different (p < 0.05) from the EC/sub 50/ of 38.1 +/- 9.1 x 10/sup -1/M found when cells are previously desensitized with isoproterenol for 10 min. GTP does not affect the EC/sub 50/ of desensitized cells. Finally, prolonged (3 hr) isoproterenol preincubation results in a small but significant (p < 0.05) loss of cyclic AMP responsiveness to histamine (67.7% +/- 11.7 of control) and PGE/sub 1/ (59.3% +/- 7.4), suggesting heterologous desensitization. These studies suggest that the human PMN is a suitable model to study both homologous and heterologous desensitization in vitro. 22 references. 6 figures. 3 tables.

  16. Autosomal recessive hereditary motor and sensory neuropathy with mental retardation, optic atrophy and pyramidal signs

    Microsoft Academic Search

    K D MacDermot; R W Walker

    1987-01-01

    A syndrome is described, consisting of severe neurogenic distal wasting, generalised muscle weakness, absent ankle reflexes, pyramidal signs, mental retardation, optic atrophy and retinal colloid bodies. A sural nerve biopsy from one case showed loss of nerve fibres suggesting the diagnosis of hereditary motor and sensory neuropathy. Progression of the disorder was very slow, all patients still being able to

  17. Sensory conduction from digit to palm and from palm to wrist in the carpal tunnel syndrome

    Microsoft Academic Search

    Fritz Buchthal; Annelise Rosenfalck

    1971-01-01

    In normal subjects the maximum and minimum conduction velocity along sensory nerve was the same from digit to palm and from palm to wrist. Severe slowing from palm to wrist in patients with the carpal tunnel syndrome was often associated with only slight slowing from digit to palm. The distal slowing is attributed to a reversible constriction of nerve fibres,

  18. Repair of peripheral nerve with vein wrapping*

    PubMed Central

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

    2014-01-01

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

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

    Microsoft Academic Search

    Zafar Nazir; Rehan Masood; Resham Rehman

    2004-01-01

    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

  20. Nerve conduction, tactile sensibility, and the electromyogram after suture or compression of peripheral nerve: a longitudinal study in man.

    PubMed Central

    Buchthal, F; Kühl, V

    1979-01-01

    In three patients sequential studies were performed of sensory and motor conduction after complete section and suture of the median nerve at the wrist and in one patient after partial section of the nerve. The sensory potential evoked by stimuli to digits III and I and recorded proximal to the suture line at the wrist appeared after a delay of three to four months, corresponding to a growth rate of 1.5-2.0 mm per day. From early in the course of regeneration the sensory potential was dispersed in 40 components. In the adult patient the cumulative amplitude increased for two years slowly and thereafter at a two times faster rate. Amplitude and tactile sensibility were normal after 40 months, but the sensory potential was still five times more dispersed than normal. The overall increase in the amplitude of the sensory potentials in children aged 10 and 12 years was three times faster than in adults. In the adults and in the children the maximum sensory conduction velocity was 10-25% of normal. It then increased at 3% per month during the first two years, and thereafter 10 times slower. Forty months after suture in the adults and 13-19 months after suture in the children the conduction velocity had reached 65-75% of normal. The pattern of discrete electrical activity during voluntary effort and the prolonged duration of motor unit potentials indicate persistent enlargement of the reinnervated motor units by peripheral sprouting. The sensory potential recovered five times faster after a compressive nerve lesion than after section and suture as seen in another patient with an affection of the ulnar nerve at the elbow. Normal tactile sensibility was attained 10 times faster than after section and suture. Maximum sensory and motor condution velocity recovered within one year from 60-70% to 80-90% of normal. PMID:448383

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

    ERIC Educational Resources Information Center

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

    2004-01-01

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

  2. The Relative Effectiveness of Systematic Desensitization and Hypnosis in Alleviating Test Anxiety in Community College Students.

    ERIC Educational Resources Information Center

    Simmons, Roy D., Jr.

    In order to determine whether or not systematic desensitization or hypnosis have any effect in alleviating the test anxiety of community college students, 30 Massasoit Community College student volunteers were matched for GPA and assigned to one of three treatment groups: (1) a systematic desensitization group, in which subjects listened to tape…

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

    PubMed Central

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

    2009-01-01

    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

  4. Too much experience: a desensitization bias in emotional perspective taking.

    PubMed

    Campbell, Troy; O'Brien, Ed; Van Boven, Leaf; Schwarz, Norbert; Ubel, Peter

    2014-02-01

    People often use their own feelings as a basis to predict others' feelings. For example, when trying to gauge how much someone else enjoys a television show, people might think "How much do I enjoy it?" and use this answer as basis for estimating others' reactions. Although personal experience (such as actually watching the show oneself) often improves empathic accuracy, we found that gaining too much experience can impair it. Five experiments highlight a desensitization bias in emotional perspective taking, with consequences for social prediction, social judgment, and social behavior. Participants who viewed thrilling or shocking images many times predicted first-time viewers would react less intensely (Experiments 1 and 2); participants who heard the same funny joke or annoying noise many times estimated less intense reactions of first-time listeners (Experiments 3 and 4); and further, participants were less likely to actually share good jokes and felt less bad about blasting others with annoying noise after they themselves became desensitized to those events (Experiments 3-5). These effects were mediated by participants' own attenuated reactions. Moreover, observers failed to anticipate this bias, believing that overexposed participants (i.e., repeatedly exposed participants who became desensitized) would make better decisions on their behalf (Experiment 5). Taken together, these findings reveal a novel paradox in emotional perspective taking: If people experience an evocative event many times, they may not become wiser companions but worse, unable to disentangle self-change from other-oriented thinking. Just as lacking exposure to others' experiences can create gaps in empathy and understanding, so may gaining too much. PMID:24467422

  5. Detection of hereditary motor sensory neuropathy type I in childhood

    Microsoft Academic Search

    T E Feasby; A F Hahn; C F Bolton; W F Brown; W J Koopman

    1992-01-01

    Clinical signs and slowed motor nerve conduction velocities were found in 17 of 36 children under 10 years of age who had one parent with hereditary motor sensory neuropathy type I (HMSN I). Four children had slowed conduction velocities at one year or less. Clinical signs were subtle and included pes planus, distal foot wasting, weakness of ankle eversion and

  6. Sensory biology: it takes Piezo2 to tango.

    PubMed

    Vásquez, Valeria; Scherrer, Gregory; Goodman, Miriam B

    2014-06-16

    A trio of papers has resolved an outstanding controversy regarding the function of Merkel cells and their afferent nerve fiber partners. Merkel cells sense mechanical stimuli (through Piezo2), fire action potentials, and are sufficient to activate downstream sensory neurons. PMID:24937283

  7. Sexual violence: psychiatric healing with eye movement reprocessing and desensitization.

    PubMed

    Posmontier, Bobbie; Dovydaitis, Tiffany; Lipman, Kenneth

    2010-08-01

    Sexual violence, which affects one in three women worldwide, can result in significant psychiatric morbidity and suicide. Eye movement desensitization and reprocessing (EMDR) offers health care providers the option of a brief psychiatric intervention that can result in psychiatric healing in as few as four sessions. Because health care providers often hear stories of sexual violence from their patients, they are in an ideal position to make recommendations for treatment. The purpose of this article is to introduce health care providers to the technique of EMDR, review safety and appropriateness, and discuss clinical and research implications. PMID:20623397

  8. Role of hepatic, intrahepatic and hepatoenteral nerves in the regulation of carbohydrate metabolism and hemodynamics of the liver and intestine.

    PubMed

    Jungermann, K; Stümpel, F

    1999-06-01

    The liver as an effector organ is the major glucose reservoir, the utilization of which is controlled by hormones but also by hepatic sympathetic nerves. The liver as a sensory organ detects a glucose concentration gradient between the hepatic artery and the portal vein by intrahepatic sensory-effector nerves, generating a cholinergic signal for an insulin-dependent net hepatic glucose uptake. The liver senses the insulin concentration by hepatoenteral sensory-effector nerves, generating a cholinergic signal to increase glucose absorption in the intestine and thus its coordinated utilization in liver, muscle and adipose tissue. PMID:10431702

  9. Chronic inflammatory pure sensory polyradiculoneuropathy: a rare CIDP variant with unusual electrophysiology.

    PubMed

    Rajabally, Yusuf A; Wong, Siew L

    2012-03-01

    We describe a patient presenting with progressive upper limb numbness and sensory ataxia of the 4 limbs. Motor nerve conduction studies were completely normal. Sensory electrophysiology showed reduced/absent upper limb sensory action potentials (SAPs). In the lower limbs, SAPs were mostly normal. Sensory conduction velocities were normal. Forearm sensory conduction blocks were present for both median nerves on antidromic testing. The maximal recordable sural SAP was preserved in comparison to maximal recordable radial SAP, consistent with an "abnormal radial normal sural" pattern. Somatosensory evoked potentials were unrecordable for tibial and median nerves. Cerebrospinal fluid protein was raised (0.99 g/L). The patient worsened on oral corticosteroids but subsequently made substantial functional recovery on intravenous immunoglobulins. This case is different to those previously reported of sensory chronic inflammatory demyelinating polyradiculoneuropathy, given its exclusive sensory electrophysiologic presentation, presence of predominant upper limb reduced sensory amplitudes, and detection of sensory conduction blocks. These electrophysiologic features were of paramount importance in establishing diagnosis and effective therapy. PMID:22538310

  10. Immunity to Nerve Growth Factor Prevents Afferent Plasticity Following Urinary Bladder Hypertrophy

    Microsoft Academic Search

    William D. Steers; Douglas J. Creedon; Jeremy B. Tuttle

    1996-01-01

    PurposeThe goal of this investigation was to examine the effect of immunity to nerve growth factor (NGF) on alterations in sensory nerves from the urinary bladder in the dorsal root ganglia (DRG) and their projections to the L6\\/S1 spinal cord following urethral obstruction in the rat.

  11. Determination of the distribution of nerve conduction velocities in chain saw operators

    Microsoft Academic Search

    S Araki; K Yokoyama; H Aono; K Murata

    1988-01-01

    By measuring the distribution of conduction velocities (DCV) in sensory fibres of the median nerve, the effects of local vibration on all faster and slower large myelinated nerve fibres were examined in 10 male chain saw operators (three operators had frequent attacks of white finger; the attacks were only occasional in four and negative in three). All parameters of DCV,

  12. Normal nerve conduction velocity and vibrotactile perception thresholds in computer users

    Microsoft Academic Search

    Helena Sandén; Micael Edblom; Anna Ekman; Artur Tenenbaum; B Gunnar Wallin; Mats Hagberg

    2005-01-01

    Objectives: A literature report described significantly raised vibration threshold within the territory of the median nerve in a group of office workers and concluded that the results indicated a change in the function of large sensory fibres. The aim of the present cross-sectional study was to compare vibrotactile perception thresholds and nerve conduction measurements in the upper extremity between female

  13. Increase in NGF content and nerve fiber sprouting in human allergic contact eczema

    Microsoft Academic Search

    Ilka Kinkelin; Sandra Mötzing; Martin Koltzenburg; Eva-Bettina Bröcker

    2000-01-01

    There is increasing evidence for an intimate interaction of the skin and the nervous system. As known from animal studies, nerve growth factor (NGF) is essential for the innervation density and functional properties of sensory neurons of the skin during embryogenesis and in adulthood, and possibly during cutaneous inflammation. This study examined NGF content and sprouting of nerves during the

  14. Electrophysiological findings in entrapment of the median nerve at wrist and elbow

    Microsoft Academic Search

    Fritz Buchthal; Annelise Rosenfalck; Werner Trojaborg

    1974-01-01

    In 117 consecutive patients with carpal tunnel syndrome and 11 patients with a compression syndrome of the median nerve at elbow, motor and sensory conduction along the median and ulnar nerves and quantitative electromyography were compared with findings in 190 normal controls of the same age. In 25% of patients with carpal tunnel syndrome in whom motor conduction and EMG

  15. Nerve Conduction Velocity in Relationship to the Severity of Renal Disease

    Microsoft Academic Search

    C. R. Blagg; F. Kemble; D. Taverner

    1968-01-01

    Summary Raised levels of blood urea and serum creatinine in patients with chronic renal failure were associated with reduced sensory and motor nerve fibre conduction velocity. Similarly raised levels of blood urea and serum creatinine were associated with increased distal sensory and motor conduction latencies.Copyright © 1968 S. Karger AG, Basel

  16. A comparative study of three cranial sensory ganglia projecting into the oral cavity: in situ hybridization analyses of neurotrophin receptors and thermosensitive cation channels

    Microsoft Academic Search

    Ichiro Matsumoto; Yasufumi Emori; Yuzo Ninomiya; Keiko Abe

    2001-01-01

    Peripheral cranial sensory nerves projecting into the oral cavity receive food intake stimuli and transmit sensory signals to the central nervous system. To describe and compare the features of the cranial sensory ganglia that innervate the oral cavity, i.e., the trigeminal, petrosal, and geniculate ganglia (TG, PG, and GG, respectively), in situ hybridization was conducted using riboprobes for neurotrophin receptors

  17. Metathoracic neurons integrating intersegmental sensory information in the locust.

    PubMed

    Matheson, Tom

    2002-03-01

    This paper describes the morphology and physiology of five types of local interneurons and three types of ascending intersegmental interneurons in the locust metathoracic ganglion that are points of convergence of sensory information from the wings. Four types of spiking local interneurons are members of a population with somata at the ventral midline. They are depolarised by stimulation of a metathoracic wing nerve, suggesting that they encode a sensory representation of this appendage. Some are also depolarised with short latencies following stimulation of a mesothoracic wing nerve, indicating that they collate intersegmental as well as local information. All the local interneurons have branches in the anterior ventral association centre or around the roots of the nerve that carries wing sensory neurons. This distinguishes them from other interneurons in the population. A fifth type of local interneuron that has unusual bilateral branching and is not a member of this population is described for the first time. The ascending interneurons are members of three populations. Neurons of each population have a characteristic pattern of responses to stimulation of the mesothoracic or metathoracic wing nerves, and some respond to tactile stimulation or movements of a hind leg. These latter interneurons thus collate information from both wings and legs. All three types of intersegmental interneurons have branches in the anterior ventral association centre or around the roots of the wing nerve. The responses of the interneurons described here shed new light on both local and intersegmental network function in this model system. PMID:11835184

  18. Sensory Guillain-Barré syndrome: A case report

    PubMed Central

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

    2014-01-01

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

  19. Schwann Cells Seeded in Acellular Nerve Grafts Improve Functional Recovery

    PubMed Central

    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

    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

  20. Immunological mechanisms for desensitization and tolerance in food allergy1

    PubMed Central

    Rachid, Rima; Umetsu, Dale T.

    2013-01-01

    Food allergy is a major public health concern in westernized countries, estimated to affect 5% of children and 3-4 % of adults. Allergen specific immunotherapy for food allergy is currently being actively evaluated, but is still experimental. The optimal protocol, in terms of the route of administration of the food, target maintenance dose, duration of maintenance therapy and the optimal patient for these procedures are still being worked out. The mechanisms underlying successful food desensitization are also unclear, in part because there is no standard immunotherapy protocol. The mechanisms involved however, may include mast cell and basophil suppression, development of food-specific IgG4 antibodies, reduction in the food specific IgE/IgG4 ratio, up-regulation and expansion of natural or inducible regulatory T cells, a skewing from a Th2 to a Th1 profile and the development of anergy and/or deletion in antigen specific cells. Additional studies are required to elucidate and understand these mechanisms by which desensitization and tolerance are achieved, and which may reveal valuable biomarkers for evaluating and following food allergic patients on immunotherapy. PMID:22821087

  1. Central motor conduction time by magnetic stimulation of the cortex and peripheral nerve conduction follow-up studies in Friedreich's ataxia

    Microsoft Academic Search

    A Cruz-Mart??nez; F Palau

    1997-01-01

    A follow-up clinical study, peripheral motor and sensory nerve conduction velocities and central motor conduction by magnetic stimulation of the cortex were performed in 13 patients with classical Friedreich's ataxia (FA) phenotype, for a period of 9–12 years. Clinical worsening was unrelated to peripheral nerve abnormalities. The amplitude of the nerve action potentials and delayed conduction velocity remained unchanged for

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

    PubMed Central

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

    2014-01-01

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

  3. Axonal transcription factors signal retrogradely in lesioned peripheral nerve

    E-print Network

    Pilpel, Yitzhak

    ; neuronal injury; STAT Introduction Regeneration of lesioned peripheral nerves is dependent neurons. The involve- ment of importins in retrograde transport suggests that transcription factors (TFs, and is transported retrogradely with dynein and importin a5 to modulate survival of peripheral sensory neurons after

  4. Central projections of the saccular and utricular nerves in macaques

    Microsoft Academic Search

    Shawn D. Newlands; Jeffrey T. Vrabec; Ian M. Purcell; C. Matthew Stewart; Brett E. Zimmerman; Adrian A. Perachio

    2003-01-01

    The central projections of the utricular and saccular nerve in macaques were examined using transganglionic labeling of vestibular afferent neurons. In these experiments, biotinylated dex- tran amine was injected directly into the saccular or utricular neuroepithelium of fascicularis (Macaca fascicularis) or rhesus (Macaca mulatta) monkeys. Two to 5 weeks later, the animals were killed and the peripheral vestibular sensory organs,

  5. An Evaluation of the Cutaneous Distribution After Obturator Nerve Block

    Microsoft Academic Search

    Florence Vial; Denis Jochum; Dioukamaly Macalou; Michel Heck; Pascal Meuret; Marc Braun; Marie-Claire Laxenaire

    2002-01-01

    decreased by 77% 17% (mean sd). In 17 patients (57%), there was no cutaneous contribution of the obtura- tor nerve. The remaining 7 patients (23%) had an area of hypoesthesia (cold sensation was blunt but still present) on the superior part of the popliteal fossa, and the other 6 (20%) had sensory deficit located at the medial aspect of the

  6. The dynamic response of warm units in human skin nerves

    Microsoft Academic Search

    F. Konietzny; H. Hensel

    1977-01-01

    Electrophysiological recordings were made from 12 specific warm receptors in the sensory nerves of human hairy skin. In all cases examined, single warm fibers were spontaneously active at normal skin temperature from about 32°C upwards, while touch, stretching, vibration or pricking the skin did not elicit any response within the receptive fields of warm units. Moderate warming of the skin

  7. Nerve biopsy findings in two cases of Tangier disease

    Microsoft Academic Search

    R. S. Kocen; R. H. M. King; P. K. Thomas; L. F. Haas

    1973-01-01

    Nerve biopsy findings are recorded for two previously reported patients with Tangier disease (hereditary high density lipoprotein deficiency). Both cases showed unusual clinical manifestations in comparison with other reported cases. The neurological disorder, symptoms from which began in the third decade, gave rise to a lower motor neuron deficit of unique distribution, which was accompanied by progressive sensory impairment limited

  8. Iatrogenic nerve injuries.

    PubMed

    Kretschmer, Thomas; Heinen, Christian W; Antoniadis, Gregor; Richter, Hans-Peter; König, Ralph W

    2009-01-01

    As long as humans have been medically treated, unfortunate cases of inadvertent injury to nerves afflicted by the therapist have occurred. Most microsurgically treated iatrogenic nerve injuries occur directly during an operation. Certain nerves are at a higher risk than others, and certain procedures and regions of the body are more prone to sustaining nerve injury. A high degree of insecurity regarding the proper measures to take can be observed among medical practitioners. A major limiting factor in successful treatment is delayed referral for evaluation and reconstructive surgery. This article on iatrogenic nerve injuries intends to focus on relevant aspects of management from a nerve surgeon's perspective. PMID:19064181

  9. Reconstruction of upper-extremity peripheral-nerve injuries with ePTFE conduits.

    PubMed

    Stanec, S; Stanec, Z

    1998-05-01

    This reported investigation was designed to determine the role of a new synthetic conduit-expanded polytetrafluoroethylene (ePTFE) tube--in clinical repair of median and ulnar nerves in the upper extremities. The main goals of this study were: to determine the effectiveness of the ePTFE conduit in clinical nerve reconstruction; to evaluate the potential of this technique in reconstruction of various nerve gaps (1.5 to 6 cm); and to analyze the results of repair with the ePTFE tube regarding different mechanisms of injury. Forty-three patients were evaluated. They had upper-extremity peripheral-nerve injuries (21 injuries to the median nerve, and 22 ulnar nerve injuries) located at the various levels of the upper extremities. All surgical procedures described in the study were secondary reconstructions, and the average delay from injury to repair was 4.2 months. With regard to the nerve-gap lengths, patients were categorized in two groups. Group 1 (gaps from 1.5 to 4 cm) included 28 patients (17 median nerve injuries and 11 ulnar nerve injuries), and Group 2 (gaps from 4.1 to 6 cm) comprised 15 patients (4 median nerve injuries and 11 ulnar nerve injuries). Results showed that 78.6 percent of patients from Group 1 demonstrated functional motor and sensory recovery, while reconstruction of only 13.3 percent of peripheral nerves from Group 2 resulted in useful reinnervation. According to published results, ePTFE conduit is a reliable and successful surgical procedure for nerve repair in reconstruction of nerve gaps up to 4 cm between the ends of median and ulnar nerves in various levels of the upper extremity. Because of its properties, ePTFE conduit has the advantages of promoting better nerve regeneration, compared to other synthetic tubes, especially in reconstruction of proximal nerve injuries, larger nerve gaps, and in cases with unfavorable mechanisms of nerve injury. PMID:9618088

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

    PubMed

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

    2007-05-01

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

  11. Characterization of human 5-HT4(d) receptor desensitization in CHO cells

    PubMed Central

    Mialet, Jeanne; Fischmeister, Rodolphe; Lezoualc'h, Frank

    2003-01-01

    Serotonin 5-HT4 receptor isoforms differ in their C-terminal tail and yet little is known about their regulation. In this study, we investigated the desensitization of two human 5-HT4 receptors stably expressed in CHO cells, with a special emphasis on the h5-HT4(d) isoform. Exposure of h5-HT4(d) and h5-HT4(e) receptors to 1 ?M 5-HT induced a rapid desensitization of the adenylyl cyclase response. The h5-HT4(d) receptor desensitized with a faster rate (t1/2<5 min) than the h5-HT4(e) receptor (t1/2=15 min) and after 10 min 5-HT treatment cAMP production was reduced by ?70%. 5-HT-induced h5-HT4(d) receptor desensitization was mimicked by 8-Bromo-cAMP, a cAMP analogue, and was inhibited by [n-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulphonamide, 2HCl] (H-89), an inhibitor of cAMP-dependent protein kinase (PKA). Inhibitors of endocytosis (sucrose, 0.45 M and concanavaline A, 0.25 mg ml?1) partially reversed the h5-HT4(d) receptor desensitization process. Given the prominent role of PKA in agonist-induced desensitization, we mutated the four putative PKA phosphorylation sites present in the third intracellular loop (Ser242, Thr253, Thr255) and the C terminal tail (Ser338) of the h5-HT4(d) receptor. Surprisingly, mutated receptors in which either one or all four putative phosphorylation sites were substituted to alanine did not impair receptor desensitization suggesting that PKA might act on nonconsensus sites. Altogether, our data demonstrate that the C-terminal tail of h5-HT4 receptors may influence the rate of agonist-induced desensitization and we provide evidence for a major role of PKA in h5-HT4(d) receptor desensitization. PMID:12569069

  12. Effects of polysialic acid on sensory innervation of the cornea.

    PubMed

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

    2015-02-15

    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

  13. Deficiency in monocarboxylate transporter 1 (MCT1) in mice delays regeneration of peripheral nerves following sciatic nerve crush.

    PubMed

    Morrison, Brett M; Tsingalia, Akivaga; Vidensky, Svetlana; Lee, Youngjin; Jin, Lin; Farah, Mohamed H; Lengacher, Sylvain; Magistretti, Pierre J; Pellerin, Luc; Rothstein, Jeffrey D

    2015-01-01

    Peripheral nerve regeneration following injury occurs spontaneously, but many of the processes require metabolic energy. The mechanism of energy supply to axons has not previously been determined. In the central nervous system, monocarboxylate transporter 1 (MCT1), expressed in oligodendroglia, is critical for supplying lactate or other energy metabolites to axons. In the current study, MCT1 is shown to localize within the peripheral nervous system to perineurial cells, dorsal root ganglion neurons, and Schwann cells by MCT1 immunofluorescence in wild-type mice and tdTomato fluorescence in MCT1 BAC reporter mice. To investigate whether MCT1 is necessary for peripheral nerve regeneration, sciatic nerves of MCT1 heterozygous null mice are crushed and peripheral nerve regeneration was quantified electrophysiologically and anatomically. Compound muscle action potential (CMAP) recovery is delayed from a median of 21 days in wild-type mice to greater than 38 days in MCT1 heterozygote null mice. In fact, half of the MCT1 heterozygote null mice have no recovery of CMAP at 42 days, while all of the wild-type mice recovered. In addition, muscle fibers remain 40% more atrophic and neuromuscular junctions 40% more denervated at 42 days post-crush in the MCT1 heterozygote null mice than wild-type mice. The delay in nerve regeneration is not only in motor axons, as the number of regenerated axons in the sural sensory nerve of MCT1 heterozygote null mice at 4 weeks and tibial mixed sensory and motor nerve at 3 weeks is also significantly reduced compared to wild-type mice. This delay in regeneration may be partly due to failed Schwann cell function, as there is reduced early phagocytosis of myelin debris and remyelination of axon segments. These data for the first time demonstrate that MCT1 is critical for regeneration of both sensory and motor axons in mice following sciatic nerve crush. PMID:25447940

  14. Peripheral nerve regeneration and neurotrophic factors

    PubMed Central

    TERENGHI, GIORGIO

    1999-01-01

    The role of neurotrophic factors in the maintenance and survival of peripheral neuronal cells has been the subject of numerous studies. Administration of exogenous neurotrophic factors after nerve injury has been shown to mimic the effect of target organ-derived trophic factors on neuronal cells. After axotomy and during peripheral nerve regeneration, the neurotrophins NGF, NT-3 and BDNF show a well defined and selective beneficial effect on the survival and phenotypic expression of primary sensory neurons in dorsal root ganglia and of motoneurons in spinal cord. Other neurotrophic factors such as CNTF, GDNF and LIF also exert a variety of actions on neuronal cells, which appear to overlap and complement those of the neurotrophins. In addition, there is an indirect contribution of GGF to nerve regeneration. GGF is produced by neurons and stimulates proliferation of Schwann cells, underlining the close interaction between neuronal and glial cells during peripheral nerve regeneration. Different possibilities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. The studies reviewed in this article show the therapeutic potential of neurotrophic factors for the treatment of peripheral nerve injury and for neuropathies. PMID:10227662

  15. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.

    PubMed

    Ince, Hülya; Ta?demir, Haydar Ali; Aydin, Murat; Ozyürek, Hamit; Tilki, Hacer Erdem

    2015-07-01

    The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test. PMID:25342307

  16. Hereditary sensory ataxic neuropathy associated with proximal muscle weakness in the lower extremities.

    PubMed

    Murakami, Tatsufumi; Fukai, Yuta; Rikimaru, Mitsue; Henmi, Shoji; Ohsawa, Yutaka; Sunada, Yoshihide

    2010-04-15

    We describe three patients from the same family with hereditary sensory ataxic neuropathy followed by proximal muscle weakness in the lower extremities. Sensory ataxic gait began as an initial symptom when patients were in their 50s. Mild proximal weakness in the lower extremities appeared several years later. Serum creatine kinase was mildly elevated. Nerve conduction studies revealed sensory dominant axonal neuropathy, and short sensory evoked potentials showed involvement of the sensory nerve axon, dorsal root ganglia and posterior funiculus of the spinal cord. Needle electromyography showed fibrillation, positive sharp waves, and multiple giant motor unit potentials, suggesting the involvement of anterior horn motor neurons or the anterior root. Autosomal recessive inheritance was considered, because of consanguinity. The disorder described here may be a new clinical entity with unique clinical manifestations. PMID:20083254

  17. Engineering a multimodal nerve conduit for repair of injured peripheral nerve.

    PubMed

    Quigley, A F; Bulluss, K J; Kyratzis, I L B; Gilmore, K; Mysore, T; Schirmer, K S U; Kennedy, E L; O'Shea, M; Truong, Y B; Edwards, S L; Peeters, G; Herwig, P; Razal, J M; Campbell, T E; Lowes, K N; Higgins, M J; Moulton, S E; Murphy, M A; Cook, M J; Clark, G M; Wallace, G G; Kapsa, R M I

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate 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. PMID:23283383

  18. Engineering a multimodal nerve conduit for repair of injured peripheral nerve

    NASA Astrophysics Data System (ADS)

    Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate 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.

  19. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  20. Ulnar nerve damage (image)

    MedlinePLUS

    ... arm. The nerve is commonly injured at the elbow because of elbow fracture or dislocation. The ulnar nerve is near ... surface of the body where it crosses the elbow, so prolonged pressure on the elbow or entrapment ...

  1. Anterograde transport of horseradish-peroxidase conjugated isolectin B4 from Griffonia simplicifolia I in spinal primary sensory neurons of the rat

    Microsoft Academic Search

    H. Fredrik Wang; Brita Robertson; Gunnar Grant

    1998-01-01

    Anterograde transport of the isolectin B4 from Griffonia simplicifolia I (B4) conjugated to horseradish peroxidase (HRP) was investigated in rat somatic and visceral primary sensory neurons at different spinal levels. Injection of B4-HRP into the L5 dorsal root ganglion (DRG) resulted in labelling in the sural nerve, but not in the gastrocnemius nerves. Free nerve endings and lanceolate-like nerve endings

  2. Engineering Peripheral Nerve Repair

    PubMed Central

    Marquardt, Laura; Sakiyama-Elbert, Shelly E.

    2013-01-01

    Current approaches for treating peripheral nerve injury have resulted in promising, yet insufficient functional recovery compared to the clinical standard of care, autologous nerve grafts. In order to design a construct that can match the regenerative potential of the autograft, all facets of nerve tissue must be incorporated in a combinatorial therapy. Engineered biomaterial scaffolds in the future will have to promote enhanced regeneration and appropriate reinnervation by targeting the highly sensitive response of regenerating nerves to their surrounding microenvironment. PMID:23790730

  3. Cranial Nerves Model

    NSDL National Science Digital Library

    Juliann Garza (University of Texas-Pan American Physician Assistant Studies)

    2010-08-16

    Lesson is designed to introduce students to cranial nerves through the use of an introductory lecture. Students will then create a three-dimensional model of the cranial nerves. An information sheet will accompany the model in order to help students learn crucial aspects of the cranial nerves.

  4. Optic Nerve Imaging

    MedlinePLUS

    ... machines can help monitor and detect loss of optic nerve fibers. The Heidelberg Retina Tomograph (HRT) is a special ... can directly measure the thickness of the nerve fiber layer and create a three dimensional representation of the optic nerve. Last reviewed on May 02, 2012 Was ...

  5. A specific substance P antagonist blocks smooth muscle contractions induced by non-cholinergic, non-adrenergic nerve stimulation

    Microsoft Academic Search

    S. Leander; R. Hĺkanson; S. Rosell; K. Folkers; F. Sundler; K. Tornqvist

    1981-01-01

    Nerve fibres containing substance P (SP) are widely distributed in the body1-3 and seem to innervate autonomic ganglia, blood vessels, epithelial structures and smooth muscle. SP stimulates secretion from exocrine glands, causes vasodilation and contracts non-vascular smooth muscle4. The presence of SP in primary sensory neurones has lent support to the view that it is associated with sensory nerve conduction,

  6. Neurology: an ancient sensory organ in crocodilians.

    PubMed

    Soares, Daphne

    2002-05-16

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

  7. Rational-Emotive Therapy versus Systematic Desensitization: A Comment on Moleski and Tosi.

    ERIC Educational Resources Information Center

    Atkinson, Leslie

    1983-01-01

    Questioned the statistical analyses of the Moleski and Tosi investigation of rational-emotive therapy versus systematic desensitization. Suggested means for lowering the error rate through a more efficient experimental design. Recommended a reanalysis of the original data. (LLL)

  8. Small Nerve Fiber Pathology in Critical Illness

    PubMed Central

    Latronico, Nicola; Filosto, Massimiliano; Fagoni, Nazzareno; Gheza, Laura; Guarneri, Bruno; Todeschini, Alice; Lombardi, Raffaella; Padovani, Alessandro; Lauria, Giuseppe

    2013-01-01

    Background Degeneration of intraepidermal nerve fibers (IENF) is a hallmark of small fiber neuropathy of different etiology, whose clinical picture is dominated by neuropathic pain. It is unknown if critical illness can affect IENF. Methods We enrolled 14 adult neurocritical care patients with prolonged intensive care unit (ICU) stay and artificial ventilation (? 3 days), and no previous history or risk factors for neuromuscular disease. All patients underwent neurological examination including evaluation of consciousness, sensory functions, muscle strength, nerve conduction study and needle electromyography, autonomic dysfunction using the finger wrinkling test, and skin biopsy for quantification of IENF and sweat gland innervation density during ICU stay and at follow-up visit. Development of infection, sepsis and multiple organ failure was recorded throughout the ICU stay. Results Of the 14 patients recruited, 13 (93%) had infections, sepsis or multiple organ failure. All had severe and non-length dependent loss of IENF. Sweat gland innervation was reduced in all except one patient. Of the 7 patients available for follow-up visit, three complained of diffuse sensory loss and burning pain, and another three showed clinical dysautonomia. Conclusions Small fiber pathology can develop in the acute phase of critical illness and may explain chronic sensory impairment and pain in neurocritical care survivors. Its impact on long term disability warrants further studies involving also non-neurologic critical care patients. PMID:24098716

  9. Signaling by sensory receptors.

    PubMed

    Julius, David; Nathans, Jeremy

    2012-01-01

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

  10. Variations of glycogen: II. Following deafferentation of Knollenorgan sensory cells, a lateral line electroreceptor of mormyrid fish

    Microsoft Academic Search

    B. A. Djebar; J.-P. Denizot

    1995-01-01

    The effect of deafferentation on glycogen metabolism was studied in the sensory cells of mormyrid Knollenorgan electroreceptors. Glycogen was visualized in the sensory cells after fixation in a solution containing potassium ferricyanide and osmium tetroxide. The density variations of glycogen were evaluated by a morphometric method. Sectioning of the afferent nerve results in a cessation of the spontaneous receptor cells

  11. Chaetotaxy and ultrastructure of sensory receptors in the cercaria of a species of Allassogonoporus Olivier, 1938 (Digenea:Lecithodendriidae)

    Microsoft Academic Search

    T. Bogéa; J. N. Caira

    2001-01-01

    A standard procedure that combines chaetotaxic, ultrastructural and neuromorphological observations has recently provided a new perspective to the study of cercarial sensory systems. In the present work, we aimed to extend the use of this combination of techniques to investigate the chaetotaxy of Allassogonoporus sp. in conjunction with the ultrastructure of sensory receptors and neuromorphology. Five nerve regions were distinguished.

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

    Microsoft Academic Search

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

    2004-01-01

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

  13. Opposite effects of KCTD subunit domains on GABA(B) receptor-mediated desensitization.

    PubMed

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

    2012-11-16

    GABA(B) receptors assemble from principle and auxiliary subunits. The principle subunits GABA(B1) and GABA(B2) form functional heteromeric GABA(B(1,2)) receptors that associate with homotetramers of auxiliary KCTD8, -12, -12b, or -16 (named after their K(+) channel tetramerization domain) subunits. These auxiliary subunits constitute receptor subtypes with distinct functional properties. KCTD12 and -12b generate desensitizing receptor responses while KCTD8 and -16 generate largely non-desensitizing receptor responses. The structural elements of the KCTDs underlying these differences in desensitization are unknown. KCTDs are modular proteins comprising a T1 tetramerization domain, which binds to GABA(B2), and a H1 homology domain. KCTD8 and -16 contain an additional C-terminal H2 homology domain that is not sequence-related to the H1 domains. No functions are known for the H1 and H2 domains. Here we addressed which domains and sequence motifs in KCTD proteins regulate desensitization of the receptor response. We found that the H1 domains in KCTD12 and -12b mediate desensitization through a particular sequence motif, T/NFLEQ, which is not present in the H1 domains of KCTD8 and -16. In addition, the H2 domains in KCTD8 and -16 inhibit desensitization when expressed C-terminal to the H1 domains but not when expressed as a separate protein in trans. Intriguingly, the inhibitory effect of the H2 domain is sequence-independent, suggesting that the H2 domain sterically hinders desensitization by the H1 domain. Evolutionary analysis supports that KCTD12 and -12b evolved desensitizing properties by liberating their H1 domains from antagonistic H2 domains and acquisition of the T/NFLEQ motif. PMID:23035119

  14. Mutations in the channel domain alter desensitization of a neuronal nicotinic receptor

    Microsoft Academic Search

    F. Revah; D. Bertrand; J.-L. Galzi; A. Devillers-Thiéry; C. Mulle; N. Hussy; S. Bertrand; M. Ballivet; J.-P. Changeux

    1991-01-01

    A VARIETY of ligand-gated ion channels undergo a fast activation process after the rapid application of agonist and also a slower transition towards desensitized or inactivated closed channel states when exposure to agonist is prolonged1-5. Desensitization involves at least two distinct closed states in the acetylcholine receptor, each with an affinity for agonists higher than those of the resting or

  15. Desensitization of the bradykinin-induced rise in intracellular free calcium in cultured endothelial cells

    Microsoft Academic Search

    Andreas Liiekhoff; Roland Zeh; Rudi Busse

    1988-01-01

    We studied the cellular mechanism involved in the desensitization of cultured endothelial cells to bradykinin. Bradykinin (10 nmol\\/l) evoked a rise in the intracellular free calcium concentration ([Cai2+]), measured with the fluorescent probe indo-1, from 137±30 (±SEM) to 623±101 nmol\\/l. Cells were desensitized to bradykinin by repetitive stimulation with the peptide over 10 min, after which they no longer responded

  16. Neuronal Injury Increases Retrograde Axonal Transport of the Neurotrophins to Spinal Sensory Neurons and Motor Neurons via Multiple Receptor Mechanisms

    Microsoft Academic Search

    Rory Curtis; James R. Tonra; Jennifer L. Stark; Krystyna M. Adryan; John S. Park; Kenneth D. Cliffer; Ronald M. Lindsay; Peter S. DiStefano

    1998-01-01

    We investigated the retrograde axonal transport of125I-labeled neurotrophins (NGF, BDNF, NT-3, and NT-4) from the sciatic nerve to dorsal root ganglion (DRG) sensory neurons and spinal motor neurons in normal rats or after neuronal injury. DRG neurons showed increased transport of all neurotrophins following crush injury to the sciatic nerve. This was maximal 1 day after sciatic nerve crush and

  17. Chinese Medicine in Diabetic Peripheral Neuropathy: Experimental Research on Nerve Repair and Regeneration

    PubMed Central

    Piao, Yuanlin; Liang, Xiaochun

    2012-01-01

    Diabetic peripheral neuropathy (DPN) is one of the most common complications of chronic diabetes mellitus. Pathological characteristics of DPN include axonal atrophy, nerve demyelination, and delayed regeneration of peripheral sensory nerve fibers. The goal of treatment in DPN is not only to ameliorate neurological symptoms but also to slow or reverse the underlying neurodegenerative process. Schwann cells and neurotrophic factors play important roles in the repair and regeneration of peripheral nerves. The present paper reviews current studies and evidence regarding the neurological effects of traditional Chinese medicine, with an emphasis on recent developments in the area of nerve repair and regeneration in DPN. PMID:22927874

  18. Biological and Electrophysiologic Effects of Poly(3,4-ethylenedioxythiophene) on Regenerating Peripheral Nerve Fibers

    PubMed Central

    Baghmanli, Ziya; Sugg, Kristoffer B.; Wei, Benjamin; Shim, Bong S.; Martin, David C.; Cederna, Paul S.; Urbanchek, Melanie G.

    2014-01-01

    Background Uninjured peripheral nerves in upper-limb amputees represent attractive sites for connectivity with neuroprostheses because their predictable internal topography allows for precise sorting of motor and sensory signals. The inclusion of poly(3,4-ethylenedioxythiophene) reduces impedance and improves charge transfer at the biotic-abiotic interface. This study evaluates the in vivo performance of poly(3,4-ethylenedioxythiophene)–coated interpositional decellularized nerve grafts across a critical nerve conduction gap, and examines the long-term effects of two different poly(3,4-ethylenedioxythiophene) formulations on regenerating peripheral nerve fibers. Methods In 48 rats, a 15-mm gap in the common peroneal nerve was repaired using a nerve graft of equivalent length, including (1) decellularized nerve chemically polymerized with poly(3,4-ethylenedioxythiophene) (dry); (2) decellularized nerve electrochemically polymerized with poly(3,4-ethylenedioxythiophene) (wet); (3) intact nerve; (4) autogenous nerve graft; (5) decellularized nerve alone; and (6) unrepaired nerve gap controls. All groups underwent electrophysiologic characterization at 3 months, and nerves were harvested for histomorphometric analysis. Results Conduction velocity was significantly faster in the dry poly(3,4-ethylenedioxythiophene) group compared with the sham, decellularized nerve, and wet poly(3,4-ethylenedioxythiophene) groups. Maximum specific force for the dry poly(3,4-ethylenedioxythiophene) group was more similar to sham than were decellularized nerve controls. Evident neural regeneration was demonstrated in both dry and wet poly(3,4-ethylenedioxythiophene) groups by the presence of normal regenerating axons on histologic cross-section. Conclusions Both poly(3,4-ethylenedioxythiophene) formulations were compatible with peripheral nerve regeneration at 3 months. This study supports poly(3,4-ethylenedioxythiophene) as a promising adjunct for peripheral nerve interfaces for prosthetic control and other biomedical applications because of its recognized ionic-to-electronic coupling potential. PMID:23897336

  19. [Sensory Systems of Infants.

    ERIC Educational Resources Information Center

    Zero To Three, 1993

    1993-01-01

    This newsletter contains six articles: (1) "Early Flavor Experiences: When Do They Start?" Julie A. Mennella and Gary K. Beauchamp); (2) "Infant Massage" (Tiffany Field); (3) "The Infant's Sixth Sense: Awareness and Regulation of Bodily Processes" (Stephen W. Porges); (4) "Sensory Contributions to Action: A Sensory Integrative Approach" (Marie E.…

  20. The role of the gastric afferent vagal nerve in ghrelin-induced feeding and growth hormone secretion in rats

    Microsoft Academic Search

    Yukari Date; Noboru Murakami; Koji Toshinai; Shigeru Matsukura; Akira Niijima; Hisayuki Matsuo; Kenji Kangawa; Masamitsu Nakazato

    2002-01-01

    Background & Aims: Visceral sensory information is transmitted to the brain through the afferent vagus nerve. Ghrelin, a peptide primarily produced in the stomach, stimulates both feeding and growth hormone (GH) secretion. How stomach-derived ghrelin exerts these central actions is still unknown. Here we determined the role of the gastric afferent vagal nerve in ghrelin's functions. Methods: Food intake and

  1. Unusually large quiescent ancient schwannoma of hypoglossal nerve.

    PubMed

    Wanjari, Sangeeta P; Wanjari, Panjab V; Parwani, Rajkumar N; Tekade, Satyajitraje A

    2013-01-01

    Ancient schwannoma is considered as a variant of schwannoma, comprising about 10% of all schwanommas. Schwannoma is a benign neoplasm derived from the nerve sheath of peripheral motor, sensory and sympathetic nerves and from the cranial nerve pairs. It usually presents as a solitary soft-tissue lesion which is slow growing, encapsulated and is often associated with nerve attached peripherally. Diagnosis is often confirmed with the microscopic examination. The long standing schwannoma attributes to degenerative changes and is termed "ancient" schwannoma. Present case is of a 68-year-old female patient who reported with an asymptomatic large swelling below mandible on the left side since last 23 years. The lesion was surgically excised under general anesthesia. PMID:24552945

  2. Effect of Age on Vascular b2Adrenergic Receptor Desensitization Is Not Mediated by the Receptor Coupling to Gai Proteins

    Microsoft Academic Search

    William E. Schutzer; Hong Xue; John F. Reed; Scott L. Mader

    Beta-adrenergic receptor (b-AR)-mediated vasorelaxation declines with age. In the vasculature, b2-AR undergoes protein kinase A-mediated desensitization that causes a switch in the G protein coupled to b2-AR; Gai links instead of Gas. We exposed Fischer 344 rat aortae of increasing age to a desensitizing dose of isoproterenol, and determined its effect on b2-AR-mediated vasorelaxation. Desensitization decreased b2-AR-mediated vasorelaxation in young

  3. A NOVEL TREATMENT MODALITY IN PATIENTS WITH PREMATURE EJECULATION RESISTANT TO CONVENTIONAL METHODS: THE NEUROMODULATION OF DORSAL PENILE NERVES BY PULSED RADIOFREQUENCY

    Microsoft Academic Search

    SEREF BASAL; SERDAR GOKTAS; ATILLA ERGIN; IBRAHIM YILDIRIM; ABDULKADIR ATIM; LUTFI TAHMAZ; MURAT DAYANC

    2009-01-01

    ABSTRACT Premature ejaculation (PE) is the most common sexual problem experienced by men, and affecting 20%–30% of them. ,Pulsed radiofrequency ,(PRF) neuromodulation ,has been shown,to be an effective treatment for a wide,range of pain conditions. We used PRF to treat PEby,desensitizing dorsal penile nerves in patients ,resistant to conventional ,treatments. Fifteen patients with a lifelong ,history of PE were ,defined

  4. [Subacute sensory neuronopathy associated with squamous cell carcinoma of the lung: a case report].

    PubMed

    Noto, Yuichi; Shiga, Kensuke; Fujinami, Jun; Mizuno, Toshiki; Nakagawa, Masanori; Tanaka, Keiko

    2009-08-01

    We report a 59-year-old man who developed dysesthesia in all extremities with severe loss of deep sensation over three months. A radiating radicular pain was also noted in the extremities. The nerve conduction study barely elicited sensory nerve action potentials both in the median and in the sural nerve. An extensive search for anti-neuronal antibodies including anti-Hu and anti-CV2 antibody was negetive. The biopsy specimen of an enlarged tracheobronchial lymph node revealed squamous cell carcinoma. The subsequent chemotherapy and radiation therapy for the neoplasm improved the radicular pain and the deep sensation to a moderate extent, leading to the diagnosis of paraneoplastic subacute sensory neuropathy (SSN). In general, cases with paraneoplastic SSN are associated mostly with small cell lung cancer, and quite rarely with squamous cell lung cancer. The early detection and the treatment of the primary tumor are crucial in a patient with subacute progression of sensory-dominant neuropathy. PMID:19827601

  5. Peripheral communications of intercostobrachial nerve Peripheral communications of the intercostobrachial nerve in relation to the alar thoracic artery

    PubMed Central

    Rustagi, Shaifaly Madan; Sharma, Mona; Singh, Nidhi; Mehta, Vandana; Suri, Rajesh K; Rath, Gayatri

    2015-01-01

    The intercostobrachial nerve (ICBN) is often encountered during axillary dissection for axillary lymph node dissection (ALND) for diagnostic and therapeutic surgery for mastectomy. The present report is a case observed in the Department of Anatomy at Vardhman Mahavir Medical College, Delhi during routine dissection of the upper extremity of a male cadaver for first year undergraduate medical students. On the right side, the medial cord of brachial plexus gave two medial cutaneous nerves of arm. Both the nerves were seen communicating with the branches of the ICBN. The ICBN and one of its branches were surrounding the termination of an alar thoracic artery. These peripheral neural connections of the ICBN with the branches of the medial cord can be a cause of sensory impairment during axillary procedures done for mastectomy or exploration of long thoracic nerves. The alar thoracic artery found in relation to the ICBN could further be a cause of vascular complications during such procedures. PMID:25802820

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

    PubMed Central

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

    2012-01-01

    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

  7. Recombinant GABAA receptor desensitization: the role of the gamma 2 subunit and its physiological significance.

    PubMed Central

    Dominguez-Perrot, C; Feltz, P; Poulter, M O

    1996-01-01

    1. The purpose of these investigations was to examine the role that the gamma 2 subunit plays in human GABAA receptor desensitization. Two different recombinant GABAA receptors (alpha 1 beta 3 and alpha 1 beta 3 gamma 2) were compared by measuring the relaxation of whole-cell currents during the application of GABA, isoguvacine or taurine. 2. At concentrations which trigger a maximum response (100-500 microM GABA) the current relaxation usually fitted the sum of two exponentials. For alpha 1 beta 3 subunit receptors these values were tau 1 = 145 +/- 12 ms and tau 2 = 6.3 +/- 2.1 s (means +/- S.E.M.). Receptors consisting of alpha 1 beta 3 gamma 2 subunits desensitized faster: tau 1 = 41.6 +/- 8.3 ms and tau 2 = 2.4 +/- 0.6 s. 3. The Hill slope, determined for each receptor subunit combination, was the same and greater than 1.0, implying two binding steps in the activation of both receptor subunit combinations. 4. For alpha 1 beta 3 subunit receptors the fast desensitization rates were unaltered by reducing the GABA concentration from the EC100 (100 microM) to the approximate EC50 values (10-20 microM), whereas for alpha 1 beta 3 gamma 2 subunit receptors a significant slowing was observed. The fast desensitization disappeared at agonist concentrations below the EC50 for both subunit combinations. In contrast, the slow desensitization appeared at agonist concentrations near the EC20. This rate was dependent on agonist concentration reaching a maximum near the EC60 value of GABA. 5. The fast desensitization rates were unaltered by changing the holding potential of the cell during agonist application. However, for alpha 1 beta 3 gamma 2 subunit receptors the slow desensitization rate increased by approximately 15- to 20-fold over the range of voltages of -60 to +40 mV. This indicates that the gamma 2 subunit makes GABAA receptor desensitization voltage dependent. 6. Recovery from desensitization was also biphasic. The first recovery phase was faster for alpha 1 beta 3 gamma 2 than for alpha 1 beta 3 subunit receptors (0.13 vs. 0.03 s-1, respectively). The second phase of recovery for the two receptors were the same (approximately 0.003 s-1). 7. There was only a poor correlation between agonist potency and the degree or time course of desensitization. Isoguvacine (EC50 approximately to 10 microM) induced biphasic relaxation for both alpha 1 beta 3 and alpha 1 beta 3 gamma 2 subunit receptors (tau 1 = 288.6 +/- 43.3 and 167 +/- 15 ms, and tau 2 = 8.0 +/- 1.9 and 4.4 +/- 0.4 S, respectively, for each subunit combination). Taurine (EC50 approximately 7 mM) usually induced monophasic relaxation for both subunit combinations (tau 2 = 7.1 +/- 1.6 and 23.0 +/- 6.6 s, respectively). 8. A computer model was developed to examine the effect of the gamma 2 subunit on the time course of a synaptic potential. It was found that the gamma 2 subunit theoretically prolongs the time course of a synaptic potential by inducing desensitization more rapidly. The subsequent relaxation of the desensitized receptors through the open state increases Popen (the probability that the GABAA receptor is in an open conducting state) altering the time course of the modelled potential. alpha 1 beta 3 subunit receptors do not desensitize sufficiently rapidly to induce this desensitized state and, therefore, are shorter in time course. These data imply that the physiological role of the gamma 2 subunit is to increase synaptic efficacy by prolonging Popen. PMID:8951718

  8. Peripherin and ATF3 genes are differentially regulated in regenerating and non-regenerating primary sensory neurons.

    PubMed

    Reid, Adam J; Welin, Dag; Wiberg, Mikael; Terenghi, Giorgio; Novikov, Lev N

    2010-01-15

    Peripheral nerve injury leads to deficient recovery of sensation and a causative factor may be that only 50-60% of primary sensory neurons succeed in regenerating axons after primary nerve repair. In this study, an in vivo rat sciatic nerve injury and regeneration model was combined with laser microdissection and quantitative real-time polymerase chain reaction with the aim of examining the gene expression of regenerative molecules in cutaneous and muscular sensory neurons. Recent studies have identified peripherin and ATF-3 molecules as crucial for neurite outgrowth propagation; our novel findings demonstrate a subpopulation of non-regenerating sensory neurons characterized by a failure to upregulate transcription of these molecules and that a greater peripherin mRNA expression in injured cutaneous neurons may potentiate this subpopulation to regenerate more axons than muscle afferent neurons following injury. The gene expression of the structural neurofilament NF-H is found to be significantly downregulated following injury in both sensory subpopulations. PMID:19913522

  9. Two cases of hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P).

    PubMed

    Mori, Chiaki; Saito, Tomoko; Saito, Toshio; Fujimura, Harutoshi; Sakoda, Saburo

    2015-01-01

    We, herein, report two independent cases with hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P) inherited in an autosomal dominant fashion. Their common clinical features are slowly progressive proximal dominant muscular atrophy, fasciculations and mild to moderate distal sensory disturbance with areflexia. Nerve conduction study revealed an absence of sensory nerve action potentials, in contrast to almost normal compound muscle action potentials. Gene analysis in both patients elucidated heterozygous mutation (c.854C>T, p.Pro285Leu) in the TFG, which is an identical mutation, already described by Ishiura et al. Okinawa and Shiga are two foci of HMSN-P in Japan. Eventually, one patient is from Okinawa and the other is from a mountain village in Shiga prefecture. When we see a patient who has symptoms suggestive of motor neuron disease with sensory neuropathy, HMSN-P should be considered as a differential diagnosis despite the patient's actual resident place. PMID:26103812

  10. Injectable systems and implantable conduits for peripheral nerve repair.

    PubMed

    Lin, Yen-Chih; Marra, Kacey G

    2012-04-01

    Acute sensory problems following peripheral nerve injury include pain and loss of sensation. Approximately 360,000 people in the United States suffer from upper extremity paralytic syndromes every year. Restoration of sufficient functional recovery after long-gap peripheral nerve damage remains a clinical challenge. Potential nerve repair therapies have increased in the past decade as the field of tissue engineering expands. The following review describes the use of biomaterials in nerve tissue engineering. Namely, the use of both synthetic and natural biomaterials, including non-degradable and degradable nerve grafts, is addressed. The enhancement of axonal regeneration can be achieved by further modification of the nerve guides. These approaches include injectable hydrogel fillers, controlled drug delivery systems, and cell incorporation. Hydrogels are a class of liquid-gel biomaterials with high water content. Injectable and gelling hydrogels can serve as growth factor delivery vehicles and cell carriers for tissue engineering applications. While natural hydrogels and polymers are suitable for short gap nerve repair, the use of polymers for relatively long gaps remains a clinical challenge. PMID:22456722

  11. Supplementary Figure 1. Experimental strategy to generate sensory hair cells in the mammalian cochlea and evaluate their morphological, molecular, and biophysical

    E-print Network

    Cai, Long

    of nerve tracts originating in the cochlear nucleus; 4) neurofilament expression by SUPPLEMENTARY with subsequent sculpting by programmed cell death. There are 5 vestibular sensory epithelia consisting of hair

  12. Distal median nerve dysfunction

    MedlinePLUS

    ... type of distal median nerve dysfunction is carpal tunnel syndrome . ... repetitive movements increase the chance of developing carpal tunnel entrapment. Conditions that affect connective tissue or cause ...

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

    PubMed Central

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

    2014-01-01

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

  14. Survival in sensitized lung transplant recipients with perioperative desensitization.

    PubMed

    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

    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

  15. Tethered ligands reveal glutamate receptor desensitization depends on subunit occupancy.

    PubMed

    Reiner, Andreas; Isacoff, Ehud Y

    2014-04-01

    Cell signaling is often mediated by the binding of multiple ligands to multisubunit receptors. The probabilistic nature and sometimes slow rate of binding encountered with diffusible ligands can impede attempts to determine how the ligand occupancy controls signaling in such protein complexes. We describe a solution to this problem that uses a photoswitched tethered ligand as a 'ligand clamp' to induce rapid and stable binding and unbinding at defined subsets of subunits. We applied the approach to study gating in ionotropic glutamate receptors (iGluRs), ligand-gated ion channels that mediate excitatory neurotransmission and plasticity at glutamatergic synapses in the brain. We probed gating in two kainate-type iGluRs, GluK2 homotetramers and GluK2-GluK5 heterotetramers. Ultrafast (submillisecond) photoswitching of an azobenzene-based ligand on specific subunits provided a real-time measure of gating and revealed that partially occupied receptors can activate without desensitizing. The findings have implications for signaling by locally released and spillover glutamate. PMID:24561661

  16. Tethered ligands reveal glutamate receptor desensitization depends on subunit occupancy

    PubMed Central

    Reiner, Andreas; Isacoff, Ehud Y.

    2014-01-01

    Cell signaling is often mediated by the binding of multiple ligands to a multi-subunit receptor. The probabilistic nature and slow rate of binding of diffusible ligands at low concentrations can impede attempts to determine how ligand occupancy controls signaling in such protein complexes. We describe a solution to this problem that uses a photoswitched tethered ligand as a “ligand clamp” to induce rapid and stable binding and unbinding at defined subsets of subunits. We applied the approach to study gating in ionotropic glutamate receptors (iGluRs), ligand-gated ion channels that mediate excitatory neurotransmission and plasticity at glutamatergic synapses in the brain. We probed gating in two kainate-type iGluRs, GluK2 homotetramers and GluK2/GluK5 heterotetramers. Ultrafast (sub-millisecond) photoswitching of an azobenzene-based ligand on specific subunits provided a real-time measure of gating and revealed that partially occupied receptors can activate without desensitizing. The findings have implications for signaling by locally released and spillover glutamate. PMID:24561661

  17. Clinical evaluation of desensitizing treatments for cervical dentin hypersensitivity.

    PubMed

    Aranha, Ana Cecilia Corręa; Pimenta, Luiz André Freire; Marchi, Giselle Maria

    2009-01-01

    The aim of this study was to compare different treatments for dentin hypersensitivity in a 6-month follow-up. One hundred and one teeth exhibiting non carious cervical lesions were selected. The assessment method used to quantify sensitivity was the cold air syringe, recorded by the visual analogue scale (VAS), prior to treatment (baseline), immediately after topical treatment, after 1 week, 1, 3 and 6 months. Teeth were randomly assigned to five groups (n = 20): G1: Gluma Desensitizer (GD); G2: Seal& (SP); G3: Oxa-gel (OG); G4: Fluoride (F); G5: Low intensity laser-LILT (660 nm/3.8 J/cm(2)/15 mW). Analysis was based on the non-parametric Kruskal-Wallis test that demonstrated statistical differences immediately after the treatment (p = 0.0165). To observe the individual effects of each treatment, data was submitted to Friedman test. It was observed that GD and SP showed immediate effect after application. Reduction in the pain level throughout the six-month follow-up was also observed. In contrast, LILT presented a gradual reduction of hypersensitivity. OG and F showed effects as of the first and third month respectively. It can be concluded that, after the 6-month clinical evaluation, all therapies showed lower VAS sensitivity values compared with baseline, independently of their different modes of action. PMID:19893971

  18. Eye movement desensitization and reprocessing for adolescent depression.

    PubMed

    Bae, Hwallip; Kim, Daeho; Park, Yong Chon

    2008-03-01

    While cognitive behavior therapy is considered to be the first-line therapy for adolescent depression, there are limited data on whether other psychotherapeutic techniques are also effective in treating adolescents with depression. This report suggests the potential application of eye movement desensitization and reprocessing (EMDR) for treatment of depressive disorder related, not to trauma, but to stressful life events. At present, EMDR has only been empirically validated for only trauma-related disorders such as posttraumatic stress disorder. Two teenagers with major depressive disorder (MDD) underwent three and seven sessions of EMDR aimed at memories of stressful life events. After treatment, their depressive symptoms decreased to the level of full remission, and the therapeutic gains were maintained after two and three months of follow up. The effectiveness of EMDR for depression is explained by the model of adaptive information processing. Given the powerful effects observed within a brief period of time, the authors suggest that further investigation of EMDR for depressive disorders is warranted. PMID:20046410

  19. Physiological correlates of eye movement desensitization and reprocessing.

    PubMed

    Elofsson, Ulf O E; von Schčele, Bo; Theorell, Töres; Söndergaard, Hans Peter

    2008-05-01

    Eye movement desensitization and reprocessing (EMDR) is an established treatment for post-traumatic stress disorder (PTSD). However, its working mechanism remains unclear. This study explored physiological correlates of eye movements during EMDR in relation to current hypotheses; distraction, conditioning, orienting response activation, and REM-like mechanisms. During EMDR therapy, fingertip temperature, heart rate, skin conductance, expiratory carbon dioxide level, and blood pulse oximeter oxygen saturation, were measured in male subjects with PTSD. The ratio between the low and high frequency components of the heart rate power spectrum (LF/HF) were computed as measures of autonomic balance. Respiratory rate was calculated from the carbon dioxide trace. Stimulation shifted the autonomic balance as indicated by decreases in heart rate, skin conductance and LF/HF-ratio, and an increased finger temperature. The breathing frequency and end-tidal carbon dioxide increased; oxygen saturation decreased during eye movements. In conclusion, eye movements during EMDR activate cholinergic and inhibit sympathetic systems. The reactivity has similarities with the pattern during REM-sleep. PMID:17604948

  20. Endothelin-1 induced desensitization in primary afferent neurons.

    PubMed

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

    2014-10-17

    Endothelin-1 (ET-1) is a known algogen that causes acute pain and sensitization in humans and spontaneous nociceptive behaviors when injected into the periphery in rats, and is elevated during vaso-occlusive episodes (VOEs) in sickle cell disease (SCD) patients. Previously, our lab has shown that a priming dose of ET-1 produces sensitization to capsaicin-induce secondary hyperalgesia. The goal of this study was to determine if the sensitization induced by ET-1 priming is occurring at the level of the primary afferent neuron. Calcium imaging in cultured dorsal root ganglion (DRG) neurons was utilized to examine the effects of ET-1 on primary afferent neurons. ET-1 induces [Ca(2+)]i transients in unprimed cells. ET-1 induced [Ca(2+)]i transients are attenuated by priming with ET-1. This priming effect occurs whether the priming dose is given 0-4 days prior to the challenge dose. Similarly, ET-1 priming decreases capsaicin-induced [Ca(2+)]i transients. At the level of the primary afferent neuron, ET-1 priming has a desensitizing effect on challenge exposures to ET-1 and capsaicin. PMID:25220703

  1. Electrical stimulation restores the specificity of sensory axon regeneration

    Microsoft Academic Search

    Thomas M. Brushart; Rajesh Jari; Valerie Verge; Charles Rohde; Tessa Gordon

    2005-01-01

    Electrical stimulation at the time of nerve repair promotes motoneurons to reinnervate appropriate pathways leading to muscle [Al-Majed, A.A., Neumann, C.M., Brushart, T.M., Gordon, T., 2000. Brief electrical stimulation promotes the speed and accuracy of motor axonal regeneration. J. Neurosci. 20, 2602–2608] and stimulates sensory neurons to regenerate [Geremia, N.M., Gordon, T., Al-Majed, A.A., Brushart, T.M., Verge, V.M., 2002. Brief

  2. Deficient “sensory” beta synchronization in Parkinson’s disease

    Microsoft Academic Search

    A. Degardin; E. Houdayer; J.-L. Bourriez; A. Destée; L. Defebvre; P. Derambure; D. Devos

    2009-01-01

    ObjectiveBeta rhythm movement-related synchronization (beta synchronization) reflects motor cortex deactivation and sensory afference processing. In Parkinson’s disease (PD), decreased beta synchronization after active movement reflects abnormal motor cortex idling and may be involved in the pathophysiology of akinesia. The objectives of the present study were to (i) compare event-related synchronization after active and passive movement and electrical nerve stimulation in

  3. Cytochemical localization of adenylyl cyclase activity within the sensory epithelium of the trout saccule.

    PubMed

    Drescher, M J; Kern, R C; Hatfield, J S; Drescher, D G

    1995-08-25

    Adenylyl cyclase, the enzyme of synthesis of cAMP, the second messenger molecule mediating signal transduction in response to sensory, neurotransmitter and hormonal stimuli, has been localized in the sensory epithelium of the rainbow trout (Salmo gairdneri R.) saccule by cytochemical detection of enzyme activity. In the sensory receptor cell, or hair cell, reaction product has been visualized in the stereocilia in close association with the outer cell membrane and also at the apical surface of the cuticular plate. A diffuse distribution of precipitate was observed within the cytoplasm of terminal endings of nerve fibers presumed to be efferent on the basis of characteristic synaptic specializations including presynaptic vesicles and a postsynaptic cistern lying within the hair cell. Occasionally, reaction product was observed to be associated with the external cell membrane of these nerve terminals. There appeared to be little or no adenylyl cyclase activity associated with the plasma membrane at the base of the hair cell or in presumptive afferent nerve endings. However, a subpopulation of nerve fiber endings which exhibited both efferent and afferent synaptic specializations contained precipitate. A concentration of adenylyl cyclase activity in hair cell stereocilia and efferent nerve terminals in the sensory epithelium is suggestive of a role for cAMP in second messenger action at these sites, possibly related to mechanosensory transduction and efferent neuromodulation, respectively. PMID:7501269

  4. Autosomal recessive type II hereditary motor and sensory neuropathy with acrodystrophy

    Microsoft Academic Search

    P. K. Thomas; D. Claus; R. H. M. King

    1999-01-01

    A family is described with presumed autosomal recessive inheritance in which three siblings developed a progressive neuropathy\\u000a that combined limb weakness and severe distal sensory loss leading to prominent mutilating changes. Electrophysiological and\\u000a nerve biopsy findings indicated an axonopathy. The disorder is therefore classifiable as type II hereditary motor and sensory\\u000a neuropathy (HMSN II). The clinical features differ from those

  5. Stereospecificity of the sensory irritation receptor for nonreactive chemicals illustrated by pinene enantiomers

    Microsoft Academic Search

    Jukka-Pekka Kasanen; Anna-Liisa Pasanen; Pertti Pasanen; Jyrki Liesivuori; Veli-Matti Kosma; Yves Alarie

    1998-01-01

    To clarify the existence of a receptor protein for sensory irritants in trigeminal nerve endings, d- [i.e. (+)] and l- [i.e. (?)] enantiomers of ?- and ?-pinene as models of nonreactive chemicals were evaluated for their potency in outbred\\u000a OF1 and NIH\\/S mice using ASTM E981-84 bioassay. All pinenes possess sensory irritation properties and also induced sedation\\u000a and signs of

  6. Peripheral nerve functions may deteriorate parallel to the progression of microangiopathy in diabetic patients.

    PubMed

    Ogawa, Kenichi; Sasaki, Hideyuki; Yamasaki, Hiroshi; Okamoto, Kunihisa; Matsuno, Shohei; Shono, Takeshi; Doi, Takuya; Arimoto, Keiko; Furuta, Hiroto; Nishi, Masahiro; Nakao, Taisei; Nanjo, Kishio

    2006-07-01

    Our aim was to obtain information to help in the early detection of impaired nerve function and to assess the severity of diabetic symmetric polyneuropathy (DPN). Various somatic and autonomic nerve functions in 40 diabetics and 20 age-matched healthy volunteers were evaluated using six objective examinations: nerve conduction study, quantitative vibratory perception threshold, heart rate variability, Valsalva test, head-up tilt and quantitative sudomotor axonal reflex test (QSART). The diabetics were divided into three groups according to the severity of their microangiopathy. The nerve function data and level of impairment were compared between a healthy control and three diabetic groups. The relationships between nerve function data and clinical background were also examined using multivariate analysis. Results were as follows: (1) all nerve dysfunctions seemed to develop parallel to the progression of microangiopathy, (2) reduced nerve conduction velocity and elevated vibratory perception thresholds in the feet might be early detectable signs of DPN, (3) vasomotor and sudomotor sympathetic functions and cardiovagal functions seemed to deteriorate with the appearance of microangiopathy, (4) lowered compound muscle action potential seemed to appear at the advanced microangiopathic condition, (5) hypohydrosis was closely related to diabetic foot ulcers. In conclusion, nerve dysfunction in diabetics might generally progress with microangiopathy from somatic sensory nerve dysfunction to autonomic nerve dysfunction and then to somatic motor nerve dysfunction. Sympathetic sudomotor dysfunction might be a sensitive predictor of diabetic foot ulcer. PMID:16829339

  7. Communication between radial nerve and medial cutaneous nerve of forearm

    PubMed Central

    Marathe, RR; Mankar, SR; Joshi, M; Sontakke, YA

    2010-01-01

    Radial nerve is usually a branch of the posterior cord of the brachial plexus. It innervates triceps, anconeous, brachialis, brachioradialis, extensor carpi radialis longus muscles and gives the posterior cutaneous nerve of the arm, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of forearm; without exhibiting any communication with the medial cutaneous nerve of forearm or any other nerve. We report communication between the radial nerve and medial cutaneous nerve of forearm on the left side in a 58-year-old male cadaver. The right sided structures were found to be normal. Neurosurgeons should keep such variations in mind while performing the surgeries of axilla and upper arm. PMID:21799623

  8. Correlating efficacy and desensitization with GluK2 ligand-binding domain movements

    PubMed Central

    Nayeem, Naushaba; Mayans, Olga; Green, Tim

    2013-01-01

    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

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

    PubMed

    McGowan, E B; Detwiler, T C

    1983-07-15

    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

  10. Short-Term Desensitization of Muscarinic K+ Current in the Heart

    PubMed Central

    Murakami, Shingo; Inanobe, Atsushi; Kurachi, Yoshihisa

    2013-01-01

    Acetylcholine (ACh) rapidly increases cardiac K+ currents (IKACh) by activating muscarinic K+ (KACh) channels followed by a gradual amplitude decrease within seconds. This phenomenon is called short-term desensitization and its precise mechanism and physiological role are still unclear. We constructed a mathematical model for IKACh to examine the conditions required to reconstitute short-term desensitization. Two conditions were crucial: two distinct muscarinic receptors (m2Rs) with different affinities for ACh, which conferred an IKACh response over a wide range of ACh concentrations, and two distinct KACh channels with different affinities for the G-protein ?? subunits, which contributed to reconstitution of the temporal behavior of IKACh. Under these conditions, the model quantitatively reproduced several unique properties of short-term desensitization observed in myocytes: 1), the peak and quasi-steady states with 0.01–100 ?M [ACh]; 2), effects of ACh preperfusion; and 3), recovery from short-term desensitization. In the presence of 10 ?M ACh, the IKACh model conferred recurring spontaneous firing after asystole of 8.9 s and 10.7 s for the Demir and Kurata sinoatrial node models, respectively. Therefore, two different populations of KACh channels and m2Rs may participate in short-term desensitization of IKACh in native myocytes, and may be responsible for vagal escape at nodal cells. PMID:24048003

  11. Measurement of Conformational Changes Accompanying Desensitization in an Ionotropic Glutamate Receptor

    SciTech Connect

    Armstrong,N.; Jasti, J.; Beich-Frandsen, M.; Gouaux, E.

    2006-01-01

    The canonical conformational states occupied by most ligand-gated ion channels, and many cell-surface receptors, are the resting, activated, and desensitized states. While the resting and activated states of multiple receptors are well characterized, elaboration of the structural properties of the desensitized state, a state that is by definition inactive, has proven difficult. Here we use electrical, chemical, and crystallographic experiments on the AMPA-sensitive GluR2 receptor, defining the conformational rearrangements of the agonist binding cores that occur upon desensitization of this ligand-gated ion channel. These studies demonstrate that desensitization involves the rupture of an extensive interface between domain 1 of 2-fold related glutamate-binding core subunits, compensating for the ca. 21{sup o} of domain closure induced by glutamate binding. The rupture of the domain 1 interface allows the ion channel to close and thereby provides a simple explanation to the long-standing question of how agonist binding is decoupled from ion channel gating upon receptor desensitization.

  12. A C-terminal lysine that controls human P2X4 receptor desensitization.

    PubMed

    Fountain, Samuel J; North, R Alan

    2006-06-01

    Receptor desensitization can determine the time course of transmitter action and profoundly alter sensitivity to drugs. Among P2X receptors, ion currents through homomeric P2X4 receptors exhibit intermediate desensitization when compared with P2X1 and P2X3 (much faster) and P2X2 and P2X7 (slower). We recorded membrane currents in HEK293 cells transfected to express the human P2X4 receptor. The decline in current during a 4-s application of ATP (100 microm) was about 30%; this was not different during whole-cell or perforated patch recording. Alanine-scanning mutagenesis of the intracellular C terminus identified two positions with much accelerated desensitization kinetics (Lys373: 92% and Tyr374: 74%). At position 373, substitution of Arg or Cys also strongly accelerated desensitization: however, in the case of K373C the wild-type phenotype was fully restored by adding ethylammonium methanethiosulfonate. At position 374, phenylalanine could replace tyrosine. These results indicate that wild-type desensitization properties requires an aromatic moiety at position 374 and an amino rather than a guanidino group at position 373. These residues lie between previously identified motifs involved in membrane trafficking (YXXXK and YXXGL) and implicates the C-terminal also in rearrangements leading to channel closing during the presence of agonist. PMID:16533808

  13. Effect of 4-aminopyridine on end-plate receptor desensitization caused by carbachol.

    PubMed

    Vital Brazil, O; Fontana, M D; Pavani, N J

    1982-12-24

    The effect of 4-aminopyridine on receptor desensitization was investigated in the isolated rat diaphragm by measuring transmembrane potential in the end-plate region. When 4-aminopyridine was added to the bath before carbachol, the depolarization produced by the agonist was permanent, that is 4-aminopyridine completely inhibited the receptor desensitization produced by prolonged exposure of the receptors to carbachol. When it was added after carbachol in the phase in which the membrane had already repolarized, the end-plate region depolarized. Therefore, 4-aminopyridine was also able to reverse the receptors from the desensitized state to the resting non-desensitized one. The effect of 4-aminopyridine was concentration-dependent. Calcium antagonized the effect of 4-aminopyridine. 4-Aminopyridine also reversed the receptors from their desensitized state to the resting one in the isolated and chronically denervated rat hemidiaphragm. The known action of the aminopyridines cannot explain the effect of 4-aminopyridine described here. It is suggested that it is caused by an action on either the receptor-ionic channel complex or the lipids of the postjunctional membrane surrounding it. PMID:7160434

  14. Successful Desensitization to Fixed Drug Eruption: The Presence of CD25+CD4+ T Cells in the Epidermis of Fixed Drug Eruption Lesions May Be Involved in the Induction of Desensitization

    Microsoft Academic Search

    Yuichi Teraki; Tetsuo Shiohara

    2004-01-01

    Background: Fixed drug eruption (FDE) is a distinct type of drug-induced eruption, in which intraepidermal CD8+ T cells in the lesional skin are the final effector cells in the epidermal injury of FDE. Desensitization is a unique approach for the management of drug eruption, which has been reported to be effective in treating FDE. However, the mechanisms underlying desensitization to

  15. Neuroepithelial circuit formed by innervation of sensory enteroendocrine cells

    PubMed Central

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

    2015-01-01

    Satiety and other core physiological functions are modulated by sensory signals arising from the surface of the gut. Luminal nutrients and bacteria stimulate epithelial biosensors called enteroendocrine cells. Despite being electrically excitable, enteroendocrine cells are generally thought to communicate indirectly with nerves through hormone secretion and not through direct cell-nerve contact. However, we recently uncovered in intestinal enteroendocrine cells a cytoplasmic process that we named neuropod. Here, we determined that neuropods provide a direct connection between enteroendocrine cells and neurons innervating the small intestine and colon. Using cell-specific transgenic mice to study neural circuits, we found that enteroendocrine cells have the necessary elements for neurotransmission, including expression of genes that encode pre-, post-, and transsynaptic proteins. This neuroepithelial circuit was reconstituted in vitro by coculturing single enteroendocrine cells with sensory neurons. We used a monosynaptic rabies virus to define the circuit’s functional connectivity in vivo and determined that delivery of this neurotropic virus into the colon lumen resulted in the infection of mucosal nerves through enteroendocrine cells. This neuroepithelial circuit can serve as both a sensory conduit for food and gut microbes to interact with the nervous system and a portal for viruses to enter the enteric and central nervous systems. PMID:25555217

  16. Effects of Topical Nasal Anesthetic on Fiberoptic Endoscopic Examination of Swallowing with Sensory Testing (FEESST)

    PubMed Central

    McCullough, Gary H.; Guidry, Tiffany J.; Mennemeier, Mark; Schluterman, Keith

    2013-01-01

    Objections to the use of topical nasal anesthesia (TNA) during fiberoptic endoscopic evaluation of swallowing (FEES) with sensory testing (FEESST) have been raised, primarily because of the possibility of desensitizing the pharyngeal and laryngeal mucosa and affecting both the sensory and motor aspects of the swallow. Furthermore, it has been suggested that TNA is not necessary during FEES as it does not improve patient comfort or make the procedure easier for the endoscopist. The purpose of this double-blind, randomized, controlled, crossover clinical trial was to determine how gel TNA during flexible endoscopic evaluation of swallowing with sensory testing affects sensation, swallowing, and comfort rating scores in healthy nondysphagic participants. Laryngopharyngeal sensory thresholds and swallowing durations were compared between two conditions: TNA and sham. Transition duration decreased statistically significantly during the TNA condition compared to the sham for 10 ml only (p < 0.05). All other swallowing measures did not change between the conditions. Laryngopharyngeal sensory thresholds and perceptions did not change between conditions. No change was observed for subject comfort scores, ease of exam, or quality of view. Future studies should evaluate TNA administration variables, including concentration, dosage amount, and method of application, to determine the optimal strategy for providing comfort while avoiding altered swallowing. PMID:23828313

  17. Sensory Complications in Patients after Scalp Mass Excision and Its Anatomical Considerations

    PubMed Central

    Yang, Jin Seo; Cho, Yong Jun; Kang, Suk Hyung

    2014-01-01

    Objective To evaluate the incidence of postsurgical sensory complications in patients with scalp masses and classify the locations of them from a surgical standpoint according to anatomical considerations. Methods A total of 121 patients who underwent surgery for scalp mass were included in this study. The authors reviewed medical records and preoperative radiologic images. We investigated the complications related to sensory changes after procedure. Enrolled patients have been divided into three groups. Group A included patients with tumors above the superior nuchal line (SNL), Group B with tumors within the trapezius muscle area and patients who had tumors on the lateral trapezius muscle area were assigned to Group C. We compared the incidence related to postoperative sensory complications and summarized their additional treatments for these with clinical outcome. Results There were 12 patients (10%) with sensory complications related on the mass excision site (Group A: 1 patient, Group B: 2 patients, Group C: 9 patients). Six patients were affected with lesser occipital nerve (LON), 2 patients on greater occipital nerve (GON) and 4 patients on GON and LON. Over 6 months after surgery, two of the twelve patients with sensory complications did not have complete recovered pain in spite of proper medications and local chemical neurolysis with 1.0% lidocaine and dexamethasone. Conclusion Occipital neuropathy should be considered as a complication related excision of scalp mass. The sensory complications are more frequent in Group C because of the anatomical characteristics of the occipital nerves and there were no statistical difference for other variables. PMID:25024823

  18. Evolution of motor and sensory deficits in amyotrophic lateral sclerosis estimated by neurophysiological techniques.

    PubMed

    Theys, P A; Peeters, E; Robberecht, W

    1999-06-01

    Although amyotrophic lateral sclerosis is a degenerative disease of the upper and lower motor neurons, there is evidence that the disease can affect other systems, including the sensory system. On the other hand, within the motor neuron pool there is possibly a predilection of the degenerative process for the motor neurons fibers with the fastest conduction velocity (MNFCV). We studied these two aspects of the disease in a group of 50 patients by prospectively assessing several sensory indices and by studying the selectivity of the spinal motor neuron loss. At baseline, nerve conduction studies and somatosensory evoked potentials showed abnormal slowing in the peripheral and central sensory pathways. Thermal thresholds for heating were elevated but were normal for cooling. In more than 60% of the patients at least one of the sensory tests studied was abnormal. However, except for a significant decrease in the amplitude of the sensory nerve action potentials of the sural nerves, these afferent dysfunctions were not progressive over the follow-up period of 6 months, in contrast to the marked deterioration in motor functions. Three different statistical models were applied to evaluate the presence of demyelination, selective loss of MNFCV, or the purely random degeneration of fast- and slow-conducting motor neurons. These data indicate a selective loss of the MNFCV and suggest that subclinical abnormalities of the sensory system in ALS are often present but almost nonprogressive. Furthermore, the amyotrophic lateral sclerosis disease process seems preferentially to affect MNFCV. PMID:10431767

  19. Motor nerve transplantation.

    PubMed

    Gray, W P; Keohane, C; Kirwan, W O

    1997-10-01

    The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 microsec preoperatively, and 26 microsec at 2 months, 29.5 microsec at 4 months, and 14 microsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle. PMID:9322851

  20. Peripheral nerve tumours: 30-year experience in the surgical treatment.

    PubMed

    Gosk, Jerzy; Gutkowska, Olga; Mazurek, Piotr; Koszewicz, Magdalena; Zió?kowski, Piotr

    2015-07-01

    Peripheral nerve tumours are relatively rare type of soft tissue tumours. The aim of this work is to present our experience with surgical treatment of this type of lesions. Clinical material consists of 94 patients (56 females, 38 males), in whom 101 tumours deriving from peripheral nervous system were removed. The patients underwent surgical treatment between 1983 and 2012. Tumours occurred mainly in the upper extremity (72 tumours), less often in the lower extremity (25 tumours). Lesions developed in major peripheral nerves (51 tumours) and small nerve branches (50 tumours). The most common symptoms reported before surgery included presence of tumour mass (100 %), positive Hoffmann-Tinel sign (95.6 %) and paraesthesia (93.4 %). Less often sensory deficit (89.1 %) and pain (71.7 %) were observed. Motor deficit was the least common manifestation (41.3 %). Benign tumours prevailed in presented material (94 tumours). In 7 cases, malignant peripheral nerve sheath tumour (MPNST) was identified. As a result of surgical treatment in the group of tumours deriving from major peripheral nerves, in 87.8 % of the patients, pain relief was achieved; in 84 %, Hoffmann-Tinel sign was negative; and in 79 %, paraesthesia resolved. Sensory function improvement was observed in 51.2 % of the patients while motor function improved in 26.3 % of the patients. None of the patients experienced tumour relapse. In the group of tumours deriving from small nerve branches, 47 patients had no signs of tumour recurrence. One female patient diagnosed with MPNST suffered a relapse. Obtaining satisfactory results of peripheral nerve tumour treatment requires both careful differential diagnosis and well thought-out strategy at every stage of therapeutic management. PMID:25727458

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

    ERIC Educational Resources Information Center

    Woods, Nathaniel A.

    A study involving 97 students (79 females and 18 males) at New York City Technical College was undertaken to determine the effectiveness of desensitization in reducing test anxiety and improving grade point averages (GPAs). The study compared the GPAs of students who completed workshops using the desensitization hierarchy developed by R. Strieby…

  2. Nicotine-induced Up-regulation and Desensitization of 4 2 Neuronal Nicotinic Receptors Depend on Subunit Ratio*

    E-print Network

    Lasalde Dominicc, Jose A. - Department of Biology, Universidad de Puerto Rico

    Nicotine-induced Up-regulation and Desensitization of 4 2 Neuronal Nicotinic Receptors Depend Caribe, Department of Physiology, Bayamo´n, Puerto Rico 00916 Desensitization induced by chronic nicotine exposure has been hypothesized to trigger the up-regulation of the 4 2 neuronal nicotinic acetylcholine

  3. Functional Recovery from Desensitization of Vanilloid Receptor TRPV1 Requires Resynthesis of Phosphatidylinositol 4,5-Bisphosphate

    Microsoft Academic Search

    Beiying Liu; Chunguang Zhang; Feng Qin

    2005-01-01

    Capsaicin and other naturally occurring pungent molecules have long been used as topical analgesics to treat a variety of chronic pain conditions. The analgesic effects of these compounds involve long-term desensitization of nociceptors after strong stimulation. To elucidate the underlying mechanisms, we studied the recovery from desensitization of the vanilloid receptor TRPV1.We showed that prolonged applications of capsaicin led to

  4. 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

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

    2004-01-01

    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

  5. On the maxillary nerve.

    PubMed

    Higashiyama, Hiroki; Kuratani, Shigeru

    2014-01-01

    The trigeminal, the fifth cranial nerve of vertebrates, represents the rostralmost component of the nerves assigned to pharyngeal arches. It consists of the ophthalmic and maxillomandibular nerves, and in jawed vertebrates, the latter is further divided into two major branches dorsoventrally. Of these, the dorsal one is called the maxillary nerve because it predominantly innervates the upper jaw, as seen in the human anatomy. However, developmentally, the upper jaw is derived not only from the dorsal part of the mandibular arch, but also from the premandibular primordium: the medial nasal prominence rostral to the mandibular arch domain. The latter component forms the premaxillary region of the upper jaw in mammals. Thus, there is an apparent discrepancy between the morphological trigeminal innervation pattern and the developmental derivation of the gnathostome upper jaw. To reconcile this, we compared the embryonic developmental patterns of the trigeminal nerve in a variety of gnathostome species. With the exception of the diapsid species studied, we found that the maxillary nerve issues a branch (nasopalatine nerve in human) that innervates the medial nasal prominence derivatives. Because the trigeminal nerve in cyclostomes also possesses a similar branch, we conclude that the vertebrate maxillomandibular nerve primarily has had a premandibular branch as its dorsal element. The presence of this branch would thus represent the plesiomorphic condition for the gnathostomes, implying its secondary loss within some lineages. The branch for the maxillary process, more appropriately called the palatoquadrate component of the maxillary nerve (V(2)), represents the apomorphic gnathostome trait that has evolved in association with the acquisition of an upper jaw. PMID:24151219

  6. Prostaglandin-dependent desensitization of human monocyte cAMP responses.

    PubMed

    Coffey, R G; Alberts, V A; Weakland, L L

    1990-12-01

    Histamine stimulated large increases of cyclic adenosine monophosphate (cAMP) in freshly isolated human blood monocytes in the presence of R02-1724, a specific cAMP phosphodiesterase inhibitor. This was mediated by H2 receptors, since it was inhibited by cimetidine but not chlorpheniramine. Stimulation was attenuated in cells aged in culture 1-2 days. Indomethacin prevented the desensitization, suggesting that a cyclooxygenase product was responsible. Desensitization was heterologous, since the adenylate cyclase responses to 5'-(N-ethylcarboxamido)adenosine (A2 receptor agonist), isoproterenol (beta-adrenoceptor agonist), and prostaglandin E2 (PGE2) also declined during culture. The loss of sensitivity to histamine was restored by incubating monocytes with PGE2 in the presence of indomethacin. The results indicate that, while PGE2 inhibits monocyte functions via cAMP, its accumulation paradoxically permits cells to escape this regulation through a heterologous desensitization of the cAMP response to itself and other agonists. PMID:2172433

  7. Delayed loss of spinal motoneurons after peripheral nerve injury in adult rats: a quantitative morphological study

    Microsoft Academic Search

    Jianjun Ma; Lev N. Novikov; Mikael Wiberg; Jan-Olof Kellerth

    2001-01-01

    .   The existence of retrograde cell death in sensory dorsal root ganglion (DRG) cells after peripheral nerve injury is well\\u000a established. However, with respect to retrograde motoneuron death after peripheral nerve injury, available data are conflicting.\\u000a This may partly be due to the cell counting techniques used. In the present study, quantitative morphometric methods have\\u000a been used to analyse retrograde

  8. Medial plantar nerve conduction velocities among patients with vibration syndrome due to chain-saw work

    Microsoft Academic Search

    M. Hirata; H. Sakakibara; S. Yamada; T. Hashiguchi; N. Toibana; H. Koshiyama; H. Hirano

    1999-01-01

    Objective: The present study examined the effect of the vibration syndrome (VS) on the peripheral nervous system in the lower extremities.\\u000a Methods: Thirty-eight patients with VS due to previous exposure to vibration from chain-saw work and 55 age-matched controls were\\u000a examined for sensory nerve conduction velocities in the medial plantar nerve (SCV-P). The patient group was divided into two\\u000a subgroups,

  9. Desensitization of prostacyclin responsiveness in a neuronal hybrid cell line: selective loss of high affinity receptors.

    PubMed Central

    Leigh, P. J.; MacDermot, J.

    1985-01-01

    The binding of [3H]-iloprost (ZK36374) to NCB-20 membranes revealed a single population of high affinity receptors (KD = 9.55 nM, Bmax = 431 fmol mg-1 protein) and a low affinity, non-saturable binding component. Desensitization of prostacyclin-responsiveness of NCB-20 cells is induced by culture in the presence of the stable prostacyclin analogue carbacyclin. Desensitization is accompanied by an increase in the Kact value for prostacyclin (64.1 nM to 175 nM), and a reduction in the prostacyclin-dependent increase in adenylate cyclase activity (41.2 to 15.1 pmol cyclic AMP min-1 mg-1 protein). Desensitization is not accompanied by changes in the coupling of the catalytic (C) to the regulatory (Ns) subunit of adenylate cyclase. In addition, the physical identity of the receptor molecule (as characterized by its sensitivity to electron bombardment in the beam of a linear accelerator) is not changed by desensitization. Desensitization of prostacyclin-dependent activation of adenylate cyclase may be explained most simply by a loss of prostacyclin receptors. The anomalous increase in the Kact (concentration of prostaglandin giving half-maximum enzyme activation) for prostacyclin-stimulated adenylate cyclase was not accompanied by a substantial change in the KD of [3H]-iloprost binding, and is explained by a loss of spare receptors. Prostacyclin responsiveness in non-dividing cells may be restored after desensitization by prolonged culture (up to 48 h) in the absence of carbacyclin. Resensitization is accompanied by restoration of the high affinity Kact value (143 nM to 45.5 nM), and is dependent on de novo protein synthesis. PMID:2992650

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

    PubMed Central

    Machado, J.A.; Ghizoni, M.F.; Bertelli, J.; Teske, Gabriel C.; Teske, Guilherme C.; Martins, D.F.; Mazzardo-Martins, L.; Cargnin-Ferreira, E.; Santos, A.R.S.; Piovezan, A.P.

    2013-01-01

    The rat models currently employed for studies of nerve regeneration present distinct disadvantages. We propose a new technique of stretch-induced nerve injury, used here to evaluate the influence of gabapentin (GBP) on nerve regeneration. Male Wistar rats (300 g; n=36) underwent surgery and exposure of the median nerve in the right forelimbs, either with or without nerve injury. The technique was performed using distal and proximal clamps separated by a distance of 2 cm and a sliding distance of 3 mm. The nerve was compressed and stretched for 5 s until the bands of Fontana disappeared. The animals were evaluated in relation to functional, biochemical and histological parameters. Stretching of the median nerve led to complete loss of motor function up to 12 days after the lesion (P<0.001), compared to non-injured nerves, as assessed in the grasping test. Grasping force in the nerve-injured animals did not return to control values up to 30 days after surgery (P<0.05). Nerve injury also caused an increase in the time of sensory recovery, as well as in the electrical and mechanical stimulation tests. Treatment of the animals with GBP promoted an improvement in the morphometric analysis of median nerve cross-sections compared with the operated vehicle group, as observed in the area of myelinated fibers or connective tissue (P<0.001), in the density of myelinated fibers/mm2 (P<0.05) and in the degeneration fragments (P<0.01). Stretch-induced nerve injury seems to be a simple and relevant model for evaluating nerve regeneration. PMID:24270909

  11. Peripheral Nerve Injuries and Transplantation of Olfactory Ensheathing Cells for Axonal Regeneration and Remyelination: Fact or Fiction?

    PubMed Central

    Radtke, Christine; Kocsis, Jeffery D.

    2012-01-01

    Successful nerve regeneration after nerve trauma is not only important for the restoration of motor and sensory functions, but also to reduce the potential for abnormal sensory impulse generation that can occur following neuroma formation. Satisfying functional results after severe lesions are difficult to achieve and the development of interventional methods to achieve optimal functional recovery after peripheral nerve injury is of increasing clinical interest. Olfactory ensheathing cells (OECs) have been used to improve axonal regeneration and functional outcome in a number of studies in spinal cord injury models. The rationale is that the OECs may provide trophic support and a permissive environment for axonal regeneration. The experimental transplantation of OECs to support and enhance peripheral nerve regeneration is much more limited. This chapter reviews studies using OECs as an experimental cell therapy to improve peripheral nerve regeneration. PMID:23202929

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

    PubMed

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

    2013-10-01

    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

  13. The anatomy and fine structure of the echidna Tachyglossus aculeatus snout with respect to its different trigeminal sensory receptors including the electroreceptors

    Microsoft Academic Search

    K. H. Andres; A. Iggo; U. Proske

    1991-01-01

    The gross anatomy and nerve supply of the bill of echidna (Tachyglossus aculeatus) is described in relation to its function as an outstanding sensory organ. The sensory innervation of the skin of the echidna snout was investigated by means of frontal serial sections, after decalcification of the specimens. A comprehensive light and electron microscopic description of the location and fine

  14. Feeding-dependent activation of enteric cells and sensory neurons by lymphatic fluid: evidence for a neurolymphocrine system

    PubMed Central

    Poole, Daniel P.; Lee, Mike; Tso, Patrick; Bunnett, Nigel W.; Yo, Sek Jin; Lieu, TinaMarie; Shiu, Amy; Wang, Jen-Chywan; Nomura, Daniel K.

    2014-01-01

    Lymphatic fluid is a plasma filtrate that can be viewed as having biological activity through the passive accumulation of molecules from the interstitial fluid. The possibility that lymphatic fluid is part of an active self-contained signaling process that parallels the endocrine system, through the activation of G-protein coupled receptors (GPCR), has remained unexplored. We show that the GPCR lysophosphatidic acid 5 (LPA5) is found in sensory nerve fibers expressing calcitonin gene-related peptide (CGRP) that innervate the lumen of lymphatic lacteals and enteric nerves. Using LPA5 as a model for nutrient-responsive GPCRs present on sensory nerves, we demonstrate that dietary protein hydrolysate (peptone) can induce c-Fos expression in enterocytes and nerves that express LPA5. Mesenteric lymphatic fluid (MLF) mobilizes intracellular calcium in cell models expressing LPA5 upon feeding in a time- and dose-dependent manner. Primary cultured neurons of the dorsal root ganglia expressing CGRP are activated by MLF, which is enhanced upon LPA5 overexpression. Activation is independent of the known LPA5 agonists, lysophosphatidic acid and farnesyl pyrophosphate. These data bring forth a pathway for the direct stimulation of sensory nerves by luminal contents and interstitial fluid. Thus, by activating LPA5 on sensory nerves, MLF provides a means for known and yet to be identified constituents of the interstitial fluid to act as signals to comprise a “neurolymphocrine” system. PMID:24578341

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

    PubMed Central

    Mantyh, William G.; Jimenez-Andrade, Juan M.; Stake, James I.; Bloom, Aaron P.; Kaczmarska, Magdalena J.; Taylor, Reid N.; Freeman, Katie T.; Ghilardi, Joseph R.; Kuskowski, Michael A.; Mantyh, Patrick W.

    2010-01-01

    For many patients, pain is the first sign of cancer and, while pain can be present at any time, the frequency and intensity of pain tend to increase with advancing stages of the disease. Thus, between 75 and 90% of patients with metastatic or advanced-stage cancer will experience significant cancer-induced pain. One major unanswered question is why cancer pain increases and frequently becomes more difficult to fully control with disease progression. To gain insight into this question we used a mouse model of bone cancer pain to demonstrate that as tumor growth progresses within bone, Tropomyosin receptor kinase A (TrkA)-expressing sensory and sympathetic nerve fibers undergo profuse sprouting and form neuroma-like structures. To address what is driving the pathological nerve reorganization we administered an antibody to nerve growth factor (anti-NGF). Early sustained administration of anti-NGF, whose cognate receptor is TrkA, blocks the pathological sprouting of sensory and sympathetic nerve fibers, the formation of neuroma-like structures, and inhibits the development of cancer pain. These results suggest that cancer cells and their associated stromal cells release NGF, which induces a pathological remodeling of sensory and sympathetic nerve fibers. This pathological remodeling of the peripheral nervous system then participates in driving cancer pain. Similar to therapies that target the cancer itself, the data presented here suggest that the earlier that therapies blocking this pathological nerve remodeling are initiated, the more effective the control of cancer pain. PMID:20851743

  16. Evaluation of the function status of the ulnar nerve in carpal tunnel syndrome.

    PubMed

    Zhang, J; Liu, N; Wang, Y W; Zhang, Z C; Zheng, L N; Zhu, J

    2015-01-01

    Many carpal tunnel syndrome (CTS) patients have symptoms in both the median and ulnar digits more frequently than in the median digits alone. This is possibly because of close anatomical contiguity of the carpal tunnel and Guyon's canal, and the high pressure may also affect the latter, causing indirect compression of ulnar nerve fibers. Thus, we evaluated the functional status of the ulnar nerve in patients with CTS in order to investigate the relationship between ulnar nerve impairment and sensory symptoms of the ulnar territory. Electrophysiological studies were conducted in CTS patients and healthy controls. CTS patients were divided into the mild/moderate group and severe group; they were further divided into the symptomatic and asymptomatic subgroups according to the sensory symptom of the fifth digit region. The findings suggest that CTS patients could have coexisting ulnar nerve wrist entrapments that might exacerbate the severity of CTS. Sensory impairment in the ulnar territory was observed more frequently in the mild/moderate stage of CTS, which is associated with ulnar nerve involvement. These findings also suggest that damage to the ulnar nerve fibers caused by compression forces in Guyon's canal may underlie the ulnar spread of symptoms in CTS. PMID:25966136

  17. Conduction studies of the normal sural nerve.

    PubMed

    Horowitz, S H; Krarup, C

    1992-03-01

    The sural nerve was studied orthodromically using the near-nerve technique in 273 normal subjects (155 females, 118 males) aged 5 to 90 years. The sensory action potential (SAP), evoked at the dorsum of the foot, was recorded at the lateral malleolus and midcalf, and at the midcalf when evoked at the lateral malleolus. In addition, the SAP was recorded at intermediate distal sites and at proximal sites at the popliteal fossa, the gluteal fold, and the S-1 root. The amplitude of the SAP recorded at midcalf was 32% higher in females than in males. This was probably due to volume-conduction properties, as differences between genders were less noticeable at more distal recording sites. The amplitude decreased steeply and exponentially with age. Conduction distance had a strong influence on the amplitude of the SAP, which decreased with increasing distance following a power relationship with an exponent of 1.4 to 1.7. This decrease was due to temporal dispersion with decreased summation and increased phase cancellation. The conduction velocity was slightly lower along the very distal course of the nerve than along more proximal segments. PMID:1557087

  18. Nerve fiber planimetry in acute and chronic nerve lesions and in nerve lesions in continuity.

    PubMed

    Guelinckx, P J; Boeckx, W D; Dom, R; Gruwez, J A

    1985-10-01

    The level of resection of damaged nerve tissue in acute and chronic nerve lesions was determined on the basis of the vascular structure, the consistency of the nerve during palpation, the amount of interfascicular connective tissue, and the mushroom formation of the fascicles. Intraoperative electrophysiologic recordings were performed on the cut nerve ends to determine the function of the axons. Postoperative planimetric analyses of cross sections made through the resected nerve stumps were performed to measure axonal and endoneural tube diameters and to correlate these results with the clinical criteria used through the operating microscope. Axons in the proximal nerve ends of acute and chronic nerve lesions displayed a similar mean diameter. Endoneural tubes in chronic nerve lesions shrunk significantly as nerve repair was delayed. In several nerve lesions in continuity, axons remained present across the injured site despite absence of electrical conduction. When comparing the results of axonal or endoneural tube diameters of chronic nerve lesions to the results of other studies or acute nerve lesions, we demonstrated that careful examination through the operating microscope provided valid information about the proper management and resection level of chronic nerve lesions. Electrophysiologic evaluation aided the surgical management but was not useful for the resection of the distal damaged nerve segment. The presence of an evoked potential in the proximal nerve ends guaranteed a nearly normal nerve fiber diameter distribution, while the absence of such a potential in the distal nerve ends indicated an abnormal, absent, or disturbed endoneural tube diameter histogram. PMID:4034768

  19. Suprascapular nerve entrapment.

    PubMed

    Corň, L; Azuelos, A; Alexandre, A

    2005-01-01

    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

  20. Intracranial facial nerve reconstruction.

    PubMed

    Yammine, F G; Dufour, J J; Mohr, G

    1999-06-01

    Surgery for tumours of the cerebellopontine angle (CPA) or the internal auditory canal (IAC) is sometimes complicated by the severing of the seventh nerve. Many procedures are available for facial reanimation. Among these, primary intracranial VII-VII reanastomosis is considered as the method of choice. This series reviews all the cases of primary intracranial facial nerve reconstruction that we have performed either directly or with the use of a nerve graft interposition. Functional results are analyzed according to the House-Brackmann grading scale. The advantages and benefits of this technique are discussed as compared with other methods of facial reanimation, namely, the hypoglossal-facial anastomosis. PMID:10410348

  1. Laminin-based Nanomaterials for Peripheral Nerve Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Neal, Rebekah Anne

    Peripheral nerve transection occurs commonly in traumatic injury, causing motor and sensory deficits distal to the site of injury. One option for surgical repair is the nerve conduit. Conduits currently on the market are hollow tubes into which the nerve ends are sutured. Although these conduits fill the gap, they often fail due to the slow rate of regeneration over long gaps. To facilitate increased speed of regeneration and greater potential for functional recovery, the ideal conduit should provide biochemically relevant signals and physical guidance cues, thus playing an active role in peripheral nerve regeneration. In this dissertation, I fabricated laminin-1 and laminin-polycaprolactone (PCL) blend nanofibers that mimic the geometry and functionality of the peripheral nerve basement membrane. These fibers resist hydration in aqueous media and require no harsh chemical crosslinkers. Adhesion and differentiation of both neuron-like and neuroprogenitor cells is improved on laminin nanofibrous meshes over two-dimensional laminin substrates. Blend meshes with varying laminin content were characterized for composition, tensile properties, degradation rates, and bioactivity in terms of cell attachment and axonal elongation. I have established that 10% (wt) laminin content is sufficient to retain the significant neurite-promoting effects of laminin critical in peripheral nerve repair. In addition, I utilized modified collector plate design to manipulate electric field gradients during electrospinning for the fabrication of aligned nanofibers. These aligned substrates provide enhanced directional guidance cues to the regenerating axons. Finally, I replicated the clinical problem of peripheral nerve transection using a rat tibial nerve defect model for conduit implantation. When the lumens of conduits were filled with nanofiber meshes of varying laminin content and alignment, I observed significant recovery of sensory and motor function over six weeks. This recovery was 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.

  2. Metabotropic glutamate receptor mGlu2 is resistant to homologous agonist-induced desensitization but undergoes protein kinase C-mediated heterologous desensitization.

    PubMed

    Lennon, Siân M; Rivero, Guadalupe; Matharu, Annelise; Howson, Patrick A; Jane, David E; Roberts, Peter J; Kelly, Eamonn

    2010-12-15

    To investigate the susceptibility of the group II metabotropic glutamate receptor mGlu2 to agonist-induced desensitization, the receptor was stably expressed in Chinese hamster ovary (CHO-mGlu2) or C6 glioma cells (C6-mGlu2). Exposure of CHO-mGlu2 cells to the group II mGlu receptor agonist (2S,1'S,2'S)-2-(carboxycyclopropyl)glycine (LCCG-1; 10 ?M) for up to 15 h did not affect the subsequent ability of LCCG-1 to inhibit forskolin-stimulated cAMP accumulation. Similarly, in C6-mGlu2 cells, prolonged exposure to LCCG-1 also did not affect the subsequent ability of LCCG-1 to inhibit cAMP formation. In contrast, exposure of CHO-mGlu2 cells to the protein kinase C activator phorbol myristate acetate (PMA) suppressed the ability of LCCG-1 to inhibit cAMP formation. Using an in vitro model of group II mGlu receptor activity, the hemisected neonatal rat spinal cord preparation, the ability of the selective group II agonist (2R,4R)-4-aminopyrrolidine-2,4-dicarboxylate ((2R,4R)-APDC) to depress the fast component of the dorsal root-evoked ventral root potential (fDR-VRP) did not desensitize when applied for up to 2 h. Together these results indicate that in contrast to most G protein-coupled receptors, the mGlu2 receptor is resistant to agonist-induced homologous desensitization, and that in vitro data suggests that resistance to desensitization is a physiologically relevant property of this mGlu receptor subtype. PMID:20826132

  3. Sensory marketing: the multi-sensory brand-experience concept

    Microsoft Academic Search

    Bertil Hultén

    2011-01-01

    Purpose – The purpose of this paper is to present the multi-sensory brand-experience concept in relation to the human mind and senses. It also seeks to propose a sensory marketing (SM) model of the multi-sensory brand-experience hypothesis. Design\\/methodology\\/approach – This paper applies exploratory and explanatory approaches to investigating the multi-sensory brand-experience concept within the context of discovery. The qualitative study

  4. Affinity-based release of glial-derived neurotrophic factor from fibrin matrices enhances sciatic nerve regeneration†

    PubMed Central

    Wood, Matthew D.; Moore, Amy M.; Hunter, Daniel A.; Tuffaha, Sami; Borschel, Gregory H.; Mackinnon, Susan E.; Sakiyama-Elbert, Shelly E.

    2008-01-01

    Glial-derived neurotrophic factor (GDNF) promotes both sensory and motor neuron survival. The delivery of GDNF to the peripheral nervous system has been shown to enhance regeneration following injury. In this study we evaluated the effect of affinity-based delivery of GDNF from a fibrin matrix in a nerve guidance conduit on nerve regeneration in a 13 mm rat sciatic nerve defect. Seven experimental groups were evaluated which received GDNF or nerve growth factor (NGF) with the delivery system within the conduit, control groups excluding one or more components of the delivery system, and nerve isografts. Nerves were harvested 6 weeks after treatment for analysis by histomorphometry and electron microscopy. The use of the delivery system (DS) with either GDNF or NGF resulted in a higher frequency of nerve regeneration vs. control groups, as evidenced by a neural structure spanning the 13 mm gap. The GDNF DS and NGF DS groups were also similar to the nerve isograft group in measures of nerve fiber density, percent neural tissue and myelinated area measurements, but not in terms of total fiber counts. In addition, both groups contained a significantly greater percentage of larger diameter fibers, with GDNF DS having the largest in comparison to all groups, suggesting more mature neural content. The delivery of GDNF via the affinity-based delivery system can enhance peripheral nerve regeneration through a silicone conduit across a critical nerve gap and offers insight into potential future alternatives to the treatment of peripheral nerve injuries. PMID:19103514

  5. Ulnar nerve dysfunction

    MedlinePLUS

    ... surface of the body where it crosses the elbow. The damage destroys the nerve covering ( myelin sheath) ... be caused by: Long-term pressure on the elbow An elbow fracture or dislocation Temporary pain and ...

  6. Diabetic Nerve Problems

    MedlinePLUS

    ... the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get it. ... change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. Controlling ...

  7. Vagus Nerve Stimulation

    PubMed Central

    Howland, Robert H.

    2014-01-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  8. Vagus Nerve Stimulation.

    PubMed

    Howland, Robert H

    2014-06-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  9. Substance P: Localization in the Central Nervous System and in Some Primary Sensory Neurons

    Microsoft Academic Search

    Tomas Hokfelt; Jan Olof Kellerth; Goran Nilsson; Bengt Pernow

    1975-01-01

    Antibodies to substance P with a high titer have been produced and used in immunohistochemical studies on the peripheral and central nervous system of the rat and the cat. Evidence was obtained for the localization of substance P in a certain population of primary sensory neurons, probably small nerve cells with unmyelinated processes. Substance P or a peptide similar to

  10. In vivo enhancement of sensory perception recovery in a tissue-engineered skin enriched with laminin

    Microsoft Academic Search

    René Caissie; Marie Gingras; Marie-France Champigny; François Berthod

    2006-01-01

    The use of autologous reconstructed skin appears to be a promising treatment for the permanent coverage of deep and extensive burns. However, the capability of reconstructed skin transplanted on wounds to promote recovery of sensory perception is a major concern. Our aim was to assess the effect of laminin on cutaneous nerve regeneration. We prepared collagen-chitosan sponges enriched with 0,

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

    Microsoft Academic Search

    Eva Haker; Henrik Egekvist; Peter Bjerring

    2000-01-01

    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

  12. Neurotrophic modulation of myelinated cutaneous innervation and mechanical sensory loss in diabetic mice

    Microsoft Academic Search

    J. A. Christianson; J. M. Ryals; M. S. Johnson; R. T. Dobrowsky; D. E. Wright

    2007-01-01

    Human diabetic patients often lose touch and vibratory sensations, but to date, most studies on diabetes-induced sensory nerve degeneration have focused on epidermal C-fibers. Here, we explored the effects of diabetes on cutaneous myelinated fibers in relation to the behavioral responses to tactile stimuli from diabetic mice. Weekly behavioral testing began prior to streptozotocin (STZ) administration and continued until 8

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

    PubMed Central

    2013-01-01

    Background Hereditary spastic paraplegias (HSPs) are characterised by lower limb spasticity due to degeneration of the corticospinal tract. We set out for an electrophysiological characterisation of motor and sensory tracts in patients with HSP. Methods We clinically and electrophysiologically examined a cohort of 128 patients with genetically confirmed or clinically probable HSP. Motor evoked potentials (MEPs) to arms and legs, somato-sensory evoked potentials of median and tibial nerves, and nerve conduction studies of tibial, ulnar, sural, and radial nerves were assessed. Results Whereas all patients showed clinical signs of spastic paraparesis, MEPs were normal in 27% of patients and revealed a broad spectrum with axonal or demyelinating features in the others. This heterogeneity can at least in part be explained by different underlying genotypes, hinting for distinct pathomechanisms in HSP subtypes. In the largest subgroup, SPG4, an axonal type of damage was evident. Comprehensive electrophysiological testing disclosed a more widespread affection of long fibre tracts involving peripheral nerves and the sensory system in 40%, respectively. Electrophysiological abnormalities correlated with the severity of clinical symptoms. Conclusions Whereas HSP is primarily considered as an upper motoneuron disorder, our data suggest a more widespread affection of motor and sensory tracts in the central and peripheral nervous system as a common finding in HSP. The distribution patterns of electrophysiological abnormalities were associated with distinct HSP genotypes and could reflect different underlying pathomechanisms. Electrophysiological measures are independent of symptomatic treatment and may therefore serve as a reliable biomarker in upcoming HSP trials. PMID:24107482

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

    PubMed Central

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

    2013-01-01

    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

  15. cAMP-induced desensitization of surface cAMP receptors in Dictyostelium: different second messengers mediate receptor phosphorylation, loss of ligand binding, degradation of receptor, and reduction of receptor mRNA levels.

    PubMed Central

    Van Haastert, P J; Wang, M; Bominaar, A A; Devreotes, P N; Schaap, P

    1992-01-01

    Surface cAMP receptors on Dictyostelium cells are linked to several second messenger systems and mediate multiple physiological responses, including chemotaxis and differentiation. Activation of the receptor also triggers events which desensitize signal transduction. These events include the following: 1) loss of ligand binding without loss of receptor protein; 2) phosphorylation of the receptor protein, which may lead to impaired signal transduction; 3) redistribution and degradation of the receptor protein; and 4) decrease of cyclic AMP (cAMP) receptor mRNA levels. These mechanisms of desensitization were investigated with the use of mutant synag7, with no activation of adenylyl cyclase; fgdC, with no activation of phospholipase C; and fgdA, with defects in both pathways. cAMP-induced receptor phosphorylation and loss of ligand binding activity was normal in all mutants. In contrast, cAMP-induced degradation of the receptor was absent in all mutants. The cAMP-induced decrease of cAMP-receptor mRNA levels was normal in mutant synag7, but absent in mutant fgdC. Finally, the cAMP analogue (Rp)-cAMPS induced loss of ligand binding without inducing second messenger responses or phosphorylation, redistribution, and degradation of the receptor. We conclude that 1) loss of ligand binding can occur in the absence of receptor phosphorylation; 2) loss of ligand binding and receptor phosphorylation do not require the activation of second messenger systems; 3) cAMP-induced degradation of the receptor may require the phosphorylation of the receptor as well as the activation of at least the synag7 and fgdC gene products; and 4) cAMP-induced decrease of receptor mRNA levels requires the activation of the fgdC gene product and not the synag7 gene product. These results imply that desensitization is composed of multiple components that are regulated by different but partly overlapping sensory transduction pathways. Images PMID:1323348

  16. Alkaline phosphatase relieves desensitization of adenylate cyclase-coupled beta-adrenergic receptors in avian erythrocyte membranes

    SciTech Connect

    Stadel, J.M.; Rebar, R.; Crooke, S.T.

    1987-05-01

    Desensitization of adenylate cyclase-coupled ..beta..-adrenergic receptors in avian erythrocytes results in 40-65% decrease in agonist-stimulated adenylate cyclase activity and correlates with increased phosphorylation of ..beta..-adrenergic receptors. To assess the role of phosphorylation in desensitization, membranes from isoproterenol- and cAMP-desensitized turkey erythrocytes were incubated with alkaline phosphatase for 30 min at 37/sup 0/C, pH = 8.0. In both cases alkaline phosphatase treatment significantly reduced desensitization of agonist-stimulated adenylate cyclase activity by 40-60%. Similar results were obtained following alkaline phosphatase treatment of membranes from isoproterenol- and cAMP-desensitized duck erythrocytes. In addition, alkaline phosphatase treatment of membranes from duck erythrocytes desensitized with phorbol 12-mystrate 13-acetate returned adenylate cyclase activity to near control values. In all experiments inclusion of 20 mM NaPO/sub 4/ to inhibit alkaline phosphatase during treatment of membranes blocked the enzyme's effect on agonist-stimulated adenylate cyclase activity. These results demonstrate a role for phosphorylation in desensitization of adenylate cyclase-coupled ..beta..-adrenergic receptors in avian erythrocytes.

  17. Optic nerve aspergillosis.

    PubMed

    Yuan, Lisi; Prayson, Richard A

    2015-07-01

    We report a 55-year-old woman with optic nerve Aspergillosis. Aspergillus is an ubiquitous airborne saprophytic fungus. Inhaled Aspergillus conidia are normally eliminated in the immunocompetent host by innate immune mechanisms; however, in immunosuppressed patients, they can cause disease. The woman had a past medical history of hypertension and migraines. She presented 1year prior to death with a new onset headache behind the left eye and later developed blurred vision and scotoma. A left temporal artery biopsy was negative for giant cell arteritis. One month prior to the current admission, she had an MRI showing optic nerve thickening with no other findings. Because of the visual loss and a positive antinuclear antibody test, she was given a trial of high dose steroids and while it significantly improved her headache, her vision did not improve. At autopsy, the left optic nerve at the level of the cavernous sinus and extending into the optic chiasm was enlarged in diameter and there was a 1.3cm firm nodule surrounding the left optic nerve. Histologically, an abscess surrounded and involved the left optic nerve. Acute angle branching, angioinvasive fungal hyphae were identified on Grocott's methenamine silver stained sections, consistent with Aspergillus spp. No gross or microscopic evidence of systemic vasculitis or infection was identified in the body. The literature on optic nerve Aspergillosis is reviewed. PMID:25861888

  18. Sublingual-Oral Rush Desensitization to Mixed Cow and Sheep Milk: A Case Report

    Microsoft Academic Search

    E Nucera; D Schiavino; A Buonomo; E Pollastrini; G Altomonte; V Pecora; M Decinti; C Lombardo; G Patriarca

    ? Abstract We attempted an oral rush desensitization with mixed cow and sheep milk in a 6-year-old boy who had had adverse reactions to cow and goat milks. Skin prick tests and specifi c immunoglobulin (Ig) E to cow, sheep and goat milks were positive. The double-blind, placebo- controlled food challenge with cow milk was positive too. He underwent a

  19. A Comparison of Systematic Desensitization and Conditioned Relaxation in Reducing Speech Anxiety.

    ERIC Educational Resources Information Center

    Heald, Gary R.

    Speech and communication departments at several universities currently offer behavioral training programs aimed at reducing communication-related anxiety. Traditionally, these programs involve the use of a "systematic desensitization" training method. An alternative behavioral training method is found in "conditioned relaxation." This paper…

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

    Microsoft Academic Search

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

    2007-01-01

    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

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

    Microsoft Academic Search

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

    2006-01-01

    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

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

    Microsoft Academic Search

    Jeanne B. Funk

    2006-01-01

    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

  3. Expectancy, False Galvanic Skin Response Feedback, and Systematic Desensitization in the Modification of Phobic Behavior

    ERIC Educational Resources Information Center

    Lick, John

    1975-01-01

    This study compared systematic desensitization and two pseudotherapy manipulations with and without false galvanic skin response feedback after every session suggesting improvement in the modification of intense snake and spider fear. The results indicated no consistent differences between the three treatment groups. (Author)

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

    ERIC Educational Resources Information Center

    MacCluskie, Kathryn C.

    1998-01-01

    States that within the last six years a new therapeutic technique for the treatment of posttraumatic stress disorder, Eye Movement Desensitization and Reprocessing (EMDR), has emerged. Examines the strengths and weaknesses of published studies concerning EMDR, describes the nature of the debate about the efficacy of EMDR, and reviews implications…

  5. Eye Movement Desensitization and Reprocessing (EMDR) Treatment for Psychologically Traumatized Individuals.

    ERIC Educational Resources Information Center

    Wilson, Sandra A.; And Others

    1995-01-01

    Studies the effects of 3 90-minute Eye Movement Desensitization and Reprocessing (EMDR) treatment sessions on traumatic memories of 80 participants. Participants receiving EMDR showed decreases in complaints and anxiety, and increases in positive cognition. Participants in the delayed-treatment condition showed no improvement in any measures in…

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

    ERIC Educational Resources Information Center

    Protinsky, Howard; Sparks, Jennifer; Flemke, Kimberly

    2001-01-01

    Eye Movement Desensitization and Reprocessing (EMDR) as a clinical technique may enhance treatment effectiveness when applied in couple therapy that is emotionally and experientially oriented. Clinical experience indicates EMDR-based interventions are useful for accessing and reprocessing intense emotions in couple interactions. EMDR can amplify…

  7. Molecular mechanism identified for activation and desensitization of prominent neurotransmitter receptor in the brain

    Cancer.gov

    Scientists at the NIH have used a technique called cryo-electron microscopy to determine a molecular mechanism for the activation and desensitization of ionotropic glutamate receptors, a prominent class of neurotransmitter receptors in the brain and spinal cord that have also been implicated in some cancers.

  8. Etomidate uniquely modulates the desensitization of recombinant ?1?3? GABAA receptors.

    PubMed

    Liu, K; Jounaidi, Y; Forman, S A; Feng, H-J

    2015-08-01

    Central GABAA receptors mediate GABAergic phasic and tonic inhibition. While synaptic ??? GABAA receptors primarily mediate phasic inhibition, extrasynaptic ??? receptors play an important role in mediating tonic inhibition. Etomidate is a general anesthetic that produces its effects by enhancing GABAA receptor activity. We previously showed that etomidate modulates the gating of oocyte-expressed ??? and ??? receptors with similar overall allosteric impact, but different pharmacological patterns. In ??? receptors, etomidate enhances apparent GABA sensitivity (reduces GABA EC50), modestly increases maximal GABA efficacy, and slows current deactivation without affecting desensitization (Zhong et al., 2008). In ??? receptors characterized by low GABA efficacy, etomidate dramatically increases responses to both low and maximal GABA. The effects of etomidate on desensitization and deactivation of ??? receptors are unknown. To investigate the kinetic effects of etomidate on ?1?3? receptors of defined subunit arrangement, we expressed concatenated trimer (?3-?1-?) and dimer (?3-?1) GABAA receptor subunit assemblies in human embryonic kidney (HEK)293T cells and recorded whole-cell voltage-clamp currents during rapid external solution exchanges. As expected, etomidate substantially increased maximal GABA-induced currents and prolonged deactivation. Moreover, desensitization was significantly decreased by etomidate. During prolonged GABA applications, etomidate enhanced steady-state currents more than peak currents. Thus, etomidate enhances tonic GABAergic inhibition through extrasynaptic ??? receptors by both augmenting gating and reducing desensitization. PMID:26028470

  9. Ceftaroline Desensitization Procedure in a Pregnant Patient With Multiple Drug Allergies

    PubMed Central

    Kuhlen, James L.; Blumenthal, Kimberly G.; Sokol, Caroline L.; Balekian, Diana S.; Weil, Ana A.; Varughese, Christy A.; Shenoy, Erica S.; Banerji, Aleena

    2015-01-01

    Validated skin testing is lacking for many drugs, including ceftaroline. The cross-reactivity between ceftaroline and other ?-lactam antibiotics is unknown. We report a case of a pregnant patient with cystic fibrosis and multiple drug allergies who required ceftaroline for methicillin-resistant Staphylococcus aureus pneumonia and underwent an uncomplicated empiric desensitization procedure.

  10. Post-traumatic stress disorder overcome by eye-movement desensitization: A case report

    Microsoft Academic Search

    JOSEPH WOLPE; JANET ABRAMS

    1991-01-01

    Summary - Post-traumatic stress disorder is an exceptionally stressful syndrome that has been extremely difficult to treat. The prognosis was recently dramatically improved by the introduction of eye-movement desensitization. This paper reports, in substantial detail, a case that was precipitated by a rape 10 years earlier, describing its manifestations and various unsuccessful attempts to treat it; followed by a detailed

  11. INJECTION FROM A TIP TRENCH AS A TURBINE TIP DESENSITIZATION METHOD

    E-print Network

    Camci, Cengiz

    the tip leakage vortex measured downstream of a turbine rotor. The coolant flow is usually bled out fromCC-122 INJECTION FROM A TIP TRENCH AS A TURBINE TIP DESENSITIZATION METHOD Part 2 : Leakage flow.edu http://www.personal.psu.edu/cxc11/ Abstract In Part 1 of this paper it was shown that discrete jets

  12. AMPA Receptor Flip\\/Flop Mutants Affecting Deactivation, Desensitization, and Modulation by Cyclothiazide, Aniracetam, and Thiocyanate

    Microsoft Academic Search

    Kathryn M. Partin; Mark W. Fleck; Mark L. Mayer

    1996-01-01

    AMPA receptor GluRA subunits with mutations at position 750, a residue shown previously to control allosteric regulation by cyclothiazide, were analyzed for modulation of deactivation and desensitization by cyclothiazide, aniracetam, and thiocyanate. Point mutations from Ser to Asn, Ala, Asp, Gly, Gln, Met, Cys, Thr, Leu, Val, and Tyr were constructed in GluRAflip. The last four of these mutants were

  13. Hemodynamic responses of eye movement desensitization and reprocessing in posttraumatic stress disorder

    Microsoft Academic Search

    Toshiyuki Ohta ni; Koji Matsuo; Kiyoto Kasai; Tadafumi Kato; Nobumasa Kato

    2009-01-01

    Eye movement desensitization and reprocessing (EMDR) is an effective psychological intervention for posttraumatic stress disorder (PTSD). Trauma-related recall (Recall) with eye movements (EMs) is thought to reduce distress. However, the neural mechanisms underlying this process remain unknown. Thirteen patients with PTSD received EMDR treatment over the course of 2–10 weeks. We assessed the change in hemoglobin concentration in the lateral

  14. Eye Movement Desensitization and Reprocessing in the Treatment of Panic Disorder With Agoraphobia

    Microsoft Academic Search

    Isabel Fernandez; Elisa Faretta

    2007-01-01

    This article describes a comprehensive treatment of a case of panic disorder with agoraphobia. A thorough history taking revealed that experiential contributors had a pivotal role in the development of the condition. Therefore, eye movement desensitization and reprocessing (EMDR) was used to address early traumatic events as well as the present stimuli that caused disturbance and had maintained symptomatology for

  15. Carboxyl-terminal domain of transient receptor potential vanilloid 1 contains distinct segments differentially involved in capsaicin- and heat-induced desensitization.

    PubMed

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

    2013-12-13

    Multiple Ca(2+)-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 Ca(2+), 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 Lys(155), 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

  16. Ultrasound in Dual Nerve Impairment after Proximal Radial Nerve Lesion

    PubMed Central

    Lämmer, Alexandra B; Schwab, Stefan; Schramm, Axel

    2015-01-01

    Introduction Sonography in classical nerve entrapment syndromes is an established and validated method. In contrast, few publications highlight lesions of the radial nerve, particularly of the posterior interosseus nerve (PIN). Method Five patients with a radial nerve lesion were investigated by electromyography, nerve conduction velocity and ultrasound. Further normative values of 26 healthy subjects were evaluated. Results Four patients presented a clinical and electrophysiological proximal axonal radial nerve lesion and one patient showed a typical posterior interosseous nerve syndrome (PINS). The patient with PINS presented an enlargement of the PIN anterior to the supinator muscle. However four patients with proximal lesions showed an unexpected significant enlargement of the PIN within the supinator muscle. Conclusion High-resolution sonography is a feasible method to demonstrate the radial nerve including its distal branches. At least in axonal radial nerve lesions, sonography might reveal abnormalities far distant from a primary proximal lesion site clearly distinct from the appearance in classical PINS. PMID:25992766

  17. Effectiveness of Nicotinic Agonists as Desensitizers at Presynaptic ?4?2- and ?4?5?2-Nicotinic Acetylcholine Receptors

    PubMed Central

    2014-01-01

    Introduction: Nicotine interacts with nicotinic acetylcholine receptors (nAChRs) and modifies neuronal functions. The net result of nicotine exposure is difficult to assess because multiple nAChR subtypes exist and are expressed on multiple classes of neurons. Nicotine, unlike the natural agonist acetylcholine, remains in tissues for hours, and during this extended exposure nAChRs desensitize. Therefore, agonists can block the natural functions of nAChRs. Higher nicotine concentrations are required to desensitize ?4?2-nAChRs containing the ?5 subunit. The aim of these experiments was to determine if this property holds true for compounds other than nicotine. Methods: [3H]-dopamine release from crude mouse striatal synaptosomal preparations was used to measure activation and desensitization of the [(?4?2)2?2] and [(?4?2)2?5] nAChR subtypes. Affinity was measured by competition with [125I]-epibatidine. Results: Nine compounds of varying affinity and efficacy were tested. All compounds partially desensitized both subtypes; concentration necessary for desensitization correlated with binding site affinity but not efficacy. All compounds showed a similar, significant shift in concentration necessary for a 50% effect when the ?5 subunit was included (averaging 8-fold higher). The extent of desensitization produced by a 10-min exposure did not correlate with affinity or efficacy of compound. Conclusion: Full or partial nicotinic agonists used as medications may effectively desensitize ?4?2-nAChRs. However, significantly higher concentrations of all compounds tested were required to elicit desensitization of ?4?5?2-nAChRs than ?4?2-nAChRs. If desensitization is the important property for a smoking cessation drug, basic screening at both subtypes may provide a mechanistic foundation for effectiveness. PMID:24052501

  18. Role of G Protein-Coupled Receptor Kinases 2 and 3 in ?-Opioid Receptor Desensitization and Internalization.

    PubMed

    Lowe, Janet D; Sanderson, Helen S; Cooke, Alexandra E; Ostovar, Mehrnoosh; Tsisanova, Elena; Withey, Sarah L; Chavkin, Charles; Husbands, Stephen M; Kelly, Eamonn; Henderson, Graeme; Bailey, Chris P

    2015-08-01

    There is ongoing debate about the role of G protein-coupled receptor kinases (GRKs) in agonist-induced desensitization of the ?-opioid receptor (MOPr) in brain neurons. In the present paper, we have used a novel membrane-permeable, small-molecule inhibitor of GRK2 and GRK3, Takeda compound 101 (Cmpd101; 3-[[[4-methyl-5-(4-pyridyl)-4H-1,2,4-triazole-3-yl] methyl] amino]-N-[2-(trifuoromethyl) benzyl] benzamidehydrochloride), to study the involvement of GRK2/3 in acute agonist-induced MOPr desensitization. We observed that Cmpd101 inhibits the desensitization of the G protein-activated inwardly-rectifying potassium current evoked by receptor-saturating concentrations of methionine-enkephalin (Met-Enk), [d-Ala(2), N-MePhe(4), Gly-ol(5)]-enkephalin (DAMGO), endomorphin-2, and morphine in rat and mouse locus coeruleus (LC) neurons. In LC neurons from GRK3 knockout mice, Met-Enk-induced desensitization was unaffected, implying a role for GRK2 in MOPr desensitization. Quantitative analysis of the loss of functional MOPrs following acute agonist exposure revealed that Cmpd101 only partially reversed MOPr desensitization. Inhibition of extracellular signal-regulated kinase 1/2, protein kinase C, c-Jun N-terminal kinase, or GRK5 did not inhibit the Cmpd101-insensitive component of desensitization. In HEK 293 cells, Cmpd101 produced almost complete inhibition of DAMGO-induced MOPr phosphorylation at Ser(375), arrestin translocation, and MOPr internalization. Our data demonstrate a role for GRK2 (and potentially also GRK3) in agonist-induced MOPr desensitization in the LC, but leave open the possibility that another, as yet unidentified, mechanism of desensitization also exists. PMID:26013542

  19. Novel targeted sensory reinnervation technique to restore functional hand sensation after transhumeral amputation.

    PubMed

    Hebert, Jacqueline S; Olson, Jaret L; Morhart, Michael J; Dawson, Michael R; Marasco, Paul D; Kuiken, Todd A; Chan, K Ming

    2014-07-01

    We present a case study of a novel variation of the targeted sensory reinnervation technique that provides additional control over sensory restoration after transhumeral amputation. The use of intraoperative somatosensory evoked potentials on individual fascicles of the median and ulnar nerves allowed us to specifically target sensory fascicles to reroute to target cutaneous nerves at a distance away from anticipated motor sites in a transhumeral amputee. This resulted in restored hand maps of the median and ulnar nerve in discrete spatially separated areas. In addition, the subject was able to use native and reinnervated muscle sites to control a robotic arm while simultaneously sensing touch and force feedback from the robotic gripper in a physiologically correct manner. This proof of principle study is the first to demonstrate the ability to have simultaneous dual flow of information (motor and sensory) within the residual limb. In working towards clinical deployment of a sensory integrated prosthetic device, this surgical method addresses the important issue of restoring a usable access point to provide natural hand sensation after upper limb amputation. PMID:24760915

  20. Subthreshold Desensitization of Human Basophils Re-capitulates the Loss of syk and Fc?RI expression Characterized by Other Methods of Desensitization

    PubMed Central

    MacGlashan, Donald

    2012-01-01

    Background Clinical desensitization of patients to drugs involves progressive exposure to escalating doses of drug over a period of 24 hours. In prior studies, this method was recapitulated in vitro to also demonstrate loss of mast cell or basophil responsiveness. However, most signaling studies of human basophils have identified changes in signaling by using other methods of inducing cellular desensitization. Objective This study examined two well-described endpoints of basophil desensitization, loss of syk or Fc?RI expression, under conditions of subthreshold desensitization. Methods The loss of FceRI and syk was examined in human basophils. Results It was shown that both loss of syk and Fc?RI/IgE occurred during an escalating series of stimulation (anti-IgE Ab) and that expression loss occurred despite the presence of little histamine release. If basophils were first cultured for 3 days in 10 ng/ml IL-3, the concentration-dependence of histamine release shifted to 100 fold lower concentrations of stimulus. However, loss of syk did not show any change in its EC50 while loss of Fc?RI also shifted 100 fold. From the perspective of early signal element activation, the marked shift in the EC50 for histamine release was not accompanied by similar shifts in the EC50s for several signaling elements. The EC50s for phospho-Src, phospho-SHIP1, phospho-Syk, or phospho-Cbl did not change while the EC50s for phospho-Erk and the cytosolic calcium response did shift 100 fold. Conclusions These studies show that under normal conditions, subthreshold desensitization leads to loss of two critical signaling molecules (Fc?RI and syk) but under at least one condition, treatment with IL-3, it is possible to markedly blunt the loss of syk, but not Fc?RI, while executing a proper subthreshold titration. These data also suggest that IL-3 modifies only the sensitivity of signaling elements that are downstream of syk activation. PMID:22702505

  1. Structured Sensory Trauma Interventions

    ERIC Educational Resources Information Center

    Steele, William; Kuban, Caelan

    2010-01-01

    This article features the National Institute of Trauma and Loss in Children (TLC), a program that has demonstrated via field testing, exploratory research, time series studies, and evidence-based research studies that its Structured Sensory Intervention for Traumatized Children, Adolescents, and Parents (SITCAP[R]) produces statistically…

  2. Brief electrical stimulation improves nerve regeneration after delayed repair in Sprague Dawley rats.

    PubMed

    Elzinga, Kate; Tyreman, Neil; Ladak, Adil; Savaryn, Bohdan; Olson, Jaret; Gordon, Tessa

    2015-07-01

    Functional recovery after peripheral nerve injury and surgical repair declines with time and distance because the injured neurons without target contacts (chronic axotomy) progressively lose their regenerative capacity and chronically denervated Schwann cells (SCs) atrophy and fail to support axon regeneration. Findings that brief low frequency electrical stimulation (ES) accelerates axon outgrowth and muscle reinnervation after immediate nerve surgery in rats and human patients suggest that ES might improve regeneration after delayed nerve repair. To test this hypothesis, common peroneal (CP) neurons were chronically axotomized and/or tibial (TIB) SCs and ankle extensor muscles were chronically denervated by transection and ligation in rats. The CP and TIB nerves were cross-sutured after three months and subjected to either sham or one hour 20Hz ES. Using retrograde tracing, we found that ES significantly increased the numbers of both motor and sensory neurons that regenerated their axons after a three month period of chronic CP axotomy and/or chronic TIB SC denervation. Muscle and motor unit forces recorded to determine the numbers of neurons that reinnervated gastrocnemius muscle demonstrated that ES significantly increased the numbers of motoneurons that reinnervated chronically denervated muscles. We conclude that electrical stimulation of chronically axotomized motor and sensory neurons is effective in accelerating axon outgrowth into chronically denervated nerve stumps and improving target reinnervation after delayed nerve repair. Possible mechanisms for the efficacy of ES in promoting axon regeneration and target reinnervation after delayed nerve repair include the upregulation of neurotrophic factors. PMID:25842267

  3. The relationship between lingual and hypoglossal nerve function and quality of life in head and neck cancer.

    PubMed

    Elfring, T; Boliek, C A; Winget, M; Paulsen, C; Seikaly, H; Rieger, J M

    2014-02-01

    Sensorimotor impairment of the tongue has the potential to affect speech and swallowing. The purpose of this study was to critically examine the effects of nerve preservation and reinnervation after reconstruction of the base of tongue on patient-perceived outcomes of quality of life (QoL) related to speech and swallowing through completion of the EORTC QLQ-H&N35 standardised questionnaire. Thirty participants with a diagnosis of base of tongue cancer underwent primary resection and reconstruction with a radial forearm free flap, which may or may not have included nerve repair to the lingual nerve, hypoglossal nerve or both. Eight QoL domains sensitive to changes in motor and sensory nerve function were included in the analysis. Transected lingual and hypoglossal nerves were associated with difficulty in swallowing, social eating, dry mouth and social contact. There were fewer problems reported when these nerves were either repaired or left intact. There were no significant differences between patient nerve status and QoL outcomes for speech, sticky saliva and use of feeding tubes. This study was the first to examine the impact of sensory or motor nerve transection and reconstruction on health-related QoL outcomes. PMID:24289234

  4. Sensory prediction for autonomous robots

    Microsoft Academic Search

    Ryo Saegusa; Francesco Nori; Giulio Sandini; Giorgio Metta; Sophie Sakka

    2007-01-01

    For a complex autonomous robotic system such as a humanoid robot, the learning-based sensory prediction is considered effective to develop a perceptual environment model by itself. We developed a learning system for an autonomous robot to predict the next sensory information from the current sensory information and the expected action. The system we consider contains a learning procedure and a

  5. Sensory Integration in Mental Health

    Microsoft Academic Search

    Barbara W. Posthuma

    1983-01-01

    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

  6. Bandwidth dependency of cochlear centrifugal pathways in modulating hearing desensitization caused by loud sound.

    PubMed

    Rajan, R

    2007-07-29

    Centrifugal olivocochlear (OC) pathways modulate cochlear hearing desensitization induced by loud sounds, but there is a null point, determined by sound bandwidth, for this effect. In a previous study, using loud sounds from the region of greatest hearing sensitivity in cats, OC pathways did not affect desensitization induced by 2-kHz wide noise, but did to narrower bandwidth (tones) or broader bandwidth (3.5 kHz-wide or 5 kHz-wide noise) trauma from the same cochlear region. The bandwidth null-point effect occurred in three very different conditions in which OC pathways modulated losses to narrower or broader bandwidth traumata, confirming the robustness of this phenomenon, and was also true for sub-component OC pathways: neither crossed nor uncrossed OC pathways individually modulated desensitization to that 2 kHz-wide noise. The medial olivocochlear system (MOCS) that is most likely to have modulated desensitization in that study, varies in its cochlear distribution; in cats, densest innervation is in the region of greatest hearing sensitivity and the decrease away from that region means MOCS effects there may not translate to other regions. This hypothesis was now tested in lower- (around 4 kHz) and higher- (around 18 kHz) frequency cochlear regions. Across this fairly large cochlear swath, no OC modulation of desensitization occurred to 2-kHz-wide bandwidth sounds, but did to broader bandwidth; thus the bandwidth dependency was constant across this swath. However, when OC effects did occur, the pattern of effects of OC sub-components could be idiosyncratic to sound bandwidth and cochlear region even for similar net OC effects. PMID:17600627

  7. Length of the TM3-4 loop of the glycine receptor modulates receptor desensitization.

    PubMed

    Langlhofer, G; Janzen, D; Meiselbach, Heike; Villmann, C

    2015-07-23

    Recent studies on the molecular determinants important for glycine receptor biogenesis and function mechanisms indicate an important role of basic residues within the intracellular loop between transmembrane domains (TM) 3 and 4. We investigate the role of loop length and loop exchange in combination with the presence or absence of basic stretches (318)RRKRR and (385)KKIDK of the human glycine receptor ?1 using expression in transfected cell lines. Exchanges of the large intracellular loop between members of the Cys-loop receptor family have been shown to keep functionality of the host receptor. Here, constructs were generated with deletion of the intracellular loop of the glycine receptor ?1, insertion of the loop from the prokaryotic Cys-loop receptor of Gloeobacter violaceus both with and without leaving the basic stretches at the N-terminal and C-terminal part of the intracellular domain. All receptor constructs were expressed at the cell surface with the significantly lowest expression of the construct with a deletion of the glycine receptor ?1 TM3-4 loop, except the two basic stretches adjoined. Functionality of the inhibitory glycine receptor chimeras was demonstrated with whole cell recordings from transfected cells. Chimeras lacking the basic stretches result in non-functionality. An analysis of receptor desensitization demonstrated that close proximity of both basic stretches resulted in large fractions of desensitizing currents. We conclude that the TM3-4 loop length is critical for glycine receptor ?1 desensitization and a direct neighborhood of both basic stretches changes receptor properties from non-desensitizing to desensitizing. PMID:26079326

  8. Serotoninergic modulation of sensory transmission to brainstem reticulospinal cells.

    PubMed

    Antri, Myriam; Auclair, François; Albrecht, Jonathan; Djeudjang, Nsima; Dubuc, Réjean

    2008-08-01

    Sensory inputs are subjected to modulation by central neural networks involved in controlling movements. It has been shown that serotonin (5-HT) modulates sensory transmission. This study examines in lampreys the effects of 5-HT on sensory transmission to brainstem reticulospinal (RS) neurons and the distribution of 5-HT cells that innervate RS cells. Cells were recorded intracellularly in the in vitro isolated brainstem of larval lampreys. Trigeminal nerve stimulation elicited disynaptic excitatory responses in RS neurons, and bath application of 5-HT reduced the response amplitude with maximum effect at 10 mum. Local ejection of 5-HT either onto the RS cells or onto the relay cells decreased sensory-evoked excitatory postsynaptic potentials (EPSPs) in RS cells. The monosynaptic EPSPs elicited from stimulation of the relay cells were also reduced by 5-HT. The reduction was maintained after blocking either N-methyl-d-aspartate (NMDA) or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors. The local ejection of glutamate over RS cells elicited excitatory responses that were only slightly depressed by 5-HT. In addition, 5-HT increased the threshold for eliciting sustained depolarizations in response to trigeminal nerve stimulation but did not prevent them. Combined 5-HT immunofluorescence with axonal tracing revealed that the 5-HT innervation of RS neurons of the middle rhombencephalic reticular nucleus comes mainly from neurons in the isthmic region, but also from neurons located in the pretectum and caudal rhombencephalon. Our results indicate that 5-HT modulates sensory transmission to lamprey brainstem RS cells. PMID:18702689

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

    PubMed Central

    2013-01-01

    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

  10. Vesicourethral function in diabetic patients: association of abnormal nerve conduction velocity with vesicourethral dysfunction.

    PubMed

    Mitsui, T; Kakizaki, H; Kobayashi, S; Morita, H; Matsumura, K; Koyanagi, T

    1999-01-01

    This study was undertaken to examine diabetic vesicourethral dysfunction in association with nerve conduction velocity. Uroflowmetry, water cystometry, International Prostate Symptom Score (IPSS), and nerve conduction velocity were analyzed in 29 diabetic patients (21 men and eight women; a mean age, 58.0 years). Nerve conduction velocity was measured for sensory nerve conduction velocity (SCV) of the sural nerve and motor nerve conduction velocity (MCV) of the peroneal nerve. Normal voiding was defined as continuous flow at the normal flow rate and residual urine <50 mL. Results of uroflowmetry and cystometry were compared with those of nerve conduction velocity. Eleven of 29 patients (38%) had voiding dysfunction. A vesical denervation supersensitivity test was negative in all patients. The mean IPSS was not significant different between patients with or without voiding dysfunction. Incidence of bladder volume at first desire to void >300 mL and maximum bladder capacity >500 mL were significantly higher in patients with abnormal SCV than those with normal SCV (P < 0.03 and 0.001, respectively). Eleven of 16 patients with abnormal MCV showed voiding dysfunction, whereas all patients with normal MCV showed normal voiding (P < 0.001). These results suggest that lower urinary tract symptoms alone cannot predict diabetic vesicourethral dysfunction and that diabetic vesicourethral dysfunction is highly correlated with abnormal nerve conduction velocity. Neurourol. Urodynam. 18:639-645, 1999. PMID:10529712

  11. Repair of sciatic nerve defects using tissue engineered nerves

    PubMed Central

    Zhang, Caishun; Lv, Gang

    2013-01-01

    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

  12. The Response of Dorsal Root Ganglion Axons to Nerve Growth Factor Gradients Depends on Spinal Level

    E-print Network

    Goodhill, Geoffrey J.

    of NGF increases nerve regeneration and prevents axotomy-induced neuronal changes, highlighting regeneration and the guidance response of peripheral neurons to gradients of NGF have not been systematically Irina Vetter,1, * Zac Pujic,1, * and Geoffrey J. Goodhill1,2 Abstract Directed sensory axon regeneration

  13. Optical Parameter Variability in Laser Nerve Stimulation: a study of pulse duration, repetition rate, and wavelength

    Microsoft Academic Search

    Agnella D. Izzo; Joseph T. Walsh; E. Duco Jansen; Mark Bendett; Jim Webb; Heather Ralph; Claus-Peter Richter

    2006-01-01

    Pulsed lasers can evoke neural activity from motor as well as sensory neurons in vivo. Lasers allow more selective spatial resolution of stimulation than the conventional electrical stimulation. To date, few studies have examined pulsed, mid-infrared laser stimulation of nerves and very little of the available optical parameter space has been studied. In this study, a pulsed diode laser, with

  14. Optical Parameter Variability in Laser Nerve Stimulation: A Study of Pulse Duration, Repetition Rate, and Wavelength

    Microsoft Academic Search

    Agnella D. Izzo; Joseph T. Walsh; E. Duco Jansen; Mark Bendett; Jim Webb; Heather Ralph; Claus-Peter Richter

    2007-01-01

    Pulsed lasers can evoke neural activity from motor as well as sensory neurons in vivo. Lasers allow more selective spatial resolution of stimulation than the conventional electrical stimulation. To date, few studies have examined pulsed, mid-infrared laser stimulation of nerves and very little of the available optical parameter space has been studied. In this study, a pulsed diode laser, with

  15. Effects of Chronic Hypoxemia on the Afferent Nerve Activities from Skeletal Muscle

    Microsoft Academic Search

    ERICK DOUSSET; PATRICK DECHERCHI; LAURENT GRELOT; YVES JAMMES

    An acute reduction of the oxygen supply to contracting muscles not only affects their metabolism but also modifies their sensori- motor control through changes in afferent discharge of the group I and group III-IV nerve fibers, the latter playing a pivotal role in the protective mechanisms against muscle fatigue. The effects of chronic hypoxemia on the muscle sensitivity are totally

  16. Sympathetic Skin Response in Hemodialysis Patients: Correlation with Nerve Conduction Studies and Adequacy of Dialysis

    Microsoft Academic Search

    N. R. Robles; M. Solis; L. Albarran; J. F. Esparrago; F. Roncero; E. Sanchez-Casado

    1999-01-01

    A sympathetic skin response (SSR) test was performed in diabetic and nondiabetic patients undergoing regular hemodialysis and the results correlated with nerve conduction studies (NCS): sensory conduction velocity (SCV) and motor conduction velocity (MCV). Comparisons were made between diabetic and nondiabetic patients and between cuprophane and polyacrylonitrile membrane dialyzed patients. Six nondiabetic uremic patients (30%) and all diabetic patients had

  17. Functional and structural nerve fiber findings in heterozygote patients with Fabry disease.

    PubMed

    Torvin Mřller, Anette; Winther Bach, Flemming; Feldt-Rasmussen, Ulla; Rasmussen, Ase; Hasholt, Lis; Lan, He; Sommer, Claudia; Křlvraa, Steen; Ballegaard, Martin; Staehelin Jensen, Troels

    2009-09-01

    Fabry disease is an X-linked inherited lysosomal disorder with dysfunction of the lysosomal enzyme alpha-galactosidase A causing accumulation of glycolipids in multiple organs including the nervous system. Pain and somatosensory disturbances are prominent manifestations of this disease. Until recently disease manifestations in female carriers of Fabry disease have been questioned. To explore the frequency of symptoms and the functional and structural involvement of the nervous system in female patients we examined the presence of pain, manifestations of peripheral neuropathy and nerve density in skin biopsies in 19 female patients with Fabry disease and 19 sex- and age-matched controls. Diaries, quantitative sensory testing, neurophysiologic tests and skin biopsies were performed. Daily pain was present in 63% of patients, with a median VAS score of 4.0. Tactile detection threshold and pressure pain threshold were lower and cold detection thresholds increased in patients. Sensory nerve action potential amplitude and maximal sensory conduction velocity were not different, whereas there was a highly significant reduction in intraepidermal nerve fiber density. We found no correlation between pain VAS score, quantitative sensory testing and intraepidermal nerve fiber density. Our study demonstrates that careful evaluation of symptoms in female Fabry patients is important as small fiber disease manifestations are present, which in some cases is only detected by skin biopsy. PMID:19665302

  18. Altered Function of Lumbar Nerve Roots in Patients With Transitional Lumbosacral Vertebrae

    Microsoft Academic Search

    Han Soo Chang; Hiroshi NAKAGAWA

    2004-01-01

    STUDY DESIGN: A retrospective study was conducted on the preoperative neurologic symptoms of patients with lumbar herniated discs. OBJECTIVE: To evaluate the possibility that the muscle innervation pattern and the sensory dermatomes of lumbar nerve roots are altered when a lumbosacral transitional vertebra is present. SUMMARY OF BACKGROUND DATA: In 1962, McCulloch et al suggested with intraoperative recordings that the

  19. The Properties and Connections of Nerve Cells in Leech Ganglia Maintained in Culture

    Microsoft Academic Search

    S. Miyazaki; J. G. Nicholls

    1976-01-01

    Segmental ganglia of the central nervous system of the leech were maintained in culture medium outside the animal for several weeks at 16 degrees C, and electrical recordings made from identified sensory and motor nerve cells. Ganglia were isolated and cultured singly, in chains and connected to the skin and muscles they normally innervate. Such preparations are suitable for a

  20. THE INITIATION AND CONDUCTION OF ACTION POTENTIALS IN THE OPTIC NERVE OF TRITONIA

    Microsoft Academic Search

    RONALD CHASE

    1974-01-01

    As noted in the preceding article (Chase, 1974), an optic nerve origin for photo- receptor spikes in the mollusc Tritonia diomedia is indicated by the small size and frequent absence of somatic action potentials. Axonal trigger sites are the rule for in- vertebrate ganglion cells (Tauc, 1962) and most peripheral sensory neurones (Edwards & Ottoson, 1958), but there are exceptions

  1. Functional Restoration Of Precision Grip Using Slip Information Obtained From Peripheral Nerve Recordings

    Microsoft Academic Search

    J. A. Hoffer; M. Haugland; T. Sinkjaer

    1991-01-01

    We have implemented, in an experimental animal model, an approach for 'closed-loop' control of functional electrical stimulation (FES) of paralyzed muscles, in which tactile sensory information is recorded by implanted nerve cuff electrodes and fed back to the controller. This appmach may be applicable for functional restoration of motor function of upper or lower libs in quadriplegia, paraplegia or hemiplegia

  2. Hyperinnervation of the Airways in Transgenic Mice Overexpressing Nerve Growth Factor

    Microsoft Academic Search

    Gary W. Hoyle; Regina M. Graham; Jeffrey B. Finkelstein; Kim-Phuong Thi Nguyen; David Gozal; Mitchell Friedman

    1998-01-01

    Neuropeptides released from sensory nerve endings are potential mediators of airway inflammation in asthma and lung injury induced by inhalation of respiratory irritants. To develop an in vivo model for as- sessing the contribution of neurogenic inflammation in these processes, we have generated transgenic mice with altered innervation of the lung. To generate mice with an increased innervation of the

  3. Overexpression of Nerve Growth Factor in Skin Selectively Affects the Survival and Functional Properties of Nociceptors

    Microsoft Academic Search

    C. L. Stucky; M. Koltzenburg; M. Schneider; M. G. Engle; K. M. Albers; B. M. Davis

    1999-01-01

    Mice that overexpress nerve growth factor (NGF-OE) in the skin have double the normal number of cutaneous sensory neurons, have increased innervation of the skin and spinal cord, and are hyperalgesic. Here, we have asked whether the increased cu- taneous NGF level results in a selective survival of only certain functional types of neurons and whether it changes the prop-

  4. Age effect on far field potentials from the brain stem after transcutaneous vagus nerve stimulation

    Microsoft Academic Search

    Andreas J. Fallgatter; Ann-Christine Ehlis; Thomas M. Ringel; Martin J. Herrmann

    2005-01-01

    Recently, a new electrophysiological method for the assessment of vagus nerve function in the brainstem has been proposed in healthy participants. Before this procedure may be applied to patients with neurodegenerative diseases, its feasibility in elderly healthy participants and a possible age effect on the measurement have to be investigated. The vagus sensory evoked potentials (VSEP) after transcutaneous electric stimulation

  5. Modulation of sensory irritation responsiveness by adenosine and malodorants.

    PubMed

    Willis, Daniel N; Morris, John B

    2013-01-01

    Respiratory tract reflex responses are an important defense mechanism against noxious airborne materials. This study was aimed at defining the effects of adenosine on sensory irritation responsiveness and its role in odorant-irritant interactions. These experiments were aimed at testing the hypothesis that adenosine, through the A2 receptor, enhances trigeminal nerve responses to multiple irritants and that odorants enhance responsiveness to irritants through A2 pathways in the female C57Bl/6 mouse. The adenosine precursor, AMP, immediately and markedly increased the sensory irritation response to capsaicin, cyclohexanone, and styrene, irritants that activate chemosensory nerves through differing receptor pathways. The neuromodulatory effect was blocked by the general adenosine receptor antagonist theophylline and by the A2 receptor-specific antagonist DMPX. Multiple odorants were examined, including R-carvone (spearmint), linalool (lavender), trimethylamine (rotting fish), mercaptoethanol, and ethyl sulfide (stench and rotten eggs). Of these, only mercaptoethanol and ethyl sulfide exhibited neuromodulatory effects, enhancing the sensory irritation response to styrene or cyclohexanone. This effect was blocked by theophylline and DMPX indicating the importance of adenosine A2 receptor pathways in this effect. These results highlight that trigeminal chemosensory responsiveness is not static, but can be quickly modulated by adenosine and select odors resulting in hyperresponsive states. PMID:23162088

  6. Spinal accessory nerve injury.

    PubMed

    Wiater, J M; Bigliani, L U

    1999-11-01

    Injury to the spinal accessory nerve can lead to dysfunction of the trapezius. The trapezius is a major scapular stabilizer and is composed of three functional components. It contributes to scapulothoracic rhythm by elevating, rotating, and retracting the scapula. The superficial course of the spinal accessory nerve in the posterior cervical triangle makes it susceptible to injury. Iatrogenic injury to the nerve after a surgical procedure is one of the most common causes of trapezius palsy. Dysfunction of the trapezius can be a painful and disabling condition. The shoulder droops as the scapula is translated laterally and rotated downward. Patients present with an asymmetric neckline, a drooping shoulder, winging of the scapula, and weakness of forward elevation. Evaluation should include a complete electrodiagnostic examination. If diagnosed within 1 year of the injury, microsurgical reconstruction of the nerve should be considered. Conservative treatment of chronic trapezius paralysis is appropriate for older patients who are sendentary. Active and healthy patients in whom 1 year of conservative treatment has failed are candidates for surgical reconstruction. Studies have shown the Eden-Lange procedure, in which the insertions of the levator scapulae, rhomboideus minor, and rhomboideus major muscles are transferred, relieves pain, corrects deformity, and improves function in patients with irreparable injury to the spinal accessory nerve. PMID:10613148

  7. Changes in sensation after nerve injury or amputation: the role of central factors.

    PubMed Central

    Braune, S; Schady, W

    1993-01-01

    Dynamic changes in somatosensory cortical maps are known to occur in experimental animals subjected to peripheral nerve transection or amputation. To study the sensory effects of central nervous system adaptation to temporary or permanent loss of input from a part of the hand, multimodality quantitative sensory tests were carried out in 11 patients with complete traumatic division and repair of the median or ulnar nerves and in six patients who had undergone amputation of one or more digits. As expected, vibration, two point discrimination, and tactile thresholds were raised in the territory of the injured nerve in a graded fashion, sensitivity being poorest in the patients with the most recent injuries. Surprisingly, localisation was better in the tips than at the base of the hypoaesthetic fingers, suggesting a central attentional gradient. Stimulus-response curves conformed to a power function whose exponent was higher in denervated than in normal skin. Changes in psychophysical functions were also discernible in the intact hand. There was no hyperaesthesia in the territory of the nerve adjacent to the injured one or in the stump in the case of amputees. Central factors contribute to the sensory changes seen after nerve injury, but the functional effects of the cortical reorganisation that follows partial deafferentation are more subtle than a simple heightening of sensitivity in the surrounding skin. PMID:8482960

  8. Recovery of nerve injury after mandibular sagittal split osteotomy. Diagnostic value of clinical and electrophysiologic tests in the follow-up.

    PubMed

    Teerijoki-Oksa, T; Jääskeläinen, S K; Forssell, K; Forssell, H

    2004-03-01

    The diagnostic value of several clinical, quantitative sensory tests (brush-stroke directional discrimination (BSD), touch detection threshold (TD), warm/cold (W/C) and sharp/blunt discrimination (S/B)), and electrophysiologic tests (mental nerve blink reflex (BR), nerve conduction study (NCS), cold (CDT), and warm (WDT) detection thresholds) in the recovery of inferior alveolar nerve (IAN) injury was evaluated in a prospective 1-year follow-up study of 20 patients after bilateral sagittal split osteotomy (BSSO). The subjective sensory alteration was assessed from patients' drawings. The predictive values of different tests at 2 weeks were determined in relation to the subjective sensory recovery at 12 months. The most pronounced recovery of the nerve damage occurred during the first 3 months according to all measures used. After 3 months, the electrophysiologic tests, especially the NCS, indicated significant further improvement. Except for the TD test, all other clinical test results were normal already at 3 months postoperatively. At early and late controls, the NCS and the thermal quantitative sensory testing could best verify the subjective sensory alteration, and most accurately assess the degree of thick and thin fibre dysfunction. At 1 year, the nerve dysfunction, as revealed by the NCS, corresponded with the figures of sensory alteration reported by the patients (35% R, 40% L). The W/C, BSD, S/B and WDT tests had the best early positive predictive values. Electrophysiologic tests had higher negative predictive values compared to clinical tests. PMID:15050068

  9. TRPA1 receptor localisation in the human peripheral nervous system and functional studies in cultured human and rat sensory neurons

    Microsoft Academic Search

    U. Anand; W. R. Otto; P. Facer; N. Zebda; I. Selmer; M. J. Gunthorpe; I. P. Chessell; M. Sinisi; R. Birch; P. Anand

    2008-01-01

    TRPA1 is a receptor expressed by sensory neurons, that is activated by low temperature (<17°C) and plant derivatives such as cinnamaldehyde and isoeugenol, to elicit sensations including pain. Using immunohistochemistry, we have, for the first time, localised TRPA1 in human DRG neurons, spinal cord motoneurones and nerve roots, peripheral nerves, intestinal myenteric plexus neurones, and skin basal keratinocytes. TRPA1 co-localised

  10. Chorda Tympani Nerve Terminal Field Maturation and Maintenance Is Severely Altered Following Changes To Gustatory Nerve Input to the Nucleus of the Solitary Tract

    PubMed Central

    Dudgeon, Sara L.; Hill, David L.

    2011-01-01

    Neural competition among multiple inputs can affect the refinement and maintenance of terminal fields in sensory systems. In the rat gustatory system, the chorda tympani, greater superficial petrosal, and glossopharyngeal nerves have distinct but overlapping terminal fields in the first central relay, the nucleus of the solitary tract (NTS). This overlap is largest at early postnatal ages followed by a significant refinement and pruning of the fields over a three-week period, suggesting that competitive mechanisms underlie the pruning. Here, we manipulated the putative competitive interactions among the three nerves by sectioning the greater superficial petrosal and glossopharyngeal nerves at postnatal day 15 (P15), P25, or at adulthood, while leaving the chorda tympani nerve intact. The terminal field of the chorda tympani nerve was assessed 35 days following nerve sections, a period before the sectioned nerves functionally regenerated. Regardless of the age when the nerves were cut, the chorda tympani nerve terminal field expanded to a volume four times larger than sham controls. Terminal field density measurements revealed that the expanded terminal field was similar to P15 control rats. Thus, it appears that the chorda tympani nerve terminal field defaults to its early postnatal field size and shape when the nerves with overlapping fields are cut, and this anatomical plasticity is retained into adulthood. These findings not only demonstrate the dramatic and lifelong plasticity in the central gustatory system, but also suggest that corresponding changes in functional and taste-related behaviors will accompany injury-induced changes in brainstem circuits. PMID:21613473

  11. Sensory Attenuation Assessed by Sensory Evoked Potentials in Functional Movement Disorders

    PubMed Central

    Macerollo, Antonella; Chen, Jui-Cheng; Pareés, Isabel; Kassavetis, Panagiotis; Kilner, James Morvan; Edwards, Mark John

    2015-01-01

    Background Functional (psychogenic) movement disorders (FMD) have features associated with voluntary movement (e.g. distractibility) but patients report movements to be out of their control. One explanation for this phenomenon is that sense of agency for movement is impaired. The phenomenon of reduction in the intensity of sensory experience when movement is self-generated and a reduction in sensory evoked potentials (SEPs) amplitude at the onset of self-paced movement (sensory attenuation) have been linked to sense of agency for movement. Methods We compared amplitude of SEPs from median nerve stimulation at rest and at the onset of a self-paced movement of the thumb in 17 patients with FMD and 17 healthy controls. Results Patients showed lack of attenuation of SEPs at the onset of movement compared to reduction in amplitude of SEPs in controls. FMD patients had significantly different ratios of movement onset to rest SEPs than did healthy controls at each electrode: 0.79 in healthy controls and 1.35 in patients at F3 (t = -4.22, p<0.001), 0.78 in healthy controls and 1.12 at patients C3 (t = -3.15, p = 0.004) and 0.77 in healthy controls and 1.05 at patients P3 (t = -2.88, p = 0.007). Conclusions Patients with FMD have reduced sensory attenuation as measured by SEPs at onset of self-paced movement. This finding can be plausibly linked to impairment of sense of agency for movement in these patients. PMID:26091500

  12. Instabilities in sensory processes

    NASA Astrophysics Data System (ADS)

    Balakrishnan, J.

    2014-07-01

    In any organism there are different kinds of sensory receptors for detecting the various, distinct stimuli through which its external environment may impinge upon it. These receptors convey these stimuli in different ways to an organism's information processing region enabling it to distinctly perceive the varied sensations and to respond to them. The behavior of cells and their response to stimuli may be captured through simple mathematical models employing regulatory feedback mechanisms. We argue that the sensory processes such as olfaction function optimally by operating in the close proximity of dynamical instabilities. In the case of coupled neurons, we point out that random disturbances and fluctuations can move their operating point close to certain dynamical instabilities triggering synchronous activity.

  13. CRYPTOGENIC SENSORY POLYNEUROPATHY

    PubMed Central

    Pasnoor, Mamatha; Dimachkie, Mazen M.; Barohn, Richard J.

    2014-01-01

    Chronic sensory or sensorimotor polyneuropathy is a common cause for referral to neurologists. Despite extensive diagnostic testing, up to one-third of these patients remain without a known cause. They are referred to as having cryptogenic sensory peripheral neuropathy (CSPN). The age of onset is variable but usually in the sixth to seventh decade of life, affecting men and women equally. CSPN symptoms progress slowly, most patients present with distal leg paresthesias or pain that progressed over years to involve the hands. On examination, there may be additional mild toe flexion and extension weakness. Electrophysiologic testing and histology reveals axonal neuropathy. Prognosis is usually favorable as most patients maintain independent ambulation. Besides patient education and reassurance, management is focused on pharmacotherapy of neuropathic pain (see Treatment of Painful Peripheral Neuropathy chapter) and physical therapy for balance training and occasionally assistive devices. PMID:23642719

  14. Hostile and Hardened? An Experimental Study on (De)Sensitization to Violence and Suffering Through Playing Video Games

    Microsoft Academic Search

    Frithjof Staude-Müller; Thomas Bliesener; Stefanie Luthman

    2008-01-01

    This study tests whether playing violent video games leads to desensitization and increased cardiovascular responding. In a laboratory experiment, 42 men spent 20 min playing either a high- or low-violence version of a \\

  15. Algal Sensory Chemical Ecology

    Microsoft Academic Search

    Charles D. Amsler

    Sensory chemical ecology is the branch of chemical ecology that focuses on chemical communications between organisms and chemical\\u000a sensing of the environment by organisms. Algae are well known to have numerous physiological responses to variations in their\\u000a chemical environment, particularly with respect to nutrients (Lobban and Harrison 1994). However, with respect to environmental\\u000a sensing it is typical for “chemical ecology”

  16. Electrophysiological findings in entrapment of the median nerve at wrist and elbow

    PubMed Central

    Buchthal, Fritz; Rosenfalck, Annelise; Trojaborg, Werner

    1974-01-01

    In 117 consecutive patients with carpal tunnel syndrome and 11 patients with a compression syndrome of the median nerve at elbow, motor and sensory conduction along the median and ulnar nerves and quantitative electromyography were compared with findings in 190 normal controls of the same age. In 25% of patients with carpal tunnel syndrome in whom motor conduction and EMG were normal, the lesion was located from abnormalities in sensory conduction. The fact that conduction along the same fibres was moderately slowed from digit to palm, severely slowed across the flexor retinaculum, and normal from wrist to elbow indicates that slowing was due to demyelination at the site of compression. Fifteen per cent of the patients with carpal tunnel syndrome had clinical and electrophysiological signs of ulnar involvement. In the other patients conduction along the ulnar nerve was as in 100 normal controls. Compression at the elbow was located by electromyographical findings rather than by abnormalities in conduction. PMID:4829536

  17. The utility of clinical neurophysiological and quantitative sensory testing for trigeminal neuropathy.

    PubMed

    Jääskeläinen, Satu K

    2004-01-01

    This article reviews the utility of neurophysiological recordings and quantitative sensory testing (QST) in providing sensitive, quantitative, and objective tests for the diagnosis and localization of damage to the trigeminal nerve. Electromyography and recordings of the masseter reflex and compound muscle action potential evoked by transcranial magnetic stimulation or direct electrical stimulation of the masseteric nerve can be of value in evaluating the function of a motor neurons supplying the muscles of mastication. Orthodromic recording of the sensory action potential and trigeminal somatosensory-evoked potential recording with the near-nerve stimulation technique are sensitive tools for the investigation of trigeminal sensory Abeta afferents, whereas recordings of polysynaptic trigeminal brainstem reflexes and tactile QST are less sensitive. At late stages of recovery, the blink reflex and masseter inhibitory reflex are often normal, but at earlier stages, the blink reflex recording has good prognostic value, and the presence of a reflex response may confirm continuity of the nerve trunk after partial laceration. Trigeminal small-fiber function (Adelta and C) can be studied with thermal QST of the cool, warm, heat pain, and cold pain detection thresholds or with laser-evoked potential recording. Thermal QST may remain abnormal years after axonal damage and aids in the diagnosis of late sequelae of trigeminal nerve injury. In a study of the diagnostic value of neurography, blink reflex and thermal QST, and various commonly used clinical sensory tests, neurophysiologic tests and thermal QST had better sensitivity (50% to 88% vs 40% to 59%) and negative predictive values (78% to 100% vs 70% to 74%) compared to clinical examination, whereas the specificity (55% to 100%) and positive predictive values (48% to 73%) were similar. At 1 year after trigeminal nerve injury, the risk of a false negative finding with clinical sensory testing was 94%, whereas the combination of nerve conduction recordings and thermal QST increased the diagnostic yield to 100% in patients with long-standing postsurgical sensory alteration. In conclusion, clinical neurophysiological recordings and QST improve the diagnostic accuracy for trigeminal neuropathy. PMID:15636020

  18. Decreased sensitivity to tartrazine after aspirin desensitization in an asthmatic patient intolerant to both aspirin and tartrazine.

    PubMed

    Michel, O; Naeije, N; Bracamonte, M; Duchateau, J; Sergysels, R

    1984-05-01

    An aspirin- and tartrazine-sensitive asthmatic patient underwent a desensitization to the adverse effects of aspirin by oral aspirin challenges. After a month of daily aspirin ingestion, the patient's reactivity to tartrazine, tested by oral challenge, was observed to the blunted. This report suggests that desensitization to the adverse effects of aspirin might protect the patient against the adverse effects of tartrazine. PMID:6721262

  19. An evaluation of in vivo desensitization and video modeling to increase compliance with dental procedures in persons with mental retardation.

    PubMed

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

    2004-01-01

    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 increased compliance for all 5 participants, whereas video modeling increased compliance for only 1 of 3 participants. PMID:15293644

  20. Effect of aspirin desensitization on T-cell cytokines and plasma lipoxins in aspirin-exacerbated respiratory disease.

    PubMed

    Aksu, Kurtulu?; Kurt, Emel; Alatas, Özkan; Gülbas, Zafer

    2014-01-01

    The pathogenesis of aspirin-exacerbated respiratory disease (AERD) is thought to be based on, mainly, overproduction of eicosanoid lipid mediators and on defective anti-inflammatory regulators. Aspirin desensitization treatment, the mainstay of controlling asthma and rhinitis in AERD patients, however, is the least understood aspect of the disease. The study was designed to determine the effect of aspirin desensitization on T-lymphocyte cytokine expression and on plasma lipoxin levels in AERD. Spirometry, skin-prick test and asthma control test were documented and intracellular cytokine expression in T lymphocytes and plasma lipoxin levels were measured in 23 AERD patients, 17 aspirin-tolerant asthmatic (ATA) patients, and 16 healthy controls. In the AERD group nasal symptom and smell scores were assessed. Of the 23 AERD patients 15 accepted to undergo aspirin desensitization protocol and 14 of them were desensitized successfully. In the desensitized AERD group, cytokine and lipoxin measurements were repeated after 1-month aspirin treatment. CD4(+) IL-10 levels were higher in AERD patients than in healthy controls and CD4(+) interferon (IFN) gamma levels were higher in AERD and ATA patients than in controls. Plasma lipoxin-A4 and 15-epi-lipoxin-A4 levels were similar among the three study groups. In the AERD group, subjects underwent aspirin desensitization followed by a 1-month aspirin treatment. Clinical parameters improved and CD4(+) IFN-gamma levels decreased significantly. No significant change in lipoxin levels was recorded. CD4(+) IFN-gamma and CD4(+) IL-10 levels in AERD patients after 1-month aspirin desensitization treatment were similar to the healthy controls. The study confirms aspirin desensitization is effective clinically in AERD patients and suggests that IFN gamma and IL-10 expression in CD4(+) T lymphocytes may be related to the mechanism of action. PMID:24717792

  1. Increased sensitivity of desensitized TRPV1 by PMA occurs through PKC?-mediated phosphorylation at S800

    Microsoft Academic Search

    Sravan Mandadi; Tomoko Tominaga; Mitsuko Numazaki; Namie Murayama; Naoaki Saito; Patricia J. Armati; Basil D. Roufogalis; Makoto Tominaga

    2006-01-01

    Important mechanisms that regulate inhibitory and facilitatory effects on TRPV1-mediated nociception are desensitization and phosphorylation, respectively. Using Ca2+-imaging, we have previously shown that desensitization of TRPV1 upon successive capsaicin applications was reversed by protein kinase C activation in dorsal root ganglion neurons and CHO cells. Here, using both Ca2+-imaging and patch-clamp methods, we show that PMA-induced activation of PKC? is

  2. Activation of protein kinase C reverses capsaicin-induced calcium-dependent desensitization of TRPV1 ion channels

    Microsoft Academic Search

    Sravan Mandadi; Mitsuko Numazaki; Makoto Tominaga; Manjunatha B Bhat; Patricia J Armati; Basil D Roufogalis

    2004-01-01

    Ca2+ selective ion channels of vanilloid receptor subtype-1 (TRPV1) in capsaicin-sensitive dorsal root ganglion (DRG) neurons and TRPV1 transfected Chinese hamster ovarian (CHO) cells are desensitized following calcium-dependent tachyphylaxis induced by successive applications of 100nM capsaicin. Tachyphylaxis of TRPV1 to 100nM capsaicin stimuli was not observed in the absence of extracellular calcium. Capsaicin sensitivity of desensitized TRPV1 ion channels recovered

  3. Micro-structural geometry of thin films intended for the inner lumen of nerve conduits affects nerve repair.

    PubMed

    Mobasseri, S A; Terenghi, G; Downes, S

    2013-07-01

    Damage to peripheral nerves can cause significant motor or sensory injuries. In serious cases, a nerve is sacrificed from another part of the body to repair a damaged nerve (autograft). The development of biodegradable polymer conduits may offer an alternative to autografts. This study investigated the surface topography and mechanical properties of smooth, pitted and grooved structures of ultra-thin poly (?-caprolactone)/poly lactic acid blended, solvent-cast films. We have investigated the effect of the groove shape on cell morphology and alignment. Photolithography and dry/wet etching was used to develop patterned silicon substrates with grooves with accurate geometries (V shaped, sloped walls and square shaped). Using a neural cell line (NG108-15), in vitro experiments confirmed good cell attachment and proliferation on all the polymer scaffolds. Imaging techniques demonstrated that there was different cellular responses and morphology according to the shape of the groove. Studies showed that the geometry, particularly the angle of the slope and the space between grooves, affected cellular responses. In addition, biomechanical studies showed that the patterned films had excellent mechanical properties and were stronger than the natural nerve. The conduit tubes were made by rolling the films around a mandrel and using a thermal welding technique to join the edges. The promising biomechanical and in vitro results demonstrate that nerve cell responses are affected by the shape of longitudinal grooves, and particularly by the angle of the slope of the groove walls. PMID:23572143

  4. Overview of Optic Nerve Disorders

    MedlinePLUS

    ... each optic nerve splits, and half of its fibers cross over to the other side. Because of this anatomic arrangement, damage along the optic nerve pathway causes specific patterns of vision loss. ...

  5. Stability and selectivity of a chronic, multi-contact cuff electrode for sensory stimulation in human amputees

    NASA Astrophysics Data System (ADS)

    Tan, Daniel W.; Schiefer, Matthew A.; Keith, Michael W.; Anderson, J. Robert; Tyler, Dustin J.

    2015-04-01

    Objective. Stability and selectivity are important when restoring long-term, functional sensory feedback in individuals with limb-loss. Our objective is to demonstrate a chronic, clinical neural stimulation system for providing selective sensory response in two upper-limb amputees. Approach. Multi-contact cuff electrodes were implanted in the median, ulnar, and radial nerves of the upper-limb. Main results. Nerve stimulation produced a selective sensory response on 19 of 20 contacts and 16 of 16 contacts in subjects 1 and 2, respectively. Stimulation elicited multiple, distinct percept areas on the phantom and residual limb. Consistent threshold, impedance, and percept areas have demonstrated that the neural interface is stable for the duration of this on-going, chronic study. Significance. We have achieved selective nerve response from multi-contact cuff electrodes by demonstrating characteristic percept areas and thresholds for each contact. Selective sensory response remains consistent in two upper-limb amputees for 1 and 2 years, the longest multi-contact sensory feedback system to date. Our approach demonstrates selectivity and stability can be achieved through an extraneural interface, which can provide sensory feedback to amputees.

  6. Postvaccinal inflammatory neuropathy: peripheral nerve biopsy in 3 cases.

    PubMed

    Vital, Claude; Vital, Anne; Gbikpi-Benissan, Georges; Longy-Boursier, Maďté; Climas, Marie-Thérčse; Castaing, Yves; Canron, Marie-Hélčne; Le Bras, Michel; Petry, Klaus

    2002-09-01

    Autoimmune inflammatory polyneuropathy (PN) can be triggered by vaccination. We report 3 such cases. A 36-year-old female nurse presented 15 days after a hepatitis B vaccination (HBV) with acute sensory disturbances in the lower limbs. She had severe ataxia but no weakness. Cerebrospinal fluid (CSF) protein level was 84 mg/100 mL, with 3 lymphocytes. A 66-year-old man presented 21 days after HBV with severe motor and sensory PN involving all 4 limbs. A 66-year-old man presented 15 days after a yellow fever vaccination with progressive motor and sensory PN involving all 4 limbs and bilateral facial paralysis. CSF protein level was 300 mg/100 mL, with 5 lymphocytes. Six weeks later, a tracheostomy was performed. In these 3 patients, the nerve deficits lasted for months. In each case, peripheral nerve biopsy showed KP1-positive histiocytes but no T-lymphocytes in the endoneurium. On ultrastructural examination, there was axonal degeneration in the first 2 cases; in case 2, a few myelinated fibers exhibited an intra-axonal macrophage but the myelin sheath was preserved. There was only 1 example of macrophage-associated demyelination in case 2, but these were numerous in case 3. It is likely that in the first 2 cases, an autoimmune reaction against some axonal or neuronal components was triggered by HBV. It induced an acute sensory ataxic PN in case 1 and an acute motor and sensory axonal neuropathy (AMSAN) in case 2. The third patient had a chronic inflammatory demyelinating PN, likely triggered by yellow fever vaccination. PMID:12365564

  7. The Desensitization Gating of the MthK K+ Channel Is Governed by Its Cytoplasmic Amino Terminus

    PubMed Central

    Kuo, Mario Meng-Chiang; Maslennikov, Innokentiy; Molden, Brent; Choe, Senyon

    2008-01-01

    The RCK-containing MthK channel undergoes two inactivation processes: activation-coupled desensitization and acid-induced inactivation. The acid inactivation is mediated by the C-terminal RCK domain assembly. Here, we report that the desensitization gating is governed by a desensitization domain (DD) of the cytoplasmic N-terminal 17 residues. Deletion of DD completely removes the desensitization, and the process can be fully restored by a synthetic DD peptide added in trans. Mutagenesis analyses reveal a sequence-specific determinant for desensitization within the initial hydrophobic segment of DD. Proton nuclear magnetic resonance (1H NMR) spectroscopy analyses with synthetic peptides and isolated RCK show interactions between the two terminal domains. Additionally, we show that deletion of DD does not affect the acid-induced inactivation, indicating that the two inactivation processes are mutually independent. Our results demonstrate that the short N-terminal DD of MthK functions as a complete moveable module responsible for the desensitization. Its interaction with the C-terminal RCK domain may play a role in the gating process. PMID:18959476

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

    PubMed Central

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

    2013-01-01

    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

  9. The desensitization gating of the MthK K+ channel is governed by its cytoplasmic amino terminus.

    PubMed

    Kuo, Mario Meng-Chiang; Maslennikov, Innokentiy; Molden, Brent; Choe, Senyon

    2008-10-28

    The RCK-containing MthK channel undergoes two inactivation processes: activation-coupled desensitization and acid-induced inactivation. The acid inactivation is mediated by the C-terminal RCK domain assembly. Here, we report that the desensitization gating is governed by a desensitization domain (DD) of the cytoplasmic N-terminal 17 residues. Deletion of DD completely removes the desensitization, and the process can be fully restored by a synthetic DD peptide added in trans. Mutagenesis analyses reveal a sequence-specific determinant for desensitization within the initial hydrophobic segment of DD. Proton nuclear magnetic resonance ((1)H NMR) spectroscopy analyses with synthetic peptides and isolated RCK show interactions between the two terminal domains. Additionally, we show that deletion of DD does not affect the acid-induced inactivation, indicating that the two inactivation processes are mutually independent. Our results demonstrate that the short N-terminal DD of MthK functions as a complete moveable module responsible for the desensitization. Its interaction with the C-terminal RCK domain may play a role in the gating process. PMID:18959476

  10. Radiation-induced changes in peripheral nerve by stereotactic radiosurgery: a study on the sciatic nerve of rabbit.

    PubMed

    Lin, Zhixiong; Wu, Vincent W C; Ju, Wenchui; Yamada, Yoshiya; Chen, Longhua

    2011-04-01

    A large fractional dose in radiotherapy produces better radiobiological results, but there is always a concern of radiation-induced damage to the normal tissues, especially peripheral nerves. This study was to evaluate the radiation-induced changes of sciatic nerve treated by stereotactic radiosurgery (SRS) in rabbit. A localization test was performed on 3 rabbits to determine the reference landmarks to the location of the sciatic nerve of rabbit in CT. Another 12 rabbits were irradiated by a dose of 25 Gy at the sciatic nerve using SRS with 5 non-coplanar arcs. The rabbits were randomized into 3 groups and euthanised at 3, 5, and 7 months after radiotherapy, respectively. Apart from the sensory and motor tests performed on the rabbits, segments of the sciatic nerve were prepared for hematoxylin and eosin staining. Histologic and ultra-structural examinations including morphometric analyses were conducted and compared with the control (non-irradiated side). Apart from the loosening of myelin layers at 5 months, no prominent changes were shown at 3 and 5 months after irradiation. At 7 months, despite the fact that the sensation and motor function tests remained intact, ultra-structural examination showed obvious vacuolation, degeneration and necrosis of the axons with myelin fragmentation. In addition, morphometric analysis indicated that, when compared with the control, there was significant reduction in fiber diameter, increase of myelin thickness and decrease of G ratio (P < 0.01). Although it remained functionally intact, a focal single dose of 25 Gy caused significant microscopic damage to the rabbit sciatic nerve at 7 months after irradiation. Escalating doses with large single fractional dose involving peripheral nerves should be carried out with caution. PMID:20652361

  11. Effects of ?-tocopherol on nerve conduction velocity and regeneration following a freeze lesion in immature diabetic rats

    Microsoft Academic Search

    A. Love; M. A. Cotter; N. E. Cameron

    1996-01-01

    We investigated whether anti-oxidant treatment with ?-tocopherol (1?g kg–1 day–1) could prevent the blunting of the normal maturational increase in motor and sensory nerve conduction velocity when diabetes\\u000a is induced by streptozotocin in young rats. A further study in the same rats examined effects on myelinated fibre regeneration\\u000a distance 14 days after a punctate sciatic nerve lesion by a liquid

  12. Effects of acetyl- and proprionyl- l-carnitine on peripheral nerve function and vascular supply in experimental diabetes

    Microsoft Academic Search

    M. A. Cotter; N. E. Cameron; A. Keegan; K. C. Dines

    1995-01-01

    l-Carnitine metabolism is abnormal in diabetes mellitus, and treatment with acetyl-l-carnitine (ALC) improves the function of cardiac muscle, retina, and peripheral nerve in experimental models. The aim was to compare the effects of ALC and proprionyl-l-carnitine (PLC) on motor and sensory nerve conduction in streptozotocin-diabetic rats and to ascertain whether their action could be mediated by a vascular mechanism. ALC

  13. Selective Tracing of Auditory Fibers in the Avian Embryonic Vestibulocochlear Nerve

    PubMed Central

    Allen-Sharpley, Michelle R.; Tjia, Michelle; Cramer, Karina S.

    2013-01-01

    The embryonic chick is a widely used model for the study of peripheral and central ganglion cell projections. In the auditory system, selective labeling of auditory axons within the VIIIth cranial nerve would enhance the study of central auditory circuit development. This approach is challenging because multiple sensory organs of the inner ear contribute to the VIIIth nerve 1. Moreover, markers that reliably distinguish auditory versus vestibular groups of axons within the avian VIIIth nerve have yet to be identified. Auditory and vestibular pathways cannot be distinguished functionally in early embryos, as sensory-evoked responses are not present before the circuits are formed. Centrally projecting VIIIth nerve axons have been traced in some studies, but auditory axon labeling was accompanied by labeling from other VIIIth nerve components 2,3. Here, we describe a method for anterograde tracing from the acoustic ganglion to selectively label auditory axons within the developing VIIIth nerve. First, after partial dissection of the anterior cephalic region of an 8-day chick embryo immersed in oxygenated artificial cerebrospinal fluid, the cochlear duct is identified by anatomical landmarks. Next, a fine pulled glass micropipette is positioned to inject a small amount of rhodamine dextran amine into the duct and adjacent deep region where the acoustic ganglion cells are located. Within thirty minutes following the injection, auditory axons are traced centrally into the hindbrain and can later be visualized following histologic preparation. This method provides a useful tool for developmental studies of peripheral to central auditory circuit formation. PMID:23542875

  14. Pattern of myelinated fibre loss in the sural nerve in neuropathy related to Type 1 (insulin-dependent) diabetes

    Microsoft Academic Search

    J. G. Llewelyn; P. K. Thomas; S. G. Gilbey; P. J. Watkins; J. R. Muddle

    1988-01-01

    Summary  Sural nerve biopsies were obtained from 17 diabetic patients with neuropathy. All patients except three had both a symmetric distal sensory and autonomic polyneuropathy related to Type 1 (insulin-dependent) diabetes mellitus; 3 patients had a purely sensory polyneuropathy. Mean age was 34.5 years (range 18–53 years). The biopsies were compared with specimens from an age-matched control series. Myelinated fibre loss

  15. Antiretroviral Therapy-Associated Acute Motor and Sensory Axonal Neuropathy

    PubMed Central

    Capers, Kimberly N.; Turnacioglu, Sinan; Leshner, Robert T.; Crawford, John R.

    2011-01-01

    Guillain-Barré syndrome (GBS) has been reported in HIV-infected patients in association with the immune reconstitution syndrome whose symptoms can be mimicked by highly active antiretroviral therapy (HAART)-mediated mitochondrial toxicity. We report a case of a 17-year-old, HIV-infected patient on HAART with a normal CD4 count and undetectable viral load, presenting with acute lower extremity weakness associated with lactatemia. Electromyography/nerve conduction studies revealed absent sensory potentials and decreased compound muscle action potentials, consistent with a diagnosis of acute motor and sensory axonal neuropathy. Lactatemia resolved following cessation of HAART; however, neurological deficits minimally improved over several months in spite of immune modulatory therapy. This case highlights the potential association between HAART, mitochondrial toxicity and acute axonal neuropathies in HIV-infected patients, distinct from the immune reconstitution syndrome. PMID:21327178

  16. Vagus Nerve Stimulation

    Microsoft Academic Search

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

    2008-01-01

    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

  17. Ischemic Nerve Block.

    ERIC Educational Resources Information Center

    Williams, Ian D.

    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…

  18. Eye movement desensitization and reprocessing (EMDR) in the treatment of war veterans.

    PubMed

    Silver, Steven M; Rogers, Susan; Russell, Mark

    2008-08-01

    Recent practice guidelines and meta-analyses have designated eye movement desensitization and reprocessing (EMDR) as a first-line treatment for trauma. Eye movement desensitization and reprocessing is an eight-phase therapeutic approach guided by an information-processing model that addresses the combat veteran's critical incidents, current triggers, and behaviors likely to prove useful in his or her future. Two case examples of combat veterans illustrate the ability of EMDR to achieve symptom reduction in a variety of clinical domains (e.g., anxiety, depression, anger, physical pain) simultaneously without requiring the patient to carry out homework assignments or discuss the details of the event. The treatment of phantom limb pain and other somatic presentations is also reviewed. The ability of EMDR to achieve positive effects without homework indicates that it can be effectively employed on consecutive days, making it especially useful during combat situations. PMID:18612994

  19. Sensory TRP channels: the key transducers of nociception and pain.

    PubMed

    Mickle, Aaron D; Shepherd, Andrew J; Mohapatra, Durga P

    2015-01-01

    Peripheral detection of nociceptive and painful stimuli by sensory neurons involves a complex repertoire of molecular detectors and/or transducers on distinct subsets of nerve fibers. The majority of such molecular detectors/transducers belong to the transient receptor potential (TRP) family of cation channels, which comprise both specific receptors for distinct nociceptive stimuli, as well as for multiple stimuli. This chapter discusses the classification, distribution, and functional properties of individual TRP channel types that have been implicated in various nociceptive and/or painful conditions. PMID:25744671

  20. Disorders of the lower cranial nerves

    PubMed Central

    Finsterer, Josef; Grisold, Wolfgang

    2015-01-01

    Lesions of the lower cranial nerves (LCN) are due to numerous causes, which need to be differentiated to optimize management and outcome. This review aims at summarizing and discussing diseases affecting LCN. Review of publications dealing with disorders of the LCN in humans. Affection of multiple LCN is much more frequent than the affection of a single LCN. LCN may be affected solely or together with more proximal cranial nerves, with central nervous system disease, or with nonneurological disorders. LCN lesions have to be suspected if there are typical symptoms or signs attributable to a LCN. Causes of LCN lesions can be classified as genetic, vascular, traumatic, iatrogenic, infectious, immunologic, metabolic, nutritional, degenerative, or neoplastic. Treatment of LCN lesions depends on the underlying cause. An effective treatment is available in the majority of the cases, but a prerequisite for complete recovery is the prompt and correct diagnosis. LCN lesions need to be considered in case of disturbed speech, swallowing, coughing, deglutition, sensory functions, taste, or autonomic functions, neuralgic pain, dysphagia, head, pharyngeal, or neck pain, cardiac or gastrointestinal compromise, or weakness of the trapezius, sternocleidomastoid, or the tongue muscles. To correctly assess manifestations of LCN lesions, precise knowledge of the anatomy and physiology of the area is required.