Stimuli of Sensory-Motor Nerves Terminate Arterial Contractile Effects of Endothelin-1 by CGRP and Dissociation of ET-1/ETA-Receptor Complexes

PubMed Central

Meens, Merlijn J. P. M. T.; Compeer, Matthijs G.; Hackeng, Tilman M.; van Zandvoort, Marc A.; Janssen, Ben J. A.; De Mey, Jo G. R.

2010-01-01

Background Endothelin-1 (ET-1), a long-acting paracrine mediator, is implicated in cardiovascular diseases but clinical trials with ET-receptor antagonists were not successful in some areas. We tested whether the quasi-irreversible receptor-binding of ET-1 (i) limits reversing effects of the antagonists and (ii) can be selectively dissociated by an endogenous counterbalancing mechanism. Methodology/Principal findings In isolated rat mesenteric resistance arteries, ETA-antagonists, endothelium-derived relaxing factors and synthetic vasodilators transiently reduced contractile effects of ET-1 but did not prevent persistent effects of the peptide. Stimuli of peri-vascular vasodilator sensory-motor nerves such as capsaicin not only reduced but also terminated long-lasting effects of ET-1. This was prevented by CGRP-receptor antagonists and was mimicked by exogenous calcitonin gene-related peptide (CGRP). Using 2-photon laser scanning microscopy in vital intact arteries, capsaicin and CGRP, but not ETA-antagonism, were observed to promote dissociation of pre-existing ET-1/ETA-receptor complexes. Conclusions Irreversible binding and activation of ETA-receptors by ET-1 (i) occur at an antagonist-insensitive site of the receptor and (ii) are selectively terminated by endogenously released CGRP. Hence, natural stimuli of sensory-motor nerves that stimulate release of endogenous CGRP can be considered for therapy of diseases involving ET-1. PMID:20532232

Substance P released from intrinsic airway neurons contributes to ozone-enhanced airway hyperresponsiveness in ferret trachea.

PubMed

Wu, Zhong-Xin; Satterfield, Brian E; Dey, Richard D

2003-08-01

Exposure to ozone (O3) induces airway hyperresponsiveness mediated partly through the release of substance P (SP) from nerve terminals in the airway wall. Although substantial evidence suggests that SP is released by sensory nerves, SP is also present in neurons of airway ganglia. The purpose of this study was to investigate the role of intrinsic airway neurons in O3-enhanced airway responsiveness in ferret trachea. To remove the effects of sensory innervation, segments of ferret trachea were maintained in culture conditions for 24 h before in vitro exposure to 2 parts/million of O3 or air for 1 h. Sensory nerve depletion was confirmed by showing that capsaicin did not affect tracheal smooth muscle responsiveness to cholinergic agonist or contractility responses to electrical field stimulation (EFS). Contractions of isolated tracheal smooth muscle to EFS were significantly increased after in vitro O3 exposure, but the constrictor response to cholinergic agonist was not altered. Pretreatment with CP-99994, an antagonist of the neurokinin 1 receptor, attenuated the increased contraction to EFS after O3 exposure but had no effect in the air exposure group. The number of SP-positive neurons in longitudinal trunk ganglia, the extent of SP innervation to superficial muscular plexus nerve cell bodies, and SP nerve fiber density in tracheal smooth muscle all increased significantly after O3 exposure. The results show that release of SP from intrinsic airway neurons contributes to O3-enhanced tracheal smooth muscle responsiveness by facilitating acetylcholine release from cholinergic nerve terminals.

Substance P immunoreactive nerve terminals in the dorsolateral nucleus of the tractus solitarius: roles in the baroreceptor reflex.

PubMed

Massari, V J; Shirahata, M; Johnson, T A; Lauenstein, J M; Gatti, P J

1998-03-02

Physiological and light microscopic evidence suggest that substance P (SP) may be a neurotransmitter contained in first-order sensory baroreceptor afferents; however, ultrastructural support for this hypothesis is lacking. We have traced the central projections of the carotid sinus nerve (CSN) in the cat by utilizing the transganglionic transport of horseradish peroxidase (HRP). The dorsolateral subnucleus of the nucleus tractus solitarius (dlNTS) was processed for the histochemical visualization of transganglionically labeled CSN afferents and for the immunocytochemical visualization of SP by dual labeling light and electron microscopic methods. Either HRP or SP was readily identified in single-labeled unmyelinated axons, myelinated axons, and nerve terminals in the dlNTS. SP immunoreactivity was also identified in unmyelinated axons, myelinated axons, and nerve terminals in the dlNTS, which were simultaneously identified as CSN primary afferents. However, only 15% of CSN terminals in the dlNTS were immunoreactive for SP. Therefore, while the ultrastructural data support the hypothesis that SP immunoreactive first-order neurons are involved in the origination of the baroreceptor reflex, they suggest that only a modest part of the total sensory input conveyed from the carotid sinus baroreceptors to the dlNTS is mediated by SP immunoreactive CSN terminals. Five types of axo-axonic synapses were observed in the dlNTS. SP immunoreactive CSN afferents were very rarely involved in these synapses. Furthermore, SP terminals were never observed to form the presynaptic element in an axo-axonic synapse with a CSN afferent. Therefore, SP does not appear to be involved in the modulation of the baroreceptor reflex in the dlNTS. Copyright 1998 Elsevier Science B.V.

Is distal motor and/or sensory demyelination a distinctive feature of anti-MAG neuropathy?

PubMed

Lozeron, Pierre; Ribrag, Vincent; Adams, David; Brisset, Marion; Vignon, Marguerite; Baron, Marine; Malphettes, Marion; Theaudin, Marie; Arnulf, Bertrand; Kubis, Nathalie

2016-09-01

To report the frequency of the different patterns of sensory and motor electrophysiological demyelination distribution in patients with anti-MAG neuropathy in comparison with patients with IgM neuropathy without MAG reactivity (IgM-NP). Thirty-five anti-MAG patients at early disease stage (20.1 months) were compared to 23 patients with IgM-NP; 21 CIDP patients and 13 patients with CMT1a neuropathy were used as gold standard neuropathies with multifocal and homogeneous demyelination, respectively. In all groups, standard motor and sensory electrophysiological parameters, terminal latency index and modified F ratio were investigated. Motor electrophysiological demyelination was divided in four profiles: distal, homogeneous, proximal, and proximo-distal. Distal sensory and sensorimotor demyelination were evaluated. Anti-MAG neuropathy is a demyelinating neuropathy in 91 % of cases. In the upper limbs, reduced TLI is more frequent in anti-MAG neuropathy, compared to IgM-NP. But, predominant distal demyelination of the median nerve is encountered in only 43 % of anti-MAG neuropathy and is also common in IgM-NP (35 %). Homogeneous demyelination was the second most frequent pattern (31 %). Concordance of electrophysiological profiles across motor nerves trunks is low and median nerve is the main site of distal motor conduction slowing. Reduced sensory conduction velocities occurs in 14 % of patients without evidence of predominant distal slowing. Simultaneous sensory and motor distal slowing was more common in the median nerve of anti-MAG neuropathy than IgM-NP. Electrophysiological distal motor demyelination and sensory demyelination are not a distinctive feature of anti-MAG reactivity. In anti-MAG neuropathy it is mainly found in the median nerve suggesting a frequent nerve compression at wrist.

Ionotropic and metabotropic receptor mediated airway sensory nerve activation.

PubMed

Lee, Min-Goo; Kollarik, Marian; Chuaychoo, Benjamas; Undem, Bradley J

2004-01-01

There are several receptors capable of inducing activating generator potentials in cough-associated afferent terminals in the airways. The chemical receptors leading to generator potentials can be subclassified into ionotropic and metabotropic types. An ionotropic receptor has an agonist-binding domain, and also serves directly as an ion channel that is opened upon binding of the agonist. Examples of ionotropic receptors found in airway sensory nerve terminals include receptors for serotonin (5-HT3 receptors), ATP (P2X receptors), acetylcholine (nicotinic receptors), receptors for capsaicin and related vanilloids (TRPV1 receptors), and acid receptors (acid sensing ion channels). Afferent nerve terminals can also be depolarized via activation of metabotropic or G-protein coupled receptors (GPCRs). Among the GPCRs that can lead to activation of airway afferent fibers include bradykinin B2 and adenosine A1 receptors. The signaling events leading to GPCR-mediated membrane depolarization are more complex than that seen with ionotropic receptors. The GPCR-mediated effects are thought to occur through classical second messenger systems such as activation of phospholipase C. This may lead to membrane depolarization through interaction with specific ionotropic receptors (such as TRPV1) and/or various types of calcium activated channels.

Modifications of Gustatory Nerve Synapses onto Nucleus of the Solitary Tract Neurons Induced by Dietary Sodium-Restriction During Development

PubMed Central

MAY, OLIVIA L.; ERISIR, ALEV; HILL, DAVID L.

2008-01-01

The terminal fields of nerves carrying gustatory information to the rat brainstem show a remarkable amount of expansion in the nucleus of the solitary tract (NTS) as a result of early dietary sodium restriction. However, the extent to which these axonal changes represent corresponding changes in synapses is not known. To identify the synaptic characteristics that accompany the terminal field expansion, the greater superficial petrosal (GSP), chorda tympani (CT), and glossopharyngeal (IX) nerves were labeled in rats fed a sodium-restricted diet during pre- and postnatal development. The morphology of these nerve terminals within the NTS region where the terminal fields of all three nerves overlap was evaluated by transmission electron microscopy. Compared to data from control rats, CT axons were the most profoundly affected. The density of CT arbors and synapses quadrupled as a result of the near life-long dietary manipulation. In contrast, axon and synapse densities of GSP and IX nerves were not modified in sodium-restricted rats. Furthermore, compared to controls, CT terminals displayed more instances of contacts with postsynaptic dendritic protrusions and IX terminals synapsed more frequently with dendritic shafts. Thus, dietary sodium restriction throughout pre- and postnatal development had differential effects on the synaptic organization of the three nerves in the NTS. These anatomical changes may underlie the impact of sensory restriction during development on the functional processing of taste information and taste-related behaviors. PMID:18366062

Modifications of gustatory nerve synapses onto nucleus of the solitary tract neurons induced by dietary sodium-restriction during development.

PubMed

May, Olivia L; Erisir, Alev; Hill, David L

2008-06-01

The terminal fields of nerves carrying gustatory information to the rat brainstem show a remarkable amount of expansion in the nucleus of the solitary tract (NTS) as a result of early dietary sodium restriction. However, the extent to which these axonal changes represent corresponding changes in synapses is not known. To identify the synaptic characteristics that accompany the terminal field expansion, the greater superficial petrosal (GSP), chorda tympani (CT), and glossopharyngeal (IX) nerves were labeled in rats fed a sodium-restricted diet during pre- and postnatal development. The morphology of these nerve terminals within the NTS region where the terminal fields of all three nerves overlap was evaluated by transmission electron microscopy. Compared to data from control rats, CT axons were the most profoundly affected. The density of CT arbors and synapses quadrupled as a result of the near life-long dietary manipulation. In contrast, axon and synapse densities of GSP and IX nerves were not modified in sodium-restricted rats. Furthermore, compared to controls, CT terminals displayed more instances of contacts with postsynaptic dendritic protrusions and IX terminals synapsed more frequently with dendritic shafts. Thus, dietary sodium restriction throughout pre- and postnatal development had differential effects on the synaptic organization of the three nerves in the NTS. These anatomical changes may underlie the impact of sensory restriction during development on the functional processing of taste information and taste-related behaviors.

Handlebar palsy--a compression syndrome of the deep terminal (motor) branch of the ulnar nerve in biking.

PubMed

Capitani, Daniel; Beer, Serafin

2002-10-01

We describe 3 patients who developed a severe palsy of the intrinsic ulnar supplied hand muscles after bicycle riding. Clinically and electrophysiologically all showed an isolated lesion of the deep terminal motor branch of the ulnar nerve leaving the hypothenar muscle and the distal sensory branch intact. This type of lesion at the canal of Guyon is quite unusual, caused in the majority of cases by chronic external pressure over the ulnar palm. In earlier reports describing this lesion in bicycle riders, most patients experienced this lesion after a long distance ride. Due to the change of riding position and shape of handlebars (horn handle) in recent years, however, even a single bicycle ride may be sufficient to cause a lesion of this ulnar branch. Especially in downhill riding, a large part of the body weight is supported by the hand on the corner of the handlebar leading to a high load at Guyon's canal. As no sensory fibres are affected, the patients are not aware of the ongoing nerve compression until a severe lesion develops. Individual adaptation of the handlebar and riding position seems to be crucial for prevention of this type of nerve lesion.

Patterned sensory nerve stimulation enhances the reactivity of spinal Ia inhibitory interneurons.

PubMed

Kubota, Shinji; Hirano, Masato; Morishita, Takuya; Uehara, Kazumasa; Funase, Kozo

2015-03-25

Patterned sensory nerve stimulation has been shown to induce plastic changes in the reciprocal Ia inhibitory circuit. However, the mechanisms underlying these changes have not yet been elucidated in detail. The aim of the present study was to determine whether the reactivity of Ia inhibitory interneurons could be altered by patterned sensory nerve stimulation. The degree of reciprocal Ia inhibition, the conditioning effects of transcranial magnetic stimulation (TMS) on the soleus (SOL) muscle H-reflex, and the ratio of the maximum H-reflex amplitude versus maximum M-wave (H(max)/M(max)) were examined in 10 healthy individuals. Patterned electrical nerve stimulation was applied to the common peroneal nerve every 1 s (100 Hz-5 train) at the motor threshold intensity of tibialis anterior muscle to induce activity changes in the reciprocal Ia inhibitory circuit. Reciprocal Ia inhibition, the TMS-conditioned H-reflex amplitude, and H(max)/M(max) were recorded before, immediately after, and 15 min after the electrical stimulation. The patterned electrical nerve stimulation significantly increased the degree of reciprocal Ia inhibition and decreased the amplitude of the TMS-conditioned H-reflex in the short-latency inhibition phase, which was presumably mediated by Ia inhibitory interneurons. However, it had no effect on H(max)/M(max). Our results indicated that patterned sensory nerve stimulation could modulate the activity of Ia inhibitory interneurons, and this change may have been caused by the synaptic modification of Ia inhibitory interneuron terminals. These results may lead to a clearer understanding of the spinal cord synaptic plasticity produced by repetitive sensory inputs. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Interplay between mast cells, enterochromaffin cells, and sensory signaling in the aging human bowel.

PubMed

Yu, Y; Daly, D M; Adam, I J; Kitsanta, P; Hill, C J; Wild, J; Shorthouse, A; Grundy, D; Jiang, W

2016-10-01

Advanced age is associated with a reduction in clinical visceral pain perception. However, the underlying mechanisms remain largely unknown. Previous studies have suggested that an abnormal interplay between mast cells, enterochromaffin (EC) cells, and afferent nerves contribute to nociception in gastrointestinal disorders. The aim of this study was to investigate how aging affects afferent sensitivity and neuro-immune association in the human bowel. Mechanical and chemical sensitivity of human bowel afferents were examined by ex vivo afferent nerve recordings. Age-related changes in the density of mast cells, EC cells, sensory nerve terminals, and mast cell-nerve micro-anatomical association were investigated by histological and immune staining. Human afferents could be broadly classified into subpopulations displaying mechanical and chemical sensitivity, adaptation, chemo-sensitization, and recruitment. Interestingly human bowel afferent nerve sensitivity was attenuated with age. The density of substance P-immunoreactive (SP-IR) nerve varicosities was also reduced with age. In contrast, the density of ileal and colonic mucosal mast cells was increased with age, as was ileal EC cell number. An increased proportion of mast cells was found in close apposition to SP-IR nerves. Afferent sensitivity in human bowel was reduced with advancing age. Augmentation of mast cells and EC cell numbers and the mast cell-nerve association suggest a compensatory mechanism for sensory neurodegeneration. © 2016 The Authors. Neurogastroenterology & Motility Published by John Wiley & Sons Ltd.

Expanded Terminal Fields of Gustatory Nerves Accompany Embryonic BDNF Overexpression in Mouse Oral Epithelia

PubMed Central

Sun, Chengsan; Dayal, Arjun

2015-01-01

Brain-derived neurotrophic factor (BDNF) is expressed in gustatory epithelia and is required for gustatory neurons to locate and innervate their correct target during development. When BDNF is overexpressed throughout the lingual epithelium, beginning embryonically, chorda tympani fibers are misdirected and innervate inappropriate targets, leading to a loss of taste buds. The remaining taste buds are hyperinnervated, demonstrating a disruption of nerve/target matching in the tongue. We tested the hypothesis here that overexpression of BDNF peripherally leads to a disrupted terminal field organization of nerves that carry taste information to the brainstem. The chorda tympani, greater superficial petrosal, and glossopharyngeal nerves were labeled in adult wild-type (WT) mice and in adult mice in which BDNF was overexpressed (OE) to examine the volume and density of their central projections in the nucleus of the solitary tract. We found that the terminal fields of the chorda tympani and greater superficial petrosal nerves and overlapping fields that included these nerves in OE mice were at least 80% greater than the respective field volumes in WT mice. The shapes of terminal fields were similar between the two groups; however, the density and spread of labels were greater in OE mice. Unexpectedly, there were also group-related differences in chorda tympani nerve function, with OE mice showing a greater relative taste response to a concentration series of sucrose. Overall, our results show that disruption in peripheral innervation patterns of sensory neurons have significant effects on peripheral nerve function and central organization of their terminal fields. PMID:25568132

Palisade endings: cholinergic sensory organs or effector organs?

PubMed

Blumer, Roland; Konakci, Kadriye Zeynep; Pomikal, Christine; Wieczorek, Grazyna; Lukas, Julius-Robert; Streicher, Johannes

2009-03-01

This study aims to complement the authors' prior findings on palisade endings in extraocular muscles (EOMs) of monkeys, and to clarify whether palisade endings are cholinergic motor or cholinergic sensory. Macaque monkeys (Macaca fascicularis, n = 10) of both sexes were analyzed using three-dimensional (3D) reconstructions, confocal laser scanning microscopy (CLSM), and conventional/immuno transmission electron microscopy (TEM). For CLSM, we used three combinations of triple fluorescent labeling. EOM wholemounts were labeled with cholinergic markers, including choline acetyltransferase (ChAT), choline transporter (ChT), vesicular acetylcholine transporter (VAChT), and a classical postsynaptic marker for motor terminals, namely alpha-bungarotoxin. Muscle fibers were counterstained with phalloidin. 3D reconstructions were done of triple-labeled palisade endings. For immuno TEM, tissue was labeled with antibody against ChAT. Concordant with prior findings, the authors demonstrated that palisade endings at the muscle fiber tips arose from nerve fibers that are ChAT-positive. In 25% of the cases, axons forming palisade endings established multiple neuromuscular contacts outside the palisade complex. Such additional neuromuscular contacts were motor terminals, as demonstrated by alpha-bungarotoxin binding. All palisade endings established nerve terminals on the tendon. In 40% of the palisade endings, nerve terminals were observed on the muscle fiber as well. Neurotendinous contacts and neuromuscular contacts in palisade endings were ChT/ChAT/VAChT-immunoreactive. Neuromuscular contacts exhibited structural features of motor terminals and were also alpha-bungarotoxin positive. The present study ascertained that palisade endings are cholinergic motor organs. Therefore, it was concluded that palisade endings are not candidates to provide eye-position signals.

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

PubMed Central

Ferreira Junior, Rui Seabra

2016-01-01

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

Identification of the visceral pain pathway activated by noxious colorectal distension in mice.

PubMed

Kyloh, Melinda; Nicholas, Sarah; Zagorodnyuk, Vladimir P; Brookes, Simon J; Spencer, Nick J

2011-01-01

In patients with irritable bowel syndrome, visceral pain is evoked more readily following distension of the colorectum. However, the identity of extrinsic afferent nerve pathway that detects and transmits visceral pain from the colorectum to the spinal cord is unclear. In this study, we identified which extrinsic nerve pathway(s) underlies nociception from the colorectum to the spinal cord of rodents. Electromyogram recordings were made from the transverse oblique abdominal muscles in anesthetized wild type (C57BL/6) mice and acute noxious intraluminal distension stimuli (100-120 mmHg) were applied to the terminal 15 mm of colorectum to activate visceromotor responses (VMRs). Lesioning the lumbar colonic nerves in vivo had no detectable effect on the VMRs evoked by colorectal distension. Also, lesions applied to the right or left hypogastric nerves failed to reduce VMRs. However, lesions applied to both left and right branches of the rectal nerves abolished VMRs, regardless of whether the lumbar colonic or hypogastric nerves were severed. Electrical stimulation applied to either the lumbar colonic or hypogastric nerves in vivo, failed to elicit a VMR. In contrast, electrical stimulation (2-5 Hz, 0.4 ms, 60 V) applied to the rectum reliably elicited VMRs, which were abolished by selective lesioning of the rectal nerves. DiI retrograde labeling from the colorectum (injection sites 9-15 mm from the anus, measured in unstretched preparations) labeled sensory neurons primarily in dorsal root ganglia (DRG) of the lumbosacral region of the spinal cord (L6-S1). In contrast, injection of DiI into the mid to proximal colon (injection sites 30-75 mm from the anus, measured in unstretched preparations) labeled sensory neurons in DRG primarily of the lower thoracic level (T6-L2) of the spinal cord. The visceral pain pathway activated by acute noxious distension of the terminal 15 mm of mouse colorectum is transmitted predominantly, if not solely, through rectal/pelvic afferent nerve fibers to the spinal cord. The sensory neurons of this spinal afferent pathway lie primarily in the lumbosacral region of the spinal cord, between L6 and S1.

Selective Deletion of Sodium Salt Taste during Development Leads to Expanded Terminal Fields of Gustatory Nerves in the Adult Mouse Nucleus of the Solitary Tract.

PubMed

Sun, Chengsan; Hummler, Edith; Hill, David L

2017-01-18

Neuronal activity plays a key role in the development of sensory circuits in the mammalian brain. In the gustatory system, experimental manipulations now exist, through genetic manipulations of specific taste transduction processes, to examine how specific taste qualities (i.e., basic tastes) impact the functional and structural development of gustatory circuits. Here, we used a mouse knock-out model in which the transduction component used to discriminate sodium salts from other taste stimuli was deleted in taste bud cells throughout development. We used this model to test the hypothesis that the lack of activity elicited by sodium salt taste impacts the terminal field organization of nerves that carry taste information from taste buds to the nucleus of the solitary tract (NST) in the medulla. The glossopharyngeal, chorda tympani, and greater superficial petrosal nerves were labeled to examine their terminal fields in adult control mice and in adult mice in which the α-subunit of the epithelial sodium channel was conditionally deleted in taste buds (αENaC knockout). The terminal fields of all three nerves in the NST were up to 2.7 times greater in αENaC knock-out mice compared with the respective field volumes in control mice. The shapes of the fields were similar between the two groups; however, the density and spread of labels were greater in αENaC knock-out mice. Overall, our results show that disruption of the afferent taste signal to sodium salts disrupts the normal age-dependent "pruning" of all terminal fields, which could lead to alterations in sensory coding and taste-related behaviors. Neural activity plays a major role in the development of sensory circuits in the mammalian brain. To date, there has been no direct test of whether taste-elicited neural activity has a role in shaping central gustatory circuits. However, recently developed genetic tools now allow an assessment of how specific taste stimuli, in this case sodium salt taste, play a role in the maturation of the terminal fields in the mouse brainstem. We found that the specific deletion of sodium salt taste during development produced terminal fields in adults that were dramatically larger than in control mice, demonstrating for the first time that sodium salt taste-elicited activity is necessary for the normal maturation of gustatory inputs into the brain. Copyright © 2017 the authors 0270-6474/17/370660-13$15.00/0.

Selective Deletion of Sodium Salt Taste during Development Leads to Expanded Terminal Fields of Gustatory Nerves in the Adult Mouse Nucleus of the Solitary Tract

PubMed Central

Sun, Chengsan; Hummler, Edith

2017-01-01

Neuronal activity plays a key role in the development of sensory circuits in the mammalian brain. In the gustatory system, experimental manipulations now exist, through genetic manipulations of specific taste transduction processes, to examine how specific taste qualities (i.e., basic tastes) impact the functional and structural development of gustatory circuits. Here, we used a mouse knock-out model in which the transduction component used to discriminate sodium salts from other taste stimuli was deleted in taste bud cells throughout development. We used this model to test the hypothesis that the lack of activity elicited by sodium salt taste impacts the terminal field organization of nerves that carry taste information from taste buds to the nucleus of the solitary tract (NST) in the medulla. The glossopharyngeal, chorda tympani, and greater superficial petrosal nerves were labeled to examine their terminal fields in adult control mice and in adult mice in which the α-subunit of the epithelial sodium channel was conditionally deleted in taste buds (αENaC knockout). The terminal fields of all three nerves in the NST were up to 2.7 times greater in αENaC knock-out mice compared with the respective field volumes in control mice. The shapes of the fields were similar between the two groups; however, the density and spread of labels were greater in αENaC knock-out mice. Overall, our results show that disruption of the afferent taste signal to sodium salts disrupts the normal age-dependent “pruning” of all terminal fields, which could lead to alterations in sensory coding and taste-related behaviors. SIGNIFICANCE STATEMENT Neural activity plays a major role in the development of sensory circuits in the mammalian brain. To date, there has been no direct test of whether taste-elicited neural activity has a role in shaping central gustatory circuits. However, recently developed genetic tools now allow an assessment of how specific taste stimuli, in this case sodium salt taste, play a role in the maturation of the terminal fields in the mouse brainstem. We found that the specific deletion of sodium salt taste during development produced terminal fields in adults that were dramatically larger than in control mice, demonstrating for the first time that sodium salt taste-elicited activity is necessary for the normal maturation of gustatory inputs into the brain. PMID:28100747

Met receptor signaling is required for sensory nerve development and HGF promotes axonal growth and survival of sensory neurons

PubMed Central

Maina, Flavio; Hilton, Mark C.; Ponzetto, Carola; Davies, Alun M.; Klein, Rüdiger

1997-01-01

The development of the nervous system is a dynamic process during which factors act in an instructive fashion to direct the differentiation and survival of neurons, and to induce axonal outgrowth, guidance to, and terminal branching within the target tissue. Here we report that mice expressing signaling mutants of the hepatocyte growth factor (HGF) receptor, the Met tyrosine kinase, show a striking reduction of sensory nerves innervating the skin of the limbs and thorax, implicating the HGF/Met system in sensory neuron development. Using in vitro assays, we find that HGF cooperates with nerve growth factor (NGF) to enhance axonal outgrowth from cultured dorsal root ganglion (DRG) neurons. HGF also enhances the neurotrophic activities of NGF in vitro, and Met receptor signaling is required for the survival of a proportion of DRG neurons in vivo. This synergism is specific for NGF but not for the related neurotrophins BDNF and NT3. By using a mild signaling mutant of Met, we have demonstrated previously that Met requires signaling via the adapter molecule Grb2 to induce proliferation of myoblasts. In contrast, the actions of HGF on sensory neurons are mediated by Met effectors distinct from Grb2. Our findings demonstrate a requirement for Met signaling in neurons during development. PMID:9407027

TFOS DEWS II pain and sensation report

PubMed Central

Belmonte, Carlos; Nichols, Jason J.; Cox, Stephanie M.; Brock, James A.; Begley, Carolyn G.; Bereiter, David A.; Dartt, Darlene A.; Galor, Anat; Hamrah, Pedram; Ivanusic, Jason J.; Jacobs, Deborah S.; McNamara, Nancy A.; Rosenblatt, Mark I.; Stapleton, Fiona; Wolffsohn, James S.

2017-01-01

Pain associated to mechanical and chemical irritation of the eye surface is mediated by trigeminal ganglia mechano- and polymodal nociceptor neurons while cold thermoreceptors detect wetness and reflexly maintain basal tear production and blinking rate. These neurons project into two regions of the trigeminal brain stem nuclear complex: ViVc, activated by changes in the moisture of the ocular surface and VcC1, mediating sensory-discriminative aspects of ocular pain and reflex blinking. ViVc ocular neurons project to brain regions that control lacrimation and spontaneous blinking and to the sensory thalamus. Secretion of the main lacrimal gland is regulated dominantly by autonomic parasympathetic nerves, reflexly activated by eye surface sensory nerves. These also evoke goblet cell secretion through unidentified efferent fibers. Neural pathways involved in the regulation of Meibonian gland secretion or mucins release have not been identified. In dry eye disease, reduced tear secretion leads to inflammation and peripheral nerve damage. Inflammation causes sensitization of polymodal and mechano-nociceptor nerve endings and an abnormal increase in cold thermoreceptor activity, altogether evoking dryness sensations and pain. Long-term inflammation and nerve injury alter gene expression of ion channels and receptors at terminals and cell bodies of trigeminal ganglion and brainstem neurons, changing their excitability, connectivity and impulse firing. Perpetuation of molecular, structural and functional disturbances in ocular sensory pathways ultimately leads to dysestesias and neuropathic pain referred to the eye surface. Pain can be assessed with a variety of questionaires while the status of corneal nerves is evaluated with esthesiometry and with in vivo confocal microscopy. PMID:28736339

Selective antagonism of muscarinic receptors is neuroprotective in peripheral neuropathy

PubMed Central

Smith, Darrell R.; Frizzi, Katie; Sabbir, Mohammad Golam; Chowdhury, Subir K. Roy; Mixcoatl-Zecuatl, Teresa; Saleh, Ali; Muttalib, Nabeel; Van der Ploeg, Randy; Ochoa, Joseline; Gopaul, Allison; Tessler, Lori; Wess, Jürgen; Jolivalt, Corinne G.

2017-01-01

Sensory neurons have the capacity to produce, release, and respond to acetylcholine (ACh), but the functional role of cholinergic systems in adult mammalian peripheral sensory nerves has not been established. Here, we have reported that neurite outgrowth from adult sensory neurons that were maintained under subsaturating neurotrophic factor conditions operates under cholinergic constraint that is mediated by muscarinic receptor–dependent regulation of mitochondrial function via AMPK. Sensory neurons from mice lacking the muscarinic ACh type 1 receptor (M1R) exhibited enhanced neurite outgrowth, confirming the role of M1R in tonic suppression of axonal plasticity. M1R-deficient mice made diabetic with streptozotocin were protected from physiological and structural indices of sensory neuropathy. Pharmacological blockade of M1R using specific or selective antagonists, pirenzepine, VU0255035, or muscarinic toxin 7 (MT7) activated AMPK and overcame diabetes-induced mitochondrial dysfunction in vitro and in vivo. These antimuscarinic drugs prevented or reversed indices of peripheral neuropathy, such as depletion of sensory nerve terminals, thermal hypoalgesia, and nerve conduction slowing in diverse rodent models of diabetes. Pirenzepine and MT7 also prevented peripheral neuropathy induced by the chemotherapeutic agents dichloroacetate and paclitaxel or HIV envelope protein gp120. As a variety of antimuscarinic drugs are approved for clinical use against other conditions, prompt translation of this therapeutic approach to clinical trials is feasible. PMID:28094765

The dimensions and characteristics of the subepidermal nerve plexus in human skin--terminal Schwann cells constitute a substantial cell population within the superficial dermis.

PubMed

Reinisch, Christina M; Tschachler, Erwin

2012-03-01

The skin constitutes the largest sensorial organ. Its nervous system consists of different types of afferent nerve fibers which spread out immediately beneath the skin surface to sense temperature, touch and pain. Our aim was to investigate the dimension and topographic relationship of the different nerve fibers of the subepidermal nerve plexus in human hairy skin and to analyze numbers and marker expression of terminal Schwann cells. Nerve fibers and Schwann cells were investigated on dermal sheet preparations and thick sections of skin from various body regions of 10 individuals. The dimension of subepidermal nerve fibers varied between different body sites with highest values in chest skin (100 ± 18 mm/mm(2)) and lowest in posterior forearm skin (53 ± 10 mm/mm(2)). The majority of fibers (85.79%) were unmyelinated, thus representing C-fibers, of which 7.84% were peptidergic. Neurofilament-positive fibers (A-fibers) accounted for 14.21% and fibers positive for both neurofilament and myelin (Aβ-fibers) for only 0.18%. The number of Schwann cells varied in accordance with nerve fiber length from 453 ± 108 on chest skin to 184 ± 58/mm(2) in skin of the posterior forearm. Terminal Schwann cells showed a marker profile comparable to Schwann cells in peripheral nerves with the notable exception of expression of NGFr, NCAM, L1CAM and CD146 on myelinating Schwann cells in the dermis but not in peripheral nerves. Our data show that terminal Schwann cells constitute a substantial cell population within the papillary dermis and that both nerve fiber length and Schwann cell numbers vary considerably between different body sites. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Distribution of CGRP and TRPV2 in Human Paranasal Sinuses.

PubMed

Sato, Tadasu; Sasahara, Nobuyuki; Kanda, Noriyuki; Sasaki, Yu; Yamaguma, Yu; Kokubun, Souichi; Yajima, Takehiro; Ichikawa, Hiroyuki

2017-01-01

Immunohistochemistry for protein gene product 9.5 (PGP 9.5), calcitonin gene-related peptide (CGRP) and the transient receptor potential cation channel subfamily V member 2 (TRPV2) was performed on human paranasal sinuses. It was found that in the paranasal sinuses, mucous membranes contain PGP 9.5-immunoreactive (PGP 9.5-IR) nerve fibers. Such nerve fibers terminated around large blood vessels as fine varicosities. Isolated PGP 9.5-IR nerve fibers were scattered beneath the epithelium. Glandular tissues were also innervated by PGP 9.5-IR nerve fibers. These fibers were numerous in the maxillary and ethmoid sinuses, and relatively rare in the frontal and sphenoid sinuses. CGRP-IR nerve fibers were common in the maxillary sinus whereas TRPV2-IR nerve fibers were abundant in the ethmoid sinus. They were located around large blood vessels in the lamina propria. Many subepithelial nerve fibers contained TRPV2 immunoreactivity in the ethmoid sinus. CGRP- and TRPV2-IR nerve fibers were very infrequent in the frontal and sphenoid sinuses. In the human trigeminal ganglion (TG), sensory neurons contained CGRP or TRPV2 immunoreactivity. CGRP-IR TG neurons were more common than TRPV2-IR TG neurons. CGRP-IR TG neurons were of various cell body sizes, whereas TRPV2-IR TG neurons were mostly medium-to-large. In addition, human spinal and principal trigeminal sensory nuclei contained abundant CGRP- and TRPV2-IR varicosities. This study indicates that CGRP- and TRPV2-containing TG neurons probably innervate the paranasal sinus mucosae, and project into spinal and principal trigeminal sensory nuclei. © 2016 S. Karger AG, Basel.

Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling

PubMed Central

Pearcey, Gregory E. P.; Noble, Steven A.; Munro, Bridget; Zehr, E. Paul

2017-01-01

Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation (CONTROL + STIM), sprints with sensory stimulation (SPRINT + STIM) and sprints without stimulation (SPRINT). Seven participants also performed a fourth session (CONTROL), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM, participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM, participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared to sprints without stimulation. These results demonstrate that sensory stimulation can substantially mitigate the fatiguing effects of sprints. PMID:29326570

Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling.

PubMed

Pearcey, Gregory E P; Noble, Steven A; Munro, Bridget; Zehr, E Paul

2017-01-01

Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation ( CONTROL + STIM ), sprints with sensory stimulation ( SPRINT + STIM ) and sprints without stimulation ( SPRINT ). Seven participants also performed a fourth session ( CONTROL ), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM , participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM , participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared to sprints without stimulation. These results demonstrate that sensory stimulation can substantially mitigate the fatiguing effects of sprints.

Thy1.2 YFP-16 Transgenic Mouse Labels a Subset of Large-Diameter Sensory Neurons that Lack TRPV1 Expression

PubMed Central

Taylor-Clark, Thomas E.; Wu, Kevin Y.; Thompson, Julie-Ann; Yang, Kiseok; Bahia, Parmvir K.; Ajmo, Joanne M.

2015-01-01

The Thy1.2 YFP-16 mouse expresses yellow fluorescent protein (YFP) in specific subsets of peripheral and central neurons. The original characterization of this model suggested that YFP was expressed in all sensory neurons, and this model has been subsequently used to study sensory nerve structure and function. Here, we have characterized the expression of YFP in the sensory ganglia (DRG, trigeminal and vagal) of the Thy1.2 YFP-16 mouse, using biochemical, functional and anatomical analyses. Despite previous reports, we found that YFP was only expressed in approximately half of DRG and trigeminal neurons and less than 10% of vagal neurons. YFP-expression was only found in medium and large-diameter neurons that expressed neurofilament but not TRPV1. YFP-expressing neurons failed to respond to selective agonists for TRPV1, P2X2/3 and TRPM8 channels in Ca2+ imaging assays. Confocal analysis of glabrous skin, hairy skin of the back and ear and skeletal muscle indicated that YFP was expressed in some peripheral terminals with structures consistent with their presumed non-nociceptive nature. In summary, the Thy1.2 YFP-16 mouse expresses robust YFP expression in only a subset of sensory neurons. But this mouse model is not suitable for the study of nociceptive nerves or the function of such nerves in pain and neuropathies. PMID:25746468

TRPV1, TRPA1, and TRPM8 channels in inflammation, energy redirection, and water retention: role in chronic inflammatory diseases with an evolutionary perspective.

PubMed

Straub, Rainer H

2014-09-01

Chronic inflammatory diseases are accompanied by a systemic response of the body, necessary to redirect energy-rich fuels to the activated immune system and to induce volume expansion. The systemic response is switched on by two major pathways: (a) circulating cytokines enter the brain, and (b) signals via sensory nerve fibers are transmitted to the brain. Concerning item b, sensory nerve terminals are equipped with a multitude of receptors that sense temperature, inflammation, osmolality, and pain. Thus, they can be important to inform the brain about peripheral inflammation. Central to these sensory modalities are transient receptor potential channels (TRP channels) on sensory nerve endings. For example, TRP vanilloid 1 (TRPV1) can be activated by heat, inflammatory factors (e.g., protons, bradykinin, anandamide), hyperosmolality, pungent irritants, and others. TRP channels are multimodal switches that transmit peripheral signals to the brain, thereby inducing a systemic response. It is demonstrated how and why these TRP channels (TRPV1, TRP ankyrin type 1 (TRPA1), and TRP melastatin type 8 (TRPM8)) are important to start up a systemic response of energy expenditure, energy allocation, and water retention and how this is linked to a continuously activated immune system in chronic inflammatory diseases.

Alterations in Corneal Sensory Nerves During Homeostasis, Aging, and After Injury in Mice Lacking the Heparan Sulfate Proteoglycan Syndecan-1.

PubMed

Pal-Ghosh, Sonali; Tadvalkar, Gauri; Stepp, Mary Ann

2017-10-01

To determine the impact of the loss of syndecan 1 (SDC1) on intraepithelial corneal nerves (ICNs) during homeostasis, aging, and in response to 1.5-mm trephine and debridement injury. Whole-mount corneas are used to quantify ICN density and thickness over time after birth and in response to injury in SDC1-null and wild-type (WT) mice. High-resolution three-dimensional imaging is used to visualize intraepithelial nerve terminals (INTs), axon fragments, and lysosomes in corneal epithelial cells using antibodies against growth associated protein 43 (GAP43), βIII tubulin, and LAMP1. Quantitative PCR was performed to quantify expression of SDC1, SDC2, SDC3, and SDC4 in corneal epithelial mRNA. Phagocytosis was assessed by quantifying internalization of fluorescently labeled 1-μm latex beads. Intraepithelial corneal nerves innervate the corneas of SDC1-null mice more slowly. At 8 weeks, ICN density is less but thickness is greater. Apically projecting intraepithelial nerve terminals and lysosome-associated membrane glycoprotein 1 (LAMP1) are also reduced in unwounded SDC1-null corneas. Quantitative PCR and immunofluorescence studies show that SDC3 expression and localization are increased in SDC1-null ICNs. Wild-type and SDC1-null corneas lose ICN density and thickness as they age. Recovery of axon density and thickness after trephine but not debridement wounds is slower in SDC1-null corneas compared with WT. Experiments assessing phagocytosis show reduced bead internalization by SDC1-null epithelial cells. Syndecan-1 deficiency alters ICN morphology and homeostasis during aging, reduces epithelial phagocytosis, and impairs reinnervation after trephine but not debridement injury. These data provide insight into the mechanisms used by sensory nerves to reinnervate after injury.

Presynaptic control of transmission along the pathway mediating disynaptic reciprocal inhibition in the cat

PubMed Central

Enríquez-Denton, M; Nielsen, J; Perreault, M-C; Morita, H; Petersen, N; Hultborn, H

2000-01-01

In cat lumbar motoneurones, disynaptic inhibitory postsynaptic potentials (IPSPs) evoked by stimulation of antagonist motor nerves were depressed for at least 150 ms following conditioning stimulation of flexor (1.7-2 times threshold (T)) and ankle extensor (5T) nerves. The aim of the present study was to investigate the possibility that this depression is caused by presynaptic inhibitory mechanisms acting at the terminals of group I afferent fibres projecting to the Ia inhibitory interneurones and/or the terminals of these interneurones to the target motoneurones. Conditioning stimulation of flexor, but not ankle extensor, nerves evoked a depression of the monosynaptic Ia excitatory postsynaptic potentials (EPSPs) recorded intracellularly in Ia inhibitory interneurones. This depression lasted between 200 and 700 ms and was not accompanied by a depression of the monosynaptic EPSPs evoked by stimulation of descending pathways. These results suggest that flexor, but not ankle extensor, group I afferent fibres can modulate sensory transmission at the synapse between Ia afferent fibres and Ia inhibitory interneurones. Conditioning stimulation of flexor muscle nerves, extensor muscle nerves and cutaneous nerves produced a long-lasting increase in excitability of the terminals of the Ia inhibitory interneurones. The increase in the excitability of the terminals was not secondary to an electrotonic spread of synaptic excitation at the soma. Indeed, concomitant with the excitability increase of the terminals there were signs of synaptic inhibition in the soma. The unitary IPSPs induced in target motoneurones following the spike activity of single Ia inhibitory interneurones were depressed by conditioning stimulation of muscle and cutaneous nerves. Since the conditioning stimulation also evoked compound IPSPs in those motoneurones, a firm conclusion as to whether unitary IPSP depression involved presynaptic inhibitory mechanism of the terminals of the interneurones could not be reached. The possibility that the changes in excitability of the Ia interneuronal terminals reflect the presence of a presynaptic inhibitory mechanism similar to that operating at the terminals of the afferent fibres (presynaptic inhibition) is discussed.1. In cat lumbar motoneurones, disynaptic inhibitory postsynaptic potentials (IPSPs) evoked by stimulation of antagonist motor nerves were depressed for at least 150 ms following conditioning stimulation of flexor (1.7-2 times threshold (T)) and ankle extensor (5T) nerves. The aim of the present study was to investigate the possibility that this depression is caused by presynaptic inhibitory mechanisms acting at the terminals of group I afferent fibres projecting to the Ia inhibitory interneurones and/or the terminals of these interneurones to the target motoneurones. PMID:10922013

Excitatory glutamate is essential for development and maintenance of the piloneural mechanoreceptor.

PubMed

Woo, Seung-Hyun; Baba, Yoshichika; Franco, Alexa M; Lumpkin, Ellen A; Owens, David M

2012-02-01

The piloneural collar in mammalian hairy skin comprises an intricate pattern of circumferential and longitudinal sensory afferents that innervate primary and secondary pelage hairs. The longitudinal afferents tightly associate with terminal Schwann cell processes to form encapsulated lanceolate nerve endings of rapidly adapting mechanoreceptors. The molecular basis for piloneural development, maintenance and function is poorly understood. Here, we show that Nefh-expressing glutamatergic neurons represent a major population of longitudinal and circumferential sensory afferents innervating the piloneural collar. Our findings using a VGLUT2 conditional-null mouse model indicate that glutamate is essential for innervation, patterning and differentiation of NMDAR(+) terminal Schwann cells during piloneural collar development. Similarly, treatment of adult mice with a selective NMDAR antagonist severely perturbed piloneural collar structure and reduced excitability of these mechanosensory neurons. Collectively, these results show that DRG-derived glutamate is essential for the proper development, maintenance and sensory function of the piloneural mechanoreceptor.

Trajectory of the main sensory and motor branches of the lumbar plexus outside the psoas muscle related to the lateral retroperitoneal transpsoas approach.

PubMed

Dakwar, Elias; Vale, Fernando L; Uribe, Juan S

2011-02-01

The minimally invasive lateral retroperitoneal transpsoas approach is increasingly used to treat various spinal disorders. Accessing the retroperitoneal space and traversing the abdominal wall poses a risk of injury to the major nervous structures and adds significant morbidity to the procedure. Most of the current literature focuses on the anatomy of the lumbar plexus within the substance of the psoas muscle. However, there is sparse knowledge regarding the trajectory of the lumbar plexus nerves that travel along the retroperitoneum and abdominal wall muscles in relation to the lateral approach to the spine. The objective of this study is to define the anatomical trajectories of the major motor and sensory branches of the lumbar plexus that are located outside the psoas muscle. Six adult fresh frozen cadaveric specimens were dissected and studied (12 sides). The relationship between the retroperitoneum, abdominal wall muscles, and the lumbar plexus nerves was analyzed in reference to the minimally invasive lateral retroperitoneal approach. Special attention was given to the lumbar plexus nerves that run outside of psoas muscle in the retroperitoneal cavity and within the abdominal muscle wall. The skin and muscles of the abdominal wall and the retroperitoneal cavity were dissected and analyzed with respect to the major motor and sensory branches of the lumbar plexus. The authors identified 4 nerves at risk during the lateral approach to the spine: subcostal, iliohypogastric, ilioinguinal, and lateral femoral cutaneous nerves. The anatomical trajectory of each of these nerves is described starting from the spinal column until their termination or exit from the pelvic cavity. There is risk of direct injury to the main motor/sensory nerves that supply the anterior abdominal muscles during the early stages of the lateral retroperitoneal transpsoas approach while obtaining access to the retroperitoneum. There is also a risk of injury to the ilioinguinal, iliohypogastric, and lateral femoral cutaneous nerves in the retroperitoneal space where they travel obliquely during the blunt retroperitoneal dissection. Moreover, there is a latent possibility of lesioning these nerves with the retractor blades against the anterior iliac crest.

Fast Synaptic Inhibition in Spinal Sensory Processing and Pain Control

PubMed Central

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

2013-01-01

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

Lacosamide diminishes dryness-induced hyperexcitability of corneal cold sensitive nerve terminals.

PubMed

Kovács, Illés; Dienes, Lóránt; Perényi, Kristóf; Quirce, Susana; Luna, Carolina; Mizerska, Kamila; Acosta, M Carmen; Belmonte, Carlos; Gallar, Juana

2016-09-15

Lacosamide is an anti-epileptic drug that is also used for the treatment of painful diabetic neuropathy acting through voltage-gated sodium channels. The aim of this work was to evaluate the effects of acute application of lacosamide on the electrical activity of corneal cold nerve terminals in lacrimo-deficient guinea pigs. Four weeks after unilateral surgical removal of the main lachrimal gland in guinea pigs, corneas were excised and superfused in vitro at 34°C for extracellular electrophysiological recording of nerve terminal impulse activity of cold thermosensitive nerve terminals. The characteristics of the spontaneous and the stimulus-evoked (cooling ramps from 34°C to 15°C) activity before and in presence of lacosamide 100µM and lidocaine 100µM were compared. Cold nerve terminals (n=34) recorded from dry eye corneas showed significantly enhanced spontaneous activity (8.0±1.1 vs. 5.2±0.7imp/s; P<0.05) and cold response (21.2±1.7 vs. 16.8±1.3imp/s; P<0.05) as well as reduced cold threshold (1.5±0.1 vs. 2.8±0.2 Δ°C; P<0.05) to cooling ramps compared to terminals (n=58) from control animals. Both lacosamide and lidocaine decreased spontaneous activity and peak response to cooling ramps significantly (P<0.05). Temperature threshold was increased by the addition of lidocaine (P<0.05) but not lacosamide (P>0.05) to the irrigation fluid. In summary, the application of lacosamide results in a significant decrease of the augmented spontaneous activity and responsiveness to cold of corneal sensory nerves from tear-deficient animals. Based on these promising results we speculate that lacosamide might be used to reduce the hyperexcitability of corneal cold receptors caused by prolonged ocular surface dryness due to hyposecretory or evaporative dry eye disease. Copyright © 2016 Elsevier B.V. All rights reserved.

More a finger than a nose: the trigeminal motor and sensory innervation of the Schnauzenorgan in the elephant-nose fish Gnathonemus petersii.

PubMed

Amey-Özel, Monique; von der Emde, Gerhard; Engelmann, Jacob; Grant, Kirsty

2015-04-01

The weakly electric fish Gnathonemus petersii uses its electric sense to actively probe the environment. Its highly mobile chin appendage, the Schnauzenorgan, is rich in electroreceptors. Physical measurements have demonstrated the importance of the position of the Schnauzenorgan in funneling the fish's self-generated electric field. The present study focuses on the trigeminal motor pathway that controls Schnauzenorgan movement and on its trigeminal sensory innervation and central representation. The nerves entering the Schnauzenorgan are very large and contain both motor and sensory trigeminal components as well as an electrosensory pathway. With the use of neurotracer techniques, labeled Schnauzenorgan motoneurons were found throughout the ventral main body of the trigeminal motor nucleus but not among the population of larger motoneurons in its rostrodorsal region. The Schnauzenorgan receives no motor or sensory innervation from the facial nerve. There are many anastomoses between the peripheral electrosensory and trigeminal nerves, but these senses remain separate in the sensory ganglia and in their first central relays. Schnauzenorgan trigeminal primary afferent projections extend throughout the descending trigeminal sensory nuclei, and a few fibers enter the facial lobe. Although no labeled neurons could be identified in the brain as the trigeminal mesencephalic root, some Schnauzenorgan trigeminal afferents terminated in the trigeminal motor nucleus, suggesting a monosynaptic, possibly proprioceptive, pathway. In this first step toward understanding multimodal central representation of the Schnauzenorgan, no direct interconnections were found between the trigeminal sensory and electromotor command system, or the electrosensory and trigeminal motor command. The pathways linking perception to action remain to be studied. © 2014 Wiley Periodicals, Inc.

Dietary correlates associated with the mental foramen in primates: implications for interpreting the fossil record.

PubMed

Muchlinski, Magdalena N; Deane, Andrew S

2016-07-01

The mandibular nerve is a sensory and motor nerve that innervates the muscles of mastication, the lower dentition, and the lower lip and surrounding structures. Although this nerve contains both efferent and afferent fibers, the mental nerve, a terminal branch of the mandibular nerve, is a strictly sensory nerve that exits the mental foramen and innervates the lower lip, the skin overlaying the mandible, and the oral mucosa around the mandible. Osteological foramina are often used as proxies for nerve cross section area and they often correlate well with some aspect of a primate's ecology (e.g., optic foramen and visual acuity). The primary objective of this study is to explore the correlation between the mental foramen and dietary preference among primates. The mental foramen of 40 primate species (n = 180) was measured from 3-D surface models of the mandible. Both conventional and phylogenetic tests indicate that although frugivores have larger mental foramina than folivores, the differences were not significant. These results show that while structures like the infraorbital foramen correlate well with diet and touch sensitivity, the mental foramen does not. Based on these findings, the mental foramen is not a suggested morphological character for interpreting of the fossil record. J. Morphol. 277:978-985, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Diagnostic value of the near-nerve needle sensory nerve conduction in sensory inflammatory demyelinating polyneuropathy.

PubMed

Odabasi, Zeki; Oh, Shin J

2018-03-01

In this study we report the diagnostic value of the near-nerve needle sensory nerve conduction study (NNN-SNCS) in sensory inflammatory demyelinating polyneuropathy (IDP) in which the routine nerve conduction study was normal or non-diagnostic. The NNN-SNCS was performed to identify demyelination in the plantar nerves in 14 patients and in the median or ulnar nerve in 2 patients with sensory IDP. In 16 patients with sensory IDP, routine NCSs were either normal or non-diagnostic for demyelination. Demyelination was identified by NNN-SNCS by dispersion and/or slow nerve conduction velocity (NCV) below the demyelination marker. Immunotherapy was initiated in 11 patients, 10 of whom improved or remained stable. NNN-SNCS played an essential role in identifying demyelinaton in 16 patients with sensory IDP, leading to proper treatment. Muscle Nerve 57: 414-418, 2018. © 2017 Wiley Periodicals, Inc.

Pre-implanted Sensory Nerve Could Enhance the Neurotization in Tissue-Engineered Bone Graft.

PubMed

Wu, Yan; Jing, Da; Ouyang, Hongwei; Li, Liang; Zhai, Mingming; Li, Yan; Bi, Long; Guoxian, Pei

2015-08-01

In our previous study, it was found that implanting the sensory nerve tract into the tissue-engineered bone to repair large bone defects can significantly result in better osteogenesis effect than tissue-engineered bone graft (TEBG) alone. To study the behavior of the preimplanted sensory nerve in the TEBG, the TEBG was constructed by seeding bone mesenchymal stem cells into β-tricalcium phosphate scaffold with (treatment group) or without (blank group) implantation of the sensory nerve. The expression of calcitonin gene-related peptide (CGRP), which helps in the healing of bone defect in the treatment group was significantly higher than the blank group at 4, 8, and 12 weeks. The expression of growth-associated protein 43 (GAP43), which might be expressed during nerve healing in the treatment group, was significantly higher than the blank group at 4 and 8 weeks. The nerve tracts of the preimplanted sensory nerve were found in the scaffold by the nerve tracing technique. The implanted sensory nerve tracts grew into the pores of scaffolds much earlier than the vascular. The implanted sensory nerve tracts traced by Dil could be observed at 4 weeks, but at the same time, no vascular was observed. In conclusion, the TEBG could be benefited from the preimplanted sensory nerve through the healing behavior of the sensory nerve. The sensory nerve fibers could grow into the pores of the TEBG rapidly, and increase the expression of CGRP, which is helpful in regulating the bone formation and the blood flow.

Terminal-Nerve-Derived Neuropeptide Y Modulates Physiological Responses in the Olfactory Epithelium of Hungry Axolotls (Ambystoma mexicanum)

PubMed Central

Mousley, Angela; Polese, Gianluca; Marks, Nikki J.; Eisthen, Heather L.

2007-01-01

The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by L-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances. PMID:16855098

Terminal nerve-derived neuropeptide y modulates physiological responses in the olfactory epithelium of hungry axolotls (Ambystoma mexicanum).

PubMed

Mousley, Angela; Polese, Gianluca; Marks, Nikki J; Eisthen, Heather L

2006-07-19

The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full-length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by l-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances.

Morphology of P2X3-immunoreactive nerve endings in the rat laryngeal mucosa.

PubMed

Takahashi, Natsumi; Nakamuta, Nobuaki; Yamamoto, Yoshio

2016-02-01

The morphological characteristics of P2X3-immunoreactive nerve endings in the laryngeal mucosa were herein examined using immunohistochemistry with confocal laser microscopy. Ramified intraepithelial nerve endings immunoreactive to P2X3 were distributed in the epiglottis and arytenoid region. The axon terminals of P2X3-immunoreactive ramified endings were beaded or flat in shape. These endings were also immunoreactive to P2X2 and not identical to the nerve endings immunoreactive to Na(+)-K(+)-ATPase α3-subunit, substance P (SP), and calcitonin gene-related peptide (CGRP). P2X3-immunoreactive axon terminals were also immunoreactive to vGLUT1, vGLUT2, and vGLUT3. In addition to ramified endings, P2X3-immunoreactive nerve endings were associated with α-gustducin-immunoreactive solitary chemosensory cells and/or SNAP25-immunoreactive neuroendocrine cells. Furthermore, P2X3-immunoreactive nerve endings were also observed in the taste bud-like chemosensory cell clusters of the stratified squamous epithelium covering epiglottic and arytenoid cartilage. The P2X3-immunoreactive nerve endings that associated with sensory and/or endocrine cells and chemosensory cell clusters were also immunoreactive to P2X2, vGLUT1, vGLUT2, and vGLUT3, but not to SP or CGRP. In conclusion, P2X3-immunoreactive nerve endings may be classified into two types, i.e., intraepithelial ramified nerve endings and nerve endings associated with chemosensory cells and neuroendocrine cells.

Prognostic factors in sensory recovery after digital nerve repair.

PubMed

Bulut, Tuğrul; Akgün, Ulaş; Çıtlak, Atilla; Aslan, Cihan; Şener, Ufuk; Şener, Muhittin

2016-01-01

The prognostic factors that affect sensory nerve recovery after digital nerve repair are variable because of nonhomogeneous data, subjective tests, and different assessment/scoring methods. The aim of this study was to evaluate the success of sensory nerve recovery after digital nerve repair and to investigate the prognostic factors in sensorial healing. Ninety-six digital nerve repairs of 63 patients were retrospectively evaluated. All nerves were repaired with end-to-end neurorraphy. The static two-point discrimination (s2PD) and Semmes Weinstein monofilament (SWM) tests were performed to evaluate sensory recovery. The association between prognostic factors such as gender, age, involved digit, time from injury to repair, length of follow-up, smoking, concomitant injuries, type of injury, and sensory recovery results were assessed. The s2PD test demonstrated excellent results in 26 nerves (27%), good results in 61 nerves (64%), and poor results in 9 nerves (9%). The results of the SWM test according to Imai classification showed that 31 nerves (32%) were normal, light touch was diminished in 38 nerves (40%), protective sensation was diminished in 17 nerves (18%), loss of protective sensation occurred in 5 nerves (5%), and 5 nerves (5%) were anesthetic. There was a negative relationship between age, smoking, concomitant injuries, and sensory recovery. Our results demonstrate that concomitant tendon, bone and vascular injuries, older age, and smoking were associated with worse sensory nerve recovery results. However, all digital nerve injuries should be repaired, regardless of these prognostic factors.

Neuroprotection and reduction of glial reaction by cannabidiol treatment after sciatic nerve transection in neonatal rats.

PubMed

Perez, Matheus; Benitez, Suzana U; Cartarozzi, Luciana P; Del Bel, Elaine; Guimarães, Francisco S; Oliveira, Alexandre L R

2013-11-01

In neonatal rats, the transection of a peripheral nerve leads to an intense retrograde degeneration of both motor and sensory neurons. Most of the axotomy-induced neuronal loss is a result of apoptotic processes. The clinical use of neurotrophic factors is difficult due to side effects and elevated costs, but other molecules might be effective and more easily obtained. Among them, some are derived from Cannabis sativa. Cannabidiol (CBD) is the major non-psychotropic component found on the surface of such plant leaves. The present study aimed to investigate the neuroprotective potential of CBD. Thus, 2-day-old Wistar rats were divided into the following experimental groups: sciatic nerve axotomy + CBD treatment (CBD group), axotomy + vehicle treatment (phosphate buffer group) and a control group (no-treatment group). The results were analysed by Nissl staining, immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling at 5 days post-lesion. Neuronal counting revealed both motor and sensory neuron rescue following treatment with CBD (15 and 30 mg/kg). Immunohistochemical analysis (obtained by synaptophysin staining) revealed 30% greater synaptic preservation within the spinal cord in the CBD-treated group. CBD administration decreased the astroglial and microglial reaction by 30 and 27%, respectively, as seen by glial fibrillary acidic protein and ionised calcium binding adaptor molecule 1 immunolabeling quantification. In line with such results, the terminal deoxynucleotidyl transferase dUTP nick end labeling reaction revealed a reduction of apoptotic cells, mostly located in the spinal cord intermediate zone, where interneurons promote sensory-motor integration. The present results show that CBD possesses neuroprotective characteristics that may, in turn, be promising for future clinical use. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Different electrophysiological profiles and treatment response in 'typical' and 'atypical' chronic inflammatory demyelinating polyneuropathy.

PubMed

Kuwabara, Satoshi; Isose, Sagiri; Mori, Masahiro; Mitsuma, Satsuki; Sawai, Setsu; Beppu, Minako; Sekiguchi, Yukari; Misawa, Sonoko

2015-10-01

Chronic inflammatory demyelinating polyneuropathy (CIDP) is currently classified into 'typical' CIDP and 'atypical' subtypes such as multifocal acquired demyelinating sensory and motor neuropathy (MADSAM). To assess the frequency of CIDP subtypes, and to elucidate clinical and electrophysiological features, and treatment response in each subtype. We reviewed data from 100 consecutive patients fulfilling criteria for CIDP proposed by the European Federation of Neurological Societies and the Peripheral Nerve Society. The Kaplan-Meier curve was used to estimate long-term outcome. Patients were classified as having typical CIDP (60%), MADSAM (34%), demyelinating acquired distal symmetric neuropathy (8%) or pure sensory CIDP (1%). Compared with patients with MADSAM, patients with typical CIDP showed more rapid progression and severe disability, and demyelination predominant in the distal nerve segments. MADSAM was characterised by multifocal demyelination in the nerve trunks. Abnormal median-normal sural sensory responses were more frequently found for typical CIDP (53% vs 13%). Patients with typical CIDP invariably responded to corticosteroids, immunoglobulin or plasmapheresis, whereas patients with MADSAM were more refractory to these treatments. The Kaplan-Meier analyses showed that 64% of patients with typical CIDP and 41% of patients with MADSAM had a clinical remission 5 years later (p=0.02). Among the CIDP spectrum, typical CIDP and MADSAM are the major subtypes, and their pathophysiology appears to be distinct. In typical CIDP, the distal nerve terminals and possibly the nerve roots, where the blood-nerve barrier is anatomically deficient, are preferentially affected, raising the possibility of antibody-mediated demyelination, whereas cellular immunity with breakdown of the barrier may be important in MADSAM neuropathy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Cytoarchitectonic study of the trigeminal ganglion in humans.

PubMed

Krastev, Dimo Stoyanov; Apostolov, Alexander

2013-01-01

The trigeminal ganglion (TG), a cluster of pseudounipolar neurons, is located in the trigeminal impression of the temporal pyramid. It is covered by a sheath of the dura mater and arachnoid and is near the rear end of the cavernous sinus. The peripheral processes of the pseudounipolar cells are involved in the formation of the first and second branch and the sensory part of the third branch of the fifth cranial nerve, and the central ones form the sensory root of the nerve, which penetrates at the level of the middle cerebellar peduncle, aside from the pons, and terminate in the sensory nuclei of the trigeminal complex. We found that the primary sensory neurons involved in sensory innervation of the orofacial complex are a diverse group. Although they possess the general structure of pseudounipolar neurons, there are significant differences among them, seen in varying intensities of staining. Based on our investigations we classified the neurons into 7 groups, i.e. large, subdivided into light and dark, medium, also light and dark, and small light and dark, and, moreover, neurons with an irregular shape of their perikarya. Further research by applying various immunohistochemical methods will clarify whether differences in the morphological patterns of the neurons are associated with differences in the neurochemical composition of various neuronal types.

Cytoarchitectonic study of the trigeminal ganglion in humans

PubMed Central

KRASTEV, DIMO STOYANOV; APOSTOLOV, ALEXANDER

2013-01-01

The trigeminal ganglion (TG), a cluster of pseudounipolar neurons, is located in the trigeminal impression of the temporal pyramid. It is covered by a sheath of the dura mater and arachnoid and is near the rear end of the cavernous sinus. The peripheral processes of the pseudounipolar cells are involved in the formation of the first and second branch and the sensory part of the third branch of the fifth cranial nerve, and the central ones form the sensory root of the nerve, which penetrates at the level of the middle cerebellar peduncle, aside from the pons, and terminate in the sensory nuclei of the trigeminal complex. We found that the primary sensory neurons involved in sensory innervation of the orofacial complex are a diverse group. Although they possess the general structure of pseudounipolar neurons, there are significant differences among them, seen in varying intensities of staining. Based on our investigations we classified the neurons into 7 groups, i.e. large, subdivided into light and dark, medium, also light and dark, and small light and dark, and, moreover, neurons with an irregular shape of their perikarya. Further research by applying various immunohistochemical methods will clarify whether differences in the morphological patterns of the neurons are associated with differences in the neurochemical composition of various neuronal types. PMID:26527926

Glutamatergic modulation of synaptic-like vesicle recycling in mechanosensory lanceolate nerve terminals of mammalian hair follicles

PubMed Central

Banks, Robert W; Cahusac, Peter M B; Graca, Anna; Kain, Nakul; Shenton, Fiona; Singh, Paramjeet; Njå, Arild; Simon, Anna; Watson, Sonia; Slater, Clarke R; Bewick, Guy S

2013-01-01

Our aim in the present study was to determine whether a glutamatergic modulatory system involving synaptic-like vesicles (SLVs) is present in the lanceolate ending of the mouse and rat hair follicle and, if so, to assess its similarity to that of the rat muscle spindle annulospiral ending we have described previously. Both types of endings are formed by the peripheral sensory terminals of primary mechanosensory dorsal root ganglion cells, so the presence of such a system in the lanceolate ending would provide support for our hypothesis that it is a general property of fundamental importance to the regulation of the responsiveness of the broad class of primary mechanosensory endings. We show not only that an SLV-based system is present in lanceolate endings, but also that there are clear parallels between its operation in the two types of mechanosensory endings. In particular, we demonstrate that, as in the muscle spindle: (i) FM1-43 labels the sensory terminals of the lanceolate ending, rather than the closely associated accessory (glial) cells; (ii) the dye enters and leaves the terminals primarily by SLV recycling; (iii) the dye does not block the electrical response to mechanical stimulation, in contrast to its effect on the hair cell and dorsal root ganglion cells in culture; (iv) SLV recycling is Ca2+ sensitive; and (v) the sensory terminals are enriched in glutamate. Thus, in the lanceolate sensory ending SLV recycling is itself regulated, at least in part, by glutamate acting through a phospholipase D-coupled metabotropic glutamate receptor. PMID:23440964

Neuropathy in non-freezing cold injury (trench foot).

PubMed Central

Irwin, M S; Sanders, R; Green, C J; Terenghi, G

1997-01-01

Non-freezing cold injury (trench foot) is characterized, in severe cases, by peripheral nerve damage and tissue necrosis. Controversy exists regarding the susceptibility of nerve fibre populations to injury as well as the mechanism of injury. Clinical and histological studies (n = 2) were conducted in a 40-year-old man with severe non-freezing cold injury in both feet. Clinical sensory tests, including two-point discrimination and pressure, vibration and thermal thresholds, indicated damage to large and small diameter nerves. On immunohistochemical assessment, terminal cutaneous nerve fibres within the plantar skin stained much less than in a normal control whereas staining to von Willebrand factor pointed to increased vascularity in all areas. The results indicate that all nerve populations (myelinated and unmyelinated) were damaged, possibly in a cycle of ischaemia and reperfusion. Images Figure 1 a Figure 1 b Figure 2 a Figure 2 b Figure 3 a Figure 3 b PMID:9306996

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.

Schwann Cell Phenotype Changes in Aging Human Dental Pulp.

PubMed

Couve, E; Lovera, M; Suzuki, K; Schmachtenberg, O

2018-03-01

Schwann cells are glial cells that support axonal development, maintenance, defense, and regeneration in the peripheral nervous system. There is limited knowledge regarding the organization, plasticity, and aging of Schwann cells within the dental pulp in adult permanent teeth. The present study sought to relate changes in the pattern of Schwann cell phenotypes between young and old adult teeth with neuronal, immune, and vascular components of the dental pulp. Schwann cells are shown to form a prominent glial network at the dentin-pulp interface, consisting of nonmyelinating and myelinating phenotypes, forming a multicellular neuroimmune interface in association with nerve fibers and dendritic cells. Schwann cell phenotypes are recognized by the expression of S100, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), Sox10, GAP43, and p75NTR markers. In young adult teeth, a dense population of nonmyelinating Schwann cells projects processes in close association with sensory nerve terminals through the odontoblast layer, reaching the adjacent predentin/dentin domain. While GAP43 and p75NTR are highly expressed in nonmyelinating Schwann cells from young adult teeth, the presence of these markers declines significantly in old adult teeth. Myelinated axons, identified by MBP expression, are mainly present at the Raschkow plexus and within nerve bundles in the dental pulp, but their density is significantly reduced in old adult versus young adult teeth. These data reveal age-related changes within the glial network of the dental pulp, in association with a reduction of coronal dental pulp innervation in old adult versus young adult teeth. The prominence of Schwann cells as a cellular component at the dentin-pulp interface supports the notion that their association with sensory nerve terminals and immune system components forms part of an integrated multicellular barrier for defense against pathogens and dentin repair.

Morphological differences in skeletal muscle atrophy of rats with motor nerve and/or sensory nerve injury★

PubMed Central

Zhao, Lei; Lv, Guangming; Jiang, Shengyang; Yan, Zhiqiang; Sun, Junming; Wang, Ling; Jiang, Donglin

2012-01-01

Skeletal muscle atrophy occurs after denervation. The present study dissected the rat left ventral root and dorsal root at L4-6 or the sciatic nerve to establish a model of simple motor nerve injury, sensory nerve injury or mixed nerve injury. Results showed that with prolonged denervation time, rats with simple motor nerve injury, sensory nerve injury or mixed nerve injury exhibited abnormal behavior, reduced wet weight of the left gastrocnemius muscle, decreased diameter and cross-sectional area and altered ultrastructure of muscle cells, as well as decreased cross-sectional area and increased gray scale of the gastrocnemius muscle motor end plate. Moreover, at the same time point, the pathological changes were most severe in mixed nerve injury, followed by simple motor nerve injury, and the changes in simple sensory nerve injury were the mildest. These findings indicate that normal skeletal muscle morphology is maintained by intact innervation. Motor nerve injury resulted in larger damage to skeletal muscle and more severe atrophy than sensory nerve injury. Thus, reconstruction of motor nerves should be considered first in the clinical treatment of skeletal muscle atrophy caused by denervation. PMID:25337102

Activation of somatosensory afferents elicit changes in vaginal blood flow and the urethrogenital reflex via autonomic efferents.

PubMed

Cai, R S; Alexander, M Sipski; Marson, L

2008-09-01

We examined the effects of pudendal sensory nerve stimulation and urethral distention on vaginal blood flow and the urethrogenital reflex, and the relationship between somatic and autonomic pathways regulating sexual responses. Distention of the urethra and stimulation of the pudendal sensory nerve were used to evoke changes in vaginal blood flow (laser Doppler perfusion monitoring) and pudendal motor nerve activity in anesthetized, spinally transected female rats. Bilateral cuts of either the pelvic or hypogastric nerve or both autonomic nerves were made, and blood flow and pudendal nerve responses were reexamined. Stimulation of the pudendal sensory nerve or urethral distention elicited consistent increases in vaginal blood flow and rhythmic firing of the pudendal motor nerve. Bilateral cuts of the pelvic plus hypogastric nerves significantly reduced vaginal blood flow responses without altering pudendal motor nerve responses. Pelvic nerve cuts also significantly reduced vaginal blood flow responses. In contrast, hypogastric nerve cuts did not significantly change vaginal blood flow. Bilateral cuts of the pudendal sensory nerve blocked pudendal motor nerve responses but stimulation of the central end evoked vaginal blood flow and pudendal motor nerve responses. Stimulation of the sensory branch of the pudendal nerve elicits vasodilatation of the vagina. The likely mechanism is via activation of spinal pathways that in turn activate pelvic nerve efferents to produced changes in vaginal blood flow. Climatic-like responses (firing of the pudendal motor nerve) occur in response to stimulation of the pudendal sensory nerve and do not require intact pelvic or hypogastric nerves.

Selective Expression of a Sodium Pump Isozyme by Cough Receptors and Evidence for Its Essential Role in Regulating Cough

PubMed Central

Mazzone, Stuart B.; Reynolds, Sandra M.; Mori, Nanako; Kollarik, Marian; Farmer, David G.; Myers, Allen C.

2009-01-01

We have identified a distinct subtype of airway vagal afferent nerve that plays an essential role in regulating the cough reflex. These afferents are exquisitely sensitive to punctate mechanical stimuli, acid, and decreases in extracellular chloride concentrations, but are insensitive to capsaicin, bradykinin, histamine, adenosine, serotonin, or changes in airway intraluminal pressures. In this study we used intravital imaging, retrograde neuronal tracing, and electrophysiological analyses to characterize the structural basis for their peculiar mechanical sensitivity and to further characterize the regulation of their excitability. In completing these experiments, we uncovered evidence for an essential role of an isozyme of Na+-K+ ATPase in regulating cough. These vagal sensory neurons arise bilaterally from the nodose ganglia and are selectively and brilliantly stained intravitally with the styryl dye FM2-10. Cough receptor terminations are confined and adherent to the extracellular matrix separating the airway epithelium and smooth muscle layers, a site of extensive remodeling in asthma and chronic obstructive pulmonary disease. The cough receptor terminals uniquely express the α3 subunit of Na+-K+ ATPase. Intravital staining of cough receptors by FM2-10, cough receptor excitability in vitro, and coughing in vivo are potently and selectively inhibited by the sodium pump inhibitor ouabain. These data provide the first detailed morphological description of the peripheral terminals of the sensory nerves regulating cough and identify a selective molecular target for their modulation. PMID:19864578

Molecular characteristics suggest an effector function of palisade endings in extraocular muscles.

PubMed

Konakci, Kadriye Zeynep; Streicher, Johannes; Hoetzenecker, Wolfram; Blumer, Michael Josef Franz; Lukas, Julius-Robert; Blumer, Roland

2005-01-01

To analyze palisade endings in cat extraocular muscles (EOMs) and to clarify whether these EOM-specific organs are sensory or motor. Twelve cats aged between 1 and 16 years were analyzed. Whole EOM tendons were immunostained using four different combinations of triple fluorescence labeling. Triple labeling included antibodies against choline acetyltransferase (ChAT), neurofilament, synaptophysin, and alpha-bungarotoxin. Preparations were examined by confocal laser scanning microscopy. ChAT-labeled EOMs were also analyzed by immunoelectron microscopy. Three-dimensional reconstructions were made of palisade endings. Palisade endings were found in the distal and proximal myotendinous regions of cat EOMs. These endings arose from thin nerve fibers coming from the muscle and extending into the tendon. There, the nerve fibers turned back 180 degrees to divide into terminal branches around the muscle fiber tips. Terminal branches established numerous contacts with the tendon attached to the muscle fiber tip and only a few contacts with the muscle fiber. Often, nerve fibers forming palisade endings on muscle fiber tips were observed to establish multiple motor contacts on muscle fibers outside palisade endings. Three-dimensional reconstructions depicted the complex morphology of the palisade endings. All nerve fibers supplying palisade endings stained positively for ChAT and neurofilament. All nerve terminals in palisade endings were ChAT and synaptophysin positive. Only neuromuscular contacts in palisade endings were positive for alpha-bungarotoxin, as well. This study provides evidence that palisade endings in cat EOMs have effector function. The findings may be of significance for strabismus surgery because palisade endings are also found in human EOMs.

[Immunocytochemical study of cholinergic innervation in the neurosensory epithelia of human vestibule].

PubMed

Kong, W; Hussl, B; Schrott-Fischer, A

1998-02-01

To investigate the cholinergic innervation of the neurosensory epithelia of human vestibule. A modified preembedding immunostaining technique for immunoelectronmicroscopy was applied to this study. A polyclonal antibody to choline acetyltransferase (ChAT) was used as the marker of cholinergic fibers. ChAT-immunoreactive products were restricted to the nerve fibers and terminals which were rich in synaptic vesicles. The ChAT-immunoreactive fibers synaps with afferent chalice as well as with type II sensory hair cells. This study demonstrates that cholinergic fibers innervate the neurosensory epithelia of human vestible. The cholinergic fibers of human vestibular sensory epithelia belong to the vestibular efferent system.

Parkinson disease affects peripheral sensory nerves in the pharynx.

PubMed

Mu, Liancai; Sobotka, Stanislaw; Chen, Jingming; Su, Hungxi; Sanders, Ira; Nyirenda, Themba; Adler, Charles H; Shill, Holly A; Caviness, John N; Samanta, Johan E; Sue, Lucia I; Beach, Thomas G

2013-07-01

Dysphagia is very common in patients with Parkinson disease (PD) and often leads to aspiration pneumonia, the most common cause of death in PD. Current therapies are largely ineffective for dysphagia. Because pharyngeal sensation normally triggers the swallowing reflex, we examined pharyngeal sensory nerves in PD patients for Lewy pathology.Sensory nerves supplying the pharynx were excised from autopsied pharynges obtained from patients with clinically diagnosed and neuropathologically confirmed PD (n = 10) and healthy age-matched controls (n = 4). We examined the glossopharyngeal nerve (cranial nerve IX), the pharyngeal sensory branch of the vagus nerve (PSB-X), and the internal superior laryngeal nerve (ISLN) innervating the laryngopharynx. Immunohistochemistry for phosphorylated α-synuclein was used to detect Lewy pathology. Axonal α-synuclein aggregates in the pharyngeal sensory nerves were identified in all of the PD subjects but not in the controls. The density of α-synuclein-positive lesions was greater in PD patients with dysphagia versus those without dysphagia. In addition, α-synuclein-immunoreactive nerve fibers in the ISLN were much more abundant than those in cranial nerve IX and PSB-X. These findings suggest that pharyngeal sensory nerves are directly affected by pathologic processes in PD. These abnormalities may decrease pharyngeal sensation, thereby impairing swallowing and airway protective reflexes and contributing to dysphagia and aspiration.

Multifocal sensory demyelinating neuropathy: Report of a case.

PubMed

Oh, Shin J

2017-10-01

Multifocal sensory demyelinating neuropathy has not been adequately reported in the literature. A 42-year-old man with numbness of the left hand for 3 years and of the right hand for 6 months had a pure multifocal sensory neuropathy involving both hands, most prominently affecting 2-point discrimination, number writing, and object recognition of the left hand. Near-nerve needle sensory and mixed nerve conduction studies were performed on the left ulnar nerve. Studies of the left ulnar nerve documented a demyelinating neuropathy characterized by temporal dispersion and marked decrease in the amplitudes of the sensory and mixed compound nerve potentials in the above-elbow-axilla segment. With intravenous immunoglobulin treatment, there was improvement in his neuropathic condition. In this study I describe a case of multifocal sensory demyelinating neuropathy as a counterpart of multifocal motor neuropathy. Muscle Nerve 56: 825-828, 2017. © 2016 Wiley Periodicals, Inc.

Sensory and motor neuropathy in a Border Collie.

PubMed

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

2005-10-15

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

Sound damage and gentamicin treatment produce different patterns of damage to the efferent innervation of the chick cochlea.

PubMed

Ofsie, M S; Hennig, A K; Messana, E P; Cotanche, D A

1997-11-01

Both sound exposure and gentamicin treatment cause damage to sensory hair cells in the peripheral chick auditory organ, the basilar papilla. This induces a regeneration response which replaces hair cells and restores auditory function. Since functional recovery requires the re-establishment of connections between regenerated hair cells and the central nervous system, we have investigated the effects of sound damage and gentamicin treatment on the neuronal elements within the cochlea. Whole-mount preparations of basilar papillae were labeled with phalloidin to label the actin cytoskeleton and antibodies to neurofilaments, choline acetyltransferase, and synapsin to label neurons; and examined by confocal laser scanning microscopy. When chicks are treated with gentamicin or exposed to acoustic overstimulation, the transverse nerve fibers show no changes from normal cochleae assayed in parallel. Efferent nerve terminals, however, disappear from areas depleted of hair cells following acoustic trauma. In contrast, efferent nerve endings are still present in the areas of hair cell loss following gentamicin treatment, although their morphological appearance is greatly altered. These differences in the response of efferent nerve terminals to sound exposure versus gentamicin treatment may account, at least in part, for the discrepancies reported in the time of recovery of auditory function.

Restoration of Trigeminal Cutaneous Sensation with Cross-Face Sural Nerve Grafts: A Novel Approach to Facial Sensory Rehabilitation.

PubMed

Catapano, Joseph; Scholl, David; Ho, Emily; Zuker, Ronald M; Borschel, Gregory H

2015-09-01

Although treating facial palsy is considered debilitating for patients, trigeminal nerve palsy and sensory deficits of the face are overlooked components of disability. Complete anesthesia leaves patients susceptible to occult injury, and facial sensation is an important component of interaction and activities of daily living. Sensory reconstruction is well established in the restoration of hand sensation; however, only one previous report proposed a surgical strategy for sensory nerve reconstruction of the face with use of nerve transfers. Nerve transfers, when used alone, have limited application because of their restricted arc of rotation in the face; extending their arc by adding nerve grafts greatly expands their utility. The following cases demonstrate the early results after V2 and V3 reconstruction with cross-face nerve grafts in three patients with acquired trigeminal nerve palsy. Cross-face nerve grafts using the sural nerve permit more proximal reconstruction of the infraorbital and mental nerves, which allows reinnervation of their entire cutaneous distribution. All patients demonstrated improved sensation in the reconstructed dermatomes, and no patients reported donor-site abnormalities. Cross-face nerve grafts result in minimal donor-site morbidity and are promising as a surgical strategy to address sensory deficits of the face. Therapeutic, V.

Parkinson Disease Affects Peripheral Sensory Nerves in the Pharynx

PubMed Central

Mu, Liancai; Sobotka, Stanislaw; Chen, Jingming; Su, Hungxi; Sanders, Ira; Nyirenda, Themba; Adler, Charles H.; Shill, Holly A.; Caviness, John N.; Samanta, Johan E.; Sue, Lucia I.; Beach, Thomas G.

2013-01-01

Dysphagia is very common in patients with Parkinson’s disease (PD) and often leads to aspiration pneumonia, the most common cause of death in PD. Unfortunately, current therapies are largely ineffective for dysphagia. As pharyngeal sensation normally triggers the swallowing reflex, we examined pharyngeal sensory nerves in PD for Lewy pathology. Sensory nerves supplying the pharynx were excised from autopsied pharynges obtained from patients with clinically diagnosed and neuropathologically confirmed PD (n = 10) and healthy age-matched controls (n = 4). We examined: the glossopharyngeal nerve (IX); the pharyngeal sensory branch of the vagus nerve (PSB-X); and the internal superior laryngeal nerve (ISLN) innervating the laryngopharynx. Immunohistochemistry for phosphorylated α-synuclein was used to detect potential Lewy pathology. Axonal α-synuclein aggregates in the pharyngeal sensory nerves were identified in all of the PD subjects but not in the controls. The density of α-synuclein-positive lesions was significantly greater in PD subjects with documented dysphagia compared to those without dysphagia. In addition, α-synuclein-immunoreactive nerve fibers in the ISLN were much more abundant than those in the IX and PSBX. These findings suggest that pharyngeal sensory nerves are directly affected by the pathologic process of PD. This anatomic pathology may decrease pharyngeal sensation impairing swallowing and airway protective reflexes, thereby contributing to dysphagia and aspiration. PMID:23771215

The Changing Sensory and Sympathetic Innervation of the Young, Adult and Aging Mouse Femur.

PubMed

Chartier, Stephane R; Mitchell, Stefanie A T; Majuta, Lisa A; Mantyh, Patrick W

2018-02-10

Although bone is continually being remodeled and ultimately declines with aging, little is known whether similar changes occur in the sensory and sympathetic nerve fibers that innervate bone. Here, immunohistochemistry and confocal microscopy were used to examine changes in the sensory and sympathetic nerve fibers that innervate the young (10 days post-partum), adult (3 months) and aging (24 months) C57Bl/6 mouse femur. In all three ages examined, the periosteum was the most densely innervated bone compartment. With aging, the total number of sensory and sympathetic nerve fibers clearly declines as the cambium layer of the periosteum dramatically thins. Yet even in the aging femur, there remains a dense sensory and sympathetic innervation of the periosteum. In cortical bone, sensory and sympathetic nerve fibers are largely confined to vascularized Haversian canals and while there is no significant decline in the density of sensory fibers, there was a 75% reduction in sympathetic nerve fibers in the aging vs. adult cortical bone. In contrast, in the bone marrow the overall density/unit area of both sensory and sympathetic nerve fibers appeared to remain largely unchanged across the lifespan. The preferential preservation of sensory nerve fibers suggests that even as bone itself undergoes a marked decline with age, the nociceptors that detect injury and signal skeletal pain remain relatively intact. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Characterization of Frequency-Dependent Responses of the Vascular System to Repetitive Vibration

PubMed Central

Krajnak, Kristine; Miller, G. Roger; Waugh, Stacey; Johnson, Claud; Kashon, Michael L.

2015-01-01

Objective Occupational exposure to hand-transmitted vibration can result in damage to nerves and sensory loss. The goal of this study was to assess the frequency-dependent effects of repeated bouts of vibration on sensory nerve function and associated changes in nerves. Methods The tails of rats were exposed to vibration at 62.5, 125, or 250 Hz (constant acceleration of 49m/s2) for 10 days. The effects on sensory nerve function, nerve morphology, and transcript expression in ventral tail nerves were measured. Results Vibration at all frequencies had effects on nerve function and physiology. However, the effects tended to be more prominent with exposure at 250 Hz. Conclusion Exposure to vibration has detrimental effects on sensory nerve function and physiology. However, many of these changes are more prominent at 250-Hz exposure than at lower frequencies. PMID:22785326

Role of renal sensory nerves in physiological and pathophysiological conditions

PubMed Central

2014-01-01

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

Axon-Sorting Multifunctional Nerve Guides: Accelerating Restoration of Nerve Function

DTIC Science & Technology

2014-10-01

factor (singly & in selected combinations) in the organotypic model system for preferential sensory or motor axon extension. Use confocal microscopy to...track axon extension of labeled sensory or motor neurons from spinal cord slices (motor) or dorsal root ganglia ( DRG ) (sensory). 20 Thy1-YFP mice...RESEARCH ACCOMPLISHMENTS: • Established a system of color-coded mixed nerve tracking using GFP and RFP expressing motor and sensory neurons (Figure 1

Using Arrays of Microelectrodes Implanted in Residual Peripheral Nerves to Provide Dextrous Control of, and Modulated Sensory Feedback from, a Hand Prosthesis

DTIC Science & Technology

2015-10-01

Modulated Sensory Feedback from, a Hand Prosthesis PRINCIPAL INVESTIGATOR: Bradley Greger, PhD CONTRACTING ORGANIZATION: Arizona State University...Residual Peripheral Nerves to Provide Dextrous Control of, and Modulated Sensory Feedback from, a Hand Prosthesis 5a. CONTRACT NUMBER 5b. GRANT...Peripheral Nerve Interface, Prosthetic Hand, Neural Prosthesis , Sensory Feedback, Micro-stimulation, Electrophysiology, Action Potentials, Micro

Peripheral Motor and Sensory Nerve Conduction following Transplantation of Undifferentiated Autologous Adipose Tissue-Derived Stem Cells in a Biodegradable U.S. Food and Drug Administration-Approved Nerve Conduit.

PubMed

Klein, Silvan M; Vykoukal, Jody; Li, De-Pei; Pan, Hui-Lin; Zeitler, Katharina; Alt, Eckhard; Geis, Sebastian; Felthaus, Oliver; Prantl, Lukas

2016-07-01

Conduits preseeded with either Schwann cells or stem cells differentiated into Schwann cells demonstrated promising results for the outcome of nerve regeneration in nerve defects. The concept of this trial combines nerve repair by means of a commercially available nerve guidance conduit and preseeding with autologous, undifferentiated, adipose tissue-derived stem cells. Adipose tissue-derived stem cells were harvested from rats and subsequently seeded onto a U.S. Food and Drug Administration-approved type I collagen conduit. Sciatic nerve gaps 10 mm in length were created, and nerve repair was performed by the transplantation of either conduits preseeded with autologous adipose tissue-derived stem cells or acellular (control group) conduits. After 6 months, the motor and sensory nerve conduction velocity were assessed. Nerves were removed and examined by hematoxylin and eosin, van Gieson, and immunohistochemistry (S100 protein) staining for the quality of axonal regeneration. Nerve gaps treated with adipose tissue-derived stem cells showed superior nerve regeneration, reflected by higher motor and sensory nerve conduction velocity values. The motor and sensory nerve conduction velocity were significantly greater in nerves treated with conduits preseeded with adipose tissue-derived stem cells than in nerves treated with conduits alone (p < 0.05). Increased S100 immunoreactivity was detected for the adipose tissue-derived stem cell group. In this group, axon arrangement inside the conduits was more organized. Transplantation of adipose tissue-derived stem cells significantly improves motor and sensory nerve conduction velocity in peripheral nerve gaps. Preseeded conduits showed a more organized axon arrangement inside the conduit in comparison with nerve conduits alone. The approach used here could readily be translated into a clinical therapy. Therapeutic, V.

Sonoanatomy of sensory branches of the ulnar nerve below the elbow in healthy subjects.

PubMed

Kim, Ki Hoon; Lee, Seok Jun; Park, Byung Kyu; Kim, Dong Hwee

2018-04-01

We identify sensory branches of the ulnar nerve-palmar ulnar cutaneous nerve (PUCN), dorsal ulnar cutaneous nerve (DUCN), and superficial sensory branch-using ultrasonography. In 60 forearms of 30 healthy adult volunteers, the origin and size of the PUCN, DUCN, and superficial sensory branch were measured by ultrasonography. The relative pathway of the DUCN to the ulnar styloid process was also investigated. The PUCN was observed in 47 forearms (78%), and the DUCN was observed in all forearms. Average distances from the pisiform to the origin of the PUCN and DUCN were 11.9 ± 1.4 and 7.0 ± 1.0 cm, respectively. Superficial and deep divisions split 0.9 ± 0.3 cm distal to the pisiform. Cross-sectional areas of the PUCN, DUCN, and superficial sensory branch were 0.3 ± 0.1, 1.5 ± 0.5, and 3.9 ± 1.0 mm 2 , respectively. Sensory branches of the ulnar nerve can be visualized by ultrasonography, helping to differentiate ulnar nerve injury originating at either wrist or elbow. Muscle Nerve 57: 569-573, 2018. © 2017 Wiley Periodicals, Inc.

Ultrastructural localization of ChAT-like immunoreactivity in the human vestibular periphery.

PubMed

Kong, W J; Hussl, B; Thumfart, W F; Schrott-Fischer, A

1998-05-01

Acetylcholine (ACh) has long been considered a neurotransmitter candidate in the efferent vestibular system of mammals. Recently, choline acetyltransferase (ChAT), the synthesizing enzyme for ACh, was immunocytochemically localized in all five end-organs of the rat vestibule (Kong et al. (1994) Hear. Res. 75, 192-200). However, there is little information in the literature concerning the cholinergic innervation in the vestibular periphery of man. In the present study the ultrastructural localization of the ChAT-like immunoreactivity in the human vestibular periphery was investigated in order to reveal the cholinergic innervation in the human vestibular end-organs. A modified method of pre-embedding immunoelectron microscopy was applied. It was found that the ChAT-like immunoreactivity was located in the bouton-type vesiculated nerve terminals in the vestibular neurosensory epithelia of man. These ChAT-like immunostained nerve terminals make synaptic contacts either with afferent chalices surrounding type I vestibular sensory hair cells, or with type II vestibular sensory hair cells. These results show that the ChAT-like immunoreactivity in the human vestibular periphery is confined to the efferent vestibular system. The ChAT-containing efferents innervate both type I hair cells and type II hair cells, making postsynaptic and presynaptic contacts, respectively. This study presents evidence that ACh is a neurotransmitter candidate in the efferent vestibular system of man.

Positional Cues in the Drosophila Nerve Cord: Semaphorins Pattern the Dorso-Ventral Axis

PubMed Central

Zlatic, Marta; Li, Feng; Strigini, Maura; Grueber, Wesley; Bate, Michael

2009-01-01

During the development of neural circuitry, neurons of different kinds establish specific synaptic connections by selecting appropriate targets from large numbers of alternatives. The range of alternative targets is reduced by well organised patterns of growth, termination, and branching that deliver the terminals of appropriate pre- and postsynaptic partners to restricted volumes of the developing nervous system. We use the axons of embryonic Drosophila sensory neurons as a model system in which to study the way in which growing neurons are guided to terminate in specific volumes of the developing nervous system. The mediolateral positions of sensory arbors are controlled by the response of Robo receptors to a Slit gradient. Here we make a genetic analysis of factors regulating position in the dorso-ventral axis. We find that dorso-ventral layers of neuropile contain different levels and combinations of Semaphorins. We demonstrate the existence of a central to dorsal and central to ventral gradient of Sema 2a, perpendicular to the Slit gradient. We show that a combination of Plexin A (Plex A) and Plexin B (Plex B) receptors specifies the ventral projection of sensory neurons by responding to high concentrations of Semaphorin 1a (Sema 1a) and Semaphorin 2a (Sema 2a). Together our findings support the idea that axons are delivered to particular regions of the neuropile by their responses to systems of positional cues in each dimension. PMID:19547742

Sensation, mechanoreceptor, and nerve fiber function after nerve regeneration.

PubMed

Krarup, Christian; Rosén, Birgitta; Boeckstyns, Michel; Ibsen Sørensen, Allan; Lundborg, Göran; Moldovan, Mihai; Archibald, Simon J

2017-12-01

Sensation is essential for recovery after peripheral nerve injury. However, the relationship between sensory modalities and function of regenerated fibers is uncertain. We have investigated the relationships between touch threshold, tactile gnosis, and mechanoreceptor and sensory fiber function after nerve regeneration. Twenty-one median or ulnar nerve lesions were repaired by a collagen nerve conduit or direct suture. Quantitative sensory hand function and sensory conduction studies by near-nerve technique, including tactile stimulation of mechanoreceptors, were followed for 2 years, and results were compared to noninjured hands. At both repair methods, touch thresholds at the finger tips recovered to 81 ± 3% and tactile gnosis only to 20 ± 4% (p < 0.001) of control. The sensory nerve action potentials (SNAPs) remained dispersed and areas recovered to 23 ± 2% and the amplitudes only to 7 ± 1% (P < 0.001). The areas of SNAPs after tactile stimulation recovered to 61 ± 11% and remained slowed. Touch sensation correlated with SNAP areas (p < 0.005) and was negatively related to the prolongation of tactile latencies (p < 0.01); tactile gnosis was not related to electrophysiological parameters. The recovered function of regenerated peripheral nerve fibers and reinnervated mechanoreceptors may differentially influence recovery of sensory modalities. Touch was affected by the number and function of regenerated fibers and mechanoreceptors. In contrast, tactile gnosis depends on the input and plasticity of the central nervous system (CNS), which may explain the absence of a direct relation between electrophysiological parameters and poor recovery. Dispersed maturation of sensory nerve fibers with desynchronized inputs to the CNS also contributes to the poor recovery of tactile gnosis. Ann Neurol 2017. Ann Neurol 2017;82:940-950. © 2017 American Neurological Association.

Behavioural, morphological and electrophysiological assessment of the effects of type 2 diabetes mellitus on large and small nerve fibres in Zucker diabetic fatty, Zucker lean and Wistar rats.

PubMed

Garcia-Perez, E; Schönberger, T; Sumalla, M; Stierstorfer, B; Solà, R; Doods, H; Serra, J; Gorodetskaya, N

2018-04-20

Peripheral neuropathy is a common complication in type 2 diabetes mellitus (T2DM). The most common presentation is in the form of a distal axonal sensory-motor polyneuropathy that involves large and small nerve fibres in variable proportion. Zucker Diabetic Fatty (ZDF), Zucker Lean (ZL) and Wistar Han (WH) rats were used to assess the behavioural, morphological and electrophysiological effects that T2DM have on peripheral large and small nerve fibres of 6- to 40-week-old rats. ZDF rats presented mechanical hypersensitivity that initially worsened in parallel to the progression of diabetes and eventually reverted at later stages of the disease. The reversal from hypersensitivity to hyposensitivity paralleled a reduction in the number of intraepithelial skin nerve terminals and in the nerve fibre lengths. However, no increased levels of degeneration of dorsal root ganglion neurons were observed. Nerve conduction studies showed a reduction in sensory and motor nerve conduction velocity (CV) in hyperglycaemic ZDF rats. Microneurography showed significant alterations in several parameters of activity-dependent slowing (ADS) of mechano-insensitive C-nociceptors in ZDF rats. Surprisingly, some of these changes were also observed in ZL rats. Moreover, we found spontaneous activity in all three strains implying that C-nociceptors become hyperexcitable and spontaneously active not only in ageing hyperglycaemic ZDF rats but also in age-matched and apparently normoglycaemic ZL and WH rats fed with the same diet. ZDF rats presented a diabetic neuropathy involving large and small nerve fibres; additionally, ZL and WH rats also showed early small abnormalities in C-fibres, clearly detected by microneurography SIGNIFICANCE: This study provides a functional description of large and small nerve fibre function in a diabetic model that recapitulates many of the findings observed in patients suffering from type 2 diabetes mellitus. © 2018 European Pain Federation - EFIC®.

Somatotopy in the Medullary Dorsal Horn As a Basis for Orofacial Reflex Behavior

PubMed Central

Panneton, W. Michael; Pan, BingBing; Gan, Qi

2017-01-01

The somatotopy of the trigeminocervical complex of the rat was defined as a basis for describing circuitry for reflex behaviors directed through the facial motor nucleus. Thus, transganglionic transport of horseradish peroxidase conjugates applied to individual nerves/peripheral receptive fields showed that nerves innervating oropharyngeal structures projected most rostrally, followed by nerves innervating snout, periocular, and then periauricular receptive fields most caudally. Nerves innervating mucosae or glabrous receptive fields terminated densely in laminae I, II, and V of the trigeminocervical complex, while those innervating hairy skin terminated in laminae I–V. Projections to lamina II exhibited the most focused somatotopy when individual cases were compared. Retrograde transport of FluoroGold (FG) deposited into the facial motor nucleus resulted in labeled neurons almost solely in lamina V of the trigeminocervical complex. The distribution of these labeled neurons paralleled the somatotopy of primary afferent fibers, e.g., those labeled after FG injections into a functional group of motoneurons innervating lip musculature were found most rostrally while those labeled after injections into motoneurons innervating snout, periocular and preauricular muscles, respectively, were found at progressively more caudal levels. Anterograde transport of injections of biotinylated dextran amine into lamina V at different rostrocaudal levels of the trigeminocervical complex confirmed the notion that the somatotopy of orofacial sensory fields parallels the musculotopy of facial motor neurons. These data suggest that neurons in lamina V are important interneurons in a simple orofacial reflex circuit consisting of a sensory neuron, interneuron and motor neuron. Moreover, the somatotopy of primary afferent fibers from the head and neck confirms the “onion skin hypothesis” and suggests rostral cervical dermatomes blend seamlessly with “cranial dermatomes.” The transition area between subnucleus interpolaris and subnucleus caudalis is addressed while the paratrigeminal nucleus is discussed as an interface between the somatic and visceral nervous systems. PMID:29066998

Central vagal sensory and motor connections: human embryonic and fetal development.

PubMed

Cheng, Gang; Zhou, Xiangtian; Qu, Jia; Ashwell, Ken W S; Paxinos, G

2004-07-30

The embryonic and fetal development of the nuclear components and pathways of vagal sensorimotor circuits in the human has been studied using Nissl staining and carbocyanine dye tracing techniques. Eight fetal brains ranging from 8 to 28 weeks of development had DiI (1,1'-dioctadecyl-3,3,3',3' tetramethylindocarbocyanine perchlorate) inserted into either the thoracic vagus nerve at the level of the sternal angle (two specimens of 8 and 9 weeks of gestation) or into vagal rootlets at the surface of the medulla (at all other ages), while a further five were used for study of cytoarchitectural development. The first central labeling resulting from peripheral application of DiI to the thoracic vagus nerve was seen at 8 weeks. By 9 weeks, labeled bipolar cells at the ventricular surface around the sulcus limitans (sl) were seen after DiI application to the thoracic vagus nerve. Subnuclear organization as revealed by both Nissl staining and carbocyanine dye tracing was found to be advanced at a relatively early fetal age, with afferent segregation in the medial Sol apparent at 13 weeks and subnuclear organization of efferent magnocellular divisions of dorsal motor nucleus of vagus nerve noticeable at the same stage. The results of the present study also confirm that vagal afferents are distributed to the dorsomedial subnuclei of the human nucleus of the solitary tract, with particular concentrations of afferent axons in the gelatinosus subnucleus. These vagal afferents appeared to have a restricted zone of termination from quite early in development (13 weeks) suggesting that there is no initial exuberance in the termination field of vagal afferents in the developing human nucleus of the solitary tract. On the other hand, the first suggestion of afferents invading 10N from the medial Sol was not seen until 20 weeks and was not well developed until 24 weeks, suggesting that direct monosynaptic connections between the sensory and effector components of the vagal sensorimotor complex do not develop until this age.

Sensory chronic inflammatory demyelinating polyneuropathy: an under-recognized entity?

PubMed

Ayrignac, Xavier; Viala, Karine; Koutlidis, Régine Morizot; Taïeb, Guillaume; Stojkovic, Tanya; Musset, Lucille; Léger, Jean-Marc; Fournier, Emmanuel; Maisonobe, Thierry; Bouche, Pierre

2013-11-01

Sensory chronic inflammatory demyelinating polyneuropathy (CIDP) can be difficult to diagnose. We report 22 patients with chronic sensory polyneuropathy with ≥1 clinical sign atypical for chronic idiopathic axonal polyneuropathy (CIAP) but no electrodiagnostic criteria for CIDP. Clinical signs atypical for CIAP were: sensory ataxia (59%), generalized areflexia (36%), cranial nerve involvement (32%), rapid upper limb involvement (40%), and age at onset ≤55 years (50%). Additional features were: normal sensory nerve action potentials (36%), abnormal radial/normal sural pattern (23%), abnormal somatosensory evoked potentials (SSEPs) (100%), elevated cerebrospinal fluid (CSF) protein (73%), and demyelinating features in 5/7 nerve biopsies. Over 90% of patients responded to immunotherapy. We conclude that all patients had sensory CIDP. Sensory CIDP patients can be misdiagnosed as having CIAP. If atypical clinical/electrophysiologic features are present, we recommend performing SSEPs and CSF examination. Nerve biopsy should be restricted to disabled patients if other examinations are inconclusive. Copyright © 2013 Wiley Periodicals, Inc.

Recovery of function, peripheral sensitization and sensory neurone activation by novel pathways following axonal injury in Aplysia californica.

PubMed

Dulin, M F; Steffensen, I; Morris, C E; Walters, E T

1995-10-01

Recovery of behavioural and sensory function was examined following unilateral pedal nerve crush in Aplysia californica. Nerve crush that transected all axons connecting the tail to the central nervous system (CNS) eliminated the ipsilateral tail-evoked siphon reflex, whose sensory input travels in the crushed tail nerve (p9). The first reliable signs of recovery of this reflex were observed within 1 week, and most animals displayed tail-evoked siphon responses within 2 weeks. Wide-dynamic-range mechanosensory neurons with somata in the ventrocaudal (VC) cluster of the ipsilateral pleural ganglion exhibited a few receptive fields (RFs) on the tail 3 weeks after unilateral pedal nerve crush, indicating that the RFs had either regenerated or been reconnected to the central somata. These RFs were smaller and sensitized compared with corresponding RFs on the contralateral, uncrushed side. Centrally conducted axon responses of VC sensory neurones to electrical stimulation distal to the nerve crush site did not reappear until at least 10 days after the crush. Because the crush site was much closer to the CNS than to the tail, the failure of axon responses to be restored earlier than the behavioural responses indicates that early stages of reflex recovery are not due to regeneration of VC sensory neurone axons into the tail. Following nerve crush, VC sensory neurones often could be activated by stimulating central connectives or peripheral nerves that do not normally contain the sensory neurone's axons. These results suggest that recovery of behavioral function after nerve injury involves complex mechanisms, including regenerative growth of axotomized VC sensory neurones, sensitization of regenerating RFs and sprouting of VC sensory neurone fibres within the CNS. Furthermore, the rapidity of behavioural recovery indicates that its initial phases are mediated by additional mechanisms, perhaps centripetal regeneration of unidentified sensory neurones having peripheral somata, or transient reconnection of proximal and distal stumps of axotomized VC cells.

The effect of early relearning on sensory recovery 4 to 9 years after nerve repair: a report of a randomized controlled study.

PubMed

Vikström, Pernilla; Rosén, Birgitta; Carlsson, Ingela K; Björkman, Anders

2018-01-01

Twenty patients randomized to early sensory relearning (nine patients) or traditional relearning (11 patients) were assessed regarding sensory recovery 4 to 9 years after median or ulnar nerve repair. Outcomes were assessed with the Rosen score, questionnaires, and self-reported single-item questions regarding function and activity. The patients with early sensory relearning had significantly better sensory recovery in the sensory domain of the Rosen score, specifically, discriminative touch or tactile gnosis and dexterity. They had significantly less self-reported problems in gripping, clumsiness, and fine motor skills. No differences were found in questionnaires between the two groups. We conclude that early sensory relearning improves long-term sensory recovery following nerve repair. I.

The vestibular nerve of the chinchilla. III. Peripheral innervation patterns in the utricular macula

NASA Technical Reports Server (NTRS)

Fernandez, C.; Goldberg, J. M.; Baird, R. A.

1990-01-01

1. Nerve fibers supplying the utricular macula of the chinchilla were labeled by extracellular injection of horseradish peroxidase into the vestibular nerve. The peripheral terminations of individual fibers were reconstructed and related to the regions of the end organ they innervated and to the sizes of their parent axons. 2. The macula is divided into medial and lateral parts by the striola, a narrow zone that runs for almost the entire length of the sensory epithelium. The striola can be distinguished from the extrastriolar regions to either side of it by the wider spacing of its hair cells. Calyx endings in the striola have especially thick walls, and, unlike similar endings in the extrastriola, many of them innervate more than one hair cell. The striola occupies 10% of the sensory epithelium; the lateral extrastriola, 50%; and the medial extrastriola, 40%. 3. The utricular nerve penetrates the bony labyrinth anterior to the end organ. Axons reaching the anterior part of the sensory epithelium run directly through the connective tissue stroma. Those supplying more posterior regions first enter a fiber layer located at the bottom of the stroma. Approximately one-third of the axons bifurcate below the epithelium, usually within 5-20 microns of the basement membrane. Bifurcations are more common in fibers destined for the extrastriola than for the striola. 4. Both calyx and bouton endings were labeled. Calyces can be simple or complex. Simple calyces innervate individual hair cells, whereas complex calyces supply 2-4 adjacent hair cells. Complex endings are more heavily concentrated in the striola than in the extrastriola. Simple calyces and boutons are found in all parts of the epithelium. Calyces emerge from the parent axon or one of its thick branches. Boutons, whether en passant or terminal, are located on thin collaterals. 5. Fibers can be classified into calyx, bouton, or dimorphic categories. The first type only has calyx endings; the second, only bouton endings; and the third, both kinds of endings. Calyx units make up 6% of the labeled fibers, bouton units less than 2%, and dimorphic units greater than 92%. The three fiber types differ in the macular zones they supply and in the diameters of their parent axons. Calyx units were restricted to the striola. The few bouton units were found in the extrastriola.(ABSTRACT TRUNCATED AT 400 WORDS).

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

PubMed

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

2007-11-01

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

The effect of hyperbaric oxygen treatment on early regeneration of sensory axons after nerve crush in the rat.

PubMed

Bajrović, Fajko F; Sketelj, Janez; Jug, Marko; Gril, Iztok; Mekjavić, Igor B

2002-09-01

Abstract The effect of hyperbaric oxygen treatment (HBO) on sensory axon regeneration was examined in the rat. The sciatic nerve was crushed in both legs. In addition, the distal stump of the sural nerve on one side was made acellular and its blood perfusion was compromised by freezing and thawing. Two experimental groups received hyperbaric exposures (2.5 ATA) to either compressed air (pO2 = 0.5 ATA) or 100% oxygen (pO2 = 2.5 ATA) 90 minutes per day for 6 days. Sensory axon regeneration in the sural nerve was thereafter assessed by the nerve pinch test and immunohistochemical reaction to neurofilament. HBO treatment increased the distances reached by the fastest regenerating sensory axons by about 15% in the distal nerve segments with preserved and with compromised blood perfusion. There was no significant difference between the rats treated with different oxygen tensions. The total number of regenerated axons in the distal sural nerve segments after a simple crush injury was not affected, whereas in the nerve segments with compromised blood perfusion treated by the higher pO2, the axon number was about 30% lower than that in the control group. It is concluded that the beneficial effect of HBO on sensory axon regeneration is not dose-dependent between 0.5 and 2.5 ATA pO2. Although the exposure to 2.5 ATA of pO2 moderately enhanced early regeneration of the fastest sensory axons, it decreased the number of regenerating axons in the injured nerves with compromised blood perfusion of the distal nerve stump.

Infraorbital nerve transposition to expand the endoscopic transnasal maxillectomy.

PubMed

Salzano, Giovanni; Turri-Zanoni, Mario; Karligkiotis, Apostolos; Zocchi, Jacopo; Dell'Aversana Orabona, Giovanni; Califano, Luigi; Battaglia, Paolo; Castelnuovo, Paolo

2017-02-01

The infraorbital nerve (ION) is a terminal branch of the maxillary nerve (V2) providing sensory innervation to the malar skin. It is sometimes necessary to sacrifice the ION and its branches to obtain adequate maxillary sinus exposure for radical resection of sinonasal tumors. Consequently, patients suffer temporary or permanent paresthesia, hypoestesthia, and neuralgia of the face. We describe an innovative technique used for preservation of the ION while removing the anterior, superior, and lateral walls of the maxillary sinus through a medial endoscopic transnasal maxillectomy. All patients who underwent transnasal endoscopic maxillectomy with ION transposition in our institute were retrospectively reviewed. Two patients were identified who had been treated for sinonasal cancers using this approach. No major complications were observed. Transient loss of ION function was observed with complete recovery of skin sensory perception within 6 months of surgery. One patient referred to a mild permanent anesthesia of the upper incisors. No diplopia or enophthalmos were encountered in any of the patients. The ION transposition is useful for selected cases of benign and malignant sinonasal tumors that do not infiltrate the ION itself but involve the surrounding portion of the maxillary sinus. Anatomic preservation of the ION seems to be beneficial to the postoperative quality of life of such patients. © 2016 ARS-AAOA, LLC.

End-to-side neurorrhaphy repairs peripheral nerve injury: sensory nerve induces motor nerve regeneration.

PubMed

Yu, Qing; Zhang, She-Hong; Wang, Tao; Peng, Feng; Han, Dong; Gu, Yu-Dong

2017-10-01

End-to-side neurorrhaphy is an option in the treatment of the long segment defects of a nerve. It involves suturing the distal stump of the disconnected nerve (recipient nerve) to the side of the intimate adjacent nerve (donor nerve). However, the motor-sensory specificity after end-to-side neurorrhaphy remains unclear. This study sought to evaluate whether cutaneous sensory nerve regeneration induces motor nerves after end-to-side neurorrhaphy. Thirty rats were randomized into three groups: (1) end-to-side neurorrhaphy using the ulnar nerve (mixed sensory and motor) as the donor nerve and the cutaneous antebrachii medialis nerve as the recipient nerve; (2) the sham group: ulnar nerve and cutaneous antebrachii medialis nerve were just exposed; and (3) the transected nerve group: cutaneous antebrachii medialis nerve was transected and the stumps were turned over and tied. At 5 months, acetylcholinesterase staining results showed that 34% ± 16% of the myelinated axons were stained in the end-to-side group, and none of the myelinated axons were stained in either the sham or transected nerve groups. Retrograde fluorescent tracing of spinal motor neurons and dorsal root ganglion showed the proportion of motor neurons from the cutaneous antebrachii medialis nerve of the end-to-side group was 21% ± 5%. In contrast, no motor neurons from the cutaneous antebrachii medialis nerve of the sham group and transected nerve group were found in the spinal cord segment. These results confirmed that motor neuron regeneration occurred after cutaneous nerve end-to-side neurorrhaphy.

End-to-side neurorrhaphy repairs peripheral nerve injury: sensory nerve induces motor nerve regeneration

PubMed Central

Yu, Qing; Zhang, She-hong; Wang, Tao; Peng, Feng; Han, Dong; Gu, Yu-dong

2017-01-01

End-to-side neurorrhaphy is an option in the treatment of the long segment defects of a nerve. It involves suturing the distal stump of the disconnected nerve (recipient nerve) to the side of the intimate adjacent nerve (donor nerve). However, the motor-sensory specificity after end-to-side neurorrhaphy remains unclear. This study sought to evaluate whether cutaneous sensory nerve regeneration induces motor nerves after end-to-side neurorrhaphy. Thirty rats were randomized into three groups: (1) end-to-side neurorrhaphy using the ulnar nerve (mixed sensory and motor) as the donor nerve and the cutaneous antebrachii medialis nerve as the recipient nerve; (2) the sham group: ulnar nerve and cutaneous antebrachii medialis nerve were just exposed; and (3) the transected nerve group: cutaneous antebrachii medialis nerve was transected and the stumps were turned over and tied. At 5 months, acetylcholinesterase staining results showed that 34% ± 16% of the myelinated axons were stained in the end-to-side group, and none of the myelinated axons were stained in either the sham or transected nerve groups. Retrograde fluorescent tracing of spinal motor neurons and dorsal root ganglion showed the proportion of motor neurons from the cutaneous antebrachii medialis nerve of the end-to-side group was 21% ± 5%. In contrast, no motor neurons from the cutaneous antebrachii medialis nerve of the sham group and transected nerve group were found in the spinal cord segment. These results confirmed that motor neuron regeneration occurred after cutaneous nerve end-to-side neurorrhaphy. PMID:29171436

Congenital sensory neuropathy

PubMed Central

Barry, J. E.; Hopkins, I. J.; Neal, B. W.

1974-01-01

Two infants with sporadic congenital sensory neuropathy are described. The criteria of generalized lack of superficial sensory appreciation, hypotonia, areflexia, together with histological evidence of abnormalities of sensory neural structures in skin and peripheral nerves have been met. No abnormality of motor or autonomic nerves was shown. ImagesFIG. PMID:4131674

Sensory nerve action potentials and sensory perception in women with arthritis of the hand.

PubMed

Calder, Kristina M; Martin, Alison; Lydiate, Jessica; MacDermid, Joy C; Galea, Victoria; MacIntyre, Norma J

2012-05-10

Arthritis of the hand can limit a person's ability to perform daily activities. Whether or not sensory deficits contribute to the disability in this population remains unknown. The primary purpose of this study was to determine if women with osteoarthritis (OA) or rheumatoid arthritis (RA) of the hand have sensory impairments. Sensory function in the dominant hand of women with hand OA or RA and healthy women was evaluated by measuring sensory nerve action potentials (SNAPs) from the median, ulnar and radial nerves, sensory mapping (SM), and vibratory and current perception thresholds (VPT and CPT, respectively) of the second and fifth digits. All SNAP amplitudes were significantly lower for the hand OA and hand RA groups compared with the healthy group (p < 0.05). No group differences were found for SNAP conduction velocities, SM, VPT, and CPT. We propose, based on these findings, that women with hand OA or RA may have axonal loss of sensory fibers in the median, ulnar and radial nerves. Less apparent were losses in conduction speed or sensory perception.

Sensory nerve action potentials and sensory perception in women with arthritis of the hand

PubMed Central

2012-01-01

Background Arthritis of the hand can limit a person’s ability to perform daily activities. Whether or not sensory deficits contribute to the disability in this population remains unknown. The primary purpose of this study was to determine if women with osteoarthritis (OA) or rheumatoid arthritis (RA) of the hand have sensory impairments. Methods Sensory function in the dominant hand of women with hand OA or RA and healthy women was evaluated by measuring sensory nerve action potentials (SNAPs) from the median, ulnar and radial nerves, sensory mapping (SM), and vibratory and current perception thresholds (VPT and CPT, respectively) of the second and fifth digits. Results All SNAP amplitudes were significantly lower for the hand OA and hand RA groups compared with the healthy group (p < 0.05). No group differences were found for SNAP conduction velocities, SM, VPT, and CPT. Discussion We propose, based on these findings, that women with hand OA or RA may have axonal loss of sensory fibers in the median, ulnar and radial nerves. Less apparent were losses in conduction speed or sensory perception. PMID:22575001

Investigating the role of MRGPRC11 and capsaicin-sensitive afferent nerves in the anti-influenza effects exerted by SLIGRL-amide in murine airways.

PubMed

Chang, Amy Y; Mann, Tracy S; McFawn, Peter K; Han, Liang; Dong, Xinzhong; Henry, Peter J

2016-05-23

The hexapeptide SLIGRL-amide activates protease-activated receptor-2 (PAR-2) and mas-related G protein-coupled receptor C11 (MRGPRC11), both of which are known to be expressed on populations of sensory nerves. SLIGRL-amide has recently been reported to inhibit influenza A (IAV) infection in mice independently of PAR-2 activation, however the explicit roles of MRGPRC11 and sensory nerves in this process are unknown. Thus, the principal aim of this study was to determine whether SLIGRL-amide-induced inhibition of influenza infection is mediated by MRGPRC11 and/or by capsaicin-sensitive sensory nerves. The inhibitory effect of SLIGRL-amide on IAV infection observed in control mice in vivo was compared to effects produced in mice that did not express MRGPRC11 (mrgpr-cluster∆ (-/-) mice) or had impaired sensory nerve function (induced by chronic pre-treatment with capsaicin). Complementary mechanistic studies using both in vivo and ex vivo approaches investigated whether the anti-IAV activity of SLIGRL-amide was (1) mimicked by either activators of MRGPRC11 (BAM8-22) or by activators (acute capsaicin) or selected mediators (substance P, CGRP) of sensory nerve function, or (2) suppressed by inhibitors of sensory nerve function (e.g. NK1 receptor antagonists). SLIGRL-amide and BAM8-22 dose-dependently inhibited IAV infection in mrgpr-cluster∆ (-/-) mice that do not express MRGPRC11. In addition, SLIGRL-amide and BAM8-22 each inhibited IAV infection in capsaicin-pre-treated mice that lack functional sensory nerves. Furthermore, the anti-IAV activity of SLIGRL-amide was not mimicked by the sensory neuropeptides substance P or CGRP, nor blocked by either NK1 (L-703,606, RP67580) and CGRP receptor (CGRP8-37) antagonists. Direct stimulation of airway sensory nerves through acute exposure to the TRPV1 activator capsaicin also failed to mimic SLIGRL-amide-induced inhibition of IAV infectivity. The anti-IAV activity of SLIGRL-amide was mimicked by the purinoceptor agonist ATP, a direct activator of mucus secretion from airway epithelial cells. Additionally, both SLIGRL-amide and ATP stimulated mucus secretion and inhibited IAV infectivity in mouse isolated tracheal segments. SLIGRL-amide inhibits IAV infection independently of MRGPRC11 and independently of capsaicin-sensitive, neuropeptide-releasing sensory nerves, and its secretory action on epithelial cells warrants further investigation.

The neglected cranial nerve: nervus terminalis (cranial nerve N).

PubMed

Vilensky, Joel A

2014-01-01

The nervus terminalis (NT; terminal nerve) was clearly identified as an additional cranial nerve in humans more than a century ago yet remains mostly undescribed in modern anatomy textbooks. The nerve is referred to as the nervus terminalis because in species initially examined its fibers were seen entering the brain in the region of the lamina terminalis. It has also been referred to as cranial nerve 0, but because there is no Roman symbol for zero, an N for the Latin word nulla is a better numerical designation. This nerve is very distinct in human fetuses and infants but also has been repeatedly identified in adult human brains. The NT fibers are unmyelinated and emanate from ganglia. The fibers pass through the cribriform plate medial to those of the olfactory nerve fila. The fibers end in the nasal mucosa and probably arise from autonomic/neuromodulatory as well as sensory neurons. The NT has been demonstrated to release luteinizing-releasing luteinizing hormone and is therefore thought to play a role in reproductive behavior. Based on the available evidence, the NT appears to be functional in adult humans and should be taught in medical schools and incorporated into anatomy/neuroanatomy textbooks. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.

Abnormal afferent nerve endings in the soft palatal mucosa of sleep apnoics and habitual snorers.

PubMed

Friberg, D; Gazelius, B; Hökfelt, T; Nordlander, B

1997-07-23

Habitual snoring precedes obstructive sleep apnea (OSA), but the pathophysiological mechanisms behind progression are still unclear. The patency of upper airways depends on a reflexogen mechanism reacting on negative intrapharyngeal pressure at inspiration, probably mediated by mucosal receptors, i.e., via afferent nerve endings. Such nerves contain a specific nerve protein, protein-gene product 9.5 (PGP 9.5) and in some cases substance P (SP) and calcitonin gene-related (CGRP). Biopsies of the soft palatial mucosa were obtained from non-smoking men ten OSA patients, 11 habitual snorers and 11 non-snoring controls. The specimens were immunohistochemically analyzed for PGP 9.5, SP and CGRP. As compared to controls, an increased number of PGP-, SP- and CGRP-immunoreactive nerves were demonstrated in the mucosa in 9/10 OSA patients and 4/11 snorers, in addition to varicose nerve endings in the papillae and epithelium. Using double staining methodology, it could be shown that SP- and CGRP-like immunoreactivities (LIs) often coexisted in these fibres, as did CGRP- and PGP 9.5-LIs. The increased density in sensory nerve terminals are interpreted to indicate an afferent nerve lesion. Our results support the hypothesis of a progressive neurogenic lesion as a contributory factor to the collapse of upper airways during sleep in OSA patients.

Rodent model for assessing the long term safety and performance of peripheral nerve recording electrodes

NASA Astrophysics Data System (ADS)

Vasudevan, Srikanth; Patel, Kunal; Welle, Cristin

2017-02-01

Objective. In the US alone, there are approximately 185 000 cases of limb amputation annually, which can reduce the quality of life for those individuals. Current prosthesis technology could be improved by access to signals from the nervous system for intuitive prosthesis control. After amputation, residual peripheral nerves continue to convey motor signals and electrical stimulation of these nerves can elicit sensory percepts. However, current technology for extracting information directly from peripheral nerves has limited chronic reliability, and novel approaches must be vetted to ensure safe long-term use. The present study aims to optimize methods to establish a test platform using rodent model to assess the long term safety and performance of electrode interfaces implanted in the peripheral nerves. Approach. Floating Microelectrode Arrays (FMA, Microprobes for Life Sciences) were implanted into the rodent sciatic nerve. Weekly in vivo recordings and impedance measurements were performed in animals to assess performance and physical integrity of electrodes. Motor (walking track analysis) and sensory (Von Frey) function tests were used to assess change in nerve function due to the implant. Following the terminal recording session, the nerve was explanted and the health of axons, myelin and surrounding tissues were assessed using immunohistochemistry (IHC). The explanted electrodes were visualized under high magnification using scanning electrode microscopy (SEM) to observe any physical damage. Main results. Recordings of axonal action potentials demonstrated notable session-to-session variability. Impedance of the electrodes increased upon implantation and displayed relative stability until electrode failure. Initial deficits in motor function recovered by 2 weeks, while sensory deficits persisted through 6 weeks of assessment. The primary cause of failure was identified as lead wire breakage in all of animals. IHC indicated myelinated and unmyelinated axons near the implanted electrode shanks, along with dense cellular accumulations near the implant site. Scanning electron microscopy (SEM) showed alterations of the electrode insulation and deformation of electrode shanks. Significance. We describe a comprehensive testing platform with applicability to electrodes that record from the peripheral nerves. This study assesses the long term safety and performance of electrodes in the peripheral nerves using a rodent model. Under this animal test platform, FMA electrodes record single unit action potentials but have limited chronic reliability due to structural weaknesses. Future work will apply these methods to other commercially-available and novel peripheral electrode technologies. This research was carried out in the Division of Biomedical Physics, Office of Science and Engineering Laboratory, Center for Devices and Radiological Health, US Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA.

Effects of clinical infrared laser on superficial radial nerve conduction

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

Greathouse, D.G.; Currier, D.P.; Gilmore, R.L.

The purposes of this study were to demonstrate the effects of infrared laser radiation on the sensory nerve conduction of a specified peripheral nerve in man and determine temperature changes in the tissue surrounding the treated nerve. Twenty healthy adults were divided into three groups: control (n = 5); experimental (n = 10), infrared laser radiation at 20 sec/cm2; and experimental (n = 5), infrared laser radiation treatment at 120 sec/cm2. Antidromic sensory nerve conduction studies were performed on the superficial radial nerve of each subject's right forearm. The infrared laser radiation was applied at a fixed intensity for fivemore » 1-cm2 segments. Latency, amplitude, and temperature measurements were recorded pretest; posttest; and posttest intervals of 1, 3, 5, 10, and 15 minutes. An analysis of variance with repeated measures was used to examine the data. No significant change was noted in the distal sensory latency or amplitude of the evoked sensory potential in either experimental or control groups as a result of the applications of the infrared laser radiation treatment. This study demonstrates that infrared laser used at clinically applied intensities does not alter conduction of sensory nerves nor does it elevate the subcutaneous temperature.« less

Studies on the cellular localization of spinal cord substance P receptors.

PubMed

Helke, C J; Charlton, C G; Wiley, R G

1986-10-01

Substance P-immunoreactivity and specific substance P binding sites are present in the spinal cord. Receptor autoradiography showed the discrete localization of substance P binding sites in both sensory and motor regions of the spinal cord and functional studies suggested an important role for substance P receptor activation in autonomic outflow, nociception, respiration and somatic motor function. In the current studies, we investigated the cellular localization of substance P binding sites in rat spinal cord using light microscopic autoradiography combined with several lesioning techniques. Unilateral injections of the suicide transport agent, ricin, into the superior cervical ganglion reduced substance P binding and cholinesterase-stained preganglionic sympathetic neurons in the intermediolateral cell column. However, unilateral electrolytic lesions of ventral medullary substance P neurons which project to the intermediolateral cell column did not alter the density of substance P binding in the intermediolateral cell column. Likewise, 6-hydroxydopamine and 5,7-dihydroxytryptamine, which destroy noradrenergic and serotonergic nerve terminals, did not reduce the substance P binding in the intermediolateral cell column. It appears, therefore, that the substance P binding sites are located postsynaptically on preganglionic sympathetic neurons rather than presynaptically on substance P-immunoreactive processes (i.e. as autoreceptors) or on monoamine nerve terminals. Unilateral injections of ricin into the phrenic nerve resulted in the unilateral destruction of phrenic motor neurons in the cervical spinal cord and caused a marked reduction in the substance P binding in the nucleus. Likewise, sciatic nerve injections of ricin caused a loss of associated motor neurons in the lateral portion of the ventral horn of the lumbar spinal cord and a reduction in the substance P binding. Sciatic nerve injections of ricin also destroyed afferent nerves of the associated dorsal root ganglia and increased the density of substance P binding in the dorsal horn. Capsaicin, which destroys small diameter primary sensory neurons, similarly increased the substance P binding in the dorsal horn. These studies show that the cellular localization of substance P binding sites can be determined by analysis of changes in substance P binding to discrete regions of spinal cord after selective lesions of specific groups of neurons. The data show the presence of substance P binding sites on preganglionic sympathetic neurons in the intermediolateral cell column and on somatic motor neurons in the ventral horn, including the phrenic motor nucleus.(ABSTRACT TRUNCATED AT 400 WORDS)

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

PubMed

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

2015-05-06

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

Rehabilitation of the trigeminal nerve

PubMed Central

Iro, Heinrich; Bumm, Klaus; Waldfahrer, Frank

2005-01-01

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

Effects of a sensory branch to the posterior external ear canal: coughing, pain, Ramsay Hunt's syndrome and Hitselberger's sign.

PubMed

Mulazimoglu, S; Flury, R; Kapila, S; Linder, T

2017-04-01

A distinct nerve innervating the external auditory canal can often be identified in close relation to the facial nerve when gradually thinning the posterior canal wall. This nerve has been attributed to coughing during cerumen removal, neuralgic pain, Hitselberger's sign and vesicular eruptions described in Ramsay Hunt's syndrome. This study aimed to demonstrate the origin and clinical impact of this nerve. In patients with intractable otalgia or severe coughing whilst inserting a hearing aid, who responded temporarily to local anaesthesia, the symptoms could be resolved by sectioning a sensory branch to the posterior canal. In a temporal bone specimen, it was revealed that this nerve is predominantly a continuation of Arnold's nerve, also receiving fibres from the glossopharyngeal nerve and facial nerve. Histologically, the communicating branch from the facial nerve was confirmed. Surgeons should be aware of the posterior auricular sensory branch and its clinical implications.

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

PubMed Central

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

2013-01-01

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

[Peripheral nerve repair: 30 centuries of scientific research].

PubMed

Desouches, C; Alluin, O; Mutaftschiev, N; Dousset, E; Magalon, G; Boucraut, J; Feron, F; Decherchi, P

2005-11-01

Nerve injury compromises sensory and motor functions. Techniques of peripheral nerve repair are based on our knowledge regarding regeneration. Microsurgical techniques introduced in the late 1950s and widely developed for the past 20 years have improved repairs. However, functional recovery following a peripheral mixed nerve injury is still incomplete. Good motor and sensory function after nerve injury depends on the reinnervation of the motor end plates and sensory receptors. Nerve regeneration does not begin if the cell body has not survived the initial injury or if it is unable to initiate regeneration. The regenerated axons must reach and reinnervate the appropriate target end-organs in a timely fashion. Recovery of motor function requires a critical number of motor axons reinnervating the muscle fibers. Sensory recovery is possible if the delay in reinnervation is short. Many additional factors influence the success of nerve repair or reconstruction. The timing of the repair, the level of injury, the extent of the zone of injury, the technical skill of the surgeon, and the method of repair and reconstruction contribute to the functional outcome after nerve injury. This review presents the recent advances in understanding of neural regeneration and their application to the management of primary repairs and nerve gaps.

Trifurcation of the tibial nerve within the tarsal tunnel.

PubMed

Develi, Sedat

2018-05-01

The tibial nerve is the larger terminal branch of the sciatic nerve and it terminates in the tarsal tunnel by giving lateral and medial plantar nerves. We present a rare case of trifurcation of the tibial nerve within the tarsal tunnel. The variant nerve curves laterally after branching from the tibial nerve and courses deep to quadratus plantae muscle. Interestingly, posterior tibial artery was also terminating by giving three branches. These branches were accompanying the terminal branches of the tibial nerve.

Fate of combat nerve injury.

PubMed

Beltran, Michael J; Burns, Travis C; Eckel, Tobin T; Potter, Benjamin K; Wenke, Joseph C; Hsu, Joseph R

2012-11-01

Assess a cohort of combat-related type III open tibia fractures with peripheral nerve injury to determine the injury mechanism and likelihood for recovery or improvement in nerve function. Retrospective study. Three military medical centers. Out of a study cohort of 213 type III open tibia fractures, 32 fractures (in 32 patients) with a total of 43 peripheral nerve injuries (peroneal or tibial) distal to the popliteal fossa met inclusion criteria and were available for follow-up at an average of 20 months (range, 2-48 months). Clinical assessment of motor and sensory nerve improvement. There was a 22% incidence of peripheral nerve injury in the study cohort. At an average follow-up of 20 months (range, 2-48 months), 89% of injured motor nerves were functional, whereas the injured sensory nerves had function in 93%. Fifty percent and 27% of motor and sensory injuries demonstrated improvement, respectively (P = 0.043). With the numbers available, there was no difference in motor or sensory improvement based on mechanism of injury, fracture severity or location, soft tissue injury, or specific nerve injured. In the subset of patients with an initially impaired sensory examination, full improvement was related to fracture location (P = 0.0164). Type III open tibia fractures sustained in combat are associated with a 22% incidence of peripheral nerve injury, and the majority are due to multiple projectile penetrating injury. Despite the severe nature of these injuries, the vast majority of patients had a functional nerve status by an average of 2-year follow-up. Based on these findings, discussions regarding limb salvage and amputation should not be overly influenced by the patient's peripheral nerve status. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

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

PubMed Central

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

2011-01-01

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

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.

Brief post-surgical electrical stimulation accelerates axon regeneration and muscle reinnervation without affecting the functional measures in carpal tunnel syndrome patients.

PubMed

Gordon, Tessa; Amirjani, Nasim; Edwards, David C; Chan, K Ming

2010-05-01

Electrical stimulation (ES) of injured peripheral nerves accelerates axonal regeneration in laboratory animals. However, clinical applicability of this intervention has never been investigated in human subjects. The aim of this pilot study was to determine the effect of ES on axonal regeneration after surgery in patients with median nerve compression in the carpal tunnel causing marked motor axonal loss. A randomized control trial was conducted to provide proof of principle for ES-induced acceleration of axon regeneration in human patients. Carpel tunnel release surgery (CTRS) was performed and in the stimulation group of patients, stainless steel electrode wires placed alongside the median nerve proximal to the surgical decompression site for immediate 1 h 20 Hz bipolar ES. Subjects were followed for a year at regular intervals. Axonal regeneration was quantified using motor unit number estimation (MUNE) and sensory and motor nerve conduction studies. Purdue Pegboard Test, Semmes Weinstein Monofilaments, and Levine's Self-Assessment Questionnaire were used to assess functional recovery. The stimulation group had significant axonal regeneration 6-8 months after the CTRS when the MUNE increased to 290+/-140 (mean+/-SD) motor units (MU) from 150+/-62 MU at baseline (p<0.05). In comparison, MUNE did not significantly improve in the control group (p>0.2). Terminal motor latency significantly accelerated in the stimulation group but not the control group (p>0.1). Sensory nerve conduction values significantly improved in the stimulation group earlier than the controls. Other outcome measures showed a significant improvement in both patient groups. We conclude that brief low frequency ES accelerates axonal regeneration and target reinnervation in humans. Copyright 2009 Elsevier Inc. All rights reserved.

[Role of short-latency somatosensory evoked potential in the diagnosis of chronic inflammatory demyelinating polyneuropathy].

PubMed

Sun, Rui-Di; Fu, Bing; Jiang, Jun

2017-05-01

To investigate the role of short-latency somatosensory evoked potential (SSEP) in the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP). A total of 48 children with a confirmed or suspected CIDP and 40 healthy children were enrolled. Nerve electrophysiological examination and/or SSEP examination was performed (the children in the healthy control group only underwent SSEP examination). Four-lead electromyography was used for nerve electrophysiological examination, including at least 4 motor nerves and 2 sensory nerves. N6 (elbow potential), N13 (cervical cord potential), and N20 (cortex potential) of the median nerve and N8 (popliteal fossa potential), N22 (lumbar cord potential), and P39 (cortex potential) of the tibial nerve were observed by SSEP examination. Among the 48 children with CIDP, 35 had demyelination in both motor and sensory nerves, 8 had demyelination in sensory nerves, and 5 had axonal degeneration. SSEP examination showed that 7 had conduction abnormality in the trunk of the brachial plexus and/or the posterior root and 33 had damage in the lumbosacral plexus and/or the posterior root. The 40 children with abnormal findings of SSEP examination included 8 children with affected sensory nerves and 5 children with secondary axonal degeneration who did not meet the electrophysiological diagnostic criteria for CIDP. Compared with the healthy control group, the CIDP group had significantly prolonged latency periods of N13 and N22 (P<0.05). SSEP can be used for the auxiliary diagnosis of CIDP, especially in CIDP children with affected sensory nerves or secondary axonal degeneration.

TRP channel functions in the gastrointestinal tract.

PubMed

Yu, Xiaoyun; Yu, Mingran; Liu, Yingzhe; Yu, Shaoyong

2016-05-01

Transient receptor potential (TRP) channels are predominantly distributed in both somatic and visceral sensory nervous systems and play a crucial role in sensory transduction. As the largest visceral organ system, the gastrointestinal (GI) tract frequently accommodates external inputs, which stimulate sensory nerves to initiate and coordinate sensory and motor functions in order to digest and absorb nutrients. Meanwhile, the sensory nerves in the GI tract are also able to detect potential tissue damage by responding to noxious irritants. This nocifensive function is mediated through specific ion channels and receptors expressed in a subpopulation of spinal and vagal afferent nerve called nociceptor. In the last 18 years, our understanding of TRP channel expression and function in GI sensory nervous system has been continuously improved. In this review, we focus on the expressions and functions of TRPV1, TRPA1, and TRPM8 in primary extrinsic afferent nerves innervated in the esophagus, stomach, intestine, and colon and briefly discuss their potential roles in relevant GI disorders.

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. Copyright © 2013. Published by Elsevier Masson SAS.

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.

Co-cultures provide a new tool to probe communication between adult sensory neurons and urothelium.

PubMed

O'Mullane, Lauren M; Keast, Janet R; Osborne, Peregrine B

2013-08-01

Recent evidence suggests that the urothelium functions as a sensory transducer of chemical, mechanical or thermal stimuli and signals to nerve terminals and other cells in the bladder wall. The cellular and molecular basis of neuro-urothelial communication is not easily studied in the intact bladder. This led us to establish a method of co-culturing dorsal root ganglion sensory neurons and bladder urothelial cells. Sensory neurons and urothelial cells obtained from dorsal root ganglia and bladders dissected from adult female Sprague-Dawley® rats were isolated by enzyme treatment and mechanical dissociation. They were plated together or separately on collagen coated substrate and cultured in keratinocyte medium for 48 to 72 hours. Retrograde tracer labeling was performed to identify bladder afferents used for functional testing. Neurite growth and complexity in neurons co-cultured with urothelial cells was increased relative to that in neuronal monocultures. The growth promoting effect of urothelial cells was reduced by the tyrosine kinase inhibitor K252a but upstream inhibition of nerve growth factor signaling with TrkA-Fc had no effect. Fura-2 calcium imaging of urothelial cells showed responses to adenosine triphosphate (100 μM) and activation of TRPV4 (4α-PDD, 10 μM) but not TRPV1 (capsaicin, 1 μM), TRPV3 (farnesyl pyrophosphate, 1 μM) or TRPA1 (mustard oil, 100 μM). In contrast, co-cultured neurons were activated by all agonists except farnesyl pyrophosphate. Co-culturing provides a new methodology for investigating neuro-urothelial interactions in animal models of urological conditions. Results suggest that neuronal properties are maintained in the presence of urothelium and neurite growth is potentiated by a nerve growth factor independent mechanism. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

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

Implications for bidirectional signaling between afferent nerves and urothelial cells-ICI-RS 2014.

PubMed

Kanai, Anthony; Fry, Christopher; Ikeda, Youko; Kullmann, Florenta Aura; Parsons, Brian; Birder, Lori

2016-02-01

To present a synopsis of the presentations and discussions from Think Tank I, "Implications for afferent-urothelial bidirectional communication" of the 2014 International Consultation on Incontinence-Research Society (ICI-RS) meeting in Bristol, UK. The participants presented what is new, currently understood or still unknown on afferent-urothelial signaling mechanisms. New avenues of research and experimental methodologies that are or could be employed were presented and discussed. It is clear that afferent-urothelial interactions are integral to the regulation of normal bladder function and that its disruption can have detrimental consequences. The urothelium is capable of releasing numerous signaling factors that can affect sensory neurons innervating the suburothelium. However, the understanding of how factors released from urothelial cells and afferent nerve terminals regulate one another is incomplete. Utilization of techniques such as viruses that genetically encode Ca(2+) sensors, based on calmodulin and green fluorescent protein, has helped to address the cellular mechanisms involved. Additionally, the epithelial-neuronal interactions in the urethra may also play a significant role in lower urinary tract regulation and merit further investigation. The signaling capabilities of the urothelium and afferent nerves are well documented, yet how these signals are integrated to regulate bladder function is unclear. There is unquestionably a need for expanded methodologies to further our understanding of lower urinary tract sensory mechanisms and their contribution to various pathologies. © 2016 Wiley Periodicals, Inc.

Functional significance of M-type potassium channels in nociceptive cutaneous sensory endings

PubMed Central

Passmore, Gayle M.; Reilly, Joanne M.; Thakur, Matthew; Keasberry, Vanessa N.; Marsh, Stephen J.; Dickenson, Anthony H.; Brown, David A.

2012-01-01

M-channels carry slowly activating potassium currents that regulate excitability in a variety of central and peripheral neurons. Functional M-channels and their Kv7 channel correlates are expressed throughout the somatosensory nervous system where they may play an important role in controlling sensory nerve activity. Here we show that Kv7.2 immunoreactivity is expressed in the peripheral terminals of nociceptive primary afferents. Electrophysiological recordings from single afferents in vitro showed that block of M-channels by 3 μM XE991 sensitized Aδ- but not C-fibers to noxious heat stimulation and induced spontaneous, ongoing activity at 32°C in many Aδ-fibers. These observations were extended in vivo: intraplantar injection of XE991 selectively enhanced the response of deep dorsal horn (DH) neurons to peripheral mid-range mechanical and higher range thermal stimuli, consistent with a selective effect on Aδ-fiber peripheral terminals. These results demonstrate an important physiological role of M-channels in controlling nociceptive Aδ-fiber responses and provide a rationale for the nocifensive behaviors that arise following intraplantar injection of the M-channel blocker XE991. PMID:22593734

Reliability, reference values and predictor variables of the ulnar sensory nerve in disease free adults.

PubMed

Ruediger, T M; Allison, S C; Moore, J M; Wainner, R S

2014-09-01

The purposes of this descriptive and exploratory study were to examine electrophysiological measures of ulnar sensory nerve function in disease free adults to determine reliability, determine reference values computed with appropriate statistical methods, and examine predictive ability of anthropometric variables. Antidromic sensory nerve conduction studies of the ulnar nerve using surface electrodes were performed on 100 volunteers. Reference values were computed from optimally transformed data. Reliability was computed from 30 subjects. Multiple linear regression models were constructed from four predictor variables. Reliability was greater than 0.85 for all paired measures. Responses were elicited in all subjects; reference values for sensory nerve action potential (SNAP) amplitude from above elbow stimulation are 3.3 μV and decrement across-elbow less than 46%. No single predictor variable accounted for more than 15% of the variance in the response. Electrophysiologic measures of the ulnar sensory nerve are reliable. Absent SNAP responses are inconsistent with disease free individuals. Reference values recommended in this report are based on appropriate transformations of non-normally distributed data. No strong statistical model of prediction could be derived from the limited set of predictor variables. Reliability analyses combined with relatively low level of measurement error suggest that ulnar sensory reference values may be used with confidence. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

IRRITANT AGONISTS AND AIR POLLUTANTS: NEUROLOGICALLY MEDIATED RESPIRATORY AND CARDIOVASCULAR RESPONSES

EPA Science Inventory

Situated within and just beneath the airway epithelium is a dense plexus of sensory nerves. These sensory (afferent) nerves serve as sentinels at the gateway between the organism and the inhaled air. This airway mucosal nerve plexus is present from the nose to the most peripheral...

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

PubMed

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

2012-05-01

As humans age there is a decline in most sensory systems including vision, hearing, taste, smell, and tactile acuity. In contrast, the frequency and severity of musculoskeletal pain generally increases with age. To determine whether the density of sensory nerve fibers that transduce skeletal pain changes with age, calcitonin gene related peptide (CGRP) and neurofilament 200 kDa (NF200) sensory nerve fibers that innervate the femur were examined in the femurs of young (4-month-old), middle-aged (13-month-old) and old (36-month-old) male F344/BNF1 rats. Whereas the bone quality showed a significant age-related decline, the density of CGRP(+) and NF200(+) nerve fibers that innervate the bone remained remarkably unchanged as did the severity of acute skeletal fracture pain. Thus, while bone mass, quality, and strength undergo a significant decline with age, the density of sensory nerve fibers that transduce noxious stimuli remain largely intact. These data may in part explain why musculoskeletal pain increases with age. Copyright © 2012 Elsevier Inc. All rights reserved.

Evaluation of pediatric upper extremity peripheral nerve injuries.

PubMed

Ho, Emily S

2015-01-01

The evaluation of motor and sensory function of the upper extremity after a peripheral nerve injury is critical to diagnose the location and extent of nerve injury as well as document functional recovery in children. The purpose of this paper is to describe an approach to the evaluation of the pediatric upper extremity peripheral nerve injuries through a critical review of currently used tests of sensory and motor function. Outcome studies on pediatric upper extremity peripheral nerve injuries in the Medline database were reviewed. The evaluation of the outcome in children less than 10 years of age with an upper extremity peripheral nerve injury includes careful observation of preferred prehension patterns, examination of muscle atrophy and sudomotor function, provocative tests, manual muscle testing and tests of sensory threshold and tactile gnosis. The evaluation of outcome in children with upper extremity peripheral nerve injuries warrants a unique approach. Copyright © 2015 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Dexmedetomidine Added to Local Anesthetic Mixture of Lidocaine and Ropivacaine Enhances Onset and Prolongs Duration of a Popliteal Approach to Sciatic Nerve Blockade.

PubMed

Hu, Xiawei; Li, Jinlei; Zhou, Riyong; Wang, Quanguang; Xia, Fangfang; Halaszynski, Thomas; Xu, Xuzhong

2017-01-01

A literature review of multiple clinical studies on mixing additives to improve pharmacologic limitation of local anesthetics during peripheral nerve blockade revealed inconsistency in success rates and various adverse effects. Animal research on dexmedetomidine as an adjuvant on the other hand has promising results, with evidence of minimum unwanted results. This randomized, double-blinded, contrastable observational study examined the efficacy of adding dexmedetomidine to a mixture of lidocaine plus ropivacaine during popliteal sciatic nerve blockade (PSNB). Sixty patients undergoing varicose saphenous vein resection using ultrasonography-guided PSNB along with femoral and obturator nerve blocks as surgical anesthesia were enrolled. All received standardized femoral and obturator nerve blocks, and the PSNB group was randomized to receive either 0.5 mL (50 µg) of dexmedetomidine (DL group) or 0.5 mL of saline (SL group) together with 2% lidocaine (9.5 mL) plus 0.75% ropovacaine (10 mL). Sensory onset and duration of lateral sural cutaneous nerve, sural nerve, superficial peroneal nerve, deep peroneal nerve, lateral plantar nerve, and medial plantar nerve were recorded. Motor onset and duration of tibial nerve and common peroneal nerve were also examined. Sensory onset of sural nerve, superficial peroneal nerve, lateral plantar nerve, and medial plantar nerve was significantly quicker in the DL group than in the SL group (P < 0.05). Sensory onset of lateral sural cutaneous nerve and deep peroneal nerve was not statistically different between the groups (P > 0.05). Motor onset of tibial nerve and common peroneal nerve was faster in the DL group than in in the SL group (P < 0.05). Duration of both sensory and motor blockade was significantly longer in the DL group than in the SL group (P < 0.05). Perineural dexmedetomidine added to lidocaine and ropivacaine enhanced efficacy of popliteal approach to sciatic nerve blockade with faster onset and longer duration. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.

Tenascin-C in peripheral nerve morphogenesis.

PubMed

Chiquet, M; Wehrle-Haller, B

1994-01-01

The extracellular matrix (ECM) molecule tenascin/cytotactin (TN-C) is expressed at a high level by satellite (glial precursor) cells in developing peripheral nerves of the chick embryo; synthesis of its mRNA peaks at the time period when axonal growth is maximal. When offered as a substrate in vitro, TN-C mediates neurite outgrowth by both motor and sensory neurons. The ability to grow neurites on TN-C is developmentally regulated: sensory neurons from 4-day chick embryos (the stage at which peripheral nerves start to develop) grow immediately and rapidly, whereas neurons from older embryos respond with a long delay. A TN-C domain responsible for this activity is located within the C-terminal (distal) portion of TN-C subunits. Integrin receptors seem to be involved on peripheral neurites because their growth on TN-C is completely blocked by antibodies to beta 1 integrins. In striking contrast to neuronal processes, nerve satellite cells can attach to a TN-C substrate but are completely inhibited in their migratory activity. Artificial substrate borders between tenascin and fibronectin or laminin act as selective barriers that allow neurites to pass while holding up satellite cells. The repulsive action of TN-C on satellite cells is similar to that observed for other cell types and is likely to be mediated by additional TN-C domains. In view of these data, it is surprising that mice seem to develop normally without a functional TN-C gene. TN-C is likely to be redundant, that is, its dual action on cell adhesion is shared by other molecules.(ABSTRACT TRUNCATED AT 250 WORDS)

Sensory neuropathy may cause central neuronal reorganization but does not respecify perceptual quality or localization of sensation.

PubMed

Ginanneschi, Federica; Mondelli, Mauro; Rossi, Alessandro

2012-10-01

Functional reorganization in the somatosensory network after peripheral nerve lesions has been suspected to modify the clinical expression of symptoms. However, no conclusive evidence exists to support this notion. We addressed this question by investigating the topographic distribution of the subjective sensory report in various chronic human mononeuropathies. We report the clinical results of 86 patients who were diagnosed with meralgia paresthetica, 86 patients with ulnar neuropathy at the elbow, and 203 patients with carpal tunnel syndrome. In the carpal tunnel syndrome group, 10% of the patients exhibited a spread of sensory symptoms beyond the innervation territory of the median nerve. As previously reported, this spread was contingent upon an indirect compressive lesion of the ulnar nerve at the wrist. In all of the patients who were affected with meralgia paresthetica or ulnar neuropathy at the elbow, the peripheral referral of sensation was always within the anatomic distribution of the affected nerve. In human neuropathies, the projected sensory symptoms are restricted to the innervation territories of the affected nerves, with no extraterritorial spread. Thus, the somatosensory localization function remains accurate, despite the central reorganization that presumably occurs after nerve injury. We conclude that reorganization of the sensory connections within the central nervous system after peripheral nerve injury in humans is a clinically silent adaptive phenomenon.

Morphological studies of the vestibular nerve

NASA Technical Reports Server (NTRS)

Bergstroem, B.

1973-01-01

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

Modulating molecular chaperones improves sensory fiber recovery and mitochondrial function in diabetic peripheral neuropathy

PubMed Central

Urban, Michael J.; Pan, Pan; Farmer, Kevin L.; Zhao, Huiping; Blagg, Brian S.J.; Dobrowsky, Rick T.

2012-01-01

Quantification of intra-epidermal nerve fibers (iENFs) is an important approach to stage diabetic peripheral neuropathy (DPN) and is a promising clinical endpoint for identifying beneficial therapeutics. Mechanistically, diabetes decreases neuronal mitochondrial function and enhancing mitochondrial respiratory capacity may aid neuronal recovery from glucotoxic insults. We have proposed that modulating the activity and expression of heat shock proteins (Hsp) may be of benefit in treating DPN. KU-32 is a C-terminal Hsp90 inhibitor that improved thermal hypoalgesia in diabetic C57Bl/6 mice but it was not determined if this was associated with an increase in iENF density and mitochondrial function. After 16 weeks of diabetes, Swiss Webster mice showed decreased electrophysiological and psychosensory responses and a >30% loss of iENFs. Treatment of the mice with ten weekly doses of 20 mg/kg KU-32 significantly reversed pre-existing deficits in nerve conduction velocity and responses to mechanical and thermal stimuli. KU-32 therapy significantly reversed the pre-existing loss of iENFs despite the identification of a sub-group of drug-treated diabetic mice that showed improved thermal sensitivity but no increase in iENF density. To determine if the improved clinical indices correlated with enhanced mitochondrial activity, sensory neurons were isolated and mitochondrial bioenergetics assessed ex vivo using extracellular flux technology. Diabetes decreased maximal respiratory capacity in sensory neurons and this deficit was improved following KU-32 treatment. In conclusion, KU-32 improved physiological and morphologic markers of degenerative neuropathy and drug efficacy may be related to enhanced mitochondrial bioenergetics in sensory neurons. PMID:22465570

Strategies for providing upper extremity amputees with tactile and hand position feedback--moving closer to the bionic arm.

PubMed

Riso, R R

1999-01-01

A continuing challenge for prostheses developers is to replace the sensory function of the hand. This includes tactile sensitivity such as finger contact, grip force, object slippage, surface texture and temperature, as well as proprioceptive sense. One approach is sensory substitution whereby an intact sensory system such as vision, hearing or cutaneous sensation elsewhere on the body is used as an input channel for information related to the prosthesis. A second technique involves using electrical stimulation to deliver sensor derived information directly to the peripheral afferent nerves within the residual limb. Stimulation of the relevant afferent nerves can ultimately come closest to restoring the original sensory perceptions of the hand, and to this end, researchers have already demonstrated some degree of functionality of the transected sensory nerves in studies with amputee subjects. This paper provides an overview of different types of nerve interface components and the advantages and disadvantages of employing each of them in sensory feedback systems. Issues of sensory perception, neurophysiology and anatomy relevant to hand sensation and function are discussed with respect to the selection of the different types of nerve interfaces. The goal of this paper is to outline what can be accomplished for implementing sensation into artificial arms in the near term by applying what is present or presently attainable technology.

PATHOLOGICAL SPROUTING OF ADULT NOCICEPTORS IN CHRONIC PROSTATE CANCER-INDUCED BONE PAIN

PubMed Central

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

2012-01-01

Pain frequently accompanies cancer. What remains unclear is why this pain frequently becomes more severe and difficult to control with disease progression. Here we test the hypothesis that with disease progression, sensory nerve fibers that innervate the tumor-bearing tissue undergo a pathological sprouting and reorganization, which in other non-malignant pathologies has been shown to generate and maintain chronic pain. Injection of canine prostate cancer cells into mouse bone induces a remarkable sprouting of calcitonin gene related peptide (CGRP+) and neurofilament 200 kDa (NF200+) sensory nerve fibers. Nearly all sensory nerve fibers that undergo sprouting also co-express tropomyosin receptor kinase A (TrkA+). This ectopic sprouting occurs in sensory nerve fibers that are in close proximity to colonies of prostate cancer cells, tumor-associated stromal cells and newly formed woven bone, which together form sclerotic lesions that closely mirror the osteoblastic bone lesions induced by metastatic prostate tumors in humans. Preventive 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. Interestingly, RT-PCR analysis indicated that the prostate cancer cells themselves do not express detectable levels of mRNA coding for NGF. This suggests that the tumor-associated stromal cells express and release NGF, which drives the pathological reorganization of nearby TrkA+ sensory nerve fibers. Therapies that prevent this reorganization of sensory nerve fibers may provide insight into the evolving mechanisms that drive cancer pain and lead to more effective control of this chronic pain state. PMID:21048122

Differential aging of median and ulnar sensory nerve parameters.

PubMed

Werner, Robert A; Franzblau, Alfred; D'Arcy, Hannah J S; Evanoff, Bradley A; Tong, Henry C

2012-01-01

Nerve conduction velocity slows and amplitude declines with aging. Median and ulnar sensory nerves were tested at the annual meetings of the American Dental Association. Seven hundred four subjects had at least two observations. The rate of change in the nerve parameters was estimated while controlling for gender, age, change in hand temperature, baseline body mass index (BMI), and change in BMI. Amplitudes of the median sensory nerve action potentials decreased by 0.58 μV per year, whereas conduction velocity decreased at a rate of 0.41 m/s per year. Corresponding values for the ulnar nerve were 0.89 μV and 0.29 m/s per year. The rates of change in amplitudes did not differ, but the median nerve demonstrated a more rapid loss of conduction velocity. The rate of change for the median conduction velocity was higher than previously reported. The rate of change of median conduction velocity was significantly greater than for the ulnar nerve. Copyright © 2011 Wiley Periodicals, Inc.

Electrophysiological follow-up of patients with chronic peripheral neuropathy induced by occupational intoxication with n-hexane.

PubMed

Wang, Cheng; Chen, Shijiu; Wang, Zengtao

2014-09-01

The aim of this study is to characterize and dynamically monitor the progress of peripheral neuropathy induced by n-hexane by electromyography and nerve conduction velocity (NCV-EMG). Twenty-five patients with n-hexane poisoning from an electronic company were investigated in the year 2009. The occupational history of these workers was collected, and toxic substance exposure was identified. Neurologic inspection and regular NCV-EMG inspection were performed for all patients upon hospital admission and after 3, 6, and 12 months of treatment. NCV-EMG results shown that patients with n-hexane poisoning have simultaneous damage on motor and sensory nerves, of which sensory nerve damage was more severe. Motor nerves of the lower limbs were severe damaged than those of the upper limbs; whereas injury of sensory nerve in the upper limbs was more severe than that of the lower limbs. After treatment, clinical signs and symptoms of the patients were significantly improved. NCV-EMG result showed a delayed worsening at 3 months then gradually recovered after 12 months. Recovery of the motor nerve was better compared with sensory nerve, with upper limbs faster than that of the lower limbs.

Nerve Transfer Versus Nerve Graft for Reconstruction of High Ulnar Nerve Injuries.

PubMed

Sallam, Asser A; El-Deeb, Mohamed S; Imam, Mohamed A

2017-04-01

To assess the efficacy of nerve transfer versus nerve grafting in restoring motor and sensory hand function in patients with complete, isolated high ulnar nerve injuries. A retrospective chart review was performed, at a minimum 2 years of follow-up, of 52 patients suffering complete, isolated high ulnar nerve injury between January 2006 and June 2013 in one specialized hand surgery unit. Twenty-four patients underwent motor and sensory nerve transfers (NT group). Twenty-eight patients underwent sural nerve grafting (NG group). Motor recovery, return of sensibility and complications were examined as outcome measures. The Medical Research Council scale was applied to evaluate sensory and motor recovery. Grip and pinch strengths of the hand were measured. Twenty of 24 patients (83.33%) in the NT group regained M3 grade or greater for the adductor pollicis, the abductor digiti minimi, and the medial 2 lumbricals and interossei, compared with only 16 of 28 patients (57.14%) in the NG group. Means for percentage recovery of grip strengths compared with the other healthy hand were significantly higher for the NT group than the NG group. Sensory recovery of S3 or greater was achieved in more than half of each group with no significant difference between groups. Nerve transfer is favored over nerve grafting in managing high ulnar nerve injuries because of better improvement of motor power and better restoration of grip functions of the hand. Therapeutic IV. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Physiological basis of tingling paresthesia evoked by hydroxy-alpha-sanshool.

PubMed

Lennertz, Richard C; Tsunozaki, Makoto; Bautista, Diana M; Stucky, Cheryl L

2010-03-24

Hydroxy-alpha-sanshool, the active ingredient in plants of the prickly ash plant family, induces robust tingling paresthesia by activating a subset of somatosensory neurons. However, the subtypes and physiological function of sanshool-sensitive neurons remain unknown. Here we use the ex vivo skin-nerve preparation to examine the pattern and intensity with which the sensory terminals of cutaneous neurons respond to hydroxy-alpha-sanshool. We found that sanshool excites virtually all D-hair afferents, a distinct subset of ultrasensitive light-touch receptors in the skin and targets novel populations of Abeta and C fiber nerve afferents. Thus, sanshool provides a novel pharmacological tool for discriminating functional subtypes of cutaneous mechanoreceptors. The identification of sanshool-sensitive fibers represents an essential first step in identifying the cellular and molecular mechanisms underlying tingling paresthesia that accompanies peripheral neuropathy and injury.

Physiological basis of tingling paresthesia evoked by hydroxy-α-sanshool

PubMed Central

Lennertz, Richard C; Tsunozaki, Makoto; Bautista, Diana M; Stucky, Cheryl L

2010-01-01

Hydroxy-α-sanshool, the active ingredient in plants of the prickly ash plant family, induces robust tingling paresthesia by activating a subset of somatosensory neurons. However, the subtypes and physiological function of sanshool-sensitive neurons remain unknown. Here we use the ex vivo skin-nerve preparation to examine the pattern and intensity with which the sensory terminals of cutaneous neurons respond to hydroxy-α-sanshool. We found that sanshool excites virtually all D-hair afferents, a distinct subset of ultra-sensitive light touch receptors in the skin, and targets novel populations of Aβ and C-fiber nerve afferents. Thus, sanshool provides a novel pharmacological tool for discriminating functional subtypes of cutaneous mechanoreceptors. The identification of sanshool-sensitive fibers represents an essential first step in identifying the cellular and molecular mechanisms underlying tingling paresthesia that accompanies peripheral neuropathy and injury. PMID:20335471

Mechanism of action of nicotine in isolated iris sphincter preparations of rabbit.

PubMed Central

Hisayama, T.; Shinkai, M.; Takayanagi, I.; Morimoto, S.; Ishida, K.

1988-01-01

1. Nicotine produced a transient contraction of rabbit isolated iris sphincter muscle, a parasympathetic ganglion-free tissue. The response to nicotine was antagonized by hexamethonium, but was insensitive to tetrodotoxin (TTX). While single treatments with atropine, capsaicin or [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-substance P (rpwwL-SP) partially blocked the response, combined treatment abolished it. 2. Chronic treatment of animals with nicotine added to the drinking water (about 12 mg kg-1 per day) had no effect on the responsiveness to nicotine or the pharmacological properties of nicotine-induced contraction. 3. These results suggest that acetylcholine and tachykinin(s) released via sodium channel-independent mechanisms from nerve terminals of parasympathetic and primary sensory nerves, respectively, are involved in the nicotine-induced contractile response. PMID:3228672

Selectivity and Longevity of Peripheral-Nerve and Machine Interfaces: A Review

PubMed Central

Ghafoor, Usman; Kim, Sohee; Hong, Keum-Shik

2017-01-01

For those individuals with upper-extremity amputation, a daily normal living activity is no longer possible or it requires additional effort and time. With the aim of restoring their sensory and motor functions, theoretical and technological investigations have been carried out in the field of neuroprosthetic systems. For transmission of sensory feedback, several interfacing modalities including indirect (non-invasive), direct-to-peripheral-nerve (invasive), and cortical stimulation have been applied. Peripheral nerve interfaces demonstrate an edge over the cortical interfaces due to the sensitivity in attaining cortical brain signals. The peripheral nerve interfaces are highly dependent on interface designs and are required to be biocompatible with the nerves to achieve prolonged stability and longevity. Another criterion is the selection of nerves that allows minimal invasiveness and damages as well as high selectivity for a large number of nerve fascicles. In this paper, we review the nerve-machine interface modalities noted above with more focus on peripheral nerve interfaces, which are responsible for provision of sensory feedback. The invasive interfaces for recording and stimulation of electro-neurographic signals include intra-fascicular, regenerative-type interfaces that provide multiple contact channels to a group of axons inside the nerve and the extra-neural-cuff-type interfaces that enable interaction with many axons around the periphery of the nerve. Section Current Prosthetic Technology summarizes the advancements made to date in the field of neuroprosthetics toward the achievement of a bidirectional nerve-machine interface with more focus on sensory feedback. In the Discussion section, the authors propose a hybrid interface technique for achieving better selectivity and long-term stability using the available nerve interfacing techniques. PMID:29163122

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 naïve 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 naïve animals. Together the results point to a novel and powerful role for VGF in neuropathic pain. PMID:19077191

Morphology and Nanomechanics of Sensory Neurons Growth Cones following Peripheral Nerve Injury

PubMed Central

Szabo, Vivien; Végh, Attila-Gergely; Lucas, Olivier; Cloitre, Thierry; Scamps, Frédérique; Gergely, Csilla

2013-01-01

A prior peripheral nerve injury in vivo, promotes a rapid elongated mode of sensory neurons neurite regrowth in vitro. This in vitro model of conditioned axotomy allows analysis of the cellular and molecular mechanisms leading to an improved neurite re-growth. Our differential interference contrast microscopy and immunocytochemistry results show that conditioned axotomy, induced by sciatic nerve injury, did not increase somatic size of adult lumbar sensory neurons from mice dorsal root ganglia sensory neurons but promoted the appearance of larger neurites and growth cones. Using atomic force microscopy on live neurons, we investigated whether membrane mechanical properties of growth cones of axotomized neurons were modified following sciatic nerve injury. Our data revealed that neurons having a regenerative growth were characterized by softer growth cones, compared to control neurons. The increase of the growth cone membrane elasticity suggests a modification in the ratio and the inner framework of the main structural proteins. PMID:23418549

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.

The use of targeted muscle reinnervation for improved myoelectric prosthesis control in a bilateral shoulder disarticulation amputee.

PubMed

Kuiken, T A; Dumanian, G A; Lipschutz, R D; Miller, L A; Stubblefield, K A

2004-12-01

A novel method for the control of a myoelectric upper limb prosthesis was achieved in a patient with bilateral amputations at the shoulder disarticulation level. Four independently controlled nerve-muscle units were created by surgically anastomosing residual brachial plexus nerves to dissected and divided aspects of the pectoralis major and minor muscles. The musculocutaneous nerve was anastomosed to the upper pectoralis major; the median nerve was transferred to the middle pectoralis major region; the radial nerve was anastomosed to the lower pectoralis major region; and the ulnar nerve was transferred to the pectoralis minor muscle which was moved out to the lateral chest wall. After five months, three nerve-muscle units were successful (the musculocutaneous, median and radial nerves) in that a contraction could be seen, felt and a surface electromyogram (EMG) could be recorded. Sensory reinnervation also occurred on the chest in an area where the subcutaneous fat was removed. The patient was fitted with a new myoelectric prosthesis using the targeted muscle reinnervation. The patient could simultaneously control two degrees-of-freedom with the experimental prosthesis, the elbow and either the terminal device or wrist. Objective testing showed a doubling of blocks moved with a box and blocks test and a 26% increase in speed with a clothes pin moving test. Subjectively the patient clearly preferred the new prosthesis. He reported that it was easier and faster to use, and felt more natural.

Effect of nitric oxide synthase inhibitor on increase in nasal mucosal blood flow induced by sensory and parasympathetic nerve stimulation in rats.

PubMed

Ogawa, Fumio; Hanamitsu, Masakazu; Ayajiki, Kazuhide; Aimi, Yoshinari; Okamura, Tomio; Shimizu, Takeshi

2010-06-01

Neural control of nasal blood flow (NBF) has not been systematically investigated. The aim of the present study was to evaluate the effect of electrical stimulation of both sensory and parasympathetic nerves innervating the nasal mucosal arteries on NBF in rats. In anesthetized rats, nasociliary (sensory) nerves and postganglionic (parasympathetic) nerves derived from the right sphenopalatine ganglion were electrically stimulated. We measured NBF with a laser-Doppler flowmeter. The nerve stimulation increased NBF on both sides and increased the mean arterial blood pressure. The increase in NBF was larger on the ipsilateral side than on the contralateral side. Hexamethonium bromide, a ganglion blocker, abolished the stimulation-induced pressure effect and the increase in NBF on the contralateral side, but did not abolish the increase in NBF on the ipsilateral side. The remaining increase in NBF was abolished by N(G)-nitro-L-arginine, a nitric oxide synthase inhibitor. Histochemical analysis with nicotinamide adenine dinucleotide phosphate-diaphorase showed neuronal nitric oxide synthase-containing nerves that innervate nasal mucosal arteries. Nitric oxide released from parasympathetic nitrergic nerves may contribute to an increase in NBF in rats. The afferent impulses induced by sensory nerve stimulation may lead to an increase in mean arterial blood pressure that is partly responsible for the increase in NBF.

Determining the functional sensibility of the hand in patients with peripheral nerve repair: Feasibility of using a novel manual tactile test for monitoring the progression of nerve regeneration.

PubMed

Hsu, Hsiu-Yun; Kuo, Li-Chieh; Kuan, Ta-Shen; Yang, Hsiu-Ching; Su, Fong-Chin; Chiu, Haw-Yen; Shieh, Shyh-Jou

Case-controlled cohort study. Sensory function is difficult to observe during nerve regeneration processes. Traditional sensory tests are limited to identifying the level of functioning hand sensation for sensory stimulus is given passively to the cutaneous surface of the hand. To examine the outcome changes in the manual tactile test (MTT), Semmes-Weinstein monofilament (SWM) and 2-point discrimination (2PD) tests for patients with nerve repair and to investigate the concurrent validity of MTT by comparing it with the results of traditional tests. Fifteen patients with nerve injury of the upper limbs were recruited, along with 15 matched healthy controls. The MTT, SWM, and 2PD tests were used to examine the sensory status of the subjects. Three subtests (barognosis, roughness differentiation, and stereognosis) in MTT showed that the patients improved with time. A moderate and mild correlation was found between the MTT and 2PD results and between the barognosis and SWM results. The MTT provides practical and functional perspectives on detecting nerve progression during the courses of degeneration and regeneration. IV. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Distribution of sensory nerve endings around the human sinus tarsi: a cadaver study

PubMed Central

Rein, Susanne; Manthey, Suzanne; Zwipp, Hans; Witt, Andreas

2014-01-01

The aim of this study was to analyse the pattern of sensory nerve endings and blood vessels around the sinus tarsi. The superficial and deep parts of the fat pads at the inferior extensor retinaculum (IER) as well as the subtalar joint capsule inside the sinus tarsi from 13 cadaver feet were dissected. The distribution of the sensory nerve endings and blood vessels were analysed in the resected specimens as the number per cm2 after staining with haematoxylin-eosin, S100 protein, low-affinity neurotrophin receptor p75, and protein gene product 9.5 using the classification of Freeman and Wyke. Free nerve endings were the predominant sensory ending (P < 0.001). Ruffini and Golgi-like endings were rarely found and no Pacini corpuscles were seen. Significantly more free nerve endings (P < 0.001) and blood vessels (P = 0.01) were observed in the subtalar joint capsule than in the superficial part of the fat pad at the IER. The deep part of the fat pad at the IER had significantly more blood vessels than the superficial part of the fat pad at the IER (P = 0.012). Significantly more blood vessels than free nerve endings were seen in all three groups (P < 0.001). No significant differences in distribution were seen in terms of right or left side, except for free nerve endings in the superficial part of the fat pad at the IER (P = 0.003). A greater number of free nerve endings correlated with a greater number of blood vessels. The presence of sensory nerve endings between individual fat cells supports the hypothesis that the fat pad has a proprioceptive role monitoring changes and that it is a source of pain in sinus tarsi syndrome due to the abundance of free nerve endings. PMID:24472004

A fine-structural survey of the pulpal innervation in the rat mandibular incisor.

PubMed

Bishop, M A

1981-02-01

The innervation of the rat incisor pulp has been studied using transmission electron microscopy and light microscopy. Transverse sections of mandibular incisor pulp (380-460 gm rats) from numerous positions in the long axis of the tooth were examined systematically in the electron microscopy. Quantitative data on total axon populations were obtained. The nerve fibers were found to pass through the lingual half of the pulp from the apical end to within 2 mm of the incisal tip. Although the nerve fibers were seen to lie amongst the connective tissue cells between the blood vessels, the electron microscopic observations showed that the blood vessels are not innervated. Throughout their pulpal course the nerve fibers showed no trace of perineurial investment. Virtually all the axons were unmyelinated. Total numbers of axons were small (233-328) and peak diameters of 0.3-0.4 microM confirmed the observed immature appearance of the nerve supply. Obvious nerve endings were seldom observed and the axons showed no structural association with odontoblasts. The evidence indicates that, although most axons terminate near the incisal end of the tooth, no specific structure is supplied. The qualitative features of the axons do not suggest autonomic function; however, they are consistent with a sensory role.

Botulinum toxin type A induces changes in the chemical coding of substance P-immunoreactive dorsal root ganglia sensory neurons supplying the porcine urinary bladder.

PubMed

Bossowska, Agnieszka; Lepiarczyk, Ewa; Mazur, Urszula; Janikiewicz, Paweł; Markiewicz, Włodzimierz

2015-11-16

Botulinum toxin (BTX) is a potent neurotoxin which blocks acetylcholine release from nerve terminals, and therefore leads to cessation of somatic motor and/or parasympathetic transmission. Recently it has been found that BTX also interferes with sensory transmission, thus, the present study was aimed at investigating the neurochemical characterization of substance P-immunoreactive (SP-IR) bladder-projecting sensory neurons (BPSN) after the toxin treatment. Investigated neurons were visualized with retrograde tracing method and their chemical profile was disclosed with double-labelling immunohistochemistry using antibodies against SP, calcitonin gene-related peptide (CGRP), pituitary adenylate cyclase activating polypeptide (PACAP), neuronal nitric oxide synthase (nNOS), galanin (GAL), calbindin (CB), and somatostatin (SOM). In the control group (n = 6), 45% of the total population of BPSN were SP-IR. Nearly half of these neurons co-expressed PACAP or CGRP (45% and 35%, respectively), while co-localization of SP with GAL, nNOS, SOM or CB was found less frequently (3.7%, 1.8%, 1.2%, and 0.7%, respectively). In BTX-treated pigs (n = 6), toxin-injections caused a decrease in the number of SP-IR cells containing CGRP, SOM or CB (16.2%, 0.5%, and 0%, respectively) and a distinct increase in these nerve cells immunopositive to GAL (27.2%). The present study demonstrates that BTX significantly modifies the chemical phenotypes of SP-IR BPSN.

β‐Endorphin, Met‐enkephalin and corresponding opioid receptors within synovium of patients with joint trauma, osteoarthritis and rheumatoid arthritis

PubMed Central

Mousa, Shaaban A; Straub, Rainer H; Schäfer, Michael; Stein, Christoph

2007-01-01

Objective Intra‐articularly applied opioid agonists or antagonists modulate pain after knee surgery and in chronic arthritis. Therefore, the expression of β‐endorphin (END), Met‐enkephalin (ENK), and μ and δ opioid receptors (ORs) within synovium of patients with joint trauma (JT), osteoarthritis (OA) and rheumatoid arthritis (RA) were examined. Methods Synovial samples were subjected to double immunohistochemical analysis of opioid peptides with immune cell markers, and of ORs with the neuronal markers calcitonin gene‐related peptide (CGRP) and tyrosine hydroxylase (TH). Results END and ENK were expressed by macrophage‐like (CD68+) and fibroblast‐like (CD68−) cells within synovial lining layers of all disorders. In the sublining layers, END and ENK were mostly expressed by granulocytes in patients with JT, and by macrophages/monocytes, lymphocytes and plasma cells in those with OA and RA. Overall, END‐ and ENK‐immunoreactive (IR) cells were more abundant in patients with RA than in those with OA and JT. ORs were found on nerve fibres and immune cells in all patients. OR‐IR nerve fibres were significantly more abundant in patients with RA than in those with OA and JT. μORs and δORs were coexpressed with CGRP but not with TH. Conclusions Parallel to the severity of inflammation, END and ENK in immune cells and their receptors on sensory nerve terminals are more abundant in patients with RA than in those with JT and OA. These findings are consistent with the notion that, with prolonged and enhanced inflammation, the immune and peripheral nervous systems upregulate sensory nerves expressing ORs and their ligands to counterbalance pain and inflammation. PMID:17324971

Effect of walking and resting after three cryotherapy modalities on the recovery of sensory and motor nerve conduction velocity in healthy subjects.

PubMed

Herrera, Esperanza; Sandoval, Maria Cristina; Camargo, Diana M; Salvini, Tania F

2011-01-01

Different cryotherapy modalities have distinct effects on sensory and motor nerve conduction parameters. However, it is unclear how these parameters change during the post-cooling period and how the exercise carried out in this period would influence the recovery of nerve conduction velocity (NCV). To compare the effects of three cryotherapy modalities on post-cooling NCV and to analyze the effect of walking on the recovery of sensory and motor NCV. Thirty six healthy young subjects were randomly allocated into three groups: ice massage (n=12), ice pack (n=12) and cold water immersion (n=12). The modalities were applied to the right leg. The subjects of each modality group were again randomized to perform a post-cooling activity: a) 30 min rest, b) walking 15 min followed by 15 min rest. The NCV of sural (sensory) and posterior tibial (motor) nerves was evaluated. Initial (pre-cooling) and final (30 min post-cooling) NCV were compared using a paired t-test. The effects of the modalities and the post-cooling activities on NCV were evaluated by an analysis of covariance. The significance level was α=0.05. There was a significant difference between immersion and ice massage on final sensory NCV (p=0.009). Ice pack and ice massage showed similar effects (p>0.05). Walking accelerated the recovery of sensory and motor NCV, regardless of the modality previously applied (p<0.0001). Cold water immersion was the most effective modality for maintaining reduced sensory nerve conduction after cooling. Walking after cooling, with any of the three modalities, enhances the recovery of sensory and motor NCV.

The RNA binding and transport proteins staufen and fragile X mental retardation protein are expressed by rat primary afferent neurons and localize to peripheral and central axons.

PubMed

Price, T J; Flores, C M; Cervero, F; Hargreaves, K M

2006-09-15

Neuronal proteins have been traditionally viewed as being derived solely from the soma; however, accumulating evidence indicates that dendritic and axonal sites are capable of a more autonomous role in terms of new protein synthesis. Such extra-somal translation allows for more rapid, on-demand regulation of neuronal structure and function than would otherwise be possible. While mechanisms of dendritic RNA transport have been elucidated, it remains unclear how RNA is trafficked into the axon for this purpose. Primary afferent neurons of the dorsal root (DRG) and trigeminal (TG) ganglia have among the longest axons in the neuraxis and such axonal protein synthesis would be advantageous, given the greater time involved for protein trafficking to occur via axonal transport. Therefore, we hypothesized that these primary sensory neurons might express proteins involved in RNA transport. Rat DRG and TG neurons expressed staufen (stau) 1 and 2 (detected at the mRNA level) and stau2 and fragile x mental retardation protein (FMRP; detected at the protein level). Stau2 mRNA was also detected in human TG neurons. Stau2 and FMRP protein were localized to the sciatic nerve and dorsal roots by immunohistochemistry and to dorsal roots by Western blot. Stau2 and FMRP immunoreactivities colocalized with transient receptor potential channel type 1 immunoreactivity in sensory axons of the sciatic nerve and dorsal root, suggesting that these proteins are being transported into the peripheral and central terminals of nociceptive sensory axons. Based on these findings, we propose that stau2 and FMRP proteins are attractive candidates to subserve RNA transport in sensory neurons, linking somal transcriptional events to axonal translation.

THE RNA BINDING AND TRANSPORT PROTEINS STAUFEN AND FRAGILE X MENTAL RETARDATION PROTEIN ARE EXPRESSED BY RAT PRIMARY AFFERENT NEURONS AND LOCALIZE TO PERIPHERAL AND CENTRAL AXONS

PubMed Central

PRICE, T. J.; FLORES, C. M.; CERVERO, F.; HARGREAVES, K. M.

2007-01-01

Neuronal proteins have been traditionally viewed as being derived solely from the soma; however, accumulating evidence indicates that dendritic and axonal sites are capable of a more autonomous role in terms of new protein synthesis. Such extra-somal translation allows for more rapid, on-demand regulation of neuronal structure and function than would otherwise be possible. While mechanisms of dendritic RNA transport have been elucidated, it remains unclear how RNA is trafficked into the axon for this purpose. Primary afferent neurons of the dorsal root (DRG) and trigeminal (TG) ganglia have among the longest axons in the neuraxis and such axonal protein synthesis would be advantageous, given the greater time involved for protein trafficking to occur via axonal transport. Therefore, we hypothesized that these primary sensory neurons might express proteins involved in RNA transport. Rat DRG and TG neurons expressed staufen (stau) 1 and 2 (detected at the mRNA level) and stau2 and fragile × mental retardation protein (FMRP; detected at the protein level). Stau2 mRNA was also detected in human TG neurons. Stau2 and FMRP protein were localized to the sciatic nerve and dorsal roots by immunohistochemistry and to dorsal roots by Western blot. Stau2 and FMRP immunoreactivities colocalized with transient receptor potential channel type 1 immunoreactivity in sensory axons of the sciatic nerve and dorsal root, suggesting that these proteins are being transported into the peripheral and central terminals of nociceptive sensory axons. Based on these findings, we propose that stau2 and FMRP proteins are attractive candidates to subserve RNA transport in sensory neurons, linking somal transcriptional events to axonal translation. PMID:16809002

A urodynamic study of surface neuromodulation versus sham in detrusor instability and sensory urgency.

PubMed

Bower, W F; Moore, K H; Adams, R D; Shepherd, R

1998-12-01

We studied the effect of surface neuromodulation on cystometric pressure and volume parameters in women with detrusor instability or sensory urgency. Electrical current was delivered to the suprapubic region and third sacral foramina via a transcutaneous electrical nerve stimulator with sham neuromodulation control. A consecutive series of women with proved detrusor instability or sensory urgency were randomized to 3 surface neuromodulation groups. Volume and pressure parameters were the main outcomes of transcutaneous electrical nerve stimulation applied during second cystometric fill. Sham transcutaneous electrical nerve stimulation did not alter the outcome measures. However, neuromodulation delivered across the suprapubic and sacral skin effected a reduction in mean maximum height of detrusor contraction. A current which inhibits motor activity was not superior to that which inhibits sensory perception in reducing detrusor pressure. Response in sensory urgency was poor. Results from our sham controlled study suggest that short-term surface neuromodulation via transcutaneous electrical nerve stimulation may have a role in the treatment of detrusor instability. Future studies must examine the clinical effect of long-term surface neuromodulation.

Capsaicin modulates acetylcholine release at the myoneural junction.

PubMed

Thyagarajan, Baskaran; Potian, Joseph G; Baskaran, Padmamalini; McArdle, Joseph J

2014-12-05

Transient receptor potential (TRP) proteins are non-selective cation channel proteins that are expressed throughout the body. Previous studies demonstrated the expression of TRP Vanilloid 1 (TRPV1), capsaicin (CAP) receptor, in sensory neurons. Recently, we reported TRPV1 expression in mouse motor nerve terminals [MNTs; (Thyagarajan et al., 2009)], where we observed that CAP protected MNTs from botulinum neurotoxin A (BoNT/A). Phrenic nerve diaphragm nerve muscle preparations (NMP) isolated from isoflurane anesthetized adult mice were analyzed for twitch tension, spontaneous (mEPCs) and nerve stimulus evoked (EPCs) acetylcholine release. When acutely applied to isolated NMP, CAP produced a concentration-dependent decline of twitch tension and produced a significant decline in the amplitude of EPCs and quantal content without any effect on the mEPCs. The suppression of nerve stimulus evoked acetylcholine release by CAP was antagonized by capsazepine (CPZ), a TRPV1 antagonist. CAP did not suppress phrenic nerve stimulus evoked acetylcholine release in TRPV1 knockout mice. Also, CAP treatment, in vitro, interfered with the localization of adapter protein 2 in cholinergic Neuro 2a cells. Wortmannin, (WMN; non-selective phosphoinositol kinase inhibitor), mimicked the effects of CAP by inhibiting the acetylcholine exocytosis. Our data suggest that TRPV1 proteins expressed at the MNT are coupled to the exo-endocytic mechanisms to regulate neuromuscular functions. Copyright © 2014 Elsevier B.V. All rights reserved.

Patients' views on early sensory relearning following nerve repair-a Q-methodology study.

PubMed

Vikström, Pernilla; Carlsson, Ingela; Rosén, Birgitta; Björkman, Anders

2017-09-26

Descriptive study. Early sensory relearning where the dynamic capacity of the brain is used has been shown to improve sensory outcome after nerve repair. However, no previous studies have examined how patients experience early sensory relearning. To describe patient's views on early sensory relearning. Statements' scores were analyzed by factor analysis. Thirty-seven consecutive adult patients with median and/or ulnar nerve repair who completed early sensory relearning were included. Three factors were identified, explaining 45% of the variance: (1) "Believe sensory relearning is meaningful, manage to get an illusion of touch and complete the sensory relearning"; (2) "Do not get an illusion of touch easily and need support in their sensory relearning" (3) "Are not motivated, manage to get an illusion of touch but do not complete sensory relearning". Many patients succeed in implementing their sensory relearning. However, a substantial part of the patient population need more support, have difficulties to create illusion of touch, and lack motivation to complete the sensory relearning. To enhance motivation and meaningfulness by relating the training clearly to everyday occupations and to the patient's life situation is a suggested way to proceed. The three unique factors indicate motivation and sense of meaningfulness as key components which should be taken into consideration in developing programs for person-centered early sensory relearning. 3. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Central projections and entries of capsaicin-sensitive muscle afferents.

PubMed

Della Torre, G; Lucchi, M L; Brunetti, O; Pettorossi, V E; Clavenzani, P; Bortolami, R

1996-03-25

The entry pathway and central distribution of A delta and C muscle afferents within the central nervous system (CNS) were investigated by combining electron microscopy and electrophysiological analysis after intramuscular injection of capsaicin. The drug was injected into the rat lateral gastrocnemius (LG) and extraocular (EO) muscles. The compound action potentials of LG nerve and the evoked field potentials recorded in semilunar ganglion showed an immediate and permanent reduction in A delta and C components. The morphological data revealed degenerating unmyelinated axons and terminals in the inner sublamina II and in the border of laminae I-II of the dorsal horn at L4-L5 and C1-C2 (subnucleus caudalis trigemini) spinal cord segments. Most degenerating terminals were the central bouton (C) of type I and II synaptic glomeruli. Furthermore, degenerating peripheral axonal endings (V2) presynaptic to normal C were found. Since V2 were previously found degenerated after cutting the oculomotor nerve (ON) or L4 ventral root, we conclude that some A delta and C afferents from LG and EO muscles entering the CNS by ON or ventral roots make axoaxonic synapses on other primary afferents to promote an afferent control of sensory input.

Different Effects of Implanting Sensory Nerve or Blood Vessel on the Vascularization, Neurotization, and Osteogenesis of Tissue-Engineered Bone In Vivo

PubMed Central

Fan, Jun-jun; Mu, Tian-wang; Qin, Jun-jun; Bi, Long; Pei, Guo-xian

2014-01-01

To compare the different effects of implanting sensory nerve tracts or blood vessel on the osteogenesis, vascularization, and neurotization of the tissue-engineered bone in vivo, we constructed the tissue engineered bone and implanted the sensory nerve tracts (group SN), blood vessel (group VB), or nothing (group Blank) to the side channel of the bone graft to repair the femur defect in the rabbit. Better osteogenesis was observed in groups SN and VB than in group Blank, and no significant difference was found between groups SN and VB at 4, 8, and 12 weeks postoperatively. The neuropeptides expression and the number of new blood vessels in the bone tissues were increased at 8 weeks and then decreased at 12 weeks in all groups and were highest in group VB and lowest in group Blank at all three time points. We conclude that implanting either blood vessel or sensory nerve tract into the tissue-engineered bone can significantly enhance both the vascularization and neurotization simultaneously to get a better osteogenesis effect than TEB alone, and the method of implanting blood vessel has a little better effect of vascularization and neurotization but almost the same osteogenesis effect as implanting sensory nerve. PMID:25101279

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

PubMed

Vaughan, Cheryl H; Bartness, Timothy J

2012-05-01

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 (T(c)) and IBAT (T(IBAT)) temperature responses. CGRP content was significantly decreased in capsaicin-treated IBAT demonstrating successful sensory nerve destruction. T(IBAT) and T(c) 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.

Sensory nerves are frequently involved in the spectrum of fisher syndrome.

PubMed

Shahrizaila, Nortina; Goh, Khean J; Kokubun, Norito; Tan, Ai H; Tan, Cheng Y; Yuki, Nobuhiro

2014-04-01

Differing patterns of neurophysiological abnormalities have been reported in patients with Fisher syndrome. Fisher syndrome is rare, and few series have incorporated prospective serial studies to define the natural history of nerve conduction studies in Guillain-Barré syndrome. In an ongoing prospective study of Guillain-Barré syndrome patients, patients who presented with Fisher syndrome and its spectrum of illness were assessed through serial neurological examinations, nerve conduction studies, and serological testing of IgG against gangliosides and ganglioside complexes. Of the 36 Guillain-Barré syndrome patients identified within 2 years, 17 had features of Fisher syndrome. Serial nerve conduction studies detected significant abnormalities in sensory nerve action potential amplitude in 94% of patients associated with 2 patterns of recovery-non-demyelinating reversible distal conduction failure and axonal regeneration. Similar changes were seen in motor nerves of 5 patients. Patients with the Fisher syndrome spectrum of illness have significant sensory involvement, which may only be evident with serial neurophysiological studies. Copyright © 2013 Wiley Periodicals, Inc.

PLCγ-activated signalling is essential for TrkB mediated sensory neuron structural plasticity

PubMed Central

2010-01-01

Background The vestibular system provides the primary input of our sense of balance and spatial orientation. Dysfunction of the vestibular system can severely affect a person's quality of life. Therefore, understanding the molecular basis of vestibular neuron survival, maintenance, and innervation of the target sensory epithelia is fundamental. Results Here we report that a point mutation at the phospholipase Cγ (PLCγ) docking site in the mouse neurotrophin tyrosine kinase receptor TrkB (Ntrk2) specifically impairs fiber guidance inside the vestibular sensory epithelia, but has limited effects on the survival of vestibular sensory neurons and growth of afferent processes toward the sensory epithelia. We also show that expression of the TRPC3 cation calcium channel, whose activity is known to be required for nerve-growth cone guidance induced by brain-derived neurotrophic factor (BDNF), is altered in these animals. In addition, we find that absence of the PLCγ mediated TrkB signalling interferes with the transformation of bouton type afferent terminals of vestibular dendrites into calyces (the largest synaptic contact of dendrites known in the mammalian nervous system) on type I vestibular hair cells; the latter are normally distributed in these mutants as revealed by an unaltered expression pattern of the potassium channel KCNQ4 in these cells. Conclusions These results demonstrate a crucial involvement of the TrkB/PLCγ-mediated intracellular signalling in structural aspects of sensory neuron plasticity. PMID:20932311

Comparison of Glutamate Turnover in Nerve Terminals and Brain Tissue During [1,6-13C2]Glucose Metabolism in Anesthetized Rats.

PubMed

Patel, Anant B; Lai, James C K; Chowdhury, Golam I M; Rothman, Douglas L; Behar, Kevin L

2017-01-01

The 13 C turnover of neurotransmitter amino acids (glutamate, GABA and aspartate) were determined from extracts of forebrain nerve terminals and brain homogenate, and fronto-parietal cortex from anesthetized rats undergoing timed infusions of [1,6- 13 C 2 ]glucose or [2- 13 C]acetate. Nerve terminal 13 C fractional labeling of glutamate and aspartate was lower than those in whole cortical tissue at all times measured (up to 120 min), suggesting either the presence of a constant dilution flux from an unlabeled substrate or an unlabeled (effectively non-communicating on the measurement timescale) glutamate pool in the nerve terminals. Half times of 13 C labeling from [1,6- 13 C 2 ]glucose, as estimated by least squares exponential fitting to the time course data, were longer for nerve terminals (Glu C4 , 21.8 min; GABA C2 21.0 min) compared to cortical tissue (Glu C4 , 12.4 min; GABA C2 , 14.5 min), except for Asp C3 , which was similar (26.5 vs. 27.0 min). The slower turnover of glutamate in the nerve terminals (but not GABA) compared to the cortex may reflect selective effects of anesthesia on activity-dependent glucose use, which might be more pronounced in the terminals. The 13 C labeling ratio for glutamate-C4 from [2- 13 C]acetate over that of 13 C-glucose was twice as large in nerve terminals compared to cortex, suggesting that astroglial glutamine under the 13 C glucose infusion was the likely source of much of the nerve terminal dilution. The net replenishment of most of the nerve terminal amino acid pools occurs directly via trafficking of astroglial glutamine.

Which Ultrasound-Guided Sciatic Nerve Block Strategy Works Faster? Prebifurcation or Separate Tibial-Peroneal Nerve Block? A Randomized Clinical Trial.

PubMed

Faiz, Seyed Hamid Reza; Imani, Farnad; Rahimzadeh, Poupak; Alebouyeh, Mahmoud Reza; Entezary, Saeed Reza; Shafeinia, Amineh

2017-08-01

Peripheral nerve block is an accepted method in lower limb surgeries regarding its convenience and good tolerance by the patients. Quick performance and fast sensory and motor block are highly demanded in this method. The aim of the present study was to compare 2 different methods of sciatic and tibial-peroneal nerve block in lower limb surgeries in terms of block onset. In this clinical trial, 52 candidates for elective lower limb surgery were randomly divided into 2 groups: sciatic nerve block before bifurcation (SG; n = 27) and separate tibial-peroneal nerve block (TPG; n = 25) under ultrasound plus nerve stimulator guidance. The mean duration of block performance, as well as complete sensory and motor block, was recorded and compared between the groups. The mean duration of complete sensory block in the SG and TPG groups was 35.4 ± 4.1 and 24.9 ± 4.2 minutes, respectively, which was significantly lower in the TPG group (P = 0.001). The mean duration of complete motor block in the SG and TPG groups was 63.3 ± 4.4 and 48.4 ± 4.6 minutes, respectively, which was significantly lower in the TPG group (P = 0.001). No nerve injuries, paresthesia, or other possible side effects were reported in patients. According to the present study, it seems that TPG shows a faster sensory and motor block than SG.

Retrograde tracing and toe spreading after experimental autologous nerve transplantation and crush injury of the sciatic nerve: a descriptive methodological study.

PubMed

van Neerven, Sabien Ga; Bozkurt, Ahmet; O'Dey, Dan Mon; Scheffel, Juliane; Boecker, Arne H; Stromps, Jan-Philipp; Dunda, Sebastian; Brook, Gary A; Pallua, Norbert

2012-04-30

Evaluation of functional and structural recovery after peripheral nerve injury is crucial to determine the therapeutic effect of a nerve repair strategy. In the present study, we examined the relationship between the structural evaluation of regeneration by means of retrograde tracing and the functional analysis of toe spreading. Two standardized rat sciatic nerve injury models were used to address this relationship. As such, animals received either a 2 cm sciatic nerve defect (neurotmesis) followed by autologous nerve transplantation (ANT animals) or a crush injury with spontaneous recovery (axonotmesis; CI animals). Functional recovery of toe spreading was observed over an observation period of 84 days. In contrast to CI animals, ANT animals did not reach pre-surgical levels of toe spreading. After the observation period, the lipophilic dye DiI was applied to label sensory and motor neurons in dorsal root ganglia (DRG; sensory neurons) and spinal cord (motor neurons), respectively. No statistical difference in motor or sensory neuron counts could be detected between ANT and CI animals.In the present study we could indicate that there was no direct relationship between functional recovery (toe spreading) measured by SSI and the number of labelled (motor and sensory) neurons evaluated by retrograde tracing. The present findings demonstrate that a multimodal approach with a variety of independent evaluation tools is essential to understand and estimate the therapeutic benefit of a nerve repair strategy.

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

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

Structure and Development of the Subesophageal Zone of the Drosophila Brain. II. Sensory Compartments

PubMed Central

Kendroud, Sarah; Bohra, Ali Asgar; Kuert, Philipp A.; Nguyen, Bao; Guillermin, Oriane; Sprecher, Simon G.; Reichert, Heinrich; VijayRaghavan, Krishnaswamy; Hartenstein, Volker

2018-01-01

The subesophageal zone (SEZ) of the Drosophila brain processes mechanosensory and gustatory sensory input from sensilla located on the head, mouth cavity and trunk. Motor output from the SEZ directly controls the movements involved in feeding behavior. In an accompanying paper (Hartenstein et al., 2017) we analyzed the systems of fiber tracts and secondary lineages to establish reliable criteria for defining boundaries between the four neuromeres of the SEZ, as well as discrete longitudinal neuropil domains within each SEZ neuromere. Here we use this anatomical framework to systematically map the sensory projections entering the SEZ throughout development. Our findings show a continuity between larval and adult sensory neuropils. Gustatory axons from internal and external taste sensilla of the larva and adult form two closely related sensory projections, (1) the anterior central sensory center (ACSC) located deep in the ventromedial neuropil of the tritocerebrum and mandibular neuromere, and (2) the anterior ventral sensory center (AVSC), occupying a superficial layer within the ventromedial tritocerebrum. Additional, presumed mechanosensory terminal axons entering via the labial nerve define the ventromedial sensory center (VMSC) in the maxilla and labium. Mechanosensory afferents of the massive array of chordotonal organs (Johnston’s organ) of the adult antenna project into the centrolateral neuropil column of the anterior SEZ, creating the antenno-mechanosensory and motor center (AMMC). Dendritic projections of dye back-filled motor neurons extend throughout a ventral layer of the SEZ, overlapping widely with the AVSC and VMSC. Our findings elucidate fundamental structural aspects of the developing sensory systems in Drosophila. PMID:28875566

Sensory and motor peripheral nerve function and lower-extremity quadriceps strength: the health, aging and body composition study.

PubMed

Strotmeyer, Elsa S; de Rekeneire, Nathalie; Schwartz, Ann V; Resnick, Helaine E; Goodpaster, Bret H; Faulkner, Kimberly A; Shorr, Ronald I; Vinik, Aaron I; Harris, Tamara B; Newman, Anne B

2009-11-01

To determine whether sensory and motor nerve function is associated cross-sectionally with quadriceps or ankle dorsiflexion strength in an older community-based population. Cross-sectional analyses within a longitudinal cohort study. Two U.S. clinical sites. Two thousand fifty-nine Health, Aging and Body Composition Study (Health ABC) participants (49.5% male, 36.7% black, aged 73-82) in 2000/01. Quadriceps and ankle strength were measured using an isokinetic dynamometer. Sensory and motor peripheral nerve function in the legs and feet was assessed using 10-g and 1.4-g monofilaments, vibration threshold, and peroneal motor nerve conduction amplitude and velocity. Monofilament insensitivity, poorest vibration threshold quartile (>60 mu), and poorest motor nerve conduction amplitude quartile (<1.7 mV) were associated with 11%, 7%, and 8% lower quadriceps strength (all P<.01), respectively, than in the best peripheral nerve function categories in adjusted linear regression models. Monofilament insensitivity and lowest amplitude quartile were both associated with 17% lower ankle strength (P<.01). Multivariate analyses were adjusted for demographic characteristics, diabetes mellitus, body composition, lifestyle factors, and chronic health conditions and included all peripheral nerve measures in the same model. Monofilament insensitivity (beta=-7.19), vibration threshold (beta=-0.097), and motor nerve conduction amplitude (beta=2.01) each contributed independently to lower quadriceps strength (all P<.01). Monofilament insensitivity (beta=-5.29) and amplitude (beta=1.17) each contributed independently to lower ankle strength (all P<.01). Neither diabetes mellitus status nor lean mass explained the associations between peripheral nerve function and strength. Reduced sensory and motor peripheral nerve function is related to poorer lower extremity strength in older adults, suggesting a mechanism for the relationship with lower extremity disability.

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

NEURAL ORGANIZATION OF SENSORY INFORMATIONS FOR TASTE,

DTIC Science & Technology

TASTE , ELECTROPHYSIOLOGY), (*NERVES, *TONGUE), NERVE CELLS, NERVE IMPULSES, PHYSIOLOGY, NERVOUS SYSTEM, STIMULATION(PHYSIOLOGY), NERVE FIBERS, RATS...HAMSTERS, STIMULATION(PHYSIOLOGY), PERCEPTION, COOLING, BEHAVIOR, PSYCHOPHYSIOLOGY, TEMPERATURE, THRESHOLDS(PHYSIOLOGY), CHEMORECEPTORS , STATISTICAL ANALYSIS, JAPAN

Improvement of hand sensibility after selective temporary anaesthesia in combination with sensory re-education.

PubMed

Hassan-Zadeh, Roghiyeh; Lajevardi, Laleh; Esfahani, Ahmadreza Roofigari; Kamali, Mohammad

2009-01-01

The results of nerve repair in adults are often poor. The study aim was to investigate the effect of repeated sessions of cutaneous forearm anaesthesia of the injured limb, in combination with sensory re-education on the recovery of the tactile discrimination and perception of touch/pressure in the injured hand after median or ulnar nerve repair. A prospective, randomized, double-blind clinical trial was designed. During a 2-week period, a topical anaesthetic cream (Lidocaine-PTC, n = 6) or placebo (n = 7) was applied repeatedly (twice a week) with occlusive bandage for 1 hour on the flexor aspect of the forearm of the same side of the nerve injury and combined with sensory re-education. Assessments of sensory function were performed prior to the experiment and after the fourth application of Lidocaine-PTC/placebo. The patients were evaluated again 4 weeks after the last Lidocaine-PTC/placebo session. Touch perception measured with Semmes-Weinstein Monofilaments (SWM), improved significantly in the Lidocaine-PTC group (p = 0.005). In placebo group, no significant changes were seen. Two{-}point discrimination improved significantly only in the Lidocaine-PTC group (p = 0.005). This finding suggests that forearm deafferentation of injured limb in combination with sensory re-education can enhance sensory recovery after nerve repair.

AIRWAY HYPERRESPONSIVENESS IN MICE FOLLOWING ANTIGEN AND PARTICULATE MATTER EXPOSURE IS VAGALLY MEDIATED

EPA Science Inventory

Sensory nerves within the airways can initiate a variety of protective reflexes. We hypothesized that insults such as exposure to antigen and particulate matter (PM) might dysregulate airway sensory nerve function, thereby contributing to enhanced airway inflammation and hyperre...

Activation of TRPM3 by a potent synthetic ligand reveals a role in peptide release

PubMed Central

Held, Katharina; Kichko, Tatjana; De Clercq, Katrien; Klaassen, Hugo; Van Bree, Rieta; Vanherck, Jean-Christophe; Marchand, Arnaud; Reeh, Peter W.; Chaltin, Patrick; Voets, Thomas; Vriens, Joris

2015-01-01

Transient receptor potential (TRP) cation channel subfamily M member 3 (TRPM3), a member of the TRP channel superfamily, was recently identified as a nociceptor channel in the somatosensory system, where it is involved in the detection of noxious heat; however, owing to the lack of potent and selective agonists, little is known about other potential physiological consequences of the opening of TRPM3. Here we identify and characterize a synthetic TRPM3 activator, CIM0216, whose potency and apparent affinity greatly exceeds that of the canonical TRPM3 agonist, pregnenolone sulfate (PS). In particular, a single application of CIM0216 causes opening of both the central calcium-conducting pore and the alternative cation permeation pathway in a membrane-delimited manner. CIM0216 evoked robust calcium influx in TRPM3-expressing somatosensory neurons, and intradermal injection of the compound induced a TRPM3-dependent nocifensive behavior. Moreover, CIM0216 elicited the release of the peptides calcitonin gene-related peptide (CGRP) from sensory nerve terminals and insulin from isolated pancreatic islets in a TRPM3-dependent manner. These experiments identify CIM0216 as a powerful tool for use in investigating the physiological roles of TRPM3, and indicate that TRPM3 activation in sensory nerve endings can contribute to neurogenic inflammation. PMID:25733887

Reciprocal synapses between outer hair cells and their afferent terminals: evidence for a local neural network in the mammalian cochlea.

PubMed

Thiers, Fabio A; Nadol, Joseph B; Liberman, M Charles

2008-12-01

Cochlear outer hair cells (OHCs) serve both as sensory receptors and biological motors. Their sensory function is poorly understood because their afferent innervation, the type-II spiral ganglion cell, has small unmyelinated axons and constitutes only 5% of the cochlear nerve. Reciprocal synapses between OHCs and their type-II terminals, consisting of paired afferent and efferent specialization, have been described in the primate cochlea. Here, we use serial and semi-serial-section transmission electron microscopy to quantify the nature and number of synaptic interactions in the OHC area of adult cats. Reciprocal synapses were found in all OHC rows and all cochlear frequency regions. They were more common among third-row OHCs and in the apical half of the cochlea, where 86% of synapses were reciprocal. The relative frequency of reciprocal synapses was unchanged following surgical transection of the olivocochlear bundle in one cat, confirming that reciprocal synapses were not formed by efferent fibers. In the normal ear, axo-dendritic synapses between olivocochlear terminals and type-II terminals and/or dendrites were as common as synapses between olivocochlear terminals and OHCs, especially in the first row, where, on average, almost 30 such synapses were seen in the region under a single OHC. The results suggest that a complex local neuronal circuitry in the OHC area, formed by the dendrites of type-II neurons and modulated by the olivocochlear system, may be a fundamental property of the mammalian cochlea, rather than a curiosity of the primate ear. This network may mediate local feedback control of, and bidirectional communication among, OHCs throughout the cochlear spiral.

Comparative study of peripheral neuropathy and nerve regeneration in NOD and ICR diabetic mice.

PubMed

Homs, Judit; Ariza, Lorena; Pagès, Gemma; Verdú, Enrique; Casals, Laura; Udina, Esther; Chillón, Miguel; Bosch, Assumpció; Navarro, Xavier

2011-09-01

The non-obese diabetic (NOD) mouse was suggested as an adequate model for diabetic autonomic neuropathy. We evaluated sensory-motor neuropathy and nerve regeneration following sciatic nerve crush in NOD males rendered diabetic by multiple low doses of streptozotocin, in comparison with similarly treated Institute for Cancer Research (ICR) mice, a widely used model for type I diabetes. Neurophysiological values for both strains showed a decline in motor and sensory nerve conduction velocity at 7 and 8 weeks after induction of diabetes in the intact hindlimb. However, amplitudes of compound muscle and sensory action potentials (CMAPs and CNAPs) were significantly reduced in NOD but not in ICR diabetic mice. Morphometrical analysis showed myelinated fiber loss in highly hyperglycemic NOD mice, but no significant changes in fiber size. There was a reduction of intraepidermal nerve fibers, more pronounced in NOD than in ICR diabetic mice. Interestingly, aldose reductase and poly(ADP-ribose) polymerase (PARP) activities were increased already at 1 week of hyperglycemia, persisting until the end of the experiment in both strains. Muscle and nerve reinnervation was delayed in diabetic mice following sciatic nerve crush, being more marked in NOD mice. Thus, diabetes of mid-duration induces more severe peripheral neuropathy and slower nerve regeneration in NOD than in ICR mice. © 2011 Peripheral Nerve Society.

Identification of cytokine-specific sensory neural signals by decoding murine vagus nerve activity.

PubMed

Zanos, Theodoros P; Silverman, Harold A; Levy, Todd; Tsaava, Tea; Battinelli, Emily; Lorraine, Peter W; Ashe, Jeffrey M; Chavan, Sangeeta S; Tracey, Kevin J; Bouton, Chad E

2018-05-22

The nervous system maintains physiological homeostasis through reflex pathways that modulate organ function. This process begins when changes in the internal milieu (e.g., blood pressure, temperature, or pH) activate visceral sensory neurons that transmit action potentials along the vagus nerve to the brainstem. IL-1β and TNF, inflammatory cytokines produced by immune cells during infection and injury, and other inflammatory mediators have been implicated in activating sensory action potentials in the vagus nerve. However, it remains unclear whether neural responses encode cytokine-specific information. Here we develop methods to isolate and decode specific neural signals to discriminate between two different cytokines. Nerve impulses recorded from the vagus nerve of mice exposed to IL-1β and TNF were sorted into groups based on their shape and amplitude, and their respective firing rates were computed. This revealed sensory neural groups responding specifically to TNF and IL-1β in a dose-dependent manner. These cytokine-mediated responses were subsequently decoded using a Naive Bayes algorithm that discriminated between no exposure and exposures to IL-1β and TNF (mean successful identification rate 82.9 ± 17.8%, chance level 33%). Recordings obtained in IL-1 receptor-KO mice were devoid of IL-1β-related signals but retained their responses to TNF. Genetic ablation of TRPV1 neurons attenuated the vagus neural signals mediated by IL-1β, and distal lidocaine nerve block attenuated all vagus neural signals recorded. The results obtained in this study using the methodological framework suggest that cytokine-specific information is present in sensory neural signals within the vagus nerve. Copyright © 2018 the Author(s). Published by PNAS.

A microneurovascular TRAM flap does not compromise abdominal sensibility more than a conventional one.

PubMed

Puonti, Helena K; Jääskeläinen, Satu K; Hallikainen, Helena K; Partanen, Taina A

2012-09-01

Classic abdominoplasty for a transverse rectus abdominis musculocutaneous (TRAM) flap breast reconstruction impairs abdominal somatosensory function at the donor site. The aim of this study was to investigate whether the type of surgical procedure has an effect on somatosensory alterations of abdominal skin after TRAM flap breast reconstruction. Sixty patients (mean ± SD age, 50 ± 6.0 years) who underwent microvascular TRAM flap breast reconstruction and 20 healthy subjects (control group; mean age, 46 ± 6.7 years) participated in the study. Twenty patients had bilateral-nerve anastomosis, 20 had single-nerve anastomosis, and 20 underwent no nerve dissection for the TRAM flap. Clinical sensory examination and tactile and thermal quantitative sensory testing were performed and a patient questionnaire was administered at a mean of 2 to 4.5 years after surgery. All surgical techniques produced significant sensory impairment below the umbilicus, but there were no significant differences in total sensibility scores between the groups with single-nerve (mean sensibility score, 21.98 ± 2.7) and double-nerve (mean sensibility score, 20.71 ± 3.6) anastomosis of the TRAM flap. The best sensibility scores were found in the group with single-nerve dissection. Fifteen percent of patients complained of mild pain, and 13 percent felt occasional tactile hyperesthesia in their abdominal skin, mostly around the umbilicus and scars. In this study, unilateral or bilateral nerve dissection when preparing and lifting a TRAM flap did not seem to increase sensory alterations or postoperative pain in the abdominal donor site after breast reconstruction surgery. Cautious microneurovascular dissection techniques may even improve sensory recovery of the abdominal skin after TRAM flap breast reconstruction surgery.

Chitin biological absorbable catheters bridging sural nerve grafts transplanted into sciatic nerve defects promote nerve regeneration.

PubMed

Wang, Zhi-Yong; Wang, Jian-Wei; Qin, Li-Hua; Zhang, Wei-Guang; Zhang, Pei-Xun; Jiang, Bao-Guo

2018-06-01

To investigate the efficacy of chitin biological absorbable catheters in a rat model of autologous nerve transplantation. A segment of sciatic nerve was removed to produce a sciatic nerve defect, and the sural nerve was cut from the ipsilateral leg and used as a graft to bridge the defect, with or without use of a chitin biological absorbable catheter surrounding the graft. The number and morphology of regenerating myelinated fibers, nerve conduction velocity, nerve function index, triceps surae muscle morphology, and sensory function were evaluated at 9 and 12 months after surgery. All of the above parameters were improved in rats in which the nerve graft was bridged with chitin biological absorbable catheters compared with rats without catheters. The results of this study indicate that use of chitin biological absorbable catheters to surround sural nerve grafts bridging sciatic nerve defects promotes recovery of structural, motor, and sensory function and improves muscle fiber morphology. © 2018 John Wiley & Sons Ltd.

Clitoral Epidermal Inclusion Cyst Resection With Intraoperative Sensory Nerve Mapping Technique.

PubMed

Wu, Cindy; Damitz, Lynn; Karrat, Kimberly M; Mintz, Alice; Zolnoun, Denniz

2016-01-01

Despite the ever increasing popularity of labial and clitoral surgeries, the best practices and long-term effects of reconstructive procedures in these regions remain unknown. This is particularly noteworthy because the presentation of nerve-related symptoms may be delayed up to a year. Despite the convention that these surgical procedures are low risk, little is known about the best practices that may reduce the postoperative complications as a result of these reconstructive surgeries. We describe a preoperative sensory mapping technique in the context of a symptomatic inclusion cyst in the clitoral region. This technique delineates anatomical and functional regions innervated by the dorsal clitoral nerve while minimizing the vascular watershed area in the midline. A prototypical case of a patient with a clitoral mass is discussed with clinical history and surgical approach. Prior to surgical excision, the dorsal clitoral nerve distribution was mapped in order to avoid a surgical incision in this sensual zone. In our practice, preoperative sensory mapping is a clinically useful planning tool that requires minimal instrumentation and no additional operating time. Sensory mapping allows identification of the functional zone innervated by the dorsal clitoral nerve, which can aid in minimizing damage to the area.

Electroneurographic findings in patients with solvent induced central nervous system dysfunction.

PubMed Central

Orbaek, P; Rosén, I; Svensson, K

1988-01-01

The function of the peripheral nervous system was examined in a group of 32 men aged 30-65 (mean 49) with diagnosed solvent induced chronic toxic encephalopathy. The subjects were examined at the time of diagnosis and 26 were re-examined after a follow up period of 22-72 months (mean 40) and compared with a group of 50 unexposed male workers aged 27-64 (mean 42) with appropriate adjustment for age. All subjects were carefully scrutinised for alcohol abuse and other neurological diseases. The results of motor fibre neurography disclosed no difference between the groups. Nevertheless, a significant decrease in motor conduction velocity was found in the patients at follow up. Sensory fibre neurography showed signs of slight axonal degeneration with significantly decreased sensory nerve action potential amplitudes in the median and sural nerves; these amplitudes increased during follow up. The duration of sensory nerve action potentials was longer in the exposed group for the median and the sural nerves. The percentage of late components was significantly higher in the median nerve. The warm-cold sensitivity in the exposed group also indicated a slight sensory dysfunction with statistically significant wider detection limits. PMID:2840109

Evidence that the extraocular motor nuclei innervate monkey palisade endings.

PubMed

Zimmermann, Lars; May, Paul J; Pastor, Angel M; Streicher, Johannes; Blumer, Roland

2011-02-04

Palisade endings are found in the extraocular muscles (EOMs) of almost every mammalian species, including primates. These nerve specializations surrounding the muscle fiber insertion have been postulated to be the proprioceptors of the EOMs. However, it was recently demonstrated that palisade endings have a cholinergic nature, which reopened the question of whether palisade endings are motor or sensory structures. In this work, we examined whether the cell bodies of palisade endings lie in EOM motor nuclei by injecting an anterograde tracer, biotinylated dextran amine, into the abducens nucleus of a macaque monkey. Tracer visualization in the lateral rectus muscle was combined with choline acetyltransferase (ChAT) and α-bungarotoxin staining. Analysis of the samples was performed by conventional light microscopy and confocal laser scanning microscopy. About 30% of the nerve fibers innervating the muscle were tracer positive. These were ChAT positive as well. Tracer positive nerve fibers established motor contacts on singly and multiply innervated muscle fibers, which were confirmed by α-bungarotoxin staining. At the transition between muscle and distal tendon, we found palisade endings that contained tracer. Palisade endings exhibited the classic morphology: axons arising from the muscle extend onto the tendon, then turn back 180° and terminate in a cuff of terminals around an individual muscle fiber tip. This finding suggests that the cell bodies of palisade endings lie in the EOM motor nuclei, which complements prior studies demonstrating a cholinergic, and possibly motor, phenotype for palisade endings. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Evidence that the extraocular motor nuclei innervate monkey palisade endings

PubMed Central

Zimmermann, Lars; May, Paul J.; Pastor, Ángel M.; Streicher, Johannes; Blumer, Roland

2011-01-01

Palisade endings are found in the extraocular muscles (EOMs) of almost every mammalian species, including primates. These nerve specializations surrounding the muscle fiber insertion have been postulated to be the proprioceptors of the EOMs. However, it was recently demonstrated that palisade endings have a cholinergic nature, which reopened the question of whether palisade endings are motor or sensory structures. In this work, we examined whether the cell bodies of palisade endings lie in EOM motor nuclei by injecting an anterograde tracer, biotinylated dextran amine, into the abducens nucleus of a macaque monkey. Tracer visualization in the lateral rectus muscle was combined with choline acetyltransferase (ChAT) and α-bungarotoxin staining. Analysis of the samples was performed by conventional light microscopy and confocal laser scanning microscopy. About 30% of the nerve fibers innervating the muscle were tracer positive. These were ChAT positive as well. Tracer positive nerve fibers established motor contacts on singly and multiply innervated muscle fibers, which were confirmed by α-bungarotoxin staining. At the transition between muscle and distal tendon, we found palisade endings that contained tracer. Palisade endings exhibited the classic morphology: axons arising from the muscle extend onto the tendon, then turn back 180° and terminate in a cuff of terminals around an individual muscle fiber tip. This finding suggests that the cell bodies of palisade endings lie in the EOM motor nuclei, which complements prior studies demonstrating a cholinergic, and possibly motor, phenotype for palisade endings. PMID:21138754

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)

Immunohistochemical Mapping of Sensory Nerve Endings in the Human Triangular Fibrocartilage Complex.

PubMed

Rein, Susanne; Semisch, Manuel; Garcia-Elias, Marc; Lluch, Alex; Zwipp, Hans; Hagert, Elisabet

2015-10-01

The triangular fibrocartilage complex is the main stabilizer of the distal radioulnar joint. While static joint stability is constituted by osseous and ligamentous integrity, the dynamic aspects of joint stability chiefly concern proprioceptive control of the compressive and directional muscular forces acting on the joint. Therefore, an investigation of the pattern and types of sensory nerve endings gives more insight in dynamic distal radioulnar joint stability. We aimed to (1) analyze the general distribution of sensory nerve endings and blood vessels; (2) examine interstructural distribution of sensory nerve endings and blood vessels; (3) compare the number and types of mechanoreceptors in each part; and (4) analyze intrastructural distribution of nerve endings at different tissue depth. The subsheath of the extensor carpi ulnaris tendon sheath, the ulnocarpal meniscoid, the articular disc, the dorsal and volar radioulnar ligaments, and the ulnolunate and ulnotriquetral ligaments were dissected from 11 human cadaver wrists. Sensory nerve endings were counted in five levels per specimen as total cell amount/cm(2) after staining with low-affinity neurotrophin receptor p75, protein gene product 9.5, and S-100 protein and thereafter classified according to Freeman and Wyke. All types of sensory corpuscles were found in the various structures of the triangular fibrocartilage complex with the exception of the ulnolunate ligament, which contained only Golgi-like endings, free nerve endings, and unclassifiable corpuscles. The articular disc had only free nerve endings. Furthermore, free nerve endings were the predominant sensory nerve ending (median, 72.6/cm(2); range, 0-469.4/cm(2)) and more prevalent than all other types of mechanoreceptors: Ruffini (median, 0; range, 0-5.6/cm(2); difference of medians, 72.6; p < 0.001), Pacini (median, 0; range, 0-3.8/cm(2); difference of medians, 72.6; p < 0.001), Golgi-like (median, 0; range, 0-2.1/cm(2); difference of medians, 72.6; p < 0.001), and unclassifiable corpuscles (median, 0; range, 0-2.5/cm(2); difference of medians, 72.6; p < 0.001). The articular disc contained fewer free nerve endings (median, 1.8; range, 0-17.8/cm(2)) and fewer blood vessels (median, 29.8; range, 0-112.2/cm(2); difference of medians: 255.9) than all other structures of the triangular fibrocartilage complex (p ≤ 0.001, respectively) except the ulnolunate ligament. More blood vessels were seen in the volar radioulnar ligament (median, 363.62; range, 117.8-871.8/cm(2)) compared with the ulnolunate ligament (median, 107.7; range, 15.9-410.3/cm(2); difference of medians: 255.91; p = 0.002) and the dorsal radioulnar ligament (median, 116.2; range, 53.9-185.1/cm(2); difference of medians: 247.47; p = 0.001). Free nerve endings were obtained in each structure more often than all other types of sensory nerve endings (p < 0.001, respectively). The intrastructural analysis revealed no differences in mechanoreceptor distribution in all investigated specimens with the numbers available, showing a homogenous distribution of proprioceptive qualities in all seven parts of the triangular fibrocartilage complex. Nociception has a primary proprioceptive role in the neuromuscular stability of the distal radioulnar joint. The articular disc and ulnolunate ligament rarely are innervated, which implies mainly mechanical functions, whereas all other structures have pronounced proprioceptive qualities, prerequisite for dynamic joint stability. Lesions of the volar and dorsal radioulnar ligaments have immense consequences not only for mechanical but also for dynamic stability of the distal radioulnar joint, and surgical reconstruction in instances of radioulnar ligament injury is important.

Muscle Activation During Peripheral Nerve Field Stimulation Occurs Due to Recruitment of Efferent Nerve Fibers, Not Direct Muscle Activation.

PubMed

Frahm, Ken Steffen; Hennings, Kristian; Vera-Portocarrero, Louis; Wacnik, Paul W; Mørch, Carsten Dahl

2016-08-01

Peripheral nerve field stimulation (PNFS) is a potential treatment for chronic low-back pain. Pain relief using PNFS is dependent on activation of non-nociceptive Aβ-fibers. However, PNFS may also activate muscles, causing twitches and discomfort. In this study, we developed a mathematical model, to investigate the activation of sensory and motor nerves, as well as direct muscle fiber activation. The extracellular field was estimated using a finite element model based on the geometry of CT scanned lumbar vertebrae. The electrode was modeled as being implanted to a depth of 10-15 mm. Three implant directions were modeled; horizontally, vertically, and diagonally. Both single electrode and "between-lead" stimulation between contralateral electrodes were modeled. The extracellular field was combined with models of sensory Aβ-nerves, motor neurons and muscle fibers to estimate their activation thresholds. The model showed that sensory Aβ fibers could be activated with thresholds down to 0.563 V, and the lowest threshold for motor nerve activation was 7.19 V using between-lead stimulation with the cathode located closest to the nerves. All thresholds for direct muscle activation were above 500 V. The results suggest that direct muscle activation does not occur during PNFS, and concomitant motor and sensory nerve fiber activation are only likely to occur when using between-lead configuration. Thus, it may be relevant to investigate the location of the innervation zone of the low-back muscles prior to electrode implantation to avoid muscle activation. © 2016 International Neuromodulation Society.

An ultrastructural study of calcitonin gene-related peptide-immunoreactive nerve fibers innervating the rat posterior longitudinal ligament. A morphologic basis for their possible efferent actions.

PubMed

Imai, S; Konttinen, Y T; Tokunaga, Y; Maeda, T; Hukuda, S; Santavirta, S

1997-09-01

The present study investigated ultrastructural characteristics of calcitonin gene-related peptide-immunoreactive nerve fibers in the posterior longitudinal ligament of the rat lumbar spine. To provide a morphologic basis for assessment of the afferent and, in particular, efferent functions of calcitonin gene-related peptide immunoreactive nerves in the posterior longitudinal ligament and their eventual role in degenerative spondylarthropathies and low back pain. Previous studies using light-microscopic localization of sensory neuronal markers such as calcitonin gene-related peptide have reported the presence of sensory fibers in the supporting structures of the vertebral column. Meanwhile, accumulating research data have suggested efferent properties for calcitonin gene-related peptide, i.e., a trophic action that alters the intrinsic properties of target cells not through transient action of synaptic transmission, but through long-lasting signal transmission by the secreted neuropeptides. To verify such trophic, paracrine actions of the calcitonin gene-related peptide-containing fibers in the posterior longitudinal ligament, however, ultrastructural details of the terminals and their spatial relationship to their eventual target structures have to be elucidated. Rat posterior longitudinal ligaments were stained immunohistochemically for calcitonin gene-related peptide. Light-microscopic analysis of the semithin sections facilitated subsequent electron microscopy of specific sites of the posterior longitudinal ligament to determine ultrastructural details and nerve fiber-target relationships. The rat lumbar posterior longitudinal ligament was found to be innervated by two distinctive calcitonin gene-related peptide immunoreactive nerve networks. In immunoelectronmicroscopy, the fibers of the deep network had numerous free nerve endings, whereas those of the superficial network showed spatial associations with other non-calcitonin gene-related peptide immunoreactive components of the network. In both systems, naked axons not covered by the Schwann cells made close spatial contact with smooth muscle cells: of blood vessels and resident posterior longitudinal ligament fibroblasts. The ultrastructural characteristics of the innervation of the rat posterior longitudinal ligament would be compatible not only with a nociceptive function, but also with neuromodulatory, vasoregulatory, and trophic functions, as has already been established in some visceral organs.

A historical perspective on the role of sensory nerves in neurogenic inflammation.

PubMed

Sousa-Valente, João; Brain, Susan D

2018-05-01

The term 'neurogenic inflammation' is commonly used, especially with respect to the role of sensory nerves within inflammatory disease. However, despite over a century of research, we remain unclear about the role of these nerves in the vascular biology of inflammation, as compared with their interacting role in pain processing and of their potential for therapeutic manipulation. This chapter attempts to discuss the progress in understanding, from the initial discovery of sensory nerves until the present day. This covers pioneering findings that these nerves exist, are involved in vascular events and act as important sensors of environmental changes, including injury and infection. This is followed by discovery of the contents they release such as the established vasoactive neuropeptides substance P and CGRP as well as anti-inflammatory peptides such as the opioids and somatostatin. The more recent emergence of the importance of the transient receptor potential (TRP) channels has revealed some of the mechanisms by which these nerves sense environmental stimuli. This knowledge enables a platform from which to learn of the potential role of neurogenic inflammation in disease and in turn of novel therapeutic targets.

Ulnar nerve entrapment in Guyon's canal due to a lipoma.

PubMed

Ozdemir, O; Calisaneller, T; Gerilmez, A; Gulsen, S; Altinors, N

2010-09-01

Guyon's canal syndrome is an ulnar nerve entrapment at the wrist or palm that can cause motor, sensory or combined motor and sensory loss due to various factors . In this report, we presented a 66-year-old man admitted to our clinic with a history of intermittent pain in the left palm and numbness in 4th and 5th finger for two years. His neurological examination revealed a sensory impairment in the right fifth finger. Also, physical examination displayed a subcutaneous mobile soft tissue in ulnar side of the wrist. Electromyographic examination confirmed the diagnosis of type-1 Guyon's canal syndrome. Under axillary blockage, a lipoma compressing the ulnar nerve was excised totally and ulnar nerve was decompressed. The symptoms were improved after the surgery and patient was symptom free on 3rd postoperative week.

Comparison of four different nerve conduction techniques of the superficial fibular sensory nerve.

PubMed

Saffarian, Mathew R; Condie, Nathan C; Austin, Erica A; Mccausland, Katie E; Andary, Michael T; Sylvain, James R; Mull, Iian R; Zemper, Eric D; Jannausch, Mary L

2017-09-01

There are many different nerve conduction study (NCS) techniques to study the superficial fibular sensory nerve (SFSN). We present reference distal latency values and comparative data regarding 4 different NCS for the SFSN. Four different NCS techniques, Spartan technique, Izzo techniques (medial and intermediate dorsal cutaneous branches), and Daube technique, were performed on (114) healthy volunteers. A total of 108 subjects with 164 legs were included. The mean latency of the Spartan technique was longest (3.9 ± 0.3 ms) while the Daube technique was the shortest (3.6 ± 0.7 ms). The mean amplitude of the Daube technique displayed the highest (15.2 ± 8.2 μV) with the Spartan technique having the lowest (8.7 ± 4.2 μV). Among the absent sensory nerve action potentials (SNAPs), the Spartan technique was absent only twice (1.2%) and the Izzo Medial technique was absent more than the other techniques (2.9%). All 4 techniques were reliable methods for obtaining the superficial fibular nerve SNAP, present in 95% of individuals. Muscle Nerve 56: 458-462, 2017. © 2017 Wiley Periodicals, Inc.

The thoracic muscular system and its innervation in third instar Calliphora vicina Larvae. II. Projection patterns of the nerves associated with the pro- and mesothorax and the pharyngeal complex.

PubMed

Schoofs, Andreas; Hanslik, Ulrike; Niederegger, Senta; Heinzel, Hans-Georg; Spiess, Roland

2010-08-01

We describe the anatomy of the nerves that project from the central nervous system (CNS) to the pro- and mesothoracic segments and the cephalopharyngeal skeleton (CPS) for third instar Calliphora larvae. Due to the complex branching pattern we introduce a nomenclature that labels side branches of first and second order. Two fine nerves that were not yet described are briefly introduced. One paired nerve projects to the ventral arms (VAs) of the CPS. The second, an unpaired nerve, projects to the ventral surface of the cibarial part of the esophagus (ES). Both nerves were tentatively labeled after the structures they innervate. The antennal nerve (AN) innervates the olfactory dorsal organ (DO). It contains motor pathways that project through the frontal connectives (FC) to the frontal nerve (FN) and innervate the cibarial dilator muscles (CDM) which mediate food ingestion. The maxillary nerve (MN) innervates the sensory terminal organ (TO), ventral organ (VO), and labial organ (LO) and comprises the motor pathways to the mouth hook (MH) elevator, MH depressor, and the labial retractor (LR) which opens the mouth cavity. An anastomosis of unknown function exists between the AN and MN. The prothoracic accessory nerve (PaN) innervates a dorsal protractor muscle of the CPS and sends side branches to the aorta and the bolwig organ (BO) (stemmata). In its further course, this nerve merges with the prothoracic nerve (PN). The architecture of the PN is extremely complex. It innervates a set of accessory pharyngeal muscles attached to the CPS and the body wall musculature of the prothorax. Several anastomoses exist between side branches of this nerve which were shown to contain motor pathways. The mesothoracic nerve (MeN) innervates a MH accessor and the longitudinal and transversal body wall muscles of the second segment. J. Morphol. 271:969-979, 2010. (c) 2010 Wiley-Liss, Inc.

Distribution, Innervation, and Cellular Organization of Taste Buds in the Sea Catfish, Plotosus japonicus.

PubMed

Nakamura, Tatsufumi; Matsuyama, Naoki; Kirino, Masato; Kasai, Masanori; Kiyohara, Sadao; Ikenaga, Takanori

2017-01-01

The gustatory system of the sea catfish Plotosus japonicus, like that of other catfishes, is highly developed. To clarify the details of the morphology of the peripheral gustatory system of Plotosus, we used whole-mount immunohistochemistry to investigate the distribution and innervation of the taste buds within multiple organs including the barbels, oropharyngeal cavity, fins (pectoral, dorsal, and caudal), and trunk. Labeled taste buds could be observed in all the organs examined. The density of the taste buds was higher along the leading edges of the barbels and fins; this likely increases the chance of detecting food. In all the fins, the taste buds were distributed in linear arrays parallel to the fin rays. Labeling of nerve fibers by anti-acetylated tubulin antibody showed that the taste buds within each sensory field are innervated in different ways. In the barbels, large nerve bundles run along the length of the organ, with fascicles branching off to innervate polygonally organized groups of taste buds. In the fins, nerve bundles run along the axis of fin rays to innervate taste buds lying in a line. In each case, small fascicles of fibers branch from large bundles and terminate within the basal portions of the taste buds. Serotonin immunohistochemistry demonstrated that most of the taste buds in all the organs examined contained disk-shaped serotonin-immunopositive cells in their basal region. This indicates a similar organization of the taste buds, in terms of the existence of serotonin-immunopositive basal cells, across the different sensory fields in this species. © 2017 S. Karger AG, Basel.

Ubiquitin–Synaptobrevin Fusion Protein Causes Degeneration of Presynaptic Motor Terminals in Mice

PubMed Central

Liu, Yun; Li, Hongqiao; Sugiura, Yoshie; Han, Weiping; Gallardo, Gilbert; Khvotchev, Mikhail; Zhang, Yinan; Kavalali, Ege T.; Südhof, Thomas C.

2015-01-01

Protein aggregates containing ubiquitin (Ub) are commonly observed in neurodegenerative disorders, implicating the involvement of the ubiquitin proteasome system (UPS) in their pathogenesis. Here, we aimed to generate a mouse model for monitoring UPS function using a green fluorescent protein (GFP)-based substrate that carries a “noncleavable” N-terminal ubiquitin moiety (UbG76V). We engineered transgenic mice expressing a fusion protein, consisting of the following: (1) UbG76V, GFP, and a synaptic vesicle protein synaptobrevin-2 (UbG76V-GFP-Syb2); (2) GFP-Syb2; or (3) UbG76V-GFP-Syntaxin1, all under the control of a neuron-specific Thy-1 promoter. As expected, UbG76V-GFP-Syb2, GFP-Syb2, and UbG76V-GFP-Sytaxin1 were highly expressed in neurons, such as motoneurons and motor nerve terminals of the neuromuscular junction (NMJ). Surprisingly, UbG76V-GFP-Syb2 mice developed progressive adult-onset degeneration of motor nerve terminals, whereas GFP-Syb2 and UbG76V-GFP-Syntaxin1 mice were normal. The degeneration of nerve terminals in UbG76V-GFP-Syb2 mice was preceded by a progressive impairment of synaptic transmission at the NMJs. Biochemical analyses demonstrated that UbG76V-GFP-Syb2 interacted with SNAP-25 and Syntaxin1, the SNARE partners of synaptobrevin. Ultrastructural analyses revealed a marked reduction in synaptic vesicle density, accompanying an accumulation of tubulovesicular structures at presynaptic nerve terminals. These morphological defects were largely restricted to motor nerve terminals, as the ultrastructure of motoneuron somata appeared to be normal at the stages when synaptic nerve terminals degenerated. Furthermore, synaptic vesicle endocytosis and membrane trafficking were impaired in UbG76V-GFP-Syb2 mice. These findings indicate that UbG76V-GFP-Syb2 may compete with endogenous synaptobrevin, acting as a gain-of-function mutation that impedes SNARE function, resulting in the depletion of synaptic vesicles and degeneration of the nerve terminals. SIGNIFICANCE STATEMENT Degeneration of motor nerve terminals occurs in amyotrophic lateral sclerosis (ALS) patients as well as in mouse models of ALS, leading to progressive paralysis. What causes a motor nerve terminal to degenerate remains unknown. Here we report on transgenic mice expressing a ubiquitinated synaptic vesicle protein (UbG76V-GFP-Syb2) that develop progressive degeneration of motor nerve terminals. These mice may serve as a model for further elucidating the underlying cellular and molecular mechanisms of presynaptic nerve terminal degeneration. PMID:26290230

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

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. 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. 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. 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. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Diagnostic utility of F waves in clinically diagnosed patients of carpal tunnel syndrome.

PubMed

Joshi, Anand G; Gargate, Ashwini R

2013-01-01

Sensory nerve conduction velocity (SNCV) of median nerve measured across the carpal tunnel, difference between distal sensory latencies (DSLs) of median and ulnar nerves and difference between distal motor latencies (DMLs) of median and ulnar nerves are commonly used nerve conduction parameters for diagnosis of carpal tunnel syndrome (CTS). These are having high degree of sensitivity and specificity. Study of median nerve F-wave minimal latency (FWML) and difference between F-wave minimal latencies (FWMLs) of median and ulnar nerves have also been reported to be useful parameters for diagnosis of CTS. However, there is controversy regarding superiority of F-wave study for diagnosis of CTS. So the aim of present study was to compare sensitivity and specificity of median FWML and difference between FWMLs of median and ulnar nerves with that of above mentioned electrophysiological parameters and to find out which parameters are having more sensitivity and specificity, for early diagnosis of CTS. Median and ulnar nerves sensory and motor conduction, median and ulnar nerves F-wave studies were carried out bilaterally in 125 clinically diagnosed patients of carpal tunnel syndrome. These parameters were also studied in 45 age matched controls. Difference between DSLs of median and ulnar nerves, median SNCV and difference between DMLs of median and ulnar nerves were having highest sensitivity and specificity while median FWML and difference between FWMLs of median and ulnar nerves was having lowest sensitivity and specificity for diagnosis of CTS. So in conclusion F-wave study is not superior parameter for diagnosis of CTS.

Neural control of renal function.

PubMed

Johns, Edward J; Kopp, Ulla C; DiBona, Gerald F

2011-04-01

The kidney is innervated with efferent sympathetic nerve fibers that directly contact the vasculature, the renal tubules, and the juxtaglomerular granular cells. Via specific adrenoceptors, increased efferent renal sympathetic nerve activity decreases renal blood flow and glomerular filtration rate, increases renal tubular sodium and water reabsorption, and increases renin release. Decreased efferent renal sympathetic nerve activity produces opposite functional responses. This integrated system contributes importantly to homeostatic regulation of sodium and water balance under physiological conditions and to pathological alterations in sodium and water balance in disease. The kidney contains afferent sensory nerve fibers that are located primarily in the renal pelvic wall where they sense stretch. Stretch activation of these afferent sensory nerve fibers elicits an inhibitory renorenal reflex response wherein the contralateral kidney exhibits a compensatory natriuresis and diuresis due to diminished efferent renal sympathetic nerve activity. The renorenal reflex coordinates the excretory function of the two kidneys so as to facilitate homeostatic regulation of sodium and water balance. There is a negative feedback loop in which efferent renal sympathetic nerve activity facilitates increases in afferent renal nerve activity that in turn inhibit efferent renal sympathetic nerve activity so as to avoid excess renal sodium retention. In states of renal disease or injury, there is activation of afferent sensory nerve fibers that are excitatory, leading to increased peripheral sympathetic nerve activity, vasoconstriction, and increased arterial pressure. Proof of principle studies in essential hypertensive patients demonstrate that renal denervation produces sustained decreases in arterial pressure. © 2011 American Physiological Society. Compr Physiol 1:699-729, 2011.

Spatial and Functional Selectivity of Peripheral Nerve Signal Recording With the Transversal Intrafascicular Multichannel Electrode (TIME).

PubMed

Badia, Jordi; Raspopovic, Stanisa; Carpaneto, Jacopo; Micera, Silvestro; Navarro, Xavier

2016-01-01

The selection of suitable peripheral nerve electrodes for biomedical applications implies a trade-off between invasiveness and selectivity. The optimal design should provide the highest selectivity for targeting a large number of nerve fascicles with the least invasiveness and potential damage to the nerve. The transverse intrafascicular multichannel electrode (TIME), transversally inserted in the peripheral nerve, has been shown to be useful for the selective activation of subsets of axons, both at inter- and intra-fascicular levels, in the small sciatic nerve of the rat. In this study we assessed the capabilities of TIME for the selective recording of neural activity, considering the topographical selectivity and the distinction of neural signals corresponding to different sensory types. Topographical recording selectivity was proved by the differential recording of CNAPs from different subsets of nerve fibers, such as those innervating toes 2 and 4 of the hindpaw of the rat. Neural signals elicited by sensory stimuli applied to the rat paw were successfully recorded. Signal processing allowed distinguishing three different types of sensory stimuli such as tactile, proprioceptive and nociceptive ones with high performance. These findings further support the suitability of TIMEs for neuroprosthetic applications, by exploiting the transversal topographical structure of the peripheral nerves.

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

PubMed

Nishikawa, Sumio

2008-09-01

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

Depressed perivascular sensory innervation of mouse mesenteric arteries with advanced age.

PubMed

Boerman, Erika M; Segal, Steven S

2016-04-15

The dilatory role for sensory innervation of mesenteric arteries (MAs) is impaired in Old (∼24 months) versus Young (∼4 months) mice. We investigated the nature of this impairment in isolated pressurized MAs. With perivascular sensory nerve stimulation, dilatation and inhibition of sympathetic vasoconstriction observed in Young MAs were lost in Old MAs along with impaired dilatation to calcitonin gene-related peptide (CGRP). Inhibiting NO and prostaglandin synthesis increased CGRP EC50 in Young and Old MAs. Endothelial denudation attenuated dilatation to CGRP in Old MAs yet enhanced dilatation to CGRP in Young MAs while abolishing all dilatations to ACh. In Old MAs, sensory nerve density was reduced and RAMP1 (CGRP receptor component) associated with nuclear regions of endothelial cells in a manner not seen in Young MAs or in smooth muscle cells of either age. With advanced age, loss of dilatory signalling mediated through perivascular sensory nerves may compromise perfusion of visceral organs. Vascular dysfunction and sympathetic nerve activity increase with advancing age. In the gut, blood flow is governed by perivascular sensory and sympathetic nerves but little is known of how their functional role is affected by advanced age. We tested the hypothesis that functional sensory innervation of mesenteric arteries (MAs) is impaired for Old (24 months) versus Young (4 months) C57BL/6 male mice. In cannulated pressurized MAs preconstricted 50% with noradrenaline and treated with guanethidine (to inhibit sympathetic neurotransmission), perivascular nerve stimulation (PNS) evoked dilatation in Young but not Old MAs while dilatations to ACh were not different between age groups. In Young MAs, capsaicin (to inhibit sensory neurotransmission) blocked dilatation and increased constriction during PNS. With no difference in efficacy, the EC50 of CGRP as a vasodilator was ∼6-fold greater in Old versus Young MAs. Inhibiting nitric oxide (l-NAME) and prostaglandin (indomethacin) synthesis increased CGRP EC50 in both age groups. Endothelial denudation reduced the efficacy of dilatation to CGRP by ∼30% in Old MAs yet increased this efficacy ∼15% in Young MAs while all dilatations to ACh were abolished. Immunolabelling revealed reduced density of sensory (CGRP) but not sympathetic (tyrosine hydroxylase) innervation for Old versus Young MAs. Whereas the distribution of CGRP receptor proteins was similar in SMCs, RAMP1 associated with nuclear regions of endothelial cells of Old but not Young MAs. With advanced age, the loss of sensory nerve function and diminished effectiveness of CGRP as a vasodilator is multifaceted and may adversely affect splanchnic perfusion. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

[Primary genital herpes with sacral meningoradiculitis].

PubMed

Carron, P-N; Anguenot, J-L; Dubuisson, J-B

2004-02-01

Herpetic genital infection is a common sexually transmitted disease, caused in most cases by type 2 Herpes simplex virus (HSV2). This virus is characterized by its neurotropic properties and its ability to establish latency in sacral sensory ganglions. Some cases of genital primo-infection are complicated by viral replication dissemination to neigbhoring nerve structures like meninges and radicular terminations. In such cases muco-cutaneous manifestations are associated with peripheral neurological impairment in the form of meningo-radiculitis. Physicians should be familiar with these neurological symptoms knowing that they always regress completely. The present report illustrates these complications and reviews the potential neurological implications described in the literature.

Activation of vagus nerve by semapimod alters substance P levels and decreases breast cancer metastasis.

PubMed

Erin, Nuray; Duymuş, Ozlem; Oztürk, Saffet; Demir, Necdet

2012-11-10

Chronic inflammation is involved in initiation as well as in progression of cancer. Semapimod, a tetravalent guanylhydrazon and formerly known as CNI-1493, inhibits the release of inflammatory cytokines from activated macrophages and this effect is partly mediated by the vagus nerve. Our previous findings demonstrated that inactivation of vagus nerve activity as well sensory neurons enhanced visceral metastasis of 4THM breast carcinoma. Hence semapimod by activating vagus nerve may inhibit breast cancer metastasis. Here, effects of semapimod on breast cancer metastasis, the role of vagal sensory neurons on this effect and changes in mediators of the neuroimmune connection, such as substance P (SP) as well as neprilysin-like activity, were examined. Vagotomy was performed on half of the control animals that were treated with semapimod following orthotopic injection of 4THM breast carcinoma cells. Semapimod decreased lung and liver metastases in control but not in vagotomized animals with an associated increased SP levels in sensory nerve endings. Semapimod also increased neprilysin-like activity in lung tissue of control animals but not in tumor-bearing animals. This is the first report demonstrating that semapimod enhances vagal sensory nerve activity and may have anti-tumoral effects under in-vivo conditions. Further studies, however, are required to elucidate the conditions and the mechanisms involved in anti-tumoral effects of semapimod. Copyright © 2012 Elsevier B.V. All rights reserved.

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

PubMed Central

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

2016-01-01

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

Miconazole enhances nerve regeneration and functional recovery after sciatic nerve crush injury.

PubMed

Lin, Tao; Qiu, Shuai; Yan, Liwei; Zhu, Shuang; Zheng, Canbin; Zhu, Qingtang; Liu, Xiaolin

2018-05-01

Improving axonal outgrowth and remyelination is crucial for peripheral nerve regeneration. Miconazole appears to enhance remyelination in the central nervous system. In this study we assess the effect of miconazole on axonal regeneration using a sciatic nerve crush injury model in rats. Fifty Sprague-Dawley rats were divided into control and miconazole groups. Nerve regeneration and myelination were determined using histological and electrophysiological assessment. Evaluation of sensory and motor recovery was performed using the pinprick assay and sciatic functional index. The Cell Counting Kit-8 assay and Western blotting were used to assess the proliferation and neurotrophic expression of RSC 96 Schwann cells. Miconazole promoted axonal regrowth, increased myelinated nerve fibers, improved sensory recovery and walking behavior, enhanced stimulated amplitude and nerve conduction velocity, and elevated proliferation and neurotrophic expression of RSC 96 Schwann cells. Miconazole was beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Muscle Nerve 57: 821-828, 2018. © 2017 Wiley Periodicals, Inc.

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

PubMed Central

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

2013-01-01

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

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

A prospective, randomized comparison between single- and multiple-injection techniques for ultrasound-guided subgluteal sciatic nerve block.

PubMed

Yamamoto, Hiroto; Sakura, Shinichi; Wada, Minori; Shido, Akemi

2014-12-01

It is believed that local anesthetic injected to obtain circumferential spread around nerves produces a more rapid onset and successful blockade after some ultrasound-guided peripheral nerve blocks. However, evidence demonstrating this point is limited only to the popliteal sciatic nerve block, which is relatively easy to perform by via a high-frequency linear transducer. In the present study, we tested the hypothesis that multiple injections of local anesthetic to make circumferential spread would improve the rate of sensory and motor blocks compared with a single-injection technique for ultrasound-guided subgluteal sciatic nerve block, which is considered a relatively difficult block conducted with a low-frequency, curved-array transducer. Ninety patients undergoing knee surgery were divided randomly into 2 groups to receive the ultrasound-guided subgluteal approach to sciatic nerve block with 20 mL of 1.5% mepivacaine with epinephrine. For group M (the multiple-injection technique), the local anesthetic was injected to create circumferential spread around the sciatic nerve without limitation on the number of needle passes. For group S (the single-injection technique), the number of needle passes was limited to 1, and the local anesthetic was injected to create spread along the dorsal surface of the sciatic nerve, during which no adjustment of the needle tip was made. Sensory and motor blockade were assessed in double-blind fashion for 30 minutes after completion of the block. The primary outcome was sensory blockade of all sciatic components tested, including tibial, superficial peroneal, and sural nerves at 30 minutes after injection. Data from 86 patients (43 in each group) were analyzed. Block execution took more time for group M than group S. The proportion of patients with complete sensory blockade of all sciatic components at 30 minutes after injection was significantly larger for group M than group S (41.9% vs 16.3%, P = 0.018). Complete motor blockade of foot and toes extension also was observed more frequently in group M than in group S (67.4% vs 34.9%, P = 0.005 and 51.2% vs 25.6%, P = 0.027, respectively). When ultrasound-guided subgluteal sciatic nerve block is conducted, multiple injections of local anesthetic to make a circumferential spread around the sciatic nerve improve the rate of sensory and motor blocks compared with a single injection.

Central projections of the lateral line and eighth nerves in the bowfin, Amia calva.

PubMed

McCormick, C A

1981-03-20

The first-order connections of the anterior and posterior lateral line nerves and of the eighth nerve were determined in the bowfin, Amia calva, using experimental degeneration and anterograde HRP transport techniques. The termination sites of these nerves define a dorsal lateralis cell column and a ventral octavus cell column. The anterior and posterior lateralis nerves distribute ipsilaterally to two medullary nuclei-nucleus medialis and nucleus caudalis. Nucleus medialis comprises the rostral two-thirds of the lateralis column and contains large, Purkinje-like cells dorsally and polygonal, granule, and fusiform cells ventrally. Nucleus caudalis is located posterior to nucleus medialis and consists of small, granule cells. Anterior lateralis fibers terminate ventrally to ventromedially in both nucleus medialis and nucleus caudalis. Posterior lateralis fibers terminate dorsally to dorsolaterally within these two nuclei. A sparse anterior lateralis input may also be present on the dendrites of one of the nuclei within the octavus cell column, nucleus magnocellularis. In contrast, the anterior and posterior rami of the eighth nerve each terminate within four medullary nuclei which comprise the octavus cell column: the anterior, magnocellular, descending, and posterior octavus nuclei. An eighth nerve projection to the medial reticular formation is also present. Some fibers of the lateralis and eighth nerves terminate within the ipsilateral eminentia granularis of the cerebellum. Lateralis fibers distribute to approximately the lateral half of this structure with posterior lateral line fibers terminating laterally and anterior lateral line fibers terminating medially. Eighth nerve fibers distribute to the medial half of the eminentia granularis.

Hereditary motor and sensory neuropathy-russe: new autosomal recessive neuropathy in Balkan Gypsies.

PubMed

Thomas, P K; Kalaydjieva, L; Youl, B; Rogers, T; Angelicheva, D; King, R H; Guergueltcheva, V; Colomer, J; Lupu, C; Corches, A; Popa, G; Merlini, L; Shmarov, A; Muddle, J R; Nourallah, M; Tournev, I

2001-10-01

A novel peripheral neuropathy of autosomal recessive inheritance has been identified in Balkan Gypsies and termed hereditary motor and sensory neuropathy-Russe (HMSN-R). We investigated 21 affected individuals from 10 families. Distal lower limb weakness began between the ages of 8 and 16 years, upper limb involvement beginning between 10 and 43 years, with an average of 22 years. This progressive disorder led to severe weakness of the lower limbs, generalized in the oldest subject (aged 57 years), and marked distal upper limb weakness. Prominent distal sensory loss involved all modalities, resulting in neuropathic joint degeneration in two instances. All patients showed foot deformity, and most showed hand deformity. Motor nerve conduction velocity was moderately reduced in the upper limbs but unobtainable in the legs. Sensory nerve action potentials were absent. There was loss of larger myelinated nerve fibers and profuse regenerative activity in the sural nerve. HMSN-R is a new form of autosomal recessive inherited HMSN caused by a single founder mutation in a 1 Mb interval on chromosome 10q.

Pain. Part 2a: Trigeminal Anatomy Related to Pain.

PubMed

Renton, Tara; Egbuniwe, Obi

2015-04-01

In order to understand the underlying principles of orofacial pain it is important to understand the corresponding anatomy and mechanisms. Paper 1 of this series explains the central nervous and peripheral nervous systems relating to pain. The trigeminal nerve is the 'great protector' of the most important region of our body. It is the largest sensory nerve of the body and over half of the sensory cortex is responsive to any stimulation within this system. This nerve is the main sensory system of the branchial arches and underpins the protection of the brain, sight, smell, airway, hearing and taste, underpinning our very existence. The brain reaction to pain within the trigeminal system has a significant and larger reaction to the threat of, and actual, pain compared with other sensory nerves. We are physiologically wired to run when threatened with pain in the trigeminal region and it is a 'miracle' that patients volunteer to sit in a dental chair and undergo dental treatment. Clinical Relevance: This paper aims to provide the dental and medical teams with a review of the trigeminal anatomy of pain and the principles of pain assessment.

[Features of peripheral nerve injuries in workers exposed to vibration: an analysis of 197 cases].

PubMed

Situ, J; Lin, C M; Qin, Z H; Zhu, D X; Lin, H; Zhang, F F; Zhang, J J

2016-12-20

Objective: To investigate the features of peripheral nerve injuries in workers exposed to vibration. Methods: A total of 197 male workers [median age: 34 years (21 - 50 years) ; median working years of vibration exposure: 7.3 years (1 - 20 years) ] engaged in grinding in an enterprise were enrolled. Their clinical data and electromyography results were analyzed to investigate the features of peripheral nerve impairment. Results: Of all workers, 96 (48.73%) had abnormal electromyography results. Of all workers, 88 (44.7%) had simple mild median nerve injury in the wrist, who accounted for 91.7% (88/96) of all workers with abnormal electromy-ography results. Six workers had ulnar nerve injury, superficial radial nerve injury, or/and superficial peroneal nerve injury and accounted for 6.3% of all workers with abnormal electromyography results. Of all workers, 88 had a reduced amplitude of median nerve sensory transduction, and 28 had slowed median nerve sensory transduction. A total of 46 workers were diagnosed with occupational hand-arm vibration disease and hospitalized for treatment. They were followed up for more than 4 months after leaving their jobs, and most of them showed improvements in neural electromyography results and returned to a normal state. Conclusion: Workers exposed to vibration have a high incidence rate of nerve injury in the hand, mainly sensory function impairment at the distal end of the median nerve, and all injuries are mild peripheral nerve injuries. After leaving the vibration job and being treated, most workers can achieve improvements and return to a normal state.

Recognizing schwannomatosis and distinguishing it from neurofibromatosis type 1 or 2.

PubMed

Westhout, Franklin D; Mathews, Marlon; Paré, Laura S; Armstrong, William B; Tully, Patricia; Linskey, Mark E

2007-06-01

Schwannomatosis has become a newly recognized classification of neurofibromatosis. Although the genetic loci are on chromosome 22, it lacks the classic bilateral vestibular schwannomas as seen in NF-2. We present the surgical treatment of 4 patients with schwannomatosis, including a brother and sister. Case 1 presented with multiple progressively enlarging peripheral nerve sheath tumors. Case 4 presented with a trigeminal schwannoma and a vagal nerve schwannoma. Three of 4 patients had spinal intradural, extramedullary nerve sheath tumors. Surgery in all was multistaged and consisted of spinal laminectomies, site-specific explorations, and microsurgical tumor dissection and resection, with intraoperative neurophysiologic monitoring (including somatosensory-evoked and motor-evoked potentials, upper extremity electromyography and intraoperative nerve action potential monitoring, as appropriate). Intraoperatively the schwannomas had cystic and solid features and in all surgical cases the tumors arose from discrete fascicles of sensory nerve roots or sensory peripheral nerve branches. None of the patients experienced neurologic worsening as a result of their resections. Pathologic analysis of specimens from all cases demonstrated schwannoma. Not all patients with multiple schwannomas of cranial nerve, spinal nerve root, or peripheral nerve origin have NF-1 or NF-2. In schwannomatosis, these lesions are present in the absence of cutaneous stigmata, neurofibromas, vestibular schwannomas, or parenchymal brain tumors. Schwannomas in schwannomatosis can be large, cystic, and multiple. However, the predominant nerve involvement seems to be sensory and discrete fascicular in origin, facilitating microsurgical resection with minimal deficit.

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.

[Treatment of painful neuromas via end-to-side neurorraphy].

PubMed

Aszmann, O C; Moser, V; Frey, M

2010-08-01

Management of the painful neuroma has been subject to controversy since the earliest descriptions of this disabling problem. Today, treatment is limited to resection of the neuroma and implantation of the nerve in a muscle at a location where it is safe from irritation and trauma. This however is not attainable in many cases and it is our clinical experience, that nerves without a target remain a source of constant discomfort and pain. Recently we reported of the feasibility of neuroma prevention through end-to-side neurorraphy into adjacent sensory and/or motor nerves to provide a target for axons deprived of their endorgan. Here we report of our first clinical experience with this method in sixteen patients with longstanding upper and lower extremity neuromas. 16 patients were included in this study. All had neuromas of different sensory nerves of both the upper and lower extremity. 11 were of iatrogenic origin, 5 were caused by different traumas. 8 had previous attempts to surgically treat the neuroma. Finally, all were treated by end-to-side neurorraphy into adjacent nerves. Postoperatively quantitative sensorymotor testing was performed to evaluate possible changes of nerve function of the recipient nerves. Pain was evaluated by visual analogue score and changes in pain medication. In no patient a sensory or motor deficit or painful sensations were induced in the target area of the recipient nerve. Some had dysaesthesias for about 6 months, which finally subsided. All but 1 patient improved in their symptoms at a follow-up of more than 2 years. Previous experimental work and present clinical results suggest that axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented without inducing sensory or motor dysfunctions in the recipient nerve. Georg Thieme Verlag KG Stuttgart New York.

Clinical and electrodiagnostic characteristics of nitrous oxide-induced neuropathy in Taiwan.

PubMed

Li, Han-Tao; Chu, Chun-Che; Chang, Kuo-Hsuan; Liao, Ming-Feng; Chang, Hong-Shiu; Kuo, Hung-Chou; Lyu, Rong-Kuo

2016-10-01

Nitrous oxide-induced neuropathy is toxic neuropathy occasionally encountered in Taiwanese neurological clinics. Only several case reports described their electrodiagnostic features. We used a case-control design to investigate the detailed electrodiagnostic characteristics and possible factors relating to severe nerve injury. We retrospectively reviewed 33 patients with nitrous oxide-induced neuropathy over a 10-year period and reported their demographic data, spinal cord MRI, laboratory examinations and nerve conduction studies. 56 healthy controls' nerve conduction studies were collected for comparison analysis. We noted significant motor and sensory amplitudes reduction, conduction velocities slowing, and latencies prolongation in most tested nerves compared to the controls. Similar nerve conduction study characteristics with prominent lower limbs' motor and sensory amplitudes reduction was observed in patient groups with or without abnormal vitamin B12 and/or homocysteine levels. Among those with lower limbs' motor or sensory amplitudes reduction <20% of the lower limit of normal, higher homocysteine levels were detected. Severe impairments of the lower limbs' sensory and motor amplitudes were frequently noted in patients with nitrous oxide exposure. Nitrous oxide exposure itself is an important factor for the development of neuropathy. Our study contributes to the understanding of electrodiagnostic features underlying the nitrous oxide-induced neuropathy. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Focal release of neurotrophic factors by biodegradable microspheres enhance motor and sensory axonal regeneration in vitro and in vivo.

PubMed

Santos, Daniel; Giudetti, Guido; Micera, Silvestro; Navarro, Xavier; Del Valle, Jaume

2016-04-01

Neurotrophic factors (NTFs) promote nerve regeneration and neuronal survival after peripheral nerve injury. However, drawbacks related with administration and bioactivity during long periods limit their therapeutic application. In this study, PLGA microspheres (MPs) were used to locally release different NTFs and evaluate whether they accelerate axonal regeneration in comparison with free NTFs or controls. ELISA, SEM, UV/visible light microscopy, organotypic cultures of DRG explants and spinal cord slices were used to characterize MP properties and the bioactivity of the released NTFs. Results of organotypic cultures showed that encapsulated NTFs maintain longer bioactivity and enhance neurite regeneration of both sensory and motor neurons compared with free NTFs. For in vivo assays, the rat sciatic nerve was transected and repaired with a silicone tube filled with collagen gel or collagen mixed with PBS encapsulated MPs (control groups) and with free or encapsulated NGF, BDNF, GDNF or FGF-2. After 20 days, a retrotracer was applied to the regenerated nerve to quantify motor and sensory axonal regeneration. NTF encapsulation in MPs improved regeneration of both motor and sensory axons, as evidenced by increased numbers of retrolabeled neurons. Hence, our results show that slow release of NTFs with PLGA MP enhance nerve regeneration. Copyright © 2016 Elsevier B.V. All rights reserved.

The visceromotor and somatic afferent nerves of the penis.

PubMed

Diallo, Djibril; Zaitouna, Mazen; Alsaid, Bayan; Quillard, Jeanine; Ba, Nathalie; Allodji, Rodrigue Sètchéou; Benoit, Gérard; Bedretdinova, Dina; Bessede, Thomas

2015-05-01

Innervation of the penis supports erectile and sensory functions. This article aims to study the efferent autonomic (visceromotor) and afferent somatic (sensory) nervous systems of the penis and to investigate how these systems relate to vascular pathways. Penises obtained from five adult cadavers were studied via computer-assisted anatomic dissection (CAAD). The number of autonomic and somatic nerve fibers was compared using the Kruskal-Wallis test. Proximally, penile innervation was mainly somatic in the extra-albugineal sector and mainly autonomic in the intracavernosal sector. Distally, both sectors were almost exclusively supplied by somatic nerve fibers, except the intrapenile vascular anastomoses that accompanied both somatic and autonomic (nitrergic) fibers. From this point, the neural immunolabeling within perivascular nerve fibers was mixed (somatic labeling and autonomic labeling). Accessory afferent, extra-albugineal pathways supplied the outer layers of the penis. There is a major change in the functional type of innervation between the proximal and distal parts of the intracavernosal sector of the penis. In addition to the pelvis and the hilum of the penis, the intrapenile neurovascular routes are the third level where the efferent autonomic (visceromotor) and the afferent somatic (sensory) penile nerve fibers are close. Intrapenile neurovascular pathways define a proximal penile segment, which guarantees erectile rigidity, and a sensory distal segment. © 2015 International Society for Sexual Medicine.

Innervated boomerang flap for finger pulp reconstruction.

PubMed

Chen, Shao-Liang; Chiou, Tai-Fung

2007-11-01

The boomerang flap originates from the dorsolateral aspect of the proximal phalanx of an adjacent digit and is supplied by the retrograde blood flow through the vascular arcades between the dorsal and palmar digital arteries. To provide sensation of the boomerang flap for finger pulp reconstruction, the dorsal sensory branch of the proper digital nerve and the superficial sensory branch of the corresponding radial or ulnar nerve are included within the skin flap. After transfer of the flap to the injured site, epineural neurorrhaphies are done between the digital nerves of the pulp and the sensory branches of the flap. We used this sensory flap in five patients, with more than 1 year follow-up, and all patients achieved measurable two-points discrimination. The boomerang flap not only preserves the proper palmar digital artery but also provides an extended and innervated skin paddle. It seems to be an alternative choice for one-stage reconstruction of major pulp defect.

Relation between trinucleotide GAA repeat length and sensory neuropathy in Friedreich's ataxia.

PubMed

Santoro, L; De Michele, G; Perretti, A; Crisci, C; Cocozza, S; Cavalcanti, F; Ragno, M; Monticelli, A; Filla, A; Caruso, G

1999-01-01

To verify if GAA expansion size in Friedreich's ataxia could account for the severity of sensory neuropathy. Retrospective study of 56 patients with Friedreich's ataxia selected according to homozygosity for GAA expansion and availability of electrophysiological findings. Orthodromic sensory conduction velocity in the median nerve was available in all patients and that of the tibial nerve in 46 of them. Data of sural nerve biopsy and of a morphometric analysis were available in 12 of the selected patients. The sensory action potential amplitude at the wrist (wSAP) and at the medial malleolus (m mal SAP) and the percentage of myelinated fibres with diameter larger than 7, 9, and 11 microm in the sural nerve were correlated with disease duration and GAA expansion size on the shorter (GAA1) and larger (GAA2) expanded allele in each pair. Pearson's correlation test and stepwise multiple regression were used for statistical analysis. A significant inverse correlation between GAA1 size and wSAP, m mal SAP, and percentage of myelinated fibres was found. Stepwise multiple regression showed that GAA1 size significantly affects electrophysiological and morphometric data, whereas duration of disease has no effect. The data suggest that the severity of the sensory neuropathy is probably genetically determined and that it is not progressive.

Influence of limb temperature on cutaneous silent periods.

PubMed

Kofler, Markus; Valls-Solé, Josep; Vasko, Peter; Boček, Václav; Štetkárová, Ivana

2014-09-01

The cutaneous silent period (CSP) is a spinal inhibitory reflex mediated by small-diameter afferents (A-delta fibers) and large-diameter efferents (alpha motoneurons). The effect of limb temperature on CSPs has so far not been assessed. In 27 healthy volunteers (11 males; age 22-58 years) we recorded median nerve motor and sensory action potentials, median nerve F-wave and CSPs induced by noxious digit II stimulation in thenar muscles in a baseline condition at room temperature, and after randomly submersing the forearm in 42 °C warm or 15 °C cold water for 20 min each. In cold limbs, distal and proximal motor and sensory latencies as well as F-wave latencies were prolonged. Motor and sensory nerve conduction velocities were reduced. Compound motor and sensory nerve action potential amplitudes did not differ significantly from baseline. CSP onset and end latencies were more delayed than distal and proximal median nerve motor and sensory latencies, whereas CSP duration was not affected. In warm limbs, opposite but smaller changes were seen in nerve conduction studies and CSPs. The observed CSP shift "en bloc" towards longer latencies without affecting CSP duration during limb cooling concurs with slower conduction velocity in both afferent and efferent fibers. Disparate conduction slowing in afferents and efferents, however, suggests that nociceptive EMG suppression is mediated by fibers of different size in the afferent than in the efferent arm, indirectly supporting the contribution of A-delta fibers as the main afferent input. Limb temperature should be taken into account when testing CSPs in the clinical setting, as different limb temperatures affect CSP latencies more than large-diameter fiber conduction function. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

N-Acetylcysteine Prevents Retrograde Motor Neuron Death after Neonatal Peripheral Nerve Injury.

PubMed

Catapano, Joseph; Zhang, Jennifer; Scholl, David; Chiang, Cameron; Gordon, Tessa; Borschel, Gregory H

2017-05-01

Neuronal death may be an overlooked and unaddressed component of disability following neonatal nerve injuries, such as obstetric brachial plexus injury. N-acetylcysteine and acetyl-L-carnitine improve survival of neurons after adult nerve injury, but it is unknown whether they improve survival after neonatal injury, when neurons are most susceptible to retrograde neuronal death. The authors' objective was to examine whether N-acetylcysteine or acetyl-L-carnitine treatment improves survival of neonatal motor or sensory neurons in a rat model of neonatal nerve injury. Rat pups received either a sciatic nerve crush or transection injury at postnatal day 3 and were then randomized to receive either intraperitoneal vehicle (5% dextrose), N-acetylcysteine (750 mg/kg), or acetyl-L-carnitine (300 mg/kg) once or twice daily. Four weeks after injury, surviving neurons were retrograde-labeled with 4% Fluoro-Gold. The lumbar spinal cord and L4/L5 dorsal root ganglia were then harvested and sectioned to count surviving motor and sensory neurons. Transection and crush injuries resulted in significant motor and sensory neuron loss, with transection injury resulting in significantly less neuron survival. High-dose N-acetylcysteine (750 mg/kg twice daily) significantly increased motor neuron survival after neonatal sciatic nerve crush and transection injury. Neither N-acetylcysteine nor acetyl-L-carnitine treatment improved sensory neuron survival. Proximal neonatal nerve injuries, such as obstetric brachial plexus injury, produce significant retrograde neuronal death after injury. High-dose N-acetylcysteine significantly increases motor neuron survival, which may improve functional outcomes after obstetrical brachial plexus injury.

Bilateral accessory breast tissue of the vulva: a case report introducing a novel labiaplasty technique.

PubMed

Wagner, I Janelle; Damitz, Lynn A; Carey, Erin; Zolnoun, Denniz

2013-05-01

We present the case of a 23-year-old female with bilateral ectopic breast tissue of the vulva, the repair of which necessitated a novel labiaplasty technique. Labiaplasty is becoming an increasingly frequent cosmetic procedure, and the popularity of brief didactic labiaplasty courses has risen in response to consumer demand. There is a paucity of detailed anatomic description of female sensory innervation patterns to the clitoris and surrounding structures. This places patients at risk for denervation of clitoral structures during labiaplasty procedures. Our novel technique proposes a method of individualized patient neurosensory mapping preoperatively, which allows for surgical planning to avoid injury to the sensory branches of the dorsal clitoral nerve. A 23-year-old female presented with bilateral vulvar masses that involved the clitoral complex, which had first become apparent during the second trimester of pregnancy, and failed to resolve in the postpartum period. We describe the preoperative planning and intraoperative approach and dissection to labiaplasty in this patient, which was complex given the size of the masses, and specifically designed to avoid injury to sensory branches of the dorsal clitoral nerve. As labiaplasty becomes more common, it is important to approach labiaplasty patients with a detailed understanding of the sensory innervation of the clitoris and surrounding structures, to avoid nerve injury and resultant sexual dysfunction. Traditional labiaplasty approaches may violate the sensory innervation patterns of the clitoral region, thus causing a sensory loss that affects patient sexual function. Our novel approach to preoperative clitoral nerve sensory mapping provides an alternative method of labiaplasty that may avoid denervation injury.

Artificial sensory organs: latest progress.

PubMed

Nakamura, Tatsuo; Inada, Yuji; Shigeno, Keiji

2018-03-01

This study introduces the latest progress on the study of artificial sensory organs, with a special emphasis on the clinical results of artificial nerves and the concept of in situ tissue engineering. Peripheral nerves have a strong potential for regeneration. An artificial nerve uses this potential to recover a damaged peripheral nerve. The polyglycolic acid collagen tube (PGA-C tube) is a bio-absorbable tube stuffed with collagen of multi-chamber structure that consists of thin collagen films. The clinical application of the PGA-C tube began in 2002 in Japan. The number of PGA-C tubes used is now beyond 300, and satisfactory results have been reported on peripheral nerve repairs. This PGA-C tube is also effective for patients suffering from neuropathic pain.

Development of the terminal nerve system in the shark Scyliorhinus canicula.

PubMed

Quintana-Urzainqui, Idoia; Anadón, Ramón; Candal, Eva; Rodríguez-Moldes, Isabel

2014-01-01

The nervus terminalis (or terminal nerve) system was discovered in an elasmobranch species more than a century ago. Over the past century, it has also been recognized in other vertebrate groups, from agnathans to mammals. However, its origin, functions or relationship with the olfactory system are still under debate. Despite the abundant literature about the nervus terminalis system in adult elasmobranchs, its development has been overlooked. Studies in other vertebrates have reported newly differentiated neurons of the terminal nerve system migrating from the olfactory epithelium to the telencephalon as part of a 'migratory mass' of cells associated with the olfactory nerve. Whether the same occurs in developing elasmobranchs (adults showing anatomically separated nervus terminalis and olfactory systems) has not yet been determined. In this work we characterized for the first time the development of the terminal nerve and ganglia in an elasmobranch, the lesser spotted dogfish (Scyliorhinus canicula), by means of tract-tracing techniques combined with immunohistochemical markers for the terminal nerve (such as FMRF-amide peptide), for the developing components of the olfactory system (Gα0 protein, GFAP, Pax6), and markers for early postmitotic neurons (HuC/D) and migrating immature neurons (DCX). We discriminated between embryonic olfactory and terminal nerve systems and determined that both components may share a common origin in the migratory mass. We also localized the exact point where they split off near the olfactory nerve-olfactory bulb junction. The study of the development of the terminal nerve system in a basal gnathostome contributes to the knowledge of the ancestral features of this system in vertebrates, shedding light on its evolution and highlighting the importance of elasmobranchs for developmental and evolutionary studies. © 2014 S. Karger AG, Basel.

Receptor units responding to movement in the octopus mantle.

PubMed

Boyle, P R

1976-08-01

1. A preparation of the mantle of Octopus which is inverted over a solid support and which exposes the stellate ganglion and associated nerves is described. 2. Afferent activity can be recorded from stellar nerves following electrical stimulation of the pallial nerve. The latency and frequency of the phasic sensory response is correlated with the contraction of the mantle musculature. 3. It is proposed that receptors cells located in the muscle, and their activity following mantle contraction, form part of a sensory feedback system in the mantle. Large, multipolar nerve cells that were found between the two main layers of circular muscle in the mantle could be such receptors.

Functional evaluation of peripheral nerve regeneration and target reinnervation in animal models: a critical overview.

PubMed

Navarro, Xavier

2016-02-01

Peripheral nerve injuries usually lead to severe loss of motor, sensory and autonomic functions in the patients. Due to the complex requirements for adequate axonal regeneration, functional recovery is often poorly achieved. Experimental models are useful to investigate the mechanisms related to axonal regeneration and tissue reinnervation, and to test new therapeutic strategies to improve functional recovery. Therefore, objective and reliable evaluation methods should be applied for the assessment of regeneration and function restitution after nerve injury in animal models. This review gives an overview of the most useful methods to assess nerve regeneration, target reinnervation and recovery of complex sensory and motor functions, their values and limitations. The selection of methods has to be adequate to the main objective of the research study, either enhancement of axonal regeneration, improving regeneration and reinnervation of target organs by different types of nerve fibres, or increasing recovery of complex sensory and motor functions. It is generally recommended to use more than one functional method for each purpose, and also to perform morphological studies of the injured nerve and the reinnervated targets. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

A new treatment for frostbite sequelae; Botulinum toxin

PubMed Central

Norheim, Arne Johan; Mercer, James; Musial, Frauke; de Weerd, Louis

2017-01-01

ABSTRACT Frostbite sequelae are a relevant occupational injury outcome for soldiers in arctic environments. A Caucasian male soldier suffered frostbite to both hands during a military winter exercise. He developed sensory-motor disturbances and cold hypersensitivity. Angiography and thermography revealed impaired blood flow while Quantitative Sensory Testing indicated impaired somato-sensory nerve function. Two years after the initial event, he received an off label treatment with Botulinum toxin distributed around the neurovascular bundles of each finger. After treatment, cold sensitivity was reduced while blood flow and somato-sensory nerve function improved. The successful treatment enabled the soldier to successfully pursue his career in the army. PMID:28452678

Hereditary sensory and autonomic neuropathy type IID caused by an SCN9A mutation.

PubMed

Yuan, Junhui; Matsuura, Eiji; Higuchi, Yujiro; Hashiguchi, Akihiro; Nakamura, Tomonori; Nozuma, Satoshi; Sakiyama, Yusuke; Yoshimura, Akiko; Izumo, Shuji; Takashima, Hiroshi

2013-04-30

To identify the clinical features of Japanese patients with suspected hereditary sensory and autonomic neuropathy (HSAN) on the basis of genetic diagnoses. On the basis of clinical, in vivo electrophysiologic, and pathologic findings, 9 Japanese patients with sensory and autonomic nervous dysfunctions were selected. Eleven known HSAN disease-causing genes and 5 related genes were screened using a next-generation sequencer. A homozygous mutation, c.3993delGinsTT, was identified in exon 22 of SCN9A from 2 patients/families. The clinical phenotype was characterized by adolescent or congenital onset with loss of pain and temperature sensation, autonomic nervous dysfunctions, hearing loss, and hyposmia. Subsequently, this mutation was discovered in one of patient 1's sisters, who also exhibited sensory and autonomic nervous system dysfunctions, with recurrent fractures being the most predominant feature. Nerve conduction studies revealed definite asymmetric sensory nerve involvement in patient 1. In addition, sural nerve pathologic findings showed loss of large myelinated fibers in patient 1, whereas the younger patient showed normal sural nerve pathology. We identified a novel homozygous mutation in SCN9A from 2 Japanese families with autosomal recessive HSAN. This loss-of-function SCN9A mutation results in disturbances in the sensory, olfactory, and autonomic nervous systems. We propose that SCN9A mutation results in the new entity of HSAN type IID, with additional symptoms including hyposmia, hearing loss, bone dysplasia, and hypogeusia.

Comparative analysis of the effects combined physical procedures and alpha-lipoic acid on the electroneurographic parameters of patients with distal sensorimotor diabetic polyneuropathy

PubMed Central

Grbovic, Vesna; Jurisic-Skevin, Aleksandra; Djukic, Svetlana; Stefanović, Srdjan; Nurkovic, Jasmin

2016-01-01

[Purpose] Painful diabetic polyneuropathy occurs as a complication in 16% of all patients with diabetes mellitus. [Subjects and Methods] A clinical, prospective open-label randomized intervention study was conducted of 60 adult patients, with distal sensorimotor diabetic neuropathy two groups of 30 patients, with diabetes mellitus type 2 with distal sensorimotor diabetic neuropathy. Patients in group A were treated with combined physical procedures, and patients in group B were treated with alpha lipoic acid. [Results] There where a statistically significant improvements in terminal latency and the amplitude of the action potential in group A patients, while group B patients showed a statistically significant improvements in conduction velocity and terminal latency of n. peroneus. Group A patients showed a statistically significant improvements in conduction velocity and terminal latency, while group B patients also showed a statistically significant improvements in conduction velocity and terminal latency. This was reflected in a significant improvements in electrophysiological parameters (conduction velocity, amplitude and latency) of the motor and sensory nerves (n. peroneus, n. suralis). [Conclusion] These results present further evidence justifying of the use of physical agents in the treatment of diabetic sensorimotor polyneuropathy. PMID:27065527

Vibration-induced multifocal neuropathy in forestry workers: electrophysiological findings in relation to vibration exposure and finger circulation.

PubMed

Bovenzi, M; Giannini, F; Rossi, S

2000-11-01

To investigate neural conduction in the upper limbs of symptomatic forestry workers with and without exposure to hand-transmitted vibration. A further aim was to assess the possible relationships between vibration exposure, nerve conduction and finger circulation in the forestry workers who used chain saws. A detailed neurophysiological investigation was performed on the upper extremities of 20 chain saw workers, 20 forestry operators with heavy manual work but without vibration exposure, and 20 healthy male controls. All subjects were screened to exclude polyneuropathy. Measurements of sensory and motor nerve conduction (velocity and amplitude) were obtained bilaterally from the median, ulnar and radial nerves. To assess peripheral vascular function, the forestry workers underwent a cold test with plethysmographic measurement of finger systolic blood pressure (FSBP). In the chain saw operators, vibration exposure was evaluated according to the International Standard ISO 5349. Indices of daily vibration exposure and lifetime cumulative vibration dose were estimated for each chain saw operator. Sensory nerve conduction in several segments of the median and radial nerves was significantly reduced in the chain saw operators compared with that in the workers doing heavy manual work and the controls. The neurophysiological pattern more frequently observed in the chain saw operators was a multifocal nerve conduction impairment to several neural segments with predominant involvement of sensory rather than motor fibres. Sensory nerve conduction velocities in the hands of the chain saw operators were inversely related to both daily and lifetime cumulative vibration exposures. In the vibration-exposed forestry workers, neither were sensori-motor complaints associated with vascular symptoms (finger whiteness) nor were electrophysiological data related to cold-induced changes in FSBP. Exposure to hand-transmitted vibration, in addition to ergonomic stress factors, can contribute to peripheral nerve disorders occurring in forestry workers who operate chain saws. The findings of this study suggest the existence of an exposure-effect relationship for vibration-induced neuropathy. Different underlying mechanisms are likely to be involved in the pathogenesis of the neurological and vascular components of the hand-arm vibration syndrome.

Free flap reconstruction of the sole of the foot with or without sensory nerve coaptation.

PubMed

Santanelli, Fabio; Tenna, Stefania; Pace, Andrea; Scuderi, Nicolò

2002-06-01

The authors present a retrospective study on major plantar foot reconstruction to evaluate the role of the free fasciocutaneous flap and the importance of sensory nerve reconstruction in improving long-term results. Between 1995 and 1999, 20 patients with major defects of the sole of the foot underwent free forearm flap reconstruction performed by the senior author (F.S.). Sensory nerve reconstruction was added to this technique in 1997. The age and sex of the patients and the cause, location, and dimensions of their defects were recorded. The patients were clinically and neurophysiologically evaluated at 3, 6, and 12 months after the procedure for the following parameters: flap contour, flap stability, load capacity, walking ability, touch sensation, pain sensation, static two-point discrimination, and thermal sensibility. Dermatomic somatosensory-evoked potentials were also tested at 12 months. Follow-up ranged from 1 to 5 years. Patients were divided into two groups according to sensory nerve reconstruction. Group A consisted of 11 patients with nerve repair, and group B consisted of nine patients without nerve repair. One patient from group A who had an idiopathic neuropathy was excluded from the study because of interference with the reinnervation process. Five more patients (three from group A and two from group B) were lost at follow-up and excluded from the study. The final sample size in each group was seven. Data from both groups were compared and statistically analyzed with the Mann-Whitney test and the Fisher exact test. Long-term results confirmed in all reconstructions long-lasting stability. During the first postoperative year, patients with sensory nerve reconstruction showed better sensibility. The statistical analyses confirmed significant differences between the two groups to be dependent upon surgical technique at 3 and 6 months. Two-point discrimination and dermatomic somatosensory-evoked potentials were recorded. After 12 months, flaps without surgical nerve repair showed progressive improvement of sensitive thresholds, achieving a good protective sensibility, similar to that of the other group, but these flaps never regained two-point discrimination or dermatomic somatosensory-evoked potentials.

Synaptic potentials in respiratory neurones during evoked phase switching after NMDA receptor blockade in the cat

PubMed Central

Pierrefiche, O; Haji, A; Foutz, A S; Takeda, R; Champagnat, J; Denavit-Saubié, M

1998-01-01

Blockade of NMDA receptors by dizocilpine impairs the inspiratory off-switch (IOS) of central origin but not the IOS evoked by stimulation of sensory afferents. To investigate whether this difference was due to the effects of different patterns of synaptic interactions on respiratory neurones, we stimulated electrically the superior laryngeal nerve (SLN) or vagus nerve in decerebrate cats before and after i.v. administration of dizocilpine, whilst recording intracellularly. Phrenic nerve responses to ipsilateral SLN or vagal stimulation were: at mid-inspiration, a transient inhibition often followed by a brief burst of activity; at late inspiration, an IOS; and at mid-expiration, a late burst of activity. In all neurones (n = 16), SLN stimulation at mid-inspiration evoked an early EPSP during phase 1 (latency to the arrest of phrenic nerve activity), followed by an IPSP in inspiratory (I) neurones (n = 8) and by a wave of EPSPs in post-inspiratory (PI) neurones (n = 8) during phase 2 (inhibition of phrenic activity). An EPSP in I neurones and an IPSP in PI neurones occurred during phase 3 (brief phrenic burst) following phase 2. Evoked IOS was associated with a fast (phase 1) activation of PI neurones, whereas during spontaneous IOS, a progressive (30-50 ms) depolarization of PI neurones preceded the arrest of phrenic activity. Phase 3 PSPs were similar to those occurring during the burst of activity seen at the start of spontaneous inspiration. Dizocilpine did not suppress the evoked phrenic inhibition and the late burst of activity. The shapes and timing of the evoked PSPs and the changes in membrane potential in I and PI neurones during the phase transition were not altered. We hypothesize that afferent sensory pathways not requiring NMDA receptors (1) terminate inspiration through a premature activation of PI neurones, and (2) evoke a late burst of phrenic activity which might be the first stage of the inspiratory on-switch. PMID:9508816

A unified model of the excitability of mouse sensory and motor axons.

PubMed

Makker, Preet G S; Matamala, José Manuel; Park, Susanna B; Lees, Justin G; Kiernan, Matthew C; Burke, David; Moalem-Taylor, Gila; Howells, James

2018-06-19

Non-invasive nerve excitability techniques have provided valuable insight into the understanding of neurological disorders. The widespread use of mice in translational research on peripheral nerve disorders and by pharmaceutical companies during drug development requires valid and reliable models that can be compared to humans. This study established a novel experimental protocol that enables comparative assessment of the excitability properties of motor and sensory axons at the same site in mouse caudal nerve, compared the mouse data to data for motor and sensory axons in human median nerve at the wrist, and constructed a mathematical model of the excitability of mouse axons. In a separate study, ischaemia was employed as an experimental manoeuvre to test the translational utility of this preparation. The patterns of mouse sensory and motor excitability were qualitatively similar to human studies under normal and ischaemic conditions. The most conspicuous differences between mouse and human studies were observed in the recovery cycle and the response to hyperpolarization. Modelling showed that an increase in temperature in mouse axons could account for most of the differences in the recovery cycle. The modelling also suggested a larger hyperpolarization-activated conductance in mouse axons. The kinetics of this conductance appeared to be much slower raising the possibility that an additional or different hyperpolarization-activated cyclic-nucleotide gated (HCN) channel isoform underlies the accommodation to hyperpolarization in mouse axons. Given a possible difference in HCN isoforms, caution should be exercised in extrapolating from studies of mouse motor and sensory axons to human nerve disorders. This article is protected by copyright. All rights reserved.

[Clinical report of hereditary motor and sensory neuropathy with proximal dominance in Shiga prefecture].

PubMed

Takahashi, Mitsuo; Mitsui, Yoshiyuki; Yorifuji, Shiro; Nakamura, Yuusaku; Tsukamoto, Yoshihumi; Nishimoto, Kazuhiro

2007-09-01

We followed eight hereditary motor and sensory neuropathy patients with proximal dominance (HMSN-P) in Shiga prefecture from 1984 to 2007. There were 4 men and 4 women from two families showing autosomal and dominant prepotency. These families were related by marriage. The average onset of disease was at 53.4 +/- 8.9 (40-68) years-old. Initial symptoms were difficulty of standing up, difficulty elevating their arms, limping, or numbness. The main feature was neurogenic muscular atrophy with proximal dominance. All deep tendon reflexes were decreased or nonexistent. Paresthesia in the hands and feet and/or decreased vibratory sense in the legs were found in six patients. High CK blood levels were recognized in three patients. EMG in four patients revealed neurogenic pattern. Nerve conduction study was conducted in two patients. MCV of the median nerve and of the tibial posterior nerve, also SCV of the median nerve and of the sural nerve were within normal range in all nerves. Amplitudes of sensory action potential or of M wave were decreased or nonexistent in five of eight nerves, and distal latency of M waves was delayed in three of four nerves. These data suggests dysfunction of distal parts of the peripheral nerve fibers and axonal degeneration of the nerve trunk. Seven patients have died, and their average death age was 69.1 +/- 8.2 (52-77) years-old. Their average affected period was 16.6 (4-30) years. Their clinical history resembles Okinawa-type HMSN-P, but without the painful muscle cramps which are distinctive Okinawa-type signs.

Breast Reinnervation: DIEP Neurotization Using the Third Anterior Intercostal Nerve

PubMed Central

Menn, Zachary K.; Eldor, Liron; Kaufman, Yoav; Dellon, A. Lee

2013-01-01

Background: The purpose of this article is to evaluate a new method of DIEP flap neurotization using a reliably located recipient nerve. We hypothesize that neurotization by this method (with either nerve conduit or direct nerve coaptation) will have a positive effect on sensory recovery. Methods: Fifty-seven deep inferior epigastric perforator (DIEP) flaps were performed on 35 patients. Neurotizations were performed to the third anterior intercostal nerve by directly coapting the flap donor nerve or coapting with a nerve conduit. Nine nonneurotized DIEP flaps served as controls and received no attempted neurotization. All patients were tested for breast sensibility in 9 areas of the flap skin-island and adjacent postmastectomy skin. Testing occurred at an average of 111 weeks (23–309) postoperatively. Results: At a mean of 111 weeks after breast reconstruction, neurotization of the DIEP flap resulted in recovery of sensibility that was statistically significantly better (lower threshold) in the flap skin (P < 0.01) and statistically significantly better than in the native mastectomy skin into which the DIEP flap was inserted (P < 0.01). Sensibility recovered in DIEP flaps neurotized using the nerve conduit was significantly better (lower threshold) than that in the corresponding areas of the DIEP flaps neurotized by direct coaptation (P < 0.01). Conclusion: DIEP flap neurotization using the third anterior intercostal nerve is an effective technique to provide a significant increase in sensory recovery for breast reconstruction patients, while adding minimal surgical time. Additionally, the use of a nerve conduit produces increased sensory recovery when compared direct coaptation. PMID:25289267

Expression of corticosteroid binding globulin in the rat olfactory system.

PubMed

Dölz, Wilfried; Eitner, Annett; Caldwell, Jack D; Jirikowski, Gustav F

2013-05-01

Glucocorticoids are known to act on the olfactory system although their mode of action is still unclear since nuclear glucocorticoid receptors are mostly absent in the olfactory mucosa. In this study we used immunocytochemistry, in situ hybridization, and RT-PCR to study the expression and distribution of corticosteroid binding globulin (CBG) in the rat olfactory system. Mucosal goblet cells could be immunostained for CBG. Nasal secretion contained measurable amounts of CBG suggesting that CBG is liberated. CBG immunoreactivity was localized in many of the basal cells of the olfactory mucosa, while mature sensory cells contained CBG only in processes as determined by double immunostaining with the olfactory marker protein OMP. This staining was most pronounced in the vomeronasal organ (VNO). The appearance of CBG in the non-sensory and sensory parts of the VNO and in nerve terminals in the accessory bulb indicated axonal transport. Portions of the periglomerular cells, the mitral cells and the tufted cells were also CBG positive. CBG encoding transcripts were confirmed by RT-PCR in homogenates of the olfactory mucosa and VNO. Olfactory CBG may be significant for uptake, accumulation and transport of glucocorticoids, including aerosolic cortisol. Copyright © 2012 Elsevier GmbH. All rights reserved.

Nervous system immunohistochemistry of the parasitic cnidarian Polypodium hydriforme at its free-living stage.

PubMed

Raikova, Ekaterina V; Raikova, Olga I

2016-04-01

Polypodium hydriforme, the only species in Polypodiozoa, which is currently considered a class of Cnidaria, and likely a sister group to Medusozoa (together with Myxozoa), is a cnidarian adapted to intracellular parasitism inside sturgeon oocytes. Free-living P. hydriforme lives on river bottoms; it walks on supporting tentacles and uses sensory tentacles to capture food and bring it to the mouth. The nervous system of free-living P. hydriforme was studied by confocal microscopy and immunohistochemistry using antibodies to FMRF-amide and α-tubulin combined with phalloidin-staining of F-actin fibres. A sensory FMRF-amide immunoreactive (IR) nerve net and an α-tubulin IR nerve net have been identified. The FMRF-amide IR nerve net underlies the epidermis along the tentacles and around the mouth; it consists of neurites emanating from epidermal sensory cells and basiepidermal ganglion cells, and it connects with cnidocytes. A deeper-lying α-tubulin IR nerve net occurs only in tentacles and looks like chains of different-sized beads crossing the mesoglea and entwining muscles. Anti-α-tubulin staining also reveals microtubules in muscle cells following the longitudinal muscle fibres or the thin circular F-actin fibres of the tentacles. Cnidocytes in the tentacles are embedded in a regular hexagonal non-neural network formed by the tubulin IR cytoskeleton of epidermal cells. Cnidocils of the cnidocytes around the mouth and in walking tentacles are identical, but those in sensory tentacles differ in length and width. The possible homology of the tubulin IR nerve net with motor nerve nets of cnidarians is discussed. The absence of a classic nerve ring around the mouth and the lack of specialised sense organs are considered to be plesiomorphic characters for Cnidaria. Copyright © 2015 Elsevier GmbH. All rights reserved.

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

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

Sridharan, Vijayalakshmi; Tripathi, Preeti; Sharma, Sunil

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

Neurogenin 1 Null Mutant Ears Develop Fewer, Morphologically Normal Hair Cells in Smaller Sensory Epithelia Devoid of Innervation

PubMed Central

Ma, Qiufu; Anderson, David J.

2000-01-01

The proneuronal gene neurogenin 1 (ngn1) is essential for development of the inner-ear sensory neurons that are completely absent in ngn1 null mutants. Neither afferent, efferent, nor autonomic nerve fibers were detected in the ears of ngn1 null mutants. We suggest that efferent and autonomic fibers are lost secondarily to the absence of afferents. In this article we show that ngn1 null mutants develop smaller sensory epithelia with morphologically normal hair cells. In particular, the saccule is reduced dramatically and forms only a small recess with few hair cells along a duct connecting the utricle with the cochlea. Hair cells of newborn ngn1 null mutants show no structural abnormalities, suggesting that embryonic development of hair cells is independent of innervation. However, the less regular pattern of dispersal within sensory epithelia may be caused by some effects of afferents or to the stunted growth of the sensory epithelia. Tracing of facial and stato-acoustic nerves in control and ngn1 null mutants showed that only the distal, epibranchial, placode-derived sensory neurons of the geniculate ganglion exist in mutants. Tracing further showed that these geniculate ganglion neurons project exclusively to the solitary tract. In addition to the normal complement of facial branchial and visceral motoneurons, ngn1 null mutants have some trigeminal motoneurons and contralateral inner-ear efferents projecting, at least temporarily, through the facial nerve. These data suggest that some neurons in the brainstem (e.g., inner-ear efferents, trigeminal motoneurons) require afferents to grow along and redirect to ectopic cranial nerve roots in the absence of their corresponding sensory roots. PMID:11545141

Double peak sensory nerve action potentials to single stimuli in nerve conduction studies.

PubMed

Leote, Joao; Pereira, Pedro; Valls-Sole, Josep

2017-05-01

In humans, sensory nerve action potentials (SNAPs) can show 2 separate deflections, i.e., double peak potentials (DPp), which necessarily means that 1 peak is delayed with respect to the other. DPps may have various origins and be due to either physical or physiological properties. We review the nature of commonly encountered DPps in clinical practice, provide the most likely interpretations for their physiological origin, and assess their reproducibility and clinical utility. We classified the DPps into 3 categories: (1) simultaneous anodal and cathodal stimulation. (2) simultaneous recording from 2 different nerves at the same site, and (3) SNAP desynchronization. Although the recording of DPps is not a standardized neurophysiological method, their study brings interesting cues about the physiology of nerve stimulation and paves the way for clinical application of such an observation. Muscle Nerve 55: 619-625, 2017. © 2016 Wiley Periodicals, Inc.

Massive Oculomotor Nerve Enlargement: A Case of Presumed Schwannomatosis.

PubMed

Donaldson, Laura; Rebello, Ryan; Rodriguez, Amadeo

2017-06-01

A 45-year-old man presented with a slowly progressive pupil-involving third nerve palsy. Magnetic resonance imaging (MRI) revealed a tubular lesion extending from the interpeduncular cistern through the cavernous sinus and into the left orbit where it branched into a superior and an inferior division, clearly outlining the anatomy of the third cranial nerve. Multiple other, less pronounced, enlarged cranial nerves were noted. The differential diagnosis included chronic inflammatory demyelinating polyneuropathy (CIDP), hereditary motor and sensory neuropathy (HMSN), neurofibromatosis (NF), and schwannomatosis. The absence of other muscle weakness and of sensory symptoms combined with normal peripheral nerve conduction studies effectively ruled out the hypertrophic polyneuropathies and pointed to a syndromic cause of multiple benign peripheral nerve sheath tumours (PNSTs). The authors are treating this case as presumed schwannomatosis, a syndrome similar to NF2 with much lower frequency of acoustic neuromas.

Massive Oculomotor Nerve Enlargement: A Case of Presumed Schwannomatosis

PubMed Central

Donaldson, Laura; Rebello, Ryan; Rodriguez, Amadeo

2017-01-01

ABSTRACT A 45-year-old man presented with a slowly progressive pupil-involving third nerve palsy. Magnetic resonance imaging (MRI) revealed a tubular lesion extending from the interpeduncular cistern through the cavernous sinus and into the left orbit where it branched into a superior and an inferior division, clearly outlining the anatomy of the third cranial nerve. Multiple other, less pronounced, enlarged cranial nerves were noted. The differential diagnosis included chronic inflammatory demyelinating polyneuropathy (CIDP), hereditary motor and sensory neuropathy (HMSN), neurofibromatosis (NF), and schwannomatosis. The absence of other muscle weakness and of sensory symptoms combined with normal peripheral nerve conduction studies effectively ruled out the hypertrophic polyneuropathies and pointed to a syndromic cause of multiple benign peripheral nerve sheath tumours (PNSTs). The authors are treating this case as presumed schwannomatosis, a syndrome similar to NF2 with much lower frequency of acoustic neuromas. PMID:28512503

Sensory signs in complex regional pain syndrome and peripheral nerve injury.

PubMed

Gierthmühlen, Janne; Maier, Christoph; Baron, Ralf; Tölle, Thomas; Treede, Rolf-Detlef; Birbaumer, Niels; Huge, Volker; Koroschetz, Jana; Krumova, Elena K; Lauchart, Meike; Maihöfner, Christian; Richter, Helmut; Westermann, Andrea

2012-04-01

This study determined patterns of sensory signs in complex regional pain syndrome (CRPS) type I and II and peripheral nerve injury (PNI). Patients with upper-limb CRPS-I (n=298), CRPS-II (n=46), and PNI (n=72) were examined with quantitative sensory testing according to the protocol of the German Research Network on Neuropathic Pain. The majority of patients (66%-69%) exhibited a combination of sensory loss and gain. Patients with CRPS-I had more sensory gain (heat and pressure pain) and less sensory loss than patients with PNI (thermal and mechanical detection, hypoalgesia to heat or pinprick). CRPS-II patients shared features of CRPS-I and PNI. CRPS-I and CRPS-II had almost identical somatosensory profiles, with the exception of a stronger loss of mechanical detection in CRPS-II. In CRPS-I and -II, cold hyperalgesia/allodynia (28%-31%) and dynamic mechanical allodynia (24%-28%) were less frequent than heat or pressure hyperalgesia (36%-44%, 67%-73%), and mechanical hypoesthesia (31%-55%) was more frequent than thermal hypoesthesia (30%-44%). About 82% of PNI patients had at least one type of sensory gain. QST demonstrates more sensory loss in CRPS-I than hitherto considered, suggesting either minimal nerve injury or central inhibition. Sensory profiles suggest that CRPS-I and CRPS-II may represent one disease continuum. However, in contrast to recent suggestions, small fiber deficits were less frequent than large fiber deficits. Sensory gain is highly prevalent in PNI, indicating a better similarity of animal models to human patients than previously thought. These sensory profiles should help prioritize approaches for translation between animal and human research. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Secretion of Growth Hormone in Response to Muscle Sensory Nerve Stimulation

NASA Technical Reports Server (NTRS)

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

1994-01-01

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

Sonography-guided recording for superficial peroneal sensory nerve conduction study.

PubMed

Kim, Ki Hoon; Park, Byung Kyu; Kim, Dong Hwee; Kim, Yuntae

2018-04-01

We sought to establish the optimal recording position for antidromic conduction of the superficial peroneal nerve (SPN) by using ultrasonography (USG). The sensory nerve action potentials (SNAPs) of the intermediate dorsal cutaneous nerve (IDCN) and medial dorsal cutaneous nerve (MDCN) in 64 limbs of 32 healthy participants were recorded (nerve conduction study [NCS]-1). Both nerves were identified by using USG, and the SNAPs were obtained from the USG-guided repositioned electrodes (NCS-2). The IDCN and MDCN were located at 29.3% ± 5.1% and 43.9% ± 4.9% of the intermalleolar distance from the lateral malleolus, respectively. Significantly greater amplitude was shown for SNAPs of both nerves in NCS-2 versus NCS-1. The optimal recording position is likely to be lateral, one-third from the lateral malleolus for the IDCN, and just lateral to the midpoint of the intermalleolar line for the MDCN. When the SPN response is unexpectedly attenuated, USG-guided repositioning of the electrodes should be considered. Muscle Nerve 57: 628-633, 2018. © 2017 Wiley Periodicals, Inc.

Substance P-immunoreactive nerves in endobronchial biopsies in cough-variant asthma and classic asthma.

PubMed

Lee, Sang Yeub; Kim, Min Kyung; Shin, Chol; Shim, Jae Jeong; Kim, Han Kyeom; Kang, Kyung Ho; Yoo, Se Hwa; In, Kwang Ho

2003-01-01

Unlike classic asthma, cough-variant asthma does not show any evidence of airway obstruction. The main symptom is a dry cough with little known pathophysiology. Hypersensitivity of the cough receptors in cough-variant asthma and an increase in the sensory nerve density of the airway epithelium in persistent dry cough patients have been reported. Therefore, it is possible that there is a higher sensory nerve density in cough-variant asthma patients than in classic asthma patients. This study was undertaken to compare the substance P (SP)-immunoreactive nerve density in mucosal biopsies of cough-variant asthma patients, classic asthma patients, and in control subjects. Bronchoscopic biopsies were performed in 6 cough-variant asthma patients, 14 classic asthma patients, and 5 normal controls. The tissues obtained were stained immunohistochemically. The SP-immunoreactive nerve density was measured in the bronchial epithelium using a light microscope at 400 x magnification. SP- immunoreactive nerve density for the cough-variant asthma group was significantly higher than that of the classic asthma group (p = 0.001), and of the normal control group (p = 0.006). It is possible that a sensory nerve abnormality within the airway may be related to hypersensitivity of the cough receptor, and that this may be one of the pathophysiologies of cough-variant asthma. Copyright 2003 S. Karger AG, Basel

Progranulin overexpression in sensory neurons attenuates neuropathic pain in mice: Role of autophagy.

PubMed

Altmann, Christine; Hardt, Stefanie; Fischer, Caroline; Heidler, Juliana; Lim, Hee-Young; Häussler, Annett; Albuquerque, Boris; Zimmer, Béla; Möser, Christine; Behrends, Christian; Koentgen, Frank; Wittig, Ilka; Schmidt, Mirko H H; Clement, Albrecht M; Deller, Thomas; Tegeder, Irmgard

2016-12-01

Peripheral or central nerve injury is a frequent cause of chronic pain and the mechanisms are not fully understood. Using newly generated transgenic mice we show that progranulin overexpression in sensory neurons attenuates neuropathic pain after sciatic nerve injury and accelerates nerve healing. A yeast-2-hybrid screen revealed putative interactions of progranulin with autophagy-related proteins, ATG12 and ATG4b. This was supported by colocalization and proteomic studies showing regulations of ATG13 and ATG4b and other members of the autophagy network, lysosomal proteins and proteins involved in endocytosis. The association of progranulin with the autophagic pathway was functionally confirmed in primary sensory neurons. Autophagy and survival were impaired in progranulin-deficient neurons and improved in progranulin overexpressing neurons. Nerve injury in vivo caused an accumulation of LC3b-EGFP positive bodies in neurons of the dorsal root ganglia and nerves suggesting an impairment of autophagic flux. Overexpression of progranulin in these neurons was associated with a reduction of the stress marker ATF3, fewer protein aggregates in the injured nerve and enhanced stump healing. At the behavioral level, further inhibition of the autophagic flux by hydroxychloroquine intensified cold and heat nociception after sciatic nerve injury and offset the pain protection provided by progranulin. We infer that progranulin may assist in removal of protein waste and thereby helps to resolve neuropathic pain after nerve injury. Copyright © 2016 Elsevier Inc. All rights reserved.

New insights on ctenophore neural anatomy: immunofluorescence study in Pleurobrachia pileus (Müller, 1776).

PubMed

Jager, Muriel; Chiori, Roxane; Alié, Alexandre; Dayraud, Cyrielle; Quéinnec, Eric; Manuel, Michaël

2011-05-15

Ctenophores are non-bilaterian animals sharing with cnidarians and bilaterians the presence of sensory receptors, nerve cells, and synapses, absent in placozoans and sponges. Although recent immunofluorescence studies have renewed our knowledge of cnidarian neuro-anatomy, ctenophores have been much less investigated despite their importance to understanding the origin and early evolution of the nervous system. In this study, the neuro-anatomy of the ctenophore Pleurobrachia pileus (Müller, 1776) was explored by whole-mount fluorescent antibody staining using antibodies against tyrosylated -tubulin, FMRFamide, and vasopressin. We describe the morphology of nerve nets and their local specializations, and the organization of the aboral neuro-sensory complex comprising the apical organ and polar fields. Two distinct nerve nets are distinguished: a mesogleal nerve net, loosely organized throughout body mesoglea, and a much more compact “nerve net” with polygonal meshes in the ectodermal epithelium. The latter is organized as a plexus of short nerve cords. This epithelial nervous system contains distinct sub-populations of dispersed FMRFamide and vasopressin immunoreactive nerve cells. In the aboral neuro-sensory complex, our most significant observations include specialized nerve nets underlying the apical organ and polar fields, a tangential bundle of actin-rich fibers (interpreted as a muscle) within the polar fields, and distinct groups of neurons labeled by anti-FMRFamide and anti-vasopressin antibodies, within the apical organ floor. These results are discussed in a comparative perspective. Copyright © 2011 Wiley-Liss, Inc., A Wiley Company.

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. Copyright 2009 Elsevier B.V. All rights reserved.

[On the nervous system of a parasitic cnidarian Polypodium hydriforme].

PubMed

Raĭkova, E V

2013-01-01

Nerve cells in a parasitic cnidarian Polypodium hydriforme at the parasitic and free-living stages of the life cycle have been localized immunocytochemically using antibodies to FMRF-amide, and their ultrastructure has been described. Ganglion cells form a net under epidermis consisting of bi- and tripolar neurons which cross the mesoglea and usually contact muscle cells and cnidocytes. Fusiform sensory and neurosecretory cells, especially characteristic to sensory tentacles, are interspersed among epidermal cells. All three types of nerve cells have dense cored vesicles about 80-120 nm in diameter. The sensory cells demonstrate a sensory flagellum-like immobile structure. Neurosecretory and sensory cells form septate junctions with epidermal cells. Ganglion cells show gap junctions between them. A centriole encircled by a fragment of nuclear envelope which is a marker of ectodermal lineage cells in Polypodium has been described in the cytoplasm of a sensory cell, thus proving the ectodermal nature of the nervous system.

Microsurgical Decompression of Inferior Alveolar Nerve After Endodontic Treatment Complications.

PubMed

Bianchi, Bernardo; Ferri, Andrea; Varazzani, Andrea; Bergonzani, Michela; Sesenna, Enrico

2017-07-01

Iatrogenic injury in oral surgery is the most frequent cause of sensory disturbance in the distribution of the inferior alveolar nerve (IAN) and mental nerve.Inferior alveolar nerve damage can occur during third molar extraction, implant location, orthognathic surgery, preprosthetic surgery, salivary gland surgery, local anesthetic injections or during the resection of benign or malignant tumors.Injuries to the IAN can be caused also by endodontic treatment of mandibular molars and premolars when filling material is forced into the tooth and mandibular canal.The sensory disturbances that could follow a damage of the IAN could be hypoesthesia, dysesthesia, hyperesthesia, anesthesia, and sometimes a painful anesthesia that strike ipsilateral lower lip, chin, and teeth. These can undermine life quality by affecting speech, chewing, and social interaction.Treatment of these complications is sometimes difficult and could consist in observation or in surgical decompression of the involved nerve to relieve the patient's symptoms and improve sensory recovery. The most debated points are the timing of intervention and the effective role of decompression in clinical outcome-improvement.The purpose of this article is to show authors' experience with 2 patients treated with microsurgical nerve decompression to remove endodontic material from the mandibular canal and providing also a comprehensive review of the literature.

Transthyretin amyloid polyneuropathies mimicking a demyelinating polyneuropathy.

PubMed

Lozeron, Pierre; Mariani, Louise-Laure; Dodet, Pauline; Beaudonnet, Guillemette; Théaudin, Marie; Adam, Clovis; Arnulf, Bertrand; Adams, David

2018-06-15

To clearly define transthyretin familial amyloid polyneuropathies (TTR-FAPs) fulfilling definite clinical and electrophysiologic European Federation of Neurological Societies/Peripheral Nerve Society criteria for chronic inflammatory demyelinating polyneuropathy (CIDP). From a cohort of 194 patients with FAP, 13 of 84 patients (15%) of French ancestry had late-onset demyelinating TTR-FAP. We compared clinical presentation and electrophysiology to a cohort with CIDP and POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes) syndrome. We assessed nerve histology and the correlation between motor/sensory amplitudes/velocities. Predictors of demyelinating TTR-FAP were identified from clinical and electrophysiologic data. Pain, dysautonomia, small fiber sensory loss above the wrists, upper limb weakness, and absence of ataxia were predictors of demyelinating TTR-FAP ( p < 0.01). The most frequent demyelinating features were prolonged distal motor latency of the median nerve and reduced sensory conduction velocity of the median and ulnar nerves. Motor axonal loss was severe and frequent in the median, ulnar, and tibial nerves ( p < 0.05) in demyelinating FAP. Ulnar nerve motor amplitude <5.4 mV and sural nerve amplitude <3.95 μV were distinguishing characteristics of demyelinating TTR-FAP. Nerve biopsy showed severe axonal loss and occasional segmental demyelination-remyelination. Misleading features of TTR-FAP fulfilling criteria for CIDP are not uncommon in sporadic late-onset TTR-FAP, which highlights the limits of European Federation of Neurological Societies/Peripheral Nerve Society criteria. Specific clinical aspects and marked electrophysiologic axonal loss are red flag symptoms that should alert to this diagnosis and prompt TTR gene sequencing. © 2018 American Academy of Neurology.

Pituitary adenylyl cyclase-activating polypeptide (PACAP) and its receptor (PAC1-R) are positioned to modulate afferent signaling in the cochlea.

PubMed

Drescher, M J; Drescher, D G; Khan, K M; Hatfield, J S; Ramakrishnan, N A; Abu-Hamdan, M D; Lemonnier, L A

2006-09-29

Pituitary adenylyl cyclase-activating polypeptide (PACAP), via its specific receptor pituitary adenylyl cyclase-activating polypeptide receptor 1 (PAC1-R), is known to have roles in neuromodulation and neuroprotection associated with glutamatergic and cholinergic neurotransmission, which, respectively, are believed to form the primary basis for afferent and efferent signaling in the organ of Corti. Previously, we identified transcripts for PACAP preprotein and multiple splice variants of its receptor, PAC1-R, in microdissected cochlear subfractions. In the present work, neural localizations of PACAP and PAC1-R within the organ of Corti and spiral ganglion were examined, defining sites of PACAP action. Immunolocalization of PACAP and PAC1-R in the organ of Corti and spiral ganglion was compared with immunolocalization of choline acetyltransferase (ChAT) and synaptophysin as efferent neuronal markers, and glutamate receptor 2/3 (GluR2/3) and neurofilament 200 as afferent neuronal markers, for each of the three cochlear turns. Brightfield microscopy giving morphological detail for individual immunolocalizations was followed by immunofluorescence detection of co-localizations. PACAP was found to be co-localized with ChAT in nerve fibers of the intraganglionic spiral bundle and beneath the inner and outer hair cells within the organ of Corti. Further, evidence was obtained that PACAP is expressed in type I afferent axons leaving the spiral ganglion en route to the auditory nerve, potentially serving as a neuromodulator in axonal terminals. In contrast to the efferent localization of PACAP within the organ of Corti, PAC1-R immunoreactivity was co-localized with afferent dendritic neuronal marker GluR2/3 in nerve fibers passing beneath and lateral to the inner hair cell and in fibers at supranuclear and basal sites on outer hair cells. Given the known association of PACAP with catecholaminergic neurotransmission in sympathoadrenal function, we also re-examined the issue of whether the organ of Corti receives adrenergic innervation. We now demonstrate the existence of nerve fibers within the organ of Corti which are immunoreactive for the adrenergic marker dopamine beta-hydroxylase (DBH). DBH immunoreactivity was particularly prominent in nerve fibers both at the base and near the cuticular plate of outer hair cells of the apical turn, extending to the non-sensory Hensen's cell region. Evidence was obtained for limited co-localization of DBH with PAC1-R and PACAP. In the process of this investigation, we obtained evidence that efferent and afferent nerve fibers, in addition to adrenergic nerve fibers, are present at supranuclear sites on outer hair cells and distributed within the non-sensory epithelium of the apical cochlear turn for rat, based upon immunoreactivity for the corresponding neuronal markers. Overall, PACAP is hypothesized to act within the organ of Corti as an efferent neuromodulator of afferent signaling via PAC1-R that is present on type I afferent dendrites, in position to afford protection from excitotoxicity. Additionally, PACAP/PAC1-R may modulate secretion of catecholamines from adrenergic terminals within the organ of Corti.

Presynaptic excitability.

PubMed

Jackson, M B

1995-01-01

Based on functional characterizations with electrophysiological techniques, the channels in nerve terminals appear to be as diverse as channels in nerve cell bodies (Table I). While most presynaptic Ca2+ channels superficially resemble either N-type or L-type channels, variations in detail have necessitated the use of subscripts and other notations to indicate a nerve terminal-specific subtype (e.g., Wang et al., 1993). Variations such as these pose a serious obstacle to the identification of presynaptic channels based solely on the effects of channel blockers on synaptic transmission. Pharmacological sensitivity alone is not likely to help in determining functional properties. Crucial details, such as voltage sensitivity and inactivation, require direct examination. It goes without saying that every nerve terminal membrane contains Ca2+ channels as an entry pathway so that Ca2+ can trigger secretion. However, there appears to be no general specification of channel type, other than the exclusion of T-type Ca2+ channels. T-type Ca2+ channels are defined functionally by strong inactivation and low threshold. Some presynaptic Ca2+ channels inactivate (posterior pituitary and Xenopus nerve terminals), and others have a somewhat reduced voltage threshold (retinal bipolar neurons and squid giant synapse). Perhaps it is just a matter of time before a nerve terminal Ca2+ channel is found with both of these properties. The high threshold and strong inactivation of T-type Ca2+ channels are thought to be adaptations for oscillations and the regulation of bursting activity in nerve cell bodies. The nerve terminals thus far examined have no endogenous electrical activity, but rather are driven by the cell body. On functional grounds, it is then reasonable to anticipate finding T-type Ca2+ channels in nerve terminals that can generate electrical activity on their own. The rarity of such behavior in nerve terminals may be associated with the rarity of presynaptic T-type Ca2+ channels. In four of the five preparations reviewed in this chapter--motor nerve, squid giant synapse, ciliary ganglion, and retina bipolar neurons--evidence was presented that supports a location for Ca2+ channels that is very close to active zones of secretion. All of these synapses secrete from clear vesicles, and the speed and specificity of transduction provided by proximity may be a common feature of these rapid synapses. In contrast, the posterior pituitary secretion apparatus may be triggered by higher-affinity Ca2+ receptors and lower concentrations of Ca2+ (Lindau et al., 1992). This would correspond with the slower performance of peptidergic secretion, but because of the large stimuli needed to evoke release from neurosecretosomes, the possibility remains that the threshold for secretion is higher than that reported. While the role of Ca2+ as a trigger of secretion dictates a requirement for voltage-activated Ca2+ channels as universal components of the presynaptic membrane, the presence of other channels is more difficult to predict. Depolarizations caused by voltage-activated Na+ channels activate the presynaptic Ca2+ channels, but whether this depolarization requires Na+ channels in the presynaptic membrane itself may depend on the electrotonic length of the nerve terminal. Variations in density between motor nerve terminals may reflect species differences in geometry. The high Na+ channel density in the posterior pituitary reflects the great electrotonic length of this terminal arbor. Whether Na+ channels are abundant or not in a presynaptic membrane, K+ channels provide the most robust mechanism for limiting depolarization-induced Ca2+ entry. K+ channel blockers enhance transmission at most synapses. In general, K+ channels are abundant in nerve terminals, although their apparent lower priority compared to Ca2+ channels in the eyes of many investigators leaves us with fewer detailed investigations in some preparations. Most nerve terminals have more than

Inflammation role in sensory neuropathy in Chinese patients with diabetes/prediabetes.

PubMed

Zeng, Jing; Xu, Yalin; Shi, Yao; Jiang, Chenyin

2018-03-01

Prediabetes involves people with glucose-metabolism impairment, and is related to different diabetic complications, like peripheral neuropathy. We aimed to explore the relationship among inflammatory (tumor necrosis factor alpha [TNFα]) and antiinflammatory (interleukin 10 [IL10]) cytokines as well as neuropathy of very distal-sensory-nerves in Chinese patients with prediabetes/diabetes. In the present study, 55 patients having prediabetes, 55 patients having type 2 diabetes mellitus (DM), and 48 controls were included. TNFα, HbA1c, and IL10 plasma levels were measured. Electrodiagnosis was conducted on dorsal-sural/medial-plantar sensory nerve, that is most distal feet sensory-nerves. Nerve conduction test (NCT) irregularities of dorsal-sural/medial-plantar sensory nerve were considerably greater in patients with prediabetes or diabetes. The means of TNFα levels demonstrated a significant increase in patients with diabetes when compared to prediabetes patients as well as controls showed a significant decrease in patients with prediabetes and diabetes contrasted with controls. No significant contrast with respect to serum biomarkers among patients having regular as well as irregular medial-plantar/dorsal-sural NCT was noted. Critical correlationship among TNFα as well as HbA1c with symptoms severity as well as disability while negative correlations of IL10 with neuropathy severity was noted. Biomarker levels of TNFα, IL10, and HbA1c were noted to differ significantly among patients without/with neuropathy. All in all, the proinflammatory phase appears to start from initial pre-clinical phases, sometime prior to advancement of diabetes. The higher neuropathy frequency in patients with prediabetes indicates conceivable causative impact; although, the prospective part of inflammation in pathogenetics of peripheral neuropathy requires more elucidation. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of peripheral sensory nerve stimulation plus task-oriented training on upper extremity function in patients with subacute stroke: a pilot randomized crossover trial.

PubMed

Ikuno, Koki; Kawaguchi, Saori; Kitabeppu, Shinsuke; Kitaura, Masaki; Tokuhisa, Kentaro; Morimoto, Shigeru; Matsuo, Atsushi; Shomoto, Koji

2012-11-01

To investigate the feasibility of peripheral sensory nerve stimulation combined with task-oriented training in patients with stroke during inpatient rehabilitation. A pilot randomized crossover trial. Two rehabilitation hospitals. Twenty-two patients with subacute stroke. Participants were randomly assigned to two groups and underwent two weeks of training in addition to conventional inpatient rehabilitation. The immediate group underwent peripheral sensory nerve stimulation combined with task-oriented training in the first week, followed by another week with task-oriented training alone. The delayed group underwent the same training in reverse order. Outcome measures were the level of fatigue and Wolf Motor Function Test. Patients were assessed at baseline, one and two weeks. All participants completed the study with no adverse events. There was no significant difference in level of fatigue between each treatment. From baseline to one week, the immediate group showed larger improvements than the delayed groups in the Wolf Motor Function Test (decrease in mean time (± SD) from 41.9 ± 16.2 seconds to 30.6 ± 11.4 seconds versus from 46.8 ± 19.4 seconds to 42.9 ± 14.7 seconds, respectively) but the difference did not reach significance after Bonferroni correction (P = 0.041). Within-group comparison showed significant improvements in the Wolf Motor Function Test mean time after the peripheral sensory nerve stimulation combined with task-oriented training periods in each group (P < 0.01). Peripheral sensory nerve stimulation is feasible in clinical settings and may enhance the effects of task-oriented training in patients with subacute stroke.

Stimulus waveform determines the characteristics of sensory nerve action potentials.

PubMed

Pereira, Pedro; Leote, João; Cabib, Christopher; Casanova-Molla, Jordi; Valls-Sole, Josep

2016-03-01

In routine nerve conduction studies supramaximal electrical stimuli generate sensory nerve action potentials by depolarization of nerve fibers under the cathode. However, stimuli of submaximal intensity may give rise to action potentials generated under the anode. We tested if this phenomenon depends on the characteristics of stimulus ending. We added a circuit to our stimulation device that allowed us to modify the end of the stimulus by increasing the time constant of the decay phase. Increasing the fall time caused a reduction of anode action potential (anAP) amplitude, and eventually abolished it, in all tested subjects. We subsequently examined the stimulus waveform in a series of available electromyographs stimulators and found that the anAP could only be obtained with stimulators that issued stimuli ending sharply. Our results prove that the anAP is generated at stimulus end, and depends on the sharpness of current shut down. Electromyographs produce stimuli of varying characteristics, which limits the reproducibility of anAP results by interested researchers. The study of anodal action potentials might be a useful tool to have a quick appraisal of distal human sensory nerve excitability. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

End-to-side neurorraphy: a long-term study of neural regeneration in a rat model.

PubMed

Tarasidis, G; Watanabe, O; Mackinnon, S E; Strasberg, S R; Haughey, B H; Hunter, D A

1998-10-01

This study evaluated long-term reinnervation of an end-to-side neurorraphy and the resultant functional recovery in a rat model. The divided distal posterior tibial nerve was repaired to the side of an intact peroneal nerve. Control groups included a cut-and-repair of the posterior tibial nerve and an end-to-end repair of the peroneal nerve to the posterior tibial nerve. Evaluations included walking-track analysis, nerve conduction studies, muscle mass measurements, retrograde nerve tracing, and histologic evaluation. Walking tracks indicated poor recovery of posterior tibial nerve function in the experimental group. No significant difference in nerve conduction velocities was seen between the experimental and control groups. Gastrocnemius muscle mass measurements revealed no functional recovery in the experimental group. Similarly, retrograde nerve tracing revealed minimal motor neuron staining in the experimental group. However, some sensory staining was seen within the dorsal root ganglia of the end-to-side group. Histologic study revealed minimal myelinated axonal regeneration in the experimental group as compared with findings in the other groups. These results suggest that predominantly sensory regeneration occurs in an end-to-side neurorraphy at an end point of 6 months.

Antinociceptive effect of vinpocetine--a comprehensive survey.

PubMed

Csillik, Bertalan; Mihály, András; Knyihár-Csillik, Elizabeth

2010-05-30

Blockade of retrograde transport of nerve growth factor (NGF) in a peripheral sensory nerve is known to induce transganglionic degenerative atrophy (TDA) of central sensory terminals in the upper dorsal horn of the related, ipsilateral segments(s) of the spinal cord. The ensuing temporary blockade of transmission of nociceptive impulses has been utilized in the therapy of intractable pain, using transcutaneous iontophoresis of the microtubule inhibitors vincristin and vinblastin, drugs which inhibit retrograde transport of NGF. Since microtubule inhibition might inhibit (at least theoretically) mitotic processes in general, we sought to find a drug which inhibits retrograde transport of NGF without microtubule inhibition. Vinpocetine, a derivate of vincamine, which does not interfere with microtubular function, was found to inhibit retrograde axoplasmic transport of NGF in peripheral sensory nerves, similarly to vincristin and vinblastin. Blockade of NGF transport is followed by transganglionic degenerative atrophy in the segmentally related, ipsilateral superficial spinal dorsal horn, characterized by depletion of the marker enzymes of nociception, fluoride resistant acid phosphatase (FRAP) and thiamine monophosphatase (TMP) from the Rolando substance and by decrease of the pain-related neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) from lamina I-II-III. Based upon these findings, it has been suggested that vinpocetine may result in a locally restricted decrease of nociception. Herewith, the structural and behavioral effects of perineurally administered vinpocetine are discussed. Nociception, induced by intraplantar injection of formalin, was mitigated by perineural application of vinpocetine; also formalin-induced expression of c-fos in the ipsilateral, segmentally related superficial dorsal horn, was prevented by this treatment. Since vinpocetine is not a microtubule inhibitor, its mode of action is enigmatic. It is assumed that the effect of vinpocetine might be related to interaction with membrane-trafficking proteins, such as signalling endosomes and the endocytosis-mediating "pincher" protein, involved in retrograde axoplasmic transport of NGF, or to interaction with glial elements, recently reported to be involved in the modulation of pain in the spinal cord. Based on animal experiments it is assumed that the temporary, locally restricted decrease of nociception, induced by vinpocetine applied via transcutaneous iontophoresis, might open up new avenues in the clinical treatment of intractable pain.

Degeneration and regeneration of motor and sensory nerves: a stereological study of crush lesions in rat facial and mental nerves.

PubMed

Barghash, Z; Larsen, J O; Al-Bishri, A; Kahnberg, K-E

2013-12-01

The aim of this study was to evaluate the degeneration and regeneration of a sensory nerve and a motor nerve at the histological level after a crush injury. Twenty-five female Wistar rats had their mental nerve and the buccal branch of their facial nerve compressed unilaterally against a glass rod for 30s. Specimens of the compressed nerves and the corresponding control nerves were dissected at 3, 7, and 19 days after surgery. Nerve cross-sections were stained with osmium tetroxide and toluidine blue and analysed using two-dimensional stereology. We found differences between the two nerves both in the normal anatomy and in the regenerative pattern. The mental nerve had a larger cross-sectional area including all tissue components. The mental nerve had a larger volume fraction of myelinated axons and a correspondingly smaller volume fraction of endoneurium. No differences were observed in the degenerative pattern; however, at day 19 the buccal branch had regenerated to the normal number of axons, whereas the mental nerve had only regained 50% of the normal number of axons. We conclude that the regenerative process is faster and/or more complete in the facial nerve (motor function) than it is in the mental nerve (somatosensory function). Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

[Changes in the innervation of the taste buds in diabetic rats].

PubMed

Hevér, Helén; Altdorfer, Károly; Zelles, Tivadar; Batbayar, Bayarchimeg; Fehér, Erzsébet

2013-03-24

Abnormal sensations such as pain and impairment of taste are symptoms of approximately 10% of patients having diabetes mellitus. The aim of the study was to investigate and quantify the different neuropeptide containing nerve fibres in the vallate papilla of the diabetic rat. Immunohistochemical methods were used to study the changes of the number of different neuropeptide containing nerve terminals located in the vallate papillae in diabetic rats. Diabetes was induced in the rats with streptozotocin. Two weeks after streptozotocin treatment the number of the substance P, galanin, vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve terminals was significantly increased (p<0.05) in the tunica mucosa of the tongue. The number of the lymphocytes and mast cells was also increased significantly. Some of the immunoreactive nerve terminals were located in the lingual epithelium both intragemmally and extragemmally and were seen to comprise dense bundles in the lamina propria just beneath the epithelium. No taste cells were immunoreactive for any of the investigated peptides. Vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve fibres were not detected in the taste buds. For weeks after streptozotocin administration the number of the substance P, calcitonin gene related peptide and galanin immunoreactive nerve terminals was decreased both intragemmally and intergemmally. In case of immediate insulin treatment, the number of the immunoreactive nerve terminals was similar to that of the controls, however, insulin treatment given 1 week later to diabetic rats produced a decreased number of nerve fibers. Morphometry revealed no significant difference in papilla size between the control and diabetic groups, but there were fewer taste buds (per papilla). Increased number of immunoreactive nerve terminals and mast cells 2 weeks after the development of diabetes was the consequence of neurogenic inflammation which might cause vasoconstriction and lesions of the oral mucosa. Taste impairment, which developed 4 weeks after streptozotocin treatment could be caused by neuropathic defects and degeneration or morphological changes in the taste buds and nerve fibres.

Peripheral neuropathy in patients with myotonic dystrophy type 2.

PubMed

Leonardis, L

2017-05-01

Myotonic dystrophy type 2 (dystrophia myotonica type 2-DM2) is an autosomal dominant multi-organ disorder. The involvement of the peripheral nervous system was found in 25%-45% of patients with myotonic dystrophy type 1, although limited data are available concerning polyneuropathy in patients with DM2, which was the aim of this study with a thorough presentation of the cases with peripheral neuropathy. Patients with genetically confirmed DM2 underwent motor nerve conduction studies of the median, ulnar, tibial and fibular nerves and sensory nerve conduction studies of the median (second finger), ulnar (fifth finger), radial (forearm) and sural nerves. Seventeen adult patients with DM2 participated in the study. Fifty-three percent (9/17) of our patients had abnormality of one or more attributes (latency, amplitude or conduction velocity) in two or more separate nerves. Four types of neuropathies were found: (i) predominantly axonal motor and sensory polyneuropathy, (ii) motor polyneuropathy, (iii) predominantly demyelinating motor and sensory polyneuropathy and (iv) mutilating polyneuropathy with ulcers. The most common forms are axonal motor and sensory polyneuropathy (29%) and motor neuropathy (18% of all examined patients). No correlations were found between the presence of neuropathy and age, CCTG repeats, blood glucose or HbA1C. Peripheral neuropathy is common in patients with DM2 and presents one of the multisystemic manifestations of DM2. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Thrombospondin-4 divergently regulates voltage-gated Ca2+ channel subtypes in sensory neurons after nerve injury.

PubMed

Pan, Bin; Guo, Yuan; Wu, Hsiang-En; Park, John; Trinh, Van Nancy; Luo, Z David; Hogan, Quinn H

2016-09-01

Loss of high-voltage-activated (HVA) calcium current (ICa) and gain of low-voltage-activated (LVA) ICa after painful peripheral nerve injury cause elevated excitability in sensory neurons. Nerve injury is also accompanied by increased expression of the extracellular matrix glycoprotein thrombospondin-4 (TSP4), and interruption of TSP4 function can reverse or prevent behavioral hypersensitivity after injury. We therefore investigated TSP4 regulation of ICa in dorsal root ganglion (DRG) neurons. During depolarization adequate to activate HVA ICa, TSP4 decreases both N- and L-type ICa and the associated intracellular calcium transient. In contrast, TSP4 increases ICa and the intracellular calcium signal after low-voltage depolarization, which we confirmed is due to ICa through T-type channels. These effects are blocked by gabapentin, which ameliorates neuropathic pain by targeting the α2δ1 calcium subunit. Injury-induced changes of HVA and LVA ICa are attenuated in TSP4 knockout mice. In the neuropathic pain model of spinal nerve ligation, TSP4 application did not further regulate ICa of injured DRG neurons. Taken together, these findings suggest that elevated TSP4 after peripheral nerve injury may contribute to hypersensitivity of peripheral sensory systems by decreasing HVA and increasing LVA in DRG neurons by targeting the α2δ1 calcium subunit. Controlling TSP4 overexpression in peripheral sensory neurons may be a target for analgesic drug development for neuropathic pain.

[The vestibular apparatus of quail embryos in an experiment on the Kosmos-1129 biosatellite].

PubMed

Lychakov, D V; Il'inskaia, E V; Dadasheva, O A; Gur'eva, T S

1993-01-01

The light microscope was used to study serial sections of labyrinths of quail embryos incubated and reared during 12 d orbiting of Cosmos 1129. On recovery the embryos were aged 9, 11.5 and 12 days. No significant deviations in the development of the vestibular apparatus in flight species were noted as compared to the controls. Given this and our experimental data about in-space development of fish and amphibians we may deduce that hypo-g does not exert a noticeable altering effect on the vestibular embryogenesis. Nevertheless, it should be pointed out that in all otolith organs and semicircular channel ampules of the flight embryos cup-form neural endings innervating type I sensory cells were markedly swollen in contrast to the control. Earlier swollen cup-form nerve endings have been found in one adult rat after 7 days of space flight aboard Cosmos 1667. However, exposure in space does not bring about a substantial swelling of bud-like nerve endings which contact type II sensory cells. Thus, a conclusion may be drawn that spaceflight factors are liable to produce shifts in the type I sensory cell--cup-form nerve ending unit but they do not affect type II sensory cell--bud-like nerve ending unit to the extent when effects can be identified by light microscopy.

Quantitative Sensory Testing and Current Perception Threshold Testing in Patients With Chronic Pain Following Lower Extremity Fracture.

PubMed

Griffioen, Mari A; Greenspan, Joel D; Johantgen, Meg; Von Rueden, Kathryn; O'Toole, Robert V; Dorsey, Susan G; Renn, Cynthia L

2018-01-01

Chronic pain is a significant problem for patients with lower extremity injuries. While pain hypersensitivity has been identified in many chronic pain conditions, it is not known whether patients with chronic pain following lower extremity fracture report pain hypersensitivity in the injured leg. To quantify and compare peripheral somatosensory function and sensory nerve activation thresholds in persons with chronic pain following lower extremity fractures with a cohort of persons with no history of lower extremity fractures. This was a cross-sectional study where quantitative sensory testing and current perception threshold testing were conducted on the injured and noninjured legs of cases and both legs of controls. A total of 14 cases and 28 controls participated in the study. Mean time since injury at the time of testing for cases was 22.3 (standard deviation = 12.1) months. The warmth detection threshold ( p = .024) and nerve activation thresholds at 2,000 Hz ( p < .001) and 250 Hz ( p = .002), respectively, were significantly higher in cases compared to controls. This study suggests that patients with chronic pain following lower extremity fractures may experience hypoesthesia in the injured leg, which contrasts with the finding of hyperesthesia previously observed in other chronic pain conditions but is in accord with patients with nerve injuries and surgeries. This is the first study to examine peripheral sensory nerve function at the site of injury in patients with chronic pain following lower extremity fractures using quantitative sensory testing and current perception threshold testing.

Intracranial stimulation of the trigeminal nerve in man. III. Sensory potentials.

PubMed Central

Cruccu, G; Inghilleri, M; Manfredi, M; Meglio, M

1987-01-01

Percutaneous electrical stimulation of the trigeminal root was performed in 18 subjects undergoing surgery for idiopathic trigeminal neuralgia or implantation of electrodes into Meckel's cave for recording of limbic epileptic activity. All subjects had normal trigeminal reflexes and evoked potentials. Sensory action potentials were recorded antidromically from the supraorbital (V1), infraorbital (V2) and mental (V3) nerves. In the awake subject, sensory potentials were usually followed by myogenic artifacts due to direct activation of masticatory muscles or reflex activation of facial muscles. In the anaesthetised and curarised subject, sensory potentials from the three nerves showed 1.4-2.2 ms onset latency, 1.9-2.7 ms peak latency and 17-29 microV amplitude. Sensory conduction velocity was computed at the onset latency (maximum CV) and at the peak latency (peak CV). On average, maximum and peak CV were 52 and 39 m/s for V1, 54 and 42 m/s for V2 and 54 and 44 m/s for V3. There was no apparent difference in CV between subjects with trigeminal neuralgia and those with epilepsy. A significant inverse correlation was found between CV and age, the overall maximum CV declining from 59 m/s (16 years) to 49 m/s (73 years). This range of CV is compatible both with histometric data and previous electrophysiological findings on trigeminal nerve conduction. Intraoperative intracranial stimulation is also proposed as a method of monitoring trigeminal function under general anaesthesia. Images PMID:3681311

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

PubMed Central

Wang, Hom-Lay; Sabalys, Gintautas

2011-01-01

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

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

PubMed

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

2016-07-01

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

Sensory Nerve Induced Inflammation Contributes to Heterotopic Ossification

PubMed Central

Salisbury, Elizabeth; Rodenberg, Eric; Sonnet, Corinne; Hipp, John; Gannon, Francis H.; Vadakkan, Tegy J.; Dickinson, Mary E.; Olmsted-Davis, Elizabeth A.; Davis, Alan R.

2012-01-01

Heterotopic ossification (HO), or bone formation in soft tissues, is often the result of traumatic injury. Much evidence has linked the release of BMPs (bone morphogenetic proteins) upon injury to this process. HO was once thought to be a rare occurrence, but recent statistics from the military suggest that as many as 60% of traumatic injuries, resulting from bomb blasts, have associated HO. In this study, we attempt to define the role of peripheral nerves in this process. Since BMP2 has been shown previously to induce release of the neuroinflammatory molecules, substance P (SP) and calcitonin gene related peptide (CGRP), from peripheral, sensory neurons, we examined this process in vivo. SP and CGRP are rapidly expressed upon delivery of BMP2 and remain elevated throughout bone formation. In animals lacking functional sensory neurons (TRPV1−/−), BMP2-mediated increases in SP and CGRP were suppressed as compared to the normal animals, and HO was dramatically inhibited in these deficient mice, suggesting that neuroinflammation plays a functional role. Mast cells, known to be recruited by SP and CGRP, were elevated after BMP2 induction. These mast cells were localized to the nerve structures and underwent degranulation. When degranulation was inhibited using cromolyn, HO was again reduced significantly. Immunohistochemical analysis revealed nerves expressing the stem cell markers nanog and Klf4, as well as the osteoblast marker osterix, after BMP2 induction, in mice treated with cromolyn. The data collectively suggest that BMP2 can act directly on sensory neurons to induce neurogenic inflammation, resulting in nerve remodeling and the migration/release of osteogenic and other stem cells from the nerve. Further, blocking this process significantly reduces HO, suggesting that the stem cell population contributes to bone formation. PMID:21678472

Where are the sensory organs of Nybelinia surmenicola (Trypanorhyncha)? A comparative analysis with Parachristianella sp. and other trypanorhynchean cestodes.

PubMed

Biserova, Natalia M; Gordeev, Ilya I; Korneva, Janetta V

2016-01-01

The sensory organs in tegument of two trypanorhynchean species--Nybelinia surmenicola (plerocercoid) and adult Parachristianella sp. (Cestoda, Trypanorhyncha)--were studied with the aim of ultrastructural description and a comparative analysis. The Nybelinia surmenicola plerocercoid lacks papillae with sensory cilia on the bothria adhesive surface. We found an unciliated sensory organ within the median bothria fold. This unciliated free nerve ending contains the central electron-dense disc, three dense supporting rings, and broad root. The nerve ending locates in the basal matrix under the tegument. The tegument of N. surmenicola has a number of ultrastructural features which make it significantly different from other Trypanorhyncha: (i) the tegumental cytoplasm has a plicated constitution in a form of high apical and deep basal folds, (ii) numerous layers of the basal matrix are presented in the subtegument, and (iii) the squamiform and bristlelike microtriches N. surmenicola lack the base and the basal plate. In contrast, numerous ciliated and unciliated receptors were found in Parachristianella sp.: six types on the bothria and one type in the strobila tegument. Ultrastructural constitution of sensory organs in the form of ciliated free nerve endings as well as unciliated basal nerve endings of Parachristianella sp. has many common features inside Eucestoda. In comparison with other Trypanorhyncha, all Nybelinia species studied have less quantity of the bothrial sensory organs. This fact may reflect behavioral patterns of Nybelinia as well as phylogenetic position into Trypanorhyncha. Our observations of living animals conventionally demonstrate the ability of N. surmenicola plerocercoids to locomote in forward direction on the Petri dish surface. The participation of the bothrial microtriches in a parasite movement has been discussed.

Parecoxib added to ropivacaine prolongs duration of axillary brachial plexus blockade and relieves postoperative pain.

PubMed

Liu, Xiaoming; Zhao, Xuan; Lou, Jian; Wang, Yingwei; Shen, Xiaofang

2013-02-01

Cyclooxygenase (COX)-2 antagonist is widely used for intravenous postoperative pain relief. Recent studies reported COX-2 in the spinal dorsal horn could modulate spinal nociceptive processes. Epidural parecoxib in rats showed no neurotoxicity. These findings suggested applying a COX-2 antagonist directly to the central or peripheral nerve might provide better analgesia. We therefore determined: (1) whether the addition of parecoxib to ropivacaine injected locally on the nerve block affected the sensory and motor block times of the brachial plexus nerve block; and (2) whether parecoxib injected locally on the nerve or intravenously had a similar analgesic adjuvant effect. We conducted a randomized controlled trial from January 2009 to November 2010 with 150 patients scheduled for elective forearm surgery, using a multiple-nerve stimulation technique. Patients were randomly allocated into one of three groups: Group A (n = 50) received ropivacaine 0.25% alone on the brachial plexus nerve; Group B (n = 50) received ropivacaine together with 20 mg parecoxib locally on the nerve block; and Group C (n = 50) received 20 mg parecoxib intravenously. We recorded the duration of the sensory and motor blocks, and the most severe pain score during a 24-hour postoperative period. Parecoxib added locally on the nerve block prolonged the motor and sensory block times compared with Group A. However, parecoxib injected intravenously had no such effect. Pain intensity scores in Group B were lower than those in Groups A and C. Parecoxib added to ropivacaine locally on the nerve block prolonged the duration of the axillary brachial plexus blockade and relieved postoperative pain for patients having forearm orthopaedic surgery. Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Use of Nerve Conduction Velocity to Assess Peripheral Nerve Health in Aging Mice

PubMed Central

Walsh, Michael E.; Sloane, Lauren B.; Fischer, Kathleen E.; Austad, Steven N.; Richardson, Arlan

2015-01-01

Nerve conduction velocity (NCV), the speed at which electrical signals propagate along peripheral nerves, is used in the clinic to evaluate nerve function in humans. A decline in peripheral nerve function is associated with a number of age-related pathologies. While several studies have shown that NCV declines with age in humans, there is little information on the effect of age on NCV in peripheral nerves in mice. In this study, we evaluated NCV in male and female C57Bl/6 mice ranging from 4 to 32 months of age. We observed a decline in NCV in both male and female mice after 20 months of age. Sex differences were detected in sensory NCV as well as the rate of decline during aging in motor nerves; female mice had slower sensory NCV and a slower age-related decline in motor nerves compared with male mice. We also tested the effect of dietary restriction on NCV in 30-month-old female mice. Dietary restriction prevented the age-related decline in sciatic NCV but not other nerves. Because NCV is clinically relevant to the assessment of nerve function, we recommend that NCV be used to evaluate healthspan in assessing genetic and pharmacological interventions that increase the life span of mice. PMID:25477428

The terminal latency of the phrenic nerve correlates with respiratory symptoms in amyotrophic lateral sclerosis.

PubMed

Park, Jin-Sung; Park, Donghwi

2017-09-01

The aim of the study was to investigate the electrophysiological parameters in phrenic nerve conduction studies (NCS) that sensitively reflect latent respiratory insufficiency present in amyotrophic lateral sclerosis (ALS). Forty-nine patients with ALS were examined, and after exclusion, 21 patients with ALS and their phrenic NCS results were reviewed. The patients were divided into two groups according to their respiratory sub-score in the ALS functional rating scale - revised (Group A, sub-score 12vs. Group B, sub-score 11). We compared the parameters of phrenic NCS between the two groups. There were no significant differences in the clinical characteristics between the two groups. Using a multivariate model, we found that the terminal latency of the phrenic nerve was the only parameter that was associated with early symptoms of respiratory insufficiency (p<0.05). The optimal cutoff value for the terminal latency of the phrenic nerve was 7.65ms (sensitivity 80%, specificity 68.2%). The significantly prolonged terminal latency of the phrenic nerve in our study may reflect a profound distal motor axonal dysfunction of the phrenic nerve in patients with ALS in the early stage of respiratory insufficiency that can be used as a sensitive electrophysiological marker reflecting respiratory symptoms in ALS. The terminal latency of the phrenic nerve is useful for early detection of respiratory insufficiency in patients with ALS. Copyright © 2017. Published by Elsevier B.V.

Methods to evaluate functional nerve recovery in adult rats: walking track analysis, video analysis and the withdrawal reflex.

PubMed

Dijkstra, J R; Meek, M F; Robinson, P H; Gramsbergen, A

2000-03-15

The aim of this study was to compare different methods for the evaluation of functional nerve recovery. Three groups of adult male Wistar rats were studied. In group A, a 12-mm gap between nerve ends was bridged by an autologous nerve graft; in rats of group B we performed a crush lesion of the sciatic nerve and group C consisted of non-operated control rats. The withdrawal reflex, elicited by an electric stimulus, was used to evaluate the recovery of sensory nerve function. To investigate motor nerve recovery we analyzed the walking pattern. Three different methods were used to obtain data for footprint analysis: photographic paper with thickened film developer on the paws, normal white paper with finger paint, and video recordings. The footprints were used to calculate the sciatic function index (SFI). From the video recordings, we also analyzed stepcycles. The withdrawal reflex is a convenient and reproducible test for the evaluation of global sensory nerve recovery. Recording walking movements on video and the analysis of footplacing is a perfect although time-consuming method for the evaluation of functional aspects of motor nerve recovery.

Auditory-nerve single-neuron thresholds to electrical stimulation from scala tympani electrodes.

PubMed

Parkins, C W; Colombo, J

1987-12-31

Single auditory-nerve neuron thresholds were studied in sensory-deafened squirrel monkeys to determine the effects of electrical stimulus shape and frequency on single-neuron thresholds. Frequency was separated into its components, pulse width and pulse rate, which were analyzed separately. Square and sinusoidal pulse shapes were compared. There were no or questionably significant threshold differences in charge per phase between sinusoidal and square pulses of the same pulse width. There was a small (less than 0.5 dB) but significant threshold advantage for 200 microseconds/phase pulses delivered at low pulse rates (156 pps) compared to higher pulse rates (625 pps and 2500 pps). Pulse width was demonstrated to be the prime determinant of single-neuron threshold, resulting in strength-duration curves similar to other mammalian myelinated neurons, but with longer chronaxies. The most efficient electrical stimulus pulse width to use for cochlear implant stimulation was determined to be 100 microseconds/phase. This pulse width delivers the lowest charge/phase at threshold. The single-neuron strength-duration curves were compared to strength-duration curves of a computer model based on the specific anatomy of auditory-nerve neurons. The membrane capacitance and resulting chronaxie of the model can be varied by altering the length of the unmyelinated termination of the neuron, representing the unmyelinated portion of the neuron between the habenula perforata and the hair cell. This unmyelinated segment of the auditory-nerve neuron may be subject to aminoglycoside damage. Simulating a 10 micron unmyelinated termination for this model neuron produces a strength-duration curve that closely fits the single-neuron data obtained from aminoglycoside deafened animals. Both the model and the single-neuron strength-duration curves differ significantly from behavioral threshold data obtained from monkeys and humans with cochlear implants. This discrepancy can best be explained by the involvement of higher level neurologic processes in the behavioral responses. These findings suggest that the basic principles of neural membrane function must be considered in developing or analyzing electrical stimulation strategies for cochlear prostheses if the appropriate stimulation of frequency specific populations of auditory-nerve neurons is the objective.

Preferential Enhancement of Sensory and Motor Axon Regeneration by Combining Extracellular Matrix Components with Neurotrophic Factors

PubMed Central

Santos, Daniel; González-Pérez, Francisco; Giudetti, Guido; Micera, Silvestro; Udina, Esther; Del Valle, Jaume; Navarro, Xavier

2016-01-01

After peripheral nerve injury, motor and sensory axons are able to regenerate but inaccuracy of target reinnervation leads to poor functional recovery. Extracellular matrix (ECM) components and neurotrophic factors (NTFs) exert their effect on different neuronal populations creating a suitable environment to promote axonal growth. Here, we assessed in vitro and in vivo the selective effects of combining different ECM components with NTFs on motor and sensory axons regeneration and target reinnervation. Organotypic cultures with collagen, laminin and nerve growth factor (NGF)/neurotrophin-3 (NT3) or collagen, fibronectin and brain-derived neurotrophic factor (BDNF) selectively enhanced sensory neurite outgrowth of DRG neurons and motor neurite outgrowth from spinal cord slices respectively. For in vivo studies, the rat sciatic nerve was transected and repaired with a silicone tube filled with a collagen and laminin matrix with NGF/NT3 encapsulated in poly(lactic-co-glycolic acid) (PLGA) microspheres (MP) (LM + MP.NGF/NT3), or a collagen and fibronectin matrix with BDNF in PLGA MPs (FN + MP.BDNF). Retrograde labeling and functional tests showed that LM + MP.NGF/NT3 increased the number of regenerated sensory neurons and improved sensory functional recovery, whereas FN + MP.BDNF preferentially increased regenerated motoneurons and enhanced motor functional recovery. Therefore, combination of ECM molecules with NTFs may be a good approach to selectively enhance motor and sensory axons regeneration and promote appropriate target reinnervation. PMID:28036084

The structure and function of cutaneous sensory receptors.

PubMed

Munger, B L; Ide, C

1988-03-01

The present review of cutaneous sensory receptors begins with a consideration of free nerve endings (FNEs) that can be considered as sensory terminals evidencing the least structural specialization of the axon and associated cells. Using the criteria established by Kruger et al (1981), FNEs of both A delta and C fibers can be identified on the basis of ultrastructural characteristics that include an intimate relationship between axons and the associated epithelium, the lack of a complete Schwann cell investment, the accumulation of numerous vesicles and other cytoplasmic organelles, and for A delta terminals a 1:1 relationship between axon and investing Schwann cell. Using these criteria, the so-called genital end bulbs of the human glans penis are merely a skein of FNEs based on the ultrastructural study of Halata and Munger (1986). Hair follicles of most species studied to date (the exception being the rabbit and to some extent the guinea pig) are multiply innervated with lanceolate, Ruffini and FNEs. The lanceolate terminals are the rapidly adapting terminals that are numerous in guard hairs. Ruffini terminals of hairs resemble those of the periodontal ligament or joint capsules and both are remarkably similar to Golgi tendon organs in terms of ultrastructural characteristics. The key ultrastructural characteristic is the encircling of collagen bundles by axons and associated Schwann and connective tissue cells. Axons frequently enter the epidermis either to terminate as FNEs or become associated with Merkel cells in glabrous skin at the base of the papillary ridges or in clusters of Merkel cells in hairy skin in touch domes or Haarscheiben. Merkel cells have clusters of apparent secretory granules polarized toward the axon and the axon is typically a slowly adapting mechanoreceptor. The function of the granules is not known. Pacinian corpuscles are the largest of the corpuscular receptors of the dermis and are characterized by an elaborate inner core of stacks of numerous thin lamellae arranged in a bilaterally symmetrical manner. Based on the fact that the lamellae are coupled with gap junctions and the outer core lamellae isolated by numerous tight junctions, the authors have proposed that the unique ionic environment may be in part responsible for the remarkable sensitivity of Pacinian corpuscles (Munger and Ide, 1987). Meissner corpuscles are a typical corpuscular receptor of murine (Ide, 1976, 1977), marsupial and primate glabrous skin (Munger, 1971). The axons typically weave back and forth between stacks of lamellae.(ABSTRACT TRUNCATED AT 400 WORDS)

Gamma-aminobutyric acid (GABA) and neuropeptides in neural areas mediating motion-induced emesis

NASA Technical Reports Server (NTRS)

Damelio, F.; Daunton, Nancy G.; Fox, Robert A.

1991-01-01

Immunocytochemical methods were employed to localize the neurotransmitter amino acid gamma-aminobutyric acid and the neuropeptides substance P and Met-enkephalin in the area postrema (AP), area subpostrema (ASP), nucleus of the tractus solitarius (NTS), dorsal motor nucleus of the vagus nerve (DMNV), and lateral vestibular nucleus (LVN). Glutamic acid decarboxylase immunoreactive (GAD-IR) terminals and fibers were observed in the AP and particularly in the ASP. A gradual decrease in the density of terminals was seen towards the solitary complex. The DMNV revealed irregularly scattered GAD-IR terminals within the neuropil or closely surrounding neuronal cell bodies. The LVN, particularly the dorsal division, showed numerous axon terminals which were mostly localize around large neurons and their proximal dendrites. Substance P immunoreactive (SP-IR) terminals and fibers showed high density in the solitary complex, in particular within the lateral division. The ASP showed medium to low density of SP-IR fibers and terminals. The AP exhibited a small number of fibers and terminals irregularly distributed. The DMNV revealed a high density of SP-IR terminals and fibers that were mainly concentrated in the periphery. Very few terminals were detected in the LVN. Met-enkephalin immunoreactive (Met-Enk-IR) fibers and terminals showed high density and uniform distribution in the DMNV. Scattered terminals and fibers were observed in the AP, ASP, and NTS (particularly the lateral division). The very few fibers were observed in the LVN surrounded the neuronal cell bodies. The present report is part of a study designed to investigate the interaction between neuropeptides and conventional neurotransmitters under conditions producing motion sickness and in the process of sensory-motor adaptation.

Projections of the optic tectum and the mesencephalic nucleus of the trigeminal nerve in the tegu lizard (Tupinambis nigropunctatus).

PubMed

Ebbesson, S O

1981-01-01

Fibers undergoing Wallerian degeneration following tectal lesions were demonstrated with the Nauta and Fink-Heimer methods and traced to their termination. Four of the five distinct fiber paths originating in the optic tectum appear related to vision, while one is related to the mesencephalic nucleus of the trigeminus. The latter component of the tectal efferents distributes fibers to 1) the main sensory nucleus of the trigeminus, 2) the motor nucleus of the trigeminus, 3) the nucleus of tractus solitarius, and 4) the intermediate gray of the cervical spinal cord. The principal ascending bundle projects to the nucleus rotundus, three components of the ventral geniculate nucleus and the nucleus ventromedialis anterior ipsilaterally, before it crosses in the supraoptic commissure and terminates in the contralateral nucleus rotundus, ventral geniculate nucleus and a hitherto unnamed region dorsal to the nucleus of the posterior accessory optic tract. Fibers leaving the tectum dorso-medially terminate in the posterodorsal nucleus ipsilaterally and the stratum griseum periventriculare of the contralateral tectum. The descending fiber paths terminate in medial reticular cell groups and the rostral spinal cord contralaterally and in the torus and the lateral reticular regions ipsilaterally. The ipsilateral fascicle also issues fibers to the magnocellular nucleus isthmi.

Oral sensory nerve damage: Causes and consequences.

PubMed

Snyder, Derek J; Bartoshuk, Linda M

2016-06-01

Oral sensations (i.e., taste, oral somatosensation, retronasal olfaction) are integrated into a composite sense of flavor, which guides dietary choices with long-term health impact. The nerves carrying this input are vulnerable to peripheral damage from multiple sources (e.g., otitis media, tonsillectomy, head injury), and this regional damage can boost sensations elsewhere in the mouth because of central interactions among nerve targets. Mutual inhibition governs this compensatory process, but individual differences lead to variation in whole-mouth outcomes: some individuals are unaffected, others experience severe loss, and some encounter sensory increases that may (if experienced early in life) elevate sweet-fat palatability and body mass. Phantom taste, touch, or pain sensations (e.g., burning mouth syndrome) may also occur, particularly in those expressing the most taste buds. To identify and treat these conditions effectively, emerging clinical tests measure regional vs. whole-mouth sensation, stimulated vs. phantom cues, and oral anatomy. Scaling methods allowing valid group comparisons have strongly aided these efforts. Overall, advances in measuring oral sensory function in health and disease show promise for understanding the varied clinical consequences of nerve damage.

Oral Sensory Nerve Damage: Causes and Consequences

PubMed Central

Snyder, Derek J.; Bartoshuk, Linda M.

2016-01-01

Oral sensations (i.e., taste, oral somatosensation, retronasal olfaction) are integrated into a composite sense of flavor, which guides dietary choices with long-term health impact. The nerves carrying this input are vulnerable to peripheral damage from multiple sources (e.g., otitis media, tonsillectomy, head injury), and this regional damage can boost sensations elsewhere in the mouth because of central interactions among nerve targets. Mutual inhibition governs this compensatory process, but individual differences lead to variation in whole-mouth outcomes: some individuals are unaffected, others experience severe loss, and some encounter sensory increases that may (if experienced early in life) elevate sweet-fat palatability and body mass. Phantom taste, touch, or pain sensations (e.g., burning mouth syndrome) may also occur, particularly in those expressing the most taste buds. To identify and treat these conditions effectively, emerging clinical tests measure regional vs. whole-mouth sensation, stimulated vs. phantom cues, and oral anatomy. Scaling methods allowing valid group comparisons have strongly aided these efforts. Overall, advances in measuring oral sensory function in health and disease show promise for understanding the varied clinical consequences of nerve damage. PMID:27511471

Substance P presynaptically depresses the transmission of sensory input to bronchopulmonary neurons in the guinea pig nucleus tractus solitarii

PubMed Central

Sekizawa, Shin-ichi; Joad, Jesse P; Bonham, Ann C

2003-01-01

Substance P modulates the reflex regulation of respiratory function by its actions both peripherally and in the CNS, particularly in the nucleus tractus solitarii (NTS), the first central site for synaptic contact of the lung and airway afferent fibres. There is considerable evidence that the actions of substance P in the NTS augment respiratory reflex output, but the precise effects on synaptic transmission have not yet been determined. Therefore, we determined the effects of substance P on synaptic transmission at the first central synapses by using whole-cell voltage clamping in an NTS slice preparation. Studies were performed on second-order neurons in the slice anatomically identified as receiving monosynaptic input from sensory nerves in the lungs and airways. This was done by the fluorescent labelling of terminal boutons after 1,1′-dioctadecyl-3,3,3′,3′-tetra-methylindocarbo-cyanine perchlorate (DiI) was applied via tracheal instillation. Substance P (1.0, 0.3 and 0.1 μM) significantly decreased the amplitude of excitatory postsynaptic currents (eEPSCs) evoked by stimulation of the tractus solitarius, in a concentration-dependent manner. The decrease was accompanied by an increase in the paired-pulse ratio of two consecutive eEPSCs, and a decrease in the frequency, but not the amplitude, of spontaneous EPSCs and miniature EPSCs, findings consistent with a presynaptic site of action. The effects were consistently and significantly attenuated by a neurokinin-1 (NK1) receptor antagonist (SR140333, 3 μM). The data suggest a new site of action for substance P in the NTS (NK1 receptors on the central terminals of sensory fibres) and a new mechanism (depression of synaptic transmission) for regulating respiratory reflex function. PMID:14561836

ENHANCING ADULT NERVE REGENERATION THROUGH THE KNOCKDOWN OF RETINOBLASTOMA PROTEIN

PubMed Central

Christie, Kimberly J.; Krishnan, Anand; Martinez, Jose A.; Purdy, Kaylynn; Singh, Bhagat; Eaton, Shane; Zochodne, Douglas

2016-01-01

Tumour suppressor pathways may offer novel targets capable of altering the plasticity of post-mitotic adult neurons. Here we describe a role for retinoblastoma (Rb) protein, widely expressed in adult sensory neurons and their axons, during regeneration. In adult sensory neurons, Rb siRNA knockdown or Rb1 deletion in vitro enhances neurite outgrowth and branching. Plasticity is achieved in part through upregulation of neuronal PPARγ; its antagonism inhibits Rb siRNA plasticity whereas a PPARγ agonist increases growth. In an in vivo regenerative paradigm following complete peripheral nerve trunk transection, direct delivery of Rb siRNA prompts increased outgrowth of axons from proximal stumps and entrains Schwann cells to accompany them for greater distances. Similarly Rb siRNA delivery following a nerve crush improves behavioural indices of motor and sensory recovery in mice. The overall findings indicate that inhibition of tumour suppressor molecules has a role to play in promoting adult neuron regeneration. PMID:24752312

Differential effects of myostatin deficiency on motor and sensory axons.

PubMed

Jones, Maria R; Villalón, Eric; Northcutt, Adam J; Calcutt, Nigel A; Garcia, Michael L

2017-12-01

Deletion of myostatin in mice (MSTN -/- ) alters structural properties of peripheral axons. However, properties like axon diameter and myelin thickness were analyzed in mixed nerves, so it is unclear whether loss of myostatin affects motor, sensory, or both types of axons. Using the MSTN -/- mouse model, we analyzed the effects of increasing the number of muscle fibers on axon diameter, myelin thickness, and internode length in motor and sensory axons. Axon diameter and myelin thickness were increased in motor axons of MSTN -/- mice without affecting internode length or axon number. The number of sensory axons was increased without affecting their structural properties. These results suggest that motor and sensory axons establish structural properties by independent mechanisms. Moreover, in motor axons, instructive cues from the neuromuscular junction may play a role in co-regulating axon diameter and myelin thickness, whereas internode length is established independently. Muscle Nerve 56: E100-E107, 2017. © 2017 Wiley Periodicals, Inc.

Protective effect of sensory denervation in inflammatory arthritis (evidence of regulatory neuroimmune pathways in the arthritic joint)

PubMed Central

Kane, D; Lockhart, J; Balint, P; Mann, C; Ferrell, W; McInnes, I

2005-01-01

Case report: The patient developed arthritis mutilans in all digits of both hands with the exception of the left 4th finger, which had prior sensory denervation following traumatic nerve dissection. Plain radiography, ultrasonography and nerve conduction studies of the hands confirmed the absence of articular disease and sensory innervation in the left 4th digit. Methods: This relationship between joint innervation and joint inflammation was investigated experimentally by prior surgical sensory denervation of the medial aspect of the knee in six Wistar rats in which carrageenan induced arthritis was subsequently induced. Prior sensory denervation—with preservation of muscle function—prevented the development of inflammatory arthritis in the denervated knee. Discussion: Observations in human and animal inflammatory arthritis suggest that regulatory neuroimmune pathways in the joint are an important mechanism that modulates the clinical expression of inflammatory arthritis. PMID:15155371

Comparison of Nerve Stimulation-guided Axillary Brachial Plexus Block, Single Injection versus Four Injections: A Prospective Randomized Double-blind Study.

PubMed

Badiger, Santoshi V; Desai, Sameer N

2017-01-01

A variety of techniques have been described for the axillary block using nerve stimulator, either with single injection, two, three, or four separate injections. Identification of all the four nerves is more difficult and time-consuming than other methods. Aim of the present study is to compare success rate, onset, and duration of sensory and motor anesthesia of axillary block using nerve stimulator, either with single injection after identification of any one of the four nerves or four separate injections following identification of each of nerve. Prospective, randomized, double-blind study. Patients undergoing forearm and hand surgeries under axillary block. One hundred patients, aged 18-75 years, were randomly allocated into two groups of 50 each. Axillary block was performed under the guidance of nerve stimulator with a mixture of 18 ml of 1.5% lignocaine and 18 ml of 0.5% bupivacaine. In the first group ( n = 50), all 36 ml of local anesthetic was injected after the identification of motor response to any one of the nerves and in Group 2, all the four nerves were identified by the motor response, and 9 ml of local anesthetic was injected at each of the nerves. The success rate of the block, onset, and duration of sensory and motor block was assessed. Categorical variables were compared using the Chi-square test, and continuous variables were compared using independent t -test. The success rate of the block with four injection technique was higher compared to single-injection technique (84% vs. 56%, P = 0.02). Four injection groups had a faster onset of sensory and motor block and prolonged duration of analgesia compared to single-injection group ( P < 0.001). There were no significant differences in the incidence of accidental arterial puncture and hemodynamic parameter between the groups. Identification of all the four nerves produced higher success rate and better quality of the block when compared to single-injection technique.

Glutamate control of pulpal blood flow in the incisor dental pulp of the rat.

PubMed

Zerari-Mailly, Fouzia; Braud, Adeline; Davido, Nicolas; Touré, Babacar; Azérad, Jean; Boucher, Yves

2012-10-01

Glutamate is present in primary sensory afferents innervating the dental pulp and is known to exert vasoactive effects. The aims of this study were (i) to assess pulpal blood flow (PBF) after glutamate infusion in the dental pulp and (ii) to observe the distribution of glutamatergic nerve fibers expressing the vesicular transporters of glutamate (VGluT). The PBF was monitored with laser Doppler flowmetry before and after glutamate (0.5 M) infusion in the dental pulp vs. saline infusion. Immunochemistry for VGluT1, 2, and 3 was performed in addition to immunochemistry for the vascular and neuronal markers smooth-muscle actin (SMA), isolectin B4 (IB4), and calcitonin gene-related peptide (CGRP). Glutamate infusion resulted in a PBF increase that lasted for 60 s. Positive immunolabeling was observed for the three glutamate transporters, but was more pronounced for VGluT3. Moreover, VGluT3 immunoreactivity was observed within nerve fibers entering the dental pulp and terminating at the periphery and at the vicinity of odontoblasts. Also, VGluT3 was colocalized with the vascular marker SMA, and in some nerve fibers with IB4, but not with CGRP. This study provides support for a control of dental pulp microcirculation by neurons expressing VGluT3. © 2012 Eur J Oral Sci.

Age-dependent effects on sensory axonal excitability in normal mice.

PubMed

Banzrai, Chimeglkham; Nodera, Hiroyuki; Higashi, Saki; Okada, Ryo; Osaki, Yusuke; Mori, Atsuko; Kaji, Ryuji

2016-01-12

Serial recordings were performed to measure sensory excitability in peripheral nerves and elucidate age-dependent changes in neuronal ion currents in the peripheral sensory nervous system. The threshold tracking technique was used to measure multiple excitability indices in the tail sensory nerves of five normal male mice at four time points (6, 10, 14, and 19 weeks of age). A separate group of four mice was also measured at 43 weeks and at 60 weeks of age. Maturation was accompanied by an increase in early hyperpolarization and superexcitability at 10 weeks. At 60 weeks, the hyperpolarizing electrotonus shifted downward, while superexcitability became greater and subexcitability (double stimuli) decreased. Computer modeling showed that the most notable age-related interval changes in excitability parameters were Barrett-Barrett, H, and slow K(+) conductances. Understanding age-related changes in the excitability of sensory axons may provide a platform for understanding age-dependent sensory symptoms and developing age-specific channel-targeting therapies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Differences in two-point discrimination and sensory threshold in the blind between braille and text reading: a pilot study.

PubMed

Noh, Ji-Woong; Park, Byoung-Sun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kang, Ji-Hye; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

2015-06-01

[Purpose] This study investigated two-point discrimination (TPD) and the electrical sensory threshold of the blind to define the effect of using Braille on the tactile and electrical senses. [Subjects and Methods] Twenty-eight blind participants were divided equally into a text-reading and a Braille-reading group. We measured tactile sensory and electrical thresholds using the TPD method and a transcutaneous electrical nerve stimulator. [Results] The left palm TPD values were significantly different between the groups. The values of the electrical sensory threshold in the left hand, the electrical pain threshold in the left hand, and the electrical pain threshold in the right hand were significantly lower in the Braille group than in the text group. [Conclusion] These findings make it difficult to explain the difference in tactility between groups, excluding both palms. However, our data show that using Braille can enhance development of the sensory median nerve in the blind, particularly in terms of the electrical sensory and pain thresholds.

Differences in two-point discrimination and sensory threshold in the blind between braille and text reading: a pilot study

PubMed Central

Noh, Ji-Woong; Park, Byoung-Sun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kang, Ji-Hye; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

2015-01-01

[Purpose] This study investigated two-point discrimination (TPD) and the electrical sensory threshold of the blind to define the effect of using Braille on the tactile and electrical senses. [Subjects and Methods] Twenty-eight blind participants were divided equally into a text-reading and a Braille-reading group. We measured tactile sensory and electrical thresholds using the TPD method and a transcutaneous electrical nerve stimulator. [Results] The left palm TPD values were significantly different between the groups. The values of the electrical sensory threshold in the left hand, the electrical pain threshold in the left hand, and the electrical pain threshold in the right hand were significantly lower in the Braille group than in the text group. [Conclusion] These findings make it difficult to explain the difference in tactility between groups, excluding both palms. However, our data show that using Braille can enhance development of the sensory median nerve in the blind, particularly in terms of the electrical sensory and pain thresholds. PMID:26180348

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

PubMed

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

2013-08-01

Mirror neurons allow us to covertly simulate the sensation and movement of others. If mirror neurons are sensory and motor neurons, why do we not actually feel this simulation- like "mirror-touch synesthetes"? Might afferent sensation normally inhibit mirror representations from reaching consciousness? We and others have reported heightened sensory referral to phantom limbs and temporarily anesthetized arms. These patients, however, had experienced illness or injury of the deafferented limb. In the current study we observe heightened sensory and motor referral to the face after unilateral nerve block for routine dental procedures. We also obtain double-blind, quantitative evidence of heightened sensory referral in healthy participants completing a mirror-touch confusion task after topical anesthetic cream is applied. We suggest that sensory and motor feedback exist in dynamic equilibrium with mirror representations; as feedback is reduced, the brain draws more upon visual information to determine- perhaps in a Bayesian manner- what to feel. Copyright © 2013 Elsevier Ltd. All rights reserved.

Chronic non-freezing cold injury results in neuropathic pain due to a sensory neuropathy

PubMed Central

Vale, Tom A; Symmonds, Mkael; Polydefkis, Michael; Byrnes, Kelly; Rice, Andrew S C; Themistocleous, Andreas C; Bennett, David L H

2017-01-01

Abstract Non-freezing cold injury develops after sustained exposure to cold temperatures, resulting in tissue cooling but not freezing. This can result in persistent sensory disturbance of the hands and feet including numbness, paraesthesia and chronic pain. Both vascular and neurological aetiologies of this pain have been suggested but remain unproven. We prospectively approached patients referred for clinical assessment of chronic pain following non-freezing cold injury between 12 February 2014 and 30 November 2016. Of 47 patients approached, 42 consented to undergo detailed neurological evaluations including: questionnaires to detail pain location and characteristics, structured neurological examination, quantitative sensory testing, nerve conduction studies and skin biopsy for intraepidermal nerve fibre assessment. Of the 42 study participants, all had experienced non-freezing cold injury while serving in the UK armed services and the majority were of African descent (76.2%) and male (95.2%). Many participants reported multiple exposures to cold. The median time between initial injury and referral was 3.72 years. Pain was principally localized to the hands and the feet, neuropathic in nature and in all study participants associated with cold hypersensitivity. Clinical examination and quantitative sensory testing were consistent with a sensory neuropathy. In all cases, large fibre nerve conduction studies were normal. The intraepidermal nerve fibre density was markedly reduced with 90.5% of participants having a count at or below the 0.05 centile of published normative controls. Using the Neuropathic Pain Special Interest Group of the International Association for the Study of Pain grading for neuropathic pain, 100% had probable and 95.2% definite neuropathic pain. Chronic non-freezing cold injury is a disabling neuropathic pain disorder due to a sensory neuropathy. Why some individuals develop an acute painful sensory neuropathy on sustained cold exposure is not yet known, but individuals of African descent appear vulnerable. Screening tools, such as the DN4 questionnaire, and treatment algorithms for neuropathic pain should now be used in the management of these patients. PMID:28969380

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

PubMed Central

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

2014-01-01

Surprisingly little is known about the impact of entrapment neuropathy on target innervation and the relationship of nerve fibre pathology to sensory symptoms and signs. Carpal tunnel syndrome is the most common entrapment neuropathy; the aim of this study was to investigate its effect on the morphology of small unmyelinated as well as myelinated sensory axons and relate such changes to somatosensory function and clinical symptoms. Thirty patients with a clinical and electrophysiological diagnosis of carpal tunnel syndrome [17 females, mean age (standard deviation) 56.4 (15.3)] and 26 age and gender matched healthy volunteers [18 females, mean age (standard deviation) 51.0 (17.3)] participated in the study. Small and large fibre function was examined with quantitative sensory testing in the median nerve territory of the hand. Vibration and mechanical detection thresholds were significantly elevated in patients with carpal tunnel syndrome (P < 0.007) confirming large fibre dysfunction and patients also presented with increased thermal detection thresholds (P < 0.0001) indicative of C and Aδ-fibre dysfunction. Mechanical and thermal pain thresholds were comparable between groups (P > 0.13). A skin biopsy was taken from a median nerve innervated area of the proximal phalanx of the index finger. Immunohistochemical staining for protein gene product 9.5 and myelin basic protein was used to evaluate morphological features of unmyelinated and myelinated axons. Evaluation of intraepidermal nerve fibre density showed a striking loss in patients (P < 0.0001) confirming a significant compromise of small fibres. The extent of Meissner corpuscles and dermal nerve bundles were comparable between groups (P > 0.07). However, patients displayed a significant increase in the percentage of elongated nodes (P < 0.0001), with altered architecture of voltage-gated sodium channel distribution. Whereas neither neurophysiology nor quantitative sensory testing correlated with patients’ symptoms or function deficits, the presence of elongated nodes was inversely correlated with a number of functional and symptom related scores (P < 0.023). Our findings suggest that carpal tunnel syndrome does not exclusively affect large fibres but is associated with loss of function in modalities mediated by both unmyelinated and myelinated sensory axons. We also document for the first time that entrapment neuropathies lead to a clear reduction in intraepidermal nerve fibre density, which was independent of electrodiagnostic test severity. The presence of elongated nodes in the target tissue further suggests that entrapment neuropathies affect nodal structure/myelin well beyond the focal compression site. Interestingly, nodal lengthening may be an adaptive phenomenon as it inversely correlates with symptom severity. PMID:25348629

Cranial nerves in the Australian lungfish, Neoceratodus forsteri, and in fossil relatives (Osteichthyes: Dipnoi).

PubMed

Kemp, A

2017-02-01

Three systems, two sensory and one protective, are present in the skin of the living Australian lungfish, Neoceratodus forsteri, and in fossil lungfish, and the arrangement and innervation of the sense organs is peculiar to lungfish. Peripheral branches of nerves that innervate the sense organs are slender and unprotected, and form before any skeletal structures appear. When the olfactory capsule develops, it traps some of the anterior branches of cranial nerve V, which emerged from the chondrocranium from the lateral sphenotic foramen. Cranial nerve I innervates the olfactory organ enclosed within the olfactory capsule and cranial nerve II innervates the eye. Cranial nerve V innervates the sense organs of the snout and upper lip, and, in conjunction with nerve IX and X, the sense organs of the posterior and lateral head. Cranial nerve VII is primarily a motor nerve, and a single branch innervates sense organs in the mandible. There are no connections between nerves V and VII, although both emerge from the brain close to each other. The third associated system consists of lymphatic vessels covered by an extracellular matrix of collagen, mineralised as tubules in fossils. Innervation of the sensory organs is separate from the lymphatic system and from the tubule system of fossil lungfish. Copyright © 2016 Elsevier Ltd. All rights reserved.

Musculocutaneous nerve injury after simulated freefall in a vertical wind-tunnel: a case report.

PubMed

Mautner, Kenneth; Keel, John C

2007-03-01

We report a case of a skydiver with isolated musculocutaneous nerve injury, which occurred after prolonged positioning of the arm during simulated freefall in a vertical wind-tunnel. Musculocutaneous nerve injury is rare, and the mechanism of isolated injury to this nerve is not entirely understood. Isolated peripheral nerve injuries such as this easily mimic other injuries and can be difficult to diagnose. The skydiver complained of right arm weakness and numbness that began after training in a vertical wind-tunnel. Exam revealed weakness in right elbow flexion and forearm supination, and diminished sensation in the right lateral forearm. Electrodiagnostic testing revealed a decreased amplitude in the right lateral antebrachial cutaneous nerve sensory nerve action potential, and fibrillations and positive sharp waves in the biceps and brachialis muscles. By 5 months, the subject reported complete sensory and motor recovery. Physical and electrodiagnostic findings corresponded to the distribution of the musculocutaneous nerve. The mechanism of injury was likely the prolonged abducted, extended, and externally rotated position of the shoulder during simulated freefall. Although isolated nerve injuries are uncommon, unusual activities and physiologic demands of athletes can result in such injuries. It is important to be aware of peripheral nerve injuries to facilitate proper diagnosis and management.

Clinical neurophysiology and quantitative sensory testing in the investigation of orofacial pain and sensory function.

PubMed

Jääskeläinen, Satu K

2004-01-01

Chronic orofacial pain represents a diagnostic and treatment challenge for the clinician. Some conditions, such as atypical facial pain, still lack proper diagnostic criteria, and their etiology is not known. The recent development of neurophysiological methods and quantitative sensory testing for the examination of the trigeminal somatosensory system offers several tools for diagnostic and etiological investigation of orofacial pain. This review presents some of these techniques and the results of their application in studies on orofacial pain and sensory dysfunction. Clinical neurophysiological investigation has greater diagnostic accuracy and sensitivity than clinical examination in the detection of the neurogenic abnormalities of either peripheral or central origin that may underlie symptoms of orofacial pain and sensory dysfunction. Neurophysiological testing may also reveal trigeminal pathology when magnetic resonance imaging has failed to detect it, so these methods should be considered complementary to each other in the investigation of orofacial pain patients. The blink reflex, corneal reflex, jaw jerk, sensory neurography of the inferior alveolar nerve, and the recording of trigeminal somatosensory-evoked potentials with near-nerve stimulation have all proved to be sensitive and reliable in the detection of dysfunction of the myelinated sensory fibers of the trigeminal nerve or its central connections within the brainstem. With appropriately small thermodes, thermal quantitative sensory testing is useful for the detection of trigeminal small-fiber dysfunction (Adelta and C). In neuropathic conditions, it is most sensitive to lesions causing axonal injury. By combining different techniques for investigation of the trigeminal system, an accurate topographical diagnosis and profile of sensory fiber pathology can be determined. Neurophysiological and quantitative sensory tests have already highlighted some similarities among various orofacial pain conditions and have shown heterogeneity within clinical diagnostic categories. With the aid of neurophysiological recordings and quantitative sensory testing, it is possible to approach a mechanism-based classification of orofacial pain.

Palisade endings in extraocular eye muscles revealed by SNAP-25 immunoreactivity.

PubMed

Eberhorn, Andreas C; Horn, Anja K E; Eberhorn, Nicola; Fischer, Petra; Boergen, Klaus-Peter; Büttner-Ennever, Jean A

2005-03-01

Palisade endings form a cuff of nerve terminals around the tip of muscle fibres. They are found only in extraocular muscles, but no definite evidence for their role in eye movements has been established. Palisade endings have been reported in all species so far investigated except the rat. In this study we demonstrate that antibodies against SNAP-25, the synaptosomal associated protein of 25 kDa, reliably visualize the complete motor, sensory and autonomic innervation of the extraocular muscles in human, monkey and rat. The SNAP-25 antibody can be combined with other immunofluorescence procedures, and is used here to study properties of palisade endings. With SNAP-25 immunolabelling putative palisade endings are identified in the rat for the first time. They are not well branched, but fulfil several criteria of palisade endings, being associated with non-twitch fibres as shown by double labelling with 'myosin heavy chain slow-twitch' antibodies. The putative palisade endings of the rat lack alpha-bungarotoxin binding, which implies that these synapses are sensory. If palisade endings are sensory then they could function as an eye muscle proprioceptor. They seem to be a general feature of all vertebrate eye muscles, unlike the other two extraocular proprioceptors, muscle spindles and Golgi tendon organs, the presence of which varies widely between species.

Palisade endings in extraocular eye muscles revealed by SNAP-25 immunoreactivity

PubMed Central

Eberhorn, Andreas C; Horn, Anja KE; Eberhorn, Nicola; Fischer, Petra; Boergen, Klaus-Peter; Büttner-Ennever, Jean A

2005-01-01

Palisade endings form a cuff of nerve terminals around the tip of muscle fibres. They are found only in extraocular muscles, but no definite evidence for their role in eye movements has been established. Palisade endings have been reported in all species so far investigated except the rat. In this study we demonstrate that antibodies against SNAP-25, the synaptosomal associated protein of 25 kDa, reliably visualize the complete motor, sensory and autonomic innervation of the extraocular muscles in human, monkey and rat. The SNAP-25 antibody can be combined with other immunofluorescence procedures, and is used here to study properties of palisade endings. With SNAP-25 immunolabelling putative palisade endings are identified in the rat for the first time. They are not well branched, but fulfil several criteria of palisade endings, being associated with non-twitch fibres as shown by double labelling with ‘myosin heavy chain slow-twitch’ antibodies. The putative palisade endings of the rat lack α-bungarotoxin binding, which implies that these synapses are sensory. If palisade endings are sensory then they could function as an eye muscle proprioceptor. They seem to be a general feature of all vertebrate eye muscles, unlike the other two extraocular proprioceptors, muscle spindles and Golgi tendon organs, the presence of which varies widely between species. PMID:15733303

Non-invasive stimulation of the vibrissal pad improves recovery of whisking function after simultaneous lesion of the facial and infraorbital nerves in rats.

PubMed

Bendella, H; Pavlov, S P; Grosheva, M; Irintchev, A; Angelova, S K; Merkel, D; Sinis, N; Kaidoglou, K; Skouras, E; Dunlop, S A; Angelov, Doychin N

2011-07-01

We have recently shown that manual stimulation of target muscles promotes functional recovery after transection and surgical repair to pure motor nerves (facial: whisking and blink reflex; hypoglossal: tongue position). However, following facial nerve repair, manual stimulation is detrimental if sensory afferent input is eliminated by, e.g., infraorbital nerve extirpation. To further understand the interplay between sensory input and motor recovery, we performed simultaneous cut-and-suture lesions on both the facial and the infraorbital nerves and examined whether stimulation of the sensory afferents from the vibrissae by a forced use would improve motor recovery. The efficacy of 3 treatment paradigms was assessed: removal of the contralateral vibrissae to ensure a maximal use of the ipsilateral ones (vibrissal stimulation; Group 2), manual stimulation of the ipsilateral vibrissal muscles (Group 3), and vibrissal stimulation followed by manual stimulation (Group 4). Data were compared to controls which underwent surgery but did not receive any treatment (Group 1). Four months after surgery, all three treatments significantly improved the amplitude of vibrissal whisking to 30° versus 11° in the controls of Group 1. The three treatments also reduced the degree of polyneuronal innervation of target muscle fibers to 37% versus 58% in Group 1. These findings indicate that forced vibrissal use and manual stimulation, either alone or sequentially, reduce target muscle polyinnervation and improve recovery of whisking function when both the sensory and the motor components of the trigemino-facial system regenerate.

CO-LOCALIZATION OF THE VANILLOID CAPSAICIN RECEPTOR AND SUBSTANCE P IN SENSORY NERVE FIBERS INNERVATING COCHLEAR AND VERTEBRO-BASILAR ARTERIES

PubMed Central

VASS, Z.; DAI, C. F.; STEYGER, P. S.; JANCSÓ, G.; TRUNE, D. R.; NUTTALL, A. L.

2014-01-01

Evidence suggests that capsaicin-sensitive substance P (SP)-containing trigeminal ganglion neurons innervate the spiral modiolar artery (SMA), radiating arterioles, and the stria vascularis of the cochlea. Antidromic electrical or chemical stimulation of trigeminal sensory nerves results in neurogenic plasma extravasation in inner ear tissues. The primary aim of this study was to reveal the possible morphological basis of cochlear vascular changes mediated by capsaicin-sensitive sensory nerves. Therefore, the distribution of SP and capsaicin receptor (transient receptor potential vanilloid type 1—TRPV1) was investigated by double immunolabeling to demonstrate the anatomical relationships between the cochlear and vertebro-basilar blood vessels and the trigeminal sensory fiber system. Extensive TRPV1 and SP expression and co-localization were observed in axons within the adventitial layer of the basilar artery, the anterior inferior cerebellar artery, the SMA, and the radiating arterioles of the cochlea. There appears to be a functional relationship between the trigeminal ganglion and the cochlear blood vessels since electrical stimulation of the trigeminal ganglion induced significant plasma extravasation from the SMA and the radiating arterioles. The findings suggest that stimulation of paravascular afferent nerves may result in permeability changes in the basilar and cochlear vascular bed and may contribute to the mechanisms of vertebro-basilar type of headache through the release of SP and stimulation of TPVR1, respectively. We propose that vertigo, tinnitus, and hearing deficits associated with migraine may arise from perturbations of capsaicin-sensitive trigeminal sensory ganglion neurons projecting to the cochlea. PMID:15026132

Parasympathetic, sympathetic, and sensory interactions in the iris: nerve growth factor regulates cholinergic ciliary ganglion innervation in vivo.

PubMed

Kessler, J A

1985-10-01

Interactions between peptidergic sensory nerves, noradrenergic sympathetic nerves, and cholinergic parasympathetic fibers were examined in the rat iris. The putative peptide neurotransmitter, substance P (SP), was used as an index of the trigeminal sensory innervation, tyrosine hydroxylase (TH) activity served to monitor the sympathetic fibers, and choline acetyltransferase (CAT) activity was used as an index of the parasympathetic innervation. Destruction of the sympathetic innervation by neonatal administration of 6-hydroxydopamine resulted in increased SP development and a smaller increase in CAT activity in the iris. Moreover, trigeminal ablation resulted in an increase in both TH and CAT activities. Finally, ciliary ganglionectomy resulted in increased SP and a smaller increase in TH activity in the iris. Administration of nerve growth factor (NGF) into the anterior chamber substantially increased both SP and TH activity in the iris and also increased CAT activity to a lesser extent. Moreover, administration of anti-NGF into the anterior chamber prevented both the sympathectomy-induced increases in SP and CAT, and the increases in TH and CAT activities after trigeminal ablation, suggesting that NGF mediated these increases. These observations suggest that the sympathetic, sensory, and parasympathetic innervations of the iris interact by altering availability of NGF elaborated by the iris. Regulation of iris CAT activity was examined in greater detail. Injection of the cholinergic toxin, AF64A, into the anterior chamber concurrently with ablation of the sympathetic and sensory innervations paradoxically increased CAT activity, whereas AF64A alone decreased CAT activity.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparative analysis of the encapsulated end-organs of mammalian skeletal muscles and of their sensory nerve endings.

PubMed

Banks, R W; Hulliger, M; Saed, H H; Stacey, M J

2009-06-01

The encapsulated sensory endings of mammalian skeletal muscles are all mechanoreceptors. At the most basic functional level they serve as length sensors (muscle spindle primary and secondary endings), tension sensors (tendon organs), and pressure or vibration sensors (lamellated corpuscles). At a higher functional level, the differing roles of individual muscles in, for example, postural adjustment and locomotion might be expected to be reflected in characteristic complements of the various end-organs, their sensory endings and afferent nerve fibres. This has previously been demonstrated with regard to the number of muscle-spindle capsules; however, information on the other types of end-organ, as well as the complements of primary and secondary endings of the spindles themselves, is sporadic and inconclusive regarding their comparative provision in different muscles. Our general conclusion that muscle-specific variability in the provision of encapsulated sensory endings does exist demonstrates the necessity for the acquisition of more data of this type if we are to understand the underlying adaptive relationships between motor control and the structure and function of skeletal muscle. The present quantitative and comparative analysis of encapsulated muscle afferents is based on teased, silver-impregnated preparations. We begin with a statistical analysis of the number and distribution of muscle-spindle afferents in hind-limb muscles of the cat, particularly tenuissimus. We show that: (i) taking account of the necessity for at least one primary ending to be present, muscles differ significantly in the mean number of additional afferents per spindle capsule; (ii) the frequency of occurrence of spindles with different sensory complements is consistent with a stochastic, rather than deterministic, developmental process; and (iii) notwithstanding the previous finding, there is a differential distribution of spindles intramuscularly such that the more complex ones tend to be located closer to the main divisions of the nerve. Next, based on a sample of tendon organs from several hind-foot muscles of the cat, we demonstrate the existence in at least a large proportion of tendon organs of a structural substrate to account for multiple spike-initiation sites and pacemaker switching, namely the distribution of sensory terminals supplied by the different first-order branches of the Ib afferent to separate, parallel, tendinous compartments of individual tendon organs. We then show that the numbers of spindles, tendon organs and paciniform corpuscles vary independently in a sample of (mainly) hind-foot muscles of the cat. Grouping muscles by anatomical region in the cat indicated the existence of a gradual proximo-distal decline in the overall average size of the afferent complement of muscle spindles from axial through hind limb to intrinsic foot muscles, but with considerable muscle-specific variability. Finally, we present some comparative data on muscle-spindle afferent complements of rat, rabbit and guinea pig, one particularly notable feature being the high incidence of multiple primary endings in the rat.

Disability following combat-sustained nerve injury of the upper limb.

PubMed

Rivera, J C; Glebus, G P; Cho, M S

2014-02-01

Injuries to the limb are the most frequent cause of permanent disability following combat wounds. We reviewed the medical records of 450 soldiers to determine the type of upper limb nerve injuries sustained, the rate of remaining motor and sensory deficits at final follow-up, and the type of Army disability ratings granted. Of 189 soldiers with an injury of the upper limb, 70 had nerve-related trauma. There were 62 men and eight women with a mean age of 25 years (18 to 49). Disabilities due to nerve injuries were associated with loss of function, neuropathic pain or both. The mean nerve-related disability was 26% (0% to 70%), accounting for over one-half of this cohort's cumulative disability. Patients injured in an explosion had higher disability ratings than those injured by gunshot. The ulnar nerve was most commonly injured, but most disability was associated with radial nerve trauma. In terms of the final outcome, at military discharge 59 subjects (84%) experienced persistent weakness, 48 (69%) had a persistent sensory deficit and 17 (24%) experienced chronic pain from scar-related or neuropathic pain. Nerve injury was the cause of frequent and substantial disability in our cohort of wounded soldiers.

Analysis of human acellular nerve allograft reconstruction of 64 injured nerves in the hand and upper extremity: a 3 year follow-up study.

PubMed

Zhu, Shuang; Liu, Jianghui; Zheng, Canbin; Gu, Liqiang; Zhu, Qingtang; Xiang, Jianping; He, Bo; Zhou, Xiang; Liu, Xiaolin

2017-08-01

Human acellular nerve allografts have been increasingly applied in clinical practice. This study was undertaken to investigate the functional outcomes of nerve allograft reconstruction for nerve defects in the upper extremity. A total of 64 patients from 13 hospitals were available for this follow-up study after nerve repair using human acellular nerve allografts. Sensory and motor recovery was examined according to the international standards for motor and sensory nerve recovery. Subgroup analysis and logistic regression analysis were conducted to identify the relationship between the known factors and the outcomes of nerve repair. Mean follow-up time was 355 ± 158 (35-819) days; mean age was 35 ± 11 (14-68) years; average nerve gap length was 27 ± 13 (10-60) mm; no signs of infection, tissue rejection or extrusion were observed among the patients; 48/64 (75%) repaired nerves experienced meaningful recovery. Univariate analysis showed that site and gap length significantly influenced prognosis after nerve repair using nerve grafts. Delay had a marginally significant relationship with the outcome. A multivariate logistic regression model revealed that gap length was an independent predictor of nerve repair using human acellular nerve allografts. The results indicated that the human acellular nerve allograft facilitated safe and effective nerve reconstruction for nerve gaps 10-60 mm in length in the hand and upper extremity. Factors such as site and gap length had a statistically significant influence on the outcomes of nerve allograft reconstruction. Gap length was an independent predictor of nerve repair using human acellular nerve allografts. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Modeling neuropeptide transport in various types of nerve terminals containing en passant boutons.

PubMed

Kuznetsov, I A; Kuznetsov, A V

2015-03-01

We developed a mathematical model for simulating neuropeptide transport inside dense core vesicles (DCVs) in axon terminals containing en passant boutons. The motivation for this research is a recent experimental study by Levitan and colleagues (Bulgari et al., 2014) which described DCV transport in nerve terminals of type Ib and type III as well as in nerve terminals of type Ib with the transcription factor DIMM. The goal of our modeling is validating the proposition put forward by Levitan and colleagues that the dramatic difference in DCV number in type Ib and type III terminals can be explained by the difference in DCV capture in type Ib and type III boutons rather than by differences in DCV anterograde transport and half-life of resident DCVs. The developed model provides a tool for studying the dynamics of DCV transport in various types of nerve terminals. The model is also an important step in gaining a better mechanistic understanding of transport processes in axons and identifying directions for the development of new models in this area. Copyright © 2014 Elsevier Inc. All rights reserved.

Peripheral ionotropic glutamate receptors contribute to Fos expression increase in the spinal cord through antidromic electrical stimulation of sensory nerves.

PubMed

Li, Jia-Heng; He, Pei-Yao; Fan, Dan-Ni; Alemujiang, Dilinapa; Huo, Fu-Quan; Zhao, Yan; Cao, Dong-Yuan

2018-06-21

Previous studies have shown that peripheral ionotropic glutamate receptors are involved in the increase in sensitivity of a cutaneous branch of spinal dorsal ramus (CBDR) through antidromic electrical stimulation (ADES) of another CBDR in the adjacent segment. CBDR in the thoracic segments run parallel to each other and no synaptic contact at the periphery is reported. The present study investigated whether the increased sensitivity of peripheral sensory nerves via ADES of a CBDR induced Fos expression changes in the adjacent segments of the spinal cord. Fos expression increased in the T8 - T12 segments of the spinal cord evoked by ADES of the T10 CBDR in rats. The increased Fos expression in the T11 and T12, but not T8 - T10 spinal cord segments, was significantly blocked by local application of either N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine maleate (MK-801) or non-NMDA receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX) into the receptive field of T11 CBDR. The results suggest that endogenous glutamate released by ADES of sensory nerve may bind to peripheral ionotropic glutamate receptors and activate adjacent sensory nerve endings to increase the sensitivity of the spinal cord. These data reveal the potential mechanisms of neuron activation in the spinal cord evoked by peripheral sensitization. Copyright © 2018 Elsevier B.V. All rights reserved.

Desmin and nerve terminal expression during embryonic development of the lateral pterygoid muscle in mice.

PubMed

Yamamoto, Masahito; Shinomiya, Takashi; Kishi, Asuka; Yamane, Shigeki; Umezawa, Takashi; Ide, Yoshinobu; Abe, Shinichi

2014-09-01

In adults, the lateral pterygoid muscle (LPM) is usually divided into the upper and lower head, between which the buccal nerve passes. Recent investigations have demonstrated foetal developmental changes in the topographical relationship between the human LPM and buccal nerve. However, as few studies have investigated this issue, we clarified the expression of desmin and nerve terminal distribution during embryonic development of the LPM in mice. We utilized immunohistochemical staining and reverse transcription chain reaction (RT-PCR) to clarify the expression of desmin and nerve terminal distribution. We observed weak expression of desmin in the LPM at embryonic day (ED) 11, followed by an increase in expression from embryonic days 12-15. In addition, starting at ED 12, we observed preferential accumulation of desmin in the vicinity of the myotendinous junction, a trend that did not change up to ED 15. Nerve terminal first appeared at ED 13 and formed regularly spaced linear arrays at the centre of the muscle fibre by ED 15. The results of immunohistochemical staining agreed with those of RT-PCR analysis. We found that desmin accumulated in the vicinity of the myotendinous junction starting at ED 12, prior to the onset of jaw movement. We speculate that the accumulation of desmin is due to factors other than mechanical stress experienced during early muscle contraction. Meanwhile, the time point at which nerve terminals first appeared roughly coincided with the onset of jaw movement. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cutaneous somatic and autonomic nerve TDP-43 deposition in amyotrophic lateral sclerosis.

PubMed

Ren, Yuting; Liu, Wenxiu; Li, Yifan; Sun, Bo; Li, Yanran; Yang, Fei; Wang, Hongfen; Li, Mao; Cui, Fang; Huang, Xusheng

2018-05-26

To evaluate the involvement of the sensory and autonomic nervous system in amyotrophic lateral sclerosis (ALS) and to determine whether TDP-43/pTDP-43 deposits in skin nerve fibers signify a valuable biomarker for ALS. Eighteen patients with ALS and 18 age- and sex-matched control subjects underwent physical examinations, in addition to donating skin biopsies from the distal leg. The density of epidermal, Meissner's corpuscle (MC), sudomotor, and pilomotor nerve fibers were measured. Confocal microscopy was used to determine the cutaneous somatic and autonomic nerve fiber density and TDP-43/pTDP-43 deposition. Intraepidermal nerve fiber density (IENFD) was reduced in individuals with ALS (P < 0.001). MC density (MCD) (P = 0.001), sweat gland nerve fiber density (SGNFD) (P < 0.001), and pilomotor nerve fiber density (PNFD) (P < 0.001) were all reduced in ALS patients. The SGNFD correlated with the small-fiber neuropathy Symptoms Inventory Questionnaire (SFN-SIQ), VAS and age. The SFN-SIQ was higher in ALS with sensory symptoms than without sensory symptoms (P = 0.000). Furthermore, the SFN-SIQ was higher in ALS with autonomic symptoms than without autonomic symptoms (P = 0.002). SFN-SIQ was higher in ALS patients that were pTDP-43 positive than pTDP-43 negative (P = 0.04), respectively. We established in the peripheral nervous system that higher SFN-SIQ and VAS was involved in ALS, indicating the loss of SGNF. The deposition of TDP-43/pTDP-43 in ALS nerve fibers may indicate an important role in the underlying pathogenesis of ALS. This observation might be used as a potential biomarker for diagnosing ALS.

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

USDA-ARS?s Scientific Manuscript database

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

Morphological and functional changes in TRPM8-expressing corneal cold thermoreceptor neurons during aging and their impact on tearing in mice.

PubMed

Alcalde, Ignacio; Íñigo-Portugués, Almudena; González-González, Omar; Almaraz, Laura; Artime, Enol; Morenilla-Palao, Cruz; Gallar, Juana; Viana, Félix; Merayo-Lloves, Jesús; Belmonte, Carlos

2018-08-01

Morphological and functional alterations of peripheral somatosensory neurons during the aging process lead to a decline of somatosensory perception. Here, we analyze the changes occurring with aging in trigeminal ganglion (TG), TRPM8-expressing cold thermoreceptor neurons innervating the mouse cornea, which participate in the regulation of basal tearing and blinking and have been implicated in the pathogenesis of dry eye disease (DED). TG cell bodies and axonal branches were examined in a mouse line (TRPM8 BAC -EYFP) expressing a fluorescent reporter. In 3 months old animals, about 50% of TG cold thermoreceptor neurons were intensely fluorescent, likely providing strongly fluorescent axons and complex corneal nerve terminals with ongoing activity at 34°C and low-threshold, robust responses to cooling. The remaining TRPM8 + corneal axons were weakly fluorescent with nonbeaded axons, sparsely ramified nerve terminals, and exhibited a low-firing rate at 34°C, responding moderately to cooling pulses as do weakly fluorescent TG neurons. In aged (24 months) mice, the number of weakly fluorescent TG neurons was strikingly high while the morphology of TRPM8 + corneal axons changed drastically; 89% were weakly fluorescent, unbranched, and often ending in the basal epithelium. Functionally, 72.5% of aged cold terminals responded as those of young animals, but 27.5% exhibited very low-background activity and abnormal responsiveness to cooling pulses. These morpho-functional changes develop in parallel with an enhancement of tear's basal flow and osmolarity, suggesting that the aberrant sensory inflow to the brain from impaired peripheral cold thermoreceptors contributes to age-induced abnormal tearing and to the high incidence of DED in elderly people. © 2018 Wiley Periodicals, Inc.

Bladder function - neurological control

MedlinePlus Videos and Cool Tools

... with urine, sensory nerves send impulses to the brain indicating that the bladder is full. The sensory ... cord to relay this information. In turn, the brain sends impulses back to the bladder instructing the ...

Silicone Molding and Lifetime Testing of Peripheral Nerve Interfaces for Neuroprostheses

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

Gupte, Kimaya; Tolosa, Vanessa

Implantable peripheral nerve cuffs have a large application in neuroprostheses as they can be used to restore sensation to those with upper limb amputations. Modern day prosthetics, while lessening the pain associated with phantom limb syndrome, have limited fine motor control and do not provide sensory feedback to patients. Sensory feedback with prosthetics requires communication between the nervous system and limbs, and is still a challenge to accomplish with amputees. Establishing this communication between the peripheral nerves in the arm and artificial limbs is vital as prosthetics research aims to provide sensory feedback to amputees. Peripheral nerve cuffs restore sensationmore » by electrically stimulating certain parts of the nerve in order to create feeling in the hand. Cuff electrodes have an advantage over standard electrodes as they have high selective stimulation by bringing the electrical interface close to the neural tissue in order to selectively activate targeted regions of a peripheral nerve. In order to further improve the selective stimulation of these nerve cuffs, there is need for finer spatial resolution among electrodes. One method to achieve a higher spatial resolution is to increase the electrode density on the cuff itself. Microfabrication techniques can be used to achieve this higher electrode density. Using L-Edit, a layout editor, microfabricated peripheral nerve cuffs were designed with a higher electrode density than the current model. This increase in electrode density translates to an increase in spatial resolution by at least one order of magnitude. Microfabricated devices also have two separate components that are necessary to understand before implantation: lifetime of the device and assembly to prevent nerve damage. Silicone molding procedures were optimized so that devices do not damage nerves in vivo, and lifetime testing was performed on test microfabricated devices to determine their lifetime in vivo. Future work of this project would include fabricating some of the designed devices and seeing how they compare to the current cuffs in terms of their electrical performance, lifetime, shape, and mechanical properties.« less

Sensory and motor peripheral nerve function and incident mobility disability.

PubMed

Ward, Rachel E; Boudreau, Robert M; Caserotti, Paolo; Harris, Tamara B; Zivkovic, Sasa; Goodpaster, Bret H; Satterfield, Suzanne; Kritchevsky, Stephen B; Schwartz, Ann V; Vinik, Aaron I; Cauley, Jane A; Simonsick, Eleanor M; Newman, Anne B; Strotmeyer, Elsa S

2014-12-01

To assess the relationship between sensorimotor nerve function and incident mobility disability over 10 years. Prospective cohort study with longitudinal analysis. Two U.S. clinical sites. Population-based sample of community-dwelling older adults with no mobility disability at 2000/01 examination (N = 2,148 [Corrected]; mean age ± SD 76.5 ± 2.9, body mass index 27.1 ± 4.6; 50.2% female, 36.6% black, 10.7% with diabetes mellitus). Motor nerve conduction amplitude (poor <1 mV) and velocity (poor <40 m/s) were measured on the deep peroneal nerve. Sensory nerve function was measured using 10- and 1.4-g monofilaments and vibration detection threshold at the toe. Lower extremity symptoms included numbness or tingling and aching or burning pain. Incident mobility disability assessed semiannually over 8.5 years (interquartile range 4.5-9.6 years) was defined as two consecutive self-reports of a lot of difficulty or inability to walk one-quarter of a mile or climb 10 steps. Nerve impairments were detected in 55% of participants, and 30% developed mobility disability. Worse motor amplitude (HR = 1.29 per SD, 95% CI = 1.16-1.44), vibration detection threshold (HR = 1.13 per SD, 95% CI = 1.04-1.23), symptoms (HR = 1.65, 95% CI = 1.26-2.17), two motor impairments (HR = 2.10, 95% CI = 1.43-3.09), two sensory impairments (HR = 1.91, 95% CI = 1.37-2.68), and three or more nerve impairments (HR = 2.33, 95% CI = 1.54-3.53) predicted incident mobility disability after adjustment. Quadriceps strength mediated relationships between certain nerve impairments and mobility disability, although most remained significant. Poor sensorimotor nerve function independently predicted mobility disability. Future work should investigate modifiable risk factors and interventions such as strength training for preventing disability and improving function in older adults with poor nerve function. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Deficiency in Monocarboxylate Transporter 1 (MCT1) in Mice Delays Regeneration of Peripheral Nerves following Sciatic Nerve Crush

PubMed Central

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

2014-01-01

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 and MCT1 tdTomato BAC reporter mice. To investigate whether MCT1 is necessary for peripheral nerve regeneration, sciatic nerves in MCT1 heterozygous null mice are crushed and peripheral nerve regeneration 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 through 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

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. Copyright © 2014 Elsevier Inc. All rights reserved.

CONGENITAL ABNORMALITIES OF CRANIAL NERVE DEVELOPMENT: OVERVIEW, MOLECULAR MECHANISMS, AND FURTHER EVIDENCE OF HETEROGENEITY AND COMPLEXITY OF SYNDROMES WITH CONGENITAL LIMITATION OF EYE MOVEMENTS

PubMed Central

Traboulsi, Elias I

2004-01-01

ABSTRACT Purpose The clinical and molecular genetic classification of syndromes with congenital limitation of eye movements and evidence of cranial nerve dysgenesis continues to evolve. This monograph details clinical and molecular genetic data on a number of families and isolated patients with congenital fibrosis of the extraocular muscles (CFEOM) and related disorders, and presents an overview of the mechanisms of abnormal patterns of motor and sensory cranial nerve development in these rare syndromes. Methods Clinical examination of one patient with CFEOM1, one family with clinical features of CFEOM2, one family with recessive CFEOM3, one family with horizontal gaze palsy and progressive scoliosis (HGPPS), and four patients with various combinations of congenital cranial nerve abnormalities. Genotyping of families with CFEOM and HGPPS for polymorphic markers in the regions of the three known CFEOM loci and in the HGPPS region, and mutation analysis of the ARIX and KIF21A genes in patients with CFEOM were performed according to standard published protocols. Results The patient with CFEOM1 had the second most common mutation in KIF21A, a 2861 G>A mutation that resulted in an R954Q substitution. The family with CFEOM2 phenotype did not map to the CFEOM2 locus. The family with recessive CFEOM3 did not map to any of the known loci. The HGPPS family mapped to 11q23–q25. One patient had optic nerve hypoplasia and fifth nerve dysfunction. Two patients had the rare combination of Möbius syndrome and CFEOM. One patient had Möbius syndrome and fifth nerve dysfunction. Conclusions There is genetic heterogeneity in CFEOM2 and CFEOM3. Abnormalities in sensory nerves can also accompany abnormalities of motor nerves, further substantiating the effect of individual mutations on developing motor as well as sensory cranial nerve nuclei. PMID:15747768

Head sensory organs of Dactylopodola baltica (Macrodasyida, Gastrotricha): a combination of transmission electron microscopical and immunocytochemical techniques.

PubMed

Liesenjohann, Thilo; Neuhaus, Birger; Schmidt-Rhaesa, Andreas

2006-08-01

The anterior and posterior head sensory organs of Dactylopodola baltica (Macrodasyida, Gastrotricha) were investigated by transmission electron microscopy (TEM). In addition, whole individuals were labeled with phalloidin to mark F-actin and with anti-alpha-tubulin antibodies to mark microtubuli and studied with confocal laser scanning microscopy. Immunocytochemistry reveals that the large number of ciliary processes in the anterior head sensory organ contain F-actin; no signal could be detected for alpha-tubulin. Labeling with anti-alpha-tubulin antibodies revealed that the anterior and posterior head sensory organs are innervated by a common stem of nerves from the lateral nerve cords just anterior of the dorsal brain commissure. TEM studies showed that the anterior head sensory organ is composed of one sheath cell and one sensory cell with a single branching cilium that possesses a basal inflated part and regularly arranged ciliary processes. Each ciliary process contains one central microtubule. The posterior head sensory organ consists of at least one pigmented sheath cell and several probably monociliary sensory cells. Each cilium branches into irregularly arranged ciliary processes. These characters are assumed to belong to the ground pattern of the Gastrotricha. Copyright 2006 Wiley-Liss, Inc.

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

PubMed

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

2016-02-01

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

Modulation of transient receptor potential vanilloid 4-mediated membrane currents and synaptic transmission by protein kinase C

PubMed Central

Cao, De-Shou; Yu, Shuang-Quan; Premkumar, Louis S

2009-01-01

Background Transient receptor potential Vanilloid (TRPV) receptors are involved in nociception and are expressed predominantly in sensory neurons. TRPV1, a non-selective cation channel has been extensively studied and is responsible for inflammatory thermal hypersensitivity. In this study, the expression and function of TRPV4 have been characterized and compared with those of TRPV1. Results Immunohistochemical studies revealed that both TRPV1 and TRPV4 were co-expressed in dorsal root ganglion (DRG) neuronal cell bodies and in the central terminals of laminae I and II of the spinal dorsal horn (DH). In Ca2+ fluorescence imaging and whole-cell patch-clamp experiments, TRPV1- and TRPV4-mediated responses were observed in a population of the same DRG neurons. Sensitization of TRPV1 has been shown to be involved in inflammatory pain conditions. Incubation with phorbol 12, 13-dibutyrate (PDBu), a PKC activator, resulted in a significant potentiation of TRPV4 currents in DRG neurons. In TRPV4 expressing HEK 293T cells, PDBu increased 4α-phorbol 12, 13-didecanoate (4α-PDD)-induced single-channel activity in cell-attached patches, which was abrogated by bisindolylmaleimide (BIM), a selective PKC inhibitor. TRPV4 is also expressed at the central terminals of sensory neurons. Activation of TRPV4 by 4α-PDD increased the frequency of miniature excitatory post synaptic currents (mEPSCs) in DRG-DH neuronal co-cultures. 4α-PDD-induced increase in the frequency of mEPSCs was further enhanced by PDBu. The expression of TRP channels has been shown in other areas of the CNS; application of 4α-PDD significantly increased the mEPSC frequency in cultured hippocampal neurons, which was further potentiated by PDBu, whereas, TRPV1 agonist capsaicin did not modulate synaptic transmission. Conclusion These results indicate that TRPV4 and TRPV1 are co-expressed in certain DRG neurons and TRPV4 can be sensitized by PKC not only in DRG neuronal cell bodies, but also in the central sensory and non-sensory nerve terminals. Co-expression of TRPV1 and TRPV4 ion channels, their modulation of synaptic transmission and their sensitization by PKC may synergistically play a role in nociception. PMID:19208258

Sensory neuropathy in two Border collie puppies.

PubMed

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

2005-06-01

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

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)

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

PubMed Central

Sanders, Richard D.

2010-01-01

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

Selectivity of the uptake of glutamate and GABA in two morphologically distinct insect neuromuscular synapses.

PubMed

van Marle, J; Piek, T; Lammertse, T; Lind, A; Van Weeren-Kramer, J

1985-11-25

The common inhibitor (CI) and slow excitor tibiae (SETi) innervated slow muscles 135cd of the locust Schistocerca gregaria were incubated under high-affinity uptake conditions either in [3H]GABA or in [3H]glutamate. [3H]GABA is accumulated in the glia of the nerve endings of the CI as well as the SETi; however, it is accumulated only in the terminal axons of the CI, not in the terminal axons of the SETi. The grain densities above the glia and above the CI terminal axons are approximately 2 grains/micron2. After incubation in [3H]glutamate the grain densities above the CI terminal axons and the SETi terminal axons are approximately 4 grains/micron2; the grain densities above the glia of both types of nerve endings are approximately 17 grains/micron2. The relatively high labeling (3 grains/micron2) of the muscles after incubation in the presence of glutamate is ascribed to the high metabolic requirements of slow muscles. The conclusion is drawn that a high-affinity uptake system for GABA is present in the CI terminal axons and in the glia of both the CI and SETi nerve endings. However, while the glutamate uptake in the CI and SETi nerve endings of the slow 135cd is comparable to the high-affinity uptake of glutamate in the fast excitor tibiae (FETi) nerve endings of the fast retractor unguis muscle, a high-affinity uptake of glutamate was only demonstrated in the glia of both types of nerve endings. A high-affinity uptake in the terminal axons of the CI and SETi may be masked by an extensively low-affinity uptake of glutamate by the muscles.

Reliability of the nerve conduction monitor in repeated measures of median and ulnar nerve latencies

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

Washington, I A

According to the Bureau of Labor Statistics, carpal tunnel syndrome (CTS), one of the most rapidly growing work-related injuries, cost American businesses up to $10 billion dollars in medical costs each year (1992). Because conservative therapy can be implemented and CTS is more reversible in it early stages, early detection will not only save industry unnecessary health care costs, but also prevent employees from experiencing debilitating pain and unnecessary surgery. In response to the growing number of cases of CTS, many companies have introduced screening tools to detect early stages of carpal tunnel syndrome. Neurotron Medical (New Jersey) has designedmore » a portable nerve conduction monitor (Nervepace S-200) which measures motor and sensory nerve latencies. The slowing of these latencies is one diagnostic indicator of carpal tunnel syndrome. In this study, we determined the reliability of the Nervepace Monitor in measure ulnar and median nerve latencies during repeated testing. The testing was performed on 28 normal subjects between the ages of 20 and 35 who had no prior symptoms of CTS. They were tested at the same time each day for three consecutive days. Nerve latencies between different ethnic groups and genders were compared. Results show that there was no significant daily variation of the median motor and lunar sensory latencies or the median sensory latencies. No significant differences of latencies was observed among ethnic groups; however, a significant difference of latencies between male and female subjects was observed (p<0.05).« less

Lipid-lowering drugs (statins) and peripheral neuropathy.

PubMed

Emad, Mohammadreza; Arjmand, Hosein; Farpour, Hamid Reza; Kardeh, Bahareh

2018-03-01

Peripheral neuropathy is a disorder with often unknown causes. Some drugs, including statins, are proposed to be among the causes of peripheral neuropathy. This study aimed at evaluating this condition by electrodiagnostic study among patients who had received statins. This case-control study was conducted in Shiraz, Iran in 2015, and included 39 patients aged 35-55 who had received statins for at least 6 months, and 39 healthy matched controls. Using electrodiagnosis, the sensory and motor wave features (amplitude, latency and nerve conduction velocity) of the peripheral nerves (Median, Ulnar, Tibial, Sural, and Peroneal) were evaluated among the subjects. Data were analyzed using SPSS software and p<0.05 was considered statistically significant. Regarding the occurrence of neuropathy, there were no significant differences in any of the definitions presented for peripheral neuropathy. However, the difference was close to significance for one definition [2 abnormalities in 2 nerves (p=0.055)]. Regarding mean values of the features, significant differences were observed in two features: amplitude of the peroneal motor nerve (p=0.048) and amplitude of the sural sensory nerve (p=0.036). Since statins are widely used, awareness regarding their side-effects would lead to better treatment. Even though no significant differences were found between the groups regarding the occurrence of peripheral neuropathy, there were significant differences in amplitudes of the sural sensory response and the peroneal motor response. This indicates the involvement of peripheral nerves. Therefore, we recommend that patients and physicians should be informed about the possible symptoms of this condition.

SUBSTANCE P IN HEART FAILURE: THE GOOD AND THE BAD

PubMed Central

Dehlin, Heather M.; Levick, Scott P.

2015-01-01

The tachykinin, substance P, is found primarily in sensory nerves. In the heart, substance P-containing nerve fibers are often found surrounding coronary vessels, making them ideally situated to sense changes in the myocardial environment. Recent studies in rodents have identified substance P as having dual roles in the heart, depending on disease etiology and/or timing. Thus far, these studies indicate that substance P may be protective acutely following ischemia-reperfusion, but damaging long-term in non-ischemic induced remodeling and heart failure. Sensory nerves may be at the apex of the cascade of events leading to heart failure, therefore, they make a promising potential therapeutic target that warrants increased investigation. PMID:24286592

Quantitative thermal sensory testing -- value of testing for both cold and warm sensation detection in evaluation of small fiber neuropathy.

PubMed

Shukla, Garima; Bhatia, Manvir; Behari, Madhuri

2005-10-01

Small fiber neuropathy is a common neurological disorder, often missed or ignored by physicians, since examination and routine nerve conduction studies are usually normal in this condition. Many methods including quantitative thermal sensory testing are currently being used for early detection of this condition, so as to enable timely investigation and treatment. This study was conducted to assess the yield of quantitative thermal sensory testing in diagnosis of small fiber neuropathy. We included patients presenting with history suggestive of positive and/or negative sensory symptoms, with normal examination findings, clinically suggestive of small fiber neuropathy, with normal or minimally abnormal routine nerve conduction studies. These patients were subjected to quantitative thermal sensory testing using a Medoc TSA-II Neurosensory analyser at two sites and for two modalities. QST data were compared with those in 120 normal healthy controls. Twenty-five patients (16 males, 9 females) with mean age 46.8+/-16.6 years (range: 21-75 years) were included in the study. The mean duration of symptoms was 1.6+/-1.6 years (range: 3 months-6 years). Eighteen patients (72%) had abnormal thresholds in at least one modality. Thermal thresholds were normal in 7 out of the 25 patients. This study demonstrates that quantitative thermal sensory testing is a fairly sensitive method for detection of small fiber neuropathy especially in patients with normal routine nerve conduction studies.

Haemangioblastoma of a cervical sensory nerve root in Von Hippel-Lindau syndrome.

PubMed

McEvoy, A W; Benjamin, E; Powell, M P

2000-10-01

Spinal haemangioblastomas are rare, accounting for only about 7% of all central nervous system cases. The case of a 40-year-old woman with a haemangioblastoma arising solely from a cervical sensory nerve root is presented. At operation via a cervical laminectomy, it was possible to resect the tumour en masse with the sensory ramus, by extending the laminectomy through the exit foramen for C6. Haemangioblastomas are commonly intramedullary, and have only been reported in this location on one previous occasion. The patient has Von Hippel-Lindau syndrome and a history of multiple solid tumours. The possible role of the Von Hippel-Lindau tumour suppressor gene in the pathogenesis of these neoplasms is discussed.

Recurrent Isolated Sixth Nerve Palsy in Relapsing-Remitting Chronic Inflammatory Demyelinating Polyneuropathy.

PubMed

Al-Bustani, Najwa; Weiss, Michael D

2015-09-01

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated sensory and motor demyelinating polyneuropathy that typically presents as a relapsing-remitting or progressive disorder. Cranial neuropathies infrequently occur in association with other more typical symptoms of CIDP. We report a case of CIDP with recurrent isolated sixth nerve palsy. Her physical examination showed a right sixth nerve palsy and absent deep tendon reflexes as the only indicator of her disease. Magnetic resonance imaging revealed thickening without enhancement of the trigeminal and sixth cranial nerves. Nerve conduction study (NCS) revealed a sensory and motor demyelinating polyneuropathy with conduction block and temporal dispersion in multiple nerves consistent with CIDP. Cerebrospinal fluid demonstrated albuminic-cytologic dissociation. She had a remarkable response to intravenous immunoglobulin and remains asymptomatic without any additional immunomodulating therapy. Isolated cranial neuropathies can rarely occur as the sole manifestation of relapsing-remitting CIDP. The profound demyelination found on NCS in this case demonstrates that there can be a dramatic discordance between the clinical and electrodiagnostic findings in some patients with this disorder.

Vagus nerve is involved in the changes in body temperature induced by intragastric administration of 1,8-cineole via TRPM8 in mice.

PubMed

Urata, Tomomi; Mori, Noriyuki; Fukuwatari, Tsutomu

2017-05-22

Transient Receptor Potential Melastatin 8 (TRPM8) is a cold receptor activated by mild cold temperature (<28°C). TRPM8 expressed in cutaneous sensory nerves is involved in cold sensation and thermoregulation. TRPM8 mRNA is detected in various tissues, including the gastrointestinal mucosa, and in the vagal afferent nerve. The relationship between vagal afferent nerve-specific expression of TRPM8 and thermoregulation remains unclear. In this study, we aimed to investigate whether TRPM8 expression in the vagal afferent nerve is involved in autonomic thermoregulation. We found that intragastric administration of 1,8-cineole, a TRPM8 agonist, increased intrascapular brown adipose tissue and colonic temperatures, and M8-B-treatment (TRPM8 antagonist) inhibited these responses. Intravenous administration of 1,8-cineole also showed similar effects. In vagotomized mice, the responses induced by intragastric administration of 1,8-cineole were attenuated. These results suggest that TRPM8 expressed in tissues apart from cutaneous sensory nerves are involved in autonomic thermoregulation response. Copyright © 2017 Elsevier B.V. All rights reserved.

Cross sectional study to evaluate the effect of duration of type 2 diabetes mellitus on the nerve conduction velocity in diabetic peripheral neuropathy.

PubMed

Hussain, Gauhar; Rizvi, S Aijaz Abbas; Singhal, Sangeeta; Zubair, Mohammad; Ahmad, Jamal

2014-01-01

To study the nerve conduction velocity in clinically undetectable and detectable peripheral neuropathy in type 2 diabetes mellitus with variable duration. This cross sectional study was conducted in diagnosed type 2 diabetes mellitus patients. They were divided in groups: Group I (n=37) with clinically detectable diabetic peripheral neuropathy of shorter duration and Group II (n=27) with clinically detectable diabetic peripheral neuropathy of longer duration. They were compared with T2DM patients (n=22) without clinical neuropathy. Clinical diagnosis was based on neuropathy symptom score (NSS) and neuropathy disability score (NDS) for signs. Nerve conduction velocity was measured in both upper and lower limbs. Median, ulnar, common peroneal and posterior tibial nerves were selected for motor nerve conduction study and median and sural nerves were selected for sensory nerve conduction study. The comparisons were done between nerve conduction velocities of motor and sensory nerves in patients of clinically detectable neuropathy and patients without neuropathy in type 2 diabetes mellitus population. This study showed significant electrophysiological changes with duration of disease. Nerve conduction velocities in lower limbs were significantly reduced even in patients of shorter duration with normal upper limb nerve conduction velocities. Diabetic neuropathy symptom score (NSS) and neuropathy disability score (NDS) can help in evaluation of diabetic sensorimotor polyneuropathy though nerve conduction study is more powerful test and can help in diagnosing cases of neuropathy. Copyright © 2013 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Nerve Growth Factor Inhibits Sympathetic Neurons' Response to an Injury Cytokine

NASA Astrophysics Data System (ADS)

Shadiack, Annette M.; Vaccariello, Stacey A.; Sun, Yi; Zigmond, Richard E.

1998-06-01

Axonal damage to adult peripheral neurons causes changes in neuronal gene expression. For example, axotomized sympathetic, sensory, and motor neurons begin to express galanin mRNA and protein, and recent evidence suggests that galanin plays a role in peripheral nerve regeneration. Previous studies in sympathetic and sensory neurons have established that galanin expression is triggered by two consequences of nerve transection: the induction of leukemia inhibitory factor (LIF) and the reduction in the availability of the target-derived factor, nerve growth factor. It is shown in the present study that no stimulation of galanin expression occurs following direct application of LIF to intact neurons in the superior cervical sympathetic ganglion. Injection of animals with an antiserum to nerve growth factor concomitant with the application of LIF, on the other hand, does stimulate galanin expression. The data suggest that the response of neurons to an injury factor, LIF, is affected by whether the neurons still receive trophic signals from their targets.

[Morphologic studies of the protective role of catechin on kanamycin otoneurotoxicity in SD rats].

PubMed

Liu, Guo-hui; Xie, Ding-hua; Wu, Wei-jing

2002-12-28

To determine the protection of catechin on aminoglycoside antibiotics otoneurotoxicity in SD rats, and observe the morphologic changes of cochlear efferent nerve terminals and outer hair cells after the injection of kanamycin and the feeding of catechin by the stomach tube. Thirty-eight SD rats were randomly assigned into three experimental groups (KM-treated, catechin-treated, KM and catechin in combination) and one control group. The KM-treated group was given kanamycin in a dose of 500 mg.(kg.d)-1 for 14 days. The catechin-treated group was given catechin once by the stomach tube in a dose of 400 mg.(kg.d)-1. Two kinds of medicine were simultaneously given in the KM+ catechin group. Transmission electron microscopy was utilized to observe the subcellular structure of efferent nerve fibers and outer hair cells. The densities of efferent nerve fibers and terminals were examined and the numbers of efferent nerve fibers and terminals were numerated by the surface preparation using modified histochemical staining for acetylcholinesterase (AchE). The damage in the group protected by catechin was relieved compared with the unprotected group. No damage was found in the catechin-treated alone group and controls. The densities and numbers of efferent nerve fibers and terminals were obviously fewer in the unprotected group than in the protected group and controls(P < 0.05). There was no significant difference in the numbers of efferent nerve fibers and terminals of the group protected by catechin compared with the controls and the catechin-treated group (P > 0.05). Catechin significantly protects MOC efferent nerves in kanamycin otoneurotoxicity.

Pungent products from garlic activate the sensory ion channel TRPA1

PubMed Central

Bautista, Diana M.; Movahed, Pouya; Hinman, Andrew; Axelsson, Helena E.; Sterner, Olov; Högestätt, Edward D.; Julius, David; Jordt, Sven-Eric; Zygmunt, Peter M.

2005-01-01

Garlic belongs to the Allium family of plants that produce organosulfur compounds, such as allicin and diallyl disulfide (DADS), which account for their pungency and spicy aroma. Many health benefits have been ascribed to Allium extracts, including hypotensive and vasorelaxant activities. However, the molecular mechanisms underlying these effects remain unknown. Intriguingly, allicin and DADS share structural similarities with allyl isothiocyanate, the pungent ingredient in wasabi and other mustard plants that induces pain and inflammation by activating TRPA1, an excitatory ion channel on primary sensory neurons of the pain pathway. Here we show that allicin and DADS excite an allyl isothiocyanate-sensitive subpopulation of sensory neurons and induce vasodilation by activating capsaicin-sensitive perivascular sensory nerve endings. Moreover, allicin and DADS activate the cloned TRPA1 channel when expressed in heterologous systems. These and other results suggest that garlic excites sensory neurons primarily through activation of TRPA1. Thus different plant genera, including Allium and Brassica, have developed evolutionary convergent strategies that target TRPA1 channels on sensory nerve endings to achieve chemical deterrence. PMID:16103371

Transient receptor potential cation channel, subfamily V, member 4 and airway sensory afferent activation: Role of adenosine triphosphate.

PubMed

Bonvini, Sara J; Birrell, Mark A; Grace, Megan S; Maher, Sarah A; Adcock, John J; Wortley, Michael A; Dubuis, Eric; Ching, Yee-Man; Ford, Anthony P; Shala, Fisnik; Miralpeix, Montserrat; Tarrason, Gema; Smith, Jaclyn A; Belvisi, Maria G

2016-07-01

Sensory nerves innervating the airways play an important role in regulating various cardiopulmonary functions, maintaining homeostasis under healthy conditions and contributing to pathophysiology in disease states. Hypo-osmotic solutions elicit sensory reflexes, including cough, and are a potent stimulus for airway narrowing in asthmatic patients, but the mechanisms involved are not known. Transient receptor potential cation channel, subfamily V, member 4 (TRPV4) is widely expressed in the respiratory tract, but its role as a peripheral nociceptor has not been explored. We hypothesized that TRPV4 is expressed on airway afferents and is a key osmosensor initiating reflex events in the lung. We used guinea pig primary cells, tissue bioassay, in vivo electrophysiology, and a guinea pig conscious cough model to investigate a role for TRPV4 in mediating sensory nerve activation in vagal afferents and the possible downstream signaling mechanisms. Human vagus nerve was used to confirm key observations in animal tissues. Here we show TRPV4-induced activation of guinea pig airway-specific primary nodose ganglion cells. TRPV4 ligands and hypo-osmotic solutions caused depolarization of murine, guinea pig, and human vagus and firing of Aδ-fibers (not C-fibers), which was inhibited by TRPV4 and P2X3 receptor antagonists. Both antagonists blocked TRPV4-induced cough. This study identifies the TRPV4-ATP-P2X3 interaction as a key osmosensing pathway involved in airway sensory nerve reflexes. The absence of TRPV4-ATP-mediated effects on C-fibers indicates a distinct neurobiology for this ion channel and implicates TRPV4 as a novel therapeutic target for neuronal hyperresponsiveness in the airways and symptoms, such as cough. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

An artificial arm/hand system with a haptic sensory function using electric stimulation of peripheral sensory nerve fibers.

PubMed

Mabuchi, Kunihiko

2013-01-01

We are currently developing an artificial arm/hand system which is capable of sensing stimuli and then transferring these stimuli to users as somatic sensations. Presently, we are evoking the virtual somatic sensations by electrically stimulating a sensory nerve fiber which innervates a single mechanoreceptor unit at the target area; this is done using a tungsten microelectrode that was percutaneously inserted into the use's peripheral nerve (a microstimulation method). The artificial arm/hand system is composed of a robot hand equipped with a pressure sensor system on its fingers. The sensor system detects mechanical stimuli, which are transferred to the user by means of the microstimulation method so that the user experiences the stimuli as the corresponding somatic sensations. In trials, the system worked satisfactorily and there was a good correlation between the pressure applied to the pressure sensors on the robot fingers and the subjective intensities of the evoked pressure sensations.

[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.

[Expression and significance of p75NTR in dorsal root ganglia in different injury models].

PubMed

Li, Fang; Cai, Yan; Zhang, Jian-Yi

2008-12-01

To determine the expression and significance of p75NTR in the neuron and glia of dorsal root ganglia (DRG) in different injury models. The models of sciatic nerve injury, spinal cord injury, and combined injury (sciatic nerve injury one week prior to spinal cord injury) were established. The rats were randomly divided into a normal group,a sciatic nerve injury group,a spinal cord injury group, and a combined injury group. The sensory neurons in the DRG were labeled by fast blue (FB) injected in the dorsal column of spinal cord 0.5mm rostral to the transection site. The expression of p75NTR in the neurons and glia of the DRG was examined with immunofluorescence histochemistry after different kinds of injury and its expression in the FB positive neurons was further observed with immunofluorescence histochemistry combined with FB retrograde labeling. The expression of p75NTR was increased in the glia, but was downregulated in sensory neurons in the sciatic nerve injury group compared with the normal group. p75NTR immunoreactive products were downregulated in the glia in the spinal cord injury group compared with the sciatic nerve injury group or the combined injury group. In the combined lesion animals, the expression of p75NTR was similar to that of the sciatic nerve injury group. Its expression in the sensory neurons of DRG was downregulated,but was upregulated in the glia. The majority of sensory neurons labeled by FB in the combined injury group were p75NTR-negative, but surrounded by p75NTR-positive glia. p75NTR immunoreactive products in the glia and neurons of DRG have significant discrepancy after injury. The glial p75NTR in the DRG may play a role in the enhanced regeneration of acsending tract in the injured spinal cord after combined injury.

In vivo exposure to nitrogen dioxide (NO2) induces a decrease in calcitonin gene-related peptide (CGRP) and tachykinin immunoreactivity in guinea-pig peripheral airways.

PubMed

Lucchini, R E; Springall, D R; Chitano, P; Fabbri, L M; Polak, J M; Mapp, C E

1996-09-01

The mammalian respiratory tract is densely innervated by sensory and autonomic fibres. Subsets of the nerves contain bioactive regulatory peptides, such as substance P, calcitonin gene-related peptide (CGRP), and neurokinins. The sensory nervous system responds to inhaled irritants, resulting in a release of neuropeptides and, thus, a decrease in the peptide immunoreactivity of the fibres. We examined the effects of inhaled nitrogen dioxide (NO2), a well-known indoor and outdoor air pollutant, on pulmonary sensory neuropeptides. Guinea-pigs were exposed for 4 h to 18 parts per million (ppm) NO2 or to air (n = 5 each). At the end of the exposure, they were killed with urethane and their lungs were fixed in 1% paraformaldehyde in phosphate-buffered saline. Cryostat sections were stained with antisera to an anatomical nerve marker, protein gene product (PGP) 9.5, and to CGRP and tachykinins, utilizing the avidin-biotinylated peroxidase method. In the noncartilaginous airways (diameter < 250 microns) of NO2-exposed animals, less tachykinin- and CGRP-immunoreactive nerve fibres were found compared with controls. No change was seen in the total nerve fibre distribution (PGP 9.5). It is concluded that the peptidergic nerves of guinea-pig peripheral airways are a sensitive indicator of exposure to nitrogen dioxide.

Assessing Decreased Sensation and Increased Sensory Phenomena in Diabetic Polyneuropathies

PubMed Central

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

2013-01-01

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

Enhancing Post-Traumatic Pain Relief with Alternative Perineural Drugs

DTIC Science & Technology

2013-11-01

producing long- duration, sensory-specific nerve block with minimal toxicity . We assessed the efficacy of the adjuvants clonidine (C), buprenorphine...influence on either LA- or M- induced nerve block. Further analysis of M effects indicated that peripheral nerve block and toxicity were due to a...hoping to identify a means to produce a nerve block in the absence of toxicity . We also hypothesized that potassium channel openers might directly

Teratogenic Effects of Pyridoxine on the Spinal Cord and Dorsal Root Ganglia of Embryonic Chickens

PubMed Central

Sharp, Andrew A.; Fedorovich, Yuri

2015-01-01

Our understanding of the role of somatosensory feedback in regulating motility during chicken embryogenesis and fetal development in general has been hampered by the lack of an approach to selectively alter specific sensory modalities. In adult mammals, pyridoxine overdose has been shown to cause a peripheral sensory neuropathy characterized by a loss of both muscle and cutaneous afferents, but predominated by a loss of proprioception. We have begun to explore the sensitivity of the nervous system in chicken embryos to the application of pyridoxine on embryonic days 7 and 8, after sensory neurons in the lumbosacral region become post-mitotic. Upon examination of the spinal cord, DRG and peripheral nerves, we find that pyridoxine causes a loss of TrkC-positive neurons, a decrease in the diameter of the muscle innervating nerve tibialis, and a reduction in the number of large diameter axons in this nerve. However, we found no change in the number of Substance P or CGRP-positive neurons, the number of motor neurons or the diameter or axonal composition of the femoral cutaneous nerve. Therefore, pyridoxine causes a peripheral sensory neuropathy in embryonic chickens largely consistent with its effects in adult mammals. However, the lesion may be more restricted to proprioception in the chicken embryo. Therefore, pyridoxine lesion induced during embryogenesis in the chicken embryo can be used to asses how the loss of sensation, largely proprioception, alters spontaneous embryonic motility and subsequent motor development. PMID:25592428

Early postnatal development of electrophysiological and histological properties of sensory sural nerves in male rats that were maternally deprived and artificially reared: Role of tactile stimulation.

PubMed

Zempoalteca, Rene; Porras, Mercedes G; Moreno-Pérez, Suelem; Ramirez-Funez, Gabriela; Aguirre-Benítez, Elsa L; González Del Pliego, Margarita; Mariscal-Tovar, Silvia; Mendoza-Garrido, Maria E; Hoffman, Kurt Leroy; Jiménez-Estrada, Ismael; Melo, Angel I

2018-04-01

Early adverse experiences disrupt brain development and behavior, but little is known about how such experiences impact on the development of the peripheral nervous system. Recently, we found alterations in the electrophysiological and histological characteristics of the sensory sural (SU) nerve in maternally deprived, artificially reared (AR) adult male rats, as compared with maternally reared (MR) control rats. In the present study, our aim was to characterize the ontogeny of these alterations. Thus, male pups of four postnatal days (PND) were (1) AR group, (2) AR and received daily tactile stimulation to the body and anogenital region (AR-Tactile group); or (3) reared by their mother (MR group). At PND 7, 14, or 21, electrophysiological properties and histological characteristics of the SU nerves were assessed. At PND 7, the electrophysiological properties and most histological parameters of the SU nerve did not differ among MR, AR, and AR-Tactile groups. By contrast, at PND 14 and/or 21, the SU nerve of AR rats showed a lower CAP amplitude and area, and a significant reduction in myelin area and myelin thickness, which were accompanied by a reduction in axon area (day 21 only) compared to the nerves of MR rats. Tactile stimulation (AR-Tactile group) partially prevented most of these alterations. These results suggest that sensory cues from the mother and/or littermates during the first 7-14 PND are relevant for the proper development and function of the adult SU nerve. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 351-362, 2018. © 2017 Wiley Periodicals, Inc.

An autopsy case of minamata disease (methylmercury poisoning)--pathological viewpoints of peripheral nerves.

PubMed

Eto, Komyo; Tokunaga, Hidehiro; Nagashima, Kazuo; Takeuchi, Tadao

2002-01-01

The outbreak of methylmercury poisoning in the geographic areas around Minamata Bay, Kumamoto, Japan in the 1950s has become known as Minamata disease. Based on earlier reports and extensive pathological studies on autopsied cases at the Kumamoto University School of Medicine, destructive lesions in the anterior portion of the calcarine cortex and depletion predominantly of granular cells in the cerebellar cortex came to be recognized as the hallmark and diagnostic yardstick of methylmercury poisoning in humans. As the number of autopsy cases of Minamata disease increased, it became apparent that the cerebral lesion was not restricted to the calcarine cortex but was relatively widespread. Less severe lesions, believed to be responsible for the motor symptoms of Minamata patients, were often found in the precentral, postcentral, and lateral temporal cortices. These patients also frequently presented with signs of sensory neuropathy affecting the distal extremities. Because of few sufficiently comprehensive studies, peripheral nerve degeneration has not been universally accepted as a cause of the sensory disturbances in Minamata patients. The present paper describes both biopsy and autopsy findings of the peripheral nerves in a male fisherman who died at the age of 64 years and showed the characteristic central nervous system lesions of Minamata disease at autopsy. A sural nerve biopsy with electron microscopy performed 1 month prior to his death showed endoneurial fibrosis and regenerated myelin sheaths. At autopsy the dorsal roots and sural nerve showed endoneurial fibrosis, loss of nerve fibers, and presence of Büngner's bands. The spinal cord showed Wallerian degeneration of the fasciculus gracilis (Goll's tract) with relative preservation of neurons in sensory ganglia. These findings support the contention that there is peripheral nerve degeneration in Minamata patients due to toxic injury from methylmercury.

[Regional nerve block in facial surgery].

PubMed

Gramkow, Christina; Sørensen, Jesper

2008-02-11

Regional nerve blocking techniques offer a suitable alternative to local infiltration anaesthesia for facial soft tissue-surgery. Moreover, they present several advantages over general anaesthesia, including smoother recovery, fewer side effects, residual analgesia into the postoperative period, earlier discharge from the recovery room and reduced costs. The branches of the trigeminal nerve and the sensory nerves originating from the upper cervical plexus can be targeted at several anatomical locations. We summarize current knowledge on facial nerve block techniques and recommend ten nerve blocks providing efficient anaesthesia for the entire head and upper-neck region.

Nerve and muscle involvement in mitochondrial disorders: an electrophysiological study.

PubMed

Mancuso, Michelangelo; Piazza, Selina; Volpi, Leda; Orsucci, Daniele; Calsolaro, Valeria; Caldarazzo Ienco, Elena; Carlesi, Cecilia; Rocchi, Anna; Petrozzi, Lucia; Calabrese, Rosanna; Siciliano, Gabriele

2012-04-01

Involvement of the peripheral nervous system in mitochondrial disorders (MD) has been previously reported. However, the exact prevalence of peripheral neuropathy and/or myopathy in MD is still unclear. In order to evaluate the prevalence of neuropathy and myopathy in MD, we performed sensory and motor nerve conduction studies (NCS) and concentric needle electromyography (EMG) in 44 unselected MD patients. NCS were abnormal in 36.4% of cases, and were consistent with a sensori-motor axonal multineuropathy (multifocal neuropathy), mainly affecting the lower limbs. EMG evidence of myopathy was present in 54.5% of patients, again mainly affecting the lower limbs. Nerve and muscle involvement was frequently subclinical. Peripheral nerve and muscle involvement is common in MD patients. Our study supports the variability of the clinical expression of MD. Further studies are needed to better understand the molecular basis underlying the phenotypic variability among MD patients.

Connexin36 Expression in Primary Afferent Neurons in Relation to the Axon Reflex and Modality Coding of Somatic Sensation.

PubMed

Nagy, J I; Lynn, B D; Senecal, J M M; Stecina, K

2018-05-07

Electrical coupling mediated by connexin36-containing gap junctions that form electrical synapses is known to be prevalent in the central nervous system, but such coupling was long ago reported also to occur between cutaneous sensory fibers. Here, we provide evidence supporting the capability of primary afferent fibers to engage in electrical coupling. In transgenic mice with enhanced green fluorescent protein (eGFP) serving as a reporter for connexin36 expression, immunofluorescence labeling of eGFP was found in subpopulations of neurons in lumbar dorsal root and trigeminal sensory ganglia, and in fibers within peripheral nerves and tissues. Immunolabeling of connexin36 was robust in the sciatic nerve, weaker in sensory ganglia than in peripheral nerve, and absent in these tissues from Cx36 null mice. Connexin36 mRNA was detected in ganglia from wild-type mice, but not in those from Cx36 null mice. Labeling of eGFP was localized within a subpopulation of ganglion cells containing substance P and calcitonin gene-releasing peptide, and in peripheral fibers containing these peptides. Expression of eGFP was also found in various proportions of sensory ganglion neurons containing transient receptor potential (TRP) channels, including TRPV1 and TRPM8. Ganglion cells labeled for isolectin B4 and tyrosine hydroxylase displayed very little co-localization with eGFP. Our results suggest that previously observed electrical coupling between peripheral sensory fibers occurs via electrical synapses formed by Cx36-containing gap junctions, and that some degree of selectivity in the extent of electrical coupling may occur between fibers belonging to subpopulations of sensory neurons identified according to their sensory modality responsiveness. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Sonographic assessment of volar digital nerve injury in the context of penetrating trauma.

PubMed

Umans, Hilary; Kessler, James; de la Lama, Mauricio; Magge, Keshav; Liebling, Ralph; Negron, Judith

2010-05-01

The purpose of this article was to report our experience using ultrasound to assess digital nerve integrity after penetrating hand trauma with sensory deficit. Ultrasound was performed in the long axis on 22 digital nerves in 11 patients using a 12-14-MHz linear array hockey stick transducer. Of 22 volar digital nerves evaluated by sonography, six were transected. All imaging findings were confirmed surgically. High-frequency ultrasound permits accurate imaging of intact and transected volar digital nerves.

High-Bandwidth Atomic Force Microscopy Reveals A Mechanical spike Accompanying the Action Potential in mammalian Nerve Terminals

NASA Astrophysics Data System (ADS)

Salzberg, Brian M.

2008-03-01

Information transfer from neuron to neuron within nervous systems occurs when the action potential arrives at a nerve terminal and initiates the release of a chemical messenger (neurotransmitter). In the mammalian neurohypophysis (posterior pituitary), large and rapid changes in light scattering accompany secretion of transmitter-like neuropeptides. In the mouse, these intrinsic optical signals are intimately related to the arrival of the action potential (E-wave) and the release of arginine vasopressin and oxytocin (S-wave). We have used a high bandwidth (20 kHz) atomic force microscope (AFM) to demonstrate that these light scattering signals are associated with changes in nerve terminal volume, detected as nanometer-scale movements of a cantilever positioned on top of the neurohypophysis. The most rapid mechanical response, the ``spike'', has duration comparable to that of the action potential (˜2 ms) and probably reflects an increase in terminal volume due to H2O movement associated with Na^+-influx. Elementary calculations suggest that two H2O molecules accompanying each Na^+-ion could account for the ˜0.5-1.0 å increase in the diameter of each terminal during the action potential. Distinguishable from the mechanical ``spike'', a slower mechanical event, the ``dip'', represents a decrease in nerve terminal volume, depends upon Ca^2+-entry, as well as on intra-terminal Ca^2+-transients, and appears to monitor events associated with secretion. A simple hypothesis is that this ``dip'' reflects the extrusion of the dense core granule that comprises the secretory products. These dynamic high bandwidth AFM recordings are the first to monitor mechanical events in nervous systems and may provide novel insights into the mechanism(s) by which excitation is coupled to secretion at nerve terminals.

Dopamine D1 and D2 Receptor Immunoreactivities in the Arcuate-Median Eminence Complex and their Link to the Tubero-Infundibular Dopamine Neurons

PubMed Central

Romero-Fernandez, W.; Borroto-Escuela, D.O.; Vargas-Barroso, V.; Narváez, M.; Di Palma, M.; Agnati, L.F.; Sahd, J. Larriva

2014-01-01

Dopamine D1 and D2 receptor immunohistochemistry and Golgi techniques were used to study the structure of the adult rat arcuate-median eminence complex, and determine the distribution of the dopamine D1 and D2 receptor immunoreactivities therein, particularly in relation to the tubero-infundibular dopamine neurons. Punctate dopamine D1 and D2 receptor immunoreactivities, likely located on nerve terminals, were enriched in the lateral palisade zone built up of nerve terminals, while the densities were low to modest in the medial palisade zone. A codistribution of dopamine D1 receptor or dopamine D2 receptor immunoreactive puncta with tyrosine hydroxylase immunoreactive nerve terminals was demonstrated in the external layer. Dopamine D1 receptor but not dopamine D2 receptor immnunoreactivites nerve cell bodies were found in the ventromedial part of the arcuate nucleus and in the lateral part of the internal layer of the median eminence forming a continuous cell mass presumably representing neuropeptide Y immunoreactive nerve cell bodies. The major arcuate dopamine/ tyrosine hydroxylase nerve cell group was found in the dorsomedial part. A large number of tyrosine hydroxylase immunoreactive nerve cell bodies in this region demonstrated punctate dopamine D1 receptor immunoreactivity but only a few presented dopamine D2 receptor immunoreactivity which were mainly found in a substantial number of tyrosine hydroxylase cell bodies of the ventral periventricular hypothalamic nucleus, also belonging to the tuberoinfundibular dopamine neurons. Structural evidence for projections of the arcuate nerve cells into the median eminence was also obtained. Distal axons formed horizontal axons in the internal layer issuing a variable number of collaterals classified into single or multiple strands located in the external layer increasing our understanding of the dopamine nerve terminal networks in this region. Dopamine D1 and D2 receptors may therefore directly and differentially modulate the activity and/or Dopamine synthesis of substantial numbers of tubero-infundibular dopamine neurons at the somatic and terminal level. The immunohistochemical work also gives support to the view that dopamine D1 receptors and/or dopamine D2 receptors in the lateral palisade zone by mediating dopamine volume transmission may contribute to the inhibition of luteinizing hormone releasing hormone release from nerve terminals in this region. PMID:25308843

Dopamine D1 and D2 receptor immunoreactivities in the arcuate-median eminence complex and their link to the tubero-infundibular dopamine neurons.

PubMed

Romero-Fernandez, W; Borroto-Escuela, D O; Vargas-Barroso, V; Narváez, M; Di Palma, M; Agnati, L F; Larriva Sahd, J; Fuxe, K

2014-07-18

Dopamine D1 and D2 receptor immunohistochemistry and Golgi techniques were used to study the structure of the adult rat arcuate-median eminence complex, and determine the distribution of the dopamine D1 and D2 receptor immunoreactivities therein, particularly in relation to the tubero-infundibular dopamine neurons. Punctate dopamine D1 and D2 receptor immunoreactivities, likely located on nerve terminals, were enriched in the lateral palisade zone built up of nerve terminals, while the densities were low to modest in the medial palisade zone. A codistribution of dopamine D1 receptor or dopamine D2 receptor immunoreactive puncta with tyrosine hydroxylase immunoreactive nerve terminals was demonstrated in the external layer. Dopamine D1 receptor but not dopamine D2 receptor immnunoreactivites nerve cell bodies were found in the ventromedial part of the arcuate nucleus and in the lateral part of the internal layer of the median eminence forming a continuous cell mass presumably representing neuropeptide Y immunoreactive nerve cell bodies. The major arcuate dopamine/ tyrosine hydroxylase nerve cell group was found in the dorsomedial part. A large number of tyrosine hydroxylase immunoreactive nerve cell bodies in this region demonstrated punctate dopamine D1 receptor immunoreactivity but only a few presented dopamine D2 receptor immunoreactivity which were mainly found in a substantial number of tyrosine hydroxylase cell bodies of the ventral periventricular hypothalamic nucleus, also belonging to the tubero-infundibular dopamine neurons. Structural evidence for projections of the arcuate nerve cells into the median eminence was also obtained. Distal axons formed horizontal axons in the internal layer issuing a variable number of collaterals classified into single or multiple strands located in the external layer increasing our understanding of the dopamine nerve terminal networks in this region.  Dopamine D1 and D2 receptors may therefore directly and differentially modulate the activity and /or Dopamine synthesis of substantial numbers of tubero-infundibular dopamine neurons at the somatic and terminal level. The immunohistochemical work also gives support to the view that dopamine D1 receptors and/or dopamine D2 receptors in the lateral palisade zone by mediating dopamine volume transmission may contribute to the inhibition of luteinizing hormone releasing hormone release from nerve terminals in this region.

Visualization of Sensory Neurons and Their Projections in an Upper Motor Neuron Reporter Line.

PubMed

Genç, Barış; Lagrimas, Amiko Krisa Bunag; Kuru, Pınar; Hess, Robert; Tu, Michael William; Menichella, Daniela Maria; Miller, Richard J; Paller, Amy S; Özdinler, P Hande

2015-01-01

Visualization of peripheral nervous system axons and cell bodies is important to understand their development, target recognition, and integration into complex circuitries. Numerous studies have used protein gene product (PGP) 9.5 [a.k.a. ubiquitin carboxy-terminal hydrolase L1 (UCHL1)] expression as a marker to label sensory neurons and their axons. Enhanced green fluorescent protein (eGFP) expression, under the control of UCHL1 promoter, is stable and long lasting in the UCHL1-eGFP reporter line. In addition to the genetic labeling of corticospinal motor neurons in the motor cortex and degeneration-resistant spinal motor neurons in the spinal cord, here we report that neurons of the peripheral nervous system are also fluorescently labeled in the UCHL1-eGFP reporter line. eGFP expression is turned on at embryonic ages and lasts through adulthood, allowing detailed studies of cell bodies, axons and target innervation patterns of all sensory neurons in vivo. In addition, visualization of both the sensory and the motor neurons in the same animal offers many advantages. In this report, we used UCHL1-eGFP reporter line in two different disease paradigms: diabetes and motor neuron disease. eGFP expression in sensory axons helped determine changes in epidermal nerve fiber density in a high-fat diet induced diabetes model. Our findings corroborate previous studies, and suggest that more than five months is required for significant skin denervation. Crossing UCHL1-eGFP with hSOD1G93A mice generated hSOD1G93A-UeGFP reporter line of amyotrophic lateral sclerosis, and revealed sensory nervous system defects, especially towards disease end-stage. Our studies not only emphasize the complexity of the disease in ALS, but also reveal that UCHL1-eGFP reporter line would be a valuable tool to visualize and study various aspects of sensory nervous system development and degeneration in the context of numerous diseases.

Vagal Afferent Innervation of the Airways in Health and Disease

PubMed Central

Mazzone, Stuart B.

2016-01-01

Vagal sensory neurons constitute the major afferent supply to the airways and lungs. Subsets of afferents are defined by their embryological origin, molecular profile, neurochemistry, functionality, and anatomical organization, and collectively these nerves are essential for the regulation of respiratory physiology and pulmonary defense through local responses and centrally mediated neural pathways. Mechanical and chemical activation of airway afferents depends on a myriad of ionic and receptor-mediated signaling, much of which has yet to be fully explored. Alterations in the sensitivity and neurochemical phenotype of vagal afferent nerves and/or the neural pathways that they innervate occur in a wide variety of pulmonary diseases, and as such, understanding the mechanisms of vagal sensory function and dysfunction may reveal novel therapeutic targets. In this comprehensive review we discuss historical and state-of-the-art concepts in airway sensory neurobiology and explore mechanisms underlying how vagal sensory pathways become dysfunctional in pathological conditions. PMID:27279650

Palisade endings in extraocular muscles of the monkey are immunoreactive for choline acetyltransferase and vesicular acetylcholine transporter.

PubMed

Konakci, Kadriye Zeynep; Streicher, Johannes; Hoetzenecker, Wolfram; Haberl, Ines; Blumer, Michael Josef Franz; Wieczorek, Grazyna; Meingassner, Josef Gottfried; Paal, Szabolcs Levente; Holzinger, Daniel; Lukas, Julius-Robert; Blumer, Roland

2005-12-01

To analyze palisade endings in extraocular muscles (EOMs) of a primate species and to examine our previous findings in cat that palisade endings are putative effector organs. Eleven monkeys (Macaca fascicularis) of both sexes, between 4 and 6 years of age were analyzed. Whole EOM myotendons were immunostained with four combinations of triple-fluorescent labeling and examined by confocal laser scanning microscopy. Labeling included antibodies against choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), neurofilament, and synaptophysin. Muscle fibers were counterstained with phalloidin. Palisade endings were observed in all monkey EOMs. Nerve fibers extended from the muscle into the tendon and looped back to divide into a terminal arborization (palisade ending) around a single muscle fiber tip. In approximately 30% of the cases, nerve fibers supplying palisade endings often established motor terminals outside the palisade complex. Nerve fibers forming palisade endings were ChAT-neurofilament positive. Axonal branches of palisade endings were ChAT-neurofilament positive as well. All palisade nerve terminals exhibited ChAT-synaptophysin immunoreactivity. Within the palisade complex, palisade nerve terminals exhibited VAChT immunoreactivity. All palisade nerve terminals were VAChT-synaptophysin immunoreactive. The results confirm that in the monkey, palisade endings contain acetylcholine and are therefore most likely effector organs. Palisade endings are also present in human EOMs and because of their location at the myotendinous junction, these organs are of crucial interest for strabismus surgery.

The subgenual organ complex in the cave cricket Troglophilus neglectus (Orthoptera: Rhaphidophoridae): comparative innervation and sensory evolution

PubMed Central

Strauß, Johannes; Stritih, Nataša; Lakes-Harlan, Reinhard

2014-01-01

Comparative studies of the organization of nervous systems and sensory organs can reveal their evolution and specific adaptations. In the forelegs of some Ensifera (including crickets and tettigoniids), tympanal hearing organs are located in close proximity to the mechanosensitive subgenual organ (SGO). In the present study, the SGO complex in the non-hearing cave cricket Troglophilus neglectus (Rhaphidophoridae) is investigated for the neuronal innervation pattern and for organs homologous to the hearing organs in related taxa. We analyse the innervation pattern of the sensory organs (SGO and intermediate organ (IO)) and its variability between individuals. In T. neglectus, the IO consists of two major groups of closely associated sensilla with different positions. While the distal-most sensilla superficially resemble tettigoniid auditory sensilla in location and orientation, the sensory innervation does not show these two groups to be distinct organs. Though variability in the number of sensory nerve branches occurs, usually either organ is supplied by a single nerve branch. Hence, no sensory elements clearly homologous to the auditory organ are evident. In contrast to other non-hearing Ensifera, the cave cricket sensory structures are relatively simple, consistent with a plesiomorphic organization resembling sensory innervation in grasshoppers and stick insects. PMID:26064547

The L1-type cell adhesion molecule Neuroglian is necessary for maintenance of sensory axon advance in the Drosophila embryo.

PubMed

Martin, Veronica; Mrkusich, Eli; Steinel, Martin C; Rice, Jason; Merritt, David J; Whitington, Paul M

2008-04-08

Cell adhesion molecules have long been implicated in the regulation of axon growth, but the precise cellular roles played by individual cell adhesion molecules and the molecular basis for their action are still not well understood. We have used the sensory system of the Drosophila embryo to shed light on the mechanism by which the L1-type cell adhesion molecule Neuroglian regulates axon growth. We have found a highly penetrant sensory axon stalling phenotype in neuroglian mutant embryos. Axons stalled at a variety of positions along their normal trajectory, but most commonly in the periphery some distance along the peripheral nerve. All lateral and dorsal cluster sensory neurons examined, except for the dorsal cluster neuron dbd, showed stalling. Sensory axons were never seen to project along inappropriate pathways in neuroglian mutants and stalled axons showed normal patterns of fasciculation within nerves. The growth cones of stalled axons possessed a simple morphology, similar to their appearance in wild-type embryos when advancing along nerves. Driving expression of the wild-type form of Neuroglian in sensory neurons alone rescued the neuroglian mutant phenotype of both pioneering and follower neurons. A partial rescue was achieved by expressing the Neuroglian extracellular domain. Over/mis-expression of Neuroglian in all neurons, oenocytes or trachea had no apparent effect on sensory axon growth. We conclude that Neuroglian is necessary to maintain axon advance along axonal substrates, but is not required for initiation of axon outgrowth, axon fasciculation or recognition of correct growth substrates. Expression of Neuroglian in sensory neurons alone is sufficient to promote axon advance and the intracellular region of the molecule is largely dispensable for this function. It is unlikely, therefore, that Nrg acts as a molecular 'clutch' to couple adhesion of F-actin within the growth cone to the extracellular substrate. Rather, we suggest that Neuroglian mediates sensory axon advance by promoting adhesion of the surface of the growth cone to its substrate. Our finding that stalling of a pioneer sensory neuron is rescued by driving Neuroglian in sensory neurons alone may suggest that Neuroglian can act in a heterophilic fashion.

The L1-type cell adhesion molecule Neuroglian is necessary for maintenance of sensory axon advance in the Drosophila embryo

PubMed Central

Martin, Veronica; Mrkusich, Eli; Steinel, Martin C; Rice, Jason; Merritt, David J; Whitington, Paul M

2008-01-01

Background Cell adhesion molecules have long been implicated in the regulation of axon growth, but the precise cellular roles played by individual cell adhesion molecules and the molecular basis for their action are still not well understood. We have used the sensory system of the Drosophila embryo to shed light on the mechanism by which the L1-type cell adhesion molecule Neuroglian regulates axon growth. Results We have found a highly penetrant sensory axon stalling phenotype in neuroglian mutant embryos. Axons stalled at a variety of positions along their normal trajectory, but most commonly in the periphery some distance along the peripheral nerve. All lateral and dorsal cluster sensory neurons examined, except for the dorsal cluster neuron dbd, showed stalling. Sensory axons were never seen to project along inappropriate pathways in neuroglian mutants and stalled axons showed normal patterns of fasciculation within nerves. The growth cones of stalled axons possessed a simple morphology, similar to their appearance in wild-type embryos when advancing along nerves. Driving expression of the wild-type form of Neuroglian in sensory neurons alone rescued the neuroglian mutant phenotype of both pioneering and follower neurons. A partial rescue was achieved by expressing the Neuroglian extracellular domain. Over/mis-expression of Neuroglian in all neurons, oenocytes or trachea had no apparent effect on sensory axon growth. Conclusion We conclude that Neuroglian is necessary to maintain axon advance along axonal substrates, but is not required for initiation of axon outgrowth, axon fasciculation or recognition of correct growth substrates. Expression of Neuroglian in sensory neurons alone is sufficient to promote axon advance and the intracellular region of the molecule is largely dispensable for this function. It is unlikely, therefore, that Nrg acts as a molecular 'clutch' to couple adhesion of F-actin within the growth cone to the extracellular substrate. Rather, we suggest that Neuroglian mediates sensory axon advance by promoting adhesion of the surface of the growth cone to its substrate. Our finding that stalling of a pioneer sensory neuron is rescued by driving Neuroglian in sensory neurons alone may suggest that Neuroglian can act in a heterophilic fashion. PMID:18397531

[Herpes zoster of the trigeminal nerve: a case report and review of the literature].

PubMed

Carbone, V; Leonardi, A; Pavese, M; Raviola, E; Giordano, M

2004-01-01

Herpes zoster (shingles) is caused when the varicella zoster virus that has remained latent since an earlier varicella infection (chicken-pox) is reactivated. Herpes Zoster is a less common and endemic disease than varicella: factors causing reactivation are still not well known, but it occurs in older and/or immunocompromised individuals. Following reactivation, centrifugal migration of herpes zoster virus (HZV) occurs along sensory nerves to produce a characteristic painful cutaneous or mucocutaneous vesicular eruption that is generally limited to the single affected dermatome. Herpes zoster may affect any sensory ganglia and its cutaneous nerve: the most common sites affected are thoracic dermatomes (56%), followed by cranial nerves (13%) and lumbar (13%), cervical (11%) and sacral nerves (4%). Among cranial nerves, the trigeminal and facial nerves are the most affected due to reactivation of HZV latent in gasserian and geniculated ganglia. The 1st division of the trigeminal nerve is commonly affected, whereas the 2nd and the 3rd are rarely involved. During the prodromal stage, the only presenting symptom may be odontalgia, which may prove to be a diagnostic challenge for the dentist, since many diseases can cause orofacial pain, and the diagnosis must be established before final treatment. A literature review of herpes zoster of the trigeminal nerve is presented and the clinical presentation, differential diagnosis and treatment modalities are underlined. A case report is presented.

Nanotechnology versus stem cell engineering: in vitro comparison of neurite inductive potentials.

PubMed

Morano, Michela; Wrobel, Sandra; Fregnan, Federica; Ziv-Polat, Ofra; Shahar, Abraham; Ratzka, Andreas; Grothe, Claudia; Geuna, Stefano; Haastert-Talini, Kirsten

2014-01-01

Innovative nerve conduits for peripheral nerve reconstruction are needed in order to specifically support peripheral nerve regeneration (PNR) whenever nerve autotransplantation is not an option. Specific support of PNR could be achieved by neurotrophic factor delivery within the nerve conduits via nanotechnology or stem cell engineering and transplantation. Here, we comparatively investigated the bioactivity of selected neurotrophic factors conjugated to iron oxide nanoparticles (np-NTFs) and of bone marrow-derived stem cells genetically engineered to overexpress those neurotrophic factors (NTF-BMSCs). The neurite outgrowth inductive activity was monitored in culture systems of adult and neonatal rat sensory dorsal root ganglion neurons as well as in the cell line from rat pheochromocytoma (PC-12) cell sympathetic culture model system. We demonstrate that np-NTFs reliably support numeric neurite outgrowth in all utilized culture models. In some aspects, especially with regard to their long-term bioactivity, np-NTFs are even superior to free NTFs. Engineered NTF-BMSCs proved to be less effective in induction of sensory neurite outgrowth but demonstrated an increased bioactivity in the PC-12 cell culture system. In contrast, primary nontransfected BMSCs were as effective as np-NTFs in sensory neurite induction and demonstrated an impairment of neuronal differentiation in the PC-12 cell system. Our results evidence that nanotechnology as used in our setup is superior over stem cell engineering when it comes to in vitro models for PNR. Furthermore, np-NTFs can easily be suspended in regenerative hydrogel matrix and could be delivered that way to nerve conduits for future in vivo studies and medical application.

Electrophysiologic alterations in the excitability of the sciatic and vagus nerves during early stages of sepsis.

PubMed

Diniz, Lúcio Ricardo Leite; Portella, Viviane Gomes; da Silva Alves, Kerly Shamira; Araújo, Pâmella Cristina da Costa; de Albuquerque Júnior, Ricardo Luiz Cavalcanti; Cavalcante de Albuquerque, Aline Alice; Coelho-de-Souza, Andrelina Noronha; Leal-Cardoso, José Henrique

2018-01-01

Nonspecific and delayed diagnosis of neurologic damage contributes to the development of neuropathies in patients with severe sepsis. The present study assessed the electrophysiologic parameters related to the excitability and conductibility of sciatic and vagus nerves during early stages of sepsis. Twenty-four hours after sepsis induced by cecal ligation and puncture (CLP) model, sciatic and vagus nerves of septic (CLP group) and control (sham group) rats were removed, and selected electric stimulations were applied to measure the parameters of the first and second components of the compound action potential. The first component originated from fibers with motor and sensory functions (Types A α and A β fibers) with a large conduction velocity (70-120 m/s), and the second component originated from fibers (Type A γ ) with sensorial function. To evaluate the presence of sensorial alterations, the sensitivity to non-noxious mechanical stimuli was measured by using the von Frey test. Hematoxylin and eosin staining of the nerves was performed. We observed an increase of rheobase followed by a decrease in the first component amplitude and a higher paw withdrawal threshold in response to the application of von Frey filaments in sciatic nerves from the CLP group compared to the sham group. Differently, a decrease in rheobase and an increase in the first component amplitude of vagal C fibers from CLP group were registered. No significant morphologic alteration was observed. Our data showed that the electrophysiologic alterations in peripheral nerves vary with the fiber type and might be identified in the first 24 h of sepsis, before clinical signs of neuromuscular disorders.

Cutaneous sensory and autonomic denervation in CADASIL.

PubMed

Nolano, Maria; Provitera, Vincenzo; Donadio, Vincenzo; Caporaso, Giuseppe; Stancanelli, Annamaria; Califano, Francesca; Pianese, Luigi; Liguori, Rocco; Santoro, Lucio; Ragno, Michele

2016-03-15

To assess the involvement of the peripheral nervous system in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) by means of immunofluorescence and confocal analysis of punch skin biopsies. We recruited 14 unrelated patients with CADASIL (M/F = 9/5; age 53.9 ± 10.5 years) and 52 healthy controls (M/F = 31/21; age 53.8 ± 9.8). Patients underwent clinical and neuroradiologic assessment. Three-millimeter punch skin biopsies were taken from the fingertip, the thigh, and the distal leg and processed using indirect immunofluorescence and a panel of primary antibodies to mark vessels and sensory and autonomic nerve fibers. Intraepidermal nerve fibers (IENF), Meissner corpuscles (MC), and sudomotor, vasomotor, and pilomotor nerves were assessed using confocal microscopy. In patients, compared to controls, we found a severe loss of IENF at the distal leg (p < 0.01), at the thigh (p < 0.01), and at the fingertip (p < 0.01) with a non-length-dependent pattern and a loss of MC (p < 0.01). A severe sudomotor, vasomotor, and pilomotor nerve fiber loss was found by semiquantitative evaluation. Along with nerve loss, a severe derangement of the vascular bed was observed. In our patient population, sensory and autonomic denervation did not correlate with age, sex, type of mutation, or MRI involvement. We found an involvement of the peripheral nervous system in patients with CADASIL through the assessment of cutaneous somatic and autonomic nerves. The neurovascular derangement observed in the skin may reflect, although to a lesser extent, what happens in the CNS. © 2016 American Academy of Neurology.

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

PubMed Central

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

2014-01-01

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

Three-dimensional analysis of vestibular efferent neurons innervating semicircular canals of the gerbil

NASA Technical Reports Server (NTRS)

Purcell, I. M.; Perachio, A. A.

1997-01-01

Anterograde labeling techniques were used to examine peripheral innervation patterns of vestibular efferent neurons in the crista ampullares of the gerbil. Vestibular efferent neurons were labeled by extracellular injections of biocytin or biotinylated dextran amine into the contralateral or ipsilateral dorsal subgroup of efferent cell bodies (group e) located dorsolateral to the facial nerve genu. Anterogradely labeled efferent terminal field varicosities consist mainly of boutons en passant with fewer of the terminal type. The bouton swellings are located predominately in apposition to the basolateral borders of the afferent calyces and type II hair cells, but several boutons were identified close to the hair cell apical border on both types. Three-dimensional reconstruction and morphological analysis of the terminal fields from these cells located in the sensory neuroepithelium of the anterior, horizontal, and posterior cristae were performed. We show that efferent neurons densely innervate each end organ in widespread terminal fields. Subepithelial bifurcations of parent axons were minimal, with extensive collateralization occurring after the axons penetrated the basement membrane of the neuroepithelium. Axonal branching ranged between the 6th and 27th orders and terminal field collecting area far exceeds that of the peripheral terminals of primary afferent neurons. The terminal fields of the efferent neurons display three morphologically heterogeneous types: central, peripheral, and planum. All cell types possess terminal fields displaying a high degree of anisotropy with orientations typically parallel to or within +/-45 degrees of the longitudinal axis if the crista. Terminal fields of the central and planum zones predominately project medially toward the transverse axis from the more laterally located penetration of the basement membrane by the parent axon. Peripheral zone terminal fields extend predominately toward the planum semilunatum. The innervation areas of efferent terminal fields display a trend from smallest to largest for the central, peripheral, and planum types, respectively. Neurons that innervate the central zone of the crista do not extend into the peripheral or planum regions. Conversely, those neurons with terminal fields in the peripheral or planum regions do not innervate the central zone of the sensory neuroepithelium. The central zone of the crista is innervated preferentially by efferent neurons with cell bodies located in the ipsilateral group e. The peripheral and planum zones of the crista are innervated preferentially by efferent neurons with cell bodies located in the contralateral group e. A model incorporating our anatomic observations is presented describing an ipsilateral closed-loop feedback between ipsilateral efferent neurons and the periphery and an open-loop feed-forward innervation from contralateral efferent neurons. A possible role for the vestibular efferent neurons in the modulation of semicircular canal afferent response dynamics is proposed.

Combination of heterologous fibrin sealant and bioengineered human embryonic stem cells to improve regeneration following autogenous sciatic nerve grafting repair.

PubMed

Mozafari, Roghayeh; Kyrylenko, Sergiy; Castro, Mateus Vidigal; Ferreira, Rui Seabra; Barraviera, Benedito; Oliveira, Alexandre Leite Rodrigues

2018-01-01

Peripheral nerve injury is a worldwide clinical problem, and the preferred surgical method for treating it is the end-to-end neurorrhaphy. When it is not possible due to a large nerve gap, autologous nerve grafting is used. However, these surgical techniques result in nerve regeneration at highly variable degrees. It is thus very important to seek complementary techniques to improve motor and sensory recovery. One promising approach could be cell therapy. Transplantation therapy with human embryonic stem cells (hESCs) is appealing because these cells are pluripotent and can differentiate into specialized cell types and have self-renewal ability. Therefore, the main objective of this study was to find conditions under which functional recovery is improved after sciatic nerve neurorrhaphy. We assumed that hESC, either alone or in combination with heterologous fibrin sealant scaffold, could be used to support regeneration in a mouse model of sciatic nerve injury and repair via autografting with end-to-end neurorrhaphy. Five millimeters of the sciatic nerve of C57BL/6 J mice were transected off and rotated 180 degrees to simulate an injury, and then stumps were sutured. Next, we applied heterologous fibrin sealant and/or human embryonic stem cells genetically altered to overexpress fibroblast growth factor 2 (FGF2) at the site of the injury. The study was designed to include six experimental groups comprising neurorrhaphy (N), neurorrhaphy + heterologous fibrin sealant (N + F), neurorrhaphy + heterologous fibrin sealant + doxycycline (N + F + D), neurorrhaphy + heterologous fibrin sealant + wild-type hESC (N + F + W), neurorrhaphy + heterologous fibrin sealant + hESC off (N + F + T), and neurorrhaphy + heterologous fibrin sealant + hESC on via doxycycline (N + F + D + T). We evaluated the recovery rate using Catwalk and von Frey functional recovery tests, as well as immunohistochemistry analysis. The experiments indicated that sensory function improved when transgenic hESCs were used. The regeneration of sensory fibers indeed led to increased reflexes, upon stimulation of the paw ipsilateral to the lesion, as seen by von-Frey evaluation, which was supported by immunohistochemistry. Overall, the present data demonstrated that transgenic embryonic stem cells, engineered to overexpress FGF-2 in an inducible fashion, could be employed to support regeneration aiming at the recovery of both motor and sensory functions.

Cellular projections from sensory hair cells form polarity-specific scaffolds during synaptogenesis

PubMed Central

Dow, Eliot; Siletti, Kimberly

2015-01-01

The assembly of a nervous system requires the extension of axons and dendrites to specific regions where they are matched with appropriate synaptic targets. Although the cues that guide long-range outgrowth have been characterized extensively, additional mechanisms are required to explain short-range guidance in neural development. Using a complementary combination of time-lapse imaging by fluorescence confocal microscopy and serial block-face electron microscopy, we identified a novel type of presynaptic projection that participates in the assembly of the vertebrate nervous system. Synapse formation by each hair cell of the zebrafish's lateral line occurs during a particular interval after the cell's birth. During the same period, projections emerge from the cellular soma, extending toward a specific subpopulation of mature hair cells and interacting with polarity-specific afferent nerve terminals. The terminals then extend along the projections to reach appropriately matched presynaptic sites, after which the projections recede. Our results suggest that presynaptic projections act as transient scaffolds for short-range partner matching, a mechanism that may occur elsewhere in the nervous system. PMID:25995190

Molecular Machines Determining the Fate of Endocytosed Synaptic Vesicles in Nerve Terminals

PubMed Central

Fassio, Anna; Fadda, Manuela; Benfenati, Fabio

2016-01-01

The cycle of a synaptic vesicle (SV) within the nerve terminal is a step-by-step journey with the final goal of ensuring the proper synaptic strength under changing environmental conditions. The SV cycle is a precisely regulated membrane traffic event in cells and, because of this, a plethora of membrane-bound and cytosolic proteins are devoted to assist SVs in each step of the journey. The cycling fate of endocytosed SVs determines both the availability for subsequent rounds of release and the lifetime of SVs in the terminal and is therefore crucial for synaptic function and plasticity. Molecular players that determine the destiny of SVs in nerve terminals after a round of exo-endocytosis are largely unknown. Here we review the functional role in SV fate of phosphorylation/dephosphorylation of SV proteins and of small GTPases acting on membrane trafficking at the synapse, as they are emerging as key molecules in determining the recycling route of SVs within the nerve terminal. In particular, we focus on: (i) the cyclin-dependent kinase-5 (cdk5) and calcineurin (CN) control of the recycling pool of SVs; (ii) the role of small GTPases of the Rab and ADP-ribosylation factor (Arf) families in defining the route followed by SV in their nerve terminal cycle. These regulatory proteins together with their synaptic regulators and effectors, are molecular nanomachines mediating homeostatic responses in synaptic plasticity and potential targets of drugs modulating the efficiency of synaptic transmission. PMID:27242505

Molecular Machines Determining the Fate of Endocytosed Synaptic Vesicles in Nerve Terminals.

PubMed

Fassio, Anna; Fadda, Manuela; Benfenati, Fabio

2016-01-01

The cycle of a synaptic vesicle (SV) within the nerve terminal is a step-by-step journey with the final goal of ensuring the proper synaptic strength under changing environmental conditions. The SV cycle is a precisely regulated membrane traffic event in cells and, because of this, a plethora of membrane-bound and cytosolic proteins are devoted to assist SVs in each step of the journey. The cycling fate of endocytosed SVs determines both the availability for subsequent rounds of release and the lifetime of SVs in the terminal and is therefore crucial for synaptic function and plasticity. Molecular players that determine the destiny of SVs in nerve terminals after a round of exo-endocytosis are largely unknown. Here we review the functional role in SV fate of phosphorylation/dephosphorylation of SV proteins and of small GTPases acting on membrane trafficking at the synapse, as they are emerging as key molecules in determining the recycling route of SVs within the nerve terminal. In particular, we focus on: (i) the cyclin-dependent kinase-5 (cdk5) and calcineurin (CN) control of the recycling pool of SVs; (ii) the role of small GTPases of the Rab and ADP-ribosylation factor (Arf) families in defining the route followed by SV in their nerve terminal cycle. These regulatory proteins together with their synaptic regulators and effectors, are molecular nanomachines mediating homeostatic responses in synaptic plasticity and potential targets of drugs modulating the efficiency of synaptic transmission.

Selective binding, uptake, and retrograde transport of tetanus toxin by nerve terminals in the rat iris. An electron microscope study using colloidal gold as a tracer

PubMed Central

1978-01-01

A series of specific macromolecules (tetanus toxin, cholera toxin, nerve growth factor [NGF], and several lectins) have been shown to be transported retrogradely with high selectivity from terminals to cell bodies in various types of neurons. Under identical experimental conditions (low protein concentrations injected), most other macromolecules, e.g. horseradish peroxidase (HRP), albumin, ferritin, are not transported in detectable amounts. In the present EM study, we demonstrate selective binding of tetanus toxin to the surface membrane of nerve terminals, followed by uptake and subsequent retorgrade axonal transport. Tetanus toxin or albumin was adsorbed to colloidal gold particles (diam 200 A). The complex was shown to be stable and well suited as an EM tracer. 1-4 h after injection into the anterior eye chamber of adult rats, tetanus toxin-gold particles were found to be selectively associated with membranes of nerve terminals and preterminal axons. Inside terminals and axons, the tracer was localized mainly in smooth endoplasmic reticulum (SER)-like membrane compartments. In contrast, association of albumin-gold complexes with nervous structures was never observed, in spite of extensive uptake into fibroblasts. Electron microscope and biochemical experiments showed selective retrograde transport of tetanus toxin-gold complexes to the superior cervical ganglion. Specific binding to membrane components at nerve terminals and subsequent internalization and retrograde transport may represent an important pathway for macromolecules carrying information from target organs to the perikarya of their innervating neurons. PMID:659508

Redistribution of Cav2.1 channels and calcium ions in nerve terminals following end-to-side neurorrhaphy: ionic imaging analysis by TOF-SIMS.

PubMed

Liu, Chiung-Hui; Chang, Hung-Ming; Tseng, To-Jung; Lan, Chyn-Tair; Chen, Li-You; Youn, Su-Chung; Lee, Jian-Jr; Mai, Fu-Der; Chou, Jui-Feng; Liao, Wen-Chieh

2016-11-01

The P/Q-type voltage-dependent calcium channel (Cav2.1) in the presynaptic membranes of motor nerve terminals plays an important role in regulating Ca 2+ transport, resulting in transmitter release within the nervous system. The recovery of Ca 2+ -dependent signal transduction on motor end plates (MEPs) and innervated muscle may directly reflect nerve regeneration following peripheral nerve injury. Although the functional significance of calcium channels and the levels of Ca 2+ signalling in nerve regeneration are well documented, little is known about calcium channel expression and its relation with the dynamic Ca 2+ ion distribution at regenerating MEPs. In the present study, end-to-side neurorrhaphy (ESN) was performed as an in vivo model of peripheral nerve injury. The distribution of Ca 2+ at regenerating MEPs following ESN was first detected by time-of-flight secondary ion mass spectrometry, and the specific localization and expression of Cav2.1 channels were examined by confocal microscopy and western blotting. Compared with other fundamental ions, such as Na + and K + , dramatic changes in the Ca 2+ distribution were detected along with the progression of MEP regeneration. The re-establishment of Ca 2+ distribution and intensity were correlated with the functional recovery of muscle in ESN rats. Furthermore, the re-clustering of Cav2.1 channels after ESN at the nerve terminals corresponded with changes in the Ca 2+ distribution. These results indicated that renewal of the Cav2.1 distribution within the presynaptic nerve terminals may be necessary for initiating a proper Ca 2+ influx and shortening the latency of muscle contraction during nerve regeneration.

Evaluating the Analgesic Effect of the GLS Inhibitor 6-Diazo-5-Oxo-L-Norleucine in Vivo

PubMed Central

Crosby, Heith A; Miller, Kenneth E

2018-01-01

Glutamate is an excitatory neurotransmitter, produced by its synthetic enzyme, glutaminase (GLS), and packaged by vesicular transporters (VGluT2) into synaptic vesicles. Primary sensory peripheral nerve and spinal synaptic terminals release glutamate during nociceptive (pain) signaling. In post-incisional and inflammation models in rats, GLS and VGluT2 production is elevated in dorsal root ganglion neuronal cell bodies and transported to peripheral and spinal terminals for increased glutamate synthesis and release. 6-Diazo-5-oxo-l-norleucine (DON) is a GLS inhibitor that produces long lasting pain relief when applied to the inflamed paw of arthritic rats, but its effect in a post-incisional model has not been evaluated. In this study, we examined the analgesic efficacy of DON in a surgical incision model by measuring thermal latency and mechanical allodynia. Following behavioral evaluation, we examined the skin for VGluT2, GLS and glutamate immunoreactivity (ir). Our findings revealed that VGluT2-ir is elevated in the stratum lucidum by approximately 19%, 64 hours post-surgical incision and attenuated by approximately 5.4% after the administration of DON. During that same period GLS-ir was elevated in dermal nerve fibers by 52% and was attenuated by approximately 27.9% after the application of DON. Additionally, glutamate-ir was elevated in epidermal nerve fibers by 35% after incision and attenuated by approximately 23% after the administration of DON. Behavioral testing 24 and 48 hours after a single local administration of DON showed five out of six animals having an analgesic response to mechanical allodynia, but not to thermal hyperalgesia. Following a surgical incision, the area of injury shows increased VGluT2-, GLS-, glutamate-ir, mechanical allodynia and no change in thermal latency. After the application of the GLS inhibitor, DON, nerve fiber of the skin showed decreased VGluT2, GLS, and glutamate-ir. Furthermore, post-incision DON treated animals exhibited decreased mechanical allodynia with no change in thermal latency when compared to control animals. PMID:29888760

Sciatic Nerve Injury After Proximal Hamstring Avulsion and Repair.

PubMed

Wilson, Thomas J; Spinner, Robert J; Mohan, Rohith; Gibbs, Christopher M; Krych, Aaron J

2017-07-01

Muscle bellies of the hamstring muscles are intimately associated with the sciatic nerve, putting the sciatic nerve at risk of injury associated with proximal hamstring avulsion. There are few data informing the magnitude of this risk, identifying risk factors for neurologic injury, or determining neurologic outcomes in patients with distal sciatic symptoms after surgery. To characterize the frequency and nature of sciatic nerve injury and distal sciatic nerve-related symptoms after proximal hamstring avulsion and to characterize the influence of surgery on these symptoms. Cohort study; Level of evidence, 3. This was a retrospective review of patients with proximal partial or complete hamstring avulsion. The outcome of interest was neurologic symptoms referable to the sciatic nerve distribution below the knee. Neurologic symptoms in operative patients were compared pre- and postoperatively. The cohort consisted of 162 patients: 67 (41.4%) operative and 95 (58.6%) nonoperative. Sciatic nerve-related symptoms were present in 22 operative and 23 nonoperative patients, for a total of 45 (27.8%) patients (8 [4.9%] motor deficits, 11 [6.8%] sensory deficits, and 36 [22.2%] with neuropathic pain). Among the operative cohort, 3 of 3 (100.0%) patients showed improvement in their motor deficit postoperatively, 3 of 4 (75.0%) patients' sensory symptoms improved, and 17 of 19 (89.5%) patients had improvement in pain. A new or worsening deficit occurred in 5 (7.5%) patients postoperatively (2 [3.1%] motor deficits, 1 [1.5%] sensory deficit, and 3 [4.5%] with new pain). Predictors of operative intervention included lower age (odds ratio [OR], 0.952; 95% CI, 0.921-0.982; P = .001) and complete avulsion (OR, 10.292; 95% CI, 2.526-72.232; P < .001). Presence of neurologic deficit was not predictive. Sciatic nerve-related symptoms after proximal hamstring avulsion are underrecognized. Currently, neurologic symptoms are not considered when determining whether to pursue operative intervention. Given the high likelihood of improvement with surgical treatment, neurologic symptoms should be considered when making a decision regarding operative treatment.

Neuroma prevention by end-to-side neurorraphy: an experimental study in rats.

PubMed

Aszmann, Oskar C; Korak, Klaus J; Rab, Matthias; Grünbeck, Matthias; Lassmann, Hans; Frey, Manfred

2003-11-01

The successful treatment of painful neuromas remains a difficult goal to attain. In this report we explore the feasibility of neuroma prevention by insertion of the proximal end of a nerve through an end-to-side neurorraphy into an adjacent mixed nerve to provide a pathway and target for axons deprived of their end organ. Experiments were performed on a total of twenty 250-g Sprague-Dawley rats. Two groups of 10 animals were prepared. Group A served as an anatomic control. In group B the right saphenous nerve was transected and implanted end-to-side through an epineurial window into the tibial nerve distal to the trifurcation of the sciatic nerve. After 12 weeks the corresponding sensory neurons were identified by retrograde labeling techniques and histomorphometric analysis of the proximal and distal tibial nerve segments, and regular histology of the end-to-side site were performed. The results of the retrograde labeling of the corresponding sensory neuron pool of the saphenus nerve showed extensive labelling of the L1 to L3 spinal ganglions after intracutaneous tracer application of the planta pedis. The morphology of the end-to-side coaptation site and histomorphologic analysis prove that sensory neurons penetrate the perineurial sheath and axons regenerate along the tibial Schwann cell tubes toward their targets. Axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented. Whether these axons will lead to disturbing sensations such as paresthesia or dysesthesia in the newly found environment or remain silent codwellers, this experiment cannot answer. Long-term results of future clinical work will have to decide whether the prevention of the neuroma through end-to-side coaptation will be an appropriate therapy for this difficult problem.

Sensing of blood pressure increase by transient receptor potential vanilloid 1 receptors on baroreceptors.

PubMed

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N; Pan, Hui-Lin

2009-12-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling revealed that TRPV1 immunoreactivity was present on nerve fibers and terminals in the adventitia of the ascending aorta and aortic arch, the nodose ganglion neurons, and afferent fibers in the solitary tract of the brainstem. RTX treatment eliminated TRPV1 immunoreactivities in the aorta, nodose ganglion, and solitary tract. Renal sympathetic nerve activity, blood pressure, and heart rate were recorded in anesthetized rats. The baroreflex was triggered by lowering and raising blood pressure through intravenous infusion of sodium nitroprusside and phenylephrine, respectively. Inhibition of sympathetic nerve activity and heart rate by the phenylephrine-induced increase in blood pressure was largely impaired in RTX-treated rats. The maximum gain of the baroreflex function was significantly lower in RTX-treated than vehicle-treated rats. Furthermore, blocking of TRPV1 receptors significantly blunted the baroreflex and decreased the maximum gain of baroreflex function in the high blood pressure range. Our findings provide important new information that TRPV1 is expressed along the entire baroreceptive afferent pathway. TRPV1 receptors expressed on baroreceptive nerve endings can function as mechanoreceptors to detect the increase in blood pressure and maintain the homoeostasis.

Sensing of Blood Pressure Increase by Transient Receptor Potential Vanilloid 1 Receptors on Baroreceptors

PubMed Central

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N.

2009-01-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling revealed that TRPV1 immunoreactivity was present on nerve fibers and terminals in the adventitia of the ascending aorta and aortic arch, the nodose ganglion neurons, and afferent fibers in the solitary tract of the brainstem. RTX treatment eliminated TRPV1 immunoreactivities in the aorta, nodose ganglion, and solitary tract. Renal sympathetic nerve activity, blood pressure, and heart rate were recorded in anesthetized rats. The baroreflex was triggered by lowering and raising blood pressure through intravenous infusion of sodium nitroprusside and phenylephrine, respectively. Inhibition of sympathetic nerve activity and heart rate by the phenylephrine-induced increase in blood pressure was largely impaired in RTX-treated rats. The maximum gain of the baroreflex function was significantly lower in RTX-treated than vehicle-treated rats. Furthermore, blocking of TRPV1 receptors significantly blunted the baroreflex and decreased the maximum gain of baroreflex function in the high blood pressure range. Our findings provide important new information that TRPV1 is expressed along the entire baroreceptive afferent pathway. TRPV1 receptors expressed on baroreceptive nerve endings can function as mechanoreceptors to detect the increase in blood pressure and maintain the homoeostasis. PMID:19726694

How many mechanosensory organs in the bushcricket leg? Neuroanatomy of the scolopidial accessory organ in Tettigoniidae (Insecta: Orthoptera).

PubMed

Strauß, Johannes; Riesterer, Anja S; Lakes-Harlan, Reinhard

2016-01-01

The subgenual organ and associated scolopidial organs are well studied in Orthoptera and related taxa. In some insects, a small accessory organ or Nebenorgan is described posterior to the subgenual organ. In Tettigoniidae (Ensifera), the accessory organ has only been noted in one species though tibial sensory organs are well studied for neuroanatomy and physiology. Here, we use axonal tracing to analyse the posterior subgenual organ innervated by the main motor nerve. Investigating seven species from different groups of Tettigoniidae, we describe a small group of scolopidial sensilla (5-9 sensory neurons) which has features characteristic of the accessory organ: posterior tibial position, innervation by the main leg nerve rather than by the tympanal nerve, orientation of dendrites in proximal or ventro-proximal direction in the leg, and commonly association with a single campaniform sensillum. The neuroanatomy is highly similar between leg pairs. We show differences in the innervation in two species of the genus Poecilimon as compared to the other species. In Poecilimon, the sensilla of the accessory organ are innervated by one nerve branch together with the subgenual organ. The results suggest that the accessory organ is part of the sensory bauplan in the leg of Tettigoniidae and probably Ensifera. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microsurgical resection of cauda equina schwannoma with nerve root preservation.

PubMed

McCormick, Paul C

2014-09-01

The occurrence of motor deficit following resection of an intradural spinal schwannoma is an uncommon but potentially serious complication. This video illustrates the technique of microsurgical resection of an L-4 sensory nerve root schwannoma with preservation of the corresponding functional L-4 motor nerve root. The video can be found here: http://youtu.be/HrZkGj1JKd4.

Large Extremity Peripheral Nerve Repair

DTIC Science & Technology

2014-10-01

Shahani B. Peripheral-nerve allotransplantation in rats immunosuppressed with transient or long-term FK-506. Journal of reconstructive microsurgery ...multicenter study of utilization and outcomes in sensory, mixed, and motor nerve reconstructions . Microsurgery . 2012 Jan;32(1):1-14. PubMed PMID: 22121093...PTB method can provide fixation strengths 6 approaching that of conventional microsurgery and that the PTB repair is unlikely to be disturbed in

Constriction of the buccal branch of the facial nerve produces unilateral craniofacial allodynia.

PubMed

Lewis, Susannah S; Grace, Peter M; Hutchinson, Mark R; Maier, Steven F; Watkins, Linda R

2017-08-01

Despite pain being a sensory experience, studies of spinal cord ventral root damage have demonstrated that motor neuron injury can induce neuropathic pain. Whether injury of cranial motor nerves can also produce nociceptive hypersensitivity has not been addressed. Herein, we demonstrate that chronic constriction injury (CCI) of the buccal branch of the facial nerve results in long-lasting, unilateral allodynia in the rat. An anterograde and retrograde tracer (3000MW tetramethylrhodamine-conjugated dextran) was not transported to the trigeminal ganglion when applied to the injury site, but was transported to the facial nucleus, indicating that this nerve branch is not composed of trigeminal sensory neurons. Finally, intracisterna magna injection of interleukin-1 (IL-1) receptor antagonist reversed allodynia, implicating the pro-inflammatory cytokine IL-1 in the maintenance of neuropathic pain induced by facial nerve CCI. These data extend the prior evidence that selective injury to motor axons can enhance pain to supraspinal circuits by demonstrating that injury of a facial nerve with predominantly motor axons is sufficient for neuropathic pain, and that the resultant pain has a neuroimmune component. Copyright © 2016 Elsevier Inc. All rights reserved.

Upper Extremity Nerve Function and Pain in Human Volunteers with Narrow versus Wide Tourniquets.

PubMed

Kovar, Florian; Jauregui, Julio J; Specht, Stacy C; Baker, Erin; Bhave, Anil; Herzenberg, John E

2016-01-01

Nerve injury is a serious potential complication associated with clinical use of tourniquets during surgery. A novel narrow, single-use silicon ring tourniquet has been introduced, which may cause less nerve compression and provide a larger field of surgical exposure than standard wide tourniquets. We investigated both types of tourniquets in the non-dominant proximal upper arm of 15 healthy human volunteers. Pain and neurological effects were assessed during 15 minute trials with each tourniquet applied 1 week apart without anesthesia according to the manufacturers' recommendations. Median nerve function was studied using the pressure-specified sensory device, an instrumented two-point discriminator, and pain was assessed by two validated instruments. Skin sores, redness, nerve damage, or neurological complications did not occur in either group. Subjects reported more pain with the narrow tourniquet; however, measurable effect on median nerve function was the same in both groups. Tourniquet application with the narrow device was more efficient, the device was easier to use, and larger surgical field exposure was obtained. We conclude that the sensory deficit with the use of narrow tourniquets is not greater than that observed with pneumatic/wide tourniquets.

Monosynaptic inputs from the nucleus tractus solitarii to the laryngeal motoneurons in the nucleus ambiguus of the rat.

PubMed

Hayakawa, T; Takanaga, A; Maeda, S; Ito, H; Seki, M

2000-11-01

The cricothyroid (CT) and the posterior cricoarytenoid (PCA) muscles in the larynx are activated by the laryngeal motoneurons located within the nucleus ambiguus; these motoneurons receive the laryngeal sensory information from the nucleus tractus solitarii (NTS) during respiration and swallowing. We investigated whether the neurons in the NTS projected directly to the laryngeal motoneurons, and what is the synaptic organization of their nerve terminals on the laryngeal motoneurons using the electron microscope. When wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) was injected into the NTS after cholera toxin subunit B-conjugated HRP (CT-HRP) was injected into the CT muscle or the PCA muscle, the anterogradely WGA-HRP-labeled terminals from the NTS were found to directly contact the retrogradely CT-HRP-labeled dendrites and soma of both the CT and the PCA motoneurons. The labeled NTS terminals comprised about 4% of the axosomatic terminals in a section through the CT motoneurons, and about 9% on both the small (PCA-A) and the large (PCA-B) PCA motoneurons. The number of labeled axosomatic terminals containing round vesicles and making asymmetric synaptic contacts (Gray's type I) was almost equal to that of the labeled terminals containing pleomorphic vesicles and making symmetric synaptic contacts (Gray's type II) on the CT motoneurons. The labeled axosomatic terminals were mostly Gray's type II on the PCA-A motoneurons, while the majority of them were Gray's type I on the PCA-B motoneurons. These results indicate that the laryngeal CT and PCA motoneurons receive a few direct excitatory and inhibitory inputs from the neurons in the NTS.

Somatosensory Neurotoxicity: Agents and Assessment Methodology.

EPA Science Inventory

The somatosensory system is comprised of a variety of sensory receptors located in the skin, muscle tendons, and visceral organs that are innervated by myelinated and nonmyelinated axons of the peripheral nervous system. These peripheral sensory nerve fibers in tum communicate so...

Somatosensory Neurotoxicity: Agents and Assessment Methodology

EPA Science Inventory

The somatosensory system is comprised of a variety of sensory receptors located in the skin, muscle tendons, and visceral organs that are innervated by myelinated and nonmyelinated axons of the peripheral nervous system. These peripheral sensory nerve fibers in turn communicate s...

Nerve fiber layer (NFL) degeneration associated with acute q-switched laser exposure in the nonhuman primate

NASA Astrophysics Data System (ADS)

Zwick, Harry; Zuclich, Joseph A.; Stuck, Bruce E.; Gagliano, Donald A.; Lund, David J.; Glickman, Randolph D.

1995-01-01

We have evaluated acute laser retinal exposure in non-human primates using a Rodenstock scanning laser ophthalmoscope (SLO) equipped with spectral imaging laser sources at 488, 514, 633, and 780 nm. Confocal spectral imaging at each laser wavelength allowed evaluation of the image plane from deep within the retinal vascular layer to the more superficial nerve fiber layer in the presence and absence of the short wavelength absorption of the macular pigment. SLO angiography included both fluorescein and indocyanine green procedures to assess the extent of damage to the sensory retina, the retinal pigment epithelium (RPE), and the choroidal vasculature. All laser exposures in this experiment were from a Q-switched Neodymium laser source at an exposure level sufficient to produce vitreous hemorrhage. Confocal imaging of the nerve fiber layer revealed discrete optic nerve sector defects between the lesion site and the macula (retrograde degeneration) as well as between the lesion site and the optic disk (Wallerian degeneration). In multiple hemorrhagic exposures, lesions placed progressively distant from the macula or overlapping the macula formed bridging scars visible at deep retinal levels. Angiography revealed blood flow disturbance at the retina as well as at the choroidal vascular level. These data suggest that acute parafoveal laser retinal injury can involve both direct full thickness damage to the sensory and non-sensory retina and remote nerve fiber degeneration. Such injury has serious functional implications for both central and peripheral visual function.

Deficient "sensory" beta synchronization in Parkinson's disease.

PubMed

Degardin, A; Houdayer, E; Bourriez, J-L; Destée, A; Defebvre, L; Derambure, P; Devos, D

2009-03-01

Beta 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 PD patients and healthy, age-matched volunteers and (ii) evaluate the effect of levodopa. Using a 128-electrode EEG system, we studied beta synchronization after active and passive index finger movement and electrical median nerve stimulation in 13 patients and 12 control subjects. Patients were recorded before and after 150% of their usual morning dose of levodopa. The peak beta synchronization magnitude in the contralateral primary sensorimotor (PSM) cortex was significantly lower in PD patients after active movement, passive movement and electrical median nerve stimulation, compared with controls. Levodopa partially reversed the drop in beta synchronization after active movement but not after passive movement or electrical median nerve stimulation. If one considers that beta synchronization reflects sensory processing, our results suggest that integration of somaesthetic afferences in the PSM cortex is abnormal in PD during active and passive movement execution and after simple electrical median nerve stimulation. Better understanding of the mechanisms involved in the deficient beta synchronization observed here could prompt the development of new therapeutic approaches aimed at strengthening defective processes. The lack of full beta synchronization restoration by levodopa might be related to the involvement of non-dopaminergic pathways.

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

Hemifacial Pain and Hemisensory Disturbance Referred from Occipital Neuralgia Caused by Pathological Vascular Contact of the Greater Occipital Nerve

PubMed Central

Choi, Jin-gyu

2017-01-01

Here we report a unique case of chronic occipital neuralgia caused by pathological vascular contact of the left greater occipital nerve. After 12 months of left-sided, unremitting occipital neuralgia, a hypesthesia and facial pain developed in the left hemiface. The decompression of the left greater occipital nerve from pathological contacts with the occipital artery resulted in immediate relief for hemifacial sensory change and facial pain, as well as chronic occipital neuralgia. Although referral of pain from the stimulation of occipital and cervical structures innervated by upper cervical nerves to the frontal head of V1 trigeminal distribution has been reported, the development of hemifacial sensory change associated with referred trigeminal pain from chronic occipital neuralgia is extremely rare. Chronic continuous and strong afferent input of occipital neuralgia caused by pathological vascular contact with the greater occipital nerve seemed to be associated with sensitization and hypersensitivity of the second-order neurons in the trigeminocervical complex, a population of neurons in the C2 dorsal horn characterized by receiving convergent input from dural and cervical structures. PMID:28331643

Hemifacial Pain and Hemisensory Disturbance Referred from Occipital Neuralgia Caused by Pathological Vascular Contact of the Greater Occipital Nerve.

PubMed

Son, Byung-Chul; Choi, Jin-Gyu

2017-01-01

Here we report a unique case of chronic occipital neuralgia caused by pathological vascular contact of the left greater occipital nerve. After 12 months of left-sided, unremitting occipital neuralgia, a hypesthesia and facial pain developed in the left hemiface. The decompression of the left greater occipital nerve from pathological contacts with the occipital artery resulted in immediate relief for hemifacial sensory change and facial pain, as well as chronic occipital neuralgia. Although referral of pain from the stimulation of occipital and cervical structures innervated by upper cervical nerves to the frontal head of V1 trigeminal distribution has been reported, the development of hemifacial sensory change associated with referred trigeminal pain from chronic occipital neuralgia is extremely rare. Chronic continuous and strong afferent input of occipital neuralgia caused by pathological vascular contact with the greater occipital nerve seemed to be associated with sensitization and hypersensitivity of the second-order neurons in the trigeminocervical complex, a population of neurons in the C2 dorsal horn characterized by receiving convergent input from dural and cervical structures.

Capsaicin-Sensitive Sensory Nerves Are Necessary for the Protective Effect of Ghrelin in Cerulein-Induced Acute Pancreatitis in Rats

PubMed Central

Bonior, Joanna; Warzecha, Zygmunt; Ceranowicz, Piotr; Gajdosz, Ryszard; Pierzchalski, Piotr; Kot, Michalina; Leja-Szpak, Anna; Nawrot-Porąbka, Katarzyna; Link-Lenczowski, Paweł; Olszanecki, Rafał; Bartuś, Krzysztof; Trąbka, Rafał; Kuśnierz-Cabala, Beata; Dembiński, Artur; Jaworek, Jolanta

2017-01-01

Ghrelin was shown to exhibit protective and therapeutic effect in the gut. Aim of the study was to investigate the role of sensory nerves (SN) in the protective effect of ghrelin in acute pancreatitis (AP). Studies were performed on male Wistar rats or isolated pancreatic acinar cells. After capsaicin deactivation of sensory nerves (CDSN) or treatment with saline, rats were pretreated intraperitoneally with ghrelin or saline. In those rats, AP was induced by cerulein or pancreases were used for isolation of pancreatic acinar cells. Pancreatic acinar cells were incubated in cerulein-free or cerulein containing solution. In rats with intact SN, pretreatment with ghrelin led to a reversal of the cerulein-induced increase in pancreatic weight, plasma activity of lipase and plasma concentration of tumor necrosis factor-α (TNF-α). These effects were associated with an increase in plasma interleukin-4 concentration and reduction in histological signs of pancreatic damage. CDSN tended to increase the severity of AP and abolished the protective effect of ghrelin. Exposure of pancreatic acinar cells to cerulein led to increase in cellular expression of mRNA for TNF-α and cellular synthesis of this cytokine. Pretreatment with ghrelin reduced this alteration, but this effect was only observed in acinar cells obtained from rats with intact SN. Moreover, CDSN inhibited the cerulein- and ghrelin-induced increase in gene expression and synthesis of heat shock protein 70 (HSP70) in those cells. Ghrelin exhibits the protective effect in cerulein-induced AP on the organ and pancreatic acinar cell level. Sensory nerves ablation abolishes this effect. PMID:28665321

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

PubMed

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

2016-01-01

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

Early compensatory sensory re-education.

PubMed

Daniele, Hugo R; Aguado, Leda

2003-02-01

After a neurorrhaphy, there will be a distal disconnection between the cortex and skin receptors, along with interruption of sensibility information. This report demonstrates the efficacy of a new sensory re-education program for achieving optimal sensation in a relatively short time. Between 1999 and 2001, in the authors' Hand Rehabilitation Department, 11 patients with previous neurorrhaphy were subjected to a program of early "compensatory sensory re-education." Lesions were caused by clean cut. There were 13 primary digital nerve procedures, 12 at the distal palmar MP level, and one at the radial dorsal branch of the index (just after emerging from the common digital nerve). The technique of compensatory sensory re-education was based on a previous, but modified, sensory re-education method. In order to evaluate the results in the compensatory sensory re-education series described, additional tests for evaluation of achieved functional sensibility were used. The authors' best results were achieved in a maximum of 8 weeks (4-8 weeks), much less time than with the original method (1-2 years). Using the British classification, it was possible to compare the achieved levels of sensibility and the time required for optimal results. The different methods of sensibility re-education may be similar, but with the authors' compensatory sensory re-education method, substantial time is saved.

Comparative study of the innervation of the facila disc of selected mammals.

PubMed

Montagna, W; Roman, N A; Macpherson, E

1975-11-01

The greatest concentration of sensory nerves in the muzzle and facial disc of mammals is in the nose. In most nocturnal mammals, these nerves penetrate the epidermis of the naked nose either or in bundles which resemble the corpuscles of Eimer. The hair follicles around the nose, lips, and eyes, as well as the heaviply innervated vibrissae follicles found in all hairy mammals except man, are well innervated; those elsewhaere are not. Everywhere on the human body both large and small follicles abound in sensory nerves. These morphologic observations suggest that in most mammals the most sensitivie areas of the skin are at the anterior and posterior ends (not reported here), and that human skin is better equipped for cutaneous sensibility than that of any other mammal.

Palisade endings are present in canine extraocular muscles and have a cholinergic phenotype

PubMed Central

RUNGALDIER, Stefanie; POMIKAL, Christine; STREICHER, Johannes; BLUMER, Roland

2016-01-01

Classical proprioceptors, like Golgi tendon organs and muscle spindles are absent in the extraocular muscles (EOMs) of most mammals. Instead, a nerve end organ was detected in the EOMs of each species including sheep, cats, rabbits, rats, monkeys, and man examined so far: the palisade ending. Until now no evidence appeared that palisade endings are present in canine EOMs. We analyzed dog EOMs by confocal laser scanning microscopy, 3D reconstruction, and transmission electron microscopy. In EOM wholemount preparations stained with antibodies against neurofilament and synaptophysin we found typical palisade endings. Nerve fibers coming from the muscle extended into the tendon. There, the nerve fibers turned 180° and returned to branch into preterminal axons which established nerve terminals around a single muscle fiber tip. Fine structural analyses revealed that each palisade ending in dog EOMs established nerve terminals on the tendon. In some palisade endings we found nerve terminals contacting the muscle fiber as well. Such neuromuscular contacts had a basal lamina in the synaptic cleft thereby resembling motor terminals. By using antibodies against choline acetyltransferase (ChAT) we proved that canine palisade endings are ChAT-immunoreactive. This study shows that palisade endings are present in canine EOMs. In line with prior findings in cat and monkey, palisade endings in dog have a cholinergic phenotype. PMID:19766165

Compartmentalized beta subunit distribution determines characteristics and ethanol sensitivity of somatic, dendritic, and terminal large-conductance calcium-activated potassium channels in the rat central nervous system.

PubMed

Wynne, P M; Puig, S I; Martin, G E; Treistman, S N

2009-06-01

Neurons are highly differentiated and polarized cells, whose various functions depend upon the compartmentalization of ion channels. The rat hypothalamic-neurohypophysial system (HNS), in which cell bodies and dendrites reside in the hypothalamus, physically separated from their nerve terminals in the neurohypophysis, provides a particularly powerful preparation in which to study the distribution and regional properties of ion channel proteins. Using electrophysiological and immunohistochemical techniques, we characterized the large-conductance calcium-activated potassium (BK) channel in each of the three primary compartments (soma, dendrite, and terminal) of HNS neurons. We found that dendritic BK channels, in common with somatic channels but in contrast to nerve terminal channels, are insensitive to iberiotoxin. Furthermore, analysis of dendritic BK channel gating kinetics indicates that they, like somatic channels, have fast activation kinetics, in contrast to the slow gating of terminal channels. Dendritic and somatic channels are also more sensitive to calcium and have a greater conductance than terminal channels. Finally, although terminal BK channels are highly potentiated by ethanol, somatic and dendritic channels are insensitive to the drug. The biophysical and pharmacological properties of somatic and dendritic versus nerve terminal channels are consistent with the characteristics of exogenously expressed alphabeta1 versus alphabeta4 channels, respectively. Therefore, one possible explanation for our findings is a selective distribution of auxiliary beta1 subunits to the somatic and dendritic compartments and beta4 to the terminal compartment. This hypothesis is supported immunohistochemically by the appearance of distinct punctate beta1 or beta4 channel clusters in the membrane of somatic and dendritic or nerve terminal compartments, respectively.

Sensing of Substrate Vibrations in the Adult Cicada Okanagana rimosa (Hemiptera: Cicadidae).

PubMed

Alt, Joscha A; Lakes-Harlan, Reinhard

2018-05-01

Detection of substrate vibrations is an evolutionarily old sensory modality and is important for predator detection as well as for intraspecific communication. In insects, substrate vibrations are detected mainly by scolopidial (chordotonal) sense organs found at different sites in the legs. Among these sense organs, the tibial subgenual organ (SGO) is one of the most sensitive sensors. The neuroanatomy and physiology of vibratory sense organs of cicadas is not well known. Here, we investigated the leg nerve by neuronal tracing and summed nerve recordings. Tracing with Neurobiotin revealed that the cicada Okanagana rimosa (Say) (Hemiptera: Cicadidae) has a femoral chordotonal organ with about 20 sensory cells and a tibial SGO with two sensory cells. Recordings from the leg nerve show that the vibrational response is broadly tuned with a threshold of about 1 m/s2 and a minimum latency of about 6 ms. The vibratory sense of cicadas might be used in predator avoidance and intraspecific communication, although no tuning to the peak frequency of the calling song (9 kHz) could be found.

Permanent reorganization of Ia afferent synapses on motoneurons after peripheral nerve injuries

PubMed Central

Alvarez, Francisco J.; Bullinger, Katie L.; Titus, Haley E.; Nardelli, Paul; Cope, Timothy C.

2010-01-01

After peripheral nerve injuries to a motor nerve the axons of motoneurons and proprioceptors are disconnected from the periphery and monosynaptic connections from group I afferents and motoneurons become diminished in the spinal cord. Following successful reinnervation in the periphery, motor strength, proprioceptive sensory encoding, and Ia afferent synaptic transmission on motoneurons partially recover. Muscle stretch reflexes, however, never recover and motor behaviors remain uncoordinated. In this review, we summarize recent findings that suggest that lingering motor dysfunction might be in part related to decreased connectivity of Ia afferents centrally. First, sensory afferent synapses retract from lamina IX causing a permanent relocation of the inputs to more distal locations and significant disconnection from motoneurons. Second, peripheral reconnection between proprioceptive afferents and muscle spindles is imperfect. As a result, a proportion of sensory afferents that retain central connections with motoneurons might not reconnect appropriately in the periphery. A hypothetical model is proposed in which the combined effect of peripheral and central reconnection deficits might explain the failure of muscle stretch to initiate or modulate firing of many homonymous motoneurons. PMID:20536938

Patterns of primary afferent depolarization of segmental and ascending intraspinal collaterals of single joint afferents in the cat.

PubMed

Rudomin, P; Lomelí, J

2007-01-01

We have examined in the anesthetized cat the threshold changes produced by sensory and supraspinal stimuli on intraspinal collaterals of single afferents from the posterior articular nerve (PAN). Forty-eight fibers were tested in the L3 segment, in or close to Clarke's column, and 70 fibers in the L6-L7 segments within the intermediate zone. Of these, 15 pairs of L3 and L6-L7 collaterals were from the same afferent. Antidromically activated fibers had conduction velocities between 23 and 74 m/s and peripheral thresholds between 1.1 and 4.7 times the threshold of the most excitable fibers (xT), most of them below 3 xT. PAN afferents were strongly depolarized by stimulation of muscle afferents and by cutaneous afferents, as well as by stimulation of the bulbar reticular formation and the midline raphe nuclei. Stimulation of muscle nerves (posterior biceps and semitendinosus, quadriceps) produced a larger PAD (primary afferent depolarization) in the L6-L7 than in the L3 terminations. Group II were more effective than group I muscle afferents. As with group I muscle afferents, the PAD elicited in PAN afferents by stimulation of muscle nerves could be inhibited by conditioning stimulation of cutaneous afferents. Stimulation of the cutaneous sural and superficial peroneal nerves increased the threshold of few terminations (i.e., produced primary afferent hyperpolarization, PAH) and reduced the threshold of many others, particularly of those tested in the L6-L7 segments. Yet, there was a substantial number of terminals where these conditioning stimuli had minor or no effects. Autogenetic stimulation of the PAN with trains of pulses increased the intraspinal threshold in 46% and reduced the threshold in 26% of fibers tested in the L6-L7 segments (no tests were made with trains of pulses on fibers ending in L3). These observations indicate that PAN afferents have a rather small autogenetic PAD, particularly if this is compared with the effects of heterogenetic stimulation. Therefore, the depression of the PAN intraspinal fields produced by autogenetic stimulation described by Rudomin et al. (Exp Brain Res DOI 10.1007/s00221-006-0600-x, 2006) may be ascribed to other mechanisms besides a GABAa PAD. It is suggested that the small or no autogenetic PAD displayed by the examined joint afferents prevents presynaptic filtering of their synaptic actions and preserves the original information generated in the periphery. This could be important for proper adjustment of limb position.

Cold bupivacaine versus magnesium sulfate added to room temperature bupivacaine in sonar-guided femoral and sciatic nerve block in arthroscopic anterior cruciate ligament reconstruction surgery.

PubMed

Alzeftawy, Ashraf Elsayed; El-Daba, Ahmad Ali

2016-01-01

Cooling of local anesthetic potentiates its action and increases its duration. Magnesium sulfate (MgSo 4 ) added to local anesthetic prolongs the duration of anesthesia and postoperative analgesia with minimal side effects. The aim of this prospective, randomized, double-blind study was to compare the effect of cold to 4°C bupivacaine 0.5% and Mg added to normal temperature (20-25°C) bupivacaine 0.5% during sonar-guided combined femoral and sciatic nerve blocks on the onset of sensory and motor block, intraoperative anesthesia, duration of sensory and motor block, and postoperative analgesia in arthroscopic anterior cruciate ligament (ACL) reconstruction surgery. A total of 90 American Society of Anesthesiologists classes I and II patients who were scheduled to undergo elective ACL reconstruction were enrolled in the study. The patients were randomly allocated to 3 equal groups to receive sonar-guided femoral and sciatic nerve blocks. In Group I, 17 ml of room temperature (20-25°C) 0.5% bupivacaine and 3 ml of room temperature saline were injected for each nerve block whereas in Group II, 17 ml of cold (4°C) 0.5% bupivacaine and 3 ml of cold saline were injected for each nerve block. In Group III, 17 ml of room temperature 0.5% bupivacaine and 3 ml of MgSo 4 5% were injected for each nerve block. The onset of sensory and motor block was evaluated every 3 min for 30 min. Surgery was started after complete sensory and motor block were achieved. Intraoperatively, the patients were evaluated for heart rate and mean arterial pressure, rescue analgesic and sedative requirements plus patient and surgeon satisfaction. Postoperatively, hemodynamics, duration of analgesia, resolution of motor block, time to first analgesic, total analgesic consumption, and the incidence of side effects were recorded. There was no statistically significant difference in demographic data, mean arterial pressure, heart rate, and duration of surgery. Onset of both sensory and motor block was significantly shorter in both Groups II and III compared to Group I. Intraoperative anesthetic quality was comparable between groups with good patient and surgeon satisfaction. The time to first analgesia was significantly longer in Groups II and III compared to Group I with nonsignificant difference between each other. Moreover, the total opioid consumption was significantly lower in Groups II and III and duration of analgesia and motor block were significantly longer in Groups II and III compared to Group I. There was no difference in the incidence of side effects. The use of cold 0.5% bupivacaine or the addition of Mg to normal temperature 0.5% bupivacaine prolongs the sensory and motor block duration without increasing side effects and enhances the quality of intra- and post-operative analgesia with better patient satisfaction in sonar-guided femoral and sciatic nerve block for arthroscopic ACL reconstruction surgery.

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

PubMed

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

2016-01-28

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

Prejunctional and postjunctional actions of heptanol and 18 beta-glycyrretinic acid in the rodent vas deferens.

PubMed

Rahman, Faisal; Manchanda, Rohit; Brain, Keith L

2009-06-15

Heptanol and 18 beta-glycyrrhetinic acid (18 beta GA) block gap junctions, but have other actions on transmitter release that have not been characterised. This study investigates the prejunctional and postjunctional effects of these compounds in guinea pig and mouse vas deferens using intracellular electrophysiological recording and confocal Ca(2+) imaging of sympathetic nerve terminals. In mice, heptanol (2 mM) reversibly decreased the amplitude of purinergic excitatory junction potentials (EJPs; 52+/-5%, P<0.05) while having little effect on spontaneous excitatory junction potentials (sEJPs). Heptanol (2 mM) reversibly abolished the nerve terminal Ca(2+) transient in 52% of terminals. 18 beta GA (10 microM) decreased the mean EJP amplitude, and increased input resistance in both mouse (137+/-17%, P<0.05) and guinea pig (354+/-50%, P<0.001) vas deferens indicating gap junction blockade. Further, 18 beta GA increased the sEJP frequency significantly in guinea pigs (by 71+/-25%, P<0.05) and in 5 out of 6 tissues in mice (19+/-3%, P<0.05). Moreover, 18 beta GA depolarised cells from both mice (11+/-1%, P<0.01) and guinea pigs (8+/-1%, P<0.005). Therefore, we conclude that heptanol (2 mM) decreases neurotransmitter release (given the decrease in EJP amplitude) by abolishing the nerve terminal action potential in a proportion of nerve terminals. 18 betaGA (10 microM) effectively blocks the gap junctions, but the increase in sEJP frequency suggests an additional prejunctional effect, which might involve the induction of spontaneous nerve terminal action potentials.

Electrophysiologic alterations in the excitability of the sciatic and vagus nerves during early stages of sepsis

PubMed Central

Diniz, Lúcio Ricardo Leite; Portella, Viviane Gomes; da Silva Alves, Kerly Shamira; Araújo, Pâmella Cristina da Costa; de Albuquerque Júnior, Ricardo Luiz Cavalcanti; Cavalcante de Albuquerque, Aline Alice; Coelho-de-Souza, Andrelina Noronha; Leal-Cardoso, José Henrique

2018-01-01

Background Nonspecific and delayed diagnosis of neurologic damage contributes to the development of neuropathies in patients with severe sepsis. The present study assessed the electrophysiologic parameters related to the excitability and conductibility of sciatic and vagus nerves during early stages of sepsis. Materials and methods Twenty-four hours after sepsis induced by cecal ligation and puncture (CLP) model, sciatic and vagus nerves of septic (CLP group) and control (sham group) rats were removed, and selected electric stimulations were applied to measure the parameters of the first and second components of the compound action potential. The first component originated from fibers with motor and sensory functions (Types Aα and Aβ fibers) with a large conduction velocity (70–120 m/s), and the second component originated from fibers (Type Aγ) with sensorial function. To evaluate the presence of sensorial alterations, the sensitivity to non-noxious mechanical stimuli was measured by using the von Frey test. Hematoxylin and eosin staining of the nerves was performed. Results We observed an increase of rheobase followed by a decrease in the first component amplitude and a higher paw withdrawal threshold in response to the application of von Frey filaments in sciatic nerves from the CLP group compared to the sham group. Differently, a decrease in rheobase and an increase in the first component amplitude of vagal C fibers from CLP group were registered. No significant morphologic alteration was observed. Conclusion Our data showed that the electrophysiologic alterations in peripheral nerves vary with the fiber type and might be identified in the first 24 h of sepsis, before clinical signs of neuromuscular disorders. PMID:29731661

Efficacy of low level laser therapy on neurosensory recovery after injury to the inferior alveolar nerve

PubMed Central

Ozen, Tuncer; Orhan, Kaan; Gorur, Ilker; Ozturk, Adnan

2006-01-01

Background The most severe complication after the removal of mandibular third molars is injury to the inferior alveolar nerve or the lingual nerve. These complications are rather uncommon (0.4% to 8.4%) and most of them are transient. However, some of them persist for longer than 6 months, which can leave various degrees of long-term permanent disability. While several methods such as pharmacologic therapy, microneurosurgery, autogenous and alloplastic grafting can be used for the treatment of long-standing sensory aberrations in the inferior alveolar nerve, there are few reports regarding low level laser treatment. This paper reports the effects of low level laser therapy in 4 patients with longstanding sensory nerve impairment following mandibular third molar surgery. Methods Four female patients had complaints of paresthesia and dysesthesia of the lip, chin and gingiva, and buccal regions. Each patient had undergone mandibular third molar surgery at least 1 year before. All patients were treated with low level laser therapy. Clinical neurosensory tests (the brush stroke directional discrimination test, 2-point discrimination test, and a subjective assessment of neurosensory function using a visual analog scale) were used before and after treatment, and the responses were plotted over time. Results When the neurosensory assessment scores after treatment with LLL therapy were compared with the baseline values prior to treatment, there was a significant acceleration in the time course, as well as in the magnitude, of neurosensory return. The VAS analysis revealed progressive improvement over time. Conclusion Low level laser therapy seemed to be conducive to the reduction of long-standing sensory nerve impairment following third molar surgery. Further studies are worthwhile regarding the clinical application of this treatment modality. PMID:16480503

Autonomic regulation. i-NANC/e-NANC.

PubMed

Widdicombe, J G

1998-11-01

The excitatory and inhibitory nonadrenergic/noncholinergic (e-NANC, i-NANC) systems have been extensively studied. The terms excitatory and inhibitory apply to airway smooth muscle, but the neurotransmitters also act on other targets-blood vessels, glands, the epithelium-where individual actions may be the opposite. Thus, the nomenclature is unsatisfactory. Of the dozen or more putative NANC transmitters, criteria to establish their roles have been met only for vasoactive intestinal polypeptide (VIP), nitric oxide (NO), and substance P/neurokinin A (SP/NKA). VIP and NO co-localize in vagal motor nerves, but they are also found in sympathetic and sensory nerves. In general they have similar actions on target tissues, and their relative importance may vary with species. SP/NKA, released from sensory nerves, is thought to mediate neurogenic inflammation, a process that may include airway smooth muscle contraction, at least in rodents. The evidence for neurogenic inflammation in humans is weak. On the motor side, and also possibly on the sensory, different nerves seem to contain different selections of neurotransmitters, but it is not known if there are different motor controls for these nerves. Cotransmission presents a major conceptual and experimental problem, since the two or more transmitters may give opposite instructions to the target tissue. Inevitably most of the studies on the NANC systems are on isolated rodent tissues, and although quantitative, they indicate little of what happens in vivo, and certainly not in humans. The cocktail of mediators that must be released from nerves and associated cells in airway tissues during pathophysiologic processes may refresh physiologists, but little is known about the concentrations of the ingredients or about the strength of their actions and their interactions on different target tissues in the mucosa.

[Experimental studies for the improvement of facial nerve regeneration].

PubMed

Guntinas-Lichius, O; Angelov, D N

2008-02-01

Using a combination of the following, it is possible to investigate procedures to improve the morphological and functional regeneration of the facial nerve in animal models: 1) retrograde fluorescence tracing to analyse collateral axonal sprouting and the selectivity of reinnervation of the mimic musculature, 2) immunohistochemistry to analyse both the terminal axonal sprouting in the muscles and the axon reaction within the nucleus of the facial nerve, the peripheral nerve, and its environment, and 3) digital motion analysis of the muscles. To obtain good functional facial nerve regeneration, a reduction of terminal sprouting in the mimic musculature seems to be more important than a reduction of collateral sprouting at the lesion site. Promising strategies include acceleration of nerve regeneration, forced induced use of the paralysed face, mechanical stimulation of the face, and transplantation of nerve-growth-promoting olfactory epithelium at the lesion site.

Amyotrophic lateral sclerosis with sensory neuropathy: part of a multisystem disorder?

PubMed Central

Isaacs, Jeremy D; Dean, Andrew F; Shaw, Christopher E; Al‐Chalabi, Ammar; Mills, Kerry R; Leigh, P Nigel

2007-01-01

Sensory involvement is thought not to be a feature of amyotrophic lateral sclerosis (ALS). However, in the setting of a specialist motor neuron disease clinic, we have identified five patients with sporadic ALS and a sensory neuropathy for which an alternative cause could not be identified. In three individuals, sensory nerve biopsy was performed, demonstrating axonal loss without features of an alternative aetiology. These findings support the hypothesis that ALS is a multisystem neurodegenerative disorder that may occasionally include sensory neuropathy among its non‐motor features. PMID:17575021

Infant botulism due to consumption of contaminated commercially prepared honey. First report from the Arabian Gulf States.

PubMed

van der Vorst, Maria M J; Jamal, Wafaa; Rotimi, Vincent O; Moosa, Alie

2006-01-01

To report the first case of infant botulism in Arabian Gulf States. A 6-week-old infant, presenting with signs of sepsis, was intubated and ventilated due to progressive weakness. Infant botulism was suspected with acute flaccid paralysis and a history of honey consumption. An electromyogram showed decreased amplitude of compound muscle action potential in all motor nerves, preserved sensory responses; the motor terminal latencies and motor conduction velocities were normal. Blood, stool and honey samples were sent for culture. Stool and honey cultures showed two identical strains of Clostridium botulinum. This case shows that the infant botulism occurred from the ingested contaminated honey. Hence vigilance should be maintained when a baby is fed honey and shows signs of progressive weakness because the disease can quickly progress to respiratory failure.

Large Extremity Peripheral Nerve Repair

DTIC Science & Technology

2014-10-01

nerve allotransplantation in rats immunosuppressed with transient or long-term FK-506. Journal of reconstructive microsurgery . 1996 Oct;12(7):451-9...outcomes in sensory, mixed, and motor nerve reconstructions . Microsurgery . 2012 Jan;32(1):1-14. PubMed PMID: 22121093. Epub 2011/11/29. eng. 12...method can provide fixation strengths 5 approaching that of conventional microsurgery and that the PTB repair is unlikely to be disturbed in vivo

Extracellular Recording of Light Responses from Optic Nerve Fibers and the Caudal Photoreceptor in the Crayfish

PubMed Central

Nesbit, Steven C.; Van Hoof, Alexander G.; Le, Chi C.; Dearworth, James R.

2015-01-01

Few laboratory exercises have been developed using the crayfish as a model for teaching how neural processing is done by sensory organs that detect light stimuli. This article describes the dissection procedures and methods for conducting extracellular recording from light responses of both the optic nerve fibers found in the animal’s eyestalk and from the caudal photoreceptor located in the ventral nerve cord. Instruction for ADInstruments’ data acquisition system is also featured for the data collection and analysis of responses. The comparison provides students a unique view on how spike activities measured from neurons code image-forming and non-image-forming processes. Results from the exercise show longer latency and lower frequency of firing by the caudal photoreceptor compared to optic nerve fibers to demonstrate evidence of different functions. After students learn the dissection, recording procedure, and the functional anatomy, they can develop their own experiments to learn more about the photoreceptive mechanisms and the sensory integration of modalities by these light-responsive interneurons. PMID:26557793

The nerve supply of the lumbar intervertebral disc.

PubMed

Edgar, M A

2007-09-01

The anatomical studies, basic to our understanding of lumbar spine innervation through the sinu-vertebral nerves, are reviewed. Research in the 1980s suggested that pain sensation was conducted in part via the sympathetic system. These sensory pathways have now been clarified using sophisticated experimental and histochemical techniques confirming a dual pattern. One route enters the adjacent dorsal root segmentally, whereas the other supply is non-segmental ascending through the paravertebral sympathetic chain with re-entry through the thoracolumbar white rami communicantes. Sensory nerve endings in the degenerative lumbar disc penetrate deep into the disrupted nucleus pulposus, insensitive in the normal lumbar spine. Complex as well as free nerve endings would appear to contribute to pain transmission. The nature and mechanism of discogenic pain is still speculative but there is growing evidence to support a 'visceral pain' hypothesis, unique in the muscloskeletal system. This mechanism is open to 'peripheral sensitisation' and possibly 'central sensitisation' as a potential cause of chronic back pain.

Formalin produces depolarizations in human airway smooth muscle in vitro.

PubMed

Richards, Ira S; DeHate, Robin B

2006-03-01

Respiratory irritants may result in airway smooth muscle (ASM) depolarization and bronchoconstriction. We examined the effect of formalin on membrane potentials in human ASM in two types of in vitro preparations: strip preparations, which contain functional sensory and motor nerve endings and cultured cells, which lack these nerve endings due to the tissue dissociation process. Depolarizations occurred in atropine-treated strip preparations in response to formalin exposures, but not in similarly-treated cultured cells, suggesting a role for non-cholinergic mediators in formalin-induced depolarization. It is suggested that formalin may act as an irritant to produce bronchoconstriction that is mediated by the release of endogenous substance P (SP) from peripheral sensory nerve endings. This is supported by our observation that exogenous SP produced depolarizations of a magnitude similar to those produced by formalin in both strip preparations and cultured cells. In addition, capsaicin, which releases endogenous SP from nerve endings, produced depolarizations of a magnitude similar to formalin in strip preparations, but was without effect in cultured cells.

Paraparetic Guillain-Barré syndrome: Nondemyelinating reversible conduction failure restricted to the lower limbs.

PubMed

Kimachi, Takeshi; Yuki, Nobuhiro; Kokubun, Norito; Yamaguchi, Shuhei; Wakerley, Benjamin R

2017-02-01

Paraparetic Guillain-Barré syndrome (GBS) is a rare subtype of GBS characterized by leg weakness and areflexia in the absence of neurological involvement of the arms, cranial nerves, or respiratory muscles. Onset is characterized by lower back, buttock, or leg pain, followed by development of symmetric flaccid limb weakness in the absence of sensory disturbance. We describe an elderly woman who developed postinfectious symmetric flaccid leg weakness in the absence of sensory disturbance. Serial nerve conduction studies were carried out over 5 months. Antecedent infection, a monophasic disease course, and the presence of cerebrospinal fluid albuminocytological dissociation suggested a diagnosis of paraparetic GBS. Serial nerve conduction studies demonstrated nondemyelinating reversible conduction failure, which was restricted to the legs. Axonal neuropathy was supported by the presence of anti-GM1 IgG antibodies. These findings suggest that patients with paraparetic GBS have axonal neuropathy, which is restricted to the lower limbs. Muscle Nerve 55: 281-285, 2017. © 2016 Wiley Periodicals, Inc.

Partially irreversible paresis of the deep peroneal nerve caused by osteocartilaginous exostosis of the fibula without affecting the tibialis anterior muscle.

PubMed

Paprottka, Felix Julian; Machens, Hans-Günther; Lohmeyer, Jörn Andreas

2012-08-01

Dysfunction of the lower limb's muscles can cause severe impairment and immobilisation of the patient. As one of the leg's major motor and sensory nerves, the deep peroneal nerve (synonym: deep fibular nerve) plays a very important role in muscle innervation in the lower extremities. We report the case of a 19-year-old female patient, who suffered from a brace-like exostosis 6-cm underneath her left fibular head causing a partially irreversible paresis of her deep peroneal nerve. This nerve damage resulted in complete atrophy of her extensor digitorum longus and extensor hallucis longus muscle, and in painful sensory disturbance at her left shin and first web space. The tibialis anterior muscle stayed intact because its motor branch left the deep peroneal nerve proximal to the nerve lesion. Diagnosis was first verified 6 years after the onset of symptoms by a magnetic resonance imaging (MRI) scan of her complete left lower leg. Subsequently, the patient was operated on in our clinic, where a neurolysis was performed and the 4-cm-long osteocartilaginous exostosis was removed. Paralysis was already irreversible but sensibility returned completely after neurolysis. The presented case shows that an osteocartilaginous exostosis can be the cause for partial deep peroneal nerve paresis. If this disorder is diagnosed at an early stage, nerve damage is reversible. Typical for an exostosis is its first appearance during the juvenile growth phase. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Anatomical organization and somatic axonal components of the lumbosacral nerves in female rabbits.

PubMed

Cruz, Yolanda; Hernández-Plata, Isela; Lucio, Rosa Angélica; Zempoalteca, René; Castelán, Francisco; Martínez-Gómez, Margarita

2017-09-01

To determine the anatomical organization and somatic axonal components of the lumbosacral nerves in female rabbits. Chinchilla adult anesthetized female rabbits were used. Anatomical, electrophysiological, and histological studies were performed. L7, S1, and some fibers from S2 and S3 form the lumbosacral trunk, which gives origin to the sciatic nerve and innervation to the gluteal region. From S2 to S3 originates the pudendal nerve, whose branches innervates the striated anal and urethra sphincters, as well as the bulbospongiosus, ischiocavernosus, and constrictor vulvae muscles. The sensory field of the pudendal nerve is ∼1800 mm 2 and is localized in the clitoral sheath and perineal and perigenital skin. The organization of the pudendal nerve varies between individuals, three patterns were identified, and one of them was present in 50% of the animals. From S3 emerge the pelvic nerve, which anastomoses to form a plexus localized between the vagina and the rectum. The innervation of the pelvic floor originates from S3 to S4 fibers. Most of the sacral spinal nerves of rabbit are mixed, carrying sensory, and motor information. Sacral nerves innervate the hind limbs, pelvic viscera, clitoris, perineal muscles, inguinal and anal glands and perineal, perigenital, and rump skin. The detailed description of the sacral nerves organization, topography, and axonal components further the knowledge of the innervation in pelvic and perinal structures of the female rabbit. This information will be useful in future studies about the physiology and physiopathology of urinary, fecal, reproductive, and sexual functions. © 2017 Wiley Periodicals, Inc.

The nervus terminalis in the chick: a FMRFamide-immunoreactive and AChE-positive nerve.

PubMed

Wirsig-Wiechmann, C R

1990-07-16

The chick terminal nerve (TN) was examined by immunocytochemical and histochemical methods. Molluscan cardioexcitatory peptide-immunoreactive (FMRFamide-ir) and acetylcholinesterase (AChE)-positive TN perikarya and fibers were distributed along olfactory and trigeminal nerves. FMRFamide-ir TN fibers terminated in the olfactory lamina propria and epithelium and in ganglia along the rostroventral nasal septum. This initial description of several populations of avian TN neurons should provide the foundation for future developmental studies of this system.

Peripheral nerve hyperexcitability with preterminal nerve and neuromuscular junction remodeling is a hallmark of Schwartz-Jampel syndrome.

PubMed

Bauché, Stéphanie; Boerio, Delphine; Davoine, Claire-Sophie; Bernard, Véronique; Stum, Morgane; Bureau, Cécile; Fardeau, Michel; Romero, Norma Beatriz; Fontaine, Bertrand; Koenig, Jeanine; Hantaï, Daniel; Gueguen, Antoine; Fournier, Emmanuel; Eymard, Bruno; Nicole, Sophie

2013-12-01

Schwartz-Jampel syndrome (SJS) is a recessive disorder with muscle hyperactivity that results from hypomorphic mutations in the perlecan gene, a basement membrane proteoglycan. Analyses done on a mouse model have suggested that SJS is a congenital form of distal peripheral nerve hyperexcitability resulting from synaptic acetylcholinesterase deficiency, nerve terminal instability with preterminal amyelination, and subtle peripheral nerve changes. We investigated one adult patient with SJS to study this statement in humans. Perlecan deficiency due to hypomorphic mutations was observed in the patient biological samples. Electroneuromyography showed normal nerve conduction, neuromuscular transmission, and compound nerve action potentials while multiple measures of peripheral nerve excitability along the nerve trunk did not detect changes. Needle electromyography detected complex repetitive discharges without any evidence for neuromuscular transmission failure. The study of muscle biopsies containing neuromuscular junctions showed well-formed post-synaptic element, synaptic acetylcholinesterase deficiency, denervation of synaptic gutters with reinnervation by terminal sprouting, and long nonmyelinated preterminal nerve segments. These data support the notion of peripheral nerve hyperexcitability in SJS, which would originate distally from synergistic actions of peripheral nerve and neuromuscular junction changes as a result of perlecan deficiency. Copyright © 2013 Elsevier B.V. All rights reserved.

Integration of Synaptic Vesicle Cargo Retrieval with Endocytosis at Central Nerve Terminals

PubMed Central

Cousin, Michael A.

2017-01-01

Central nerve terminals contain a limited number of synaptic vesicles (SVs) which mediate the essential process of neurotransmitter release during their activity-dependent fusion. The rapid and accurate formation of new SVs with the appropriate cargo is essential to maintain neurotransmission in mammalian brain. Generating SVs containing the correct SV cargo with the appropriate stoichiometry is a significant challenge, especially when multiple modes of endocytosis exist in central nerve terminals, which occur at different locations within the nerve terminals. These endocytosis modes include ultrafast endocytosis, clathrin-mediated endocytosis (CME) and activity-dependent bulk endocytosis (ADBE) which are triggered by specific patterns of neuronal activity. This review article will assess the evidence for the role of classical adaptor protein complexes in SV retrieval, discuss the role of monomeric adaptors and how interactions between specific SV cargoes can facilitate retrieval. In addition it will consider the evidence for preassembled plasma membrane cargo complexes and their role in facilitating these endocytosis modes. Finally it will present a unifying model for cargo retrieval at the presynapse, which integrates endocytosis modes in time and space. PMID:28824381

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

Yamamura, K.; Maehara, N.; Terayama, K.

Segmental demyelination and axonal degeneration of motor nerves induced by lead exposure is well known in man, and animals. The effect of lead acetate exposure to man may involve the cranial nerves, since vertigo and sensory neuronal deafness have been reported among lead workers. However, there are few reports concerning the dose-effects of lead acetate both to the peripheral nerve and the cranial VII nerve with measurement of blood lead concentration. The authors investigated the effects of lead acetate to the cochlea and the VIII nerve using CM (cochlear microphonics) and AP (action potential) of the guinea pigs. The effectsmore » of lead acetate to the sciatic nerve were measured by MCV of the sciatic nerve with measurement of blood lead concentration.« less

Effect of O-methyl-β-cyclodextrin-modified magnetic nanoparticles on the uptake and extracellular level of l-glutamate in brain nerve terminals.

PubMed

Horák, Daniel; Beneš, Milan; Procházková, Zuzana; Trchová, Miroslava; Borysov, Arsenii; Pastukhov, Artem; Paliienko, Konstantin; Borisova, Tatiana

2017-01-01

Changes in cholesterol concentration in the plasma membrane of presynaptic nerve terminals nonspecifically modulate glutamate transport and homeostasis in the central nervous system. Reduction of the cholesterol content in isolated rat brain nerve terminals (synaptosomes) using cholesterol-depleting agents decreases the glutamate uptake and increases the extracellular level of glutamate in nerve terminals. Extraction of cholesterol from the plasma membrane and its further removal from the synaptosomes by external magnetic field can be achieved by means of magnetic nanoparticles with immobilized cholesterol-depleting agent such as O-methyl-β-cyclodextrin (MCD). A simple approach is developed for preparation of maghemite (γ-Fe 2 O 3 ) nanoparticles containing chemically bonded MCD. The method is based on preparation of a silanization agent containing MCD. It is synthesized by the reaction of triethoxy(3-isocyanatopropyl)silane with MCD. Base-catalyzed silanization of superparamagnetic γ-Fe 2 O 3 provides a relatively stable colloid product containing 48μmol of MCDg -1 . MCD-modified γ-Fe 2 O 3 nanoparticles decrease the initial rate of the uptake and accumulation of l-[ 14 C]glutamate and increase the extracellular l-[ 14 C]glutamate level in the preparation of nerve terminals. The effect of MCD-immobilized nanoparticles is the same as that of MCD solution; moreover, magnetic manipulation of the nanoparticles enables removal of bonded cholesterol. Copyright © 2016 Elsevier B.V. All rights reserved.

ACUDIN - ACUpuncture and laser acupuncture for treatment of DIabetic peripheral Neuropathy: a randomized, placebo-controlled, partially double-blinded trial.

PubMed

Meyer-Hamme, Gesa; Friedemann, Thomas; Greten, Henry Johannes; Plaetke, Rosemarie; Gerloff, Christian; Schroeder, Sven

2018-04-13

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes mellitus with significant clinical sequelae that can affect a patient's quality of life. Metabolic and microvascular factors are responsible for nerve damage, causing loss of nerve function, numbness, painful sensory symptoms, and muscle weakness. Therapy is limited to anti-convulsant or anti-depressant drugs for neuropathic pain and paresthesia. However, reduced sensation, balance and gait problems are insufficiently covered by this treatment. Previous data suggests that acupuncture, which has been in use in Traditional Chinese Medicine for many years, may potentially complement the treatment options for peripheral neuropathy. Nevertheless, more objective data on clinical outcome is necessary to generally recommend acupuncture to the public. We developed a study design for a prospective, randomized (RCT), placebo-controlled, partially double-blinded trial for investigating the effect of acupuncture on DPN as determined by nerve conduction studies (NCS) with the sural sensory nerve action potential amplitude as the primary outcome. The sural sensory nerve conduction velocity, tibial motor nerve action potential amplitude, tibial motor nerve conduction velocity, the neuropathy deficit score, neuropathy symptom score, and numeric rating scale questionnaires are defined as secondary outcomes. One hundred and eighty patients with type 2 diabetes mellitus will be randomized into three groups (needle acupuncture, verum laser acupuncture, and placebo laser acupuncture). We hypothesize that needle and laser acupuncture have beneficial effects on electrophysiological parameters and clinical and subjective symptoms in relation to DPN in comparison with placebo. The ACUDIN trial aims at investigating whether classical needle acupuncture and/or laser acupuncture are efficacious in the treatment of DPN. For the purpose of an objective parameter, NCS were chosen as outcome measures. Acupuncture treatment may potentially improve patients' quality of life and reduce the socio-economic burden caused by DPN. German Clinical Trial Register (DRKS), No. DRKS00008562 , trial search portal of the WHO ( http://apps.who.int/trialsearch/ ).

Electrophysiology of Cranial Nerve Testing: Cranial Nerves IX and X.

PubMed

Martinez, Alberto R M; Martins, Melina P; Moreira, Ana Lucila; Martins, Carlos R; Kimaid, Paulo A T; França, Marcondes C

2018-01-01

The cranial nerves IX and X emerge from medulla oblongata and have motor, sensory, and parasympathetic functions. Some of these are amenable to neurophysiological assessment. It is often hard to separate the individual contribution of each nerve; in fact, some of the techniques are indeed a composite functional measure of both nerves. The main methods are the evaluation of the swallowing function (combined IX and X), laryngeal electromyogram (predominant motor vagal function), and heart rate variability (predominant parasympathetic vagal function). This review describes, therefore, the techniques that best evaluate the major symptoms presented in IX and X cranial nerve disturbance: dysphagia, dysphonia, and autonomic parasympathetic dysfunction.

Mechanisms of Disease: involvement of the urothelium in bladder dysfunction

PubMed Central

Birder, Lori A; de Groat, William C

2011-01-01

SUMMARY Although the urinary bladder urothelium has classically been thought of as a passive barrier to ions and solutes, a number of novel properties have been recently attributed to urothelial cells. Studies have revealed that the urothelium is involved in sensory mechanisms (i.e. the ability to express a number of sensor molecules or respond to thermal, mechanical and chemical stimuli) and can release chemical mediators. Localization of afferent nerves next to the urothelium suggests that urothelial cells could be targets for neurotransmitters released from bladder nerves or that chemicals released by urothelial cells could alter afferent nerve excitability. Taken together, these and other findings highlighted in this article suggest a sensory function for the urothelium. Elucidation of mechanisms that influence urothelial function might provide insights into the pathology of bladder dysfunction. PMID:17211425

Sensory and motor peripheral nerve function and longitudinal changes in quadriceps strength.

PubMed

Ward, Rachel E; Boudreau, Robert M; Caserotti, Paolo; Harris, Tamara B; Zivkovic, Sasa; Goodpaster, Bret H; Satterfield, Suzanne; Kritchevsky, Stephen; Schwartz, Ann V; Vinik, Aaron I; Cauley, Jane A; Newman, Anne B; Strotmeyer, Elsa S

2015-04-01

Poor peripheral nerve function is common in older adults and may be a risk factor for strength decline, although this has not been assessed longitudinally. We assessed whether sensorimotor peripheral nerve function predicts strength longitudinally in 1,830 participants (age = 76.3 ± 2.8, body mass index = 27.2 ± 4.6kg/m(2), strength = 96.3 ± 34.7 Nm, 51.0% female, 34.8% black) from the Health ABC study. Isokinetic quadriceps strength was measured semiannually over 6 years. Peroneal motor nerve conduction amplitude and velocity were recorded. Sensory nerve function was assessed with 10-g and 1.4-g monofilaments and average vibration detection threshold at the toe. Lower-extremity neuropathy symptoms were self-reported. Worse vibration detection threshold predicted 2.4% lower strength in men and worse motor amplitude and two symptoms predicted 2.5% and 8.1% lower strength, respectively, in women. Initial 10-g monofilament insensitivity predicted 14.2% lower strength and faster strength decline in women and 6.6% lower strength in men (all p < .05). Poor nerve function predicted lower strength and faster strength decline. Future work should examine interventions aimed at preventing declines in strength in older adults with impaired nerve function. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Increased thrombospondin-4 after nerve injury mediates disruption of intracellular calcium signaling in primary sensory neurons

PubMed Central

Guo, Yuan; Zhang, Zhiyong; Wu, Hsiang-en; Luo, Z. David; Hogan, Quinn H.; Pan, Bin

2017-01-01

Painful nerve injury disrupts Ca2+ signaling in primary sensory neurons by elevating plasma membrane Ca2+-ATPase (PMCA) function and depressing sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) function, which decreases endoplasmic reticulum (ER) Ca2+ stores and stimulates store-operated Ca2+ entry (SOCE). The extracellular matrix glycoprotein thrombospondin-4 (TSP4), which is increased after painful nerve injury, decreases Ca2+ current (ICa) through high-voltage–activated Ca2+ channels and increases ICa through low-voltage–activated Ca2+ channels in dorsal root ganglion neurons, which are events similar to the effect of nerve injury. We therefore examined whether TSP4 plays a critical role in injury-induced disruption of intracellular Ca2+ signaling. We found that TSP4 increases PMCA activity, inhibits SERCA, depletes ER Ca2+ stores, and enhances store-operated Ca2+ influx. Injury-induced changes of SERCA and PMCA function are attenuated in TSP4 knock-out mice. Effects of TSP4 on intracellular Ca2+ signaling are attenuated in voltage-gated Ca2+ channel α2δ1 subunit (Cavα2δ1) conditional knock-out mice and are also Protein Kinase C (PKC) signaling dependent. These findings suggest that TSP4 elevation may contribute to the pathogenesis of chronic pain following nerve injury by disrupting intracellular Ca2+ signaling via interacting with the Cavα2δ1 and the subsequent PKC signaling pathway. Controlling TSP4 mediated intracellular Ca2+ signaling in peripheral sensory neurons may be a target for analgesic drug development for neuropathic pain. PMID:28232180

Sensory cortex hyperexcitability predicts short survival in amyotrophic lateral sclerosis.

PubMed

Shimizu, Toshio; Bokuda, Kota; Kimura, Hideki; Kamiyama, Tsutomu; Nakayama, Yuki; Kawata, Akihiro; Isozaki, Eiji; Ugawa, Yoshikazu

2018-05-01

To investigate somatosensory cortex excitability and its relationship to survival prognosis in patients with amyotrophic lateral sclerosis (ALS). A total of 145 patients with sporadic ALS and 73 healthy control participants were studied. We recorded compound muscle action potential and sensory nerve action potential of the median nerve and the median nerve somatosensory evoked potential (SEP), and we measured parameters, including onset-to-peak amplitude of N13 and N20 and peak-to-peak amplitude between N20 and P25 (N20p-P25p). Clinical prognostic factors, including ALS Functional Rating Scale-Revised, were evaluated. We followed up patients until the endpoints (death or tracheostomy) and analyzed factors associated with survival using multivariate analysis in the Cox proportional hazard model. Compared to controls, patients with ALS showed a larger amplitude of N20p-P25p in the median nerve SEP. Median survival time after examination was shorter in patients with N20p-P25p ≥8 μV (0.82 years) than in those with N20p-P25p <8 μV (1.68 years, p = 0.0002, log-rank test). Multivariate analysis identified a larger N20p-P25p amplitude as a factor that was independently associated with shorter survival ( p = 0.002). Sensory cortex hyperexcitability predicts short survival in patients with ALS. © 2018 American Academy of Neurology.

Influence of local noxious heat stimulation on sensory nerve activity in the feline dental pulp.

PubMed

Ahlberg, K F

1978-05-01

The present investigation was undertaken to develop an experimental model in which noxious heat stimulation was used to produce increased intradental sensory nerve activity in canine teeth of anesthetized cats. Two techniques were evaluated in which both the method of recording and the nature of the stimulus varied. Slow heating (approx 1 degree C/s) to 47 degree C of the tooth surface (combined with recording from electrodes in open dentinal cavities) did not produce any persistent nerve activity. Repeated periods of brief intense heating (approx 60 degrees C/s) (combined with recording from amalgam electrodes placed on cavity floors) resulted in an immediate response and an afterdischarge (phase 3) generally persisting for 20--60 min. Maximum phase 3 activity was characteristic for the individual cat and ranged from 0.2 to 50.2 imp/s. mean value 10.6 imp/s (S.D. +/- 9.2). A systematically higher phase 3 activity was recorded in lower compared to upper canine teeth (p less than 0.05). The maximum phase 3 response generally occurred after 3-8 stimulations; the median number of required stimuli was 3. Repeated brief heat stimulations combined with the closed cavity recording technique may be used as an experimental model by which the mechanisms behind increases in intradental sensory nerve activity associated with tissue damage can be studied.

Early electrophysiological findings in Fisher-Bickerstaff syndrome.

PubMed

Alberti, M A; Povedano, M; Montero, J; Casasnovas, C

2017-09-06

The term Fisher-Bickerstaff syndrome (FBS) has been proposed to describe the clinical spectrum encompassing Miller-Fisher syndrome (MFS) and Bickerstaff brainstem encephalitis. The pathophysiology of FBS and the nature of the underlying neuropathy (demyelinating or axonal) are still subject to debate. This study describes the main findings of an early neurophysiological study on 12 patients diagnosed with FBS. Retrospective evaluation of clinical characteristics and electrophysiological findings of 12 patients with FBS seen in our neurology department within 10 days of disease onset. Follow-up electrophysiological studies were also evaluated, where available. The most frequent electrophysiological finding, present in 5 (42%) patients, was reduced sensory nerve action potential (SNAP) amplitude in one or more nerves. Abnormalities were rarely found in motor neurography, with no signs of demyelination. The cranial nerve exam revealed abnormalities in 3 patients (facial neurography and/or blink reflex test). Three patients showed resolution of SNAP amplitude reduction in serial neurophysiological studies, suggesting the presence of reversible sensory nerve conduction block. Results from cranial MRI scans were normal in all patients. An electrophysiological pattern of sensory axonal neuropathy, with no associated signs of demyelination, is an early finding of FBS. Early neurophysiological evaluation and follow-up are essential for diagnosing patients with FBS. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Peptidomics and Secretomics of the Mammalian Peripheral Sensory-Motor System

NASA Astrophysics Data System (ADS)

Tillmaand, Emily G.; Yang, Ning; Kindt, Callie A. C.; Romanova, Elena V.; Rubakhin, Stanislav S.; Sweedler, Jonathan V.

2015-12-01

The dorsal root ganglion (DRG) and its anatomically and functionally associated spinal nerve and ventral and dorsal roots are important components of the peripheral sensory-motor system in mammals. The cells within these structures use a number of peptides as intercellular signaling molecules. We performed a variety of mass spectrometry (MS)-based characterizations of peptides contained within and secreted from these structures, and from isolated and cultured DRG cells. Liquid chromatography-Fourier transform MS was utilized in DRG and nerve peptidome analysis. In total, 2724 peptides from 296 proteins were identified in tissue extracts. Neuropeptides are among those detected, including calcitonin gene-related peptide I, little SAAS, and known hemoglobin-derived peptides. Solid phase extraction combined with direct matrix-assisted laser desorption/ionization time-of-flight MS was employed to investigate the secretome of these structures. A number of peptides were detected in the releasate from semi-intact preparations of DRGs and associated nerves, including neurofilament- and myelin basic protein-related peptides. A smaller set of analytes was observed in releasates from cultured DRG neurons. The peptide signals observed in the releasates have been mass-matched to those characterized and identified in homogenates of entire DRGs and associated nerves. This data aids our understanding of the chemical composition of the mammalian peripheral sensory-motor system, which is involved in key physiological functions such as nociception, thermoreception, itch sensation, and proprioception.

Peptidomics and Secretomics of the Mammalian Peripheral Sensory-Motor System.

PubMed

Tillmaand, Emily G; Yang, Ning; Kindt, Callie A C; Romanova, Elena V; Rubakhin, Stanislav S; Sweedler, Jonathan V

2015-12-01

The dorsal root ganglion (DRG) and its anatomically and functionally associated spinal nerve and ventral and dorsal roots are important components of the peripheral sensory-motor system in mammals. The cells within these structures use a number of peptides as intercellular signaling molecules. We performed a variety of mass spectrometry (MS)-based characterizations of peptides contained within and secreted from these structures, and from isolated and cultured DRG cells. Liquid chromatography-Fourier transform MS was utilized in DRG and nerve peptidome analysis. In total, 2724 peptides from 296 proteins were identified in tissue extracts. Neuropeptides are among those detected, including calcitonin gene-related peptide I, little SAAS, and known hemoglobin-derived peptides. Solid phase extraction combined with direct matrix-assisted laser desorption/ionization time-of-flight MS was employed to investigate the secretome of these structures. A number of peptides were detected in the releasate from semi-intact preparations of DRGs and associated nerves, including neurofilament- and myelin basic protein-related peptides. A smaller set of analytes was observed in releasates from cultured DRG neurons. The peptide signals observed in the releasates have been mass-matched to those characterized and identified in homogenates of entire DRGs and associated nerves. This data aids our understanding of the chemical composition of the mammalian peripheral sensory-motor system, which is involved in key physiological functions such as nociception, thermoreception, itch sensation, and proprioception.

Mass Spectrometry Imaging and GC-MS Profiling of the Mammalian Peripheral Sensory-Motor Circuit

NASA Astrophysics Data System (ADS)

Rubakhin, Stanislav S.; Ulanov, Alexander; Sweedler, Jonathan V.

2015-06-01

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) has evolved to become an effective discovery tool in science and clinical diagnostics. Here, chemical imaging approaches are applied to well-defined regions of the mammalian peripheral sensory-motor system, including the dorsal root ganglia (DRG) and adjacent nerves. By combining several MSI approaches, analyte coverage is increased and 195 distinct molecular features are observed. Principal component analysis suggests three chemically different regions within the sensory-motor system, with the DRG and adjacent nerve regions being the most distinct. Investigation of these regions using gas chromatography-mass spectrometry corroborate these findings and reveal important metabolic markers related to the observed differences. The heterogeneity of the structurally, physiologically, and functionally connected regions demonstrates the intricate chemical and spatial regulation of their chemical composition.

Biological Correlates of Cognitive, Sensory and Motor Abilities

DTIC Science & Technology

1975-04-01

specialized, histologically modified ends of sensory nerve fibers. The receptors are designed to respond to a particular form of energy at a much lower...consider the comparativ ■ approach as having rich potential. It is believed to be the only currently available means of definitely establish- ing

Role of Netrin-1 Signaling in Nerve Regeneration

PubMed Central

Dun, Xin-Peng; Parkinson, David B.

2017-01-01

Netrin-1 was the first axon guidance molecule to be discovered in vertebrates and has a strong chemotropic function for axonal guidance, cell migration, morphogenesis and angiogenesis. It is a secreted axon guidance cue that can trigger attraction by binding to its canonical receptors Deleted in Colorectal Cancer (DCC) and Neogenin or repulsion through binding the DCC/Uncoordinated (Unc5) A–D receptor complex. The crystal structures of Netrin-1/receptor complexes have recently been revealed. These studies have provided a structure based explanation of Netrin-1 bi-functionality. Netrin-1 and its receptor are continuously expressed in the adult nervous system and are differentially regulated after nerve injury. In the adult spinal cord and optic nerve, Netrin-1 has been considered as an inhibitor that contributes to axon regeneration failure after injury. In the peripheral nervous system, Netrin-1 receptors are expressed in Schwann cells, the cell bodies of sensory neurons and the axons of both motor and sensory neurons. Netrin-1 is expressed in Schwann cells and its expression is up-regulated after peripheral nerve transection injury. Recent studies indicated that Netrin-1 plays a positive role in promoting peripheral nerve regeneration, Schwann cell proliferation and migration. Targeting of the Netrin-1 signaling pathway could develop novel therapeutic strategies to promote peripheral nerve regeneration and functional recovery. PMID:28245592

Utility of nerve conduction studies for diagnosis of injury to the medial branch of the superficial radial nerve.

PubMed

Kon, Tomoya; Suzuki, Chieko; Hotta, Ryotaro; Funamizu, Yukihisa; Haga, Rie; Ueno, Tatsuya; Nishijima, Haruo; Arai, Akira; Nunomura, Jinichi; Nukada, Hitoshi; Tomiyama, Masahiko; Baba, Masayuki

2017-09-01

The clinical utility of nerve conduction study (NCS) for the distal medial branch of the superficial radial nerve (SRN) has not yet been clarified. Therefore, we investigated the clinical utility of NCS in patients with suspected SRN injury and compared the results with those in healthy control subjects. Bilateral NCS of the medial branch of the SRN was performed in two patients with suspected injury of the medial branch of the SRN, and in 20 healthy control subjects. A surface recording electrode was placed at the medial side of the metacarpophalangeal joint of the thumb. The SRN was then stimulated at a location 12 cm proximal from the recording electrode. The mean sensory nerve action potential in the two patients was significantly lower than that of the controls (6.75 ± 0.92 vs. 23.8 ± 8.2 μV, P  < 0.05). The side-to-side differences in sensory nerve action potential in the two patients were significantly higher than in the controls (55 ± 7.1 vs. 11 ± 7.8%, P  < 0.05). NCS may be useful for diagnosing injury of the medial branch of the SRN.

Bronchial mucosal immunoreactivity of sensory neuropeptides in severe airway diseases.

PubMed

Chanez, P; Springall, D; Vignola, A M; Moradoghi-Hattvani, A; Polak, J M; Godard, P; Bousquet, J

1998-09-01

Neuropeptides act on most of the components of the bronchial environment. They influence bronchomotor tone and bronchial vascular caliber and permeability. To investigate the nonadrenergic, noncholinergic system within the airways in asthma and chronic bronchitis, we performed endobronchial biopsies in 16 normal human volunteers, 49 patients with asthma of varying severity, including 16 patients treated with oral corticosteroids, and 13 patients with chronic bronchitis. Frozen sections of biopsies stained with specific antibodies against the neural marker PGP 9.5, vasoactive intestinal peptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP), and neuropeptide Y (NPY) were analyzed for the presence of nerves through indirect immunofluorescence. Nerves were present in most of the biopsies and were found within and below the epithelium and adjacent to smooth muscle, glands, and blood vessels. By comparison with those in normal subjects, the numbers of VIP-immunoreactive nerves were not significantly decreased in patients with asthma and chronic bronchitis, but NPY-immunoreactive nerves were significantly decreased in the smooth muscle of these latter two groups of patients (p < 0.005). There was no correlation between disease severity and the number of nerves found in the biopsies. This study does not confirm previous findings in autopsy material of some defects in sensory and VIP-containing nerves in severe asthma.

Efficacy of Tricaine Methanesulfonate (MS-222) as an Anesthetic Agent for Blocking Sensory-Motor Responses in Xenopus laevis Tadpoles

PubMed Central

Ramlochansingh, Carlana; Branoner, Francisco; Chagnaud, Boris P.; Straka, Hans

2014-01-01

Anesthetics are drugs that reversibly relieve pain, decrease body movements and suppress neuronal activity. Most drugs only cover one of these effects; for instance, analgesics relieve pain but fail to block primary fiber responses to noxious stimuli. Alternately, paralytic drugs block synaptic transmission at neuromuscular junctions, thereby effectively paralyzing skeletal muscles. Thus, both analgesics and paralytics each accomplish one effect, but fail to singularly account for all three. Tricaine methanesulfonate (MS-222) is structurally similar to benzocaine, a typical anesthetic for anamniote vertebrates, but contains a sulfate moiety rendering this drug more hydrophilic. MS-222 is used as anesthetic in poikilothermic animals such as fish and amphibians. However, it is often argued that MS-222 is only a hypnotic drug and its ability to block neural activity has been questioned. This prompted us to evaluate the potency and dynamics of MS-222-induced effects on neuronal firing of sensory and motor nerves alongside a defined motor behavior in semi-intact in vitro preparations of Xenopus laevis tadpoles. Electrophysiological recordings of extraocular motor discharge and both spontaneous and evoked mechanosensory nerve activity were measured before, during and after administration of MS-222, then compared to benzocaine and a known paralytic, pancuronium. Both MS-222 and benzocaine, but not pancuronium caused a dose-dependent, reversible blockade of extraocular motor and sensory nerve activity. These results indicate that MS-222 as benzocaine blocks the activity of both sensory and motor nerves compatible with the mechanistic action of effective anesthetics, indicating that both caine-derivates are effective as single-drug anesthetics for surgical interventions in anamniotes. PMID:24984086

Four novel cases of periaxin-related neuropathy and review of the literature.

PubMed

Marchesi, C; Milani, M; Morbin, M; Cesani, M; Lauria, G; Scaioli, V; Piccolo, G; Fabrizi, G M; Cavallaro, T; Taroni, F; Pareyson, D

2010-11-16

To report 4 cases of autosomal recessive hereditary neuropathy associated with novel mutations in the periaxin gene (PRX) with a review of the literature. Periaxin protein is required for the maintenance of peripheral nerve myelin. Patients with PRX mutations have early-onset autosomal recessive demyelinating Charcot-Marie-Tooth disease (CMT4F) or Déjèrine-Sottas neuropathy (DSN). Only 12 different mutations have been described thus far. Case reports and literature review. Four patients from 3 unrelated families (2 siblings and 2 unrelated patients) were affected by an early-onset, slowly progressive demyelinating neuropathy with relevant sensory involvement. All carried novel frameshift or nonsense mutations in the PRX gene. The 2 siblings were compound heterozygotes for 2 PRX null mutations (p.Q547X and p.K808SfsX2), the third patient harbored a homozygous nonsense mutation (p.E682X), and the last patient had a homozygous 2-nt insertion predicting a premature protein truncation (p.S259PfsX55). Electrophysiologic analysis showed a severe slowing of motor nerve conduction velocities (MNCVs, between 3 and 15.3 m/s) with undetectable sensory nerve action potentials (SNAPs). Sural nerve biopsy, performed in 2 patients, demonstrated a severe demyelinating neuropathy and onion bulb formations. Interestingly, we observed some variability of disease severity within the same family. These cases and review of the literature indicate that PRX-related neuropathies have early onset but overall slow progression. Typical features are prominent sensory involvement, often with sensory ataxia; a moderate-to-dramatic reduction of MNCVs and almost invariable absence of SNAPs; and pathologic demyelination with classic onion bulbs, and less commonly myelin folding and basal lamina onion bulbs.

Sensory re-education after nerve injury of the upper limb: a systematic review.

PubMed

Oud, Tanja; Beelen, Anita; Eijffinger, Elianne; Nollet, Frans

2007-06-01

To systematically review the available evidence for the effectiveness of sensory re-education to improve the sensibility of the hand in patients with a peripheral nerve injury of the upper limb. Studies were identified by an electronic search in the databases MEDLINE, Cumulative Index to Nursing & Allied Health Literature (CINAHL), EMBASE, the Cochrane Library, the Physiotherapy Evidence Database (PEDro), and the database of the Dutch National Institute of Allied Health Professions (Doconline) and by screening the reference lists of relevant articles. Two reviewers selected studies that met the following inclusion criteria: all designs except case reports, adults with impaired sensibility of the hand due to a peripheral nerve injury of the upper limb, and sensibility and functional sensibility as outcome measures. The methodological quality of the included studies was independently assessed by two reviewers. A best-evidence synthesis was performed, based on design, methodological quality and significant findings on outcome measures. Seven studies, with sample sizes ranging from 11 to 49, were included in the systematic review and appraised for content. Five of these studies were of poor methodological quality. One uncontrolled study (N = 1 3 ) was considered to be of sufficient methodological quality, and one randomized controlled trial (N = 49) was of high methodological quality. Best-evidence synthesis showed that there is limited evidence for the effectiveness of sensory re-education, provided by a statistically significant improvement in sensibility found in one high-quality randomized controlled trial. There is a need for further well-defined clinical trials to assess the effectiveness of sensory re-education of patients with impaired sensibility of the hand due to a peripheral nerve injury.

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

PubMed

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

2015-03-01

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. 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. 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. 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. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

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

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

PubMed Central

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

2016-01-01

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

Infra Patellar Branch of Saphenous Nerve Injury during Hamstring Graft Harvest: Vertical versus Oblique Incisions.

PubMed

Joshi, A; Kayasth, N; Shrestha, S; Kc, B R

2016-09-01

Autologous hamstring grafts are commonly used for anterior cruciate ligament reconstruction. The injury of infrapatellar branch of saphenous nerve is one of the concerns leading to various pattern of sensory loss in the operated leg. An oblique incision to harvest the graft has been reported to be better than the vertical one.The aim of this study was to compare the incidence, recovery of nerve injury and final outcome in patients with hamstring harvest of vertical or oblique incision. A total of 146 patients who underwent hamstring graft harvest for anterior cruciate ligament reconstruction, were included in the study. They were randomized into two (Vertical and Oblique) groups as per the incisions used. The sensory loss along the Infra Patellar Branch of Saphenous Nerve was documented on 3rd day. Recovery of the nerve injury was monitoredat three, six and 12 months follow-ups. At final follow up Tegner Lysholm score and scale was recorded to compare between two groups. The incidence of infrapatellar branch of saphenous nerve injury was 25% in vertical group and 16.36% in oblique group. Recovery of nerve injury started earlier in oblique group compared to vertical group. The mean TegnerLyshom score was not significantly different in both the groups. Oblique incision to harvest hamstring graft has lesser incidence of infrapatellar branch of saphenous nerve injury, recovers earlier and does not have any adverse effect on final outcome compared to the vertical incision.

Pudendal and median nerve sensory perception threshold: a comparison between normative studies.

PubMed

Quaghebeur, Jörgen; Wyndaele, Jean Jacques

2014-12-01

For the evaluation of sensory innervation, normative data are necessary as a comparison. To compare our current perception thresholds (CPTs) with normative data from other research. Healthy volunteers were assessed for 2000, 250, and 5 Hz CPTs of the median and pudendal nerve and data were compared with other studies. Normative data in the studied group n = 41 (male: 21; female: 20) for the median nerve, 2 kHz, 250 Hz, and 5 Hz were respectively: 241.85 ± 67.72 (140-444); 106.27 ± 39.12 (45-229); 82.05 ± 43.40 (13-271). Pudendal nerve CPTs 250 Hz were: 126.44 ± 69.46 (6-333). For men 2 kHz: 349.95 ± 125.76 (100-588); 5 Hz: 132.67 ± 51.81 (59-249) and women 2 kHz:226.20 ± 119.65 (64-528); 5 Hz: 92.45 ± 44.66 (35-215). For the median nerve no statistical differences for gender were shown. For the pudendal nerve, only 250 Hz showed no difference for gender (t-test: 0.516). Comparison of our data with CPTs of other normative data showed no agreement for the pudendal nerve. For the median nerve only 2 kHz showed agreement in three studies and for 5 Hz with one study. Comparing normative data of multiple studies shows a variety of results and poor agreement. Therefore, referring to normative data of other studies should be handled with caution.

Quantitative monitoring of activity-dependent bulk endocytosis of synaptic vesicle membrane by fluorescent dextran imaging

PubMed Central

Clayton, Emma Louise; Cousin, Michael Alan

2012-01-01

Activity-dependent bulk endocytosis (ADBE) is the dominant synaptic vesicle (SV) retrieval mode in central nerve terminals during periods of intense neuronal activity. Despite this fact there are very few real time assays that report the activity of this critical SV retrieval mode. In this paper we report a simple and quantitative assay of ADBE using uptake of large flourescent dextrans as fluid phase markers. We show that almost all dextran uptake occurs in nerve terminals, using co-localisation with the fluorescent probe FM1-43. We also demonstrate that accumulated dextran cannot be unloaded by neuronal stimulation, indicating its specific loading into bulk endosomes and not SVs. Quantification of dextran uptake was achieved by using thresholding analysis to count the number of loaded nerve terminals, since monitoring the average fluorescence intensity of these nerve terminals did not accurately report the extent of ADBE. Using this analysis we showed that dextran uptake occurs very soon after stimulation and that it does not persist when stimulation terminates. Thus we have devised a simple and quantitative method to monitor ADBE in living neurones, which will be ideal for real time screening of small molecule inhibitors of this key SV retrieval mode. PMID:19766140

The gut-brain axis rewired: adding a functional vagal nicotinic "sensory synapse".

PubMed

Perez-Burgos, Azucena; Mao, Yu-Kang; Bienenstock, John; Kunze, Wolfgang A

2014-07-01

It is generally accepted that intestinal sensory vagal fibers are primary afferent, responding nonsynaptically to luminal stimuli. The gut also contains intrinsic primary afferent neurons (IPANs) that respond to luminal stimuli. A psychoactive Lactobacillus rhamnosus (JB-1) that affects brain function excites both vagal fibers and IPANs. We wondered whether, contrary to its primary afferent designation, the sensory vagus response to JB-1 might depend on IPAN to vagal fiber synaptic transmission. We recorded ex vivo single- and multiunit afferent action potentials from mesenteric nerves supplying mouse jejunal segments. Intramural synaptic blockade with Ca(2+) channel blockers reduced constitutive or JB-1-evoked vagal sensory discharge. Firing of 60% of spontaneously active units was reduced by synaptic blockade. Synaptic or nicotinic receptor blockade reduced firing in 60% of vagal sensory units that were stimulated by luminal JB-1. In control experiments, increasing or decreasing IPAN excitability, respectively increased or decreased nerve firing that was abolished by synaptic blockade or vagotomy. We conclude that >50% of vagal afferents function as interneurons for stimulation by JB-1, receiving input from an intramural functional "sensory synapse." This was supported by myenteric plexus nicotinic receptor immunohistochemistry. These data offer a novel therapeutic target to modify pathological gut-brain axis activity.-Perez-Burgos, A., Mao, Y.-K., Bienenstock, J., Kunze, W. A. The gut-brain axis rewired: adding a functional vagal nicotinic "sensory synapse." © FASEB.

Nanofibrous scaffolds for the guidance of stem cell-derived neurons for auditory nerve regeneration.

PubMed

Hackelberg, Sandra; Tuck, Samuel J; He, Long; Rastogi, Arjun; White, Christina; Liu, Liqian; Prieskorn, Diane M; Miller, Ryan J; Chan, Che; Loomis, Benjamin R; Corey, Joseph M; Miller, Josef M; Duncan, R Keith

2017-01-01

Impairment of spiral ganglion neurons (SGNs) of the auditory nerve is a major cause for hearing loss occurring independently or in addition to sensory hair cell damage. Unfortunately, mammalian SGNs lack the potential for autonomous regeneration. Stem cell based therapy is a promising approach for auditory nerve regeneration, but proper integration of exogenous cells into the auditory circuit remains a fundamental challenge. Here, we present novel nanofibrous scaffolds designed to guide the integration of human stem cell-derived neurons in the internal auditory meatus (IAM), the foramen allowing passage of the spiral ganglion to the auditory brainstem. Human embryonic stem cells (hESC) were differentiated into neural precursor cells (NPCs) and seeded onto aligned nanofiber mats. The NPCs terminally differentiated into glutamatergic neurons with high efficiency, and neurite projections aligned with nanofibers in vitro. Scaffolds were assembled by seeding GFP-labeled NPCs on nanofibers integrated in a polymer sheath. Biocompatibility and functionality of the NPC-seeded scaffolds were evaluated in vivo in deafened guinea pigs (Cavia porcellus). To this end, we established an ouabain-based deafening procedure that depleted an average 72% of SGNs from apex to base of the cochleae and caused profound hearing loss. Further, we developed a surgical procedure to implant seeded scaffolds directly into the guinea pig IAM. No evidence of an inflammatory response was observed, but post-surgery tissue repair appeared to be facilitated by infiltrating Schwann cells. While NPC survival was found to be poor, both subjects implanted with NPC-seeded and cell-free control scaffolds showed partial recovery of electrically-evoked auditory brainstem thresholds. Thus, while future studies must address cell survival, nanofibrous scaffolds pose a promising strategy for auditory nerve regeneration.

[A case of hereditary sensory and autonomic neuropathy type 1E with frontal lobe dysfunction as an initial symptom].

PubMed

Watanabe, Masashi; Matsumoto, Yushi; Okamoto, Kensho; Okuda, Bungo; Mizuta, Ikuko; Mizuno, Toshiki

2017-12-27

A 49-year-old man had developed gradually personality change, gait disturbance, and hearing loss for five years. On admission, he presented with frontal release signs, stuttering, vertical gaze palsy, sensorineural deafness, muscle rigidity, ataxia, and sensory disturbance with areflexia in the lower extremities. Brain MRI demonstrated atrophy in the cerebellum and midbrain tegmentum as well as cerebral atrophy, predominantly in the frontal lobe. He was tentatively diagnosed as progressive supranuclear palsy on the basis of clinical features and imagings. On nerve conduction study, no sensory nerve action potentials were elicited in the upper and lower extremities. Details of family history revealed a hereditary sensory neuropathy with autosomal dominant inheritance in his relatives. Because genetic analysis showed a rare missense mutation (c.1483T>C, p.Y495H) in DNA methyltransferase 1 gene, we diagnosed him as having hereditary sensory and autonomic neuropathy type 1E (HSAN1E). In addition, p.M232R mutation in prion protein gene was detected. It should be kept in mind that there are some patients with HSAN1E presenting with frontal lobe dysfunction as an initial symptom and with clinical features mimicking progressive supranuclear palsy.

[Operative treatment of painful neuromas].

PubMed

Stokvis, Annemieke; Coert, J Henk

2011-01-01

3-5% of patients with traumatic or iatrogenic peripheral nerve injury develop a painful neuroma, especially following trauma of small cutaneous sensory nerve branches. Neuroma pain is difficult to treat and often leads to loss of function and reduction of quality of life. Patients with a painful neuroma present with spontaneous electric, shooting or burning pain, allodynia, hyperalgesia and cold intolerance. The diagnosis is based on the medical history and physical examination, supplemented by Tinel's test and a diagnostic nerve blockade. Lasting pain relief is possible by means of surgical neuroma treatment performed by a plastic surgeon. Surgical treatment consists of repair or denervation of the nerve with relocation of the nerve stump in bone or muscle tissue or a vein. Referral of neuroma patients without delay to a plastic surgeon or multidisciplinary consultation is important, because the symptoms become increasingly difficult to treat over time. 3-5% of patients with traumatic or iatrogenic peripheral nerve injury develop a painful neuroma, especially following trauma of small cutaneous sensory nerve branches. Neuroma pain is difficult to treat and often leads to loss of function and reduction of quality of life. Patients with a painful neuroma present with spontaneous electric, shooting or burning pain, allodynia, hyperalgesia and cold intolerance. The diagnosis is based on the medical history and physical examination, supplemented by Tinel's test and a diagnostic nerve blockade. Lasting pain relief is possible by means of surgical neuroma treatment performed by a plastic surgeon. Surgical treatment consists of repair or denervation of the nerve with relocation of the nerve stump in bone or muscle tissue or a vein. Referral of neuroma patients without delay to a plastic surgeon or multidisciplinary consultation is important, because the symptoms become increasingly difficult to treat over time.

Central projections of gustatory receptor neurons in the medial and the lateral sensilla styloconica of Helicoverpa armigera larvae.

PubMed

Tang, Qing-Bo; Zhan, Huan; Cao, Huan; Berg, Bente G; Yan, Feng-Ming; Zhao, Xin-Cheng

2014-01-01

Food selection behavior of lepidopteran larvae is predominantly governed by the activation of taste neurons present in two sensilla styloconica located on the galea of the maxilla. In this study, we present the ultrastructure of the sensilla styloconica and the central projection pattern of their associated receptor neurons in larvae of the heliothine moth, Helicoverpa armigera. By means of light microscopy and scanning electron microscopy, the previous findings of two morphologically fairly similar sensilla comprising a socketed conic tip inserted into a large peg were confirmed. However, the peg size of the medial sensillum was found to be significantly bigger than that of the lateral sensillum. The sensory neurons derived from each sensillum styloconicum were mapped separately using anterograde staining experiments combined with confocal laser-scanning microscopy. For determining the afferents' target regions relative to each other, we reconstructed the labeled axons and placed them into a common reference framework. The sensory axons from both sensilla projected via the ipsilateral maxillary nerve to the suboesophageal ganglion and further through the ipsilateral circumoesophageal connective to the brain. In the suboesophageal ganglion, the sensory projections targeted two areas of the ipsilateral maxillary neuropil, one located in the ventrolateral neuromere and the other adjacent to the neuromere midline. In the brain, the axon terminals targeted the dorso-anterior area of the ipsilateral tritocerebrum. As confirmed by the three-dimensional reconstructions, the target regions of the neural projections originating from each of the two sensilla styloconica were identical.

Effect of sensory denervation on the structure and physiologic responsiveness of rabbit lacrimal gland.

PubMed

Meneray, M A; Bennett, D J; Nguyen, D H; Beuerman, R W

1998-01-01

This work was conducted to determine the effects of unilateral trigeminal ganglion ablation on lacrimal gland structure and secretory activity. Adult male New Zealand rabbits underwent unilateral thermocoagulation of the ophthalmic division of the trigeminal ganglion. Sensory denervation was affirmed by anatomic inspection of the lesion and transmission electron microscopy (TEM) of the lacrimal gland innervation. Eight to 10 days after the procedure, the intraorbital lacrimal glands were removed from both sides. To compare the physiologic competence of the intact and denervated glands, freshly isolated gland fragments from the paired intact and denervated glands were stimulated with carbachol (100 microM), isoproterenol (10 microM), phorbol-12,13-dibutyrate (PDBu, 10 microM), forskolin (40 microM), or vehicle. Total secreted protein was measured at 30 or 60 min after the establishment of baseline values. Intact and denervated glands also were examined by light and TEM, and the morphologic appearance of the acinar structures as well as the appearance of nerves innervating the gland after denervation were assessed. Similar experiments were conducted with animals that underwent unilateral superior cervical ganglionectomy. Tissues from sensory denervated glands released significantly more protein than did tissues from innervated glands in response to in vitro stimulation by carbachol or isoproterenol but not in response to PDBu or forskolin. Microscopy showed that the acinar cells that had undergone sensory denervation showed a massive accumulation of secretory granules. The secretory granules filled the entire cytoplasmic space and displaced the ellipsoidal nuclei to the extreme periphery. Examination of segments of nerves revealed numerous unmyelinated axons, a few small-diameter myelinated axons, and a large amount of nerve degeneration after sensory denervation. In contrast to the effects of sensory denervation, sympathetic denervation did not alter either the acinar appearance or secretory responsiveness of the gland. Loss of the considerable sensory innervation from the trigeminal ganglion has pronounced effects on the pharmacologic responsiveness and the structure of the lacrimal gland. The effects of sensory innervation on the gland may be mediated through two possible pathways: direct input to the gland or control of the preganglionic parasympathetic pathway.

Muscular innervation of the proximal duodenum of the guinea pig.

PubMed

Iino, S

2000-10-01

We investigated the muscular structure and innervation of the gastroduodenal junction in the guinea pig. In the gastroduodenal junction, the innermost layer of the circular muscle contained numerous nerve fibers and terminals. Since this nerve network continued onto the deep muscular plexus (DMP) of the duodenum, we surmised that the numerous nerve fibers in the gastroduodenal junction were specialized DMP in the most proximal part of the duodenum. The innermost layer containing many nerve fibers was about 1,000 microm in length and 100 microm in thickness in the proximal duodenum. This layer contained numerous connective tissue fibers composed of collagen and elastic fibers. Five to 30 smooth muscle cells lay in contact with each other and were surrounded by fine connective tissue. The nerve fibers in the proximal duodenum contained nerve terminals immunoreactive for choline acetyltransferase, dynorphin, enkephalin, galanin, gastrin-releasing peptide, nitric oxide synthase, substance P, and vasoactive intestinal polypeptide. Adrenergic fibers which contained tyrosine hydroxylase immunoreactivity were rare in the proximal duodenum. In the innermost layer of the proximal duodenum, there were numerous c-Kit immunopositive cells that were in contact with nerve terminals. This study allowed us to clarify the specific architecture of the most proximal portion of the duodenum. The functional significance of the proximal duodenum in relation to the electrical connection and neural cooperation of the musculature between the antrum and the duodenum is also discussed.

Distribution of Injectate and Sensory-Motor Blockade After Adductor Canal Block.

PubMed

Gautier, Philippe E; Hadzic, Admir; Lecoq, Jean-Pierre; Brichant, Jean Francois; Kuroda, Maxine M; Vandepitte, Catherine

2016-01-01

The analgesic efficacy reported for the adductor canal block may be related to the spread of local anesthetic outside the adductor canal. Fifteen patients undergoing knee surgery received ultrasound-guided injections of local anesthetic at the level of the adductor hiatus. Sensory-motor block and spread of contrast solution were assessed. Sensation was rated as "markedly diminished" or "absent" in the saphenous nerve distribution and "slightly diminished" in the sciatic nerve territory without motor deficits. Contrast solution was found in the popliteal fossa. The spread of injectate to the popliteal fossa may contribute to the analgesic efficacy of adductor canal block.

The two nerve rings of the hypostomal nervous system of Hydra vulgaris-an immunohistochemical analysis.

PubMed

Hufnagel, L A; Kass-Simon, G

2016-11-01

In Hydra vulgaris, physiological and pharmacological evidence exists for a hypostomal circumferential neuro-effector pathway that initiates ectodermal pacemaker activity at tentacular-hypostomal loci coordinating body and tentacle contractions. Here, we describe an ectodermal nerve ring that runs below and between the tentacles, and an anti-GABA B receptor antibody-labeled ring coincident with it. The location of this ring is consistent with the physiology of the hypostomal pacemaker systems of hydra. We also describe a distally located, ectodermal ring of nerve fibers that is not associated with anti-GABA B receptor antibody labeling. The neurites and cell bodies of sensory cells contribute to both rings. The location of the distal ring and its sensory cell neurites suggests an involvement in the behavior of the mouth. Between the two rings is a network of anastomosing sensory and ganglion cell bodies and their neurites. Phase contrast, darkfield, and antibody-labeled images reveal that the mouth of hydra comprises five or six epithelial folds whose endoderm extensively labels with anti-GABA B receptor antibody, suggesting that endodermal metabotrobic GABA receptors are also involved in regulating mouth behavior.

Silencing the Kir4.1 potassium channel subunit in satellite glial cells of the rat trigeminal ganglion results in pain-like behavior in the absence of nerve injury.

PubMed

Vit, Jean-Philippe; Ohara, Peter T; Bhargava, Aditi; Kelley, Kanwar; Jasmin, Luc

2008-04-16

Growing evidence suggests that changes in the ion buffering capacity of glial cells can give rise to neuropathic pain. In the CNS, potassium ion (K+) buffering is dependent on the glia-specific inward rectifying K+ channel Kir4.1. We recently reported that the satellite glial cells that surround primary sensory neurons located in sensory ganglia of the peripheral nervous system also express Kir4.1, whereas the neurons do not. In the present study, we show that, in the rat trigeminal ganglion, the location of the primary sensory neurons for face sensation, specific silencing of Kir4.1 using RNA interference leads to spontaneous and evoked facial pain-like behavior in freely moving rats. We also show that Kir4.1 in the trigeminal ganglion is reduced after chronic constriction injury of the infraorbital nerve. These findings suggests that neuropathic pain can result from a change in expression of a single K+ channel in peripheral glial cells, raising the possibility of targeting Kir4.1 to treat pain in general and particularly neuropathic pain that occurs in the absence of nerve injury.

Silencing the Kir4.1 potassium channel subunit in satellite glial cells of the rat trigeminal ganglion results in pain-like behavior in the absence of nerve injury

PubMed Central

Vit, Jean-Philippe; Ohara, Peter T.; Bhargava, Aditi; Kelley, Kanwar; Jasmin, Luc

2008-01-01

Growing evidence suggests that changes in the ion buffering capacity of glial cells can give rise to neuropathic pain. In the CNS, potassium ion (K+) buffering is dependent on the glia-specific inward rectifying K+ channel Kir4.1. We recently reported that the satellite glial cells (SGCs) that surround primary sensory neurons located in sensory ganglia of the peripheral nervous system also express Kir4.1 while the neurons do not. In the present study we show that in the rat trigeminal ganglion, the location of the primary sensory neurons for face sensation, specific silencing of Kir4.1 using RNA interference leads to spontaneous and evoked facial pain-like behavior in freely moving rats. We also show that Kir4.1 in the trigeminal ganglion is reduced following chronic constriction injury of the infraorbital nerve. These findings suggests that neuropathic pain can result from a change in expression of a single K+ channel in peripheral glial cells, raising the possibility of targeting Kir4.1 to treat pain in general, and particularly neuropathic pain that occurs in the absence of nerve injury. PMID:18417695

Effects of omega-conotoxin GVIA on the activation of capsaicin-sensitive afferent sensory nerves in guinea pig airway tissues.

PubMed

Morimoto, H; Matsuda, A; Ohori, M; Fujii, T

1996-06-01

We examined the effects of Ca2+ channel antagonists on various respiratory reactions induced by the activation of capsaicin-sensitive afferent sensory nerves. Intravenous (i.v.) injection of the N-type Ca2+ channel antagonist omega-conotoxin GVIA (CgTX) (1-20 micrograms/kg) dose-dependently inhibited capsaicin-induced guinea pig bronchoconstriction, whereas i.v. administration of the L-type antagonist nicardipine (100 micrograms/kg), the P-type antagonist omega-agatoxin IVA (AgaTX) (20 micrograms/kg) or the OPQ family-type antagonist omega-conotoxin MVIIC (CmTX) (20 micrograms/kg) had no effect. However, CgTX (20 micrograms/kg) failed to inhibit substance P-induced guinea pig bronchoconstriction. CgTX (20 micrograms/kg) significantly inhibited cigarette smoke-induced guinea pig tracheal plasma extravasation, but not the substance P-induced reaction. CgTX also reduced electrical field stimulation-induced guinea pig bronchial smooth muscle contraction (0.01-10 microM) and capsaicin-induced substance P-like immunoreactivity release from guinea pig lung (0.14 microM). This evidence suggests that N-type Ca2+ channels modulate tachykinin release from capsaicin-sensitive afferent sensory nerve endings in guinea pig airway tissue.

Role of TRPV1 in acupuncture modulation of reflex excitatory cardiovascular responses.

PubMed

Guo, Zhi-Ling; Fu, Liang-Wu; Su, Hou-Fen; Tjen-A-Looi, Stephanie C; Longhurst, John C

2018-05-01

We have shown that acupuncture, including manual and electroacupuncture (MA and EA), at the P5-6 acupoints stimulates afferent fibers in the median nerve (MN) to modulate sympathoexcitatory cardiovascular reflexes through central regulation of autonomic function. However, the mechanisms underlying acupuncture activation of these sensory afferent nerves and their cell bodies in the dorsal root ganglia (DRG) are unclear. Transient receptor potential vanilloid type 1 (TRPV1) is present in sensory nerve fibers distributed in the general region of acupoints like ST36 and BL 40 located in the hindlimb. However, the contribution of TRPV1 to activation of sensory nerves by acupuncture, leading to modulation of pressor responses, has not been studied. We hypothesized that TRPV1 participates in acupuncture's activation of sensory afferents and their associated cell bodies in the DRG to modulate pressor reflexes. Local injection of iodoresiniferatoxin (Iodo-RTX; a selective TRPV1 antagonist), but not 5% DMSO (vehicle), into the P6 acupoint on the forelimb reversed the MA's inhibition of pressor reflexes induced by gastric distension (GD). Conversely, inhibition of GD-induced sympathoexcitatory responses by EA at P5-6 was unchanged after administration of Iodo-RTX into P5-6. Single-unit activity of Group III or IV bimodal afferents sensitive to both mechanical and capsaicin stimuli responded to MA stimulation at P6. MA-evoked activity was attenuated significantly ( P < 0.05) by local administration of Iodo-RTX ( n = 12) but not by 5% DMSO ( n = 12) into the region of the P6 acupoint in rats. Administration of Iodo-RTX into P5-6 did not reduce bimodal afferent activity evoked by EA stimulation ( n = 8). Finally, MA at P6 and EA at P5-6 induced phosphorylation of extracellular signal-regulated kinases (ERK; an intracellular signaling messenger involved in cellular excitation) in DRG neurons located at C 7-8 spinal levels receiving MN inputs. After TRPV1 was knocked down in the DRG at these spinal levels with intrathecal injection of TRPV1-siRNA, expression of phosphorylated ERK in the DRG neuron was reduced in MA-treated, but not EA-treated animals. These data suggest that TRPV1 in Group III and IV bimodal sensory afferent nerves contributes to acupuncture inhibition of reflex increases in blood pressure and specifically plays an important role during MA but not EA.

Microsurgical reconstruction of large nerve defects using autologous nerve grafts.

PubMed

Daoutis, N K; Gerostathopoulos, N E; Efstathopoulos, D G; Misitizis, D P; Bouchlis, G N; Anagnostou, S K

1994-01-01

Between 1986 and 1993, 643 patients with peripheral nerve trauma were treated in our clinic. Primary neurorraphy was performed in 431 of these patients and nerve grafting in 212 patients. We present the functional results after nerve grafting in 93 patients with large nerve defects who were followed for more than 2 years. Evaluation of function was based on the Medical Research Council (MRC) classification for motor and sensory recovery. Factors affecting functional outcome, such as age of the patient, denervation time, length of the defect, and level of the injury were noted. Good results according to the MRC classification were obtained in the majority of cases, although function remained less than that of the uninjured side.

The 'glial' glutamate transporter, EAAT2 (Glt-1) accounts for high affinity glutamate uptake into adult rodent nerve endings.

PubMed

Suchak, Sachin K; Baloyianni, Nicoletta V; Perkinton, Michael S; Williams, Robert J; Meldrum, Brian S; Rattray, Marcus

2003-02-01

The excitatory amino acid transporters (EAAT) removes neurotransmitters glutamate and aspartate from the synaptic cleft. Most CNS glutamate uptake is mediated by EAAT2 into glia, though nerve terminals show evidence for uptake, through an unknown transporter. Reverse-transcriptase PCR identified the expression of EAAT1, EAAT2, EAAT3 and EAAT4 mRNAs in primary cultures of mouse cortical or striatal neurones. We have used synaptosomes and glial plasmalemmal vesicles (GPV) from adult mouse and rat CNS to identify the nerve terminal transporter. Western blotting showed detectable levels of the transporters EAAT1 (GLAST) and EAAT2 (Glt-1) in both synaptosomes and GPVs. Uptake of [3H]D-aspartate or [3H]L-glutamate into these preparations revealed sodium-dependent uptake in GPV and synaptosomes which was inhibited by a range of EAAT blockers: dihydrokainate, serine-o-sulfate, l-trans-2,4-pyrrolidine dicarboxylate (PDC) (+/-)-threo-3-methylglutamate and (2S,4R )-4-methylglutamate. The IC50 values found for these compounds suggested functional expression of the 'glial, transporter, EAAT2 in nerve terminals. Additionally blockade of the majority EAAT2 uptake sites with 100 micro m dihydrokainate, failed to unmask any functional non-EAAT2 uptake sites. The data presented in this study indicate that EAAT2 is the predominant nerve terminal glutamate transporter in the adult rodent CNS.

Projections from the nucleus reticularis magnocellularis to the rat cervical cord using electrical stimulation and iontophoretic injection methods.

PubMed

Watanabe, Shigeo; Kitamura, Taiko; Watanabe, Lisa; Sato, Hitoshi; Yamada, Jinzo

2003-03-01

The aim of this study is to clarify the fiber distribution of the nucleus reticularis magnocellularis (NRMC) and adjacent areas in the rat spinal cord. Biotinylated dextran amine was injected iontophoretically through a glass capillary into the areas, in which a single cell responded to noxious electrical stimulation of the sciatic nerve and to a pinch of the thigh skin with multiple spikes. Labeled fibers descended bilaterally through the ventral funiculi of the medulla oblongata and then through the ventral and lateral funiculi of the cervical cord with an ipsilateral predominance, and terminated in the spinal gray (laminae I-X). A single fiber sometimes ran through several laminae while bifurcating many short branches with axon varicosities and terminal buttons in one transverse section, that is, through laminae V, VII and X, through laminae V, IIl-IV and I-II, and through laminae VII to I-II. The present study showed that the wide distribution of a single fiber and a mass of fibers descending from the NRMC and adjacent areas might modulate not only somatic sensory and motor functions but also autonomic functions in the spinal cord.

Molecular Basis of Infrared Detection by Snakes

PubMed Central

Gracheva, Elena O.; Ingolia, Nicolas T.; Kelly, Yvonne M.; Cordero-Morales, Julio F.; Hollopeter, Gunther; Chesler, Alexander T.; Sánchez, Elda E.; Perez, John C.; Weissman, Jonathan S.; Julius, David

2010-01-01

Snakes possess a unique sensory system for detecting infrared radiation, enabling them to generate a ‘thermal image’ of predators or prey. Infrared signals are initially received by the pit organ, a highly specialized facial structure that is innervated by nerve fibers of the somatosensory system. How this organ detects and transduces infrared signals into nerve impulses is not known. Here we use an unbiased transcriptional profiling approach to identify TRPA1 channels as infrared receptors on sensory nerve fibers that innervate the pit organ. TRPA1 orthologues from pit bearing snakes (vipers, pythons, and boas) are the most heat sensitive vertebrate ion channels thus far identified, consistent with their role as primary transducers of infrared stimuli. Thus, snakes detect infrared signals through a mechanism involving radiant heating of the pit organ, rather than photochemical transduction. These findings illustrate the broad evolutionary tuning of TRP channels as thermosensors in the vertebrate nervous system. PMID:20228791

Nedocromil sodium modulates nonadrenergic, noncholinergic bronchoconstrictor nerves in guinea pig airways in vitro.

PubMed

Verleden, G M; Belvisi, M G; Stretton, C D; Barnes, P J

1991-01-01

Nonadrenergic, noncholinergic (NANC) neural bronchoconstrictor responses in guinea pig airways are due to the release of tachykinins from sensory nerves. We have performed an in vitro study using electrical field stimulation (EFS; 40 V, 0.5 ms, 8 Hz for 20 s) in guinea pig bronchi to investigate the effect of nedocromil sodium (NS) on NANC bronchoconstrictor responses. NS inhibited NANC bronchoconstriction in bronchi in a concentration-dependent manner, with a maximum inhibition of 40 +/- 4% (p less than 0.001, n = 6) at 100 microM. Cromolyn sodium, however, produced only 9 +/- 8% inhibition at the same molar concentration (p less than 0.05). NS did not affect the contractile response to substance P, nor did it modulate the cholinergic bronchoconstrictor response to EFS in tracheal smooth muscle. These results indicate that NS may modulate the release of tachykinins from airway sensory nerves.

Palisade endings are present in canine extraocular muscles and have a cholinergic phenotype.

PubMed

Rungaldier, Stefanie; Pomikal, Christine; Streicher, Johannes; Blumer, Roland

2009-11-20

Classical proprioceptors, like Golgi tendon organs and muscle spindles are absent in the extraocular muscles (EOMs) of most mammals. Instead, a nerve end organ was detected in the EOMs of each species including sheep, cat, rabbit, rat, monkey, and human examined so far: the palisade ending. Until now no clear evidence appeared that palisade endings are also present in canine EOMs. Here, we analyzed dog EOMs by confocal laser scanning microscopy, 3D reconstruction, and transmission electron microscopy. In EOM wholemount preparations stained with antibodies against neurofilament and synaptophysin we could demonstrate typical palisade endings. Nerve fibers coming from the muscle extend into the tendon. There, the nerve fibers turn 180 degrees and return to branch into preterminal axons which establish nerve terminals around a single muscle fiber tip. Fine structural analysis revealed that each palisade ending in dog EOMs establish nerve terminals on the tendon. In some palisade endings we found nerve terminals contacting the muscle fiber as well. Such neuromuscular contacts have a basal lamina in the synaptic cleft. By using an antibody against choline acetyltransferase (ChAT) we proved that canine palisade endings are ChAT-immunoreactive. This study shows that palisade endings are present in canine EOMs. In line with prior findings in cat and monkey, palisade endings in dog have a cholinergic phenotype.

Renal dopamine containing nerves. What is their functional significance?

PubMed

DiBona, G F

1990-06-01

Biochemical and morphological studies indicate that there are nerves within the kidney that contain dopamine and that various structures within the kidney contain dopamine receptors. However, the functional significance of these renal dopamine containing nerves in relation to renal dopamine receptors is unknown. The functional significance could be defined by demonstrating that an alteration in one or more renal functions occurring in response to reflex or electrical activation of efferent renal nerves is dependent on release of dopamine as the neurotransmitter from the renal nerve terminals acting on renal dopamine receptors. Thus, the hypothesis becomes: reflex or electrical activation of efferent renal nerves causes alterations in renal function (eg, renal blood flow, water and solute handling) that are inhibited by specific and selective dopamine receptor antagonists. As reviewed herein, the published experimental data do not support the hypothesis. Therefore, the view that alterations in one or more renal functions occurring in response to reflex or electrical activation of efferent renal nerves are dependent on release of dopamine as the neurotransmitter from the renal nerve terminals acting on renal dopamine receptors remains unproven.

Mechanisms of peripheral immune-cell-mediated analgesia in inflammation: clinical and therapeutic implications.

PubMed

Hua, Susan; Cabot, Peter J

2010-09-01

Peripheral mechanisms of endogenous pain control are significant. In peripheral inflamed tissue, an interaction between immune-cell-derived opioids and opioid receptors localized on sensory nerve terminals results in potent, clinically measurable analgesia. Opioid peptides and the mRNA encoding their precursor proteins are present in immune cells. These cells 'home' preferentially to injured tissue, where they secrete opioids to reduce pain. Investigation of the mechanisms underlying the migration of opioid-containing immune cells to inflamed tissue is an active area of research, with recent data demonstrating the importance of cell adhesion molecules in leukocyte adhesion to both the endothelium in vascular transmigration and to neurons within peripheral inflamed tissue. This review summarizes the physiological mechanisms and clinical significance of this unique endogenous peripheral analgesic pathway and discusses therapeutic implications for the development of novel targeted peripheral analgesics. Copyright 2010 Elsevier Ltd. All rights reserved.

Chronic inflammatory demyelinating polyneuropathy associated with primary biliary cirrhosis.

PubMed

Murata, Ken-ya; Ishiguchi, Hiroshi; Ando, Ryuki; Miwa, Hideto; Kondo, Tomoyoshi

2013-12-01

We report a patient with chronic inflammatory demyelinating polyneuropathy associated with primary biliary cirrhosis (PBC). Except for minimal biochemical abnormalities, clinical symptoms of PBC were not observed, and we diagnosed our patient with asymptomatic PBC from the results of a liver biopsy. Although the patient noticed little muscle weakness, an electrophysiological study demonstrated slow conduction velocities and prolonged distal latencies, with definite conduction blocks in the median, ulnar, and tibial nerves. The disturbed sensory pattern was asymmetrical, and sensory nerve action potentials were not evoked. From these observations, we diagnosed this patient with chronic inflammatory demyelinating polyneuropathy. Neuropathy associated with PBC is very rare. We must differentiate demyelinating neuropathy with PBC in patients with asymmetrical sensory dominant neuropathy with high immunoglobulin M titers, and investigate for the presence of anti-mitochondrial antibodies to rule out a complication of asymptomatic PBC. Copyright © 2013 Elsevier Ltd. All rights reserved.

Neurotrophin signaling and visceral hypersensitivity.

PubMed

Qiao, Li-Ya

2014-06-01

Neurotrophin family are traditionally recognized for their nerve growth promoting function and are recently identified as crucial factors in regulating neuronal activity in the central and peripheral nervous systems. The family members including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) are reported to have distinct roles in the development and maintenance of sensory phenotypes in normal states and in the modulation of sensory activity in disease. This paper highlights receptor tyrosine kinase (Trk) -mediated signal transduction by which neurotrophins regulate neuronal activity in the visceral sensory reflex pathways with emphasis on the distinct roles of NGF and BDNF signaling in physiologic and pathophysiological processes. Viscero-visceral cross-organ sensitization exists widely in human diseases. The role of neurotrophins in mediating neural cross talk and interaction in primary afferent neurons in the dorsal root ganglia (DRG) and neurotrophin signal transduction in the context of cross-organ sensitization are also discussed.

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

PubMed

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

2003-05-01

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

Galileo Galilei's vision of the senses.

PubMed

Piccolino, Marco; Wade, Nicholas J

2008-11-01

Neuroscientists have become increasingly aware of the complexities and subtleties of sensory processing. This applies particularly to the complex elaborations of nerve signals that occur in the sensory circuits, sometimes at the very initial stages of sensory pathways. Sensory processing is now known to be very different from a simple neural copy of the physical signal present in the external world, and this accounts for the intricacy of neural organization that puzzled great investigators of neuroanatomy such as Santiago Ramón Y Cajal a century ago. It will surprise present-day sensory neuroscientists, applying their many modern methods, that the conceptual basis of the contemporary approach to sensory function had been recognized four centuries ago by Galileo Galilei.

Association between Computer Use and Entrapment Neuropathies in the Wrist Region

ERIC Educational Resources Information Center

Colak, S.; Bamac, B.; Colak, T.; Ozbek, A.

2013-01-01

There is general consensus in the literature that computer use is often associated with an increased prevalence of hand and wrist disorders. Symptoms may be associated with specific clinical entities such as peripheral nerve entrapment. Motor and sensory nerve conduction velocity and vibration threshold in the hand of computer users have been…

CHRONIC DIETARY EXPOSURE WITH INTERMITTENT SPIKE DOSES OF CHLORPYRIFOS FALLS TO ALTER SOMATOSENSORY EVOKED POTENTIALS, COMPOUND NERVE ACTION POTENTIALS, OR NERVE CONDUCTION VELOCITY IN RATS.

EPA Science Inventory

Human exposure to pesticides is often characterized by chronic low level exposure with intermittent spiked higher exposures. Cholinergic transmission is involved in sensory modulation in the cortex and cerebellum, and therefore may be altered following chlorpyrifos (CPF) exposure...

Should sensory function after median nerve injury and repair be quantified using two-point discrimination as the critical measure?

PubMed

Jerosch-Herold, C

2000-12-01

Two-point discrimination (2PD) is widely used for evaluating outcome from peripheral nerve injury and repair. It is the only quantifiable measure used in the British Medical Research Council (MRC) classification that was developed by Highet in 1954. This paper reports the results of a study of 41 patients with complete median nerve lacerations to the wrist or forearm. Two-point discrimination thresholds were assessed together with locognosia (locognosia is the ability to localise a sensory stimulus on the body's surface), tactile gnosis, and touch threshold. Using the MRC classification 29 (71%) patients had a result of S2 or below, 11 (27%) were S3, and only one scored S3+. Patients scored much better on the other tests and showed progressive recovery. It remains too difficult for patients to obtain a measurable threshold value on 2PD and the test therefore lacks responsiveness. The rating of outcome from peripheral nerve repair should not be based solely on 2PD testing and must include other tests of tactile sensibility.

Results of neurolysis in established upper limb Volkmann's ischemic contracture

PubMed Central

Meena, Dinesh K; Thalanki, Srikiran; Patni, Poornima; Meena, Ram Khiladi; Bairawa, Dinesh; Bhatia, Chirag

2016-01-01

Background: Treatment of established cases of Volkmann's ischemic contracture (VIC) of upper limb is very tedious. Since the period of Volkmann, various experimental works are being performed for its treatment, but none are effective. Disabilities from nerve palsy and hand muscle paralysis are more problematic than any other deformity in VIC. To solve these problems, we conducted a study to see the result of neurolysis of median and ulnar nerve and their subcutaneous placement in established cases of VIC. Materials and Methods: Twelve cases of established VIC operated between July 2007 and August 2010 with complete records and followup were included in the study. VIC of lower limb and contracture of nonischemic etiology were excluded from the study. Their evaluation was done by the British Medical Research Council grading system for sensory and motor recovery. Followup was done for an average period of 24.3 months (range 15-30 months) (the average age was 8.3 years). Results: To study the results, we divided the cases into two series. One group consisted of cases which were operated within 6 months from onset of VIC. The second group consisted of cases which were operated after 6 months from onset of VIC. Our results revealed that there was no statistically significant difference between the two groups operated, though both had significant improvement in motor and sensory recovery in both median and ulnar nerve distribution. Conclusions: Neurolysis of the nerves definitely improved the outcome for motor and sensory components of median and ulnar nerves but the timing of the surgery did not play a role in the outcome contrary to the clinical assumption. This study can serve as a template and further such studies could help us find the answer to a long standing issue. PMID:27904214

Early electrophysiological findings in acute inflammatory demyelinating polyradiculoneuropathy variant of Guillain-Barre syndrome in the Pakistani population - a comparison with global data.

PubMed

Wali, Ahmad; Kanwar, Dureshahwar; Khan, Safoora A; Khan, Sara

2017-12-01

Acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and acute motor axonal neuropathy are the most common variants of Guillian-Barre syndrome documented in the Asian population. However, the variability of early neurophysiologic findings in the Asian population compared to western data has not been documented. Eighty-seven cases of AIDP were retrospectively reviewed for their demographic, clinical, electrophysiological, and laboratory data. Mean age of subjects was 31 ± 8 years with males more commonly affected. Motor symptoms (97%) at presentation predominated. Common early nerve conduction findings included low motor amplitudes (85%), recordable sural sensory responses (85%), and absent H-reflex responses (65%). Prolonged F-latencies were found most commonly in posterior tibial nerves (23%) in the lower limbs and median and ulnar nerves (18%) in the upper limbs. Blink reflex (BR) studies were performed in 57 patients and were abnormal in 80% of those with clinical facial weakness and in 17 of 52 patients (33%) with no clinical cranial nerve signs, suggesting subclinical cranial nerve involvement. Abnormal motor and sensory amplitudes are seen early. Prolonged distal latencies, temporal dispersion/conduction blocks and sural sparing pattern are other common early nerve conduction study findings of AIDP seen in the Pakistani population. There are no significant differences in abnormalities of conduction velocities and delayed reflex responses compared to published data. The BR can help in the early diagnosis of AIDP. © 2017 Peripheral Nerve Society.

"Long-term stability of stimulating spiral nerve cuff electrodes on human peripheral nerves".

PubMed

Christie, Breanne P; Freeberg, Max; Memberg, William D; Pinault, Gilles J C; Hoyen, Harry A; Tyler, Dustin J; Triolo, Ronald J

2017-07-11

Electrical stimulation of the peripheral nerves has been shown to be effective in restoring sensory and motor functions in the lower and upper extremities. This neural stimulation can be applied via non-penetrating spiral nerve cuff electrodes, though minimal information has been published regarding their long-term performance for multiple years after implantation. Since 2005, 14 human volunteers with cervical or thoracic spinal cord injuries, or upper limb amputation, were chronically implanted with a total of 50 spiral nerve cuff electrodes on 10 different nerves (mean time post-implant 6.7 ± 3.1 years). The primary outcome measures utilized in this study were muscle recruitment curves, charge thresholds, and percent overlap of recruited motor unit populations. In the eight recipients still actively involved in research studies, 44/45 of the spiral contacts were still functional. In four participants regularly studied over the course of 1 month to 10.4 years, the charge thresholds of the majority of individual contacts remained stable over time. The four participants with spiral cuffs on their femoral nerves were all able to generate sufficient moment to keep the knees locked during standing after 2-4.5 years. The dorsiflexion moment produced by all four fibular nerve cuffs in the active participants exceeded the value required to prevent foot drop, but no tibial nerve cuffs were able to meet the plantarflexion moment that occurs during push-off at a normal walking speed. The selectivity of two multi-contact spiral cuffs was examined and both were still highly selective for different motor unit populations for up to 6.3 years after implantation. The spiral nerve cuffs examined remain functional in motor and sensory neuroprostheses for 2-11 years after implantation. They exhibit stable charge thresholds, clinically relevant recruitment properties, and functional muscle selectivity. Non-penetrating spiral nerve cuff electrodes appear to be a suitable option for long-term clinical use on human peripheral nerves in implanted neuroprostheses.

Unusual presentation Of Sjögren-associated neuropathy with plasma cell-rich infiltrate.

PubMed

Naddaf, Elie; Berini, Sarah E; B Dyck, P James; Laughlin, Ruple S

2017-04-01

Sjögren syndrome is thought to be a lymphocyte-driven process. Peripheral nervous system involvement occurs in about 20%-25% of patients. A sensory-predominant, large-fiber peripheral neuropathy is most common, and it is usually associated with a subacute to chronic presentation. We report a rare case of an acute Sjögren-associated, sensory predominant, length-dependent peripheral neuropathy mimicking Guillain-Barré syndrome. The patient presented with sensory ataxia preceded by fever and polyarthralgia. She gave a history of years of dry eyes and dry mouth. She had a positive Shirmer test, abnormal salivary gland scan, and positive SS-A and SS-B antibodies. A sural nerve biopsy showed an unusual, dense, non-IgG4, polyclonal, plasma-cell perivascular infiltrate. The patient responded to treatment with weekly pulse intravenous methylprednisolone. Sjögren syndrome can present with acute-onset, sensory predominant peripheral neuropathy. The role of plasma cells in Sjögren syndrome is unexplored and deserves further study. Muscle Nerve 55: 605-608, 2017. © 2016 Wiley Periodicals, Inc.

Allergen challenge sensitizes TRPA1 in vagal sensory neurons and afferent C-fiber subtypes in guinea pig esophagus.

PubMed

Liu, Zhenyu; Hu, Youtian; Yu, Xiaoyun; Xi, Jiefeng; Fan, Xiaoming; Tse, Chung-Ming; Myers, Allen C; Pasricha, Pankaj J; Li, Xingde; Yu, Shaoyong

2015-03-15

Transient receptor potential A1 (TRPA1) is a newly defined cationic ion channel, which selectively expresses in primary sensory afferent nerve, and is essential in mediating inflammatory nociception. Our previous study demonstrated that TRPA1 plays an important role in tissue mast cell activation-induced increase in the excitability of esophageal vagal nodose C fibers. The present study aims to determine whether prolonged antigen exposure in vivo sensitizes TRPA1 in a guinea pig model of eosinophilic esophagitis (EoE). Antigen challenge-induced responses in esophageal mucosa were first assessed by histological stains and Ussing chamber studies. TRPA1 function in vagal sensory neurons was then studied by calcium imaging and by whole cell patch-clamp recordings in 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)-labeled esophageal vagal nodose and jugular neurons. Extracellular single-unit recordings were performed in vagal nodose and jugular C-fiber neuron subtypes using ex vivo esophageal-vagal preparations with intact nerve endings in the esophagus. Antigen challenge significantly increased infiltrations of eosinophils and mast cells in the esophagus. TRPA1 agonist allyl isothiocyanate (AITC)-induced calcium influx in nodose and jugular neurons was significantly increased, and current densities in esophageal DiI-labeled nodose and jugular neurons were also significantly increased in antigen-challenged animals. Prolonged antigen challenge decreased esophageal epithelial barrier resistance, which allowed intraesophageal-infused AITC-activating nodose and jugular C fibers at their nerve endings. Collectively, these results demonstrated that prolonged antigen challenge sensitized TRPA1 in esophageal sensory neurons and afferent C fibers. This novel finding will help us to better understand the molecular mechanism underlying esophageal sensory and motor dysfunctions in EoE. Copyright © 2015 the American Physiological Society.

Allergen challenge sensitizes TRPA1 in vagal sensory neurons and afferent C-fiber subtypes in guinea pig esophagus

PubMed Central

Liu, Zhenyu; Hu, Youtian; Yu, Xiaoyun; Xi, Jiefeng; Fan, Xiaoming; Tse, Chung-Ming; Myers, Allen C.; Pasricha, Pankaj J.; Li, Xingde

2015-01-01

Transient receptor potential A1 (TRPA1) is a newly defined cationic ion channel, which selectively expresses in primary sensory afferent nerve, and is essential in mediating inflammatory nociception. Our previous study demonstrated that TRPA1 plays an important role in tissue mast cell activation-induced increase in the excitability of esophageal vagal nodose C fibers. The present study aims to determine whether prolonged antigen exposure in vivo sensitizes TRPA1 in a guinea pig model of eosinophilic esophagitis (EoE). Antigen challenge-induced responses in esophageal mucosa were first assessed by histological stains and Ussing chamber studies. TRPA1 function in vagal sensory neurons was then studied by calcium imaging and by whole cell patch-clamp recordings in 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI)-labeled esophageal vagal nodose and jugular neurons. Extracellular single-unit recordings were performed in vagal nodose and jugular C-fiber neuron subtypes using ex vivo esophageal-vagal preparations with intact nerve endings in the esophagus. Antigen challenge significantly increased infiltrations of eosinophils and mast cells in the esophagus. TRPA1 agonist allyl isothiocyanate (AITC)-induced calcium influx in nodose and jugular neurons was significantly increased, and current densities in esophageal DiI-labeled nodose and jugular neurons were also significantly increased in antigen-challenged animals. Prolonged antigen challenge decreased esophageal epithelial barrier resistance, which allowed intraesophageal-infused AITC-activating nodose and jugular C fibers at their nerve endings. Collectively, these results demonstrated that prolonged antigen challenge sensitized TRPA1 in esophageal sensory neurons and afferent C fibers. This novel finding will help us to better understand the molecular mechanism underlying esophageal sensory and motor dysfunctions in EoE. PMID:25591867

Clinical, physiological and pathological characterisation of the sensory predominant peripheral neuropathy in copper deficiency.

PubMed

Taylor, Sean W; Laughlin, Ruple S; Kumar, Neeraj; Goodman, Brent; Klein, Christopher J; Dyck, Peter J; Dyck, P James B

2017-10-01

Myelopathy is considered the most common neurological complication of copper deficiency. Concurrent peripheral neuropathy has been recognised in association with copper deficiency but has not been well characterised. To characterise the clinical, physiological and pathological features of copper-deficient peripheral neuropathy. Patients with simultaneous copper deficiency (<0.78 μg/mL) and peripheral neuropathy seen at the Mayo Clinic from 1985 to 2005 were identified. 34 patients were identified (median age 55 years, range 36-78) including 24 women and 10 men. Myelopathy was found in 21 patients. Median serum copper level was 0.11 μg/mL (range 0-0.58). The most frequent clinical and electrophysiological pattern of neuropathy was a sensory predominant length-dependent peripheral neuropathy (71%). Somatosensory evoked potentials demonstrated central slowing supporting myelopathy (96%). Quantitative sensory testing demonstrated both small and large fibre involvement (100%). Autonomic reflex screens (77%) and thermoregulatory sweat test (67%) confirmed sudomotor dysfunction. 14 cutaneous nerve biopsies revealed loss of myelinated nerve fibres (86%), increased regenerative clusters (50%), increased rates of axonal degeneration (91%) and increased numbers of empty nerve strands (73%). 71% of biopsies demonstrated epineurial perivascular inflammation. An axonal, length-dependent sensory predominant peripheral neuropathy causing sensory ataxia is characteristic of copper deficiency usually co-occurring with myelopathy. Neurophysiological testing confirms involvement of large, greater than small fibres. The pathological findings suggest axonal degeneration and repair. Inflammatory infiltrates are common but are small and of doubtful pathological significance. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Nerve ultrasound shows subclinical peripheral nerve involvement in neurofibromatosis type 2.

PubMed

Telleman, Johan A; Stellingwerff, Menno D; Brekelmans, Geert J; Visser, Leo H

2018-02-01

Neurofibromatosis type 2 (NF2) is mainly associated with central nervous system (CNS) tumors. Peripheral nerve involvement is described in symptomatic patients, but evidence of subclinical peripheral nerve involvement is scarce. We conducted a cross-sectional pilot study in 2 asymptomatic and 3 minimally symptomatic patients with NF2 to detect subclinical peripheral nerve involvement. Patients underwent clinical examination, nerve conduction studies (NCS), and high-resolution ultrasonography (HRUS). A total of 30 schwannomas were found, divided over 20 nerve segments (33.9% of all investigated nerve segments). All patients had at least 1 schwannoma. Schwannomas were identified with HRUS in 37% of clinically unaffected nerve segments and 50% of nerve segments with normal NCS findings. HRUS shows frequent subclinical peripheral nerve involvement in NF2. Clinicians should consider peripheral nerve involvement as a cause of weakness and sensory loss in the extremities in patients with this disease. Muscle Nerve 57: 312-316, 2018. © 2017 Wiley Periodicals, Inc.

The Minimum Effective Dose of Lidocaine Needed to Block Evoked Potentials in the Sciatic Nerve of the Rat

DTIC Science & Technology

1998-10-01

which include the sciatic nerve, will be described. Gilman and Newman (1996) describe the PNS in their book, Manter and Gatz’s Essentials of Clinical ...Neural Blockade in Clinical Anesthesia and Management of Pain. He wrote that sensory and motor messages are transported along a nerve in the form of an...different groups of local anesthetics, the esters (procaine, chloroprocaine, tetracaine) and the amides (lidocaine, mepivacaine, bupivacaine , etidocaine

Immunohistochemical localization of two types of choline acetyltransferase in neurons and sensory cells of the octopus arm.

PubMed

Sakaue, Yuko; Bellier, Jean-Pierre; Kimura, Shin; D'Este, Loredana; Takeuchi, Yoshihiro; Kimura, Hiroshi

2014-01-01

Cholinergic structures in the arm of the cephalopod Octopus vulgaris were studied by immunohistochemistry using specific antisera for two types (common and peripheral) of acetylcholine synthetic enzyme choline acetyltransferase (ChAT): antiserum raised against the rat common type ChAT (cChAT), which is cross-reactive with molluscan cChAT, and antiserum raised against the rat peripheral type ChAT (pChAT), which has been used to delineate peripheral cholinergic structures in vertebrates, but not previously in invertebrates. Western blot analysis of octopus extracts revealed a single pChAT-positive band, suggesting that pChAT antiserum is cross-reactive with an octopus counterpart of rat pChAT. In immunohistochemistry, only neuronal structures of the octopus arm were stained by cChAT and pChAT antisera, although the pattern of distribution clearly differed between the two antisera. cChAT-positive varicose nerve fibers were observed in both the cerebrobrachial tract and neuropil of the axial nerve cord, while pChAT-positive varicose fibers were detected only in the neuropil of the axial nerve cord. After epitope retrieval, pChAT-positive neuronal cells and their processes became visible in all ganglia of the arm, including the axial and intramuscular nerve cords, and in ganglia of suckers. Moreover, pChAT-positive structures also became detectable in nerve fibers connecting the different ganglia, in smooth nerve fibers among muscle layers and dermal connective tissues, and in sensory cells of the suckers. These results suggest that the octopus arm has two types of cholinergic nerves: cChAT-positive nerves from brain ganglia and pChAT-positive nerves that are intrinsic to the arm.

Peripheral nerves are pathologically small in cerebellar ataxia neuropathy vestibular areflexia syndrome: a controlled ultrasound study.

PubMed

Pelosi, L; Mulroy, E; Leadbetter, R; Kilfoyle, D; Chancellor, A M; Mossman, S; Wing, L; Wu, T Y; Roxburgh, R H

2018-04-01

Sensory neuronopathy is a cardinal feature of cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS). Having observed that two patients with CANVAS had small median and ulnar nerves on ultrasound, we set out to examine this finding systematically in a cohort of patients with CANVAS, and compare them with both healthy controls and a cohort of patients with axonal neuropathy. We have previously reported preliminary findings in seven of these patients with CANVAS and seven healthy controls. We compared the ultrasound cross-sectional area of median, ulnar, sural and tibial nerves of 14 patients with CANVAS with 14 healthy controls and 14 age- and gender-matched patients with acquired primarily axonal neuropathy. We also compared the individual nerve cross-sectional areas of patients with CANVAS and neuropathy with the reference values of our laboratory control population. The nerve cross-sectional area of patients with CANVAS was smaller than that of both the healthy controls and the neuropathy controls, with highly significant differences at most sites (P < 0.001). Conversely, the nerve cross-sectional areas in the upper limb were larger in neuropathy controls than healthy controls (P < 0.05). On individual analysis, the ultrasound abnormality was sufficiently characteristic to be detected in all but one patient with CANVAS. Small nerves in CANVAS probably reflect nerve thinning from loss of axons due to ganglion cell loss. This is distinct from the ultrasound findings in axonal neuropathy, in which nerve size was either normal or enlarged. Our findings indicate a diagnostic role for ultrasound in CANVAS sensory neuronopathy and in differentiating neuronopathy from neuropathy. © 2018 EAN.

Impaired peripheral nerve regeneration in type-2 diabetic mouse model.

PubMed

Pham, Vuong M; Tu, Nguyen Huu; Katano, Tayo; Matsumura, Shinji; Saito, Akira; Yamada, Akihiro; Furue, Hidemasa; Ito, Seiji

2018-01-01

Peripheral neuropathy is one of the most common and serious complications of type-2 diabetes. Diabetic neuropathy is characterized by a distal symmetrical sensorimotor polyneuropathy, and its incidence increases in patients 40 years of age or older. In spite of extensive research over decades, there are few effective treatments for diabetic neuropathy besides glucose control and improved lifestyle. The earliest changes in diabetic neuropathy occur in sensory nerve fibers, with initial degeneration and regeneration resulting in pain. To seek its effective treatment, here we prepared a type-2 diabetic mouse model by giving mice 2 injections of streptozotocin and nicotinamide and examining the ability for nerve regeneration by using a sciatic nerve transection-regeneration model previously established by us. Seventeen weeks after the last injection, the mice exhibited symptoms of type-2 diabetes, that is, impaired glucose tolerance, decreased insulin level, mechanical hyperalgesia, and impaired sensory nerve fibers in the plantar skin. These mice showed delayed functional recovery and nerve regeneration by 2 weeks compared with young healthy mice and by 1 week compared with age-matched non-diabetic mice after axotomy. Furthermore, type-2 diabetic mice displayed increased expression of PTEN in their DRG neurons. Administration of a PTEN inhibitor at the cutting site of the nerve for 4 weeks promoted the axonal transport and functional recovery remarkably. This study demonstrates that peripheral nerve regeneration was impaired in type-2 diabetic model and that its combination with sciatic nerve transection is suitable for the study of the pathogenesis and treatment of early diabetic neuropathy. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Physiological improvement with moderate exercise in type II diabetic neuropathy.

PubMed

Fisher, M A; Langbein, W E; Collins, E G; Williams, K; Corzine, L

2007-01-01

The objective of this study was to demonstrate improvement in nerve function with moderate exercise in patients with type II diabetic neuropathies. Fives subjects with type II diabetes mellitus and distal, predominantly sensory polyneuropathies were studied. The subjects completed an 8-week program of a supervised moderate exercise program (40-75% of maximal 02 uptake reserve) with a subsequent 16-week program of monitored similar exercise. The same experienced electrophysiologist performed the electrodiagnostic studies both before and after the 24-week exercise period. These studies monitored physiological changes (conduction velocities, response amplitudes) in motor and sensory fibers as well as F-wave latencies. The exercise program produced a documented increase in aerobic exercise capacity. Despite the small number of subjects studied and the relatively short exercise period, there was a statistically significant improvement in nearly all electrophysiological parameters evaluated post exercise including motor conduction velocities and amplitudes, sensory conduction velocities, and F-wave latencies. This improvement included a statistically significant improvement in absolute median motor evoked response amplitudes as well as the recording of sensory nerve action potentials not present prior to exercise. There were no adverse effects from the exercise. This study supports the hypothesis that exercise can be performed safely in patients with type II diabetic neuropathies and can produce improvement in their nerve function. This study also supports the hypothesis that ischemia may have a meaningful role in the pathogenesis of neuropathies in patients with type II diabetes mellitus.

Coexistence of calbindin D-28k and NADPH-diaphorase in vagal and glossopharyngeal sensory neurons of the rat.

PubMed

Ichikawa, H; Helke, C J

1996-10-07

The presence and coexistence of calbindin D-28k-immunoreactivity (ir) and nicotinamide adenosine dinucleotide phosphate (NADPH)-diaphorase activity (a marker of neurons that are presumed to convert L-arginine to L-citrulline and nitric oxide) were examined in the glossopharyngeal and vagal sensory ganglia (jugular, petrosal and nodose ganglia) of the rat. Calbindin D-28k-ir nerve cells were found in moderate and large numbers in the petrosal and nodose ganglia, respectively. Some calbindin D-28k-ir nerve cells were also observed in the jugular ganglion. NADPH-diaphorase positive nerve cells were localized to the jugular and nodose ganglia and were rare in the petrosal ganglion. A considerable portion (33-51%) of the NADPH-diaphorase positive neurons in these ganglia colocalized calbindin D-28k-ir. The presence and colocalization of calbindin D-28k-ir and NADPH-diaphorase activity in neurotransmitter-identified subpopulations of visceral sensory neurons were also studied. In all three ganglia, calcitonin gene-related peptide (CGRP)-ir was present in many NADPH-diaphorase positive neurons, a subset of which also contained calbindin D-28k-ir. In the nodose ganglion, many (42%) of tyrosine hydroxylase (TH)-ir neurons also contained NADPH diaphorase activity but did not contain calbindin D-28k-ir. These data are consistent with a potential co-operative role for calbindin D-28k and NADPH-diaphorase in the functions of a subpopulation of vagal and glossopharyngeal sensory neurons.

The prevalence of early subclinical somatic neuropathy in children and adolescents with Type 1 diabetes mellitus and its association with the persistence of autoantibodies to glutamic acid decarboxylase (GAD) and islet antigen-2 (IA-2).

PubMed

Louraki, Maria; Katsalouli, Marina; Kanaka-Gantenbein, Christina; Kafassi, Nikolitsa; Critselis, Eleni; Kallinikou, Dimitra; Tsentidis, Charalampos; Karavanaki, Kyriaki

2016-07-01

To evaluate the prevalence of early somatic neuropathy in children and adolescents with Type 1 diabetes mellitus (Type 1 DM) and its association with the presence of glutamic acid decarboxylase and islet antigen-2 autoantibodies (GADA and IA-2A). A cross-sectional study was conducted in a hospital-based cohort of pediatric Type 1 DM patients (n=85, mean(±SD) age: 13.5±3.4years, mean(±SD) disease duration 5.5±3.4years). Peripheral neuropathy was assessed with nerve conduction studies (NCS). GADA and IA-2A titers were measured with radioligand assays. Among the study population, 34.1% had at least one abnormal electrophysiological parameter, although predominantly asymptomatic. The highest rates of abnormality were detected in sensory peroneal nerve (25.9%) followed by sural nerve (15.3%). Affected patients were not different in terms of age, diabetes duration or glycaemic control. Among the participants, 62.4% had positive GADA, 58.8% positive IA-2A and 42.4% double antibody positivity. Abnormal NCS correlated neither with GADA nor with IA-2A levels or positivity. However lower sensory nerve action potential in the peroneal nerve, indicative of early axonal dysfunction, was observed in patients with GADA or IA-2A positivity. Absence of both antibodies was associated with better action potentials in all the examined nerves of the lower limbs. Impaired indices of subclinical peripheral primarily sensory neuropathy were present among one third of Type 1 DM children and adolescents, with no impact of diabetes duration or glycaemic control. GADA and IA-2A seem to be involved in the development of axonal degeneration, in a pathway which remains to be identified. Copyright © 2016. Published by Elsevier Ireland Ltd.

Sensory Symptom Profiles and Co-Morbidities in Painful Radiculopathy

PubMed Central

Gockel, Ulrich; Brosz, Mathias; Freynhagen, Rainer; Tölle, Thomas R.; Baron, Ralf

2011-01-01

Painful radiculopathies (RAD) and classical neuropathic pain syndromes (painful diabetic polyneuropathy, postherpetic neuralgia) show differences how the patients express their sensory perceptions. Furthermore, several clinical trials with neuropathic pain medications failed in painful radiculopathy. Epidemiological and clinical data of 2094 patients with painful radiculopathy were collected within a cross sectional survey (painDETECT) to describe demographic data and co-morbidities and to detect characteristic sensory abnormalities in patients with RAD and compare them with other neuropathic pain syndromes. Common co-morbidities in neuropathic pain (depression, sleep disturbance, anxiety) do not differ considerably between the three conditions. Compared to other neuropathic pain syndromes touch-evoked allodynia and thermal hyperalgesia are relatively uncommon in RAD. One distinct sensory symptom pattern (sensory profile), i.e., severe painful attacks and pressure induced pain in combination with mild spontaneous pain, mild mechanical allodynia and thermal hyperalgesia, was found to be characteristic for RAD. Despite similarities in sensory symptoms there are two important differences between RAD and other neuropathic pain disorders: (1) The paucity of mechanical allodynia and thermal hyperalgesia might be explained by the fact that the site of the nerve lesion in RAD is often located proximal to the dorsal root ganglion. (2) The distinct sensory profile found in RAD might be explained by compression-induced ectopic discharges from a dorsal root and not necessarily by nerve damage. These differences in pathogenesis might explain why medications effective in DPN and PHN failed to demonstrate efficacy in RAD. PMID:21573064

Association between basal metabolic function and bone metabolism in postmenopausal women with type 2 diabetes.

PubMed

Ogata, Makiko; Ide, Risa; Takizawa, Miho; Tanaka, Mizuho; Tetsuo, Tamaki; Sato, Asako; Iwasaki, Naoko; Uchigata, Yasuko

2015-01-01

Diabetes is a risk factor for osteoporosis, and glycemic control is critical during osteoporosis treatment in patients with type 2 diabetes (T2D). However, diabetic therapies have potentially adverse effects on bone metabolism. Additionally, biomarkers for bone metabolism are directly affected by drug therapies for osteoporosis. This study examined resting energy expenditure (REE) and respiratory quotient (RQ) as indices of bone metabolism in postmenopausal Japanese women with T2D. Forty-six postmenopausal Japanese women with T2D were examined. Procollagen type 1 N-terminal propeptide (P1NP, a fasting serum bone formation marker) and carboxy-terminal collagen cross-links-1 (CTX-1, a resorption marker) were evaluated, along with intact parathyroid hormone, 25-hydroxyvitamin D (25[OH]D), urine microalbumin, motor nerve conduction velocity, sensory nerve conduction velocity, R-R interval, body composition, REE, RQ, and bone mineral density at the nondominant distal radius. The mean T-score was low with high variance (-1.7 ± 1.6), and 18 patients (39%) met the criteria for osteoporosis. REE was positively correlated with body mass index (β = 0.517; r(2) = 0.250), serum calcium (β = 0.624; r(2) = 0.200), glycated hemoglobin A1C for the previous 6 mo (β = 0.395; r(2) = 0.137), and the serum P1NP/CTX-1 ratio (β = 0.380; r(2) = 0.144). RQ was positively correlated with serum 25(OH)D (β = 0.387; r(2) = 0.131). The basal metabolic rate and diabetic pathophysiology are interrelated with bone turnover. Copyright © 2015 Elsevier Inc. All rights reserved.

Intraganglionic AAV6 results in efficient and long-term gene transfer to peripheral sensory nervous system in adult rats.

PubMed

Yu, Hongwei; Fischer, Gregory; Ferhatovic, Lejla; Fan, Fan; Light, Alan R; Weihrauch, Dorothee; Sapunar, Damir; Nakai, Hiroyuki; Park, Frank; Hogan, Quinn H

2013-01-01

We previously demonstrated safe and reliable gene transfer to the dorsal root ganglion (DRG) using a direct microinjection procedure to deliver recombinant adeno-associated virus (AAV) vector. In this study, we proceed to compare the in vivo transduction patterns of self-complementary (sc) AAV6 and AAV8 in the peripheral sensory pathway. A single, direct microinjection of either AAV6 or AAV8 expressing EGFP, at the adjusted titer of 2×10(9) viral particle per DRG, into the lumbar (L) 4 and L5 DRGs of adult rats resulted in efficient EGFP expression (48±20% for AAV6 and 25±4% for AAV8, mean ± SD) selectively in sensory neurons and their axonal projections 3 weeks after injection, which remained stable for up to 3 months. AAV6 efficiently transfers EGFP to all neuronal size groups without differential neurotropism, while AAV8 predominantly targets large-sized neurons. Neurons transduced with AAV6 penetrate into the spinal dorsal horn (DH) and terminate predominantly in superficial DH laminae, as well as in the dorsal columns and deeper laminae III-V. Only few AAV8-transduced afferents were evident in the superficial laminae, and spinal EGFP was mostly present in the deeper dorsal horn (lamina III-V) and dorsal columns, with substantial projections to the ventral horn. AAV6-mediated EGFP-positive nerve fibers were widely observed in the medial plantar skin of ipsilateral hindpaws. No apparent inflammation, tissue damage, or major pain behaviors were observed for either AAV serotype. Taken together, both AAV6 and AAV8 are efficient and safe vectors for transgene delivery to primary sensory neurons, but they exhibit distinct functional features. Intraganglionic delivery of AAV6 is more uniform and efficient compared to AAV8 in gene transfer to peripheral sensory neurons and their axonal processes.

Bladder outlet obstruction triggers neural plasticity in sensory pathways and contributes to impaired sensitivity in erectile dysfunction.

PubMed

Malykhina, Anna P; Lei, Qi; Chang, Shaohua; Pan, Xiao-Qing; Villamor, Antonio N; Smith, Ariana L; Seftel, Allen D

2013-05-15

Lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) are common problems in aging males worldwide. The objective of this work was to evaluate the effects of bladder neck nerve damage induced by partial bladder outlet obstruction (PBOO) on sensory innervation of the corpus cavernosum (CC) and CC smooth muscle (CCSM) using a rat model of PBOO induced by a partial ligation of the bladder neck. Retrograde labeling technique was used to label dorsal root ganglion (DRG) neurons that innervate the urinary bladder and CC. Contractility and relaxation of the CCSM was studied in vitro, and expression of nitric oxide synthase (NOS) was evaluated by Western blotting. Concentration of the sensory neuropeptides substance P (SP) and calcitonin gene-related peptide was measured by ELISA. Partial obstruction of the bladder neck caused a significant hypertrophy of the urinary bladders (2.5-fold increase at 2 wk). Analysis of L6-S2 DRG sections determined that sensory ganglia received input from both the urinary bladder and CC with 5-7% of all neurons double labeled from both organs. The contractile responses of CC muscle strips to KCl and phenylephrine were decreased after PBOO, followed by a reduced relaxation response to nitroprusside. A significant decrease in neuronal NOS expression, but not in endothelial NOS or protein kinase G (PKG-1), was detected in the CCSM of the obstructed animals. Additionally, PBOO caused some impairment to sensory nerves as evidenced by a fivefold downregulation of SP in the CC (P ≤ 0.001). Our results provide evidence that PBOO leads to the impairment of bladder neck afferent innervation followed by a decrease in CCSM relaxation, downregulation of nNOS expression, and reduced content of sensory neuropeptides in the CC smooth muscle. These results suggest that nerve damage in PBOO may contribute to LUTS-ED comorbidity and trigger secondary changes in the contraction/relaxation mechanisms of CCSM.

Triazines facilitate neurotransmitter release of synaptic terminals located in hearts of frog (Rana ridibunda) and honeybee (Apis mellifera) and in the ventral nerve cord of a beetle (Tenebrio molitor).

PubMed

Papaefthimiou, Chrisovalantis; Zafeiridou, Georgia; Topoglidi, Aglaia; Chaleplis, George; Zografou, Stella; Theophilidis, George

2003-07-01

Three triazine herbicides, atrazine, simazine and metribuzine, and some of their major metabolites (cyanuric acid and 6-azauracil) were investigated for their action on synaptic terminals using three different isolated tissue preparations from the atria of the frog, Rana ridibunda, the heart of the honeybee, Apis mellifera macedonica, and the ventral nerve cord of the beetle, Tenebrio molitor. The results indicate that triazines facilitate the release of neurotransmitters from nerve terminals, as already reported for the mammalian central nervous system. The no observed effect concentration, the maximum concentration of the herbicide diluted in the saline that has no effect on the physiological properties of the isolated tissue, was estimated for each individual preparation. According to their relative potency, the three triazines tested can be ranked as follows: atrazine (cyanuric acid), simazine>metribuzine (6-azauracil). The action of these compounds on the cholinergic (amphibians, insects), adrenergic (amphibian) and octopaminergic (insects) synaptic terminals is discussed.

Dynamics of the sensory response to urethral flow over multiple time scales in rat

PubMed Central

Danziger, Zachary C; Grill, Warren M

2015-01-01

The pudendal nerve carries sensory information from the urethra that controls spinal reflexes necessary to maintain continence and achieve efficient micturition. Despite the key role urethral sensory feedback plays in regulation of the lower urinary tract, there is little information about the characteristics of urethral sensory responses to physiological stimuli, and the quantitative relationship between physiological stimuli and the evoked sensory activation is unknown. Such a relation is critical to understanding the neural control of the lower urinary tract and how dysfunction arises in disease states. We systematically quantified pudendal afferent responses to fluid flow in the urethra in vivo in the rat. We characterized the sensory response across a range of stimuli, and describe a previously unreported long-term neural accommodation phenomenon. We developed and validated a compact mechanistic mathematical model capable of reproducing the pudendal sensory activity in response to arbitrary profiles of urethral flows. These results describe the properties and function of urethral afferents that are necessary to understand how sensory disruption manifests in lower urinary tract pathophysiology. Key points Sensory information from the urethra is essential to maintain continence and to achieve efficient micturition and when compromised by disease or injury can lead to substantial loss of function. Despite the key role urethral sensory information plays in the lower urinary tract, the relationship between physiological urethral stimuli, such as fluid flow, and the neural sensory response is poorly understood. This work systematically quantifies pudendal afferent responses to a range of fluid flows in the urethra in vivo and describes a previously unknown long-term neural accommodation phenomenon in these afferents. We present a compact mechanistic mathematical model that reproduces the pudendal sensory activity in response to urethral flow. These results have implications for understanding urinary tract dysfunction caused by neuropathy or nerve damage, such as urinary retention or incontinence, as well as for the development of strategies to mitigate the symptoms of these conditions. PMID:26041695

Correlation between afferent rearrangements and behavioral deficits after local excitotoxic insult in the mammalian vestibule: a rat model of vertigo symptoms.

PubMed

Gaboyard-Niay, Sophie; Travo, Cécile; Saleur, Aurélie; Broussy, Audrey; Brugeaud, Aurore; Chabbert, Christian

2016-10-01

Damage to inner ear afferent terminals is believed to result in many auditory and vestibular dysfunctions. The sequence of afferent injuries and repair, as well as their correlation with vertigo symptoms, remains poorly documented. In particular, information on the changes that take place at the primary vestibular endings during the first hours following a selective insult is lacking. In the present study, we combined histological analysis with behavioral assessments of vestibular function in a rat model of unilateral vestibular excitotoxic insult. Excitotoxicity resulted in an immediate but transient alteration of the balance function that was resolved within a week. Concomitantly, vestibular primary afferents underwent a sequence of structural changes followed by spontaneous repair. Within the first two hours after the insult, a first phase of pronounced vestibular dysfunction coincided with extensive swelling of afferent terminals. In the next 24 h, a second phase of significant but incomplete reduction of the vestibular dysfunction was accompanied by a resorption of swollen terminals and fiber retraction. Eventually, within 1 week, a third phase of complete balance restoration occurred. The slow and progressive withdrawal of the balance dysfunction correlated with full reconstitution of nerve terminals. Competitive re-innervation by afferent and efferent terminals that mimicked developmental synaptogenesis resulted in full re-afferentation of the sensory epithelia. By deciphering the sequence of structural alterations that occur in the vestibule during selective excitotoxic impairment, this study offers new understanding of how a vestibular insult develops in the vestibule and how it governs the heterogeneity of vertigo symptoms. © 2016. Published by The Company of Biologists Ltd.

Extralaryngeal division of the recurrent laryngeal nerve: a new description for the inferior laryngeal nerve.

PubMed

Yalcin, Bulent; Tunali, Selcuk; Ozan, Hasan

2008-05-01

Extralaryngeal division of the recurrent laryngeal nerve was contradictory in the literature. We aimed to investigate extralaryngeal division of the nerve, and also propose a new description for the inferior laryngeal nerve. Sixty specimens (120 sides) were examined for this project, including 41 men and 19 women cadavers between the ages of 40 and 89 years at death. In one right side, terminal segment of the nerve gave off many small branches surrounding the inferior thyroid artery then reaching the larynx, trachea, thyroid gland and esophagus. In eight sides, terminal segment of the nerve had no extralaryngeal division and entered the larynx as a single trunk. In 110 sides, the nerve had extralaryngeal division. One hundred and three nerves had two laryngeal and one to three extralaryngeal branches. Two types were described in this group. In type I (66 nerves), both branches arose from the same level of nerve. Type I had two subtypes: type Ia, the origin of the branches was just below the inferior constrictor muscle; type Ib, the origin of the branches was 15-35 mm below the muscle. In type II (37 nerves), the laryngeal branches arose just 3-5 mm above the extralaryngeal branches. We observed that the laryngeal and extralaryngeal branches arose generally from the same point of the recurrent laryngeal nerve. The inferior laryngeal nerve is thus very short, or even nonexistent. Therefore, we suggest that if the term "superior laryngeal nerve" is a given, standard, and accepted term, then the term "inferior laryngeal nerve" should also be accepted instead of the term "recurrent laryngeal nerve."

Prevalence of the accessory deep peroneal nerve: A cadaveric study and meta-analysis.

PubMed

Tomaszewski, Krzysztof A; Roy, Joyeeta; Vikse, Jens; Pękala, Przemysław A; Kopacz, Paweł; Henry, Brandon Michael

2016-05-01

The accessory deep peroneal nerve (ADPN) is a common anatomical variant arising from the superficial peroneal nerve (SPN) and, when present, is often responsible for partial or complete innervation of the extensor digitorum brevis muscle (EDBM). The nerve lies posterior to the peroneus brevis muscle, traveling posterior to the lateral malleolus to terminate in the ankle by giving off sensory branches to the ankle and joints. Although the EDBM is usually supplied by the deep peroneal nerve (DPN), in the presence of an ADPN, electrodiagnostic procedures may be complicated. Due to the lack of detailed anatomical knowledge on the topography of the ADPN, its presence posterior to the lateral malleolus can be iatrogenically injured during surgical procedures on the ankle using a lateral approach. Therefore, this meta-analysis aimed to provide a comprehensive, evidence-based assessment of the anatomical characteristics of the ADPN, supplemented with data from our own cadaveric dissection. A comprehensive search of all major electronic databases, including Pubmed, Embase, Scopus, Web of Science, ScienceDirect, SciELO, and BIOSIS was performed. All articles with data on prevalence, symmetry and innervation of the EDBM by the ADPN were included. The anatomical data was then extracted and pooled into a meta-analysis using MetaXL 2.0. In addition, we dissected 21 cadavers (n=42 lower limbs) bilaterally to find the ADPN. A total of 19 studies (n=6070 lower limbs) were included in the meta-analysis. The pooled prevalence of the ADPN was 18.8% (95%CI:14.2-24.0) with a 39.3% prevalence rate for cadaveric studies. The ADPN was present more commonly unilaterally (67.0%) and when it was present, provided branches to the EDBM in 79.5% of cases. In our cadaveric study, the ADPN was identified in 5 of the 42 lower limbs dissected (11.9%); on the right side in 3 lower limbs and on the left side in 2 lower limbs. The ADPN is a clinically important nerve and has been inculpated in unexplained cases of chronic ankle pain and EDBM atrophy. The variability in detection of the ADPN using electrophysiological techniques can lead to misdiagnoses of peroneal nerve lesions and increase the risk for iatrogenic injury to the ADPN, especially in laterally approaching ankle procedures and sural nerve biopsies. Copyright © 2016 Elsevier B.V. All rights reserved.

Surgical Approaches to Facial Nerve Deficits

PubMed Central

Birgfeld, Craig; Neligan, Peter

2011-01-01

The facial nerve is one of the most commonly injured cranial nerves. Once injured, the effects on form, function, and psyche are profound. We review the anatomy of the facial nerve from the brain stem to its terminal branches. We also discuss the physical exam findings of facial nerve injury at various levels. Finally, we describe various reconstructive options for reanimating the face and restoring both form and function. PMID:22451822

Peripheral nerve conduits: technology update

PubMed Central

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

2014-01-01

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

Occlusion of carotid artery and hypergravity loading of animals caused similar effects on L-[14C]glutamate uptake in rat brain nerve terminals

NASA Astrophysics Data System (ADS)

Borisova, Tatiana; Sivko, Roman; Krisanova, Natalia

Changes in sodium-dependent L-[14C]glutamate uptake in rat brain nerve terminals was com-paratively analysed after hypergravity loading of animals (centrifugation of rats in special con-tainers at 10 G for 1 hour) and unilateral occlusion of carotid artery (20 min). The initial velocity of L-[14C]glutamate uptake was decreased from 2.5 ± 0.2 nmol x min-1 x mg-1 of proteins to 2.05 ± 0.1 nmol x min-1 x mg-1 of proteins after hypergravity and after occlusion -up to 2.25 ± 0.1 nmol x min-1 x mg-1 of proteins. Recently, we have shown that a decrease in L-[14C]glutamate uptake was at least partially caused by the redaction in the membrane potential of nerve terminals and the proton gradient of synaptic vesicles. These parameters were analysed after unilateral occlusion of carotid artery, where one brain hemisphere was used as a control, whereas the second one as subjected to ischemic/hypoxic conditions. Similarly with hypergravity, we revealed a decrease in the membrane potential of nerve terminals by ˜ 10 % and a reduction of the proton gradient of synaptic vesicles by ˜ 5 % after occlusion of carotid artery. Thus, a decrease in the activity of glutamate transporters after hypergrav-ity and unilateral occlusion of carotid artery was at least partially caused by changes in the membrane potential of nerve terminals and the proton gradient of synaptic vesicles. This fact may be considered in support of the suggestion that ischemia/hypoxia was a main unspecific stressor, which caused the alterations in glutamatergic neurotransmission under conditions of hypergravity.

Heteroreceptors Modulating CGRP Release at Neurovascular Junction: Potential Therapeutic Implications on Some Vascular-Related Diseases.

PubMed

González-Hernández, Abimael; Marichal-Cancino, Bruno A; Lozano-Cuenca, Jair; López-Canales, Jorge S; Muñoz-Islas, Enriqueta; Ramírez-Rosas, Martha B; Villalón, Carlos M

2016-01-01

Calcitonin gene-related peptide (CGRP) is a 37-amino-acid neuropeptide belonging to the calcitonin gene peptide superfamily. CGRP is a potent vasodilator with potential therapeutic usefulness for treating vascular-related disease. This peptide is primarily located on C- and A δ -fibers, which have extensive perivascular presence and a dual sensory-efferent function. Although CGRP has two major isoforms ( α -CGRP and β -CGRP), the α -CGRP is the isoform related to vascular actions. Release of CGRP from afferent perivascular nerve terminals has been shown to result in vasodilatation, an effect mediated by at least one receptor (the CGRP receptor). This receptor is an atypical G-protein coupled receptor (GPCR) composed of three functional proteins: (i) the calcitonin receptor-like receptor (CRLR; a seven-transmembrane protein), (ii) the activity-modifying protein type 1 (RAMP1), and (iii) a receptor component protein (RCP). Although under physiological conditions, CGRP seems not to play an important role in vascular tone regulation, this peptide has been strongly related as a key player in migraine and other vascular-related disorders (e.g., hypertension and preeclampsia). The present review aims at providing an overview on the role of sensory fibers and CGRP release on the modulation of vascular tone.