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1

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

PubMed Central

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

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

2013-01-01

2

Impaired sensory nerve function and axon morphology in mice with diabetic neuropathy  

PubMed Central

Diabetes is the most prevalent metabolic disorder in the United States, and between 50% and 70% of diabetic patients suffer from diabetes-induced neuropathy. Yet our current knowledge of the functional changes in sensory nerves and their distal terminals caused by diabetes is limited. Here, we set out to investigate the functional and morphological consequences of diabetes on specific subtypes of cutaneous sensory nerves in mice. Diabetes was induced in C57Bl/6 mice by a single intraperitoneal injection of streptozotocin. After 6–8 wk, mice were characterized for behavioral sensitivity to mechanical and heat stimuli followed by analysis of sensory function using teased nerve fiber recordings and histological assessment of nerve fiber morphology. Diabetes produced severe functional impairment of C-fibers and rapidly adapting A?-fibers, leading to behavioral hyposensitivity to both mechanical and heat stimuli. Electron microscopy images showed that diabetic nerves have axoplasm with more concentrated organelles and frequent axon-myelin separations compared with control nerves. These changes were restricted to the distal nerve segments nearing their innervation territory. Furthermore, the relative proportion of A?-fibers was reduced in diabetic skin-nerve preparations compared with nondiabetic control mice. These data identify significant deficits in sensory nerve terminal function that are associated with distal fiber loss, morphological damage, and behavioral hyposensitivity in diabetic C57Bl/6 mice. These findings suggest that diabetes damages sensory nerves, leading to functional deficits in sensory signaling that underlie the loss of tactile acuity and pain sensation associated with insensate diabetic neuropathy.

Lennertz, Richard C.; Medler, Karen A.; Bain, James L.; Wright, Douglas E.

2011-01-01

3

Peripheral nerve damage facilitates functional innervation of brain grafts in adult sensory cortex.  

PubMed Central

The neural pathways that relay information from cutaneous receptors to the cortex provide the somatic sensory information needed for cortical function. The last sensory relay neurons in this pathway have cell bodies in the thalamus and axons that synapse on neurons in the somatosensory cortex. After cortical lesions that damage mature thalamocortical fibers in the somatosensory cortex, we have attempted to reestablish somatosensory cortical function by grafting embryonic neocortical cells into the lesioned area. Such grafts survive in adult host animals but are not innervated by thalamic neurons, and consequently the grafted neurons show little if any spontaneous activity and no responses to cutaneous stimuli. We have reported that transection of peripheral sensory nerves prior to grafting "conditions" or "primes" the thalamic neurons in the ventrobasal complex so that they extend axons into grafts subsequently placed in the cortical domain of the cut nerve. In this report we present evidence that the ingrowth of ventrobasal fibers leads to graft neurons that become functionally integrated into the sensory circuitry of the host brain. Specifically, the conditioning lesions made prior to grafting produce graft neurons that are spontaneously active and can be driven by natural activation of cutaneous receptors or electrical stimulation of the transected nerve after it regenerates. Furthermore, oxidative metabolism in these grafts reaches levels that are comparable to normal cortex, whereas without prior nerve cut, oxidative metabolism is abnormally low in neocortical grafts. We conclude that damage to the sensory periphery transsynaptically stimulates reorganization of sensory pathways through mechanisms that include axonal elongation and functional synaptogenesis. Images

Ebner, F F; Erzurumlu, R S; Lee, S M

1989-01-01

4

Median Nerve Mistaken for Palmaris Longus Tendon: Restoration of Function with Sensory Nerve Transfers  

Microsoft Academic Search

Intraoperative iatrogenic nerve injuries occur despite vigilance in the operating room. Most of these injuries occur as a\\u000a result of patient positioning, traction or pressure injury, hematoma, or technical error. The median nerve is especially susceptible\\u000a to injury during carpal tunnel release. A rare but devastating injury of the median nerve is complete transection. The number\\u000a of devastating injuries is

Renata V. Weber; Susan E. Mackinnon

2007-01-01

5

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

PubMed

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

Fernandes, E S; Fernandes, M A; Keeble, J E

2012-05-01

6

Temporary Sensory Protection of Denervated and Skeletal Muscle: A Quantitative Ultrastructural and Functional Assessment of Nerve and Muscle  

Microsoft Academic Search

Peripheral nerve injuries have a devastating impact on muscle function due to the distance the axons must regenerate to reinnervate the target muscle. By the time the axons reinnervate the muscle, it has strophied and lost itself receptiveness resulting in impaired function. The objective of this study was to answer the following questions: 1. Do sensory axons delay muscle atrophy

Karen Lynn Veltri

2003-01-01

7

Temporary sensory protection of denervated skeletal muscle: A quantitative ultrastructural and functional assessment of nerve and muscle  

Microsoft Academic Search

Peripheral nerve injuries have a devastating impact on muscle function due to the distance the axons must regenerate to reinnervate the target muscle. By the time the axons reinnervate the muscle, it has atrophied and lost its receptiveness resulting in impaired function. The objective of this study was to answer the following questions: (1) Do sensory axons delay muscle atrophy

Karen Lynn Veltri

2003-01-01

8

Sensory nerves in lung and airways.  

PubMed

Sensory nerves innervating the lung and airways play an important role in regulating various cardiopulmonary functions and maintaining homeostasis under both healthy and disease conditions. Their activities conducted by both vagal and sympathetic afferents are also responsible for eliciting important defense reflexes that protect the lung and body from potential health-hazardous effects of airborne particulates and chemical irritants. This article reviews the morphology, transduction properties, reflex functions, and respiratory sensations of these receptors, focusing primarily on recent findings derived from using new technologies such as neural immunochemistry, isolated airway-nerve preparation, cultured airway neurons, patch-clamp electrophysiology, transgenic mice, and other cellular and molecular approaches. Studies of the signal transduction of mechanosensitive afferents have revealed a new concept of sensory unit and cellular mechanism of activation, and identified additional types of sensory receptors in the lung. Chemosensitive properties of these lung afferents are further characterized by the expression of specific ligand-gated ion channels on nerve terminals, ganglion origin, and responses to the action of various inflammatory cells, mediators, and cytokines during acute and chronic airway inflammation and injuries. Increasing interest and extensive investigations have been focused on uncovering the mechanisms underlying hypersensitivity of these airway afferents, and their role in the manifestation of various symptoms under pathophysiological conditions. Several important and challenging questions regarding these sensory nerves are discussed. Searching for these answers will be a critical step in developing the translational research and effective treatments of airway diseases. PMID:24692141

Lee, Lu-Yuan; Yu, Jerry

2014-01-01

9

Sensory nerves have altered function contralateral to a monoarthritis and may contribute to the symmetrical spread of inflammation  

PubMed Central

Rheumatoid arthritis (RA) and rat models of RA exhibit symmetrical mirror-image spread. Many studies have sought to understand the underlying mechanisms and have reported contralateral effects that are manifested in many different forms. It is now well accepted that neurogenic mechanisms contribute to the symmetrical spread of inflammation. However, very few investigators have directly assessed changes in contralateral nerve function and there is a paucity of data. In the present study our aim was to investigate whether there are changes, in particular in the nervous system but also in the vascular system contralateral to an inflamed rat knee joint, that might precede overt inflammation and symmetrical spread. Three to five days following Complete Freund's Adjuvant (CFA) injection we found spontaneous antidromic (away from the CNS) activity in the homologous sensory nerve contralateral to the inflamed joint. Antidromic activity of this nature is known to result in the peripheral release of pro-inflammatory and vasoactive neuropeptides. Importantly, this activity was modulated by systemic analgesic treatment. Furthermore, levels of Evans blue dye extravasation were significantly increased in the joint contralateral to inflammation, indicating altered vascular function. These data suggest that contralateral increases in sensory neural activity and vascular function may account for the symmetrical spread of RA, and that early analgesic treatment may prevent or delay the spread of this debilitating disease.

Kelly, Sara; Dunham, James Philip; Donaldson, Lucy Frances

2007-01-01

10

Refractory Period in Human Sensory Nerve Fibres  

Microsoft Academic Search

Relative and absolute refractory periods were determined in sensory fibres of 24 median nerves and in 19 sural nerves of 30 volunteers aged 20–60 years, who had no sign of a neuromuscular disorder. The critical interval of conduction (absolute refractory period) was found to be about 0.7 msec. In median as well as in sural nerve the relative refractory periods

W. Tackmann; H. J. Lehmann

1974-01-01

11

Mapping sensory nerve communications between peripheral nerve territories.  

PubMed

The human cutaneous sensory map has been a work in progress over the past century, depicting sensory territories supplied by both the spinal and cranial nerves. Two critical discoveries, which shaped our understanding of cutaneous innervation, were sensory dermatome overlap between contiguous spinal levels and axial lines across areas where no sensory overlap exists. These concepts define current dermatome maps. We wondered whether the overlap between contiguous sensory territories was even tighter: if neural communications were present in the peripheral nerve territories consistently connecting contiguous spinal levels? A literature search using peer-reviewed articles and established anatomy texts was performed aimed at identifying the presence of communications between sensory nerves in peripheral nerve territories and their relationship to areas of adjacent and non-adjacent spinal or cranial nerves and axial lines (lines of discontinuity) in the upper and lower limbs, trunk and perineum, and head and neck regions. Our findings demonstrate the consistent presence of sensory nerve communications between peripheral nerve territories derived from spinal nerves within areas of axial lines in the upper and lower limbs, trunk and perineum, and head and neck. We did not find examples of communications crossing axial lines in the limbs or lines of discontinuity in the face, but did find examples crossing axial lines in the trunk and perineum. Sensory nerve communications are common. They unify concepts of cutaneous innervation territories and their boundaries, and refine our understanding of the sensory map of the human skin. Clin. Anat. 27:681-690, 2014. © 2013 Wiley Periodicals, Inc. PMID:23824984

Ladak, Adil; Tubbs, R Shane; Spinner, Robert J

2014-07-01

12

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

PubMed

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

Spina, D; Page, C P

2013-10-01

13

Antidromic sensory nerve conduction study of the digital branches of the medial plantar nerve: A novel method to detect early diabetic sensory axonal polyneuropathy.  

PubMed

Introduction: Distal sensory neuropathy is the most common form of diabetic neuropathy. We developed a novel antidromic technique for assessment of distal nerve function for early diagnosis of diabetic neuropathy. Methods: Diabetic and control groups underwent standard and more distal sensory nerve conduction studies (NCS); sensory nerve action potentials (SNAPs) of the proper digital branches of the medial plantar nerve were recorded with our method after stimulation at the sole and recording from digits I and II. Results: Comparison between controls and diabetics showed a statistically significant difference in mean SNAP amplitudes for all nerves tested. A higher percentage of abnormal SNAPs was obtained with our technique than with either conventional or more distal NCS in all patients. Conclusions: As compared with clinical evaluation and other NCS, our antidromic stimulation was the most sensitive method to detect abnormal sensory nerve conduction in symptomatic and asymptomatic diabetic patients. Muscle Nerve 50:193-199, 2014. PMID:24282067

Squintani, Giovanna; Zoppini, Giacomo; Donato, Francesco; Pineschi, Elena; Donini, Diana; Stoico, Vincenzo; Moretto, Giuseppe; Bonora, Enzo; Morini, Alberto

2014-08-01

14

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

PubMed Central

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?sensory fibers in the median, ulnar and radial nerves. Less apparent were losses in conduction speed or sensory perception.

2012-01-01

15

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

Microsoft Academic Search

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

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

1992-01-01

16

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

PubMed Central

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

Shepherd, Andrew J.; Mohapatra, Durga P.

2012-01-01

17

Patterns of slow transport in sensory nerves  

SciTech Connect

An examination of the pattern of outflow of radioactivity in sciatic nerves was made at times from 1 to 82 days in the rat and up to 132 days in the cat after injecting the L5 and L7 dorsal root ganglia, respectively, with 3H-leucine. Slow waves moving at a rate of 1-2 mm/day were looked for on the basis of their reported presence in the motor fibers of the rat. A consistent pattern of slow waves was not seen in the cat or rat sensory fibers of the sciatic nerves nor was evidence of a slow wave found in the cat dorsal columns. Irregularities in the pattern of outflow which at times appeared as waves did so in an irregular fashion, a pattern inconsistent with a steady progression of slow waves in the fibers. The decrease of radioactivity appearing first near the ganglia helps create the impression of a wave along with irregular decreases in the overall levels of radio-activity with time. The results were explained on the basis of the unitary hypothesis. The labeled components are considered to be moved down the fiber by the fast transport mechanism, those components dropping off locally in the fibers early on, constituting the slow wave. As those components turn over locally in the various organelles of fiber and are further redistributed, they may at times give rise to what appears as waves.

Stromska, D.P.; Ochs, S.

1981-09-01

18

Sensory Nerve Terminal Mitochondrial Dysfunction Activates Airway Sensory Nerves via Transient Receptor Potential (TRP) Channels  

PubMed Central

Mitochondrial dysfunction and subsequent oxidative stress has been reported for a variety of cell types in inflammatory diseases. Given the abundance of mitochondria at the peripheral terminals of sensory nerves and the sensitivity of transient receptor potential (TRP) ankyrin 1 (A1) and TRP vanilloid 1 (V1) to reactive oxygen species (ROS) and their downstream products of lipid peroxidation, we investigated the effect of nerve terminal mitochondrial dysfunction on airway sensory nerve excitability. Here we show that mitochondrial dysfunction evoked by acute treatment with antimycin A (mitochondrial complex III Qi site inhibitor) preferentially activated TRPA1-expressing “nociceptor-like” mouse bronchopulmonary C-fibers. Action potential discharge was reduced by the TRPA1 antagonist HC-030031. Inhibition of TRPV1 further reduced C-fiber activation. In mouse dissociated vagal neurons, antimycin A induced Ca2+ influx that was significantly reduced by pharmacological inhibition or genetic knockout of either TRPA1 or TRPV1. Inhibition of both TRPA1 and TRPV1 was required to abolish antimycin A-induced Ca2+ influx in vagal neurons. Using an HEK293 cell expression system, antimycin A induced concentration-dependent activation of both hTRPA1 and hTRPV1 but failed to activate nontransfected cells. Myxothiazol (complex III Qo site inhibitor) inhibited antimycin A-induced TRPA1 activation, as did the reducing agent dithiothreitol. Scavenging of both superoxide and hydrogen peroxide inhibited TRPA1 activation following mitochondrial modulation. In conclusion, we present evidence that acute mitochondrial dysfunction activates airway sensory nerves preferentially via TRPA1 through the actions of mitochondrially-derived ROS. This represents a novel mechanism by which inflammation may be transduced into nociceptive electrical signaling.

Nesuashvili, Lika; Hadley, Stephen H.; Bahia, Parmvir K.

2013-01-01

19

Comparison of skin barrier function and sensory nerve electric current perception threshold between IgE-high extrinsic and IgE-normal intrinsic types of atopic dermatitis.  

PubMed

Background Two types of atopic dermatitis (AD) have been proposed, with different pathophysiological mechanisms underlying this seemingly heterogeneous disorder. The extrinsic type shows high IgE levels presumably as a consequence of skin barrier damage and feasible allergen permeation, whereas the intrinsic type exhibits normal IgE levels and is not mediated by allergen-specific IgE. Objectives To investigate the relationship between pruritus perception threshold and skin barrier function of patients with AD in a comparison between the extrinsic and intrinsic types. Methods Enrolled in this study were 32 patients with extrinsic AD, 17 with intrinsic AD and 24 healthy individuals. The barrier function of the stratum corneum was assessed by skin surface hydration and transepidermal water loss (TEWL), and pruritus perception was evaluated by the electric current perception threshold (CPT) of sensory nerves upon neuroselective transcutaneous electric stimulation. Results Skin surface hydration was significantly lower and TEWL was significantly higher in extrinsic AD than intrinsic AD or normal controls. Although there was no statistically significant difference in CPT among extrinsic AD, intrinsic AD and normal controls, CPT was significantly correlated with skin surface hydration and inversely with TEWL in intrinsic AD and normal controls, but not extrinsic AD. Finally, CPT was correlated with the visual analogue scale of itch in the nonlesional skin of patients with extrinsic but not intrinsic AD. Conclusions Patients with extrinsic AD have an impaired barrier, which increases the pre-existing pruritus but rather decreases sensitivity to external stimuli. In contrast, patients with intrinsic AD retain a normal barrier function and sensory reactivity to external pruritic stimuli. PMID:19785593

Mori, T; Ishida, K; Mukumoto, S; Yamada, Y; Imokawa, G; Kabashima, K; Kobayashi, M; Bito, T; Nakamura, M; Ogasawara, K; Tokura, Y

2010-01-01

20

Sensory capacity of reinnervated skin after redirection of amputated upper limb nerves to the chest  

Microsoft Academic Search

Targeted reinnervation is a new neural-machine interface that has been developed to help improve the function of new- generation prosthetic limbs. Targeted reinnervation is a surgical procedure that takes the nerves that once innervated a severed limb and redirects them to proximal muscle and skin sites. The sensory afferents of the redirected nerves reinnervate the skin overlying the transfer site.

Paul D. Marasco; Aimee E. Schultz; Todd A. Kuiken

2009-01-01

21

A reversible functional sensory neuropathy model.  

PubMed

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

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

2014-06-13

22

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

PubMed Central

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

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

2013-01-01

23

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

PubMed

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

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

2013-01-01

24

Sensory recovery after microsurgical repair of digital nerves.  

PubMed

The authors study 65 cases of repair of digital nerve lesions performed in 60 patients. They evaluate the quality of sensory recovery by clinical (Dellon and Weber Tests) and electrophysiological tests (velocity, amplitude and duration of the Compound Sensory Action Potential). The results show a complete recovery in 26%, a recovery of discrimination sensitivity in 73.8% and a recovery of protective sensation in 96.9% of the cases. Age and severity of the associated trauma are the most important factors influencing the quality of the sensory recovery. PMID:7846993

Vertruyen, M F; Burgeon, M A; Dachy, B S; Ley, R E

1994-01-01

25

Sensory nerves mediate neurogenic escape in rat gut.  

PubMed

We investigated the involvement of primary sensory nerves in intestinal autoregulatory escape induced by postganglionic nerve stimulation (NS) in anesthetized rats. Anterior mesenteric artery (AMA) blood flow velocity (BF) was measured with a pulsed Doppler flowmeter. Periarterial NS elicited an abrupt fall in BF, which was followed by a recovery in BF toward the basal value, despite sustained NS. This recovery from NS constituted the neurogenic escape phenomenon. Vasoconstrictor responses to NS were abolished by periarterial application of tetrodotoxin. Acute, surgical interruption of proximal periarterial nerves had no effect on BF responses to distal NS, suggesting a peripheral rather than a central nervous mechanism for the escape phenomenon. Escape from NS-induced vasoconstriction was significantly inhibited by prior administration of the selective sensory neurotoxin capsaicin as either subcutaneous injection in neonatal life, acute application to periarterial nerves, or acute injection into the jejunal lumen. In rats pretreated 24 h with reserpine, NS provoked a vasodilator response that was inhibited by intrajejunal capsaicin. Increases in arterial blood pressure (BP) and heart rate observed during NS were blocked by periarterial (but not intrajejunal) application of capsaicin. Transmural electrical field stimulation elicited significantly greater nerve-induced contractions in AMA rings from control rats. Our findings support the hypothesis that postganglionic NS activates both vasoconstrictor sympathetic nerve branches and vasodilator afferent C-fibers. The latter nerves release vasodilator peptides in the periphery during continuous low frequency NS that appear to be essential for autoregulatory escaped in our model. PMID:2316694

Remak, G; Hottenstein, O D; Jacobson, E D

1990-03-01

26

The radial sensory nerve. An anatomic study.  

PubMed

The superficial branch of the radial nerve was dissected using loupe magnification in 20 cadaver forearms. The nerve was found to arise between the tendons of the branchioradialis and extensor carpi radialis longus 8.6 cm proximal to the radial styloid, piercing the forearm fascia 6.0 cm from the radial styloid. An average of 5.8 branches crossed the wrist joint. Innervation to the dorsum of the digits was variable, with 45% of specimens innervating the radial 2 1/2 digits and 30% innervating the radial 3 1/2 digits. Sixteen specimens had branches directly overlying the typical transverse incision for De Quervain's release and 12 specimens had branches directly overlying the 3-4 wrist arthroscopy portal. An appreciation for the location of the superficial radial nerve in the forearm, the variation of its digital innervation, and the proximity of branches to commonly used surgical incisions is important when performing surgical procedures over the dorsum of the hand and wrist. PMID:7955689

Auerbach, D M; Collins, E D; Kunkle, K L; Monsanto, E H

1994-11-01

27

Local substitution of GDF-15 improves axonal and sensory recovery after peripheral nerve injury.  

PubMed

The growth/differentiation factor-15, GDF-15, has been found to be secreted by Schwann cells in the lesioned peripheral nervous system. To investigate whether GDF-15 plays a role in peripheral nerve regeneration, we substituted exogenous GDF-15 into 10-mm sciatic nerve gaps in adult rats and compared functional and morphological regeneration to a vehicle control group. Over a period of 11 weeks, multiple functional assessments, including evaluation of pinch reflexes, the Static Sciatic Index and of electrophysiological parameters, were performed. Regenerated nerves were then morphometrically analyzed for the number and quality of regenerated myelinated axons. Substitution of GDF-15 significantly accelerated sensory recovery while the effects on motor recovery were less strong. Although the number of regenerated myelinated axons was significantly reduced after GDF-15 treatment, the regenerated axons displayed advanced maturation corroborating the results of the functional assessments. Our results suggest that GDF-15 is involved in the complex orchestration of peripheral nerve regeneration after lesion. PMID:22955564

Mensching, Leonore; Börger, Ann-Kathrin; Wang, Xialong; Charalambous, Petar; Unsicker, Klaus; Haastert-Talini, Kirsten

2012-11-01

28

Functional Reorganization in Somatosensory Cortical Areas 3b and 1 of Adult Monkeys After Median Nerve Repair: Possible Relationships to Sensory Recovery in Humans  

Microsoft Academic Search

Previous studies have shown that the primary somatosensory cortex of adult mammals undergoes somatotopic reorganization in response to peripheral nerve transection. The present study assesses how cortical organization is affected when a transected nerve subsequently regenerates. The median nerve to one hand of adult owl monkeys was transected and repaired. Following nerve regeneration, the representations of the hand in cortical

John T. Wall; Jon H. Kaas; Mriganka Sur; Randall J. Nelson; Daniel J. Felleman; Michael M. Merzenich

29

Motor, sensory and autonomic nerve terminals containing NAP-22 immunoreactivity in the rat muscle.  

PubMed

Neuron-enriched acidic protein having a molecular mass of 22 kDa, NAP-22, is a Ca(2+)-dependent calmodulin-binding protein and is phosphorylated with protein kinase C (PKC). This protein is localized to the biological membrane via myristoylation and found in the membrane fraction of the brain and in the synaptic vesicle fraction. Recent studies showed that NAP-22 is localized in the membrane raft domain in a cholesterol-dependent manner and suggest a role for NAP-22 in maturation and/or maintenance of nerve terminals by controlling cholesterol-dependent membrane dynamics. The present study revealed the immunohistochemical distribution of NAP-22 in the peripheral nerves in rat muscles. In all examined muscles, nerve terminals in the motor endplates showed NAP-22 immunoreactivity associated with the membranes of synaptic vesicles and nerve terminals. In the muscle spindles, annulospiral endings, which made spirals around the intrafusal muscles, showed intense NAP-22 immunoreactivity. Autonomic nerve fibers around the intramuscular blood vessels also showed the immunoreactivity for NAP-22. NAP-22 immunoreactivity in these peripheral nerves was observed from birth to adulthood (100 days after birth). Though growth-associated protein-43 (GAP-43) immunoreactivity in these nerves was observed from birth, this immunoreactivity decreased from 20 days after birth. These findings suggest that NAP-22 is distributed and regulates functions in the motor, sensory and autonomic nerve terminals in the peripheral nervous system. PMID:14988044

Iino, Satoshi; Taguchi, Katsutoshi; Maekawa, Shohei; Nojyo, Yoshiaki

2004-03-26

30

Altered Temperature and Taste Responses from Cross-Regenerated Sensory Nerves in the Rat'S Tongue.  

National Technical Information Service (NTIS)

The paper examines electrophysiological changes associated with regeneration of a tongue sensory nerve to a different part of the tongue. Normally, the chorda tympani nerve innervates the anterior two thirds of the rat tongue and the IXth (glossopharyngea...

B. Oakley

1966-01-01

31

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

PubMed

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. PMID:3681311

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

1987-10-01

32

Uses of Skin Biopsy for Sensory and Autonomic Nerve Assessment  

PubMed Central

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

Myers, M. Iliza; Peltier, Amanda C.

2013-01-01

33

Long interpositional nerve graft consistently induces incomplete motor and sensory recovery in the rat  

Microsoft Academic Search

Motor and sensory regeneration was studied in a 40mm long graft interposed between the sectioned stumps of the rat median nerve. Animals were behaviorally assessed from 1 to 720 days after surgery by the grasping and modified Randall–Sellito tests. Rats recovered grasping function 43.7 (S.D.±2.6) days after surgery. Grasping strength attained 50 and 65% of the normal control group, 280

Jayme Augusto Bertelli; Adair Roberto Soares dos Santos; Madjid Taleb; João Batista Calixto; Jean Claude Mira; Marcos Flávio Ghizoni

2004-01-01

34

Functions of the Renal Nerves.  

ERIC Educational Resources Information Center

Discusses renal neuroanatomy, renal vasculature, renal tubules, renin secretion, renorenal reflexes, and hypertension as related to renal nerve functions. Indicates that high intensitites of renal nerve stimulation have produced alterations in several renal functions. (A chart with various stimulations and resultant renal functions and 10-item,…

Koepke, John P.; DiBona, Gerald F.

1985-01-01

35

Different multiple regeneration capacities of motor and sensory axons in peripheral nerve.  

PubMed

After peripheral nerve injury, axons often project sprouts from the node of Ranvier proximal to the damage site. It is well known that one parent axon can sprout and maintain several regenerating axons. If enough endoneurial tubes in the distal stump are present for the regenerating axons to grow along, then the number of mature myelinated nerve fibers in the distal stump will be greater than the number in the proximal stump. "Multiple regeneration" is used to describe this phenomenon in the peripheral nerve. According to previous studies, a prominent nerve containing many axons can be repaired by the multiple regenerating axons sprouting from another nerve that contains fewer axons. Most peripheral nerves contain a mixture of myelinated motor and sensory axons as well as unmyelinated sensory and autonomic axons. In this study, a multiple regeneration animal model was developed by bridging the proximal common peroneal nerve with the distal common peroneal nerve and the tibial nerve. Differences in the multiple regeneration ratio of motor and sensory nerves were evaluated using histomorphometry one month after ablating the dorsal root ganglion (DRGs) and ventral roots, respectively. The results suggest that the motor nerves have a significantly larger multiple regeneration ratio than the sensory nerves at two different time points. PMID:22409279

Jianping, Peng; Xiaofeng, Yin; Yanhua, Wang; Zhenwei, Wang; Yuhui, Kou; Chungui, Xu; Peixun, Zhang; Baoguo, Jiang

2012-10-01

36

The effect of nerve growth factor on developing primary sensory neurons of the trigeminal nerve in chick embryos  

Microsoft Academic Search

The response to nerve growth factor (NGF) of two sensory neuron populations of the trigeminal nerve was studied in chick embryos. NGF promoted neuronal survival and cellular hypertrophy in the Gasserian ganglia with minimal effect on the neuron population of the mesencephalic trigeminal nucleus. NGF induced prolific neurite outgrowth from cultured Gasserian ganglia, in contrast, cultured mesencephalic trigeminal neurons remained

Charles Straznicky; Robert A. Rush

1985-01-01

37

The sensory branch distribution of the suprascapular nerve: an anatomic study.  

PubMed

The suprascapular nerve is responsible for most of the sensory innervation to the shoulder joint and is potentially at risk during surgery. In this study, 31 shoulders in 22 cadavers were dissected to investigate the sensory innervation of the shoulder joint by the suprascapular nerve, with special reference to its sensory branches. In 27 shoulders (87.1%), a small sensory branch was observed that splits off from the main stem of the suprascapular nerve proximal (48.2%), inferior (40.7%), or distal (11.1%) to the transverse scapular ligament. This percentage is considerably higher than has been previously found. In 74.2% of the shoulders, an acromial branch was also found, originating just proximal to the scapular neck, running to the infraspinatus tendon. These cadaveric results indicate that sensory branches to the shoulder joint are more common and numerous than previously described and therefore should be considered in shoulder surgery and nerve blocks to this area. PMID:18262803

Vorster, Willie; Lange, Christopher P E; Briët, Robert J P; Labuschagne, Barend C J; du Toit, Don F; Muller, Christo J F; de Beer, Joe F

2008-01-01

38

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

PubMed Central

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.

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

2013-01-01

39

Peripheral Nerve Injuries: A Comparative Study of the Anatomical and Functional Results Following Primary Nerve Repair in Chimpanzees.  

National Technical Information Service (NTIS)

Six techniques of nerve repair were compared with respect to their morphologic findings and ultimate motor and sensory function. Only when the nerve repair was encased in a thin and elastic tube of Silastic approximately 1 cm in length and with an interna...

T. B. Ducker G. J. Hayes

1968-01-01

40

Sensory nerves, neurogenic inflammation and pain: missing components of alternative irritation strategies? A review and a potential strategy.  

PubMed

The eyes and skin are highly innervated by sensory nerves; stimulation of these nerves by irritants may give rise to neurogenic inflammation, leading to sensory irritation and pain. Few in vitro models of neurogenic inflammation have been described in conjunction with alternative skin and eye irritation methods, despite the fact that the sensory innervation of these organs is well-documented. To date, alternative approaches to the Draize skin and eye irritation tests have proved largely successful at classifying severe irritants, but are generally poor at discriminating between agents with mild to moderate irritant potential. We propose that the development of in vitro models for the prediction of sensory stimulation will assist in the re-classification of the irritant potential of agents that are under-predicted by current in vitro strategies. This review describes the range of xenobiotics known to cause inflammation and pain through the stimulation of sensory nerves, as well as the endogenous mediators and receptor types that are involved. In particular, it focuses on the vanilloid receptor, its activators and its regulation, as these receptors function as integrators of responses to numerous noxious stimuli. Cell culture models and ex vivo preparations that have the potential to serve as predictors of sensory irritation are also described. In addition, as readily available sensory neuron cell line models are few in number, stem cell lines (with the capacity to differentiate into sensory neurons) are explored. Finally, a preliminary strategy to enable assessment of whether incorporation of a sensory component will enhance the predictive power of current in vitro eye and skin testing strategies is proposed. PMID:15612874

Garle, Michael J; Fry, Jeffrey R

2003-01-01

41

[Dynamics of restoration of the motor and sensory functions of the upper extremity after suturing].  

PubMed

In 46 patients 63 nerves of upper extremities were sutured and clinico-electroneuromyographic investigations performed. The restitution of motor and sensory functions ran slowly over 7 to 36 months depending on the level injured. Full restoration of motor functions surpassed the restoration of sensory functions in the autonomic zone of the nerve lesioned. Electroneuromyographic investigation showed that clinical healing provides no real indices of the final nerve regeneration as the nervous condition velocity remained altered. This allows recommending nonsurgical treatment for several months after surgery under electroneuromyographic control. PMID:2665400

Kankava, D M; Baratashvili, N N; Kvirkveliia, N B

1989-01-01

42

Proprioceptors and sensory nerves in the legs of a spider, Cupiennius salei (Arachnida, Araneida)  

Microsoft Academic Search

Retrograde CoS-impregnation was used to trace and map the course of sensory nerves and the distribution and innervation of the various proprioceptor types in all leg segments of Cupiennius salei, a Ctenid spider.

Ernst-August Seyfarth; Wolfgang Eckweiler; Klaus Hammer

1985-01-01

43

Superficial radial sensory nerve potentials in immune-mediated and diabetic neuropathies  

Microsoft Academic Search

ObjectiveThe pattern of abnormal median-normal sural sensory nerve action potential (SNAP) is frequently found in acute\\/chronic inflammatory demyelinating polyneuropathy (AIDP\\/CIDP), whereas sural\\/radial SNAP amplitude ratio is sensitive to detect dying-back degeneration. To investigate whether radial SNAP and its amplitude ratio to median or sural SNAP provide additional particular patterns of sensory nerve involvement.

Noriko Tamura; Satoshi Kuwabara; Sonoko Misawa; Masahiro Mori; Miho Nakata; Takamichi Hattori

2005-01-01

44

Sensory capacity of reinnervated skin after redirection of amputated upper limb nerves to the chest  

PubMed Central

Targeted reinnervation is a new neural-machine interface that has been developed to help improve the function of new-generation prosthetic limbs. Targeted reinnervation is a surgical procedure that takes the nerves that once innervated a severed limb and redirects them to proximal muscle and skin sites. The sensory afferents of the redirected nerves reinnervate the skin overlying the transfer site. This creates a sensory expression of the missing limb in the amputee's reinnervated skin. When these individuals are touched on this reinnervated skin they feel as though they are being touched on their missing limb. Targeted reinnervation takes nerves that once served the hand, a skin region of high functional importance, and redirects them to less functionally relevant skin areas adjacent to the amputation site. In an effort to better understand the sensory capacity of the reinnervated target skin following this procedure, we examined grating orientation thresholds and point localization thresholds on two amputees who had undergone the targeted reinnervation surgery. Grating orientation thresholds and point localization thresholds were also measured on the contralateral normal skin of the targeted reinnervation amputees and on analogous sites in able-bodied controls. Grating orientation thresholds for the reinnervated skin of the targeted reinnervation amputees were found to be similar to normal ranges for both the amputees’ contralateral skin and also for the control population. Point localization thresholds for these amputees were found to be lower for their reinnervated skin than for their contralateral skin. Reinnervated point localization thresholds values were also lower in comparison to homologous chest sites on the control population. Mechanisms appear to be in place to maximize re-established touch input in targeted reinnervation amputees. It seems that sound sensory function is provided to the denervated skin of the residual limb when connected to afferent pathways once serving highly functionally relevant regions of the brain. This suggests that tactile interface devices could be used to give a physiologically appropriate sense of touch to a prosthetic limb, which would likely help with better functional utilization of the prosthetic device and possibly help to more effectively integrate the device with the user's self-image.

Schultz, Aimee E.; Kuiken, Todd A.

2009-01-01

45

Novel purinergic sensitivity develops in injured sensory axons following sciatic nerve transection in rat  

Microsoft Academic Search

Teased fibers were made from 153 spontaneous A afferents ending in sciatic nerve end neuromas of 3–14 days standing, 21 A afferents from intact sensory endings in the contralateral sciatic nerve, and 50 intact A afferents from the sciatic nerve in intact rats. Ninety-two percent of the injured fibers responded to adenosine 5?-triphosphate (ATP) (i.v.). However, few fibers from the

Yong Chen; Yi-Hong Zhang; Zhi-Qi Zhao

2001-01-01

46

Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas  

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

47

Melanocortin receptor 4 is induced in nerve-injured motor and sensory neurons of mouse.  

PubMed

We previously identified melanocortin receptor 4 (MC4R) in a search for genes associated with hypoglossal nerve regeneration. As melanocortins promote nerve regeneration after axonal injury, we investigated whether MC4R functions as a key receptor for peripheral nerve regeneration. In situ hybridization revealed that MC4R mRNA is induced in mouse hypoglossal motor neurons after axonal injury, whereas mRNAs for MC1R, MC2R, MC3R, and MC5R are not expressed either before or after nerve injury. This result was confirmed by RT-PCR. The level of MC4R mRNA expression increased significantly from day 3 after axotomy, reached a peak on day 5, and decreased to the control level on day 14. Similar induction of MC4R was observed in axotomized mouse dorsal root ganglia (DRGs). MC4R mRNA expression was induced exclusively among the MCR family in the L4-6 DRG after sciatic nerve injury. We further examined whether alpha-melanocortin stimulating hormone (alpha-MSH) promotes neurite elongation via MC4R. In mouse DRG neuron culture, alpha-MSH significantly promoted neurite outgrowth at a concentration of 10(-8) mol/L. This neurite-elongation effect was entirely inhibited by the addition of a selective MC4R blocker, JKC-363. Therefore, it is concluded that alpha-MSH could stimulate neurite elongation via MC4R in DRG neurons. The present results suggest that induction of MC4R is crucial for motor and sensory neurons to regenerate after axonal injury. PMID:17286587

Tanabe, Katsuhisa; Gamo, Kazushige; Aoki, Shunsuke; Wada, Keiji; Kiyama, Hiroshi

2007-05-01

48

Artemin induced functional recovery and reinnervation after partial nerve injury.  

PubMed

Systemic artemin promotes regeneration of dorsal roots to the spinal cord after crush injury. However, it is unclear whether systemic artemin can also promote peripheral nerve regeneration, and functional recovery after partial lesions distal to the dorsal root ganglion (DRG) remains unknown. In the present investigation, male Sprague Dawley rats received axotomy, ligation, or crush of the L5 spinal nerve or sham surgery. Starting the day of injury, animals received intermittent subcutaneous artemin or vehicle across 2weeks. Sensory thresholds to tactile or thermal stimuli were monitored for 6weeks after injury. Immunohistochemical analyses of the DRG and nerve regeneration were performed at the 6-week time point. Artemin transiently reversed tactile and thermal hypersensitivity after axotomy, ligation, or crush injury. Thermal and tactile hypersensitivity reemerged within 1week of treatment termination. However, artemin-treated rats with nerve crush, but not axotomy or ligation, subsequently showed gradual return of sensory thresholds to preinjury baseline levels by 6weeks after injury. Artemin normalized labeling for NF200, IB4, and CGRP in nerve fibers distal to the crush injury, suggesting persistent normalization of nerve crush-induced neurochemical changes. Sciatic and intradermal administration of dextran or cholera toxin B distal to the crush injury site resulted in labeling of neuronal profiles in the L5 DRG, suggesting regeneration functional restoration of nonmyelinated and myelinated fibers across the injury site into cutaneous tissue. Artemin also diminished ATF3 and caspase 3 expression in the L5 DRG, suggesting persistent neuroprotective actions. A limited period of artemin treatment elicits disease modification by promoting sensory reinnervation of distal territories and restoring preinjury sensory thresholds. PMID:24269493

Wang, Ruizhong; Rossomando, Anthony; Sah, Dinah W Y; Ossipov, Michael H; King, Tamara; Porreca, Frank

2014-03-01

49

Vagal nerve function in obesity: therapeutic implications.  

PubMed

The primal need for nutrients is satisfied by mechanisms for sensing internal stores and detecting food; ATP is the most primitive signal. With increasing density of sensory neurons and glia (the primordial brain) and the emergence of autonomic neural activity throughout the endoderm, transmitters and other signaling molecules enable alimentation before the appearance of innate storage functions. Memory and, ultimately, cognition are prerequisites for processing and producing food to facilitate assimilation and safeguard the supply of nutrients. The gut-brain-gut axis via the vagus nerve is the autonomic neurohumoral pathway integrating these elements of energy homeostasis. Humans uniquely override obligate nutrient needs, eating in the absence of deprivation, resulting in pathological chronic overnutrition arising from dysautonomia. Obesity surgery circumvents powerful redundant mechanisms of alimentation and reduces excess stores of body fat from chronic overnutrition while preventing re-accumulation of fat. All bariatric operations, whether purely restrictive, maldigestive and malabsorptive, or combinations, rely on regulatory mechanisms related to autonomic nervous system function and the brain-gut axis. We review the functional anatomy and the importance of the vagus nerve for maintaining maladaptive chronic overnutrition and describe interventions to abrogate its effects. In aggregate, the preponderance of evidence supported by laboratory and clinical mechanistic studies interrupting abdominal bi-directional vagal transmission demonstrates that the majority of patients report less "hunger" and lose weight. PMID:19618240

Kral, John G; Paez, Wencesley; Wolfe, Bruce M

2009-10-01

50

Gait phase information provided by sensory nerve activity during walking: applicability as state controller feedback for FES  

Microsoft Academic Search

In this study, we extracted gait-phase information from natural sensory nerve signals of primarily cutaneous origin recorded in the forelimbs of cats during walking on a motorized treadmill. Nerve signals were recorded in seven cats using nerve cuff or patch electrodes chronically implanted on the median, ulnar, and\\/or radial nerves. Features in the electroneurograms that were related to paw contact

K. D. Strange; J. A. Hoffer; J. B. Wagenaar

1999-01-01

51

Sensory nerve repair in perforator flaps for autologous breast reconstruction: sensational or senseless?  

PubMed

The spontaneous return of sensation in autologously reconstructed breasts, especially in the Transverse Rectus Abdominis Myocutaneous (TRAM) flap, generated the belief that sensory reinnervation by nerve repair of the flap would be superfluous. This study compares the sensation of the following non-reconstructed and reconstructed breasts: (1) non-operated breasts; (2) flaps of patients reconstructed with the Deep Inferior Epigastric Perforator (DIEP) flap with sensory nerve repair; (3) flaps of patients reconstructed with the Deep Inferior Epigastric Perforator (DIEP) flap without nerve repair; and (4) flaps of patients reconstructed with the free TRAM flap without nerve repair. Statistically significant lower pressure thresholds were found for DIEP flaps with nerve repair through Semmes-Weinstein testing. More segments of the DIEP flaps with nerve repair reacted to cold, warm and vibratory stimuli compared to flaps without nerve repair. Delayed but satisfactory sensory evoked potential responses were obtained for all reconstructed breasts, but in 46% of TRAM flaps no response could be registered compared with 23% and 0% for DIEP flaps without and with nerve repair, respectively. Questionnaires confirmed the objective data and showed return of erogenous sensation in 30% of the patients with DIEP flaps with nerve repair. Our data reconfirm the possibility of spontaneous return of sensation in pedicled and/or free lower abdominal flaps without nerve repair. Nerve repair in free DIEP flaps nevertheless does restore sensation earlier postoperatively, increases the quality and quantity of sensation in the flap and has a higher chance of providing erogenous sensation. The benefits obtained outweigh the disadvantages of the increased operating time. PMID:10343589

Blondeel, P N; Demuynck, M; Mete, D; Monstrey, S J; Van Landuyt, K; Matton, G; Vanderstraeten, G G

1999-01-01

52

Sensory nerve conduction velocity and vibratory sensibility in juvenile diabetics. Relationship to endogenous insulin.  

PubMed

Sensory nerve conduction velocity (NCV) and the vibratory sense (biothesiometry) were determined in 67 children and adolescents with insulin dependent diabetes. Age at onset of diabetes varied between 1-14 years (mean +/- S.D. 6.5 +/- 3.6) and the duration of diabetes between 4-17 years (7.7 +/- 3.4). Within +/- 3 months of the nerve function tests blood was drawn for determination of C-peptide and insulin antibodies (IgG and IRI). A low NCV (less than 50 m/s) in the sural nerve and/or an abnormal vibratory sense (greater than or equal to 1.0 microns) were found in 34 patients (50.7%). Measurable fasting serum C-peptide 0.04-0.60 pmol/ml (0.17 +/- 0.15) was found in 16 patients (23.9%). All but one patients had insulin antibodies with IgG 0.130-11.029 mU/ml (2.957 +/- 2.509) and total IRI 10-9120 muU/ml (1204 +/- 1723). In multiple regression analysis we did not find any correlation between nerve function and sex, age, or age at onset of diabetes, and there was only a weak relationship between NCV and duration. However, there was a positive correlation between NCV and C-peptide (p less than 0.001). Vibration sense was also better among patients with C-peptide (p less than 0.05). The results support the view that insulin deficiency contributes to peripheral diabetic neuropathy. PMID:525341

Ludvigsson, J; Johannesson, G; Heding, L; Häger, A; Larsson, Y

1979-09-01

53

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

PubMed

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 cm(2) 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

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

2014-04-01

54

Latent addition in motor and sensory fibres of human peripheral nerve.  

PubMed Central

1. The time constants of motor and sensory nerve fibres were studied in normal human ulnar nerves by the method of latent addition, using threshold tracking to follow the recovery of excitability after brief conditioning current pulses. The 60 microseconds test and conditioning stimuli were applied at the wrist, and the conditioning stimuli were set to 90, 60, 30, -30, -60 and -90% of the control threshold current. Compound muscle action potentials were recorded from abductor digiti minimi, and sensory nerve action potentials from the little finger. 2. Recovery from depolarizing conditioning pulses was slower than recovery from hyperpolarizing pulses and strongly dependent on conditioning pulse amplitude. The voltage dependence of latent addition was attributed to subthreshold activation of sodium channels (local response). 3. Motor and sensory nerve excitability generally recovered from -90% hyperpolarizing pulses as the sum of two exponential components, although the slow component was negligible in some motor nerves. The fast component (time constant 43.3 +/- 2.0 microseconds, mean +/- S.E.M., n = 9) was similar between motor and sensory fibres in the same subject. It showed no consistent voltage dependence, and was attributed to a passive input time constant of the fibres. The slow component of recovery from hyperpolarizing pulses was greater in sensory than in motor fibres and was voltage dependent: it could be greatly increased in motor and sensory fibres by steady depolarization. It was attributed to a regenerative membrane current, active at the resting potential in sensory and at least some motor nerves. 4. The latent addition responses were compared with the computed responses of four theoretical models. Both motor and sensory responses were well fitted by a model in which a fraction of the sodium channels (less in motor than in sensory fibres) were activated at potentials 20 mV more negative than normal and at half the normal rate, and did not inactivate. 5. It is concluded that the differences in latent addition between motor and sensory fibres are primarily due to differences in non-classical, voltage-dependent ion channels, active close to the resting potential. These "threshold channels' may help to account for the longer strength-duration time constant of sensory fibres, for their lower rheobase, and for their greater tendency to fire repetitively.

Bostock, H; Rothwell, J C

1997-01-01

55

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

PubMed Central

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

2013-01-01

56

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

PubMed Central

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.

Szabo, Vivien; Vegh, Attila-Gergely; Lucas, Olivier; Cloitre, Thierry; Scamps, Frederique; Gergely, Csilla

2013-01-01

57

Morphology and nanomechanics of sensory neurons growth cones following peripheral nerve injury.  

PubMed

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

Martin, Marta; Benzina, Ouafa; Szabo, Vivien; Végh, Attila-Gergely; Lucas, Olivier; Cloitre, Thierry; Scamps, Frédérique; Gergely, Csilla

2013-01-01

58

Optical survey of initial expression of synaptic function in the embryonic chick trigeminal sensory nucleus.  

PubMed

We examined the initial expression of synaptic function in the embryonic chick trigeminal nucleus using voltage-sensitive dye recording. Brainstem preparations with three trigeminal nerve afferents, the ophthalmic nerve (N.V1), maxillary nerve (N.V2) and mandibular nerve (N.V3), were dissected from 5.5- to 6.5-day-old chick embryos. In our previous study [Sato et al., 1999], we detected slow signals corresponding to glutamatergic excitatory postsynaptic potentials and identified the principal sensory nucleus of the trigeminal nerve (Pr5), spinal sensory nucleus of the trigeminal nerve (Sp5) and trigeminal motor nucleus. In this study, we examined the effects of removing Mg(2+) from the physiological solution, which enhanced N-methyl-d-aspartate receptor function in the sensory nuclei. In 6.5-day-old (St 29) embryos, the slow signal was observed in Pr5 and Sp5 only when N.V1 was stimulated, whereas it appeared in Mg(2+)-free solution with every nerve stimulation. In 6-day-old (St 28) embryos, the slow signal was observed in Sp5 with N.V1 stimulation, and the appearance of synaptic function in Mg(2+)-free solution varied, depending on the nerves and preparations used. In 5.5-day-old (St 27) embryos, synaptic function was not detected even when external Mg(2+) was removed. These results indicate that the initial expression of synaptic function in the trigeminal system occurs earlier than previously considered, and that the developmental organization of synaptic function differs among the three trigeminal nerves and between the two sensory nuclei. PMID:24769319

Momose-Sato, Yoko; Sato, Katsushige

2014-06-01

59

Intraepithelial Vagal Sensory Nerve Terminals in Rat Pulmonary Neuroepithelial Bodies Express P2X 3 Receptors  

Microsoft Academic Search

The neurotransmitters\\/modulators involved in the interaction between pulmonary neuroepithelial bodies (NEBs) and the va- gal sensory component of their innervation have not yet been elucidated. Because P2X 3 purinoreceptors are known to be strongly expressed in peripheral sensory neurons, the aim of the present study was to examine the localization of nerve endings expressing P2X 3 purinoreceptors in the rat

Inge Brouns; Dirk Adriaensen; Geoff Burnstock; Jean-Pierre Timmermans

60

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

PubMed Central

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

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

2010-01-01

61

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

PubMed

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

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

2010-10-01

62

Sensory axon targeting is increased by NGF gene therapy within the lesioned adult femoral nerve  

PubMed Central

Even though peripheral nerves regenerate well, axons are often misrouted and reinnervate inappropriate distal pathways post-injury. Misrouting most likely occurs at branch points where regenerating axons make choices. Here, we show that the accuracy of sensory axon reinnervation is enhanced by overexpression of the guidance molecule nerve growth factor (NGF) distal to the bifurcation. We used the femoral nerve as model, which contains both sensory and motor axons that intermingle in the parent trunk and distally segregate into the saphenous (SB) and motor branch (MB). Transection of the parent trunk resulted in misrouting of axon reinnervation to SB and MB. To enhance sensory axon targeting, recombinant adenovirus encoding NGF was injected along the SB close to the bifurcation one week post-injury. The accuracy of axon reinnervation was assessed by retrograde tracing at 3 or 8 weeks after nerve injury. NGF overexpression significantly increased the accuracy of SB axon reinnervation to the appropriate nerve branch, in a manner independent of enhancing axon regeneration. This novel finding provides in vivo evidence that gradient expression of neurotrophin can be used to enhance targeting of distal peripheral pathways to increase axon regeneration into the appropriate nerve branch.

Hu, Xinhua; Cai, Jie; Yang, Jun; Smith, George M.

2009-01-01

63

Hydrophilic Polymers Enhance Early Functional Outcomes after Nerve Autografting  

PubMed Central

Background Approximately 12% of operations for traumatic neuropathy are for patients with segmental nerve loss and less than 50% of these injuries obtain meaningful functional recovery. Polyethylene glycol (PEG) therapy has been shown to improve functional outcomes after nerve severance and we hypothesized this therapy could also benefit nerve autografting. Methods A segmental rat sciatic nerve injury model was used, whereby a 0.5 cm defect was repaired with an autograft using microsurgery. Experimental animals were treated with solutions containing methylene blue (MB) and PEG; control animals did not receive PEG. Compound Actions Potentials (CAPs) were recorded before nerve transection, after solution therapy, and at 72 hours postoperatively. The animals underwent behavioral testing at 24 and 72 hours postoperatively. After sacrifice, nerves were fixed, sectioned, and immunostained to allow for quantitative morphometric analysis. Results The introduction of hydrophilic polymers greatly improved morphological and functional recovery of rat sciatic axons at 1–3 days following nerve autografting. PEG therapy restored CAPs in all animals and CAPs were still present 72 hours postoperatively. No CAPS were detectable in control animals. Footfall asymmetry scores and sciatic functional index scores were significantly improved for PEG therapy group at all time points (p <0.05 and p<0.001; p <0.001 and p <0.01). Sensory and motor axon counts were increased distally in nerves treated with PEG compared to control (p = 0.0189 and p = 0.0032). Conclusions PEG therapy improves early physiologic function, behavioral outcomes, and distal axonal density after nerve autografting.

Sexton, Kevin W.; Pollins, Alonda C.; Cardwell, Nancy L.; Del Corral, Gabriel A.; Bittner, George D.; Shack, R. Bruce; Nanney, Lillian B.; Thayer, Wesley P.

2014-01-01

64

Multifocal acquired demyelinating sensory and motor neuropathy presenting as a peripheral nerve tumor.  

PubMed

A man with multifocal acquired demyelinating sensory and motor neuropathy (MADSAM), or Lewis-Sumner syndrome, presented with a progressive left lumbosacral plexus lesion resembling a neurofibroma. After 7 years he developed a left ulnar nerve lesion with conduction block in its upper segment. Treatment with intravenous immunoglobulin improved the symptoms and signs of both lesions. We conclude that inflammatory neuropathy must be considered in the differential diagnosis of peripheral nerve tumors, and that unifocal lesions may precede multifocal involvement in MADSAM by several years. In addition, we discuss the clinical features in 9 patients attending a specialist peripheral nerve clinic and review the literature. PMID:16609974

Allen, David C; Smallman, Clare A; Mills, Kerry R

2006-09-01

65

Osseoperception: Sensory Function and Proprioception  

Microsoft Academic Search

Tooth loss and its replacement have significant functional and psychosocial consequences. The removal of intra-dental and periodontal mechanoreception accompanying tooth loss changes the fine proprioceptive control of jaw function and influences the precision of magnitude, direction, and rate of occlusal load application. With the loss of all teeth, complete denture restoration is a compromise replacement which only partially restores function.

I. Klineberg; G. Murray

1999-01-01

66

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

Microsoft Academic Search

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,

G Cruccu; M Inghilleri; M Manfredi; M Meglio

1987-01-01

67

Effects of Latrodectus Spider Venoms on Sensory and Motor Nerve Terminals of Muscle Spindles  

Microsoft Academic Search

The effects of the venoms of the spiders Latrodectus mactans tredecimguttatus (black widow) and Latrodectus mactans hasselti (red back) on sensory nerve terminals in muscle spindles were studied in the mouse. A sublethal dose of venom was injected into tibialis anterior and extensor digitorum longus muscles of one leg. After survival from 30 minutes to 6 weeks muscles were examined

L. S. Queiroz; L. W. Duchen

1982-01-01

68

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

PubMed

Peripheral nerve injury is often followed by incomplete and unsatisfactory functional recovery and may be associated with sensory and motor impairment of the affected limb. Therefore, a novel method is needed to improve the speed of recovery and the final functional outcome after peripheral nerve injuries. This report investigates the effect of lentiviral-mediated transfer of conserved dopamine neurotrophic factor (CDNF) on regeneration of the rat peripheral nerve in a transection model in vivo. We observed notable overexpression of CDNF protein in the distal sciatic nerve after recombinant CDNF lentiviral vector application. We evaluated sciatic nerve regeneration after surgery using light and electron microscopy and the functional recovery using the sciatic functional index and target muscle weight. HE staining revealed better ordered structured in the CDNF-treated group at 8 weeks post-surgery. Quantitative analysis of immunohistochemistry of NF200 and S-100 in the CDNF group revealed significant improvement of axonal and Schwann cell regeneration compared with the control groups at 4 weeks and 8 weeks after injury. The thickness of the myelination around the axons in the CDNF group was significantly higher than in the control groups at 8 weeks post-surgery. The CDNF group displayed higher muscle weights and significantly increased sciatic nerve index values. Our findings suggest that CDNF gene therapy could provide durable and stable CDNF protein concentration and has the potential to enhance peripheral nerve regeneration, morphological and functional recovery following nerve injury, which suggests a promising strategy for peripheral nerve repair. PMID:24076387

Cheng, Lei; Liu, Yi; Zhao, Hua; Zhang, Wen; Guo, Ying-Jun; Nie, Lin

2013-10-18

69

Phenotyping sensory nerve endings in vitro in the mouse  

PubMed Central

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

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

2014-01-01

70

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

PubMed

Peripheral nerve injury in vivo promotes a regenerative growth in vitro characterized by an improved neurite regrowth. Knowledge of the conditioning injury effects on both morphology and mechanical properties of live sensory neurons could be instrumental to understand the cellular and molecular mechanisms leading to this regenerative growth. In the present study, we use differential interference contrast microscopy, fluorescence microscopy, and atomic force microscopy (AFM) to show that conditioned axotomy, induced by sciatic nerve injury, does not increase somatic size of sensory neurons from adult mice lumbar dorsal root ganglia but promotes the appearance of longer and larger neurites and growth cones. AFM on live neurons is also employed to investigate changes in morphology and membrane mechanical properties of somas of conditioned neurons following sciatic nerve injury. Mechanical analysis of the soma allows distinguishing neurons having a regenerative growth from control ones, although they show similar shapes and sizes. PMID:24165740

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

2013-10-01

71

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

72

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

PubMed Central

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

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

2014-01-01

73

Autoradiographic location of sensory nerve endings in dentin of monkey teeth  

SciTech Connect

We have used the autoradiographic method to locate trigeminal nerve endings in monkey teeth. The nerve endings were labeled in two adult female Macaca fascicularis by 20 hours of axonal transport of radioactive protein (/sup 3/H-L-proline). We found a few labeled axons in contralateral mandibular central incisors and one mandibular canine. In ipsilateral teeth, numerous myelinated and unmyelinated axons were labeled; they formed a few terminal branches in the roots but primarily branched in the crown to form the peripheral plexus of Raschkow and to terminate as free endings in the odontoblast layer, predentin, and as far as 120 micrometers into dentinal tubules. Electron microscopic autoradiography showed that the radioactive axonally transported protein was confined to sensory axons and endings; odontoblasts and dentin matrix were not significantly labeled. Labeled free nerve endings were closely apposed to odontoblasts in dentin but did not form distinctive junctions with them. Nerve endings were most numerous in the regular tubular dentin of the crown adjacent to the tip of the pulp horn, occurring in at least half of the dentinal tubules there. Our results show tha dentinal sensory nerve endings in primate teeth can be profuse, sparse, or absent depending on the location and structure of dentin and its adjacent pulp. When dentin was innervated, the tubules were straight and contained odontoblast processes, the predentin was wide, the odontoblast cell bodies were relatively columnar, and there was an adjacent cell-free zone and pulpal nerve plexus.

Byers, M.R.; Dong, W.K.

1983-04-01

74

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

SciTech Connect

Highlights: •CDNF was successfully transfected by a lentiviral vector into the distal sciatic nerve. •CDNF improved S-100, NF200 expression and nerve regeneration after sciatic injury. •CDNF improved the remyelination and thickness of the regenerated sciatic nerve. •CDNF improved gastrocnemius muscle weight and sciatic functional recovery. -- Abstract: Peripheral nerve injury is often followed by incomplete and unsatisfactory functional recovery and may be associated with sensory and motor impairment of the affected limb. Therefore, a novel method is needed to improve the speed of recovery and the final functional outcome after peripheral nerve injuries. This report investigates the effect of lentiviral-mediated transfer of conserved dopamine neurotrophic factor (CDNF) on regeneration of the rat peripheral nerve in a transection model in vivo. We observed notable overexpression of CDNF protein in the distal sciatic nerve after recombinant CDNF lentiviral vector application. We evaluated sciatic nerve regeneration after surgery using light and electron microscopy and the functional recovery using the sciatic functional index and target muscle weight. HE staining revealed better ordered structured in the CDNF-treated group at 8 weeks post-surgery. Quantitative analysis of immunohistochemistry of NF200 and S-100 in the CDNF group revealed significant improvement of axonal and Schwann cell regeneration compared with the control groups at 4 weeks and 8 weeks after injury. The thickness of the myelination around the axons in the CDNF group was significantly higher than in the control groups at 8 weeks post-surgery. The CDNF group displayed higher muscle weights and significantly increased sciatic nerve index values. Our findings suggest that CDNF gene therapy could provide durable and stable CDNF protein concentration and has the potential to enhance peripheral nerve regeneration, morphological and functional recovery following nerve injury, which suggests a promising strategy for peripheral nerve repair.

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

2013-10-18

75

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

PubMed

Sensory maximum nerve conduction velocity (MNCV) and motor MNCV were monitored in altogether 14 beagle dogs anaesthetized with pentobarbital. Sensory MNCV was determined by averaging cortically evoked potentials from somatosensory area I (SS I) in response to repeated electrical stimulation of digital paw pads, tibial nerve at calcaneus or sciatic nerve at trochanter. Sensory MNCV determined from paw to tibial nerve at calcaneus was 53 m/sec, from tibial nerve at calcaneus to sciatic nerve at trochanter 64 m/sec and from sciatic nerve at trochanter to crotex SS I 53 m/sec. Motor peripheral MNCV determined in the customary way from sciatic nerve at trochanter to tibial nerve at calcaneus was 68 m/sec and distal latency 3.6 msec. Motor central MNCV from motor cortex to the sciatic nerve at the trochanter in 5 unanaesthetized dogs was 57 m/sec. These testing procedures serve for quantitative assessment of possible impairment of impulse transmission in the central and peripheral sensory and motor pathway of beagle dogs used in routine toxicity studies. PMID:7180741

Schaeppi, U; Teste, M; Siegenthaler, U

1982-10-01

76

Sensory function in severe semilobar holoprosencephaly  

Microsoft Academic Search

We report a 4-year-old child with severe semi-lobar holoprosencephaly (HPE) not expected to survive after birth. Magnetic resonance imaging (MRI) revealed agenesis of the corpus callosum, absence of the third ventricle, fused thalami and basal ganglia. To investigate sensory function, visual, auditory and somatosensory evoked potential and imaging studies were carried out. The visual response evoked by human face stimuli

Alki Liasis; Darius Hildebrand; Chris Clark; Ximena Katz; Roxana Gunny; Bram Stieltjes; David Taylor

2009-01-01

77

Sensory Neuron Downregulation of the Kv9.1 Potassium Channel Subunit Mediates Neuropathic Pain following Nerve Injury  

PubMed Central

Chronic neuropathic pain affects millions of individuals worldwide, is typically long-lasting, and remains poorly treated with existing therapies. Neuropathic pain arising from peripheral nerve lesions is known to be dependent on the emergence of spontaneous and evoked hyperexcitability in damaged nerves. Here, we report that the potassium channel subunit Kv9.1 is expressed in myelinated sensory neurons, but is absent from small unmyelinated neurons. Kv9.1 expression was strongly and rapidly downregulated following axotomy, with a time course that matches the development of spontaneous activity and pain hypersensitivity in animal models. Interestingly, siRNA-mediated knock-down of Kv9.1 in naive rats led to neuropathic pain behaviors. Diminished Kv9.1 function also augmented myelinated sensory neuron excitability, manifested as spontaneous firing, hyper-responsiveness to stimulation, and persistent after-discharge. Intracellular recordings from ex vivo dorsal root ganglion preparations revealed that Kv9.1 knock-down was linked to lowered firing thresholds and increased firing rates under physiologically relevant conditions of extracellular potassium accumulation during prolonged activity. Similar neurophysiological changes were detected in animals subjected to traumatic nerve injury and provide an explanation for neuropathic pain symptoms, including poorly understood conditions such as hyperpathia and paresthesias. In summary, our results demonstrate that Kv9.1 dysfunction leads to spontaneous and evoked neuronal hyperexcitability in myelinated fibers, coupled with development of neuropathic pain behaviors.

Tsantoulas, Christoforos; Zhu, Lan; Shaifta, Yasin; Grist, John; Ward, Jeremy P. T.; Raouf, Ramin; Michael, Gregory J.; McMahon, Stephen B.

2013-01-01

78

Sensory function in severe semilobar holoprosencephaly.  

PubMed

We report a 4-year-old child with severe semi-lobar holoprosencephaly (HPE) not expected to survive after birth. Magnetic resonance imaging (MRI) revealed agenesis of the corpus callosum, absence of the third ventricle, fused thalami and basal ganglia. To investigate sensory function, visual, auditory and somatosensory evoked potential and imaging studies were carried out. The visual response evoked by human face stimuli evoked larger responses over the left side of the holosphere as compared to responses evoked by checkerboard pattern, while auditory evoked potentials were evident over the frontal regions to both pure tones and speech stimuli. No consistent scalp somatosensory evoked potentials were evident. This case demonstrates that electrophysiological measures are able to identify and quantify sensory processing not expected to be present based on the anatomical presentation of the cortex in a child with severe HPE. PMID:19153870

Liasis, Alki; Hildebrand, Darius; Clark, Chris; Katz, Ximena; Gunny, Roxana; Stieltjes, Bram; Taylor, David

2009-01-01

79

Sensory nerve repair in perforator flaps for autologous breast reconstruction: sensational or senseless?  

Microsoft Academic Search

SUMMARY. The spontaneous return of sensation in autologously reconstructed breasts, especially in the Transverse Rectus Abdominis Myocutaneous (TRAM) flap, generated the belief that sensory reinnervation by nerve repair of the flap would be superfluous.This study compares the sensation of the following non-reconstructed and reconstructed breasts: (1) non-operated breasts; (2) flaps of patients reconstructed with the Deep Inferior Epigastric Perforator (DIEP)

P. N. Blondeel; M. Demuynck; D. Mete; S. J. Monstrey; K. Van Landuyt

1999-01-01

80

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

Microsoft Academic Search

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

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

2002-01-01

81

Effect of dopamine receptor agonists on sensory nerve activity: possible therapeutic targets for the treatment of asthma and COPD.  

PubMed

Sensory nerves regulate central and local reflexes such as airway plasma leakage, and cough and their function may be enhanced during inflammation. Evidence suggests that dopamine receptor agonists may inhibit sensory nerve-mediated responses. In this study dopamine inhibited vagal sensory nerve induced microvascular leakage in the rat. In order to characterize the receptor involved rat vagus preparations were utilized. Quinagolide (D(2/3) agonist), ropinirole (D(2/3/4) agonist), SKF 38393 (D(1/5) agonist), AR-C68397AA (Viozan) (dual D(2)/B(2) agonist) and dopamine inhibited hypertonic saline induced depolarization by approximately 50%. Data suggests that AR-C68397AA and quinagolide also inhibited depolarization of the human vagus. The quinagolide response was blocked by sulpiride (D(2/3) antagonist) but not SCH 23390 (D(1/5) antagonist); ropinirole was partially blocked by sulpiride, totally blocked by spiperone (at a concentration that blocks all dopamine receptors) but not by SCH 23390. The response to SKF 38393 was not blocked by sulpiride but was by SCH 23390. The inhibition evoked by AR-C68397AA was only partially blocked by SCH 23390 but not by sulpiride or spiperone whereas dopamine was blocked by spiperone. The effect of dopamine was not stimulus-specific as it inhibited capsaicin-induced depolarization of the rat vagus in a spiperone sensitive manner. In conclusion, dopamine receptor ligands inhibit depolarization of the rat and human vagus. These data suggest that dopamine receptor agonists may be of therapeutic benefit in the treatment of symptoms such as cough and mucus secretion which are evident in respiratory diseases such as asthma and chronic obstructive pulmonary disease. PMID:12055141

Birrell, Mark A; Crispino, Natascia; Hele, David J; Patel, Hema J; Yacoub, Magdi H; Barnes, Peter J; Belvisi, Maria G

2002-06-01

82

Rapid immunostaining of live nerve for identification of sensory and motor fasciculi.  

PubMed

Six New Zealand white rabbits were anesthetized with pentobarbital, and sciatic nerves were exposed and cut at the mid thigh. Both proximal and distal ends were incubated directly with Blue-SAb in a micropipe of 5 mm diameter covering the nerve trunk ends for 30 minutes at room temperature. After removal of the micropipe, the nerve ends were washed with physiological saline. Blue-stained fasciculi, i.e., sensory fasciculi were seen among unstained ones under the operating microscope. This method requires no histological sections. Neural cells of the spinal cord and ganglion were cultured in RPM11640 medium containing Bright Blue. The growth and metabolism of the neural cells were tested by MTT assay and their morphology was observed. Statistical difference between the experiment and control groups was determined, indicating that Bright Blue had no effect on the neural cells and their repairing power. This rapid immunostaining technique offers a good approach for the identification and accurate coaptation of sensory fasciculi in peripheral nerve repair. PMID:1284789

Gu, X S; Yan, Z Q; Yan, W X; Chen, C F

1992-11-01

83

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

PubMed

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

Koplovitch, Pini; Minert, Anne; Devor, Marshall

2012-07-01

84

Secretion of Growth Hormone in Response to Muscle Sensory Nerve Stimulation  

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

85

Evaluation of the motor and sensory components of the pudendal nerve.  

PubMed

Extensive neurophysiological investigations consisting of different techniques to evaluate the efferents and afferents of the pudendal nerve were carried out in 27 healthy subjects. These investigations included motor evoked potential recordings from the external anal sphincter in response to magnetic stimulation of the cortex and lumbosacral roots, measurement of sacral reflex latency to magnetic and electrical stimulation, and cortical sensory evoked potential recording after stimulation of the dorso-genital nerve and anal canal. Motor latencies after transcranial magnetic stimulation to the anal sphincter were 25.1 +/- 2.9 msec at rest and 20.9 +/- 2.0 msec with voluntary sphincter contraction (facilitation). Motor latency after lumbosacral root stimulation was 3.7 +/- 1.0 msec. Mean sacral reflex latency after magnetic stimulation was 43.8 +/- 11.2 msec and was significantly longer than after electrical stimulation (37.0 +/- 7.2 msec; P < 0.05). P1 latency of the sensory evoked potentials after dorso-genital nerve stimulation was 40 +/- 3 msec and was significantly shorter than after anal stimulation 46 +/- 3 msec (P < 0.01). Evoked potential recording allows us to study both upper and lower motor neuron components to the anal sphincter. The present study paves the way for the combined application of these tests in the evaluation of disorders of the pelvic floor. PMID:7511520

Loening-Baucke, V; Read, N W; Yamada, T; Barker, A T

1994-02-01

86

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

PubMed Central

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

2012-01-01

87

Assessment of sensory thresholds and nociceptive fiber growth after sciatic nerve injury reveals the differential contribution of collateral reinnervation and nerve regeneration to neuropathic pain.  

PubMed

Following traumatic peripheral nerve injury reinnervation of denervated targets may be achieved by regeneration of injured axons and by collateral sprouting of neighbor undamaged axons. Experimental models commonly use sciatic nerve injuries to assess nerve regeneration and neuropathic pain, but behavioral tests for evaluating sensory recovery often disregard the pattern of hindpaw innervation. This may lead to confounding attribution of recovery of sensory responses to improvement in sciatic nerve regeneration instead of collateral reinnervation by the undamaged saphenous nerve. We used a standardized methodology to assess the separate contribution of collateral and regenerative skin reinnervation on sensory responses. Section and suture of the sciatic nerve induced loss of sensibility in the lateral and central areas of the injured paw, but nociceptive responses rapidly recovered by expansion of the intact saphenous innervation territory. We used electronic Von Frey and Plantar test devices to measure mechanical and thermal withdrawal thresholds in specific sites of the injured paw: lateral site innervated by the sciatic nerve, medial site that remained innervated by the saphenous nerve, and central site originally innervated by the sciatic nerve but affected by saphenous sprouting. After sciatic section, signs of early hyperalgesia developed in medial and central paw areas due to saphenous sprouting and expansion. The regenerating sciatic nerve fibers reached the paw at 3-4weeks and a late mechanical hyperalgesia was observed at the lateral site. Immunohistochemical staining of sensory fibers innervating the medial and lateral areas revealed a different pattern of skin reinnervation. Hypersensitivity in the intact saphenous nerve area was paralleled by early fiber sprout growth in the subepidermal plexus, but not entering the epidermis. On the other side, late sciatic hyperalgesia was accompanied by gradual skin reinnervation after 4weeks. The standardization of algesimetry testing in sciatic nerve injury models, as proposed in this study, provides a suitable model for studying in parallel neuropathic pain and sensory nerve regeneration processes. Our results also indicate that collateral sprouting and axonal regeneration contribute differently in the initiation and maintenance of neuropathic pain. PMID:24552688

Cobianchi, Stefano; de Cruz, Julia; Navarro, Xavier

2014-05-01

88

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

PubMed Central

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

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

2012-01-01

89

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

Microsoft Academic Search

We have recently shown that manual stimulation of target muscles promotes functional recovery after transection and surgical\\u000a repair to pure motor nerves (facial: whisking and blink reflex; hypoglossal: tongue position). However, following facial nerve\\u000a repair, manual stimulation is detrimental if sensory afferent input is eliminated by, e.g., infraorbital nerve extirpation.\\u000a To further understand the interplay between sensory input and motor

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

2011-01-01

90

Lamellar cells of sensory receptors and perineural cells of nerve endings of pig skin contain cytokeratins.  

PubMed

The lamellar cells of the sensory corpuscles of the pig dermis must be considered to be epithelial cells as they contain cytokeratins. The cytokeratins detected are similar to those found in simple epithelia. Moreover, lamellar cells are embedded in an extracellular matrix reminiscent of the basement membrane of epithelium since it contains laminin and collagen IV. The perineural cells surrounding the nerves of pig dermis present the same features. These results suggest that lamellar cells and perineural cells have the same origin. The nature of the lamellar and perineural cells of the rabbit or human dermis is not as clear since cytokeratins were not detected in those cells. These results, together with recent observations on Merkel cells, may indicate that epithelio-neuronal junctions are a general feature of cutaneous sensory receptors. PMID:2436379

Ortonne, J P; Verrando, P; Pautrat, G; Darmon, M

1987-01-01

91

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

PubMed

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

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

2004-01-15

92

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

PubMed Central

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

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

2013-01-01

93

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

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

94

Cortical Brain Mapping of Peripheral Nerves Using Functional Magnetic Resonance Imaging in a Rodent Model  

PubMed Central

The regions of the body have cortical and subcortical representation in proportion to their degree of innervation. The rat forepaw has been studied extensively in recent years using functional magnetic resonance imaging (fMRI)—typically by stimulation using electrodes directly inserted into the skin of the forepaw. Here, we stimulate using surgically implanted electrodes. A major distinction is that stimulation of the skin of the forepaw is mostly sensory, whereas direct nerve stimulation reveals not only the sensory system but also deep brain structures associated with motor activity. In this paper, we seek to define both the motor and sensory cortical and subcortical representations associated with the four major nerves of the rodent upper extremity. We electrically stimulated each nerve (median, ulnar, radial, and musculocutaneous) during fMRI acquisition using a 9.4T Bruker scanner. A current level of 0.5-1.0 mA and a frequency of 5 Hz were used while keeping the duration constant. A distinct pattern of cortical activation was found for each nerve that can be correlated with known sensorimotor afferent and efferent pathways to the rat forepaw. This direct nerve stimulation rat model can provide insight into peripheral nerve injury.

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

2008-01-01

95

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

SciTech Connect

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

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

1984-07-01

96

From genes to pain: nerve growth factor and hereditary sensory and autonomic neuropathy type V.  

PubMed

Hereditary sensory and autonomic neuropathy type V (HSAN V) is an autosomal recessive disorder characterized by the loss of deep pain perception. The anomalous pain and temperature sensations are due to the absence of nociceptive sensory innervation. The neurotrophin nerve growth factor (NGF), by binding to tropomyosin receptor A (TrkA) and p75NTR receptors, is essential for the development and survival of sensory neurons, and for pain perception during adulthood. Recently a homozygous missense mutation (R100W) in the NGF gene has been identified in HSAN V patients. Interestingly, alterations in NGF signalling, due to mutations in the NGF TRKA gene, have also been involved in another congenital insensitivity to pain, HSAN IV, characterized not only by absence of reaction to painful stimuli, but also anhidrosis and mental retardation. These symptoms are absent in HSAN V patients. Unravelling the mechanisms that underlie the differences between HSAN IV and V could assist in better understanding NGF biology. This review highlights the recent key findings in the understanding of HSAN V, including insights into the molecular mechanisms of the disease, derived from genetic studies of patients with this disorder. PMID:24494679

Capsoni, Simona

2014-02-01

97

Distribution of sensory neurones of the pudendal nerve in the dorsal root ganglia and their projection to the spinal cord  

Microsoft Academic Search

The morphology and distribution of the sensory neurones of the pudendal nerve within the spinal ganglia of rats were investigated by use of horseradish peroxidase (HRP). The labelling was visualized in diaminobenzidine (DAB) or tetramethyl-benzidine (TMB)-stained sections. Injection of HRP directly into the pudendal nerve labelled perikarya predominantly in the sixth lumbar DRG (L6). Following injection of HRP into the

D. C. M. Taylor; H.-W. Korf; Fr.-K. Pierau

1982-01-01

98

Mechanical sensitization of cutaneous sensory fibers in the spared nerve injury mouse model  

PubMed Central

Background The spared nerve injury (SNI) model of neuropathic pain produces robust and reproducible behavioral mechanical hypersensitivity. Although this rodent model of neuropathic pain has been well established and widely used, peripheral mechanisms underlying this phenotype remain incompletely understood. Here we investigated the role of cutaneous sensory fibers in the maintenance of mechanical hyperalgesia in mice post-SNI. Findings SNI produced robust, long-lasting behavioral mechanical hypersensitivity compared to sham and naïve controls beginning by post-operative day (POD) 1 and continuing through at least POD 180. We performed teased fiber recordings on single cutaneous fibers from the spared sural nerve using ex vivo skin-nerve preparations. Recordings were made between POD 16–42 after SNI or sham surgery. A?-mechanoreceptors (AM) and C fibers, many of which are nociceptors, from SNI mice fired significantly more action potentials in response to suprathreshold mechanical stimulation than did fibers from either sham or naïve control mice. However, there was no increase in spontaneous activity. Conclusions To our knowledge, this is the first study evaluating the contribution of primary afferent fibers in the SNI model. These data suggest that enhanced suprathreshold firing in AM and C fibers may play a role in the marked, persistent mechanical hypersensitivity observed in this model. These results may provide insight into mechanisms underlying neuropathic pain in humans.

2013-01-01

99

Hand sensory-motor cortical network assessed by functional source separation.  

PubMed

The functional source separation procedure (FSS) was applied to identify the activities of the primary sensorimotor areas (SM1) devoted to hand control. FSS adds a functional constraint to the cost function of the basic independent component analysis, and obtains source activity all along different processing states. Magnetoencephalographic signals from the left SM1 were recorded in 14 healthy subjects during a simple sensorimotor paradigm--galvanic right median nerve stimuli intermingled with submaximal isometric thumb opposition. Two functional sources related to the sensory flow in the primary cortex were extracted requiring maximal responsiveness to the nerve stimulation at around 20 and 30 ms (S1a, S1b). Maximal cortico-muscular coherence was required for the extraction of the motor source (M1). Sources were multiplied by the Euclidean norm of their corresponding weight vectors, allowing amplitude comparisons among sources in a fixed position. In all subjects, S1a, S1b, M1 were successfully obtained, positioned consistently with the SM1 organization, and behaved as physiologically expected during the movement and processing of the sensory stimuli. The M1 source reacted to the nerve stimulation with higher intensity at latencies around 30 ms than around 20 ms. The FSS method was demonstrated to be able to obtain the dynamics of different primary cortical network activities, two devoted mainly to sensory inflow, and the other to the motor control of the contralateral hand. It was possible to observe each source both during pure sensory processing and during motor tasks. In all conditions, a direct comparison of source intensities can be achieved. PMID:17318837

Porcaro, Camillo; Barbati, Giulia; Zappasodi, Filippo; Rossini, Paolo M; Tecchio, Franca

2008-01-01

100

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

PubMed

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. PMID:20947214

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

101

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

PubMed Central

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

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

2010-01-01

102

[Preliminary study on simulating sensory nerves of intestinal contents using ultrasound detecting system].  

PubMed

Successful assessing intestinal lumen content with ultrasound signals might lay a strong basis for the development of the artificial anal sphincter. In the present study, we utilized a modified MLU02-212 ultrasonic gas bubble detector to test the distal part of proximal colon in each rabbit, for the group of twenty healthy New Zealand rabbits. Voltage signals of solid, liquid, gas and empty content of the lumen were collected and compared. The results indicated that there were significant differences among the voltage signals in the 4 conditions (P = 0.000), respectively. Multiple comparison showed significant differences existed in any pair of the four conditions (P = 0.000). Three signal non-overlapping regions existed in these 4 conditions. Thus it seemed that ultrasound could be utilized to distinguish various contents inside the intestinal lumen and could act as "artificial sensory nerve". PMID:22616169

Li, Jianguo; Huang, Zonghai; Shi, Fujun; Chen, Fei; Zhang, Quanan

2012-04-01

103

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

PubMed Central

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

2011-01-01

104

Motor nerve transfers to restore extrinsic median nerve function: case report.  

PubMed

Active pronation is important for many activities of daily living. Loss of median nerve function including pronation is a rare sequela of humerus fracture. Tendon transfers to restore pronation are reserved for the obstetrical brachial plexus palsy patient. Transfer of expendable motor nerves is a treatment modality that can be used to restore active pronation. Nerve transfers are advantageous in that they do not require prolonged immobilization postoperatively, avoid operating within the zone of injury, reinnervate muscles in their native location prior to degeneration of the motor end plates, and result in minimal donor deficit. We report a case of lost median nerve function after a humerus fracture. Pronation was restored with transfer of the extensor carpi radialis brevis branch of the radial nerve to the pronator teres branch of the median nerve. Anterior interosseous nerve function was restored with transfer of the supinator branch to the anterior interosseous nerve. Clinically evident motor function was seen at 4 months postoperatively and continued to improve for the following 18 months. The patient has 4+/5 pronator teres, 4+/5 flexor pollicis longus, and 4-/5 index finger flexor digitorum profundus function. The transfer of the extensor carpi radialis brevis branch of the radial nerve to the pronator teres and supinator branch of the radial nerve to the anterior interosseous nerve is a novel, previously unreported method to restore extrinsic median nerve function. PMID:18807095

Hsiao, Eugene C; Fox, Ida K; Tung, Thomas H; Mackinnon, Susan E

2009-03-01

105

Vagal Nerve Function in Obesity: Therapeutic Implications  

Microsoft Academic Search

The primal need for nutrients is satisfied by mechanisms for sensing internal stores and detecting food; ATP is the most primitive\\u000a signal. With increasing density of sensory neurons and glia (the primordial brain) and the emergence of autonomic neural activity\\u000a throughout the endoderm, transmitters and other signaling molecules enable alimentation before the appearance of innate storage\\u000a functions. Memory and, ultimately,

John G. Kral; Wencesley Paez; Bruce M. Wolfe

2009-01-01

106

Sterol-like compound from sensory ganglia. Effect of a nerve growth factor and insulin on its biosynthesis  

PubMed Central

1. Sensory ganglia from 8-day-old chick embryos were incubated with a specific nerve growth factor and with insulin. 2. From the total lipid extract of the ganglia a compound with steroid characteristics was isolated. 3. The synthesis of this compound, measured spectrophotometrically, diminished after addition of the nerve growth factor and insulin to the incubation medium. 4. The incorporation of sodium [2-14C]acetate and dl-[2-14C]mevalonic acid into total lipids of the sensory ganglia was stimulated by the nerve growth factor and insulin, but the radioactivity of the sterol-like compound was slightly lower. The incorporation of labelled mevalonic acid either into total lipids or into the sterol-like compound was about 25% lower. 5. About 20% of the acetate incorporated into total lipids and about 87% of the mevalonic acid were recovered in the sterol-like compound.

Liuzzi, Antonia; Foppen, Fredrik H.

1968-01-01

107

Depolarization of sensory nerve endings and impulse initiation in common carotid baroreceptors  

PubMed Central

1. Electrical events in the peripheral nerve terminals of baroreceptors were investigated following isolation and identification of receptive fields innervated by single baroreceptor fibres. A slow potential change, that is a local depolarization which had the characteristics of a generator (receptor) potential, was recorded from the common carotid baroreceptor fibres at a point close to the sensory terminals. 2. The slow potential increased in amplitude with increasing stimulus strength and its time course increased with increasing duration of the mechanical stimulus. Action potentials were initiated from the slow potential when the applied mechanical stimulus was suprathreshold. 3. The slow potentials evoked by a train of subthreshold stimuli summed to evoke action potentials. 4. When a high-frequency train of suprathreshold stimuli was applied to the baroreceptors, the slow potential following a preceding one from which an action potential was initiated failed to fire the nerve fibre. 5. When the sodium content of the Ringer—Locke solution was decreased, the slow potential remained after blockage of the action potential. 6. The slow potential remained after abolishing the spike potential by application of tetrodotoxin.

Matsuura, S.

1973-01-01

108

VEGF induces sensory and motor peripheral plasticity, alters bladder function, and promotes visceral sensitivity  

PubMed Central

Background This work tests the hypothesis that bladder instillation with vascular endothelial growth factor (VEGF) modulates sensory and motor nerve plasticity, and, consequently, bladder function and visceral sensitivity. In addition to C57BL/6J, ChAT-cre mice were used for visualization of bladder cholinergic nerves. The direct effect of VEGF on the density of sensory nerves expressing the transient receptor potential vanilloid subfamily 1 (TRPV1) and cholinergic nerves (ChAT) was studied one week after one or two intravesical instillations of the growth factor. To study the effects of VEGF on bladder function, mice were intravesically instilled with VEGF and urodynamic evaluation was assessed. VEGF-induced alteration in bladder dorsal root ganglion (DRG) neurons was performed on retrogradly labeled urinary bladder afferents by patch-clamp recording of voltage gated Na+ currents. Determination of VEGF-induced changes in sensitivity to abdominal mechanostimulation was performed by application of von Frey filaments. Results In addition to an overwhelming increase in TRPV1 immunoreactivity, VEGF instillation resulted in an increase in ChAT-directed expression of a fluorescent protein in several layers of the urinary bladder. Intravesical VEGF caused a profound change in the function of the urinary bladder: acute VEGF (1 week post VEGF treatment) reduced micturition pressure and longer treatment (2 weeks post-VEGF instillation) caused a substantial reduction in inter-micturition interval. In addition, intravesical VEGF resulted in an up-regulation of voltage gated Na+ channels (VGSC) in bladder DRG neurons and enhanced abdominal sensitivity to mechanical stimulation. Conclusions For the first time, evidence is presented indicating that VEGF instillation into the mouse bladder promotes a significant increase in peripheral nerve density together with alterations in bladder function and visceral sensitivity. The VEGF pathway is being proposed as a key modulator of neural plasticity in the pelvis and enhanced VEGF content may be associated with visceral hyperalgesia, abdominal discomfort, and/or pelvic pain.

2012-01-01

109

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

PubMed Central

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.

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

2009-01-01

110

Long sensory tracts (cuneate fascicle) in cervical somatosensory evoked potential after median nerve stimulation.  

PubMed

Low amplitude high frequency waves (LHW) were investigated in normal and patient cervical somatosensory evoked potentials after median nerve stimulation (CSEP) in parallel to normal and patient conducted somatosensory evoked potentials (SEP) after tibial nerve stimulation. Normal recordings were obtained in five subjects undergoing dorsal root entry zone (DREZ) coagulation for pain relief. Patient recordings were obtained in 11 subjects suffering from either syringomyelia, spinal cord tumour, or both. All recordings were made intraoperatively from the dorsal spinal cord surface using the subpial recording technique. Normal CSEP showed typical triphasic potential starting with an initial P9, followed by N13 and a final positivity, P1. Numerous LHW were superimposed on slow triphasic potential. To improve the visibility of LHW, slow triphasic potential was removed from the original CSEP. Potentials thus obtained contained only high frequency components of CSEP, i.e. LHW. They were compared with conducted SEP after tibial nerve stimulation. Comparison revealed similarities in high frequency, low amplitude and general wave form, LHW thus showing characteristics of conducted potential. Duration was found to be significantly shorter than normal duration in both patient LHW (Student's t-test, P < 0.0005) and patient conducted SEP (Student's t-test, P = 0.064). A shorter duration was associated with worsening of configuration in patient LHW and patient conducted SEP. These changes of LHW could not be connected with distortion of N13 seen in patient CSEP. A shorter duration and worsening of configuration in patient LHW were most prominent in cases with a loss of vibration and posture senses, but were also observed in cases where only pain and temperature senses were affected. We therefore concluded that cuneate fascicle is the most likely generator of LHW, although the participation of other cervical long sensory tracts, e.g. spinothalamic tract, cannot be ruled out. PMID:9402889

Prestor, B; Gnidovec, B; Golob, P

1997-11-01

111

Functional sensory function recovery of random-pattern abdominal skin flap in the repair of fingertip skin defects  

PubMed Central

The fingertip skin defect is a common hand injury often accompanied by tendon or bone exposure, and is normally treated with flaps. The aim of this study was to evaluate the functional sensory recovery of random-pattern abdominal skin flap in the repair of fingertip cutaneous deficiency. A total of 23 patients, aged between 18 and 50 years (mean age, 31 years) with fingertip cutaneous deficiency (30 digits) were treated with random-pattern abdominal skin flaps. The post-debridement defect area measured from 0.7×1.2 to 2.5×3 cm. The flap pedicle was divided three weeks after surgery, which marked the onset of the second stage. A second surgery was performed on 2 patients after 3 months and on another set of 2 patients after 6 months to create a thinner flap. Tissue was dissected during surgery for a histological examination. All the flaps survived and the post-operative follow-up ranged from 2 weeks to 6 months. Patients were satisfied with the appearance of their fingers and the flaps. All flaps demonstrated satisfactory flexibility and texture and sensory recovery was achieved. Only 4 patients were subjected to a second surgery to make the flap thinner. The flaps for the 3-month tissue section had several low-density, free nerve endings, whereas those of the 6-month section had more intensive free nerve endings, nerve tracts, tactile cells and lamellar corpuscles. Random-pattern abdominal skin flap therefore repairs fingertip skin defects achieving sensory recovery.

YU, YA-DONG; ZHANG, YING-ZE; BI, WEI-DONG; WU, TAO

2013-01-01

112

Electrical stimulation accelerates axonal and functional peripheral nerve regeneration across long gaps.  

PubMed

Short-term low-frequency electrical stimulation (ESTIM) of proximal peripheral nerve stumps prior to end-to-end coaptation or tubular bridging of small distances has been reported to increase preferential motor reinnervation and functional motor recovery in animal models and human patients undergoing carpal tunnel release surgery. We investigated the effects of ESTIM on regeneration across rat sciatic nerve gaps, which exceed distances that allow spontaneous regeneration. Three different reconstruction approaches were combined with ESTIM in the experimental groups. Nerve gaps (13 mm) were bridged using (I) nerve autotransplantation, (II) transplantation of differentially filled silicone tubes, or (III) transplantation of tubular grafts containing fibroblast growth factor-2 overexpressing Schwann cells (SCs) for gene therapy. The regeneration outcome was followed for up to 8 weeks, and functionally as well as histomorphometrically analyzed in comparison to non-stimulated control groups. Combining ESTIM with nerve autotransplantation significantly increased the nerve fiber density in the regenerated nerve, and the grade of functional recovery as detected by electrodiagnostic recordings from the gastrocnemius muscle. The combination of ESTIM with transplantation of naïve SCs increased the regeneration of gap-bridging nerve tissue. Although macroscopic tissue regeneration was not further improved after combining ESTIM with FGF-2(21/23-kD) gene therapy, the latter resulted in a high rate of regenerated nerves that functionally reconnected to the target muscle. Based on our results, brief ESTIM shows high potential to accelerate axonal as well as functional (motor and sensory) outcomes in the clinical setting of peripheral nerve gap reconstruction in human patients. PMID:21265597

Haastert-Talini, Kirsten; Schmitte, Ruth; Korte, Nele; Klode, Dorothee; Ratzka, Andreas; Grothe, Claudia

2011-04-01

113

Phenotyping the Function of TRPV1-Expressing Sensory Neurons by Targeted Axonal Silencing  

PubMed Central

Specific somatosensations may be processed by different subsets of primary afferents. C-fibers expressing heat-sensitive TRPV1 channels are proposed, for example, to be heat but not mechanical pain detectors. To phenotype in rats the sensory function of TRPV1+ afferents, we rapidly and selectively silenced only their activity, by introducing the membrane-impermeant sodium channel blocker QX-314 into these axons via the TRPV1 channel pore. Using tandem mass spectrometry we show that upon activation with capsaicin, QX-314 selectively accumulates in the cytosol only of TRPV1-expressing cells, and not in control cells. Exposure to QX-314 and capsaicin induces in small DRG neurons a robust sodium current block within 30 s. In sciatic nerves, application of extracellular QX-314 with capsaicin persistently reduces C-fiber but not A-fiber compound action potentials and this effect does not occur in TRPV1?/? mice. Behavioral phenotyping after selectively silencing TRPV1+ sciatic nerve axons by perineural injections of QX-314 and capsaicin reveals deficits in heat and mechanical pressure but not pinprick or light touch perception. The response to intraplantar capsaicin is substantially reduced, as expected. During inflammation, silencing TRPV1+ axons abolishes heat, mechanical, and cold hyperalgesia but tactile and cold allodynia remain following peripheral nerve injury. These results indicate that TRPV1-expressing sensory neurons process particular thermal and mechanical somatosensations, and that the sensory channels activated by mechanical and cold stimuli to produce pain in naive/inflamed rats differ from those in animals after peripheral nerve injury.

Brenneis, Christian; Kistner, Katrin; Puopolo, Michelino; Segal, David; Roberson, David; Sisignano, Marco; Labocha, Sandra; Ferreiros, Nerea; Strominger, Amanda; Cobos, Enrique J.; Ghasemlou, Nader; Geisslinger, Gerd; Reeh, Peter W.; Bean, Bruce P.; Woolf, Clifford J.

2013-01-01

114

Sensory and Cognitive Factors Influencing Functional Ability in Older Adults  

Microsoft Academic Search

Background: Age-related sensory and cognitive impairments have been related to functional performance in older adults. With regard to cognitive abilities, processing speed in particular may be strongly related to older adults’ abilities to perform everyday tasks. Identifying and comparing cognitive correlates of functional performance is particularly important in order to design interventions to promote independence and prevent functional disability. Objective:

Kimberly M. Wood; Jerri D. Edwards; Olivio J. Clay; Virginia G. Wadley; Daniel L. Roenker; Karlene K. Ball

2005-01-01

115

Changes in nerve function and nerve fibre structure induced by acute, graded compression.  

PubMed Central

Rabbit tibial nerves were subjected to direct, acute graded compression by means of an inflatable compression chamber. The acute and long term effects of 50, 200 and 400 mmHg applied for two hours on nerve function and nerve fibre structure were investigated. A pressure of 50 mmHg applied for two hours induced only minimal or no acute deterioration of maximal conduction velocity and nerve fibre structure. Conduction velocity was gradually reduced during compression at 200-400 mmHg pressure for two hours and in those cases the recovery of nerve conduction after pressure release was incomplete. Ultrastructural analysis revealed pronounced, early nerve fibre damage in these nerves. Three weeks after compression, nerves compressed at 50 mmHg for two hours had normal afferent and motor conduction velocity, although there were morphological signs of slight nerve fibre damage. Nerves compressed at 200 mmHg for two hours exhibited reduction of conduction velocity only at the level of compression, in contrast to the nerves compressed at 400 mmHg for two hours in which conduction velocity was reduced both at the level of compression and distal to the compressed segment. Morphologically, the nerves compressed at 200-400 mmHg for two hours showed varying degrees of demyelination and axonal degeneration three weeks after compression. Images

Rydevik, B; Nordborg, C

1980-01-01

116

Use of Synthetic Nerve Grafts to Restore Cavernous Nerve Function Following Prostate Cancer Surgery: In Vitro and In Vivo Studies.  

National Technical Information Service (NTIS)

The hypothesis of this proposal is that interposition of micropatterned biodegradable polymer based nerve grafts to replace resected or damaged cavernous nerves can facilitate return of erectile function by engendering directional nerve growth in an anima...

B. R. Konety

2007-01-01

117

Limb lengthening and peripheral nerve function--factors associated with deterioration of conduction  

PubMed Central

Background and purpose Limb lengthening is performed for a diverse range of orthopedic problems. A high rate of complications has been reported in these patients, which include motor and sensory loss as a result of nerve damage. We investigated the effect of limb lengthening on peripheral nerve function. Patients and methods 36 patients underwent electrophysiological testing at 3 points: (1) preoperatively, (2) after application of external fixator/corticotomy but before lengthening, and (3) after lengthening. The limb-length discrepancy was due to a congenital etiology (n = 19), a growth disturbance (n = 9), or a traumatic etiology (n = 8). Results 2 of the traumatic etiology patients had significant changes evident on electrophysiological testing preoperatively. They both deteriorated further with lengthening. 7 of the 21 patients studied showed deterioration in nerve function after lengthening, but not postoperatively, indicating that this was due to the lengthening process and not to the surgical procedure. All of these patients had a congenital etiology for their leg-length discrepancy. Interpretation As detailed electrophysiological tests were carried out before surgery, after surgery but before lengthening, and finally after completion of lengthening, it was possible to distinguish between the effects of the operation and the effects of lengthening on nerve function. The results indicate that the etiology, site (femur or tibia), and nerve (common peroneal or tibial) had a bearing on the risk of nerve injury and that these factors had a far greater effect than the total amount of lengthening.

2013-01-01

118

The relationship between sensory impairment and functional independence among elderly  

Microsoft Academic Search

BACKGROUND: It has been well established that increasing age is associated with decreasing functional ability in older adults. It is important to understand the specific factors that affect instrumental activities of daily living (IADL) and functional independence among older adults with sensory disabilities. METHODS: Nationally representative sample of adults aged 55 years and older with seeing or hearing disabilities were

Parminder Raina; Micheline Wong; Helen Massfeller

2004-01-01

119

Clinical application of sensory protection of denervated muscle  

PubMed Central

Following proximal peripheral nerve injury, motor recovery is often poor due to prolonged muscle denervation and loss of regenerative potential. The transfer of a sensory nerve to denervated muscle results in improved functional recovery in experimental models. The authors here report the first clinical case of sensory protection. Following a total hip arthroplasty, this patient experienced a complete sciatic nerve palsy with no recovery at 3 months postsurgery and profound denervation confirmed electrodiagnostically. He underwent simultaneous neurolysis of the sciatic nerve and saphenous nerve transfers to the tibialis anterior branch of the peroneal nerve and gastrocnemius branch from the tibial nerve. He noted an early proprioceptive response. Electromyography demonstrated initially selective amelioration of denervation potentials followed by improved motor recovery in sensory protected muscles only. The patient reported clinically significant functional improvements in activities of daily living. The authors hypothesize that the presence of a sensory nerve during muscle denervation can improve functional motor recovery.

Bain, James R.; Hason, Yaniv; Veltri, Karen; Fahnestock, Margaret; Quartly, Caroline

2012-01-01

120

Expression of P0 protein in sural nerve of a patient with hereditary motor and sensory neuropathy type III.  

PubMed

We present expression of Po protein and Po mRNA on the sural nerve of a patient with hereditary motor and sensory neuropathy type III. This patient was identified with a point mutation in Po gene, which resulted in the substitution of glycine for arginine in transmembrane domain of P0 protein. An electron microscopic examination revealed very thin myelinated fibers surrounded by multilamellated onion bulbs composed with greatly proliferated Schwann cells. An immunocytochemical and immunoblot analysis is showed P0 protein normally expressed in myelin on the sural nerve. By in situ hybridization, mRNA of P0 protein was detected at normal levels in Schwann cell cytoplasm. Those observations indicated that there was no truncated myelin P0 protein in peripheral nerve of this patient. PMID:7523605

Tachi, N; Kasai, K; Chiba, S; Naganuma, M; Uyemura, K; Hayasaka, K

1994-06-01

121

Transcutaneous electrical nerve stimulation produces variable changes in somatosensory evoked potentials, sensory perception and pain threshold: clinical implications for pain relief.  

PubMed Central

Transcutaneous electrical nerve stimulation decreased early and late somatosensory evoked potential amplitudes and stimulus intensity ratings, and elevated sensory detection threshold, in normal subjects. Effects on pain threshold depended on pre-treatment threshold. These findings are relevant to treatment of clinical pain by transcutaneous electrical nerve stimulation.

Golding, J F; Ashton, H; Marsh, R; Thompson, J W

1986-01-01

122

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

PubMed Central

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

Zele, Tilen; Tomsic, Martin; Sketelj, Janez; Bajrovic, Fajko F.

2012-01-01

123

Preliminary Evaluation of a Sensory and Psychomotor Functional Test Battery for Carpal Tunnel Syndrome: Part 2—Industrial Subjects  

Microsoft Academic Search

This study evaluated the Wisconsin functional sensory and psychomotor test battery for carpal tunnel syndrome (CTS). Subjects were 27 employees recruited from a food processing plant. Both hands of all subjects were examined and categorized by presence or absence of symptoms and nerve conduction study (NCS) findings (Symptom\\/NCS, Symptom\\/NCS, Symptom\\/NCS, and Symptom\\/NCS). Symptom\\/NCS category hands had significantly better performance (15–60%)

Robert G. Radwin; J. Steven Moore; Margaret Roberts; James M. T. Garrity; Theresa Oswald

1997-01-01

124

Cannabinoid receptor agonists inhibit sensory nerve activation in guinea pig airways.  

PubMed

We examined the effects of cannabinoid receptor agonists on various respiratory reactions induced by the activation of capsaicin-sensitive afferent sensory nerves (C-fibers). (R)-(+)-[2,3-dihydro-5-methyl-3-[(4-merpholino)methyl]pyrrolo-[1,2,3-de]-1,4-benzoxazin-6-yl](1-naphthyl)methanone (WIN 55212-2) dose-dependently inhibited electrical field stimulation- and capsaicin-induced guinea pig bronchial smooth muscle contraction, but not the neurokinin A-induced contraction. A cannabinoid CB2 receptor antagonist, [N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)pyrazole-3-carboxamide] (SR 144528), reduced the inhibitory effect of WIN 55212-2, but not a cannabinoid CB1 antagonist, [N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamidehydrochloride] (SR 141716A). A cannabinoid CB2 agonist, JWH 133, also inhibited electrical field stimulation-induced guinea pig bronchial smooth muscle contraction and its inhibitory effect was blocked by SR 144528. The inhibitory effect of WIN 55212-2 on electrical field stimulation-induced bronchial contraction was reduced by the pretreatment of large conductance Ca(2+)-activated K+ channel (Maxi-K+ channel) blockers, iberiotoxin and charybdotoxin, but not other K+ channel blockers, dendrotoxin or glibenclamide. A Maxi-K+ channel opener, 1-(2'-hydroxy-5'-trifluoromethylphenyl)-5-trifluoromethyl-2(3H)benzimidazolone (NS1619), inhibited bronchial contraction induced by electrical field stimulation. WIN 55212-2 and JWH 133 blocked the capsaicin-induced release of substance P-like immunoreactivity from guinea pig airway tissues. These findings suggest that WIN 55212-2 inhibit the activation of C-fibers via cannabinoid CB2 receptors and Maxi-K+ channels in guinea pig airways. PMID:15306537

Yoshihara, Shigemi; Morimoto, Hiroshi; Yamada, Yumi; Abe, Toshio; Arisaka, Osamu

2004-11-01

125

Proximal sensory neuropathies of the Leg.  

PubMed

This article addresses the proximal sensory neuropathies of the leg, concentrating on those nerves that are purely sensory or have a predominately sensory onset. These include the lateral femoral cutaneous nerve, the ilioinguinal nerve, the genitofemoral nerve, and the posterior femoral cutaneous nerve. The obturator and femoral nerves are also summarily mentioned with respect to their sensory symptoms. PMID:10393758

Reid, V; Cros, D

1999-08-01

126

[A case of acute autonomic, sensory and motor neuropathy with swelling and gadolinium enhancement of bilateral trigeminal nerve on MRI and dissociation between superficial and deep sensation disturbance].  

PubMed

We report a case of a 46-year old man with acute autonomic, sensory and motor neuropathy (AASMN). He developed severe orthostatic hypotension, anuria,anhydrosis, tonic pupil with dysarthria, dysphagia, jaw claudication, and dysesthesia and sharp pain several days after symptom of upper respiratory infection. Neurological examination revealed severely decreased superficial sensation with normal deep sensation. Brain MRI findings showed bilateral trigeminal nerve swelling with gadolinium (Gd) enhancement. His motor and sensory symptoms and MRI abnormality were improved after the administration of intravenous immunoglobulin and intravenous methylprednisolone therapy; however his autonomic symptoms scarcely reacted to these immunotherapies. As long as we investigated in AASMN cases, bilateral trigeminal nerve swelling with Gd enhancement and dissociation between superficial and deep sensation disturbance have not reported, suggesting that the present case mainly disrupted C nerve fibers distributing postganglionic autonomic and temperature-pain sensory nerves. PMID:23470893

Naito, Hiroyuki; Doi, Hikaru; Inamizu, Saeko; Ito, Hijiri; Araki, Takehisa

2013-01-01

127

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

PubMed Central

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

Cruz Martinez, A; Barrio, M; Perez Conde, M C; Gutierrez, A M

1978-01-01

128

Pudendal nerve function during pregnancy and after delivery  

Microsoft Academic Search

The aim of the study was to assess pudendal nerve function serially during pregnancy and after delivery. Twenty-eight women\\u000a participated at 14, 30 and 36 weeks of pregnancy and 12 weeks postpartum. A prospective study of pudendal nerve terminal motor\\u000a latency during pregnancy and after delivery was carried out. Results showed that pudendal nerve terminal motor latency did\\u000a not increase

T. Tetzschner; M. Sørensen; G. Lose; J. Christiansen

1997-01-01

129

The relationship between sensory impairment and functional independence among elderly  

PubMed Central

Background It has been well established that increasing age is associated with decreasing functional ability in older adults. It is important to understand the specific factors that affect instrumental activities of daily living (IADL) and functional independence among older adults with sensory disabilities. Methods Nationally representative sample of adults aged 55 years and older with seeing or hearing disabilities were categorised into three sensory classifications: "Seeing Disabled but Hearing Abled" (SD-HA), "Hearing Disabled but Seeing Abled" (HD-SA), and both "Seeing and Hearing Disabled" (SD-HD). The additional category of "Seeing Disabled and/or Hearing Disabled" (SD and/or HD) was created to calculate the total of all individuals from the above categories who either had a seeing or hearing disability or both sensory disabilities. Respondents were asked to indicate whether they received assistance in performing seven IADL and their level of functional independence. Results The most common factors that affect IADL were heavy chores, grocery shopping and housework. Individuals with both seeing and hearing disabilities (SD-HD) reported having the most IADL restrictions, followed by individuals with only seeing disabilities (SD-HA) and only hearing disabilities (HD-SA). Individuals with severe sensory disabilities were generally more likely to report IADL restrictions and less likely to have decision-making control and be happy with their lives. In each sensory classification, females aged 55–64 years and 65 years and older reported more IADL restrictions than males. Conclusion Both seeing and hearing disabilities have a significant impact on restricting an individual's IADL.

Raina, Parminder; Wong, Micheline; Massfeller, Helen

2004-01-01

130

Continuous Femoral Nerve Blocks: The Impact of Catheter Tip Location Relative to the Femoral Nerve (Anterior Versus Posterior) on Quadriceps Weakness and Cutaneous Sensory Block  

PubMed Central

Background During a continuous femoral nerve block, the influence of catheter tip position relative to the femoral nerve on infusion characteristics remains unknown. Methods We inserted bilateral femoral perineural catheters in volunteers (ultrasound-guided, needle in-plane). Subjects’ dominant side was randomized to have the catheter tip placed either anterior or posterior to the femoral nerve. The contralateral limb received the alternative position. Ropivacaine 0.1% was administered through both catheters concurrently for 6 hours (4 mL/h). Outcome measures included the maximum voluntary isometric contraction (MVIC) of the quadriceps femoris muscle and tolerance to cutaneous electrical current over to the distal quadriceps tendon. Measurements were performed at Hour 0 (baseline), and on the hour until Hour 9, as well as Hour 22. The primary endpoint was the MVIC of the quadriceps at Hour 6. Results As a percentage of the baseline measurement, quadriceps MVIC for limbs with anterior (n=16) and posterior (n=16) catheter tip placement did not differ to a statistically significant degree at Hour 6 (mean [SD] 29% [26] vs. 30% [28], respectively; 95% CI: ?22% to 20%; p=0.931), or at any other time point. However, the maximum tolerance to cutaneous electrical current was higher in limbs with anterior compared to posterior catheter tip placement at Hour 6 (20 [23] vs. 6 [4] mA, respectively; 95% CI: 1 mA to 27 mA; p=0.035), as well as at Hours 1, 7, 8, and 9 (p<0.04). Conclusions This study documents the significant (70–80%) quadriceps femoris weakness induced by a continuous femoral nerve block infusion at a relatively low dose of ropivacaine (4 mg/h) delivered through a perineural catheter located both anterior and posterior to the femoral nerve. In contrast, an anterior placement increases cutaneous sensory block compared with a posterior insertion, without a concurrent relative increase in motor block.

Ilfeld, Brian M.; Loland, Vanessa J.; Sandhu, NavParkash S.; Suresh, Preetham J.; Bishop, Michael J.; Donohue, Michael C.; Ferguson, Eliza J.; Madison, Sarah J.

2012-01-01

131

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

PubMed Central

Although a variety of industrial chemicals, as well as several chemotherapeutic agents used to treat cancer or HIV, preferentially induce a peripheral sensory neuropathy what remains unclear is why these agents induce a sensory vs. a motor or mixed neuropathy. Previous studies have shown that the endothelial cells that vascularize the dorsal root ganglion (DRG), which houses the primary afferent sensory neurons, are unique in that they have large fenestrations and are permeable to a variety of low and high molecular weight agents. In the present report we used whole-mount preparations, immunohistochemistry, and confocal laser scanning microscopy to show that the cell body-rich area of the L4 mouse DRG has a 7 fold higher density of CD31+ capillaries than cell fiber rich area of the DRG or the distal or proximal aspect of the sciatic nerve. This dense vascularization, coupled with the high permeability of these capillaries, may synergistically contribute, and in part explain, why many potentially neurotoxic agents preferentially accumulate and injure cells within the DRG. Currently, cancer survivors and HIV patients constitute the largest and most rapidly expanding groups that have chemically induced peripheral sensory neuropathy. Understanding the unique aspects of the vascularization of the DRG and closing the endothelial fenestrations of the rich vascular bed of capillaries that vascularize the DRG before intravenous administration of anti-neoplastic or anti-HIV therapies, may offer a mechanism based approach to attenuate these chemically induced peripheral neuropathies in these patients.

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

2008-01-01

132

Olfactory Cilia: Linking Sensory Cilia Function and Human Disease  

PubMed Central

The olfactory system gives us an awareness of our immediate environment by allowing us to detect airborne stimuli. The components necessary for detection of these odorants are compartmentalized in the cilia of olfactory sensory neurons. Cilia are microtubule-based organelles, which can be found projecting from the surface of almost any mammalian cell, and are critical for proper olfactory function. Mislocalization of ciliary proteins and/or the loss of cilia cause impaired olfactory function, which is now recognized as a clinical manifestation of a broad class of human diseases, termed ciliopathies. Future work investigating the mechanisms of olfactory cilia function will provide us important new information regarding the pathogenesis of human sensory perception diseases.

Jenkins, Paul M.; McEwen, Dyke P.

2009-01-01

133

Glycomimetic functionalized collagen hydrogels for peripheral nerve repair  

NASA Astrophysics Data System (ADS)

Despite the innate regenerative potential of the peripheral nervous system, functional recovery is often limited. The goal of this dissertation was to develop a clinically relevant biomaterial strategy to (1) encourage the regrowth of axons and (2) direct them down their appropriate motor tracts. To this end, we use peptide mimics of two glycans, polysialic acid (PSA) and an epitope first discovered on human natural killer cells (HNK-1), to functionalize type I collagen hydrogels. Previous studies have shown that these molecules, in their glycan and glycomimetic form, are associated with acceleration of neurite outgrowth, glial cell proliferation, and motoneuron targeting. In vitro, we demonstrated the retained functionality of the peptide glycomimetics after conjugation to a type I collagen backbone. While HNK-functionalized collagen increased motor neurite outgrowth, PSA-functionalized collagen encouraged motor and sensory neurite outgrowth and Schwann cell extension and proliferation. When we introduce these glycomimetic-functionalized collagen hydrogels into a critical gap femoral nerve model, we show that both PSA and HNK-functionalized hydrogels yielded a significant increase in functional recovery when compared to saline, native and scramble-coupled hydrogels. However, there was an interesting divergence in the morphological results: PSA-functionalized hydrogels increased axon count and HNK-functionalized hydrogels increased motoneuron targeting and myelination. We believed that these differences may be attributed to distinct mechanisms by which the glycomimetics impart their benefit. Interestingly, however, we found no synergistic gain in recovery with the use of our composite hydrogels which we speculated may be due to an inadequate dose of the individual glycomimetic. To address this possibility, we show that increasing the amount of functionalized peptide functionalized in our composite hydrogels led to increases in axon count and area of regeneration, but does not affect the degree of functional recovery. Finally, in order to assess potential mechanisms by which our glycomimetics impart benefit, we describe a novel platform for studying neural cell/biomaterial interaction through the use of two types of motoneuron cultures, dissociated spinal cord neurons and organotypic spinal cord slices. We show promising evidence that this strategy can be used to probe signaling pathways potentially involved in the action of these bioactives.

Masand, Shirley Narain

134

Exorcizing the animal spirits: Jan Swammerdam on nerve function  

Microsoft Academic Search

For more than 1,500 years, nerves were thought to function through the action of 'animal spirits'. In the seventeenth century, René Descartes conceived of these 'spirits' as liquids or gases, and used the idea to explain reflex action. But he was rapidly proven wrong by a young Dutchman, Jan Swammerdam. Swammerdam's elegant experiments pioneered the frog nerve–muscle preparation and laid

Matthew Cobb

2002-01-01

135

Loss of Corneal Sensory Nerve Fibers in SIV-Infected Macaques: An Alternate Approach to Investigate HIV-Induced PNS Damage.  

PubMed

Peripheral neuropathy is the most frequent neurological complication of HIV infection, affecting more than one-third of infected patients, including patients treated with antiretroviral therapy. Although emerging noninvasive techniques for corneal nerve assessments are increasingly being used to diagnose and monitor peripheral neuropathies, corneal nerve alterations have not been characterized in HIV. Here, to determine whether SIV infection leads to corneal nerve fiber loss, we immunostained corneas for the nerve fiber marker ?III tubulin. We developed and applied both manual and automated methods to measure nerves in the corneal subbasal plexus. These counting methods independently indicated significantly lower subbasal corneal nerve fiber density among SIV-infected animals that rapidly progressed to AIDS compared with slow progressors. Concomitant with decreased corneal nerve fiber density, rapid progressors had increased levels of SIV RNA and CD68-positive macrophages and expression of glial fibrillary acidic protein by glial satellite cells in the trigeminal ganglia, the location of the neuronal cell bodies of corneal sensory nerve fibers. In addition, corneal nerve fiber density was directly correlated with epidermal nerve fiber length. These findings indicate that corneal nerve assessment has great potential to diagnose and monitor HIV-induced peripheral neuropathy and to set the stage for introducing noninvasive techniques to measure corneal nerve fiber density in HIV clinical settings. PMID:24828391

Dorsey, Jamie L; Mangus, Lisa M; Oakley, Jonathan D; Beck, Sarah E; Kelly, Kathleen M; Queen, Suzanne E; Metcalf Pate, Kelly A; Adams, Robert J; Marfurt, Carl F; Mankowski, Joseph L

2014-06-01

136

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

PubMed Central

Most small unmyelinated neurons in adult rat dorsal ganglia (DRG) express one or more of the co-receptors targeted by glial cell line-derived neurotrophic factor (GDNF), neurturin and artemin (GFR?1, GFR?2 and GFR?3 respectively). The function of these GDNF family ligands (GFLs) is not fully elucidated but recent evidence suggests GFLs could function in sensory neuron regeneration after nerve injury and peripheral nociceptor sensitisation. In this study, we used immunohistochemistry to determine if the DRG neurons targeted by each GFL change after sciatic nerve injury. We compared complete sciatic nerve transection and the chronic constriction model and found the pattern of changes incurred by each injury was broadly similar. In lumbar spinal cord, there was a widespread increase in neuronal GFR?1 immunoreactivity (IR) in the L1-6 dorsal horn. GFR?3-IR also increased but in a more restricted area. In contrast, GFR?2-IR decreased in patches of superficial dorsal horn and this loss was more extensive after transection injury. No change in calcitonin gene-related peptide-IR was detected after either injury. Analysis of double-immunolabelled L5 DRG sections suggested the main effect of injury on GFR?1- and GFR?3-IR was to increase expression in both myelinated and unmyelinated neurons. In contrast, no change in basal expression of GFR?2-IR was detected in DRG by analysis of fluorescence intensity and there was a small but significant reduction in GFR?2-IR neurons. Our results suggest the DRG neuronal populations targeted by GDNF, neurturin or artemin, and the effect of exogenous GFLs could change significantly after a peripheral nerve injury.

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

2010-01-01

137

Afferent Nerve Regulation of Bladder Function in Health and Disease  

PubMed Central

The afferent innervation of the urinary bladder consists primarily of small myelinated (A?) and unmyelinated (C-fiber) axons that respond to chemical and mechanical stimuli. Immunochemical studies indicate that bladder afferent neurons synthesize several putative neurotransmitters, including neuropeptides, glutamic acid, aspartic acid, and nitric oxide. The afferent neurons also express various types of receptors and ion channels, including transient receptor potential channels, purinergic, muscarinic, endothelin, neurotrophic factor, and estrogen receptors. Patch-clamp recordings in dissociated bladder afferent neurons and recordings of bladder afferent nerve activity have revealed that activation of many of these receptors enhances neuronal excitability. Afferent nerves can respond to chemicals present in urine as well as chemicals released in the bladder wall from nerves, smooth muscle, inflammatory cells, and epithelial cells lining the bladder lumen. Pathological conditions alter the chemical and electrical properties of bladder afferent pathways, leading to urinary urgency, increased voiding frequency, nocturia, urinary incontinence, and pain. Neurotrophic factors have been implicated in the pathophysiological mechanisms underlying the sensitization of bladder afferent nerves. Neurotoxins such as capsaicin, resiniferatoxin, and botulinum neurotoxin that target sensory nerves are useful in treating disorders of the lower urinary tract.

de Groat, William C.; Yoshimura, Naoki

2012-01-01

138

Surgical and conservative methods for restoring impaired motor function - facial nerve, spinal accessory nerve, hypoglossal nerve (not including vagal nerve or swallowing)  

PubMed Central

The present review gives a survey of rehabilitative measures for disorders of the motor function of the mimetic muscles (facial nerve), and muscles innervated by the spinal accessory and hypoglossal nerves. The dysfunction can present either as paralysis or hyperkinesis (hyperkinesia). Conservative and surgical treatment options aimed at restoring normal motor function and correcting the movement disorders are described. Static reanimation techniques are not dealt with. The final section describes the use of botulinum toxin in the therapy of dysphagia.

Laskawi, R.; Rohrbach, S.

2005-01-01

139

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

PubMed Central

Background Bilateral sagittal split ramus osteotomy (BSSRO) is a common orthognatic surgical procedure. Sensory disturbances in the inferior alveolar nerve, including hypoesthesia and dysesthesia, are frequently observed after BSSRO, even without distinct nerve injury. The mechanisms that underlie individual differences in the vulnerability to sensory disturbances have not yet been elucidated. Methods The present study investigated the relationships between genetic polymorphisms and the vulnerability to sensory disturbances after BSSRO in a genome-wide association study (GWAS). A total of 304 and 303 patients who underwent BSSRO were included in the analyses of hypoesthesia and dysesthesia, respectively. Hypoesthesia was evaluated using the tactile test 1 week after surgery. Dysesthesia was evaluated by interview 4 weeks after surgery. Whole-genome genotyping was conducted using Illumina BeadChips including approximately 300,000 polymorphism markers. Results Hypoesthesia and dysesthesia occurred in 51 (16.8%) and 149 (49.2%) subjects, respectively. Significant associations were not observed between the clinical data (i.e., age, sex, body weight, body height, loss of blood volume, migration length of bone fragments, nerve exposure, duration of anesthesia, and duration of surgery) and the frequencies of hypoesthesia and dysesthesia. Significant associations were found between hypoesthesia and the rs502281 polymorphism (recessive model: combined ?2 = 24.72, nominal P = 6.633 × 10-7), between hypoesthesia and the rs2063640 polymorphism (recessive model: combined ?2 = 23.07, nominal P = 1.563 × 10-6), and between dysesthesia and the nonsynonymous rs2677879 polymorphism (trend model: combined ?2 = 16.56, nominal P = 4.722 × 10-5; dominant model: combined ?2 = 16.31, nominal P = 5.369 × 10-5). The rs502281 and rs2063640 polymorphisms were located in the flanking region of the ARID1B and ZPLD1 genes on chromosomes 6 and 3, whose official names are “AT rich interactive domain 1B (SWI1-like)” and “zona pellucida-like domain containing 1”, respectively. The rs2677879 polymorphism is located in the METTL4 gene on chromosome 18, whose official name is “methyltransferase like 4”. Conclusions The GWAS of sensory disturbances after BSSRO revealed associations between genetic polymorphisms located in the flanking region of the ARID1B and ZPLD1 genes and hypoesthesia and between a nonsynonymous genetic polymorphism in the METTL4 gene and dysesthesia.

2013-01-01

140

Dietary sodium modulates the interaction between efferent and afferent renal nerve activity by altering activation of ?2-adrenoceptors on renal sensory nerves  

PubMed Central

Activation of efferent renal sympathetic nerve activity (ERSNA) increases afferent renal nerve activity (ARNA), which then reflexively decreases ERSNA via activation of the renorenal reflexes to maintain low ERSNA. The ERSNA-ARNA interaction is mediated by norepinephrine (NE) that increases and decreases ARNA by activation of renal ?1-and ?2-adrenoceptors (AR), respectively. The ERSNA-induced increases in ARNA are suppressed during a low-sodium (2,470 ± 770% s) and enhanced during a high-sodium diet (5,670 ± 1,260% s). We examined the role of ?2-AR in modulating the responsiveness of renal sensory nerves during low- and high-sodium diets. Immunohistochemical analysis suggested the presence of ?2A-AR and ?2C-AR subtypes on renal sensory nerves. During the low-sodium diet, renal pelvic administration of the ?2-AR antagonist rauwolscine or the AT1 receptor antagonist losartan alone failed to alter the ARNA responses to reflex increases in ERSNA. Likewise, renal pelvic release of substance P produced by 250 pM NE (from 8.0 ± 1.3 to 8.5 ± 1.6 pg/min) was not affected by rauwolscine or losartan alone. However, rauwolscine+losartan enhanced the ARNA responses to reflex increases in ERSNA (4,680 ± 1,240%·s), and renal pelvic release of substance P by 250 pM NE, from 8.3 ± 0.6 to 14.2 ± 0.8 pg/min. During a high-sodium diet, rauwolscine had no effect on the ARNA response to reflex increases in ERSNA or renal pelvic release of substance P produced by NE. Losartan was not examined because of low endogenous ANG II levels in renal pelvic tissue during a high-sodium diet. Increased activation of ?2-AR contributes to the reduced interaction between ERSNA and ARNA during low-sodium intake, whereas no/minimal activation of ?2-AR contributes to the enhanced ERSNA-ARNA interaction under conditions of high sodium intake.

Cicha, Michael Z.; Smith, Lori A.; Ruohonen, Saku; Scheinin, Mika; Fritz, Nicolas; Hokfelt, Tomas

2011-01-01

141

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

PubMed

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

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

2010-01-15

142

A new paradigm of electrical stimulation to enhance sensory neural function.  

PubMed

The ability to improve peripheral neural transmission would have significant therapeutic potential in medicine. A technology of this kind could be used to restore and/or enhance sensory function in individuals with depressed sensory function, such as older adults or patients with peripheral neuropathies. The goal of this study was to investigate if a new paradigm of subsensory electrical noise stimulation enhances somatosensory function. Vibration (50Hz) was applied with a Neurothesiometer to the plantar aspect of the foot in the presence or absence of subsensory electrical noise (1/f type). The noise was applied at a proximal site, on a defined region of the tibial nerve path above the ankle. Vibration perception thresholds (VPT) of younger adults were measured in control and experimental conditions, in the absence or presence of noise respectively. An improvement of ?16% in VPT was found in the presence of noise. These are the first data to demonstrate that modulation of axonal transmission with externally applied electrical noise improves perception of tactile stimuli in humans. PMID:24894033

Breen, Paul P; OLaighin, Gearóid; McIntosh, Caroline; Dinneen, Sean F; Quinlan, Leo R; Serrador, Jorge M

2014-08-01

143

Prefabricated nerve conduits advance histomorphological and functional outcomes in nerve regeneration of the sciatic nerve of the rat.  

PubMed

Bridging a nerve defect is sometimes necessary to achieve nerve regeneration after injury. Different methods and conduit designs have been considered, but only isograft transplants or prefabricated conduits are available. This study presents a comparison of prefabricated conduits and isograft transplants in rats, with the aim of making suggestions for clinical settings. In rats of inbred strains LEW and DA, a 1.5cm defect of the sciatic nerve was reconstructed by isograft (n=10) or conduit (n=10). Untreated rats (n=10), sham-operated rats (n=10) and nerves of the non-operated contralateral limb served as controls. Regeneration was evaluated by histomorphological examination and with walking track analysis of the ankle stance angle (ASA) and the sciatic functional index (SFI). After 16 weeks, myelinization and ASA in the conduit group were significantly superior to that in the isograft group. There was no significant difference in SFI between the groups. Reconstruction in the isograft group showed a negative impact on the non-operated side. Conduits and isografts did not reach the morphological or functional levels of untreated or sham-operated animals. The results suggest preferential conduits should be used for nerve reconstruction. PMID:20594806

Rustemeyer, J; Dicke, U

2010-09-01

144

Human Sensory Functions. Part 1: Visual Functions Zintuiglijke Functies van de Mens. Deel 1: Visuele Functies.  

National Technical Information Service (NTIS)

A contribution to a handbook on psychonomy relating to sensory functions is presented. The properties of the human eye are described, including optical image formation, image quality, the retina, photometry, light and dark adaptation, and color vision.

J. J. Vos

1974-01-01

145

Nerve function in workers with long term exposure to trichloroethene.  

PubMed Central

Certain functions of the nervous system were examined in 31 printing workers (mean age 44) exposed to trichloroethene (mean duration 16 years) and 28 controls (mean age 45). In the sural nerve the conduction velocity (SNCV), response amplitude, and refractory period (SRP) were measured. The latencies of the masseter and the blink reflex were determined to test the trigeminal nerve. In the peroneal nerve the conduction velocity of fast and slow nerve fibres, the response amplitude, and the refractory period were determined. As a measure of autonomic nerve function the response of the heart rate was determined to isometric muscle contraction and deep breathing. Individual cumulative exposure was calculated on the basis of exposure levels in the past. The mean cumulative exposure of the exposed workers was 704 ppm x years. For the assessment of the exposure effect relation a multiple linear regression model was used. A slight reduction (-1.1 m/s) in the SNCV was found and a prolongation (0.4 ms) of the SRP (mean of the controls 1.95 ms). The latency of the masseter reflex (mean 10.4 ms) had increased (0.4 ms). With respect to the blink reflex no prolongation was found. No impairment was found in the functions of motor and autonomic nerves. This study shows that the refractory period may be a sensitive indicator of preclinical toxic neuropathies. Long term exposure to trichloroethene at threshold limit values (about 35 ppm) may slightly affect the trigeminal and sural nerves.

Ruijten, M W; Verberk, M M; Salle, H J

1991-01-01

146

Neurophysiological assessment of auditory, peripheral nerve, somatosensory, and visual system functions after developmental exposure to ethanol vapors.  

PubMed

Ethanol-blended gasoline entered the market in response to demand for domestic renewable energy sources, and may result in increased inhalation of ethanol vapors in combination with other volatile gasoline constituents. It is important to understand potential risks of inhalation of ethanol vapors by themselves, and also as a baseline for evaluating the risks of ethanol combined with a complex mixture of hydrocarbon vapors. Because sensory dysfunction has been reported after developmental exposure to ethanol, we evaluated the effects of developmental exposure to ethanol vapors on neurophysiological measures of sensory function as a component of a larger project evaluating developmental ethanol toxicity. Pregnant Long-Evans rats were exposed to target concentrations 0, 5000, 10,000, or 21,000ppm ethanol vapors for 6.5h/day over GD9-GD20. Sensory evaluations of male offspring began between PND106 and PND128. Peripheral nerve function (compound action potentials, nerve conduction velocity (NCV)), somatosensory (cortical and cerebellar evoked potentials), auditory (brainstem auditory evoked responses), and visual evoked responses were assessed. Visual function assessment included pattern elicited visual evoked potentials (VEPs), VEP contrast sensitivity, and electroretinograms recorded from dark-adapted (scotopic), light-adapted (photopic) flashes, and UV flicker and green flicker. No consistent concentration-related changes were observed for any of the physiological measures. The results show that gestational exposure to ethanol vapor did not result in detectable changes in peripheral nerve, somatosensory, auditory, or visual function when the offspring were assessed as adults. PMID:24607749

Boyes, William K; Degn, Laura L; Martin, Sheppard A; Lyke, Danielle F; Hamm, Charles W; Herr, David W

2014-01-01

147

Putative neurotrophic factors and functional recovery from peripheral nerve damage in the rat.  

PubMed Central

1. In rats, recovery of sensory-motor function following a crush lesion of the sciatic or tibial nerve was monitored by measuring foot reflex withdrawal from a local noxious stimulation of the foot sole. 2. Putative neurotrophic compounds were tested on this functional recovery model: melanocortins (peptides derived from ACTH (corticotropin) and alpha-MSH (melanotropin], gangliosides and nimodipine were effective whereas isaxonine and TRH (thyrotropin releasing hormone) were not. 3. Structure-activity studies with melanocortins revealed a similar effectiveness of alpha-MSH, [N-Leu4, D-Phe7]-alpha-MSH, desacetyl-alpha-MSH and the ACTH analogue ORG 2766, questioning the validity of the previously suggested notion that the melanotrophic properties of these peptides are responsible for their neurotrophic effect. 4. As recovery of function after peripheral nerve damage follows a similar time course in hypophysectomized (five days post operation) and sham-operated rats, effective melanocortin therapy does not mimic an endogenous peptide signal in the repair process from pituitary origin. 5. Subcutaneous treatment with ORG 2766 (7.5 micrograms kg-1 48 h-1) facilitates recovery of function following peripheral nerve damage in young (6-7 weeks old), mature (5 month old) and old (20 month old) rats. 6. In view of the diversity in structure of the effective neurotrophic factors and the complexity of nerve repair, the present data support the notion that peripheral nerve repair may be facilitated by different humoral factors likely to be active on different aspects of the recovery process.

Van der Zee, C. E.; Brakkee, J. H.; Gispen, W. H.

1991-01-01

148

Upper Airway Sensory Function in Children with Obstructive Sleep Apnea Syndrome  

PubMed Central

Study Objectives: Children with the obstructive sleep apnea syndrome (OSAS) have impaired responses to hypercapnia, subatmospheric pressure, and inspiratory resistive loading during sleep. This may be due, in part, to an impairment in the afferent limb of the upper airway sensory pathway. Therefore, we hypothesized that children with OSAS had diminished upper airway sensation compared to controls. Design: Case-control Setting: Academic hospital Participants: Subjects with OSAS aged 6–16 years, and age- and BMI-matched controls. Interventions: Two-point discrimination (TPD) was measured during wakefulness with modified calipers in the anterior tongue, right interior cheek, and hard palate. Results: Thirteen children with OSAS and 9 controls were tested. The age (mean ± SD) for OSAS and controls was 11 ± 4 vs. 13 ± 2 years (NS); OSAS BMI Z score 2.4 ± 0.5, controls 2.2 ± 0.5 (NS); OSAS apnea hypopnea index 31 ± 48, controls 0.4 ± 0.5 events/hour (P < 0.001). Children with OSAS had impaired TPD in the anterior tongue (median [range]) = 9 [3–14] mm, controls 3 [1–7], P = 0.002) and hard palate (OSAS 6 [3–9] mm, controls 3 [1–4], P < 0.001). TPD in the cheek was similar between the groups (P = 0.12). Conclusion: TPD in the anterior tongue and hard palate was impaired in children with OSAS during wakefulness. We speculate that this impairment might be due to a primary sensory function abnormality or secondary to nerve damage and/or hypoxemia caused by OSAS. Further studies after treatment of OSAS are needed. Citation: Tapia IE; Bandla P; Traylor J; Karamessinis L; Huang J; Marcus CL. Upper airway sensory function in children with obstructive sleep apnea syndrome. SLEEP 2010;33(7):968–972.

Tapia, Ignacio E.; Bandla, Preetam; Traylor, Joel; Karamessinis, Laurie; Huang, Jingtao; Marcus, Carole L.

2010-01-01

149

Biochemical, morphological, and functional changes during peripheral nerve regeneration  

Microsoft Academic Search

The success of axon regeneration after nerve injury should be judged by the extent to which the target organs regain their\\u000a function. Recovery of muscle contraction involves axon regeneration, reestablishment of nerve-muscle connections, recovery\\u000a of transmission, and muscle force. All these processes were investigated under the same experimental conditions and correlated\\u000a in order to better understand their time-course and interdependence.

Samo Ribari?; Aneta Stefanovska; Miro Brzin; Miran Kogov?ek; Peter Kro?elj

1991-01-01

150

Facial nerve sensory responses recorded from the geniculate ganglion of Gallus gallus var. domesticus  

Microsoft Academic Search

The extracellular responses of single sensory afferent cell bodies were recorded from the geniculate ganglion of the chicken following chemical, mechanical and thermal stimulation of the oral cavity using glass coated tungsten microelectrodes. Forty eight chemoreceptive units were identified from the anterior and posterior palate, and from the anterior mandibular area of the lower jaw. Their response characteristics to tyrode

Michael J. Gentle

1987-01-01

151

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

PubMed Central

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

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

2014-01-01

152

Electrospun micro- and nanofiber tubes for functional nervous regeneration in sciatic nerve transections  

Microsoft Academic Search

BACKGROUND: Although many nerve prostheses have been proposed in recent years, in the case of consistent loss of nervous tissue peripheral nerve injury is still a traumatic pathology that may impair patient's movements by interrupting his motor-sensory pathways. In the last few decades tissue engineering has opened the door to new approaches;: however most of them make use of rigid

Silvia Panseri; Carla Cunha; Joseph Lowery; Ubaldo Del Carro; Francesca Taraballi; Stefano Amadio; Angelo Vescovi; Fabrizio Gelain

2008-01-01

153

Fos protein-like immunoreactive neurons induced by electrical stimulation in the trigeminal sensory nuclear complex of rats with chronically injured peripheral nerve.  

PubMed

The rat trigeminal sensory nuclear complex (TSNC) was examined for Fos protein-like immunoreactive (Fos-LI) neurons induced by electrical stimulation (ES) of the lingual nerve (LN) at 2 weeks after injury to the LN or the inferior alveolar nerve (IAN). Intensity-dependent increase in the number of Fos-LI neurons was observed in the subnucleus oralis (Vo) and caudalis (Vc) of the spinal trigeminal tract nucleus irrespective of nerve injury. The number of Fos-LI neurons induced by ES of the chronically injured LN at A-fiber intensity (0.1 mA) was significantly increased in the Vo but not the Vc. On the other hand, in rats with chronically injured IAN, the number of Fos-LI neurons induced by ES of the LN at C-fiber intensity (10 mA) was significantly increased in the Vc but not the Vo. These results indicated that injury of a nerve innervating intraoral structures increased the c-Fos response of Vo neurons to A-fiber intensity ES of the injured nerve. A similar nerve injury enhanced the c-Fos response of Vc neurons to C-fiber intensity ES of a spared uninjured nerve innervating an intraoral territory neighboring that of the injured nerve. The present result show that nerve injury causes differential effects on c-Fos expression in the Vo and Vc, which may explain complexity of neuropathic pain symptoms in clinical cases. PMID:22456943

Fujisawa, Naoko; Terayama, Ryuji; Yamaguchi, Daisuke; Omura, Shinji; Yamashiro, Takashi; Sugimoto, Tomosada

2012-06-01

154

Novel targeted sensory reinnervation technique to restore functional hand sensation after transhumeral amputation.  

PubMed

We present a case study of a novel variation of the targeted sensory reinnervation technique that provides additional control over sensory restoration after transhumeral amputation. The use of intraoperative somatosensory evoked potentials on individual fascicles of the median and ulnar nerves allowed us to specifically target sensory fascicles to reroute to target cutaneous nerves at a distance away from anticipated motor sites in a transhumeral amputee. This resulted in restored hand maps of the median and ulnar nerve in discrete spatially separated areas. In addition, the subject was able to use native and reinnervated muscle sites to control a robotic arm while simultaneously sensing touch and force feedback from the robotic gripper in a physiologically correct manner. This proof of principle study is the first to demonstrate the ability to have simultaneous dual flow of information (motor and sensory) within the residual limb. In working towards clinical deployment of a sensory integrated prosthetic device, this surgical method addresses the important issue of restoring a usable access point to provide natural hand sensation after upper limb amputation. PMID:24760915

Hebert, Jacqueline S; Olson, Jaret L; Morhart, Michael J; Dawson, Michael R; Marasco, Paul D; Kuiken, Todd A; Chan, K Ming

2014-07-01

155

Expression of p-Akt in Sensory Neurons and Spinal Cord after Peripheral Nerve Injury  

Microsoft Academic Search

Akt has been implicated in pro-survival and anti-apoptotic activities in many cell types, including dorsal root ganglion (DRG) and spinal motor neurons. In this immunohistochemical study we have monitored phosphorylated Akt (p-Akt) levels in adult mouse DRGs and spinal cord following unilateral peripheral sciatic nerve transection (axotomy) or carrageenan-induced inflammation. In control animals around half of the lumbar DRG neuron

Tie-Jun Sten Shi; Ping Huang; Jan Mulder; Sandra Ceccatelli; Tomas Hökfelt

2009-01-01

156

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

Microsoft Academic Search

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

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

1990-01-01

157

Thermographic evaluation of hind paw skin temperature and functional recovery of locomotion after sciatic nerve crush in rats  

PubMed Central

INTRODUCTION: Peripheral nerves are often damaged by direct mechanical injury, diseases, and tumors. The peripheral nerve injuries that result from these conditions can lead to a partial or complete loss of motor, sensory, and autonomic functions, which in turn are related to changes in skin temperature, in the involved segments of the body. The aim of this study was to evaluate the changes in hind paw skin temperature after sciatic nerve crush in rats in an attempt to determine whether changes in skin temperature correlate with the functional recovery of locomotion. METHODS: Wistar rats were divided into three groups: control (n?=?7), sham (n?=?25), and crush (n?=?25). All groups were subjected to thermographic, functional, and histological assessments. RESULTS: ?T in the crush group was different from the control and sham groups at the 1st, 3rd and 7rd postoperative days (p<0.05). The functional recovery from the crush group returned to normal values between the 3rd and 4th week post-injury, and morphological analysis of the nerve revealed incomplete regeneration at the 4th week after injury. DISCUSSION: This study is the first demonstration that sciatic nerve crush in rats induces an increase in hind paw skin temperature and that skin temperature changes do not correlate closely with functional recovery

Z. Sacharuk, Viviane; A. Lovatel, Gisele; Ilha, Jocemar; Marcuzzo, Simone; Severo do Pinho, Alexandre; L. Xavier, Leder; A. Zaro, Milton; Achaval, Matilde

2011-01-01

158

Long term functional plasticity of sensory inputs mediated by olfactory learning  

PubMed Central

Sensory inputs are remarkably organized along all sensory pathways. While sensory representations are known to undergo plasticity at the higher levels of sensory pathways following peripheral lesions or sensory experience, less is known about the functional plasticity of peripheral inputs induced by learning. We addressed this question in the adult mouse olfactory system by combining odor discrimination studies with functional imaging of sensory input activity in awake mice. Here we show that associative learning, but not passive odor exposure, potentiates the strength of sensory inputs up to several weeks after the end of training. We conclude that experience-dependent plasticity can occur in the periphery of adult mouse olfactory system, which should improve odor detection and contribute towards accurate and fast odor discriminations. DOI: http://dx.doi.org/10.7554/eLife.02109.001

Abraham, Nixon M; Vincis, Roberto; Lagier, Samuel; Rodriguez, Ivan; Carleton, Alan

2014-01-01

159

Neonatal sensory deprivation and the development of cortical function: unilateral and bilateral sensory deprivation result in different functional outcomes.  

PubMed

The normal development of sensory perception in mammals depends on appropriate sensory experience between birth and maturity. Numerous reports have shown that trimming some or all of the large mystacial vibrissa (whiskers) on one side of the face after birth has a detrimental effect on the maturation of cortical function. The objective of the present study was to understand the differences that occur after unilateral whisker trimming compared with those that occur after bilateral deprivation. Physiological deficits produced by bilateral trimming (BD) of all whiskers for 2 mo after birth were compared with the deficits produced by unilateral trimming (UD) for the same period of time using extracellular recording under urethan anesthesia from single cells in rat barrel cortex. Fast spiking (FSUs) and regular spiking (RSUs) units were separated and their properties compared in four subregions identified by histological reconstructions of the electrode penetrations, namely: layer IV barrel and septum, and layers II/III above a barrel and above a septum. UD upregulated responses in layer IV septa and in layers II/III above septa and perturbed the timing of responses to whisker stimuli. After BD, nearly all responses were decreased, and poststimulus latencies were increased. Circuit changes are proposed as an argument for how inputs arising from the spared whiskers project to the undeprived cortex and, via commissural fibers, could upregulate septal responses after UD. Following BD, more global neural deficits create a signature difference in the outcome of UD and BD in rat barrel cortex. PMID:20427621

Popescu, Maria V; Ebner, Ford F

2010-07-01

160

Functional imaging of the hemodynamic sensory gating response in schizophrenia.  

PubMed

The cortical (auditory and prefrontal) and/or subcortical (thalamic and hippocampal) generators of abnormal electrophysiological responses during sensory gating remain actively debated in the schizophrenia literature. Functional magnetic resonance imaging has the spatial resolution for disambiguating deep or simultaneous sources but has been relatively under-utilized to investigate generators of the gating response. Thirty patients with chronic schizophrenia (SP) and 30 matched controls participated in the current experiment. Hemodynamic response functions (HRFs) for single (S1) and pairs (S1 + S2) of identical ("gating-out" redundant information) or nonidentical ("gating-in" novel information) tones were generated through deconvolution. Increased or prolonged activation for patients in conjunction with deactivation for controls was observed within auditory cortex, prefrontal cortex, and thalamus in response to single tones during the late hemodynamic response, and these group differences were not associated with clinical or cognitive symptomatology. Although patient hyperactivation to paired-tones conditions was present in several regions of interest, the effects were not statistically significant for either the gating-out or gating-in conditions. Finally, abnormalities in the postundershoot of the auditory HRF were also observed for both single and paired-tones conditions in patients. In conclusion, the amalgamation of the entire electrophysiological response to both S1 and S2 stimuli may limit hemodynamic sensitivity to paired tones during sensory gating, which may be more readily overcome by paradigms that use multiple stimuli rather than pairs. Patient hyperactivation following single tones is suggestive of deficits in basic inhibition, neurovascular abnormalities, or a combination of both factors. PMID:22461278

Mayer, Andrew R; Ruhl, David; Merideth, Flannery; Ling, Josef; Hanlon, Faith M; Bustillo, Juan; Cañive, Jose

2013-09-01

161

Microscale Electrode Implantation during Nerve Repair: Effects on Nerve Morphology, Electromyography, and Recovery of Muscle Contractile Function  

PubMed Central

Background Our goal is to develop a peripheral nerve electrode with long-term stability and fidelity for use in nerve-machine interfaces. Microelectromechanical systems (MEMS) use silicon probes that contain multi-channel actuators, sensors, and electronics. We tested the null hypothesis that implantation of MEMS probes do not have a detrimental effect on peripheral nerve function or regeneration. Methods A rat hindlimb, peroneal nerve model was utilized in all experimental groups: a) intact nerve (Control, n= 10); b) nerve division and repair (Repair, n= 9); and c) Nerve division, insertion of MEMS probe, and repair (Repair + Probe, n=9). Nerve morphology, nerve to muscle compound action potential (CMAP) studies, walking tracks, and extensor digitorum longus (EDL) muscle function tests were evaluated following an 80 day recovery. Results Repair and Repair + Probe showed no differences in axon count, axon size, percent non-neural area, CMAP amplitude, latency, muscle mass, muscle force, or walking track scores. Though there was some local fibrosis around each MEMS probe, this did not lead to measurable detrimental effects in any anatomic or functional outcome measurements. Conclusions The lack of a significant difference between Repair and Repair + Probe groups in histology, CMAP, walking tracks, and muscle force suggests that MEMS electrodes are compatible with regenerating axons and show promise for establishing chemical and electrical interfaces with peripheral nerves.

Urbanchek, Melanie G; Wei, Benjamin; Egeland, Brent M; Abidian, Mohammad R; Kipke, Daryl R; Cederna, Paul S

2011-01-01

162

[Comparison of cross face nerve graft with masseteric nerve as donor nerves for free functional muscle transfers in facial reanimation surgery].  

PubMed

Several surgical techniques have been proposed for the reconstruction of the smile in facial paralysis. The 2-stage approach utilising a cross-facial nerve graft (CFNG) and subsequent free functional muscle transfer represents the "gold standard". A single-stage alternative is the use of the masseteric nerve as donor nerve. Here we have retrospectively analysed the outcome of 8 patients who were treated with either of these procedures (4 per treatment group). We compared the oral commisure excursion between the 2 groups. Use of the masseteric nerve led to reinnervation of the muscle graft within 3 months. The 2-stage procedure required more than 12 months from the first procedure until first muscle contractions could be observed. A spontaneous smile could not be achieved in all patients when the masseteric nerve was used. The oral commisure excursion was symmetrical when compared to the healthy side in both groups, however the excursion was significantly higher in the masseteric nerve group compared to the CFNG group of patients. Most patients with the masseteric nerve as a donor nerve underwent a secondary procedure, which involved thinning of the muscle flap. In conclusion, the use of the masseteric nerve as a donor nerve for facial reanimation surgery is a single-stage alternative to the use of a CFNG as donor nerve. It delivers reliable results with strong muscle contractions with limitations in regard to achieving a spontaneous smile. PMID:23970401

Eisenhardt, S U; Thiele, J R; Stark, G B; Bannasch, H

2013-08-01

163

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

PubMed Central

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

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

2009-01-01

164

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

PubMed

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

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

2011-10-01

165

Effect of Lead Exposure and Ergonomic Stressors on Peripheral Nerve Function  

PubMed Central

In this study we investigated the effect of recent and chronic lead exposure, and its interaction with ergonomic stressors, on peripheral nerve function. In a cross-sectional design, we used retrospective exposure data on 74 primary lead smelter workers. We measured blood and bone lead levels and, from historical records, calculated lead dose metrics reflecting cumulative lead exposure: working-lifetime integrated blood lead (IBL) and working-lifetime weighted-average blood lead (TWA). We additionally created five metrics related to IBL that cumulated exposure only above increasing blood lead levels ranging from 20 to 60 ?g/dL (IBL20–IBL60). Current perception threshold (CPT) assessed large myelinated (CPT2000), small myelinated (CPT250), and unmyelinated (CPT5) sensory nerve fibers. Using multiple linear regression, we modeled CPT on the different measures of lead dose after adjusting for relevant covariates. CPT had a curvilinear relationship with TWA, with a minimum at a TWA of 28 ?g/dL. Both TWA and IBL accounted for a significant percentage of the variance of CPT2000 (?R2 = 8.7% and 3.9%, respectively). As the criterion blood lead level increased from IBL20 through IBL60, so did the percentage of CPT2000 variance explained, with ?R2 ranging from 5.8% (p < 0.03) for IBL20 to 23.3% (p < 0.00) for IBL60. IBL60 also significantly contributed to the explanation of variance of CPT250 and significantly interacted with ergonomic stressors. Measures of chronic blood lead exposure are associated with impairment of large and small myelinated sensory nerve fibers. This effect is enhanced at the highest doses by ergonomic stressors.

Bleecker, Margit L.; Ford, D. Patrick; Vaughan, Christopher G.; Lindgren, Karen N.; Tiburzi, Michael J.; Walsh, Karin Scheetz

2005-01-01

166

Ultrasound study is useful to discriminate between axonotmesis and neurotmesis also in very small nerves: a case of sensory digital ulnar branch study.  

PubMed

Discrimination between axonotmesis and neurotmesis is crucial in traumatic nerve injury. We present the case of a 43-year-old woman which presented hypoesthesia in the fourth and fifth right fingers, started after surgery for Dupuytren syndrome. At ultrasound study, the ulnar digital sensory branch was identified. Before the division into the two terminal branches, a neuroma was observed, while neurotmesis was excluded. This case shows the utility of ultrasonography in peripheral nervous system examination and the possibility of visualization of very small nerves and their terminal branches. PMID:23243650

Renna, Rosaria; Rosaria, Renna; Coraci, Daniele; Daniele, Coraci; De Franco, Paola; Erra, Carmen; Ceruso, Massimo; Padua, Luca

2012-12-01

167

Understanding cochlear function through auditory-nerve activity: A Zwislocki perspective  

NASA Astrophysics Data System (ADS)

Dr. Joe Zwislocki served as my dissertation advisor during those tumultuous years in cochlear physiology when our understanding of outer hair cell (OHC) function was evolving from that of a sensory cell to that of a mechanical amplifier. Spoendlin had recently demonstrated that 90%-95% of auditory-nerve afferents originated from inner hair cells (IHCs), but the characteristics of IHC receptor potentials remained an enigma. Otoacoustic emissions and OHC electromotility were terms yet to be defined. Theories relating auditory-nerve activity to basilar-membrane mechanics included concepts of second filters, basilar-membrane nonlinearities, and phase opposition. It was a fertile time for theories and experiments attempting to describe a black-box system that did not yield its mysteries easily. Around 1977, IHC receptor potentials were found to be as sharply tuned as auditory-nerve responses, and the era of cochlear micromechanics began. Joe Zwislocki, as usual, has played a primary role in defining this new era, utilizing the relationships between the OHC stereocilia and the tectorial membrane as his modeling clay.

Schmiedt, Richard A.

2003-04-01

168

A biomaterials approach to peripheral nerve regeneration: bridging the peripheral nerve gap and enhancing functional recovery  

PubMed Central

Microsurgical techniques for the treatment of large peripheral nerve injuries (such as the gold standard autograft) and its main clinically approved alternative—hollow nerve guidance conduits (NGCs)—have a number of limitations that need to be addressed. NGCs, in particular, are limited to treating a relatively short nerve gap (4 cm in length) and are often associated with poor functional recovery. Recent advances in biomaterials and tissue engineering approaches are seeking to overcome the limitations associated with these treatment methods. This review critically discusses the advances in biomaterial-based NGCs, their limitations and where future improvements may be required. Recent developments include the incorporation of topographical guidance features and/or intraluminal structures, which attempt to guide Schwann cell (SC) migration and axonal regrowth towards their distal targets. The use of such strategies requires consideration of the size and distribution of these topographical features, as well as a suitable surface for cell–material interactions. Likewise, cellular and molecular-based therapies are being considered for the creation of a more conductive nerve microenvironment. For example, hurdles associated with the short half-lives and low stability of molecular therapies are being surmounted through the use of controlled delivery systems. Similarly, cells (SCs, stem cells and genetically modified cells) are being delivered with biomaterial matrices in attempts to control their dispersion and to facilitate their incorporation within the host regeneration process. Despite recent advances in peripheral nerve repair, there are a number of key factors that need to be considered in order for these new technologies to reach the clinic.

Daly, W.; Yao, L.; Zeugolis, D.; Windebank, A.; Pandit, A.

2012-01-01

169

Depletion of Calcium Stores in Injured Sensory Neurons: Anatomic and Functional Correlates  

PubMed Central

Background Painful nerve injury leads to disrupted Ca2+ signaling in primary sensory neurons, including decreased endoplasmic reticulum (ER) Ca2+ storage. The present study examines potential causes and functional consequences of Ca2+ store limitation after injury. Methods Neurons were dissociated from axotomized fifth lumbar (L5) and the adjacent L4 dorsal root ganglia following L5 spinal nerve ligation that produced hyperalgesia, and were compared to neurons from control animals. Intracellular Ca2+ levels were measured with Fura-2 microfluorometry, and ER was labeled with probes or antibodies. Ultrastructural morphology was analyzed by electron microscopy of nondissociated dorsal root ganglia, and intracellular electrophysiological recordings were obtained from intact ganglia. Results Live neuron staining with BODIPY FL-X thapsigargin (Invitrogen, Carlsbad, CA) revealed a 40% decrease in sarco-endoplasmic reticulum Ca2+-ATPase binding in axotomized L5 neurons and a 34% decrease in L4 neurons. Immunocytochemical labeling for the ER Ca2+-binding protein calreticulin was unaffected by injury. Total length of ER profiles in electron micrographs was reduced by 53% in small axotomized L5 neurons, but increased in L4 neurons. Cisternal stacks of ER and aggregation of ribosomes occurred less frequently in axotomized neurons. Ca2+-induced Ca2+ release, examined by microfluorometry with dantrolene, was eliminated in axotomized neurons. Pharmacologic blockade of Ca2+-induced Ca2+ release with dantrolene produced hyperexcitability in control neurons, confirming its functional importance. Conclusions After axotomy, ER Ca2+ stores are reduced by anatomic loss and possibly diminished sarco-endoplasmic reticulum Ca2+-ATPase. The resulting disruption of Ca2+-induced Ca2+ release and protein synthesis may contribute to the generation of neuropathic pain.

Gemes, Geza; Rigaud, Marcel; Weyker, Paul D.; Abram, Stephen E.; Weihrauch, Dorothee; Poroli, Mark; Zoga, Vasiliki; Hogan, Quinn H.

2010-01-01

170

A Reevaluation of the Common Factor Theory of Shared Variance Among Age, Sensory Function, and Cognitive Function in Older Adults  

Microsoft Academic Search

The common cause hypothesis of the relationship among age, sensory measures, and cognitive measures in very old adults was reevaluated. Both sensory function and processing speed were evaluated as mediators of the rela- tionship between age and cognitive function. Cognitive function was a latent variable that comprised 3 factors in- cluding memory, speed, and verbal ability. The sample was population

Kaarin J. Anstey; Mary A. Luszcz; Linnett Sanchez

2001-01-01

171

Quantitative Evaluation of Median Nerve Motor Function in Carpal Tunnel Syndrome Using Load Cell : Correlation with Clinical, Electrodiagnostic, and Ultrasonographic Findings  

PubMed Central

Objective Major complaints of carpal tunnel syndrome (CTS) are sensory components. However, motor deficit also impedes functional status of hand. Contrary to evaluation of sensory function, the objective, quantitative evaluation of median nerve motor function is not easy. The motor function of median was evaluated quantitatively using load cell and its correlation with findings of electrodiagnostic study (EDS) was evaluated. Methods Objective motor function of median nerve was evaluated by load cell and personal computer-based measurement system. All of the measurement was done in patients diagnosed as having idiopathic CTS by clinical features and EDS findings. The strength of thumb abduction and index finger flexion was measured in each hand three times, and the average value was used to calculate thumb index ratio (TIR). The correlation of TIR with clinical, EDS, and ultrasonographic findings were evaluated. Results The TIR was evaluated in 67 patients (119 hands). There were 14 males and 53 females, mean age were 57.6 years (range 28 to 81). The higher preoperative nerve conductive studies grade of the patients, the lower TIR was observed [p<0.001, analysis of variance (ANOVA)]. TIR of cases with thenar atrophy were significantly lower than those without (p<0.001, t-test). TIR were significantly lower in patients with severe median nerve swelling in ultrasonography (p=0.042, ANOVA). Conclusion Measurements of median nerve motor function using load cell is a valuable evaluation tool in CTS. It might be helpful in detecting subclinical motor dysfunction before muscle atrophy develops.

Kim, Dong Hwan; Park, Sung Bae; Lee, Sang Hyung; Son, Young-Je; Chung, Gih Sung

2013-01-01

172

Effects of ibogaine on sensory-motor function, activity, and spatial learning in rats  

Microsoft Academic Search

Ibogaine, a naturally occurring alkaloid, has been show to reduce naloxone-precipitated withdrawal symptoms from morphine. Given the clinical possibilities, it is important to determine ibogaine's effects on sensory-motor function, activity, learning, and memory. Long-Evans rats injected with doses of 20–60 mg\\/kg of ibogaine displayed slower response times on sensory and sensory-motor tests and were impaired in performing specific motor reflexes

Raymond P. Kesner; Pamela Jackson-Smith; Clarissa Henry; Kelly Amann

1995-01-01

173

Apoptosis and impaired axonal regeneration of sensory neurons after nerve crush in diabetic rats.  

PubMed

We investigated the possible induction of apoptosis of dorsal root ganglion (DRG) neurons and the defect of nerve regeneration after crush injury with reference to the JNK/c-jun and cAMP pathway in streptozocin-induced diabetic rats. In addition, the effects of a PGE1 analogue were tested in diabetic rats. At day 0 (before axonal injury), no TUNEL-positive DRG neurons were observed in any group. From day 1 to 7 after axonal injury, TUNEL-positive DRG neurons were seen in diabetic rats, but not in non-diabetic or PGE1-treated diabetic rats. The regeneration distance at day 7 after crush injury was shorter in diabetic rats than in the other groups of rats. The time course of JNK/c-jun phosphorylation did not parallel apoptosis. At day 7, the cAMP content of DRG was higher than that at day 0 in non-diabetic and PGE1-treated rats, whereas it was not increased after 7 days in diabetic rats. These results indicate that in diabetic rats apoptosis of DRG neurons is induced by axonal injury independently of the JNK/c-jun and cAMP pathway and that PGE1 rescues DRG neurons from apoptosis and improves axonal regeneration in diabetic rats. PMID:10757497

Kogawa, S; Yasuda, H; Terada, M; Maeda, K; Kikkawa, R

2000-03-20

174

Effects of Noise on Non-Auditory Sensory Functions and Performance.  

National Technical Information Service (NTIS)

The effects of moderately intense impact and continuous noise on sensory-perceptual functions and on various task performances dependent on those functions are studied in male student volunteers to determine whether present occupational noise limits prote...

M. Loeb P. D. Jones

1976-01-01

175

Direct radial to ulnar nerve transfer to restore intrinsic muscle function in combined proximal median and ulnar nerve injury: case report and surgical technique.  

PubMed

A distal median to ulnar nerve transfer for timely restoration of critical intrinsic muscle function is possible in isolated ulnar nerve injuries but not for combined ulnar and median nerve injuries. We used a distal nerve transfer to restore ulnar intrinsic function in the case of a proximal combined median and ulnar nerve injury. Transfer of the nonessential radial nerve branches to the abductor pollicis longus, extensor pollicis brevis, and extensor indicis proprius to the motor branch of the ulnar nerve was performed in a direct end-to-end fashion via an interosseous tunnel. This method safely and effectively restored intrinsic function before terminal muscle degeneration. PMID:24836915

Phillips, Benjamin Z; Franco, Michael J; Yee, Andrew; Tung, Thomas H; Mackinnon, Susan E; Fox, Ida K

2014-07-01

176

Functionally Approached Body (FAB) Strategies for Young Children Who Have Behavioral and Sensory Processing Challenges  

ERIC Educational Resources Information Center

Functionally Approached Body (FAB) Strategies offer a clinical approach to help parents of young children with behavioral and sensory processing strategies. This article introduces the FAB Strategies, clinical strategies developed by the author for understanding and addressing young children's behavioral and sensory processing challenges. The FAB…

Pagano, John

2005-01-01

177

NonRandom Distribution and Sensory Functions of Primary Cilia in Vascular Smooth Muscle Cells  

Microsoft Academic Search

Although primary cilia are increasingly recognized to play sensory roles in several cellular systems, their role in vascular smooth muscle cells (VSMCs) has not been defined. We examined in situ position\\/orientation of primary cilia and ciliary proteins in VSMCs and tested the hypothesis that primary cilia of VSMCs exert sensory functions. By immunofluorescence and electron microscopic imaging, primary cilia of

C. J. Lu; H. Du; J. Wu; D. A. Jansen; K. L. Jordan; N. Xu; G. C. Sieck; Q. Qian

2008-01-01

178

Rehabilitation of the trigeminal nerve  

PubMed Central

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.

Iro, Heinrich; Bumm, Klaus; Waldfahrer, Frank

2005-01-01

179

Relationship of estimated dietary intake of n-3 polyunsaturated fatty acids from fish with peripheral nerve function after adjusting for mercury exposure  

PubMed Central

Background Some clinical studies have suggested that ingestion of n-3 polyunsaturated fatty acids (PUFA) has neuroprotective effects on peripheral nerve function. However, few epidemiological studies have examined the effect of dietary n-3 PUFA intake from fish consumption on peripheral nerve function, and none have controlled for co-occurrence of methylmercury exposure from fish consumption. Objectives We evaluated the effect of estimated dietary n-3 PUFA intake on peripheral nerve function after adjusting for biomarkers of methylmercury and elemental mercury in a convenience sample of 515 dental professionals. Methods We measured sensory nerve conduction (peak latency and amplitude) of the median, ulnar and sural nerves and total mercury concentrations in hair and urine samples. We estimated daily intake (mg/day) of the total n-3 PUFA, n-3 docosahexaenoic acid (DHA), and n-3 eicosapentaenoic acid (EPA) based on a self-administrated fish consumption frequency questionnaire. We also collected information on mercury exposure, demographics and other covariates. Results The estimated median intakes of total n-3 PUFA, n-3 EPA, and n-3 DHA were 447, 105, and 179 mg/day, respectively. The mean mercury concentrations in urine (1.05?g/L) and hair (0.49?g/g) were not significantly different from the US general population. We found no consistent association between n-3 PUFA intake and sensory nerve conduction after adjusting for mercury concentrations in hair and urine although some positive associations were observed with the sural nerve. Conclusions In a convenience sample of dental professionals, we found little evidence suggesting that dietary intake of n-3 PUFAs from fish has any impact on peripheral nerve function after adjustment for methylmercury exposure from fish and elemental mercury exposure from dental amalgam.

Wang, Yi; Goodrich, Jaclyn M.; Werner, Robert; Gillespie, Brenda; Basu, Niladri; Franzblau, Alfred

2013-01-01

180

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

PubMed Central

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 ?M XE991 sensitized A?- but not C-fibers to noxious heat stimulation and induced spontaneous, ongoing activity at 32°C in many A?-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 A?-fiber peripheral terminals. These results demonstrate an important physiological role of M-channels in controlling nociceptive A?-fiber responses and provide a rationale for the nocifensive behaviors that arise following intraplantar injection of the M-channel blocker XE991.

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

2012-01-01

181

Presynaptic inhibition of olfactory sensory neurons: new mechanisms and potential functions.  

PubMed

Presynaptic inhibition is the suppression of neurotransmitter release from a neuron by inhibitory input onto its presynaptic terminal. In the olfactory system, the primary sensory afferents from the olfactory neuroepithelium to the brain's olfactory bulb are strongly modulated by a presynaptic inhibition that has been studied extensively in brain slices and in vivo. In rodents, this inhibition is mediated by ?-amino butyric acid (GABA) and dopamine released from bulbar interneurons. The specialized GABAergic circuit is now well understood to include a specific subset of GAD65-expressing periglomerular interneurons that stimulate presynaptic GABAB receptors to reduce presynaptic calcium conductance. This inhibition is organized to permit the selective modulation of neurotransmitter release from specific populations of olfactory sensory neurons based on their odorant receptor expression, includes specialized microcircuits to create a tonically active inhibition and a separate feedback inhibition evoked by sensory input, and can be modulated by centrifugal projections from other brain regions. Olfactory nerve output can also be modulated by dopaminergic circuitry, but this literature is more difficult to interpret. Presynaptic inhibition of olfactory afferents may extend their dynamic range but could also create state-dependent or odorant-specific sensory filters on primary sensory representations. New directions exploring this circuit's role in olfactory processing are discussed. PMID:23761680

McGann, John P

2013-07-01

182

Skin-derived stem cells transplanted into resorbable guides provide functional nerve regeneration after sciatic nerve resection.  

PubMed

The regeneration in the peripheral nervous system is often incomplete and the treatment of severe lesions with nerve tissue loss is primarily aimed at recreating nerve continuity. Guide tubes of various types, filled with Schwann cells, stem cells, or nerve growth factors are attractive as an alternative therapy to nerve grafts. In this study, we evaluated whether skin-derived stem cells (SDSCs) can improve peripheral nerve regeneration after transplantation into nerve guides. We compared peripheral nerve regeneration in adult rats with sciatic nerve gaps of 16 mm after autologous transplantation of GFP-labeled SDSCs into two different types of guides: a synthetic guide, obtained by dip coating with a L-lactide and trimethylene carbonate (PLA-TMC) copolymer and a collagen-based guide. The sciatic function index and the recovery rates of the compound muscle action potential were significantly higher in the animals that received SDSCs transplantation, in particular, into the collagen guide, compared to the control guides filled only with PBS. For these guides the morphological and immunohistochemical analysis demonstrated an increased number of myelinated axons expressing S100 and Neurofilament 70, suggesting the presence of regenerating nerve fibers along the gap. GFP positive cells were found around regenerating nerve fibers and few of them were positive for the expression of glial markers as S-100 and glial fibrillary acidic protein. RT-PCR analysis confirmed the expression of S100 and myelin basic protein in the animals treated with the collagen guide filled with SDSCs. These data support the hypothesis that SDSCs could represent a tool for future cell therapy applications in peripheral nerve regeneration. PMID:17203471

Marchesi, C; Pluderi, M; Colleoni, F; Belicchi, M; Meregalli, M; Farini, A; Parolini, D; Draghi, L; Fruguglietti, M E; Gavina, M; Porretti, L; Cattaneo, A; Battistelli, M; Prelle, A; Moggio, M; Borsa, S; Bello, L; Spagnoli, D; Gaini, S M; Tanzi, M C; Bresolin, N; Grimoldi, N; Torrente, Y

2007-03-01

183

Collagen VI regulates peripheral nerve myelination and function.  

PubMed

Collagen VI is an extracellular matrix protein with broad distribution in several tissues. Although Col6a1 is expressed by Schwann cells, the role of collagen VI in the peripheral nervous system (PNS) is yet unknown. Here we show that Schwann cells, but not axons, contribute to collagen VI deposition in peripheral nerves. By using Col6a1-null mice, in which collagen VI deposition is compromised, we demonstrate that lack of collagen VI leads to increased myelin thickness (P<0.001) along with 60-130% up-regulation in myelin-associated proteins and disorganized C fibers in the PNS. The hypermyelination of PNS in Col6a1(-/-) mice is supported by alterations of signaling pathways involved in myelination, including increase of P-FAK, P-AKT, P-ERK1, P-ERK2, and P-p38 (4.15, 1.67, 2.47, 3.34, and 2.60-fold, respectively) and reduction of vimentin (0.49-fold), P-JNK (0.74-fold), and P-c-Jun (0.50-fold). Pathologically, Col6a1(-/-) mice display an impairment of nerve conduction velocity and motor coordination (P<0.05), as well as a delayed response to acute pain stimuli (P<0.001), indicating that lack of collagen VI causes functional defects of peripheral nerves. Altogether, these results indicate that collagen VI is a critical component of PNS contributing to the structural integrity and proper function of peripheral nerves. PMID:24277578

Chen, Peiwen; Cescon, Matilde; Megighian, Aram; Bonaldo, Paolo

2014-03-01

184

Altered Function of Lumbar Nerve Roots in Patients With Transitional Lumbosacral Vertebrae  

Microsoft Academic Search

STUDY DESIGN: A retrospective study was conducted on the preoperative neurologic symptoms of patients with lumbar herniated discs. OBJECTIVE: To evaluate the possibility that the muscle innervation pattern and the sensory dermatomes of lumbar nerve roots are altered when a lumbosacral transitional vertebra is present. SUMMARY OF BACKGROUND DATA: In 1962, McCulloch et al suggested with intraoperative recordings that the

Han Soo Chang; Hiroshi NAKAGAWA

2004-01-01

185

Preservation of Facial Nerve Function Repaired by Using Fibrin Glue-Coated Collagen Fleece for a Totally Transected Facial Nerve during Vestibular Schwannoma Surgery  

PubMed Central

Recently, the increasing rates of facial nerve preservation after vestibular schwannoma (VS) surgery have been achieved. However, the management of a partially or completely damaged facial nerve remains an important issue. The authors report a patient who was had a good recovery after a facial nerve reconstruction using fibrin glue-coated collagen fleece for a totally transected facial nerve during VS surgery. And, we verifed the anatomical preservation and functional outcome of the facial nerve with postoperative diffusion tensor (DT) imaging facial nerve tractography, electroneurography (ENoG) and House-Brackmann (HB) grade. DT imaging tractography at the 3rd postoperative day revealed preservation of facial nerve. And facial nerve degeneration ratio was 94.1% at 7th postoperative day ENoG. At postoperative 3 months and 1 year follow-up examination with DT imaging facial nerve tractography and ENoG, good results for facial nerve function were observed.

Choi, Kyung-Sik; Kim, Min-Su; Jang, Sung-Ho

2014-01-01

186

Functional Recovery Following an End to Side Neurorrhaphy of the Accessory Nerve to the Suprascapular Nerve: Case Report  

PubMed Central

The use of end-to-side neurrorhaphy remains a controversial topic in peripheral nerve surgery. The authors report the long-term functional outcome following a modified end-to-side motor reinnervation using the spinal accessory to innervate the suprascapular nerve following a C5 to C6 avulsion injury. Additionally, functional outcomes of an end-to-end neurotization of the triceps branch to the axillary nerve and double fascicular transfer of the ulnar and medial nerve to the biceps and brachialis are presented. Excellent functional recoveries are found in respect to shoulder abduction and flexion and elbow flexion. Electronic supplementary material The online version of this article (doi:10.1007/s11552-009-9242-3) contains supplementary material, which is available to authorized users.

Ray, Wilson Z.; Kasukurthi, Rahul; Yee, Andrew

2009-01-01

187

A controlled trial of the retraining of the sensory function of the hand in stroke patients.  

PubMed Central

A controlled trial of retraining of the sensory function of the hand was undertaken in hemiplegic patients after the period of spontaneous recovery. Twenty hemiplegic patients with sensory deficit in the hand, two or more years after stroke, received systematic retraining three times a week for six weeks. Sensation in the plegic hand was tested before and after this period in these patients and in 19 untreated control patients. The treated group showed large and significant gains on all sensory tests (P < 0.001), while no change occurred in the control group. It is concluded that somatosensory deficit can be alleviated even years after stroke and that rehabilitation for stroke patients should include sensory retraining for those with sensory deficit.

Yekutiel, M; Guttman, E

1993-01-01

188

Motor and sensory function of the proximal stomach in reflux disease and after laparoscopic Nissen fundoplication  

Microsoft Academic Search

OBJECTIVE:After Nissen fundoplication, dyspeptic symptoms such as fullness and early satiety develop in >30% of patients. These symptoms may result from alterations in proximal gastric motor and sensory function.METHODS:We have evaluated proximal gastric motor and sensory function using an electronic barostat in 12 patients after successful laparoscopic Nissen fundoplications (median follow-up; 12 months). Twelve age- and gender-matched patients with severe

M. K Vu; J. W. A Straathof; P. J v. d. Schaar; J. W Arndt; J Ringers; C. B. H. W Lamers; A. A. M Masclee

1999-01-01

189

Effects of Local Compression on Peroneal Nerve Function in Humans  

NASA Technical Reports Server (NTRS)

A new apparatus was developed to compress the anterior compartment selectively and reproducibly in humans. Thirty-five normal volunteers were studied to determine short-term thresholds of local tissue pressure that produce significant neuromuscular dysfunction. Local tissue fluid pressure adjacent to the deep peroneal nerve was elevated by the compression apparatus and continuously monitored for 2-3 h by the slit catheter technique. Elevation of tissue fluid pressure to within 35-40 mm Hg of diastolic blood pressure (approx. 40 mm Hg of in situ pressure in our subjects) elicited a consistent progression of neuromuscular deterioration including, in order, (a) gradual loss of sensation, as assessed by Semmes-Weinstein monofilaments, (b) subjective complaints, (c) reduced nerve conduction velocity, (d) decreased action potential amplitude of the extensor digitorum brevis muscle, and (e) motor weakness of muscles within the anterior compartment. Generally, higher intracompartment at pressures caused more rapid deterioration of neuromuscular function. In two subjects, when in situ compression levels were 0 and 30 mm Hg, normal neuromuscular function was maintained for 3 h. Threshold pressures for significant dysfunction were not always the same for each functional parameter studied, and the magnitudes of each functional deficit did not always correlate with compression level. This variable tolerance to elevated pressure emphasizes the need to monitor clinical signs and symptoms carefully in the diagnosis of compartment syndromes. The nature of the present studies was short term; longer term compression of myoneural tissues may result in dysfunction at lower pressure thresholds.

Hargens, Alan R.; Botte, Michael J.; Swenson, Michael R.; Gelberman, Richard H.; Rhoades, Charles E.; Akeson, Wayne H.

1993-01-01

190

Experimental beta beta'-iminodipropionitrile (IDPN) neuropathy: neurofilament profile of sensory, motor and autonomic nerves as seen by immunocytochemistry on whole-mount preparations.  

PubMed

IDPN-induced changes in a variety of sensory, motor and autonomic nerves were studied by whole-mount immunocytochemistry. A full range of proximo-distal accumulations of neurofilament-like material was found, from paranuclear round bodies in perikarya to distal and preterminal axonal dilations. Conversely, both terminal areas and nodal-paranodal regions of myelinated axons showed striking, sharply localized loss of neurofilament-immunostaining. The latter change, when transport of neurofilaments is halted by IDPN, may indicate their local processing and/or differential transport at nodal-paranodal regions. PMID:7820635

Ferri, G L; Cichi, A; Bastone, A; Gaudio, R M; Frontali, N; Dahl, D

1994-09-19

191

Reliability of clinical tests to evaluate nerve function and mechanosensitivity of the upper limb peripheral nervous system  

Microsoft Academic Search

BACKGROUND: Clinical tests to assess peripheral nerve disorders can be classified into two categories: tests for afferent\\/efferent nerve function such as nerve conduction (bedside neurological examination) and tests for increased mechanosensitivity (e.g. upper limb neurodynamic tests (ULNTs) and nerve palpation). Reliability reports of nerve palpation and the interpretation of neurodynamic tests are scarce. This study therefore investigated the intertester reliability

Annina B Schmid; Florian Brunner; Hannu Luomajoki; Ulrike Held; Lucas M Bachmann; Sabine Künzer; Michel W Coppieters

2009-01-01

192

Partial Recovery of Respiratory Function and Diaphragm Reinnervation following Unilateral Vagus Nerve to Phrenic Nerve Anastomosis in Rabbits  

PubMed Central

Respiratory dysfunction is the leading cause of mortality following upper cervical spinal cord injury (SCI). Reinnervation of the paralyzed diaphragm via an anastomosis between phrenic nerve and a donor nerve is a potential strategy to mitigate ventilatory deficits. In this study, anastomosis of vagus nerve (VN) to phrenic nerve (PN) in rabbits was performed to assess the potential capacity of the VN to compensate for lost PN inputs. At first, we compared spontaneous discharge pattern, nerve thickness and number of motor fibers between these nerves. The PN exhibited a highly rhythmic discharge while the VN exhibited a variable frequency discharge pattern. The rabbit VN had fewer motor axons (105.3±12.1 vs. 268.1±15.4). Nerve conduction and respiratory function were measured 20 weeks after left PN transection with or without left VN-PN anastomosis. Compared to rabbits subjected to unilateral phrenicotomy without VN-PN anastomosis, diaphragm muscle action potential (AP) amplitude was improved by 292%, distal latency by 695%, peak inspiratory flow (PIF) by 22.6%, peak expiratory flow (PRF) by 36.4%, and tidal volume by 21.8% in the anastomosis group. However, PIF recovery was only 28.0%, PEF 28.2%, and tidal volume 31.2% of Control. Our results suggested that VN-PN anastomosis is a promising therapeutic strategy for partial restoration of diaphragm reinnervation, but further modification and improvements are necessary to realize the full potential of this technique.

Li, Lijun; Sun, Guixin; Tan, Jun

2013-01-01

193

Gangliosides are functional nerve cell ligands for myelin-associated glycoprotein (MAG), an inhibitor of nerve regeneration  

PubMed Central

Myelin-associated glycoprotein (MAG) binds to the nerve cell surface and inhibits nerve regeneration. The nerve cell surface ligand(s) for MAG are not established, although sialic acid-bearing glycans have been implicated. We identify the nerve cell surface gangliosides GD1a and GT1b as specific functional ligands for MAG-mediated inhibition of neurite outgrowth from primary rat cerebellar granule neurons. MAG-mediated neurite outgrowth inhibition is attenuated by (i) neuraminidase treatment of the neurons; (ii) blocking neuronal ganglioside biosynthesis; (iii) genetically modifying the terminal structures of nerve cell surface gangliosides; and (iv) adding highly specific IgG-class antiganglioside mAbs. Furthermore, neurite outgrowth inhibition is mimicked by highly multivalent clustering of GD1a or GT1b by using precomplexed antiganglioside Abs. These data implicate the nerve cell surface gangliosides GD1a and GT1b as functional MAG ligands and suggest that the first step in MAG inhibition is multivalent ganglioside clustering.

Vyas, Alka A.; Patel, Himatkumar V.; Fromholt, Susan E.; Heffer-Lauc, Marija; Vyas, Kavita A.; Dang, Jiyoung; Schachner, Melitta; Schnaar, Ronald L.

2002-01-01

194

Sensory Functions for Degenerin/Epithelial Sodium Channels (DEG/ENaC)  

PubMed Central

All animals use a sophisticated array of receptor proteins to sense their external and internal environments. Major advances have been made in recent years in understanding the molecular and genetic bases for sensory transduction in diverse modalities, indicating that both metabotropic and ionotropic pathways are important in sensory functions. Here, I review the historical background and recent advances in understanding the roles of a relatively newly discovered family of receptors, the degenerin/epithelial sodium channels (DEG/ENaC). These animal-specific cation channels show a remarkable sequence and functional diversity in different species and seem to exert their functions in diverse sensory modalities. Functions for DEG/ENaC channels have been implicated in mechanosensation as well as chemosensory transduction pathways. In spite of overall sequence diversity, all family members share a unique protein topology that includes just two transmembrane domains and an unusually large and highly structured extracellular domain, that seem to be essential for both their mechanical and chemical sensory functions. This review will discuss many of the recent discoveries and controversies associated with sensory function of DEG/ENaC channels in both vertebrate and invertebrate model systems, covering the role of family members in taste, mechanosensation, and pain.

Ben-Shahar, Yehuda

2012-01-01

195

Novel roles for osteopontin and clusterin in peripheral motor and sensory axon regeneration.  

PubMed

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

Wright, Megan C; Mi, Ruifa; Connor, Emmalynn; Reed, Nicole; Vyas, Alka; Alspalter, Manula; Coppola, Giovanni; Geschwind, Daniel H; Brushart, Thomas M; Höke, Ahmet

2014-01-29

196

The acute effect of straining on pelvic floor neurological function  

Microsoft Academic Search

Integrity of sensory and motor function is essential in the maintenance of continence. The pudendal nerve assumes a central role being a mixed sensory and motor nerve. Neuropathic changes may therefore lead to incontinence and stretch injury to the pudendal nerve has been implicated as an aetiological factor. However pudendal neuropathy, altered anal sensation and perineal descent do not always

A. F. Engel; M. A. Kamm

1994-01-01

197

Kv7.2 regulates the function of peripheral sensory neurons.  

PubMed

The Kv7 (KCNQ) family of voltage-gated K(+) channels regulates cellular excitability. The functional role of Kv7.2 has been hampered by the lack of a viable Kcnq2-null animal model. In this study, we generated homozygous Kcnq2-null sensory neurons using the Cre-Lox system; in these mice, Kv7.2 expression is absent in the peripheral sensory neurons, whereas the expression of other molecular components of nodes (including Kv7.3), paranodes, and juxtaparanodes is not altered. The conditional Kcnq2-null animals exhibit normal motor performance but have increased thermal hyperalgesia and mechanical allodynia. Whole-cell patch recording technique demonstrates that Kcnq2-null sensory neurons have increased excitability and reduced spike frequency adaptation. Taken together, our results suggest that the loss of Kv7.2 activity increases the excitability of primary sensory neurons. J. Comp. Neurol. 522:3262-3280, 2014. © 2014 Wiley Periodicals, Inc. PMID:24687876

King, Chih H; Lancaster, Eric; Salomon, Daniela; Peles, Elior; Scherer, Steven S

2014-12-01

198

Biomechanical and functional variation in rat sciatic nerve following cuff electrode implantation  

PubMed Central

Background Nerve cuff electrodes are commonly and successfully used for stimulating peripheral nerves. On the other hand, they occasionally induce functional and morphological changes following chronic implantation, for reasons not always clear. We hypothesize that restriction of nerve mobility due to cuff implantation may alter nerve conduction. Methods We quantified acute changes in nerve-muscle electrophysiology, using electromyography, and nerve kinematics in anesthetized Sprague Dawley rat sciatic nerves during controlled hindlimb joint movement. We compared electrophysiological and biomechanical response in uncuffed nerves and those secured within a cuff electrode using analysis of variance (ANOVA) and regression analysis. Results Tethering resulting from cuff implantation resulted in altered nerve strain and a complex biomechanical environment during joint movement. Coincident with biomechanical changes, electromyography revealed significantly increased variability in the response of conduction latency and amplitude in cuffed, but not free, nerves following joint movement. Conclusion Our findings emphasize the importance of the mechanical interface between peripheral nerves and their devices on neurophysiological performance. This work has implications for nerve device design, implantation, and prediction of long-term efficacy.

2014-01-01

199

Neuroma-in-continuity of the median nerve managed by nerve expansion and direct suture with vein conduit.  

PubMed

Autologous nerve grafting is the current standard for bridging large gaps in major sensory and motor nerves. It allows both function and pain improvement with predictable results. Clinical observations of nerve elongation caused by tumours have prompted experimental animal studies of induced gradual elongation of the nerve stump proximal to the gap. This technique allows direct suturing of the two nerve ends to bridge the gap. Here, we describe a case of neuroma-in-continuity of the median nerve managed by resection and direct suture after nerve elongation with a tissue expander. We are not aware of similar reported cases. Secondary repair 3 years after the initial injury improved the pain and hypersensitivity and restored a modest degree of protective sensory function (grade S1). PMID:24704261

Jeudy, J; Raimbeau, G; Rabarin, F; Fouque, P A; Saint-Cast, Y; Césari, B; Bigorre, N

2014-06-01

200

Seasonal variations in cholinesterase activity, nerve conduction velocity and lung function among sprayers exposed to mixture of pesticides.  

PubMed

Pesticide spraying operation is associated with the increased risk of adverse health effects among sprayers who do not follow safe farm work practices. A study was conducted among pesticide sprayers in North India to evaluate the clinical and subclinical variations in their vital health parameters before and after the pesticide spraying season. Blood cholinesterase levels, pulmonary function test, nerve conduction velocity and self-reported symptoms were studied among 18 eligible and consenting male sprayers. Mean acetylcholinesterase activity was reduced by 55 % in the post-exposure assessment (P<0.001) as compared to pre-exposure levels. Mean forced expiratory volume in 1 s was 20 % lower in the post-exposure assessment as compared to the pre-exposure level (P<0.05). No significant change was observed in the motor and sensory nerve conduction velocity in the median nerve of sprayers before and after the spraying activity. Also, no significant variation was observed with respect to self-reported symptoms except weakness in arms and legs (P<0.05). The significant decline in lung function and acetylcholinesterase level after pesticide exposure reflects the strongly negative effect of exposure to pesticides during spraying activity. More longitudinal studies among pesticide sprayers must be undertaken to further substantiate the cause-effect relationship between pesticide exposure and its subclinical effects. There is a strong necessity to minimise the exposure through the use of personal protective equipment in pesticide sprayers. PMID:23636596

Pathak, Manoj Kumar; Fareed, Mohammad; Srivastava, Anup Kumar; Pangtey, Balram Singh; Bihari, Vipin; Kuddus, Mohammed; Kesavachandran, C

2013-10-01

201

Function of sural nerve reflexes during human walking  

PubMed Central

The functions of ipsilateral cutaneous reflexes were studied with short trains of stimuli presented pseudorandomly to the sural nerve during human walking. Electromyograms (EMG) of lower (tibialis anterior (TA), soleus, lateral (LG) and medial (MG) gastrocnemius) and upper leg (vastus lateralis and biceps femoris) muscles were recorded, together with ankle, knee and hip joint angles. Net reflex EMG responses were quantified in each of the sixteen parts of the step cycle. The kinematic measurements included ankle eversion- inversion, and ankle, knee and hip flexion-extension. The function of the sural reflexes depended upon the part of the step cycle in which the nerve was stimulated and the intensity of stimulation. During stance, reflexes in MG and TA muscles in response to a medium intensity of stimulation (1.9 × radiating threshold, × RT) were closely associated with ankle eversion and dorsiflexion responses, respectively. These responses could assist in accommodation to uneven terrain that applies pressure to the lateral side of the foot (sural innervation area). Non-noxious, high intensity (2.3 × RT) stimulation resulted in strong suppression of LG and MG during stance which was correlated to a small reduction in ankle plantarflexion. At this higher intensity the response would function to prevent the foot from moving more forcefully onto a potentially harmful obstacle. During swing, ankle dorsiflexion increased and was significantly correlated to the net TA EMG response after both medium and high intensity stimulation. Knee flexion was increased throughout swing at both intensities of stimulation. These responses may serve in an avoidance response in which the swing limb is brought past an obstacle without destabilizing contact. The net EMG and kinematic responses suggest that cutaneous reflexes stabilize human gait against external perturbations produced by an uneven surface in stance or obstacles encountered during swing.

Zehr, E P; Stein, R B; Komiyama, T

1998-01-01

202

EFFICACY OF A NOVEL DEVICE FOR ASSESSMENT OF AUTONOMIC SENSORY FUNCTION IN THE RAT BLADDER  

PubMed Central

Purpose We developed and tested the efficacy of an implantable bladder device which, when combined with the Neurometer®, can be used to assess fiber-specific afferent sensation of the bladder in the rat. Materials and Methods We developed an implantable bladder device which applies selective nerve fiber stimuli (250 Hz for small myelinated (A?), and 5 Hz for unmyelinated (C) fibers) to the bladder mucosa in the rat in order to obtain the bladder sensory perception threshold (SPT) values. We performed three experiments on fifty-five female Sprague-Dawley rats, examining the effects of our device on voiding habits; assessing the inter-observer reliability of SPT; and the effects of intravesical administration of resiniferatoxin and lidocaine on the SPT. Results The SPT values obtained by two blinded, independent observers were not different from one another (p= 0.41). The SPT values obtained at both stimulation frequencies remained constant for at least 3 weeks after device implantation. A significant increase in SPT values after instillation of resiniferatoxin (p = 0.02) was noted at a stimulus frequency of 5 Hz, whereas intravesical lidocaine led to an immediate increase in SPT at both 250 and 5 Hz. Device implantation led to an early decreased voided volume and increased frequency of voids, however these parameters returned to normal after 4 days. Conclusions Assessment of bladder afferent sensation with our newly developed device is feasible in rats, and provides sensory perception thresholds that appear to be fiber-type selective for autonomic bladder afferent nerves.

Abouassaly, Robert; Liu, Guiming; Yamada, Yasuhiro; Ukimura, Osamu; Daneshgari, Firouz

2014-01-01

203

Manual stimulation of facial muscles improves functional recovery after hypoglossal–facial anastomosis and interpositional nerve grafting of the facial nerve in adult rats  

Microsoft Academic Search

The facial nerve in humans is often prone to injuries requiring surgical intervention. In the best case, nerve reconstruction is achieved by a facial–facial anastomosis (FFA), i.e. suture of the proximal and distal stumps of the severed facial nerve. Although a method of choice, FFA rarely leads to a satisfactory functional recovery. We have recently devised and validated, in an

Orlando Guntinas-Lichius; Gregor Hundeshagen; Thomas Paling; Michael Streppel; Maria Grosheva; Andrey Irintchev; Emmanouil Skouras; Athanasia Alvanou; Srebrina K. Angelova; Stefanie Kuerten; Nektarios Sinis; Sarah A. Dunlop; Doychin N. Angelov

2007-01-01

204

Altered rectal sensory response induced by balloon distention in patients with functional abdominal pain syndrome  

Microsoft Academic Search

BACKGROUND: Functional abdominal pain syndrome (FAPS) has chronic unexplained abdominal pain and is similar to the psychiatric diagnosis of somatoform pain disorder. A patient with irritable bowel syndrome (IBS) also has chronic unexplained abdominal pain, and rectal hypersensitivity is observed in a majority of the patients. However, no reports have evaluated the visceral sensory function of FAPS precisely. We aimed

Tsukasa Nozu; Miwako Kudaira

2009-01-01

205

Functional motor recovery is improved due to local placement of GDNF microspheres after delayed nerve repair.  

PubMed

The majority of bioengineering strategies to promote peripheral nerve regeneration after injury have focused on therapies to bridge large nerve defects while fewer therapies are being developed to treat other nerve injuries, such as nerve transection. We constructed delivery systems using fibrin gels containing either free GDNF or polylactide-glycolic acid (PLGA) microspheres with GDNF to treat delayed nerve repair, where ELISA verified GDNF release. We determined the formulation of microspheres containing GDNF that optimized nerve regeneration and functional recovery in a rat model of delayed nerve repair. Experimental groups underwent delayed nerve repair and treatment with GDNF microspheres in fibrin glue at the repair site or control treatments (empty microspheres or free GDNF without microspheres). Contractile muscle force, muscle mass, and MUNE were measured 12 weeks following treatment, where GDNF microspheres (2 weeks formulation) were superior compared to either no GDNF or short-term release of free GDNF to nerve. Nerve histology distal to the repair site demonstrated increased axon counts and fiber diameters due to GDNF microspheres (2 weeks formulation). GDNF microspheres partially reversed the deleterious effects of chronic nerve injury, and recovery was slightly favored with the 2 weeks formulation compared to the 4 weeks formulation. PMID:23239194

Wood, Matthew D; Gordon, Tessa; Kemp, Stephen W P; Liu, Edward H; Kim, Howard; Shoichet, Molly S; Borschel, Gregory H

2013-05-01

206

Rapid recovery of serratus anterior muscle function after microneurolysis of long thoracic nerve injury  

Microsoft Academic Search

BACKGROUND: Injury to the long thoracic nerve is a common cause of winging scapula. When the serratus anterior muscle is unable to function, patients often lose the ability to raise their arm overhead on the affected side. METHODS: Serratus anterior function was restored through decompression, neurolysis, and tetanic electrical stimulation of the long thoracic nerve. This included partial release of

Rahul K Nath; Sonya E Melcher

2007-01-01

207

Protein Tyrosine Phosphatase Receptor Type O regulates development and function of the sensory nervous system  

PubMed Central

The roles of protein tyrosine phosphatases (PTPs) in differentiation and axon targeting by dorsal root ganglion (DRG) neurons are essentially unknown. The type III transmembrane PTP, PTPRO, is expressed in DRG neurons, and is implicated in the guidance of motor and retinal axons. We examined the role of PTPRO in DRG development and function using PTPRO-/- mice. The number of peptidergic nociceptive neurons in the DRG of PTPRO-/- mice was significantly decreased, while the total number of sensory neurons appeared unchanged. In addition, spinal pathfinding by both peptidergic and proprioceptive neurons was abnormal in PTPRO-/- mice. Lastly, PTPRO-/- mice performed abnormally on tests of thermal pain and sensorimotor coordination, suggesting that both nociception and proprioception were perturbed. Our data indicate that PTPRO is required for peptidergic differentiation and process outgrowth of sensory neurons, as well as mature sensory function, and provide the first evidence that RPTPs regulate DRG development.

Gonzalez-Brito, Manuel R.; Bixby, John L.

2009-01-01

208

Advances of Peripheral Nerve Repair Techniques to Improve Hand Function: A Systematic Review of Literature  

PubMed Central

Concepts of neuronal damage and repair date back to ancient times. The research in this topic has been growing ever since and numerous nerve repair techniques have evolved throughout the years. Due to our greater understanding of nerve injuries and repair we now distinguish between central and peripheral nervous system. In this review, we have chosen to concentrate on peripheral nerve injuries and in particular those involving the hand. There are no reviews bringing together and summarizing the latest research evidence concerning the most up-to-date techniques used to improve hand function. Therefore, by identifying and evaluating all the published literature in this field, we have summarized all the available information about the advances in peripheral nerve techniques used to improve hand function. The most important ones are the use of resorbable poly[(R)-3-hydroxybutyrate] (PHB), epineural end-to-end suturing, graft repair, nerve transfer, side to side neurorrhaphy and end to side neurorrhaphy between median, radial and ulnar nerves, nerve transplant, nerve repair, external neurolysis and epineural sutures, adjacent neurotization without nerve suturing, Agee endoscopic operation, tourniquet induced anesthesia, toe transfer and meticulous intrinsic repair, free auto nerve grafting, use of distal based neurocutaneous flaps and tubulization. At the same time we found that the patient’s age, tension of repair, time of repair, level of injury and scar formation following surgery affect the prognosis. Despite the thorough findings of this systematic review we suggest that further research in this field is needed.

P, Mafi; S, Hindocha; M, Dhital; M, Saleh

2012-01-01

209

TrkB-like immunoreactivity in trigeminal sensory nerve fibers of the rat molar tooth pulp: development and response to nerve injury  

Microsoft Academic Search

The localization of TrkB, a signal transducing receptor for brain-derived neurotrophic factor and neurotrophin-4, was studied in the rat mandibular molar pulp during development and following nerve injury. Sections were incubated with rabbit polyclonal antiserum against the catalytic part of the TrkB receptor, thus only binding to full-length TrkB receptors, and examined by immunofluorescence microscopy and EM immunocytochemistry. At embryonic

E. Foster; M. Risling; K. Fried

1995-01-01

210

Etifoxine improves peripheral nerve regeneration and functional recovery  

Microsoft Academic Search

Peripheral nerves show spontaneous regenerative responses, but recovery after injury or peripheral neuropathies (toxic, diabetic, or chronic inflammatory demyelinating polyneuropathy syndromes) is slow and often incomplete, and at present no efficient treatment is available. Using well-defined peripheral nerve lesion paradigms, we assessed the therapeutic usefulness of etifoxine, recently identified as a ligand of the translocator protein (18 kDa) (TSPO), to

Christelle Girard; Song Liu; Françoise Cadepond; David Adams; Catherine Lacroix; Marc Verleye; Jean-Marie Gillardin; Etienne-Emile Baulieu; Michael Schumacher; Ghislaine Schweizer-Groyer

2008-01-01

211

Beyond traditional approaches to understanding the functional role of neuromodulators in sensory cortices  

PubMed Central

Over the last two decades, a vast literature has described the influence of neuromodulatory systems on the responses of sensory cortex neurons (review in Gu, 2002; Edeline, 2003; Weinberger, 2003; Metherate, 2004, 2011). At the single cell level, facilitation of evoked responses, increases in signal-to-noise ratio, and improved functional properties of sensory cortex neurons have been reported in the visual, auditory, and somatosensory modality. At the map level, massive cortical reorganizations have been described when repeated activation of a neuromodulatory system are associated with a particular sensory stimulus. In reviewing our knowledge concerning the way the noradrenergic and cholinergic system control sensory cortices, I will point out that the differences between the protocols used to reveal these effects most likely reflect different assumptions concerning the role of the neuromodulators. More importantly, a gap still exists between the descriptions of neuromodulatory effects and the concepts that are currently applied to decipher the neural code operating in sensory cortices. Key examples that bring this gap into focus are the concept of cell assemblies and the role played by the spike timing precision (i.e., by the temporal organization of spike trains at the millisecond time-scale) which are now recognized as essential in sensory physiology but are rarely considered in experiments describing the role of neuromodulators in sensory cortices. Thus, I will suggest that several lines of research, particularly in the field of computational neurosciences, should help us to go beyond traditional approaches and, ultimately, to understand how neuromodulators impact on the cortical mechanisms underlying our perceptual abilities.

Edeline, Jean-Marc

2012-01-01

212

Functional Analysis of Aberrant Behavior Maintained by Automatic Reinforcement: Assessments of Specific Sensory Reinforcers.  

ERIC Educational Resources Information Center

A study developed a systematic functional assessment package to reduce the stereotypy and self-injurious behaviors maintained by nonsocial reinforcement in two individuals with mental retardation. Differential reinforcement of zero rates of responding (DRO) procedures using stimuli within the targeted sensory classes were successful in eliminated…

Patel, Meeta R.; Carr, James E.; Kim, Christine; Robles, Adel; Eastridge, Dixie

2000-01-01

213

EFFECTS OF 2,4-DITHIOBIURET ON SENSORY AND MOTOR FUNCTION  

EPA Science Inventory

2,4-Dithiobiuret exposure causes a delayed onset muscle weakness in rats that has been attributed to depressed neuromuscular transmission. he present study compares the effects of DTB on sensory and motor function in rats. dult male Long-Evans hooded rats were exposed to saline, ...

214

Functional oropharyngeal sensory disruption interferes with the cortical control of swallowing  

PubMed Central

Background Sensory input is crucial to the initiation and modulation of swallowing. From a clinical point of view, oropharyngeal sensory deficits have been shown to be an important cause of dysphagia and aspiration in stroke patients. In the present study we therefore investigated effects of functional oropharyngeal disruption on the cortical control of swallowing. We employed whole-head MEG to study cortical activity during self-paced volitional swallowing with and without topical oropharyngeal anesthesia in ten healthy subjects. A simple swallowing screening-test confirmed that anesthesia caused swallowing difficulties with decreased swallowing speed and reduced volume per swallow in all subjects investigated. Data were analyzed by means of synthetic aperture magnetometry (SAM) and the group analysis of the individual SAM data was performed using a permutation test. Results The analysis of normal swallowing revealed bilateral activation of the mid-lateral primary sensorimotor cortex. Oropharyngeal anesthesia led to a pronounced decrease of both sensory and motor activation. Conclusion Our results suggest that a short-term decrease in oropharyngeal sensory input impedes the cortical control of swallowing. Apart from diminished sensory activity, a reduced activation of the primary motor cortex was found. These findings facilitate our understanding of the pathophysiology of dysphagia.

Teismann, Inga K; Steinstraeter, Olaf; Stoeckigt, Kati; Suntrup, Sonja; Wollbrink, Andreas; Pantev, Christo; Dziewas, Rainer

2007-01-01

215

Loss of Bardet-Biedl syndrome proteins causes defects in peripheral sensory innervation and function  

PubMed Central

Reception and interpretation of environmental stimuli is critical for the survival of all organisms. Here, we show that the ablation of BBS1 and BBS4, two genes mutated in Bardet–Biedl syndrome and that encode proteins that localize near the centrioles of sensory neurons, leads to alterations of s.c. sensory innervation and trafficking of the thermosensory channel TRPV1 and the mechanosensory channel STOML3, with concomitant defects in peripheral thermosensation and mechanosensation. The thermosensory phenotype is recapitulated in Caenorhabditis elegans, because BBS mutants manifest deficient thermosensory responses at both physiological and nociceptive temperatures and defective trafficking of OSM-9, a polymodal sensory channel protein and a functional homolog of TRPV1 or TRPV4. Our findings suggest a hitherto unrecognized, but essential, role for mammalian basal body proteins in the acquisition of mechano- and thermosensory stimuli and highlight potentially clinical features of ciliopathies in humans.

Tan, Perciliz L.; Barr, Travis; Inglis, Peter N.; Mitsuma, Norimasa; Huang, Susan M.; Garcia-Gonzalez, Miguel A.; Bradley, Brian A.; Coforio, Stephanie; Albrecht, Phillip J.; Watnick, Terry; Germino, Gregory G.; Beales, Philip L.; Caterina, Michael J.; Leroux, Michel R.; Rice, Frank L.; Katsanis, Nicholas

2007-01-01

216

Morphometric study of the sensory neuron and peripheral nerve changes induced by chronic cisplatin (DDP) administration in rats  

Microsoft Academic Search

We performed a morphological, morphometric and toxicological study on the spinal ganglia and peripheral nerves of the rat after chronic administration of cisplatin (cis-dichlorodiammineplatinum II; DDP) with two different schedules. Severe damage of the spinal ganglia neurons was demonstrated with predominant involvement of the nucleus and nucleolus associated with a decrease in the cell size. Morphological and morphometric changes also

G. Cavaletti; G. Tredici; P. Marmiroli; M. G. Petruccioli; I. Barajon; D. Fabbrica

1992-01-01

217

Neuronal Nitric Oxide Synthase mRNA Upregulation in Rat Sensory Neurons after Spinal Nerve Ligation: Lack of a Role in Allodynia Development  

Microsoft Academic Search

Pharmacological evidence suggests a functional role for spinal nitric oxide (NO) in the modulation of thermal and\\/or inflamma- tory hyperalgesia. To assess the role of NO in nerve injury- induced tactile allodynia, we examined neuronal NO synthase (nNOS) expression in the spinal cord and dorsal root ganglia (DRG) of rats with tactile allodynia because of either tight ligation of the

Z. David Luo; S. R. Chaplan; B. P. Scott; D. Cizkova; N. A. Calcutt; T. L. Yaksh

1999-01-01

218

Quantitative sensory testing.  

PubMed

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

Siao, Peter; Cros, Didier P

2003-05-01

219

Insomnia-related complaints correlate with functional connectivity between sensory-motor regions.  

PubMed

According to the hyperarousal theory of insomnia, difficulty in initiating or maintaining sleep occurs as a result of increased cognitive and physiological arousal caused by acute stressors and associated cognitive rumination, placing the individual in a perpetual cycle of hyperarousal and increased sensitivity to sensory stimulation. We tested the hypothesis that difficulty in initiating or maintaining sleep would be associated with increased functional connectivity between primary sensory processing and motor planning regions. Fifty-eight healthy adults (29 men, 29 women) completed a self-report inventory about sleep onset and maintenance problems and underwent a 6-min resting-state functional MRI scan. Bilateral regions of interest (ROIs) were placed in primary visual cortex, auditory cortex, olfactory cortex, and the supplementary motor cortex, and the mean processed signal time course was extracted and correlated with each of the other ROIs. Difficulty in falling asleep was associated with increased functional connectivity between the primary visual cortex and other sensory regions such as the primary auditory cortex, olfactory cortex, and the supplementary motor cortex. The primary auditory cortex also showed greater connectivity with the supplementary motor cortex in those with sleep initiation problems. Problems with sleep maintenance were associated with greater connectivity between the primary visual cortex and the olfactory cortex. Consistent with the predictions of the hyperarousal model, difficulty in falling asleep was associated with greater functional connectivity between primary sensory and supplementary motor regions. Such augmented functional connectivity may contribute to the sustained sensory processing of environmental stimuli, potentially prolonging the latency to sleep. PMID:23399993

Killgore, William D S; Schwab, Zachary J; Kipman, Maia; Deldonno, Sophie R; Weber, Mareen

2013-03-27

220

Combinatorial expression of TRPV channel proteins defines their sensory functions and subcellular localization in C. elegans neurons.  

PubMed

C. elegans OSM-9 is a TRPV channel protein involved in sensory transduction and adaptation. Here, we show that distinct sensory functions arise from different combinations of OSM-9 and related OCR TRPV proteins. Both OSM-9 and OCR-2 are essential for several forms of sensory transduction, including olfaction, osmosensation, mechanosensation, and chemosensation. In neurons that express both OSM-9 and OCR-2, tagged OCR-2 and OSM-9 proteins reside in sensory cilia and promote each other's localization to cilia. In neurons that express only OSM-9, tagged OSM-9 protein resides in the cell body and acts in sensory adaptation rather than sensory transduction. Thus, alternative combinations of TRPV proteins may direct different functions in distinct subcellular locations. Animals expressing the mammalian TRPV1 (VR1) channel in ASH nociceptor neurons avoid the TRPV1 ligand capsaicin, allowing selective, drug-inducible activation of a specific behavior. PMID:12160748

Tobin, David; Madsen, David; Kahn-Kirby, Amanda; Peckol, Erin; Moulder, Gary; Barstead, Robert; Maricq, Andres; Bargmann, Cornelia

2002-07-18

221

Biomagnetic functional localization of a peripheral nerve in man.  

PubMed Central

The first detection of the magnetic field of a stimulated peripheral nerve in man is presented. The measurement was performed noninvasively and in vivo on a healthy subject. The spatio-temporal field distribution is utilized to calculate the location of bioelectric activity on the basis of the equivalent current dipole model. The localization of the active nerve tissue is confirmed by a computer tomography image of the upper arm cross-section. Furthermore, a calculation of the total current distribution in the nerve explains the observed morphology of the signal. Images FIGURE 5

Trahms, L; Erne, S N; Trontelj, Z; Curio, G; Aust, P

1989-01-01

222

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

PubMed

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

Witherspoon, Jw; Smirnova, Iv; McIff, Te

2014-07-01

223

Complexity of sensory environment drives the expression of candidate-plasticity gene, nerve growth factor induced-A.  

PubMed

Exposure of animals to an enriched environment triggers widespread modifications in brain circuitry and function. While this paradigm leads to marked plasticity in animals chronically or acutely exposed to the enriched environment, the molecular mechanisms that enable or regulate such modifications require further characterization. To this end, we have investigated the expression profiles of both mRNA and protein products of a candidate-plasticity gene, nerve growth factor induced-A (NGFI-A), in the brains of rats exposed to increased environmental complexity. We found that NGFI-A mRNA is markedly up-regulated throughout the brains of animals exposed to the enriched environment, but not in the brains of either handled-only or undisturbed control groups. The most pronounced effects were observed in the somatosensory and visual cortices, in layers III and V, while more modest increases were observed in all other cortical layers, with the exception of layer I. A striking NGFI-A mRNA up-regulation was also observed in the striatum and hippocampal formation, notably in the CA1 subfield, of animals exposed to the enriched environment paradigm. Immunocytochemistry was also used to investigate the distribution of NGFI-A protein in response to the environmental enrichment protocol. A marked increase in the number of NGFI-A positive nuclei was identified in the enriched environment condition, as compared to undisturbed and handled-only controls, throughout the rat brain. While the greatest number of NGFI-A immunolabeled neurons was found in cortical layers III and V, up-regulation of NGFI-A protein was also detectable in layers II, IV and VI, in both the somatosensory and visual cortices. NGFI-A immunopositive neurons were also more numerous in the CA1 subfield of the hippocampal formation of animals exposed to the enriched environment, but remained at basal levels in both control groups. Our results implicate NGFI-A as one of the possible early genetic signals that ultimately lead to plastic changes in the CNS. PMID:12074899

Pinaud, R; Tremere, L A; Penner, M R; Hess, F F; Robertson, H A; Currie, R W

2002-01-01

224

Vascularized Nerve Grafts and Vascularized Fascia for Upper Extremity Nerve Reconstruction  

PubMed Central

Since 1976, experimental and clinical studies have suggested the superiority of vascularized nerve grafts. In this study, a 27-year experience of the senior author is presented regarding vascularized nerve grafts and fascia for complex upper extremity nerve reconstruction. The factors influencing outcomes as well as a comparison with conventional nerve grafts is presented. Since 1981, 21 vascularized nerve grafts, other than vascularized ulnar nerve, were used for reconstruction of nerve injuries in the upper extremity. Indications were prolonged denervation time, failure of the previously used conventional nerve grafts, and excessive scar in the recipient site. Injury was in the hand/wrist area (n?=?5), in the forearm (n?=?4), in the elbow (n?=?2), in the arm (n?=?4), or in the plexus (n?=?6). Vascularized sural (n?=?9), saphenous (n?=?8), superficial radial (n?=?3), and peroneal (superficial and deep) nerves were used. The mean follow-up was 31.4 months. Vascularized nerve grafts for upper extremity injuries provided good to excellent sensory return in severely scarred upper extremities in patients in whom conventional nerve grafts had failed. They have also provided relief of causalgia after painful neuroma resection and motor function recovery in selective cases even for above the elbow injuries. Small diameter vascularized nerve grafts should be considered for bridging long nerve gaps in regions of excessive scar or for reconstructions where conventional nerve grafts have failed.

Kostopoulos, Vasileios K.

2009-01-01

225

Assessment of functional recovery of sciatic nerve in rats submitted to low-level laser therapy with different fluences. An experimental study: laser in functional recovery in rats.  

PubMed

Peripheral nerve lesions caused sensory and motor deficits along the distribution of the injured nerve. Numerous researches have been carried out to enhance and/or accelerate the recovery of such lesions. The objective of this study was to assess the functional recovery of sciatic nerve in rats subjected to different fluences of low-level laser therapy (LLLT). Thirty-six animals were randomly divided into four groups: one consisting of sham rats and three others irradiated with progressive fluencies of 10 J/cm(2), 40 J/cm(2) and 80 J/cm(2) of laser AsGaAl (830 nm) for 21 consecutive days. They were evaluated by the Sciatic Functional Index (SFI) method. The crush injury was performed by using a portable device with dead weight of 5,000 g whose load was applied for 10 min. A digital camera was used to record the footprints left on the acrylic track, before surgery and after, on the 7th, 14th, and 21st days. The results also showed that on the 7th day, there was a difference between the groups irradiated with 40 J/cm(2), when compared with the sham group (p??0.05). It was possible to observe that the LLLT at fluency of 40 J/cm(2) and 80 J/cm(2) had a positive influence on the acceleration of the functional nerve recovery. PMID:24426674

Marcolino, Alexandre Marcio; Barbosa, Rafael Inácio; das Neves, Lais Mara Siqueira; Mazzer, Nilton; de Jesus Guirro, Rinaldo Roberto; de Cássia Registro Fonseca, Marisa

2013-12-01

226

The contribution of sensory system functional connectivity reduction to clinical pain in fibromyalgia.  

PubMed

Fibromyalgia typically presents with spontaneous body pain with no apparent cause and is considered pathophysiologically to be a functional disorder of somatosensory processing. We have investigated potential associations between the degree of self-reported clinical pain and resting-state brain functional connectivity at different levels of putative somatosensory integration. Resting-state functional magnetic resonance imaging was obtained in 40 women with fibromyalgia and 36 control subjects. A combination of functional connectivity-based measurements were used to assess (1) the basic pain signal modulation system at the level of the periaqueductal gray (PAG); (2) the sensory cortex with an emphasis on the parietal operculum/secondary somatosensory cortex (SII); and (3) the connectivity of these regions with the self-referential "default mode" network. Compared with control subjects, a reduction of functional connectivity was identified across the 3 levels of neural processing, each showing a significant and complementary correlation with the degree of clinical pain. Specifically, self-reported pain in fibromyalgia patients correlated with (1) reduced connectivity between PAG and anterior insula; (2) reduced connectivity between SII and primary somatosensory, visual, and auditory cortices; and (3) increased connectivity between SII and the default mode network. The results confirm previous research demonstrating abnormal functional connectivity in fibromyalgia and show that alterations at different levels of sensory processing may contribute to account for clinical pain. Importantly, reduced functional connectivity extended beyond the somatosensory domain and implicated visual and auditory sensory modalities. Overall, this study suggests that a general weakening of sensory integration underlies clinical pain in fibromyalgia. PMID:24792477

Pujol, Jesus; Macià, Dídac; Garcia-Fontanals, Alba; Blanco-Hinojo, Laura; López-Solà, Marina; Garcia-Blanco, Susana; Poca-Dias, Violant; Harrison, Ben J; Contreras-Rodríguez, Oren; Monfort, Jordi; Garcia-Fructuoso, Ferran; Deus, Joan

2014-08-01

227

Functional diversity among sensory receptors in a Drosophila olfactory circuit  

PubMed Central

The ability of an animal to detect, discriminate, and respond to odors depends on the function of its olfactory receptor neurons (ORNs), which in turn depends ultimately on odorant receptors. To understand the diverse mechanisms used by an animal in olfactory coding and computation, it is essential to understand the functional diversity of its odor receptors. The larval olfactory system of Drosophila melanogaster contains 21 ORNs and a comparable number of odorant receptors whose properties have been examined in only a limited way. We systematically screened them with a panel of ?500 odorants, yielding >10,000 receptor–odorant combinations. We identify for each of 19 receptors an odorant that excites it strongly. The responses elicited by each of these odorants are analyzed in detail. The odorants elicited little cross-activation of other receptors at the test concentration; thus, low concentrations of many of these odorants in nature may be signaled by a single ORN. The receptors differed dramatically in sensitivity to their cognate odorants. The responses showed diverse temporal dynamics, with some odorants eliciting supersustained responses. An intriguing question in the field concerns the roles of different ORNs and receptors in driving behavior. We found that the cognate odorants elicited behavioral responses that varied across a broad range. Some odorants elicited strong physiological responses but weak behavioral responses or weak physiological responses but strong behavioral responses.

Mathew, Dennis; Martelli, Carlotta; Kelley-Swift, Elizabeth; Brusalis, Christopher; Gershow, Marc; Samuel, Aravinthan D. T.; Emonet, Thierry; Carlson, John R.

2013-01-01

228

Error-Based Analysis of Optimal Tuning Functions Explains Phenomena Observed in Sensory Neurons  

PubMed Central

Biological systems display impressive capabilities in effectively responding to environmental signals in real time. There is increasing evidence that organisms may indeed be employing near optimal Bayesian calculations in their decision-making. An intriguing question relates to the properties of optimal encoding methods, namely determining the properties of neural populations in sensory layers that optimize performance, subject to physiological constraints. Within an ecological theory of neural encoding/decoding, we show that optimal Bayesian performance requires neural adaptation which reflects environmental changes. Specifically, we predict that neuronal tuning functions possess an optimal width, which increases with prior uncertainty and environmental noise, and decreases with the decoding time window. Furthermore, even for static stimuli, we demonstrate that dynamic sensory tuning functions, acting at relatively short time scales, lead to improved performance. Interestingly, the narrowing of tuning functions as a function of time was recently observed in several biological systems. Such results set the stage for a functional theory which may explain the high reliability of sensory systems, and the utility of neuronal adaptation occurring at multiple time scales.

Yaeli, Steve; Meir, Ron

2010-01-01

229

Role of Pituitary Adenylate-Cyclase Activating Polypeptide and Tac1 gene derived tachykinins in sensory, motor and vascular functions under normal and neuropathic conditions.  

PubMed

Pituitary Adenylate-Cyclase Activating Polypeptide (PACAP) and Tac1 gene-encoded tachykinins (substance P: SP, neurokinin A: NKA) are expressed in capsaicin-sensitive nerves, but their role in nociception, inflammation and vasoregulation is unclear. Therefore, we investigated the function of these neuropeptides and the NK1 tachykinin receptor (from Tacr1 gene) in the partial sciatic nerve ligation-induced traumatic mononeuropathy model using gene deficient (PACAP(-/-), Tac1(-/-), and Tacr1(-/-)) mice. Mechanonociceptive threshold of the paw was measured with dynamic plantar aesthesiometry, motor coordination with Rota-Rod and cutaneous microcirculation with laser Doppler imaging. Neurogenic vasodilation was evoked by mustard oil stimulating sensory nerves. In wildtype mice 30-40% mechanical hyperalgesia developed one week after nerve ligation, which was not altered in Tac1(-/-) and Tacr1(-/-) mice, but was absent in PACAP(-/-) animals. Motor coordination of the PACAP(-/-) and Tac1(-/-) groups was significantly worse both before and after nerve ligation compared to their wildtypes, but it did not change in Tacr1(-/-) mice. Basal postoperative microcirculation on the plantar skin of PACAP(-/-) mice did not differ from the wildtypes, but was significantly lower in Tac1(-/-) and Tacr1(-/-) ones. In contrast, mustard oil-induced neurogenic vasodilation was significantly smaller in PACAP(-/-) mice, but not in Tacr1(-/-) and Tac1(-/-) animals. Both PACAP and SP/NKA, but not NK1 receptors participate in normal motor coordination. Tachykinins maintain basal cutaneous microcirculation. PACAP is a crucial mediator of neuropathic mechanical hyperalgesia and neurogenic vasodilation. Therefore identifying its target and developing selective, potent antagonists, might open promising new perspectives for the treatment of neuropathic pain and vascular complications. PMID:23499760

Botz, Bálint; Imreh, András; Sándor, Katalin; Elekes, Krisztián; Szolcsányi, János; Regl?di, Dóra; Quinn, John P; Stewart, James; Zimmer, Andreas; Hashimoto, Hitoshi; Helyes, Zsuzsanna

2013-05-01

230

Pain ratings, sensory thresholds, and psychosocial functioning in women with provoked vestibulodynia.  

PubMed

Psychosocial and psychophysical functioning in 25 women with and 25 without provoked vestibulodynia (PVD) were examined. Participants underwent quantitative sensory testing and completed psychosocial measures. Women with PVD displayed lower pain thresholds, higher pain ratings, lower sexual functioning and sexual self-efficacy, and higher levels of somatization and catastrophization than controls. Lower psychosocial functioning correlated with decreased vulvar pressure-pain threshold and increased cotton-swab test pain ratings. For PVD women, decreased sexual function and sexual self-efficacy were associated with higher vulvar pressure-pain ratings. Findings suggest that women with PVD would benefit from treatment that addresses pain-focused and psychosocial components. PMID:19466666

Sutton, Katherine S; Pukall, Caroline F; Chamberlain, Susan

2009-01-01

231

Role of Urothelial Nerve Growth Factor in Human Bladder Function  

PubMed Central

Aims To test whether nerve growth factor (NGF) concentration in human bladder urothelium/suburothelium is related to detrusor overactivity (DO), bladder sensation, detrusor contractility, or other aspects of lower urinary tract function. Materials and Methods Concentration of NGF was measured (using ELISA) in superficial bladder biopsies from 27 women (mean age 52 years, range 22–82) after comprehensive videourodynamics and bladder diary. Approximately half (12/27) showed clear DO and half did not. Results There was no evidence for increased NGF concentration in subjects with DO (association negative by Mann–Whitney test, P = 0.23). NGF was not significantly associated with two measures of detrusor contractility (Spearman’s r = ?0.29, P = 0.17; r = ?0.20, P = 0.33); nor with four measures inversely related to sensation: volume at strong desire to void and maximum capacity on cystometry (r = ?0.13, P = 0.53; r = ?0.23, P = 0.28), and maximum voided volume and mean daytime voided volume on bladder diary (r = ?0.29, P = 0.16; r = ?0.16, P = 0.44). It was significantly associated with 24-hr urine output on bladder diary (Spearman’s r = ?0.55, P = 0.004). Conclusions Elevated NGF levels in human urothelium/suburothelium are not strongly associated with DO, detrusor contractility or increased bladder sensation. NGF levels are lower in subjects with higher 24-hr urine output. This observation is consistent with a role for NGF in an active process (trafficking) involved in bladder filling.

Birder, Lori A.; Wolf-Johnston, Amanda; Griffiths, Derek; Resnick, Neil M.

2011-01-01

232

Nerve repair, grafting, and nerve transfers.  

PubMed

Advances in the field of peripheral nerve surgery have increased our understanding of the complex cellular and molecular events involved in nerve injury and repair. Application of these important discoveries has led to important developments in the techniques of nerve repair, nerve grafting, nerve allografts, end-to-side repairs, and nerve-to-nerve transfers. As our understanding of this dynamic field increases, further improvement in functional outcomes after nerve injury and repair can be expected. PMID:12737353

Dvali, Linda; Mackinnon, Susan

2003-04-01

233

Characteristics of bilateral hand function in individuals with unilateral dystonia due to perinatal stroke: sensory and motor aspects.  

PubMed

The authors assessed bilateral motor and sensory function in individuals with upper limb dystonia due to unilateral perinatal stroke and explored interrelationships of motor function and sensory ability. Reach kinematics and tactile sensation were measured in 7 participants with dystonia and 9 healthy volunteers. The dystonia group had poorer motor (hold time, reach time, shoulder/elbow correlation) and sensory (spatial discrimination, stereognosis) outcomes than the control group on the nondominant side. On the dominant side, only sensation (spatial discrimination, stereognosis) was poorer in the dystonia group compared with the control group. In the dystonia group, although sensory and motor outcomes were uncorrelated, dystonia severity was related to poorer stereognosis, longer hold and reach times, and decreased shoulder/elbow coordination. Findings of bilateral sensory deficits in dystonia can be explained by neural reorganization. Visual compensation for somatosensory changes in the nonstroke hemisphere may explain the lack of bilateral impairments in reaching. PMID:24396131

de Campos, Ana Carolina; Kukke, Sahana N; Hallett, Mark; Alter, Katharine E; Damiano, Diane L

2014-05-01

234

Acetyl-L-carnitine corrects the altered peripheral nerve function of experimental diabetes.  

PubMed

Acetyl-L-carnitine (ALC) has been shown to facilitate the repair of transected sciatic nerves. The effect of ALC (50 mg/kg/d) on the diminished nerve conduction velocity (NCV) of rats with streptozotocin (STZ)-induced hyperglycemia of 3 weeks' duration was evaluated. The aldose reductase inhibitor, sorbinil, which is reported to normalize the impaired NCV associated with experimental diabetes, was used as a positive control. Aldose reductase inhibitors are thought to have an effect by decreasing peripheral nerve sorbitol content and increasing nerve myo-inositol. Treatment of STZ-diabetic rats with either ALC or sorbinil resulted in normal NCV. Sorbinil treatment was associated with normalized sciatic nerve sorbitol and myo-inositol; ALC treatment did not reduce the elevated sorbitol levels, but sciatic nerve myo-inositol content was no different from nondiabetic levels. Both ALC and sorbinil treatment of STZ-diabetic rats were associated with a reduction in the elevated malondialdehyde (MDA) content of diabetic sciatic nerve, indicating reduced lipid peroxidation. The beneficial effects of sorbinil and ALC on the altered peripheral nerve function associated with diabetes were similar, but their effects on the polyol pathway (frequently implicated in the pathogenesis of peripheral neuropathy) were different. PMID:7752919

Lowitt, S; Malone, J I; Salem, A F; Korthals, J; Benford, S

1995-05-01

235

EFFECTS OF HYPERGLYCEMIA ON RAT CAVERNOUS NERVE AXONS: A FUNCTIONAL AND ULTRASTRUCTURAL STUDY  

PubMed Central

The present study explored parallel changes in the physiology and structure of myelinated (A?) and unmyelinated (C) small diameter axons in the cavernous nerve of rats associated with streptozotocin-induced hyperglycemia. Damage to these axons is thought to play a key role in diabetic autonomic neuropathy and erectile dysfunction, but their pathophysiology has been poorly studied. Velocities in slow conducting fibers were measured by applying multiple unit procedures; histopathology was evaluated with both light and electron microscopy. To our knowledge, these are the initial studies of slow nerve conduction velocities in the distal segments of the cavernous nerve. We report that hyperglycemia is associated with a substantial reduction in the amplitude of the slow conducting response, as well as a slowing of velocities within this very slow range (<2.5 m/sec). Even with prolonged hyperglycemia (> 4 months), histopathological abnormalities were mild and limited to the distal segments of the cavernous nerve. Structural findings included dystrophic changes in nerve terminals, abnormal accumulations of glycogen granules in unmyelinated and preterminal axons, and necrosis of scattered smooth muscle fibers. The onset of slowing of velocity in the distal cavernous nerve occurred subsequent to slowing in somatic nerves in the same rats. The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy.

Zotova, Elena G.; Schaumburg, Herbert H.; Raine, Cedric S.; Cannella, Barbara; Tar, Moses; Melman, Arnold; Arezzo, Joseph C.

2008-01-01

236

Failure of action potential propagation in sensory neurons: mechanisms and loss of afferent filtering in C-type units after painful nerve injury  

PubMed Central

The T-junction of sensory neurons in the dorsal root ganglion (DRG) is a potential impediment to action potential (AP) propagation towards the CNS. Using intracellular recordings from rat DRG neuronal somata during stimulation of the dorsal root, we determined that the maximal rate at which all of 20 APs in a train could successfully transit the T-junction (following frequency) was lowest in C-type units, followed by A-type units with inflected descending limbs of the AP, and highest in A-type units without inflections. In C-type units, following frequency was slower than the rate at which AP trains could be produced in either dorsal root axonal segments or in the soma alone, indicating that the T-junction is a site that acts as a low-pass filter for AP propagation. Following frequency was slower for a train of 20 APs than for two, indicating that a cumulative process leads to propagation failure. Propagation failure was accompanied by diminished somatic membrane input resistance, and was enhanced when Ca2+-sensitive K+ currents were augmented or when Ca2+-sensitive Cl? currents were blocked. After peripheral nerve injury, following frequencies were increased in axotomized C-type neurons and decreased in axotomized non-inflected A-type neurons. These findings reveal that the T-junction in sensory neurons is a regulator of afferent impulse traffic. Diminished filtering of AP trains at the T-junction of C-type neurons with axotomized peripheral processes could enhance the transmission of activity that is ectopically triggered in a neuroma or the neuronal soma, possibly contributing to pain generation.

Gemes, Geza; Koopmeiners, Andrew; Rigaud, Marcel; Lirk, Philipp; Sapunar, Damir; Bangaru, Madhavi Latha; Vilceanu, Daniel; Garrison, Sheldon R; Ljubkovic, Marko; Mueller, Samantha J; Stucky, Cheryl L; Hogan, Quinn H

2013-01-01

237

Neurophysiological Diagnosis of Acquired Sensory Ganglionopathies  

Microsoft Academic Search

We examined 29 patients with chronic progressive ganglionopathy of different etiology. Neurophysiological abnormalities were dominated by a widespread decrease in sensory nerve action potential amplitudes, which involved both upper and lower limb nerves, even in patients with asymmetrical or patchy clinical presentation. This impairment of sensory nerve conduction, reflecting a nonlength-dependent pattern of peripheral axon degeneration, should be considered the

Giuseppe Lauria; Davide Pareyson; Angelo Sghirlanzoni

2003-01-01

238

Immunohistochemical, Ultrastructural and Functional Analysis of Axonal Regeneration through Peripheral Nerve Grafts Containing Schwann Cells Expressing BDNF, CNTF or NT3  

PubMed Central

We used morphological, immunohistochemical and functional assessments to determine the impact of genetically-modified peripheral nerve (PN) grafts on axonal regeneration after injury. Grafts were assembled from acellular nerve sheaths repopulated ex vivo with Schwann cells (SCs) modified to express brain-derived neurotrophic factor (BDNF), a secretable form of ciliary neurotrophic factor (CNTF), or neurotrophin-3 (NT3). Grafts were used to repair unilateral 1 cm defects in rat peroneal nerves and 10 weeks later outcomes were compared to normal nerves and various controls: autografts, acellular grafts and grafts with unmodified SCs. The number of regenerated ?III-Tubulin positive axons was similar in all grafts with the exception of CNTF, which contained the fewest immunostained axons. There were significantly lower fiber counts in acellular, untransduced SC and NT3 groups using a PanNF antibody, suggesting a paucity of large caliber axons. In addition, NT3 grafts contained the greatest number of sensory fibres, identified with either IB4 or CGRP markers. Examination of semi- and ultra-thin sections revealed heterogeneous graft morphologies, particularly in BDNF and NT3 grafts in which the fascicular organization was pronounced. Unmyelinated axons were loosely organized in numerous Remak bundles in NT3 grafts, while the BDNF graft group displayed the lowest ratio of umyelinated to myelinated axons. Gait analysis revealed that stance width was increased in rats with CNTF and NT3 grafts, and step length involving the injured left hindlimb was significantly greater in NT3 grafted rats, suggesting enhanced sensory sensitivity in these animals. In summary, the selective expression of BDNF, CNTF or NT3 by genetically modified SCs had differential effects on PN graft morphology, the number and type of regenerating axons, myelination, and locomotor function.

Godinho, Maria Joao; Teh, Lip; Pollett, Margaret A.; Goodman, Douglas; Hodgetts, Stuart I.; Sweetman, Iain; Walters, Mark; Verhaagen, Joost; Plant, Giles W.; Harvey, Alan R.

2013-01-01

239

Activity-dependent silencing reveals functionally distinct itch-generating sensory neurons.  

PubMed

The peripheral terminals of primary sensory neurons detect histamine and non-histamine itch-provoking ligands through molecularly distinct transduction mechanisms. It remains unclear, however, whether these distinct pruritogens activate the same or different afferent fibers. Using a strategy of reversibly silencing specific subsets of murine pruritogen-sensitive sensory axons by targeted delivery of a charged sodium-channel blocker, we found that functional blockade of histamine itch did not affect the itch evoked by chloroquine or SLIGRL-NH2, and vice versa. Notably, blocking itch-generating fibers did not reduce pain-associated behavior. However, silencing TRPV1(+) or TRPA1(+) neurons allowed allyl isothiocyanate or capsaicin, respectively, to evoke itch, implying that certain peripheral afferents may normally indirectly inhibit algogens from eliciting itch. These findings support the presence of functionally distinct sets of itch-generating neurons and suggest that targeted silencing of activated sensory fibers may represent a clinically useful anti-pruritic therapeutic approach for histaminergic and non-histaminergic pruritus. PMID:23685721

Roberson, David P; Gudes, Sagi; Sprague, Jared M; Patoski, Haley A W; Robson, Victoria K; Blasl, Felix; Duan, Bo; Oh, Seog Bae; Bean, Bruce P; Ma, Qiufu; Binshtok, Alexander M; Woolf, Clifford J

2013-07-01

240

Assessment of canine sensory function by using sine-wave electrical stimuli paradigm.  

PubMed

The paradigm of sine-wave electrical stimuli has been used for sensory neurological assessment in humans. In the present study, we applied the paradigm to the dog for the quantitative assessment of sensory function. Sine-wave electrical current stimuli at frequencies of 2000, 250, and 5Hz were delivered to bipolar electrodes attached to the skin surface of the hind paws. The stimulation intensity was gradually increased, and the minimum intensity required to elicit the lifting behavior in the stimulated paw was determined as current threshold (CT) for each of the three frequencies. Dogs consistently showed the lifting behavior at CTs without showing aversive behaviors such as vocalization and wriggling. The baseline CTs (mean+/-SEM, n=12) were 4430+/-110microA for CT2000, 2215+/-173microA for CT250, and 2305+/-152microA for CT5. The CTs immediately increased after bolus intravenous injection of fentanyl at 10microg/kg, although the significant increase disappeared within 1h. The time course for the CTs was parallel to that of plasma fentanyl concentration. In conclusion, the present study applied the paradigm of transcutaneous sine-wave electrical stimuli to the dog, and used the hind paw lifting as endpoint behavior. This paradigm is simple, non-invasive, useful in the assessment of sensory function, and can be adapted to investigate the pharmacokinetics/pharmacodynamics relation of drugs. Further studies are needed to give the conclusive interpretation of the endpoint behavior. PMID:20570687

Watabiki, Tomonari; Nagakura, Yukinori; Wegner, Kirsten; Kakimoto, Shuichiro; Tozier, Nicolle A; Malkmus, Shelle A; Yaksh, Tony L

2010-10-01

241

Activity-dependent silencing reveals functionally distinct itch-generating sensory neurons  

PubMed Central

The peripheral terminals of primary sensory neurons detect histamine and non-histamine itch-provoking ligands through molecularly distinct transduction mechanisms. It remains unclear, however, whether these distinct pruritogens activate the same or different afferent fibers. We utilized a strategy of reversibly silencing specific subsets of murine pruritogen-sensitive sensory axons by targeted delivery of a charged sodium-channel blocker and found that functional blockade of histamine itch did not affect the itch evoked by chloroquine or SLIGRL-NH2, and vice versa. Notably, blocking itch-generating fibers did not reduce pain-associated behavior. However, silencing TRPV1+ or TRPA1+ neurons allowed AITC or capsaicin respectively to evoke itch, implying that certain peripheral afferents may normally indirectly inhibit algogens from eliciting itch. These findings support the presence of functionally distinct sets of itch-generating neurons and suggest that targeted silencing of activated sensory fibers may represent a clinically useful anti-pruritic therapeutic approach for histaminergic and non-histaminergic pruritus.

Roberson, David P.; Gudes, Sagi; Sprague, Jared M.; Patoski, Haley A. W.; Robson, Victoria K.; Blasl, Felix; Duan, Bo; Oh, Seog Bae; Bean, Bruce P.; Ma, Qiufu

2013-01-01

242

Dual sensory loss and depressive symptoms: the importance of hearing, daily functioning, and activity engagement.  

PubMed

Background: The association between dual sensory loss (DSL) and mental health has been well established. However, most studies have relied on self-report data and lacked measures that would enable researchers to examine causal pathways between DSL and depression. This study seeks to extend this research by examining the effects of DSL on mental health, and identify factors that explain the longitudinal associations between sensory loss and depressive symptoms. Methods: Piecewise linear-mixed models were used to analyze 16-years of longitudinal data collected on up to five occasions from 1611 adults (51% men) aged between 65 and 103?years. Depressive symptoms were assessed by the Centre for Epidemiological Studies Depression (CES-D). Vision loss (VL) was defined by corrected visual acuity >0.3 logMAR in the better eye, blindness, or glaucoma. Hearing loss (HL) was defined by pure-tone average (PTA) >25?dB in the better hearing ear. Analyses were adjusted for socio-demographics, medical conditions, lifestyle behaviors, activities of daily living (ADLs), cognitive function, and social engagement. Results: Unadjusted models indicated that higher levels of depressive symptoms were associated with HL (B?=?1.16, SE?=?0.33) and DSL (B?=?2.15, SE?=?0.39) but not VL. Greater rates of change in depressive symptoms were also evident after the onset of HL (B?=?0.16, SE?=?0.06, p?sensory loss were explained by difficulties with ADLs, and social engagement. Conclusion: Vision and HL are highly prevalent among older adults and their co-occurrence may compound their respective impacts on health, functioning, and activity engagement, thereby exerting strong effects on the mental health and wellbeing of those affected. There is therefore a need for rehabilitation programs to be sensitive to the combined effects of sensory loss on individuals. PMID:24379769

Kiely, Kim M; Anstey, Kaarin J; Luszcz, Mary A

2013-01-01

243

Dual Sensory Loss and Depressive Symptoms: The Importance of Hearing, Daily Functioning, and Activity Engagement  

PubMed Central

Background: The association between dual sensory loss (DSL) and mental health has been well established. However, most studies have relied on self-report data and lacked measures that would enable researchers to examine causal pathways between DSL and depression. This study seeks to extend this research by examining the effects of DSL on mental health, and identify factors that explain the longitudinal associations between sensory loss and depressive symptoms. Methods: Piecewise linear-mixed models were used to analyze 16-years of longitudinal data collected on up to five occasions from 1611 adults (51% men) aged between 65 and 103?years. Depressive symptoms were assessed by the Centre for Epidemiological Studies Depression (CES-D). Vision loss (VL) was defined by corrected visual acuity >0.3 logMAR in the better eye, blindness, or glaucoma. Hearing loss (HL) was defined by pure-tone average (PTA) >25?dB in the better hearing ear. Analyses were adjusted for socio-demographics, medical conditions, lifestyle behaviors, activities of daily living (ADLs), cognitive function, and social engagement. Results: Unadjusted models indicated that higher levels of depressive symptoms were associated with HL (B?=?1.16, SE?=?0.33) and DSL (B?=?2.15, SE?=?0.39) but not VL. Greater rates of change in depressive symptoms were also evident after the onset of HL (B?=?0.16, SE?=?0.06, p?sensory loss were explained by difficulties with ADLs, and social engagement. Conclusion: Vision and HL are highly prevalent among older adults and their co-occurrence may compound their respective impacts on health, functioning, and activity engagement, thereby exerting strong effects on the mental health and wellbeing of those affected. There is therefore a need for rehabilitation programs to be sensitive to the combined effects of sensory loss on individuals.

Kiely, Kim M.; Anstey, Kaarin J.; Luszcz, Mary A.

2013-01-01

244

A novel biological role for the phospholipid lysophosphatidylinositol in nociceptive sensitization via activation of diverse G-protein signalling pathways in sensory nerves in vivo.  

PubMed

The rich diversity of lipids and the specific signalling pathways they recruit provides tremendous scope for modulation of biological functions. Lysophosphatidylinositol (LPI) is emerging as a key modulator of cell proliferation, migration, and function, and holds important pathophysiological implications due to its high levels in diseased tissues, such as in cancer. Here we report a novel role for LPI in sensitization of peripheral sensory neurons, which was evident as exaggerated sensitivity to painful and innocuous pressure. Histopathological analyses indicated lack of involvement of myelin pathology and immune cell recruitment by LPI. Using pharmacological and conditional genetic tools in mice, we delineated receptor-mediated from non-receptor-mediated effects of LPI and we observed that GPR55, which functions as an LPI receptor when heterologously expressed in mammalian cells, only partially mediates LPI-induced actions in the context of pain sensitization in vivo; we demonstrate that, in vivo, LPI functions by activating G?(13) as well as G?(q/11) arms of G-protein signalling in sensory neurons. This study thus reports a novel pathophysiological function for LPI and elucidates underlying molecular mechanisms. PMID:23973358

Gangadharan, Vijayan; Selvaraj, Deepitha; Kurejova, Martina; Njoo, Christian; Gritsch, Simon; Škoricová, Dagmar; Horstmann, Heinz; Offermanns, Stefan; Brown, Andrew J; Kuner, Thomas; Tappe-Theodor, Anke; Kuner, Rohini

2013-12-01

245

Functional and structural analysis of partial optic nerve avulsion due to blunt trauma: Case report  

PubMed Central

Partial optic nerve avulsion (ONA) secondary to finger gouging is an uncommon but devastating injury. A 21-year-old man who had an acute vision loss after accidentally getting poked by himself in his right eye when he fell down during jogging is reported. The patient was diagnosed with partial ONA. Magnetic resonance imaging revealed intact optic nerve. Optical coherence tomography (OCT) revealed deep cavity at the inferior-temporal half of the optic disc. Retinal nerve fiber layer thickness was also thin at the inferior quadrant with circumpapillary OCT scan. Visual field test and electrophysiological tests showed functional abnormality compatible with optic nerve lesion. Diagnostic tools for anatomical and functional evaluation may reveal the course of this injury.

Mumcuoglu, Tarkan; Durukan, Hakan A; Erdurman, Cuneyt; Hurmeric, Volkan; Gundogan, Fatih C

2010-01-01

246

A pilot study examining activity participation, sensory responsiveness, and competence in children with high functioning Autism Spectrum Disorder.  

PubMed

This pilot study explored activity patterns in children with and without ASD and examined the role of sensory responsiveness in determining children's level of competence in activity performance. Twenty-six children with high functioning ASD and twenty-six typically-developing children 6-12 years old were assessed using the Sensory Profile and the Child Behavior Checklist. Results reflect differences in the types of activities and jobs/chores engaged in by children with ASD compared to children without ASD. Significant differences were seen in overall level of competence in activities, social, and school performance. Children demonstrating more frequent Sensory Sensitivity and Sensory Avoiding had significantly lower competence scores than children with fewer behaviors in these domains, suggesting that sensory responsiveness may impact the ability to participate successfully. PMID:21221753

Reynolds, Stacey; Bendixen, Roxanna M; Lawrence, Tami; Lane, Shelly J

2011-11-01

247

Visual evoked potential monitoring of optic nerve function during surgery.  

PubMed Central

A study was made with intra-operative flash--visual evoked potentials (VEP) monitored using a fibre-optic/contact lens photo stimulator in 57 patients undergoing intra-orbital surgical procedures with potential risk to the optic nerve. The VEPs recorded under enflurane and nitrous oxide anaesthesia did not differ significantly in latency or amplitude from the pre-operative recordings. Transient abolition of the VEP was seen under many circumstances and did not correlate with the outcome of surgery, but absence of a previously normal VEP for more than four minutes during surgical manipulation within the orbit did show a correlation with post operative impairment of vision. The technique provides early warning to the surgeon of threats to the integrity of the optic nerve.

Harding, G F; Bland, J D; Smith, V H

1990-01-01

248

Fibre function and perception during cutaneous nerve block.  

PubMed

In awake human subjects, neural responses in radial nerves to electrical stimulation were recorded with intrafascicular tungsten microelectrodes. Changes in the activity of individual fibre groups during blocking procedures were recorded and correlated with simultaneous alterations in the perception of standardized stimuli. Light touch sensibility in hairy skin appeared to depend on the integrity of A-beta-gamma fibres, cold and pinprick on A-delta fibres, and warmth and dull pain on C fibres. PMID:1185225

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

1975-09-01

249

Fibre function and perception during cutaneous nerve block.  

PubMed

In awake human subjects, neural responses in cutaneous nerves to electrical stimulation were recorded with intrafascicular tungsten micro-electrodes. Changes in the activity of individual fibre groups during blocking procedures were recorded and correlated with simultaneous alterations in the perception of standardized stimuli. Light touch sensibility in hairy skin was mediated by A-beta-gamma fibres, cold and pinprick by A-delta fibres and warmth and dull pain by C fibres. PMID:1215398

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

1975-01-01

250

Prevention of paclitaxel-evoked painful peripheral neuropathy by acetyl-L-carnitine: effects on axonal mitochondria, sensory nerve fiber terminal arbors, and cutaneous Langerhans cells.  

PubMed

Prophylactic treatment with acetyl-L-carnitine (ALCAR) prevents the neuropathic pain syndrome that is evoked by the chemotherapeutic agent, paclitaxel. The paclitaxel-evoked pain syndrome is associated with degeneration of the intraepidermal terminal arbors of primary afferent neurons, with the activation of cutaneous Langerhans cells, and with an increased incidence of swollen and vacuolated axonal mitochondria in A-fibers and C-fibers. Previous work suggests that ALCAR is neuroprotective in other nerve injury models and that it improves mitochondrial dysfunction. Thus, we examined whether the prophylactic efficacy of ALCAR was associated with the prevention of intraepidermal terminal arbor degeneration, the inhibition of Langerhans cell activation, or the inhibition of swelling and vacuolation of axonal mitochondria. In animals with a confirmed ALCAR effect, we found no evidence of a neuroprotective effect on the paclitaxel-evoked degeneration of sensory terminal arbors or an inhibition of the paclitaxel-evoked activation of Langerhans cells. However, ALCAR treatment completely prevented the paclitaxel-evoked increase in the incidence of swollen and vacuolated C-fiber mitochondria, while having no effect on the paclitaxel-evoked changes in A-fiber mitochondria. Our results suggest that the efficacy of prophylactic ALCAR treatment against the paclitaxel-evoked pain may be related to a protective effect on C-fiber mitochondria. PMID:18078936

Jin, Hai Wei; Flatters, Sarah J L; Xiao, Wen Hua; Mulhern, Howard L; Bennett, Gary J

2008-03-01

251

Functional assessment of sensory functions after photothrombotic stroke in the barrel field of mice.  

PubMed

Motor, sensory and cognitive deficits are common impairments observed in human stroke as well as in animal stroke models. Using a battery of behavioural tests we assessed sensorimotor deficits after photothrombotic stroke localized within or beyond cortical representation of mouse sensory vibrissae. We found restricted, modality specific behavioural consequences in the acute post-stroke period. Among incorporated tests, adhesive removal test, novelty exploration test and sensory labyrinth task were sensitive to the somatosensory cortical deficits. Injured animals explored new objects significantly longer, they also needed distinctly more time to contact and to remove the adhesive tape placed on whiskers contralateral to the infarct. Moreover, we observed that after stroke animals were unable to solve the sensory labyrinth depending only upon tactile sensation from whiskers with injured cortical representation. Spontaneous recovery could be observed within the first post-stroke week for adhesive tape removal and within 14 days for labyrinth performance. However, for the novel object exploration we did not observed the recovery for the period of 18 days after stroke. Moreover, new object exploration test performance differed between the somatosensory and visual cortical impairments. We suggest that those three tests might be valuable in assessing the usefulness of therapies designed to support brain repair after experimental stroke. PMID:24388975

Liguz-Lecznar, Monika; Zakrzewska, Renata; Daniszewska, Katarzyna; Kossut, Malgorzata

2014-03-15

252

Functional role of peripheral opioid receptors in the regulation of cardiac spinal afferent nerve activity during myocardial ischemia  

PubMed Central

Thinly myelinated A?-fiber and unmyelinated C-fiber cardiac sympathetic (spinal) sensory nerve fibers are activated during myocardial ischemia to transmit the sensation of angina pectoris. Although recent observations showed that myocardial ischemia increases the concentrations of opioid peptides and that the stimulation of peripheral opioid receptors inhibits chemically induced visceral and somatic nociception, the role of opioids in cardiac spinal afferent signaling during myocardial ischemia has not been studied. The present study tested the hypothesis that peripheral opioid receptors modulate cardiac spinal afferent nerve activity during myocardial ischemia by suppressing the responses of cardiac afferent nerve to ischemic mediators like bradykinin and extracellular ATP. The nerve activity of single unit cardiac afferents was recorded from the left sympathetic chain (T2–T5) in anesthetized cats. Forty-three ischemically sensitive afferent nerves (conduction velocity: 0.32–3.90 m/s) with receptive fields in the left and right ventricles were identified. The responses of these afferent nerves to repeat ischemia or ischemic mediators were further studied in the following protocols. First, epicardial administration of naloxone (8 ?mol), a nonselective opioid receptor antagonist, enhanced the responses of eight cardiac afferent nerves to recurrent myocardial ischemia by 62%, whereas epicardial application of vehicle (PBS) did not alter the responses of seven other cardiac afferent nerves to ischemia. Second, naloxone applied to the epicardial surface facilitated the responses of seven cardiac afferent nerves to epicardial ATP by 76%. Third, administration of naloxone enhanced the responses of seven other afferent nerves to bradykinin by 85%. In contrast, in the absence of naloxone, cardiac afferent nerves consistently responded to repeated application of ATP (n = 7) or bradykinin (n = 7). These data suggest that peripheral opioid peptides suppress the responses of cardiac sympathetic afferent nerves to myocardial ischemia and ischemic mediators like ATP and bradykinin.

Longhurst, John C.

2013-01-01

253

Celecoxib accelerates functional recovery after sciatic nerve crush in the rat  

PubMed Central

The inflammatory response appears to be essential in the modulation of the degeneration and regeneration process after peripheral nerve injury. In injured nerves, cyclooxygenase-2 (COX-2) is strongly upregulated around the injury site, possibly playing a role in the regulation of the inflammatory response. In this study we investigated the effect of celecoxib, a COX-2 inhibitor, on functional recovery after sciatic nerve crush in rats. Unilateral sciatic nerve crush injury was performed on 10 male Wistar rats. Animals on the experimental group (n = 5) received celecoxib (10 mg/kg ip) immediately before the crush injury and daily for 7 days after the injury. Control group (n = 5) received normal saline at equal regimen. A sham group (n = 5), where sciatic nerve was exposed but not crushed, was also evaluated. Functional recovery was then assessed by calculating the sciatic functional index (SFI) on days 0,1,7,14 and 21 in all groups, and registering the day of motor and walking onset. In comparison with control group, celecoxib treatment (experimental group) had significant beneficial effects on SFI, with a significantly better score on day 7. Anti-inflammatory drug celecoxib should be considered in the treatment of peripheral nerve injuries, but further studies are needed to explain the mechanism of its neuroprotective effects.

2008-01-01

254

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

PubMed Central

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

Vaughan, Cheryl H.

2012-01-01

255

Ultrastructural Changes in Spinal Motoneurons and Locomotor Functional Study after Sciatic Nerve Repair in Conduit Tube  

PubMed Central

Objective(s) Motor deficit and neuron degeneration is seen after nerve transection. The aim of this study is to determine whether a poled polyvinelidene fluoride (PVDF) tube with other supportive strategies can protect the neuronal morphology and motor function after sciatic nerve transaction in rats. Materials and Methods After transection of the left sciatic nerve in 60 male Wistar rats (200-250 g), the epineural group was sutured end to end. In the autograft rats, a 10 mm piece of sciatic nerve was rotated 180 °C and sutured back into the nerve gap. In the nerve guidance channel (NGC) group, polarized piezoelectric PVDF tube containing NGF and collagen gel was sutured in the gap. In control group sciatic nerve was removed (10 mm) without repair. After one, four and eight weeks, the L4-L6 spinal cord segment was removed for histological study using transmission electron microscope. Functional outcome was assessed using the Basso, Bresnahan and Beattie (BBB) locomotor scale at both four and eight weeks after the lesion. Results Chromatin condensation was seen after 4 weeks in the repair groups. Cell membrane shrinkage and mitochondrial degeneration was observed after 4 and 8 weeks respectively, in the autografted and NGC rats. In the control group, chromatin condensation, cell membrane shrinkage with mitochondrial degeneration and vacuolization of perikaryon was seen after 1, 4 and 8 weeks, respectively. At 56 days, the functional recovery of the epineural rats significantly increased in comparison to the other groups (P< 0.05). Conclusion The epineural suture has more efficacies, and NGC may be used as a proper substitute for autograft in nerve injury.

Delaviz, Hamdollah; Faghihi, Abolfazel; Mohamadi, Jamshid; Roozbehi, Amrollah

2012-01-01

256

Ageing alters perivascular nerve function of mouse mesenteric arteries in vivo.  

PubMed

Abstract? Mesenteric arteries (MAs) are studied widely in vitro but little is known of their reactivity in vivo. Transgenic animals have enabled Ca(2+) signalling to be studied in isolated MAs but the reactivity of these vessels in vivo is undefined. We tested the hypothesis that ageing alters MA reactivity to perivascular nerve stimulation (PNS) and adrenoreceptor (AR) activation during blood flow control. First- (1A), second- (2A) and third-order (3A) MAs of pentobarbital-anaesthetized Young (3-6 months) and Old (24-26 months) male and female Cx40(BAC)-GCaMP2 transgenic mice (C57BL/6 background; positive or negative for the GCaMP2 transgene) were studied with intravital microscopy. A segment of jejunum was exteriorized and an MA network was superfused with physiological salt solution (pH 7.4, 37°C). Resting tone was 10% in MAs of Young and Old mice; diameters were ?5% (1A), 20% (2A) and 40% (3A) smaller (P 0.05) in Old mice. Throughout MA networks, vasoconstriction increased with PNS frequency (1-16 Hz) but was ?20% less in Young vs. Old mice (P 0.05) and was inhibited by tetrodotoxin (1 ?m). Capsaicin (10 ?m; to inhibit sensory nerves) enhanced MA constriction to PNS (P 0.05) by ?20% in Young but not Old mice. Phenylephrine (an ?1AR agonist) potency was greater in Young mice (P 0.05) with similar efficacy (?60% constriction) across ages and MA branches. Constrictions to UK14304 (an ?2AR agonist) were less (?20%; P 0.05) and were unaffected by ageing. Irrespective of sex or transgene expression, ageing consistently reduced the sensitivity of MAs to ?1AR vasoconstriction while blunting the attenuation of sympathetic vasoconstriction by sensory nerves. These findings imply substantive alterations in splanchnic blood flow control with ageing. PMID:23247111

Westcott, Erika B; Segal, Steven S

2013-03-01

257

Ageing alters perivascular nerve function of mouse mesenteric arteries in vivo  

PubMed Central

Mesenteric arteries (MAs) are studied widely in vitro but little is known of their reactivity in vivo. Transgenic animals have enabled Ca2+ signalling to be studied in isolated MAs but the reactivity of these vessels in vivo is undefined. We tested the hypothesis that ageing alters MA reactivity to perivascular nerve stimulation (PNS) and adrenoreceptor (AR) activation during blood flow control. First- (1A), second- (2A) and third-order (3A) MAs of pentobarbital-anaesthetized Young (3–6 months) and Old (24–26 months) male and female Cx40BAC-GCaMP2 transgenic mice (C57BL/6 background; positive or negative for the GCaMP2 transgene) were studied with intravital microscopy. A segment of jejunum was exteriorized and an MA network was superfused with physiological salt solution (pH 7.4, 37°C). Resting tone was ? 10% in MAs of Young and Old mice; diameters were ?5% (1A), 20% (2A) and 40% (3A) smaller (P? 0.05) in Old mice. Throughout MA networks, vasoconstriction increased with PNS frequency (1–16 Hz) but was ?20% less in Young vs. Old mice (P? 0.05) and was inhibited by tetrodotoxin (1 ?m). Capsaicin (10 ?m; to inhibit sensory nerves) enhanced MA constriction to PNS (P? 0.05) by ?20% in Young but not Old mice. Phenylephrine (an ?1AR agonist) potency was greater in Young mice (P? 0.05) with similar efficacy (?60% constriction) across ages and MA branches. Constrictions to UK14304 (an ?2AR agonist) were less (?20%; P? 0.05) and were unaffected by ageing. Irrespective of sex or transgene expression, ageing consistently reduced the sensitivity of MAs to ?1AR vasoconstriction while blunting the attenuation of sympathetic vasoconstriction by sensory nerves. These findings imply substantive alterations in splanchnic blood flow control with ageing.

Westcott, Erika B; Segal, Steven S

2013-01-01

258

The effect of dentinal stimulation on pulp nerve function and pulp morphology in the dog.  

PubMed

The effect of dentinal stimulation on pulpal nerve responses and pulp morphology has been studied in the dog. Canine tooth (n = 25) dentin was stimulated by drilling, probing, and air-blasting for from two to five hours. Acid-etching was used to open dentinal tubules. All test teeth showed disruption of the odontoblast layer and its separation from the predentin; also, dislocation of odontoblast nuclei into dentinal tubules was found in most cases. Single-fiber (n = 14, conduction velocity = 24.3 +/- 7.4 (SD) m/s) recordings of the responses of canine tooth pulpal nerves to dentinal stimulation were made in ten of the stimulated teeth. No changes in the sensitivity of the nerves to dentinal stimulation could be detected. It is concluded that pulpal nerve function and morphological changes of the pulp are not clearly correlated. The condition of the dentin surface seems to be the important factor. PMID:3478386

Hirvonen, T J; Närhi, M V

1986-11-01

259

Large-scale somatotopic refinement via functional synapse elimination in the sensory thalamus of developing mice.  

PubMed

Functional synapse elimination and strengthening are crucial developmental processes in the formation of precise neuronal circuits in the somatosensory system, but the underlying alterations in topographical organization are not yet fully understood. To address this issue, we generated transgenic mice in which afferent fibers originating from the whisker-related brain region, called the maxillary principal trigeminal nucleus (PrV2), were selectively visualized with genetically expressed fluorescent protein. We found that functional synapse elimination drove and established large-scale somatotopic refinement even after the thalamic barreloid architecture was formed. Before functional synapse elimination, the whisker sensory thalamus was innervated by afferent fibers not only from the PrV2, but also from the brainstem nuclei representing other body parts. Most notably, only afferent fibers from PrV2 onto a whisker sensory thalamic neuron selectively survived and were strengthened, whereas other afferent fibers were preferentially eliminated via their functional synapse elimination. This large-scale somatotopic refinement was at least partially dependent on somatosensory experience. These novel results uncovered a previously unrecognized role of developmental synapse elimination in the large-scale, instead of the fine-scale, somatotopic refinement even after the initial segregation of the barreloid map. PMID:24453317

Takeuchi, Yuichi; Asano, Hidetsugu; Katayama, Yoko; Muragaki, Yoshihiro; Imoto, Keiji; Miyata, Mariko

2014-01-22

260

Functional connectivity and laterality of the motor and sensory components in the volitional swallowing network  

PubMed Central

Functional neuroimaging has shown that multiple brain regions are active during volitional swallowing. Little is known, however, about which regions integrate motor execution and sensory feedback in the swallowing system. Although unilateral brain lesions in either hemisphere can produce swallowing deficits, some functional neuroimaging studies indicate that the left hemisphere has greater activation in certain sensory and motor-related swallowing regions. In this study, correlation coefficients were computed for five seed regions during volitional saliva swallowing to determine the functional relationships of these regions with the rest of the brain: the anterior and posterior insula, inferior frontal gyrus (BA44), primary sensory cortex (S1), and primary motor cortex (M1). A laterality index (LI) was derived that accounts for relative differences in total, positive connected voxels for the left/right hemisphere seeds. Clusters of significantly connected voxels were greater from the anterior and posterior insula than from the other three seed regions. Interactions of the insula with other brain regions were greater on the left than on the right during volitional swallowing. Group means showed laterality in the anterior insula (LI = 0.25) and the posterior insula (LI = 0.33). BA44 showed a lesser degree of difference in left versus right hemisphere interactions (LI = 0.12) while S1 did not show lateralization (LI = 0.02) and M1 showed some predominance of interactions in the right hemisphere (LI = ?0.19). The greater connectivity from the left hemisphere insula to brain regions within and across hemispheres suggests that the insula is a primary integrative region for volitional swallowing in humans.

Reynolds, Richard C.; Chen, Gang; Horwitz, Barry; Ludlow, Christy L.

2012-01-01

261

Successful tactile based visual sensory substitution use functions independently of visual pathway integrity  

PubMed Central

Purpose: Neuronal reorganization after blindness is of critical interest because it has implications for the rational prescription of artificial vision devices. The purpose of this study was to distinguish the microstructural differences between perinatally blind (PB), acquired blind (AB), and normally sighted controls (SCs) and relate these differences to performance on functional tasks using a sensory substitution device (BrainPort). Methods: We enrolled 52 subjects (PB n = 11; AB n = 35; SC n = 6). All subjects spent 15 h undergoing BrainPort device training. Outcomes of light perception, motion, direction, temporal resolution, grating, and acuity were tested at baseline and after training. Twenty-six of the subjects were scanned with a three Tesla MRI scanner for diffusion tensor imaging (DTI), and with a positron emission tomography (PET) scanner for mapping regional brain glucose consumption during sensory substitution function. Non-parametric models were used to analyze fractional anisotropy (FA; a DTI measure of microstructural integrity) of the brain via region-of-interest (ROI) analysis and tract-based spatial statistics (TBSS). Results: At baseline, all subjects performed all tasks at chance level. After training, light perception, time resolution, location and grating acuity tasks improved significantly for all subject groups. ROI and TBSS analyses of FA maps show areas of statistically significant differences (p ? 0.025) in the bilateral optic radiations and some visual association connections between all three groups. No relationship was found between FA and functional performance with the BrainPort. Discussion: All subjects showed performance improvements using the BrainPort irrespective of nature and duration of blindness. Definite brain areas with significant microstructural integrity changes exist among PB, AB, and NC, and these variations are most pronounced in the visual pathways. However, the use of sensory substitution devices is feasible irrespective of microstructural integrity of the primary visual pathways between the eye and the brain. Therefore, tongue based devices devices may be usable for a broad array of non-sighted patients.

Lee, Vincent K.; Nau, Amy C.; Laymon, Charles; Chan, Kevin C.; Rosario, Bedda L.; Fisher, Chris

2014-01-01

262

Sensory Biology: It Takes Piezo2 to Tango.  

PubMed

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

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

2014-06-16

263

Comparison of Immunohistochemical and Functional Reinnervation of Skin and Muscle after Peripheral Nerve Injury  

Microsoft Academic Search

In order to investigate the usefulness of immunohistochemical detection of regenerating axons as a correlate of functional recovery, reinnervation of mouse foot pads, hairy skin, and muscle were studied at several intervals along 3 months after sciatic nerve crush using immunohistochemical markers PGP 9.5 and CGRP. These histological results were compared with functional recovery of sweat glands (SGs), plantar muscles,

Enrique Verdú; Xavier Navarro

1997-01-01

264

Nerve and Nerve Root Biomechanics  

Microsoft Academic Search

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

Kristen J. Nicholson; Beth A. Winkelstein

265

Importance of tissue morphology relative to patient reports of symptoms and functional limitations resulting from median nerve pathology.  

PubMed

Significant data exist for the personal, environmental, and occupational risk factors for carpal tunnel syndrome. Few data, however, explain the interrelationship of tissue morphology to these factors among patients with clinical presentation of median nerve pathology. Therefore, our primary objective was to examine the relationship of various risk factors that may be predictive of subjective reports of symptoms or functional deficits accounting for median nerve morphology. Using diagnostic ultrasonography, we observed real-time median nerve morphology among 88 participants with varying reports of symptoms or functional limitations resulting from median nerve pathology. Body mass index, educational level, and nerve morphology were the primary predictive factors. Monitoring median nerve morphology with ultrasonography may provide valuable information for clinicians treating patients with symptoms of median nerve pathology. Sonographic measurements may be a useful clinical tool for improving treatment planning and provision, documenting patient status, or measuring clinical outcomes of prevention and rehabilitation interventions. PMID:23245784

Roll, Shawn C; Evans, Kevin D; Li, Xiaobai; Sommerich, Carolyn M; Case-Smith, Jane

2013-01-01

266

Prospective Study of Motor, Sensory, Psychological and Autonomic Functions in Patients with Irritable Bowel Syndrome  

PubMed Central

Background/Aim To assess pathophysiology in irritable bowel syndrome (IBS). Methods 122 IBS patients (3 male) and 41 healthy females underwent: questionnaires (symptoms, psychology), autonomic, gut transit, gastric volumes (GV), satiation, rectal compliance and sensation (thresholds and pain ratings) testing. Proportions of patients with abnormal (<10th and >90th percentiles) motor or sensory functions according to bowel symptoms [constipation (C), diarrhea (D), mixed (M)], pain/bloat and number of primary symptoms were estimated. Results IBS subgroups (C, D, M) were similar in age, gastric and small bowel transit, satiation, GV, rectal compliance, sensory thresholds or pain ratings. IBS was associated with BMI, somatic symptoms, anxiety and depression scores. Significant associations were observed with colonic transit (IBS-C [p=0.078] and IBS-D [p<0.05] at 24 h; IBS-D [p<0.01] and IBS-M [p=0.056] at 48 h): 32% IBS had abnormal colonic transit: 20.5% at 24 h and 11.5% at 48 h. Overall, 20.5% IBS patients had increased sensation to distensions: hypersensitivity (<10th percentile thresholds) in 7.6%, and hyperalgesia (pain sensation ratings to distension >90th percentile for ratings in health) in 13%. Conversely, 16.5% of IBS patients had reduced rectal sensation. Pain >6 times per year and bloating were not significantly associated with motor, satiation, or sensory functions. Endorsing 1–2 or 3–4 primary IBS symptoms were associated with abnormal transit and sensation in IBS. Conclusion In tertiary referral (predominantly female) patients with IBS, colonic transit (32%) is the most prevalent physiological abnormality; 21% had increased and 17% decreased rectal pain sensations. Comprehensive physiological assessment may help optimize management in IBS.

Camilleri, Michael; McKinzie, Sanna; Busciglio, Irene; Low, Phillip A.; Sweetser, Seth; Burton, Duane; Baxter, Kari; Ryks, Michael; Zinsmeister, Alan R.

2008-01-01

267

A gain-of-function screen for genes that affect the development of the Drosophila adult external sensory organ.  

PubMed Central

The Drosophila adult external sensory organ, comprising a neuron and its support cells, is derived from a single precursor cell via several asymmetric cell divisions. To identify molecules involved in sensory organ development, we conducted a tissue-specific gain-of-function screen. We screened 2293 independent P-element lines established by P. Rorth and identified 105 lines, carrying insertions at 78 distinct loci, that produced misexpression phenotypes with changes in number, fate, or morphology of cells of the adult external sensory organ. On the basis of the gain-of-function phenotypes of both internal and external support cells, we subdivided the candidate lines into three classes. The first class (52 lines, 40 loci) exhibits partial or complete loss of adult external sensory organs. The second class (38 lines, 28 loci) is associated with increased numbers of entire adult external sensory organs or subsets of sensory organ cells. The third class (15 lines, 10 loci) results in potential cell fate transformations. Genetic and molecular characterization of these candidate lines reveals that some loci identified in this screen correspond to genes known to function in the formation of the peripheral nervous system, such as big brain, extra macrochaetae, and numb. Also emerging from the screen are a large group of previously uncharacterized genes and several known genes that have not yet been implicated in the development of the peripheral nervous system.

Abdelilah-Seyfried, S; Chan, Y M; Zeng, C; Justice, N J; Younger-Shepherd, S; Sharp, L E; Barbel, S; Meadows, S A; Jan, L Y; Jan, Y N

2000-01-01

268

The toe-spreading reflex of the rabbit revisited—functional evaluation of complete peroneal nerve lesions  

Microsoft Academic Search

Summary Although a variety of electrophysiological and morphological tests are available for studying nerve regeneration in animals, these endpoints do not necessarily correlate with the return of muscle function. Recent efforts have focusedon the assessment of function as the endpoint of nerve regeneration. One of the best known of these tests is the sciatic function index in rats. For rabbits,

H. Cristina Schmitz; G. M. Beer

2001-01-01

269

Assessing corneal nerve structure and function in diabetic neuropathy.  

PubMed

The accurate detection and quantification of human diabetic peripheral neuropathy are important to define at-risk patients, anticipate deterioration and assess new therapies. Two emerging ophthalmic techniques, namely, corneal confocal microscopy and corneal aesthesiometry, demonstrate the ability to diagnose, quantify severity and assess therapeutic benefit in diabetic peripheral neuropathy. Corneal confocal microscopy allows quantification of corneal nerve morphology and non-contact corneal aesthesiometry assesses corneal sensitivity. The present review provides a detailed critique of the rationale, practical application in terms of the instruments used to capture images and the basis on which images are interpreted and analysed. We also critically evaluate how these two new non-invasive ophthalmic tests can be deployed to diagnose diabetic and other peripheral neuropathies. PMID:22594548

Tavakoli, Mitra; Petropoulos, Ioannis N; Malik, Rayaz A

2012-05-01

270

Hereditary sensory radicular neuropathy: defective neurogenic inflammation.  

PubMed

Hereditary sensory radicular neuropathy exhibits autosomal dominant inheritance with complete penetrance in males and incomplete penetrance in females. Newer tests of small sensory nerve function were used in screening 8 family members aged between 14 and 66 years. All exhibited some frequent features of the disorder with an onset in the 2nd or 3rd decade, foot ulceration, foot callus, loss of pin prick, thermal and light touch sensation, and some reduction in vibration acuity and proprioception in the lower limbs. The hands were involved in 3 of 8, muscle involvement was present in 5 of 8, but deafness was not detected by audiometry. Nerve conduction velocity, sensory action potentials, latency and amplitude, thermal acuity, vibration acuity and axon reflex flares were measured in all patients. One sural nerve biopsy confirmed the presence of peripheral fibre loss in this predominantly sensory neuropathy. Chemically evoked axon reflex tests were used to evaluate the extent of primary sensory nerve fibre involvement. All patients were tested using a Moor MBF 3-D dual channel laser Doppler velocimeter. Acetylcholine or phenylephrine iontophoretically applied as 16 mC doses evoked absent or tiny axon reflexes in areas of impaired pin prick sensation. By contrast, direct microvascular dilator responses to nitroprusside (smooth muscle dependent) and acetylcholine (endothelium-dependent) were present but somewhat reduced in areas with defective neurogenic inflammation. These results differ significantly from the responses obtained in age-matched healthy controls (P < 0.05). Foot pressure analysis was performed for orthoses in 2 affected members with foot ulceration using the Musgrave Footprint system.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1343862

Westerman, R A; Block, A; Nunn, A; Delaney, C A; Hahn, A; Dennett, X; Carr, R W

1992-01-01

271

Set and setting: how behavioral state regulates sensory function and plasticity.  

PubMed

Recently developed neuroimaging and electrophysiological techniques are allowing us to answer fundamental questions about how behavioral states regulate our perception of the external environment. Studies using these techniques have yielded surprising insights into how sensory processing is affected at the earliest stages by attention and motivation, and how new sensory information received during wakefulness (e.g., during learning) continues to affect sensory brain circuits (leading to plastic changes) during subsequent sleep. This review aims to describe how brain states affect sensory response properties among neurons in primary and secondary sensory cortices, and how this relates to psychophysical detection thresholds and performance on sensory discrimination tasks. This is not intended to serve as a comprehensive overview of all brain states, or all sensory systems, but instead as an illustrative description of how three specific state variables (attention, motivation, and vigilance [i.e., sleep vs. wakefulness]) affect sensory systems in which they have been best studied. PMID:23792020

Aton, Sara J

2013-11-01

272

NEUROPHYSIOLOGICAL EVALUATION OF SENSORY SYSTEMS'  

EPA Science Inventory

Exposure to many neurotoxic compounds has been shown to produce a sensory system dysfunction. Neurophysiological assessment of sensory function in humans and animal models often uses techniques known as sensory evoked potentials. Because both humans and animals show analogous res...

273

Model-based analysis and design of nerve cuff electrodes for restoring bladder function by selective stimulation of the pudendal nerve  

NASA Astrophysics Data System (ADS)

Objective. Electrical stimulation of the pudendal nerve (PN) is being developed as a means to restore bladder function in persons with spinal cord injury. A single nerve cuff electrode placed on the proximal PN trunk may enable selective stimulation of distinct fascicles to maintain continence or evoke micturition. The objective of this study was to design a nerve cuff that enabled selective stimulation of the PN. Approach. We evaluated the performance of both flat interface nerve electrode (FINE) cuff and round cuff designs, with a range of FINE cuff heights and number of contacts, as well as multiple contact orientations. This analysis was performed using a computational model, in which the nerve and fascicle cross-sectional positions from five human PN trunks were systematically reshaped within the nerve cuff. These cross-sections were used to create finite element models, with electric potentials calculated and applied to a cable model of a myelinated axon to evaluate stimulation selectivity for different PN targets. Subsequently, the model was coupled to a genetic algorithm (GA) to identify solutions that used multiple contact activation to maximize selectivity and minimize total stimulation voltage. Main results. Simulations did not identify any significant differences in selectivity between FINE and round cuffs, although the latter required smaller stimulation voltages for target activation due to preserved localization of targeted fascicle groups. Further, it was found that a ten contact nerve cuff generated sufficient selectivity for all PN targets, with the degree of selectivity dependent on the relative position of the target within the nerve. The GA identified solutions that increased fitness by 0.7-45.5% over single contact activation by decreasing stimulation of non-targeted fascicles. Significance. This study suggests that using an optimal nerve cuff design and multiple contact activation could enable selective stimulation of the human PN trunk for restoration of bladder function.

Kent, Alexander R.; Grill, Warren M.

2013-06-01

274

Model-based analysis and design of nerve cuff electrodes for restoring bladder function by selective stimulation of the pudendal nerve  

PubMed Central

Objective Electrical stimulation of the pudendal nerve (PN) is being developed as a means to restore bladder function in persons with spinal cord injury. A single nerve cuff electrode placed on the proximal PN trunk may enable selective stimulation of distinct fascicles to maintain continence or evoke micturition. The objective of this study was to design a nerve cuff that enabled selective stimulation of the PN. Approach We evaluated the performance of both flat interface nerve electrode (FINE) cuff and round cuff designs, with a range of FINE cuff heights and number of contacts, as well as multiple contact orientations. This analysis was performed using a computational model, in which the nerve and fascicle cross-sectional positions from five human PN trunks were systematically reshaped within the nerve cuff. These cross-sections were used to create finite element models, with electric potentials calculated and applied to a cable model of a myelinated axon to evaluate stimulation selectivity for different PN targets. Subsequently, the model was coupled to a genetic algorithm (GA) to identify solutions that used multiple contact activation to maximize selectivity and minimize total stimulation voltage. Main results Simulations did not identify any significant differences in selectivity between FINE and round cuffs, although the latter required smaller stimulation voltages for target activation due to preserved localization of targeted fascicle groups. Further, it was found that a 10 contact nerve cuff generated sufficient selectivity for all PN targets, with the degree of selectivity dependent on the relative position of the target within the nerve. The GA identified solutions that increased fitness by 0.7–45.5% over single contact activation by decreasing stimulation of non-targeted fascicles. Significance This study suggests that using an optimal nerve cuff design and multiple contact activation could enable selective stimulation of the human PN trunk for restoration of bladder function.

Kent, Alexander R; Grill, Warren M

2013-01-01

275

Sensory processing during viewing of cinematographic material: computational modeling and functional neuroimaging.  

PubMed

The investigation of brain activity using naturalistic, ecologically-valid stimuli is becoming an important challenge for neuroscience research. Several approaches have been proposed, primarily relying on data-driven methods (e.g. independent component analysis, ICA). However, data-driven methods often require some post-hoc interpretation of the imaging results to draw inferences about the underlying sensory, motor or cognitive functions. Here, we propose using a biologically-plausible computational model to extract (multi-)sensory stimulus statistics that can be used for standard hypothesis-driven analyses (general linear model, GLM). We ran two separate fMRI experiments, which both involved subjects watching an episode of a TV-series. In Exp 1, we manipulated the presentation by switching on-and-off color, motion and/or sound at variable intervals, whereas in Exp 2, the video was played in the original version, with all the consequent continuous changes of the different sensory features intact. Both for vision and audition, we extracted stimulus statistics corresponding to spatial and temporal discontinuities of low-level features, as well as a combined measure related to the overall stimulus saliency. Results showed that activity in occipital visual cortex and the superior temporal auditory cortex co-varied with changes of low-level features. Visual saliency was found to further boost activity in extra-striate visual cortex plus posterior parietal cortex, while auditory saliency was found to enhance activity in the superior temporal cortex. Data-driven ICA analyses of the same datasets also identified "sensory" networks comprising visual and auditory areas, but without providing specific information about the possible underlying processes, e.g., these processes could relate to modality, stimulus features and/or saliency. We conclude that the combination of computational modeling and GLM enables the tracking of the impact of bottom-up signals on brain activity during viewing of complex and dynamic multisensory stimuli, beyond the capability of purely data-driven approaches. PMID:23202431

Bordier, Cecile; Puja, Francesco; Macaluso, Emiliano

2013-02-15

276

The short- and long-term effects of Seprafilm on peripheral nerves: a histological and functional study.  

PubMed

Extraneural scar reduction is an important goal in peripheral nerve microsurgery. The use of biosynthetic materials, such as Seprafilm , reduces postoperative adhesions in abdominopelvic gynecologic and orthopedic surgery. The study evaluates the safety of Seprafilm in proximity to nerve tissue in a noninjury (phase 1) and injury (phase 2) model. Phase 1 groups were: (1) sciatic nerve exposure and neurolysis (n = 15), (2) Seprafilm placement superficial to the nerve (n = 15), and (3) circumferentially wrapping Seprafilm around the nerve (n = 15). Outcome measures at 45 and 90 days included wound inspection, histomorphometry, and stereological analysis of vascularity. Phase II groups were: (1) sciatic nerve cut and repair alone (n = 15) or (2) nerve wrapped with Seprafilm (n = 15). Nerves were evaluated at 18, 32, and 42 days postoperatively, and animals underwent biweekly functional walking tracks. In phase I, no significant differences were detected between groups. In phase II, fewer perineural scar bands were seen with Seprafilm . Histomorphometric differences favoring Seprafilm at 18 days and favoring control at 42 days were noted ( P < 0.05), though no differences in functional outcomes were detected. Qualitatively less perineural scar tissue was seen when using Seprafilm . No functional or histological deleterious effects were noted from placing Seprafilm on intact nerves or cut and repaired nerves. PMID:19396746

Magill, Christina Kenney; Tuffaha, Sami H; Yee, Andrew; Luciano, Janina P; Hunter, Daniel A; Mackinnon, Susan E; Borschel, Gregory H

2009-07-01

277

The effects of low level laser treatment on recovery of nerve conduction and motor function after compression injury in the rat sciatic nerve.  

PubMed

An animal study is presented examining the effect of low level laser (LLL) treatment on nerve regeneration following axonotmesis. Twenty animals received a standardised injury to the right sciatic nerve using a time, load and length sequence (10 min, 150 N, 5 mm) known to cause extensive axonal degeneration of the rat sciatic nerve. The LLL treatment was administered using a hand-held laser probe in light contact with the skin on the dorsal aspect of the hind leg overlying the site of the axonotmesis injury to the sciatic nerve. A group of 10 animals were treated with 6J of LLL (GaAlAs 830 nm) daily for a period of 28 d. Ten more animals were treated daily with a sham exposure setting and served as controls. Nerve function was assessed by a recognised method of walking tract print analysis; the "Sciatic Functional Index" (SFI), and nerve regeneration was assessed by recording the evoked compound action potentials (cAP) in the common peroneal nerve. At 21 d post-injury, the laser-treated group had a significantly lower median SFI than the sham laser-treated group, indicating that the real laser treatment had improved functional recovery in the nerve. However, no differences were found between the evoked cAP parameters that were measured in the laser-treated and sham laser-treated groups. Histological examination reiterated the lack of difference between the two groups. Consequently, the effects of LLL on recovery must have occurred more peripherally to the point measured. PMID:8521121

Khullar, S M; Brodin, P; Messelt, E B; Haanaes, H R

1995-10-01

278

Impaired endolysosomal function disrupts Notch signaling in optic nerve astrocytes  

PubMed Central

Astrocytes migrate from the optic nerve into the inner retina, forming a template upon which retinal vessels develop. In the Nuc1 rat, mutation in the gene encoding ?A3/A1-crystallin disrupts both Notch signaling in astrocytes and formation of the astrocyte template. Here we show that loss of ?A3/A1-crystallin in astrocytes does not impede Notch ligand binding or extracellular cleavages. However, it affects V-ATPase activity, thereby compromising acidification of the endolysosomal compartments, leading to reduced ?-secretase-mediated processing and release of the Notch intracellular domain (NICD). Lysosomal-mediated degradation of Notch is also impaired. These defects decrease the level of NICD in the nucleus, inhibiting expression of Notch target genes. Overexpression of ?A3/A1-crystallin in those same astrocytes restored V-ATPase activity and normal endolysosomal acidification, thereby increasing the levels of ?-secretase to facilitate optimal Notch signaling. We postulate that ?A3/A1-crystallin is essential for normal endolysosomal acidification, and thereby, normal activation of Notch signaling in astrocytes.

Valapala, Mallika; Hose, Stacey; Gongora, Celine; Dong, Lijin; Wawrousek, Eric F.; Zigler, J. Samuel; Sinha, Debasish

2013-01-01

279

Sensory integration dysfunction affects efficacy of speech therapy on children with functional articulation disorders  

PubMed Central

Background Articulation disorders in young children are due to defects occurring at a certain stage in sensory and motor development. Some children with functional articulation disorders may also have sensory integration dysfunction (SID). We hypothesized that speech therapy would be less efficacious in children with SID than in those without SID. Hence, the purpose of this study was to compare the efficacy of speech therapy in two groups of children with functional articulation disorders: those without and those with SID. Method: A total of 30 young children with functional articulation disorders were divided into two groups, the no-SID group (15 children) and the SID group (15 children). The number of pronunciation mistakes was evaluated before and after speech therapy. Results: There were no statistically significant differences in age, sex, sibling order, education of parents, and pretest number of mistakes in pronunciation between the two groups (P > 0.05). The mean and standard deviation in the pre- and post-test number of mistakes in pronunciation were 10.5 ± 3.2 and 3.3 ± 3.3 in the no-SID group, and 10.1 ± 2.9 and 6.9 ± 3.5 in the SID group, respectively. Results showed great changes after speech therapy treatment (F = 70.393; P < 0.001) and interaction between the pre/post speech therapy treatment and groups (F = 11.119; P = 0.002). Conclusions: Speech therapy can improve the articulation performance of children who have functional articulation disorders whether or not they have SID, but it results in significantly greater improvement in children without SID. SID may affect the treatment efficiency of speech therapy in young children with articulation disorders.

Tung, Li-Chen; Lin, Chin-Kai; Hsieh, Ching-Lin; Chen, Ching-Chi; Huang, Chin-Tsan; Wang, Chun-Hou

2013-01-01

280

A Novel Internal Fixator Device for Peripheral Nerve Regeneration  

PubMed Central

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

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

2013-01-01

281

Upregulation of the T-type calcium current in small rat sensory neurons after chronic constrictive injury of the sciatic nerve.  

PubMed

Recent data indicate that peripheral T-type Ca2+ channels are instrumental in supporting acute pain transmission. However, the function of these channels in chronic pain processing is less clear. To address this issue, we studied the expression of T-type Ca2+ currents in small nociceptive dorsal root ganglion (DRG) cells from L4-5 spinal ganglia of adult rats with neuropathic pain due to chronic constrictive injury (CCI) of the sciatic nerve. In control rats, whole cell recordings revealed that T-type currents, measured in 10 mM Ba2+ as a charge carrier, were present in moderate density (20 +/- 2 pA/pF). In rats with CCI, T-type current density (30 +/- 3 pA/pF) was significantly increased, but voltage- and time-dependent activation and inactivation kinetics were not significantly different from those in controls. CCI-induced neuropathy did not significantly change the pharmacological sensitivity of T-type current in these cells to nickel. Collectively, our results indicate that CCI-induced neuropathy significantly increases T-type current expression in small DRG neurons. Our finding that T-type currents are upregulated in a CCI model of peripheral neuropathy and earlier pharmacological and molecular studies suggest that T-type channels may be potentially useful therapeutic targets for the treatment of neuropathic pain associated with partial mechanical injury to the sciatic nerve. PMID:18417624

Jagodic, Miljen M; Pathirathna, Sriyani; Joksovic, Pavle M; Lee, WooYong; Nelson, Michael T; Naik, Ajit K; Su, Peihan; Jevtovic-Todorovic, Vesna; Todorovic, Slobodan M

2008-06-01

282

Serial Vagus Nerve Stimulation Functional MRI in Treatment-Resistant Depression  

Microsoft Academic Search

Vagus nerve stimulation (VNS) therapy has shown antidepressant effects in open acute and long-term studies of treatment-resistant major depression. Mechanisms of action are not fully understood, although clinical data suggest slower onset therapeutic benefit than conventional psychotropic interventions. We set out to map brain systems activated by VNS and to identify serial brain functional correlates of antidepressant treatment and symptomatic

Ziad Nahas; Charlotte Teneback; Jeong-Ho Chae; Qiwen Mu; Chris Molnar; Frank A Kozel; John Walker; Berry Anderson; Jejo Koola; Samet Kose; Mikhail Lomarev; Daryl E Bohning; Mark S George

2007-01-01

283

Pudendal nerve function in women with symptomatic utero-vaginal prolapse  

Microsoft Academic Search

Pelvic floor function has been studied in 27 women with symptomatic utero-vaginal prolapse and 15 age-matched control subjects. There was no evidence in the patients on physiological testing of significant denervation of the pelvic floor muscles, with no significant difference in the maximum resting and squeeze anal pressures, the pudendal nerve terminal motor latency or external anal sphincter fibre density

M. A. Beevors; D. Z. Lubowski; D. W. King; M. A. Carlton

1991-01-01

284

Retinal function in infants with optic nerve hypoplasia: electroretinograms to large patterns and photopic flash  

Microsoft Academic Search

Optic nerve hypoplasia (ONH), which is defined as a congenital deficiency of retinal ganglion cells, may also involve more distal layers of the retina. We investigated electrophysiological function of the retina in ONH using electroretinograms (ERGs). ERGs were recorded from 48 subjects (3.5–35 months) with unilateral or bilateral ONH. Pattern reversal (4° checks) was presented under chloral hydrate sedation, using

Daphne L. McCulloch; P. Garcia-Fillion; G. B. van Boeme; M. S. Borchert

2006-01-01

285

The plasminogen activator system modulates sympathetic nerve function  

PubMed Central

Sympathetic neurons synthesize and release tissue plasminogen activator (t-PA). We investigated whether t-PA modulates sympathetic activity. t-PA inhibition markedly reduced contraction of the guinea pig vas deferens to electrical field stimulation (EFS) and norepinephrine (NE) exocytosis from cardiac synaptosomes. Recombinant t-PA (rt-PA) induced exocytotic and carrier-mediated NE release from cardiac synaptosomes and cultured neuroblastoma cells; this was a plasmin-independent effect but was potentiated by a fibrinogen cleavage product. Notably, hearts from t-PA–null mice released much less NE upon EFS than their wild-type (WT) controls (i.e., a 76.5% decrease; P < 0.01), whereas hearts from plasminogen activator inhibitor-1 (PAI-1)–null mice released much more NE (i.e., a 275% increase; P < 0.05). Furthermore, vasa deferentia from t-PA–null mice were hyporesponsive to EFS (P < 0.0001) but were normalized by the addition of rt-PA. In contrast, vasa from PAI-1–null mice were much more responsive (P < 0.05). Coronary NE overflow from hearts subjected to ischemia/reperfusion was much smaller in t-PA–null than in WT control mice (P < 0.01). Furthermore, reperfusion arrhythmias were significantly reduced (P < 0.05) in t-PA–null hearts. Thus, t-PA enhances NE release from sympathetic nerves and contributes to cardiac arrhythmias in ischemia/reperfusion. Because the risk of arrhythmias and sudden cardiac death is increased in hyperadrenergic conditions, targeting the NE-releasing effect of t-PA may have valuable therapeutic potential.

Schaefer, Ulrich; Machida, Takuji; Vorlova, Sandra; Strickland, Sidney; Levi, Roberto

2006-01-01

286

Drosophila Notch Receptor Activity Suppresses Hairless Function during Adult External Sensory Organ Development  

PubMed Central

The neurogenic Notch locus of Drosophila encodes a receptor necessary for cell fate decisions within equivalence groups, such as proneural clusters. Specification of alternate fates within clusters results from inhibitory communication among cells having comparable neural fate potential. Genetically, Hairless (H) acts as an antagonist of most neurogenic genes and may insulate neural precursor cells from inhibition. H function is required for commitment to the bristle sensory organ precursor (SOP) cell fate and for daughter cell fates. Using Notch gain-of-function alleles and conditional expression of an activated Notch transgene, we show that enhanced signaling produces H-like loss-of-function phenotypes by suppressing bristle SOP cell specification or by causing an H-like transformation of sensillum daughter cell fates. Furthermore, adults carrying Notch gain of function and H alleles exhibit synergistic enhancement of mutant phenotypes. Over-expression of an H(+) transgene product suppressed virtually all phenotypes generated by Notch gain-of-function genotypes. Phenotypes resulting from over-expression of the H(+) transgene were blocked by the Notch gain-of-function products, indicating a balance between Notch and H activity. The results suggest that H insulates SOP cells from inhibition and indicate that H activity is suppressed by Notch signaling.

Lyman, D. F.; Yedvobnick, B.

1995-01-01

287

Dual simulated childbirth injuries result in slowed recovery of pudendal nerve and urethral function  

PubMed Central

Aims Pelvic floor muscle trauma and pudendal nerve injury have been implicated in stress urinary incontinence (SUI) development after childbirth. In this study, we investigated how combinations of these injuries affect recovery. Methods Sixty-seven female Sprague-Dawley rats underwent vaginal distension (VD), pudendal nerve crush (PNC), PNC and VD (PNC+VD), pudendal nerve transection (PNT), or served as unmanipulated controls. Four days, 3 weeks, or 6 weeks after injury, we simultaneously recorded pudendal nerve motor branch potentials (PNMBP), external urethral sphincter electromyography (EUS EMG), and transurethral bladder pressure under urethane anesthesia. The presence of a guarding reflex (increased frequency & amplitude of PNMBP or EUS EMG activity) during leak point pressure (LPP) testing was determined. Results Controls consistently demonstrated a guarding reflex. Four days after VD, EUS EMG activity was eliminated, but PNMBP activity reflected the guarding reflex; EUS EMG activity recovered after 3 weeks. Four days after PNC, both EUS EMG and PNMBP activity were eliminated, but demonstrated significant recovery at 3 weeks. Four days after PNC+VD both EUS EMG and nerve activity were eliminated, and little recovery was observed after 3 weeks with significant recovery of the guarding reflex 6 weeks after injury. Little recovery was observed at all time points after PNT. LPP results mirrored the reduction in EUS EMG activity. Conclusion Functional recovery occurs more slowly after PNC+VD than after either PNC or VD alone. Future work will be aimed at testing methods to facilitate neuroregeneration and recovery after this clinically relevant dual injury.

Jiang, Hai-Hong; Pan, Hui Q; Gustilo-Ashby, A. Marcus; Gill, Bradley; Glaab, Jonathan; Zaszczurynski, Paul; Damaser, Margot

2008-01-01

288

SMN is required for sensory-motor circuit function in Drosophila  

PubMed Central

Summary Spinal muscular atrophy (SMA) is a lethal human disease characterized by motor neuron dysfunction and muscle deterioration due to depletion of the ubiquitous Survival Motor Neuron (SMN) protein. Drosophila SMN mutants have reduced muscle size and defective locomotion, motor rhythm and motor neuron neurotransmission. Unexpectedly, restoration of SMN in either muscles or motor neurons did not alter these phenotypes. Instead, SMN must be expressed in proprioceptive neurons and interneurons in the motor circuit to non-autonomously correct defects in motor neurons and muscles. SMN depletion disrupts the motor system subsequent to circuit development and can be mimicked by the inhibition of motor network function. Furthermore, increasing motor circuit excitability by genetic or pharmacological inhibition of K+ channels can correct SMN-dependent phenotypes. These results establish sensory-motor circuit dysfunction as the origin of motor system deficits in this SMA model and suggest that enhancement of motor neural network activity could ameliorate the disease.

Imlach, Wendy L.; Beck, Erin S.; Choi, Ben Jiwon; Lotti, Francesco; Pellizzoni, Livio; McCabe, Brian D.

2012-01-01

289

Effect of a chloride channel activator, lubiprostone, on colonic sensory and motor functions in healthy subjects  

PubMed Central

Lubiprostone, a bicyclic fatty acid chloride channel activator, is efficacious in treatment of chronic constipation and constipation-predominant irritable bowel syndrome. The study aim was to compare effects of lubiprostone and placebo on colonic sensory and motor functions in humans. In double-blind, randomized fashion, 60 healthy adults received three oral doses of placebo or 24 ?g lubiprostone per day in a parallel-group, placebo-controlled trial. A barostat-manometry tube was placed in the left colon by flexible sigmoidoscopy and fluoroscopy. We measured treatment effects on colonic sensation and motility with validated methods, with the following end points: colonic compliance, fasting and postprandial tone and motility indexes, pain thresholds, and sensory ratings to distensions. Among participants receiving lubiprostone or placebo, 26 of 30 and 28 of 30, respectively, completed the study. There were no overall effects of lubiprostone on compliance, fasting tone, motility indexes, or sensation. However, there was a treatment-by-sex interaction effect for compliance (P = 0.02), with lubiprostone inducing decreased fasting compliance in women (P = 0.06) and an overall decreased colonic tone contraction after a standard meal relative to fasting tone (P = 0.014), with greater effect in women (P < 0.01). Numerical differences of first sensation and pain thresholds (P = 0.11 in women) in the two groups were not significant. We concluded that oral lubiprostone 24 ?g does not increase colonic motor function. The findings of decreased colonic compliance and decreased postprandial colonic tone in women suggest that motor effects are unlikely to cause accelerated colonic transit with lubiprostone, although they may facilitate laxation. Effects of lubiprostone on sensitivity deserve further study.

Sweetser, Seth; Busciglio, Irene A.; Camilleri, Michael; Bharucha, Adil E.; Szarka, Lawrence A.; Papathanasopoulos, Athanasios; Burton, Duane D.; Eckert, Deborah J.; Zinsmeister, Alan R.

2009-01-01

290

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

PubMed

A significant fraction of military soldiers sustain nerve injury and use tobacco or nicotine containing products. Healing of nerve injuries is influenced by many factors, such as degree of original injury, healing potential of the nerve, and general health of patient. However, recently, it has been demonstrated that the presence of retained insoluble metal fragments decreases healing. The effects of systemic nicotine administration, with or without metal fragments at the site of nerve injury, were evaluated. Both the nicotine-administered groups (nicotine, nicotine + shrapnel) showed significant increase in the peroneal function compared with untreated controls, as assessed by paw area (p < 0.05). Furthermore, to test possible role of altered sensory function, we used the hot plate assay. Latency to withdraw paw from a hot plate was significantly shorter in nicotine groups (p < 0.05). These data indicate that nicotine improves sensory and motor aspects of nerve function, in the presence or absence of shrapnel. PMID:22165666

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

2011-11-01

291

Interaction of Endothelin with Renal Nerves Modulates Kidney Function in Spontaneously Hypertensive Rats  

Microsoft Academic Search

Background and Methods: We investigated kidney function, renal endothelin-1 concentration, prepro-endothelin-1 mRNA as well as endothelin receptor A and B mRNA expression and receptor properties in normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) with intact renal nerves and 7 days after renal denervation. In addition, responses of renal function to the non-selective ETA\\/ETB receptor blocker bosentan (10 mg\\/kg

Radoslav A. Girchev; Angela Bäcker; Petia P. Markova; Herbert J. Kramer

2006-01-01

292

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

PubMed Central

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.

2012-01-01

293

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

PubMed

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. PMID:22546145

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

2012-01-01

294

Loudness function derives from data on electrical discharge rates in auditory nerve fibers  

NASA Technical Reports Server (NTRS)

Judgements of the loudness of pure-tone sound stimuli yield a loudness function which relates perceived loudness to stimulus amplitude. A loudness function is derived from physical evidence alone without regard to human judgments. The resultant loudness function is L=K(q-q0), where L is loudness, q is effective sound pressure (specifically q0 at the loudness threshold), and K is generally a weak function of the number of stimulated auditory nerve fibers. The predicted function is in agreement with loudness judgment data reported by Warren, which imply that, in the suprathreshold loudness regime, decreasing the sound-pressure level by 6 db results in halving the loudness.

Howes, W. L.

1973-01-01

295

Refinements in the technique of 'awake' electrical nerve stimulation in the management of chronic low ulnar nerve injuries.  

PubMed

The standard technique in the management of chronic low ulnar nerve injuries includes excision of the neuroma and reconstruction using sural nerve grafts in the fully anaesthetised patient. It has been shown that using this standard technique, disappointing results may be observed and that significant improvement in results could be obtained if intra-operative matching of sensory and motor fascicles is performed. This study reports on eight patients with chronic ulnar nerve injuries managed using the technique of electrical fascicular orientation and sural nerve grafting. In all patients, intra-operative electrical stimulation of the fascicles in the proximal stump was done in the awake state. Several refinements in technique are described including detailing pre-operative patient education, anaesthetic considerations and in the technique of nerve dissection. Assessment was done using a sensory grading system mainly based on static two-point discrimination and a motor grading system based on intrinsic muscle function and key pinch power. At final follow up satisfactory sensory (S3+ or S4) and motor (M3 or M4) recovery was obtained in almost all cases. It was concluded that intra-operative electrical fascicular orientation was reliable and that our refinements in the technique ensured better communication with the patient during surgery, resulted in a smoother awakening without apprehension, and provided an easier nerve dissection with preservation of the blood supply of the distal nerve segment. PMID:15488501

Al-Qattan, M M

2004-11-01

296

Sensory Conversion Devices  

NASA Astrophysics Data System (ADS)

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

Medelius, Pedro

297

Outcome following Nerve Repair of High Isolated Clean Sharp Injuries of the Ulnar Nerve  

PubMed Central

Objective The detailed outcome of surgical repair of high isolated clean sharp (HICS) ulnar nerve lesions has become relevant in view of the recent development of distal nerve transfer. Our goal was to determine the outcome of HICS ulnar nerve repair in order to create a basis for the optimal management of these lesions. Methods High ulnar nerve lesions are defined as localized in the area ranging from the proximal forearm to the axilla just distal to the branching of the medial cord of the brachial plexus. A meta-analysis of the literature concerning high ulnar nerve injuries was performed. Additionally, a retrospective study of the outcome of nerve repair of HICS ulnar nerve injuries at our institution was performed. The Rotterdam Intrinsic Hand Myometer and the Rosén-Lundborg protocol were used. Results The literature review identified 46 papers. Many articles presented outcomes of mixed lesion groups consisting of combined ulnar and median nerves, or the outcome of high and low level injuries was pooled. In addition, outcome was expressed using different scoring systems. 40 patients with HICS ulnar nerve lesions were found with sufficient data for further analysis. In our institution, 15 patients had nerve repair with a median interval between trauma and reconstruction of 17 days (range 0–516). The mean score of the motor and sensory domain of the Rosen's Scale instrument was 58% and 38% of the unaffected arm, respectively. Two-point discrimination never reached less then 12 mm. Conclusion From the literature, it was not possible to draw a definitive conclusion on outcome of surgical repair of HICS ulnar nerve lesions. Detailed neurological function assessment of our own patients showed that some ulnar nerve function returned. Intrinsic muscle strength recovery was generally poor. Based on this study, one might cautiously argue that repair strategies of HICS ulnar nerve lesions need to be improved.

Post, Rene; de Boer, Kornelis S.; Malessy, Martijn J. A.

2012-01-01

298

Inter-dependent regulation of afferent renal nerve activity and renal function: Role of TRPV1, NK1 and CGRP receptors  

PubMed Central

Our previous studies have shown that the activation of the transient receptor potential vanilloid type 1 (TRPV1) expressed in the renal pelvis leads to an increase in ipsilateral afferent renal nerve activity (ARNA) and contralateral renal excretory function, but the molecular mechanisms of TRPV1 action are largely unknown. This study tests the hypothesis that activation of receptors of neurokinin 1 (NK1) or calcitonin gene-related peptide (CGRP) by endogenously released substance P (SP) or CGRP following TRPV1 activation, respectively, governs TRPV1-induced increases in ARNA and renal excretory function. Capsaicin (CAP, 0.04, 0.4, 4nM), a selective TRPV1 agonist, administrated into the renal pelvis dose-dependently increased ARNA. CAP (4nM)-induced increases in ipsilateral ARNA or contralateral urine flow rate (Uflow) and urinary sodium excretion (UNa) were abolished by capsazepine (CAPZ), a selective TRPV1 antagonist, RP67580, or L703,606, selective NK1 antagonists, but not by CGRP8-37, a selective CGRP receptor antagonist. Both SP (7.4nM) and CGRP (0.13?M) increased ARNA, Uflow, or UNa, and increases in these parameters induced by CGRP but not SP were abolished by CAPZ. CAP at 4nM perfused into the renal pelvis caused the release of SP and CGRP, which was blocked by CAPZ but not by RP67580, L703,606, or CGRP8-37. Immunofluorescence results showed that NK1 receptors were expressed in sensory neurons in dorsal root ganglion (DRG) and sensory nerve fibers innervating the renal pelvis. Taken together, our data indicate that NK1 activation induced by SP release upon TRPV1 activation governs TRPV1 function and a TRPV1-dependent mechanism is operant in CGRP action.

Xie, Chaoqin; Sachs, Jeffrey R.; Wang, Donna H.

2009-01-01

299

Targeted delivery of Tet1 peptide functionalized polymersomes to the rat cochlear nerve  

PubMed Central

Polymersomes are nanosized vesicles formed from amphiphilic block copolymers, and have been identified as potential drug delivery vehicles to the inner ear. The aim of this study was to provide targeting to specific cells within the inner ear by functionalizing the polymersome surface with Tet1 peptide sequence. Tet1 peptide specifically binds to the trisialoganglioside clostridial toxin receptor on neurons and was expected to target the polymersomes toward the cochlear nerve. The Tet1 functionalized PEG-b-PCL polymersomes were administered using routine drug delivery routes: transtympanic injection and cochleostomy. Delivery via cochleostomy of Tet1 functionalized polymersomes resulted in cochlear nerve targeting; in contrast this was not seen after transtympanic injection.

Zhang, Ya; Zhang, Weikai; Johnston, Alexander H; Newman, Tracey A; Pyykko, Ilmari; Zou, Jing

2012-01-01

300

Microelectronic neural bridge for signal regeneration and function rebuilding over two separate nerves  

NASA Astrophysics Data System (ADS)

According to the feature of neural signals, a micro-electronic neural bridge (MENB) has been designed. It consists of two electrode arrays for neural signal detection and functional electrical stimulation (FES), and a microelectronic circuit for signal amplifying, processing, and FES driving. The core of the system is realized in 0.5-?m CMOS technology and used in animal experiments. A special experimental strategy has been designed to demonstrate the feasibility of the system. With the help of the MENB, the withdrawal reflex function of the left/right leg of one spinal toad has been rebuilt in the corresponding leg of another spinal toad. According to the coherence analysis between the source and regenerated neural signals, the controlled spinal toad's sciatic nerve signal is delayed by 0.72 ms in relation to the sciatic nerve signal of the source spinal toad and the cross-correlation function reaches a value of 0.73. This shows that the regenerated signal is correlated with the source sciatic signal significantly and the neural activities involved in reflex function have been regenerated. The experiment demonstrates that the MENB is useful in rebuilding the neural function between nerves of different bodies.

Xiaoyan, Shen; Zhigong, Wang; Xiaoying, Lü; Shushan, Xie; Zonghao, Huang

2011-06-01

301

Attempts to restore visual function after optic nerve damage in adult mammals.  

PubMed

Retinal ganglion cells (RGCs) and their axons, i.e., optic nerve (ON) fibers, provide a good experimental model for research on damaged CNS neurons and their functional ecovery. After the ON transection most RGCs undergo retrograde and anterograde degeneration but they can be rescued and regenerated by transplantation of a piece of peripheral nerve (PN). When the nerve graft was bridged to the visual center, regenerating RGC axons can restore the central visual projection. Behavioral recovery of relatively simple visual function has been proved in such PN-grafted rodents. Intravitreal injections of various neurotrophic factors and cytokines to activate intracellular signaling mechanism of RGCs and electrical stimulation to the cut end of ON have promoting effects on their survival and axonal regeneration. Axotomized RGCs in adult cats are also shown to survive and regenerate their axons through the PN graft. Among the cat RGC types, Y cells, which function as visual motion detector, tend to survive and regenerate axons better than others. X cells, which are essential for acute vision, suffer from rapid death after ON transection but they can be rescued by intravitreal application of neurotrophins accompanied with elevation of cAMP. To restore visual function in adult mammals with damaged optic pathway, the comprehensive and integrative strategies of multiple approaches will be needed, taking care of functional diversity of RGC types. PMID:16955708

Miyoshi, Tomomitsu; Kurimoto, Takuji; Fukuda, Yutaka

2006-01-01

302

Special nerve functions and colour discrimination in workers with long term low level exposure to carbon disulphide  

Microsoft Academic Search

Certain functions of the peripheral and autonomic nervous systems, and colour discrimination were examined in 45 workers (mean age 49; mean exposure to carbon disulphide (CS2) 20 years) and 37 controls (mean age 48). Conduction velocity and refractory period of the peroneal and sural nerves were determined. The conduction velocity of the slower fibres of the peroneal nerve was measured

M W Ruijten; H J Sallé; M M Verberk; H Muijser

1990-01-01

303

Electrophysiological Assessment of Sensory and Cognitive Function in Children Exposed to Lead: A Review,  

National Technical Information Service (NTIS)

Studies of the effects of lead absorption on sensory evoked and slow brain potentials in children are reviewed. Studies of slow wave voltage in children during sensory conditioning indicated a linear relationship to blood lead level in two studies; an eff...

D. A. Otto

1987-01-01

304

ELECTROPHYSIOLOGICAL ASSESSMENT OF SENSORY AND COGNITIVE FUNCTION IN CHILDREN EXPOSED TO LEAD: A REVIEW  

EPA Science Inventory

Studies of the effects of lead absorption on sensory evoked and slow brain potentials in children are reviewed. Studies of slow wave voltage in children during sensory conditioning indicated a linear relationship to blood lead level in two studies; an effect that could not be rep...

305

Characterization of Neurotrophin and Trk Receptor Functions in Developing Sensory Ganglia: Direct NT-3 Activation of TrkB Neurons In Vivo  

PubMed Central

Summary Spinal sensory ganglia have been shown to contain neuronal subpopulations with different functions and neurotrophin dependencies. Neurotrophins act, in large part, through Trk receptor tyrosine kinases: nerve growth factor (NGF) via TrkA, brain-derived neurotrophic factor (BDNF) and neurotrophin-4/5 (NT-4/5) via TrkB, and neurotrophin-3 (NT-3) via TrkC. In the present paper, we use antibodies to TrkA, TrkB, and TrkC to characterize their expression patterns and to determine which subpopulations of cells are lost in mice lacking individual neurotrophins or Trk receptors. Despite previous reports of Trk receptor mRNAs in neural crest cells, we detect Trk receptor proteins only in neurons and not in neural crest cells or neuronal precursors. Comparisons of neonatal mice deficient in NT-3 or its cognate receptor TrkC have shown that there is a much greater deficiency in spinal sensory neurons in the former, suggesting that NT-3 may activate receptors in addition to TrkC. Using the same antibodies, we show that, during the major period of neurogenesis, NT-3 is required to maintain neurons that express TrkB in addition to those that express TrkC but is not essential for neurons expressing TrkA. Results also indicate that survival of cells expressing both receptors can be maintained by activation of either one alone. NT-3 can thus activate more than one Trk receptor in vivo, which when coexpressed are functionally redundant.

Farinas, Isabel; Wilkinson, George A.; Backus, Carey; Patapoutian, Ardem

2009-01-01

306

Acetyl salicylic acid locally enhances functional recovery after sciatic nerve transection in rat.  

PubMed

Local effect of acetyl salicylic acid (ASA) on peripheral nerve regeneration was studied using a rat sciatic nerve transection model. Forty-five male healthy White Wistar rats were divided into three experimental groups (n = 15), randomly: Sham-operation (SHAM), control (SIL), and ASA-treated (SIL/ASA) groups. In SHAM group after anesthesia left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis the muscle was sutured. In SIL group the left sciatic nerve was exposed the same way and transected proximal to tibio-peroneal bifurcation leaving a 10-mm gap. Proximal and distal stumps were each inserted into a silicone tube and filled with 10 ?l phosphate buffered solution. In SIL/ASA group defect was bridged using a silicone tube filled with 10 ?l acetyl salisylic acid (0.1 mg/ml). Each group was subdivided into three subgroups of five animals each and were studied 4, 8, and 12 weeks after surgery. Data were analyzed statistically by factorial analysis of variance (ANOVA) and the Bonferroni test for pair-wise comparisons. Functional study confirmed faster and better recovery of regenerated axons in SIL/ASA than in SIL group (p < 0.05). Gastrocnemius muscle mass in SIL/ASA was significantly more than in SIL group. Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in SIL/ASA were significantly higher than in control group. In immuohistochemistry, location of reactions to S-100 in SIL/ASA was clearly more positive than in SIL group. Response to local treatment of ASA demonstrates that it influences and improves functional recovery of peripheral nerve regeneration. PMID:24140781

Mohammadi, Rahim; Amini, Keyvan; Abdollahi-Pirbazari, Mehdi; Yousefi, Alireza

2013-01-01

307

Surgical outcomes of lateral approach for jugular foramen schwannoma: postoperative facial nerve and lower cranial nerve functions  

Microsoft Academic Search

The lateral surgical approach to jugular foramen schwannomas (JFS) may result in complications such as temporary facial nerve\\u000a palsy (FNP) and hearing loss due to the complicated anatomical location. Ten patients with JFS surgically treated by variable\\u000a methods of lateral approach were retrospectively reviewed with emphasis on surgical methods, postoperative FNP, and lower\\u000a cranial nerve status. Gross total removal of

Yang-Sun Cho; Yoon Kyoung So; Kwan Park; Chung-Hwan Baek; Han-Sin Jeong; Sung Hwa Hong; Won-Ho Chung

2009-01-01

308

[Localization and functional role of gangliosides from nerve tissue of vertebrates].  

PubMed

Gangliosides in the animal organism are typical components of plasma membranes of nerve cells in which the concentration of polysialogangliosides is especially high. The high concentration of tri- and tetrasialoganyliosides and ganglioside GD1b is peculiar to primary cultures of nerve cells, whereas these gangliosides are practically not present in the culture of the transformed nerve cells which have lost their ability to sinaptogenesis, they are not found in cultures of oligodendro- and astroglia as well. The addition of exogenic gangliosides to nerve cells cultures stimulates the formation of processes in these cells and promotes their survivability. The neuritogenic and neuronotrophic effect of gangliosides, their participation in the processes of neurons' regeneration are shown in the in vivo experiments. Gangliosides are carriers of antigenic determinants typical of the cellular surface of neurons (or other cells) as well as of cells of different malignant tumours; typical carcinoembryonal antigenes are revealed among them. Such functions of gangliosides as participation in the processes of intercellular interaction, adhesion, pneuritogenic effect, possible participation to memorize one or another habit are, probably, interrelated and mutually conditioned. Recently the data, being in controversy with the notion that gangliosides are components of receptors of hormones and mediators, are obtained. Evidently, it ought to speak about the modulation of cell response by them on the action of these effectors. PMID:3293294

Avrova, N F; Gulaia, N M

1988-01-01

309

Peripheral nerve structure and function in long-term galactosemic dogs: morphometric and electron microscopic analyses.  

PubMed

Experimental galactosemia for activating the polyol pathway is used extensively to explore the pathogenesis of diabetic complications. However, despite the presence of severe neuropathy in galactosemic rats, changes in the peripheral nerve have not been well established in galactosemic dogs. We therefore conducted biochemical, electrophysiological, and morphometric studies on peripheral nervous systems (PNS) in dogs given a 30% galactose diet for 44 months. Age- and sex-matched dogs given a 30% cellulose diet were used as control. Chronic galactosemia resulted in accumulation of galactitol and decrease in myo-inositol in the sciatic nerve. Electrophysiological and teased fiber analyses demonstrated no significant abnormalities in the ulnar and peroneal nerves in galactosemic dogs. Morphometric analyses revealed a tendency of myelinated fiber atrophy (24% reduction of average fiber size) associated with 20% decrease (P < 0.05 vs control) in mean myelinated fiber occupancy rate in the peroneal nerve in galactosemic dogs. In the anterior mesenteric ganglion, there was a slight but significant increase (8%) in mean neuronal cell size in galactosemic dogs (P < 0.05 vs control). Electron microscopy revealed that galactosemia did not produce dystrophic and degenerative changes in the autonomic ganglion in dogs. We conclude that structural and functional changes in the PNS of galactosemic dogs are mild and different from those of the rat model. These findings suggest that the severity of peripheral neuropathy induced by chronic galactosemia may be species dependent. PMID:10208276

Sugimoto, K; Kasahara, T; Yonezawa, H; Yagihashi, S

1999-04-01

310

Disentangling different functional roles of evoked K-complex components: Mapping the sleeping brain while quenching sensory processing.  

PubMed

During non-REM sleep the largest EEG response evoked by sensory stimulation is the K-complex (eKC), composed of an initial positive bump (P200) followed by a bistable cortical response: a giant negative deflection (N550) and a large positive one (P900), respectively reflecting down states and up states of < 1 Hz oscillations.Sensory-modality-independent topology of N550 and P900, with maximal detection rate on fronto-central areas, has been consistently reported, suggesting that sensory inputs arise to the cortex avoiding specific primary sensory areas. However, these studies neglected latencies of all KC components as a function of electrode sites.Our aim is to identify, component by component, which topological/dynamical properties of eKCs depend on stimulus modality and which are mainly related to local cortical properties. We measured temporal and morphological features of acoustic, tactile and visual eKCs to disentangle specific sensory excitatory activities from aspecific responses due to local proneness to bistability, measured by means of the N550 descending steepness (synchronization in falling into down state).While confirming the sensory-modality independence of N550 and P900 topology with maximal detection rate in fronto-central areas, four main original results emerge from this study: (i) the topology of P200 latency depends on the sensory modality with earliest waves in the stimulation-related primary sensory areas; (ii) P200 rapidly travels as a cortical excitation; (iii) P200-like excitations when KCs are not evoked are detected over the scalp with significantly smaller amplitudes in fronto-central areas, compared to eKC P200s; and (iv) N550 latency mirrors its mean local steepness which is a function of topological proneness to bistability.From these results we can describe the emergence N550/P900 complex as the interplay between a waxing P200 cortical travel and higher fronto-central proneness to bistability.In conclusion, eKCs exhibit a physiological dichotomy: P200 acts as a traveling cortical excitation whose function is to induce the bistable cortical response (N550/P900), which in turn is crucial for maintaining sleep and unconsciousness. PMID:24513527

Laurino, Marco; Menicucci, Danilo; Piarulli, Andrea; Mastorci, Francesca; Bedini, Remo; Allegrini, Paolo; Gemignani, Angelo

2014-02-01

311

Improvement of sensorimotor functions in old age by passive sensory stimulation  

PubMed Central

Sensorimotor functions decrease in old age. The well-documented loss of tactile acuity in elderly is accompanied by deterioration of haptic performance and fine manipulative movements. Physical training and exercise can maintain sensorimotor fitness into high age. However, regular schedules of training require discipline and physical fitness. We here present an alternative interventional paradigm to enhance tactile, haptic, and fine motor performance based on passive, sensory stimulation by means of tactile coactivation. This approach is based on patterned, synchronous tactile stimulation applied to the fingertips for 3 hours. The stimulation drives plastic reorganizational changes in somatosensory cortex that affect perception and behavior: We demonstrate that following 3 hours of coactivation tactile acuity as well as haptic object exploration and fine motor performance are improved for at least 96 hours. Because this kind of intervention does not require active participation or attention of the subjects, we anticipate that coactivation is a prime candidate for future therapeutic interventions in patients with impaired sensorimotor abilities. It can be assumed that the maintenance and restoration of sensorimotor functions can ensure and preserve independence of daily living. Further optimizing of the stimulation protocol can be assumed to strengthen both the range and durability of its efficacy.

Kalisch, Tobias; Tegenthoff, Martin; Dinse, Hubert R

2008-01-01

312

Physiological, Sensory, and Functional Measures in a Model of Wrist Muscle Injury and Recovery  

PubMed Central

ABSTRACT Purpose: To evaluate the effectiveness of muscle rehabilitation modalities, it is first necessary to develop a model to test measures that would assess physiological, sensory, and functional muscle recovery. This study attempted to develop such a model for wrist injury. Subjects: Healthy male and female adults (n = 25). Methods: Subjects performed wrist muscle damage assessment, soreness, discomfort, difficulty, and functional motor task tests before and 1, 2, and 7 days after eccentric wrist muscle contractions. Wrist-related motor task tests, including the perception of discomfort and difficulty during performance, were also conducted. Results: At 24 hours post–eccentric exercises, wrist extension and flexion force declined (p < 0.05) and soreness (p < 0.05) and circumference (p < 0.05) increased; all returned to normal by 7 days post-exercise. At 24 and 48 hours post-exercise, perception of discomfort and difficulty was elevated during performance of motor tasks (p < 0.05). The completion speed of motor tasks was unaffected at any time post–eccentric exercise (p > 0.05). Conclusions: Loss of wrist muscle force, increased soreness, task discomfort, and difficulty were noted following eccentric exercise. However, subjects appeared able to compensate, such that the speed of completion of motor tasks was not slowed. Longer or more specific motor tasks may be necessary to mimic real work performance decrement and recovery.

Brown, Lindsay; Brant, Aron; Enns, Deborah; Bryden, Pamela J.

2008-01-01

313

Molecular Evolution of the Infrared Sensory Gene TRPA1 in Snakes and Implications for Functional Studies  

PubMed Central

TRPA1 is a calcium ion channel protein recently identified as the infrared receptor in pit organ-containing snakes. Therefore, understanding the molecular evolution of TRPA1 may help to illuminate the origin of “heat vision” in snakes and reveal the molecular mechanism of infrared sensitivity for TRPA1. To this end, we sequenced the infrared sensory gene TRPA1 in 24 snake species, representing nine snake families and multiple non-snake outgroups. We found that TRPA1 is under strong positive selection in the pit-bearing snakes studied, but not in other non-pit snakes and non-snake vertebrates. As a comparison, TRPV1, a gene closely related to TRPA1, was found to be under strong purifying selection in all the species studied, with no difference in the strength of selection between pit-bearing snakes and non-pit snakes. This finding demonstrates that the adaptive evolution of TRPA1 specifically occurred within the pit-bearing snakes and may be related to the functional modification for detecting infrared radiation. In addition, by comparing the TRPA1 protein sequences, we identified 11 amino acid sites that were diverged in pit-bearing snakes but conserved in non-pit snakes and other vertebrates, 21 sites that were diverged only within pit-vipers but conserved in the remaining snakes. These specific amino acid substitutions may be potentially functional important for infrared sensing.

Jiang, Ke; Zhang, Peng

2011-01-01

314

Combining Peripheral Nerve Grafts and Chondroitinase Promotes Functional Axonal Regeneration in the Chronically Injured Spinal Cord  

PubMed Central

Because there currently is no treatment for spinal cord injury, most patients are living with long-standing injuries. Therefore, strategies aimed at promoting restoration of function to the chronically injured spinal cord have high therapeutic value. For successful regeneration, long-injured axons must overcome their poor intrinsic growth potential as well as the inhibitory environment of the glial scar established around the lesion site. Acutely injured axons that regenerate into growth-permissive peripheral nerve grafts (PNGs) reenter host tissue to mediate functional recovery if the distal graft– host interface is treated with chondroitinase ABC (ChABC) to cleave inhibitory chondroitin sulfate proteoglycans in the scar matrix. To determine whether a similar strategy is effective for a chronic injury, we combined grafting of a peripheral nerve into a highly relevant, chronic, cervical contusion site with ChABC treatment of the glial scar and glial cell line-derived neurotrophic factor (GDNF) stimulation of long-injured axons. We tested this combination in two grafting paradigms: (1) a peripheral nerve that was grafted to span a chronic injury site or (2) a PNG that bridged a chronic contusion site with a second, more distal injury site. Unlike GDNF–PBS treatment, GDNF–ChABC treatment facilitated axons to exit the PNG into host tissue and promoted some functional recovery. Electrical stimulation of axons in the peripheral nerve bridge induced c-Fos expression in host neurons, indicative of synaptic contact by regenerating fibers. Thus, our data demonstrate, for the first time, that administering ChABC to a distal graft interface allows for functional axonal regeneration by chronically injured neurons.

Tom, Veronica J.; Sandrow-Feinberg, Harra R.; Miller, Kassi; Santi, Lauren; Connors, Theresa; Lemay, Michel A.; Houle, John D.

2010-01-01

315

Pancreatic acinar AR42J cells express functional nerve growth factor receptors  

Microsoft Academic Search

The factors regulating the diVerentiation of the endocrine cells of the pancreas are still unknown. In previous studies, we have demonstrated that, like neurones, various ‚-cell lines express functional neurotrophin receptors. Moreover, Trk-A, the nerve growth factor (NGF) high-aYnity receptor, is expressed in vivo in mature rat islets and early during development in the pancreatic ductal network that represents the

F Miralles; P Czernichow; R Scharfmann

1999-01-01

316

Action of cismethrin and deltamethrin on functional attributes of isolated presynaptic nerve terminals from rat brain  

Microsoft Academic Search

Isolated presynaptic nerve terminals (synaptosomes) prepared from rat brain were used to evaluate the actions of a tremor (T)-syndrome (cismethrin) and a choreoathetosis-salivation (CS)-syndrome (deltamethrin) pyrethroid on the functional attributes of synaptosomes by measuring calcium influx and endogenous neurotransmitter (l-glutamate) release with fluorescent assays. Both cismethrin and deltamethrin stimulated calcium influx, however, only deltamethrin enhanced Ca2+-dependent neurotransmitter release and its

Steven B. Symington; Richard K. Frisbie; Kim D. Lu; J. Marshall Clark

2007-01-01

317

SIRT1 Promotes RGC Survival and Delays Loss of Function Following Optic Nerve Crush  

PubMed Central

Purpose. Activation of SIRT1 deacetylase prevents retinal ganglion cell (RGC) loss in experimental optic neuritis, an inflammatory optic neuropathy. While mechanisms of this effect are not known, evidence suggests it involves reduction of oxidative stress. We hypothesized that SIRT1 reduces RGC loss due to oxidative stress in noninflammatory optic neuropathies, and examined effects following traumatic injury. Methods. Optic nerve crush injury was induced in wild-type C57BL/6 mice, mice overexpressing SIRT1, and mice with conditional deletion of SIRT1 in neurons. Wild-type mice were treated daily with vehicle or 250 mg/kg resveratrol, a naturally occurring polyphenol that activates SIRT1. RGC function was assessed by pupillometry and optokinetic responses (OKR), and RGC survival was measured. Superoxide levels were measured to assess oxidative stress. Results. Significant decreases in pupillary light responses, OKR and RGC survival occurred 1 week after optic nerve crush, with progressive worsening at 2 to 4 weeks. Resveratrol treatment and SIRT1 overexpression delayed RGC loss and loss of pupillary light responses following optic nerve crush, although no change in RGC loss occurred in neuronal SIRT1-deficient mice. A significant accumulation of superoxide was detected in wild-type optic nerves following crush, and was reduced in mice overexpressing SIRT1 or treated with resveratrol. Conclusions. SIRT1 delays RGC loss following traumatic injury. Effects are associated with reduced oxidative stress. Results suggest SIRT1-activating drugs may have a specific role in preventing traumatic optic nerve damage, and suggest a broader role for this strategy in treating a variety of optic neuropathies that may include a component of oxidative stress.

Zuo, Ling; Khan, Reas S.; Lee, Vivian; Dine, Kimberly; Wu, Wen; Shindler, Kenneth S.

2013-01-01

318

Nitric oxide as an endogenous peripheral modulator of visceral sensory neuronal function.  

PubMed

Nitric oxide (NO) plays important roles in CNS and smooth muscle function. Here we reveal an additional function in peripheral sensory transmission. We hypothesized that endogenous NO modulates the function of gastrointestinal vagal afferent endings. The nonselective NO synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester hydrochloride increased responses to tactile mechanical stimuli of mucosal afferent endings in two species, in some cases severalfold. This was mimicked by a neuronal NOS inhibitor but not an endothelial NOS inhibitor. NOS inhibitors did not affect the responsiveness of smooth muscle afferent endings, suggesting that the endogenous source of NO is exclusively accessible to mucosal receptors. The role of the NO-soluble guanylyl cyclase (sGC)-cGMP pathway was confirmed using the sGC inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one and the cGMP phosphodiesterase 5' inhibitor sildenafil. The first enhanced and the second inhibited mechanosensory function. Exogenous NO, from the donor S-nitroso-N-acetylpenicillamine, significantly reduced mechanosensitivity of both types of ending. Up to one-third of stomach-projecting afferent neurons in the nodose ganglia expressed neuronal NOS (nNOS). However, anterograde-traced vagal endings were nNOS negative, indicating NOS is not transported peripherally and there are alternative sources of NO for afferent modulation. A subpopulation of enteroendocrine cells in the gut mucosa were nNOS positive, which were found anatomically in close apposition with mucosal vagal afferent endings. These results indicate an inhibitory neuromodulatory role of epithelial NO, which targets a select population of vagal afferents. This interaction is likely to play a role in generation of symptoms and behaviors from the upper gastrointestinal system. PMID:19494147

Page, Amanda J; O'Donnell, Tracey A; Cooper, Nicole J; Young, Richard L; Blackshaw, L Ashley

2009-06-01

319

Frequency control of motor patterning by negative sensory feedback.  

PubMed

The sensory system plays a key role in the generation of behavior by providing the nervous system with information about the environment and feedback about body movements such that motor output can continuously be adapted to changing circumstances. Although the effects of sensory organs on nervous system function have been demonstrated in many systems, the impact of sensory activity has rarely been studied in conditions in which motor output and sensory activity can interact as they do in behaving animals. In such situations, emergent properties may surface and govern the characteristics of the motor system. We studied the dynamics of sensorimotor interaction with a combination of electrophysiological experiments and computational modeling in the locust flight pattern generator, including its sensory components. The locust flight motor output is produced by a central pattern generator that interacts with phasic sensory feedback from the tegula, a proprioceptor that signals downstroke movement of the wing. We modeled the flight control system, and we tested the model predictions by replacing tegula feedback in the animal with artificial feedback through computer-controlled electric stimulation of the appropriate sensory nerves. With reference to the cycle frequency in the locust flight rhythm, our results show that motor patterns can be regulated via the variation of sensory feedback loops. In closed-loop conditions, tegula feedback strength determines cycle frequency in the model and the biological preparation such that stronger feedback results in lower frequencies. This regulatory mechanism appears to be a general emergent property of negative feedback systems. PMID:17728446

Ausborn, Jessica; Stein, Wolfgang; Wolf, Harald

2007-08-29

320

Early Interfaced Neural Activity from Chronic Amputated Nerves  

PubMed Central

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

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

2009-01-01

321

Functional electrical stimulation of the left recurrent laryngeal nerve using a vagus nerve stimulator in a normal horse.  

PubMed

The aim of this study was to assess the feasibility of implanting an existing vagus nerve stimulating (VNS) electrode around the recurrent laryngeal nerve. The stimulus response characteristics required to achieve abduction of the ipsilateral arytenoid by the VNS electrode in the normal horse could then be determined. The electrode was wound around the left recurrent laryngeal nerve at the cervical level and connected to a pulse generator. Stimulus response characteristics were obtained by measuring stimulated arytenoid displacement endoscopically in the standing, non-sedated horse. A full and sustained abduction of the arytenoid was obtained with a stimulation frequency of 25 Hz and intensity of 1 mA with a pulse width of 250 ?s. PMID:20724182

Vanschandevijl, Katleen; Nollet, Heidi; Vonck, Kristl; Raedt, Rorecht; Boon, Paul; Roost, DirkVan; Martens, Ann; Deprez, Piet

2011-09-01

322

Functional and anatomical characteristics of the nerve-brown adipose interaction in the rat  

NASA Technical Reports Server (NTRS)

Experiments were conducted on 12 male rats to study the coupling of signals from the sympathetic nervous system to the brown adipose tissue. Analysis of electron photomicrographs revealed considerable morphological heterogeneity among the nerves entering and leaving the interscapular fat pad. In response to electrical simulation of the nerves, the temperature of the brown fat increased following a rapid but transient temperature drop. Such changes were observed only on the ipsilateral side, indicating that the innervation to the interscapular brown fat of the rat is functionally bilateral rather than diffuse. The finding that brown fat is capable of responding in a graded fashion correlates well with observations suggesting that clusters of brown adipocytes may be electrically coupled.

Flaim, K. E.; Horowitz, J. M.; Horwitz, B. A.

1976-01-01

323

Deletion of Nrf2 impairs functional recovery, reduces clearance of myelin debris and decreases axonal remyelination after peripheral nerve injury  

PubMed Central

Oxidative stress is generated in several peripheral nerve injury models. In response to oxidative stress, the transcription factor Nrf2 is activated to induce expression of antioxidant responsive element (ARE) genes. The role of Nrf2 in peripheral nerve injury has not been studied to date. In this study, we used a sciatic nerve crush model to examine how deletion of Nrf2 affects peripheral nerve degeneration and regeneration. Our study demonstrated that functional recovery in the Nrf2-/- mice were impaired compared to the wild type mice after sciatic nerve crush. Larger myelin debris were present in the distal nerve stump of the Nrf2-/- mice than in the wild type mice. The presence of larger myelin debris in the Nrf2-/- mice coincides with less macrophages accumulation in the distal nerve stump. Less accumulation of macrophages may have contributed to slower clearance of myelin and thus resulted in the presence of larger myelin debris. Meanwhile, axonal regeneration is comparatively lower in the Nrf2-/- mice than in the wild type mice. Even after 3 months post the injury, more thinly myelinated axon fibers were present in the Nrf2-/- mice than in the wild type mice. Taken collectively, these data support the concept of therapeutic intervention with Nrf2 activators following nerve injury.

Zhang, Linxia; Johnson, Delinda; Johnson, Jeffrey A.

2013-01-01

324

Genetics Home Reference: Hereditary sensory and autonomic neuropathy type V  

MedlinePLUS

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

325

Functional outcome of anterior transposition of the vascularized ulnar nerve for cubital tunnel syndrome  

Microsoft Academic Search

Anterior transposition of the ulnar nerve is a widely used treatment for cubital tunnel syndrome, but neurolysis performed at the time of surgery may impair the blood supply to the ulnar nerve. This study compared the results of intramuscular anterior transposition of the ulnar nerve with or without preserving the extrinsic vessels of the ulnar nerve in 35 patients. The

A. Asami; K. Morisawa; T. Tsuruta

1998-01-01

326

Comparison of nerve, vessel, and cartilage grafts in promoting peripheral nerve regeneration.  

PubMed

Peripheral nerve injury primarily occurs due to trauma as well as factors such as tumors, inflammatory diseases, congenital deformities, infections, and surgical interventions. The surgical procedure to be performed as treatment depends on the etiology, type of injury, and the anatomic region. The goal of treatment is to minimize loss of function due to motor and sensory nerve loss at the distal part of the injury. Regardless of the cause of the injury, the abnormal nerve regeneration due to incomplete nerve regeneration, optimal treatment of peripheral nerve injuries should provide adequate coaptation of proximal and distal sides without tension, preserving the neurotrophic factors within the repair line. The gold standard for the treatment of nerve defects is the autograft; however, due to denervation of the donor site, scarring, and neuroma formation, many studies have aimed to develop simpler methods, better functional results, and less morbidity. In this study, a defect 1 cm in length was created on the sciatic nerve of rats. The rats were treated with the following procedures: group 1, autograft; group 2, allogeneic aorta graft; group 3, diced cartilage graft in allogeneic aorta graft; and group 4, tubularized cartilage graft in allogeneic aorta graft. Group 5 was the control group. The effects of cartilage tissue in nerve regeneration were evaluated by functional and histomorphological methods.Group 1, for which the repair was performed with an autograft, was evaluated to be the most similar to the control group. There was not a statistically significant difference in myelination and Schwann cell rates between group 2, in which an allogeneic aorta graft was used, and group 3, in which diced cartilage in an allogeneic aorta graft was used. In group 4, myelination and Schwann cell formation were observed; however, they were scattered and irregular, likely due to increased fibrosis.In all of the groups, nerve regeneration at various rates was observed both functionally and histomorphologically. This study demonstrates that cartilage tissue has promoting effects in nerve regeneration. PMID:23917545

Frat, Cemal; Geyik, Ylmaz; Aytekin, Ahmet Hamdi; Gül, Mehmet; Kam?l, Suat; Yi?itcan, Birgül; Ozcan, Cemal

2014-07-01

327

Evaluation of symptom heterogeneity in neuropathic pain using assessments of sensory functions.  

PubMed

Classification of neuropathic pain has been based on disease entities, anatomical localization, or histological observations. Over the past decade, there has been an explosion in our understanding of the basic mechanisms of neuropathic pain. The exciting advances in basic science are paralleled by the recognition from clinical investigations that neuropathic pain is not a monolithic entity, but instead presents as a composite of pain and other sensory symptoms. Attempts are under way to supplement the traditional classification with a classification that links pain and sensory symptoms with neurobiological mechanisms. This mechanism- or symptom-based classification takes both negative and positive sensory symptoms into account. By using a battery of several standardized quantitative sensory tests, the characteristic profile of sensory symptoms can be elucidated in each patient. Moreover, in questionnaires the verbal descriptors can depict the quality and intensity of the individual pain. The approach of classifying and subgrouping patients with neuropathic pain on the basis of symptoms or signs opens up new possibilities for stratifying patients in clinical trials. First, in clinical proof-of-concept trials the study population can be enriched prospectively on the basis of entry criteria defined a priori. This enrichment with patients who potentially require a specific treatment should increase the likelihood for positive trial outcomes. Second, in clinical practice it becomes possible to establish an individualized therapy--that is, to identify the particular patients who require a specific treatment option. PMID:19789076

Arning, Kathrin; Baron, Ralf

2009-10-01

328

Search for frequency-specific effects of millimeter-wave radiation on isolated nerve function  

SciTech Connect

Effects of a short-term exposure to millimeter waves on the compound action potential (CAP) conduction were studied in an isolated frog sciatic nerve preparation. CAPs were evoked by either a low-rate or a high-rate electrical stimulation of the nerve. The low-rate stimulation did not alter the functional state of the nerve, and the amplitude, latency, and peak latency of CAPs could stay virtually stable for hours. Microwave irradiation for 10--60 min at 0.24--1.5 mW/cm{sup 2}, either at various constant frequencies or with a stepwise frequency change, did not cause any detectable changes in CAP conduction or nerve refractoriness. The effect observed under irradiation at a higher field intensity of 2--3 mW/cm{sup 2} was a subtle and transient reduction of CAP latency and peak latency along with a rise of the test CAP amplitude. These changes could be evoked by any tested frequency of the radiation; they reversed shortly after cessation of exposure and were both qualitatively and quantitatively similar to the effect of conventional heating of 0.3--0.4 C. The high-rate electrical stimulation caused gradual and reversible decrease of the amplitude of conditioning and test CAPs and increased their latencies and peak latencies. These changes were essentially the same with and without irradiation, except for attenuation of the decrease of the test CAP amplitude. This effect was observed at both field intensities, but was statistically significant only for certain frequencies of the radiation. Within the studied limits, this effect appeared to be dependent on the frequency rather than on the intensity of the radiation, but this observation requires additional experimental confirmation.

Pakhomov, A.G.; Campbell, C.B.G. [Army Medical Research Detachment of the Walter Reed Army Inst. of Research, Brooks AFB, TX (United States). Microwave Bioeffects Branch] [Army Medical Research Detachment of the Walter Reed Army Inst. of Research, Brooks AFB, TX (United States). Microwave Bioeffects Branch; Prol, H.K.; Mathur, S.P.; Akyel, Y. [McKesson BioServices, Brooks AFB, TX (United States)] [McKesson BioServices, Brooks AFB, TX (United States)

1997-06-01

329

Male-male courtship behavior induced by ectopic expression of the Drosophila white gene: role of sensory function and age.  

PubMed

Male-male courtship behavior was recently reported to be induced in large populations of Drosophila (e.g., 600-1500 flies) by ectopic expression of the white (w) gene. Little is known about the basis of this behavior; in male-female courtship, sensory cues are believed to play an important role. Previous data are consistent with the possibility that misexpression of w causes abnormal reception or processing of sensory information. We show here that w-induced male-male courtship occurs in isolated pairs of flies. Thus the behavior does not depend on sensory cues found only among large populations of flies, or on cues produced only by a small subset of such populations. This finding enabled quantitative analysis of mechanisms that underlie the behavior. Specifically, male-male courtship does not depend on the reception of olfactory information, nor on the reception or generation of auditory cues, as determined by surgical ablation of antennae, maxillary palps, or wings. Although the rapid onset of the behavior following w induction suggested that its basis could lie in a modulation of sensory physiology, we found visual, olfactory, and gustatory function to be normal in physiological or behavioral tests. The only sensory deprivation to produce an effect on male-male courtship was testing under dim red light; the percentage of flies courting another male was reduced to one-fourth of control values. A striking age dependence of the behavior is also documented: courtship between paired male mini-w+ flies was not observed in tests of very young (1-day-old) flies, but occurs at high levels between the ages of 1 and 4 weeks. PMID:8844509

Hing, A L; Carlson, J R

1996-08-01

330

Taxol-induced sensory disturbance is characterized by preferential impairment of myelinated fiber function in cancer patients.  

PubMed

Taxol produces neuropathic pain with three distinct zones of involvement in the extremities. Most distally is an area of on-going pain and proximal to this is a zone of sensory disturbance but not overt pain. These two areas were confined in all but one case to the glabrous skin of the hands and/or feet. More proximal is an area not recognized by the patients as involved with pain or sensory disturbance yet wherein quantitative sensory tests nevertheless reveal altered sensibility. Impairment of perception to light touch, normally conveyed by myelinated fibers, was dramatically altered in all three areas, being approximately 50-fold greater than normal in areas of pain and sensory disturbance as well as in areas of skin perceived by the patients as not affected. Impairment of perception to sharpness, normally conveyed by small myelinated fibers, was most pronounced in areas of on-going pain, intermediate in areas of sensory disturbance and near baseline in more proximal skin of chemotherapy patients. In contrast to mechanical sensibility, thermal thresholds for warm and heat pain detection were normal throughout. Finally, chemotherapy patients showed paradoxical burning pain to skin cooling that was most pronounced in proximal areas of skin thought to be unaffected by the patients, intermediate in the border zone of altered sensibility and least pronounced in areas of on-going pain. These data suggest that taxol produces a neuropathy characterized by pronounced impairment of function in A-beta myelinated fibers, intermediate impairment of A-delta myelinated fibers, and a relative sparing of C-fibers. PMID:15082135

Dougherty, Patrick M; Cata, Juan P; Cordella, Joseph V; Burton, Allen; Weng, Han-Rong

2004-05-01

331

Phasic and tonic patterns of locus coeruleus output differentially modulate sensory network function in the awake rat.  

PubMed

Neurons of the nucleus locus coeruleus (LC) discharge with phasic bursts of activity superimposed on highly regular tonic discharge rates. Phasic bursts are elicited by bottom-up input mechanisms involving novel/salient sensory stimuli and top-down decision making processes; whereas tonic rates largely fluctuate according to arousal levels and behavioral states. Although it is generally believed that these two modes of activity differentially modulate information processing in LC targets, the unique role of phasic versus tonic LC output on signal processing in cells, circuits, and neural networks of waking animals is not well understood. In the current study, simultaneous recordings of individual neurons within ventral posterior medial thalamus and barrel field cortex of conscious rats provided evidence that each mode of LC output produces a unique modulatory impact on single neuron responsiveness to sensory-driven synaptic input and representations of sensory information across ensembles of simultaneously recorded cells. Each mode of LC activation specifically modulated the relationship between sensory-stimulus intensity and the subsequent responses of individual neurons and neural ensembles. Overall these results indicate that phasic versus tonic modes of LC discharge exert fundamentally different modulatory effects on target neuronal circuits within the rodent trigeminal somatosensory system. As such, each mode of LC output may differentially influence signal processing as a means of optimizing behaviorally relevant neural computations within this sensory network. Likely the ability of the LC system to differentially regulate neural responses and local circuit operations according to behavioral demands extends to other brain regions including those involved in higher cognitive functions. PMID:20980542

Devilbiss, David M; Waterhouse, Barry D

2011-01-01

332

Analysis of Graph Invariants in Functional Neocortical Circuitry Reveals Generalized Features Common to Three Areas of Sensory Cortex  

PubMed Central

Correlations in local neocortical spiking activity can provide insight into the underlying organization of cortical microcircuitry. However, identifying structure in patterned multi-neuronal spiking remains a daunting task due to the high dimensionality of the activity. Using two-photon imaging, we monitored spontaneous circuit dynamics in large, densely sampled neuronal populations within slices of mouse primary auditory, somatosensory, and visual cortex. Using the lagged correlation of spiking activity between neurons, we generated functional wiring diagrams to gain insight into the underlying neocortical circuitry. By establishing the presence of graph invariants, which are label-independent characteristics common to all circuit topologies, our study revealed organizational features that generalized across functionally distinct cortical regions. Regardless of sensory area, random and -nearest neighbors null graphs failed to capture the structure of experimentally derived functional circuitry. These null models indicated that despite a bias in the data towards spatially proximal functional connections, functional circuit structure is best described by non-random and occasionally distal connections. Eigenvector centrality, which quantifies the importance of a neuron in the temporal flow of circuit activity, was highly related to feedforwardness in all functional circuits. The number of nodes participating in a functional circuit did not scale with the number of neurons imaged regardless of sensory area, indicating that circuit size is not tied to the sampling of neocortex. Local circuit flow comprehensively covered angular space regardless of the spatial scale that we tested, demonstrating that circuitry itself does not bias activity flow toward pia. Finally, analysis revealed that a minimal numerical sample size of neurons was necessary to capture at least 90 percent of functional circuit topology. These data and analyses indicated that functional circuitry exhibited rules of organization which generalized across three areas of sensory neocortex.

Gururangan, Suchin S.; Sadovsky, Alexander J.; MacLean, Jason N.

2014-01-01

333

Onset of cholinergic efferent synaptic function in sensory hair cells of the rat cochlea  

PubMed Central

In the developing mammalian cochlea, the sensory hair cells receive efferent innervation originating in the superior olivary complex. This input is mediated by ?9/?10 nicotinic acetylcholine receptors (nAChRs) and is inhibitory due to the subsequent activation of calcium-dependent SK2 potassium channels. We examined the acquisition of this cholinergic efferent input using whole-cell voltage-clamp recordings from inner hair cells (IHCs) in acutely excised apical turns of the rat cochlea from embryonic day 21 to postnatal day 8 (P8). Responses to 1 mM acetylcholine (ACh) were detected from P0 on in almost every IHC. The ACh-activated current amplitude increased with age and demonstrated the same pharmacology as ?9-containing nAChRs. Interestingly, at P0, the ACh response was not coupled to SK2 channels, so that the initial cholinergic response was excitatory and could trigger action potentials in IHCs. Coupling to SK current was detected earliest at P1 in a subset of IHCs and by P3 in every IHC studied. Clustered nAChRs and SK2 channels were found on IHCs from P1 on using Alexa Fluor 488 conjugated ?-bungarotoxin and SK2 immunohistochemistry. The number of nAChRs clusters increased with age to 16 per IHC at P8. Cholinergic efferent synaptic currents first appeared in a subset of IHCs at P1 and by P3 in every IHC studied, contemporaneously with ACh-evoked SK currents, suggesting that SK2 channels may be necessary at onset of synaptic function. An analogous pattern of development was observed for the efferent synapses that form later (P6–P8) on outer hair cells in the basal cochlea.

Roux, Isabelle; Wersinger, Eric; McIntosh, J. Michael; Fuchs, Paul A.; Glowatzki, Elisabeth

2011-01-01

334

P2X3 and TRPV1 functionally interact and mediate sensitization of trigeminal sensory neurons  

PubMed Central

Musculoskeletal pain conditions, particularly those associated with temporomandibular joint and muscle disorders (TMD) affect a large percentage of the population. Identifying mechanisms underlying hyperalgesia could contribute to the development of new treatment strategies for the management of TMD and other muscle pain conditions. In this study, we provide evidence of functional interactions between two ligand-gated channels, P2X3 and TRPV1, in trigeminal sensory neurons, and propose that the interactions serve as an underlying mechanism for the development of mechanical hyperalgesia. Mechanical sensitivity of the masseter muscle was assessed in lightly anesthetized rats via an electronic anesthesiometer (Ro et al., 2009). Direct intramuscular injection of a selective P2X3 agonist, ??meATP, induced a dose- and time-dependent hyperalgesia. Mechanical sensitivity in the contralateral muscle was unaffected suggesting local P2X3 mediate the hyperalgesia. Anesthetizing the overlying skin had no effect on ??meATP-induced hyperalgesia confirming the contribution of P2X3 from muscle. Importantly, the ??meATP-induced hyperalgesia was prevented by pretreatment of the muscle with a TRPV1 antagonist, AMG9810. P2X3 was co-expressed with TRPV1 in masseter muscle afferents confirming the possibility for intracellular interactions. Additionally, in a subpopulation of P2X3/TRPV1 positive neurons, capsaicin-induced Ca2+ transients were significantly amplified following P2X3 activation. Finally, activation of P2X3 induced phosphorylation of serine, but not threonine, residues in TRPV1 in trigeminal ganglia cultures. Significant phosphorylation was observed at 15 min, the time point at which behavioral hyperalgesia was prominent. Previously, activation of either P2X3 or TRPV1 had been independently implicated in the development of mechanical hyperalgesia. Our data propose P2X3 and TRPV1 interact in a facilitatory manner, which could contribute to the peripheral sensitization known to underlie masseter hyperalgesia.

Saloman, Jami L.; Chung, Man-Kyo; Ro, Jin Y.

2012-01-01

335

Sensory Neuron-Derived Eph Regulates Glomerular Arbors and Modulatory Function of a Central Serotonergic Neuron  

PubMed Central

Olfactory sensory neurons connect to the antennal lobe of the fly to create the primary units for processing odor cues, the glomeruli. Unique amongst antennal-lobe neurons is an identified wide-field serotonergic neuron, the contralaterally-projecting, serotonin-immunoreactive deutocerebral neuron (CSDn). The CSDn spreads its termini all over the contralateral antennal lobe, suggesting a diffuse neuromodulatory role. A closer examination, however, reveals a restricted pattern of the CSDn arborization in some glomeruli. We show that sensory neuron-derived Eph interacts with Ephrin in the CSDn, to regulate these arborizations. Behavioural analysis of animals with altered Eph-ephrin signaling and with consequent arborization defects suggests that neuromodulation requires local glomerular-specific patterning of the CSDn termini. Our results show the importance of developmental regulation of terminal arborization of even the diffuse modulatory neurons to allow them to route sensory-inputs according to the behavioural contexts.

Aggarwal, Aman; Diegelmann, Soeren; Evers, Jan Felix; Karandikar, Hrishikesh; Landgraf, Matthias; VijayRaghavan, K.

2013-01-01

336

Accelerating axonal growth promotes motor recovery after peripheral nerve injury in mice  

PubMed Central

Although peripheral nerves can regenerate after injury, proximal nerve injury in humans results in minimal restoration of motor function. One possible explanation for this is that injury-induced axonal growth is too slow. Heat shock protein 27 (Hsp27) is a regeneration-associated protein that accelerates axonal growth in vitro. Here, we have shown that it can also do this in mice after peripheral nerve injury. While rapid motor and sensory recovery occurred in mice after a sciatic nerve crush injury, there was little return of motor function after sciatic nerve transection, because of the delay in motor axons reaching their target. This was not due to a failure of axonal growth, because injured motor axons eventually fully re-extended into muscles and sensory function returned; rather, it resulted from a lack of motor end plate reinnervation. Tg mice expressing high levels of Hsp27 demonstrated enhanced restoration of motor function after nerve transection/resuture by enabling motor synapse reinnervation, but only within 5 weeks of injury. In humans with peripheral nerve injuries, shorter wait times to decompression surgery led to improved functional recovery, and, while a return of sensation occurred in all patients, motor recovery was limited. Thus, absence of motor recovery after nerve damage may result from a failure of synapse reformation after prolonged denervation rather than a failure of axonal growth.

Ma, Chi Him Eddie; Omura, Takao; Cobos, Enrique J.; Latremoliere, Alban; Ghasemlou, Nader; Brenner, Gary J.; van Veen, Ed; Barrett, Lee; Sawada, Tomokazu; Gao, Fuying; Coppola, Giovanni; Gertler, Frank; Costigan, Michael; Geschwind, Dan; Woolf, Clifford J.

2011-01-01

337

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

Microsoft Academic Search

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

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

1998-01-01

338

Aspects of static and dynamic motor function in peripheral nerve regeneration: SSI and CatWalk gait analysis.  

PubMed

Assessment of the therapeutic potential of interventions to bridge-repair peripheral nerve defects heavily relies on the demonstration of improved functional outcome. In the present study we used CatWalk gait analysis (locomotor-test) and Static Sciatic Index (SSI) (static-toe-spread-test) to assess the behavioural benefits of autologous nerve transplantation (ANT) repair of 2-cm rat sciatic nerve defects (neurotmesis-lesion). A reproducible and standardised rat sciatic nerve crush lesion model (axonotmesis-lesion) was used to assess the extent of recovery supported by maximal axon regeneration (measured by SSI and CatWalk). Animals were behaviourally followed for a period of 10 weeks. SSI analysis showed that ANT induced a significant improvement in motor deficit from about -95 to -65, however, CatWalk analysis did not show any major indication of locomotor recovery. This discrepancy might suggest that improvements in static motor functions (such as toe spreading) could reflect an early indicator for the recovery of function. We also noted differences in axon regeneration including increased axon density, smaller axon diameters and thinner myelin sheaths in the distal region of the ANT in comparison to the equivalent region of crushed and normal nerves. This difference in axon regeneration may be related to the clearly improved toe spreading function. We conclude that SSI and CatWalk present different advantages and disadvantages for the assessment of motor recovery after bridge-repair of peripheral nerve defects. PMID:21168447

Bozkurt, A; Scheffel, J; Brook, G A; Joosten, E A; Suschek, C V; O'Dey, D M; Pallua, N; Deumens, R

2011-05-16

339

Diverse subthreshold cross-modal sensory interactions in the thalamic reticular nucleus: implications for new pathways of cross-modal attentional gating function.  

PubMed

Our attention to a sensory cue of a given modality interferes with attention to a sensory cue of another modality. However, an object emitting various sensory cues attracts attention more effectively. The thalamic reticular nucleus (TRN) could play a pivotal role in such cross-modal modulation of attention given that cross-modal sensory interaction takes place in the TRN, because the TRN occupies a highly strategic position to function in the control of gain and/or gating of sensory processing in the thalamocortical loop. In the present study cross-modal interactions between visual and auditory inputs were examined in single TRN cells of anesthetised rats using juxta-cellular recording and labeling techniques. Visual or auditory responses were modulated by subthreshold sound or light stimuli, respectively, in the majority of recordings (46 of 54 visual and 60 of 73 auditory cells). However, few bimodal sensory cells were found. Cells showing modulation of the sensory response were distributed in the whole visual and auditory sectors of the TRN. Modulated cells sent axonal projections to first-order or higher-order thalamic nuclei. Suppression predominated in modulation that took place not only in primary responses but also in late responses repeatedly evoked after sensory stimulation. Combined sensory stimulation also evoked de-novo responses, and modulated response latency and burst spiking. These results indicate that the TRN incorporates sensory inputs of different modalities into single cell activity to function in sensory processing in the lemniscal and non-lemniscal systems. This raises the possibility that the TRN constitutes neural pathways involved in cross-modal attentional gating. PMID:24646412

Kimura, Akihisa

2014-05-01

340

Active compounds and distinctive sensory features provided by American ginseng (Panax quinquefolius L.) extract in a new functional milk beverage.  

PubMed

American ginseng (Panax quinquefolius L.) has recognized neurocognitive effects, and a ginsenoside-rich extract of the root of the plant has been shown to improve cognitive functions in young adults. This study aimed at assessing the chemical and sensory profiles of a UHT-treated, low-lactose functional milk containing American ginseng. Individual ginsenosides in the milk were analyzed by HPLC. Descriptive sensory analysis was performed by a trained panel to quantitatively document sensory changes resulting from the addition of ginseng and the UHT process on flavored and unflavored milks. Consumer acceptance of the product was also investigated. Total ginsenoside content in the UHT-treated milk enriched with the ginseng extract after UHT process treatment was 7.52 mg/100 g of milk, corresponding to a recovery of 67.6% compared with the content in the unprocessed extract. The intake of 150 to 300 mL of this ginseng-enriched milk provides the amount of total ginsenosides (11.5 to 23 mg) necessary to improve cognitive function after its consumption. Both the presence of ginsenosides and their thermal treatment affected some sensory properties of the milk, most notably an increase in bitterness and metallic taste, the appearance of a brownish color, and a decrease in milky flavor. Levels of brown color, bitterness, and metallic taste were highest in the industrially processed ginseng-enriched milk. The bitterness attributable to ginseng extract was reduced by addition of vanilla flavor and sucralose. A consumer exploratory study revealed that a niche of consumers exists who are willing to consume this type of product. PMID:22818438

Tárrega, A; Salvador, A; Meyer, M; Feuillère, N; Ibarra, A; Roller, M; Terroba, D; Madera, C; Iglesias, J R; Echevarría, J; Fiszman, S

2012-08-01

341

A glial DEG/ENaC channel functions with neuronal channel DEG-1 to mediate specific sensory functions in C. elegans  

PubMed Central

Mammalian neuronal DEG/ENaC channels known as ASICs (acid-sensing ion channels) mediate sensory perception and memory formation. ASICS are closed at rest and are gated by protons. Members of the DEG/ENaC family expressed in epithelial tissues are called ENaCs and mediate Na+ transport across epithelia. ENaCs exhibit constitutive activity and strict Na+ selectivity. We report here the analysis of the first DEG/ENaC in Caenorhabditis elegans with functional features of ENaCs that is involved in sensory perception. ACD-1 (acid-sensitive channel, degenerin-like) is constitutively open and impermeable to Ca2+, yet it is required with neuronal DEG/ENaC channel DEG-1 for acid avoidance and chemotaxis to the amino acid lysine. Surprisingly, we document that ACD-1 is required in glia rather than neurons to orchestrate sensory perception. We also report that ACD-1 is inhibited by extracellular and intracellular acidification and, based on the analysis of an acid-hypersensitive ACD-1 mutant, we propose a mechanism of action of ACD-1 in sensory responses based on its sensitivity to protons. Our findings suggest that channels with ACD-1 features may be expressed in mammalian glia and have important functions in controlling neuronal function.

Wang, Ying; Apicella, Alfonso; Lee, Sun-Kyung; Ezcurra, Marina; Slone, Robert D; Goldmit, Maya; Schafer, William R; Shaham, Shai; Driscoll, Monica; Bianchi, Laura

2008-01-01

342

Mice Lacking the Extracellular Matrix Protein WARP Develop Normally but Have Compromised Peripheral Nerve Structure and Function*  

PubMed Central

WARP is a recently identified extracellular matrix molecule with restricted expression in permanent cartilages and a distinct subset of basement membranes in peripheral nerves, muscle, and the central nervous system vasculature. WARP interacts with perlecan, and we also demonstrate here that WARP binds type VI collagen, suggesting a function in bridging connective tissue structures. To understand the in vivo function of WARP, we generated a WARP-deficient mouse strain. WARP-null mice were healthy, viable, and fertile with no overt abnormalities. Motor function and behavioral testing demonstrated that WARP-null mice exhibited a significantly delayed response to acute painful stimulus and impaired fine motor coordination, although general motor function was not affected, suggesting compromised peripheral nerve function. Immunostaining of WARP-interacting ligands demonstrated that the collagen VI microfibrillar matrix was severely reduced and mislocalized in peripheral nerves of WARP-null mice. Further ultrastructural analysis revealed reduced fibrillar collagen deposition within the peripheral nerve extracellular matrix and abnormal partial fusing of adjacent Schwann cell basement membranes, suggesting an important function for WARP in stabilizing the association of the collagenous interstitial matrix with the Schwann cell basement membrane. In contrast, other WARP-deficient tissues such as articular cartilage, intervertebral discs, and skeletal muscle showed no detectable abnormalities, and basement membranes formed normally. Our data demonstrate that although WARP is not essential for basement membrane formation or musculoskeletal development, it has critical roles in the structure and function of peripheral nerves.

Allen, Justin M.; Zamurs, Laura; Brachvogel, Bent; Schlotzer-Schrehardt, Ursula; Hansen, Uwe; Lamande, Shireen R.; Rowley, Lynn; Fitzgerald, Jamie; Bateman, John F.

2009-01-01

343

Topiramate promotes neurite outgrowth and recovery of function after nerve injury.  

PubMed

Topiramate is a structurally novel neurotherapeutic agent with a unique combination of pharmacological properties and currently is available in most world markets for treating several seizure disorders. Because its pharmacological profile was suggestive of possible activity as a neuroprotectant, topiramate was evaluated and found to be active in several animal models of stroke or neuropathic pain. This prompted an evaluation of topiramate as a possible neurotrophic agent. In this study, topiramate enhanced the recovery of facial nerve function after injury when administered orally at therapeutically relevant doses, and significantly increased neurite outgrowth in cell cultures derived from fetal rat cortical and hippocampal tissues. PMID:11303740

Smith-Swintosky, V L; Zhao, B; Shank, R P; Plata-Salaman, C R

2001-04-17

344

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

PubMed Central

This study investigated the function of the adhesion molecule L1 in unmyelinated fibers of the peripheral nervous system (PNS) by analysis of L1- deficient mice. We demonstrate that L1 is present on axons and Schwann cells of sensory unmyelinated fibers, but only on Schwann cells of sympathetic unmyelinated fibers. In L1-deficient sensory nerves, Schwann cells formed but failed to retain normal axonal ensheathment. L1-deficient mice had reduced sensory function and loss of unmyelinated axons, while sympathetic unmyelinated axons appeared normal. In nerve transplant studies, loss of axonal-L1, but not Schwann cell-L1, reproduced the L1-deficient phenotype. These data establish that heterophilic axonal-L1 interactions mediate adhesion between unmyelinated sensory axons and Schwann cells, stabilize the polarization of Schwann cell surface membranes, and mediate a trophic effect that assures axonal survival.

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

1999-01-01

345

Distribution and putative function of autonomic nerve fibres in the bill skin of the platypus (Ornithorhynchus anatinus).  

PubMed Central

The electroreceptors located in the bill skin of the platypus are modified secretory glands. The electroreceptive nerve terminals form bare endings in close proximity to the duct of these glands. In this study, we describe the autonomic innervation of the glands and a separate specialized autonomic innervation of the epidermal portion of the glandular duct. A range of immunohistochemical labels showed that the gland cells of the electroreceptors have a non-noradrenergic (putative parasympathetic) innervation. Phalloidin labelling revealed a 'sphincter' of epidermal luminal cells that labelled strongly for actin. These actin-dense keratinocytes were seen to have a noradrenergic (putative sympathetic) innervation. Fine-diameter sensory fibres containing substance P (presumably C-fibre thermoreceptors or polymodal nociceptors) were observed to terminate in the superficial epidermis surrounding the pore of the gland. When the bill of the platypus is dry these pores were closed. However, when room temperature water was washed over the bill, the pores opened. It is proposed that this autonomic and sensory innervation, along with the actin sphincter, mediates the opening and closing of the pores. By doing this, the platypus prevents the desiccation of the bare electrosensory nerve terminals when it is out of the water, and it may also be a way to regulate the impedance of the internal electrical circuit presented to the water at the pores.

Manger, P R; Keast, J R; Pettigrew, J D; Troutt, L

1998-01-01

346

Functional evidence for presynaptic P2X7 receptors in adult rat cerebrocortical nerve terminals.  

PubMed

The presynaptic P2X7 receptor (P2X7R) plays an important role in the modulation of transmitter release. We recently demonstrated that, in nerve terminals of the adult rat cerebral cortex, P2X7R activation induced Ca2+-dependent vesicular glutamate release and significant Ca2+-independent glutamate efflux through the P2X7R itself. In the present study, we investigated the effect of the new selective P2X(7)R competitive antagonist 3-(5-(2,3-dichlorophenyl)-1H-tetrazol-1-yl)methyl pyridine (A-438079) on cerebrocortical terminal intracellular calcium (intrasynaptosomal calcium concentration;[Ca2+](i) signals and glutamate release, and evaluated whether P2X7R immunoreactivity was consistent with these functional tests. A-438079 inhibited functional responses. P2X7R immunoreactivity was found in about 45% of cerebrocortical terminals, including glutamatergic and non-glutamatergic terminals. This percentage was similar to that of synaptosomes showing P2X7R-mediated [Ca2+]i signals. These findings provide compelling evidence of functional presynaptic P2X7R in cortical nerve terminals. PMID:18977353

Alloisio, Susanna; Cervetto, Chiara; Passalacqua, Mario; Barbieri, Raffaella; Maura, Guido; Nobile, Mario; Marcoli, Manuela

2008-11-26

347

Dye-filling of the amphid sheath glia: implications for the functional relationship between sensory neurons and glia in Caenorhabditis elegans.  

PubMed

The nervous system is composed of cells including neurons and glia. It has been believed that the former cells play central roles in various neural functions while the latter ones have only supportive functions for neurons. However, recent findings suggest that glial cells actively participate in neural activities, and the cooperation between neurons and glia is important for nervous system functions. In Caenorhabditis elegans, amphid sensory organs in the head also consist of sensory neurons and glia-like support cells (amphid socket and amphid sheath cells). Ciliary endings of some sensory neurons exposed to the environment detect various chemicals, molecules and signals, and the cilia of some neurons can also take up fluorescent dyes such as DiI. Here, we show that the amphid sheath glia are also stained with DiI and that its uptake by the amphid sheath cells correlates with DiI-filling of sensory neurons, suggesting that the amphid sheath glia might interact with sensory neurons. Furthermore, the localization of the amphid sheath cell reporter F52E1.2SP::YFP is abnormal in che-2 mutants, which have defective cilia. These findings imply that sensory neurons might affect amphid sheath glia functions in the amphid sensory organ of C. elegans. PMID:21295547

Ohkura, Kiyotaka; Bürglin, Thomas R

2011-03-11

348

Evidence for Glutamate as a Neuroglial Transmitter within Sensory Ganglia  

PubMed Central

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

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

2013-01-01

349

Evidence for glutamate as a neuroglial transmitter within sensory ganglia.  

PubMed

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

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

2013-01-01

350

EVALUATION OF SENSORY SYSTEM FUNCTION USING REFLEX MODIFICATION OF THE STARTLE RESPONSE  

EPA Science Inventory

Methods to measure damage to sensory systems following toxicant exposure vary from rapid and subjective tests (e.g., pinna reflex) to time-consuming and objective tests (e.g., psychophysical tests). eflex modification of the startle response represents an alternative technique in...

351

Glaucoma progression detection using structural retinal nerve fiber layer measurements and functional visual field points.  

PubMed

Machine learning classifiers were employed to detect glaucomatous progression using longitudinal series of structural data extracted from retinal nerve fiber layer thickness measurements and visual functional data recorded from standard automated perimetry tests. Using the collected data, a longitudinal feature vector was created for each patient's eye by computing the norm 1 difference vector of the data at the baseline and at each follow-up visit. The longitudinal features from each patient's eye were then fed to the machine learning classifier to classify each eye as stable or progressed over time. This study was performed using several machine learning classifiers including Bayesian, Lazy, Meta, and Tree, composing different families. Combinations of structural and functional features were selected and ranked to determine the relative effectiveness of each feature. Finally, the outcomes of the classifiers were assessed by several performance metrics and the effectiveness of structural and functional features were analyzed. PMID:24658239

Yousefi, Siamak; Goldbaum, Michael H; Balasubramanian, Madhusudhanan; Jung, Tzyy-Ping; Weinreb, Robert N; Medeiros, Felipe A; Zangwill, Linda M; Liebmann, Jeffrey M; Girkin, Christopher A; Bowd, Christopher

2014-04-01

352

Downregulation of Tetrodotoxin-Resistant Sodium Currents and Upregulation of a Rapidly Repriming Tetrodotoxin-Sensitive Sodium Current in Small Spinal Sensory Neurons after Nerve Injury  

Microsoft Academic Search

Clinical and experimental studies have shown that spinal sen- sory neurons become hyperexcitable after axonal injury, and electrophysiological changes have suggested that this may be attributable to changes in sodium current expression. We have demonstrated previously that sodium channel a-III mRNA lev- els are elevated and sodium channel a-SNS mRNA levels are reduced in rat spinal sensory neurons after axotomy.

Theodore R. Cummins; Stephen G. Waxman

1997-01-01

353

Caenorhabditis elegans TRPV Channels Function in a Modality-Specific Pathway to Regulate Response to Aberrant Sensory Signaling  

PubMed Central

Olfaction and some forms of taste (including bitter) are mediated by G protein-coupled signal transduction pathways. Olfactory and gustatory ligands bind to chemosensory G protein-coupled receptors (GPCRs) in specialized sensory cells to activate intracellular signal transduction cascades. G protein-coupled receptor kinases (GRKs) are negative regulators of signaling that specifically phosphorylate activated GPCRs to terminate signaling. Although loss of GRK function usually results in enhanced cellular signaling, Caenorhabditis elegans lacking GRK-2 function are not hypersensitive to chemosensory stimuli. Instead, grk-2 mutant animals do not chemotax toward attractive olfactory stimuli or avoid aversive tastes and smells. We show here that loss-of-function mutations in the transient receptor potential vanilloid (TRPV) channels OSM-9 and OCR-2 selectively restore grk-2 behavioral avoidance of bitter tastants, revealing modality-specific mechanisms for TRPV channel function in the regulation of C. elegans chemosensation. Additionally, a single amino acid point mutation in OCR-2 that disrupts TRPV channel-mediated gene expression, but does not decrease channel function in chemosensory primary signal transduction, also restores grk-2 bitter taste avoidance. Thus, loss of GRK-2 function may lead to changes in gene expression, via OSM-9/OCR-2, to selectively alter the levels of signaling components that transduce or regulate bitter taste responses. Our results suggest a novel mechanism and multiple modality-specific pathways that sensory cells employ in response to aberrant signal transduction.

Ezak , Meredith J.; Hong , Elizabeth; Chaparro-Garcia , Angela; Ferkey , Denise M.

2010-01-01

354

Functional and morphological assessment of a standardized rat sciatic nerve crush injury with a non-serrated clamp.  

PubMed

Peripheral nerve researchers frequently use the rat sciatic nerve crush as a model for axonotmesis. Unfortunately, studies from various research groups report results from different crush techniques and by using a variety of evaluation tools, making comparisons between studies difficult. The purpose of this investigation was to determine the sequence of functional and morphologic changes after an acute sciatic nerve crush injury with a non-serrated clamp, giving a final standardized pressure of p = 9 MPa. Functional recovery was evaluated using the sciatic functional index (SFI), the extensor postural thrust (EPT) and the withdrawal reflex latency (WRL), before injury, and then at weekly intervals until week 8 postoperatively. The rats were also evaluated preoperatively and at weeks 2, 4, and 8 by ankle kinematics, toe out angle (TOA), and gait-stance duration. In addition, the motor nerve conduction velocity (MNCV) and the gastrocnemius-soleus weight parameters were measured just before euthanasia. Finally, structural, ultrastructural and histomorphometric analyses were carried out on regenerated nerve fibers. At 8 weeks after the crush injury, a full functional recovery was predicted by SFI, EPT, TOA, and gait-stance duration, while all the other parameters were still recovering their original values. On the other hand, only two of the histomorphometric parameters of regenerated nerve fibers, namely myelin thickness/axon diameter ratio and fiber/axon diameter ratio, returned to normal values while all other parameters were significantly different from normal values. The employment of traditional methods of functional evaluation in conjunction with the modern techniques of computerized analysis of gait and histomorphometric analysis should thus be recommended for an overall assessment of recovery in the rat sciatic nerve crush model. PMID:15684656

Varejão, Artur S P; Cabrita, António M; Meek, Marcel F; Bulas-Cruz, José; Melo-Pinto, Pedro; Raimondo, Stefania; Geuna, Stefano; Giacobini-Robecchi, Maria G

2004-11-01

355

Developmental dynamics of functionally specific primary sensory afferent projections in the chicken embryo  

Microsoft Academic Search

The central projections of specific subpopulations of lumbar primary afferents were selectively labeled with the lipophilic tracer DiI in fixed preparations of the chicken embryo. Muscle or cutaneous afferents were selectively labeled by applying DiI to identified peripheral nerves. Medial or lateral afferent populations were selectively labeled by partially lesioning the dorsal root. Muscle and cutaneous afferent populations each contribute

A. L. Eide; Joel C. Glover

1997-01-01

356

Functionalized gold nanoparticle supported sensory mechanisms applied in detection of chemical and biological threat agents: a review.  

PubMed

There is a great necessity for development of novel sensory concepts supportive of smart sensing capabilities in defense and homeland security applications for detection of chemical and biological threat agents. A smart sensor is a detection device that can exhibit important features such as speed, sensitivity, selectivity, portability, and more importantly, simplicity in identifying a target analyte. Emerging nanomaterial based sensors, particularly those developed by utilizing functionalized gold nanoparticles (GNPs) as a sensing component potentially offer many desirable features needed for threat agent detection. The sensitiveness of physical properties expressed by GNPs, e.g. color, surface plasmon resonance, electrical conductivity and binding affinity are significantly enhanced when they are subjected to functionalization with an appropriate metal, organic or biomolecular functional groups. This sensitive nature of functionalized GNPs can be potentially exploited in the design of threat agent detection devices with smart sensing capabilities. In the presence of a target analyte (i.e., a chemical or biological threat agent) a change proportional to concentration of the analyte is observed, which can be measured either by colorimetric, fluorimetric, electrochemical or spectroscopic means. This article provides a review of how functionally modified gold colloids are applied in the detection of a broad range of threat agents, including radioactive substances, explosive compounds, chemical warfare agents, biotoxins, and biothreat pathogens through any of the four sensory means mentioned previously. PMID:22244163

Upadhyayula, Venkata K K

2012-02-17

357

Evidence of GLP-1-mediated neuroprotection in an animal model of pyridoxine-induced peripheral sensory neuropathy  

Microsoft Academic Search

Pyridoxine (vitamin B6) intoxicated rodents develop a peripheral neuropathy characterized by sensory nerve conduction deficits associated with disturbances of nerve fiber geometry and axonal atrophy. To investigate the possibility that glucagon-like peptide-1 (7–36)-amide (GLP-1) receptor agonism may influence axonal structure and function through neuroprotection neurotrophic support, effects of GLP-1 and its long acting analog, Exendin-4 (Ex4) treatment on pyridoxine-induced peripheral

TracyAnn Perry; Harold W. Holloway; Ananda Weerasuriya; Peter R. Mouton; Kara Duffy; Julie A. Mattison; Nigel H. Greig

2007-01-01

358

The Endocranial Anatomy of Therizinosauria and Its Implications for Sensory and Cognitive Function  

PubMed Central

Background Therizinosauria is one of the most enigmatic and peculiar clades among theropod dinosaurs, exhibiting an unusual suite of characters, such as lanceolate teeth, a rostral rhamphotheca, long manual claws, and a wide, opisthopubic pelvis. This specialized anatomy has been associated with a shift in dietary preferences and an adaptation to herbivory. Despite a large number of discoveries in recent years, the fossil record for Therizinosauria is still relatively poor, and cranial remains are particularly rare. Methodology/Principal Findings Based on computed tomographic (CT) scanning of the nearly complete and articulated skull of Erlikosaurus andrewsi, as well as partial braincases of two other therizinosaurian taxa, the endocranial anatomy is reconstructed and described. The wider phylogenetic range of the described specimens permits the evaluation of sensory and cognitive capabilities of Therizinosauria in an evolutionary context. The endocranial anatomy reveals a mosaic of plesiomorphic and derived characters in therizinosaurians. The anatomy of the olfactory apparatus and the endosseous labyrinth suggests that olfaction, hearing, and equilibrium were well-developed in therizinosaurians and might have affected or benefited from an enlarged telencephalon. Conclusion/Significance This study presents the first appraisal of the evolution of endocranial anatomy and sensory adaptations in Therizinosauria. Despite their phylogenetically basal position among maniraptoran dinosaurs, therizinosaurians had developed the neural pathways for a well developed sensory repertoire. In particular olfaction and hearing may have played an important role in foraging, predator evasion, and/or social complexity.

Lautenschlager, Stephan; Rayfield, Emily J.; Altangerel, Perle; Zanno, Lindsay E.; Witmer, Lawrence M.

2012-01-01

359

Assessment of lingual nerve injury using different surgical variables for mandibular third molar surgery: a clinical study.  

PubMed

The objective of this study was to investigate the incidence of sensory impairment of the lingual nerves following lower third molar removal and to compare the outcome with various operative variables. A total of 1200 mandibular third molars were removed under local anaesthesia. Predictor variables were categorized as lingual flap retraction, tooth sectioning, and buccal guttering. The outcome variable was the presence or absence of lingual nerve impairment. Different operative techniques were performed to identify independent predictors. Of the 1200 patients, 67 (5.6%) experienced transient sensory impairment at the 1-week follow-up. In all cases this resolved completely during the study period, except for four (0.3%) patients who suffered permanent impairment of lingual nerve function. Factors that predicted lingual nerve injury were lingual flap retraction, tooth sectioning, and buccal guttering. The incidence of lingual nerve injury was greater when combinations of these operative variables were used. PMID:24582384

Yadav, S; Verma, A; Sachdeva, A

2014-07-01

360

Use of chitosan scaffolds for repairing rat sciatic nerve defects.  

PubMed

Neurotmesis must be surgically treated by direct end-to-end suture of the two nerve stumps or by a nerve graft harvested from elsewhere in the body in case of tissue loss. To avoid secondary damage due to harvesting of the nerve graft, a tube-guide can be used to bridge the nerve gap. Previously, our group developed and tested hybrid chitosan membranes for peripheral nerve tubulization and showed that freeze-dried chitosan type III membranes were particularly effective for improving peripheral nerve functional recovery after axonotmesis. Chitosan type III membranes have about 110 microm pores and about 90% of porosity, due to the employment of freeze-drying technique. The present study aimed to verify if chitosan type III membranes can be successfully used also for improving peripheral nerve functional recovery after neurotmesis of the rat sciatic nerve. Sasco Sprague-Dawley adult rats were divided into 6 groups: Group 1: end-to-end neurorrhaphy enwrapped by chitosan membrane type III (End-to-EndChitll); Group 2: 10mm-nerve gap bridged by an autologous nerve graft enwrapped by chitosan membrane type III (Graf180degreeChitIII); Group 3: 10 mm-nerve gap bridged by chitosan type III tube-guides (GapChitIII); These 3 experimental groups were compared with 3 control groups, respectively: Group 4: 10 mm-nerve gap bridged by an autologous nerve graft (Graft180degree); Group 5: 10 mm-nerve gap bridged by PLGA 90:10 tube-guides (PLGA); Group 6: end-to-end neurorrhaphy alone (End-to-End). Motor and sensory functional recovery were evaluated throughout a healing period of 20 weeks using extensor postural thrust (EPT), withdrawal reflex latency (WRL) and ankle kinematics. Regenerated nerves withdrawn at the end of the experiment were analysed histologically. Results showed that nerve regeneration was successful in all experimental and control groups and that chitosan type III tubulization induced a significantly better nerve regeneration and functional recovery in comparison to PLGA tubulization control. Further investigation is needed to explore the mechanisms at the basis of the positive effects of chitosan type III on axonal regeneration. PMID:21287974

Simões, Maria J; Amado, Sandra; Gärtner, Andrea; Armada-Da-Silva, Paulo A S; Raimondo, Stefania; Vieira, Marcia; Luís, Ana L; Shirosaki, Yuki; Veloso, António P; Santos, José D; Varejão, Artur S P; Geuna, Stefano; Maurício, Ana C

2010-01-01

361

Effect of an Adipose-Derived Stem Cell and Nerve Growth Factor-Incorporated Hydrogel on Recovery of Erectile Function in a Rat Model of Cavernous Nerve Injury  

PubMed Central

Postprostatectomy erectile dysfunction (ED) is the major problem for patients with clinically localized prostate cancer. Recently, gene and stem cell-based therapy of the corpus cavernosum has been attempted for postprostatectomy ED, but those therapies are limited by rapid blood flow and disruption of the normal architecture of the corpus cavernosum. In this study, we attempted to regenerate the damaged cavernous nerve (CN), which is the main cause of ED. We investigated the effectiveness of human adipose-derived stem cell (hADSC) and nerve growth factor-incorporated hyaluronic acid-based hydrogel (NGF-hydrogel) application on the CN in a rat model of bilateral cavernous nerve crush injury. Four weeks after the operation, erectile function was assessed by detecting the intracavernous pressure (ICP)/arterial pressure level by CN electrostimulation. The ICP was significantly increased by application of hADSC with NGF-hydrogel compared to the other experimental groups. CN and penile tissue were collected for histological examination. PKH-26 labeled hADSC colocalized with beta III tubulin were shown in CN tissue sections. hADSC/NGF-hydrogel treatment prevented smooth muscle atrophy in the corpus cavernosum. In addition, the hADSC/NGF-hydrogel group showed increased endothelial nitric oxide synthase protein expression. This study suggests that application of hADSCs with NGF-hydrogel on the CN might be a promising treatment for postprostatectomy ED.

Kim, In Gul; Piao, Shuyu; Lee, Ji Young; Hong, Sung Hoo; Hwang, Tae-Kon; Kim, Sae Woong; Kim, Choung Soo; Ra, Jeong Chan; Noh, Insup

2013-01-01

362

Effects of Electroacupuncture on Facial Nerve Function and HSV-1 DNA Quantity in HSV-1 Induced Facial Nerve Palsy Mice  

PubMed Central

Acupuncture is a common and effective therapeutic method to treat facial nerve palsy (FNP). However, its underlying mechanism remains unclear. This study was aimed to investigate the effects of electroacupuncture on symptoms and content of HSV-1 DNA in FNP mice. Mice were randomized into four groups, an electroacupuncture treatment group, saline group, model animal group, and blank control group. Electroacupuncture was applied at Jiache (ST6) and Hegu (LI4) in electroacupuncture group once daily for 14 days, while electroacupuncture was not applied in model animal group. In electroacupuncture group, mice recovered more rapidly and HSV-1 DNA content also decreased more rapidly, compared with model animal group. We conclude that electroacupuncture is effective to alleviate symptoms and promote the reduction of HSV-1 in FNP.

Tang, Hongzhi; Feng, Shuwei; Chen, Jiao; Yang, Mingxiao; Zhong, Zhendong; Li, Ying; Liang, Fanrong

2014-01-01

363

Restoration of diaphragmatic function after diaphragm reinnervation by inferior laryngeal nerve; experimental study in rabbits  

PubMed Central

Objectives To assess the possibilities of reinnervation in a paralyzed hemidiaphragm via an anastomosis between phrenic nerve and inferior laryngeal nerve in rabbits. Reinnervation of a paralyzed diaphragm could be an alternative to treat patients with ventilatory insufficiency due to upper cervical spine injuries. Material and method Rabbits were divided into five groups of seven rabbits each. Groups I and II were respectively the healthy and the denervated control groups. The 3 other groups were all reinnervated using three different surgical procedures. In groups III and IV, phrenic nerve was respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the trunk of the inferior laryngeal nerve. In group V, the fifth and fourth cervical roots were respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the nerve of the sternothyroid muscle (originating from the hypoglossal nerve). Animals were evaluated 4 months later using electromyography, transdiaphragmatic pressure measurements, sonomicrometry and histological examination. Results A poor inspiratory activity was found in quiet breathing in the reinnervated groups, with an increasing pattern of activity during effort. In the reinnervated groups, transdiaphragmatic pressure measurements and sonomicrometry were higher in group III with no significant differencewith groups IV and V. Conclusion Inspiratory contractility of an hemidiaphragm could be restored with immediate anastomosis after phrenic nerve section between phrenic nerve and inferior laryngeal nerve.

Derrey, Stephane; verin, Eric; Laquerriere, Annie; de Barros, Angelique Boishardy; Lacoume, Yann; Freger, Pierre; Marie, Jean Paul

2006-01-01

364

Nerve Growth Factor-Regulated Emergence of Functional Delta-Opioid Receptors  

PubMed Central

Sorting of intracellular G protein-coupled receptors (GPCRs) either to lysosomes for degradation or to plasma membrane for surface insertion and functional expression is a key process regulating signaling strength of GPCRs across the plasma membrane in adult mammalian cells. However, little is known about the molecular mechanisms governing the dynamic process of receptor sorting to the plasma membrane for functional expression under normal and pathological conditions. In this study, we demonstrate that delta-opioid receptor (DOPr), a GPCR constitutively targeted to intracellular compartments, is driven to the surface membrane of central synaptic terminals and becomes functional by the neurotrophin nerve growth factor (NGF) in native brainstem neurons. The NGF-triggered DOPr translocation is predominantly mediated by the signaling pathway involving the tyrosine receptor kinase A, Ca++-mobilizing phospholipase C and Ca++/calmodulin-dependent protein kinase II. Importantly, it requires interactions with the cytoplasmic sorting protein Na+/H+ exchange regulatory factor-1 (NHERF-1) and N-Ethyl-maleimide-sensitive factor-regulated exocytosis. In addition, this NGF-mediated mechanism is likely responsible for the emergence of functional DOPr induced by chronic opioids. Thus, NGF may function as a key molecular switch that redirects the sorting of intracellularly targeted DOPr to plasma membrane, resulting in new functional DOPr on central synapses under chronic opioid conditions.

Bie, Bihua; Zhang, Zhi; Cai, You-Qing; Zhu, Wei; Zhang, Yong; Dai, Jaile; Lowenstein, Charles J.; Weinman, Edward J.; Pan, Zhizhong Z.

2010-01-01

365

Neuromuscular recovery using calcium protease inhibition after median nerve repair in primates.  

PubMed Central

Inhibition of calcium-activated neutral protease, in muscle and nerve, by the tripeptide leupeptin after median nerve transection and epineural repair in monkeys (Cebus apella) was studied. Results indicate that inhibition of the protease after nerve repair facilitates morphologic recovery in denervated thenar muscles and in distal thenar nerve branches. In addition, functional recovery was facilitated in leupeptin-treated animals after nerve repair as measured by sensory and motor conduction velocities. Toxicologic testing showed that leupeptin, administered at 18 mg/kg, intramuscularly, twice daily, for 6 months did not adversely affect hematology, clotting, or plasma complement component C3 profiles. These data indicate that leupeptin is an effective and safe adjunct to peripheral nerve repair. Images

Badalamente, M A; Hurst, L C; Stracher, A

1989-01-01

366

Social Effects via Olfactory Sensory Stimuli on Reproductive Function and Dysfunction in Cooperative Breeding Marmosets and Tamarins  

PubMed Central

Most primates are social species whose reproduction is influenced by their social relationships. The cotton-top tamarin, Saguinus oedipus, and the common marmoset, Callithrix jacchus, are cooperative breeding species where the family structure alters reproductive function in many ways. While primates receive social effects on reproduction via all sensory stimuli, the marmosets and tamarins are particularly influenced by olfactory/chemosensory stimuli. The olfactory sensory processing is the ‘social glue’ that keeps the family together. This review describes a number of studies using the marmosets and tamarins at the University of Wisconsin to demonstrate how odor cues are used for altering reproductive function and dysfunction. Several key studies will be discussed to show the role of odor signaling of the female reproductive state. The suppressive effects of odors are mediated by priming odors and can cause a suppressive influence on ovulation in young females via their mother’s scents. Additionally, odor cues from the infant function as priming odors to ensure that fathers and mothers are present and receptive to their parental care duties. Neural pathways occur via the processing of priming odors that consequently stimulate alterations in the behavioral and endocrine response to the stimuli. The dynamics of the cooperative breeding system ensure that offspring have essential needs met and that they develop in a family environment. Olfactory communication plays a key role in maintenance of the social system of Callitrichid monkeys.

Ziegler, Toni E.

2012-01-01

367

Co-Transplantation of Olfactory Ensheathing Cells from Mucosa and Bulb Origin Enhances Functional Recovery after Peripheral Nerve Lesion  

PubMed Central

Olfactory ensheathing cells (OECs) represent an interesting candidate for cell therapy and could be obtained from olfactory mucosa (OM-OECs) or olfactory bulbs (OB-OECs). Recent reports suggest that, depending on their origin, OECs display different functional properties. We show here the complementary and additive effects of co-transplanting OM-OECs and OB-OECs after lesion of a peripheral nerve. For this, a selective motor denervation of the laryngeal muscles was performed by a section/anastomosis of the recurrent laryngeal nerve (RLN). Two months after surgery, recovery of the laryngeal movements and synkinesis phenonema were analyzed by videolaryngoscopy. To complete these assessments, measure of latency and potential duration were determined by electrophysiological recordings and myelinated nerve fiber profiles were defined based on toluidine blue staining. To explain some of the mechanisms involved, tracking of GFP positive OECs was performed. It appears that transplantation of OM-OECs or OB-OECs displayed opposite abilities to improve functional recovery. Indeed, OM-OECs increased recuperation of laryngeal muscles activities without appropriate functional recovery. In contrast, OB-OECs induced some functional recovery by enhancing axonal regrowth. Importantly, co-transplantation of OM-OECs and OB-OECs supported a major functional recovery, with reduction of synkinesis phenomena. This study is the first which clearly demonstrates the complementary and additive properties of OECs obtained from olfactory mucosa and olfactory bulb to improve functional recovery after transplantation in a nerve lesion model.

Bon-Mardion, Nicolas; Duclos, Celia;