Diffusion tensor imaging of the auditory nerve in patients with acquired single-sided deafness

DEFF Research Database (Denmark)

Vos, Sjoerd; Haakma, Wieke; Versnel, Huib

2015-01-01

following cochlear hair cell loss, and the amount of degeneration may considerably differ between the two ears, also in patients with bilateral deafness. A measure that reflects the nerve's condition would help to assess the best of both nerves and decide accordingly which ear should be implanted......A cochlear implant (CI) can restore hearing in patients with profound sensorineural hearing loss by direct electrical stimulation of the auditory nerve. Therefore, the viability of the auditory nerve is vitally important in successful hearing recovery. However, the nerve typically degenerates...... single-sided sensorineural hearing loss. A specialized acquisition protocol was designed for a 3 T MRI scanner to image the small nerve bundle. The nerve was reconstructed using fiber tractography and DTI metrics - which reflect the nerve's microstructural properties - were computed per tract. Comparing...

One-tone suppression in the frog auditory nerve

DEFF Research Database (Denmark)

Christensen-Dalsgaard, J; Jørgensen, M B

1996-01-01

Sixty-seven fibers of a sample of 401 in the auditory nerve of grassfrogs (Rana temporaria) showed one-tone suppression, i.e., their spontaneous activity was suppressed by tones. All fibers were afferents from the amphibian papilla with best frequencies between 100 and 400 Hz. Best suppression...

A model of auditory nerve responses to electrical stimulation

DEFF Research Database (Denmark)

Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

Cochlear implants (CI) stimulate the auditory nerve (AN) with a train of symmetric biphasic current pulses comprising of a cathodic and an anodic phase. The cathodic phase is intended to depolarize the membrane of the neuron and to initiate an action potential (AP) and the anodic phase to neutral......Cochlear implants (CI) stimulate the auditory nerve (AN) with a train of symmetric biphasic current pulses comprising of a cathodic and an anodic phase. The cathodic phase is intended to depolarize the membrane of the neuron and to initiate an action potential (AP) and the anodic phase......-and-fire neuron with two partitions responding individually to anodic and cathodic stimulation. Membrane noise was parameterized based on reported relative spread of AN neurons. Firing efficiency curves and spike-latency distributions were simulated for monophasic and symmetric biphasic stimulation...

Innervation of the renal proximal convoluted tubule of the rat

International Nuclear Information System (INIS)

Barajas, L.; Powers, K.

1989-01-01

Experimental data suggest the proximal tubule as a major site of neurogenic influence on tubular function. The functional and anatomical axial heterogeneity of the proximal tubule prompted this study of the distribution of innervation sites along the early, mid, and late proximal convoluted tubule (PCT) of the rat. Serial section autoradiograms, with tritiated norepinephrine serving as a marker for monoaminergic nerves, were used in this study. Freehand clay models and graphic reconstructions of proximal tubules permitted a rough estimation of the location of the innervation sites along the PCT. In the subcapsular nephrons, the early PCT (first third) was devoid of innervation sites with most of the innervation occurring in the mid (middle third) and in the late (last third) PCT. Innervation sites were found in the early PCT in nephrons located deeper in the cortex. In juxtamedullary nephrons, innervation sites could be observed on the PCT as it left the glomerulus. This gradient of PCT innervation can be explained by the different tubulovascular relationships of nephrons at different levels of the cortex. The absence of innervation sites in the early PCT of subcapsular nephrons suggests that any influence of the renal nerves on the early PCT might be due to an effect of neurotransmitter released from renal nerves reaching the early PCT via the interstitium and/or capillaries

SOLITARY CHEMORECEPTOR CELL SURVIVAL IS INDEPENDENT OF INTACT TRIGEMINAL INNERVATION

Science.gov (United States)

Gulbransen, Brian; Silver, Wayne; Finger, Tom

2008-01-01

Nasal solitary chemoreceptor cells (SCCs) are a population of specialized chemosensory epithelial cells presumed to broaden trigeminal chemoreceptivity in mammals (Finger et al., 2003). SCCs are innervated by peptidergic trigeminal nerve fibers (Finger et al., 2003) but it is currently unknown if intact innervation is necessary for SCC development or survival. We tested the dependence of SCCs on innervation by eliminating trigeminal nerve fibers during development with neurogenin-1 knockout mice, during early postnatal development with capsaicin desensitization, and during adulthood with trigeminal lesioning. Our results demonstrate that elimination of innervation at any of these times does not result in decreased SCC numbers. In conclusion, neither SCC development nor mature cell maintenance is dependent on intact trigeminal innervation. PMID:18300260

Involuntary movement during mastication in patients with long-term facial paralysis reanimated with a partial gracilis free neuromuscular flap innervated by the masseteric nerve.

Science.gov (United States)

Rozen, Shai; Harrison, Bridget

2013-07-01

Midface reanimation in patients with chronic facial paralysis is not always possible with an ipsilateral or contralateral facial nerve innervating a free neuromuscular tissue transfer. Alternate use of nonfacial nerves is occasionally indicated but may potentially result in inadvertent motions. The goal of this study was to objectively review videos of patients who underwent one-stage reanimation with a gracilis muscle transfer innervated by the masseteric nerve for (1) inadvertent motion during eating, (2) characterization of masticatory patterns, and (3) social hindrance perceived by the patients during meals. Between the years 2009 and 2012, 18 patients underwent midfacial reanimation with partial gracilis muscle transfer coapted to the masseter nerve for treatment of midfacial paralysis. Sixteen patients were videotaped in detail while eating. Involuntary midface movement on the reconstructed side and mastication patterns were assessed. In addition, 16 patients were surveyed as to whether involuntary motion constituted a problem in their daily lives. All 16 patients videotaped during mastication demonstrated involuntary motion on the reconstructed side while eating. Several unique masticatory patterns were noted as well. Only one of the 16 patients reported involuntary motion as a minor disturbance in daily life during meals. All patients with chronic facial paralysis who plan to undergo midface reanimation with a free tissue transfer innervated by the ipsilateral masseter nerve should be told that they would universally have involuntary animation during mastication. Most patients do not consider this a major drawback in their daily lives. Therapeutic, IV.

Perception of stochastically undersampled sound waveforms: A model of auditory deafferentation

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Enrique A Lopez-Poveda

2013-07-01

Full Text Available Auditory deafferentation, or permanent loss of auditory nerve afferent terminals, occurs after noise overexposure and aging and may accompany many forms of hearing loss. It could cause significant auditory impairment but is undetected by regular clinical tests and so its effects on perception are poorly understood. Here, we hypothesize and test a neural mechanism by which deafferentation could deteriorate perception. The basic idea is that the spike train produced by each auditory afferent resembles a stochastically digitized version of the sound waveform and that the quality of the waveform representation in the whole nerve depends on the number of aggregated spike trains or auditory afferents. We reason that because spikes occur stochastically in time with a higher probability for high- than for low-intensity sounds, more afferents would be required for the nerve to faithfully encode high-frequency or low-intensity waveform features than low-frequency or high-intensity features. Deafferentation would thus degrade the encoding of these features. We further reason that due to the stochastic nature of nerve firing, the degradation would be greater in noise than in quiet. This hypothesis is tested using a vocoder. Sounds were filtered through ten adjacent frequency bands. For the signal in each band, multiple stochastically subsampled copies were obtained to roughly mimic different stochastic representations of that signal conveyed by different auditory afferents innervating a given cochlear region. These copies were then aggregated to obtain an acoustic stimulus. Tone detection and speech identification tests were performed by young, normal-hearing listeners using different numbers of stochastic samplers per frequency band in the vocoder. Results support the hypothesis that stochastic undersampling of the sound waveform, inspired by deafferentation, impairs speech perception in noise more than in quiet, consistent with auditory aging effects.

Perception of stochastically undersampled sound waveforms: a model of auditory deafferentation

Science.gov (United States)

Lopez-Poveda, Enrique A.; Barrios, Pablo

2013-01-01

Auditory deafferentation, or permanent loss of auditory nerve afferent terminals, occurs after noise overexposure and aging and may accompany many forms of hearing loss. It could cause significant auditory impairment but is undetected by regular clinical tests and so its effects on perception are poorly understood. Here, we hypothesize and test a neural mechanism by which deafferentation could deteriorate perception. The basic idea is that the spike train produced by each auditory afferent resembles a stochastically digitized version of the sound waveform and that the quality of the waveform representation in the whole nerve depends on the number of aggregated spike trains or auditory afferents. We reason that because spikes occur stochastically in time with a higher probability for high- than for low-intensity sounds, more afferents would be required for the nerve to faithfully encode high-frequency or low-intensity waveform features than low-frequency or high-intensity features. Deafferentation would thus degrade the encoding of these features. We further reason that due to the stochastic nature of nerve firing, the degradation would be greater in noise than in quiet. This hypothesis is tested using a vocoder. Sounds were filtered through ten adjacent frequency bands. For the signal in each band, multiple stochastically subsampled copies were obtained to roughly mimic different stochastic representations of that signal conveyed by different auditory afferents innervating a given cochlear region. These copies were then aggregated to obtain an acoustic stimulus. Tone detection and speech identification tests were performed by young, normal-hearing listeners using different numbers of stochastic samplers per frequency band in the vocoder. Results support the hypothesis that stochastic undersampling of the sound waveform, inspired by deafferentation, impairs speech perception in noise more than in quiet, consistent with auditory aging effects. PMID:23882176

Changes in Properties of Auditory Nerve Synapses following Conductive Hearing Loss.

Science.gov (United States)

Zhuang, Xiaowen; Sun, Wei; Xu-Friedman, Matthew A

2017-01-11

Auditory activity plays an important role in the development of the auditory system. Decreased activity can result from conductive hearing loss (CHL) associated with otitis media, which may lead to long-term perceptual deficits. The effects of CHL have been mainly studied at later stages of the auditory pathway, but early stages remain less examined. However, changes in early stages could be important because they would affect how information about sounds is conveyed to higher-order areas for further processing and localization. We examined the effects of CHL at auditory nerve synapses onto bushy cells in the mouse anteroventral cochlear nucleus following occlusion of the ear canal. These synapses, called endbulbs of Held, normally show strong depression in voltage-clamp recordings in brain slices. After 1 week of CHL, endbulbs showed even greater depression, reflecting higher release probability. We observed no differences in quantal size between control and occluded mice. We confirmed these observations using mean-variance analysis and the integration method, which also revealed that the number of release sites decreased after occlusion. Consistent with this, synaptic puncta immunopositive for VGLUT1 decreased in area after occlusion. The level of depression and number of release sites both showed recovery after returning to normal conditions. Finally, bushy cells fired fewer action potentials in response to evoked synaptic activity after occlusion, likely because of increased depression and decreased input resistance. These effects appear to reflect a homeostatic, adaptive response of auditory nerve synapses to reduced activity. These effects may have important implications for perceptual changes following CHL. Normal hearing is important to everyday life, but abnormal auditory experience during development can lead to processing disorders. For example, otitis media reduces sound to the ear, which can cause long-lasting deficits in language skills and verbal

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

Science.gov (United States)

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

1990-01-01

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

Netrin-1 controls sympathetic arterial innervation.

Science.gov (United States)

Brunet, Isabelle; Gordon, Emma; Han, Jinah; Cristofaro, Brunella; Broqueres-You, Dong; Liu, Chun; Bouvrée, Karine; Zhang, Jiasheng; del Toro, Raquel; Mathivet, Thomas; Larrivée, Bruno; Jagu, Julia; Pibouin-Fragner, Laurence; Pardanaud, Luc; Machado, Maria J C; Kennedy, Timothy E; Zhuang, Zhen; Simons, Michael; Levy, Bernard I; Tessier-Lavigne, Marc; Grenz, Almut; Eltzschig, Holger; Eichmann, Anne

2014-07-01

Autonomic sympathetic nerves innervate peripheral resistance arteries, thereby regulating vascular tone and controlling blood supply to organs. Despite the fundamental importance of blood flow control, how sympathetic arterial innervation develops remains largely unknown. Here, we identified the axon guidance cue netrin-1 as an essential factor required for development of arterial innervation in mice. Netrin-1 was produced by arterial smooth muscle cells (SMCs) at the onset of innervation, and arterial innervation required the interaction of netrin-1 with its receptor, deleted in colorectal cancer (DCC), on sympathetic growth cones. Function-blocking approaches, including cell type-specific deletion of the genes encoding Ntn1 in SMCs and Dcc in sympathetic neurons, led to severe and selective reduction of sympathetic innervation and to defective vasoconstriction in resistance arteries. These findings indicate that netrin-1 and DCC are critical for the control of arterial innervation and blood flow regulation in peripheral organs.

Unilateral variant motor innervations of flexure muscles of arm

Directory of Open Access Journals (Sweden)

A S Yogesh

2010-01-01

Full Text Available The musculocutaneous nerve usually branches out from the lateral cord of brachial plexus. It innervates the corcobrachialis, biceps brachii and brachialis muscles and continues as the lateral cutaneous nerve of forearm without exhibiting any communication with the median nerve or any other nerve. We report unilateral variation in motor innervations of the left arm in a 58-year-old male cadaver. The musculocutaneous nerve was found to be absent. A muscular branch of the median nerve was supplying the coracobrachialis muscle. In the middle of arm, the median nerve was found to be branching out, bifurcating and supplying the long and short head of biceps. The median nerve was found to be giving a separate branch, which supplied the brachialis muscle and continued as the lateral cutaneous nerve of forearm. The right sided structures were found to be normal. Surgeons should keep such variations in mind while performing arm surgeries.

Organization of the auditory brainstem in a lizard, Gekko gecko. I. Auditory nerve, cochlear nuclei, and superior olivary nuclei

DEFF Research Database (Denmark)

Tang, Y. Z.; Christensen-Dalsgaard, J.; Carr, C. E.

2012-01-01

We used tract tracing to reveal the connections of the auditory brainstem in the Tokay gecko (Gekko gecko). The auditory nerve has two divisions, a rostroventrally directed projection of mid- to high best-frequency fibers to the nucleus angularis (NA) and a more dorsal and caudal projection of lo...... of auditory connections in lizards and archosaurs but also different processing of low- and high-frequency information in the brainstem. J. Comp. Neurol. 520:17841799, 2012. (C) 2011 Wiley Periodicals, Inc...

Neurons of self-defence: neuronal innervation of the exocrine defence glands in stick insects.

Science.gov (United States)

Stolz, Konrad; von Bredow, Christoph-Rüdiger; von Bredow, Yvette M; Lakes-Harlan, Reinhard; Trenczek, Tina E; Strauß, Johannes

2015-01-01

Stick insects (Phasmatodea) use repellent chemical substances (allomones) for defence which are released from so-called defence glands in the prothorax. These glands differ in size between species, and are under neuronal control from the CNS. The detailed neural innervation and possible differences between species are not studied so far. Using axonal tracing, the neuronal innervation is investigated comparing four species. The aim is to document the complexity of defence gland innervation in peripheral nerves and central motoneurons in stick insects. In the species studied here, the defence gland is innervated by the intersegmental nerve complex (ISN) which is formed by three nerves from the prothoracic (T1) and suboesophageal ganglion (SOG), as well as a distinct suboesophageal nerve (Nervus anterior of the suboesophageal ganglion). In Carausius morosus and Sipyloidea sipylus, axonal tracing confirmed an innervation of the defence glands by this N. anterior SOG as well as N. anterior T1 and N. posterior SOG from the intersegmental nerve complex. In Peruphasma schultei, which has rather large defence glands, only the innervation by the N. anterior SOG was documented by axonal tracing. In the central nervous system of all species, 3-4 neuron types are identified by axonal tracing which send axons in the N. anterior SOG likely innervating the defence gland as well as adjacent muscles. These neurons are mainly suboesophageal neurons with one intersegmental neuron located in the prothoracic ganglion. The neuron types are conserved in the species studied, but the combination of neuron types is not identical. In addition, the central nervous system in S. sipylus contains one suboesophageal and one prothoracic neuron type with axons in the intersegmental nerve complex contacting the defence gland. Axonal tracing shows a very complex innervation pattern of the defence glands of Phasmatodea which contains different neurons in different nerves from two adjacent body segments

Anatomic Patterns of Renal Arterial Sympathetic Innervation: New Aspects for Renal Denervation.

Science.gov (United States)

Imnadze, Guram; Balzer, Stefan; Meyer, Baerbel; Neumann, Joerg; Krech, Rainer Horst; Thale, Joachim; Franz, Norbert; Warnecke, Henning; Awad, Khaled; Hayek, Salim S; Devireddy, Chandan

2016-12-01

Initial studies of catheter-based renal arterial sympathetic denervation to lower blood pressure in resistant hypertensive patients renewed interest in the sympathetic nervous system's role in the pathogenesis of hypertension. However, the SYMPLICITY HTN-3 study failed to meet its prespecified blood pressure lowering efficacy endpoint. To date, only a limited number of studies have described the microanatomy of renal nerves, of which, only two involve humans. Renal arteries were harvested from 15 cadavers from the Klinikum Osnabruck and Schuchtermann Klinik, Bad Rothenfelde. Each artery was divided longitudinally in equal thirds (proximal, middle, and distal), with each section then divided into equal superior, inferior, anterior, and posterior quadrants, which were then stained. Segments containing no renal nerves were given a score value = 0, 1-2 nerves with diameter 4 nerves or nerve diameter ≥600 µm a score = 3. A total of 22 renal arteries (9 right-sided, 13 left-sided) were suitable for examination. Overall, 691 sections of 5 mm thickness were prepared. Right renal arteries had significantly higher mean innervation grade (1.56 ± 0.85) compared to left renal arteries (1.09 ± 0.87) (P renal artery has significantly higher innervation scores than the left. The anterior and superior quadrants of the renal arteries scored higher in innervation than the posterior and inferior quadrants did. The distal third of the renal arteries are more innervated than the more proximal segments. These findings warrant further evaluation of the spatial innervation patterns of the renal artery in order to understand how it may enhance catheter-based renal arterial denervation procedural strategy and outcomes. The SYMPLICITY HTN-3 study dealt a blow to the idea of the catheter-based renal arterial sympathetic denervation. We investigated the location and patterns of periarterial renal nerves in cadaveric human renal arteries. To quantify the density of the

Spatiotemporal dynamics of re-innervation and hyperinnervation patterns by uninjured CGRP fibers in the rat foot sole epidermis after nerve injury

NARCIS (Netherlands)

L.S. Duraku (Liron); S.M. Hossaini (Mehdi); S. Hoendervangers (Sieske); H.E. Falke; S. Kambiz (Shoista); V. Mudera (Vivek); J.C. Holstege (Jan); E.T. Walbeehm (Erik); T.J.H. Ruigrok (Tom)

2012-01-01

textabstractThe epidermis is innervated by fine nerve endings that are important in mediating nociceptive stimuli. However, their precise role in neuropathic pain is still controversial. Here, we have studied the role of epidermal peptidergic nociceptive fibers that are located adjacent to injured

Nerve canals at the fundus of the internal auditory canal on high-resolution temporal bone CT

International Nuclear Information System (INIS)

Ji, Yoon Ha; Youn, Eun Kyung; Kim, Seung Chul

2001-01-01

To identify and evaluate the normal anatomy of nerve canals in the fundus of the internal auditory canal which can be visualized on high-resolution temporal bone CT. We retrospectively reviewed high-resolution (1 mm thickness and interval contiguous scan) temporal bone CT images of 253 ears in 150 patients who had not suffered trauma or undergone surgery. Those with a history of uncomplicated inflammatory disease were included, but those with symptoms of vertigo, sensorineural hearing loss, or facial nerve palsy were excluded. Three radiologists determined the detectability and location of canals for the labyrinthine segment of the facial, superior vestibular and cochlear nerve, and the saccular branch and posterior ampullary nerve of the inferior vestibular nerve. Five bony canals in the fundus of the internal auditory canal were identified as nerve canals. Four canals were identified on axial CT images in 100% of cases; the so-called singular canal was identified in only 68%. On coronal CT images, canals for the labyrinthine segment of the facial and superior vestibular nerve were seen in 100% of cases, but those for the cochlear nerve, the saccular branch of the inferior vestibular nerve, and the singular canal were seen in 90.1%, 87.4% and 78% of cases, respectiveIy. In all detectable cases, the canal for the labyrinthine segment of the facial nerve was revealed as one which traversed anterolateralIy, from the anterosuperior portion of the fundus of the internal auditory canal. The canal for the cochlear nerve was located just below that for the labyrinthine segment of the facial nerve, while that canal for the superior vestibular nerve was seen at the posterior aspect of these two canals. The canal for the saccular branch of the inferior vestibular nerve was located just below the canal for the superior vestibular nerve, and that for the posterior ampullary nerve, the so-called singular canal, ran laterally or posteolateralIy from the posteroinferior aspect of

Nerve canals at the fundus of the internal auditory canal on high-resolution temporal bone CT

Energy Technology Data Exchange (ETDEWEB)

Ji, Yoon Ha; Youn, Eun Kyung; Kim, Seung Chul [Sungkyunkwan Univ., School of Medicine, Seoul (Korea, Republic of)

2001-12-01

To identify and evaluate the normal anatomy of nerve canals in the fundus of the internal auditory canal which can be visualized on high-resolution temporal bone CT. We retrospectively reviewed high-resolution (1 mm thickness and interval contiguous scan) temporal bone CT images of 253 ears in 150 patients who had not suffered trauma or undergone surgery. Those with a history of uncomplicated inflammatory disease were included, but those with symptoms of vertigo, sensorineural hearing loss, or facial nerve palsy were excluded. Three radiologists determined the detectability and location of canals for the labyrinthine segment of the facial, superior vestibular and cochlear nerve, and the saccular branch and posterior ampullary nerve of the inferior vestibular nerve. Five bony canals in the fundus of the internal auditory canal were identified as nerve canals. Four canals were identified on axial CT images in 100% of cases; the so-called singular canal was identified in only 68%. On coronal CT images, canals for the labyrinthine segment of the facial and superior vestibular nerve were seen in 100% of cases, but those for the cochlear nerve, the saccular branch of the inferior vestibular nerve, and the singular canal were seen in 90.1%, 87.4% and 78% of cases, respectiveIy. In all detectable cases, the canal for the labyrinthine segment of the facial nerve was revealed as one which traversed anterolateralIy, from the anterosuperior portion of the fundus of the internal auditory canal. The canal for the cochlear nerve was located just below that for the labyrinthine segment of the facial nerve, while that canal for the superior vestibular nerve was seen at the posterior aspect of these two canals. The canal for the saccular branch of the inferior vestibular nerve was located just below the canal for the superior vestibular nerve, and that for the posterior ampullary nerve, the so-called singular canal, ran laterally or posteolateralIy from the posteroinferior aspect of

Noradrenergic and cholinergic innervation of the bone marrow.

Science.gov (United States)

Artico, Marco; Bosco, Sandro; Cavallotti, Carlo; Agostinelli, Enzo; Giuliani-Piccari, Gabriella; Sciorio, Salvatore; Cocco, Lucio; Vitale, Marco

2002-07-01

Bone marrow is supplied by sensory and autonomic innervation. Although it is well established that hematopoiesis is regulated by cytokines and cell-to-cell contacts, the role played by neuromediators on the proliferation, differentiation and release of hematopoietic cells is still controversial. We studied the innervation of rat femur bone marrow by means of fluorescence histochemistry and immunohistochemistry. Glyoxylic acid-induced fluorescence was used to demonstrate catecholaminergic nerve fibers. The immunoperoxidase method with nickel amplification was applied to detect the distribution of nerve fibers using antibodies against the general neuronal marker PGP 9.5 (neuron-specific cytoplasmic protein), while the cholinacetyltransferase immunoreactivity was studied by immunohistochemistry. Our results show the presence of an extensive network of innervation in the rat bone marrow, providing a morphological basis for the neural modulation of hemopoiesis.

Function and morphology correlates of rectal nerve mechanoreceptors innervating the guinea pig internal anal sphincter.

Science.gov (United States)

Lynn, P A; Brookes, S J H

2011-01-01

Mechanoreceptors to the internal anal sphincter (IAS) contribute to continence and normal defecation, yet relatively little is known about their function or morphology. We investigated the function and structure of mechanoreceptors to the guinea pig IAS. Extracellular recordings from rectal nerve branches to the IAS in vitro, combined with anterograde labeling of recorded nerve trunks, were used to characterize extrinsic afferent nerve endings activated by circumferential distension. Slowly adapting, stretch-sensitive afferents were recorded in rectal nerves to the IAS. Ten of 11 were silent under basal conditions and responded to circumferential stretch in a saturating linear manner. Rectal nerve afferents responded to compression with von Frey hairs with low thresholds (0.3-0.5 mN) and 3.4 ± 0.5 discrete, elongated mechanosensitive fields of innervation aligned parallel to circular muscle bundles (length = 62 ± 16 mm, n = 10). Anterogradely labeled rectal nerve axons typically passed through sparse irregular myenteric ganglia adjacent to the IAS, before ending in extensive varicose arrays within the circular muscle and, to a lesser extent, the longitudinal muscle overlying the IAS. Few (8%) IAS myenteric ganglia contained intraganglionic laminar endings. In eight preparations, mechanotransduction sites were mapped in combination with successful anterograde fills. Mechanotransduction sites were strongly associated with extensive fine varicose arrays within the circular muscle (P IAS are likely to correspond to extensive fine varicose arrays within the circular muscle. © 2010 Blackwell Publishing Ltd.

Cell-type specific short-term plasticity at auditory nerve synapses controls feed-forward inhibition in the dorsal cochlear nucleus

Directory of Open Access Journals (Sweden)

Miloslav eSedlacek

2014-07-01

Full Text Available Feedforward inhibition represents a powerful mechanism by which control of the timing and fidelity of action potentials in local synaptic circuits of various brain regions is achieved. In the cochlear nucleus, the auditory nerve provides excitation to both principal neurons and inhibitory interneurons. Here, we investigated the synaptic circuit associated with fusiform cells (FCs, principal neurons of the dorsal cochlear nucleus (DCN that receive excitation from auditory nerve fibers and inhibition from tuberculoventral cells (TVCs on their basal dendrites in the deep layer of DCN. Despite the importance of these inputs in regulating fusiform cell firing behavior, the mechanisms determining the balance of excitation and feed-forward inhibition in this circuit are not well understood. Therefore, we examined the timing and plasticity of auditory nerve driven feed-forward inhibition (FFI onto FCs. We find that in some FCs, excitatory and inhibitory components of feed-forward inhibition had the same stimulation thresholds indicating they could be triggered by activation of the same fibers. In other FCs, excitation and inhibition exhibit different stimulus thresholds, suggesting FCs and TVCs might be activated by different sets of fibers. In addition we find that during repetitive activation, synapses formed by the auditory nerve onto TVCs and FCs exhibit distinct modes of short-term plasticity. Feed-forward inhibitory post-synaptic currents (IPSCs in FCs exhibit short-term depression because of prominent synaptic depression at the auditory nerve-TVC synapse. Depression of this feedforward inhibitory input causes a shift in the balance of fusiform cell synaptic input towards greater excitation and suggests that fusiform cell spike output will be enhanced by physiological patterns of auditory nerve activity.

Cell-type specific short-term plasticity at auditory nerve synapses controls feed-forward inhibition in the dorsal cochlear nucleus.

Science.gov (United States)

Sedlacek, Miloslav; Brenowitz, Stephan D

2014-01-01

Feed-forward inhibition (FFI) represents a powerful mechanism by which control of the timing and fidelity of action potentials in local synaptic circuits of various brain regions is achieved. In the cochlear nucleus, the auditory nerve provides excitation to both principal neurons and inhibitory interneurons. Here, we investigated the synaptic circuit associated with fusiform cells (FCs), principal neurons of the dorsal cochlear nucleus (DCN) that receive excitation from auditory nerve fibers and inhibition from tuberculoventral cells (TVCs) on their basal dendrites in the deep layer of DCN. Despite the importance of these inputs in regulating fusiform cell firing behavior, the mechanisms determining the balance of excitation and FFI in this circuit are not well understood. Therefore, we examined the timing and plasticity of auditory nerve driven FFI onto FCs. We find that in some FCs, excitatory and inhibitory components of FFI had the same stimulation thresholds indicating they could be triggered by activation of the same fibers. In other FCs, excitation and inhibition exhibit different stimulus thresholds, suggesting FCs and TVCs might be activated by different sets of fibers. In addition, we find that during repetitive activation, synapses formed by the auditory nerve onto TVCs and FCs exhibit distinct modes of short-term plasticity. Feed-forward inhibitory post-synaptic currents (IPSCs) in FCs exhibit short-term depression because of prominent synaptic depression at the auditory nerve-TVC synapse. Depression of this feedforward inhibitory input causes a shift in the balance of fusiform cell synaptic input towards greater excitation and suggests that fusiform cell spike output will be enhanced by physiological patterns of auditory nerve activity.

Cholinergic innervation of human mesenteric lymphatic vessels.

Science.gov (United States)

D'Andrea, V; Bianchi, E; Taurone, S; Mignini, F; Cavallotti, C; Artico, M

2013-11-01

The cholinergic neurotransmission within the human mesenteric lymphatic vessels has been poorly studied. Therefore, our aim is to analyse the cholinergic nerve fibres of lymphatic vessels using the traditional enzymatic techniques of staining, plus the biochemical modifications of acetylcholinesterase (AChE) activity. Specimens obtained from human mesenteric lymphatic vessels were subjected to the following experimental procedures: 1) drawing, cutting and staining of tissues; 2) staining of total nerve fibres; 3) enzymatic staining of cholinergic nerve fibres; 4) homogenisation of tissues; 5) biochemical amount of proteins; 6) biochemical amount of AChE activity; 6) quantitative analysis of images; 7) statistical analysis of data. The mesenteric lymphatic vessels show many AChE positive nerve fibres around their wall with an almost plexiform distribution. The incubation time was performed at 1 h (partial activity) and 6 h (total activity). Moreover, biochemical dosage of the same enzymatic activity confirms the results obtained with morphological methods. The homogenates of the studied tissues contain strong AChE activity. In our study, the lymphatic vessels appeared to contain few cholinergic nerve fibres. Therefore, it is expected that perivascular nerve stimulation stimulates cholinergic nerves innervating the mesenteric arteries to release the neurotransmitter AChE, which activates muscarinic or nicotinic receptors to modulate adrenergic neurotransmission. These results strongly suggest, that perivascular cholinergic nerves have little or no effect on the adrenergic nerve function in mesenteric arteries. The cholinergic nerves innervating mesenteric arteries do not mediate direct vascular responses.

Selective pelvic autonomic nerve stimulation with simultaneous intraoperative monitoring of internal anal sphincter and bladder innervation.

Science.gov (United States)

Kneist, W; Kauff, D W; Koch, K P; Schmidtmann, I; Heimann, A; Hoffmann, K P; Lang, H

2011-01-01

Pelvic autonomic nerve preservation avoids postoperative functional disturbances. The aim of this feasibility study was to develop a neuromonitoring system with simultaneous intraoperative verification of internal anal sphincter (IAS) activity and intravesical pressure. 14 pigs underwent low anterior rectal resection. During intermittent bipolar electric stimulation of the inferior hypogastric plexus (IHP) and the pelvic splanchnic nerves (PSN), electromyographic signals of the IAS and manometry of the urinary bladder were observed simultaneously. Stimulation of IHP and PSN as well as simultaneous intraoperative monitoring could be realized with an adapted neuromonitoring device. Neurostimulation resulted in either bladder or IAS activation or concerted activation of both. Intravesical pressure increase as well as amplitude increase of the IAS neuromonitoring signal did not differ significantly between stimulation of IHP and PSN [6.0 cm H(2)O (interquartile range [IQR] 3.5-9.0) vs. 6.0 cm H(2)O (IQR 3.0-10.0) and 12.1 μV (IQR 3.0-36.7) vs. 40.1 μV (IQR 9.0-64.3)] (p > 0.05). Pelvic autonomic nerve stimulation with simultaneous intraoperative monitoring of IAS and bladder innervation is feasible. The method may enable neuromonitoring with increasing selectivity for pelvic autonomic nerve preservation. Copyright © 2011 S. Karger AG, Basel.

Innervation of the cow's inner ear derived from micro-computed tomography

Science.gov (United States)

Costeur, Loic; Mennecart, Bastien; Khimchenko, Anna; Müller, Bert; Schulz, Georg

2017-09-01

The innervation of the inner ear has been thoroughly investigated in humans and in some animal models such as the guinea pig, the rabbit, the cat, the dog, the rat, the pig and some monkeys. Ruminant inner ears are still poorly known and their innervation was never investigated despite its potential interest in phylogenetic reconstructions. Following earlier works on the ontogeny of the cow's ear, we expand our understanding of this structure by reconstructing the fine innervation pattern of the inner ear of the cow in two ontogenetic stages, at 7 months gestation and at an adult age. Since we work on dry skeletal specimens, only the endocast of the innervation inside the petrosal bone was reconstructed up to the internal acoustic meatus. The paths of the facial and vestibulocochlear nerves could be reconstructed together with that of the spiral ganglion canal. The nerves have a very fibrous pattern. The bony cavities of the ampular and utricular branches of the vestibulocochlear nerve could also be reconstructed. Our observations confirm that not all bony structures are present in foetal stages since the branch of cranial nerve VII is not visible on the foetus but very broad on the adult stage. The fibrous pattern within the modiolus connecting the spiral canal to the cochlear nerve is also less dense than in the adult stage. The shape of the branch of cranial nerve VII is very broad in the cow ending in a large hiatus Fallopii; this, together with the above-mentioned particularities, could constitute relevant observations for phylogenetical purposes when more data will be made available.

Development of the intrinsic and extrinsic innervation of the gut.

Science.gov (United States)

Uesaka, Toshihiro; Young, Heather M; Pachnis, Vassilis; Enomoto, Hideki

2016-09-15

The gastrointestinal (GI) tract is innervated by intrinsic enteric neurons and by extrinsic efferent and afferent nerves. The enteric (intrinsic) nervous system (ENS) in most regions of the gut consists of two main ganglionated layers; myenteric and submucosal ganglia, containing numerous types of enteric neurons and glial cells. Axons arising from the ENS and from extrinsic neurons innervate most layers of the gut wall and regulate many gut functions. The majority of ENS cells are derived from vagal neural crest cells (NCCs), which proliferate, colonize the entire gut, and first populate the myenteric region. After gut colonization by vagal NCCs, the extrinsic nerve fibers reach the GI tract, and Schwann cell precursors (SCPs) enter the gut along the extrinsic nerves. Furthermore, a subpopulation of cells in myenteric ganglia undergoes a radial (inward) migration to form the submucosal plexus, and the intrinsic and extrinsic innervation to the mucosal region develops. Here, we focus on recent progress in understanding the developmental processes that occur after the gut is colonized by vagal ENS precursors, and provide an up-to-date overview of molecular mechanisms regulating the development of the intrinsic and extrinsic innervation of the GI tract. Copyright © 2016 Elsevier Inc. All rights reserved.

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

Science.gov (United States)

Parkins, C W; Colombo, J

1987-12-31

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

[Efferent innervation of the arteries of human leptomeninx in arterial hypertension].

Science.gov (United States)

Chertok, V M; Kotsiuba, A E; Babich, E V

2009-01-01

Structure of the efferent nerve plexuses (adrenergic, acetylcholinestherase- and cholinacetyltranspherase-positive, NO-dependent), was studied in the arteries of human leptomeninx with different diameters. Material was obtained from the corpses of the healthy people and of the patients with initial stages of arterial hypertension (AH). It was shown that the concentrations of cholinergic and adrenergic nerve fibers and varicosities in axon terminal part, innervating the arteries with the diameters ranging from 450 till 100 microm, were not significantly different. In these arteries, NO-ergic plexuses were also detected. In patients with AH, regardless the arterial diameters, the significant increase (up to 15-20%) of adrenergic nerve fiber and varicosity concentrations was found. The changes in cholinergic nerve fiber concentration were found to depend on the vessel diameter: the significant decrease of these parameter was observed only in arteries with the diameter of 100-200 microm. No significant changes in nerve plexus concentration was noticed in the arteries with greater or smaller diameter. In NO-ergic neural conductors, the enzyme activity decreased only in the large arteries, and remained almost unchanged in the small vascular branches. The changes in the vasomotor innervation described in AH, are interpreted as a vasomotor innervation dysfunction of the leptomeninx arteries that may result in the hemodynamic disturbances.

Immunomodulation stimulates the innervation of engineered tooth organ.

Directory of Open Access Journals (Sweden)

Tunay Kökten

Full Text Available The sensory innervation of the dental mesenchyme is essential for tooth function and protection. Sensory innervation of the dental pulp is mediated by axons originating from the trigeminal ganglia and is strictly regulated in time. Teeth can develop from cultured re-associations between dissociated dental epithelial and mesenchymal cells from Embryonic Day 14 mouse molars, after implantation under the skin of adult ICR mice. In these conditions however, the innervation of the dental mesenchyme did not occur spontaneously. In order to go further with this question, complementary experimental approaches were designed. Cultured cell re-associations were implanted together with trigeminal ganglia for one or two weeks. Although axonal growth was regularly observed extending from the trigeminal ganglia to all around the forming teeth, the presence of axons in the dental mesenchyme was detected in less than 2.5% of samples after two weeks, demonstrating a specific impairment of their entering the dental mesenchyme. In clinical context, immunosuppressive therapy using cyclosporin A was found to accelerate the innervation of transplanted tissues. Indeed, when cultured cell re-associations and trigeminal ganglia were co-implanted in cyclosporin A-treated ICR mice, nerve fibers were detected in the dental pulp, even reaching odontoblasts after one week. However, cyclosporin A shows multiple effects, including direct ones on nerve growth. To test whether there may be a direct functional relationship between immunomodulation and innervation, cell re-associations and trigeminal ganglia were co-implanted in immunocompromised Nude mice. In these conditions as well, the innervation of the dental mesenchyme was observed already after one week of implantation, but axons reached the odontoblast layer after two weeks only. This study demonstrated that immunodepression per se does stimulate the innervation of the dental mesenchyme.

142 Key words: Brachialis, radial nerve, musculocutaneous nerve.

African Journals Online (AJOL)

AWORI KIRSTEEN

The innervation of brachialis muscle by the musculocutaneous nerve has been described as either type I or type II and the main trunk to this muscle is rarely absent. The contribution .... brachialis muscle by fiber analysis of supply nerves].

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

Science.gov (United States)

Kemp, A

2017-02-01

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

Autonomic cardiac innervation

Science.gov (United States)

Hasan, Wohaib

2013-01-01

Autonomic cardiac neurons have a common origin in the neural crest but undergo distinct developmental differentiation as they mature toward their adult phenotype. Progenitor cells respond to repulsive cues during migration, followed by differentiation cues from paracrine sources that promote neurochemistry and differentiation. When autonomic axons start to innervate cardiac tissue, neurotrophic factors from vascular tissue are essential for maintenance of neurons before they reach their targets, upon which target-derived trophic factors take over final maturation, synaptic strength and postnatal survival. Although target-derived neurotrophins have a central role to play in development, alternative sources of neurotrophins may also modulate innervation. Both developing and adult sympathetic neurons express proNGF, and adult parasympathetic cardiac ganglion neurons also synthesize and release NGF. The physiological function of these “non-classical” cardiac sources of neurotrophins remains to be determined, especially in relation to autocrine/paracrine sustenance during development.   Cardiac autonomic nerves are closely spatially associated in cardiac plexuses, ganglia and pacemaker regions and so are sensitive to release of neurotransmitter, neuropeptides and trophic factors from adjacent nerves. As such, in many cardiac pathologies, it is an imbalance within the two arms of the autonomic system that is critical for disease progression. Although this crosstalk between sympathetic and parasympathetic nerves has been well established for adult nerves, it is unclear whether a degree of paracrine regulation occurs across the autonomic limbs during development. Aberrant nerve remodeling is a common occurrence in many adult cardiovascular pathologies, and the mechanisms regulating outgrowth or denervation are disparate. However, autonomic neurons display considerable plasticity in this regard with neurotrophins and inflammatory cytokines having a central regulatory

Significance of bone changes at the meatus acusticus internus in tumours of the auditory nerve and in the 'empty' extended internal auditory meatus

Energy Technology Data Exchange (ETDEWEB)

Grehn, S.

1988-06-01

The unilateral extension of shortening of the internal auditory meatus is a very safe bony sign of the presence of a neurinoma of the auditory nerve. Differential diagnosis is necessary to exclude an 'empty' extended internal auditory meatus. On the other hand, 31% of the definitely established neurinomas do not show up in the plain tomogram. These facts prove that despite the presence or absence of allegedly definite bony changes at the internal auditory meatus further diagnostic measures are imperative, especially an air meatography in conjunction with high resolution computed tomography.

Noise Stress Induces an Epidermal Growth Factor Receptor/Xeroderma Pigmentosum-A Response in the Auditory Nerve.

Science.gov (United States)

Guthrie, O'neil W

2017-03-01

In response to toxic stressors, cancer cells defend themselves by mobilizing one or more epidermal growth factor receptor (EGFR) cascades that employ xeroderma pigmentosum-A (XPA) to repair damaged genes. Recent experiments discovered that neurons within the auditory nerve exhibit basal levels of EGFR+XPA co-expression. This finding implied that auditory neurons in particular or neurons in general have the capacity to mobilize an EGFR+XPA defense. Therefore, the current study tested the hypothesis that noise stress would alter the expression pattern of EGFR/XPA within the auditory nerve. Design-based stereology was used to quantify the proportion of neurons that expressed EGFR, XPA, and EGFR+XPA with and without noise stress. The results revealed an intricate neuronal response that is suggestive of alterations to both co-expression and individual expression of EGFR and XPA. In both the apical and middle cochlear coils, the noise stress depleted EGFR+XPA expression. Furthermore, there was a reduction in the proportion of neurons that expressed XPA-alone in the middle coils. However, the noise stress caused a significant increase in the proportion of neurons that expressed EGFR-alone in the middle coils. The basal cochlear coils failed to mobilize a significant response to the noise stress. These results suggest that EGFR and XPA might be part of the molecular defense repertoire of the auditory nerve.

Noise Stress Induces an Epidermal Growth Factor Receptor/Xeroderma Pigmentosum–A Response in the Auditory Nerve

Science.gov (United States)

Guthrie, O’neil W.

2017-01-01

In response to toxic stressors, cancer cells defend themselves by mobilizing one or more epidermal growth factor receptor (EGFR) cascades that employ xeroderma pigmentosum–A (XPA) to repair damaged genes. Recent experiments discovered that neurons within the auditory nerve exhibit basal levels of EGFR+XPA co-expression. This finding implied that auditory neurons in particular or neurons in general have the capacity to mobilize an EGFR+XPA defense. Therefore, the current study tested the hypothesis that noise stress would alter the expression pattern of EGFR/XPA within the auditory nerve. Design-based stereology was used to quantify the proportion of neurons that expressed EGFR, XPA, and EGFR+XPA with and without noise stress. The results revealed an intricate neuronal response that is suggestive of alterations to both co-expression and individual expression of EGFR and XPA. In both the apical and middle cochlear coils, the noise stress depleted EGFR+XPA expression. Furthermore, there was a reduction in the proportion of neurons that expressed XPA-alone in the middle coils. However, the noise stress caused a significant increase in the proportion of neurons that expressed EGFR-alone in the middle coils. The basal cochlear coils failed to mobilize a significant response to the noise stress. These results suggest that EGFR and XPA might be part of the molecular defense repertoire of the auditory nerve. PMID:28056182

Towards Clinical Application of Neurotrophic Factors to the Auditory Nerve; Assessment of Safety and Efficacy by a Systematic Review of Neurotrophic Treatments in Humans

NARCIS (Netherlands)

Bezdjian, Aren; Kraaijenga, Véronique J C; Ramekers, Dyan; Versnel, Huib; Thomeer, Hans G X M; Klis, Sjaak F L; Grolman, Wilko

2016-01-01

Animal studies have evidenced protection of the auditory nerve by exogenous neurotrophic factors. In order to assess clinical applicability of neurotrophic treatment of the auditory nerve, the safety and efficacy of neurotrophic therapies in various human disorders were systematically reviewed.

Is it time for cardiac innervation imaging?

Energy Technology Data Exchange (ETDEWEB)

Knuuti, J. [Turku Univ., Turku (Finland) Turku PET Center; Sipola, P. [Kuopio Univ., Kuopio (Finland)

2005-03-01

The autonomic nervous system plays an important role in the regulation of cardiac function and the regional distribution of cardiac nerve terminals can be visualized using scintigraphic techniques. The most commonly used tracer is iodine-123-metaiodobenzylguanidine (MIBG) but C-11-hydroxyephedrine has also been used with PET. When imaging with MIBG, the ratio of heart-to-mediastinal counts is used as an index of tracer uptake, and regional distribution is also assessed from tomographic images. The rate of clearance of the tracer can also be measured and indicates the function of the adrenergic system. Innervation imaging has been applied in patients with susceptibility to arrythmias, coronary artery disease, hypertrophic and dilated cardiomyopathy and anthracycline induced cardiotoxicity. Abnormal adrenergic innervation or function appear to exist in many pathophysiological conditions indicating that sympathetic neurons are very susceptible to damage. Abnormal findings in innervation imaging also appear to have significant prognostic value especially in patients with cardiomyopathy. Recently, it has also been shown that innervation imaging can monitor drug-induced changes in cardiac adrenergic activity. Although innervation imaging holds great promise for clinical use, the method has not received wider clinical acceptance. Larger randomized studies are required to confirm the value of innervation imaging in various specific indications.

Reduced Sympathetic Innervation in Endometriosis is Associated to Semaphorin 3C and 3F Expression.

Science.gov (United States)

Scheerer, Claudia; Frangini, Sergio; Chiantera, Vito; Mechsner, Sylvia

2017-09-01

Endometriosis is a chronic inflammatory disease and one of the most common causes of pelvic pain. The mechanisms underlying pain emergence or chronic inflammation during endometriosis remain unknown. Several chronic inflammatory diseases including endometriosis show reduced amounts of noradrenergic nerve fibers. The source of the affected innervation is still unclear. Semaphorins represent potential elicitors, due to their known role as axonal guidance cues, and are suggested as nerve repellent factors in different chronic inflammatory diseases. Therefore, semaphorins might influence the progress of neuroinflammatory mechanisms during endometriosis. Here, we analyzed the noradrenergic innervation and the expression of the specific semaphorins and receptors possibly involved in the neuroimmunomodulation in endometriosis. Our studies revealed an affected innervation and a significant increase of semaphorins and their receptors in peritoneal endometriotic tissue. Thereby, the expression of the receptors was identified on the membrane of noradrenergic nerve fibers and vessels. Macrophages and activated fibroblasts were found in higher density levels and additionally express semaphorins in peritoneal endometriotic tissue. Inflammation leads to an increased release of immune cells, which secrete a variety of inflammatory factors capable of affecting innervation. Therefore, our data suggests that the chronic inflammatory condition in endometriosis might contribute to the increase of semaphorins, which could possibly affect the innervation in peritoneal endometriosis.

Innervation and immunohistochemical characteristics of epididymis in Alpaca camelid (Vicugna pacos

Directory of Open Access Journals (Sweden)

Giovanna Liguori

2013-03-01

Full Text Available Alpacas (Vicugna pacos are domesticated camelids indigenous to south America and recently also bred in Europe and Italy for their high quality wool. There is little data available regarding the innervation of the male reproductive tract of this species. In the present study, the distribution of protein gene product 9.5 (PGP 9.5, neuropeptide Y (NPY, tyrosine hydroxilase (TH, calcitonin gene related peptide (CGRP and substance P (SP was analyzed in the epididymis by using immunohistochemical methods. Specimens of the caput, corpus and cauda epididymis were fixed in Bouin’s fluid and processed for immunohistochemistry analysis with primary antibodies against PGP 9.5, NPY, TH, CGRP and SP. Immunopositivity to PGP 9.5 and TH and NPY was observed in nerve fibre bundles and in single nerve fibres contained into the peritubular connective tissue. Many TH and NPY immunopositive cells were found to innervate blood vessels. Rare CGRP and SP immunopositive nerves were observed. Several PGP 9,5 and NPY immunopositive epithelial cells were observed in the caput epididymis. The results of the present study suggest a role for the innervations in modulate reproductive functions in the alpaca epididymis.

The human thoracic duct is functionally innervated by adrenergic nerves

DEFF Research Database (Denmark)

Telinius, Niklas; Baandrup, Ulrik; Rumessen, Jüri Johs.

2013-01-01

) that is predominantly adrenergic. TDs harvested from 51 patients undergoing esophageal and cardia cancer surgery were either fixed for structural investigations or maintained in vitro for the functional assessment of innervation by isometric force measurements and electrical field stimulation (EFS). Electron microscopy......, and methacholine was demonstrated by exogenous application to human TD ring segments. Norepinephrine provided the most consistent responses, whereas responses to the other agonists varied. We conclude that the human TD is functionally innervated with both cholinergic and adrenergic components, with the latter...

The cochlear nerve canal and internal auditory canal in children with normal cochlea but cochlear nerve deficiency

International Nuclear Information System (INIS)

Yan, Fei; Li, Jianhong; Xian, Junfang; Wang, Zhenchang; Mo, Lingyan

2013-01-01

Background: There is an increasing frequency of requests for cochlear implantation (CI) in deaf children and more detailed image information is necessary for selecting appropriate candidates. Cochlear nerve deficiency (CND) is a contraindication to CI. Magnetic resonance imaging (MRI) has been used to evaluate the integrity of the cochlear nerve. The abnormalities of the cochlear nerve canal (CNC) and internal auditory canal (IAC) have been reported to be associated with CND. Purpose: To correlate CNC manifestation, size, and IAC diameter on high-resolution CT (HRCT) with CND diagnosed by MRI in children. Material and Methods: HRCT images from 35 sensorineurally deaf children who had normal cochlea but bilateral or unilateral CND diagnosed by MRI were studied retrospectively. The CNC and IAC manifestation and size were assessed and correlated with CND. Results: CND was diagnosed by MRI in 54/70 ears (77.1%). Thirty-two ears had an absent cochlear nerve (59.3%), while 22 ears had a small cochlear nerve (40.7%). The CNC diameter was 2.0 mm in 11 ears (20.4%). The IAC diameter was 3.0 mm in 29 ears (53.7%). Conclusion: The hypoplastic CNC might be more highly indicative of CND than that of a narrow IAC

Endodontic periapical lesion-induced mental nerve paresthesia

Science.gov (United States)

Shadmehr, Elham; Shekarchizade, Neda

2015-01-01

Paresthesia is a burning or prickling sensation or partial numbness, resulting from neural injury. The symptoms can vary from mild neurosensory dysfunction to total loss of sensation in the innervated area. Only a few cases have described apical periodontitis to be the etiological factor of impaired sensation in the area innervated by the inferior alveolar and mental nerves. The aim of the present paper is to report a case of periapical lesion-induced paresthesia in the innervation area of the mental nerve, which was successfully treated with endodontic retreatment. PMID:25878687

Innervation of the thick ascending limb of Henle

International Nuclear Information System (INIS)

Barajas, L.; Powers, K.V.

1988-01-01

The overlap of accumulations of autoradiographic grains (AAGs) on profiles of the thick ascending limb of Henle (TALH) was measured in autoradiograms of sections from rat kidneys with monoaminergic nerves labeled by means of tritiated norepinephrine. The amount of AAG overlap was used as an indirect means of quantifying innervation along the TALHs of superficial, mid-cortical, and juxtamedullary nephrons. The density of innervation along the TALH showed nephron heterogeneity; the juxtamedullary nephrons with a high pre- and postjuxtaglomerular apparatus (JGA) TALH density of innervation and the upper and midcortical nephrons with high TALH innervation densities at the level of the JGA. The pre-JGA TALH of the juxtamedullary nephrons had a significantly higher (P less than 0.001) density of innervation than the midcortical or superficial nephrons. The TALHs of juxtamedullary nephrons were found to have substantially more innervation than the TALHs of the other nephrons. For all three populations of nephrons, the pre-JGA TALH had the greatest amount of innervation. Neural regulation of TALH function would occur mainly along the pre-JGA and level of the JGA TALH. This regulation would increase TALH NaCl reabsorption (decrease luminal NaCl concentration) and therefore influence 1) the urinary concentrating mechanism, and 2) renin secretion via the macula densa mechanism. The innervation of the TALH was predominantly associated with the vasculature of the TALH's own nephron. However, innervation associated with medullary ray capillary beds from deeper nephrons was observed on pre-JGA TALHs from superficial and midcortical nephrons

Innervation of the thick ascending limb of Henle

Energy Technology Data Exchange (ETDEWEB)

Barajas, L.; Powers, K.V.

1988-08-01

The overlap of accumulations of autoradiographic grains (AAGs) on profiles of the thick ascending limb of Henle (TALH) was measured in autoradiograms of sections from rat kidneys with monoaminergic nerves labeled by means of tritiated norepinephrine. The amount of AAG overlap was used as an indirect means of quantifying innervation along the TALHs of superficial, mid-cortical, and juxtamedullary nephrons. The density of innervation along the TALH showed nephron heterogeneity; the juxtamedullary nephrons with a high pre- and postjuxtaglomerular apparatus (JGA) TALH density of innervation and the upper and midcortical nephrons with high TALH innervation densities at the level of the JGA. The pre-JGA TALH of the juxtamedullary nephrons had a significantly higher (P less than 0.001) density of innervation than the midcortical or superficial nephrons. The TALHs of juxtamedullary nephrons were found to have substantially more innervation than the TALHs of the other nephrons. For all three populations of nephrons, the pre-JGA TALH had the greatest amount of innervation. Neural regulation of TALH function would occur mainly along the pre-JGA and level of the JGA TALH. This regulation would increase TALH NaCl reabsorption (decrease luminal NaCl concentration) and therefore influence 1) the urinary concentrating mechanism, and 2) renin secretion via the macula densa mechanism. The innervation of the TALH was predominantly associated with the vasculature of the TALH's own nephron. However, innervation associated with medullary ray capillary beds from deeper nephrons was observed on pre-JGA TALHs from superficial and midcortical nephrons.

Transposition of branches of radial nerve innervating supinator to posterior interosseous nerve for functional reconstruction of finger and thumb extension in 4 patients with middle and lower trunk root avulsion injuries of brachial plexus.

Science.gov (United States)

Wu, Xia; Cong, Xiao-Bing; Huang, Qi-Shun; Ai, Fang-Xin; Liu, Yu-Tian; Lu, Xiao-Cheng; Li, Jin; Weng, Yu-Xiong; Chen, Zhen-Bing

2017-12-01

This study aimed to investigate the reconstruction of the thumb and finger extension function in patients with middle and lower trunk root avulsion injuries of the brachial plexus. From April 2010 to January 2015, we enrolled in this study 4 patients diagnosed with middle and lower trunk root avulsion injuries of the brachial plexus via imaging tests, electrophysiological examinations, and clinical confirmation. Muscular branches of the radial nerve, which innervate the supinator in the forearm, were transposed to the posterior interosseous nerve to reconstruct the thumb and finger extension function. Electrophysiological findings and muscle strength of the extensor pollicis longus and extensor digitorum communis, as well as the distance between the thumb tip and index finger tip, were monitored. All patients were followed up for 24 to 30 months, with an average of 27.5 months. Motor unit potentials (MUP) of the extensor digitorum communis appeared at an average of 3.8 months, while MUP of the extensor pollicis longus appeared at an average of 7 months. Compound muscle action potential (CMAP) appeared at an average of 9 months in the extensor digitorum communis, and 12 months in the extensor pollicis longus. Furthermore, the muscle strength of the extensor pollicis longus and extensor digitorum communis both reached grade III at 21 months. Lastly, the average distance between the thumb tip and index finger tip was 8.8 cm at 21 months. In conclusion, for patients with middle and lower trunk injuries of the brachial plexus, transposition of the muscular branches of the radial nerve innervating the supinator to the posterior interosseous nerve for the reconstruction of thumb and finger extension function is practicable and feasible.

[Motor nerves of the face. Surgical and radiologic anatomy of facial paralysis and their surgical repair].

Science.gov (United States)

Vacher, C; Cyna-Gorse, F

2015-10-01

Motor innervation of the face depends on the facial nerve for the mobility of the face, on the mandibular nerve, third branch of the trigeminal nerve, which gives the motor innervation of the masticator muscles, and the hypoglossal nerve for the tongue. In case of facial paralysis, the most common palliative surgical techniques are the lengthening temporalis myoplasty (the temporal is innervated by the mandibular nerve) and the hypoglossal-facial anastomosis. The aim of this work is to describe the surgical anatomy of these three nerves and the radiologic anatomy of the facial nerve inside the temporal bone. Then the facial nerve penetrates inside the parotid gland giving a plexus. Four branches of the facial nerve leave the parotid gland: they are called temporal, zygomatic, buccal and marginal which give innervation to the cutaneous muscles of the face. Mandibular nerve gives three branches to the temporal muscles: the anterior, intermediate and posterior deep temporal nerves which penetrate inside the deep aspect of the temporal muscle in front of the infratemporal line. The hypoglossal nerve is only the motor nerve to the tongue. The ansa cervicalis, which is coming from the superficial cervical plexus and joins the hypoglossal nerve in the submandibular area is giving the motor innervation to subhyoid muscles and to the geniohyoid muscle. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Delayed peripheral nerve repair: methods, including surgical ?cross-bridging? to promote nerve regeneration

OpenAIRE

Gordon, Tessa; Eva, Placheta; Borschel, Gregory H.

2015-01-01

Despite the capacity of Schwann cells to support peripheral nerve regeneration, functional recovery after nerve injuries is frequently poor, especially for proximal injuries that require regenerating axons to grow over long distances to reinnervate distal targets. Nerve transfers, where small fascicles from an adjacent intact nerve are coapted to the nerve stump of a nearby denervated muscle, allow for functional return but at the expense of reduced numbers of innervating nerves. A 1-hour per...

Experimental study of motor nerve innervation of uvala muscle%悬雍垂肌运动神经支配的实验研究

Institute of Scientific and Technical Information of China (English)

仲维剑; 张奎启; 王宏青

2001-01-01

目的探讨悬雍垂肌运动神经来源及走行路径。方法以家兔为研究对象，应用辣根过氧化物酶（horseridish peroxidase，HRP）逆行追踪技术，配合使用颅内的脑神经根切断术。结果悬雍垂肌的运动神经元位于同侧疑核中；切断一侧副神经延脑根后，疑核内的标记神经元消失。结论悬雍垂肌是疑核内运动神经元的轴突，经副神经延脑根出颅，再经由迷走神经咽支进行支配。%Objective　To investigate the motor nerve innervation of uvala muscle. Methods　Horseridish peroxidase (HRP) retrograde tracing technique was used in conjunction with selective intracranial severing of cranial nerve rootlets in 8 rabbies. Results　Following HRP injection into uvala muscles, labeled motoneurons were located in the rostral section of nucleus ambiguus. No labeled motoneurons were found in the facial nucleus. Labled motoneurons were ipslaterally abolished after the cranial rootlets of accessory nerve on one side were intracranially severed. Conclusions　Uvala muscles are innervated by the motoneurons in the nucleus ambiguus. The axons of those motoneurons come out of the cranium through the cranial rootlet of the accessory nerve, then join the vagus， distributed via the pharyngeal branches of vagus.

Anatomy of the trigeminal nerve

NARCIS (Netherlands)

van Eijden, T.M.G.J.; Langenbach, G.E.J.; Baart, J.A.; Brand, H.S.

2017-01-01

The trigeminal nerve is the fifth cranial nerve (n. V), which plays an important role in the innervation of the head and neck area, together with other cranial and spinal nerves. Knowledge of the nerve’s anatomy is very important for the correct application of local anaesthetics.

Sensory innervation of the temporomandibular joint in the mouse.

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Dreessen, D; Halata, Z; Strasmann, T

1990-01-01

The sensory innervation of the temporomandibular joints (TMJs) of 8 STR/IN mice was investigated by means of light and electron microscopy. Through the cutting of complete semithin sections in series it was possible to investigate the joints thoroughly. Additionally, one joint with its nerve supply was reconstructed three-dimensionally with a computerized three-dimensional programme. The reconstruction was based on one complete semithin section series. The joint's nerve supply originates from the nervus auriculotemporalis and additionally from motor branches of the n. mandibularis: n. massetericus, n. pterygoideus lateralis and the nn. temporales posteriores. The greatest number of nerve fibres and endings is located in the dorsolateral part of the joint capsule. They lie only in the stratum fibrosum and subsynovially. Neither the stratum synoviale nor the discus articularis contain any nerve fibres or endings, whereas the peri-articular loose connective tissue is richly innervated. The only type of nerve ending observed within the joint was the free nerve ending, which is assumed to serve not only as a nociceptor but also as a polymodal mechanoreceptor. Merely within the insertion of the musculus pterygoideus lateralis at the collum mandibulae single stretch receptors of the Ruffini type were observed. Ultrastructurally, they correspond to those described in the cat's knee joint. Neither lamellated nor nerve endings of the Golgi or Pacini type were observed in the joint or in the peri-articular connective tissue. The unexpected paucity of nerve fibres and endings in the TMJ itself of the mouse suggests that the afferent information from the joint is less important for position sense and movement than the afferent information from muscles, tendons and periodontal ligaments.

Innervation of the sheep pineal gland by nonsympathetic nerve fibers containing NADPH-diaphorase activity

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López-Figueroa, Manuel O.; Ravault, Jean-Paul; Cozzi, Bruno

1997-01-01

Neuroanatomy, NADPH-diaphorase, nitric oxide, innervation, superior cervical ganglionectomy, neuropeptide Y.......Neuroanatomy, NADPH-diaphorase, nitric oxide, innervation, superior cervical ganglionectomy, neuropeptide Y....

Anatomical aspects of the nerves of the leg and foot of the giant anteater (Myrmecophaga tridactyla, Linnaeus, 1758

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V.S. Cruz

2014-10-01

Full Text Available Although distal stifle joint nerve distribution has been well established in domestic animals, this approach is scarcely reported in wild animals. Therefore, the aim of this study was to describe the nerves of the leg and foot of Myrmecophaga tridactyla with emphasis on their ramification, distribution, topography and territory of innervation. For this purpose, six adult cadavers fixed and preserved in 10% formalin solution were used. The nerves of the leg and foot of the M. tridactyla were the saphenous nerve (femoral nerve branch, fibular and tibial nerves and lateral sural cutaneous nerve (branches of the sciatic nerve and caudal sural cutaneous nerve (tibial nerve branch. The saphenous nerve branches to the skin, the craniomedial surface of the leg, the medial surface of the tarsal and metatarsal regions and the dorsomedial surface of the digits I and II (100% of cases, III (50% of cases and IV (25% of cases. The lateral sural cutaneous nerve innervates the skin of the craniolateral region of the knee and leg. The fibular nerve innervates the flexor and extensor muscles of the tarsal region of the digits and skin of the craniolateral surface of the leg and dorsolateral surface of the foot. The tibial nerve innervates the extensor muscles of the tarsal joint and flexor, adductor and abductor muscles of the digits and the skin of the plantar surface. The caudal sural cutaneous nerve innervates the skin of the caudal surface of the leg. The nerves responsible for the leg and foot innervation were the same as reported in domestic and wild animals, but with some differences, such as the more distal division of the common fibular nerve, the absence of dorsal metatarsal branches of the deep fibular nerve and a greater involvement of the saphenous nerve in the digital innervation with branches to the digits III and IV, in addition to digits I and II.

Loss of Sympathetic Nerves in Spleens from Patients with End Stage Sepsis

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Donald B. Hoover

2017-12-01

Full Text Available The spleen is an important site for central regulation of immune function by noradrenergic sympathetic nerves, but little is known about this major region of neuroimmune communication in humans. Experimental studies using animal models have established that sympathetic innervation of the spleen is essential for cholinergic anti-inflammatory responses evoked by vagal nerve stimulation, and clinical studies are evaluating this approach for treating inflammatory diseases. Most data on sympathetic nerves in spleen derive from rodent studies, and this work has established that remodeling of sympathetic innervation can occur during inflammation. However, little is known about the effects of sepsis on spleen innervation. Our primary goals were to (i localize noradrenergic nerves in human spleen by immunohistochemistry for tyrosine hydroxylase (TH, a specific noradrenergic marker, (ii determine if nerves occur in close apposition to leukocytes, and (iii determine if splenic sympathetic innervation is altered in patients who died from end stage sepsis. Staining for vesicular acetylcholine transporter (VAChT was done to screen for cholinergic nerves. Archived paraffin tissue blocks were used. Control samples were obtained from trauma patients or patients who died after hemorrhagic stroke. TH + nerves were associated with arteries and arterioles in all control spleens, occurring in bundles or as nerve fibers. Individual TH + nerve fibers entered the perivascular region where some appeared in close apposition to leukocytes. In marked contrast, spleens from half of the septic patients lacked TH + nerves fibers and the average abundance of TH + nerves for the septic group was only 16% of that for the control group (control: 0.272 ± 0.060% area, n = 6; sepsis: 0.043 ± 0.026% area, n = 8; P < 0.005. All spleens lacked cholinergic innervation. Our results provide definitive evidence for the distribution of noradrenergic

Innervation of the Anterior Sacroiliac Joint.

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Cox, Marcus; Ng, Garrett; Mashriqi, Faizullah; Iwanaga, Joe; Alonso, Fernando; Tubbs, Kevin; Loukas, Marios; Oskouian, Rod J; Tubbs, R Shane

2017-11-01

Sacroiliac joint pain can be disabling and recalcitrant to medical therapy. The innervation of this joint is poorly understood, especially its anterior aspect. Therefore, the present cadaveric study was performed to better elucidate this anatomy. Twenty-four cadaveric sides underwent dissection of the anterior sacroiliac joint, with special attention given to any branches from regional nerves to this joint. No femoral, obturator, or lumbosacral trunk branches destined to the anterior sacroiliac joint were identified in the 24 sides. In 20 sides, one or two small branches (less than 0.5 mm in diameter) were found to arise from the L4 ventral ramus (10%), the L5 ventral ramus (80%), or simultaneously from both the L4 and L5 ventral rami (10%). The length of the branches ranged from 5 to 31 mm (mean, 14 mm). All these branches arose from the posterior part of the nerves and traveled to the anterior surface of the sacroiliac joint. No statistical significance was found between sides or sexes. An improved knowledge of the innervation of the anterior sacroiliac joint might decrease suffering in patients with chronic sacroiliac joint pain. Copyright © 2017 Elsevier Inc. All rights reserved.

The cochlear nerve canal and internal auditory canal in children with normal cochlea but cochlear nerve deficiency

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Yan, Fei; Li, Jianhong; Xian, Junfang; Wang, Zhenchang [Dept. of Radiology, Beijing Tongren Hospital, Capital Medical Univ., Beijing (China)], e-mail: cjr.wzhch@vip.163.com; Mo, Lingyan [Dept. of Otorhinolaryngology, Beijing Tongren Hospital, Capital Medical Univ., Beijing (China)

2013-04-15

Background: There is an increasing frequency of requests for cochlear implantation (CI) in deaf children and more detailed image information is necessary for selecting appropriate candidates. Cochlear nerve deficiency (CND) is a contraindication to CI. Magnetic resonance imaging (MRI) has been used to evaluate the integrity of the cochlear nerve. The abnormalities of the cochlear nerve canal (CNC) and internal auditory canal (IAC) have been reported to be associated with CND. Purpose: To correlate CNC manifestation, size, and IAC diameter on high-resolution CT (HRCT) with CND diagnosed by MRI in children. Material and Methods: HRCT images from 35 sensorineurally deaf children who had normal cochlea but bilateral or unilateral CND diagnosed by MRI were studied retrospectively. The CNC and IAC manifestation and size were assessed and correlated with CND. Results: CND was diagnosed by MRI in 54/70 ears (77.1%). Thirty-two ears had an absent cochlear nerve (59.3%), while 22 ears had a small cochlear nerve (40.7%). The CNC diameter was <1.5 mm in 36 ears (66.7%). The CNC diameter ranged between 1.5 and 2.0 mm in seven ears (13.0%) and was >2.0 mm in 11 ears (20.4%). The IAC diameter was <3.0 mm in 25 ears (46.3%) and >3.0 mm in 29 ears (53.7%). Conclusion: The hypoplastic CNC might be more highly indicative of CND than that of a narrow IAC.

Needle in the external auditory canal: an unusual complication of inferior alveolar nerve block.

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Ribeiro, Leandro; Ramalho, Sara; Gerós, Sandra; Ferreira, Edite Coimbra; Faria e Almeida, António; Condé, Artur

2014-06-01

Inferior alveolar nerve block is used to anesthetize the ipsilateral mandible. The most commonly used technique is one in which the anesthetic is injected directly into the pterygomandibular space, by an intraoral approach. The fracture of the needle, although uncommon, can lead to potentially serious complications. The needle is usually found in the pterygomandibular space, although it can migrate and damage adjacent structures, with variable consequences. The authors report an unusual case of a fractured needle, migrating to the external auditory canal, as a result of an inferior alveolar nerve block. Copyright © 2014 Elsevier Inc. All rights reserved.

Sympathetic Innervation Promotes Arterial Fate by Enhancing Endothelial ERK Activity.

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Pardanaud, Luc; Pibouin-Fragner, Laurence; Dubrac, Alexandre; Mathivet, Thomas; English, Isabel; Brunet, Isabelle; Simons, Michael; Eichmann, Anne

2016-08-19

Arterial endothelial cells are morphologically, functionally, and molecularly distinct from those found in veins and lymphatic vessels. How arterial fate is acquired during development and maintained in adult vessels is incompletely understood. We set out to identify factors that promote arterial endothelial cell fate in vivo. We developed a functional assay, allowing us to monitor and manipulate arterial fate in vivo, using arteries isolated from quails that are grafted into the coelom of chick embryos. Endothelial cells migrate out from the grafted artery, and their colonization of host arteries and veins is quantified. Here we show that sympathetic innervation promotes arterial endothelial cell fate in vivo. Removal of sympathetic nerves decreases arterial fate and leads to colonization of veins, whereas exposure to sympathetic nerves or norepinephrine imposes arterial fate. Mechanistically, sympathetic nerves increase endothelial ERK (extracellular signal-regulated kinase) activity via adrenergic α1 and α2 receptors. These findings show that sympathetic innervation promotes arterial endothelial fate and may lead to novel approaches to improve arterialization in human disease. © 2016 American Heart Association, Inc.

Modeling auditory-nerve responses to electrical stimulation

DEFF Research Database (Denmark)

Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

2014-01-01

μs, which is large enough to affect the temporal coding of sounds and hence, potentially, the communication abilities of the CI listener. In the present study, two recently proposed models of electric stimulation of the AN [1,2] were considered in terms of their efficacy to predict the spike timing...... for anodic and cathodic stimulation of the AN of cat [3]. The models’ responses to the electrical pulses of various shapes [4,5,6] were also analyzed. It was found that, while the models can account for the firing rates in response to various biphasic pulse shapes, they fail to correctly describe the timing......Cochlear implants (CI) directly stimulate the auditory nerve (AN), bypassing the mechano-electrical transduction in the inner ear. Trains of biphasic, charge balanced pulses (anodic and cathodic) are used as stimuli to avoid damage of the tissue. The pulses of either polarity are capable...

Communication between radial nerve and medial cutaneous nerve of forearm

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R R Marathe

2010-01-01

Full Text Available Radial nerve is usually a branch of the posterior cord of the brachial plexus. It innervates triceps, anconeous, brachialis, brachioradialis, extensor carpi radialis longus muscles and gives the posterior cutaneous nerve of the arm, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of forearm; without exhibiting any communication with the medial cutaneous nerve of forearm or any other nerve. We report communication between the radial nerve and medial cutaneous nerve of forearm on the left side in a 58-year-old male cadaver. The right sided structures were found to be normal. Neurosurgeons should keep such variations in mind while performing the surgeries of axilla and upper arm.

The vestibulocochlear nerve (VIII).

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

2013-10-01

The vestibulocochlear nerve (8th cranial nerve) is a sensory nerve. It is made up of two nerves, the cochlear, which transmits sound and the vestibular which controls balance. It is an intracranial nerve which runs from the sensory receptors in the internal ear to the brain stem nuclei and finally to the auditory areas: the post-central gyrus and superior temporal auditory cortex. The most common lesions responsible for damage to VIII are vestibular Schwannomas. This report reviews the anatomy and various investigations of the nerve. Copyright © 2013. Published by Elsevier Masson SAS.

Time course of dynamic range adaptation in the auditory nerve

Science.gov (United States)

Wang, Grace I.; Dean, Isabel; Delgutte, Bertrand

2012-01-01

Auditory adaptation to sound-level statistics occurs as early as in the auditory nerve (AN), the first stage of neural auditory processing. In addition to firing rate adaptation characterized by a rate decrement dependent on previous spike activity, AN fibers show dynamic range adaptation, which is characterized by a shift of the rate-level function or dynamic range toward the most frequently occurring levels in a dynamic stimulus, thereby improving the precision of coding of the most common sound levels (Wen B, Wang GI, Dean I, Delgutte B. J Neurosci 29: 13797–13808, 2009). We investigated the time course of dynamic range adaptation by recording from AN fibers with a stimulus in which the sound levels periodically switch from one nonuniform level distribution to another (Dean I, Robinson BL, Harper NS, McAlpine D. J Neurosci 28: 6430–6438, 2008). Dynamic range adaptation occurred rapidly, but its exact time course was difficult to determine directly from the data because of the concomitant firing rate adaptation. To characterize the time course of dynamic range adaptation without the confound of firing rate adaptation, we developed a phenomenological “dual adaptation” model that accounts for both forms of AN adaptation. When fitted to the data, the model predicts that dynamic range adaptation occurs as rapidly as firing rate adaptation, over 100–400 ms, and the time constants of the two forms of adaptation are correlated. These findings suggest that adaptive processing in the auditory periphery in response to changes in mean sound level occurs rapidly enough to have significant impact on the coding of natural sounds. PMID:22457465

Afferent nerves regulating the cough reflex: Mechanisms and Mediators of Cough in Disease

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Canning, Brendan J.

2010-01-01

Bronchopulmonary C-fibers and acid-sensitive, capsaicin-insensitive mechanoreceptors innervating the larynx, trachea and large bronchi regulate the cough reflex. These vagal afferent nerves may interact centrally with sensory input arising from afferent nerves innervating the intrapulmonary airways or even extrapulmonary afferents such as those innervating the nasal mucosa and esophagus to produce chronic cough or enhanced cough responsiveness. The mechanisms of cough initiation in health and in disease are briefly described. PMID:20172253

Effect of Bluetooth headset and mobile phone electromagnetic fields on the human auditory nerve.

Science.gov (United States)

Mandalà, Marco; Colletti, Vittorio; Sacchetto, Luca; Manganotti, Paolo; Ramat, Stefano; Marcocci, Alessandro; Colletti, Liliana

2014-01-01

The possibility that long-term mobile phone use increases the incidence of astrocytoma, glioma and acoustic neuroma has been investigated in several studies. Recently, our group showed that direct exposure (in a surgical setting) to cell phone electromagnetic fields (EMFs) induces deterioration of auditory evoked cochlear nerve compound action potential (CNAP) in humans. To verify whether the use of Bluetooth devices reduces these effects, we conducted the present study with the same experimental protocol. Randomized trial. Twelve patients underwent retrosigmoid vestibular neurectomy to treat definite unilateral Ménière's disease while being monitored with acoustically evoked CNAPs to assess direct mobile phone exposure or alternatively the EMF effects of Bluetooth headsets. We found no short-term effects of Bluetooth EMFs on the auditory nervous structures, whereas direct mobile phone EMF exposure confirmed a significant decrease in CNAPs amplitude and an increase in latency in all subjects. The outcomes of the present study show that, contrary to the finding that the latency and amplitude of CNAPs are very sensitive to EMFs produced by the tested mobile phone, the EMFs produced by a common Bluetooth device do not induce any significant change in cochlear nerve activity. The conditions of exposure, therefore, differ from those of everyday life, in which various biological tissues may reduce the EMF affecting the cochlear nerve. Nevertheless, these novel findings may have important safety implications. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

The sympathetic innervation of the heart: Important new insights.

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Coote, J H; Chauhan, R A

2016-08-01

Autonomic control of the heart has a significant influence over development of life threatening arrhythmias that can lead to sudden cardiac death. Sympathetic activity is known to be upregulated during these conditions and hence the sympathetic nerves present a target for treatment. However, a better understanding of the anatomy and physiology of cardiac sympathetic nerves is required for the progression of clinical interventions. This review explores the organization of the cardiac sympathetic nerves, from the preganglionic origin to the postganglionic innervations, and provides an overview of literature surrounding anti-arrhythmic therapies including thoracic sympathectomy and dorsal spinal cord stimulation. Several features of the innervation are clear. The cardiac nerves differentially supply the nodal and myocardial tissue of the heart and are dependent on activity generated in spinal neurones in the upper thoracic cord which project to synapse with ganglion cells in the stellate complex on each side. Networks of spinal interneurones determine the pattern of activity. Groups of spinal neurones selectively target specific regions of the heart but whether they exhibit a functional selectivity has still to be elucidated. Electrical or ischemic signals can lead to remodeling of nerves in the heart or ganglia. Surgical and electrical methods are proving to be clinically beneficial in reducing atrial and ventricular arrhythmias, heart failure and severe cardiac pain. This is a rapidly developing area and we need more basic understanding of how these methods work to ensure safety and reduction of side effects. Copyright © 2016 Elsevier B.V. All rights reserved.

Magnetic resonance imaging patterns of mononeuropathic denervation in muscles with dual innervation

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Sneag, Darryl B.; Lee, Susan C.; Melisaratus, Darius P. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States); Feinberg, Joseph H. [Physical Medicine and Rehabilitation, Hospital for Special Surgery, New York, NY (United States); Amber, Ian [MedStar Georgetown University Hospital, Department of Radiology, DC, Washington (United States)

2017-12-15

Magnetic resonance imaging (MRI) of mononeuropathy in muscles with dual innervation depicts geographic denervation corresponding to the affected nerve. Knowledge of the normal distribution of a muscle's neural supply is clinically relevant as partial muscle denervation represents a potential imaging pitfall that can be confused with other pathology, such as muscle strain. This article reviews the normal innervation pattern of extremity muscles with dual supply, providing illustrative examples of mononeuropathy affecting such muscles. (orig.)

Magnetic resonance imaging patterns of mononeuropathic denervation in muscles with dual innervation

International Nuclear Information System (INIS)

Sneag, Darryl B.; Lee, Susan C.; Melisaratus, Darius P.; Feinberg, Joseph H.; Amber, Ian

2017-01-01

Magnetic resonance imaging (MRI) of mononeuropathy in muscles with dual innervation depicts geographic denervation corresponding to the affected nerve. Knowledge of the normal distribution of a muscle's neural supply is clinically relevant as partial muscle denervation represents a potential imaging pitfall that can be confused with other pathology, such as muscle strain. This article reviews the normal innervation pattern of extremity muscles with dual supply, providing illustrative examples of mononeuropathy affecting such muscles. (orig.)

[Microscopic innervation of the spermatic ducts and testis. I. Vas deferens].

Science.gov (United States)

Suárez-Garnacho, S; Vega, J A; Alvarez Arenal, A; Pérez Casas, A; Alvarez Menéndez, J C; Hernández, L C

1989-01-01

The microscopic innervation of the vas deferens in the rat was studied both in light and electron microscope. The nerve fibres form perivascular, intramuscular and subepithelial plexuses. Inside the connective tissue surrounding the vas deferens both isolated nerve fibres and sensory corpuscles (glomerular and Ruffine-like types) were observed. The varicosities and endings of nerve fibres contain synaptic vesicles of different sizes and electron characteristics. These varicosities were closely related to the smooth muscle cells and some of them lacked of Schwannian sheath. The nervous fibres were not in direct contact with the epithelial cells.

A region-specific quantitative profile of autonomic innervation of the canine left atrium and pulmonary veins.

Science.gov (United States)

Gao, Chong-han; Wang, Fei; Jiang, Rong; Zhang, Jin; Mou, Huamin; Yin, Yue-hui

2011-07-05

The aim of the present study was to determine and quantify the cardiac autonomic innervation of the canine atria and pulmonary vein. Tissue specimens were taken from the canine pulmonary veins (PVs), posterior left atrium (PLA), left atrial roof (LAR), anterior left atrium (ALA), interatrial septum (IAS), and left atrial appendage (LAA) respectively for immunohistochemical analysis and nerve density determination. Both sympathetic and parasympathetic nerve densities decreased in the order: PLA>PV>IAS>LAR>ALA>LAA. For sympathetic nerve, multiple comparisons between any two regions showed a significant difference (PIAS vs. LAR, and LAR vs. ALA; for parasympathetic nerve, all the differences between any pair of regions were statistically significant (PIAS vs. LAR, LAR vs. ALA, and ALA vs. LAA. For both nerve types, there was a decreasing gradient of nerve densities from the external to internal layer (P<0.001, for each comparisons). Nerve density at the ostia for either nerve type was significantly higher than at the distal segments of PVs (P<0.001). In summary, the LA and PVs are innervated by sympathetic and parasympathetic nerves in a regionally heterogeneous way, which may be important for the pathophysiological investigation and ablation therapy of atrial fibrillation (AF). Copyright © 2011 Elsevier B.V. All rights reserved.

Richly innervated soft tissues covering the superficial aspect of the extensor origin in patients with chronic painful tennis elbow - Implication for treatment?

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Spang, C; Alfredson, H

2017-06-01

Tennis elbow is difficult to treat. The results of surgical treatments are not convincing. Treatment studies on Achilles and patellar tendinopathy targeting the richly innervated and vascularized soft tissues outside the tendon have shown promising outcomes. The innervation patterns in the fibrous/fatty tissues superficially to the elbow extensor origin have not been clarified. Nine tissue specimens from the fibrous/fatty tissue covering the extensor origin was taken from seven patients (mean age: 45 years) undergoing surgical treatment for chronic painful tennis elbow. The specimens were stained for morphology (haematoxylin and eosin, H and E) and immunohistochemically for general nerve marker protein gene product 9.5 (PGP 9.5) and markers for sympathetic (tyrosine hydroxylase, TH) and sensory nerve fibres (calcitonin gene-related peptide, CGRP). All specimens contained multiple blood vessels and nerve structures indicated by morphology and immunoreactions. There was a frequent occurrence of TH reactions, especially peri-vascularly, but also in nerve fascicles. Immunoreactions for CGRP were seen in nerve fascicles and isolated nerve fibres. The results provide new information on the innervation patterns of the superficial tissues of the extensor origin and their potential as source of tennis elbow pain. IV.

Asymmetric Bilateral Variations in the Musculocutaneous and Median Nerves with High Branching of Brachial Artery

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Vandana Tomar

2012-01-01

Full Text Available Brachial Plexus is formed by the union of the anterior rami of cervical 5, 6, 7, 8 and thoracic 1 nerves. These nerves unite and divide to form the key nerves innervating the upper limb. Variations in the course of these nerves are clinically important to anesthetists, neurologists and orthopedicians. We report bilateral variations in the arterial and neural structures in the upper limb of a 65 year old cadaver. The muscles of the arm on one side were innervated by the median nerve with absence of musculocutaneous. While on the other side the musculocutaneous nerve contributed to the formation of the median nerve. There was a presence of high bifurcation of brachial artery on both sides. Knowledge of such variations in the innervations of muscles and the arterial supply of the limbs are important to remember before performing any reconstructive procedures or interventions on the limb.

Sensory Innervation of the Nonspecialized Connective Tissues in the Low Back of the Rat

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Corey, Sarah M.; Vizzard, Margaret A.; Badger, Gary J.; Langevin, Helene M.

2011-01-01

Chronic musculoskeletal pain, including low back pain, is a worldwide debilitating condition; however, the mechanisms that underlie its development remain poorly understood. Pathological neuroplastic changes in the sensory innervation of connective tissue may contribute to the development of nonspecific chronic low back pain. Progress in understanding such potentially important abnormalities is hampered by limited knowledge of connective tissue's normal sensory innervation. The goal of this study was to evaluate and quantify the sensory nerve fibers terminating within the nonspecialized connective tissues in the low back of the rat. With 3-dimensional reconstructions of thick (30–80 μm) tissue sections we have for the first time conclusively identified sensory nerve fiber terminations within the collagen matrix of connective tissue in the low back. Using dye labeling techniques with Fast Blue, presumptive dorsal root ganglia cells that innervate the low back were identified. Of the Fast Blue-labeled cells, 60–88% also expressed calcitonin gene-related peptide (CGRP) immunoreactivity. Based on the immunolabeling with CGRP and the approximate size of these nerve fibers (≤2 μm) we hypothesize that they are Aδ or C fibers and thus may play a role in the development of chronic pain. PMID:21411968

EVOLUTION OF NEUROENDOCRINE CELL POPULATION AND PEPTIDERGIC INNERVATION, ASSESSED BY DISCRIMINANT ANALYSIS, DURING POSTNATAL DEVELOPMENT OF THE RAT PROSTATE

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Rosario Rodríguez

2011-05-01

Full Text Available Serotonin immunoreactive neuroendocrine cells and peptidergic nerves (NPY and VIP could have a role in prostate growth and function. In the present study, rats grouped by stages of postnatal development (prepubertal, pubertal, young and aged adults were employed in order to ascertain whether age causes changes in the number of serotoninergic neuroendocrine cells and the length of NPY and VIP fibres. Discriminant analysis was performed in order to ascertain the classificatory power of stereologic variables (absolute and relative measurements of cell number and fibre length on age groups. The following conclusions were drawn: a discriminant analysis confirms the androgen-dependence of both neuroendocrine cells and NPYVIP innervation during the postnatal development of the rat prostate; b periglandular innervation has more relevance than interglandular innervation in classifying the rats in age groups; and c peptidergic nerves from ventral, ampullar and periductal regions were more age-dependent than nerves from the dorso-lateral region.

Innervation of taste buds revealed with Brainbow-labeling in mouse.

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Zaidi, Faisal N; Cicchini, Vanessa; Kaufman, Daniel; Ko, Elizabeth; Ko, Abraham; Van Tassel, Heather; Whitehead, Mark C

2016-12-01

Nerve fibers that surround and innervate the taste bud were visualized with inherent fluorescence using Brainbow transgenic mice that were generated by mating the founder line L with nestin-cre mice. Multicolor fluorescence revealed perigemmal fibers as branched within the non-taste epithelium and ending in clusters of multiple rounded swellings surrounding the taste pore. Brainbow-labeling also revealed the morphology and branching pattern of single intragemmal fibers. These taste bud fibers frequently innervated both the peripheral bud, where immature gemmal cells are located, and the central bud, where mature, differentiated cells are located. The fibers typically bore preterminal and terminal swellings, growth cones with filopodia, swellings, and rounded retraction bulbs. These results establish an anatomical substrate for taste nerve fibers to contact and remodel among receptor cells at all stages of their differentiation, an interpretation that was supported by staining with GAP-43, a marker for growing fibers and growth cones. © 2016 Anatomical Society.

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

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

2017-01-01

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

Towards Clinical Application of Neurotrophic Factors to the Auditory Nerve; Assessment of Safety and Efficacy by a Systematic Review of Neurotrophic Treatments in Humans

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Aren Bezdjian

2016-11-01

Full Text Available Animal studies have evidenced protection of the auditory nerve by exogenous neurotrophic factors. In order to assess clinical applicability of neurotrophic treatment of the auditory nerve, the safety and efficacy of neurotrophic therapies in various human disorders were systematically reviewed. Outcomes of our literature search included disorder, neurotrophic factor, administration route, therapeutic outcome, and adverse event. From 2103 articles retrieved, 20 randomized controlled trials including 3974 patients were selected. Amyotrophic lateral sclerosis (53% was the most frequently reported indication for neurotrophic therapy followed by diabetic polyneuropathy (28%. Ciliary neurotrophic factor (50%, nerve growth factor (24% and insulin-like growth factor (21% were most often used. Injection site reaction was a frequently occurring adverse event (61% followed by asthenia (24% and gastrointestinal disturbances (20%. Eighteen out of 20 trials deemed neurotrophic therapy to be safe, and six out of 17 studies concluded the neurotrophic therapy to be effective. Positive outcomes were generally small or contradicted by other studies. Most non-neurodegenerative diseases treated by targeted deliveries of neurotrophic factors were considered safe and effective. Hence, since local delivery to the cochlea is feasible, translation from animal studies to human trials in treating auditory nerve degeneration seems promising.

Dual Innervation of Neonatal Merkel Cells in Mouse Touch Domes

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Luo, Wenqin

2014-01-01

Merkel cell-neurite complexes are specialized mechanosensory end organs that mediate discriminative touch sensation. It is well established that type I slowly adapting (SAI) mechanoreceptors, which express neural filament heavy chain (NFH), innervate Merkel cells. It was previously shown that neurotrophic factor NT3 and its receptor TrkC play crucial roles in controlling touch dome Merkel cell innervation of NFH+ fibers. In addition, nerve fibers expressing another neurotrophic tyrosine receptor kinase (NTRK), Ret, innervate touch dome Merkel cells as well. However, the relationship between afferents responsive to NT3/TrkC signaling and those expressing Ret is unclear. It is also controversial if these Ret+ fibers belong to the early or late Ret+ DRG neurons, which are defined based on the co-expression and developmental dependence of TrkA. To address these questions, we genetically traced Ret+ and TrkC+ fibers and analyzed their developmental dependence on TrkA. We found that Merkel cells in neonatal mouse touch domes receive innervation of two types of fibers: one group is Ret+, while the other subset expresses TrkC and NFH. In addition, Ret+ fibers depend on TrkA for their survival and normal innervation whereas NFH+ Merkel cell innervating fibers are almost unaltered in TrkA mutant mice, supporting that Ret+ and NFH+/TrkC+ afferents are two distinct groups. Ret signaling, on the other hand, plays a minor role for the innervation of neonatal touch domes. In contrast, Merkel cells in the glabrous skin are mainly contacted by NFH+/TrkC+ afferents. Taken together, our results suggest that neonatal Merkel cells around hair follicles receive dual innervation while Merkel cells in the glabrous skin are mainly innervated by only SAI mechanoreceptors. In addition, our results suggest that neonatal Ret+ Merkel cell innervating fibers most likely belong to the late but not early Ret+ DRG neurons. PMID:24637732

Evoked electromyography to rocuronium in orbicularis oris and gastrocnemius in facial nerve injury in rabbits.

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Xing, Yian; Chen, Lianhua; Li, Shitong

2013-11-01

Muscles innervated by the facial nerve show different sensitivities to muscle relaxants than muscles innervated by somatic nerves, especially in the presence of facial nerve injury. We compared the evoked electromyography (EEMG) response of orbicularis oris and gastrocnemius in with and without a non-depolarizing muscle relaxant in a rabbit model of graded facial nerve injury. Differences in EEMG response and inhibition by rocuronium were measured in the orbicularis oris and gastrocnemius muscles 7 to 42 d after different levels of facial nerve crush injuries in adult rabbits. Baseline EEMG of orbicularis oris was significantly smaller than those of the gastrocnemius. Gastrocnemius was more sensitive to rocuronium than the facial muscles (P rocuronium was negatively correlated with the magnitude of facial nerve injury but the sensitivity to rocuronium was not. No significant difference was found in the onset time and the recovery time of rocuronium among gastrocnemius and normal or damaged facial muscles. Muscles innervated by somatic nerves are more sensitive to rocuronium than those innervated by the facial nerve, but while facial nerve injury reduced EEMG responses, the sensitivity to rocuronium is not altered. Partial neuromuscular blockade may be a suitable technique for conducting anesthesia and surgery safely when EEMG monitoring is needed to preserve and protect the facial nerve. Additional caution should be used if there is a risk of preexisting facial nerve injury. Copyright © 2013 Elsevier Inc. All rights reserved.

Estrogen Replacement Regulates Vaginal Innervations in Ovariectomized Adult Virgin Rats: A Histological Study

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Ting Li

2017-01-01

Full Text Available Background. Our previous Gräfenberg spot findings confirmed that the distal-third areas of the anterior vaginal wall bore a significantly greater number of nerves and sexual hormone may have certain degree of influence on these significant differences. However, the role of estrogen in vaginal innervations remains controversial. Methods. To investigate whether hormonal-neural interactions occur in the vagina, sixty rats were randomly divided into six groups: Sham-operated, ovariectomy, and 4 treatment groups. After 2 weeks of treatment, vaginal biopsies were prepared with hematoxylin and eosin and PGP9.5 using immunohistochemistry. Results. The density of small nerve fibers was significantly higher in the distal-half areas of intact vaginal walls than the proximal-half areas (P=0.001. In contrast, the overall PGP 9.5-ir fiber innervation density was significantly decreased in the OVX rats subjected to surgical menopause. Sustained estrogen administration for 2 weeks resulted in nerve fiber proliferation, with values reaching normal levels in the low-dose estradiol valerate group. Conclusion. Our findings indicate that systemic hormonal therapy with low-dose estradiol valerate is effective and safe for treating deficient vaginal innervation caused by low level of estrogen activity in menopausal women and may aid studies to identify an optimal estradiol dose to provide relief from vaginal discomfort.

Analysis of electrically evoked compound action potential of the auditory nerve in children with bilateral cochlear implants.

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Caldas, Fernanda Ferreira; Cardoso, Carolina Costa; Barreto, Monique Antunes de Souza Chelminski; Teixeira, Marina Santos; Hilgenberg, Anacléia Melo da Silva; Serra, Lucieny Silva Martins; Bahmad Junior, Fayez

2016-01-01

The cochlear implant device has the capacity to measure the electrically evoked compound action potential of the auditory nerve. The neural response telemetry is used in order to measure the electrically evoked compound action potential of the auditory nerve. To analyze the electrically evoked compound action potential, through the neural response telemetry, in children with bilateral cochlear implants. This is an analytical, prospective, longitudinal, historical cohort study. Six children, aged 1-4 years, with bilateral cochlear implant were assessed at five different intervals during their first year of cochlear implant use. There were significant differences in follow-up time (p=0.0082) and electrode position (p=0.0019) in the T-NRT measure. There was a significant difference in the interaction between time of follow-up and electrode position (p=0.0143) when measuring the N1-P1 wave amplitude between the three electrodes at each time of follow-up. The electrically evoked compound action potential measurement using neural response telemetry in children with bilateral cochlear implants during the first year of follow-up was effective in demonstrating the synchronized bilateral development of the peripheral auditory pathways in the studied population. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Peribronchial innervation of the rat lung.

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Artico, Marco; Bosco, Sandro; Bronzetti, Elena; Felici, Laura M; Pelusi, Giuseppe; Lo Vasco, Vincenza Rita; Vitale, Marco

2004-10-01

Mammalian peribronchial tissue is supplied by several peptide-containing nerve fibers. Although it is well established that different neuropeptides exert significant effects on bronchial and vascular tone in the lungs, the role played by some neuromediators on the general regulation, differentiation and release of locally active substances is still controversial. We studied the innervation of rat peribronchial tissue by immunohistochemical techniques. The immunoperoxidase method with nickel amplification was applied to detect the distribution of nerve fibers using antibodies against the general neuronal marker PGP 9.5 (neuron-specific cytoplasmic protein), while the cholinacetyltransferase immunoreactivity was studied by immunohistochemistry. A slight immunoreactivity for NT receptors is observed in lung bronchial epithelium. There is increasing evidence that NTs may act with a paracrine mechanism regulating functional activity of neuronal and non-neuronal structures. A specific immunoreactivity for NTs and NT receptors was also demonstrated within different layers of large, medium and small sized intrapulmonary arteries and veins, according to a recent study of our group. Moreover our data describe the expression of NTs and NT receptors in lymphoid aggregates of the lung (BALT) in which both lymphocytes and macrophages express TrkA receptor and synthesize NTs. Our results show the presence of an extensive network of innervation in the rat peribronchial tissue, confirming a morphological basis for a possible neural modulation of the respiratory mucosa and the physiological/pathophysiological mechanisms of the lung.

Magnetic resonance imaging of the internal auditory canal

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Daniels, D.L.; Herfkins, R.; Koehler, P.R.; Millen, S.J.; Shaffer, K.A.; Williams, A.L.; Haughton, V.M.

1984-01-01

Three patients with exclusively or predominantly intracanalicular neuromas and 5 with presumably normal internal auditory canals were examined with prototype 1.4- or 1.5-tesla magnetic resonance (MR) scanners. MR images showed the 7th and 8th cranial nerves in the internal auditory canal. The intracanalicular neuromas had larger diameter and slightly greater signal strength than the nerves. Early results suggest that minimal enlargement of the nerves can be detected even in the internal auditory canal

External auditory canal cholesteatoma and keratosis obturans: the role of imaging in preventing facial nerve injury.

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McCoul, Edward D; Hanson, Matthew B

2011-12-01

We conducted a retrospective study to compare the clinical characteristics of external auditory canal cholesteatoma (EACC) with those of a similar entity, keratosis obturans (KO). We also sought to identify those aspects of each disease that may lead to complications. We identified 6 patients in each group. Imaging studies were reviewed for evidence of bony erosion and the proximity of disease to vital structures. All 6 patients in the EACC group had their diagnosis confirmed by computed tomography (CT), which demonstrated widening of the bony external auditory canal; 4 of these patients had critical erosion of bone adjacent to the facial nerve. Of the 6 patients with KO, only 2 had undergone CT, and neither exhibited any significant bony erosion or expansion; 1 of them developed osteomyelitis of the temporal bone and adjacent temporomandibular joint. Another patient manifested KO as part of a dermatophytid reaction. The essential component of treatment in all cases of EACC was microscopic debridement of the ear canal. We conclude that EACC may produce significant erosion of bone with exposure of vital structures, including the facial nerve. Because of the clinical similarity of EACC to KO, misdiagnosis is possible. Temporal bone imaging should be obtained prior to attempts at debridement of suspected EACC. Increased awareness of these uncommon conditions is warranted to prompt appropriate investigation and prevent iatrogenic complications such as facial nerve injury.

Postnatal reduction of BDNF regulates the developmental remodeling of taste bud innervation.

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Huang, Tao; Ma, Liqun; Krimm, Robin F

2015-09-15

The refinement of innervation is a common developmental mechanism that serves to increase the specificity of connections following initial innervation. In the peripheral gustatory system, the extent to which innervation is refined and how refinement might be regulated is unclear. The initial innervation of taste buds is controlled by brain-derived neurotrophic factor (BDNF). Following initial innervation, taste receptor cells are added and become newly innervated. The connections between the taste receptor cells and nerve fibers are likely to be specific in order to retain peripheral coding mechanisms. Here, we explored the possibility that the down-regulation of BDNF regulates the refinement of taste bud innervation during postnatal development. An analysis of BDNF expression in Bdnf(lacZ/+) mice and real-time reverse transcription polymerase chain reaction (RT-PCR) revealed that BDNF was down-regulated between postnatal day (P) 5 and P10. This reduction in BDNF expression was due to a loss of precursor/progenitor cells that express BDNF, while the expression of BDNF in the subpopulations of taste receptor cells did not change. Gustatory innervation, which was identified by P2X3 immunohistochemistry, was lost around the perimeter where most progenitor/precursor cells are located. In addition, the density of innervation in the taste bud was reduced between P5 and P10, because taste buds increase in size without increasing innervation. This reduction of innervation density was blocked by the overexpression of BDNF in the precursor/progenitor population of taste bud cells. Together these findings indicate that the process of BDNF restriction to a subpopulation of taste receptor cells between P5 and P10, results in a refinement of gustatory innervation. We speculate that this refinement results in an increased specificity of connections between neurons and taste receptor cells during development. Copyright © 2015 Elsevier Inc. All rights reserved.

Postnatal reduction of BDNF regulates the developmental remodeling of taste bud innervation

Science.gov (United States)

Huang, Tao; Ma, Liqun; Krimm, Robin F

2015-01-01

The refinement of innervation is a common developmental mechanism that serves to increase the specificity of connections following initial innervation. In the peripheral gustatory system, the extent to which innervation is refined and how refinement might be regulated is unclear. The initial innervation of taste buds is controlled by brain-derived neurotrophic factor (BDNF). Following initial innervation, taste receptor cells are added and become newly innervated. The connections between the taste receptor cells and nerve fibers are likely to be specific in order to retain peripheral coding mechanisms. Here, we explored the possibility that the down-regulation of BDNF regulates the refinement of taste bud innervation during postnatal development. An analysis of BDNF expression in BdnflacZ/+ mice and real-time reverse transcription polymerase chain reaction (RT-PCR) revealed that BDNF was down-regulated between postnatal day (P) 5 and P10. This reduction in BDNF expression was due to a loss of precursor/progenitor cells that express BDNF, while the expression of BDNF in the subpopulations of taste receptor cells did not change. Gustatory innervation, which was identified by P2X3 immunohistochemistry, was lost around the perimeter where most progenitor/precursor cells are located. In addition, the density of innervation in the taste bud was reduced between P5 and P10, because taste buds increase in size without increasing innervation. This reduction of innervation density was blocked by the overexpression of BDNF in the precursor/progenitor population of taste bud cells. Together these findings indicate that the process of BDNF restriction to a subpopulation of taste receptor cells between P5 and P10, results in a refinement of gustatory innervation. We speculate that this refinement results in an increased specificity of connections between neurons and taste receptor cells during development. PMID:26164656

The role of Sema3–Npn-1 signaling during diaphragm innervation and muscle development

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Huettl, Rosa-Eva; Hanuschick, Philipp; Amend, Anna-Lena; Alberton, Paolo; Aszodi, Attila; Huber, Andrea B.

2016-01-01

ABSTRACT Correct innervation of the main respiratory muscle in mammals, namely the thoracic diaphragm, is a crucial pre-requisite for the functionality of this muscle and the viability of the entire organism. Systemic impairment of Sema3A–Npn-1 (Npn-1 is also known as NRP1) signaling causes excessive branching of phrenic nerves in the diaphragm and into the central tendon region, where the majority of misguided axons innervate ectopic musculature. To elucidate whether these ectopic muscles are a result of misguidance of myoblast precursors due to the loss of Sema3A–Npn-1 signaling, we conditionally ablated Npn-1 in somatic motor neurons, which led to a similar phenotype of phrenic nerve defasciculation and, intriguingly, also formation of innervated ectopic muscles. We therefore hypothesize that ectopic myocyte fusion is caused by additional factors released by misprojecting growth cones. Slit2 and its Robo receptors are expressed by phrenic motor axons and migrating myoblasts, respectively, during innervation of the diaphragm. In vitro analyses revealed a chemoattractant effect of Slit2 on primary diaphragm myoblasts. Thus, we postulate that factors released by motor neuron growth cones have an influence on the migration properties of myoblasts during establishment of the diaphragm. PMID:27466379

Ontogeny and innervation of taste buds in mouse palatal gustatory epithelium.

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Rashwan, Ahmed; Konishi, Hiroyuki; El-Sharaby, Ashraf; Kiyama, Hiroshi

2016-01-01

We investigated the relationship between mouse taste bud development and innervation of the soft palate. We employed scanning electron microscopy and immunohistochemistry using antibodies against protein gene product 9.5 and peripherin to detect sensory nerves, and cytokeratin 8 and α-gustducin to stain palatal taste buds. At E14, nerve fibers were observed along the medial border of the palatal shelves that tracked toward the epithelium. At E15.5, primordial stages of taste buds in the basal lamina of the soft palate first appeared. At E16, the taste buds became large spherical masses of columnar cells scattered in the soft palate basal lamina. At E17, the morphology and also the location of taste buds changed. At E18-19, some taste buds acquired a more elongated shape with a short neck, extending a variable distance from the soft palate basal lamina toward the surface epithelium. At E18, mature taste buds with taste pores and perigemmal nerve fibers were observed on the surface epithelium of the soft palate. The expression of α-gustducin was demonstrated at postnatal day 1 and the number of pored taste buds increased with age and they became pear-shaped at 8 weeks. The percent of pored fungiform-like papillae at birth was 58.3% of the whole palate; this increased to 83.8% at postnatal day 8 and reached a maximum of 95.7% at 12 weeks. The innervation of the soft palate was classified into three types of plexuses in relation to taste buds: basal nerve plexus, intragemmal and perigemmal nerve fibers. This study reveals that the nerve fibers preceded the development of taste buds in the palate of mice, and therefore the nerve fibers have roles in the initial induction of taste buds in the soft palate. Copyright © 2015 Elsevier B.V. All rights reserved.

Nerve supply of the subscapularis during anterior shoulder surgery: definition of a potential risk area.

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Leschinger, Tim; Hackl, Michael; Zeifang, Felix; Scaal, Martin; Müller, Lars Peter; Wegmann, Kilian

2017-01-01

The purpose of the study was to evaluate the position of the subscapular nerves relative to surgical landmarks during exposure and to analyze the pattern of innervation of the subscapularis to avoid injury during anterior shoulder surgery. 20 embalmed human cadaveric shoulder specimens were used in the study. The muscular insertions of the subscapular nerves were marked and their closest branches to the musculotendinous junction and the coracoid process were measured in horizontal and vertical distances. In addition, the innervation pattern of each specimen was documented. 14/20 specimens showed an innervation of the subscapularis with an upper, middle and lower subscapular nerve branch. Even though the nerve branches were in average more than 2 cm medial to the musculotendinous junction, minimal distances of 1.1-1.3 cm were found. The mean vertical distance as measured from the medial base of the coracoid to the nerve innervation point into the muscle was 0.7 cm for the upper nerve branch, 2.2 cm for the middle nerve branch and 4.4 cm for the lower nerve branch. The subscapularis has a variable nerve supply, which increases the risk of muscle denervation during open shoulder surgery. Dissection or release should be avoided at the anterior aspect of the subscapularis muscle more than 1 cm medial to the musculotendinous junction. In approaches with a horizontal incision of the subscapularis, splitting should be performed at a vertical distance of 3.2-3.6 cm to the coracoid base to avoid iatrogenic subscapular nerve injuries.

Richly innervated soft tissues covering the superficial aspect of the extensor origin in patients with chronic painful tennis elbow – Implication for treatment?

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Spang, C.; Alfredson, H.

2017-01-01

Background: Tennis elbow is difficult to treat. The results of surgical treatments are not convincing. Treatment studies on Achilles and patellar tendinopathy targeting the richly innervated and vascularized soft tissues outside the tendon have shown promising outcomes. The innervation patterns in the fibrous/fatty tissues superficially to the elbow extensor origin have not been clarified. Methods: Nine tissue specimens from the fibrous/fatty tissue covering the extensor origin was taken from seven patients (mean age: 45 years) undergoing surgical treatment for chronic painful tennis elbow. The specimens were stained for morphology (haematoxylin & eosin, H&E) and immunohistochemically for general nerve marker protein gene product 9.5 (PGP 9.5) and markers for sympathetic (tyrosine hydroxylase, TH) and sensory nerve fibres (calcitonin gene-related peptide, CGRP). Results: All specimens contained multiple blood vessels and nerve structures indicated by morphology and immunoreactions. There was a frequent occurrence of TH reactions, especially peri-vascularly, but also in nerve fascicles. Immunoreactions for CGRP were seen in nerve fascicles and isolated nerve fibres. Conclusion: The results provide new information on the innervation patterns of the superficial tissues of the extensor origin and their potential as source of tennis elbow pain. Level of Evidence: IV. PMID:28574416

Sympathetic Innervation during Development Is Necessary for Pancreatic Islet Architecture and Functional Maturation

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Philip Borden

2013-07-01

Full Text Available Sympathetic neurons depend on target-derived neurotrophic cues to control their survival and growth. However, whether sympathetic innervation contributes reciprocally to the development of target tissues is less clear. Here, we report that sympathetic innervation is necessary for the formation of the pancreatic islets of Langerhans and for their functional maturation. Genetic or pharmacological ablation of sympathetic innervation during development resulted in altered islet architecture, reduced insulin secretion, and impaired glucose tolerance in mice. Similar defects were observed with pharmacological blockade of β-adrenergic signaling. Conversely, the administration of a β-adrenergic agonist restored islet morphology and glucose tolerance in deinnervated animals. Furthermore, in neuron-islet cocultures, sympathetic neurons promoted islet cell migration in a β-adrenergic-dependent manner. This study reveals that islet architecture requires extrinsic inductive cues from neighboring tissues such as sympathetic nerves and suggests that early perturbations in sympathetic innervation might underlie metabolic disorders.

Topographical and functional anatomy of trapezius muscle innervation by spinal accessory nerve and C2 to C4 nerves of cervical plexus.

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Gavid, M; Mayaud, A; Timochenko, A; Asanau, A; Prades, J M

2016-10-01

The aim of this study was to determine the existence and the frequency of communicating branches between the spinal accessory nerve (SAN) and the C2, C3 and C4 roots of the cervical plexus. The present study also aimed to elucidate whether these branches contain motor fibers or not. Dissection of the cervical region was performed on twelve adult cadavers. A powered operating microscope was necessary to dissect the SAN and its branches and also to dissect C2, C3 and C4 nerve branches. In a second step, data from 13 patients who underwent 25 modified neck dissections under trapezius muscle's monitoring were collected. At the end of surgery, intraoperative stimulation on the SAN, C2, C3 and C4 nerve branches was performed. Registered potentials in the three parts of the trapezius muscle, using the NIM Medtronic system, were analyzed. During cadaver dissection, 18 (78 %) communicating branches were identified between the SAN and C2, 11 (48 %) between the SAN and C3, 12 (52 %) between the SAN and C4. Intraoperative stimulation of the SAN and its branch for the trapezius muscle provided a significant electroneurographic response in the three parts of the trapezius muscle in all subjects. Intraoperative stimulation of C3 led to recordable contractions of the trapezius muscle in 5 (20 %) modified neck surgeries, stimulation of C4 led to recordable contractions during 5 (20 %) modified neck dissections. One case of contraction was recorded after intraoperative stimulation of C2 (7 %). Although we were able to identify at least one communicating branch between the SAN and the roots of the cervical plexus in each cadaver dissection, the cervical plexus is not always involved in trapezius motor innervation. Intraoperative electroneurography demonstrated that a motor input from the cervical plexus to the trapezius muscle was provided in only 32 % of cases. Therefore, SAN trunk and C3-C4 roots should be carefully preserved during modified neck dissection to protect

Early Corneal Innervation and Trigeminal Alterations in Parkinson Disease: A Pilot Study.

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Arrigo, Alessandro; Rania, Laura; Calamuneri, Alessandro; Postorino, Elisa Imelde; Mormina, Enricomaria; Gaeta, Michele; Marino, Silvia; Di Lorenzo, Giuseppe; Quartarone, Angelo; Anastasi, Giuseppe; Puzzolo, Domenico; Aragona, Pasquale

2018-04-01

To describe corneal innervation and trigeminal alterations in drug-naive patients with Parkinson disease (PD). A case series study was conducted by recruiting 3 early drug-naive patients with PD, 2 men and 1 woman (age: 72, 68, and 66, respectively). Ophthalmologic assessment included Ocular Surface Disease Index questionnaire, visual acuity by the logarithm of the minimum angle of resolution score, pupillary light reflexes, extrinsic ocular movements, corneal sensitivity, and slit-lamp examination. Corneal innervation parameter changes were evaluated in vivo using the Confoscan 4 confocal microscope, and they were compared with a control data set. The Heidelberg Retina Tomograph 3 (HRT3) has been used to assess retinal alterations in our patients, if compared with normal range values provided by the HRT3. Moreover, 3T magnetic resonance imaging (MRI) analysis of water diffusion property changes of trigeminal nerves was performed. All data were analyzed and compared with 2 control data sets made by 14 age-matched controls. Patients with PD showed profound alterations of corneal innervation and of trigeminal diffusion MRI parameters, compared with controls. Strong differences (PD vs. controls) were found for deep nerve tortuosity (Kallinikos mean 19.94 vs. 2.13) and the number of beadings (mean 34.2 vs. 15.5). HRT3 retinal evaluation revealed less structural changes compared with the normal range. Diffusion MRI showed profound changes of white matter diffusion properties (PD vs. controls), with fractional anisotropy decrement (mean 0.3029 vs. 0.3329) and mean diffusivity increment (mean 0.00127 vs. 0.00106). Corneal innervation changes might occur earlier in patients with PD than in retinal ones. Confocal corneal innervation analysis might provide possible early biomarkers for a better PD evaluation and for its earlier diagnosis.

BDNF is required for taste axon regeneration following unilateral chorda tympani nerve section.

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Meng, Lingbin; Huang, Tao; Sun, Chengsan; Hill, David L; Krimm, Robin

2017-07-01

Taste nerves readily regenerate to reinnervate denervated taste buds; however, factors required for regeneration have not yet been identified. When the chorda tympani nerve is sectioned, expression of brain-derived neurotrophic factor (BDNF) remains high in the geniculate ganglion and lingual epithelium, despite the loss of taste buds. These observations suggest that BDNF is present in the taste system after nerve section and may support taste nerve regeneration. To test this hypothesis, we inducibly deleted Bdnf during adulthood in mice. Shortly after Bdnf gene recombination, the chorda tympani nerve was unilaterally sectioned causing a loss of both taste buds and neurons, irrespective of BDNF levels. Eight weeks after nerve section, however, regeneration was differentially affected by Bdnf deletion. In control mice, there was regeneration of the chorda tympani nerve and taste buds reappeared with innervation. In contrast, few taste buds were reinnervated in mice lacking normal Bdnf expression such that taste bud number remained low. In all genotypes, taste buds that were reinnervated were normal-sized, but non-innervated taste buds remained small and atrophic. On the side of the tongue contralateral to the nerve section, taste buds for some genotypes became larger and all taste buds remained innervated. Our findings suggest that BDNF is required for nerve regeneration following gustatory nerve section. Copyright © 2017 Elsevier Inc. All rights reserved.

Trigeminal neuralgia and facial nerve paralysis

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Borges, Alexandra [IPOFG, Department of Radiology, Lisbon (Portugal)

2005-03-01

The trigeminal nerve is the largest of the cranial nerves. It provides sensory input from the face and motor innervation to the muscles of mastication. The facial nerve is the cranial nerve with the longest extracranial course, and its main functions include motor innervation to the muscles of facial expression, sensory control of lacrimation and salivation, control of the stapedial reflex and to carry taste sensation from the anterior two-thirds of the tongue. In order to be able adequately to image and follow the course of these cranial nerves and their main branches, a detailed knowledge of neuroanatomy is required. As we are dealing with very small anatomic structures, high resolution dedicated imaging studies are required to pick up normal and pathologic nerves. Whereas CT is best suited to demonstrate bony neurovascular foramina and canals, MRI is preferred to directly visualize the nerve. It is also the single technique able to detect pathologic processes afflicting the nerve without causing considerable expansion such as is usually the case in certain inflammatory/infectious conditions, perineural spread of malignancies and in very small intrinsic tumours. Because a long course from the brainstem nuclei to the peripheral branches is seen, it is useful to subdivide the nerve in several segments and then tailor the imaging modality and the imaging study to that specific segment. This is particularly true in cases where topographic diagnosis can be used to locate a lesion in the course of these nerves. (orig.)

Trigeminal neuralgia and facial nerve paralysis

International Nuclear Information System (INIS)

Borges, Alexandra

2005-01-01

The trigeminal nerve is the largest of the cranial nerves. It provides sensory input from the face and motor innervation to the muscles of mastication. The facial nerve is the cranial nerve with the longest extracranial course, and its main functions include motor innervation to the muscles of facial expression, sensory control of lacrimation and salivation, control of the stapedial reflex and to carry taste sensation from the anterior two-thirds of the tongue. In order to be able adequately to image and follow the course of these cranial nerves and their main branches, a detailed knowledge of neuroanatomy is required. As we are dealing with very small anatomic structures, high resolution dedicated imaging studies are required to pick up normal and pathologic nerves. Whereas CT is best suited to demonstrate bony neurovascular foramina and canals, MRI is preferred to directly visualize the nerve. It is also the single technique able to detect pathologic processes afflicting the nerve without causing considerable expansion such as is usually the case in certain inflammatory/infectious conditions, perineural spread of malignancies and in very small intrinsic tumours. Because a long course from the brainstem nuclei to the peripheral branches is seen, it is useful to subdivide the nerve in several segments and then tailor the imaging modality and the imaging study to that specific segment. This is particularly true in cases where topographic diagnosis can be used to locate a lesion in the course of these nerves. (orig.)

Neurophysiological assessment of auditory, peripheral nerve, somatosensory, and visual system function after developmental exposure to gasoline, E15, and E85 vapors.

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U.S. Environmental Protection Agency — Visual, auditory, somatosensory, and peripheral nerve evoked responses. This dataset is associated with the following publication: Herr , D., D. Freeborn , L. Degn ,...

Effects of acoustic noise on the auditory nerve compound action potentials evoked by electric pulse trains.

Science.gov (United States)

Nourski, Kirill V; Abbas, Paul J; Miller, Charles A; Robinson, Barbara K; Jeng, Fuh-Cherng

2005-04-01

This study investigated the effects of acoustic noise on the auditory nerve compound action potentials in response to electric pulse trains. Subjects were adult guinea pigs, implanted with a minimally invasive electrode to preserve acoustic sensitivity. Electrically evoked compound action potentials (ECAP) were recorded from the auditory nerve trunk in response to electric pulse trains both during and after the presentation of acoustic white noise. Simultaneously presented acoustic noise produced a decrease in ECAP amplitude. The effect of the acoustic masker on the electric probe was greatest at the onset of the acoustic stimulus and it was followed by a partial recovery of the ECAP amplitude. Following cessation of the acoustic noise, ECAP amplitude recovered over a period of approximately 100-200 ms. The effects of the acoustic noise were more prominent at lower electric pulse rates (interpulse intervals of 3 ms and higher). At higher pulse rates, the ECAP adaptation to the electric pulse train alone was larger and the acoustic noise, when presented, produced little additional effect. The observed effects of noise on ECAP were the greatest at high electric stimulus levels and, for a particular electric stimulus level, at high acoustic noise levels.

Innervated boomerang flap for finger pulp reconstruction.

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Chen, Shao-Liang; Chiou, Tai-Fung

2007-11-01

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

Egr3 dependent sympathetic target tissue innervation in the absence of neuron death.

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Lin Li

Full Text Available Nerve Growth Factor (NGF is a target tissue derived neurotrophin required for normal sympathetic neuron survival and target tissue innervation. NGF signaling regulates gene expression in sympathetic neurons, which in turn mediates critical aspects of neuron survival, axon extension and terminal axon branching during sympathetic nervous system (SNS development. Egr3 is a transcription factor regulated by NGF signaling in sympathetic neurons that is essential for normal SNS development. Germline Egr3-deficient mice have physiologic dysautonomia characterized by apoptotic sympathetic neuron death and abnormal innervation to many target tissues. The extent to which sympathetic innervation abnormalities in the absence of Egr3 is caused by altered innervation or by neuron death during development is unknown. Using Bax-deficient mice to abrogate apoptotic sympathetic neuron death in vivo, we show that Egr3 has an essential role in target tissue innervation in the absence of neuron death. Sympathetic target tissue innervation is abnormal in many target tissues in the absence of neuron death, and like NGF, Egr3 also appears to effect target tissue innervation heterogeneously. In some tissues, such as heart, spleen, bowel, kidney, pineal gland and the eye, Egr3 is essential for normal innervation, whereas in other tissues such as lung, stomach, pancreas and liver, Egr3 appears to have little role in innervation. Moreover, in salivary glands and heart, two tissues where Egr3 has an essential role in sympathetic innervation, NGF and NT-3 are expressed normally in the absence of Egr3 indicating that abnormal target tissue innervation is not due to deregulation of these neurotrophins in target tissues. Taken together, these results clearly demonstrate a role for Egr3 in mediating sympathetic target tissue innervation that is independent of neuron survival or neurotrophin deregulation.

Three-dimensional reconstruction of the cranial and anterior spinal nerves in early tadpoles of Xenopus laevis (Pipidae, Anura).

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Naumann, Benjamin; Olsson, Lennart

2018-04-01

Xenopus laevis is one of the most widely used model organism in neurobiology. It is therefore surprising, that no detailed and complete description of the cranial nerves exists for this species. Using classical histological sectioning in combination with fluorescent whole mount antibody staining and micro-computed tomography we prepared a detailed innervation map and a freely-rotatable three-dimensional (3D) model of the cranial nerves and anterior-most spinal nerves of early X. laevis tadpoles. Our results confirm earlier descriptions of the pre-otic cranial nerves and present the first detailed description of the post-otic cranial nerves. Tracing the innervation, we found two previously undescribed head muscles (the processo-articularis and diaphragmatico-branchialis muscles) in X. laevis. Data on the cranial nerve morphology of tadpoles are scarce, and only one other species (Discoglossus pictus) has been described in great detail. A comparison of Xenopus and Discoglossus reveals a relatively conserved pattern of the post-otic and a more variable morphology of the pre-otic cranial nerves. Furthermore, the innervation map and the 3D models presented here can serve as an easily accessible basis to identify alterations of the innervation produced by experimental studies such as genetic gain- and loss of function experiments. © 2017 Wiley Periodicals, Inc.

Development of cardiac parasympathetic neurons, glial cells, and regional cholinergic innervation of the mouse heart.

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Fregoso, S P; Hoover, D B

2012-09-27

Very little is known about the development of cardiac parasympathetic ganglia and cholinergic innervation of the mouse heart. Accordingly, we evaluated the growth of cholinergic neurons and nerve fibers in mouse hearts from embryonic day 18.5 (E18.5) through postnatal day 21(P21). Cholinergic perikarya and varicose nerve fibers were identified in paraffin sections immunostained for the vesicular acetylcholine transporter (VAChT). Satellite cells and Schwann cells in adjacent sections were identified by immunostaining for S100β calcium binding protein (S100) and brain-fatty acid binding protein (B-FABP). We found that cardiac ganglia had formed in close association to the atria and cholinergic innervation of the atrioventricular junction had already begun by E18.5. However, most cholinergic innervation of the heart, including the sinoatrial node, developed postnatally (P0.5-P21) along with a doubling of the cross-sectional area of cholinergic perikarya. Satellite cells were present throughout neonatal cardiac ganglia and expressed primarily B-FABP. As they became more mature at P21, satellite cells stained strongly for both B-FABP and S100. Satellite cells appeared to surround most cardiac parasympathetic neurons, even in neonatal hearts. Mature Schwann cells, identified by morphology and strong staining for S100, were already present at E18.5 in atrial regions that receive cholinergic innervation at later developmental times. The abundance and distribution of S100-positive Schwann cells increased postnatally along with nerve density. While S100 staining of cardiac Schwann cells was maintained in P21 and older mice, Schwann cells did not show B-FABP staining at these times. Parallel development of satellite cells and cholinergic perikarya in the cardiac ganglia and the increase in abundance of Schwann cells and varicose cholinergic nerve fibers in the atria suggest that neuronal-glial interactions could be important for development of the parasympathetic nervous

Rapid effects of hearing song on catecholaminergic activity in the songbird auditory pathway.

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Lisa L Matragrano

Full Text Available Catecholaminergic (CA neurons innervate sensory areas and affect the processing of sensory signals. For example, in birds, CA fibers innervate the auditory pathway at each level, including the midbrain, thalamus, and forebrain. We have shown previously that in female European starlings, CA activity in the auditory forebrain can be enhanced by exposure to attractive male song for one week. It is not known, however, whether hearing song can initiate that activity more rapidly. Here, we exposed estrogen-primed, female white-throated sparrows to conspecific male song and looked for evidence of rapid synthesis of catecholamines in auditory areas. In one hemisphere of the brain, we used immunohistochemistry to detect the phosphorylation of tyrosine hydroxylase (TH, a rate-limiting enzyme in the CA synthetic pathway. We found that immunoreactivity for TH phosphorylated at serine 40 increased dramatically in the auditory forebrain, but not the auditory thalamus and midbrain, after 15 min of song exposure. In the other hemisphere, we used high pressure liquid chromatography to measure catecholamines and their metabolites. We found that two dopamine metabolites, dihydroxyphenylacetic acid and homovanillic acid, increased in the auditory forebrain but not the auditory midbrain after 30 min of exposure to conspecific song. Our results are consistent with the hypothesis that exposure to a behaviorally relevant auditory stimulus rapidly induces CA activity, which may play a role in auditory responses.

Structural organization and pattern of innervations of human Meissner’s corpuscle: a light microscopic study

OpenAIRE

Gh. Mohd. Bhat; Naseer Ahmad Shah; Mohd. Saleem Itoo; Bashir Ahmad Shah; Shaheen Shahdad; Javeed Ahmad Khan

2013-01-01

Background: Human glabrous skin has very rich nerve supply in the form of specialized nerve endings like Meissner’s corpuscles, Pacinian corpuscles, Krause end bulbs etc for carrying sensory information to brain. Aim of study: To study the structure, pattern of innervations and nerve terminations of human Meissner’s corpuscle. Methods: Skin samples from sixty human beings (age range 2 to 72 years) were taken, sections prepared and stained with a cytological (Haematoxylin – Eosi...

"In Situ Vascular Nerve Graft" for Restoration of Intrinsic Hand Function: An Anatomical Study.

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Mozaffarian, Kamran; Zemoodeh, Hamid Reza; Zarenezhad, Mohammad; Owji, Mohammad

2018-06-01

In combined high median and ulnar nerve injury, transfer of the posterior interosseous nerve branches to the motor branch of the ulnar nerve (MUN) is previously described in order to restore intrinsic hand function. In this operation a segment of sural nerve graft is required to close the gap between the donor and recipient nerves. However the thenar muscles are not innervated by this nerve transfer. The aim of the present study was to evaluate whether the superficial radial nerve (SRN) can be used as an "in situ vascular nerve graft" to connect the donor nerves to the MUN and the motor branch of median nerve (MMN) at the same time in order to address all denervated intrinsic and thenar muscles. Twenty fresh male cadavers were dissected in order to evaluate the feasibility of this modification of technique. The size of nerve branches, the number of axons and the tension at repair site were evaluated. This nerve transfer was technically feasible in all specimens. There was no significant size mismatch between the donor and recipient nerves Conclusions: The possible advantages of this modification include innervation of both median and ulnar nerve innervated intrinsic muscles, preservation of vascularity of the nerve graft which might accelerate the nerve regeneration, avoidance of leg incision and therefore the possibility of performing surgery under regional instead of general anesthesia. Briefly, this novel technique is a viable option which can be used instead of conventional nerve graft in some brachial plexus or combined high median and ulnar nerve injuries when restoration of intrinsic hand function by transfer of posterior interosseous nerve branches is attempted.

Macrophage-Mediated Glial Cell Elimination in the Postnatal Mouse Cochlea

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LaShardai N. Brown

2017-12-01

Full Text Available Hearing relies on the transmission of auditory information from sensory hair cells (HCs to the brain through the auditory nerve. This relay of information requires HCs to be innervated by spiral ganglion neurons (SGNs in an exclusive manner and SGNs to be ensheathed by myelinating and non-myelinating glial cells. In the developing auditory nerve, mistargeted SGN axons are retracted or pruned and excessive cells are cleared in a process referred to as nerve refinement. Whether auditory glial cells are eliminated during auditory nerve refinement is unknown. Using early postnatal mice of either sex, we show that glial cell numbers decrease after the first postnatal week, corresponding temporally with nerve refinement in the developing auditory nerve. Additionally, expression of immune-related genes was upregulated and macrophage numbers increase in a manner coinciding with the reduction of glial cell numbers. Transient depletion of macrophages during early auditory nerve development, using transgenic CD11bDTR/EGFP mice, resulted in the appearance of excessive glial cells. Macrophage depletion caused abnormalities in myelin formation and transient edema of the stria vascularis. Macrophage-depleted mice also showed auditory function impairment that partially recovered in adulthood. These findings demonstrate that macrophages contribute to the regulation of glial cell number during postnatal development of the cochlea and that glial cells play a critical role in hearing onset and auditory nerve maturation.

A Rare Variation of the Human Median Nerve Direction

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Barfi

2016-04-01

Full Text Available Introduction The brachial plexus, a complex network of nerves, innervates to the upper limbs. Variation in the course of the nerves in the upper limb is common. Case Presentation This paper describes two cases of upper limb variations in a cadaver dissected at Lorestan University of Medical Sciences. In the first variation, the median nerve in the arm has a different route, so that the median moves deep into the brachialis muscle. In the latter case, after piercing the coracobrachialis muscle a musculocutaneous nerve exists between the brachialis and biceps and goes to the lateral region of the forearm. This is known as the lateral cutaneous nerve of the forearm nerve, and innervates the skin of the lateral part of the forearm and the dorsal part of the hand. Conclusions Because of the possibility of damage to the brachial plexus branches is high in upper limb injuries and surgeries, full knowledge of normal anatomy and variations of these branches is essential for orthopedic specialists, neurosurgeons, radiologists, and anatomists.

Origins of the sympathetic innervation to the nasal-associated lymphoid tissue (NALT): an anatomical substrate for a neuroimmune connection.

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Marafetti, Lucas E; Romeo, Horacio E

2014-11-15

The participation of sympathetic nerve fibers in the innervation of the nasal-associated lymphoid tissues (NALT) was investigated in hamsters. Vesicular monoamine transporter 2 (VMAT2), an established sympathetic marker, is expressed in all neurons of superior cervical ganglia (SCG). In addition, VMAT2 -immunoreactive nerve fibers were localized in the NALT as well as in adjacent anatomical structures of the upper respiratory tract. Unilateral surgical ablation of the SCG abolished VMAT2 innervation patterns ipsilaterally while the contra lateral side is unaffected. These results provide the anatomical substrate for a neuroimmune connection in the NALT. Copyright © 2014 Elsevier B.V. All rights reserved.

Fascicular Phrenic Nerve Neurotization for Restoring Physiological Motion in a Congenital Diaphragmatic Hernia Reconstruction With a Reverse Innervated Latissimus Dorsi Muscle Flap.

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Horta, Ricardo; Henriques-Coelho, Tiago; Costa, Joana; Estevão-Costa, José; Monteiro, Diana; Dias, Mariana; Braga, José; Silva, Alvaro; Azevedo, Inês; Amarante, José Manuel

2015-08-01

Congenital diaphragmatic hernia is a severe developmental anomaly characterized by the malformation of the diaphragm. An innervated reversed latissimus dorsi flap reconstruction for recurrent congenital diaphragmatic hernia has been described as an alternative to prosthetic patch repair to achieve pleuroperitoneal separation. However, there is very little supporting scientific data; therefore, there is no real basic understanding of the condition of the phrenic nerve in the absence of diaphragmatic muscle or even the neurotization options for restoring neodiaphragmatic muscle motion. We have reviewed the literature regarding phrenic nerve anatomy and neurotization options, and to our knowledge, this is the first time that the application of a fascicular repair is being described where the continuity of one remaining fascicle of the diaphragm has been preserved close to the phrenic nerve distal division. The procedure was undertaken in a 3 year-old boy, with the diagnosis of congenital large posteromedial diaphragmatic hernia and dependence of mechanical ventilation in consequence of severe bronchopulmonary dysplasia.The phrenic nerve divides itself into several terminal branches, usually three, at the diaphragm level, or just above it. This allows the selective coaptation of separate fascicular branches. In the case described, videofluoroscopy evaluation showed no evidence of paradoxical neodiaphragmatic motion, with synchronous contraction movements and intact pleura-peritoneal separation. The child is now asymptomatic and shows improvement of his previous restrictive pulmonary disease.We believe that fascicular repair can achieve some reinnervation of the flap without jeopardizing the potential of diaphragmatic function by contraction of reminiscent native diaphragm.

Intrinsic and extrinsic innervation of the heart in zebrafish (Danio rerio).

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Stoyek, Matthew R; Croll, Roger P; Smith, Frank M

2015-08-01

In the vertebrate heart the intracardiac nervous system is the final common pathway for autonomic control of cardiac output, but the neuroanatomy of this system is not well understood. In this study we investigated the innervation of the heart in a model vertebrate, the zebrafish. We used antibodies against acetylated tubulin, human neuronal protein C/D, choline acetyltransferase, tyrosine hydroxylase, neuronal nitric oxide synthase, and vasoactive intestinal polypeptide to visualize neural elements and their neurotransmitter content. Most neurons were located at the venous pole in a plexus around the sinoatrial valve; mean total number of cells was 197 ± 23, and 92% were choline acetyltransferase positive, implying a cholinergic role. The plexus contained cholinergic, adrenergic, and nitrergic axons and vasoactive intestinal polypeptide-positive terminals, some innervating somata. Putative pacemaker cells near the plexus showed immunoreactivity for hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) and the transcription factor Islet-1 (Isl1). The neurotracer neurobiotin showed that extrinsic axons from the left and right vagosympathetic trunks innervated the sinoatrial plexus proximal to their entry into the heart; some extrinsic axons from each trunk also projected into the medial dorsal plexus region. Extrinsic axons also innervated the atrial and ventricular walls. An extracardiac nerve trunk innervated the bulbus arteriosus and entered the arterial pole of the heart to innervate the proximal ventricle. We have shown that the intracardiac nervous system in the zebrafish is anatomically and neurochemically complex, providing a substrate for autonomic control of cardiac effectors in all chambers. © 2015 Wiley Periodicals, Inc.

Directionality of auditory nerve fiber responses to pure tone stimuli in the grassfrog, Rana temporaria. II. Spike timing

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Jørgensen, M B; Christensen-Dalsgaard, J

1997-01-01

We studied the directionality of spike timing in the responses of single auditory nerve fibers of the grass frog, Rana temporaria, to tone burst stimulation. Both the latency of the first spike after stimulus onset and the preferred firing phase during the stimulus were studied. In addition, the ...

The visceromotor and somatic afferent nerves of the penis.

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

2015-05-01

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

Electrophysiologic studies of cutaneous nerves of the thoracic limb of the dog.

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Kitchell, R L; Whalen, L R; Bailey, C S; Lohse, C L

1980-01-01

The cutaneous innervation of the thoracic limb was investigated in 36 barbiturate-anesthetized dogs, using electrophysiologic techniques. The cutaneous area (CA) innervated by each cutaneous nerve was delineated in at least five dogs by stroking the hair in the area with a small watercolor brush while recording from the nerve. Mapping of adjacent CA revealed areas of considerable overlapping. The part of the CA of a given nerve supplied by only that nerve is referred to as its autonomous zone. Of all nerves arising from the brachial plexus, only the suprascapular, subscapular, lateral thoracic, thoracodorsal, and cranial and caudal pectoral nerves lacked cutaneous afferents. The dorsal cutaneous branch of C6 had a CA, but no grossly demonstrable dorsal cutaneous branches for C7 C8, or T1 were found. The cervical nerves had ventral cutaneous branches, but no lateral cutaneous branches. Thoracic nerves T2-T4 had dorsal, ventral, and lateral cutaneous branches. The cutaneous branches of the brachiocephalic, axillary, musculocutaneous, radial, median, and ulnar nerves all had CA which were overlapped by adjacent CA, thus their autonomous zones were much smaller than the cutaneous areas usually depicted for these nerves in anatomy and neurology textbooks.

Facial nerve problems and Bell's palsy

OpenAIRE

Sala, DV; Venter, C; Valenas, O

2015-01-01

Bell's palsy is paralysis or weakness of muscle at the hemifacial level, a form of temporary facial paralysis, probable a virus infection or trauma, to one or two facial nerves. Damage to the facial nerve innervating the muscles on one side of the face result in a flabby appearance, fell the respective hemiface. Nerve damage can also affect the sense of taste and salivary and lacrimal secretion. This condition begins suddenly, often overnight, and usually gets better on its own within a few w...

Target innervation is necessary for neuronal polyploidization in the terrestrial slug Limax.

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Matsuo, Ryota; Yamagishi, Miki; Wakiya, Kyoko; Tanaka, Yoko; Ito, Etsuro

2013-08-01

The brain of gastropod mollusks contains many giant neurons with polyploid genomic DNAs. Such DNAs are generated through repeated DNA endoreplication during body growth. However, it is not known what triggers DNA endoreplication in neurons. There are two possibilities: (1) DNAs are replicated in response to some unknown molecules in the hemolymph that reflect the nutritive status of the animal; or (2) DNAs are replicated in response to some unknown factors that are retrogradely transported through axons from the innervated target organs. We first tested whether hemolymph with rich nutrition could induce DNA endoreplication. We tested whether the transplanted brain exhibits enhanced DNA endoreplication like an endogenous brain does when transplanted into the homocoel of the body of a slug whose body growth is promoted by an increased food supply. However, no enhancement was observed in the frequency of DNA endoreplication when we compared the transplanted brains in the growth-promoted and growth-suppressed host slugs, suggesting that the humoral environment is irrelevant to triggering the body growth-dependent DNA endoreplication. Next, we tested the requirement of target innervation by surgically dissecting a unilateral posterior pedal nerve of an endogenous brain. Substantially lower number of neurons exhibited DNA endoreplication in the pedal ganglion ipsilateral to the dissected nerve. These results support the view that enhanced DNA endoreplication is mediated by target innervation and is not brought about through the direct effect of humoral factors in the hemolymph during body growth. Copyright © 2013 Wiley Periodicals, Inc.

Electrophysiology of Extraocular Cranial Nerves: Oculomotor, Trochlear, and Abducens Nerve.

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Hariharan, Praveen; Balzer, Jeffery R; Anetakis, Katherine; Crammond, Donald J; Thirumala, Parthasarathy D

2018-01-01

The utility of extraocular cranial nerve electrophysiologic recordings lies primarily in the operating room during skull base surgeries. Surgical manipulation during skull base surgeries poses a risk of injury to multiple cranial nerves, including those innervating extraocular muscles. Because tumors distort normal anatomic relationships, it becomes particularly challenging to identify cranial nerve structures. Studies have reported the benefits of using intraoperative spontaneous electromyographic recordings and compound muscle action potentials evoked by electrical stimulation in preventing postoperative neurologic deficits. Apart from surgical applications, electromyography of extraocular muscles has also been used to guide botulinum toxin injections in patients with strabismus and as an adjuvant diagnostic test in myasthenia gravis. In this article, we briefly review the rationale, current available techniques to monitor extraocular cranial nerves, technical difficulties, clinical and surgical applications, as well as future directions for research.

Tone and call responses of units in the auditory nerve and dorsal medullary nucleus of Xenopus laevis

DEFF Research Database (Denmark)

Elliott, Taffeta M.; Christensen-Dalsgaard, Jakob; Kelley, Darcy B.

2007-01-01

The clawed frog Xenopus laevis produces vocalizations consisting of distinct patterns of clicks. This study provides the first description of spontaneous, pure-tone and communication-signal evoked discharge properties of auditory nerve (n.VIII) fibers and dorsal medullary nucleus (DMN) cells...... in an obligatorily aquatic anuran. Responses of 297 n.VIII and 253 DMN units are analyzed for spontaneous rates (SR), frequency tuning, rate-intensity functions, and firing rate adaptation, with a view to how these basic characteristics shape responses to recorded call stimuli. Response properties generally resemble......Hz with approximately 500 Hz in 3 dB bandwidth. SRs range from 0 to 80 (n.VIII) and 0 to 73 spikes/s (DMN). Nerve and DMN units of all CFs follow click rates in natural calls,

Morfofisiologia da inervação do diafragma de ovinos Morphophysiology of diaphragm innervation in sheep

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Ana E.F. de Almeida

2008-09-01

Full Text Available Foram estudados em 30 diafragmas de ovinos da raça Santa Inês, a origem, a divisão e a distribuição dos nervos frênicos direito e esquerdo (Fde e a participação de outros nervos na inervação do diafragma. Mediante fixação e dissecação das peças foi observado que os nervos frênicos (F originam-se a partir dos ramos ventrais do 5º (C5 e 6º (C6 nervos espinhais cervicais (Ec tanto à direita (46,67% como à esquerda (43,33%. Os F finalizam em tronco lombocostal e ramo esternal à direita (40,00% e em ramo lombar, costal e esternal à esquerda (36,68%. Os ramos lombares dos F inervam à esquerda (96,67% o pilar homolateral do diafragma e, à direita (50,00% fornecem filetes à veia caudal. Os ramos costais dos F ramificam à esquerda (90,00% e à direita (76,67% as regiões dorsal e ventral da pars costalis. Os ramos esternais dos F inervam à direita (100,00% e à esquerda (83,33% a pars sternalis e a região ventral da pars costalis do mesmo lado. Os nervos intercostais (VIII ao XII pares, 63,33% contribuem na inervação do diafragma de ovinos da raça Santa Inês.Thirty diaphragms of sheep of Santa Inês breed were studied regarding their origin, division and arrangement of the right and left phrenic nerves (Fde, and the participation of other nerves in the innervation of the diaphragm. By fixing and dissecting pieces, it was found that phrenic nerves (F frequently come from the ventral branches of the 5th (C5 and 6th (C6 cervical spinal nerves (Ec, at right (46.67% and at left (43.33%. The F often form a lumbocostal trunk, sternal branches at right (40.00% and lumbar, costal and esternal branches at left (36.68%. The lumbar branches of F innervate frequently at left (96.67% the homolateral pillar of the diaphragma, and at right (50.00% they give fillets to Vena cava caudalis. The costal branches of the F innervate at left (90.00% and at right (76.66% the dorsal and ventral regions of the pars costalis. The sternal branches of

Waveform efficiency analysis of auditory nerve fiber stimulation for cochlear implants

International Nuclear Information System (INIS)

Navaii, Mehdi Lotfi; Sadhedi, Hamed; Jalali, Mohsen

2013-01-01

Evaluation of the electrical stimulation efficiency of various stimulating waveforms is an important issue for efficient neural stimulator design. Concerning the implantable micro devices design, it is also necessary to consider the feasibility of hardware implementation of the desired waveforms. In this paper, the charge, power and energy efficiency of four waveforms (i.e. square, rising ramp, triangular and rising ramp-decaying exponential) in various durations have been simulated and evaluated based on the computational model of the auditory nerve fibers. Moreover, for a fair comparison of their feasibility, a fully integrated current generator circuit has been developed so that the desired stimulating waveforms can be generated. The simulation results show that stimulation with the square waveforms is a proper choice in short and intermediate durations while the rising ramp-decaying exponential or triangular waveforms can be employed for long durations.

Morphological study of the sensory innervation of the rat labial mucosa.

Science.gov (United States)

Yamamoto, T; Tazaki, M; Sakada, S

1986-02-01

The sensory innervation of the rat labial mucosa was investigated by means of methylene blue vital staining and osmic acid staining. Sensory receptors in this region were of three kinds (free nerve endings, encapsulated corpuscles and bush-like nerve endings) which constituted separate sensory units respectively. The encapsulated corpuscles were observed in the deep part of lamina propria, and distributed mainly in the margin of labial mucosa. Almost all (78.8%) of encapsulated corpuscles were of a simple type which had a non-branched axon terminal. No clew-like type corpuscles or glomerular-Meissner corpuscles were observed. The bush-like nerve endings were located in the lamina propria close to the epithelium, and localized in the central part of labial mucosa where the formation of papillae was remarkable. The density of the encapsulated corpuscles in the entire mucosa was 3.5-5.3/mm2, and that of the bush-like nerve endings in the densely distributed area was 38.9-60.6/mm2.

Potential Role of Semaphorin 3A and Its Receptors in Regulating Aberrant Sympathetic Innervation in Peritoneal and Deep Infiltrating Endometriosis.

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Liang, Yanchun; Wang, Wei; Huang, Jiaming; Tan, Hao; Liu, Tianyu; Shang, Chunliang; Liu, Duo; Guo, Luyan; Yao, Shuzhong

2015-01-01

Previous studies have demonstrated the involvement of nerve repellent factors in regulation of the imbalanced innervation of endometriosis. This prospective study aims to explore the role of Sema 3A in regulating aberrant sympathetic innervation in peritoneal and deep infiltrating endometriosis. Ectopic endometriotic lesion were collected from patients with peritoneal endometriosis (n = 24) and deep infiltrating endometriosis of uterosacral ligament (n = 20) undergoing surgery for endometriosis. Eutopic endometrial samples were collected from patients with endometriosis (n = 22) or without endometriosis (n = 26). Healthy peritoneum (n = 13) from the lateral pelvic wall and healthy uterosacral ligament (n = 13) were obtained from patients who had no surgical and histological proof of endometriosis during hysterectomy for uterine fibroids. Firstly, we studied the immunostaining of Sema 3A, Plexin A1 and NRP-1 in all the tissues described above. Then we studied the nerve fiber density (NFD) of endometriosis-associated (sympathetic) nerve and para-endometriotic (sympathetic) nerve by double immunofluorescence staining. Finally we analyzed the relationship between expression of Sema 3A in stromal cells of endometriotic lesion and the aberrant innervation of endometriosis. Semi-quantitative immunostaining demonstrated that (1) Higher immunostaining of Sema 3A were found in the eutopic endometrial glandular epithelial cells from patients with endometriosis (p = 0.041) than those without endometriosis; (2) Sema 3A immunostaining was higher in glandular epithelial cells of peritoneal endometriosis (Pendometriosis, while its expression in ectopic stormal cells in both groups were significantly lower than that from eutopic endometrium of women without endometirosis (Pendometriosis-associated sympathetic nerve of peritoneal endometriosis (pendometriosis of uterosacral ligament (pperitoneal and deep infiltrating endometriosis.

Potential Role of Semaphorin 3A and Its Receptors in Regulating Aberrant Sympathetic Innervation in Peritoneal and Deep Infiltrating Endometriosis

Science.gov (United States)

Liang, Yanchun; Wang, Wei; Huang, Jiaming; Tan, Hao; Liu, Tianyu; Shang, Chunliang; Liu, Duo; Guo, Luyan; Yao, Shuzhong

2015-01-01

Previous studies have demonstrated the involvement of nerve repellent factors in regulation of the imbalanced innervation of endometriosis. This prospective study aims to explore the role of Sema 3A in regulating aberrant sympathetic innervation in peritoneal and deep infiltrating endometriosis. Ectopic endometriotic lesion were collected from patients with peritoneal endometriosis (n = 24) and deep infiltrating endometriosis of uterosacral ligament (n = 20) undergoing surgery for endometriosis. Eutopic endometrial samples were collected from patients with endometriosis (n = 22) or without endometriosis (n = 26). Healthy peritoneum (n = 13) from the lateral pelvic wall and healthy uterosacral ligament (n = 13) were obtained from patients who had no surgical and histological proof of endometriosis during hysterectomy for uterine fibroids. Firstly, we studied the immunostaining of Sema 3A, Plexin A1 and NRP-1 in all the tissues described above. Then we studied the nerve fiber density (NFD) of endometriosis-associated (sympathetic) nerve and para-endometriotic (sympathetic) nerve by double immunofluorescence staining. Finally we analyzed the relationship between expression of Sema 3A in stromal cells of endometriotic lesion and the aberrant innervation of endometriosis. Semi-quantitative immunostaining demonstrated that (1) Higher immunostaining of Sema 3A were found in the eutopic endometrial glandular epithelial cells from patients with endometriosis (p = 0.041) than those without endometriosis; (2) Sema 3A immunostaining was higher in glandular epithelial cells of peritoneal endometriosis (Pendometriosis, while its expression in ectopic stormal cells in both groups were significantly lower than that from eutopic endometrium of women without endometirosis (Pendometriosis-associated sympathetic nerve of peritoneal endometriosis (pendometriosis of uterosacral ligament (pendometriosis. PMID:26720585

Electrophysiologic studies of cutaneous nerves of the forelimb of the cat.

Science.gov (United States)

Kitchell, R L; Canton, D D; Johnson, R D; Maxwell, S A

1982-10-01

The cutaneous innervation of the forelimb was investigated in 20 barbiturate-anesthetized cats by using electrophysiological techniques. The cutaneous area (CA) innervated by each cutaneous nerve was delineated in at least six cats by brushing the hair in the CA with a small watercolor brush while recording from the nerve. Mapping of adjacent CA revealed larger overlap zones (OZ) than were noted in the dog. Remarkable findings were that the brachiocephalic nerve arose from the axillary nerve and the CA comparable to that supplied by the cutaneous branch of the brachiocephalic nerve in the dog was supplied by a cutaneous branch of the suprascapular nerve. The CA supplied by the communicating branch from the musculocutaneous to the median nerve was similar in both species except that the communicating branch arose proximal to any other branches of the musculocutaneous nerve in the cat, whereas it was a terminal branch in the dog. The superficial branch of the radial nerve gave off cutaneous brachial branches in the cat proximal to the lateral cutaneous antebrachial nerve. The CA of the palmar branches of the ulnar nerve did not completely overlap the CA of the palmar branches of the median nerve as occurred in the dog; thus an autonomous zone (AZ) for the CA of the palmar branches of the median nerve is present in the cat, whereas no AZ existed for the CA of this nerve in the dog.

Taste Bud-Derived BDNF Is Required to Maintain Normal Amounts of Innervation to Adult Taste Buds.

Science.gov (United States)

Meng, Lingbin; Ohman-Gault, Lisa; Ma, Liqun; Krimm, Robin F

2015-01-01

Gustatory neurons transmit chemical information from taste receptor cells, which reside in taste buds in the oral cavity, to the brain. As adult taste receptor cells are renewed at a constant rate, nerve fibers must reconnect with new taste receptor cells as they arise. Therefore, the maintenance of gustatory innervation to the taste bud is an active process. Understanding how this process is regulated is a fundamental concern of gustatory system biology. We speculated that because brain-derived neurotrophic factor (BDNF) is required for taste bud innervation during development, it might function to maintain innervation during adulthood. If so, taste buds should lose innervation when Bdnf is deleted in adult mice. To test this idea, we first removed Bdnf from all cells in adulthood using transgenic mice with inducible CreERT2 under the control of the Ubiquitin promoter. When Bdnf was removed, approximately one-half of the innervation to taste buds was lost, and taste buds became smaller because of the loss of taste bud cells. Individual taste buds varied in the amount of innervation each lost, and those that lost the most innervation also lost the most taste bud cells. We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds. Taste buds were confirmed as the source of BDNF regulating innervation. We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood.

Beneficial auditory and cognitive effects of auditory brainstem implantation in children.

Science.gov (United States)

Colletti, Liliana

2007-09-01

This preliminary study demonstrates the development of hearing ability and shows that there is a significant improvement in some cognitive parameters related to selective visual/spatial attention and to fluid or multisensory reasoning, in children fitted with auditory brainstem implantation (ABI). The improvement in cognitive paramenters is due to several factors, among which there is certainly, as demonstrated in the literature on a cochlear implants (CIs), the activation of the auditory sensory canal, which was previously absent. The findings of the present study indicate that children with cochlear or cochlear nerve abnormalities with associated cognitive deficits should not be excluded from ABI implantation. The indications for ABI have been extended over the last 10 years to adults with non-tumoral (NT) cochlear or cochlear nerve abnormalities that cannot benefit from CI. We demonstrated that the ABI with surface electrodes may provide sufficient stimulation of the central auditory system in adults for open set speech recognition. These favourable results motivated us to extend ABI indications to children with profound hearing loss who were not candidates for a CI. This study investigated the performances of young deaf children undergoing ABI, in terms of their auditory perceptual development and their non-verbal cognitive abilities. In our department from 2000 to 2006, 24 children aged 14 months to 16 years received an ABI for different tumour and non-tumour diseases. Two children had NF2 tumours. Eighteen children had bilateral cochlear nerve aplasia. In this group, nine children had associated cochlear malformations, two had unilateral facial nerve agenesia and two had combined microtia, aural atresia and middle ear malformations. Four of these children had previously been fitted elsewhere with a CI with no auditory results. One child had bilateral incomplete cochlear partition (type II); one child, who had previously been fitted unsuccessfully elsewhere

Imbalance between sympathetic and sensory innervation in peritoneal endometriosis.

Science.gov (United States)

Arnold, Julia; Barcena de Arellano, Maria L; Rüster, Carola; Vercellino, Giuseppe F; Chiantera, Vito; Schneider, Achim; Mechsner, Sylvia

2012-01-01

To investigate possible mechanisms of pain pathophysiology in patients with peritoneal endometriosis, a clinical study on sensory and sympathetic nerve fibre sprouting in endometriosis was performed. Peritoneal lesions (n=40) and healthy peritoneum (n=12) were immunostained and analysed with anti-protein gene product 9.5 (PGP 9.5), anti-substance P (SP) and anti-tyrosine hydroxylase (TH), specific markers for intact nerve fibres, sensory nerve fibres and sympathetic nerve fibres, respectively, to identify the ratio of sympathetic and sensory nerve fibres. In addition, immune cell infiltrates in peritoneal endometriotic lesions were analysed and the nerve growth factor (NGF) and interleukin (IL)-1β expression was correlate with the nerve fibre density. Peritoneal fluids from patients with endometriosis (n=40) and without endometriosis (n=20) were used for the in vitro neuronal growth assay. Cultured chicken dorsal root ganglia (DRG) and sympathetic ganglia were stained with anti-growth associated protein 43 (anti-GAP 43), anti-SP and anti-TH. We could detect an increased sensory and decreased sympathetic nerve fibres density in peritoneal lesions compared to healthy peritoneum. Peritoneal fluids of patients with endometriosis compared to patients without endometriosis induced an increased sprouting of sensory neurites from DRG and decreased neurite outgrowth from sympathetic ganglia. In conclusion, this study demonstrates an imbalance between sympathetic and sensory nerve fibres in peritoneal endometriosis, as well as an altered modulation of peritoneal fluids from patients with endometriosis on sympathetic and sensory innervation which might directly be involved in the maintenance of inflammation and pain. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of autonomic nerve stimulation on colorectal motility in rats

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Tong, Wei Dong; Ridolfi, Timothy J.; Kosinski, Lauren; Ludwig, Kirk; Takahashi, Toku

2010-01-01

Background Several disease processes of the colon and rectum, including constipation and incontinence, have been associated with abnormalities of the autonomic nervous system. However, the autonomic innervation to the colon and rectum are not fully understood. The aims of this study were to investigate the effect of stimulation of vagus nerves, pelvic nerves (PN) and hypogastric nerves (HGN) on colorectal motility in rats. Methods Four strain gauge transducers were implanted on the proximal colon, mid colon, distal colon and rectum to record circular muscle contractions in rats. Electrical stimulation was administered to the efferent distal ends of the cervical vagus nerve, PN and HGN. Motility index (MI) was evaluated before and during stimulation. Key Results Electrical stimulation (5–20 Hz) of the cervical vagus elicited significant contractions in the mid colon and distal colon, whereas less pronounced contractions were observed in the proximal colon. PN stimulation elicited significant contractions in the rectum as well as the mid colon and distal colon. Atropine treatment almost completely abolished the contractions induced by vagus nerve and PN stimulation. HGN stimulation caused relaxations in the rectum, mid colon and distal colon. The relaxations in response to HGN stimulation were abolished by propranolol. Conclusions & Inferences Vagal innervation extends to the distal colon, while the PN has projections in the distribution of the rectum through the mid colon. This suggests a pattern of dual parasympathetic innervation in the left colon. Parasympathetic fibers regulate colorectal contractions via muscarinic receptors. The HGN mainly regulates colorectal relaxations via beta-adrenoceptors. PMID:20067587

Malformation of the eighth cranial nerve in children.

Science.gov (United States)

de Paula-Vernetta, Carlos; Muñoz-Fernández, Noelia; Mas-Estellés, Fernando; Guzmán-Calvete, Abel; Cavallé-Garrido, Laura; Morera-Pérez, Constantino

2016-01-01

Prevalence of congenital sensorineural hearing loss (SNHL) is approximately 1.5-6 in every 1,000 newborns. Dysfunction of the auditory nerve (auditory neuropathy) may be involved in up to 1%-10% of cases; hearing losses because of vestibulocochlear nerve (VCN) aplasia are less frequent. The objectives of this study were to describe clinical manifestations, hearing thresholds and aetiology of children with SNHL and VCN aplasia. We present 34 children (mean age 20 months) with auditory nerve malformation and profound HL taken from a sample of 385 children implanted in a 10-year period. We studied demographic characteristics, hearing, genetics, risk factors and associated malformations (Casselman's and Sennaroglu's classifications). Data were processed using a bivariate descriptive statistical analysis (P<.05). Of all the cases, 58.8% were bilateral (IIa/IIa and I/I were the most common). Of the unilateral cases, IIb was the most frequent. Auditory screening showed a sensitivity of 77.4%. A relationship among bilateral cases and systemic pathology was observed. We found a statistically significant difference when comparing hearing loss impairment and patients with different types of aplasia as defined by Casselman's classification. Computed tomography (CT) scan yielded a sensitivity of 46.3% and a specificity of 85.7%. However, magnetic resonance imaging (MRI) was the most sensitive imaging test. Ten percent of the children in a cochlear implant study had aplasia or hypoplasia of the auditory nerve. The degree of auditory loss was directly related to the different types of aplasia (Casselman's classification) Although CT scan and MRI are complementary, the MRI is the test of choice for detecting auditory nerve malformation. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

Absence of the musculocutaneous nerve with innervation of coracobrachialis, biceps brachii, brachialis and the lateral border of the forearm by branches from the lateral cord of the brachial plexus

Science.gov (United States)

NAKATANI, TOSHIO; TANAKA, SHIGENORI; MIZUKAMI, SHIGEKI

1997-01-01

Anomalies of the brachial plexus and its terminal branches are not uncommon. Variations in the course and branches of the musculocutaneous nerve have been noted (Clemente, 1985; Bergman et al. 1988) and its absence was reported by Le Minor (1990). Several anomalies were present in the left plexus of a 59-y-old Japanese man (Fig.). There were no anterior and posterior divisions of the middle trunk, although there were communications between the posterior, medial and lateral cords. The musculocutaneous nerve was absent (Le Minor, 1990) and the medial and lateral roots of the median nerve did not unite in the axillary fossa but in the upper arm about 5 cm distal to the lower border of latissimus dorsi (Adachi, 1928; Buch-Hansen, 1955). The hitherto unreported findings were branches arising directly from the lateral cord to supply coracobrachialis, both heads of biceps brachii and brachialis. The lateral cutaneous nerve of the forearm was derived from the lateral cord with a small contribution from the medial root of the median nerve. Since there were communications between the posterior cord (a continuation of the middle trunk) and the medial and lateral cords, it is theoretically possibly, but not proven, that the root values of branches innervating the flexor muscles of the arm and forearm and the skin of lateral border of the forearm were normal. PMID:9419004

Scaffoldless tissue-engineered nerve conduit promotes peripheral nerve regeneration and functional recovery after tibial nerve injury in rats

Institute of Scientific and Technical Information of China (English)

Aaron M. Adams; Keith W. VanDusen; Tatiana Y. Kostrominova; Jacob P. Mertens; Lisa M. Larkin

2017-01-01

Damage to peripheral nerve tissue may cause loss of function in both the nerve and the targeted muscles it innervates. This study compared the repair capability of engineered nerve conduit (ENC), engineered fibroblast conduit (EFC), and autograft in a 10-mm tibial nerve gap. ENCs were fabricated utilizing primary fibroblasts and the nerve cells of rats on embryonic day 15 (E15). EFCs were fabricated utilizing primary fi-broblasts only. Following a 12-week recovery, nerve repair was assessed by measuring contractile properties in the medial gastrocnemius muscle, distal motor nerve conduction velocity in the lateral gastrocnemius, and histology of muscle and nerve. The autografts, ENCs and EFCs reestablished 96%, 87% and 84% of native distal motor nerve conduction velocity in the lateral gastrocnemius, 100%, 44% and 44% of native specific force of medical gastrocnemius, and 63%, 61% and 67% of native medial gastrocnemius mass, re-spectively. Histology of the repaired nerve revealed large axons in the autograft, larger but fewer axons in the ENC repair, and many smaller axons in the EFC repair. Muscle histology revealed similar muscle fiber cross-sectional areas among autograft, ENC and EFC repairs. In conclusion, both ENCs and EFCs promot-ed nerve regeneration in a 10-mm tibial nerve gap repair, suggesting that the E15 rat nerve cells may not be necessary for nerve regeneration, and EFC alone can suffice for peripheral nerve injury repair.

Delayed peripheral nerve repair: methods, including surgical 'cross-bridging' to promote nerve regeneration.

Science.gov (United States)

Gordon, Tessa; Eva, Placheta; Borschel, Gregory H

2015-10-01

Despite the capacity of Schwann cells to support peripheral nerve regeneration, functional recovery after nerve injuries is frequently poor, especially for proximal injuries that require regenerating axons to grow over long distances to reinnervate distal targets. Nerve transfers, where small fascicles from an adjacent intact nerve are coapted to the nerve stump of a nearby denervated muscle, allow for functional return but at the expense of reduced numbers of innervating nerves. A 1-hour period of 20 Hz electrical nerve stimulation via electrodes proximal to an injury site accelerates axon outgrowth to hasten target reinnervation in rats and humans, even after delayed surgery. A novel strategy of enticing donor axons from an otherwise intact nerve to grow through small nerve grafts (cross-bridges) into a denervated nerve stump, promotes improved axon regeneration after delayed nerve repair. The efficacy of this technique has been demonstrated in a rat model and is now in clinical use in patients undergoing cross-face nerve grafting for facial paralysis. In conclusion, brief electrical stimulation, combined with the surgical technique of promoting the regeneration of some donor axons to 'protect' chronically denervated Schwann cells, improves nerve regeneration and, in turn, functional outcomes in the management of peripheral nerve injuries.

BDNF Increases Survival and Neuronal Differentiation of Human Neural Precursor Cells Cotransplanted with a Nanofiber Gel to the Auditory Nerve in a Rat Model of Neuronal Damage

Directory of Open Access Journals (Sweden)

Yu Jiao

2014-01-01

Full Text Available Objectives. To study possible nerve regeneration of a damaged auditory nerve by the use of stem cell transplantation. Methods. We transplanted HNPCs to the rat AN trunk by the internal auditory meatus (IAM. Furthermore, we studied if addition of BDNF affects survival and phenotypic differentiation of the grafted HNPCs. A bioactive nanofiber gel (PA gel, in selected groups mixed with BDNF, was applied close to the implanted cells. Before transplantation, all rats had been deafened by a round window niche application of β-bungarotoxin. This neurotoxin causes a selective toxic destruction of the AN while keeping the hair cells intact. Results. Overall, HNPCs survived well for up to six weeks in all groups. However, transplants receiving the BDNF-containing PA gel demonstrated significantly higher numbers of HNPCs and neuronal differentiation. At six weeks, a majority of the HNPCs had migrated into the brain stem and differentiated. Differentiated human cells as well as neurites were observed in the vicinity of the cochlear nucleus. Conclusion. Our results indicate that human neural precursor cells (HNPC integration with host tissue benefits from additional brain derived neurotrophic factor (BDNF treatment and that these cells appear to be good candidates for further regenerative studies on the auditory nerve (AN.

The lower cranial nerves: IX, X, XI, XII.

Science.gov (United States)

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

2013-10-01

The lower cranial nerves innervate the pharynx and larynx by the glossopharyngeal (CN IX) and vagus (CN X) (mixed) nerves, and provide motor innervation of the muscles of the neck by the accessory nerve (CN XI) and the tongue by the hypoglossal nerve (CN XII). The symptomatology provoked by an anomaly is often discrete and rarely in the forefront. As with all cranial nerves, the context and clinical examinations, in case of suspicion of impairment of the lower cranial nerves, are determinant in guiding the imaging. In fact, the impairment may be located in the brain stem, in the peribulbar cisterns, in the foramens or even in the deep spaces of the face. The clinical localization of the probable seat of the lesion helps in choosing the adapted protocol in MRI and eventually completes it with a CT-scan. In the bulb, the intra-axial pathology is dominated by brain ischemia (in particular, with Wallenberg syndrome) and multiple sclerosis. Cisternal pathology is tumoral with two tumors, schwannoma and meningioma. The occurrence is much lower than in the cochleovestibular nerves as well as the leptomeningeal nerves (infectious, inflammatory or tumoral). Finally, foramen pathology is tumoral with, outside of the usual schwannomas and meningiomas, paragangliomas. For radiologists, fairly hesitant to explore these lower cranial pairs, it is necessary to be familiar with (or relearn) the anatomy, master the exploratory technique and be aware of the diagnostic possibilities. Copyright © 2013 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Taste Bud-Derived BDNF Is Required to Maintain Normal Amounts of Innervation to Adult Taste Buds123

Science.gov (United States)

Meng, Lingbin; Ohman-Gault, Lisa; Ma, Liqun

2015-01-01

Abstract Gustatory neurons transmit chemical information from taste receptor cells, which reside in taste buds in the oral cavity, to the brain. As adult taste receptor cells are renewed at a constant rate, nerve fibers must reconnect with new taste receptor cells as they arise. Therefore, the maintenance of gustatory innervation to the taste bud is an active process. Understanding how this process is regulated is a fundamental concern of gustatory system biology. We speculated that because brain-derived neurotrophic factor (BDNF) is required for taste bud innervation during development, it might function to maintain innervation during adulthood. If so, taste buds should lose innervation when Bdnf is deleted in adult mice. To test this idea, we first removed Bdnf from all cells in adulthood using transgenic mice with inducible CreERT2 under the control of the Ubiquitin promoter. When Bdnf was removed, approximately one-half of the innervation to taste buds was lost, and taste buds became smaller because of the loss of taste bud cells. Individual taste buds varied in the amount of innervation each lost, and those that lost the most innervation also lost the most taste bud cells. We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds. Taste buds were confirmed as the source of BDNF regulating innervation. We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood. PMID:26730405

Effect of rocuronium on the level and mode of pre-synaptic acetylcholine release by facial and somatic nerves, and changes following facial nerve injury in rabbits.

Science.gov (United States)

Tan, Jinghua; Xu, Jing; Xing, Yian; Chen, Lianhua; Li, Shitong

2015-01-01

Muscles innervated by the facial nerve show differential sensitivities to muscle relaxants than muscles innervated by somatic nerves. The evoked electromyography (EEMG) response is also proportionally reduced after facial nerve injury. This forms the theoretical basis for proper utilization of muscle relaxants to balance EEMG monitoring and immobility under general anesthesia. (1) To observe the relationships between the level and mode of acetylcholine (ACh) release and the duration of facial nerve injury, and the influence of rocuronium in an in vitro rabbit model. (2) To explore the pre-synaptic mechanisms of discrepant responses to a muscle relaxant. Quantal and non-quantal ACh release were measured by using intracellular microelectrode recording in the orbicularis oris 1 to 42 days after graded facial nerve injury and in the gastrocnemius with/without rocuronium. Quantal ACh release was significantly decreased by rocuronium in the orbicularis oris and gastrocnemius, but significantly more so in gastrocnemius. Quantal release was reduced after facial nerve injury, which was significantly correlated with the severity of nerve injury in the absence but not in the presence of rocuronium. Non-quantal ACh release was reduced after facial nerve injury, with many relationships observed depending on the extent of the injury. The extent of inhibition of non-quantal release by rocuronium correlated with the grade of facial nerve injury. These findings may explain why EEMG amplitude might be diminished after acute facial nerve injury but relatively preserved after chronic injury and differential responses in sensitivity to rocuronium.

The spatiotemporal development of innervation in spinal ligaments of chickens.

OpenAIRE

Jiang, H; Moreau, M; Greidanus, N; Bilo, J; Russell, G; Raso, J; Bagnall, K

1996-01-01

The development of the innervation of both central and lateral (intertransverse) spinal ligaments was investigated in chickens between the time of hatching and 13 wk of age. A total of 36 White Leghorn chickens in 4 groups of 9 at ages 0, 2, 7, and 13 wk were used. The spinal ligaments were dissected, serially sectioned and labelled with a monoclonal antibody against neurofilament protein and observed using either conventional fluorescence or confocal microscopy. Only a few nerve elements wer...

Absence of the musculocutaneous nerve: a rare anatomical variation with possible clinical-surgical implications

Directory of Open Access Journals (Sweden)

José Humberto Tavares Guerreiro Fregnani

Full Text Available CONTEXT: The musculocutaneous nerve is one of the terminal branches of the lateral fasciculus of the brachial plexus, and is responsible for innervation of the flexor musculature of the elbow and for skin sensitivity on the lateral surface of the forearm. Its absence has been described previously, but its real prevalence is unknown. CASE REPORT: A case of absence of the musculocutaneous nerve that was observed during the dissection of the right arm of a male cadaver is described. The area of innervation was supplied by the median nerve. From this, three branches emerged: one to the coracobrachialis muscle, another to the biceps brachii muscle and the third to the brachialis muscle. This last branch continued as a lateral antebrachial cutaneous nerve. This is an anatomical variation that has clinical-surgical implications, considering that injury to the median nerve in this case would have caused unexpected paralysis of the flexor musculature of the elbow and hypoesthesia of the lateral surface of the forearm.

Reinnervation of Paralyzed Muscle by Nerve-Muscle-Endplate Band Grafting

Science.gov (United States)

2015-10-01

Antoniadis G, Braun V, Rath SA, Richter HP. Evaluation of iatrogenic lesions in 722 surgically treated cases of peripheral nerve trauma. J Neurosurg...achieved by end-to-end approximation: review of 2,181 nerve lesions . Microsurgery. 1993;14(4):244- 246. 18 25. McAllister RM, Gilbert SE, Calder JS...innervation through irreparable damage to its nerve . DNI has been used for selective reinnervation of paralyzed laryngeal and facial muscles [15,16] as well

Developmental Changes in the Connective Tissues of the Porcine Recurrent Laryngeal Nerve

OpenAIRE

Campbell, Ellen O.; Samlan, Robin A.; McMullen, Nathaniel T.; Cook, Sarah; Smiley-Jewell, Suzette; Barkmeier-Kraemer, Julie

2013-01-01

The recurrent laryngeal nerve (RLN) branches from the vagus cranial nerve to innervate structures important for voicing and swallowing. Damage to this nerve, commonly associated with surgery or idiopathic etiologies that largely occur with aging, results in impaired voicing and swallowing. Sunderland proposed a model of peripheral nerve damage whereby a nerve’s ability to resist damage from stretch and compression is determined by the quantity and composition of its epineurial connective tiss...

Delayed peripheral nerve repair: methods, including surgical ′cross-bridging′ to promote nerve regeneration

Directory of Open Access Journals (Sweden)

Tessa Gordon

2015-01-01

Full Text Available Despite the capacity of Schwann cells to support peripheral nerve regeneration, functional recovery after nerve injuries is frequently poor, especially for proximal injuries that require regenerating axons to grow over long distances to reinnervate distal targets. Nerve transfers, where small fascicles from an adjacent intact nerve are coapted to the nerve stump of a nearby denervated muscle, allow for functional return but at the expense of reduced numbers of innervating nerves. A 1-hour period of 20 Hz electrical nerve stimulation via electrodes proximal to an injury site accelerates axon outgrowth to hasten target reinnervation in rats and humans, even after delayed surgery. A novel strategy of enticing donor axons from an otherwise intact nerve to grow through small nerve grafts (cross-bridges into a denervated nerve stump, promotes improved axon regeneration after delayed nerve repair. The efficacy of this technique has been demonstrated in a rat model and is now in clinical use in patients undergoing cross-face nerve grafting for facial paralysis. In conclusion, brief electrical stimulation, combined with the surgical technique of promoting the regeneration of some donor axons to ′protect′ chronically denervated Schwann cells, improves nerve regeneration and, in turn, functional outcomes in the management of peripheral nerve injuries.

Innervation pattern of polycystic ovaries in the women.

Science.gov (United States)

Wojtkiewicz, Joanna; Jana, Barbara; Kozłowska, Anna; Crayton, Robert; Majewski, Mariusz; Zalecki, Michał; Baranowski, Włodzimierz; Radziszewski, Piotr

2014-11-01

The aim of the present study was to determine the changes in both the distribution pattern and density of nerve fibers containing dopamine β-hydroxylase (DβH), vesicular acetylcholine transporter (VAChT), neuronal nitric oxide synthase (nNOS), substance P (SP), calcitonin gene related peptide (CGRP), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), somatostatin (SOM), galanin (GAL) and pituitary adenylate cyclase-activating polypeptide (PACAP) in the human polycystic ovaries. In the polycystic ovaries, when compared to the immunoreactions pattern observed in the control gonads, following changes were revealed: (1) an increase in the number of DβH-, VAChT-, VIP- or GAL-immunoreactive (IR) nerve fibers within the stroma as well as in the number of DβH-IR fibers near primordial follicles and medullar veins and venules; (2) a reduction in the number of nerve fibers containing nNOS, CGRP, SOM, PACAP within the stroma and in the numbers of CGRP-IR fibers around arteries; (3) an appearance of SP- and GAL-IR fibers around medullar and cortical arteries, arterioles, veins and venules, with except of GAL-IR fibers supplying medullar veins; and (4) the lack of nNOS-IR nerve fibers near primordial follicles and VIP-IR nerves around medullar arteries and arterioles. In conclusion, our results suggest that the changes in the innervation pattern of the polycystic ovaries in human may play an important role in the pathogenesis and/or course of this disorder. Copyright © 2014. Published by Elsevier B.V.

Taste bud cells and nerves

OpenAIRE

武田,正子/内田,暢彦/鈴木,裕子; タケダ,マサコ/ウチダ,ノブヒコ/スズキ,ユウコ; TAKEDA,Masako/UCHIDA,Nobuhiko/SUZUKI,Yuko

2002-01-01

Sectioning of glossopharyngeal nerves which innervate the taste buds in the circumvallate papillae caused apoptosis of taste buds, the numbers decreasing and the taste buds disappearing after 11 days. This indicates that gustatory nerves may release a trophic substance that induces and maintains taste buds. Taste bud cells contain neurotrophins, NCAM, NSE, PGP9.5, and NeuroD which are specific markers of neurons. The BDNF and GDNF of neurotrophins, and Trk B and GFRαl of their receptors were ...

Central projections of the sensory innervation of the rat middle meningeal artery

DEFF Research Database (Denmark)

Liu, Y.; Broman, J.; Edvinsson, L.

2008-01-01

Headaches, especially migraine, involve not only pain but also aspects such as vasodilation of cranial vessels and sensitization of nerve endings, processes dependent on and connected to the central nervous system. To understand pathogenic mechanisms of headache, it is important to elucidate...... the central projections of sensory nerves that innervate cranial vessels, of which the middle meningeal artery (MMA) is the largest artery supplying the dura mater. In this study, cholera toxin subunit b (CTb) or wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) was applied on the adventitia....... Labeled nerve terminations were found ipsilaterally in the lateral part of the spinal dorsal horn of segments C1-C3 and in the caudal and interpolar parts of the spinal trigeminal nucleus. WGA-HRP labeled terminations were mainly located in laminae I and II, whereas CTb labeled terminations located...

MRI-based 3D pelvic autonomous innervation: a first step towards image-guided pelvic surgery

Energy Technology Data Exchange (ETDEWEB)

Bertrand, M.M. [University Montpellier I, Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nimes, Montpellier (France); Macri, F.; Beregi, J.P. [Nimes University Hospital, University Montpellier 1, Radiology Department, Nimes (France); Mazars, R.; Prudhomme, M. [University Montpellier I, Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nimes, Montpellier (France); Nimes University Hospital, University Montpellier 1, Digestive Surgery Department, Nimes (France); Droupy, S. [Nimes University Hospital, University Montpellier 1, Urology-Andrology Department, Nimes (France)

2014-08-15

To analyse pelvic autonomous innervation with magnetic resonance imaging (MRI) in comparison with anatomical macroscopic dissection on cadavers. Pelvic MRI was performed in eight adult human cadavers (five men and three women) using a total of four sequences each: T1, T1 fat saturation, T2, diffusion weighed. Images were analysed with segmentation software in order to extract nervous tissue. Key height points of the pelvis autonomous innervation were located in every specimen. Standardised pelvis dissections were then performed. Distances between the same key points and the three anatomical references forming a coordinate system were measured on MRIs and dissections. Concordance (Lin's concordance correlation coefficient) between MRI and dissection was calculated. MRI acquisition allowed an adequate visualization of the autonomous innervation. Comparison between 3D MRI images and dissection showed concordant pictures. The statistical analysis showed a mean difference of less than 1 cm between MRI and dissection measures and a correct concordance correlation coefficient on at least two coordinates for each point. Our acquisition and post-processing method demonstrated that MRI is suitable for detection of autonomous pelvic innervations and can offer a preoperative nerve cartography. (orig.)

Levels of Bifurcation of the Sciatic Nerve among Ugandans at ...

African Journals Online (AJOL)

Background: The sciatic nerve is derived from the lumbo-sacral plexus, It is the thickest nerve in the whole body, it exits the gluteal region through the lower part of the greater sciatic foramen, it is the main innervator of the posterior thigh, the leg and foot, it usually ends halfway down the back of the thigh by dividing into the ...

Pathology of the vestibulocochlear nerve

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De Foer, Bert [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: bert.defoer@GZA.be; Kenis, Christoph [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: christophkenis@hotmail.com; Van Melkebeke, Deborah [Department of Neurology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Deborah.vanmelkebeke@Ugent.be; Vercruysse, Jean-Philippe [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: jphver@yahoo.com; Somers, Thomas [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Thomas.somers@GZA.be; Pouillon, Marc [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: marc.pouillon@GZA.be; Offeciers, Erwin [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Erwin.offeciers@GZA.be; Casselman, Jan W. [Department of Radiology, AZ Sint-Jan AV Hospital, Ruddershove 10, Bruges (Belgium); Consultant Radiologist, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium); Academic Consultent, University of Ghent (Belgium)], E-mail: jan.casselman@azbrugge.be

2010-05-15

There is a large scala of pathology affecting the vestibulocochlear nerve. Magnetic resonance imaging is the method of choice for the investigation of pathology of the vestibulocochlear nerve. Congenital pathology mainly consists of agenesis or hypoplasia of the vestibulocochlear nerve. Tumoral pathology affecting the vestibulocochlear nerve is most frequently located in the internal auditory canal or cerebellopontine angle. Schwannoma of the vestibulocochlear nerve is the most frequently found tumoral lesion followed by meningeoma, arachnoid cyst and epidermoid cyst. The most frequently encountered pathologies as well as some more rare entities are discussed in this chapter.

Pathology of the vestibulocochlear nerve

International Nuclear Information System (INIS)

De Foer, Bert; Kenis, Christoph; Van Melkebeke, Deborah; Vercruysse, Jean-Philippe; Somers, Thomas; Pouillon, Marc; Offeciers, Erwin; Casselman, Jan W.

2010-01-01

There is a large scala of pathology affecting the vestibulocochlear nerve. Magnetic resonance imaging is the method of choice for the investigation of pathology of the vestibulocochlear nerve. Congenital pathology mainly consists of agenesis or hypoplasia of the vestibulocochlear nerve. Tumoral pathology affecting the vestibulocochlear nerve is most frequently located in the internal auditory canal or cerebellopontine angle. Schwannoma of the vestibulocochlear nerve is the most frequently found tumoral lesion followed by meningeoma, arachnoid cyst and epidermoid cyst. The most frequently encountered pathologies as well as some more rare entities are discussed in this chapter.

Neurophysiologic intraoperative monitoring of the vestibulocochlear nerve.

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Simon, Mirela V

2011-12-01

Neurosurgical procedures involving the skull base and structures within can pose a significant risk of damage to the brain stem and cranial nerves. This can have life-threatening consequences and/or result in devastating neurologic deficits. Over the past decade, intraoperative neurophysiology has significantly evolved and currently offers a great tool for live monitoring of the integrity of nervous structures. Thus, dysfunction can be identified early and prompt modification of the surgical management or operating conditions, leads to avoidance of permanent structural damage.Along these lines, the vestibulocochlear nerve (CN VIII) and, to a greater extent, the auditory pathways as they pass through the brain stem are especially at risk during cerebelopontine angle (CPA), posterior/middle fossa, or brain stem surgery. CN VIII can be damaged by several mechanisms, from vascular compromise to mechanical injury by stretch, compression, dissection, and heat injury. Additionally, cochlea itself can be significantly damaged during temporal bone drilling, by noise, mechanical destruction, or infarction, and because of rupture, occlusion, or vasospasm of the internal auditory artery.CN VIII monitoring can be successfully achieved by live recording of the function of one of its parts, the cochlear or auditory nerve (AN), using the brain stem auditory evoked potentials (BAEPs), electrocochleography (ECochG), and compound nerve action potentials (CNAPs) of the cochlear nerve.This is a review of these techniques, their principle, applications, methodology, interpretation of the evoked responses, and their change from baseline, within the context of surgical and anesthesia environments, and finally the appropriate management of these changes.

Vasoactive intestinal polypeptide (VIP) innervation of the human eyelid glands.

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Seifert, P; Spitznas, M

1999-06-01

This study was conducted to obtain morphological proof of innervating nerve fibres in the glands of the human eyelid (accessory lacrimal glands of Wolfring, meibomian glands, goblet cells, glands of Zeis, glands of Moll, sweat glands, glands of lanugo hair follicles) and identification of the secretomotorically active neuropeptide vasoactive intestinal polypeptide (VIP) as a common transmitter. Epoxy-embedded ultrathin sections of tissue samples from human eyelids were studied using electron microscopy. Paraffin sections fixed in Bouin-Hollande solution were immunostained with rabbit antiserum against VIP. With the electron microscope we were able to identify nerves in the glandular stroma of all the glands examined with the exception of goblet cells. Intraepithelial single axons were only seen in the parenchyma of Wolfring glands. The morphological findings corresponded with the immunological finding of VIP-positive, nerve-like structures in the same locations, with the exception of lanugo hair follicle glands, and goblet cells. Our findings indicate that the glands of the eyelids and main lacrimal gland represent a functional unit with VIP as a possible common stimulating factor. Copyright 1999 Academic Press.

Bilateral duplication of the internal auditory canal

International Nuclear Information System (INIS)

Weon, Young Cheol; Kim, Jae Hyoung; Choi, Sung Kyu; Koo, Ja-Won

2007-01-01

Duplication of the internal auditory canal is an extremely rare temporal bone anomaly that is believed to result from aplasia or hypoplasia of the vestibulocochlear nerve. We report bilateral duplication of the internal auditory canal in a 28-month-old boy with developmental delay and sensorineural hearing loss. (orig.)

Narrow, duplicated internal auditory canal

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Ferreira, T. [Servico de Neurorradiologia, Hospital Garcia de Orta, Avenida Torrado da Silva, 2801-951, Almada (Portugal); Shayestehfar, B. [Department of Radiology, UCLA Oliveview School of Medicine, Los Angeles, California (United States); Lufkin, R. [Department of Radiology, UCLA School of Medicine, Los Angeles, California (United States)

2003-05-01

A narrow internal auditory canal (IAC) constitutes a relative contraindication to cochlear implantation because it is associated with aplasia or hypoplasia of the vestibulocochlear nerve or its cochlear branch. We report an unusual case of a narrow, duplicated IAC, divided by a bony septum into a superior relatively large portion and an inferior stenotic portion, in which we could identify only the facial nerve. This case adds support to the association between a narrow IAC and aplasia or hypoplasia of the vestibulocochlear nerve. The normal facial nerve argues against the hypothesis that the narrow IAC is the result of a primary bony defect which inhibits the growth of the vestibulocochlear nerve. (orig.)

RESISTIN, AN ADIPOKINE WITH NON-GENERALISED ACTIONS ON SYMPATHETIC NERVE ACTIVITY

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Emilio eBadoer

2015-11-01

Full Text Available The World Health Organisation has called obesity a global epidemic. There is a strong association between body weight gain and blood pressure. A major determinant of blood pressure is the level of activity in sympathetic nerves innervating cardiovascular organs. A characteristic of obesity, in both humans and in animal models, is an increase in sympathetic nerve activity to the skeletal muscle vasculature and to the kidneys. Obesity is now recognised as a chronic, low level inflammatory condition and pro-inflammatory cytokines are elevated including those produced by adipose tissue. The most well known adipokine released from fat tissue is leptin. The adipokine, resistin,, is also released from adipose tissue. Resistin can act in the central nervous system to influence the sympathetic nerve activity. Here, we review the effects of resistin on sympathetic nerve activity and compare them with leptin. We build an argument that resistin and leptin may have complex interactions. Firstly, they may augment each other as both are excitatory on sympathetic nerves innervating cardiovascular organs; In contrast, they could antagonize each other’s actions on brown adipose tissue, a key metabolic organ. These interactions may be important in conditions in which leptin and resistin are elevated, such as in obesity.

Central Somatosensory Networks Respond to a De Novo Innervated Penis : A Proof of Concept in Three Spina Bifida Patients

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Kortekaas, Rudie; Nanetti, Luca; Overgoor, Max L. E.; de Jong, Bauke M.; Georgiadis, Janniko R.

Introduction. Spina bifida (SB) causes low spinal lesions, and patients often have absent genital sensation and a highly impaired sex life. TOMAX (TO MAX-imize sensation, sexuality and quality of life) is a surgical procedure whereby the penis is newly innervated using a sensory nerve originally

Biomarkers of neuropathic pain in skin nerve degeneration neuropathy: contact heat-evoked potentials as a physiological signature.

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Wu, Shao-Wei; Wang, Yi-Chia; Hsieh, Paul-Chen; Tseng, Ming-Tsung; Chiang, Ming-Chang; Chu, Chih-Pang; Feng, Fang-Ping; Lin, Yea-Huey; Hsieh, Sung-Tsang; Chao, Chi-Chao

2017-03-01

Contact heat-evoked potentials (CHEPs) have become an established method of assessing small-fiber sensory nerves; however, their potential as a physiological signature of neuropathic pain symptoms has not been fully explored. To investigate the diagnostic efficacy in examining small-fiber sensory nerve degeneration, the relationship with skin innervations, and clinical correlates with sensory symptoms, we recruited 188 patients (115 men) with length-dependent sensory symptoms and reduced intraepidermal nerve fiber (IENF) density at the distal leg to perform CHEP, quantitative sensory testing, and nerve conduction study. Fifty-seven age- and sex-matched controls were enrolled for comparison of CHEP and skin innervation. Among patients with neuropathy, 144 patients had neuropathic pain and 64 cases had evoked pain. Compared with quantitative sensory testing and nerve conduction study parameters, CHEP amplitudes showed the highest sensitivity for diagnosing small-fiber sensory nerve degeneration and exhibited the strongest correlation with IENF density in multiple linear regression. Contact heat-evoked potential amplitudes were strongly correlated with the degree of skin innervation in both patients with neuropathy and controls, and the slope of the regression line between CHEP amplitude and IENF density was higher in patients with neuropathy than in controls. Patients with evoked pain had higher CHEP amplitude than those without evoked pain, independent of IENF density. Receiver operating characteristic analysis showed that CHEP had better performance in diagnosing small-fiber sensory nerve degeneration than thermal thresholds. Furthermore, CHEPs showed superior classification accuracy with respect to evoked pain. In conclusion, CHEP is a sensitive tool to evaluate pathophysiology of small-fiber sensory nerve and serves as a physiological signature of neuropathic pain symptoms.

Rat whisker movement after facial nerve lesion: evidence for autonomic contraction of skeletal muscle.

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Heaton, James T; Sheu, Shu Hsien; Hohman, Marc H; Knox, Christopher J; Weinberg, Julie S; Kleiss, Ingrid J; Hadlock, Tessa A

2014-04-18

Vibrissal whisking is often employed to track facial nerve regeneration in rats; however, we have observed similar degrees of whisking recovery after facial nerve transection with or without repair. We hypothesized that the source of non-facial nerve-mediated whisker movement after chronic denervation was from autonomic, cholinergic axons traveling within the infraorbital branch of the trigeminal nerve (ION). Rats underwent unilateral facial nerve transection with repair (N=7) or resection without repair (N=11). Post-operative whisking amplitude was measured weekly across 10weeks, and during intraoperative stimulation of the ION and facial nerves at ⩾18weeks. Whisking was also measured after subsequent ION transection (N=6) or pharmacologic blocking of the autonomic ganglia using hexamethonium (N=3), and after snout cooling intended to elicit a vasodilation reflex (N=3). Whisking recovered more quickly and with greater amplitude in rats that underwent facial nerve repair compared to resection (Pfacial-nerve-mediated whisking was elicited by electrical stimulation of the ION, temporarily diminished following hexamethonium injection, abolished by transection of the ION, and rapidly and significantly (Pfacial nerve resection. This study provides the first behavioral and anatomical evidence of spontaneous autonomic innervation of skeletal muscle after motor nerve lesion, which not only has implications for interpreting facial nerve reinnervation results, but also calls into question whether autonomic-mediated innervation of striated muscle occurs naturally in other forms of neuropathy. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Bilateral absence of musculocutaneous nerve

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Mathada V Ravishankar

2012-01-01

Full Text Available Brachial plexus is an important group of spinal nerve plexus that supplies the muscles of the upper limb via the ventral rami of the Cervical 5 - Thoracic 1 fibers of the spinal nerves. It is not uncommon to notice the variations during cadaveric dissections in many regions of the body, at different levels, such as, roots, trunks, division, cords, communications, and branches as reported in the literature. Although the nerve supply of the body musculature takes place in the fetal life itself, its course, branching pattern, innervations, and communication can show variable patterns as the fetal development progresses. One such anomaly was noticed during our routine cadaveric dissection in the Department of Anatomy, Jawaharlal Nehru Medical College, Belgaum, showing bilateral absence of the musculocutaneous nerve, which obviously drew the attention of the students of medicine, physiotherapy, and learning clinicians as well.

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

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

2016-01-01

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

Fast negative feedback enables mammalian auditory nerve fibers to encode a wide dynamic range of sound intensities.

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Mark Ospeck

Full Text Available Mammalian auditory nerve fibers (ANF are remarkable for being able to encode a 40 dB, or hundred fold, range of sound pressure levels into their firing rate. Most of the fibers are very sensitive and raise their quiescent spike rate by a small amount for a faint sound at auditory threshold. Then as the sound intensity is increased, they slowly increase their spike rate, with some fibers going up as high as ∼300 Hz. In this way mammals are able to combine sensitivity and wide dynamic range. They are also able to discern sounds embedded within background noise. ANF receive efferent feedback, which suggests that the fibers are readjusted according to the background noise in order to maximize the information content of their auditory spike trains. Inner hair cells activate currents in the unmyelinated distal dendrites of ANF where sound intensity is rate-coded into action potentials. We model this spike generator compartment as an attenuator that employs fast negative feedback. Input current induces rapid and proportional leak currents. This way ANF are able to have a linear frequency to input current (f-I curve that has a wide dynamic range. The ANF spike generator remains very sensitive to threshold currents, but efferent feedback is able to lower its gain in response to noise.

Auditory brainstem response latency in forward masking, a marker of sensory deficits in listeners with normal hearing thresholds

DEFF Research Database (Denmark)

Mehraei, Golbarg; Paredes Gallardo, Andreu; Shinn-Cunningham, Barbara G.

2017-01-01

In rodent models, acoustic exposure too modest to elevate hearing thresholds can nonetheless cause auditory nerve fiber deafferentation, interfering with the coding of supra-threshold sound. Low-spontaneous rate nerve fibers, important for encoding acoustic information at supra-threshold levels...... and in noise, are more susceptible to degeneration than high-spontaneous rate fibers. The change in auditory brainstem response (ABR) wave-V latency with noise level has been shown to be associated with auditory nerve deafferentation. Here, we measured ABR in a forward masking paradigm and evaluated wave......-V latency changes with increasing masker-to-probe intervals. In the same listeners, behavioral forward masking detection thresholds were measured. We hypothesized that 1) auditory nerve fiber deafferentation increases forward masking thresholds and increases wave-V latency and 2) a preferential loss of low...

Functional recovery of denervated skeletal muscle with sensory or mixed nerve protection: a pilot study.

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Qing Tian Li

Full Text Available 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.

The nerve endings of the acetabular labrum.

Science.gov (United States)

Kim, Y T; Azuma, H

1995-11-01

The nerve endings of the human acetabular labrum were investigated. Twenty-three acetabular labra were obtained from 24 fresh human cadavers, stained with Suzuki's silver impregnation and an immunohistochemical technique for neurogenic specific protein S-100, and examined by light and electron microscopy. Ramified free nerve endings were seen in all specimens by silver staining, and also were observed by the immunohistochemical technique for S-100 protein. Sensory nerve end organs, such as a Vater-Pacini corpuscle, Golgi-Mazzoni corpuscle, Ruffini corpuscle, and articular corpuscle (Krause corpuscle), were observed by silver staining. Collagen fibers were scattered sparsely in the superficial layer of the labrum, and nerve endings were observed mostly in this region. Collagen fibers were sparse, and nerve endings also were observed in some regions among the collagen fiber bundles in the inner layer. Innervation of the acetabular labrum was confirmed in this study, suggesting that nerve endings in the labrum may be involved in nociceptive and proprioceptive mechanisms.

Correlation between corneal innervation and inflammation evaluated with confocal microscopy and symptomatology in patients with dry eye syndromes: a preliminary study.

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Tepelus, Tudor C; Chiu, Gloria B; Huang, Jianyan; Huang, Ping; Sadda, SriniVas R; Irvine, John; Lee, Olivia L

2017-09-01

To evaluate corneal innervation and inflammatory cell infiltration using in vivo confocal microscopy (IVCM) and to correlate these findings with subjective symptoms of dry eye, as measured by the Ocular Surface Disease Index (OSDI) in patients with non-Sjögren's (NSDE) and Sjögren's syndrome dry eyes (SSDE). Central corneal images were prospectively captured from 10 age-matched healthy control eyes, 24 eyes with clinically diagnosed NSDE and 44 eyes with clinically diagnosed SSDE, using IVCM (HRT III RCM). Density, tortuosity and reflectivity of corneal nerves, presence of inflammatory dendritic cells (DCs) and OSDI scores were evaluated. Images obtained by IVCM from 78 eyes were analyzed. The density of nerve fibers was 1562 ± 996 μm/frame in the SSDE group, 2150 ± 1015 μm/frame in the NSDE group and 2725 ± 687 μm/frame in the control group (P eyes affected with NSDE and SSDE are characterized by alterations in corneal innervation and infiltration of inflammatory DCs. Corneal nerve density and reflectivity are correlated with severity of subjective dry eye symptoms, as measured by OSDI score.

Neuromuscular partitioning in the extensor carpi radialis longus and brevis based on intramuscular nerve distribution patterns: A three-dimensional modeling study.

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Ravichandiran, Mayoorendra; Ravichandiran, Nisanthini; Ravichandiran, Kajeandra; McKee, Nancy H; Richardson, Denyse; Oliver, Michele; Agur, Anne M

2012-04-01

Differential activation of specific regions within a skeletal muscle has been linked to the presence of neuromuscular compartments. However, few studies have investigated the extra- or intramuscular innervation throughout the muscle volume of extensor carpi radialis longus (ECRL) and brevis (ECRB). The aim of this study was to determine the presence of neuromuscular partitions in ECRL and ECRB based on the extra- and intramuscular innervation using three-dimensional modeling. The extra- and intramuscular nerve distribution was digitized and reconstructed in 3D in all the muscle volumes using Autodesk Maya in seven formalin embalmed cadaveric specimens (mean age, 75.7 ± 15.2 years). The intramuscular nerve distribution was modeled in all the muscle volumes. ECRL was found to have two neuromuscular compartments, superficial and deep. One branch from the radial nerve proper was found to innervate ECRL. This branch was divided into anterior and posterior branches to the superficial and deep compartments, respectively. Five innervation patterns were identified in ECRB with partitioning of the muscle belly into two, three, or four compartments, in a proximal to distal direction depending on the number of nerve branches entering the muscle belly. The ECRL and ECRB both demonstrated neuromuscular compartmentalization based on intramuscular innervation. According to the partitioning hypothesis, a muscle may be differentially activated depending on the required function of the muscle, thus allowing multifunctional muscles to contribute to a variety of movements. Therefore, the increased number of neuromuscular partitions in ECRB when compared with ECRL could be due to the need for more differential recruitment in the ECRB depending on force requirements. Copyright © 2011 Wiley Periodicals, Inc.

Precise auditory-vocal mirroring in neurons for learned vocal communication.

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Prather, J F; Peters, S; Nowicki, S; Mooney, R

2008-01-17

Brain mechanisms for communication must establish a correspondence between sensory and motor codes used to represent the signal. One idea is that this correspondence is established at the level of single neurons that are active when the individual performs a particular gesture or observes a similar gesture performed by another individual. Although neurons that display a precise auditory-vocal correspondence could facilitate vocal communication, they have yet to be identified. Here we report that a certain class of neurons in the swamp sparrow forebrain displays a precise auditory-vocal correspondence. We show that these neurons respond in a temporally precise fashion to auditory presentation of certain note sequences in this songbird's repertoire and to similar note sequences in other birds' songs. These neurons display nearly identical patterns of activity when the bird sings the same sequence, and disrupting auditory feedback does not alter this singing-related activity, indicating it is motor in nature. Furthermore, these neurons innervate striatal structures important for song learning, raising the possibility that singing-related activity in these cells is compared to auditory feedback to guide vocal learning.

Double muscle innervation using end-to-side neurorrhaphy in rats Dupla inervação muscular com neurorrafia término-lateral em ratos

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Elisangela Jeronymo Stipp-Brambilla

2012-01-01

Full Text Available CONTEXT AND OBJECTIVE: One of the techniques used for treating facial paralysis is double muscle innervation using end-to-end neurorrhaphy with sectioning of healthy nerves. The aim of this study was to evaluate whether double muscle innervation by means of end-to-side neurorrhaphy could occur, with maintenance of muscle innervation. DESIGN AND SETTING: Experimental study developed at the Experimental Research Center, Faculdade de Medicina de Botucatu, Unesp. METHODS: One hundred rats were allocated to five groups as follows: G1, control group; G2, the peroneal nerve was sectioned; G3, the tibial nerve was transected and the proximal stump was end-to-side sutured to the intact peroneal nerve; G4, 120 days after the G3 surgery, the peroneal nerve was sectioned proximally to the neurorrhaphy; G5, 120 days after the G3 surgery, the peroneal and tibial nerves were sectioned proximally to the neurorrhaphy. RESULTS: One hundred and fifty days after the surgery, G3 did not show any change in tibial muscle weight or muscle fiber diameter, but the axonal fiber diameter in the peroneal nerve distal to the neurorrhaphy had decreased. Although G4 showed atrophy of the cranial tibial muscle 30 days after sectioning the peroneal nerve, the electrophysiological test results and axonal diameter measurement confirmed that muscle reinnervation had occurred. CONCLUSION: These findings suggest that double muscle innervation did not occur through end-to-side neurorrhaphy; the tibial nerve was not able to maintain muscle innervation after the peroneal nerve had been sectioned, although muscle reinnervation was found to have occurred, 30 days after the peroneal nerve had been sectioned.CONTEXTO E OBJETIVO: Uma das técnicas utilizadas para tratamento da paralisia facial é a dupla inervação muscular com neurorrafia término-terminal, seccionando-se nervos sadios. O objetivo deste trabalho foi avaliar a ocorrência de dupla inervação muscular através de

Anatomical study of the articular branches innervated the hip and knee joint with reference to mechanism of referral pain in hip joint disease patients.

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Sakamoto, Junya; Manabe, Yoshitaka; Oyamada, Joichi; Kataoka, Hideki; Nakano, Jiro; Saiki, Kazunobu; Okamoto, Keishi; Tsurumoto, Toshiyuki; Okita, Minoru

2018-03-25

Referred pain in the anterior knee joint is the most common symptom in hip disease patients. The development of referred pain is considered to be related to dichotomizing peripheral sensory fibers. However, no gross anatomical findings identify any dichotomizing fibers innervating both the hip and knee joints. We dissected the femoral and obturator nerves in human cadavers to investigate the distribution of the articular branches in the hip and knee joints. Fourteen embalmed left lower limbs from 14 Japanese adult cadavers (five from females, nine from males, average age 73.8 ± 14.1 years) were observed macroscopically. The articular branches of the femoral and obturator nerves were dissected at the anterior margin of the groin toward the thigh region. After dissections of the articular nerves of the hip joints, the femoral and obturator nerves were exposed from proximally to distally to identify the articular nerves of the knee joints. The branching pattern of the articular branches in the hip and knee joints was recorded. In six of 14 limbs (42.9%), the femoral nerve supplied articular branches to the anteromedial aspect of both the hip and knee joints. These articular branches were derived from the same bundle of femoral nerve. These gross anatomical findings suggested that dichotomizing peripheral sensory fibers innervate the hip and knee joints and these could relate to the referred pain confirmed in the anterior knee joints of patients with hip disease. Clin. Anat., 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Changes of the vasculature and innervation in the anterior segment of the RCS rat eye.

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May, Christian Albrecht

2011-12-01

Investigating the anterior eye segment vasculature and innervation of dystrophic RCS rats, two major unique findings were observed: in the iris, young adult animals with retinal dystrophy showed an increase in substance P nerve fibres and a dilation of arterioles and capillaries. This finding continued during ageing. In the pars plana region, the surface covered by venules decreased continuously with age. In older animals, this decrease was parallelled by a local decrease of sympathetic TH-positive nerve fibres supplying these venules. For both conditions, no comparable data exists so far in the literature. They might point to a unique situation in the anterior eye segment of the dystrophic RCS rat. Copyright © 2011 Elsevier Ltd. All rights reserved.

Anatomy, Physiology and Function of the Auditory System

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Kollmeier, Birger

The human ear consists of the outer ear (pinna or concha, outer ear canal, tympanic membrane), the middle ear (middle ear cavity with the three ossicles malleus, incus and stapes) and the inner ear (cochlea which is connected to the three semicircular canals by the vestibule, which provides the sense of balance). The cochlea is connected to the brain stem via the eighth brain nerve, i.e. the vestibular cochlear nerve or nervus statoacusticus. Subsequently, the acoustical information is processed by the brain at various levels of the auditory system. An overview about the anatomy of the auditory system is provided by Figure 1.

Anterograde Tracing Method using DiI to Label Vagal Innervation of the Embryonic and Early Postnatal Mouse Gastrointestinal Tract

Science.gov (United States)

Murphy, Michelle C.; Fox, Edward A.

2007-01-01

The mouse is an extremely valuable model for studying vagal development in relation to strain differences, genetic variation, gene manipulations, or pharmacological manipulations. Therefore, a method using 1, 1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) was developed for labeling vagal innervation of the gastrointestinal (GI) tract in embryonic and postnatal mice. DiI labeling was adapted and optimized for this purpose by varying several facets of the method. For example, insertion and crushing of DiI crystals into the nerve led to faster DiI diffusion along vagal axons and diffusion over longer distances as compared with piercing the nerve with a micropipette tip coated with dried DiI oil. Moreover, inclusion of EDTA in the fixative reduced leakage of DiI out of nerve fibers that occurred with long incubations. Also, mounting labeled tissue in PBS was superior to glycerol with n-propyl gallate, which resulted in reduced clarity of DiI labeling that may have been due to DiI leaking out of fibers. Optical sectioning of flattened wholemounts permitted examination of individual tissue layers of the GI tract wall. This procedure aided identification of nerve ending types because in most instances each type innervates a different tissue layer. Between embryonic day 12.5 and postnatal day 8, growth of axons into the GI tract, formation and patterning of fiber bundles in the myenteric plexus and early formation of putative afferent and efferent nerve terminals were observed. Thus, the DiI tracing method developed here has opened up a window for investigation during an important phase of vagal development. PMID:17418900

Auditory Neural Prostheses – A Window to the Future

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Mohan Kameshwaran

2015-06-01

Full Text Available Hearing loss is one of the commonest congenital anomalies to affect children world-over. The incidence of congenital hearing loss is more pronounced in developing countries like the Indian sub-continent, especially with the problems of consanguinity. Hearing loss is a double tragedy, as it leads to not only deafness but also language deprivation. However, hearing loss is the only truly remediable handicap, due to remarkable advances in biomedical engineering and surgical techniques. Auditory neural prostheses help to augment or restore hearing by integration of an external circuitry with the peripheral hearing apparatus and the central circuitry of the brain. A cochlear implant (CI is a surgically implantable device that helps restore hearing in patients with severe-profound hearing loss, unresponsive to amplification by conventional hearing aids. CIs are electronic devices designed to detect mechanical sound energy and convert it into electrical signals that can be delivered to the coch­lear nerve, bypassing the damaged hair cells of the coch­lea. The only true prerequisite is an intact auditory nerve. The emphasis is on implantation as early as possible to maximize speech understanding and perception. Bilateral CI has significant benefits which include improved speech perception in noisy environments and improved sound localization. Presently, the indications for CI have widened and these expanded indications for implantation are related to age, additional handicaps, residual hearing, and special etiologies of deafness. Combined electric and acoustic stimulation (EAS / hybrid device is designed for individuals with binaural low-frequency hearing and severe-to-profound high-frequency hearing loss. Auditory brainstem implantation (ABI is a safe and effective means of hearing rehabilitation in patients with retrocochlear disorders, such as neurofibromatosis type 2 (NF2 or congenital cochlear nerve aplasia, wherein the cochlear nerve is damaged

Ontogeny of neuro-insular complexes and islets innervation in the human pancreas.

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Alexandra E. Proshchina

2014-04-01

Full Text Available The ontogeny of the neuro-insular complexes (NIC and the islets innervation in human pancreas has not been studied in detail. Our aim was to describe the developmental dynamics and distribution of the nervous system structures in the endocrine part of human pancreas. We used doublestaining with antibodies specific to pan-neural markers (neuron-specific enolase (NSE and S100 protein and to hormones of pancreatic endocrine cells. NSE and S100-positive nerves and ganglia were identified in the human fetal pancreas from gestation week (gw 10 onwards. Later the density of S100 and NSE-positive fibers increased. In adults this network was sparse. The islets innervation started to form from gw 14. NSE-containing endocrine cells were identified from gw 12 onwards. Additionally, S100-positive cells were detected both in the periphery and within some of the islets starting at gw 14. The analysis of islets innervation has shown that the fetal pancreas contained neuro-insular complexes and the number of these complexes was reduced in adults. The highest density of neuro-insular complexes is detected during middle and late fetal periods, when the mosaic islets, typical for adults, form. The close integration between the developing pancreatic islets and the nervous system structures may play an important role not only in the hormone secretion, but also in the islets morphogenesis.

Ontogeny of neuro-insular complexes and islets innervation in the human pancreas.

Science.gov (United States)

Proshchina, Alexandra E; Krivova, Yulia S; Barabanov, Valeriy M; Saveliev, Sergey V

2014-01-01

The ontogeny of the neuro-insular complexes (NIC) and the islets innervation in human pancreas has not been studied in detail. Our aim was to describe the developmental dynamics and distribution of the nervous system structures in the endocrine part of human pancreas. We used double-staining with antibodies specific to pan-neural markers [neuron-specific enolase (NSE) and S100 protein] and to hormones of pancreatic endocrine cells. NSE and S100-positive nerves and ganglia were identified in the human fetal pancreas from gestation week (gw) 10 onward. Later the density of S100 and NSE-positive fibers increased. In adults, this network was sparse. The islets innervation started to form from gw 14. NSE-containing endocrine cells were identified from gw 12 onward. Additionally, S100-positive cells were detected both in the periphery and within some of the islets starting at gw 14. The analysis of islets innervation has shown that the fetal pancreas contained NIC and the number of these complexes was reduced in adults. The highest density of NIC is detected during middle and late fetal periods, when the mosaic islets, typical for adults, form. The close integration between the developing pancreatic islets and the nervous system structures may play an important role not only in the hormone secretion, but also in the islets morphogenesis.

Imaging the trigeminal nerve

International Nuclear Information System (INIS)

Borges, Alexandra; Casselman, Jan

2010-01-01

Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

Imaging the trigeminal nerve

Energy Technology Data Exchange (ETDEWEB)

Borges, Alexandra [Radiology Department, Instituto Portugues de Oncologia Francisco Gentil, Centro de Lisboa, Rua Prof. Lima Basto, 1093, Lisboa (Portugal)], E-mail: borgalexandra@gmail.com; Casselman, Jan [Department of Radiology, A. Z. St Jan Brugge and A. Z. St Augustinus Antwerpen Hospitals (Belgium)

2010-05-15

Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

Nerve endings in the heart of teleosts.

Science.gov (United States)

Kumar, S

1979-01-01

The nerve endings in the heart of fishes were studied using silver impregnation techniques. The heart chambers are profusely innervated by the sympathetic, parasympathetic (vagal) and postganglionic fibers of the intracardiac ganglia situated at the sinuatrial and the atrioventricular junctions. The plexuses are composed of medullated and nonmedullated fibers. The nerve fibers generally end freely and are slightly branched or unbranched terminations of myelinated and unmyelinated fibers. Moreover, a few nerve fibers end redundant in the form of end-rings, bulb-like, bush-like, club-shaped end end-coil like structures. The complex unencapsulated types of endings are also found in the myocardium of the atrium and the ventricle. The encapsulated endings (Vater-Pacinian; Krause end-bulb) could not be observed.

Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration.

Science.gov (United States)

Mahmoud, Ahmed I; O'Meara, Caitlin C; Gemberling, Matthew; Zhao, Long; Bryant, Donald M; Zheng, Ruimao; Gannon, Joseph B; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Poss, Kenneth D; Lee, Richard T

2015-08-24

Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

Renal sympathetic nerve ablation for treatment-resistant hypertension

Science.gov (United States)

Krum, Henry; Schlaich, Markus; Sobotka, Paul

2013-01-01

Hypertension is a major risk factor for increased cardiovascular events with accelerated sympathetic nerve activity implicated in the pathogenesis and progression of disease. Blood pressure is not adequately controlled in many patients, despite the availability of effective pharmacotherapy. Novel procedure- as well as device-based strategies, such as percutaneous renal sympathetic nerve denervation, have been developed to improve blood pressure in these refractory patients. Renal sympathetic denervation not only reduces blood pressure but also renal as well as systemic sympathetic nerve activity in such patients. The reduction in blood pressure appears to be sustained over 3 years after the procedure, which suggests absence of re-innervation of renal sympathetic nerves. Safety appears to be adequate. This approach may also have potential in other disorders associated with enhanced sympathetic nerve activity such as congestive heart failure, chronic kidney disease and metabolic syndrome. This review will focus on the current status of percutaneous renal sympathetic nerve denervation, clinical efficacy and safety outcomes and prospects beyond refractory hypertension. PMID:23819768

The CT features of recurrent laryngeal nerve paralysis

International Nuclear Information System (INIS)

Wu Bin; Peng Weijun; Gu Yajia; Yang Tianxi; Wang Hongshi

2006-01-01

Objective: To describe the CT appearance of recurrent laryngeal nerve paralysis, discuss the anatomic and pathologic basis of this paralysis, and evaluate CT diagnosis. Methods: 32 cases of recurrent laryngeal nerve paralysis clinical confirmed were analyzed retrospectively. All of these patients had the CT scans from the level of hyoid bone to the upper thorax, the slice and interval are 5 mm. Results: CT findings of recurrent laryngeal nerve paralysis included: oblique of aryepiglottic fold, dislocation of arytenoid cartilage and cricoarytenoid joint, dilation and relaxation of piriform sinus for 27 cases (84.4%); wide and asymmetrical ventricle of larynx for 16 cases (50.0%); asymmetrical and fix of vocal fold for 11 cases (34.4%) et al. Conclusion: The recurrent laryngeal nerve innervate all the intrinsic muscles of the larynx except cricothyroid muscle, paralysis of the nerve leads to atrophy of related muscles. CT scan demonstrate the larynx morphologic changes of recurrent nerve paralysis and is helpful to identify the etiology. (authors)

Relationships between the integrity and function of lumbar nerve roots as assessed by diffusion tensor imaging and neurophysiology

Energy Technology Data Exchange (ETDEWEB)

Chiou, S.Y.; Strutton, P.H. [Imperial College London, The Nick Davey Laboratory, Division of Surgery, Human Performance Group, Department of Surgery and Cancer, Faculty of Medicine, London (United Kingdom); Hellyer, P.J. [Imperial College London, Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, London (United Kingdom); Imperial College London, Department of Bioengineering, London (United Kingdom); Sharp, D.J. [Imperial College London, Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, London (United Kingdom); Newbould, R.D. [Imanova, Ltd, London (United Kingdom); Patel, M.C. [Charing Cross Hospital, Imaging Department, Imperial College Healthcare NHS Trust, London (United Kingdom)

2017-09-15

Diffusion tensor imaging (DTI) has shown promise in the measurement of peripheral nerve integrity, although the optimal way to apply the technique for the study of lumbar spinal nerves is unclear. The aims of this study are to use an improved DTI acquisition to investigate lumbar nerve root integrity and correlate this with functional measures using neurophysiology. Twenty healthy volunteers underwent 3 T DTI of the L5/S1 area. Regions of interest were applied to L5 and S1 nerve roots, and DTI metrics (fractional anisotropy, mean, axial and radial diffusivity) were derived. Neurophysiological measures were obtained from muscles innervated by L5/S1 nerves; these included the slope of motor-evoked potential input-output curves, F-wave latency, maximal motor response, and central and peripheral motor conduction times. DTI metrics were similar between the left and right sides and between vertebral levels. Conversely, significant differences in DTI measures were seen along the course of the nerves. Regression analyses revealed that DTI metrics of the L5 nerve correlated with neurophysiological measures from the muscle innervated by it. The current findings suggest that DTI has the potential to be used for assessing lumbar spinal nerve integrity and that parameters derived from DTI provide quantitative information which reflects their function. (orig.)

Localization of cholecystokininlike immunoreactivity in the rat spinal cord, with particular reference to the autonomic innervation of the pelvic organs

DEFF Research Database (Denmark)

Schrøder, H D

1983-01-01

tracing and immunocytochemistry revealed that the two cholecystokinin terminal fields characteristic for L1-L2 and that surrounding the intermediolateral nucleus in L6-S1 were situated corresponding to preganglionic neurons innervating pelvic organs through the hypogastric nerve or the pelvic nerves...... from the more cranial part with respect to type of afferent connections. The origin of the spinal cholecystokinin was investigated and it was found that neither complete transection of the spinal cord nor ipsilateral sectioning of three or four dorsal roots induced visible changes...

The significance of a hypoplastic bony canal for the cochlear nerve in patients with sensorineural hearing loss: CT and MRI findings

International Nuclear Information System (INIS)

Choi, Yoon Jung; Park, Sang Yoo; Kim, Myung Soon; Sung, Ki Jun

2004-01-01

The purpose of this study is to evaluate the significance of the hypoplastic canal for the cochlear nerve in patients with sensorineural hearing loss (SNHL) and the relationship between the hypoplastic bony canal and aplasia or hypoplasia of the cochlear nerve. A retrospective review of high resolution temporal CT(HRCT) and MRI findings was conducted. The narrow bony canal of the cochlear nerve and the relative size of the internal auditory canal were correlated with the cochlear nerve deficiency on MRI. The comparative size of the component nerves (facial, cochlear, superior vestibular, inferior vestibular nerve), and the relative size of the internal auditory canal and the bony canal of the cochlear nerve were measured. The clinical history and the results of the clinical examination were reviewed for each patient. High resolution MRI showed aplasia of the common vestibulocochlear nerve in one patient and a deficiency of the cochlear nerve in 9 patients. These abnormalities occurred in association with a prominent narrowing of the canal for the cochlear nerve and a stenosis of the internal auditory canal, which was observed on temporal bone CT in 9 patients with congenital SNHL. Three patients had normal IAC, despite the presence of a hypoplastic cochlear nerve on the side on which they had SNHL. In one patient, the narrowing of the canal for the cochlear nerve and internal auditory canal were not found to be associated with acquired SNHL. The hypoplastic bony canal for the cochlear nerve might be more highly indicative of congenital cochlear nerve deficiency than that of the narrow internal auditory canal, and the position of the crista falciformis should also be carefully

The significance of a hypoplastic bony canal for the cochlear nerve in patients with sensorineural hearing loss: CT and MRI findings

Energy Technology Data Exchange (ETDEWEB)

Choi, Yoon Jung; Park, Sang Yoo; Kim, Myung Soon; Sung, Ki Jun [College of Medicine, Yonsei Univ., Wonju (Korea, Republic of)

2004-04-01

The purpose of this study is to evaluate the significance of the hypoplastic canal for the cochlear nerve in patients with sensorineural hearing loss (SNHL) and the relationship between the hypoplastic bony canal and aplasia or hypoplasia of the cochlear nerve. A retrospective review of high resolution temporal CT(HRCT) and MRI findings was conducted. The narrow bony canal of the cochlear nerve and the relative size of the internal auditory canal were correlated with the cochlear nerve deficiency on MRI. The comparative size of the component nerves (facial, cochlear, superior vestibular, inferior vestibular nerve), and the relative size of the internal auditory canal and the bony canal of the cochlear nerve were measured. The clinical history and the results of the clinical examination were reviewed for each patient. High resolution MRI showed aplasia of the common vestibulocochlear nerve in one patient and a deficiency of the cochlear nerve in 9 patients. These abnormalities occurred in association with a prominent narrowing of the canal for the cochlear nerve and a stenosis of the internal auditory canal, which was observed on temporal bone CT in 9 patients with congenital SNHL. Three patients had normal IAC, despite the presence of a hypoplastic cochlear nerve on the side on which they had SNHL. In one patient, the narrowing of the canal for the cochlear nerve and internal auditory canal were not found to be associated with acquired SNHL. The hypoplastic bony canal for the cochlear nerve might be more highly indicative of congenital cochlear nerve deficiency than that of the narrow internal auditory canal, and the position of the crista falciformis should also be carefully.

Inferior alveolar nerve block: Alternative technique.

Science.gov (United States)

Thangavelu, K; Kannan, R; Kumar, N Senthil

2012-01-01

Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages.

A hardware model of the auditory periphery to transduce acoustic signals into neural activity

Directory of Open Access Journals (Sweden)

Takashi eTateno

2013-11-01

Full Text Available To improve the performance of cochlear implants, we have integrated a microdevice into a model of the auditory periphery with the goal of creating a microprocessor. We constructed an artificial peripheral auditory system using a hybrid model in which polyvinylidene difluoride was used as a piezoelectric sensor to convert mechanical stimuli into electric signals. To produce frequency selectivity, the slit on a stainless steel base plate was designed such that the local resonance frequency of the membrane over the slit reflected the transfer function. In the acoustic sensor, electric signals were generated based on the piezoelectric effect from local stress in the membrane. The electrodes on the resonating plate produced relatively large electric output signals. The signals were fed into a computer model that mimicked some functions of inner hair cells, inner hair cell–auditory nerve synapses, and auditory nerve fibers. In general, the responses of the model to pure-tone burst and complex stimuli accurately represented the discharge rates of high-spontaneous-rate auditory nerve fibers across a range of frequencies greater than 1 kHz and middle to high sound pressure levels. Thus, the model provides a tool to understand information processing in the peripheral auditory system and a basic design for connecting artificial acoustic sensors to the peripheral auditory nervous system. Finally, we discuss the need for stimulus control with an appropriate model of the auditory periphery based on auditory brainstem responses that were electrically evoked by different temporal pulse patterns with the same pulse number.

Sympathetic nerve-derived ATP regulates renal medullary blood flow via vasa recta pericytes

Directory of Open Access Journals (Sweden)

Scott S Wildman

2013-10-01

Full Text Available Pericyte cells are now known to be a novel locus of blood flow control, being able to regulate capillary diameter via their unique morphology and expression of contractile proteins. We have previously shown that exogenous ATP causes constriction of vasa recta via renal pericytes, acting at a variety of membrane bound P2 receptors on descending vasa recta, and therefore may be able to regulate medullary blood flow (MBF. Regulation of MBF is essential for appropriate urine concentration and providing essential oxygen and nutrients to this region of high, and variable, metabolic demand. Various sources of endogenous ATP have been proposed, including from epithelial, endothelial and red blood cells in response to stimuli such as mechanical stimulation, local acidosis, hypoxia, and exposure to various hormones. Extensive sympathetic innervation of the nephron has previously been shown, however the innervation reported has focused around the proximal and distal tubules, and ascending loop of Henle. We hypothesise that sympathetic nerves are an additional source of ATP acting at renal pericytes and therefore regulate MBF. Using a rat live kidney slice model in combination with video imaging and confocal microscopy techniques we firstly show sympathetic nerves in close proximity to vasa recta pericytes in both the outer and inner medulla. Secondly, we demonstrate pharmacological stimulation of sympathetic nerves in situ (by tyramine evokes pericyte-mediated vasoconstriction of vasa recta capillaries; inhibited by the application of the P2 receptor antagonist suramin. Lastly, tyramine-evoked vasoconstriction of vasa recta by pericytes is significantly less than ATP-evoked vasoconstriction. Sympathetic innervation may provide an additional level of functional regulation in the renal medulla that is highly localized. It now needs to be determined under which physiological/pathophysiological circumstances that sympathetic innervation of renal pericytes is

Imaging of Cranial Nerves III, IV, VI in Congenital Cranial Dysinnervation Disorders.

Science.gov (United States)

Kim, Jae Hyoung; Hwang, Jeong Min

2017-06-01

Congenital cranial dysinnervation disorders are a group of diseases caused by abnormal development of cranial nerve nuclei or their axonal connections, resulting in aberrant innervation of the ocular and facial musculature. Its diagnosis could be facilitated by the development of high resolution thin-section magnetic resonance imaging. The purpose of this review is to describe the method to visualize cranial nerves III, IV, and VI and to present the imaging findings of congenital cranial dysinnervation disorders including congenital oculomotor nerve palsy, congenital trochlear nerve palsy, Duane retraction syndrome, Möbius syndrome, congenital fibrosis of the extraocular muscles, synergistic divergence, and synergistic convergence. © 2017 The Korean Ophthalmological Society.

Distribution and innervation of putative peripheral arterial chemoreceptors in the red-eared slider (Trachemys scripta elegans).

Science.gov (United States)

Reyes, Catalina; Fong, Angelina Y; Milsom, William K

2015-06-15

Peripheral arterial chemoreceptors have been isolated to the common carotid artery, aorta, and pulmonary artery of turtles. However, the putative neurotransmitters associated with these chemoreceptors have not yet been described. The goal of the present study was to determine the neurochemical content, innervations, and distribution of putative oxygen-sensing cells in the central vasculature of turtles and to derive homologies with peripheral arterial chemoreceptors of other vertebrates. We used tract tracing together with immunohistochemical markers for cholinergic cells (vesicular acetylcholine transporter [VAChT]), tyrosine hydroxylase (TH; the rate-limiting enzyme in catecholamine synthesis), and serotonin (5HT) to identify putative oxygen-sensing cells and to determine their anatomical relation to branches of the vagus nerve (Xth cranial nerve). We found potential oxygen-sensing cells in all three chemosensory areas innervated by branches of the Xth cranial nerve. Cells containing either 5HT or VAChT were found in all three sites. The morphology and size of these cells resemble glomus cells found in amphibians, mammals, tortoises, and lizards. Furthermore, we found populations of cholinergic cells located at the base of the aorta and pulmonary artery that are likely involved in efferent regulation of vessel resistance. Catecholamine-containing cells were not found in any of the putative chemosensitive areas. The presence of 5HT- and VAChT-immunoreactive cells in segments of the common carotid artery, aorta, and pulmonary artery appears to reflect a transition between cells containing the major neurotransmitters seen in fish (5HT) and mammals (ACh and adenosine). © 2015 Wiley Periodicals, Inc.

Selective reinnervation: a comparison of recovery following microsuture and conduit nerve repair.

Science.gov (United States)

Evans, P J; Bain, J R; Mackinnon, S E; Makino, A P; Hunter, D A

1991-09-20

Selective reinnervation was studied by comparing the regeneration across a conventional neurorraphy versus a conduit nerve repair. Lewis rats underwent right sciatic nerve transection followed by one of four different nerve repairs (n = 8/group). In groups I and II a conventional neurorraphy was performed and in groups III and IV the proximal and distal stumps were coapted by use of a silicone conduit with an interstump gap of 5 mm. The proximal and distal stumps in groups I and III were aligned anatomically correct and the proximal stump was rotated 180 degrees in groups II and IV (i.e. proximal peroneal nerve opposite the distal tibial nerve and the proximal tibial nerve opposite the distal peroneal nerve). By 14 weeks, there was an equivalent, but incomplete return in sciatic function index (SFI) in groups I, III, and IV as measured by walking track analysis. However, the SFI became unmeasurable by 6 weeks in all group II animals. At 14 weeks, the percent innervation of the tibialis anterior and medial gastronemius muscles by the peroneal and tibial nerves respectively was estimated by selective compound muscle action potential amplitude recordings. When fascicular alignment was reversed, there was greater tibial (P = 0.02) and lesser peroneal (P = 0.005) innervation of the gastrocnemius muscle in the conduit (group IV) versus the neurorraphy (group II) group. This suggests that the gastrocnemius muscle may be selectively reinnervated by the tibial nerve. However, there was no evidence of selective reinnervation of the tibialis anterior muscle. Despite these differences, the functional recovery in both conduit repair groups (III and IV) was equivalent to a correctly aligned microsuture repair (group I) and superior to that in the incorrectly aligned microsuture repair (group II).

In vivo intraoperative hypoglossal nerve stimulation for quantitative tongue motion analysis

NARCIS (Netherlands)

van Alphen, M.J.A.; Eskes, M.; Smeele, L.E.; Balm, A.J.M.; Balm, Alfonsus Jacobus Maria; van der Heijden, Ferdinand

2017-01-01

This is the first study quantitatively measuring tongue motion in 3D after in vivo intraoperative neurostimulation of the hypoglossal nerve and its branches during a neck dissection procedure. Firstly, this study is performed to show whether this set-up is suitable for innervating different muscles

Neuronal tracing of oral nerves in a velvet worm – Implications for the evolution of the ecdysozoan brain

Directory of Open Access Journals (Sweden)

Christine eMartin

2014-02-01

Full Text Available As one of the closest relatives of arthropods, Onychophora plays an important role in understanding the evolution of arthropod body plans. Currently there is controversy surrounding the evolution of the brain among the ecdysozoan clades, which shows a collar-shaped, circumoral organisation in cycloneuralians but a ganglionic architecture in panarthropods. Based on the innervation pattern of lip papillae surrounding the mouth, the onychophoran brain has been interpreted as a circumoral ring, suggesting that this organisation is an ancestral feature of Ecdysozoa. However, this interpretation is inconsistent with other published data. To explore the evolutionary origin of the onychophoran mouth and to shed light on the evolution of the ecdysozoan brains, we analysed the innervation pattern and morphogenesis of the oral lip papillae in the onychophoran Euperipatoides rowelli using DNA labelling, immunocytochemistry and neuronal tracing techniques. Our morphogenetic data revealed that the seven paired and one unpaired oral lip papillae arise from three anterior-most body segments. Retrograde fills show that only the first and the third nerves supplying the lip papillae are associated with cell bodies within the brain, whereas the second nerve exclusively receives fibres from somata of peripheral neurons located in the lip papillae. According to our anterograde fills and immunocytochemical data, the first nerve supplies the anterior-most pair of lip papillae, whereas the second and the third nerves are associated with the second to fifth and second to eighth lip papillae, respectively. These data suggest that the lip papillae of E. rowelli are mainly innervated by the proto- and deutocerebrum, whereas there are only a few additional cell bodies situated posterior to the brain. According to these findings, the overall innervation pattern of the oral lip papillae in E. rowelli is incompatible with the interpretation of the onychophoran brain as a

Functional anatomy of the hypoglossal innervated muscles of the rat tongue: a model for elongation and protrusion of the mammalian tongue.

Science.gov (United States)

McClung, J R; Goldberg, S J

2000-12-01

This anatomical investigation in the rat was designed to illustrate the detailed organization of the tongue's muscles and their innervation in order to elucidate the actions of the muscles of the higher mammalian tongue and thereby clarify the protrusor subdivision of the hypoglossal-tongue complex. The hypoglossal innervated, extrinsic styloglossus, hyoglossus, and genioglossus and the intrinsic transversus, verticalis and longitudinalis linguae muscles were observed by microdissection and analysis of serial transverse-sections of the tongue. Sihler's staining technique was applied to whole rat tongues to demonstrate the hypoglossal nerve branching patterns. Dissections of the tongue demonstrate the angles at which the extrinsic muscles act on the base of the tongue. The Sihler stained hypoglossal nerves demonstrate branches to the styloglossus and hyoglossus emanating from its lateral division while branches to the genioglossus muscle exit from its medial division. The largest portions of both XIIth nerve divisions can be seen to enter the body of the tongue to innervate the intrinsic muscles. Transverse sections of the tongue demonstrate the organization of the intrinsic muscle fibers of the tongue. Longitudinal muscle fibers run along the entire circumference of the tongue. Alternating sheets of transverse lingual and vertical lingual muscles can be observed to insert into the circumference of the tongue. Most importantly in clarifying tongue protrusion, we demonstrate the transversus muscle fibers enveloping the most superior and inferior portions of the longitudinalis muscles. Longitudinal muscle fascicles are completely encircled and thus are likely to be compressed by transverse muscle fascicles resulting in elongation of the tongue. We discuss our findings in relation to biomechanical studies, that describe the tongue as a muscular hydrostat and thereby define the "elongation-protrusion apparatus" of the mammalian tongue. In so doing, we clarify the

Experimental study of vascularized nerve graft: evaluation of nerve regeneration using choline acetyltransferase activity.

Science.gov (United States)

Iwai, M; Tamai, S; Yajima, H; Kawanishi, K

2001-01-01

A comparative study of nerve regeneration was performed on vascularized nerve graft (VNG) and free nerve graft (FNG) in Fischer strain rats. A segment of the sciatic nerve with vascular pedicle of the femoral artery and vein was harvested from syngeneic donor rat for the VNG group and the sciatic nerve in the same length without vascular pedicle was harvested for the FNG group. They were transplanted to a nerve defect in the sciatic nerve of syngeneic recipient rats. At 2, 4, 6, 8, 12, 16, and 24 weeks after operation, the sciatic nerves were biopsied and processed for evaluation of choline acetyltransferase (CAT) activity, histological studies, and measurement of wet weight of the muscle innervated by the sciatic nerve. Electrophysiological evaluation of the grafted nerve was also performed before sacrifice. The average CAT activity in the distal to the distal suture site was 383 cpm in VNG and 361 cpm in FNG at 2 weeks; 6,189 cpm in VNG and 2,264 cpm in FNG at 4 weeks; and 11,299 cpm in VNG and 9,424 cpm in FNG at 6 weeks postoperatively. The value of the VNG group was statistically higher than that of the FNG group at 4 weeks postoperatively. Electrophysiological and histological findings also suggested that nerve regeneration in the VNG group was superior to that in the FNG group during the same period. However, there was no significant difference between the two groups after 6 weeks postoperatively in any of the evaluations. The CAT measurement was useful in the experiments, because it was highly sensitive and reproducible. Copyright 2001 Wiley-Liss, Inc.

Afferent Innervation, Muscle Spindles, and Contractures Following Neonatal Brachial Plexus Injury in a Mouse Model.

Science.gov (United States)

Nikolaou, Sia; Hu, Liangjun; Cornwall, Roger

2015-10-01

We used an established mouse model of elbow flexion contracture after neonatal brachial plexus injury (NBPI) to test the hypothesis that preservation of afferent innervation protects against contractures and is associated with preservation of muscle spindles and ErbB signaling. A model of preganglionic C5 through C7 NBPI was first tested in mice with fluorescent axons using confocal imaging to confirm preserved afferent innervation of spindles despite motor end plate denervation. Preganglionic and postganglionic injuries were then created in wild-type mice. Four weeks later, we assessed total and afferent denervation of the elbow flexors by musculocutaneous nerve immunohistochemistry. Biceps muscle volume and cross-sectional area were measured by micro computed tomography. An observer who was blinded to the study protocol measured elbow flexion contractures. Biceps spindle and muscle fiber morphology and ErbB signaling pathway activity were assessed histologically and immunohistochemically. Preganglionic and postganglionic injuries caused similar total denervation and biceps muscle atrophy. However, after preganglionic injuries, afferent innervation was partially preserved and elbow flexion contractures were significantly less severe. Spindles degenerated after postganglionic injury but were preserved after preganglionic injury. ErbB signaling was inactivated in denervated spindles after postganglionic injury but ErbB signaling activity was preserved in spindles after preganglionic injury with retained afferent innervation. Preganglionic and postganglionic injuries were associated with upregulation of ErbB signaling in extrafusal muscle fibers. Contractures after NBPI are associated with muscle spindle degeneration and loss of spindle ErbB signaling activity. Preservation of afferent innervation maintained spindle development and ErbB signaling activity, and protected against contractures. Pharmacologic modulation of ErbB signaling, which is being investigated as a

Absence of both auditory evoked potentials and auditory percepts dependent on timing cues.

Science.gov (United States)

Starr, A; McPherson, D; Patterson, J; Don, M; Luxford, W; Shannon, R; Sininger, Y; Tonakawa, L; Waring, M

1991-06-01

An 11-yr-old girl had an absence of sensory components of auditory evoked potentials (brainstem, middle and long-latency) to click and tone burst stimuli that she could clearly hear. Psychoacoustic tests revealed a marked impairment of those auditory perceptions dependent on temporal cues, that is, lateralization of binaural clicks, change of binaural masked threshold with changes in signal phase, binaural beats, detection of paired monaural clicks, monaural detection of a silent gap in a sound, and monaural threshold elevation for short duration tones. In contrast, auditory functions reflecting intensity or frequency discriminations (difference limens) were only minimally impaired. Pure tone audiometry showed a moderate (50 dB) bilateral hearing loss with a disproportionate severe loss of word intelligibility. Those auditory evoked potentials that were preserved included (1) cochlear microphonics reflecting hair cell activity; (2) cortical sustained potentials reflecting processing of slowly changing signals; and (3) long-latency cognitive components (P300, processing negativity) reflecting endogenous auditory cognitive processes. Both the evoked potential and perceptual deficits are attributed to changes in temporal encoding of acoustic signals perhaps occurring at the synapse between hair cell and eighth nerve dendrites. The results from this patient are discussed in relation to previously published cases with absent auditory evoked potentials and preserved hearing.

Afferent innervation of the utricular macula in pigeons

Science.gov (United States)

Si, Xiaohong; Zakir, Mridha Md; Dickman, J. David

2003-01-01

Biotinylated dextran amine (BDA) was used to retrogradely label afferents innervating the utricular macula in adult pigeons. The pigeon utriclar macula consists of a large rectangular-shaped neuroepithelium with a dorsally curved anterior edge and an extended medioposterior tail. The macula could be demarcated into several regions based on cytoarchitectural differences. The striola occupied 30% of the macula and contained a large density of type I hair cells with fewer type II hair cells. Medial and lateral extrastriola zones were located outside the striola and contained only type II hair cells. A six- to eight-cell-wide band of type II hair cells existed near the center of the striola. The reversal line marked by the morphological polarization of hair cells coursed throughout the epithelium, near the peripheral margin, and through the center of the type II band. Calyx afferents innervated type I hair cells with calyceal terminals that contained between 2 and 15 receptor cells. Calyx afferents were located only in the striola region, exclusive of the type II band, had small total fiber innervation areas and low innervation densities. Dimorph afferents innervated both type I and type II hair cells with calyceal and bouton terminals and were primarily located in the striola region. Dimorph afferents had smaller calyceal terminals with few type I hair cells, extended fiber branches with bouton terminals and larger innervation areas. Bouton afferents innervated only type II hair cells in the extrastriola and type II band regions. Bouton afferents innervating the type II band had smaller terminal fields with fewer bouton terminals and smaller innervation areas than fibers located in the extrastriolar zones. Bouton afferents had the most bouton terminals on the longest fibers, the largest innervation areas with the highest innervation densities of all afferents. Among all afferents, smaller terminal innervation fields were observed in the striola and large fields were

Low-frequency versus high-frequency synchronisation in chirp-evoked auditory brainstem responses

DEFF Research Database (Denmark)

Rønne, Filip Munch; Gøtsche-Rasmussen, Kristian

2011-01-01

This study investigates the frequency specific contribution to the auditory brainstem response (ABR) of chirp stimuli. Frequency rising chirps were designed to compensate for the cochlear traveling wave delay, and lead to larger wave-V amplitudes than for click stimuli as more auditory nerve fibr...

Facial Nerve Schwannoma of the Cerebellopontine Angle: A Diagnostic Challenge

OpenAIRE

Lassaletta, Luis; Roda, José María; Frutos, Remedios; Patrón, Mercedes; Gavilán, Javier

2002-01-01

Facial nerve schwannomas are rare lesions that may involve any segment of the facial nerve. Because of their rarity and the lack of a consistent clinical and radiological pattern, facial nerve schwannomas located at the cerebellopontine angle (CPA) and internal auditory canal (IAC) represent a diagnostic and therapeutic challenge for clinicians. In this report, a case of a CPA/IAC facial nerve schwannoma is presented. Contemporary diagnosis and management of this rare lesion are analyzed.

Anatomical study of the motor branches of the median nerve to the forearm and guidelines for selective neurectomy.

Science.gov (United States)

Parot, Catalina; Leclercq, Caroline

2016-07-01

The median nerve is responsible for the motor innervation of most of the muscles usually involved in upper limb spasticity. Selective neurectomy is one of the treatments utilized to reduce spasticity. The purpose of this study was to describe the variations of the motor branches of the median nerve in the forearm and draw recommendations for an appropriate planning of selective neurectomy. The median nerve was dissected in the forearm of 20 fresh cadaver upper limbs. Measurements included number, origin, division, and entry point of each motor branch into the muscles. One branch for the pronator teres was the most common pattern. In 9/20 cases, it arose as a common trunk with other branches. A single trunk innervated the flexor carpi radialis with a common origin with other branches in 17/20 cases. Two, three or four branches innervated the flexor digitorum superficialis, the first one frequently through a common trunk with other branches. They were very difficult to identify unless insertions of pronator teres and flexor digitorum superficialis were detached. The flexor digitorum profundus received one to five branches and flexor pollicis longus one to two branches from the anterior interosseous nerve. There is no regular pattern of the motor branches of the median nerve in the forearm. Our findings differ in many points from the classical literature. Because of the frequency of common trunks for different muscles, we recommend the use of peroperative electrical stimulation. Selective neurotomy of flexor digitorum superficialis is technically difficult, because the entry point of some of their terminal branches occurs just below the arch and deep to the muscle belly.

Adaptation in the auditory system: an overview

Directory of Open Access Journals (Sweden)

David ePérez-González

2014-02-01

Full Text Available The early stages of the auditory system need to preserve the timing information of sounds in order to extract the basic features of acoustic stimuli. At the same time, different processes of neuronal adaptation occur at several levels to further process the auditory information. For instance, auditory nerve fiber responses already experience adaptation of their firing rates, a type of response that can be found in many other auditory nuclei and may be useful for emphasizing the onset of the stimuli. However, it is at higher levels in the auditory hierarchy where more sophisticated types of neuronal processing take place. For example, stimulus-specific adaptation, where neurons show adaptation to frequent, repetitive stimuli, but maintain their responsiveness to stimuli with different physical characteristics, thus representing a distinct kind of processing that may play a role in change and deviance detection. In the auditory cortex, adaptation takes more elaborate forms, and contributes to the processing of complex sequences, auditory scene analysis and attention. Here we review the multiple types of adaptation that occur in the auditory system, which are part of the pool of resources that the neurons employ to process the auditory scene, and are critical to a proper understanding of the neuronal mechanisms that govern auditory perception.

Naftidrofuryl affects neurite regeneration by injured adult auditory neurons.

Science.gov (United States)

Lefebvre, P P; Staecker, H; Moonen, G; van de Water, T R

1993-07-01

Afferent auditory neurons are essential for the transmission of auditory information from Corti's organ to the central auditory pathway. Auditory neurons are very sensitive to acute insult and have a limited ability to regenerate injured neuronal processes. Therefore, these neurons appear to be a limiting factor in restoration of hearing function following an injury to the peripheral auditory receptor. In a previous study nerve growth factor (NGF) was shown to stimulate neurite repair but not survival of injured auditory neurons. In this study, we have demonstrated a neuritogenesis promoting effect of naftidrofuryl in an vitro model for injury to adult auditory neurons, i.e. dissociated cell cultures of adult rat spiral ganglia. Conversely, naftidrofuryl did not have any demonstrable survival promoting effect on these in vitro preparations of injured auditory neurons. The potential uses of this drug as a therapeutic agent in acute diseases of the inner ear are discussed in the light of these observations.

Unilateral sectioning of the superior ovarian nerve of rats with polycystic ovarian syndrome restores ovulation in the innervated ovary

Directory of Open Access Journals (Sweden)

Morales-Ledesma Leticia

2010-08-01

Full Text Available Abstract The present study tested the hypothesis that if polycystic ovary syndrome (PCOS results from activating the noradrenergic outflow to the ovary, unilaterally sectioning the superior ovarian nerve (SON will result in ovulation by the denervated ovary, and the restoration of progesterone (P4, testosterone (T and estradiol (E2 normal serum level. A single 2 mg dose of estradiol valerate (EV to adult rats results in the development of a syndrome similar to the human PCOS. Ten-day old rats were injected with EV or vehicle solution (Vh and were submitted to sham surgery, unilateral or bilateral sectioning of the SON at 24-days of age. The animals were sacrificed at 90 to 92 days of age, when they presented vaginal estrus preceded by a pro-estrus smear. In EV-treated animals, unilateral sectioning of the SON restored ovulation by the innervated ovary and unilateral or bilateral sectioning of the SON normalized testosterone and estradiol levels. These results suggest that aside from an increase in ovarian noradrenergic tone in the ovaries, in the pathogenesis of the PCOS participate other neural influences arriving to the ovaries via the SON, regulating spontaneous ovulation. Changes in P4, T and E2 serum levels induced by EV treatment seem to be controlled by neural signals arising from the abdominal wall and other signals arriving to the ovaries through the SON, and presents asymmetry.

Binaural processing by the gecko auditory periphery.

Science.gov (United States)

Christensen-Dalsgaard, Jakob; Tang, Yezhong; Carr, Catherine E

2011-05-01

Lizards have highly directional ears, owing to strong acoustical coupling of the eardrums and almost perfect sound transmission from the contralateral ear. To investigate the neural processing of this remarkable tympanic directionality, we combined biophysical measurements of eardrum motion in the Tokay gecko with neurophysiological recordings from the auditory nerve. Laser vibrometry shows that their ear is a two-input system with approximately unity interaural transmission gain at the peak frequency (∼ 1.6 kHz). Median interaural delays are 260 μs, almost three times larger than predicted from gecko head size, suggesting interaural transmission may be boosted by resonances in the large, open mouth cavity (Vossen et al. 2010). Auditory nerve recordings are sensitive to both interaural time differences (ITD) and interaural level differences (ILD), reflecting the acoustical interactions of direct and indirect sound components at the eardrum. Best ITD and click delays match interaural transmission delays, with a range of 200-500 μs. Inserting a mold in the mouth cavity blocks ITD and ILD sensitivity. Thus the neural response accurately reflects tympanic directionality, and most neurons in the auditory pathway should be directional.

Parkinson disease affects peripheral sensory nerves in the pharynx.

Science.gov (United States)

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

2013-07-01

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

Salvage of cervical motor radiculopathy using peripheral nerve transfer reconstruction.

Science.gov (United States)

Afshari, Fardad T; Hossain, Taushaba; Miller, Caroline; Power, Dominic M

2018-05-10

Motor nerve transfer surgery involves re-innervation of important distal muscles using either an expendable motor branch or a fascicle from an adjacent functioning nerve. This technique is established as part of the reconstructive algorithm for traumatic brachial plexus injuries. The reproducible outcomes of motor nerve transfer surgery have resulted in exploration of the application of this technique to other paralysing conditions. The objective of this study is to report feasibility and increase awareness about nerve transfer as a method of improving upper limb function in patients with cervical motor radiculopathy of different aetiology. In this case series we report 3 cases with different modes of injury to the spinal nerve roots with significant and residual motor radiculopathy that have been successfully treated with nerve transfer surgery with good functional outcomes. The cases involved iatrogenic nerve root injury, tumour related root compression and degenerative root compression. Nerve transfer surgery may offer reliable reconstruction for paralysis when there has been no recovery following a period of conservative management. However the optimum timing of nerve transfer intervention is not yet identified for patients with motor radiculopathy.

MRI enhancement of the facial nerve with Gd-DTPA, 2; Investigation of enhanced nerve portions in patients with facial palsy

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Masahiro [Kansai Medical School, Moriguchi, Osaka (Japan)

1993-08-01

We performed enhanced MRI using Gd-DTPA in 84 patients with facial palsy. After assessing enhancement of the normal facial nerve, we examined enhancement in patients with Bell's palsy and Ramsay Hunt syndrome. In 95% of patients with Bell's palsy, enhancement was obtained in the distal IAC and labyrinthine portions. In 72%, enhancement was significant from the distal IAC portion through the vertical portion. In some of the patients who underwent enhanced MRI twice, increased signal intensity was observed in distal portions such as the vertical portion. In many cases of Ramsay Hunt syndrome, enhancement was seen extensively in the IAC portion through the vertical portion. In the subjects with internal auditory symptoms such as vertigo and tinnitus, enhancement of the IAC portion was seen not only in the facial nerve but also in the vestibular and the cochlear nerves. These results suggest that the vascular permeability of lesions in Bell's palsy may be increased from the distal IAC portion to the vertical portion. Judging from the present findings with Ramsay Hunt syndrome, symptoms related to the enhanced portions suggest that accompanying internal auditory symptoms occur due to inflammation of the IAC portions of cochlear and vestibular nerves. (author).

Localized hypertrophic neuropathy of the sciatic nerve in children: MRI findings

International Nuclear Information System (INIS)

Roux, Adrien; Treguier, Catherine; Bruneau, Bertrand; Marin, Franck; Gandon, Yves; Gauvrit, Jean-Yves; Riffaud, Laurent; Violas, Philippe; Michel, Anne

2012-01-01

Localized hypertrophic neuropathy (LHN) of the sciatic nerve in children is a rare condition characterized by a painless neurological deficit in the sciatic nerve territory. To demonstrate the role of MRI using a specific protocol and describe the primary findings in LHN. Imaging in four children (age 2 years to 12 years) is presented. All children presented with lower limb asymmetry. Three had a steppage gait. LHN was confirmed by electrophysiological studies and by MRI of the whole sciatic nerve with a dedicated protocol covering the lumbar spine and the lower limb. There were four direct MRI findings: (1) linear and focal hypertrophy with progressive enlargement of a peripheral nerve or plexus diameter, (2) abnormal hyperintensity of the nerve on T2-weighted images, (3) preserved fascicular configuration, and (4) variable enhancement after intravenous gadolinium administration. In addition there were atrophy and fatty infiltration of innervated muscles. MRI was helpful for determining the extent of lesions and in excluding peripheral nerve compression or tumour. MRI of the whole sciatic nerve is the method of choice for diagnosing LHN of the sciatic nerve. (orig.)

Localized hypertrophic neuropathy of the sciatic nerve in children: MRI findings

Energy Technology Data Exchange (ETDEWEB)

Roux, Adrien; Treguier, Catherine; Bruneau, Bertrand; Marin, Franck; Gandon, Yves; Gauvrit, Jean-Yves [University Hospital, Department of Radiology, Hopital Sud, 16 Boulevard de Bulgarie, BP 90347, Rennes cedex 2 (France); Riffaud, Laurent [University Hospital, Department of Pediatric Neurosurgery, Hopital Sud, Rennes (France); Violas, Philippe [University Hospital, Department of Pediatric Surgery, Hopital Sud, Rennes (France); Michel, Anne [University Hospital, Department of Neurological Functional Explorations, Hopital Sud, Rennes (France)

2012-08-15

Localized hypertrophic neuropathy (LHN) of the sciatic nerve in children is a rare condition characterized by a painless neurological deficit in the sciatic nerve territory. To demonstrate the role of MRI using a specific protocol and describe the primary findings in LHN. Imaging in four children (age 2 years to 12 years) is presented. All children presented with lower limb asymmetry. Three had a steppage gait. LHN was confirmed by electrophysiological studies and by MRI of the whole sciatic nerve with a dedicated protocol covering the lumbar spine and the lower limb. There were four direct MRI findings: (1) linear and focal hypertrophy with progressive enlargement of a peripheral nerve or plexus diameter, (2) abnormal hyperintensity of the nerve on T2-weighted images, (3) preserved fascicular configuration, and (4) variable enhancement after intravenous gadolinium administration. In addition there were atrophy and fatty infiltration of innervated muscles. MRI was helpful for determining the extent of lesions and in excluding peripheral nerve compression or tumour. MRI of the whole sciatic nerve is the method of choice for diagnosing LHN of the sciatic nerve. (orig.)

Ultrasound of the sural nerve: Normal anatomy on cadaveric dissection and case series

International Nuclear Information System (INIS)

Belsack, Dries; Jager, Tjeerd; Scafoglieri, Aldo; Vanderdood, Kurt; Van Hedent, Eddy; Vanhoenacker, Filip; Marcelis, Stefaan; De Maeseneer, Michel

2013-01-01

The sural nerve is a small sensory nerve innervating the lateral aspect of the ankle and foot. Clinical symptoms of pathology may present as atypical sensory changes in this region. We present the normal anatomy and ultrasound technique for examination of the sural nerve based on an anatomical dissection, as well as imaging in a normal volunteer. We also present a case series (n = 10) of different conditions of the sural nerve that we encountered based on a review of interesting cases from 4 institutions. The pathological conditions included neuropathy related to stripping or venous laser surgery, compression by abscess, Lyme disease, nerve tumors, traumatic transsection, and encasement by fibrous plaque and edema. Ultrasound with its exquisite resolution is the preferred imaging method for examining the sural nerve in patients with unexplained sensory changes at the lateral aspect of the ankle and foot

Ultrasound of the sural nerve: Normal anatomy on cadaveric dissection and case series

Energy Technology Data Exchange (ETDEWEB)

Belsack, Dries, E-mail: dries.belsack@uzbrussel.be [Department of Radiology, UZ Brussel, Laarbeeklaan 101, 1090 Jette, Brussels (Belgium); Jager, Tjeerd, E-mail: tjeerd.jager@asz.be [Department of Radiology, Aalsters Stedelijk Ziekenhuis, Merestraat 80, 9300 Aalst (Belgium); Scafoglieri, Aldo, E-mail: aldo.scafoglieri@vub.ac.be [Department of Experimental Anatomy, Free University Brussels, Laarbeeklaan 103, 1090 Jette (Belgium); Vanderdood, Kurt, E-mail: kvanderd@yahoo.com [Department of Radiology, Maaslandziekenhuis, Dr H van der Hoffplein 1, 6162 Sittard-Geleen, Sittard (Netherlands); Van Hedent, Eddy, E-mail: eddy.vanhedent@asz.be [Department of Radiology, Aalsters Stedelijk Ziekenhuis, Merestraat 80, 9300 Aalst (Belgium); Vanhoenacker, Filip, E-mail: filip.vanhoenacker@telenet.be [Department of Radiology, AZ Sint-Maarten, Duffel-Mechelen, Rooienberg 25, 2570 Duffel (Belgium); Marcelis, Stefaan, E-mail: stefaan.marcelis@sintandriesstielt.be [Department of Radiology, Sint Andriesziekenhuis, Krommewalstraat 11, 8700 Tielt (Belgium); De Maeseneer, Michel, E-mail: michel.demaeseneer@uzbrussel.be [Department of Radiology, UZ Brussel, Laarbeeklaan 101, 1090 Jette, Brussels (Belgium)

2013-11-01

The sural nerve is a small sensory nerve innervating the lateral aspect of the ankle and foot. Clinical symptoms of pathology may present as atypical sensory changes in this region. We present the normal anatomy and ultrasound technique for examination of the sural nerve based on an anatomical dissection, as well as imaging in a normal volunteer. We also present a case series (n = 10) of different conditions of the sural nerve that we encountered based on a review of interesting cases from 4 institutions. The pathological conditions included neuropathy related to stripping or venous laser surgery, compression by abscess, Lyme disease, nerve tumors, traumatic transsection, and encasement by fibrous plaque and edema. Ultrasound with its exquisite resolution is the preferred imaging method for examining the sural nerve in patients with unexplained sensory changes at the lateral aspect of the ankle and foot.

Flexible adaptation to an artificial recurrent connection from muscle to peripheral nerve in man.

Science.gov (United States)

Kato, Kenji; Sasada, Syusaku; Nishimura, Yukio

2016-02-01

Controlling a neuroprosthesis requires learning a novel input-output transformation; however, how subjects incorporate this into limb control remains obscure. To elucidate the underling mechanisms, we investigated the motor adaptation process to a novel artificial recurrent connection (ARC) from a muscle to a peripheral nerve in healthy humans. In this paradigm, the ulnar nerve was electrically stimulated in proportion to the activation of the flexor carpi ulnaris (FCU), which is ulnar-innervated and monosynaptically innervated from Ia afferents of the FCU, defined as the "homonymous muscle," or the palmaris longus (PL), which is not innervated by the ulnar nerve and produces similar movement to the FCU, defined as the "synergist muscle." The ARC boosted the activity of the homonymous muscle and wrist joint movement during a visually guided reaching task. Participants could control muscle activity to utilize the ARC for the volitional control of wrist joint movement and then readapt to the absence of the ARC to either input muscle. Participants reduced homonymous muscle recruitment with practice, regardless of the input muscle. However, the adaptation process in the synergist muscle was dependent on the input muscle. The activity of the synergist muscle decreased when the input was the homonymous muscle, whereas it increased when it was the synergist muscle. This reorganization of the neuromotor map, which was maintained as an aftereffect of the ARC, was observed only when the input was the synergist muscle. These findings demonstrate that the ARC induced reorganization of neuromotor map in a targeted and sustainable manner. Copyright © 2016 the American Physiological Society.

Hidden Hearing Loss and Computational Models of the Auditory Pathway: Predicting Speech Intelligibility Decline

Science.gov (United States)

2016-11-28

Title: Hidden Hearing Loss and Computational Models of the Auditory Pathway: Predicting Speech Intelligibility Decline Christopher J. Smalt...representation of speech intelligibility in noise. The auditory-periphery model of Zilany et al. (JASA 2009,2014) is used to make predictions of...auditory nerve (AN) responses to speech stimuli under a variety of difficult listening conditions. The resulting cochlear neurogram, a spectrogram

Estrogen replacement avoids the decrease of bladder innervations in ovariectomized adult virgin rats: in vivo stereological study.

Science.gov (United States)

de Fraga, Rogerio; Palma, Paulo; Dambros, Miriam; Riccetto, Cassio L Z; Mandarim-de-Lacerda, Carlos; Miyaoka, Ricardo

2009-05-01

The authors quantified the nerve fibers in the bladder wall of ovariectomized rats with and without estradiol replacement. This study was conducted on 40 Wistar rats (3 months old). Group 1: remained intact; Group 2: underwent bilateral ovariectomy, and after 30 days was started on subcutaneous sesame oil replacement (0.2 ml per day) for 90 days; Group 3: sham-operated, and after 30 days was started on subcutaneous sesame oil replacement (0.2 ml per day) for 90 days; Group 4: bilateral ovariectomy, and after 30 days was started on subcutaneous injection of 17β-estradiol (10 μg/kg body weight) for 90 days. S-100 was used to stain nerves myelinized fibers on paraffin rat bladder sections. The G-50 grid system was used to quantitatively analyze the fibers. Long-term estrogen deprivation caused significant changes in bladder innervations, which can be characterized by a decreased number of nerve fibers by 65% (p < 0.001).

Unilateral pure trigeminal motor nerve neuropathy: A rare case report

Directory of Open Access Journals (Sweden)

Nishant K Srivastava

2014-01-01

Full Text Available Unilateral pure trigeminal motor nerve neuropathy is an extremely rare and unique condition, characterized by atrophy of the muscles, innervated by the motor branch of the trigeminal nerve. We report such a case in a 25-year-old male patient. The diagnosis was made on the basis of clinical and radiological examinations. Magnetic Resonance Imaging (MRI proved to be the key for establishing the diagnosis, which showed atrophy and fatty infiltration over the affected side of the muscles of mastication. We were unable to establish the cause of the condition even after performing a brain MRI.

[Impact of hypoglycemic episodes on nerves conduction and auditory and visual evoked potentials in children with type 1 diabetes].

Science.gov (United States)

Wysocka-Mincewicz, Marta; Trippenbach-Dulska, Hanna; Emeryk-Szajewska, Barbara; Zakrzewska-Pniewska, Beata; Kochanek, Krzysztof; Pańkowska, Ewa

2007-01-01

Hypoglycemia is an acute disturbance of energy, especially impacting the central nervous system, but direct influence on peripheral nervous function is not detected. The aim of the study was to establish the influence of hypoglycemic moderate and severe episodes on the function of peripheral nerves, hearing and visual pathway. 97 children with type 1 diabetes (mean age 15.4+/-2.16 years, mean duration of diabetes 8.11+/-2.9 years, mean HbA1c 8,58+/-1.06%), at least 10 years old and with at least 3 years duration of diabetes, were included to study. Nerve conduction studies, visual (VEP) and auditory (ABR) evoked potentials were performed with standard surface stimulating and recording techniques. Moderate hypoglycemic episodes were defined as events of low glycemia requiring help of another person but without loss of consciousness and/or convulsions but recurrent frequently in at least one year. Severe hypoglycemia was defined as events with loss of consciousness and/or convulsions. Univariate ANOVA tests of significance or H Kruskal-Wallis test were used, depending on normality of distribution. The subgroups with a history of hypoglycemic episodes had significant delay in all conduction parameters in the sural nerve (amplitude pwave III latency and interval I-III in subgroups with episodes of hypoglycemia (pwave III and interval I-III. Frequent moderate hypoglycemic episodes were strong risk factors for damage of the peripheral and central nervous systems, comparable with impact of several severe hypoglycemias.

Associations between xerostomia, histopathological alterations, and autonomic innervation of labial salivary glands in men in late midlife.

Science.gov (United States)

Sørensen, Christiane Elisabeth; Larsen, Jytte Overgaard; Reibel, Jesper; Lauritzen, Martin; Mortensen, Erik Lykke; Osler, Merete; Pedersen, Anne Marie Lynge

2014-09-01

One aim of the present study was to investigate whether symptoms of oral dryness (xerostomia) during daytime, assessed in a study group of middle-aged male positive and negative outliers in cognition scores, were associated with age-related degenerative changes in human labial salivary glands and with quantitative measures of the glandular autonomic innervation. Another aim was to study the relation between the autonomic innervation and loss of secretory acinar cells in these glands. Labial salivary gland biopsies were taken from the lower lip from 190 men, born in 1953 and members of the Danish Metropolit birth cohort, who were examined for age-related changes in cognitive function and dental health as part of the Copenhagen University Center for Healthy Aging clinical neuroscience project. The glands were routinely processed and semi-quantitatively analyzed for inflammation, acinar atrophy, fibrosis, and adipocyte infiltration. Sections of labial salivary gland tissue were stained with the panneuronal marker PGP 9.5. In a subsample of 51 participants, the autonomic innervation of the glands was analyzed quantitatively by use of stereology. Labial salivary gland tissue samples from 33% of all participants displayed moderate to severe acinar atrophy and fibrosis (31%). Xerostomia was not significantly associated with structural changes of labial salivary glands, but in the subsample it was inversely related to the total nerve length in the glandular connective tissue. Acinar atrophy and fibrosis were negatively correlated with the parenchymal innervation and positively related to diffuse inflammation. The results from the present study indicate that aspects of the autonomic innervation of labial salivary glands may play a role in the occurrence of xerostomia which in the present study group was not significantly associated with degenerative changes in these glands. The findings further indicate that the integrity of labial salivary gland acini is related to the

[Facial nerve neurinomas].

Science.gov (United States)

Sokołowski, Jacek; Bartoszewicz, Robert; Morawski, Krzysztof; Jamróz, Barbara; Niemczyk, Kazimierz

2013-01-01

Evaluation of diagnostic, surgical technique, treatment results facial nerve neurinomas and its comparison with literature was the main purpose of this study. Seven cases of patients (2005-2011) with facial nerve schwannomas were included to retrospective analysis in the Department of Otolaryngology, Medical University of Warsaw. All patients were assessed with history of the disease, physical examination, hearing tests, computed tomography and/or magnetic resonance imaging, electronystagmography. Cases were observed in the direction of potential complications and recurrences. Neurinoma of the facial nerve occurred in the vertical segment (n=2), facial nerve geniculum (n=1) and the internal auditory canal (n=4). The symptoms observed in patients were analyzed: facial nerve paresis (n=3), hearing loss (n=2), dizziness (n=1). Magnetic resonance imaging and computed tomography allowed to confirm the presence of the tumor and to assess its staging. Schwannoma of the facial nerve has been surgically removed using the middle fossa approach (n=5) and by antromastoidectomy (n=2). Anatomical continuity of the facial nerve was achieved in 3 cases. In the twelve months after surgery, facial nerve paresis was rated at level II-III° HB. There was no recurrence of the tumor in radiological observation. Facial nerve neurinoma is a rare tumor. Currently surgical techniques allow in most cases, the radical removing of the lesion and reconstruction of the VII nerve function. The rate of recurrence is low. A tumor of the facial nerve should be considered in the differential diagnosis of nerve VII paresis. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

A Model of Electrically Stimulated Auditory Nerve Fiber Responses with Peripheral and Central Sites of Spike Generation

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Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

2017-01-01

. A single ANF is modeled as a network of two exponential integrateand-fire point-neuron models, referred to as peripheral and central axons of the ANF. The peripheral axon is excited by the cathodic charge, inhibited by the anodic charge, and exhibits longer spike latencies than the central axon......A computational model of cat auditory nerve fiber (ANF) responses to electrical stimulation is presented. The model assumes that (1) there exist at least two sites of spike generation along the ANF and (2) both an anodic (positive) and a cathodic (negative) charge in isolation can evoke a spike......; the central axon is excited by the anodic charge, inhibited by the cathodic charge, and exhibits shorter spike latencies than the peripheral axon. The model also includes subthreshold and suprathreshold adaptive feedback loops which continuously modify the membrane potential and can account for effects...

Regenerative potential of silk conduits in repair of peripheral nerve injury in adult rats.

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Huang, W; Begum, R; Barber, T; Ibba, V; Tee, N C H; Hussain, M; Arastoo, M; Yang, Q; Robson, L G; Lesage, S; Gheysens, T; Skaer, Nicholas J V; Knight, D P; Priestley, J V

2012-01-01

Various attempts have been made to develop artificial conduits for nerve repair, but with limited success. We describe here conduits made from Bombyx mori regenerated silk protein, and containing luminal fibres of Spidrex(®), a silk-based biomaterial with properties similar to those of spider silk. Assessment in vitro demonstrated that Spidrex(®) fibres support neurite outgrowth. For evaluation in vivo, silk conduits 10 mm in length and containing 0, 100, 200 or 300 luminal Spidrex(®) fibres, were implanted to bridge an 8 mm gap in the rat sciatic nerve. At 4 weeks, conduits containing 200 luminal Spidrex(®) fibres (PN200) supported 62% and 59% as much axon growth as autologous nerve graft controls at mid-conduit and distal nerve respectively. Furthermore, Spidrex(®) conduits displayed similar Schwann cell support and macrophage response to controls. At 12 weeks, animals implanted with PN200 conduits showed similar numbers of myelinated axons (81%) to controls, similar gastrocnemius muscle innervation, and similar hindpaw stance assessed by Catwalk footprint analysis. Plantar skin innervation was 73% of that of controls. PN200 Spidrex(®) conduits were also effective at bridging longer (11 and 13 mm) gaps. Our results show that Spidrex(®) conduits promote excellent axonal regeneration and function recovery, and may have potential for clinical application. Copyright © 2011 Elsevier Ltd. All rights reserved.

The auriculotemporal nerve in etiology of migraine headaches: compression points and anatomical variations.

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Chim, Harvey; Okada, Haruko C; Brown, Matthew S; Alleyne, Brendan; Liu, Mengyuan T; Zwiebel, Samantha; Guyuron, Bahman

2012-08-01

The auriculotemporal nerve has been identified as one of the peripheral trigger sites for migraine headaches. However, its distal course is poorly mapped following emergence from the parotid gland. In addition, a reliable anatomical landmark for locating the potential compression points along the course of the nerve during surgery has not been sufficiently described. Twenty hemifaces on 10 fresh cadavers were dissected to trace the course of the auriculotemporal nerve from the inferior border of the zygomatic arch to its termination in the temporal scalp. The compression points were mapped and the distances were measured from the most anterosuperior point of the external auditory meatus, which was used as a fixed anatomical landmark. Three potential compression points along the course of the auriculotemporal nerve were identified. Compression points 1 and 2 corresponded to preauricular fascial bands. Compression point 1 was centered 13.1±5.9 mm anterior and 5.0±7.0 mm superior to the most anterosuperior point of the external auditory meatus, whereas compression point 2 was centered at 11.9±6.0 mm anterior and 17.2±10.4 mm superior to the most anterosuperior point of the external auditory meatus. A significant relationship was found between the auriculotemporal nerve and superficial temporal artery (compression point 3) in 80 percent of hemifaces, with three patterns of interaction: a single site of artery crossing over the nerve (62.5 percent), a helical intertwining relationship (18.8 percent), and nerve crossing over the artery (18.8 percent). Findings from this cadaver study provide information relevant to the operative localization of potential compression points along the auriculotemporal nerve.

Cutaneous collateral axonal sprouting re-innervates the skin component and restores sensation of denervated Swine osteomyocutaneous alloflaps.

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Zuhaib Ibrahim

Full Text Available Reconstructive transplantation such as extremity and face transplantation is a viable treatment option for select patients with devastating tissue loss. Sensorimotor recovery is a critical determinant of overall success of such transplants. Although motor function recovery has been extensively studied, mechanisms of sensory re-innervation are not well established. Recent clinical reports of face transplants confirm progressive sensory improvement even in cases where optimal repair of sensory nerves was not achieved. Two forms of sensory nerve regeneration are known. In regenerative sprouting, axonal outgrowth occurs from the transected nerve stump while in collateral sprouting, reinnervation of denervated tissue occurs through growth of uninjured axons into the denervated tissue. The latter mechanism may be more important in settings where transected sensory nerves cannot be re-apposed. In this study, denervated osteomyocutaneous alloflaps (hind- limb transplants from Major Histocompatibility Complex (MHC-defined MGH miniature swine were performed to specifically evaluate collateral axonal sprouting for cutaneous sensory re-innervation. The skin component of the flap was externalized and serial skin sections extending from native skin to the grafted flap were biopsied. In order to visualize regenerating axonal structures in the dermis and epidermis, 50 um frozen sections were immunostained against axonal and Schwann cell markers. In all alloflaps, collateral axonal sprouts from adjacent recipient skin extended into the denervated skin component along the dermal-epidermal junction from the periphery towards the center. On day 100 post-transplant, regenerating sprouts reached 0.5 cm into the flap centripetally. Eight months following transplant, epidermal fibers were visualized 1.5 cm from the margin (rate of regeneration 0.06 mm per day. All animals had pinprick sensation in the periphery of the transplanted skin within 3 months post

Roles of neural stem cells in the repair of peripheral nerve injury.

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Wang, Chong; Lu, Chang-Feng; Peng, Jiang; Hu, Cheng-Dong; Wang, Yu

2017-12-01

Currently, researchers are using neural stem cell transplantation to promote regeneration after peripheral nerve injury, as neural stem cells play an important role in peripheral nerve injury repair. This article reviews recent research progress of the role of neural stem cells in the repair of peripheral nerve injury. Neural stem cells can not only differentiate into neurons, astrocytes and oligodendrocytes, but can also differentiate into Schwann-like cells, which promote neurite outgrowth around the injury. Transplanted neural stem cells can differentiate into motor neurons that innervate muscles and promote the recovery of neurological function. To promote the repair of peripheral nerve injury, neural stem cells secrete various neurotrophic factors, including brain-derived neurotrophic factor, fibroblast growth factor, nerve growth factor, insulin-like growth factor and hepatocyte growth factor. In addition, neural stem cells also promote regeneration of the axonal myelin sheath, angiogenesis, and immune regulation. It can be concluded that neural stem cells promote the repair of peripheral nerve injury through a variety of ways.

The morphological substrate for Renal Denervation: Nerve distribution patterns and parasympathetic nerves. A post-mortem histological study.

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van Amsterdam, Wouter A C; Blankestijn, Peter J; Goldschmeding, Roel; Bleys, Ronald L A W

2016-03-01

Renal Denervation as a possible treatment for hypertension has been studied extensively, but knowledge on the distribution of nerves surrounding the renal artery is still incomplete. While sympathetic and sensory nerves have been demonstrated, there is no mention of the presence of parasympathetic nerve fibers. To provide a description of the distribution patterns of the renal nerves in man, and, in addition, provide a detailed representation of the relative contribution of the sympathetic, parasympathetic and afferent divisions of the autonomic nervous system. Renal arteries of human cadavers were each divided into four longitudinal segments and immunohistochemically stained with specific markers for afferent, parasympathetic and sympathetic nerves. Nerve fibers were semi-automatically quantified by computerized image analysis, and expressed as cross-sectional area relative to the distance to the lumen. A total of 3372 nerve segments were identified in 8 arteries of 7 cadavers. Sympathetic, parasympathetic and afferent nerves contributed for 73.5% (95% CI: 65.4-81.5%), 17.9% (10.7-25.1%) and 8.7% (5.0-12.3%) of the total cross-sectional nerve area, respectively. Nerves are closer to the lumen in more distal segments and larger bundles that presumably innervate the kidney lie at 1-3.5mm distance from the lumen. The tissue-penetration depth of the ablation required to destroy 50% of the nerve fibers is 2.37 mm in the proximal segment and 1.78 mm in the most distal segments. Sympathetic, parasympathetic and afferent nerves exist in the vicinity of the renal artery. The results warrant further investigation of the role of the parasympathetic nervous system on renal physiology, and may contribute to refinement of the procedure by focusing the ablation on the most distal segment. Copyright © 2015 Elsevier GmbH. All rights reserved.

Abnormal Auditory Gain in Hyperacusis: Investigation with a Computational Model

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Peter U. Diehl

2015-07-01

Full Text Available Hyperacusis is a frequent auditory disorder that is characterized by abnormal loudness perception where sounds of relatively normal volume are perceived as too loud or even painfully loud. As Hyperacusis patients show decreased loudness discomfort levels (LDLs and steeper loudness growth functions, it has been hypothesized that hyperacusis might be caused by an increase in neuronal response gain in the auditory system. Moreover, since about 85% of hyperacusis patients also experience tinnitus, the conditions might be caused by a common mechanism. However, the mechanisms that give rise to hyperacusis have remained unclear.Here we have used a computational model of the auditory system to investigate candidate mechanisms for hyperacusis. Assuming that perceived loudness is proportional to the summed activity of all auditory nerve fibers, the model was tuned to reproduce normal loudness perception. We then evaluated a variety of potential hyperacusis gain mechanisms by determining their effects on model equal-loudness contours and comparing the results to the LDLs of hyperacusis patients with normal hearing thresholds. Hyperacusis was best accounted for by an increase in nonlinear gain in the central auditory system. Good fits to the average patient LDLs were obtained for a general increase in gain that affected all frequency channels to the same degree, and also for a frequency-specific gain increase in the high-frequency range. Moreover, the gain needed to be applied after subtraction of spontaneous activity of the auditory nerve, which is in contrast to current theories of tinnitus generation based on amplification of spontaneous activity. Hyperacusis and tinnitus might therefore be caused by different changes in neuronal processing in the central auditory system.

A comparison of anesthetic agents and their effects on the response properties of the peripheral auditory system.

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Dodd, F; Capranica, R R

1992-10-01

Anesthetic agents were compared in order to identify the most appropriate agent for use during surgery and electrophysiological recordings in the auditory system of the tokay gecko (Gekko gecko). Each agent was first screened for anesthetic and analgesic properties and, if found satisfactory, it was subsequently tested in electrophysiological recordings in the auditory nerve. The following anesthetic agents fulfilled our criteria and were selected for further screening: sodium pentobarbital (60 mg/kg); sodium pentobarbital (30 mg/kg) and oxymorphone (1 mg/kg); 3.2% isoflurane; ketamine (440 mg/kg) and oxymorphone (1 mg/kg). These agents were subsequently compared on the basis of their effect on standard response properties of auditory nerve fibers. Our results verified that different anesthetic agents can have significant effects on most of the parameters commonly used in describing the basic response properties of the auditory system in vertebrates. We therefore conclude from this study that the selection of an appropriate experimental protocol is critical and must take into consideration the effects of anesthesia on auditory responsiveness. In the tokay gecko, we recommend 3.2% isoflurane for general surgical procedures; and for electrophysiological recordings in the eighth nerve we recommend barbiturate anesthesia of appropriate dosage in combination if possible with an opioid agent to provide additional analgesic action.

Novel drug delivering conduit for peripheral nerve regeneration

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Labroo, Pratima; Shea, Jill; Edwards, Kyle; Ho, Scott; Davis, Brett; Sant, Himanshu; Goodwin, Isak; Gale, Bruce; Agarwal, Jay

2017-12-01

Objective. This paper describes the design of a novel drug delivery apparatus integrated with a poly lactic-co-glycolic acid (PLGA) based nerve guide conduit for controlled local delivery of nerve growth factor (NGF) and application in peripheral nerve gap injury. Approach. An NGF dosage curve was acquired to determine the minimum in vitro concentration for optimal neurite outgrowth of dorsal root ganglion (DRG) cells; PLGA based drug delivery devices were then designed and tested in vitro and in vivo across 15 mm rat sciatic nerve gap injury model. Main results. The drug delivery nerve guide was able to release NGF for 28 d at concentrations (0.1-10 ng ml-1) that were shown to enhance DRG neurite growth. Furthermore, the released NGF was bioactive and able to enhance DRG neurite growth. Following these tests, optimized NGF-releasing nerve conduits were implanted across 15 mm sciatic nerve gaps in a rat model, where they demonstrated significant myelination and muscle innervation in vivo as compared to empty nerve conduits (p  design process and provides increased versatility for releasing a variety of different growth factors. This innovative device has the potential for broad applicability and allows for easier customization to change the type of drugs and dosage of individual drugs without devising a completely new biomaterial-drug conjugate each time.

Efficient Healing Takes Some Nerve: Electrical Stimulation Enhances Innervation in Cutaneous Human Wounds.

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Emmerson, Elaine

2017-03-01

Cutaneous nerves extend throughout the dermis and epidermis and control both the functional and reparative capacity of the skin. Denervation of the skin impairs cutaneous healing, presenting evidence that nerves provide cues essential for timely wound repair. Sebastian et al. demonstrate that electrical stimulation promotes reinnervation and neural differentiation in human acute wounds, thus accelerating wound repair. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

Engineering a multimodal nerve conduit for repair of injured peripheral nerve

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

2013-02-01

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

[Preliminary investigation of treatment of ulnar nerve defect by end-to-side neurorrhaphy].

Science.gov (United States)

Luo, Y; Wang, T; Fang, H

1997-11-01

In the repair of the defect of peripheral nerve, it was necessary to find an operative method with excellent therapeutic effect but simple technique. Based on the experimental study, one case of old injury of the ulnar nerve was treated by end-to-side neurorraphy with the intact median nerve. In this case the nerve defect was over 3 cm and unable to be sutured directly. The patient was followed up for fourteen months after the operation. The recovery of the sensation and the myodynamia was evaluated. The results showed that: the sensation and the motor function innervated by ulnar nerve were recovered. The function of the hand was almost recovered to be normal. It was proved that the end-to-side neurorraphy between the distal stump with the intact median nerve to repair the defect of the ulnar nerve was a new operative procedure for nerve repair. Clinically it had good effect with little operative difficulty. This would give a bright prospect to repair of peripheral nerve defect in the future.

Analysis of Spontaneous and Nerve-Evoked Calcium Transients in Intact Extraocular Muscles in Vitro

Science.gov (United States)

Feng, Cheng-Yuan; Hennig, Grant W.; Corrigan, Robert D.; Smith, Terence K.; von Bartheld, Christopher S.

2012-01-01

Extraocular muscles (EOMs) have unique calcium handling properties, yet little is known about the dynamics of calcium events underlying ultrafast and tonic contractions in myofibers of intact EOMs. Superior oblique EOMs of juvenile chickens were dissected with their nerve attached, maintained in oxygenated Krebs buffer, and loaded with fluo-4. Spontaneous and nerve stimulation-evoked calcium transients were recorded and, following calcium imaging, some EOMs were double-labeled with rhodamine-conjugated alpha-bungarotoxin (rhBTX) to identify EOM myofiber types. EOMs showed two main types of spontaneous calcium transients, one slow type (calcium waves with 1/2max duration of 2–12 s, velocity of 25–50 μm/s) and two fast “flash-like” types (Type 1, 30–90 ms; Type 2, 90–150 ms 1/2max duration). Single pulse nerve stimulation evoked fast calcium transients identical to the fast (Type 1) calcium transients. Calcium waves were accompanied by a local myofiber contraction that followed the calcium transient wavefront. The magnitude of calcium-wave induced myofiber contraction far exceeded those of movement induced by nerve stimulation and associated fast calcium transients. Tetrodotoxin eliminated nerve-evoked transients, but not spontaneous transients. Alpha-bungarotoxin eliminated both spontaneous and nerve-evoked fast calcium transients, but not calcium waves, and caffeine increased wave activity. Calcium waves were observed in myofibers lacking spontaneous or evoked fast transients, suggestive of multiply-innervated myofibers, and this was confirmed by double-labeling with rhBTX. We propose that the abundant spontaneous calcium transients and calcium waves with localized contractions that do not depend on innervation may contribute to intrinsic generation of tonic functions of EOMs. PMID:22579493

MRI enhancement of the facial nerve with Gd-DTPA, 2; Investigation of enhanced nerve portions in patients with facial palsy

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Yanagida, Masahiro (Kansai Medical School, Moriguchi, Osaka (Japan))

1993-08-01

We performed enhanced MRI using Gd-DTPA in 84 patients with facial palsy. After assessing enhancement of the normal facial nerve, we examined enhancement in patients with Bell's palsy and Ramsay Hunt syndrome. In 95% of patients with Bell's palsy, enhancement was obtained in the distal IAC and labyrinthine portions. In 72%, enhancement was significant from the distal IAC portion through the vertical portion. In some of the patients who underwent enhanced MRI twice, increased signal intensity was observed in distal portions such as the vertical portion. In many cases of Ramsay Hunt syndrome, enhancement was seen extensively in the IAC portion through the vertical portion. In the subjects with internal auditory symptoms such as vertigo and tinnitus, enhancement of the IAC portion was seen not only in the facial nerve but also in the vestibular and the cochlear nerves. These results suggest that the vascular permeability of lesions in Bell's palsy may be increased from the distal IAC portion to the vertical portion. Judging from the present findings with Ramsay Hunt syndrome, symptoms related to the enhanced portions suggest that accompanying internal auditory symptoms occur due to inflammation of the IAC portions of cochlear and vestibular nerves. (author).

Conductive Hearing Loss Has Long-Lasting Structural and Molecular Effects on Presynaptic and Postsynaptic Structures of Auditory Nerve Synapses in the Cochlear Nucleus.

Science.gov (United States)

Clarkson, Cheryl; Antunes, Flora M; Rubio, Maria E

2016-09-28

Sound deprivation by conductive hearing loss increases hearing thresholds, but little is known about the response of the auditory brainstem during and after conductive hearing loss. Here, we show in young adult rats that 10 d of monaural conductive hearing loss (i.e., earplugging) leads to hearing deficits that persist after sound levels are restored. Hearing thresholds in response to clicks and frequencies higher than 8 kHz remain increased after a 10 d recovery period. Neural output from the cochlear nucleus measured at 10 dB above threshold is reduced and followed by an overcompensation at the level of the lateral lemniscus. We assessed whether structural and molecular substrates at auditory nerve (endbulb of Held) synapses in the cochlear nucleus could explain these long-lasting changes in hearing processing. During earplugging, vGluT1 expression in the presynaptic terminal decreased and synaptic vesicles were smaller. Together, there was an increase in postsynaptic density (PSD) thickness and an upregulation of GluA3 AMPA receptor subunits on bushy cells. After earplug removal and a 10 d recovery period, the density of synaptic vesicles increased, vesicles were also larger, and the PSD of endbulb synapses was larger and thicker. The upregulation of the GluA3 AMPAR subunit observed during earplugging was maintained after the recovery period. This suggests that GluA3 plays a role in plasticity in the cochlear nucleus. Our study demonstrates that sound deprivation has long-lasting alterations on structural and molecular presynaptic and postsynaptic components at the level of the first auditory nerve synapse in the auditory brainstem. Despite being the second most prevalent form of hearing loss, conductive hearing loss and its effects on central synapses have received relatively little attention. Here, we show that 10 d of monaural conductive hearing loss leads to an increase in hearing thresholds, to an increased central gain upstream of the cochlear nucleus at

Fungiform taste bud degeneration in C57BL/6J mice following chorda-lingual nerve transection.

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Guagliardo, Nick A; Hill, David L

2007-09-10

Taste buds are dependent on innervation for normal morphology and function. Fungiform taste bud degeneration after chorda tympani nerve injury has been well documented in rats, hamsters, and gerbils. The current study examines fungiform taste bud distribution and structure in adult C57BL/6J mice from both intact taste systems and after unilateral chorda-lingual nerve transection. Fungiform taste buds were visualized and measured with the aid of cytokeratin 8. In control mice, taste buds were smaller and more abundant on the anterior tip (taste buds were smaller and fewer on the side of the tongue ipsilateral to the transection and continued to decrease in both size and number until 15 days posttransection. Degenerating fungiform taste buds were smaller due to a loss of taste bud cells rather than changes in taste bud morphology. While almost all taste buds disappeared in more posterior fungiform papillae by 15 days posttransection, the anterior tip of the tongue retained nearly half of its taste buds compared to intact mice. Surviving taste buds could not be explained by an apparent innervation from the remaining intact nerves. Contralateral effects of nerve transection were also observed; taste buds were larger due to an increase in the number of taste bud cells. These data are the first to characterize adult mouse fungiform taste buds and subsequent degeneration after unilateral nerve transection. They provide the basis for more mechanistic studies in which genetically engineered mice can be used. (c) 2007 Wiley-Liss, Inc.

Sympathetic Nerve Injury in Thyroid Cancer

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Evangelos Diamantis

2018-04-01

Full Text Available The double innervation of the thyroid comes from the sympathetic and parasympathetic nervous system. Injury rates during surgery are at 30% but can be minimized by upwardly preparing the thyroid vessels at the level of thyroid capsule. Several factors have been accused of increasing the risk of injury including age and tumor size. Our aim was to investigate of there is indeed any possible correlations between these factors and a possible increase in injury rates following thyroidectomy. Seven studies were included in the meta-analysis. Statistical correlation was observed for a positive relationship between injury of the sympathetic nerve and thyroid malignancy surgery (p < 0.001; I2 = 74% No statistical correlations were observed for a negative or positive relationship between injury of the sympathetic nerve and tumor size. There was also no statistically significant value observed for the correlation of the patients’ age with the risk of sympathetic nerve injury (p = 0.388. Lack of significant correlation reported could be due to the small number of studies and great heterogeneity between them.

Intraoperative Electrocochleographic Characteristics of Auditory Neuropathy Spectrum Disorder in Cochlear Implant Subjects

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William J. Riggs

2017-07-01

Full Text Available Auditory neuropathy spectrum disorder (ANSD is characterized by an apparent discrepancy between measures of cochlear and neural function based on auditory brainstem response (ABR testing. Clinical indicators of ANSD are a present cochlear microphonic (CM with small or absent wave V. Many identified ANSD patients have speech impairment severe enough that cochlear implantation (CI is indicated. To better understand the cochleae identified with ANSD that lead to a CI, we performed intraoperative round window electrocochleography (ECochG to tone bursts in children (n = 167 and adults (n = 163. Magnitudes of the responses to tones of different frequencies were summed to measure the “total response” (ECochG-TR, a metric often dominated by hair cell activity, and auditory nerve activity was estimated visually from the compound action potential (CAP and auditory nerve neurophonic (ANN as a ranked “Nerve Score”. Subjects identified as ANSD (45 ears in children, 3 in adults had higher values of ECochG-TR than adult and pediatric subjects also receiving CIs not identified as ANSD. However, nerve scores of the ANSD group were similar to the other cohorts, although dominated by the ANN to low frequencies more than in the non-ANSD groups. To high frequencies, the common morphology of ANSD cases was a large CM and summating potential, and small or absent CAP. Common morphologies in other groups were either only a CM, or a combination of CM and CAP. These results indicate that responses to high frequencies, derived primarily from hair cells, are the main source of the CM used to evaluate ANSD in the clinical setting. However, the clinical tests do not capture the wide range of neural activity seen to low frequency sounds.

Fungiform Taste Bud Degeneration in C57BL/6J Mice Following Chorda-Lingual Nerve Transection

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Guagliardo, Nick A.; Hill, David L.

2007-01-01

Taste buds are dependent on innervation for normal morphology and function. Fungiform taste bud degeneration after chorda tympani nerve injury has been well documented in rats, hamsters, and gerbils. The current study examines fungiform taste bud distribution and structure in adult C57BL/6J mice from both intact taste systems and after unilateral chorda-lingual nerve transection. Fungiform taste buds were visualized and measured with the aid of cytokeratin 8. In control mice, taste buds were ...

Unique Phrenic Nerve-Sparing Regional Anesthetic Technique for Pain Management after Shoulder Surgery

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Jason K. Panchamia

2017-01-01

Full Text Available Background. Ipsilateral phrenic nerve blockade is a common adverse event after an interscalene brachial plexus block, which can result in respiratory deterioration in patients with preexisting pulmonary conditions. Diaphragm-sparing nerve block techniques are continuing to evolve, with the intention of providing satisfactory postoperative analgesia while minimizing hemidiaphragmatic paralysis after shoulder surgery. Case Report. We report the successful application of a combined ultrasound-guided infraclavicular brachial plexus block and suprascapular nerve block in a patient with a complicated pulmonary history undergoing a total shoulder replacement. Conclusion. This case report briefly reviews the important innervations to the shoulder joint and examines the utility of the infraclavicular brachial plexus block for postoperative pain management.

Presbycusis and auditory brainstem responses: a review

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Shilpa Khullar

2011-06-01

Full Text Available Age-related hearing loss or presbycusis is a complex phenomenon consisting of elevation of hearing levels as well as changes in the auditory processing. It is commonly classified into four categories depending on the cause. Auditory brainstem responses (ABRs are a type of early evoked potentials recorded within the first 10 ms of stimulation. They represent the synchronized activity of the auditory nerve and the brainstem. Some of the changes that occur in the aging auditory system may significantly influence the interpretation of the ABRs in comparison with the ABRs of the young adults. The waves of ABRs are described in terms of amplitude, latencies and interpeak latency of the different waves. There is a tendency of the amplitude to decrease and the absolute latencies to increase with advancing age but these trends are not always clear due to increase in threshold with advancing age that act a major confounding factor in the interpretation of ABRs.

Electrical stimulation of paralyzed vibrissal muscles reduces endplate reinnervation and does not promote motor recovery after facial nerve repair in rats.

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Sinis, Nektarios; Horn, Frauke; Genchev, Borislav; Skouras, Emmanouil; Merkel, Daniel; Angelova, Srebrina K; Kaidoglou, Katerina; Michael, Joern; Pavlov, Stoyan; Igelmund, Peter; Schaller, Hans-Eberhard; Irintchev, Andrey; Dunlop, Sarah A; Angelov, Doychin N

2009-10-01

The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work has suggested that electrical stimulation (ES) of denervated muscles could be beneficial. Here we tested whether ES has a positive influence on functional recovery after injury and surgical repair of the facial nerve. Outcomes at 2 months were compared to animals receiving sham stimulation (SS). Starting on the first day after end-to-end suture (facial-facial anastomosis), electrical stimulation (square 0.1 ms pulses at 5 Hz at an ex tempore established threshold amplitude of between 3.0 and 5.0V) was delivered to the vibrissal muscles for 5 min a day, 3 times a week. Restoration of vibrissal motor performance following ES or SS was evaluated using the video-based motion analysis and correlated with the degree of collateral axonal branching at the lesion site, the number of motor endplates in the target musculature and the quality of their reinnervation, i.e. the degree of mono- versus poly-innervation. Neither protocol reduced collateral branching. ES did not improve functional outcome, but rather reduced the number of innervated motor endplates to approximately one-fifth of normal values and failed to reduce the proportion of poly-innervated motor endplates. We conclude that ES is not beneficial for recovery of whisker function after facial nerve repair in rats.

Changes of medium-latency SEP-components following peripheral nerve lesion

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Straschill Max

2006-10-01

Full Text Available Abstract Background Animal studies have demonstrated complex cortical reorganization following peripheral nerve lesion. Central projection fields of intact nerves supplying skin areas which border denervated skin, extended into the deafferentiated cortical representation area. As a consequence of nerve lesions and subsequent reorganization an increase of the somatosensory evoked potentials (SEPs was observed in cats when intact neighbouring nerves were stimulated. An increase of SEP-components of patients with nerve lesions may indicate a similar process of posttraumatic plastic cortical reorganization. Methods To test if a similar process of post-traumatic plastic cortical reorganization does occur in humans, the SEP of intact neighbouring hand nerves were recorded in 29 patients with hand nerve lesions. To hypothetically explain the observed changes of SEP-components, SEP recording following paired stimulation of the median nerve was performed in 12 healthy subjects. Results Surprisingly 16 of the 29 patients (55.2% showed a reduction or elimination of N35, P45 and N60. Patients with lesions of two nerves showed more SEP-changes than patients with a single nerve lesion (85.7%; 6/7 nerves; vs. 34.2%; 13/38 nerves; Fisher's exact test, p Conclusion The results of the present investigation do not provide evidence of collateral innervation of peripherally denervated cortical neurons by neurons of adjacent cortical representation areas. They rather suggest that secondary components of the excitatory response to nerve stimulation are lost in cortical areas, which surround the denervated region.

Rapid, automated mosaicking of the human corneal subbasal nerve plexus.

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Vaishnav, Yash J; Rucker, Stuart A; Saharia, Keshav; McNamara, Nancy A

2017-11-27

Corneal confocal microscopy (CCM) is an in vivo technique used to study corneal nerve morphology. The largest proportion of nerves innervating the cornea lie within the subbasal nerve plexus, where their morphology is altered by refractive surgery, diabetes and dry eye. The main limitations to clinical use of CCM as a diagnostic tool are the small field of view of CCM images and the lengthy time needed to quantify nerves in collected images. Here, we present a novel, rapid, fully automated technique to mosaic individual CCM images into wide-field maps of corneal nerves. We implemented an OpenCV image stitcher that accounts for corneal deformation and uses feature detection to stitch CCM images into a montage. The method takes 3-5 min to process and stitch 40-100 frames on an Amazon EC2 Micro instance. The speed, automation and ease of use conferred by this technique is the first step toward point of care evaluation of wide-field subbasal plexus (SBP) maps in a clinical setting.

Evaluation of peripheral compression and auditory nerve fiber intensity coding using auditory steady-state responses

DEFF Research Database (Denmark)

Encina Llamas, Gerard; M. Harte, James; Epp, Bastian

2015-01-01

. Evaluation of these properties provides information about the health state of the system. It has been shown that a loss of outer hair cells leads to a reduction in peripheral compression. It has also recently been shown in animal studies that noise over-exposure, producing temporary threshold shifts, can....... The results indicate that the slope of the ASSR level growth function can be used to estimate peripheral compression simultaneously at four frequencies below 60 dB SPL, while the slope above 60 dB SPL may provide information about the integrity of intensity coding of low-SR fibers.......The compressive nonlinearity of the auditory system is assumed to be an epiphenomenon of a healthy cochlea and, particularly, of outer-hair cell function. Another ability of the healthy auditory system is to enable communication in acoustical environments with high-level background noises...

Stabilization of acetylcholine receptors at the neuromuscular synapse: the role of the nerve.

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Ramsay, D A; Drachman, D B; Drachman, R J; Stanley, E F

1992-05-29

The majority of acetylcholine receptors (AChRs) at innervated neuromuscular junctions (NMJs) are stable, with half-lives averaging about 11 days in rodent muscles. In addition to the stable AChRs, approximately 18% of AChRs at these innervated junctions are rapidly turned over (RTOs), with half lives of less than 24 h. We have postulated that RTOs may be precursors of stable AChRs, and that the motor nerve may influence their stabilization. This hypothesis was tested by: (i) labeling AChRs in mouse sternomastoid (SM) muscles with 125I-alpha-BuTx; (ii) denervating one SM muscle in each mouse, and (iii) following the fate of the labeled AChRs through a 5-day period when RTOs were either stabilized or degraded. The hypothesis predicts that denervation should preclude stabilization of RTOs, resulting in a deficit of stable AChRs in denervated muscles. The results showed a highly significant (P less than 0.002) deficit of stable AChRs in denervated as compared with innervated muscles. Control experiments excluded the possibility that this deficit could be attributed to independent accelerated degradation of either RTOs or pre-existing stable AChRs. The observed deficit was quantitatively consistent with the deficit predicted by a mathematical model based on interruption of stabilization following denervation. We conclude that: (i) the observed deficit after denervation of NMJs is due to failure of stabilization of pre-existing RTOs; (ii) RTOs at normally innervated NMJs are precursors of stable AChRs; (iii) stabilization occurs after the insertion of AChRs at NMJs, and (iv) motor nerves play a key role in stabilization of RTOs. The concept of receptor stabilization has important implications for understanding the biology of the neuromuscular junction and post-synaptic plasticity.

Peripheral origins and functional characteristics of vibration-sensitive VIIIth nerve fibers in the frog Rana temporaria

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Jøgensen, Morten Buhl; Christensen-Dalsgaard, Jakob

1991-01-01

were studied. 2) Vibration-sensitive fibers were found in both the anterior and posterior branch of the VIIIth nerve. 3) No vibration-sensitive fibers were found in the lagenar nerve. 4) The vibration-sensitive fibers in the posterior branch probably innervated the amphibian papilla and many...... of these fibers also responded to low-frequency sound. 5) The vibration-sensitive fibers in the anterior branch probably innervated the sacculus and the utriculus. 6) Hence, the grassfrog has at least two, and probably three, vibration-sensitive organs in the inner ear. 7) All fibers had V-shaped vibrational...... tuning curves. In the posterior branch best frequencies (BFs) ranged from 10 to 300 Hz, in the anterior branch from 10 to 100 Hz. In the posterior branch spike-rate thresholds at BF ranged from 0.04 to 1.28 cm/s2, in the anterior branch from 0.02 to 1.28 cm/s2. All fibers showed strong synchronization...

Corneal Reinnervation and Sensation Recovery in Patients With Herpes Zoster Ophthalmicus: An In Vivo and Ex Vivo Study of Corneal Nerves.

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Cruzat, Andrea; Hamrah, Pedram; Cavalcanti, Bernardo M; Zheng, Lixin; Colby, Kathryn; Pavan-Langston, Deborah

2016-05-01

To study corneal reinnervation and sensation recovery in Herpes zoster ophthalmicus (HZO). Two patients with HZO were studied over time with serial corneal esthesiometry and laser in vivo confocal microscopy (IVCM). A Boston keratoprosthesis type 1 was implanted, and the explanted corneal tissues were examined by immunofluorescence histochemistry for βIII-tubulin to stain for corneal nerves. The initial central corneal IVCM performed in each patient showed a complete lack of the subbasal nerve plexus, which was in accordance with severe loss of sensation (0 of 6 cm) measured by esthesiometry. When IVCM was repeated 2 years later before undergoing surgery, case 1 showed a persistent lack of central subbasal nerves and sensation (0 of 6). In contrast, case 2 showed regeneration of the central subbasal nerves (4786 μm/mm) with partial recovery of corneal sensation (2.5 of 6 cm). Immunostaining of the explanted corneal button in case 1 showed no corneal nerves, whereas case 2 showed central and peripheral corneal nerves. Eight months after surgery, IVCM was again repeated in the donor tissue around the Boston keratoprosthesis in both patients to study innervation of the corneal transplant. Case 1 showed no nerves, whereas case 2 showed new nerves growing from the periphery into the corneal graft. We demonstrate that regaining corneal innervation and corneal function are possible in patients with HZO as shown by corneal sensation, IVCM, and ex vivo immunostaining, indicating zoster neural damage is not always permanent and it may recover over an extended period of time.

MRI enhancement of the facial nerve with Gd-DTPA, 2

International Nuclear Information System (INIS)

Yanagida, Masahiro

1993-01-01

We performed enhanced MRI using Gd-DTPA in 84 patients with facial palsy. After assessing enhancement of the normal facial nerve, we examined enhancement in patients with Bell's palsy and Ramsay Hunt syndrome. In 95% of patients with Bell's palsy, enhancement was obtained in the distal IAC and labyrinthine portions. In 72%, enhancement was significant from the distal IAC portion through the vertical portion. In some of the patients who underwent enhanced MRI twice, increased signal intensity was observed in distal portions such as the vertical portion. In many cases of Ramsay Hunt syndrome, enhancement was seen extensively in the IAC portion through the vertical portion. In the subjects with internal auditory symptoms such as vertigo and tinnitus, enhancement of the IAC portion was seen not only in the facial nerve but also in the vestibular and the cochlear nerves. These results suggest that the vascular permeability of lesions in Bell's palsy may be increased from the distal IAC portion to the vertical portion. Judging from the present findings with Ramsay Hunt syndrome, symptoms related to the enhanced portions suggest that accompanying internal auditory symptoms occur due to inflammation of the IAC portions of cochlear and vestibular nerves. (author)

Effect of fascicle composition on ulnar to musculocutaneous nerve transfer (Oberlin transfer) in neonatal brachial plexus palsy.

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Smith, Brandon W; Chulski, Nicholas J; Little, Ann A; Chang, Kate W C; Yang, Lynda J S

2018-06-01

OBJECTIVE Neonatal brachial plexus palsy (NBPP) continues to be a problematic occurrence impacting approximately 1.5 per 1000 live births in the United States, with 10%-40% of these infants experiencing permanent disability. These children lose elbow flexion, and one surgical option for recovering it is the Oberlin transfer. Published data support the use of the ulnar nerve fascicle that innervates the flexor carpi ulnaris as the donor nerve in adults, but no analogous published data exist for infants. This study investigated the association of ulnar nerve fascicle choice with functional elbow flexion outcome in NBPP. METHODS The authors conducted a retrospective study of 13 cases in which infants underwent ulnar to musculocutaneous nerve transfer for NBPP at a single institution. They collected data on patient demographics, clinical characteristics, active range of motion (AROM), and intraoperative neuromonitoring (IONM) (using 4 ulnar nerve index muscles). Standard statistical analysis compared pre- and postoperative motor function improvement between specific fascicle transfer (1-2 muscles for either wrist flexion or hand intrinsics) and nonspecific fascicle transfer (> 2 muscles for wrist flexion and hand intrinsics) groups. RESULTS The patients' average age at initial clinic visit was 2.9 months, and their average age at surgical intervention was 7.4 months. All NBPPs were unilateral; the majority of patients were female (61%), were Caucasian (69%), had right-sided NBPP (61%), and had Narakas grade I or II injuries (54%). IONM recordings for the fascicular dissection revealed a donor fascicle with nonspecific innervation in 6 (46%) infants and specific innervation in the remaining 7 (54%) patients. At 6-month follow-up, the AROM improvement in elbow flexion in adduction was 38° in the specific fascicle transfer group versus 36° in the nonspecific fascicle transfer group, with no statistically significant difference (p = 0.93). CONCLUSIONS Both specific and

The vagal innervation of the gut and immune homeostasis.

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Matteoli, Gianluca; Boeckxstaens, Guy E

2013-08-01

The central nervous system interacts dynamically with the immune system to modulate inflammation through humoral and neural pathways. Recently, in animal models of sepsis, the vagus nerve (VN) has been proposed to play a crucial role in the regulation of the immune response, also referred to as the cholinergic anti-inflammatory pathway. The VN, through release of acetylcholine, dampens immune cell activation by interacting with α-7 nicotinic acetylcholine receptors. Recent evidence suggests that the vagal innervation of the gastrointestinal tract also plays a major role controlling intestinal immune activation. Indeed, VN electrical stimulation potently reduces intestinal inflammation restoring intestinal homeostasis, whereas vagotomy has the reverse effect. In this review, we will discuss the current understanding concerning the mechanisms and effects involved in the cholinergic anti-inflammatory pathway in the gastrointestinal tract. Deeper investigation on this counter-regulatory neuroimmune mechanism will provide new insights in the cross-talk between the nervous and immune system leading to the identification of new therapeutic targets to treat intestinal immune disease.

Low Median Nerve Palsy as Initial Manifestation of Churg-Strauss Syndrome.

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Roh, Young Hak; Koh, Young Do; Noh, Jung Ho; Gong, Hyun Sik; Baek, Goo Hyun

2017-06-01

Anterior interosseous nerve (AIN) syndrome is typically characterized by forearm pain and partial or complete dysfunction of the AIN-innervated muscles. Although the exact etiology and pathophysiology of the disorder remain unclear, AIN syndrome is increasingly thought to be an inflammatory condition of the nerve rather than a compressive neuropathy because the symptoms often resolve spontaneously following prolonged observation. However, peripheral neuropathy can be 1 of the first symptoms of systemic vasculitis that needs early systemic immunotherapy to prevent extensive nerve damage. Churg-Strauss syndrome (CSS; eosinophilic granulomatosis with polyangiitis) is 1 type of primary systemic vasculitis that frequently damages the peripheral nervous system. CSS-associated neuropathy usually involves nerves of the lower limb, and few studies have reported on the involvement of the upper limb alone. We report on a rare case of low median nerve palsy as the initial manifestation of CSS. The patient recovered well with early steroid treatment for primary systemic vasculitis. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Preganglionic innervation of the pancreas islet cells in the rat

NARCIS (Netherlands)

LUITEN, PGM; TERHORST, GJ; KOOPMANS, SJ; RIETBERG, M; STEFFENS, AB

1984-01-01

The position and number of preganglionic somata innervating the insulin-secreting β-cells of the endocrine pancreas were investigated in Wistar rats. This question was approached by comparing the innervation of the pancreas of normal rats with the innervation of the pancreas in alloxan-induced

Effect of cochlear nerve electrocautery on the adult cochlear nucleus.

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Iseli, Claire E; Merwin, William H; Klatt-Cromwell, Cristine; Hutson, Kendall A; Ewend, Matthew G; Adunka, Oliver F; Fitzpatrick, Douglas C; Buchman, Craig A

2015-04-01

Electrocauterization and subsequent transection of the cochlear nerve induce greater injury to the cochlear nucleus than sharp transection alone. Some studies show that neurofibromatosis Type 2 (NF2) patients fit with auditory brainstem implants (ABIs) fail to achieve speech perception abilities similar to ABI recipients without NF2. Reasons for these differences remain speculative. One hypothesis posits poorer performance to surgically induced trauma to the cochlear nucleus from electrocautery. Sustained electrosurgical depolarization of the cochlear nerve may cause excitotoxic-induced postsynaptic nuclear injury. Equally plausible is that cautery in the vicinity of the cochlear nucleus induces necrosis. The cochlear nerve was transected in anesthetized adult gerbils sharply with or without bipolar electrocautery at varying intensities. Gerbils were perfused at 1, 3, 5, and 7 days postoperatively; their brainstem and cochleas were embedded in paraffin and sectioned at 10 μm. Alternate sections were stained with flourescent markers for neuronal injury or Nissl substance. In additional experiments, anterograde tracers were applied directly to a sectioned eighth nerve to verify that fluorescent-labeled profiles seen were terminating auditory nerve fibers. Cochlear nerve injury was observed from 72 hours postoperatively and was identical across cases regardless of surgical technique. Postsynaptic cochlear nucleus injury was not seen after distal transection of the nerve. By contrast, proximal transection was associated with trauma to the cochlear nucleus. Distal application of bipolar electrocautery seems safe for the cochlear nucleus. Application near the root entry zone must be used cautiously because this may compromise nuclear viability needed to support ABI stimulation.

Hypoglossal-facial nerve "side"-to-side neurorrhaphy for facial paralysis resulting from closed temporal bone fractures.

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Su, Diya; Li, Dezhi; Wang, Shiwei; Qiao, Hui; Li, Ping; Wang, Binbin; Wan, Hong; Schumacher, Michael; Liu, Song

2018-06-06

Closed temporal bone fractures due to cranial trauma often result in facial nerve injury, frequently inducing incomplete facial paralysis. Conventional hypoglossal-facial nerve end-to-end neurorrhaphy may not be suitable for these injuries because sacrifice of the lesioned facial nerve for neurorrhaphy destroys the remnant axons and/or potential spontaneous innervation. we modified the classical method by hypoglossal-facial nerve "side"-to-side neurorrhaphy using an interpositional predegenerated nerve graft to treat these injuries. Five patients who experienced facial paralysis resulting from closed temporal bone fractures due to cranial trauma were treated with the "side"-to-side neurorrhaphy. An additional 4 patients did not receive the neurorrhaphy and served as controls. Before treatment, all patients had suffered House-Brackmann (H-B) grade V or VI facial paralysis for a mean of 5 months. During the 12-30 months of follow-up period, no further detectable deficits were observed, but an improvement in facial nerve function was evidenced over time in the 5 neurorrhaphy-treated patients. At the end of follow-up, the improved facial function reached H-B grade II in 3, grade III in 1 and grade IV in 1 of the 5 patients, consistent with the electrophysiological examinations. In the control group, two patients showed slightly spontaneous innervation with facial function improved from H-B grade VI to V, and the other patients remained unchanged at H-B grade V or VI. We concluded that the hypoglossal-facial nerve "side"-to-side neurorrhaphy can preserve the injured facial nerve and is suitable for treating significant incomplete facial paralysis resulting from closed temporal bone fractures, providing an evident beneficial effect. Moreover, this treatment may be performed earlier after the onset of facial paralysis in order to reduce the unfavorable changes to the injured facial nerve and atrophy of its target muscles due to long-term denervation and allow axonal

Electrophysiological study in the infraorbital nerve of the rat: Spontaneous and evoked activity

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AlbarracIn, A L [Catedra de Neurociencias, Facultad de Medicina, Universidad Nacional de Tucuman, Av. Roca 2200, PC 4000 (Argentina); Farfan, F D [Departamento de BioingenierIa, FACET, Universidad Nacional de Tucuman, INSIBIO - CONICET, CC 327, PC 4000 (Argentina); Felice, C J [Departamento de BioingenierIa, FACET, Universidad Nacional de Tucuman, INSIBIO - CONICET, CC 327, PC 4000 (Argentina)

2007-11-15

In this work we present some studies in the afferent nerve of the rat vibrissae. Studies on spontaneous activity (SA) in this sensorial system are of long data. Nevertheless, SA recordings in the nerve of a single vibrissa have not been made until present. In this work, we use an algorithm based on signal decomposition with Continuous Wavelet Transform (CWT) to analyse the discharges of two nerves. The action potentials of both nerves were detected and the firing rates were calculated. These results suggest that the firing rate of one vibrissa innervation is low considering that this nerve contains hundred of fibers. In addition, we present preliminary studies suggesting important effects of the hair shaft length in the afferent discharge during the vibrissae movements. The experiments consisted in recording the nerve activity after the vibrissae were sectioned at two different levels. The results showed important differences in the signal energy contents. It suggests that the hair shaft length would produce a differential activation of the mechanoreceptors located in the vibrissae follicle.

Electrophysiological study in the infraorbital nerve of the rat: Spontaneous and evoked activity

International Nuclear Information System (INIS)

AlbarracIn, A L; Farfan, F D; Felice, C J

2007-01-01

In this work we present some studies in the afferent nerve of the rat vibrissae. Studies on spontaneous activity (SA) in this sensorial system are of long data. Nevertheless, SA recordings in the nerve of a single vibrissa have not been made until present. In this work, we use an algorithm based on signal decomposition with Continuous Wavelet Transform (CWT) to analyse the discharges of two nerves. The action potentials of both nerves were detected and the firing rates were calculated. These results suggest that the firing rate of one vibrissa innervation is low considering that this nerve contains hundred of fibers. In addition, we present preliminary studies suggesting important effects of the hair shaft length in the afferent discharge during the vibrissae movements. The experiments consisted in recording the nerve activity after the vibrissae were sectioned at two different levels. The results showed important differences in the signal energy contents. It suggests that the hair shaft length would produce a differential activation of the mechanoreceptors located in the vibrissae follicle

Brachial branches of the medial antebrachial cutaneous nerve: A case report with its clinical significance and a short review of the literature

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Kapetanakis Stylianos

2016-01-01

Full Text Available The medial antebrachial cutaneous nerve (MACN is a branch of the brachial plexus with a great variation within its branches. Knowledge of these variations is critical to neurologists, hand surgeons, plastic surgeons, and vascular surgeons. The aim of this study was to search for variations of the MACN and to discuss their clinical significance. For this study, six arm cadavers from three fresh cadavers were dissected and examined to find and study possible anatomical variations of the MACN. The authors report a rare case of a variation of the MACN, in which there are four brachial cutaneous branches, before the separation to anterior (volar and posterior (ulnar branch, that provide sensory innervation to the medial, inferior half of the arm, in the area that is commonly innervated from the medial brachial cutaneous nerve. To our knowledge, this is the first documented case of this nerve variation. This variation should be taken into serious consideration for the differential diagnosis of patients with complaints of hypoesthesia, pain, and paresthesia and for the surgical operations in the medial part of the arm.

Remodelling of cardiac sympathetic re-innervation with thoracic spinal cord stimulation improves left ventricular function in a porcine model of heart failure.

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Liao, Song-Yan; Liu, Yuan; Zuo, Mingliang; Zhang, Yuelin; Yue, Wensheng; Au, Ka-Wing; Lai, Wing-Hon; Wu, Yangsong; Shuto, Chika; Chen, Peter; Siu, Chung-Wah; Schwartz, Peter J; Tse, Hung-Fat

2015-12-01

Thoracic spinal cord stimulation (SCS) has been shown to improve left ventricular ejection fraction (LVEF) in heart failure (HF). Nevertheless, the optimal duration (intermittent vs. continuous) of stimulation and the mechanisms of action remain unclear. We performed chronic thoracic SCS at the level of T1-T3 (50 Hz, pulse width 0.2 ms) in 30 adult pigs with HF induced by myocardial infarction and rapid ventricular pacing for 4 weeks. All the animals were treated with daily oral metoprolol succinate (25 mg) plus ramipril (2.5 mg), and randomized to a control group (n = 10), intermittent SCS (4 h ×3, n = 10) or continuous SCS (24 h, n = 10) for 10 weeks. Serial measurements of LVEF and +dP/dt and serum levels of norepinephrine and B-type natriuretic peptide (BNP) were measured. After sacrifice, immunohistological studies of myocardial sympathetic and parasympathetic nerve sprouting and innervation were performed. Echocardiogram revealed a significant increase in LVEF and +dP/dt at 10 weeks in both the intermittent and continuous SCS group compared with controls (P < 0.05). In both SCS groups, there was diffuse sympathetic nerve sprouting over the infarct, peri-infarct, and normal regions compared with only the peri-infarct and infarct regions in the control group. In addition, sympathetic innervation at the peri-infarct and infarct regions was increased following SCS, but decreased in the control group. Myocardium norepinephrine spillover and serum BNP at 10 weeks was significantly decreased only in the continuous SCS group (P < 0.05). In a porcine model of HF, SCS induces significant remodelling of cardiac sympathetic innervation over the peri-infarct and infarct regions and is associated with improved LV function and reduced myocardial norepinephrine spillover. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Small vestibular schwannomas presenting with facial nerve palsy.

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Espahbodi, Mana; Carlson, Matthew L; Fang, Te-Yung; Thompson, Reid C; Haynes, David S

2014-06-01

To describe the surgical management and convalescence of two patients presenting with severe facial nerve weakness associated with small intracanalicular vestibular schwannomas (VS). Retrospective review. Two adult female patients presenting with audiovestibular symptoms and subacute facial nerve paralysis (House-Brackmann Grade IV and V). In both cases, post-contrast T1-weighted magnetic resonance imaging revealed an enhancing lesion within the internal auditory canal without lateral extension beyond the fundus. Translabyrinthine exploration demonstrated vestibular nerve origin of tumor, extrinsic to the facial nerve, and frozen section pathology confirmed schwannoma. Gross total tumor resection with VIIth cranial nerve preservation and decompression of the labyrinthine segment of the facial nerve was performed. Both patients recovered full motor function between 6 and 8 months after surgery. Although rare, small VS may cause severe facial neuropathy, mimicking the presentation of facial nerve schwannomas and other less common pathologies. In the absence of labyrinthine extension on MRI, surgical exploration is the only reliable means of establishing a diagnosis. In the case of confirmed VS, early gross total resection with facial nerve preservation and labyrinthine segment decompression may afford full motor recovery-an outcome that cannot be achieved with facial nerve grafting.

Retrograde axonal transport of 125I-nerve growth factor in rat ileal mesenteric nerves. Effect of streptozocin diabetes

International Nuclear Information System (INIS)

Schmidt, R.E.; Plurad, S.B.; Saffitz, J.E.; Grabau, G.G.; Yip, H.K.

1985-01-01

The retrograde axonal transport of intravenously (i.v.) administered 125 I-nerve growth factor ( 125 I-NGF) was examined in mesenteric nerves innervating the small bowel of rats with streptozocin (STZ) diabetes using methods described in detail in the companion article. The accumulation of 125 I-NGF distal to a ligature on the ileal mesenteric nerves of diabetic animals was 30-40% less than in control animals. The inhibition of accumulation of 125 I-NGF in diabetic animals was greater at a ligature tied 2 h after i.v. administration than at a ligature tied after 14 h, which suggests that the diabetic animals may have a lag in initiation of NGF transport in the terminal axon or retardation of transport at some site along the axon. The 125 I-NGF transport defect was observed as early as 3 days after the induction of diabetes, a time before the development of structural axonal lesions, and did not worsen at later times when dystrophic axonopathy is present. Both the ileal mesenteric nerves, which eventually develop dystrophic axonopathy in experimental diabetes, and the jejunal mesenteric nerves, which never develop comparable structural alterations, showed similar 125 I-NGF transport deficits, suggesting that the existence of the transport abnormality does not predict the eventual development of dystrophic axonal lesions. Autoradiographic localization of 125 I-NGF in the ileal mesenteric nerves of animals that had been diabetic for 11-13 mo demonstrated decreased amounts of 125 I-NGF in transit in unligated paravascular nerve fascicles. There was, however, no evidence for focal retardation of transported 125 I-NGF at the sites of dystrophic axonal lesions

Clinical Outcomes following median to radial nerve transfers

Science.gov (United States)

Ray, Wilson Z.; Mackinnon, Susan E.

2010-01-01

Purpose In this study the authors evaluate the clinical outcomes in patients with radial nerve palsy who underwent nerve transfers utilizing redundant fascicles of median nerve (innervating the flexor digitorum superficialis and flexor carpi radialis muscles) to the posterior interosseous nerve and the nerve to the extensor carpi radialis brevis. Methods A retrospective review of the clinical records of 19 patients with radial nerve injuries who underwent nerve transfer procedures using the median nerve as a donor nerve were included. All patients were evaluated using the Medical Research Council (MRC) grading system. Results The mean age of patients was 41 years (range 17 – 78 years). All patients received at least 12 months of follow-up (20.3 ± 5.8 months). Surgery was performed at a mean of 5.7 ± 1.9 months post-injury. Post-operative functional evaluation was graded according to the following scale: grades MRC 0/5 - MRC 2/5 were considered poor outcomes, while MRC of 3/5 was a fair result, MRC grade 4/5 was a good result, and grade 4+/5 was considered an excellent outcome. Seventeen patients (89%) had a complete radial nerve palsy while two patients (11%) had intact wrist extension but no finger or thumb extension. Post-operatively all patients except one had good to excellent recovery of wrist extension. Twelve patients recovered good to excellent finger and thumb extension, two patients had fair recovery, five patients had a poor recovery. Conclusions The radial nerve is a commonly injured nerve, causing significant morbidity in affected patients. The median nerve provides a reliable source of donor nerve fascicles for radial nerve reinnervation. This transfer was first performed in 1999 and evolved over the subsequent decade. The important nuances of both surgical technique and motor re-education critical for to the success of this transfer have been identified and are discussed. PMID:21168979

Electrophysiology and Innervation of the Photosensitive Epistellar Body in the Lesser Octopus Eledone cirrhosa.

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Cobb, C S; Williamson, R

1998-08-01

The innervation and responses to light of the cephalopod epistellar body were investigated in preparations isolated from the stellate ganglia of the lesser or northern octopus, Eledone cirrhosa. Extracellular generator potentials in response to flashes of light were recorded from these photosensitive vesicles, with the amplitude of the response being found to be dependent upon the intensity of the flash and the level of ambient illumination. Intracellular recordings from photoreceptor cells of the epistellar body showed that they had resting potentials of about -49 +/- 7 mV (mean +/- SD, n = 43) and were depolarized by flashes of white, but not red (>650 nm) light. The evoked depolarization consisted of a transient component, followed by a steady plateau in which the amplitude of the depolarization was well correlated with the log of the stimulus intensity. The evoked depolarizations induced action potentials in the photoreceptor cells, with the frequency of firing being well correlated with the stimulus intensity. The morphologies of individual photoreceptor cells were visualized by intracellular injections of the fluorescent dye Lucifer yellow, and the path of the epistellar nerve across the stellate ganglion, into the pallial nerve, toward the brain was traced using the lipophilic dye Di-I. This pathway was confirmed physiologically by recording light-evoked responses from the cut end of the pallial nerve.

Role of Schwann cells in the regeneration of penile and peripheral nerves

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Lin Wang

2015-01-01

Full Text Available Schwann cells (SCs are the principal glia of the peripheral nervous system. The end point of SC development is the formation of myelinating and nonmyelinating cells which ensheath large and small diameter axons, respectively. They play an important role in axon regeneration after injury, including cavernous nerve injury that leads to erectile dysfunction (ED. Despite improvement in radical prostatectomy surgical techniques, many patients still suffer from ED postoperatively as surgical trauma causes traction injuries and local inflammatory changes in the neuronal microenvironment of the autonomic fibers innervating the penis resulting in pathophysiological alterations in the end organ. The aim of this review is to summarize contemporary evidence regarding: (1 the origin and development of SCs in the peripheral and penile nerve system; (2 Wallerian degeneration and SC plastic change following peripheral and penile nerve injury; (3 how SCs promote peripheral and penile nerve regeneration by secreting neurotrophic factors; (4 and strategies targeting SCs to accelerate peripheral nerve regeneration. We searched PubMed for articles related to these topics in both animal models and human research and found numerous studies suggesting that SCs could be a novel target for treatment of nerve injury-induced ED.

Effect of age at cochlear implantation on auditory and speech development of children with auditory neuropathy spectrum disorder.

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Liu, Yuying; Dong, Ruijuan; Li, Yuling; Xu, Tianqiu; Li, Yongxin; Chen, Xueqing; Gong, Shusheng

2014-12-01

To evaluate the auditory and speech abilities in children with auditory neuropathy spectrum disorder (ANSD) after cochlear implantation (CI) and determine the role of age at implantation. Ten children participated in this retrospective case series study. All children had evidence of ANSD. All subjects had no cochlear nerve deficiency on magnetic resonance imaging and had used the cochlear implants for a period of 12-84 months. We divided our children into two groups: children who underwent implantation before 24 months of age and children who underwent implantation after 24 months of age. Their auditory and speech abilities were evaluated using the following: behavioral audiometry, the Categories of Auditory Performance (CAP), the Meaningful Auditory Integration Scale (MAIS), the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS), the Standard-Chinese version of the Monosyllabic Lexical Neighborhood Test (LNT), the Multisyllabic Lexical Neighborhood Test (MLNT), the Speech Intelligibility Rating (SIR) and the Meaningful Use of Speech Scale (MUSS). All children showed progress in their auditory and language abilities. The 4-frequency average hearing level (HL) (500Hz, 1000Hz, 2000Hz and 4000Hz) of aided hearing thresholds ranged from 17.5 to 57.5dB HL. All children developed time-related auditory perception and speech skills. Scores of children with ANSD who received cochlear implants before 24 months tended to be better than those of children who received cochlear implants after 24 months. Seven children completed the Mandarin Lexical Neighborhood Test. Approximately half of the children showed improved open-set speech recognition. Cochlear implantation is helpful for children with ANSD and may be a good optional treatment for many ANSD children. In addition, children with ANSD fitted with cochlear implants before 24 months tended to acquire auditory and speech skills better than children fitted with cochlear implants after 24 months. Copyright © 2014

Microsurgical Decompression of the Cochlear Nerve to Treat Disabling Tinnitus via an Endoscope-Assisted Retrosigmoid Approach: The Padua Experience.

Science.gov (United States)

Di Stadio, Arianna; Colangeli, Roberta; Dipietro, Laura; Martini, Alessandro; Parrino, Daniela; Nardello, Ennio; D'Avella, Domenico; Zanoletti, Elisabetta

2018-05-01

The use of surgical cochlear nerve decompression is controversial. This study aimed at investigating the safety and validity of microsurgical decompression via an endoscope-assisted retrosigmoid approach to treat tinnitus in patients with neurovascular compression of the cochlear nerve. Three patients with disabling tinnitus resulting from a loop in the internal auditory canal were evaluated with magnetic resonance imaging and tests of pure tone auditory, tinnitus, and auditory brain response (ABR) to identify the features of the cochlear nerve involvement. We observed a loop with a caliber greater than 0.8 mm in all patients. Patients were treated via an endoscope-assisted retrosigmoid microsurgical decompression. After surgery, none of the patients reported short-term or long-term complications. After surgery, tinnitus resolved immediately in 2 patients, whereas in the other patient symptoms persisted although they improved; in all patients, hearing was preserved and ABR improved. Microsurgical decompression via endoscope-assisted retrosigmoid approach is a promising, safe, and valid procedure for treating tinnitus caused by cochlear nerve compression. This procedure should be considered in patients with disabling tinnitus who have altered ABR and a loop that has a caliber greater than 0.8 mm and is in contact with the cochlear nerve. Copyright © 2018 Elsevier Inc. All rights reserved.

Sonic hedgehog from both nerves and epithelium is a key trophic factor for taste bud maintenance.

Science.gov (United States)

Castillo-Azofeifa, David; Losacco, Justin T; Salcedo, Ernesto; Golden, Erin J; Finger, Thomas E; Barlow, Linda A

2017-09-01

The integrity of taste buds is intimately dependent on an intact gustatory innervation, yet the molecular nature of this dependency is unknown. Here, we show that differentiation of new taste bud cells, but not progenitor proliferation, is interrupted in mice treated with a hedgehog (Hh) pathway inhibitor (HPI), and that gustatory nerves are a source of sonic hedgehog (Shh) for taste bud renewal. Additionally, epithelial taste precursor cells express Shh transiently, and provide a local supply of Hh ligand that supports taste cell renewal. Taste buds are minimally affected when Shh is lost from either tissue source. However, when both the epithelial and neural supply of Shh are removed, taste buds largely disappear. We conclude Shh supplied by taste nerves and local taste epithelium act in concert to support continued taste bud differentiation. However, although neurally derived Shh is in part responsible for the dependence of taste cell renewal on gustatory innervation, neurotrophic support of taste buds likely involves a complex set of factors. © 2017. Published by The Company of Biologists Ltd.

Effects on auditory-nerve fibers of opening the otic capsule at the apex of the chinchilla cochlea

Science.gov (United States)

Recio-Spinoso, Alberto; Temchin, Andrei N.; Ruggero, Mario A.

2015-12-01

Vibration responses to clicks measured at the apex of chinchilla cochleae with open otic capsules have onsets much shorter than those of responses of auditory-nerve fibers (ANFs) corrected for synaptic and neural delays. Apical vibration responses to tones in open cochleae also differ in other respects from the responses to tones of ANFs with low characteristic frequency (CF) in normal chinchilla cochleae. To further specify the origin(s) of these differences, we recorded from chinchilla ANFs after delicately opening a small hole in the otic capsule overlying scala vestibuli in the cochlear apex. In those cochleae, the earliest ANF responses to clicks are often evoked by condensation (rather than rarefaction) clicks and responses to tones often exhibit level-dependent phase changes different from those in normal cochleae. These findings are largely consistent with, and seem to account for, apical vibration responses of cochleae with open otic capsules. An unexpected finding is that the tuning curves of ANFs with moderately high CF and normal CF thresholds often had hypersensitive tails.

Evaluation of peripheral auditory pathways and brainstem in obstructive sleep apnea

Directory of Open Access Journals (Sweden)

Erika Matsumura

Full Text Available Abstract Introduction Obstructive sleep apnea causes changes in normal sleep architecture, fragmenting it chronically with intermittent hypoxia, leading to serious health consequences in the long term. It is believed that the occurrence of respiratory events during sleep, such as apnea and hypopnea, can impair the transmission of nerve impulses along the auditory pathway that are highly dependent on the supply of oxygen. However, this association is not well established in the literature. Objective To compare the evaluation of peripheral auditory pathway and brainstem among individuals with and without obstructive sleep apnea. Methods The sample consisted of 38 adult males, mean age of 35.8 (±7.2, divided into four groups matched for age and Body Mass Index. The groups were classified based on polysomnography in: control (n = 10, mild obstructive sleep apnea (n = 11 moderate obstructive sleep apnea (n = 8 and severe obstructive sleep apnea (n = 9. All study subjects denied a history of risk for hearing loss and underwent audiometry, tympanometry, acoustic reflex and Brainstem Auditory Evoked Response. Statistical analyses were performed using three-factor ANOVA, 2-factor ANOVA, chi-square test, and Fisher's exact test. The significance level for all tests was 5%. Results There was no difference between the groups for hearing thresholds, tympanometry and evaluated Brainstem Auditory Evoked Response parameters. An association was observed between the presence of obstructive sleep apnea and changes in absolute latency of wave V (p = 0.03. There was an association between moderate obstructive sleep apnea and change of the latency of wave V (p = 0.01. Conclusion The presence of obstructive sleep apnea is associated with changes in nerve conduction of acoustic stimuli in the auditory pathway in the brainstem. The increase in obstructive sleep apnea severity does not promote worsening of responses assessed by audiometry, tympanometry and Brainstem

The effect of patient positioning on MR imaging of the internal auditory canal

International Nuclear Information System (INIS)

Daniels, D.L.; Czervionke, L.F.; Yu, S.; Ho, P.S.P.; Pech, P.; Pojunas, K.W.; Williams, A.L.; Haughton, V.M.

1988-01-01

Identification of individual cranial nerves and complete exclusion of tumor in the internal auditory canal may be difficult with MR, especially in imperfectly positioned patients. MR studies of the temporal bones in patients and in normal volunteers positioned non-rotated or canted were correlated with corresponding cryomicrotomic sections. Especially in axial images, oblique sectioning of cranial nerves VII and VIII may cause difficulty in identifying individual nerves. A combination of axial and coronal short TR and TE images can be used to confidently exclude intracanalicular tumor in most cases. (orig.)

An unbiased stereological method for efficiently quantifying the innervation of the heart and other organs based on total length estimations

DEFF Research Database (Denmark)

Mühlfeld, Christian; Papadakis, Tamara; Krasteva, Gabriela

2010-01-01

Quantitative information about the innervation is essential to analyze the structure-function relationships of organs. So far, there has been no unbiased stereological tool for this purpose. This study presents a new unbiased and efficient method to quantify the total length of axons in a given...... reference volume, illustrated on the left ventricle of the mouse heart. The method is based on the following steps: 1) estimation of the reference volume; 2) randomization of location and orientation using appropriate sampling techniques; 3) counting of nerve fiber profiles hit by a defined test area within...

Radioanatomy of the singular nerve canal

Energy Technology Data Exchange (ETDEWEB)

Muren, C. [Dept. of Diagnostic Radiology, Sabbatsbergs Hospital, Stockholm (Sweden); Wadin, K. [University Hospital, Uppsala (Sweden); Dimopoulos, P. [University Hospital, Uppsala (Sweden)

1991-08-01

The singular canal conveys vestibular nerve fibers from the ampulla of the posterior semicircular canal to the posteroinferior border of the internal auditory meatus. Radiographic identification of this anatomic structure helps to distinguish it from a fracture. It is also a landmark in certain surgical procedures. Computed tomography (CT) examinations of deep-frozen temporal bone specimens were compared with subsequently prepared plastic casts of these bones, showing good correlation between the anatomy and the images. The singular canal and its variable anatomy were studied in CT examinations of 107 patients. The singular canal could be identified, in both the axial and in the coronal planes. Its point of entry into the internal auditory meatus varied considerably. (orig.)

Anatomical study of the forearm and hand nerves of the domestic cat ( Felis catus), puma ( Puma concolor) and jaguar ( Panthera onca).

Science.gov (United States)

Sánchez, H L; Silva, L B; Rafasquino, M E; Mateo, A G; Zuccolilli, G O; Portiansky, E L; Alonso, C R

2013-04-01

The innervation of the forearm and hand regions of cats has not been well described despite its importance for any surgery or any neurological disorder. It is probably the main area where disorders of peripheral nerves in this species are observed. In felines, the forelimbs facilitate the jump and represent the most important way for capturing prey. The main muscles and nerves involved in this activity are located in the region of the forearm and hand. The aim of the present study was to provide a detailed description of the innervation of the forearm and hand regions of the jaguar and puma, in comparison with that of the domestic cat, contributing thus with the anatomical knowledge of the area for applying it to surgery and pathology. The forearms of three pumas and two jaguars (all of them fixed in formalin) and of six domestic cats (fresh) were dissected. The nerves path and their forearm distribution patterns of all three species were described. The analysed results indicate that the observed variations between species are minimal; thus, the anatomy described for domestic cats can be widely applied to American wild felids. © 2012 Blackwell Verlag GmbH.

Cortical cholinergic innervation: Distribution and source in monkeys

International Nuclear Information System (INIS)

Struble, R.G.; Cork, L.C.; Coyle, J.T.; Lehmann, J.; Mitchell, S.J.; Price, D.L.

1986-01-01

In Alzheimer's disease (AD) and its late-life variant, senile dementia of the Alzheimer's type (SDAT), the predominant neurochemical abnormalities are marked decrements in the activities of ChAT and AChE, the high affinity uptake of tritium-choline, and synthesis of acetylcholine. Two studies are undertaken to delineate more clearly the variability of cortical cholinergic innervation and the contribution of the Ch system, particularly the Ch4, to this cholinergic innervation. In the first study, ChAT activity was assessed in multiple samples of neocortex from seven normal cynomolgus monkeys. In the second study, the nbM was lesioned in order to determine the contribution of the Ch system to cortical cholinergic innervation

Gd-DTPA enhancement of the facial nerve in Ramsay Hunt's syndrome

Energy Technology Data Exchange (ETDEWEB)

Kato, Tsutomu; Yanagida, Masahiro; Yamauchi, Yasuo [Kansai Medical School, Moriguchi, Osaka (Japan); and others

1992-10-01

A total of 21 MR images in 16 Ramsay Hunt's syndrome were evaluated. In all images, the involved side of peripheral facial nerve were enhanced in intensity after Gd-DTPA. However, 2 cases had recovered facial palsy when MR images were taken. Nine of 19 cases with the enhancement of internal auditory canal portion had vertigo or tinnitus. Thus, it was suggested that the enhancement of internal auditory canal portion and clinical feature are closely related. (author).

Gd-DTPA enhancement of the facial nerve in Ramsay Hunt's syndrome

International Nuclear Information System (INIS)

Kato, Tsutomu; Yanagida, Masahiro; Yamauchi, Yasuo

1992-01-01

A total of 21 MR images in 16 Ramsay Hunt's syndrome were evaluated. In all images, the involved side of peripheral facial nerve were enhanced in intensity after Gd-DTPA. However, 2 cases had recovered facial palsy when MR images were taken. Nine of 19 cases with the enhancement of internal auditory canal portion had vertigo or tinnitus. Thus, it was suggested that the enhancement of internal auditory canal portion and clinical feature are closely related. (author)

The Underlying Mechanism of Preventing Facial Nerve Stimulation by Triphasic Pulse Stimulation in Cochlear Implant Users Assessed With Objective Measure.

Science.gov (United States)

Bahmer, Andreas; Baumann, Uwe

2016-10-01

Triphasic pulse stimulation prevents from facial nerve stimulation (FNS) because of a different electromyographic input-output function compared with biphasic pulse stimulation. FNS is sometimes observed in cochlear implant users as an unwanted side effect of electrical stimulation of the auditory nerve. The common stimulation applied in current cochlear implant consists of biphasic pulse patterns. Two common clinical remedies to prevent unpleasant FNS caused by activation of certain electrodes are to expand their pulse phase duration or simply deactivate them. Unfortunately, in some patients these methods do not provide sufficient FNS prevention. In these patients triphasic pulse can prevent from FNS. The underlying mechanism is yet unclear. Electromyographic (EMG) recordings of muscles innervated by the facial nerve (musculi orbicularis ori and oculi) were applied to quantitatively assess the effects on FNS. Triphasic and biphasic fitting maps were compared in four subjects with severe FNS. Based on the recordings, a model is presented which intends to explain the beneficial effects of triphasic pulse application. Triphasic stimulation provided by fitting of an OPUS 2 speech processor device. For three patients, EMG was successfully recorded depending on stimulation level up to uncomfortable and intolerable FNS stimulation as upper boarder. The obtained EMG recordings demonstrated high individual variability. However, a difference between the input-output function for biphasic and triphasic pulse stimulation was visually observable. Compared with standard biphasic stimulation, triphasic pulses require higher stimulation levels to elicit an equal amount of FNS, as reflected by EMG amplitudes. In addition, we assume a steeper slope of the input-output function for biphasic pulse stimulation compared with triphasic pulse stimulation. Triphasic pulse stimulation prevents from FNS because of a smaller gradient of EMG input-output function compared with biphasic pulse

Measurement of functional cholinergic innervation in rat heart with a novel vesamicol receptor ligand

International Nuclear Information System (INIS)

Coffeen, Paul R.; Efange, S.M.N.; Haidet, George C.; McKnite, Scott; Langason, Rosemary B.; Khare, A.B.; Pennington, Jennifer; Lurie, Keith G.

1996-01-01

Regional differences in cholinergic activity in the cardiac conduction system have been difficult to study. We tested the utility of (+)-m-[ 125 I]iodobenzyl)trozamicol(+)-[ 125 I]MIBT), a novel radioligand that binds to the vesamicol receptor located on the synaptic vesicle in presynaptic cholinergic neurons, as a functional marker of cholinergic activity in the conduction system. The (+)-[ 125 I]MIBT was injected intravenously into four rats. Three hours later, the rats were killed and their hearts were frozen. Quantitative autoradiography was performed on 20-micron-thick sections that were subsequently stained for acetylcholinesterase to identify specific conduction-system elements. Marked similarities existed between (+)-[ 125 I]MIBT uptake and acetylcholinesterase-positive regions. Optical densitometric analysis of regional (+)-[ 125 I]MIBT uptake revealed significantly greater (+)-[ 125 I]MIBT binding (nCi/mg) in the atrioventricular node (AVN) and His bundle regions compared with other conduction and contractile elements (AVN: 3.43 ± 0.37; His bundle: 2.16 ± 0.30; right bundle branch: 0.95 ± 0.13; right atrium: 0.68 ± 0.05; right ventricle: 0.57 ± 0.03; and left ventricle: 0.57 ± 0.03; p 125 I]MIBT binds avidly to cholinergic nerve tissue innervating specific conduction-system elements. Thus, (+)-[ 125 I]MIBT may be a useful functional marker in studies on cholinergic innervation in the cardiac conduction system

Median nerve fascicular anatomy as a basis for distal neural prostheses.

Science.gov (United States)

Planitzer, Uwe; Steinke, Hanno; Meixensberger, Jürgen; Bechmann, Ingo; Hammer, Niels; Winkler, Dirk

2014-05-01

Functional electrical stimulation (FES) serves as a possible therapy to restore missing motor functions of peripheral nerves by means of cuff electrodes. FES is established for improving lower limb function. Transferring this method to the upper extremity is complex, due to a lack of anatomical data on the physiological configuration of nerve fascicles. Our study's aim was to provide an anatomical basis for FES of the median nerve in the distal forearm and hand. We investigated 21 distal median nerves from 12 body donors. The peripheral fascicles were traced back by removing the external and interfascicular epineurium and then assigned to 4 quadrants. A distinct motor and sensory distribution was observed. The fascicles innervating the thenar eminence and the first lumbrical muscle originated from the nerves' radial parts in 82%. The fascicle supplying the second lumbrical muscle originated from the ulnar side in 78%. No macroscopically visible plexus formation was observed for the distal median nerve in the forearm. The findings on the distribution of the motor branches of the median nerve and the missing plexus formation may likely serve as an anatomical basis for FES of the distal forearm. However, due to the considerable variability of the motor branches, cuff electrodes will need to be adapted individually in FES. Taking into account the sensory distribution of the median nerve, FES may also possibly be applied in the treatment of regional pain syndromes. Copyright © 2013 Elsevier GmbH. All rights reserved.

Immmunohistochemical study of the blood and lymphatic vasculature and the innervation of mouse gut and gut-associated lymphoid tissue.

Science.gov (United States)

Ma, B; von Wasielewski, R; Lindenmaier, W; Dittmar, K E J

2007-02-01

The blood and lymphatic vascular system of the gut plays an important role in tissue fluid homeostasis, nutrient absorption and immune surveillance. To obtain a better understanding of the anatomic basis of these functions, the blood and lymphatic vasculature of the lower segment of mouse gut and several constituents of gut-associated lymphoid tissue (GALT) including Peyer's patch, specialized lymphoid nodules in the caecum, small lymphoid aggregates and lymphoid nodules in the colon were studied by using confocal microscopy. Additionally, the innervation and nerve/immune cell interactions in the gut and Peyer's patch were investigated by using cell surface marker PGP9.5 and Glial fibrillary acidic protein (GFAP). In the gut and Peyer's patch, the nerves have contact with B cell, T cell and B220CD3 double-positive cells. Dendritic cells, the most important antigen-presenting cells, were closely apposed to some nerves. Some dendritic cells formed membrane-membrane contact with nerve terminals and neuron cell body. Many fine nerve fibres, which are indirectly detected by GFAP, have contact with dendritic cells and other immune cells in the Peyer's patch. Furthermore, the expression of Muscarinic Acetylcholine receptor (subtype M2) was characterized on dendritic cells and other cell population. These findings are expected to provide a route to understand the anatomic basis of neuron-immune regulation/cross-talk and probably neuroinvasion of prion pathogens in the gut and GALT.

Macroscopic Innervation of the Dura Mater Covering the Middle Cranial Fossa in Humans Correlated to Neurovascular Headache.

Science.gov (United States)

Lee, Shin-Hyo; Hwang, Seung-Jun; Koh, Ki-Seok; Song, Wu-Chul; Han, Sang-Don

2017-01-01

The trigeminovascular system within the cranial dura mater is a possible cause of headaches. The aim of this study is to investigate macroscopically dural innervation around the middle meningeal artery (MMA) in the middle cranial fossa. Forty-four sides of the cranial dura overlying the skull base obtained from 24 human cadavers were stained using Sihler's method. Overall, the nervus spinosus (NS) from either the maxillary or mandibular trigeminal divisions ran along the lateral wall of the middle meningeal vein rather than that of the MMA. Distinct bundles of the NS running along the course of the frontal branches of the MMA were present in 81.8% of cases ( N = 36). Others did not form dominant nerve bundles, instead giving off free nerve endings along the course of the MMA or dural connective tissue. The distribution of these nerve endings was similar to that of the course of the frontal, parietal and petrosal branches of the MMA (11.4%). The others were not restricted to a perivascular plexus, crossing the dural connective tissues far from the MMA (6.8%). These findings indicate that the NS generally travels alongside the course of the frontal branches of the MMA and terminates in the vicinity of the pterion.

Macroscopic Innervation of the Dura Mater Covering the Middle Cranial Fossa in Humans Correlated to Neurovascular Headache

Directory of Open Access Journals (Sweden)

Shin-Hyo Lee

2017-12-01

Full Text Available The trigeminovascular system within the cranial dura mater is a possible cause of headaches. The aim of this study is to investigate macroscopically dural innervation around the middle meningeal artery (MMA in the middle cranial fossa. Forty-four sides of the cranial dura overlying the skull base obtained from 24 human cadavers were stained using Sihler’s method. Overall, the nervus spinosus (NS from either the maxillary or mandibular trigeminal divisions ran along the lateral wall of the middle meningeal vein rather than that of the MMA. Distinct bundles of the NS running along the course of the frontal branches of the MMA were present in 81.8% of cases (N = 36. Others did not form dominant nerve bundles, instead giving off free nerve endings along the course of the MMA or dural connective tissue. The distribution of these nerve endings was similar to that of the course of the frontal, parietal and petrosal branches of the MMA (11.4%. The others were not restricted to a perivascular plexus, crossing the dural connective tissues far from the MMA (6.8%. These findings indicate that the NS generally travels alongside the course of the frontal branches of the MMA and terminates in the vicinity of the pterion.

Catecholamine innervation of the caudal spinal cord in the rat

DEFF Research Database (Denmark)

Schrøder, H D; Skagerberg, G

1985-01-01

matter were found to contain catecholamines. In the dorsal horn the most intense fluorescence was seen in the superficial layers. The motoneuron neuropil exhibited the most prominent catecholamine-fluorescence of the ventral horn layers. In the sixth lumbar segment, which contains the motor nuclei....... In the intermediate gray the intermediolateral nucleus in thoracic and upper lumbar segments was the most heavily innervated area, followed by the medial lumbar sympathetic group, which contains the majority of the sympathetic preganglionic neurons innervating the pelvic organs. The parasympathetic intermediolateral...... nucleus in the upper sacral segments received a catecholamine innervation of moderate density. The catecholamine innervation pattern is discussed in relation to the patterns of other putative transmitters. The distribution of catecholamine fluorescence in relation to nuclei that control the pelvic organs...

PrP expression, PrPSc accumulation and innervation of splenic compartments in sheep experimentally infected with scrapie.

Directory of Open Access Journals (Sweden)

Randi Sørby

Full Text Available BACKGROUND: In prion disease, the peripheral expression of PrP(C is necessary for the transfer of infectivity to the central nervous system. The spleen is involved in neuroinvasion and neural dissemination in prion diseases but the nature of this involvement is not known. The present study undertook the investigation of the spatial relationship between sites of PrP(Sc accumulation, localisation of nerve fibres and PrP(C expression in the tissue compartments of the spleen of scrapie-inoculated and control sheep. METHODOLOGY/PRINCIPAL FINDINGS: Laser microdissection and quantitative PCR were used to determine PrP mRNA levels and results were compared with immunohistochemical protocols to distinguish PrP(C and PrP(Sc in tissue compartments of the spleen. In sheep experimentally infected with scrapie, the major sites of accumulation of PrP(Sc in the spleen, namely the lymphoid nodules and the marginal zone, expressed low levels of PrP mRNA. Double immunohistochemical labelling for PrP(Sc and the pan-nerve fibre marker, PGP, was used to evaluate the density of innervation of splenic tissue compartments and the intimacy of association between PrP(Sc and nerves. Some nerve fibres were observed to accompany blood vessels into the PrP(Sc-laden germinal centres. However, the close association between nerves and PrP(Sc was most apparent in the marginal zone. Other sites of close association were adjacent to the wall of the central artery of PALS and the outer rim of germinal centres. CONCLUSIONS/SIGNIFICANCE: The findings suggest that the degree of PrP(Sc accumulation does not depend on the expression level of PrP(C. Though several splenic compartments may contribute to neuroinvasion, the marginal zone may play a central role in being the compartment with most apparent association between nerves and PrP(Sc.

Novel Approaches for the Treatment of the Patient with Resistant Hypertension: Renal Nerve Ablation

Science.gov (United States)

Gulati, Vinay; White, William B.

2013-01-01

Sympathetic innervation of the kidneys plays a major role in the pathogenesis of hypertension through modulation of renin secretion, glomerular filtration rate and renal absorption of sodium. Targeted interventions for renal nerve ablation are being developed for treatment of drug resistant hypertension in the USA and rest of the world. Early studies with the use of radiofrequency based renal denervation systems have shown encouraging results with significant reduction of blood pressure in patients inadequately controlled despite nearly maximal drug therapy regimens. Thus far, the renal denervation procedure has been associated with minimal side effects. Long term efficacy and safety beyond 3 years needs to be determined for renal nerve ablation. This review focuses on the physiology of the renal sympathetic system, the rationale for renal nerve ablation and current evidence in support of the available therapeutic renal denervation systems. PMID:24244757

Evaluation of peripheral auditory pathways and brainstem in obstructive sleep apnea.

Science.gov (United States)

Matsumura, Erika; Matas, Carla Gentile; Magliaro, Fernanda Cristina Leite; Pedreño, Raquel Meirelles; Lorenzi-Filho, Geraldo; Sanches, Seisse Gabriela Gandolfi; Carvallo, Renata Mota Mamede

2016-11-25

Obstructive sleep apnea causes changes in normal sleep architecture, fragmenting it chronically with intermittent hypoxia, leading to serious health consequences in the long term. It is believed that the occurrence of respiratory events during sleep, such as apnea and hypopnea, can impair the transmission of nerve impulses along the auditory pathway that are highly dependent on the supply of oxygen. However, this association is not well established in the literature. To compare the evaluation of peripheral auditory pathway and brainstem among individuals with and without obstructive sleep apnea. The sample consisted of 38 adult males, mean age of 35.8 (±7.2), divided into four groups matched for age and Body Mass Index. The groups were classified based on polysomnography in: control (n=10), mild obstructive sleep apnea (n=11) moderate obstructive sleep apnea (n=8) and severe obstructive sleep apnea (n=9). All study subjects denied a history of risk for hearing loss and underwent audiometry, tympanometry, acoustic reflex and Brainstem Auditory Evoked Response. Statistical analyses were performed using three-factor ANOVA, 2-factor ANOVA, chi-square test, and Fisher's exact test. The significance level for all tests was 5%. There was no difference between the groups for hearing thresholds, tympanometry and evaluated Brainstem Auditory Evoked Response parameters. An association was observed between the presence of obstructive sleep apnea and changes in absolute latency of wave V (p=0.03). There was an association between moderate obstructive sleep apnea and change of the latency of wave V (p=0.01). The presence of obstructive sleep apnea is associated with changes in nerve conduction of acoustic stimuli in the auditory pathway in the brainstem. The increase in obstructive sleep apnea severity does not promote worsening of responses assessed by audiometry, tympanometry and Brainstem Auditory Evoked Response. Copyright © 2016 Associação Brasileira de

First branchial cleft fistula associated with external auditory canal stenosis and middle ear cholesteatoma.

Science.gov (United States)

Abdollahi Fakhim, Shahin; Naderpoor, Masoud; Mousaviagdas, Mehrnoosh

2014-10-01

First branchial cleft anomalies manifest with duplication of the external auditory canal. This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection. It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear.

Gd-DTPA-enhanced MR imaging in facial nerve paralysis

International Nuclear Information System (INIS)

Tien, R.D.; Dillon, W.P.

1989-01-01

GD-DTPA-enhanced MR imaging was used to evaluate 11 patients with facial nerve paralysis (five acute idiopathic facial palsy (Bell palsy), three chronic recurrent facial palsy, one acute facial palsy after local radiation therapy, one chronic facial dyskinesia, and one facial neuroma). In eight of 11 patients, there was marked enhancement of the infratemporal facial nerve from the labyrinthine segment to the stylomastoid foramen. Two patients had additional contrast enhancement in the internal auditory canal segment. In one patient, enhancement persisted (but to a lesser degree) 8 weeks after symptoms had resolved. In one patient, no enhancement was seen 15 months after resolution of Bell palsy. The facial neuroma was seen as a focal nodular enhancement in the mastoid segment of the facial nerve

Rehabilitation, Using Guided Cerebral Plasticity, of a Brachial Plexus Injury Treated with Intercostal and Phrenic Nerve Transfers.

Science.gov (United States)

Dahlin, Lars B; Andersson, Gert; Backman, Clas; Svensson, Hampus; Björkman, Anders

2017-01-01

Recovery after surgical reconstruction of a brachial plexus injury using nerve grafting and nerve transfer procedures is a function of peripheral nerve regeneration and cerebral reorganization. A 15-year-old boy, with traumatic avulsion of nerve roots C5-C7 and a non-rupture of C8-T1, was operated 3 weeks after the injury with nerve transfers: (a) terminal part of the accessory nerve to the suprascapular nerve, (b) the second and third intercostal nerves to the axillary nerve, and (c) the fourth to sixth intercostal nerves to the musculocutaneous nerve. A second operation-free contralateral gracilis muscle transfer directly innervated by the phrenic nerve-was done after 2 years due to insufficient recovery of the biceps muscle function. One year later, electromyography showed activation of the biceps muscle essentially with coughing through the intercostal nerves, and of the transferred gracilis muscle by deep breathing through the phrenic nerve. Voluntary flexion of the elbow elicited clear activity in the biceps/gracilis muscles with decreasing activity in intercostal muscles distal to the transferred intercostal nerves (i.e., corresponding to eighth intercostal), indicating cerebral plasticity, where neural control of elbow flexion is gradually separated from control of breathing. To restore voluntary elbow function after nerve transfers, the rehabilitation of patients operated with intercostal nerve transfers should concentrate on transferring coughing function, while patients with phrenic nerve transfers should focus on transferring deep breathing function.

Representation of acoustic signals in the eighth nerve of the Tokay gecko: I. Pure tones.

Science.gov (United States)

Sams-Dodd, F; Capranica, R R

1994-06-01

A systematic study of the encoding properties of 146 auditory nerve fibers in the Tokay gecko (Gekko gecko, L) was conducted with respect to pure tones and two-tone rate suppression. Our aim was a comprehensive understanding of the peripheral encoding of simple tonal stimuli and their representation by temporal synchronization and spike rate codes as a prelude to subsequent studies of more complex signals. Auditory nerve fibers in the Tokay gecko have asymmetrical, V-shaped excitatory tuning curves with best excitatory frequencies that range from 200-5100 Hz and thresholds between 4-35 dB SPL. A low-frequency excitatory 'tail' extends far into the low-frequency range and two-tone suppression is present only on the high frequency side of the tuning curve. The response properties to pure tones at different loci within a tuning curve can differ greatly, due to evident interactions between the representations of temporal, spectral and intensity stimulus features. For frequencies below 1250 Hz, pure tones are encoded by both temporal synchronization and spike rate codes, whereas above this frequency a fiber's ability to encode the waveform periodicity is lost and only a rate code predominates. These complimentary representations within a tuning curve raise fundamental issues which need to be addressed in interpreting how more complex, bioacoustic communication signals are represented in the peripheral and central auditory system. And since auditory nerve fibers in the Tokay gecko exhibit tonal sensitivity, selective frequency tuning, and iso-intensity and iso-frequency contours that seem comparable to similar measures in birds and mammals, these issues likely apply to most higher vertebrates in general. The simpler wiring diagram of the reptilian auditory system, coupled with the Tokay gecko's remarkable vocalizations, make this animal a good evolutionary model in which to experimentally explore the encoding of more complex sounds of communicative significance.

Cortical Representations of Speech in a Multitalker Auditory Scene.

Science.gov (United States)

Puvvada, Krishna C; Simon, Jonathan Z

2017-09-20

The ability to parse a complex auditory scene into perceptual objects is facilitated by a hierarchical auditory system. Successive stages in the hierarchy transform an auditory scene of multiple overlapping sources, from peripheral tonotopically based representations in the auditory nerve, into perceptually distinct auditory-object-based representations in the auditory cortex. Here, using magnetoencephalography recordings from men and women, we investigate how a complex acoustic scene consisting of multiple speech sources is represented in distinct hierarchical stages of the auditory cortex. Using systems-theoretic methods of stimulus reconstruction, we show that the primary-like areas in the auditory cortex contain dominantly spectrotemporal-based representations of the entire auditory scene. Here, both attended and ignored speech streams are represented with almost equal fidelity, and a global representation of the full auditory scene with all its streams is a better candidate neural representation than that of individual streams being represented separately. We also show that higher-order auditory cortical areas, by contrast, represent the attended stream separately and with significantly higher fidelity than unattended streams. Furthermore, the unattended background streams are more faithfully represented as a single unsegregated background object rather than as separated objects. Together, these findings demonstrate the progression of the representations and processing of a complex acoustic scene up through the hierarchy of the human auditory cortex. SIGNIFICANCE STATEMENT Using magnetoencephalography recordings from human listeners in a simulated cocktail party environment, we investigate how a complex acoustic scene consisting of multiple speech sources is represented in separate hierarchical stages of the auditory cortex. We show that the primary-like areas in the auditory cortex use a dominantly spectrotemporal-based representation of the entire auditory

Innervation of the mammalian esophagus.

Science.gov (United States)

Neuhuber, Winfried L; Raab, Marion; Berthoud, Hans-Rudolf; Wörl, Jürgen

2006-01-01

Understanding the innervation of the esophagus is a prerequisite for successful treatment of a variety of disorders, e.g., dysphagia, achalasia, gastroesophageal reflux disease (GERD) and non-cardiac chest pain. Although, at first glance, functions of the esophagus are relatively simple, their neuronal control is considerably complex. Vagal motor neurons of the nucleus ambiguus and preganglionic neurons of the dorsal motor nucleus innervate striated and smooth muscle, respectively. Myenteric neurons represent the interface between the dorsal motor nucleus and smooth muscle but they are also involved in striated muscle innervation. Intraganglionic laminar endings (IGLEs) represent mechanosensory vagal afferent terminals. They also establish intricate connections with enteric neurons. Afferent information is implemented by the swallowing central pattern generator in the brainstem, which generates and coordinates deglutitive activity in both striated and smooth esophageal muscle and orchestrates esophageal sphincters as well as gastric adaptive relaxation. Disturbed excitation/inhibition balance in the lower esophageal sphincter results in motility disorders, e.g., achalasia and GERD. Loss of mechanosensory afferents disrupts adaptation of deglutitive motor programs to bolus variables, eventually leading to megaesophagus. Both spinal and vagal afferents appear to contribute to painful sensations, e.g., non-cardiac chest pain. Extrinsic and intrinsic neurons may be involved in intramural reflexes using acetylcholine, nitric oxide, substance P, CGRP and glutamate as main transmitters. In addition, other molecules, e.g., ATP, GABA and probably also inflammatory cytokines, may modulate these neuronal functions.

3D-engineering of Cellularized Conduits for Peripheral Nerve Regeneration

Science.gov (United States)

Hu, Yu; Wu, Yao; Gou, Zhiyuan; Tao, Jie; Zhang, Jiumeng; Liu, Qianqi; Kang, Tianyi; Jiang, Shu; Huang, Siqing; He, Jiankang; Chen, Shaochen; Du, Yanan; Gou, Maling

2016-08-01

Tissue engineered conduits have great promise for bridging peripheral nerve defects by providing physical guiding and biological cues. A flexible method for integrating support cells into a conduit with desired architectures is wanted. Here, a 3D-printing technology is adopted to prepare a bio-conduit with designer structures for peripheral nerve regeneration. This bio-conduit is consisted of a cryopolymerized gelatin methacryloyl (cryoGelMA) gel cellularized with adipose-derived stem cells (ASCs). By modeling using 3D-printed “lock and key” moulds, the cryoGelMA gel is structured into conduits with different geometries, such as the designed multichannel or bifurcating and the personalized structures. The cryoGelMA conduit is degradable and could be completely degraded in 2-4 months in vivo. The cryoGelMA scaffold supports the attachment, proliferation and survival of the seeded ASCs, and up-regulates the expression of their neurotrophic factors mRNA in vitro. After implanted in a rat model, the bio-conduit is capable of supporting the re-innervation across a 10 mm sciatic nerve gap, with results close to that of the autografts in terms of functional and histological assessments. The study describes an indirect 3D-printing technology for fabricating cellularized designer conduits for peripheral nerve regeneration, and could lead to the development of future nerve bio-conduits for clinical use.

Asymmetry of the multifidus muscle in lumbar radicular nerve compression

International Nuclear Information System (INIS)

Farshad, Mazda; Gerber, Christian; Farshad-Amacker, Nadja A.; Dietrich, Tobias J.; Laufer-Molnar, Viviane; Min, Kan

2014-01-01

The multifidus muscle is the only paraspinal lumbar muscle that is innervated by a single nerve root. This study aimes to evaluate if the asymmetry of the multifidus muscle is related to the severity of compression of the nerve root or the duration of radiculopathy. MRI scans of 79 patients with symptomatic single level, unilateral, lumbar radiculopathy were reviewed for this retrospective case series with a nested case-control study. The cross-sectional area (CSA) of the multifidus muscle and the perpendicular distance of the multifidus to the lamina (MLD) were measured bilaterally by two radiologists and set into relation to the severity of nerve compression, duration of radiculopathy and probability of an indication for surgical decompression. In 67 recessal and 12 foraminal symptomatic nerve root compressions, neither the MLD ratio (severe 1.19 ± 0.55 vs less severe nerve compression: 1.12 ± 0.30, p = 0.664) nor the CSA ratio (severe 1 ± 0.16 vs less severe 0.98 ± 0.13, p = 0.577) nor the duration of symptoms significantly correlated with the degree of nerve compression. MR measurements of multifidus were not different in patients with (n = 20) and those without (n = 59) clinical muscle weakness in the extremity caused by nerve root compression. A MLD >1.5 was, however, associated with the probability of an indication for surgical decompression (OR 3, specificity 92 %, PPV 73 %). Asymmetry of the multifidus muscle correlates with neither the severity nor the duration of nerve root compression in the lumbar spine. Severe asymmetry with substantial multifidus atrophy seems associated with the probability of an indication of surgical decompression. (orig.)

Asymmetry of the multifidus muscle in lumbar radicular nerve compression

Energy Technology Data Exchange (ETDEWEB)

Farshad, Mazda; Gerber, Christian; Farshad-Amacker, Nadja A.; Dietrich, Tobias J.; Laufer-Molnar, Viviane; Min, Kan [Balgrist University Hospital, University of Zuerich, Zuerich (Switzerland)

2014-01-15

The multifidus muscle is the only paraspinal lumbar muscle that is innervated by a single nerve root. This study aimes to evaluate if the asymmetry of the multifidus muscle is related to the severity of compression of the nerve root or the duration of radiculopathy. MRI scans of 79 patients with symptomatic single level, unilateral, lumbar radiculopathy were reviewed for this retrospective case series with a nested case-control study. The cross-sectional area (CSA) of the multifidus muscle and the perpendicular distance of the multifidus to the lamina (MLD) were measured bilaterally by two radiologists and set into relation to the severity of nerve compression, duration of radiculopathy and probability of an indication for surgical decompression. In 67 recessal and 12 foraminal symptomatic nerve root compressions, neither the MLD ratio (severe 1.19 ± 0.55 vs less severe nerve compression: 1.12 ± 0.30, p = 0.664) nor the CSA ratio (severe 1 ± 0.16 vs less severe 0.98 ± 0.13, p = 0.577) nor the duration of symptoms significantly correlated with the degree of nerve compression. MR measurements of multifidus were not different in patients with (n = 20) and those without (n = 59) clinical muscle weakness in the extremity caused by nerve root compression. A MLD >1.5 was, however, associated with the probability of an indication for surgical decompression (OR 3, specificity 92 %, PPV 73 %). Asymmetry of the multifidus muscle correlates with neither the severity nor the duration of nerve root compression in the lumbar spine. Severe asymmetry with substantial multifidus atrophy seems associated with the probability of an indication of surgical decompression. (orig.)

Gd-DTPA enhancement of the facial nerve in Ramsay Hunt's syndrome

Energy Technology Data Exchange (ETDEWEB)

Kato, Tsutomu; Yanagida, Masahiro; Yamauchi, Yasuo (Kansai Medical School, Moriguchi, Osaka (Japan)) (and others)

1992-10-01

A total of 21 MR images in 16 Ramsay Hunt's syndrome were evaluated. In all images, the involved side of peripheral facial nerve were enhanced in intensity after Gd-DTPA. However, 2 cases had recovered facial palsy when MR images were taken. Nine of 19 cases with the enhancement of internal auditory canal portion had vertigo or tinnitus. Thus, it was suggested that the enhancement of internal auditory canal portion and clinical feature are closely related. (author).

Neuroethology of ultrasonic hearing in nocturnal butterflies (Hedyloidea)

DEFF Research Database (Denmark)

Yack, Jayne E.; Kalko, Elisabeth K.V.; Surlykke, Annemarie

2007-01-01

Nocturnal Hedyloidea butterflies possess ultrasound-sensitive ears that mediate evasive flight maneuvers. Tympanal ear morphology, auditory physiology and behavioural responses to ultrasound are described for Macrosoma heliconiaria, and evidence for hearing is described for eight other hedylid...... species. The ear is formed by modifications of the cubital and subcostal veins at the forewing base, where the thin (1-3 m), ovoid (520 £ 220 )mpanal membrane occurs in a cavity. The ear is innervated by nerve IIN1c, with three chordotonal organs attaching to separate regions of the tympanal membrane...

Outcomes and Time to Emergence of Auditory Skills After Cochlear Implantation of Children With Charge Syndrome.

Science.gov (United States)

Young, Nancy M; Tournis, Elizabeth; Sandy, Jenelle; Hoff, Stephen R; Ryan, Maura

2017-09-01

Review perioperative complications, benefits, and the timeframe over which auditory skills develop in children with CHARGE syndrome who receive a cochlear implant (CI). IRB-approved retrospective chart review of children with CHARGE syndrome who had at least 12 months of cochlear implant use. Tertiary care children's hospital. Twelve children, seven males and five females. Mean age implant = 3.5 years (1.7-8.2 yr); mean duration follow-up = 4.7 years (1.5-10.1 yr). Cochlear implantation. Auditory skills categorized into four levels, temporal bone imaging findings, perioperative complications, time to emergence of speech perception, expressive communication mode. All children imaged with magnetic resonance imaging had cochlear nerve deficiency in at least one ear. Speech awareness threshold improved with the CI compared with aided preoperative in 83% of children, with means of 51.7 dB SAT preoperative and 27.1 dB with the CI (p ≤ 0.002). Overall, four children improved to auditory Level 2 (improved detection), three obtained Level 3 (closed-set speech perception), and three had open-set speech perception with their CIs (Level 4) that was first evident at 3.5, 3.3, and 0.8 years postimplant testing. Two children had minimal or limited improvement. One child with hypoplasia of the cochlear nerve obtained open-set levels. Auditory skills may develop slowly in children with CHARGE syndrome who receive a CI but most can achieve at least improved detection. In our series, half acquired some speech perception ability. Cochlear nerve deficiency is frequent, but should not be a contraindication to implantation.

Renaut bodies in nerves of the trunk of the African elephant, Loxodonta africana.

Science.gov (United States)

Witter, Kirsti; Egger, Gunter F; Boeck, Peter

2007-05-01

Renaut bodies are loosely textured, cell-sparse structures in the subperineurial space of peripheral nerves, frequently found at sites of nerve entrapment. The trunk of the elephant is a mobile, richly innervated organ, which serves for food gathering, object grasping and as a tactile organ. These functions of the trunk lead to distortion and mechanical compression of its nerves, which can therefore be expected to contain numerous Renaut bodies. Samples of the trunk wall of an adult African elephant (Loxodonta africana) were examined histologically using conventional staining methods, immunohistochemistry, and lectin histochemistry. Architecture of nerve plexuses and occurrence of Renaut bodies in the elephant trunk were compared with those in tissues surrounding the nasal vestibule of the pig. Prominent nerve plexuses were found in all layers of the elephant trunk. Almost all (81%) nerve profiles contained Renaut bodies, a basophilic, discrete subperineurial layer resembling cushions around the nerve core. In contrast, Renaut bodies were seen in only 15% of nerve profiles in the porcine nasal vestibule. Within Renaut bodies, fusiform fibroblasts and round, ruff-like cells were placed into a matrix of acidic glycosaminoglycans with delicate collagen and very few reticular fibers. The turgor of this matrix is thought to protect nerves against compression and shearing strain. Renaut bodies are readily stained with alcian blue (pH 2.5) favorably in combination with immunohistochemical markers of nerve fibers. They should be regarded as a physiological response to repeated mechanical insults and are distinct from pathological alterations. alterations. (c) 2007 Wiley-Liss, Inc.

Auditory brainstem activity and development evoked by apical versus basal cochlear implant electrode stimulation in children.

Science.gov (United States)

Gordon, K A; Papsin, B C; Harrison, R V

2007-08-01

The role of apical versus basal cochlear implant electrode stimulation on central auditory development was examined. We hypothesized that, in children with early onset deafness, auditory development evoked by basal electrode stimulation would differ from that evoked more apically. Responses of the auditory nerve and brainstem, evoked by an apical and a basal implant electrode, were measured over the first year of cochlear implant use in 50 children with early onset severe to profound deafness who used hearing aids prior to implantation. Responses at initial stimulation were of larger amplitude and shorter latency when evoked by the apical electrode. No significant effects of residual hearing or age were found on initial response amplitudes or latencies. With implant use, responses evoked by both electrodes showed decreases in wave and interwave latencies reflecting decreased neural conduction time through the brainstem. Apical versus basal differences persisted with implant experience with one exception; eIII-eV interlatency differences decreased with implant use. Acute stimulation shows prolongation of basally versus apically evoked auditory nerve and brainstem responses in children with severe to profound deafness. Interwave latencies reflecting neural conduction along the caudal and rostral portions of the brainstem decreased over the first year of implant use. Differences in neural conduction times evoked by apical versus basal electrode stimulation persisted in the caudal but not rostral brainstem. Activity-dependent changes of the auditory brainstem occur in response to both apical and basal cochlear implant electrode stimulation.

Pudendal and median nerve sensory perception threshold: a comparison between normative studies.

Science.gov (United States)

Quaghebeur, Jörgen; Wyndaele, Jean Jacques

2014-12-01

For the evaluation of sensory innervation, normative data are necessary as a comparison. To compare our current perception thresholds (CPTs) with normative data from other research. Healthy volunteers were assessed for 2000, 250, and 5 Hz CPTs of the median and pudendal nerve and data were compared with other studies. Normative data in the studied group n = 41 (male: 21; female: 20) for the median nerve, 2 kHz, 250 Hz, and 5 Hz were respectively: 241.85 ± 67.72 (140-444); 106.27 ± 39.12 (45-229); 82.05 ± 43.40 (13-271). Pudendal nerve CPTs 250 Hz were: 126.44 ± 69.46 (6-333). For men 2 kHz: 349.95 ± 125.76 (100-588); 5 Hz: 132.67 ± 51.81 (59-249) and women 2 kHz:226.20 ± 119.65 (64-528); 5 Hz: 92.45 ± 44.66 (35-215). For the median nerve no statistical differences for gender were shown. For the pudendal nerve, only 250 Hz showed no difference for gender (t-test: 0.516). Comparison of our data with CPTs of other normative data showed no agreement for the pudendal nerve. For the median nerve only 2 kHz showed agreement in three studies and for 5 Hz with one study. Comparing normative data of multiple studies shows a variety of results and poor agreement. Therefore, referring to normative data of other studies should be handled with caution.

Sensory nerve endings in the penis in green monkey (Cercopithecus aethiops sabaeus).

Science.gov (United States)

Malinovský, L; Sommerová, J

1977-01-01

The authors examined the sensory innervation of the skin in the penis in green monkey in four adult individuals both in the light and in the elctron microscope. They found 3 kings of nerve endings. The free nerve endings were the most frequently occurring kind of nerve endings in the superficial layers of the corium--altogether 6,444 in number. The second kind of sensory nerve endings is represented by the glomerular endings out of which 96 per cent were found in the papillae. The typical Meissner's endings were observed in the light microscopy only rarely. Deeper in the corium the authors also found single simple sensory corpuscles and Pacinian corpuscles. Studying the ultrastructure the authors found in the papillae of the corium 4 types of glomerular endings: quite simple glomerular endings with irregularly arranged Schwann cells, larger and more complicated glomerular endings having a thicker capsule, endings with lamellar system around the terminals and typical Meissner's endings. In the epidermis the authors observed naked axons which passed in the spaces among the epidermal cells. They contained an accumulation of mitochondria. In the basal cell layer of the epidermis there was a small amount of Langerhans cells.

Cervical Vestibular Evoked Myogenic Potential in Hypoglossal Nerve Schwannoma: A Case Report.

Science.gov (United States)

Rajasekaran, Aravind Kumar; Savardekar, Amey Rajan; Shivashankar, Nagaraja Rao

2018-02-01

Schwannoma of the hypoglossal nerve is rare. This case report documents an atypical abnormality of the cervical vestibular evoked myogenic potential (cVEMP) in a patient with schwannoma of the hypoglossal nerve. The observed abnormality was attributed to the proximity of the hypoglossal nerve to the spinal accessory nerve in the medullary cistern and base of the skull. To report cVEMP abnormality in a patient with hypoglossal nerve schwannoma and provide an anatomical correlation for this abnormality. Case report. A 44-yr-old woman. Pure-tone and speech audiometry, tympanometry, acoustic stapedial reflex, auditory brainstem response, and cVEMP testing were performed. The audiological test results were normal except for the absence of cVEMP on the lesion side (right). A cVEMP abnormality indicating a compromised spinal accessory nerve was observed in a patient with hypoglossal nerve schwannoma. This case report highlights the importance of recording cVEMP in relevant neurological conditions and provides clinical proof for the involvement of the spinal accessory nerve in the vestibulocollic reflex pathway. American Academy of Audiology

First Branchial Cleft Fistula Associated with External Auditory Canal Stenosis and Middle Ear Cholesteatoma

Science.gov (United States)

Abdollahi fakhim, Shahin; Naderpoor, Masoud; Mousaviagdas, Mehrnoosh

2014-01-01

Introduction: First branchial cleft anomalies manifest with duplication of the external auditory canal. Case Report: This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection. Conclusion: It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear. PMID:25320705

First Branchial Cleft Fistula Associated with External Auditory Canal Stenosis and Middle Ear Cholesteatoma

Directory of Open Access Journals (Sweden)

shahin abdollahi fakhim

2014-10-01

Full Text Available Introduction: First branchial cleft anomalies manifest with duplication of the external auditory canal.   Case Report: This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection.   Conclusion:  It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear.

Discrete innervation of murine taste buds by peripheral taste neurons.

Science.gov (United States)

Zaidi, Faisal N; Whitehead, Mark C

2006-08-09

The peripheral taste system likely maintains a specific relationship between ganglion cells that signal a particular taste quality and taste bud cells responsive to that quality. We have explored a measure of the receptoneural relationship in the mouse. By injecting single fungiform taste buds with lipophilic retrograde neuroanatomical markers, the number of labeled geniculate ganglion cells innervating single buds on the tongue were identified. We found that three to five ganglion cells innervate a single bud. Injecting neighboring buds with different color markers showed that the buds are primarily innervated by separate populations of geniculate cells (i.e., multiply labeled ganglion cells are rare). In other words, each taste bud is innervated by a population of neurons that only connects with that bud. Palate bud injections revealed a similar, relatively exclusive receptoneural relationship. Injecting buds in different regions of the tongue did not reveal a topographic representation of buds in the geniculate ganglion, despite a stereotyped patterned arrangement of fungiform buds as rows and columns on the tongue. However, ganglion cells innervating the tongue and palate were differentially concentrated in lateral and rostral regions of the ganglion, respectively. The principal finding that small groups of ganglion cells send sensory fibers that converge selectively on a single bud is a new-found measure of specific matching between the two principal cellular elements of the mouse peripheral taste system. Repetition of the experiments in the hamster showed a more divergent innervation of buds in this species. The results indicate that whatever taste quality is signaled by a murine geniculate ganglion neuron, that signal reflects the activity of cells in a single taste bud.

[Neurophysiological identification of the cranial nerves in endoscopic endonasal surgery of skull base tumors].

Science.gov (United States)

Shkarubo, A N; Ogurtsova, A A; Moshchev, D A; Lubnin, A Yu; Andreev, D N; Koval', K V; Chernov, I V

2016-01-01

Intraoperative identification of the cranial nerves is a useful technique in removal of skull base tumors through the endoscopic endonasal approach. Searching through the scientific literature found one pilot study on the use of triggered electromyography (t-EMG) for identification of the VIth nerve in endonasal endoscopic surgery of skull base tumors (D. San-Juan, et al, 2014). The study objective was to prevent iatrogenic injuries to the cranial nerves without reducing the completeness of tumor tissue resection. In 2014, 5 patients were operated on using the endoscopic endonasal approach. Surgeries were performed for large skull base chordomas (2 cases) and trigeminal nerve neurinomas located in the cavernous sinus (3). Intraoperatively, identification of the cranial nerves was performed by triggered electromyography using a bipolar electrode (except 1 case of chordoma where a monopolar electrode was used). Evaluation of the functional activity of the cranial nerves was carried out both preoperatively and postoperatively. Tumor resection was total in 4 out of 5 cases and subtotal (chordoma) in 1 case. Intraoperatively, the IIIrd (2 patients), Vth (2), and VIth (4) cranial nerves were identified. No deterioration in the function of the intraoperatively identified nerves was observed in the postoperative period. In one case, no responses from the VIth nerve on the right (in the cavernous sinus region) were intraoperatively obtained, and deep paresis (up to plegia) of the nerve-innervated muscles developed in the postoperative period. The nerve function was not impaired before surgery. The t-EMG technique is promising and requires further research.

Internal auditory canal (IAC) stenosis: imaging Findings

International Nuclear Information System (INIS)

Ortiz Jimenez, Johanna; Roa, Jose Luis; Figuero A, Ramon E

2011-01-01

Objectives: To describe the computed tomography (CT) and magnetic resonance (MR) findings in a patient with a diagnosis of internal auditory canal (IAC) stenosis. To describe the embryological development of the IAC structures and the natural history of IAC stenosis. Methods: A 4 year old girl presents with sensorineural hearing loss and bilateral recurrent otitis media. The temporal bone CT shows diminished left IAC diameter (less than 2 mm), right IAC absence and normal inner ear structures. These findings are pathognomonic for left IAC stenosis. The MR findings include left IAC stenosis and IAC neural structures absence secondary to aplasia of the vestibulocochlear nerve on each IAC . Results: Hypoplasia/aplasia of the vestibulocochlear nerve in association with IAC stenosis is an important consideration in the differential diagnosis of sensorineural hearing loss, as it is a relative contraindication for cochlear implant placement. Conclusions: IAC stenosis and vestibulocochlear nerve hypoplasia/aplasia must be excluded as an etiology of sensorineural hearing loss. The diagnosis can be made by CT and MR.

Internal auditory canal (IAC) stenosis: Imaging findings

International Nuclear Information System (INIS)

Ortiz J, Johanna; Roa, Jose L; Figueroa Ramon E

2011-01-01

Objectives: To describe the computed tomography (CT) and magnetic resonance (MR) findings in a patient with a diagnosis of internal auditory canal (IAC) stenosis. To describe the embryological development of the IAC structures and the natural history of IAC stenosis. Methods: A 4 year old girl presents with sensorineural hearing loss and bilateral recurrent otitis media. The temporal bone CT shows diminished left IAC diameter (less than 2 mm), right IAC absence and normal inner ear structures. These findings are pathognomonic for left IAC stenosis. The MR findings include left IAC stenosis and IAC neural structures absence secondary to aplasia of the vestibulocochlear nerve on each IAC. Results: Hypoplasia/aplasia of the vestibulocochlear nerve in association with IAC stenosis is an important consideration in the differential diagnosis of sensorineural hearing loss, as it is a relative contraindication for cochlear implant placement. Conclusions: IAC stenosis and vestibulocochlear nerve hypoplasia/aplasia must be excluded as an etiology of sensorineural hearing loss. The diagnosis can be made by CT and MR.

Innervation status in chronic vocal fold paralysis and implications for laryngeal reinnervation.

Science.gov (United States)

Lin, R Jun; Smith, Libby J; Munin, Michael C; Sridharan, Shaum; Rosen, Clark A

2018-01-22

Treatment options for symptomatic unilateral vocal fold paralysis (VFP) include vocal fold augmentation, laryngeal framework surgery, and laryngeal reinnervation. Laryngeal reinnervation (LR) has been suggested to provide "tone" to the paralyzed VF. This implies a loss of tone as a result of denervation without reinnervation. We performed laryngeal electromyography (LEMG) in patients with chronic VFP to understand the innervation status associated with a chronically paralyzed vocal fold. Retrospective review of LEMG data in adult patients with chronic VFP from January 2009 to December 2014. LEMG was performed at least 6 months after-onset of VFP. Qualitative LEMG, quantitative LEMG, and adductory synkinesis testing were performed, and the parameters were collected. Twenty-seven vocal folds were studied (23 unilateral VFP and 2 bilateral VFP). Average age was 59 ± 17 years. The median duration from recurrent laryngeal nerve injury to LEMG was 8.5 months (range 6-90 months). The majority of patients, 24 of 27 (89%), had motor unit potentials during phonation tasks on LEMG, and only 3 of 27 (11%) patients were electrically silent. Quantitative LEMG showed 287.8 mean turns per second (normal ≥ 400). Motor unit configuration was normal in 12 of 27 (44%), polyphasic in 12 of 27 (44%), and absent in the electrically silent patients. Adductory synkinesis was found in 6 of 20 (30%) patients. Chronic vocal fold paralysis is infrequently associated with absent motor-unit recruitment, indicating some degree of preserved innervation and/or reinnervation in these patients. LEMG should be part of the routine workup for chronic VFP prior to consideration of LR. 4. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

Effects of chronic alcohol consumption, withdrawal and nerve growth factor on neuropeptide Y expression and cholinergic innervation of the rat dentate hilus.

Science.gov (United States)

Pereira, Pedro A; Rocha, João P; Cardoso, Armando; Vilela, Manuel; Sousa, Sérgio; Madeira, M Dulce

2016-05-01

Several studies have demonstrated the vulnerability of the hippocampal formation (HF) to chronic alcohol consumption and withdrawal. Among the brain systems that appear to be particularly vulnerable to the effects of these conditions are the neuropeptide Y (NPY)-ergic and the cholinergic systems. Because these two systems seem to closely interact in the HF, we sought to study the effects of chronic alcohol consumption (6months) and subsequent withdrawal (2months) on the expression of NPY and on the cholinergic innervation of the rat dentate hilus. As such, we have estimated the areal density and the somatic volume of NPY-immunoreactive neurons, and the density of the cholinergic varicosities. In addition, because alcohol consumption and withdrawal are associated with impaired nerve growth factor (NGF) trophic support and the administration of exogenous NGF alters the effects of those conditions on various cholinergic markers, we have also estimated the same morphological parameters in withdrawn rats infused intracerebroventricularly with NGF. NPY expression increased after withdrawal and returned to control values after NGF treatment. Conversely, the somatic volume of these neurons did not differ among all groups. On other hand, the expression of vesicular acetylcholine transporter (VAChT) was reduced by 24% in ethanol-treated rats and by 46% in withdrawn rats. The administration of NGF to withdrawn rats increased the VAChT expression to values above control levels. These results show that the effects of prolonged alcohol intake and protracted withdrawal on the hilar NPY expression differ from those induced by shorter exposures to ethanol and by abrupt withdrawal. They also suggest that the normalizing effect of NGF on NPY expression might rely on the NGF-induced improvement of cholinergic neurotransmission in the dentate hilus. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of high-density, multi-contact nerve cuffs for activation of grasp muscles in monkeys

Science.gov (United States)

Brill, N. A.; Naufel, S. N.; Polasek, K.; Ethier, C.; Cheesborough, J.; Agnew, S.; Miller, L. E.; Tyler, D. J.

2018-06-01

Objective. The objective of this work was to evaluate whether nerve cuffs can selectively activate hand muscles for functional electrical stimulation (FES). FES typically involves identifying and implanting electrodes in many individual muscles, but nerve cuffs only require implantation at a single site around the nerve. This method is surgically more attractive. Nerve cuffs may also more effectively stimulate intrinsic hand muscles, which are difficult to implant and stimulate without spillover to adjacent muscles. Approach. To evaluate its ability to selectively activate muscles, we implanted and tested the flat interface nerve electrode (FINE), which is designed to selectively stimulate peripheral nerves that innervate multiple muscles (Tyler and Durand 2002 IEEE Trans. Neural Syst. Rehabil. Eng. 10 294-303). We implanted FINEs on the nerves and bipolar intramuscular wires for recording compound muscle action potentials (CMAPs) from up to 20 muscles in each arm of six monkeys. We then collected recruitment curves while the animals were anesthetized. Main result. A single FINE implanted on an upper extremity nerve in the monkey can selectively activate muscles or small groups of muscles to produce multiple, independent hand functions. Significance. FINE cuffs can serve as a viable supplement to intramuscular electrodes in FES systems, where they can better activate intrinsic and extrinsic muscles with lower currents and less extensive surgery.

Successful Implantation of Bioengineered, Intrinsically Innervated, Human Internal Anal Sphincter

Science.gov (United States)

Raghavan, Shreya; Gilmont, Robert R.; Miyasaka, Eiichi A.; Somara, Sita; Srinivasan, Shanthi; Teitelbaum, Daniel H; Bitar, Khalil N.

2011-01-01

Background & Aims To restore fecal continence, the weakened pressure of the internal anal sphincter (IAS) must be increased. We bioengineered intrinsically innervated human IAS, to emulate sphincteric physiology, in vitro. Methods We co-cultured human IAS circular smooth muscle with immortomouse fetal enteric neurons. We investigated the ability of bioengineered innervated human IAS, implanted in RAG1−/− mice, to undergo neovascularization and preserve the physiology of the constituent myogenic and neuronal components. Results The implanted IAS was neovascularized in vivo; numerous blood vessels were observed with no signs of inflammation or infection. Real-time force acquisition from implanted and pre-implant IAS showed distinct characteristics of IAS physiology. Features included the development of spontaneous myogenic basal tone; relaxation of 100% of basal tone in response to inhibitory neurotransmitter vasoactive intestinal peptide (VIP) and direct electrical field stimulation of the intrinsic innervation; inhibition of nitrergic and VIPergic EFS-induced relaxation (by antagonizing nitric oxide synthesis or receptor interaction); contraction in response to cholinergic stimulation with acetylcholine; and intact electromechanical coupling (evidenced by direct response to potassium chloride). Implanted, intrinsically innervated bioengineered human IAS tissue preserved the integrity and physiology of myogenic and neuronal components. Conclusion Intrinsically innervated human IAS bioengineered tissue can be successfully implanted in mice. This approach might be used to treat patients with fecal incontinence. PMID:21463628

Review of the State of Renal Nerve Ablation for Patients with Severe and Resistant Hypertension

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Gulati, Vinay; White, William B.

2013-01-01

Through modulation of renin secretion, glomerular filtration rate and renal absorption of sodium, the sympathetic innervation of the kidneys plays an important role in the pathogenesis of hypertension. Renal nerve ablation technology is being developed for treatment of drug-treatment resistant hypertension worldwide. Preliminary research with the use of radiofrequency based renal denervation systems have demonstrated encouraging results with significant reduction of blood pressure in patients inadequately controlled despite nearly maximal drug therapy regimens. From work done thus far, the renal denervation procedure has not been associated with serious adverse effects. Long term efficacy and safety still needs to be established for renal nerve ablation. This review focuses on the impact of the renal sympathetic system on blood pressure regulation, the clinical rationale for renal nerve ablation in severe and drug-treatment resistant hypertension and current evidence from the more advanced renal denervation devices. PMID:23953998

Retinal nerve fiber layer thickness and neuropsychiatric manifestations in systemic lupus erythematosus.

Science.gov (United States)

Shulman, S; Shorer, R; Wollman, J; Dotan, G; Paran, D

2017-11-01

Background Cognitive impairment is frequent in systemic lupus erythematosus. Atrophy of the corpus callosum and hippocampus have been reported in patients with systemic lupus erythematosus, and diffusion tensor imaging studies have shown impaired white matter integrity, suggesting that white matter damage in systemic lupus erythematosus may underlie the cognitive impairment as well as other neuropsychiatric systemic lupus erythematosus manifestations. Retinal nerve fiber layer thickness, as assessed by optical coherence tomography, has been suggested as a biomarker for white matter damage in neurologic disorders such as multiple sclerosis, Alzheimer's disease and Parkinson's disease. Retinal nerve fiber layer thinning may occur early, even in patients with mild clinical symptoms. Aim The objective of this study was to assess the association of retinal nerve fiber layer thickness, as a biomarker of white matter damage in systemic lupus erythematosus patients, with neuropsychiatric systemic lupus erythematosus manifestations, including cognitive impairment. Methods Twenty-one consecutive patients with systemic lupus erythematosus underwent neuropsychological testing using a validated computerized battery of tests as well as the Rey-Auditory verbal learning test. All 21 patients, as well as 11 healthy, age matched controls, underwent optical coherence tomography testing to assess retinal nerve fiber layer thickness. Correlations between retinal nerve fiber layer thickness and results in eight cognitive domains assessed by the computerized battery of tests as well as the Rey-Auditory verbal learning test were assessed in patients with systemic lupus erythematosus, with and without neuropsychiatric systemic lupus erythematosus, and compared to retinal nerve fiber layer thickness in healthy controls. Results No statistically significant correlation was found between retinal nerve fiber layer thickness in patients with systemic lupus erythematosus as compared to healthy

[A comparison of time resolution among auditory, tactile and promontory electrical stimulation--superiority of cochlear implants as human communication aids].

Science.gov (United States)

Matsushima, J; Kumagai, M; Harada, C; Takahashi, K; Inuyama, Y; Ifukube, T

1992-09-01

Our previous reports showed that second formant information, using a speech coding method, could be transmitted through an electrode on the promontory. However, second formant information can also be transmitted by tactile stimulation. Therefore, to find out whether electrical stimulation of the auditory nerve would be superior to tactile stimulation for our speech coding method, the time resolutions of the two modes of stimulation were compared. The results showed that the time resolution of electrical promontory stimulation was three times better than the time resolution of tactile stimulation of the finger. This indicates that electrical stimulation of the auditory nerve is much better for our speech coding method than tactile stimulation of the finger.

α-Synuclein deficiency and efferent nerve degeneration in the mouse cochlea: a possible cause of early-onset presbycusis.

Science.gov (United States)

Park, S N; Back, S A; Choung, Y H; Kim, H L; Akil, O; Lustig, L R; Park, K H; Yeo, S W

2011-11-01

Efferent nerves under the outer hair cells (OHCs) play a role in the protection of these cells from loud stimuli. Previously, we showed that cochlear α-synuclein expression is localized to efferent auditory synapses at the base of the OHCs. To prove our hypothesis that α-synuclein deficiency and efferent auditory deficit might be a cause of hearing loss, we compared the morphology of efferent nerve endings and α-synuclein expression within the cochleae of two mouse models of presbycusis. Comparative animal study of presbycusis. The C57BL/6J(C57) mouse strain, a well-known model of early-onset hearing loss, and the CBA mouse strain, a model of relatively late-onset hearing loss, were examined. Auditory brainstem responses and distortion product otoacoustic emissions were recorded, and cochlear morphology with efferent nerve ending was compared. Western blotting was used to examine α-synuclein expression in the cochlea. Compared with CBA mice, C57 mice showed earlier onset high-frequency hearing loss and decreased function in OHCs, especially within high-frequency regions. C57 mice demonstrated more severe pathologic changes within the cochlea, particularly within the basal turn, than CBA mice of the same age. Weaker α-synuclein and synaptophysin expression in the efferent nerve endings and cochlear homogenates in C57 mice was observed. Our results support the hypothesis that efferent nerve degeneration, possibly due to differential α-synuclein expression, is a potential cause of early-onset presbycusis. Further studies at the cellular level are necessary to verify our results. Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Autonomic innervation of the heart. Role of molecular imaging

Energy Technology Data Exchange (ETDEWEB)

Slart, Riemer H.J.A; Elsinga, Philip H. [Univ. Medical Center Groningen (Netherlands). Nuclear Medicine and Molecular Imaging; Tio, Rene A. [Univ. Medical Center Groningen (Netherlands). Thorax Center Cardiology; Schwaiger, Markus (ed.) [Technische Univ. Muenchen Klinikum Rechts der Isar (Germany). Nuklearmedizinische Klinik

2015-03-01

Reviews in detail the value of SPECT-CT and PET-CT in the imaging of cardiac innervation. Details the role of imaging in a range of conditions and diseases. Includes important background on pathophysiology, tracers, radiopharmaceutical production, and kinetic modeling software. This book explains in detail the potential value of the hybrid modalities, SPECT-CT and PET-CT, in the imaging of cardiac innervation in a wide range of conditions and diseases, including ischemic heart disease, diabetes mellitus, heart failure, amyloidosis, heart transplantation, and ventricular arrhythmias. Imaging of the brain-heart axis in neurodegenerative disease and stress and of cardiotoxicity is also discussed. The roles of the various available tracers are fully considered, and individual chapters address radiopharmaceutical development under GMP, imaging physics, and kinetic modeling software. Highly relevant background information is included on the autonomic nervous system of the heart and its pathophysiology, and in addition future perspectives are discussed. Awareness of the importance of autonomic innervation of the heart for the optimal management of cardiac patients is growing, and there is an evident need for objective measurement techniques or imaging modalities. In this context, Autonomic Innervation of the Heart will be of wide interest to clinicians, researchers, and industry.

Autonomic innervation of the heart. Role of molecular imaging

International Nuclear Information System (INIS)

Slart, Riemer H.J.A; Elsinga, Philip H.; Tio, Rene A.; Schwaiger, Markus

2015-01-01

Reviews in detail the value of SPECT-CT and PET-CT in the imaging of cardiac innervation. Details the role of imaging in a range of conditions and diseases. Includes important background on pathophysiology, tracers, radiopharmaceutical production, and kinetic modeling software. This book explains in detail the potential value of the hybrid modalities, SPECT-CT and PET-CT, in the imaging of cardiac innervation in a wide range of conditions and diseases, including ischemic heart disease, diabetes mellitus, heart failure, amyloidosis, heart transplantation, and ventricular arrhythmias. Imaging of the brain-heart axis in neurodegenerative disease and stress and of cardiotoxicity is also discussed. The roles of the various available tracers are fully considered, and individual chapters address radiopharmaceutical development under GMP, imaging physics, and kinetic modeling software. Highly relevant background information is included on the autonomic nervous system of the heart and its pathophysiology, and in addition future perspectives are discussed. Awareness of the importance of autonomic innervation of the heart for the optimal management of cardiac patients is growing, and there is an evident need for objective measurement techniques or imaging modalities. In this context, Autonomic Innervation of the Heart will be of wide interest to clinicians, researchers, and industry.

Lipofibromatous Hamartoma of the Plantar Nerve An Extremely Rare Localization.

Science.gov (United States)

Mert, Murat; Hacısalihoglu, Payam

2018-03-01

Lipofibromatous hamartoma (LFH) is a rare, benign, tumor-like soft-tissue lesion that affects the peripheral nerves and forms a palpable neurogenic mass. Lipofibromatous hamartoma is associated with pain and sensory and/or motor deficits in the area of innervation of the affected nerve. This report describes a rare case of LFH of the plantar nerve. A 48-year-old woman presented to our outpatient orthopedic clinic with pain and a burning sensation on her left foot. The patient had a history of Morton's neuroma and had undergone a tarsal tunnel operation 2 years earlier at another center. None of her symptoms was alleviated by two previous operations. Magnetic resonance imaging with contrast revealed tenosynovitis of the flexor hallucis longus tendon and signal changes at deep tissue planes of the foot at the levels of the second and third toes, on the dorsal site and subcutaneous soft-tissue planes, suggesting edema and Morton's neuroma. The lesion was excised under spinal anesthesia, and histopathologic examination of the specimen revealed a diagnosis of LFH. The patient was discharged without any symptoms and her foot was normal at 8-month outpatient follow-up, with no indications of postoperative complications and/or recurrence.

Differential roles of stretch-sensitive pelvic nerve afferents innervating mouse distal colon and rectum

OpenAIRE

Feng, Bin; Brumovsky, Pablo R.; Gebhart, Gerald F.

2010-01-01

Information about colorectal distension (i.e., colorectal dilation by increased intraluminal pressure) is primarily encoded by stretch-sensitive colorectal afferents in the pelvic nerve (PN). Despite anatomic differences between rectum and distal colon, little is known about the functional roles of colonic vs. rectal afferents in the PN pathway or the quantitative nature of mechanosensory encoding. We utilized an in vitro mouse colorectum-PN preparation to investigate pressure-encoding charac...

Adult plasticity in the subcortical auditory pathway of the maternal mouse.

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Jason A Miranda

Full Text Available Subcortical auditory nuclei were traditionally viewed as non-plastic in adulthood so that acoustic information could be stably conveyed to higher auditory areas. Studies in a variety of species, including humans, now suggest that prolonged acoustic training can drive long-lasting brainstem plasticity. The neurobiological mechanisms for such changes are not well understood in natural behavioral contexts due to a relative dearth of in vivo animal models in which to study this. Here, we demonstrate in a mouse model that a natural life experience with increased demands on the auditory system - motherhood - is associated with improved temporal processing in the subcortical auditory pathway. We measured the auditory brainstem response to test whether mothers and pup-naïve virgin mice differed in temporal responses to both broadband and tone stimuli, including ultrasonic frequencies found in mouse pup vocalizations. Mothers had shorter latencies for early ABR peaks, indicating plasticity in the auditory nerve and the cochlear nucleus. Shorter interpeak latency between waves IV and V also suggest plasticity in the inferior colliculus. Hormone manipulations revealed that these cannot be explained solely by estrogen levels experienced during pregnancy and parturition in mothers. In contrast, we found that pup-care experience, independent of pregnancy and parturition, contributes to shortening auditory brainstem response latencies. These results suggest that acoustic experience in the maternal context imparts plasticity on early auditory processing that lasts beyond pup weaning. In addition to establishing an animal model for exploring adult auditory brainstem plasticity in a neuroethological context, our results have broader implications for models of perceptual, behavioral and neural changes that arise during maternity, where subcortical sensorineural plasticity has not previously been considered.

Adult plasticity in the subcortical auditory pathway of the maternal mouse.

Science.gov (United States)

Miranda, Jason A; Shepard, Kathryn N; McClintock, Shannon K; Liu, Robert C

2014-01-01

Subcortical auditory nuclei were traditionally viewed as non-plastic in adulthood so that acoustic information could be stably conveyed to higher auditory areas. Studies in a variety of species, including humans, now suggest that prolonged acoustic training can drive long-lasting brainstem plasticity. The neurobiological mechanisms for such changes are not well understood in natural behavioral contexts due to a relative dearth of in vivo animal models in which to study this. Here, we demonstrate in a mouse model that a natural life experience with increased demands on the auditory system - motherhood - is associated with improved temporal processing in the subcortical auditory pathway. We measured the auditory brainstem response to test whether mothers and pup-naïve virgin mice differed in temporal responses to both broadband and tone stimuli, including ultrasonic frequencies found in mouse pup vocalizations. Mothers had shorter latencies for early ABR peaks, indicating plasticity in the auditory nerve and the cochlear nucleus. Shorter interpeak latency between waves IV and V also suggest plasticity in the inferior colliculus. Hormone manipulations revealed that these cannot be explained solely by estrogen levels experienced during pregnancy and parturition in mothers. In contrast, we found that pup-care experience, independent of pregnancy and parturition, contributes to shortening auditory brainstem response latencies. These results suggest that acoustic experience in the maternal context imparts plasticity on early auditory processing that lasts beyond pup weaning. In addition to establishing an animal model for exploring adult auditory brainstem plasticity in a neuroethological context, our results have broader implications for models of perceptual, behavioral and neural changes that arise during maternity, where subcortical sensorineural plasticity has not previously been considered.

Intratemporal facial nerve neuromas and their mimics: CT and MR findings

Energy Technology Data Exchange (ETDEWEB)

Han, Moon Hee; Chang, Kee Hyun; Lee, Kyung Hwan; Cha, Sang Hoon; Kim, Chong Sun [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Sang Joon [Chungang Gil General Hospital, Seoul (Korea, Republic of)

1992-05-15

CT and MR findings of nine cases with intra temporal facial nerve neuromas were described and compared with CT findings of 3 cases with facial nerve palsy and facial nerve canal erosion which may mimic facial nerve neuroma. The tympanic segment of the facial nerve was involved in 8 cases, mastoid segment in 7 cases and labyrinthine segment in 5 cases. The lesions were easily diagnosed with high resolution CT with bone algorithms by showing the expansion of bony structures along the course of the facial nerves. In 4 cases with large vertical segment tumors, extensive destruction of mastoid air cells and external auditory canals posed difficulty in making a diagnosis. Two out of 5 cases with labyrinthine segment involvement were presented as middle cranial fossa masses. MRI with enhancement was performed in 4 cases and was useful in characterizing the lesion as a tumor with its superior sensitivity to enhancement. Three cases of facial neuroma-mimicking lesion including post-inflammatory peri neural thickening, peri neural extension from parotid adenoid cystic carcinoma, and congenita; cholesteatoma showed irregular erosion or mild expansion of the facial nerve canal which may be helpful for differential diagnosis from neuromas.

Intramuscular Distribution of the Abducens Nerve in the Lateral Rectus Muscle for the Management of Strabismus.

Science.gov (United States)

Shin, Hyun Jin; Lee, Shin-Hyo; Shin, Kang-Jae; Koh, Ki-Seok; Song, Wu-Chul

2018-06-01

To elucidate the intramuscular distribution and branching patterns of the abducens nerve in the lateral rectus (LR) muscle so as to provide anatomical confirmation of the presence of compartmentalization, including for use in clinical applications such as botulinum toxin injections. Thirty whole-mount human cadaver specimens were dissected and then Sihler's stain was applied. The basic dimensions of the LR and its intramuscular nerve distribution were investigated. The distances from the muscle insertion to the point at which the abducens nerve enters the LR and to the terminal nerve plexus were also measured. The LR was 46.0 mm long. The abducens nerve enters the muscle on the posterior one-third of the LR and then typically divides into a few branches (average of 1.8). This supports a segregated abducens nerve selectively innervating compartments of the LR. The intramuscular nerve distribution showed a Y-shaped ramification with root-like arborization. The intramuscular nerve course finished around the middle of the LR (24.8 mm posterior to the insertion point) to form the terminal nerve plexus. This region should be considered the optimal target site for botulinum toxin injections. We have also identified the presence of an overlapping zone and communicating nerve branches between the neighboring LR compartments. Sihler's staining is a useful technique for visualizing the entire nerve network of the LR. Improving the knowledge of the nerve distribution patterns is important not only for researchers but also clinicians to understand the functions of the LR and the diverse pathophysiology of strabismus.

Chapter 24: Electrical stimulation for improving nerve regeneration: where do we stand?

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Gordon, Tessa; Sulaiman, Olewale A R; Ladak, Adil

2009-01-01

While injured neurons regenerate their axons in the peripheral nervous system, it is well recognized that functional recovery is frequently poor. Animal experiments in which injured motoneurons remain without peripheral targets (chronic axotomy) and Schwann cells in distal nerve stumps remain without innervation (chronic denervation) revealed that it is the duration of chronic axotomy and Schwann cell denervation that accounts for this poor functional recovery and not irreversible muscle atrophy that has been so commonly thought to be the reason. More recently, we demonstrated that axon outgrowth across lesion sites is a major contributing factor to the long delays incurred between the injury and the reinnervation of denervated targets. In the rat, a period of 1 month transpires before all motoneurons regenerate their axons across a lesion site. We have developed a technique of 1 h low-frequency electrical stimulation (ES) of the proximal nerve stump just after surgical repair of a transected peripheral nerve that greatly accelerates axon outgrowth. This technique has been applied in patients after carpal tunnel release surgery where the ES promoted the regeneration of all median nerves to reinnervate thenar muscles within 6-8 months, which contrasted with failure of any injured nerves to reinnervate muscles in the same time frame without ES. These findings are very promising such that the ES method could become a clinically viable tool for accelerating axon regeneration and muscle reinnervation.

Quantitation of cardiac sympathetic innervation in rabbits using 11C-hydroxyephedrine PET: relation to 123I-MIBG uptake

International Nuclear Information System (INIS)

Nomura, Yusuke; Kajinami, Kouji; Matsunari, Ichiro; Takamatsu, Hiroyuki; Murakami, Yoshihiro; Matsuya, Takahiro; Chen, Wei-Ping; Taki, Junichi; Nakajima, Kenichi; Nekolla, Stephan G.

2006-01-01

Although 11 C-hydroxyephedrine ( 11 C-HED) PET is used to map cardiac sympathetic innervation, no studies have shown the feasibility of quantitation of 11 C-HED PET in small- to medium-sized animals. Furthermore, its relation to 123 I-MIBG uptake, the most widely used sympathetic nervous tracer, is unknown. The aims of this study were to establish in vivo sympathetic nerve imaging in rabbits using 11 C-HED PET, and to compare the retention of 11 C-HED with that of 123 I-MIBG. Twelve rabbits were assigned to three groups; control (n=4), chemical denervation by 6-hydroxydopamine (6-OHDA) (n=4) and reserpine treated to inhibit vesicular uptake (n=4). After simultaneous injection of 11 C-HED and 123 I-MIBG, all animals underwent dynamic 11 C-HED PET for 40 min with arterial blood sampling. The 11 C-HED retention fraction and normalised 11 C-HED activity measured by tissue sampling were compared with those measured by PET. Both the 11 C-HED retention fraction and the normalised 11 C-HED activity measured by PET correlated closely with those measured by tissue sampling (R=0.96027, p 11 C-HED and 123 I-MIBG. Reserpine pretreatment reduced 11 C-HED retention by 50%, but did not reduce 123 I-MIBG retention at 40 min after injection. Non-invasive quantitation of cardiac sympathetic innervation using 11 C-HED PET is feasible and gives reliable estimates of cardiac sympathetic innervation in rabbits. Additionally, although both 11 C-HED and 123 I-MIBG are specific for sympathetic neurons, 11 C-HED may be more specific for intravesicular uptake than 123 I-MIBG in some situations, such as that seen in reserpine pretreatment. (orig.)

Cerebellopontine angle and internal auditory canal: neurovascular anatomy on gas CT cisternograms

International Nuclear Information System (INIS)

Bird, C.R.; Hasso, A.N.; Drayer, B.P.; Hinshaw, D.B. Jr.; Thompson, J.R.

1985-01-01

The authors reviewed 103 normal gas CT cisternograms to delineate the appearance of normal neurovascular structures in the cerebellopontine angle (CPA) and internal auditory canal (IAC). Cranial nerves VII and VIII were identified in the CPA in 97% of cases, either separately (53%) or as a bundle (44%). Intracanalicular branches of the VIIIth cranial nerve were identified in 20% of cases, and cranial nerve V was visualized in the CPA in 14%. The characteristic vascular loop, usually the anterior inferior cerebellar artery, was visible in 35% of cases, and, in 22% of visualized cases, was in an intracanalicular location. In 10% of cases, greater than 66% of the IAC was occupied by the neurovascular bundle. Familiarity with the normal anatomy and variations seen on gas CT cisternograms is necessary to prevent false-positive interpretations

Comparison of trophic factors' expression between paralyzed and recovering muscles after facial nerve injury. A quantitative analysis in time course.

Science.gov (United States)

Grosheva, Maria; Nohroudi, Klaus; Schwarz, Alisa; Rink, Svenja; Bendella, Habib; Sarikcioglu, Levent; Klimaschewski, Lars; Gordon, Tessa; Angelov, Doychin N

2016-05-01

After peripheral nerve injury, recovery of motor performance negatively correlates with the poly-innervation of neuromuscular junctions (NMJ) due to excessive sprouting of the terminal Schwann cells. Denervated muscles produce short-range diffusible sprouting stimuli, of which some are neurotrophic factors. Based on recent data that vibrissal whisking is restored perfectly during facial nerve regeneration in blind rats from the Sprague Dawley (SD)/RCS strain, we compared the expression of brain derived neurotrophic factor (BDNF), fibroblast growth factor-2 (FGF2), insulin growth factors 1 and 2 (IGF1, IGF2) and nerve growth factor (NGF) between SD/RCS and SD-rats with normal vision but poor recovery of whisking function after facial nerve injury. To establish which trophic factors might be responsible for proper NMJ-reinnervation, the transected facial nerve was surgically repaired (facial-facial anastomosis, FFA) for subsequent analysis of mRNA and proteins expressed in the levator labii superioris muscle. A complicated time course of expression included (1) a late rise in BDNF protein that followed earlier elevated gene expression, (2) an early increase in FGF2 and IGF2 protein after 2 days with sustained gene expression, (3) reduced IGF1 protein at 28 days coincident with decline of raised mRNA levels to baseline, and (4) reduced NGF protein between 2 and 14 days with maintained gene expression found in blind rats but not the rats with normal vision. These findings suggest that recovery of motor function after peripheral nerve injury is due, at least in part, to a complex regulation of lesion-associated neurotrophic factors and cytokines in denervated muscles. The increase of FGF-2 protein and concomittant decrease of NGF (with no significant changes in BDNF or IGF levels) during the first week following FFA in SD/RCS blind rats possibly prevents the distal branching of regenerating axons resulting in reduced poly-innervation of motor endplates. Copyright �

Flexible multichannel vagus nerve electrode for stimulation and recording for heart failure treatment.

Science.gov (United States)

Xue, Ning; Martinez, Ignacio Delgado; Sun, Jianhai; Cheng, Yuhua; Liu, Chunxiu

2018-07-30

Vagus nerve stimulation is an emerging bioelectronic medicine to modulate cardiac function, as the nerve provides parasympathetic innervation to the heart. In this study, we developed a polyimide based 2D cuff electrode to wrap around on the vagus nerve. Thanks to the tiny size and bendable protruding structure of the contact tips of the device, the electrode sites are able to flexibly bend to touch the nerve, selectively record and stimulate the vagus nerve. Gold, platinum and platinum black materials were chosen to compose the electrodes for nerve stimulation and recording, respectively. Since the platinum black has ~30 times larger charge delivery capacity (CDC) than gold, Pt black electrode is used for nerve stimulation. The electrochemical impedance spectroscopy and cyclic voltammetry measurement of the three materials were conducted in vitro, revealing the results of 405 kΩ, 41 kΩ, 10.5 kΩ, @1 kHz and 0.81 mC/cm 2 , 4.26 mC/cm 2 , 25.5 mC/cm 2 , respectively (n = 3). The cuff electrodes were implanted into the right-sided vagus nerve of rats for in vivo experiment. Biphasic current configuration was implemented for nerve stimulation with frequency of 10 Hz, pulse during of 300 μs and various currents stimulus. The result shows the heart beat frequency drops up to 36% during the stimulation and was able to return the regular frequency as stimulation was removed. Subsequently, the vagus nerve signals were recorded with the four channel cuff electrodes. The magnitude of the compound nerve action potentials (CNAPs) is ~10 μV and the signal to noise ratio (SNR) is ~20. Copyright © 2018 Elsevier B.V. All rights reserved.

Pulsed radiofrequency on radial nerve under ultrasound guidance for treatment of intractable lateral epicondylitis.

Science.gov (United States)

Oh, Dae Seok; Kang, Tae Hyung; Kim, Hyae Jin

2016-06-01

Lateral epicondylitis is a painful and functionally limiting disorder. Although lateral elbow pain is generally self-limiting, in a minority of people symptoms persist for a long time. When various conservative treatments fail, surgical approach is recommended. Surgical denervation of several nerves that innervate the lateral humeral epicondyle could be considered in patients with refractory pain because it denervates the region of pain. Pulsed radiofrequency is a minimally invasive procedure that improves chronic pain when applied to various neural tissues without causing any significant destruction and painful complication. This procedure is safe, minimally invasive, and has less risk of complications relatively compared to the surgical approach. The radial nerve can be identified as a target for pulsed radiofrequency lesioning in lateral epicondylitis. This innovative method of pulsed radiofrequency applied to the radial nerve has not been reported before. We reported on two patients with intractable lateral epicondylitis suffering from elbow pain who did not respond to nonoperative treatments, but in whom the ultrasound-guided pulsed radiofrequency neuromodulation of the radial nerve induced symptom improvement. After a successful diagnostic nerve block, radiofrequency probe adjustment around the radial nerve was performed on the lateral aspect of the distal upper arm under ultrasound guidance and multiple pulsed treatments were applied. A significant reduction in pain was reported over the follow-up period of 12 weeks.

Detailed anatomy of the abducens nerve in the lateral rectus muscle.

Science.gov (United States)

Nam, Yong Seok; Kim, In-Beom; Shin, Sun Young

2017-10-01

The aims of this study were to elucidate the detailed anatomy of the abducens nerve in the lateral rectus muscle (LRM) and the intramuscular innervation pattern using Sihler staining. In this cohort study, 32 eyes of 16 cadavers were assessed. Dissection was performed from the LRM origin to its insertion. The following distances were measured: from LRM insertion to the bifurcation point of the abducens nerve, from LRM insertion to the entry site of the superior branch or inferior branch, from the upper border of the LRM to the entry site of the superior branch, from the lower border of LRM to the entry site of inferior branch, and the widths of the main trunk and superior and inferior branches. The single trunk of the abducens nerve divided into two branches 37 mm from insertion of the LRM, and 22 of 32 (68.8%) orbits showed only two superior and inferior branches with no subdivision. The superior branch entered the LRM more anteriorly (P = 0.037) and the superior branch was thinner than the inferior branch (P = 0.040). The most distally located intramuscular nerve ending was observed at 52.9 ± 3.5% of the length of each muscle. Non-overlap between the superior and inferior intramuscular arborization of the nerve was detected in 27 of 32 cases (84.4%). Five cases (15.6%) showed definite overlap of the superior and inferior zones. This study revealed the detailed anatomy of the abducens nerve in the LRM and provides helpful information to understand abducens nerve palsy. Clin. Anat. 30:873-877, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Catecholaminergic and serotoninergic fibres innervate the ventricular system of the hedgehog CNS.

Science.gov (United States)

Michaloudi, H C; Papadopoulos, G C

1996-01-01

Immunocytochemistry with antisera against serotonin (5-HT), dopamine (DA) and noradrenaline (NA) was used to detect monoaminergic (MA) fibres in the ventricular system of the hedgehog Erinaceus europaeus. Light microscopic examination of immunocytochemically stained sections revealed that the ventricular system of the hedgehog is unique among mammals in that the choroid plexuses receive CA axons and that the supraependyma and subependyma of the cerebral ventricles and the spinal central canal are innervated both by serotoninergic and catecholaminergic (CA) fibres. Supraependymal 5-HT axons were generally more abundant and created at places a large number of interconnected basket-like structures, whereas CA fibres were usually directed towards the ventricular lumen. In the lateral ventricles, CA fibres were more numerous in the ependyma lining grey matter, whereas a higher 5-HT innervation density was observed in the area between the corpus callosum and the caudate nucleus or the septum. In the 3rd ventricle, the ependyma of its dorsal part exhibited a higher 5-HT and NA innervation density, whereas DA fibres were preferentially distributed in the ventral half of the basal region. The ependyma lining the cerebral aqueduct displayed a higher MA innervation density in its ventral part. The ependymal wall of the 4th ventricle exhibited an extremely dense 5-HT innervation, mainly in the floor of the ventricle, relatively fewer NA fibres and only sparse DA ones. Few NA and relatively more 5-HT fibres were detected in the ependyma of the central canal. Finally, the circumventricular organs were unevenly innervated by the 3 types of MA fibres. The extensive monoaminergic innervation of the hedgehog ventricular system described here probably reflects a transitory evolutionary stage in the phylogeny of the MA systems with presently unknown functional implications. Images Fig. 1 Fig. 2 Figs 3-8 Figs 9-14 Figs 15-20 PMID:8886949

Auditory-motor learning influences auditory memory for music.

Science.gov (United States)

Brown, Rachel M; Palmer, Caroline

2012-05-01

In two experiments, we investigated how auditory-motor learning influences performers' memory for music. Skilled pianists learned novel melodies in four conditions: auditory only (listening), motor only (performing without sound), strongly coupled auditory-motor (normal performance), and weakly coupled auditory-motor (performing along with auditory recordings). Pianists' recognition of the learned melodies was better following auditory-only or auditory-motor (weakly coupled and strongly coupled) learning than following motor-only learning, and better following strongly coupled auditory-motor learning than following auditory-only learning. Auditory and motor imagery abilities modulated the learning effects: Pianists with high auditory imagery scores had better recognition following motor-only learning, suggesting that auditory imagery compensated for missing auditory feedback at the learning stage. Experiment 2 replicated the findings of Experiment 1 with melodies that contained greater variation in acoustic features. Melodies that were slower and less variable in tempo and intensity were remembered better following weakly coupled auditory-motor learning. These findings suggest that motor learning can aid performers' auditory recognition of music beyond auditory learning alone, and that motor learning is influenced by individual abilities in mental imagery and by variation in acoustic features.

A Narrow Internal Auditory Canal with Duplication in a Patient with Congenital Sensorineural Hearing Loss

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Baik, Hye Won; Yu, Hye On; Kim, Kyung Soo; Kim, Gi Hyeon [Chung-Ang University Hospital, College of Medicine, Seoul (Korea, Republic of)

2008-07-15

A narrow internal auditory canal (IAC) with duplication is a rare anomaly of the temporal bone. It is associated with congenital sensorineural hearing loss. Aplasia or hypoplasia of the vestibulocochlear nerve may cause the hearing loss. We present an unusual case of an isolated narrow IAC with duplication that was detected by a CT scan. In this case, the IAC was divided by a bony septum into an empty stenotic inferoposterior portion and a large anterosuperior portion containing the facial nerve that was clearly delineated on MRI.

Selective plasticity of primary afferent innervation to the dorsal horn and autonomic nuclei following lumbosacral ventral root avulsion and reimplantation in long term studies.

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Wu, Lisa; Wu, Jun; Chang, Huiyi H; Havton, Leif A

2012-02-01

Previous studies involving injuries to the nerves of the cauda equina and the conus medullaris have shown that lumbosacral ventral root avulsion in rat models results in denervation and dysfunction of the lower urinary tract, retrograde and progressive cell death of the axotomized motor and parasympathetic neurons, as well as the emergence of neuropathic pain. Root reimplantation has also been shown to ameliorate several of these responses, but experiments thus far have been limited to studying the effects of lesion and reimplantation local to the lumbosacral region. Here, we have expanded the region of investigation after lumbosacral ventral root avulsion and reimplantation to include the thoracolumbar sympathetic region of the spinal cord. Using a retrograde tracer injected into the major pelvic ganglion, we were able to define the levels of the spinal cord that contain sympathetic preganglionic neurons innervating the lower urinary tract. We have conducted studies on the effects of the lumbosacral ventral root avulsion and reimplantation models on the afferent innervation of the dorsal horn and autonomic nuclei at both thoracolumbar and lumbosacral levels through immunohistochemistry for the markers calcitonin gene-related peptide (CGRP) and vesicular glutamate transporter 1 (VGLUT1). Surprisingly, our experiments reveal a selective and significant decrease of CGRP-positive innervation in the dorsal horn at thoracolumbar levels that is partially restored with root reimplantation. However, no similar changes were detected at the lumbosacral levels despite the injury and repair targeting efferent neurons, and being performed at the lumbosacral levels. Despite the changes evident in the thoracolumbar dorsal horn, we find no changes in afferent innervation of the autonomic nuclei at either sympathetic or parasympathetic segmental levels by CGRP or VGLUT1. We conclude that even remote, efferent root injuries and repair procedures can have an effect on remote and non

Mechanisms mediating the trophic effect of nerves during vertebrate limb regeneration

International Nuclear Information System (INIS)

Munaim, S.I.

1986-01-01

Salamanders regenerate their appendages after amputation and nerves are required for this process. Experiments were designed to test the idea that one way nerves could affect blastema cell proliferation is by influencing the metabolism of extracellular matrix (ECM) components and to identify neurotrophic factors which promote blastema cell mitosis. Temporal and spatial differences of glycosaminoglycans (GAGs) synthesis is innervated and denervated limbs were examined. Hyaluronic acid (HA) was found to be the major GAG produced during the proliferative period and chondroitin sulfate during differentiation. Denervation reduced synthesis of both these components by half. Dorsal root ganglia and fibroblast growth factor (FGF), a brain-derived mitogen, similarly doubled GAG synthesis in cultured blastemas, the FGF-effect being primarily on HA production. Histochemical and autoradiographical results confirmed the biochemical data. Autoradiography of the limb tissue showed heaviest labeling of the ECM with 3 H-acetate in areas which also stained most intensely with the dye, carbocyanine DBTC. Denervation reduced the staining and the radioactive labeling. These data indicate that nerves affect synthesis and accumulation of GAGs in the regenerating limb, which may be one way blastema cell proliferation is promoted

Adrenergic innervation of the rat hypothalamus

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Palkovits, M.; Mezey, E.; Záborszky, L.; Feminger, A.; Versteeg, D.H.G.; Wijnen, H.J.L.M.; Jong, Wybren de; Fekete, M.I.K.; Herman, J.P.; Kanyicska, B.

The adrenergic innervation of the hypothalamus was studied by measuring hypothalamic adrenaline levels following surgical transection of the lower brain stem or electrolytic lesion of the medullary adrenaline-containing cell groups. The adrenaline levels in some hypothalamic nuclei and in the median

Chronic Conductive Hearing Loss Leads to Cochlear Degeneration.

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Liberman, M Charles; Liberman, Leslie D; Maison, Stéphane F

2015-01-01

Synapses between cochlear nerve terminals and hair cells are the most vulnerable elements in the inner ear in both noise-induced and age-related hearing loss, and this neuropathy is exacerbated in the absence of efferent feedback from the olivocochlear bundle. If age-related loss is dominated by a lifetime of exposure to environmental sounds, reduction of acoustic drive to the inner ear might improve cochlear preservation throughout life. To test this, we removed the tympanic membrane unilaterally in one group of young adult mice, removed the olivocochlear bundle in another group and compared their cochlear function and innervation to age-matched controls one year later. Results showed that tympanic membrane removal, and the associated threshold elevation, was counterproductive: cochlear efferent innervation was dramatically reduced, especially the lateral olivocochlear terminals to the inner hair cell area, and there was a corresponding reduction in the number of cochlear nerve synapses. This loss led to a decrease in the amplitude of the suprathreshold cochlear neural responses. Similar results were seen in two cases with conductive hearing loss due to chronic otitis media. Outer hair cell death was increased only in ears lacking medial olivocochlear innervation following olivocochlear bundle cuts. Results suggest the novel ideas that 1) the olivocochlear efferent pathway has a dramatic use-dependent plasticity even in the adult ear and 2) a component of the lingering auditory processing disorder seen in humans after persistent middle-ear infections is cochlear in origin.

Reactive microglia after taste nerve injury: comparison to nerve injury models of chronic pain [v1; ref status: indexed, http://f1000r.es/wh

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Dianna L Bartel

2013-02-01

Full Text Available The chorda tympani (CT, which innervates taste buds on the anterior portion of the tongue, is susceptible to damage during inner ear surgeries. Injury to the CT causes a disappearance of taste buds, which is concurrent with significant microglial responses at central nerve terminals in the nucleus of the solitary tract (nTS. The resulting taste disturbances that can occur may persist for months or years, long after the nerve and taste buds have regenerated. These persistent changes in taste sensation suggest alterations in central functioning and may be related to the microglial responses. This is reminiscent of nerve injuries that result in chronic pain, where microglial reactivity is essential in maintaining the altered sensation (i.e., pain. In these models, methods that diminish microglial responses also diminish the corresponding pain behavior. Although the CT nerve does not contain nociceptive pain fibers, the microglial reactivity after CT damage is similar to that described in pain models. Therefore, methods that decrease microglial responses in pain models were used here to test if they could also affect microglial reactivity after CT injury. Treatment with minocycline, an antibiotic that dampens pain responsive microglia, was largely ineffective in diminishing microglial responses after CT injury. In addition, signaling through the toll-like 4 receptor (TLR4 does not seem to be required after CT injury as blocking or deleting TLR4 had no effect on microglial reactivity. These results suggest that microglial responses following CT injury rely on different signaling mechanisms than those described in nerve injuries resulting in chronic pain.

Unilateral duplicated abducens nerve coursing through both the sphenopetroclival venous gulf and cavernous sinus: a case report.

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Coquet, Thomas; Lefranc, Michel; Chenin, Louis; Foulon, Pascal; Havet, Éric; Peltier, Johann

2018-03-15

In this anatomy report, we describe the first case of abducens nerve duplication limited to the sphenopetroclival venous gulf and the cavernous sinus. The objective point of division of the two duplicated roots was localized at the gulfar face of the dural porus, just distal to the unique cisternal trunk of the abducens nerve, as it pierced the petroclival dural mater. In the gulfar segment, both roots traveled through a variant of Dorello's canal called the "petrosphenoidal canal" and remained separated through the posterior half of the cavernous sinus. Both roots finally fused in the anterior half of the cavernous sinus to innervate the lateral rectus muscle as a single trunk. Although many variants of the abducens nerve have been reported over the recent decades, this anatomic variation has never been previously described and enriches the continuum of abducens nerve variations reported in the literature data. Awareness of this variation is crucial for neurosurgeons, especially during clival or petrosal surgical approaches used for resection of skull base chordomas.

Central Somatosensory Networks Respond to a De Novo Innervated Penis: A Proof of Concept in Three Spina Bifida Patients.

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Kortekaas, Rudie; Nanetti, Luca; Overgoor, Max L E; de Jong, Bauke M; Georgiadis, Janniko R

2015-09-01

Spina bifida (SB) causes low spinal lesions, and patients often have absent genital sensation and a highly impaired sex life. TOMAX (TO MAX-imize sensation, sexuality and quality of life) is a surgical procedure whereby the penis is newly innervated using a sensory nerve originally targeting the inguinal area. Most TOMAX-treated SB patients initially experience penile stimulation as inguinal sensation, but eventually, the perception shifts to penis sensation with erotic feelings. The brain mechanisms mediating this perceptual shift, which are completely unknown, could hold relevance for understanding the brain's role in sexual development. The aim of this study was to study how a newly perceived penis would be mapped onto the brain after a lifelong disconnection. Three TOMAX-treated SB patients participated in a functional magnetic resonance imagery experiment while glans penis, inguinal area, and index finger were stimulated with a paint brush. Brush stimulation-induced activation of the primary somatosensory cortex (SI) and functional connectivity between SI and remote cerebral regions. Stimulation of the re-innervated side of the glans penis and the intact contralateral inguinal area activated a very similar location on SI. Yet, connectivity analysis identified distinct SI functional networks. In all three subjects, the middle cingulate cortex (MCC) and the parietal operculum-insular cortex (OIC) were functionally connected to SI activity during glans penis stimulation, but not to SI activity induced by inguinal stimulation. Investigating central somatosensory network activity to a de novo innervated penis in SB patients is feasible and informative. The consistent involvement of MCC and OIC above and beyond the brain network expected on the basis of inguinal stimulation suggests that these areas mediate the novel penis sensation in these patients. The potential role of MCC and OIC in this process is discussed, along with recommendations for further research. �

Progranulin promotes peripheral nerve regeneration and reinnervation: role of notch signaling.

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Altmann, Christine; Vasic, Verica; Hardt, Stefanie; Heidler, Juliana; Häussler, Annett; Wittig, Ilka; Schmidt, Mirko H H; Tegeder, Irmgard

2016-10-22

Peripheral nerve injury is a frequent cause of lasting motor deficits and chronic pain. Although peripheral nerves are capable of regrowth they often fail to re-innervate target tissues. Using newly generated transgenic mice with inducible neuronal progranulin overexpression we show that progranulin accelerates axonal regrowth, restoration of neuromuscular synapses and recovery of sensory and motor functions after injury of the sciatic nerve. Oppositely, progranulin deficient mice have long-lasting deficits in motor function tests after nerve injury due to enhanced losses of motor neurons and stronger microglia activation in the ventral horn of the spinal cord. Deep proteome and gene ontology (GO) enrichment analysis revealed that the proteins upregulated in progranulin overexpressing mice were involved in 'regulation of transcription' and 'response to insulin' (GO terms). Transcription factor prediction pointed to activation of Notch signaling and indeed, co-immunoprecipitation studies revealed that progranulin bound to the extracellular domain of Notch receptors, and this was functionally associated with higher expression of Notch target genes in the dorsal root ganglia of transgenic mice with neuronal progranulin overexpression. Functionally, these transgenic mice recovered normal gait and running, which was not achieved by controls and was stronger impaired in progranulin deficient mice. We infer that progranulin activates Notch signaling pathways, enhancing thereby the regenerative capacity of partially injured neurons, which leads to improved motor function recovery.

Anatomical basis for simultaneous block of greater and third occipital nerves, with an ultrasound-guided technique.

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Kariya, Ken; Usui, Yosuke; Higashi, Naoko; Nakamoto, Tatsuo; Shimbori, Hironobu; Terada, Satoshi; Takahashi, Hideo; Ueta, Hisashi; Kitazawa, Yusuke; Sawanobori, Yasushi; Okuda, Yasuhisa; Matsuno, Kenjiro

2017-11-13

In some headache disorders, for which the greater occipital nerve block is partly effective, the third occipital nerve is also suggested to be involved. We aimed to establish a simple technique for simultaneously blocking the greater and third occipital nerves. We performed a detailed examination of dorsal neck anatomy in 33 formalin-fixed cadavers, and deduced two candidate target points for blocking both the greater and third occipital nerves. These target points were tested on three Thiel-fixed cadavers. We performed ultrasound-guided dye injections into these points, examined the results by dissection, and selected the most suitable injection point. Finally, this target point was tested in three healthy volunteers. We injected 4 ml of local anesthetic and 1 ml of radiopaque material at the selected point, guided with a standard ultrasound system. Then, the pattern of local anesthetic distribution was imaged with computed tomography. We deduced that the most suitable injection point was the medial head of the semispinalis capitis muscle at the C1 level of the cervical vertebra. Both nerves entered this muscle, in close proximity, with little individual variation. In healthy volunteers, an anesthetic injected was confined to the muscle and induced anesthesia in the skin areas innervated by both nerves. The medial head of the semispinalis capitis muscle is a suitable landmark for blocking the greater and third occipital nerves simultaneously, by which occipital nerve involvement in various headache disorders may be rapidly examined and treated.

Capsaicin-Sensitive Sensory Nerves Indirectly Modulate Motor Function of the Urinary Bladder

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Hsi-Hsien Chang

2018-06-01

Full Text Available Purpose The urinary bladder (UB is innervated by both sensory and autonomic nerves. Recent studies have shown that sensory neuropeptides induced contractions in the detrusor muscle. Therefore, in a mouse model, we investigated the presence of interactions between the submucosal sensory nerves and the autonomic nerves that regulate the motor function of the detrusor muscle. Methods UB samples from male C57BL/6 mice were isolated, cut into strips, and mounted in an organ bath. Dose-response curves to norepinephrine and phenylephrine were studied in UB strips with and without mucosa, and the effects of preincubation with a receptor antagonist and various drugs on relaxation were also studied using tissue bath myography. Results Phenylephrine-induced relaxation of the UB strips showed concentration-related effects. This relaxation appeared in both mucosa-intact and mucosa-denuded UB strips, and was significantly inhibited by lidocaine, silodosin, and guanethidine (an adrenergic neuronal blocker. Meanwhile, phenylephrine-induced relaxation was inhibited by pretreatment with propranolol and calcitonin gene-related peptide (CGRP–depletory capsaicin in UB strips with and without mucosa. Conclusions The present study suggests that phenylephrine activates the α-1A adrenergic receptor (AR of the sensory nerve, and then activates capsaicin-sensitive sensory nerves to release an unknown substance that facilitates the release of norepinephrine from adrenergic nerves. Subsequently, norepinephrine stimulates β-ARs in the detrusor muscle in mice, leading to neurogenic relaxation of the UB. Further animal and human studies are required to prove this concept and to validate its clinical usefulness.

Exploring vocal recovery after cranial nerve injury in Bengalese finches.

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Urbano, Catherine M; Peterson, Jennifer R; Cooper, Brenton G

2013-02-08

Songbirds and humans use auditory feedback to acquire and maintain their vocalizations. The Bengalese finch (Lonchura striata domestica) is a songbird species that rapidly modifies its vocal output to adhere to an internal song memory. In this species, the left side of the bipartite vocal organ is specialized for producing louder, higher frequencies (≥2.2kHz) and denervation of the left vocal muscles eliminates these notes. Thus, the return of higher frequency notes after cranial nerve injury can be used as a measure of vocal recovery. Either the left or right side of the syrinx was denervated by resection of the tracheosyringeal portion of the hypoglossal nerve. Histologic analyses of syringeal muscle tissue showed significant muscle atrophy in the denervated side. After left nerve resection, songs were mainly composed of lower frequency syllables, but three out of five birds recovered higher frequency syllables. Right nerve resection minimally affected phonology, but it did change song syntax; syllable sequence became abnormally stereotyped after right nerve resection. Therefore, damage to the neuromuscular control of sound production resulted in reduced motor variability, and Bengalese finches are a potential model for functional vocal recovery following cranial nerve injury. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Magnetic resonance imaging of facial nerve schwannoma.

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Thompson, Andrew L; Aviv, Richard I; Chen, Joseph M; Nedzelski, Julian M; Yuen, Heng-Wai; Fox, Allan J; Bharatha, Aditya; Bartlett, Eric S; Symons, Sean P

2009-12-01

This study characterizes the magnetic resonance (MR) appearances of facial nerve schwannoma (FNS). We hypothesize that the extent of FNS demonstrated on MR will be greater compared to prior computed tomography studies, that geniculate involvement will be most common, and that cerebellar pontine angle (CPA) and internal auditory canal (IAC) involvement will more frequently result in sensorineural hearing loss (SNHL). Retrospective study. Clinical, pathologic, and enhanced MR imaging records of 30 patients with FNS were analyzed. Morphologic characteristics and extent of segmental facial nerve involvement were documented. Median age at initial imaging was 51 years (range, 28-76 years). Pathologic confirmation was obtained in 14 patients (47%), and the diagnosis reached in the remainder by identification of a mass, thickening, and enhancement along the course of the facial nerve. All 30 lesions involved two or more contiguous segments of the facial nerve, with 28 (93%) involving three or more segments. The median segments involved per lesion was 4, mean of 3.83. Geniculate involvement was most common, in 29 patients (97%). CPA (P = .001) and IAC (P = .02) involvement was significantly related to SNHL. Seventeen patients (57%) presented with facial nerve dysfunction, manifesting in 12 patients as facial nerve weakness or paralysis, and/or in eight with involuntary movements of the facial musculature. This study highlights the morphologic heterogeneity and typical multisegment involvement of FNS. Enhanced MR is the imaging modality of choice for FNS. The neuroradiologist must accurately diagnose and characterize this lesion, and thus facilitate optimal preoperative planning and counseling.

Voluntary Exercise Training: Analysis of Mice in Uninjured, Inflammatory, and Nerve-Injured Pain States.

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Tayler D Sheahan

Full Text Available Both clinical and animal studies suggest that exercise may be an effective way to manage inflammatory and neuropathic pain conditions. However, existing animal studies commonly use forced exercise paradigms that incorporate varying degrees of stress, which itself can elicit analgesia, and thus may complicate the interpretation of the effects of exercise on pain. We investigated the analgesic potential of voluntary wheel running in the formalin model of acute inflammatory pain and the spared nerve injury model of neuropathic pain in mice. In uninjured, adult C57BL/6J mice, 1 to 4 weeks of exercise training did not alter nociceptive thresholds, lumbar dorsal root ganglia neuronal excitability, or hindpaw intraepidermal innervation. Further, exercise training failed to attenuate formalin-induced spontaneous pain. Lastly, 2 weeks of exercise training was ineffective in reversing spared nerve injury-induced mechanical hypersensitivity or in improving muscle wasting or hindpaw denervation. These findings indicate that in contrast to rodent forced exercise paradigms, short durations of voluntary wheel running do not improve pain-like symptoms in mouse models of acute inflammation and peripheral nerve injury.

Anatomy of the nerves and ganglia of the aortic plexus in males

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Beveridge, Tyler S; Johnson, Marjorie; Power, Adam; Power, Nicholas E; Allman, Brian L

2015-01-01

It is well accepted that the aortic plexus is a network of pre- and post-ganglionic nerves overlying the abdominal aorta, which is primarily involved with the sympathetic innervation to the mesenteric, pelvic and urogenital organs. Because a comprehensive anatomical description of the aortic plexus and its connections with adjacent plexuses are lacking, these delicate structures are prone to unintended damage during abdominal surgeries. Through dissection of fresh, frozen human cadavers (n = 7), the present study aimed to provide the first complete mapping of the nerves and ganglia of the aortic plexus in males. Using standard histochemical procedures, ganglia of the aortic plexus were verified through microscopic analysis using haematoxylin & eosin (H&E) and anti-tyrosine hydroxylase stains. All specimens exhibited four distinct sympathetic ganglia within the aortic plexus: the right and left spermatic ganglia, the inferior mesenteric ganglion and one previously unidentified ganglion, which has been named the prehypogastric ganglion by the authors. The spermatic ganglia were consistently supplied by the L1 lumbar splanchnic nerves and the inferior mesenteric ganglion and the newly characterized prehypogastric ganglion were supplied by the left and right L2 lumbar splanchnic nerves, respectively. Additionally, our examination revealed the aortic plexus does have potential for variation, primarily in the possibility of exhibiting accessory splanchnic nerves. Clinically, our results could have significant implications for preserving fertility in men as well as sympathetic function to the hindgut and pelvis during retroperitoneal surgeries. PMID:25382240

Pharyngeal arch deficiencies affect taste bud development in the circumvallate papilla with aberrant glossopharyngeal nerve formation.

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Okubo, Tadashi; Takada, Shinji

2015-07-01

The pharyngeal arches (PAs) generate cranial organs including the tongue. The taste placodes, formed in particular locations on the embryonic tongue surface, differentiate into taste buds harbored in distinct gustatory papillae. The developing tongue also has a complex supply of cranial nerves through each PA. However, the relationship between the PAs and taste bud development is not fully understood. Ripply3 homozygous mutant mice, which have impaired third/fourth PAs, display a hypoplastic circumvallate papilla and lack taste buds, although the taste placode is normally formed. Formation of the glossopharyngeal ganglia is defective and innervation toward the posterior tongue is completely missing in Ripply3 mutant embryos at E12.5. Moreover, the distribution of neuroblasts derived from the epibranchial placode is severely, but not completely, atenuated, and the neural crest cells are diminished in the third PA region of Ripply3 mutant embryos at E9.5-E10.5. In Tbx1 homozygous mutant embryos, which exhibit another type of deficiency in PA development, the hypoplastic circumvallate papilla is observed along with abnormal formation of the glossopharyngeal ganglia and severely impaired innervation. PA deficiencies affect multiple aspects of taste bud development, including formation of the cranial ganglia and innervation to the posterior tongue. © 2015 Wiley Periodicals, Inc.

Labyrinthine Artery Aneurysm as an Internal Auditory Canal Mass

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Diaz, Rodney C.; Konia, Thomas; Brunberg, James

2013-01-01

We present the first case report of a labyrinthine artery aneurysm masquerading as an internal auditory canal tumor. A 72-year-old woman presented with sudden onset right facial paralysis, facial pain, hearing loss, and vertigo. She demonstrated dense right-sided facial paralysis involving all branches of the facial nerve, left beating horizontal nystagmus, and anacusis of the right ear. Magnetic resonance imaging with contrast demonstrated a 6 × 7 mm peripherally enhancing lesion with lack o...

Neuroanatomical Evidence for Catecholamines as Modulators of Audition and Acoustic Behavior in a Vocal Teleost.

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Forlano, Paul M; Sisneros, Joseph A

2016-01-01

The plainfin midshipman fish (Porichthys notatus) is a well-studied model to understand the neural and endocrine mechanisms underlying vocal-acoustic communication across vertebrates. It is well established that steroid hormones such as estrogen drive seasonal peripheral auditory plasticity in female Porichthys in order to better encode the male's advertisement call. However, little is known of the neural substrates that underlie the motivation and coordinated behavioral response to auditory social signals. Catecholamines, which include dopamine and noradrenaline, are good candidates for this function, as they are thought to modulate the salience of and reinforce appropriate behavior to socially relevant stimuli. This chapter summarizes our recent studies which aimed to characterize catecholamine innervation in the central and peripheral auditory system of Porichthys as well as test the hypotheses that innervation of the auditory system is seasonally plastic and catecholaminergic neurons are activated in response to conspecific vocalizations. Of particular significance is the discovery of direct dopaminergic innervation of the saccule, the main hearing end organ, by neurons in the diencephalon, which also robustly innervate the cholinergic auditory efferent nucleus in the hindbrain. Seasonal changes in dopamine innervation in both these areas appear dependent on reproductive state in females and may ultimately function to modulate the sensitivity of the peripheral auditory system as an adaptation to the seasonally changing soundscape. Diencephalic dopaminergic neurons are indeed active in response to exposure to midshipman vocalizations and are in a perfect position to integrate the detection and appropriate motor response to conspecific acoustic signals for successful reproduction.

Organization of ascending auditory pathways in the pigeon (Columba livia) as determined by autoradiographic methods

International Nuclear Information System (INIS)

Correia, M.J.; Eden, A.R.; Westlund, K.N.; Coulter, J.D.

1982-01-01

A mixture of tritiated proline and fucose was injected into the labyrinthine endolymphatic space of 5 white king pigeons (Columba livia). Using standard autoradiographic techniques, the authors observed transsynaptic labeling in ascending auditory pathways to the level of the mesencephalon. Auditory system structures, ipsilateral to the injection site, which labeled heavily were the cochlear nerve, the magnocellular and angular nuclei, and the superior olive. Those ipsilateral structures which were slightly labeled were the lateral lemniscus and the dorsal part of the lateral mesencephalic nucleus. Contralateral structures which labeled were the superior olive, lateral lemniscus, and dorsal part of the lateral mesencephalic nucleus. The results of this study suggest that ascending auditory pathways (to the level of mesencephalon) in the pigeon are more similar to those described for mammals in general than previously thought. (Auth.)

Organization of ascending auditory pathways in the pigeon (Columba livia) as determined by autoradiographic methods

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Correia, M.J.; Eden, A.R.; Westlund, K.N.; Coulter, J.D. (Texas Univ., Galveston (USA). Medical Branch)

1982-02-25

A mixture of tritiated proline and fucose was injected into the labyrinthine endolymphatic space of 5 white king pigeons (Columba livia). Using standard autoradiographic techniques, the authors observed transsynaptic labeling in ascending auditory pathways to the level of the mesencephalon. Auditory system structures, ipsilateral to the injection site, which labeled heavily were the cochlear nerve, the magnocellular and angular nuclei, and the superior olive. Those ipsilateral structures which were slightly labeled were the lateral lemniscus and the dorsal part of the lateral mesencephalic nucleus. Contralateral structures which labeled were the superior olive, lateral lemniscus, and dorsal part of the lateral mesencephalic nucleus. The results of this study suggest that ascending auditory pathways (to the level of mesencephalon) in the pigeon are more similar to those described for mammals in general than previously thought.

Comprehensive evaluation of a child with an auditory brainstem implant.

Science.gov (United States)

Eisenberg, Laurie S; Johnson, Karen C; Martinez, Amy S; DesJardin, Jean L; Stika, Carren J; Dzubak, Danielle; Mahalak, Mandy Lutz; Rector, Emily P

2008-02-01

We had an opportunity to evaluate an American child whose family traveled to Italy to receive an auditory brainstem implant (ABI). The goal of this evaluation was to obtain insight into possible benefits derived from the ABI and to begin developing assessment protocols for pediatric clinical trials. Case study. Tertiary referral center. Pediatric ABI Patient 1 was born with auditory nerve agenesis. Auditory brainstem implant surgery was performed in December, 2005, in Verona, Italy. The child was assessed at the House Ear Institute, Los Angeles, in July 2006 at the age of 3 years 11 months. Follow-up assessment has continued at the HEAR Center in Birmingham, Alabama. Auditory brainstem implant. Performance was assessed for the domains of audition, speech and language, intelligence and behavior, quality of life, and parental factors. Patient 1 demonstrated detection of sound, speech pattern perception with visual cues, and inconsistent auditory-only vowel discrimination. Language age with signs was approximately 2 years, and vocalizations were increasing. Of normal intelligence, he exhibited attention deficits with difficulty completing structured tasks. Twelve months later, this child was able to identify speech patterns consistently; closed-set word identification was emerging. These results were within the range of performance for a small sample of similarly aged pediatric cochlear implant users. Pediatric ABI assessment with a group of well-selected children is needed to examine risk versus benefit in this population and to analyze whether open-set speech recognition is achievable.

Reversible induction of phantom auditory sensations through simulated unilateral hearing loss.

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Roland Schaette

Full Text Available Tinnitus, a phantom auditory sensation, is associated with hearing loss in most cases, but it is unclear if hearing loss causes tinnitus. Phantom auditory sensations can be induced in normal hearing listeners when they experience severe auditory deprivation such as confinement in an anechoic chamber, which can be regarded as somewhat analogous to a profound bilateral hearing loss. As this condition is relatively uncommon among tinnitus patients, induction of phantom sounds by a lesser degree of auditory deprivation could advance our understanding of the mechanisms of tinnitus. In this study, we therefore investigated the reporting of phantom sounds after continuous use of an earplug. 18 healthy volunteers with normal hearing wore a silicone earplug continuously in one ear for 7 days. The attenuation provided by the earplugs simulated a mild high-frequency hearing loss, mean attenuation increased from 30 dB at 3 and 4 kHz. 14 out of 18 participants reported phantom sounds during earplug use. 11 participants presented with stable phantom sounds on day 7 and underwent tinnitus spectrum characterization with the earplug still in place. The spectra showed that the phantom sounds were perceived predominantly as high-pitched, corresponding to the frequency range most affected by the earplug. In all cases, the auditory phantom disappeared when the earplug was removed, indicating a causal relation between auditory deprivation and phantom sounds. This relation matches the predictions of our computational model of tinnitus development, which proposes a possible mechanism by which a stabilization of neuronal activity through homeostatic plasticity in the central auditory system could lead to the development of a neuronal correlate of tinnitus when auditory nerve activity is reduced due to the earplug.

Nerve supply to the internal anal sphincter differs from that to the distal rectum: an immunohistochemical study of cadavers.

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Kinugasa, Yusuke; Arakawa, Takashi; Murakami, Gen; Fujimiya, Mineko; Sugihara, Kenichi

2014-04-01

Fecal incontinence is a common problem after anal sphincter-preserving operations. The intersphincteric autonomic nerves supplying the internal anal sphincter (IAS) are formed by the union of: (1) nerve fibers from Auerbach's nerve plexus of the most distal part of the rectum and (2) the inferior rectal branches of the pelvic plexus (IRB-PX) running along the conjoint longitudinal muscle coat. The aim of the present study is to identify the detailed morphology of nerves to the IAS. The study comprised histological and immunohistochemical evaluations of paraffin-embedded sections from a large block of anal canal from the preserved 10 cadavers. The IRB-PX came from the superior aspect of the levator ani and ran into the anal canal on the anterolateral side. These nerves contained both sympathetic and parasympathetic fibers, but the sympathetic content was much higher than in nerves from the distal rectum. All intramural ganglion cells in the distal rectum were neuronal nitric oxide synthase-positive and tyrosine hydroxylase-negative and were restricted to above the squamous-columnar epithelial junction. Parasympathetic nerves formed a lattice-like plexus in the circular smooth muscles of the distal rectum, whereas the IAS contained short, longitudinally running sympathetic and parasympathetic nerves, although sympathetic nerves were dominant. The major autonomic nerve input to the IAS seemed not to originate from the distal rectum but from the IRB-PX. Injury to the IRB-PX during surgery seemed to result in loss of innervation to the major part of the IAS.

Removal of vestibular schwannoma and facial nerve preservation using small suboccipital retrosigmoid craniotomy

Institute of Scientific and Technical Information of China (English)

CHEN Ling; CHEN Li-hua; LING Feng; LIU Yun-sheng; Madjid Samii; Amir Samii

2010-01-01

Background Vestibular schwannoma, the commonest form of intracranial schwannoma, arises from the Schwann cells investing the vestibular nerve. At present, the surgery for vestibular schwannoma remains one of the most complicated operations demanding for surgical skills in neurosurgery. And the trend of minimal invasion should also be the major influence on the management of patients with vestibular schwannomas. We summarized the microsurgical removal experience in a recent series of vestibular schwannomas and presented the operative technique and cranial nerve preservation in order to improve the rates of total tumor removal and facial nerve preservation.Methods A retrospective analysis was performed in 145 patients over a 7-year period who suffered from vestibular schwannomas that had been microsurgicaily removed by suboccipital retrosigmoid transmeatus approach with small craniotomy. CT thinner scans revealed the tumor size in the internal auditory meatus and the relationship of the posterior wall of the internal acoustic meatus to the bone labyrinths preoperatively. Brain stem evoked potential was monitored intraoperatively. The posterior wall of the internal acoustic meatus was designedly drilled off. Patient records and operative reports, including data from the electrophysiological monitoring, follow-up audiometric examinations, and neuroradiological findings were analyzed.Results Total tumor resection was achieved in 140 cases (96.6%) and subtotal resection in 5 cases. The anatomical integrity of the facial nerve was preserved in 91.0% (132/145) of the cases. Intracranial end-to-end anastomosis of the facial nerve was performed in 7 cases. Functional preservation of the facial nerve was achieved in 115 patients (Grade Ⅰ and Grade Ⅱ, 79.3%). No patient died in this series. Preservation of nerves and vessels were as important as tumor removal dudng the operation. CT thinner scan could show the relationship between the posterior wall of the internal

Evaluation of the Auditory Pathway in Traffic Policemen

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Vipul Indora

2017-04-01

Full Text Available Background: Traffic policemen working at heavy traffic junctions are continuously exposed to high level of noise and its health consequences. Objective: To assess the hearing pathway in traffic policemen by means of brainstem evoked response audiometry (BERA, mid-latency response (MLR, and slow vertex response (SVR. Methods: In this observational comparative study, BERA, MLR, and SVR were tested in 35 male traffic policemen with field posting of more than 3 years. 35 age-matched men working in our college served as controls. Results: Increase in the latencies of waves I and III of BERA, and IPL I-III were observed. Compared to controls, the MLR and SVR waves showed no significant changes in studied policemen. Conclusion: We found that chronic exposure of traffic policemen to noise resulted in delayed conduction in peripheral part of the auditory pathway, ie, auditory nerve up to the level of superior olivary nucleus; no impairment was observed at the level of sub-cortical, cortical, or the association areas.

Ramsay Hunt syndrome with unilateral polyneuropathy involving cranial nerves V, VII, VIII, and XII in a diabetic patient.

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Sun, Wei-Lian; Yan, Jian-Liang; Chen, Li-Li

2011-01-01

Ramsay Hunt syndrome is a rare complication of the varicella zoster virus, defined as a peripheral facial palsy that typically results from involvement of the facial and auditory nerves. Ramsay Hunt syndrome can be associated with cranial nerves V, VI, IX, and X but rarely with XII. We describe an atypical case of Ramsay Hunt syndrome with multiple cranial nerve involvement of nerves V, VII, VIII, and XII. Antiviral drugs, antibiotics, insulin, and traditional Chinese drugs were administered immediately after admission. After 3 months of combination therapy, the patient had recovered satisfactorily. Herpes zoster can cause severe infections in diabetic patients and should be treated as soon after detection as possible. Ramsay Hunt syndrome should be recognized as a polycranial neuritis characterized by damage to sensory and motor nerves. In addition to facial and vestibular nerve paralysis, Ramsay Hunt syndrome may also involve cranial nerves V and XII.

Modeling the time-varying and level-dependent effects of the medial olivocochlear reflex in auditory nerve responses.

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Smalt, Christopher J; Heinz, Michael G; Strickland, Elizabeth A

2014-04-01

The medial olivocochlear reflex (MOCR) has been hypothesized to provide benefit for listening in noisy environments. This advantage can be attributed to a feedback mechanism that suppresses auditory nerve (AN) firing in continuous background noise, resulting in increased sensitivity to a tone or speech. MOC neurons synapse on outer hair cells (OHCs), and their activity effectively reduces cochlear gain. The computational model developed in this study implements the time-varying, characteristic frequency (CF) and level-dependent effects of the MOCR within the framework of a well-established model for normal and hearing-impaired AN responses. A second-order linear system was used to model the time-course of the MOCR using physiological data in humans. The stimulus-level-dependent parameters of the efferent pathway were estimated by fitting AN sensitivity derived from responses in decerebrate cats using a tone-in-noise paradigm. The resulting model uses a binaural, time-varying, CF-dependent, level-dependent OHC gain reduction for both ipsilateral and contralateral stimuli that improves detection of a tone in noise, similarly to recorded AN responses. The MOCR may be important for speech recognition in continuous background noise as well as for protection from acoustic trauma. Further study of this model and its efferent feedback loop may improve our understanding of the effects of sensorineural hearing loss in noisy situations, a condition in which hearing aids currently struggle to restore normal speech perception.

Bilateral irradiation of head and neck induces and enhanced expression of substance P in the parasympathetic innervation of the submandibular gland

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Forsgren, S; Franzen, L; Funegard, U; Gustafsson, H; Henriksson, R [Umeaa Univ. (Sweden). Dept. of Oncology, Anatomy and Oto-laryngology

1992-01-01

Substance P and calcitonin gene-related peptide (CGRP) are present in nerve fibers innervating the submandibular gland. Radiotherapy of tumours in the head and neck region usually embraces the salivary glands in the irradiated field and consequently a dramatic decrease in salivary function is seen. In this study, the submandibular glands and ganglia of rats subjected to fractionated irradiation were examined by use of immunohistochemical techniques for demonstration of substance P and CGRP. Irradiation was given on five consecutive days with unilateral or bilateral irradiation techniques. Specimens of control and experimental animals were processed in parallel. A marked increase in the expression of substance P in the ganglionic cells-presumably parasympathetic-and in the number of fibers showing substance P-like immunoreactivity in association with acini and small ducts was seen in response to bilateral irradiation. No changes in the pattern of CGRP immunoreactivity occurred. In the trigeminal ganglion, which supplies the submandibular gland with the majority of the sensory substance P-and CGRP-containing nerve fibers, no changes in the expression of substance P or CGRP immunoreactivity were seen. The results suggest that bilateral irradiation leads to an increase in the synthesis of substance P-like substance in the parasympathetic ganglionic cells supplying the submandibular gland with secretory nerves, and can thus be an additional factor in explaining the altered secretory capacity of salivary glands. (author).

Quantified distribution of the noradrenaline innervation in the hippocampus of adult rat

International Nuclear Information System (INIS)

Oleskevich, S.; Descarries, L.; Lacaille, J.C.

1989-01-01

A recently developed radioautographic technique, based on the uptake labeling of monoamine terminals in vitro, was used to quantify the noradrenaline (NA) innervation in adult rat hippocampus. After incubation of brain slices with 1 microM 3H-NA, the NA varicosities were visualized as small aggregates of silver grains, in light microscope radioautographs prepared at 3 equidistant horizontal levels across the ventral 2/3 of the hippocampus. Using a computer-assisted image analyzer, counts were obtained from the subiculum (SUB), 3 sectors of Ammon's horn (CA1, CA3-a, CA3-b) and 3 sectors of the dentate gyrus (DG-medial blade, crest, and lateral blade), every lamina being sampled in each region. After a double correction for duration of radioautographic exposure and section thickness, and following measurement of varicosity diameter in electron microscope radioautographs, it was possible to express these results in number of terminals per volumetric unit of tissue. It was thus found that the overall density of hippocampal NA innervation averages 2.1 million varicosities/mm3 of tissue, a value almost twice as high as that in cerebral cortex. This innervation is 20% denser ventrally than dorsally and is heterogeneous both in terms of regional and laminar distribution. SUB and DG are more strongly innervated than Ammon's horn, wherein CA1 has the lowest overall density. In SUB and CA1, there is a clear predilection of NA varicosities for the stratum moleculare. In CA3, there is a narrow band of even stronger innervation in the stratum radiatum, near the apical border of the stratum pyramidale, contrasting with a 3 times lower density in this cell layer and the stratum oriens. In DG, the NA innervation is again the weakest in the cell body layer and exhibits an almost 3-fold greater density in the polymorph layer, the highest of all hippocampus

A fine structural localization of the non-specific cholinesterase activity in glomerular nerve formations (endings).

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Dubový, P

1990-01-01

Snout glabrous skin (rhinarium) of the cat is innervated not only by typical simple lamellar corpuscles but also glomerular formations. In contrast to simple lamellar corpuscles, glomerular nerve formations are located away the dermal papillae. In cross sections, glomerular nerve formation consists of several axonal profiles enveloped by 1-2 cytoplasmic lamellae of Schwann cells. The space among them is filled by collagenous microfibrils and the basal lamina-like material. Capsule was composed from fibroblast-like cells without definite basal lamina. An electron-dense reaction product due to non-specific cholinesterase activity was associated with Schwann cells and their processes surrounding unmyelinated terminal portion of the sensory axons. Abundant reaction product was bound to the collagenous microfibrils and was deposited in extracellular matrix between Schwann cell processes. These results are further evidence for the presence of the non-specific cholinesterase molecules as integral component of the extracellular matrix in sensory corpuscles. On the basis of histochemical study two possible explanation are considered for functional involving of this enzyme in sensory nerve formations.

Morphological pattern of intrinsic nerve plexus distributed on the rabbit heart and interatrial septum

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Saburkina, Inga; Gukauskiene, Ligita; Rysevaite, Kristina; Brack, Kieran E; Pauza, Audrys G; Pauziene, Neringa; Pauza, Dainius H

2014-01-01

Although the rabbit is routinely used as the animal model of choice to investigate cardiac electrophysiology, the neuroanatomy of the rabbit heart is not well documented. The aim of this study was to examine the topography of the intrinsic nerve plexus located on the rabbit heart surface and interatrial septum stained histochemically for acetylcholinesterase using pressure-distended whole hearts and whole-mount preparations from 33 Californian rabbits. Mediastinal cardiac nerves entered the venous part of the heart along the root of the right cranial vein (superior caval vein) and at the bifurcation of the pulmonary trunk. The accessing nerves of the venous part of the heart passed into the nerve plexus of heart hilum at the heart base. Nerves approaching the heart extended epicardially and innervated the atria, interatrial septum and ventricles by five nerve subplexuses, i.e. left and middle dorsal, dorsal right atrial, ventral right and left atrial subplexuses. Numerous nerves accessed the arterial part of the arterial part of the heart hilum between the aorta and pulmonary trunk, and distributed onto ventricles by the left and right coronary subplexuses. Clusters of intrinsic cardiac neurons were concentrated at the heart base at the roots of pulmonary veins with some positioned on the infundibulum. The mean number of intrinsic neurons in the rabbit heart is not significantly affected by aging: 2200 ± 262 (range 1517–2788; aged) vs. 2118 ± 108 (range 1513–2822; juvenile). In conclusion, despite anatomic differences in the distribution of intrinsic cardiac neurons and the presence of well-developed nerve plexus within the heart hilum, the topography of all seven subplexuses of the intrinsic nerve plexus in rabbit heart corresponds rather well to other mammalian species, including humans. PMID:24527844

Hemifacial Pain and Hemisensory Disturbance Referred from Occipital Neuralgia Caused by Pathological Vascular Contact of the Greater Occipital Nerve.

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Son, Byung-Chul; Choi, Jin-Gyu

2017-01-01

Here we report a unique case of chronic occipital neuralgia caused by pathological vascular contact of the left greater occipital nerve. After 12 months of left-sided, unremitting occipital neuralgia, a hypesthesia and facial pain developed in the left hemiface. The decompression of the left greater occipital nerve from pathological contacts with the occipital artery resulted in immediate relief for hemifacial sensory change and facial pain, as well as chronic occipital neuralgia. Although referral of pain from the stimulation of occipital and cervical structures innervated by upper cervical nerves to the frontal head of V1 trigeminal distribution has been reported, the development of hemifacial sensory change associated with referred trigeminal pain from chronic occipital neuralgia is extremely rare. Chronic continuous and strong afferent input of occipital neuralgia caused by pathological vascular contact with the greater occipital nerve seemed to be associated with sensitization and hypersensitivity of the second-order neurons in the trigeminocervical complex, a population of neurons in the C2 dorsal horn characterized by receiving convergent input from dural and cervical structures.

Narrow duplicated internal auditory canal: radiological findings and review of the literature

International Nuclear Information System (INIS)

Demir, Oezguen Ilhan; Cakmakci, Handan; Men, Sueleyman; Erdag, Taner Kemal

2005-01-01

Narrow duplicated internal auditory canal (IAC) is a rare malformation of the temporal bone that is associated with ipsilateral congenital sensorineural hearing loss. This may be an isolated finding or a part of a syndrome. Radiological examination should demonstrate aplasia or hypoplasia of the neural components of the narrow IAC, to guide the surgical approach. We report a 7-year-old boy with Klippel-Feil syndrome with a narrow double IAC with no sensorineural hearing loss but with conductive hearing loss. In this patient, the IAC consisted of two separate narrow bony canals clearly seen on 3D temporal bone CT and one nerve that was delineated on MRI. The contralateral external auditory canal was stenotic and the ossicles were dysplastic. (orig.)

Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

International Nuclear Information System (INIS)

Gimelli, Alessia; Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia; Marzullo, Paolo

2016-01-01

To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic "9"9"mTc-tetrofosmin and "1"2"3I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target. (orig.)

Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

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Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia [University Hospital of Pisa, Cardio-Thoracic and Vascular Department, Pisa (Italy); Marzullo, Paolo [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); CNR, Institute of Clinical Physiology, Pisa (Italy)

2016-12-15

To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic {sup 99m}Tc-tetrofosmin and {sup 123}I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target

Innervation Patterns of Sea Otter (Enhydra lutris Mystacial Follicle-Sinus Complexes

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Christopher Douglas Marshall

2014-10-01

Full Text Available Sea otters (Enhydra lutris are the most recent group of mammals to return to the sea, and may exemplify divergent somatosensory tactile systems among mammals. Therefore, we quantified the mystacial vibrissal array of sea otters and histologically processed follicle-sinus complexes (F-SCs to test the hypotheses that the number of myelinated axons per F-SC is greater than that found for terrestrial mammalian vibrissae and that their organization and microstructure converge with those of pinniped vibrissae. A mean of 120.5 vibrissae were arranged rostrally on a broad, blunt muzzle in 7-8 rows and 9-13 columns. The F-SCs of sea otters are tripartite in their organization and similar in microstructure to pinnipeds rather than terrestrial species. Each F-SC was innervated by a mean 1339±408.3 axons. Innervation to the entire mystacial vibrissal array was estimated at 161,313 axons. Our data support the hypothesis that the disproportionate expansion of the coronal gyrus in somatosensory cortex of sea otters is related to the high innervation investment of the mystacial vibrissal array, and that quantifying innervation investment is a good proxy for tactile sensitivity. We predict that the tactile performance of sea otter mystacial vibrissae is comparable to that of harbor seals, sea lions and walruses¬.

Neuregulin-1 signaling is essential for nerve-dependent axolotl limb regeneration.

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Farkas, Johanna E; Freitas, Polina D; Bryant, Donald M; Whited, Jessica L; Monaghan, James R

2016-08-01

The Mexican axolotl (Ambystoma mexicanum) is capable of fully regenerating amputated limbs, but denervation of the limb inhibits the formation of the post-injury proliferative mass called the blastema. The molecular basis behind this phenomenon remains poorly understood, but previous studies have suggested that nerves support regeneration via the secretion of essential growth-promoting factors. An essential nerve-derived factor must be found in the blastema, capable of rescuing regeneration in denervated limbs, and its inhibition must prevent regeneration. Here, we show that the neuronally secreted protein Neuregulin-1 (NRG1) fulfills all these criteria in the axolotl. Immunohistochemistry and in situ hybridization of NRG1 and its active receptor ErbB2 revealed that they are expressed in regenerating blastemas but lost upon denervation. NRG1 was localized to the wound epithelium prior to blastema formation and was later strongly expressed in proliferating blastemal cells. Supplementation by implantation of NRG1-soaked beads rescued regeneration to digits in denervated limbs, and pharmacological inhibition of NRG1 signaling reduced cell proliferation, blocked blastema formation and induced aberrant collagen deposition in fully innervated limbs. Taken together, our results show that nerve-dependent NRG1/ErbB2 signaling promotes blastemal proliferation in the regenerating limb and may play an essential role in blastema formation, thus providing insight into the longstanding question of why nerves are required for axolotl limb regeneration. © 2016. Published by The Company of Biologists Ltd.

Unilateral severe chronic periodontitis associated with ipsilateral surgical resection of cranial nerves V, VI, and VII.

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Zavarella, Matthew M; Leblebicioglu, Binnaz; Claman, Lewis J; Tatakis, Dimitris N

2006-01-01

The central and peripheral nervous systems participate in several local physiological and pathological processes. There is experimental evidence that the inflammatory, local immune, and wound healing responses of a tissue can be modulated by its innervation. The aim of this clinical report is to present a case of unilateral severe periodontitis associated with ipsilateral surgical resection of the fifth, sixth, and seventh cranial nerves and to discuss the possible contribution of the nervous system to periodontal pathogenesis. A 39-year-old female patient with a history of a cerebrovascular accident caused by a right pontine arteriovenous malformation and destruction of the right fifth, sixth, and seventh cranial nerves was diagnosed with severe chronic periodontitis affecting only the right maxillary and mandibular quadrants. The patient's oral hygiene was similar for right and left sides of the mouth. Percentages of tooth surfaces carrying dental plaque were 41% and 36% for right and left sides, respectively. Non-surgical and surgical periodontal therapy was performed, and the patient was placed on a regular periodontal maintenance schedule. Healing following initial periodontal therapy and osseous periodontal surgery occurred without complications. Follow-up clinical findings at 1 year revealed stable periodontal health. This case report suggests that periodontal innervation may contribute to the regulation of local processes involved in periodontitis pathogenesis. It also suggests that periodontal therapy can be performed successfully at sites and in patients affected by paralysis.

Adrenergic innervation of the developing chick heart: neural crest ablations to produce sympathetically aneural hearts

International Nuclear Information System (INIS)

Kirby, M.; Stewart, D.

1984-01-01

Ablation of various regions of premigratory trunk neural crest which gives rise to the sympathetic trunks was used to remove sympathetic cardiac innervation. Neuronal uptake of [ 3 H]-norepinephrine was used as an index of neuronal development in the chick atrium. Following ablation of neural crest over somites 10-15 or 15-20, uptake was significantly decreased in the atrium at 16 and 17 days of development. Ablation of neural crest over somites 5-10 and 20-25 caused no decrease in [ 3 H]-norepinephrine uptake. Removal of neural crest over somites 5-25 or 10-20 caused approximately equal depletions of [ 3 H]-norepinephrine uptake in the atrium. Cardiac norepinephrine concentration was significantly depressed following ablation of neural crest over somites 5-25 but not over somites 10-20. Light-microscopic and histofluorescent preparations confirmed the absence of sympathetic trunks in the region of the normal origin of the sympathetic cardiac nerves following neural crest ablation over somites 10-20. The neural tube and dorsal root ganglia were damaged in the area of the neural-crest ablation; however, all of these structures were normal cranial and caudal to the lesioned area. Development of most of the embryos as well as the morphology of all of the hearts was normal following the lesion. These results indicate that it is possible to produce sympathetically aneural hearts by neural-crest ablation; however, sympathetic cardiac nerves account for an insignificant amount of cardiac norepinephrine

A phenomenological model of the electrically stimulated auditory nerve fiber: temporal and biphasic response properties

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Colin eHorne

2016-02-01

Full Text Available We present a phenomenological model of electrically stimulated auditory nerve fibers (ANFs. The model reproduces the probabilistic and temporal properties of the ANF response to both monophasic and biphasic stimuli, in isolation. The main contribution of the model lies in its ability to reproduce statistics of the ANF response (mean latency, jitter, and firing probability under both monophasic and cathodic-anodic biphasic stimulation, without changing the model’s parameters. The response statistics of the model depend on stimulus level and duration of the stimulating pulse, reproducing trends observed in the ANF. In the case of biphasic stimulation, the model reproduces the effects of pseudomonophasic pulse shapes and also the dependence on the interphase gap (IPG of the stimulus pulse, an effect that is quantitatively reproduced. The model is fitted to ANF data using a procedure that uniquely determines each model parameter. It is thus possible to rapidly parameterize a large population of neurons to reproduce a given set of response statistic distributions.Our work extends the stochastic leaky integrate and fire (SLIF neuron, a well-studied phenomenological model of the electrically stimulated neuron. We extend the SLIF neuron so as to produce a realistic latency distribution by delaying the moment of spiking. During this delay, spiking may be abolished by anodic current. By this means, the probability of the model neuron responding to a stimulus is reduced when a trailing phase of opposite polarity is introduced. By introducing a minimum wait period that must elapse before a spike may be emitted, the model is able to reproduce the differences in the threshold level observed in the ANF for monophasic and biphasic stimuli. Thus, the ANF response to a large variety of pulse shapes are reproduced correctly by this model.

Streptozocin-induced type-1 diabetes mellitus results in decreased density of CGRP sensory and TH sympathetic nerve fibers that are positively correlated with bone loss at the mouse femoral neck.

Science.gov (United States)

Enríquez-Pérez, Iris A; Galindo-Ordoñez, Karla E; Pantoja-Ortíz, Christian E; Martínez-Martínez, Arisaí; Acosta-González, Rosa I; Muñoz-Islas, Enriqueta; Jiménez-Andrade, Juan M

2017-08-10

Type-1 diabetes mellitus (T1DM) results in loss of innervation in some tissues including epidermis and retina; however, the effect on bone innervation is unknown. Likewise, T1DM results in pathological bone loss and increased risk of fracture. Thus, we quantified the density of calcitonin gene-related peptide (CGRP + ) sensory and tyrosine hydroxylase (TH + ) sympathetic nerve fibers and determined the association between the innervation density and microarchitecture of trabecular bone at the mouse femoral neck. Ten weeks-old female mice received 5 daily administrations of streptozocin (i.p. 50mg/kg) or citrate (control group). Twenty weeks later, femurs were analyzed by microCT and processed for immunohistochemistry. Confocal microscopy analysis revealed that mice with T1DM had a significant loss of both CGRP + and TH + nerve fibers in the bone marrow at the femoral neck. Likewise, microCT analysis revealed a significant decrease in the trabecular bone mineral density (tBMD), bone volume/total volume ratio (BV/TB), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp) in mice with T1DM as compared to control mice. Analysis of correlation revealed a positive and significant association between density of CGRP + or TH + nerve fibers with tBMD, BV/TV, Tb.Th and Tb.Sp, but not with trabecular number (there was a positive association only for CGRP + ) and degree of anisotropy (DA). This study suggests an interaction between sensory and sympathetic nervous system and T1DM-induced bone loss. Identification of the factors involved in the loss of CGRP + sensory and TH + sympathetic fibers and how they regulate bone loss may result in new avenues to treat T1DM-related osteoporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Retrospective case series of the imaging findings of facial nerve hemangioma.

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Yue, Yunlong; Jin, Yanfang; Yang, Bentao; Yuan, Hui; Li, Jiandong; Wang, Zhenchang

2015-09-01

The aim was to compare high-resolution computed tomography (HRCT) and thin-section magnetic resonance imaging (MRI) findings of facial nerve hemangioma. The HRCT and MRI characteristics of 17 facial nerve hemangiomas diagnosed between 2006 and 2013 were retrospectively analyzed. All patients included in the study suffered from a space-occupying lesion of soft tissues at the geniculate ganglion fossa. Affected nerve was compared for size and shape with the contralateral unaffected nerve. HRCT showed irregular expansion and broadening of the facial nerve canal, damage of the bone wall and destruction of adjacent bone, with "point"-like or "needle"-like calcifications in 14 cases. The average CT value was 320.9 ± 141.8 Hu. Fourteen patients had a widened labyrinthine segment; 6/17 had a tympanic segment widening; 2/17 had a greater superficial petrosal nerve canal involvement, and 2/17 had an affected internal auditory canal (IAC) segment. On MRI, all lesions were significantly enhanced due to high blood supply. Using 2D FSE T2WI, the lesion detection rate was 82.4 % (14/17). 3D fast imaging employing steady-state acquisition (3D FIESTA) revealed the lesions in all patients. HRCT showed that the average number of involved segments in the facial nerve canal was 2.41, while MRI revealed an average of 2.70 segments (P facial nerve hemangioma were typical, revealing irregular masses growing along the facial nerve canal, with calcifications and rich blood supply. Thin-section enhanced MRI was more accurate in lesion detection and assessment compared with HRCT.

Mast Cells Synthesize, Store, and Release Nerve Growth Factor

Science.gov (United States)

Leon, A.; Buriani, A.; dal Toso, R.; Fabris, M.; Romanello, S.; Aloe, L.; Levi-Montalcini, R.

1994-04-01

Mast cells and nerve growth factor (NGF) have both been reported to be involved in neuroimmune interactions and tissue inflammation. In many peripheral tissues, mast cells interact with the innervating fibers. Changes in the behaviors of both of these elements occur after tissue injury/inflammation. As such conditions are typically associated with rapid mast cell activation and NGF accumulation in inflammatory exudates, we hypothesized that mast cells may be capable of producing NGF. Here we report that (i) NGF mRNA is expressed in adult rat peritoneal mast cells; (ii) anti-NGF antibodies clearly stain vesicular compartments of purified mast cells and mast cells in histological sections of adult rodent mesenchymal tissues; and (iii) medium conditioned by peritoneal mast cells contains biologically active NGF. Mast cells thus represent a newly recognized source of NGF. The known actions of NGF on peripheral nerve fibers and immune cells suggest that mast cell-derived NGF may control adaptive/reactive responses of the nervous and immune systems toward noxious tissue perturbations. Conversely, alterations in normal mast cell behaviors may provoke maladaptive neuroimmune tissue responses whose consequences could have profound implications in inflammatory disease states, including those of an autoimmune nature.

Neurovascular compression syndrome of the eighth cranial nerve

International Nuclear Information System (INIS)

Itoh, Akinori

2010-01-01

Neurovascular compression syndrome (NVCS) involves neuropathy due to intracranial blood vessels compressing the cranial nerves. NVCS of the eighth cranial nerve is less reportedly established as a clinical entity than that of the fifth and seventh cranial nerves. We report 17 cases of NVCS of the eighth cranial nerve and their clinical features. Clinical symptoms and test findings among our subjects indicated that most were aged more than 65 years, were unilateral, had intermittent tinnitus, suffered attacks lasting a few seconds dozens of times a day, experienced dizziness concomitantly with tinnitus, aggravated tinnitus and dizziness when tilting the head toward the affected side and looking downward (positional tinnitus, positional dizziness), heard specific tinnitus sounds such as crackling differing from those in cochlear tinnitus, had mild or no hearing loss, were diagnosed with retrocochlear hearing disturbance due to an interpeak latency delay between waves I and III of the auditory brainstem response (ABR), often had no nystagmus or canal paresis (CP), were found in constructive interference steady state magnetic resonance imaging (CISS MRI) to have compression of the eighth cranial nerve by the vertebral artery (VA) or the anterior inferior cerebellar artery (AICA), rarely had concomitant facial spasms, and had tinnitus and dizziness markedly suppressed by carbamazepine. With the number of elderly individuals continuing to increase, cases of NVCS due to arteriosclerotic changes in cerebral blood vessels are expected to increase, making it necessary to consider NVCS in elderly subjects with dizziness, tinnitus, and hearing loss. (author)

Neurovascular compression syndrome of the eighth cranial nerve

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Itoh, Akinori [Saitama Medical Univ., Faculty of Medicine, Moroyama, Saitama (Japan)

2010-04-15

Neurovascular compression syndrome (NVCS) involves neuropathy due to intracranial blood vessels compressing the cranial nerves. NVCS of the eighth cranial nerve is less reportedly established as a clinical entity than that of the fifth and seventh cranial nerves. We report 17 cases of NVCS of the eighth cranial nerve and their clinical features. Clinical symptoms and test findings among our subjects indicated that most were aged more than 65 years, were unilateral, had intermittent tinnitus, suffered attacks lasting a few seconds dozens of times a day, experienced dizziness concomitantly with tinnitus, aggravated tinnitus and dizziness when tilting the head toward the affected side and looking downward (positional tinnitus, positional dizziness), heard specific tinnitus sounds such as crackling differing from those in cochlear tinnitus, had mild or no hearing loss, were diagnosed with retrocochlear hearing disturbance due to an interpeak latency delay between waves I and III of the auditory brainstem response (ABR), often had no nystagmus or canal paresis (CP), were found in constructive interference steady state magnetic resonance imaging (CISS MRI) to have compression of the eighth cranial nerve by the vertebral artery (VA) or the anterior inferior cerebellar artery (AICA), rarely had concomitant facial spasms, and had tinnitus and dizziness markedly suppressed by carbamazepine. With the number of elderly individuals continuing to increase, cases of NVCS due to arteriosclerotic changes in cerebral blood vessels are expected to increase, making it necessary to consider NVCS in elderly subjects with dizziness, tinnitus, and hearing loss. (author)

Developmental profiles of the intrinsic properties and synaptic function of auditory neurons in preterm and term baboon neonates.

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Kim, Sei Eun; Lee, Seul Yi; Blanco, Cynthia L; Kim, Jun Hee

2014-08-20

The human fetus starts to hear and undergoes major developmental changes in the auditory system during the third trimester of pregnancy. Although there are significant data regarding development of the auditory system in rodents, changes in intrinsic properties and synaptic function of auditory neurons in developing primate brain at hearing onset are poorly understood. We performed whole-cell patch-clamp recordings of principal neurons in the medial nucleus of trapezoid body (MNTB) in preterm and term baboon brainstem slices to study the structural and functional maturation of auditory synapses. Each MNTB principal neuron received an excitatory input from a single calyx of Held terminal, and this one-to-one pattern of innervation was already formed in preterm baboons delivered at 67% of normal gestation. There was no difference in frequency or amplitude of spontaneous excitatory postsynaptic synaptic currents between preterm and term MNTB neurons. In contrast, the frequency of spontaneous GABA(A)/glycine receptor-mediated inhibitory postsynaptic synaptic currents, which were prevalent in preterm MNTB neurons, was significantly reduced in term MNTB neurons. Preterm MNTB neurons had a higher input resistance than term neurons and fired in bursts, whereas term MNTB neurons fired a single action potential in response to suprathreshold current injection. The maturation of intrinsic properties and dominance of excitatory inputs in the primate MNTB allow it to take on its mature role as a fast and reliable relay synapse. Copyright © 2014 the authors 0270-6474/14/3411399-06$15.00/0.

Automated characterization of nerve fibers labeled fluorescently: determination of size, class and spatial distribution.

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Prodanov, Dimiter; Feirabend, Hans K P

2008-10-03

Morphological classification of nerve fibers could help interpret the assessment of neural regeneration and the understanding of selectivity of nerve stimulation. Specific populations of myelinated nerve fibers can be investigated by retrograde tracing from a muscle followed by microscopic measurements of the labeled fibers at different anatomical levels. Gastrocnemius muscles of adult rats were injected with the retrograde tracer Fluoro-Gold. After a survival period of 3 days, cross-sections of spinal cords, ventral roots, sciatic, and tibial nerves were collected and imaged on a fluorescence microscope. Nerve fibers were classified using a variation-based criterion acting on the distribution of their equivalent diameters. The same criterion was used to classify the labeled axons using the size of the fluorescent marker. Measurements of the axons were paired to those of the entire fibers (axons+myelin sheaths) in order to establish the correspondence between so-established axonal and fiber classifications. It was found that nerve fibers in L6 ventral roots could be classified into four populations comprising two classes of Aalpha (denoted Aalpha1 and Aalpha2), Agamma, and an additional class of Agammaalpha fibers. Cut-off borders between Agamma and Agammaalpha fiber classes were estimated to be 5.00+/-0.09 microm (SEM); between Agammaalpha and Aalpha1 fiber classes to be 6.86+/-0.11 microm (SEM); and between Aalpha1 and Aalpha2 fiber classes to be 8.66+/-0.16 microm (SEM). Topographical maps of the nerve fibers that innervate the gastrocnemius muscles were constructed per fiber class for the spinal root L6. The major advantage of the presented approach consists of the combined indirect classification of nerve fiber types and the construction of topographical maps of so-identified fiber classes.

The role of the auditory brainstem in processing musically-relevant pitch

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Gavin M. Bidelman

2013-05-01

Full Text Available Neuroimaging work has shed light on the cerebral architecture involved in processing the melodic and harmonic aspects of music. Here, recent evidence is reviewed illustrating that subcortical auditory structures contribute to the early formation and processing of musically-relevant pitch. Electrophysiological recordings from the human brainstem and population responses from the auditory nerve reveal that nascent features of tonal music (e.g., consonance/dissonance, pitch salience, harmonic sonority are evident at early, subcortical levels of the auditory pathway. The salience and harmonicity of brainstem activity is strongly correlated with listeners’ perceptual preferences and perceived consonance for the tonal relationships of music. Moreover, the hierarchical ordering of pitch intervals/chords described by the Western music practice and their perceptual consonance is well-predicted by the salience with which pitch combinations are encoded in subcortical auditory structures. While the neural correlates of consonance can be tuned and exaggerated with musical training, they persist even in the absence of musicianship or long-term enculturation. As such, it is posited that the structural foundations of musical pitch might result from innate processing performed by the central auditory system. A neurobiological predisposition for consonant, pleasant sounding pitch relationships may be one reason why these pitch combinations have been favored by composers and listeners for centuries. It is suggested that important perceptual dimensions of music emerge well before the auditory signal reaches cerebral cortex and prior to attentional engagement. While cortical mechanisms are no doubt critical to the perception, production, and enjoyment of music, the contribution of subcortical structures implicates a more integrated, hierarchically organized network underlying music processing within the brain.

Time computations in anuran auditory systems

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Gary J Rose

2014-05-01

Full Text Available Temporal computations are important in the acoustic communication of anurans. In many cases, calls between closely related species are nearly identical spectrally but differ markedly in temporal structure. Depending on the species, calls can differ in pulse duration, shape and/or rate (i.e., amplitude modulation, direction and rate of frequency modulation, and overall call duration. Also, behavioral studies have shown that anurans are able to discriminate between calls that differ in temporal structure. In the peripheral auditory system, temporal information is coded primarily in the spatiotemporal patterns of activity of auditory-nerve fibers. However, major transformations in the representation of temporal information occur in the central auditory system. In this review I summarize recent advances in understanding how temporal information is represented in the anuran midbrain, with particular emphasis on mechanisms that underlie selectivity for pulse duration and pulse rate (i.e., intervals between onsets of successive pulses. Two types of neurons have been identified that show selectivity for pulse rate: long-interval cells respond well to slow pulse rates but fail to spike or respond phasically to fast pulse rates; conversely, interval-counting neurons respond to intermediate or fast pulse rates, but only after a threshold number of pulses, presented at optimal intervals, have occurred. Duration-selectivity is manifest as short-pass, band-pass or long-pass tuning. Whole-cell patch recordings, in vivo, suggest that excitation and inhibition are integrated in diverse ways to generate temporal selectivity. In many cases, activity-related enhancement or depression of excitatory or inhibitory processes appear to contribute to selective responses.

Reorganization of Motor Cortex by Vagus Nerve Stimulation Requires Cholinergic Innervation.

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Hulsey, Daniel R; Hays, Seth A; Khodaparast, Navid; Ruiz, Andrea; Das, Priyanka; Rennaker, Robert L; Kilgard, Michael P

2016-01-01

Vagus nerve stimulation (VNS) paired with forelimb training drives robust, specific reorganization of movement representations in the motor cortex. The mechanisms that underlie VNS-dependent enhancement of map plasticity are largely unknown. The cholinergic nucleus basalis (NB) is a critical substrate in cortical plasticity, and several studies suggest that VNS activates cholinergic circuitry. We examined whether the NB is required for VNS-dependent enhancement of map plasticity in the motor cortex. Rats were trained to perform a lever pressing task and then received injections of the immunotoxin 192-IgG-saporin to selectively lesion cholinergic neurons of the NB. After lesion, rats underwent five days of motor training during which VNS was paired with successful trials. At the conclusion of behavioral training, intracortical microstimulation was used to document movement representations in motor cortex. VNS paired with forelimb training resulted in a substantial increase in the representation of proximal forelimb in rats with an intact NB compared to untrained controls. NB lesions prevent this VNS-dependent increase in proximal forelimb area and result in representations similar to untrained controls. Motor performance was similar between groups, suggesting that differences in forelimb function cannot account for the difference in proximal forelimb representation. Together, these findings indicate that the NB is required for VNS-dependent enhancement of plasticity in the motor cortex and may provide insight into the mechanisms that underlie the benefits of VNS therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

Trauma-Induced Heterotopic Ossification Regulates the Blood-Nerve Barrier

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Zbigniew Gugala

2018-06-01

Full Text Available De novo bone formation can occur in soft tissues as a result of traumatic injury. This process, known as heterotopic ossification (HO, has recently been linked to the peripheral nervous system. Studies suggest that HO may resemble neural crest-derived bone formation and is activated through the release of key bone matrix proteins leading to opening of the blood-nerve barrier (BNB. One of the first steps in this process is the activation of a neuro-inflammatory cascade, which results in migration of chondro-osseous progenitors, and other cells from both the endoneurial and perineurial regions of the peripheral nerves. The perineurial cells undergo brown adipogenesis, to form essential support cells, which regulate expression and activation of matrix metallopeptidase 9 (MMP9 an essential regulatory protein involved in opening the BNB. However, recent studies suggest that, in mice, a key bone matrix protein, bone morphogenetic protein 2 (BMP2 is able to immediately cross the BNB to activate signaling in specific cells within the endoneurial compartment. BMP signaling correlates with bone formation and appears critical for the induction of HO. Surprisingly, several other bone matrix proteins have also been reported to regulate the BNB, leading us to question whether these matrix proteins are important in regulating the BNB. However, this temporary regulation of the BNB does not appear to result in degeneration of the peripheral nerve, but rather may represent one of the first steps in innervation of the newly forming bone.

Auditory agnosia.

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Slevc, L Robert; Shell, Alison R

2015-01-01

Auditory agnosia refers to impairments in sound perception and identification despite intact hearing, cognitive functioning, and language abilities (reading, writing, and speaking). Auditory agnosia can be general, affecting all types of sound perception, or can be (relatively) specific to a particular domain. Verbal auditory agnosia (also known as (pure) word deafness) refers to deficits specific to speech processing, environmental sound agnosia refers to difficulties confined to non-speech environmental sounds, and amusia refers to deficits confined to music. These deficits can be apperceptive, affecting basic perceptual processes, or associative, affecting the relation of a perceived auditory object to its meaning. This chapter discusses what is known about the behavioral symptoms and lesion correlates of these different types of auditory agnosia (focusing especially on verbal auditory agnosia), evidence for the role of a rapid temporal processing deficit in some aspects of auditory agnosia, and the few attempts to treat the perceptual deficits associated with auditory agnosia. A clear picture of auditory agnosia has been slow to emerge, hampered by the considerable heterogeneity in behavioral deficits, associated brain damage, and variable assessments across cases. Despite this lack of clarity, these striking deficits in complex sound processing continue to inform our understanding of auditory perception and cognition. © 2015 Elsevier B.V. All rights reserved.

Interdependency between mechanical parameters and afferent nerve discharge in remodeled diabetic Goto-Kakizaki rat intestine.

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Zhao, Jingbo; Yang, Jian; Liao, Donghua; Gregersen, Hans

2017-01-01

Gastrointestinal disorders are very common in diabetic patients, but the pathogenesis is still not well understood. Peripheral afferent nerves may be involved due to the complex regulation of gastrointestinal function by the enteric nervous system. We aimed to characterize the stimulus-response function of afferent fibers innervating the jejunum in the Goto-Kakizaki (GK) type 2 diabetic rat model. A key question is whether changes in afferent firing arise from remodeled tissue or from adaptive afferent processes. Seven 32-week-old male GK rats and seven age-matched normal Wistar rats were studied. Firing from mesenteric afferent nerves was recorded in excised jejunal segments of seven GK rats and seven normal Wistar rats during ramp test, stress relaxation test, and creep test. The circumferential stress-strain, spike rate increase ratio (SRIR), and single unit firing rates were calculated for evaluation of interdependency of the mechanical stimulations and the afferent nerve discharge. Elevated sensitivity to mechanical stimuli was found for diabetic nerve bundles and single unit activity ( P <0.05). The stress relaxed less in the diabetic intestinal segment ( P <0.05). Linear association between SRIR and the thickness of circumferential muscle layer was found at high stress levels as well as for SRIR and the glucose level. Altered viscoelastic properties and elevated mechanosensitivity were found in the GK rat intestine. The altered nerve signaling is related to muscle layer remodeling and glucose levels and may contribute to gastrointestinal symptoms experienced by diabetic patients.

Risk of Damage to the Somatic Innervation of the Penis during the AdVanceProcedure: An Anatomical Study.

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Hogewoning, Cornelis R C; Elzevier, Henk W; Pelger, Rob C M; Bekker, Milou D; DeRuiter, Marco C

2015-08-01

One of the methods to treat post radical prostatectomy stress urinary incontinence is the AdVance (American Medical Systems, Minnetonka, MN, USA) male sling procedure. During this procedure, the somatic innervation of the penis may be at risk for injury. Six AdVance procedures were performed in six donated bodies at the Anatomy and Embryology Department of the Leiden University Medical Centre. The pelves were dissected and the shortest distance between the sling and the dorsal nerve of the penis (DNP) was documented. The aim of this study was to describe the anatomical relation between the AdVance male sling and penile nerves based on the dissection of six adult male pelves. The AdVance male sling procedure was conducted in six donated male bodies. After placement, the pelves were dissected and the shortest distance between sling and the DNP was documented. The main outcome measure was the distance between the AdVance male sling and the DNP. The mean distance of the sling to the DNP was 4.1 mm and was found situated directly next to the nerve (distance 0 mm) in 4 out of 12 (33%) hemipelves. The distance of the sling to the obturator neurovascular bundle was 30 mm or more in all six bodies. Damage to the DNP caused by the AdVance male sling procedure appears to be an extremely rare complication, which has not been described in current literature. The proximity of the AdVance to the DNP could, however, pose a risk that should be taken into consideration by physicians and patients when opting for surgery. © 2015 International Society for Sexual Medicine.

Synaptic Plasticity in Cardiac Innervation and Its Potential Role in Atrial Fibrillation

OpenAIRE

Jesse L. Ashton; Rebecca A. B. Burton; Gil Bub; Bruce H. Smaill; Bruce H. Smaill; Johanna M. Montgomery

2018-01-01

Synaptic plasticity is defined as the ability of synapses to change their strength of transmission. Plasticity of synaptic connections in the brain is a major focus of neuroscience research, as it is the primary mechanism underpinning learning and memory. Beyond the brain however, plasticity in peripheral neurons is less well understood, particularly in the neurons innervating the heart. The atria receive rich innervation from the autonomic branch of the peripheral nervous system. Sympathetic...

Molecular cloning of a human gene that is a member of the nerve growth factor family

Energy Technology Data Exchange (ETDEWEB)

Jones, K.R.; Reichardt, L.F. (Howard Hughes Medical Institute, San Francisco, CA (USA))

1990-10-01

Cell death within the developing vertebrate nervous system is regulated in part by interactions between neurons and their innervation targets that are mediated by neurotrophic factors. These factors also appear to have a role in the maintenance of the adult nervous system. Two neurotrophic factors, nerve growth factor and brain-derived neurotrophic factor, share substantial amino acid sequence identity. The authors have used a screen that combines polymerase chain reaction amplification of genomic DNA and low-stringency hybridization with degenerate oligonucleotides to isolate human BDNF and a human gene, neurotrophin-3, that is closely related to both nerve growth factor and brain-derived neurotrophic factor. mRNA products of the brain-derived neurotrophic factor and neurotrophin-3 genes were detected in the adult human brain, suggesting that these proteins are involved in the maintenance of the adult nervous system. Neurotrophin-3 is also expected to function in embryonic neural development.

Repetitive trauma and nerve compression.

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Carragee, E J; Hentz, V R

1988-01-01

Repetitive movement of the upper extremity, whether recreational or occupational, may result in various neuropathies, the prototype of which is the median nerve neuropathic in the carpal canal. The pathophysiology of this process is incompletely understood but likely involves both mechanical and ischemic features. Experimentally increased pressures within the carpal canal produced reproducible progressive neuropathy. Changes in vibratory (threshold-type) sensibility appears to be more sensitive than two-point (innervation density-type) sensibility. The specific occupational etiologies of carpal neuropathy are obscured by methodologic and sociological difficulties, but clearly some occupations have high incidences of CTS. History and physical examination are usually sufficient for the diagnosis, but diagnostic assistance when required is available through electrophysiological testing, CT scanning, and possibly MRI. Each of these tests has limitations in both sensitivity and specificity. Treatment by usual conservative means should be combined with rest from possible provocative activities. Surgical release of the carpal canal is helpful in patients failing conservative therapy. Occupational modifications are important in both treatment and prevention of median neuropathy due to repetitive trauma.

Adipose-derived stromal cells enhance auditory neuron survival in an animal model of sensory hearing loss.

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Schendzielorz, Philipp; Vollmer, Maike; Rak, Kristen; Wiegner, Armin; Nada, Nashwa; Radeloff, Katrin; Hagen, Rudolf; Radeloff, Andreas

2017-10-01

A cochlear implant (CI) is an electronic prosthesis that can partially restore speech perception capabilities. Optimum information transfer from the cochlea to the central auditory system requires a proper functioning auditory nerve (AN) that is electrically stimulated by the device. In deafness, the lack of neurotrophic support, normally provided by the sensory cells of the inner ear, however, leads to gradual degeneration of auditory neurons with undesirable consequences for CI performance. We evaluated the potential of adipose-derived stromal cells (ASCs) that are known to produce neurotrophic factors to prevent neural degeneration in sensory hearing loss. For this, co-cultures of ASCs with auditory neurons have been studied, and autologous ASC transplantation has been performed in a guinea pig model of gentamicin-induced sensory hearing loss. In vitro ASCs were neuroprotective and considerably increased the neuritogenesis of auditory neurons. In vivo transplantation of ASCs into the scala tympani resulted in an enhanced survival of auditory neurons. Specifically, peripheral AN processes that are assumed to be the optimal activation site for CI stimulation and that are particularly vulnerable to hair cell loss showed a significantly higher survival rate in ASC-treated ears. ASC transplantation into the inner ear may restore neurotrophic support in sensory hearing loss and may help to improve CI performance by enhanced AN survival. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Auditory hair cell defects as potential cause for sensorineural deafness in Wolf-Hirschhorn syndrome

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Mohi Ahmed

2015-09-01

Full Text Available WHSC1 is a histone methyltransferase (HMT that catalyses the addition of methyl groups to lysine 36 on histone 3. In humans, WHSC1 haploinsufficiency is associated with all known cases of Wolf-Hirschhorn syndrome (WHS. The cardinal feature of WHS is a craniofacial dysmorphism, which is accompanied by sensorineural hearing loss in 15% of individuals with WHS. Here, we show that WHSC1-deficient mice display craniofacial defects that overlap with WHS, including cochlea anomalies. Although auditory hair cells are specified normally, their stereocilia hair bundles required for sound perception fail to develop the appropriate morphology. Furthermore, the orientation and cellular organisation of cochlear hair cells and their innervation are defective. These findings identify, for the first time, the likely cause of sensorineural hearing loss in individuals with WHS.

Auditory and audio-visual processing in patients with cochlear, auditory brainstem, and auditory midbrain implants: An EEG study.

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Schierholz, Irina; Finke, Mareike; Kral, Andrej; Büchner, Andreas; Rach, Stefan; Lenarz, Thomas; Dengler, Reinhard; Sandmann, Pascale

2017-04-01

There is substantial variability in speech recognition ability across patients with cochlear implants (CIs), auditory brainstem implants (ABIs), and auditory midbrain implants (AMIs). To better understand how this variability is related to central processing differences, the current electroencephalography (EEG) study compared hearing abilities and auditory-cortex activation in patients with electrical stimulation at different sites of the auditory pathway. Three different groups of patients with auditory implants (Hannover Medical School; ABI: n = 6, CI: n = 6; AMI: n = 2) performed a speeded response task and a speech recognition test with auditory, visual, and audio-visual stimuli. Behavioral performance and cortical processing of auditory and audio-visual stimuli were compared between groups. ABI and AMI patients showed prolonged response times on auditory and audio-visual stimuli compared with NH listeners and CI patients. This was confirmed by prolonged N1 latencies and reduced N1 amplitudes in ABI and AMI patients. However, patients with central auditory implants showed a remarkable gain in performance when visual and auditory input was combined, in both speech and non-speech conditions, which was reflected by a strong visual modulation of auditory-cortex activation in these individuals. In sum, the results suggest that the behavioral improvement for audio-visual conditions in central auditory implant patients is based on enhanced audio-visual interactions in the auditory cortex. Their findings may provide important implications for the optimization of electrical stimulation and rehabilitation strategies in patients with central auditory prostheses. Hum Brain Mapp 38:2206-2225, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Neurological complications in thyroid surgery: a surgical point of view on laryngeal nerves.

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EMANUELA eVARALDO

2014-07-01

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

Neuro-otological and peripheral nerve involvement in Fabry disease

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Sergio Carmona

2017-07-01

Full Text Available Fabry disease (FD is an X-linked lysosomal storage disease, with multisystemic glycosphingolipids deposits. Neuro-otological involvement leading to hearing loss and vestibular dysfunctions has been described, but there is limited information about the frequency, site of lesion, or the relationship with peripheral neuropathy. The aim was to evaluate the presence of auditory and vestibular symptoms, and assess neurophysiological involvement of the VIII cranial nerve, correlating these findings with clinical and neurophysiological features of peripheral neuropathy. We studied 36 patients with FD with a complete neurological and neuro-otological evaluation including nerve conduction studies, quantitative sensory testing (to evaluate small fiber by warm and cold threshold detection and cold and heat pain, vestibular evoked myogenic potentials, videonistagmography, audiometry and brainstem auditory evoked potentials. Neuro-otologic symptoms included hearing loss (22.2%, vertigo (27.8% or both (25%. An involvement of either cochlear or vestibular function was identified in most patients (75%. In 70% of our patients the involvement of both cochlear and vestibular function could not be explained by a neural or vascular mechanism. Small fiber neuropathy was identified in 77.7%. There were no significant associations between neurootological and QST abnormalities. Neuro-otologic involvement is frequent and most likely under-recognized in patients with FD. It lacks a specific neural or vascular pattern, suggesting multi-systemic, end organ damage. Small fiber neuropathy is an earlier manifestation of FD, but there is no correlation between the development of neuropathy and neuro-otological abnormalities.

Auditory Reserve and the Legacy of Auditory Experience

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Erika Skoe

2014-11-01

Full Text Available Musical training during childhood has been linked to more robust encoding of sound later in life. We take this as evidence for an auditory reserve: a mechanism by which individuals capitalize on earlier life experiences to promote auditory processing. We assert that early auditory experiences guide how the reserve develops and is maintained over the lifetime. Experiences that occur after childhood, or which are limited in nature, are theorized to affect the reserve, although their influence on sensory processing may be less long-lasting and may potentially fade over time if not repeated. This auditory reserve may help to explain individual differences in how individuals cope with auditory impoverishment or loss of sensorineural function.

Mechanism of sphingosine 1-phosphate- and lysophosphatidic Acid-induced up-regulation of adhesion molecules and eosinophil chemoattractant in nerve cells.

LENUS (Irish Health Repository)

Costello, Richard W

2012-02-01

The lysophospholipids sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) act via G-protein coupled receptors S1P(1-5) and LPA(1-3) respectively, and are implicated in allergy. Eosinophils accumulate at innervating cholinergic nerves in asthma and adhere to nerve cells via intercellular adhesion molecule-1 (ICAM-1). IMR-32 neuroblastoma cells were used as an in vitro cholinergic nerve cell model. The G(i) coupled receptors S1P(1), S1P(3), LPA(1), LPA(2) and LPA(3) were expressed on IMR-32 cells. Both S1P and LPA induced ERK phosphorylation and ERK- and G(i)-dependent up-regulation of ICAM-1 expression, with differing time courses. LPA also induced ERK- and G(i)-dependent up-regulation of the eosinophil chemoattractant, CCL-26. The eosinophil granule protein eosinophil peroxidase (EPO) induced ERK-dependent up-regulation of transcription of S1P(1), LPA(1), LPA(2) and LPA(3), providing the situation whereby eosinophil granule proteins may enhance S1P- and\\/or LPA- induced eosinophil accumulation at nerve cells in allergic conditions.

Mechanism of sphingosine 1-phosphate- and lysophosphatidic Acid-induced up-regulation of adhesion molecules and eosinophil chemoattractant in nerve cells.

LENUS (Irish Health Repository)

Costello, Richard W

2011-05-01

The lysophospholipids sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) act via G-protein coupled receptors S1P(1-5) and LPA(1-3) respectively, and are implicated in allergy. Eosinophils accumulate at innervating cholinergic nerves in asthma and adhere to nerve cells via intercellular adhesion molecule-1 (ICAM-1). IMR-32 neuroblastoma cells were used as an in vitro cholinergic nerve cell model. The G(i) coupled receptors S1P(1), S1P(3), LPA(1), LPA(2) and LPA(3) were expressed on IMR-32 cells. Both S1P and LPA induced ERK phosphorylation and ERK- and G(i)-dependent up-regulation of ICAM-1 expression, with differing time courses. LPA also induced ERK- and G(i)-dependent up-regulation of the eosinophil chemoattractant, CCL-26. The eosinophil granule protein eosinophil peroxidase (EPO) induced ERK-dependent up-regulation of transcription of S1P(1), LPA(1), LPA(2) and LPA(3), providing the situation whereby eosinophil granule proteins may enhance S1P- and\\/or LPA- induced eosinophil accumulation at nerve cells in allergic conditions.

Inhibition of Parkinsonian tremor with cutaneous afferent evoked by transcutaneous electrical nerve stimulation.

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Hao, Man-Zhao; Xu, Shao-Qin; Hu, Zi-Xiang; Xu, Fu-Liang; Niu, Chuan-Xin M; Xiao, Qin; Lan, Ning