The action of ultrasound on peripheral nerve fibers and nerve endings

1961 ◽  
Vol 50 (6) ◽  
pp. 1331-1334 ◽  
Author(s):  
V. K. Voskoboinikov
Keyword(s):  
Peripheral Nerve ◽  
Nerve Fibers ◽  
Nerve Endings

Electrophysiological Evidence for Tetrodotoxin-Resistant Sodium Channels in Slowly Conducting Dural Sensory Fibers

1999 ◽  
Vol 81 (2) ◽  
pp. 413-424 ◽  
Author(s):  
A. M. Strassman ◽  
S. A. Raymond
Keyword(s):  
Peripheral Nerve ◽  
Sodium Channel ◽  
Sodium Channels ◽  
Sensory Neurons ◽  
Nerve Fibers ◽  
Nerve Endings ◽  
Complete Suppression ◽  
Axonal Membrane ◽  
Electrophysiological Evidence ◽  
Significant Difference

Electrophysiological evidence for tetrodotoxin-resistant sodium channels in mechanosensitive nerve endings of slowly conducting fibers in the intracranial dura. A tetrodotoxin (TTX)-resistant sodium channel was recently identified that is expressed only in small diameter neurons of peripheral sensory ganglia. The peripheral axons of sensory neurons appear to lack this channel, but its presence has not been investigated in peripheral nerve endings, the site of sensory transduction in vivo. We investigated the effect of TTX on mechanoresponsiveness in nerve endings of sensory neurons that innervate the intracranial dura. Because the degree of TTX resistance of axonal branches could potentially be affected by factors other than channel subtype, the neurons were also tested for sensitivity to lidocaine, which blocks both TTX-sensitive and TTX-resistant sodium channels. Single-unit activity was recorded from dural afferent neurons in the trigeminal ganglion of urethan-anesthetized rats. Response thresholds to mechanical stimulation of the dura were determined with von Frey monofilaments while exposing the dura to progressively increasing concentrations of TTX or lidocaine. Neurons with slowly conducting axons were relatively resistant to TTX. Application of 1 μM TTX produced complete suppression of mechanoresponsiveness in all (11/11) fast A-δ units [conduction velocity (c.v.) 5–18 m/s] but only 50% (5/10) of slow A-δ units (1.5 <c.v.<5 m/s) and 13% (2/15) of C units (c.v. ≤1.5 m/s). The mean TTX concentration that produced complete suppression of mechanoresponsiveness was ∼270-fold higher in C units than in fast A-δ units. In contrast, no significant difference was found between C and A-δ units in the concentration of lidocaine required for complete suppression of mechanoresponsiveness, indicating that the greater TTX resistance of mechanoresponsiveness in C units is not attributable to differences in safety factor unrelated to channel subtype. These data offer indirect evidence that a TTX-resistant channel subtype is expressed in the terminal axonal branches of many of the more slowly conducting (C and slow A-δ) dural afferents. The channel appears to be present in these fibers, but not in the faster A-δ fibers, in sufficient numbers to support the initiation and propagation of mechanically induced impulses. Comparison with previous data on the absence of TTX resistance in peripheral nerve fibers suggests that the TTX-resistant sodium channel may be a distinctive feature of the receptive rather than the conductive portion of the sensory neuron’s axonal membrane.

scholarly journals Malignant Peripheral Nerve Sheath Tumor in the Nasal Cavity of a Neonate: A Case Report

2021 ◽  
pp. 014556132110141
Author(s):  
Xiufang Chi ◽  
Yue Wang ◽  
Haoming Yang ◽  
Cheng Xing ◽  
Jiamin Gan ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Peripheral Nerve ◽  
Nasal Cavity ◽  
Nerve Fibers ◽  
Nerve Sheath Tumor ◽  
Rare Tumor ◽  
Nasal Mass ◽  
Peripheral Nerve Sheath Tumor ◽  
Related Literature ◽  
Nerve Sheath

Malignant peripheral nerve sheath tumor (MPNST) is a rare tumor that can develop on the lining of nerves and within the network of nerve fibers in different organs, and it is commonly found in the head and neck, limbs, and trunk. These tumors can occur in patients of any age. They most commonly occur in adults aged 20 to 50 years; however, fewer cases of this tumor in children have been reported. To date, no neonatal case of MPNST in the nasal cavity has been reported. Here, we report the case of a 4-day-old female newborn who presented with a nasal mass that re-enlarged after surgery and was diagnosed as MPNST of the nasal cavity on the basis of pathological results. This is the first report of MPNST in the nasal cavity of a neonate. Differential diagnosis and treatment of nasal masses have been proposed in the related literature.

scholarly journals Bone marrow mesenchymal stem cell-derived exosome uptake and retrograde transport can occur at peripheral nerve endings

2019 ◽  
Vol 47 (1) ◽  
pp. 2918-2929 ◽  
Author(s):  
Rui Ren ◽  
Xiao-Hong Tan ◽  
Jiu-Hong Zhao ◽  
Quan-Peng Zhang ◽  
Xian-Fang Zhang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Peripheral Nerve ◽  
Retrograde Transport ◽  
Nerve Endings

scholarly journals Fast-spiking GABA circuit dynamics in the auditory cortex predict recovery of sensory processing following peripheral nerve damage

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jennifer Resnik ◽  
Daniel B Polley
Keyword(s):  
Peripheral Nerve ◽  
Auditory Cortex ◽  
Sensory Processing ◽  
Cortical Neurons ◽  
Sensory Nerve ◽  
Intracortical Inhibition ◽  
Nerve Fibers ◽  
Nerve Damage ◽  
Inhibitory Neurons ◽  
Sound Processing

Cortical neurons remap their receptive fields and rescale sensitivity to spared peripheral inputs following sensory nerve damage. To address how these plasticity processes are coordinated over the course of functional recovery, we tracked receptive field reorganization, spontaneous activity, and response gain from individual principal neurons in the adult mouse auditory cortex over a 50-day period surrounding either moderate or massive auditory nerve damage. We related the day-by-day recovery of sound processing to dynamic changes in the strength of intracortical inhibition from parvalbumin-expressing (PV) inhibitory neurons. Whereas the status of brainstem-evoked potentials did not predict the recovery of sensory responses to surviving nerve fibers, homeostatic adjustments in PV-mediated inhibition during the first days following injury could predict the eventual recovery of cortical sound processing weeks later. These findings underscore the potential importance of self-regulated inhibitory dynamics for the restoration of sensory processing in excitatory neurons following peripheral nerve injuries.

scholarly journals Muscle graft as a substitute for peripheral nerve graft in rats

2009 ◽  
Vol 24 (3) ◽  
pp. 221-225 ◽  
Author(s):  
Aristides Palhares ◽  
Fausto Viterbo ◽  
Ricardo Galesso Cardoso
Keyword(s):  
Peripheral Nerve ◽  
Nerve Injury ◽  
Nerve Fibers ◽  
Nerve Graft ◽  
Muscle Graft ◽  
Nerve Grafts ◽  
Peripheral Nerve Graft ◽  
Histological Appearance ◽  
Almost All

PURPOSE: To evaluate the applicability of the use of autogenous muscle treated in various ways, as a substitute of the nerve grafts. METHODS: Rats were divided into seven groups that received, as a treatment for a standard nerve injury, the following types of grafts: fresh muscle, muscle fixed with 10% formaldehyde, muscle frozen in a freezer, muscle frozen in refrigerator, nerveless muscle, peripheral nerve and a group was without any treatment. It assessed the histological appearance of the nerve fibers in the segment repaired. RESULTS: The evaluation of the segment nervous repaired showed nerve fibers through the graft in almost all groups, but the methodology employed has not adequately characterized the differences between the groups. CONCLUSION: This study showed the migration of nerves fibers through all grafts used.

scholarly journals 4.7-T diffusion tensor imaging of acute traumatic peripheral nerve injury

2015 ◽  
Vol 39 (3) ◽  
pp. E9 ◽  
Author(s):  
Richard B. Boyer ◽  
Nathaniel D. Kelm ◽  
D. Colton Riley ◽  
Kevin W. Sexton ◽  
Alonda C. Pollins ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Diffusion Tensor ◽  
Ex Vivo ◽  
Nerve Fibers ◽  
Nerve Transection ◽  
Nerve Injuries

Diagnosis and management of peripheral nerve injury is complicated by the inability to assess microstructural features of injured nerve fibers via clinical examination and electrophysiology. Diffusion tensor imaging (DTI) has been shown to accurately detect nerve injury and regeneration in crush models of peripheral nerve injury, but no prior studies have been conducted on nerve transection, a surgical emergency that can lead to permanent weakness or paralysis. Acute sciatic nerve injuries were performed microsurgically to produce multiple grades of nerve transection in rats that were harvested 1 hour after surgery. High-resolution diffusion tensor images from ex vivo sciatic nerves were obtained using diffusion-weighted spin-echo acquisitions at 4.7 T. Fractional anisotropy was significantly reduced at the injury sites of transected rats compared with sham rats. Additionally, minor eigenvalues and radial diffusivity were profoundly elevated at all injury sites and were negatively correlated to the degree of injury. Diffusion tensor tractography showed discontinuities at all injury sites and significantly reduced continuous tract counts. These findings demonstrate that high-resolution DTI is a promising tool for acute diagnosis and grading of traumatic peripheral nerve injuries.

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