Effect of changes in extracellular ionic medium on equilibrium potentials of the extrasynaptic membrane of denervated muscle

1969 ◽  
Vol 3 (4) ◽  
pp. 1-4
Author(s):  
L. G. Magazanik ◽  
T. V. Potapova
Keyword(s):  
Denervated Muscle ◽  
Ionic Medium ◽  
Extrasynaptic Membrane

Human motor endplate remodeling after traumatic nerve injury

2020 ◽  
pp. 1-8
Author(s):  
Ranjan Gupta ◽  
Justin P. Chan ◽  
Jennifer Uong ◽  
Winnie A. Palispis ◽  
David J. Wright ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Injury ◽  
Surgical Intervention ◽  
Linear Regression Analysis ◽  
Motor Endplate ◽  
Nerve Injuries ◽  
Denervated Muscle ◽  
Sequence Of Events ◽  
Human Motor ◽  
Denervated Muscles

OBJECTIVECurrent management of traumatic peripheral nerve injuries is variable with operative decisions based on assumptions that irreversible degeneration of the human motor endplate (MEP) follows prolonged denervation and precludes reinnervation. However, the mechanism and time course of MEP changes after human peripheral nerve injury have not been investigated. Consequently, there are no objective measures by which to determine the probability of spontaneous recovery and the optimal timing of surgical intervention. To improve guidance for such decisions, the aim of this study was to characterize morphological changes at the human MEP following traumatic nerve injury.METHODSA prospective cohort (here analyzed retrospectively) of 18 patients with traumatic brachial plexus and axillary nerve injuries underwent biopsy of denervated muscles from the upper extremity from 3 days to 6 years after injury. Muscle specimens were processed for H & E staining and immunohistochemistry, with visualization via confocal and two-photon excitation microscopy.RESULTSImmunohistochemical analysis demonstrated varying degrees of fragmentation and acetylcholine receptor dispersion in denervated muscles. Comparison of denervated muscles at different times postinjury revealed progressively increasing degeneration. Linear regression analysis of 3D reconstructions revealed significant linear decreases in MEP volume (R = −0.92, R2 = 0.85, p = 0.001) and surface area (R = −0.75, R2 = 0.56, p = 0.032) as deltoid muscle denervation time increased. Surprisingly, innervated and structurally intact MEPs persisted in denervated muscle specimens from multiple patients 6 or more months after nerve injury, including 2 patients who had presented > 3 years after nerve injury.CONCLUSIONSThis study details novel and critically important data about the morphology and temporal sequence of events involved in human MEP degradation after traumatic nerve injuries. Surprisingly, human MEPs not only persisted, but also retained their structures beyond the assumed 6-month window for therapeutic surgical intervention based on previous clinical studies. Preoperative muscle biopsy in patients being considered for nerve transfer may be a useful prognostic tool to determine MEP viability in denervated muscle, with surviving MEPs also being targets for adjuvant therapy.

Adrenalectomy eliminates both fiber-type differences and starvation effects on denervated muscle

1988 ◽  
Vol 255 (6) ◽  
pp. E850-E856 ◽  
Author(s):  
R. R. Almon ◽  
D. C. Dubois
Keyword(s):  
Muscle Mass ◽  
Extensor Digitorum Longus ◽  
Fiber Type ◽  
Sprague Dawley ◽  
Denervated Muscle ◽  
Adrenalectomized Animal ◽  
Sprague Dawley Rats ◽  
Starvation Effects ◽  
The Difference ◽  
Denervated Muscles

This report describes changes in muscle mass of innervated and denervated pairs of muscles taken from intact and adrenalectomized 250-g male Sprague-Dawley rats provided with different diets. Diets ranged from a nutritionally complete liquid diet to starvation (water only). In the intact animals, muscles with a more tonic character (soleus) are less sensitive to starvation than are muscles with a more phasic character (extensor digitorum longus), whereas the opposite is true of denervation. In the intact animals, starvation greatly increased the amount of atrophy following denervation. In the adrenalectomized animals, starvation had no effect on the amounts of atrophy following denervation. Furthermore, adrenalectomy virtually eliminated the fiber-type differences in the amount of atrophy following denervation. In addition, a comparison between denervated muscles from intact animals and adrenalectomized animals subjected to starvation demonstrates that all denervated muscles from the adrenalectomized animals atrophy less. Finally, it was observed that although an adrenalectomized animal can tolerate 6 days of starvation, an adrenalectomized-castrated animal cannot tolerate even short periods of starvation. The difference appears to be due to low amounts of corticosterone of testicular origin.

Revision Targeted Muscle Reinnervation Improves Secondary Pain Insult in an Upper Extremity Amputee: A Case Report

Hand ◽  
2021 ◽  
pp. 155894472199246
Author(s):  
David D. Rivedal ◽  
Meng Guo ◽  
James Sanger ◽  
Aaron Morgan
Keyword(s):  
Neuropathic Pain ◽  
Peripheral Nerves ◽  
Nerve Biopsy ◽  
Sensory Cortex ◽  
Denervated Muscle ◽  
Unique Case ◽  
Targeted Muscle Reinnervation ◽  
Muscle Reinnervation ◽  
And Function ◽  
The Brain

Targeted muscle reinnervation (TMR) has been shown to improve phantom and neuropathic pain in both the acute and chronic amputee population. Through rerouting of major peripheral nerves into a newly denervated muscle, TMR harnesses the plasticity of the brain, helping to revert the sensory cortex back toward the preinsult state, effectively reducing pain. We highlight a unique case of an above-elbow amputee for sarcoma who was initially treated with successful transhumeral TMR. Following inadvertent nerve biopsy of a TMR coaptation site, his pain returned, and he was unable to don his prosthetic. Revision of his TMR to a more proximal level was performed, providing improved pain and function of the amputated arm. This is the first report to highlight the concept of secondary neuroplasticity and successful proximal TMR revision in the setting of multiple insults to the same extremity.

Recovery of Tetanic Contractility of Denervated Muscle: A Step Toward a Walking Aid for Foot Drop

2013 ◽  
Author(s):  
A. Marcante ◽  
R. Zanato ◽  
M. Ferrero ◽  
S. Zampieri ◽  
H. Kern ◽  
...  
Keyword(s):  
Foot Drop ◽  
Denervated Muscle ◽  
Walking Aid

Preservation of Denervated Muscle by Sensory Protection in Rats

1997 ◽  
Vol 13 (05) ◽  
pp. 337-343 ◽  
Author(s):  
Nicolas Hynes ◽  
James Bain ◽  
Achilleas Thoma ◽  
Karen Veltri ◽  
John Maguire
Keyword(s):  
Denervated Muscle

The Effects of Electrical Stimulation on Denervated Muscle Using Implantable Electrodes

1988 ◽  
Vol 4 (04) ◽  
pp. 251-255 ◽  
Author(s):  
Koichi Nemoto ◽  
H. Williams ◽  
Keiko Nemoto ◽  
John Lough ◽  
R. Chiu
Keyword(s):  
Electrical Stimulation ◽  
Denervated Muscle ◽  
Implantable Electrodes

Equilibrium potentials of postsynaptic membrane activated by various cholinomimetics during changes in extracellular ionic medium

1969 ◽  
Vol 3 (3) ◽  
pp. 41-50
Author(s):  
V. L. Dunin-Barkovskii ◽  
S. A. Kovalev ◽  
L. G. Magazanik ◽  
T. V. Potapova ◽  
L. M. Chailakhyan
Keyword(s):  
Postsynaptic Membrane ◽  
Ionic Medium
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