Is Increased Voluntary Motor Activity Beneficial or Detrimental During the Period of Motor Nerve Regeneration/Reinnervation?

1996 ◽  
Vol 21 (3) ◽  
pp. 218-224 ◽  
Author(s):  
Martine Soucy ◽  
Kevin Seburn ◽  
Phillip Gardiner
Keyword(s):  
Daily Activity ◽  
Axon Regeneration ◽  
Motor Nerve ◽  
Nerve Crush ◽  
Lateral Gastrocnemius ◽  
Regeneration Rate ◽  
Voluntary Motor Activity ◽  
Increased Activity ◽  
Key Words Exercise Training ◽  
Voluntary Wheel

A model of partial denervation of the rat lateral gastrocnemius was used to investigate the effects of daily activity (treadmill plus voluntary wheel exercise) on the regeneration/reinnervation of motoneurons recovering from nerve crush. It appears that increased activity has no effect on axon regeneration rate, but may be detrimental to the reinnervation process. Key words: exercise, training, denervation, motoneuron, axotomie

Muscle-derived GDNF facilitates motor nerve recovery following sciatic nerve crush injury

2007 ◽  
Vol 205 (3) ◽  
pp. S92
Author(s):  
Terence M. Myckatyn ◽  
Christina Kenney ◽  
Alice Tong ◽  
Jessica Duan ◽  
Daniel Hunter ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Motor Nerve ◽  
Crush Injury ◽  
Sciatic Nerve Crush ◽  
Nerve Crush ◽  
Nerve Recovery ◽  
Nerve Crush Injury

Homosynaptic depression and transmitter turnover in spinal monosynaptic pathway

1977 ◽  
Vol 40 (1) ◽  
pp. 95-105 ◽  
Author(s):  
R. Capek ◽  
B. Esplin
Keyword(s):  
Transmitter Release ◽  
Motor Nerve ◽  
Drug Effects ◽  
Medial Gastrocnemius ◽  
Lateral Gastrocnemius ◽  
Homosynaptic Depression ◽  
Dorsal Root Reflex ◽  
Frequency Of Stimulation ◽  
Fractional Release ◽  
Stimulation Of

1. The transmission in the spinal monosynaptic pathway was studied during repetitive stimulation of a motor nerve by 10 stimuli at 2, 5, or 10 Hz in spinal cats. Initially, the amplitudes of the monosynaptic responses rapidly declined, reaching a plateau after a few stimuli. The level of the plateau was inversely related to the frequency of stimulation. 2. This depression of monosynaptic response was seen only when the same pathway was stimulated; the response elicited from the lateral gastrocnemius was not depressed when preceded by stimulation of the medial gastrocnemius nerve and vice versa. Pretreatment with semicarbazide left the homosynaptic depression unchanged while suppressing the dorsal root reflex. The participation of a depolarization of primary afferents in the described depression is, therefore, unlikely. 3. The decrease of transmitter release by successive volleys, which is the cause of the observed depression, could conceivably be related to the depletion of transmitter stores. 4. A procedure is described, based on this assumption, which allows the calculation of transmitter turnover. The input-output relation in the spinal monosynaptic pathway is used to convert the amplitudes of monosynaptic responses to the amounts of transmitter, both relative to the maximum response. The changes of transmitter release are analyzed under the assumption that each volley releases instantaneously a constant fraction of the transmitter store available for release and that this store is replenished at a constant fraction of the depleted part per second. 5. The values of fractional release per volley were about 0.4, irrespective of frequency of stimulation. 6. The values of fractional replenishment per second ranged from about 1 to 5 on the average, depending directly on the frequency of stimulation. 7. It is suggested that the described procedure might be useful in analyzing drug effects on synaptic transmission.

Inhibition of miR-21 ameliorates excessive astrocyte activation and promotes axon regeneration following optic nerve crush

2018 ◽  
Vol 137 ◽  
pp. 33-49 ◽  
Author(s):  
Hong-Jiang Li ◽  
Yuan-Bo Pan ◽  
Zhao-Liang Sun ◽  
Yi-Yu Sun ◽  
Xi-Tao Yang ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Axon Regeneration ◽  
Optic Nerve Crush ◽  
Astrocyte Activation ◽  
Nerve Crush

Respiratory motor nerve activities during spontaneous bladder contractions

1994 ◽  
Vol 77 (3) ◽  
pp. 1349-1354 ◽  
Author(s):  
M. J. Gdovin ◽  
S. L. Knuth ◽  
D. Bartlett
Keyword(s):  
Hypoglossal Nerve ◽  
Motor Nerve ◽  
Upper Airway ◽  
Respiratory Response ◽  
Airway Patency ◽  
Pelvic Nerves ◽  
Initial Decrease ◽  
Posterior Cricoarytenoid ◽  
Increased Activity ◽  
Nerve Discharge

We monitored spontaneous bladder contractions (SBCs) in decerebrate vagotomized paralyzed ventilated cats while recording respiratory motor nerve activities and intravesical pressure under isovolumetric conditions. Phrenic nerve discharge diminished during SBCs, as did the activities of the hypoglossal nerve, the nasolabial branch of the facial nerve, and inspiratory (posterior cricoarytenoid) and expiratory (thyroarytenoid) branches of the recurrent laryngeal nerve. Hypoglossal activity was most strikingly reduced during SBCs, disappearing completely in some animals. The triangularis sterni nerve exhibited an initial decrease, followed by an increase in activity during SBCs, whereas the cranial iliohypogastric nerve showed increased activity. The changes in nerve activities during SBCs could also be elicited by passive distension of the bladder and were abolished by bilateral section of the pelvic nerves. These findings extend the understanding of reflexes originating from the urinary bladder to include a coordinated respiratory response and suggest that these reflexes may compromise upper airway patency under some conditions.

scholarly journals Peroneal motor nerve crush injury and hyperbaric oxygen effect

1995 ◽  
Vol 105 (10) ◽  
pp. 1061-1065 ◽  
Author(s):  
Perry M. Santos ◽  
Sherri L. Williams ◽  
James Covey
Keyword(s):  
Hyperbaric Oxygen ◽  
Motor Nerve ◽  
Crush Injury ◽  
Oxygen Effect ◽  
Nerve Crush ◽  
Nerve Crush Injury

scholarly journals Promoting axon regeneration in the adult CNS by modulation of the melanopsin/GPCR signaling

2016 ◽  
Vol 113 (7) ◽  
pp. 1937-1942 ◽  
Author(s):  
Songshan Li ◽  
Chao Yang ◽  
Li Zhang ◽  
Xin Gao ◽  
Xuejie Wang ◽  
...  
Keyword(s):  
Axonal Regeneration ◽  
Axon Regeneration ◽  
Ganglion Cells ◽  
Mammalian Target Of Rapamycin ◽  
Light Response ◽  
Cns Injury ◽  
Nerve Crush ◽  
Gpcr Signaling ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog

Cell-type–specific G protein-coupled receptor (GPCR) signaling regulates distinct neuronal responses to various stimuli and is essential for axon guidance and targeting during development. However, its function in axonal regeneration in the mature CNS remains elusive. We found that subtypes of intrinsically photosensitive retinal ganglion cells (ipRGCs) in mice maintained high mammalian target of rapamycin (mTOR) levels after axotomy and that the light-sensitive GPCR melanopsin mediated this sustained expression. Melanopsin overexpression in the RGCs stimulated axonal regeneration after optic nerve crush by up-regulating mTOR complex 1 (mTORC1). The extent of the regeneration was comparable to that observed after phosphatase and tensin homolog (Pten) knockdown. Both the axon regeneration and mTOR activity that were enhanced by melanopsin required light stimulation and Gq/11 signaling. Specifically, activating Gq in RGCs elevated mTOR activation and promoted axonal regeneration. Melanopsin overexpression in RGCs enhanced the amplitude and duration of their light response, and silencing them with Kir2.1 significantly suppressed the increased mTOR signaling and axon regeneration that were induced by melanopsin. Thus, our results provide a strategy to promote axon regeneration after CNS injury by modulating neuronal activity through GPCR signaling.

scholarly journals Distribution of Mesenchymal Stem Cells and Effects on Neuronal Survival and Axon Regeneration after Optic Nerve Crush and Cell Therapy

PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e110722 ◽  
Author(s):  
Louise Alessandra Mesentier-Louro ◽  
Camila Zaverucha-do-Valle ◽  
Almir Jordão da Silva-Junior ◽  
Gabriel Nascimento-dos-Santos ◽  
Fernanda Gubert ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Optic Nerve ◽  
Cell Therapy ◽  
Axon Regeneration ◽  
Neuronal Survival ◽  
Optic Nerve Crush ◽  
Nerve Crush
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