Soleus and Tibialis Anterior EMG Activity During Locomotion Before and After Sciatic Nerve Transection

Application of chondroitinase ABC (ChABC) to injured peripheral nerves improves axon regeneration, but it is not known whether functional recovery is also improved. Recordings of EMG activity [soleus (Sol) M response and H reflexes] evoked by nerve stimulation and of Sol and tibialis anterior (TA) EMG activity and hindlimb and foot kinematics during slope walking were made to determine whether ChABC treatment of the sciatic nerve at the time of transection improves functional recovery. Recovery of evoked EMG responses began as multiple small responses with a wide range of latencies that eventually coalesced into one or two more distinctive and consistent responses (the putative M response and the putative H reflex) in both groups. Both the initial evoked responses and the time course of their maturation returned sooner in the ChABC group than in the untreated (UT) group. The reinnervated Sol and TA were coactivated during treadmill locomotion during downslope, level, and upslope walking throughout the study period in both UT and ChABC-treated rats. By 10 wk after nerve transection and repair, locomotor activity in Sol, but not TA, had returned to its pretransection pattern. There was an increased reliance on central control of Sol activation across slopes for both groups as interpreted from elevated prestance Sol EMG activity that was no longer modulated with slope. Limb length and orientation during locomotion were similar to those observed prior to nerve injury during upslope walking only in the ChABC-treated rats. Thus treatment of cut nerves with ChABC leads to improvements in functional recovery.

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Altered expression of myosin mRNA and protein in rat soleus and tibialis anterior following reinnervation

AJP Cell Physiology ◽

10.1152/ajpcell.1996.271.6.c2016 ◽

1996 ◽

Vol 271 (6) ◽

pp. C2016-C2026 ◽

Cited By ~ 11

Author(s):

K. A. Huey ◽

S. C. Bodine

Keyword(s):

Sciatic Nerve ◽

Tibialis Anterior ◽

Mrna Level ◽

Ribonuclease Protection Assay ◽

Sciatic Nerve Crush ◽

Nerve Transection ◽

Nerve Crush ◽

Altered Expression ◽

Sciatic Nerve Transection ◽

Mhc Iib

Myosin heavy chain (MHC) expression was studied in rat soleus and tibialis anterior (TA) at the mRNA and protein levels following reinnervation 8 and 32 wk after sciatic nerve injury. A sciatic nerve crush or transection injury was produced in the midthigh region of adult female Sprague-Dawley rats. A ribonuclease protection assay was developed to measure four of the adult MHCs (I, IIa, IIx, IIb) in a single sample. MHC mRNA and protein were measured and compared in the same muscles. Eight and thirty-two weeks after a crush injury, the MHC mRNA profiles were similar to control with the exception of soleus MHC IIa and TA MHC IIb, which were significantly less than control at both time points. In contrast, reinnervation of the soleus following a sciatic nerve transection injury resulted in an MHC isoform shift characterized by increases in the relative amounts of fast myosin (IIa and IIx) and a decrease in slow myosin. As expected, significant changes first occurred at the mRNA level followed by changes in protein expression. Thirty-two weeks after transection injury and repair, the primary MHC mRNA isoform in the soleus was MHC IIx. Moreover, at 32 wk, MHC IIb mRNA was detected in 50% of the reinnervated soleus following a transection injury. Reinnervation of the TA following sciatic nerve transection led to replacement of the MHC IIb isoform with MHC IIx.

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Effects of treadmill training on functional recovery following peripheral nerve injury in rats

Journal of Neurophysiology ◽

10.1152/jn.00946.2012 ◽

2013 ◽

Vol 109 (11) ◽

pp. 2645-2657 ◽

Cited By ~ 35

Author(s):

Tiffany Boeltz ◽

Meredith Ireland ◽

Kristin Mathis ◽

Jennifer Nicolini ◽

Karen Poplavski ◽

...

Keyword(s):

Sciatic Nerve ◽

Nerve Injury ◽

Functional Recovery ◽

Tibialis Anterior ◽

Axon Regeneration ◽

Treadmill Training ◽

Female Rats ◽

Nerve Transection ◽

Sciatic Nerve Transection ◽

Daily Exercise

Exercise, in the form of moderate daily treadmill training following nerve transection and repair leads to enhanced axon regeneration, but its effect on functional recovery is less well known. Female rats were exercised by walking continuously, at a slow speed (10 m/min), for 1 h/day on a level treadmill, beginning 3 days after unilateral transection and surgical repair of the sciatic nerve, and conducted 5 days/wk for 2 wk. In Trained rats, both direct muscle responses to tibial nerve stimulation and H reflexes in soleus reappeared earlier and increased in amplitude more rapidly over time than in Untrained rats. The efficacy of the restored H reflex was greater in Trained rats than in Untrained controls. The reinnervated tibialis anterior and soleus were coactivated during treadmill locomotion in Untrained rats. In Trained animals, the pattern of activation of soleus, but not tibialis anterior, was not significantly different from that found in Intact rats. The overall length of the hindlimb during level and up- and downslope locomotion was conserved after nerve injury in both groups. This conservation was achieved by changes in limb orientation. Limb length was conserved effectively in all rats during downslope walking but only in Trained rats during level and upslope walking. Moderate daily exercise applied immediately after sciatic nerve transection is sufficient to promote axon regeneration, to restore muscle reflexes, and to improve the ability of rats to cope with different biomechanical demands of slope walking.

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Recovery of Electromyographic Activity After Transection and Surgical Repair of the Rat Sciatic Nerve

Journal of Neurophysiology ◽

10.1152/jn.01035.2006 ◽

2007 ◽

Vol 97 (2) ◽

pp. 1127-1134 ◽

Cited By ~ 29

Author(s):

Arthur W. English ◽

Yi Chen ◽

Jonathan S. Carp ◽

Jonathan R. Wolpaw ◽

Xiang Yang Chen

Keyword(s):

Sciatic Nerve ◽

Surgical Repair ◽

Tibial Nerve ◽

Emg Activity ◽

Electromyographic Activity ◽

Nerve Transection ◽

Posterior Tibial Nerve Stimulation ◽

Sciatic Nerve Transection ◽

Posterior Tibial ◽

Tibial Nerve Stimulation

The recovery of soleus (SOL), gastrocnemius (GAS), and tibialis anterior (TA) electromyographic activity (EMG) after transection and surgical repair of the sciatic nerve was studied in Sprague–Dawley rats using chronically implanted stimulation and recording electrodes. Spontaneous EMG activity in SOL and GAS and direct muscle (M) responses to posterior tibial nerve stimulation persisted for ≤2 days after sciatic nerve transection, but SOL and GAS H-reflexes disappeared immediately. Spontaneous EMG activity began to return 2–3 wk after transection, rose nearly to pretransection levels by 60 days, and persisted for the duration of the study period (120 days). Recovery of stimulus-evoked EMG responses began about 30 days after sciatic nerve transection as multiple small responses with a wide range of latencies. Over time, the latencies of these fractionated responses shortened, their amplitudes increased, and they merged into a distinct short-latency component (the putative M response) and a distinct long-latency component (the putative H-reflex). The extent of recovery of stimulation-evoked EMG was modest: even 100 days after sciatic nerve transection, the responses were still much smaller than those before transection. Similar gradual development of responses to posterior tibial nerve stimulation was also seen in TA, suggesting that some regenerating fibers sent branches into both tibial and common peroneal nerves.

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Faculty Opinions recommendation of Sciatic nerve transection triggers release and intercellular transfer of a genetically expressed macromolecular tracer in dorsal root ganglia.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13396998.14765124 ◽

2011 ◽

Author(s):

Michael Andresen ◽

Tally Largent-Milnes

Keyword(s):

Sciatic Nerve ◽

Dorsal Root Ganglia ◽

Dorsal Root ◽

Nerve Transection ◽

Sciatic Nerve Transection ◽

Intercellular Transfer

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Effects of Taxol on Regeneration in a Rat Sciatic Nerve Transection Model

Scientific Reports ◽

10.1038/srep42280 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 8

Author(s):

Shih-Tien Hsu ◽

Chun-Hsu Yao ◽

Yuan-Man Hsu ◽

Jia-Horng Lin ◽

Yung-Hsiang Chen ◽

...

Keyword(s):

Growth Factors ◽

Sciatic Nerve ◽

Peripheral Nerve ◽

Nerve Regeneration ◽

Nerve Transection ◽

Cremophor El ◽

Neuronal Connectivity ◽

Sciatic Nerve Transection ◽

Expression Levels ◽

Nerve Growth Factors

Abstract Recent studies describe taxol as a candidate treatment for promoting central nerve regeneration. However, taxol has serious side effects including peripheral neurotoxicity, and little information is known about the effect of taxol on peripheral nerve regeneration. We investigated the effects of taxol on regeneration in a rat sciatic nerve transection model. Rats were divided into four groups (n = 10): normal saline (i.p.) as the control, Cremophor EL vehicle, and 2 or 6 mg/kg of taxol in the Cremophor EL solution (four times in day-2, 4, 6, and 8), respectively. We evaluated neuronal electrophysiology, animal behaviour, neuronal connectivity, macrophage infiltration, location and expression levels of calcitonin gene-related peptide (CGRP), and expression levels of both nerve growth factors and immunoregulatory factors. In the high-dose taxol group (6 mg/kg), neuronal electrophysiological function was significantly impaired. Licking latencies were significantly changed while motor coordination was unaffected. Neuronal connectivity, macrophage density, and expression levels of CGRP was dramatically reduced. Expression levels of nerve growth factors and immunoregulatory factors was also reduced, while it was increased in the low-dose taxol group (2 mg/kg). These results indicate that taxol can modulate local inflammatory conditions, impair nerve regeneration, and impede recovery of a severe peripheral nerve injury.

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