| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Physiology, Université de Montréal, Montreal, Quebec, Canada
Submitted 10 March 2005; accepted in final form 17 June 2005
We used microwire electrodes chronically implanted into the hindlimb representation of the motor cortex as well as into the pyramidal tract to test the hypothesis that the corticospinal system contributes to the locomotor plasticity that is observed after cutaneous denervation of the cat hindpaw. A total of 23 electrodes implanted into the motor cortex in three cats trained to walk on a treadmill produced phase-dependent, short-latency, twitch responses in hindlimb flexor and extensor muscles during locomotion. After a unilateral cutaneous denervation of the hindpaw, the cats showed transient deficits in locomotion, including a dragging of the hindpaw along the treadmill belt during the swing phase. This deficit rapidly recovered over the course of a few days. The recovery of locomotion was accompanied by an increase in the magnitude of the responses evoked in different muscles by the cortical stimulation at all 23 cortical sites. Response magnitude increased rapidly within the first 1–2 wk postdenervation before attaining a plateau at 
3 wk. In two cats, for which detailed information was obtained, response magnitude in the knee flexor, semitendinosus (St), was increased by >250% at 14/18 sites (mean increase = 1,235%). Increased responses in the St to stimulation were also observed at two of the four pyramidal tract sites after the denervation but were relatively smaller (max = 593%) than those evoked by the cortical stimulation. We suggest that the denervation produces changes in both cortical and spinal excitability that, together, produce a change in corticospinal efficacy that contributes to the recovery of locomotor function.
This article has been cited by other articles:
|
|
 |
|
  A. Frigon and S. Rossignol Locomotor and Reflex Adaptation After Partial Denervation of Ankle Extensors in Chronic Spinal Cats J Neurophysiol, September 1, 2008; 100(3): 1513 - 1522. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Giszter, M. R. Davies, A. Ramakrishnan, U. I. Udoekwere, and W. J. Kargo Trunk Sensorimotor Cortex Is Essential for Autonomous Weight-Supported Locomotion in Adult Rats Spinalized as P1/P2 Neonates J Neurophysiol, August 1, 2008; 100(2): 839 - 851. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Frigon and S. Rossignol Adaptive changes of the locomotor pattern and cutaneous reflexes during locomotion studied in the same cats before and after spinalization J. Physiol., June 15, 2008; 586(12): 2927 - 2945. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Frigon and S. Rossignol Plasticity of Reflexes From the Foot During Locomotion After Denervating Ankle Extensors in Intact Cats J Neurophysiol, October 1, 2007; 98(4): 2122 - 2132. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Bernard, L. Bouyer, J. Provencher, and S. Rossignol Study of Cutaneous Reflex Compensation During Locomotion After Nerve Section in the Cat J Neurophysiol, June 1, 2007; 97(6): 4173 - 4185. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. G. Deliagina, G. N. Orlovsky, P. V. Zelenin, and I. N. Beloozerova Neural Bases of Postural Control Physiology, June 1, 2006; 21(3): 216 - 225. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
