HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 98/4/2122    most recent 00490.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Frigon, A. Articles by Rossignol, S. Search for Related Content PubMed PubMed Citation Articles by Frigon, A. Articles by Rossignol, S.

Plasticity of Reflexes From the Foot During Locomotion After Denervating Ankle Extensors in Intact Cats

Groupe de Recherche sur le Système Nerveux Central, Department of Physiology, Faculty of Medicine, Université de Montréal, Montreal, Canada

Submitted 1 May 2007; accepted in final form 25 July 2007

Although sensory feedback is important in regulating the timing and magnitude of muscle activity during locomotion few studies have evaluated how it changes after peripheral nerve lesions. To assess this, reflexes evoked by stimulating a nerve before and after denervating other nerves can be quantified to determine changes. The aim of this study was to investigate consequences of denervating ankle extensor muscles, the lateral gastrocnemius, and soleus (LGS) on reflexes from the plantar foot surface evoked by stimulating the tibialis (Tib) nerve. Three cats (n = 3) were trained to walk on a treadmill and chronically implanted with electrodes in 14 hindlimb muscles bilaterally to record EMG activity. A stimulating cuff electrode was placed around the left Tib nerve (Tib) nerve at the ankle to evoke reflexes. Several control values of EMGs, limb kinematics, and Tib nerve reflexes were obtained during locomotion for at least 3 wk before the left LGS nerve was cut. We found that the locomotor EMG bursts of several muscles was altered, with a large increase in amplitude in the early days postneurectomy followed by a gradual decrease toward intact values later on. There were changes in the stimulated locomotor EMG bursts (Tib nerve reflexes) of ipsilateral flexors and extensors and of contralateral ankle extensors, which dissociated from changes in baseline locomotor EMG (e.g., nonstimulated bursts during reflex trials). The functional significance of these changes in muscle activity and reflex pathways on the recovery of locomotion after denervating ankle extensors is discussed.

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]

				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 Short-Latency Crossed Inhibitory Responses in Extensor Muscles During Locomotion in the Cat J Neurophysiol, February 1, 2008; 99(2): 989 - 998. [Abstract] [Full Text] [PDF]