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

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal 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 Google Scholar Google Scholar Articles by Burke, D Articles by Pierrot-Deseilligny, E Search for Related Content PubMed PubMed Citation Articles by Burke, D Articles by Pierrot-Deseilligny, E

Département de Rééducation, Hôpital de la Salpêtrière, Paris, France.

1. The possibility was investigated that the facilitation of the transmission in the propriospinal-like system during voluntary contraction, documented in the companion paper (Burke, Gracies, Mazevet, Meunier & Pierrot-Deseilligny, 1992), is due to a decrease in presynaptic inhibition of afferents projecting to propriospinal-like neurones. 2. The radial nerve was stimulated to evoke presynaptic inhibition of the monosynaptic Ia projections to forearm flexor motoneurones (Berardelli, Day, Marsden & Rothwell, 1987) and, hopefully, of the afferent input to propriospinal-like neurones projecting to these motoneurones. 3. The propriospinal-like excitation of forearm motoneurones evoked from mixed afferent inputs was depressed by radial nerve stimulation, and this depression was long-lasting (200 ms). Despite the convergence of mixed nerve and cutaneous afferents onto common propriospinal-like neurones, the radial stimulation did not depress the cutaneous-induced excitation. This differential effect and the time course of the depression suggest that it results from presynaptic inhibition of mixed nerve afferents (presumably large muscle afferents) projecting to propriospinal-like neurones. 4. With voluntary contractions, phasic or tonic, the radial-induced depression of the propriospinal-like excitation evoked by mixed nerve afferents was much greater than at rest, but the cutaneous-evoked excitation was unchanged. Thus, with voluntary contractions, there was no evidence of decreased gating of the afferent input to propriospinal-like neurones whether the input was of muscle or cutaneous origin and it is concluded that changes in presynaptic inhibition cannot account for the facilitation of the transmission in the propriospinal-like system during voluntary contraction. 5. By contrast, presynaptic inhibition of the monosynaptic Ia projections to motoneurones was consistently reduced at the onset of contraction, and to a much lesser extent during a weak tonic contraction.

This article has been cited by other articles:

				C. Iglesias, V. Marchand-Pauvert, G. Lourenco, D. Burke, and E. Pierrot-Deseilligny Task-related changes in propriospinal excitation from hand muscles to human flexor carpi radialis motoneurones J. Physiol., August 1, 2007; 582(3): 1361 - 1379. [Abstract] [Full Text] [PDF]

				P. G. Martin, S. C. Gandevia, and J. L. Taylor Muscle fatigue changes cutaneous suppression of propriospinal drive to human upper limb muscles J. Physiol., April 1, 2007; 580(1): 211 - 223. [Abstract] [Full Text] [PDF]

				S. C. Gandevia Spinal and Supraspinal Factors in Human Muscle Fatigue Physiol Rev, October 1, 2001; 81(4): 1725 - 1789. [Abstract] [Full Text] [PDF]

				P Marque, M Simonetta-Moreau, E Maupas, and C F Roques Facilitation of transmission in heteronymous group II pathways in spastic hemiplegic patients J. Neurol. Neurosurg. Psychiatry, January 1, 2001; 70(1): 36 - 42. [Abstract] [Full Text] [PDF]

				C. Aymard, R. Katz, C. Lafitte, E. Lo, A. Penicaud, P. Pradat-Diehl, and S. Raoul Presynaptic inhibition and homosynaptic depression: A comparison between lower and upper limbs in normal human subjects and patients with hemiplegia Brain, August 1, 2000; 123(8): 1688 - 1702. [Abstract] [Full Text] [PDF]