Modulation of vastus medialis motoneuronal excitability by sciatic nerve afferents

Abstract

We activated the sciatic nerve afferents by either the discharge of a magnetic coil or a needle inserted near the nerve. Both types of stimulation induced facilitation of the vastus medialis (VM) H reflex, and of the VM response to transcranial magnetic stimulation, at the joint time of arrival of conditioning and test volleys, while a subsequent inhibition was induced only in the H reflex. We conclude that sciatic nerve afferents induce reciprocal inhibition of VM motoneurons presynaptically on the Ia afferent terminals. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:936–939, 1998.