Peripheral sensory activation of cortical circuits in the human leg motor cortex

Abstract

Inputs from lower leg afferents can access both spinal and/or cortical circuits to facilitated on-going motor commands and prune unwanted motor activity. In the leg, this afferent facilitation may contribute to obstacle avoidance and stability during gait, but cortical inhibition analogous to short-latency afferent inhibition (SAI) and the effect of sensory input on intracortical excitability have yet to be reported. The purpose of this study was to first characterize the effect of excitatory afferent inputs from the lower leg on intracortical circuits, and secondly, to investigate the occurrence of SAI in the leg motor cortex.