Recent experiments have extended our understanding of how sensory informati
on in premotor networks controlling motor output is processed during locomo
tion, and at what level the efficacy of specific sensory-motor pathways is
determined. Phasic presynaptic inhibition of sensory transmission combined
with postsynaptic alterations of excitatory and inhibitory synaptic transmi
ssion from interneurons of the premotor networks contribute to the modulati
on of reflex pathways and to the generation of reflex reversal. These mecha
nisms play an important role in adapting the operation of central networks
to external demands and thus help optimize sensory-motor integration.