[Responses of lumbar flexor motoneurons to stimulation of limb afferents]

Interaction of PSPs elicited by stimulation of hindlimb and forelimb afferent nerves was studied in lumbar flexor motoneurons of anesthetized cats. Activation of forelimb afferents evoked EPSPs of considerable duration; no IPSPs were observed. Stimulation of hindlimb flexor afferents evoked EPSPs in the same motoneurons, their early component being of segmental origin and their late component--of spino-bulbo-spinal one. Interaction of afferent systems of fore--and hindlimbs caused a long-lasting depression of EPSPs. The depression of EPSPs was not followed by generation of IPSPs in motoneurons, Possible integrative levels of interlimb inhibitory coordination are discussed.