title: Stimulus--response relationships during locomotion.
abstract: Crossed hind limb responses to high intensity stimulation of the superficial peroneal nerve in the cat were studied under various conditions. In precollicularly decerebrate cats walking on a treadmill, the same stimulus train evokes a crossed extension response during the contralateral stance phase and a crossed flexion response during the contralateral swing phase. In acute spinal cats (Th 13) injected with clonidine, a similar stimulus train can evoke a crossed extension response when the limb is manually placed in flexion and a crossed flexion response when the limb is positioned in extension. During "fictive" locomotion, induced in spinal paralyzed cats by nialamide an L-DOPA, the same stimulus may increase the amplitude and (or) the duration of crossed flexor or crossed extensor activity (in-phase responses). In some instances in these preparations, the crossed responses may be out-of-phase with the central rhythm. It is concluded that crossed hind limb responses during locomotion are selected by both central and peripheral mechanisms.
mesh_terms: D000818:Animals; D002415:Cats; D004558:Electric Stimulation; D004576:Electromyography; D006614:Hindlimb / Q000502:physiology*; D008124:Locomotion; D010543:Peroneal Nerve / Q000502:physiology