[Synaptic responses of propriospinal neurons on stimulation of the locomotor strip of the dorsolateral funiculus of the cat].

Stepping points in the dorsolateral funiculus of thoracic and cervical divisions of the spinal cord were found in mesencephalic cats. Synaptic responses of single neurons at level Th12-Th13 to microstimulation of these points were recorded extracellularly. Latencies of these responses increase when the distance between the stepping point and the site of the recording is over 20 mm, and paired stimuli have now to be delivered to evoke responses. Neurons responding orthodromically to stimulation of the stepping strip send their axons into the ventrolateral funiculus near the grey matter. Occurrence of antidromic responses among neurons sending their axons in the caudal direction is 37% in the average till the distance between the recording and stimulation sites is up to 40 mm. Half of neurons with synaptic responses to stimulation of the stepping point can be also excited by a train of 3-6 stimuli applied to the midbrain locomotor point. Revealed neurons may contribute to propagation of the activity to the stepping generator of the hindlimb.