[Activity of spinal cord neurons and their responses to stimulation of the "stepping" strip during spontaneous locomotor rhythmicity].

Spike activity of single neurons in the upper cervical segments C2-C3 or at the brachial enlargement C5-C6 was recorded in decerebrated cats during spontaneous locomotor rhythm after transection of the spinal cord at the low thoracic level. The shortest interspike intervals in 66% of cyclically active neurons at C5 were observed during electrical activity of extensor muscles of the ipsilateral forelimb. Only 8% of these neurons responded to stimulation of the stepping strip. The shortest interspike intervals in 65% of cyclically active neurons at C2 were observed during a silent period in extensor activity. 45% of C2 neurons responded to stimulation of the stepping strip. 87% of non-cyclic neurons responded to stimulation of the strip, were located at the C2 level.