[Rhombencephalic "locomotor area" of turtles]

Abstract

Electric stimulation (20-30/s, 10-20 muA) of the rhombencephalon in the decerebrated turtle may evoke cyclic coordinated movements of the limbs. The "locomotor region" is a strip oriented in the rostrocaudal direction which corresponds to the lateral reticular formation. Ipsi- and contralateral synpatic responses of single neurons were recorded extracellularly both in the medial and lateral reticular formations; the responses were evoked by stimulation of the "locomotor region" (2/s, 10-30 muA). The usual latencies of these responses were 3-12 ms (with the mode of 5-6 ms). Excitation of the "locomotor region" is followed by extensive propagation of activity in the rhombencephalon. The possible mechanisms of this propagation are considered.