SEQUENTIAL BEHAVIOR INDUCED REPEATEDLY BY STIMULATION OF THE RED NUCLEUS IN FREE MONKEYS

Abstract

Rhesus monkeys in a colony were stimulated by means of intracerebral electrodes controlled by radio, for 5 seconds every minute, day and night, for periods up to 14 days. Stimulations of the red nucleus evoked a reliable sequence of behavior including bipedal locomotion, climbing, vocalization, and social interactions. During periods of spontaneous sleep, stimulations produced only a small head movement, but the whole behavioral sequence reappeared as soon as the animal awoke. In monkeys injected with chlorpromazine, the evoked behavior was inhibited in the same way as during spontaneous sleep, while the administration of atropine, Regitine, and Indurol which blocked both sympathetic and parasympathetic systems, produced only minor modifications of the sequential response.