[Inhibition of the behavioral responses of cats after discontinuing electric stimulation of the caudate nucleus].

A prolonged suppression of behavior occurs in free-moving cats after disruption of low-frequency stimulation of the caudate nucleus head. Its outward manifestations and EEG-pattern look like those of natural sleep. However, unlike sleep, during caudate suppression motor functions are more affected, the activation response to presented test-stimuli is shorter, and the emotionality of animals is weaker. The suppression is most pronounced following the stimulation of rostro-medio-dorsal parts of the nucleus head. In small doses the neuroleptic haloperidol enhances, and the psychostimulant d,l-amphetamine decrease the caudate effect. It is suggested that the trace response triggered by the stimulation of the caudate nucleus is closer to behavioral suppression than to sleep and that it depends on the activity of the dopaminergic mechanisms.