Psychopharmacological analysis of hypothalamically-induced emotions.

The effect of minor tranquilizers and neuroleptics was compared on self-stimulation and escape behaviourelicited by electrical stimulation of the hypothalamic nuclei in rabbits. It was shown that while tranquilizers (diazepam, oxazepam and meprobamate) increased the rate of self-stimulation elicited from the lateral hypothalamus, neuroleptics considerably suppressed such behaviour. Tranquilizers caused a remarkable reversal of the escape behaviour into a high-rate self-stimulation, both responses being induced from the same electrodes within the medial hypothalamus. Neuroleptics (chlorpromazine, reserpine and haloperidol) had not such an influence, though they somewhat increased the general activity of the animals. The reversing effect of the tranquilizers was compared with similar findings obtained after electrolytic ablation of the ventral hippocampus. It is suggested that the hippocampus has an inhibitory influence on the hypothalamic motivational system thus providing substantially for the animals' survival in a hostile environment.