Analysis of Autonomic Hypothalamic Functions in the Intact Organism *

Abstract

If the posterior hypothalamic excitability is . increased by injection of metrazol or strychnine into this structure or by subthreshold stimulation of the posterior hypothalamus, the return of the blood pressure from the hypotensive effect of mecholyl is accelerated and often followed by a hypertensive phase absent under control conditions. If the posterior hypothalamic excitability is diminished by injection of barbiturates into this structure or by posterior hypothalamic lesions, the hypotensive action of mecholyl and similar drugs is aggravated. From these experiments it is concluded that the action of mecholyl depends on the excitability of the posterior hypothalamus. The study of the nor-epinephrine-induced slowing of the pulse rate shows that this reflex depends on the excitability of the anterior hypothalamus. On the basis of these tests, it is possible to ascertain the state of the excitability of the parasympathetic and sympathetic systems at the hypothalamic level. It is suggested that the treatment of functional psychoses be guided by the nature and degree of autonomic hypothalamic disturbances determined in each patient before and during the period of attempted therapy and be directed toward the restitution of a normal autonomic balance.