INFLUENCE OF STIMULATION OF SOME SUBCORTICAL AREAS ON ELECTROCARDIOGRAM

Abstract

Experiments were performed on cats under ether anesthesia. The stimulation technique of Hess was used and the position of the electrodes was microscopically verified. Stimulation of the basal ganglia had no effect on the ecg; only the globus pallidus produces any reaction of the heart. The hypothalamus gave different effects according to the site of the stimulation. Irritation of the anterior lateral part produced a depressor effect: slowing of the heart with a decrease of blood pressure. This reaction was abolished by vagotomy. During the stimulation of the more posterior part of the hypothalamus ventricular extrasystoles, shifting of the pacemaker and changes in the T-wave were observed, accompanied by a marked rise of blood pressure. Vagotomy was without influence on the phenomenon. Effects seen after cessation of the stimulation of the vagus were ventricular extrasystoles, dissociation of conduction, rate changes and changes in T-wave. The ecg changes were abolished by section of the vagi. The arrhythmia occurring after stimulation is probably caused by a different mechanism from that which occurs during stimulation. Stimulation of the corpora quadrigemina gave practically the same result as that resulting from stimulation of the posterior hypothalamus.