Cardioaccelerator and cardioaugmentor points in hypothalamus of the dog

¹ Department of Pharmacology, College of Physicians and Surgeons, Columbia University, New York City

Comparison of cardioaccelerator and cardioaugmentor responses elicited from the two halves of the hypothalamus of 21 open-chested, vagotomized dogs under chloralose anesthesia showed that stimulation of the right side generally resulted in marked acceleration accompanied by moderate augmentation, whereas stimulation on the left caused pronounced augmentation associated with only moderate acceleration. These differences in degree were statistically significant. This finding suggests that the hypothalamic sympathetic pathways for the cardiac controls, like those of other sympathetic functions, descend predominantly on the ipsilateral sides of the spinal cord.