Brain stem augmentation of cardiovascular activity

¹ Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland

Midpontile ischemic decerebration in vagotomized mesencephalic cats produced marked tachycardia and hypertension. Subsequent transection of the brain stem at or above the midpontile level did not affect the cardiovascular hyperactivity. Transection at the pontomedullary junction abolished the brain stem augmentation of heart rate and blood pressure. The results suggest the existence of a cardiovascular augmenter area in the caudal half of the pons and a cardiovascular depressor area in a more rostral portion of the brain stem.