Abstract
Feedforward control by higher brain centers (central command) plays a role in autonomic regulation of the cardiovascular system during exercise. To reveal central control of cardiac autonomic outflows, a series of experiments have been conducted in our laboratory using conscious or decerebrate animals. Contrary to the traditional concept of vagal withdrawal, central command does not decrease cardiac vagal outflow but allows cardiac sympathetic nerve activity (CSNA) to augment for cardiac acceleration at the onset of exercise. Presumably, central command may also cause an increase in preganglionic adrenal sympathetic nerve activity (AdSNA) at the same time, which in turn releases adrenaline into systemic circulation and contributes to an additional increase in heart rate (HR).
