CORTICAL MODULATION OF THE CARDIOVASCULAR-SYSTEM

Cortical modulation of central cardiovascular control mechanisms has b een recognized for many decades. However, it is only recently that the mechanisms underlying cortical influences on circulatory function hav e been systematically examined. This review considers the view that ce rtain regions of the cerebral cortex, including the medial prefrontal cortex (MPFC) and insular cortex (IC), participate in specific aspects of central circulatory control. Anatomical investigations indicate th at these cortical areas are connected with hypothalamic, midbrain, pon tine and medullary brain regions involved in cardiovascular control. L esions of the MPFC and IC have demonstrated modulation of the activity of cardiovascular reflexes such as the baroreceptor heart rate reflex and involvement in conditioned cardiovascular responses. Electrophysi ological studies have provided evidence that cortical regions are able to influence premotor sympathoexcitatory vasomotor neurons within the rostral ventrolateral medulla and subsequently alter sympathetic vaso motor tone. Cortical regions such as the IC receive visceral sensory i nformation arising from baroreceptors and chemoreceptors within the ca rdiovascular system. In contrast, the MPFC receives afferents predomin antly from limbic sources, although its outputs include structures ass ociated with central sympathetic vasomotor control. Cortical modulatio n of circulatory function has been demonstrated in man and may underli e the cardiovascular components of a number of conditions. It is sugge sted that cortical areas involved in visceral sensory or visceral moto r processes associated with circulatory function may uc involved in ge neration of patterns oi cardiovascular responses specific for certain behaviours. (C) 1997 Elsevier Science Ltd.