THE DORSOMEDIAL HYPOTHALAMUS AND THE ORGANIZATION OF THE CARDIOVASCULAR RESPONSE TO EMOTIONAL STRESS: A FUNCTIONAL PERSPECTIVE

Abstract

Emotional stress results in activation of specific pathways into central nervous system, which produces autonomic, behavioral and endocrine responses. It is known that repetitive or continuous exposition to stress situations may result in various pathologic states, for example, arterial hypertension. Classically, the hypothalamus plays an essential role in the integration of physiological responses to emotional stress. Recent studies demonstrate that a specific nucleus from hypothalamus, the dorsomedial hypothalamus (DMH), is an essential component of central pathways that mediate the cardiovascular response to emotional stress. Inhibition of neurons in this area reduces the increases in heart rate and blood pressure in rats submitted to emotional stress paradigms. Conversely, pharmacological activation of DMH neurons evokes increases on heart rate, blood pressure, adrenocorticotrophic hormone, locomotor activity and sympathetic activity. The similarity of this response with that produced during emotional stress suggests that this area is crucial in the integration of the physiological responses to emotional stress. The present review will discuss the central pathways used by DMH in the organization of the cardiovascular response to emotional stress.