Central circuit mechanisms of sympathetic and behavioral responses to psychological stress

Abstract

Psychological stress causes a variety of physiological responses in mammals, such as sympathetic thermogenesis, hyperthermia, tachycardia and avoidance behavior from stressors. These responses are all for coping with stressors. In the brain, psychological stress and emotions are processed in the corticolimbic system, while the hypothalamus and brainstem are responsible for maintaining homeostasis. However, the psychosomatic neural pathway that connects the corticolimbic system and the hypothalamus has not been determined. We have previously reported that psychological stress induces thermogenesis in brown adipose tissue, hyperthermia and tachycardia by activating a monosynaptic neural pathway from the dorsomedial hypothalamus (DMH) to the rostral medullary raphe region. Recently, we further discovered that the DMH receives glutamatergic excitatory stress inputs from the dorsal peduncular cortex and dorsal tenia tecta, unexplored areas located at the ventral limit of the medial prefrontal cortex. This cortico-hypothalamic psychosomatic pathway mediates master signaling that drives a variety of sympathetic and behavioral responses to psychological stress.