Under stress, animals change their behavior, such as through “fight or flight” or “freezing” response. Simultaneously, physiological responses essential for stress adaptation are triggered in the body. Cardiovascular regulation, including changes in blood pressure and heart rate, is a critical stress response.
Researchers have focused on the lateral habenula, a brain region where neurons are activated in response to stress. They investigated the neural mechanisms underlying cardiovascular responses by activating the lateral habenula in experiments using rats. Activation of the lateral habenula caused changes in blood pressure and heart rate. However, pharmacologically blocking of dopamine neurotransmission suppressed the blood pressure and heart rate changes induced by lateral habenula activation. Furthermore, these changes were also suppressed when the activity of the ventral tegmental area, which receives input from neurons in the lateral habenula, was pharmacologically inhibited. These results suggest that the cardiovascular responses caused by lateral habenula activation are mediated by the dopaminergic system, specifically by dopamine neurons in the ventral tegmental area.
Based on the findings of this study, further research into the neural mechanisms regulating cardiovascular responses during stress is expected to provide a better understanding of the behavioral changes induced by stress and the mechanisms that maintain homeostasis in the body.
The research was supported by the Japan Society for the Promotion of Science Kakenhi (19H03339, 22K19477, and 24K22082). YS was also supported by a Japan Science and Technology Agency scholarship SPRING (JPMJSP2124).