Association of stress-related limbic activity and baseline interleukin-6 plasma levels in healthy adults

Abstract

Several studies suggest a link between acute changes in inflammatory parameters due to an endotoxin or (psychological) stressor and the brain’s stress response. The extent to which basal circulating levels of inflammatory markers are associated with the brain’s stress response has been hardly investigated so far. In the present study, plasma levels of the cytokine interleukin (IL)-6 were obtained as a baseline measure of peripheral inflammatory processes and linked to neural markers of psychosocial stress using a modified version of the Montreal Imaging Stress Task in a sample of N=65 healthy subjects. Of three a-priori defined regions of interest – the amygdala, anterior insula, and anterior cingulate cortex – baseline IL-6 was significantly and negatively associated with stress-related neural activation in the right amygdala and left anterior insula. Our results suggest that baseline inflammatory physiology might be related to differences in the neural stress response and that this relationship could be inverse to that previously shown by studies on acutely induced inflammation.