Alternations in functional connectivity of amygdalar subregions under acute social stress

The amygdala has long been considered a vital region involved in acute and chronic stress responses. Extensive evidences from animal and human studies suggest that the functional connectivity of amygdalar subnuclei (basolateral amygdala (BLA), centromedial amygdala (CMA) and superficial amygdala (SFA)) undergo specific alterations in stress-related psychopathology. However, whether and how intrinsic functional connectivity within the amygdalar subcomponents is differently altered in the aftermath of an acute stressor remains unknown. In the present study, using a within-subject design, we examined the impact of acute psychological social stress on the functional connectivity of amygdalar subregions at rest. Results showed that stress mainly affected the connectivity pattern of CMA. In particular, in the stress condition compared with the control, the connectivity of CMA to left posterior cingulate cortex and right thalamus was decreased under stress, while the connectivity of CMA to left caudate connectivity was increased at rest post-stressor. The findings suggest that healthy individuals may adapt to threatening surroundings by reducing threatening information input, and shifting to well-learned procedural behaviors.