Altered functional connectivity between medial prefrontal cortex and the inferior brainstem in major depression during appraisal of subjective emotional responses: A preliminary study

Objective: We tested the hypothesis that reduced rostral anterior cingulate cortex (rACC)-subcortical functional connectivity in depressed subjects might account for depression-related autonomic dysregulation. Methods: Ten healthy and ten depressed subjects categorized their immediate subjective emotional responses to picture sets while undergoing functional magnetic resonance imaging and electrocardiography. Using an rACC cluster commonly activated in both groups by emotion categorization as a seed region, we then performed voxel-wise functional connectivity analyses to examine rACC connectivity across the brain in depressed and control subjects. Results: rACC had significantly stronger connectivity with a region of the inferior pons in controls than in depressed subjects. Within-subjects differences in rACC-pons connectivity also significantly correlated with measures of both heart rate variability and depression severity. Conclusions: These findings support the hypothesis that autonomic dysregulation in depression may be associated with a functional disconnection between rACC and autonomic brainstem nuclei.