Altered amygdala resting-state functional connectivity following acupuncture stimulation at BaiHui (GV20) in first-episode drug-Naïve major depressive disorder

Amygdala is an important locus of dysfunction implicated in major depressive disorder(MDD). Aberrant amygdala networks(AN) had been reported in resting-state functional magnetic resonance imaging (rs-fMRI) study. The safety and efficacy of acupuncture treatment for MDD have been verified in previous clinical studies. This study is aimed to investigate whether acupuncture at GV20 could modulate the abnormal AN of patients with the first-episode, drug-naïve MDD by using rs-fMRI combined with functional connectivity (FC) method. Thirty MDD patient underwent 6-min rs-fMRI scans respectively before and after 20-min electro-acupuncture stimulate(EAS) at GV20. Twenty-nine healthy subjects underwent only a 6-min rs-fMRI scan. Based on the amygdala as the seed region, FC method was adopted to examine abnormal AN in patients by comparing with healthy subjects and to evaluate the influence of EAS on intrinsic connectivity within the AN in patients with MDD. Compared to healthy subjects, MDD patients had aberrant intrinsic AN which mainly showed increased FC between amygdala and hippocampus, precuneus, precentral gyrus and angular gyrus, as well as decreased FC between amygdala and orbital frontal cortex(OFC). Moreover, our results indicated that EAS at GV20 induced increased/decreased FC between amygdala and certain regions in MDD patients. In addition, the intrinsic amygdala FC within other certain brain regions in MDD patients were regulated by EAS at GV20. The abnormal AN of MDD patients could be modulated by EAS at GV20. Our findings may further provide the potential imaging evidence to support the modulatory mechanisms of acupuncture on MDD.