Regulated aberrant amygdala functional connectivity in premenstrual syndrome via electro-acupuncture stimulation at sanyinjiao acupoint（SP6）

Background: Acupuncture is an effective therapy for premenstrual syndrome (PMS). However, the mechanisms behind this method are still unclear. Our previous study found that aberrant amygdala resting-state functional networks were involved in PMS. Thereby, a deep investigation on the alterations of amygdala resting-state functional networks induced by acupuncture stimulation might contribute to a better understanding of the intricate mechanisms of acupuncture treatment on PMS. Methods: Twenty three PMS patients were recruited in this study. All patients received a 6-minute electro-acupuncture stimulation (EAS) at Sanyinjiao acupoint (SP6) and underwent two 6-minute resting-state fMRI scannings before and after EAS. With amygdala as the seed region, functional connectivity (FC) method was adopted to examine EAS-related modulation of intrinsic connectivity in PMS patients by comparing pre-EAS. Results: The results showed that EAS at SP6 induced increased FC between the left amygdala and brainstem, right hippocampus, and decreased FC between the left amygdala and left thalamus, bilateral supplementary motor area (SMA). Moreover, the results also showed that EAS at SP6 induced increased FC between the right amygdala and brainstem, right hippocampus, right orbitofrontal cortex, bilateral anterior cingulate cortex (ACC), and decreased FC between the right amygdala and right SMA. Conclusions: Based on the results of our previous study, our findings might improve our understanding of neural mechanisms behind acupuncture effects on PMS.