Partial correlation investigation on the default mode network involved in acupuncture: An fMRI study

Certain clinical reports and researches have shown that acupuncture effects can sustain a period during the post-stimulation state, and modulate the default mode network (DMN). In this study, partial correlation approach was utilized to investigate whether or not electro-acupuncture stimulation (EAS) at the three acupoints (GB37 (Guangming), BL60 (Kunlun) and KI8 (Jiaoxin)) and one sham point on the left leg modulated the DMN and how to change the intrinsic connectivity of the DMN. The results indicated that DMN could be modulated after EAS, and there existed different modulation patterns of the four points. Meanwhile, we found that the posterior cingulate cortex and precuneus (PCC/pC) strongly interacted with other nodes during the pre- and post-stimulation states. The correlation was interrupted between the PCC/pC and anterior cingulate cortex (ACC). The orbital prefrontal cortex (OFC) negatively interacted with the left medial temporal cortex (lMTC) at the acupoints. We suggested that the distinct modulation patterns to the DMN attributed to the different effects evoked by the three acupoints and one sham point.