Objective: To observe the changes of brain rest-state functional connectivity following electroacupuncture (EA) stimulation of right Xia-Jiquan (HT 1), Shaohai (HT 3), Lingdao (HT 4) and Shenmen (HT 7) of the Heart Meridian and non-acupoints in healthy volunteers so as to provide an imaging basis for clinical treatment of some related disorders.
Methods: A total of 20 healthy volunteers who met the inclusion criteria were randomly divided into HT-acupoint group (n=10 cases) and non-acupoint group (n=10 cases) according to the visiting sequence. EA (2 Hz, 2-5 mA) was applied to the right HT 1-HT 3, and HT 4-HT 7 (two outputs of the EA stimulator being connected to two acupuncture needle handles) and non-acupoints (4 spots on the imaginary mid-line between the HT and the Pericardium Meridian apart from the 4 acupoints HT 1-HT 3, and HT 4-HT 7) for 6 min. All the subjects underwent resting-state (rs) fMRI using an Achieva 1.5 T magnetic resonance image (MRI) scanner before and after EA stimulation. The bilateral posterior cingulate was used as the seed point and the functional connectivity data was analyzed by using DPARSF software and rs-fMRI data analysis toolkit.
Results: After EA stimulation of both acupoints and non-acupoints, a similar functional connectivity change was found in the bilateral postcentral gyrus, right inferior parietal lobule, and right inferior frontal gyrus. After EA of acupoints of the HT Meridian, an enhancement of brain functional connectivity was found in the left inferior temporal gyrus and right parahippocampal gyrus, and the newly activated brain regions were the left precentral gyrus, right precuneus, left angular gyrus, left inferior occipital gyrus and the left insula. After EA stimulation of non-acupoints, an increased functional connectivity was found in the left superior temporal gyrus, which was different from EA of acupoints of HT Meridian.
Conclusions: EA stimulation of acupoints of the HT Meridian can enhance the rs functional connectivity in some brain regions as the postcentral gyrus, inferior temporal gyrus, etc. which is related to mediating information of somatosensory, cognitive, affective, memory, cardiovascular activities, etc. in healthy volunteer subjects. The only difference between the two EA groups is an enhanced functional connectivity found in the left superior temporal gyrus after EA of non-acupoints.