Investigation of acupoint specificity by functional connectivity analysis based on graph theory

Acupoint specificity is still a contentious issue and remains to be verified whether brain, response is as specific as the purported indication of different acupoints. Previous fMRI acupuncture, studies based on multiple-block design may not be able to fully disclose acupuncture effects. Both, recent studies and certain clinical reports have indicated that there exists time-sustainability during, acupuncture even after the stimulus being terminated. Further understanding of how such external, intervention interacts with post-stimulus resting brain networks may enlighten us to gain an, appreciation of the physiological function and integrated mechanisms involved in acupuncture. In our, study, we adopted a modified non-repeated event-related (NRER) design, and utilized the graph theory, based functional connectivity analysis to investigate the neural specificity of the PC6, with the same, meridian acupoint PC7 and a different meridian acupoint GB37 as separate controls. Under the, construct of this network model, some brain regions with a larger degree of connectivity indicated, stronger interactions with other brain regions and were considered to be important nodes in this, network. We identified that the two most important brain areas were the right nodule and right uvula, following acupuncture at PC6, and the right amygdala and right inferior parietal lobe following, acupuncture at PC7. Following the GB37, the two regions with the larger degree of connectivity were, the posterior cingulate cortex (PCC) and middle occipital gyrus. These specific regions may mediate the, specific effects of acupuncture. Results showed that different modulatory brain networks may support, the point specificity of acupuncture.