OBJECTIVETo observe the effect of needling at Weizhong (BL 40) acupoint in inducing metabolic changes in brain with positron emission tomography and dynamic contrast (PET/CT) imaging for exploring the mechanism of central regulation of acupuncture.

METHODSPET/CT was performed before and during needling Weizhong acupoint of right leg by electro-acupuncture in 8 healthy volunteers, and also in other 8 subjects without any acupoint stimulation for control. Difference of brain functional images between the two groups before and during needling was analyzed by pairing t-test with statistical parametric mapping.

RESULTSThe needling evoked mean activated cerebral functional regions were: left Broadmann area (BA) 10, 11, 22, 38, 39, 40, 44-46, right BA10, bilateral BA18, 19, and left cerebellar cortex, claustrum and insula (t > 3.36, P < 0.01, k >30 voxels); its mean inhibited brain functional regions were: bilateral BA24, left BA7, 8, 19, 40, right BA 1, 3, 6, 20, 44, and left substantia nigra.

CONCLUSIONThere is a certain connection between Weizhong acupoint and the brain. Needling this acupoint could exert effects through activating or inhibiting brain function in specific regions and neurohumoral regulation. One of the central regulation mechanisms of acupuncture was functional activation in superior, middle, and inferior frontal gyrus, insula and cerebellum and functional inhibition in callosal gyrus, lobi parietalis and substantia nigra. This study further demonstrated PET/CT is useful in revealing TCM meridian theory and could provide objective proof of central regulation for acupuncture treatment.