A new MRI study shows that acupuncture affects brain activity differently than needle stimulation at non-acupuncture points. Researchers sought to compare the central modulating mechanisms of acupuncture and sham acupuncture on the brain by measuring changes of amplitude low-frequency fluctuation (ALFF) using fMRI technology. ALFF measures the intensity of regional spontaneous brain activity, particularly in the posterior cingulate cortex, precuneus, medial prefrontal cortex and bilateral inferior parietal lobule.
One group received acupuncture at acupoint Sp6 (Sanyinjiao) and the other group received sham acupuncture. The needles were retained for 4 minutes during the fMRI neuroimaging process. The Sp6 acupuncture group changes were primarily in the inferior parietal lobe. The sham group showed enhanced activity in the precuneus, which is part of the superior parietal lobe of the brain. The Sp6 acupuncture also showed increased ALFF in the fusiform temporal gyrus and medial frontal gyrus. As a result, the researchers concluded that acupuncture has significantly different cortical effects than sham needling.1
Another recent study demonstrates the neurophysiological effects of acupuncture using MRIs. The researchers applied acupuncture to acupoints GB40 (Qixu) and K3 (Taixi). Results showed that GB40 stimulation enhanced “connectivity between the superior temporal gyrus (STG) and anterior insula.” K3 (Taixi) increased the connection strength between the STG and the postcentral gyrus. This distinction between GB40’s enhancement of the precentral gyrus and K3’s enhancement of the postcentral gyrus demonstrates acupuncture’s causal specificity of stimulation to differing acupuncture points.2
Zhongguo Zhen Jiu. 2012 Jan;32(1):47-52. [Evaluation of the post-effect of acupuncture at Sanyinjiao (SP 6) under sleep deprivation by resting-state amplitude of low-frequency fluctuation: a fMRI study]. Dai XJ, Min YJ, Gong HH, Gao L, Wang SY, Zhou FQ, Xiao XZ, Liu BX. Department of Radiation, The First Affiliated Hospital, Nanchang, Jiangxi, China.
Zhong, C., Bai, L., Dai, R., Xue, T., Wang, H., Feng, Y., Liu, Z., You, Y., Chen, S. and Tian, J. (2011), Modulatory effects of acupuncture on resting-state networks: A functional MRI study combining independent component analysis and multivariate granger causality analysis. Journal of Magnetic Resonance Imaging.