title: Prolonged repeated acupuncture stimulation induces habituation effects in pain-related brain areas: an FMRI study.
abstract: Most previous studies of brain responses to acupuncture were designed to investigate the acupuncture instant effect while the cumulative effect that should be more important in clinical practice has seldom been discussed. In this study, the neural basis of the acupuncture cumulative effect was analyzed. For this experiment, forty healthy volunteers were recruited, in which more than 40 minutes of repeated acupuncture stimulation was implemented at acupoint Zhusanli (ST36). Three runs of acupuncture fMRI datasets were acquired, with each run consisting of two blocks of acupuncture stimulation. Besides general linear model (GLM) analysis, the cumulative effects of acupuncture were analyzed with analysis of covariance (ANCOVA) to find the association between the brain response and the cumulative duration of acupuncture stimulation in each stimulation block. The experimental results showed that the brain response in the initial stage was the strongest although the brain response to acupuncture was time-variant. In particular, the brain areas that were activated in the first block and the brain areas that demonstrated cumulative effects in the course of repeated acupuncture stimulation overlapped in the pain-related areas, including the bilateral middle cingulate cortex, the bilateral paracentral lobule, the SII, and the right thalamus. Furthermore, the cumulative effects demonstrated bimodal characteristics, i.e. the brain response was positive at the beginning, and became negative at the end. It was suggested that the cumulative effect of repeated acupuncture stimulation was consistent with the characteristic of habituation effects. This finding may explain the neurophysiologic mechanism underlying acupuncture analgesia.
authors.affiliation: Laboratory of Digital Medical Imaging, Medical Imaging Center, First Affiliated Hospital, Anhui University of Chinese Medicine, Hefei, Anhui, China.
authors.forename: Chuanfu
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Acupuncture and Moxibustion, First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, Anhui, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Biomedical Engineering, Kyung Hee University, Yongin, Republic of Korea.
authors.forename: Kyungmo
authors.initials: K
authors.lastname: Park
authors.affiliation: College of Medical Information engineering, Anhui University of Chinese Medicine, Hefei, Anhui, China.
authors.forename: Hongli
authors.initials: H
authors.lastname: Wu
authors.affiliation: School of Information Science and Technology, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Hu
authors.affiliation: Laboratory of Digital Medical Imaging, Medical Imaging Center, First Affiliated Hospital, Anhui University of Chinese Medicine, Hefei, Anhui, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: CAS Key Laboratory of Brain Function & Disease and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Bu
authors.affiliation: Laboratory of Digital Medical Imaging, Medical Imaging Center, First Affiliated Hospital, Anhui University of Chinese Medicine, Hefei, Anhui, China.
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Xu
authors.affiliation: School of Information Science and Technology, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Bensheng
authors.initials: B
authors.lastname: Qiu
authors.affiliation: CAS Key Laboratory of Brain Function & Disease and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Xiaochu
authors.initials: X
authors.lastname: Zhang
mesh_terms: D015670:Acupuncture Therapy / Q000379:methods*; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D005260:Female; D006185:Habituation, Psychophysiologic; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010146:Pain / Q000523:psychology*; D059408:Pain Management / Q000379:methods*; D013997:Time Factors; D055815:Young Adult