Abstract
Acupuncture-induced sensations have historically been associated with clinical efficacy. These sensations are atypical, arising from sub-dermal receptors, and their neural encoding is not well known. In this fMRI study, subjects were stimulated at acupoint PC-6, while rating sensation with a custom-built, MR-compatible potentiometer. Separate runs included real (ACUP) and sham (SHAM) acupuncture, the latter characterized by non-insertive, cutaneous stimulation. FMRI data analysis was guided by the on-line rating timeseries, thereby localizing brain correlates of acupuncture sensation. Sensation ratings correlated with stimulation more (p < 0.001) for SHAM (r = 0.63) than for ACUP (r = 0.32). ACUP induced stronger and more varied sensations with significant persistence into no-stimulation blocks, leading to more run-time spent rating low and moderate sensations compared to SHAM. ACUP sensation correlated with activation in regions associated with sensorimotor (SII, insula) and cognitive (dorsomedial prefrontal cortex (dmPFC)) processing, and deactivation in default-mode network (DMN) regions (posterior cingulate, precuneus). Compared to SHAM, ACUP yielded greater activity in both anterior and posterior dmPFC and dlPFC. In contrast, SHAM produced greater activation in sensorimotor (SI, SII, insula) and greater deactivation in DMN regions. Thus, brain encoding of ACUP sensation (more persistent and varied, leading to increased cognitive load) demonstrated greater activity in both cognitive/evaluative (posterior dmPFC) and emotional/interoceptive (anterior dmPFC) cortical regions. Increased cognitive load and dmPFC activity may be a salient component of acupuncture analgesia - sensations focus attention and accentuate bodily awareness, contributing to enhanced top-down modulation of any nociceptive afference and central pain networks. Hence, acupuncture may function as a somatosensory-guided mind-body therapy.
| Original language | English |
|---|---|
| Pages (from-to) | 1055-1065 |
| Number of pages | 11 |
| Journal | NeuroImage |
| Volume | 47 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Sept 2009 |
Bibliographical note
Funding Information:We would like to thank the National Center for Complementary and Alternative Medicine, NIH for funding support: K01-AT002166, R01-AT004714 (Napadow), P01-AT002048 (Rosen), K01-AT004481 (Dhond), K01-AT01111 (Harris) and F05-AT003770 (Park). We also acknowledge the NCRR (P41-RR14075, GCRC M01-RR01066), the Mental Illness and Neuroscience Discovery (MIND) Institute. Dr. Park was also supported by the Institute of Information Technology Advancement, Korea IITA-2008-(C1090-0801-0002). Dr. Harris was also supported by Department of Army grant DAMD-Award Number W81XWH-07-2-0050, and Dana Foundation Award in Brain and Immuno-imaging. We would also like to thank Bruce Rosen and Ted Kaptchuk (K24-AT004095) for helpful comments on the interpretation of our data. The content is solely the responsibility of the authors and does not necessarily represent the official views of our funding agencies.