FMRI Connectivity Analysis of Acupuncture Effects on an Amygdala-Associated Brain Network

Abstract

BackgroundRecently, increasing evidence has indicated that the primary acupuncture effects are mediated by the central nervous system. However, specific brain networks underpinning these effects remain unclear.ResultsIn the present study using fMRI, we employed a within-condition interregional covariance analysis method to investigate functional connectivity of brain networks involved in acupuncture. The fMRI experiment was performed before, during and after acupuncture manipulations on healthy volunteers at an acupuncture point, which was previously implicated in a neural pathway for pain modulation. We first identified significant fMRI signal changes during acupuncture stimulation in the left amygdala, which was subsequently selected as a functional reference for connectivity analyses. Our results have demonstrated that there is a brain network associated with the amygdala during a resting condition. This network encompasses the brain structures that are implicated in both pain sensation and pain modulation. We also found that such a pain-related network could be modulated by both verum acupuncture and sham acupuncture. Furthermore, compared with a sham acupuncture, the verum acupuncture induced a higher level of correlations among the amygdala-associated network.ConclusionOur findings indicate that acupuncture may change this amygdala-specific brain network into a functional state that underlies pain perception and pain modulation.

Divergent neural processes specific to the acute and sustained phases of verum and SHAM acupuncture

“…More recently, Qin et al used the nonrepeated eventrelated fMRI (NRER-fMRI, Fig. 1A) design to investigate delayed responses after acupuncture administration (3,15). As compared with the ''on-off'' design paradigm, this one has the advantage of considering the spatial and temporal information respectively in the whole process of acupuncture.…”

Characterizing acupuncture stimuli using brain imaging with fMRI – a systematic review and meta-analysis of the literature

“…Zhang et al [148] and Bai et al [149] found that acupuncture stimulation may induce the modulation of thè`a cupuncture-related'' network, represented by significant changes of functional connectivity in several regions of the brain, such as the bilateral frontal gyrus, bilateral temporal gyrus, inferior parietal lobe, middle occipital gyrus, pre-and postcentral gyrus, anterior cingulate cortex (ACC), parahippocampus, insula, tonsil, pyramis, culmen, precuneus and cuneus. Qin et al [150,151] identified an amygdala-related network during the resting state both after verum and penetrating sham acupuncture at a nearby point. Compared to sham, verum acupuncture increased the connectivity between the amygdala, the PAG (periaqueductal gray) and the insula, and decreased the connectivity between the amygdala with the middle frontal cortex, the postcentral gyrus and the posterior cingulate cortex (PCC).…”

Spatiotemporal Modulation of Central Neural Pathway Underlying Acupuncture Action: A Systematic Review

“…Qin et al have proposed a newly experimental paradigm, namely the nonrepeated event-related fMRI (NRER-fMRI) design, to explore the prolonged effects of acupuncture on the restingstate brain networks [34]. Compared with the acupuncture at a non-acupoint (NAP), there was a higher level of correlations among the amygdala-associated networks following acupuncture at ST36.…”