Influence of credibility on autonomic response modulation to phantom acupuncture.

<p>Phasic and tonic responses for heart rate (<b>A</b> and <b>D</b>), skin conductance (<b>B</b> and <b>E</b>), and pupil size (<b>C</b> and <b>F</b>) were contrasted between credible (PHNTc) and non-credible (PHNTnc) phantom acupuncture. n.b. *<0.05, **<0.01. Error bars represent standard error of the mean.</p

Temporal evolution of autonomic response to real (REAL) and phantom (credible, PHNTc; non-credible, PHNTnc) acupuncture.

<p>Needle insertion, whether real or phantom, produced significantly greater (A) HR decrease, (B) SC increase and (C) PS increase, compared to needle manipulation. ANS response to needle manipulation was relatively stable over all 8 manipulations for REAL (n = 20), PHNTc (n = 11), and PHNTnc (n = 9). SC increase was greater for REAL compared to PHNTc and especially PHNTnc, consistently over all stimuli. Error bars represent standard error of the mean.</p

Study flow.

<p>Among twenty healthy subjects, ten received real acupuncture (REAL) first, while the rest received phantom acupuncture (PHNT) first, and they were re-classified into phantom credible (PHNTc) and phantom non-credible (PHNTnc) according to the needling credibility in phantom acupuncture (PHNT).</p

Influence of credibility on acupuncture sensations to phantom acupuncture.

<p>PHNTc reported significantly greater sensation intensity for numbness and dull pain (i.e. <i>deqi</i> sensations). n.b. *<0.05, **<0.01, ***<0.001. Error bars represent standard error of the mean.</p

Experimental protocol.

<p><b>A.</b> The paradigm consisted of 3-minute event-related stimulation (STIM, 3-second stimulation, ISI mean = 19.5 sec) surrounded by two 2-minute rest sessions (BASE and POST). <b>B.</b> Acupuncture stimulation location (PC6). <b>C.</b> Experimental setup for REAL and PHNT sessions. n.b. Figure in <b>B.</b> was modified from an image in ‘WHO Regional Office for the Western Pacific, 2008, WHO Standard Acupuncture Point Locations in the Western Pacific Region, Manila’.</p

ROIs analysis results of the four overlapped areas between the activated areas in the first block and the habituated areas in the course of repeated acupuncture stimulation.

<p>The brain responses to acupuncture stimulation were increasingly decreased as the acupuncture cumulative duration became longer. The characteristic of habitation was bimodal, i.e. positive brain response was found in the first block of acupuncture stimulation, then it began to decrease and brain response became negative in the last (<i>R</i>: Pearson’s correlation coefficient).</p

Descriptive analysis of differences due to various methods of acupuncture manipulation.

<p>Words in italics means statistically significant;</p><p>Amyg = Amygdala, ant. = anterior, BA = Brodmann area, BG = basal gyrus, Bil. = bilateral, C = Chinese, Cau = caudate nucleus, Ce = cerebellum, Cing = cingulate, Cing-am = anterior middle cingulate, CingC = cingulate cortex, CingG = cingulate gyrus, CN = China, CO = central operculum, Con. = contralateral, Cun = cuneus, DE = Germany, dlPFC = dorsolateral prefrontal cortex, E = English, EA =  electro-acupuncture, ERRM = even reinforcing and reducing method, Fop = frontal operculum, H = hippocampus, Hyp = hypothalamus, IFG = inferior frontal gyrus, IN = insula, Ipsi = ipsilateral, IPL = inferior parietal lobule, ITG = inferior temporal gyrus, L = left, latS = lateral sulcus, LN = lenticular nucleus, MA =  manual acupuncture, MC = motor cortex, MEFG = medial frontal gyrus, MFG = middle frontal gyrus, MOG = middle occipital gyrus, NA =  information unavailable, Nac = nucleus accumbens, NCT =  non-randomized controlled trial, NRP = nucleus raphe pontis, NSD =  non statistically different, OB = observer blinded, OC = occipital cortex, OG = orbital gyrus, OL = occipital lobe, P = pons, PB =  patient blinded, PFG = prefrontal gyrus, PO = parietal operculum, postCG = postcentral gyrus, preCG = precentral gyrus, preCun = precuneus, PTC = parieto-temporal cortex, Put = putamen, R = right, RCT/P = parallel group randomized trial, RIO =  randomized intervention order, rpm = rotations per minute, SI = primary somatosensory area, SII = second somatosensory area, SMA = supplementary motor area, stimu = stimulation, STG = superior temporal gyrus, supCol = superior colliculi, Th = thalamus, TL = temporal lobe, Tpole = temporal pole, TTG = transverse temporal gyri, V1 = primary visual cortices, Y = yes.</p

Prolonged Repeated Acupuncture Stimulation Induces Habituation Effects in Pain-Related Brain Areas: An fMRI Study

<div><p>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 <i>Zhusanli</i> (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.</p></div

Overlapped areas between the activated areas in the first block and the cumulated areas and their overlapped ratio.

<p>Overlapped areas between the activated areas in the first block and the cumulated areas and their overlapped ratio.</p

Demonstration of acupuncture sensation composition of different degrees in the both sides of acupoints.

<p>The acupuncture sensations were labeled on the x-axis, including soreness (Sore), numbness (Numb), heaviness (Heav), fullness (Full), spreading (Sprd) and aching (Achg). The different degrees of sensations were marked with different colors as shown in the legend. The numbers on the y-axis indicated the cases for each kind of sensation.</p