Analgesic Effects Of Acupuncture At Zusanli (ST36) On Functional Connectivity In Subjects With Different Sensitivity Constitution

ObjectiveTo explore the analgesic effects of acupuncture at zusanli(ST36)on the resting networks in subjects with different sensitivity constitution.MethodA total of 40 healthy subjects were divided into two groups(highly sensitive constitution to acupuncture and poorly sensitive constitution to acupuncture,HA and PA)based on traditional Chinese medicine theory on constitution.A 3.0T fMRI scanner was utilized during acupuncture of the two groups at acupoint ST36 to obtain functional connectivity data in the brain.The pressure pain thresholds(PPT)before and after acupuncture in all participants were measured.The paired-t test and two sample-t test were used to compare analgesia effect and press pain threshold change rate in two groups before and after acupuncture.The fMRI data was successively obtained and analyzed with DPARSF2.3,MATLAB2009 A,and REST1.8 software and functional connection images were analyzed by interest correlation analysis method with posterior cingulate cortex(PCC)as the regions of interest(ROI)andcompared functional network connectivity changes in the two groups before and after acupuncture.To analyse acupuncture analgesia effects mechanism in different sensitive groups combining the acupuncture analgesia date and functional connectivity.Results1.The VAS score in the HA group was higher(P < 0.01)than in the PA group.2.The PPT in the two groups increased after acupuncture stimulation(P < 0.05),with the change rate of PPT in the HA group higher than in the PA group(P < 0.01);3.Posterior cingulate cortex,precentral,and angular were discovered in the block sequence of HA and PA groups comparing after and before acupuncture.(P < 0.01,Alphasim correction,T > 2.74);4.The posterior cingulate cortex(PCC)was chosen as the region of interest(ROIs).The function connectivity between PCC and left parahippocampal,right hippocampal,right orbital frontal gyrus,and cerebellar peduncles Crus1 and Crus2 increased,and the function connectivity between PCC and right middle cingulate gyrus,right middle temporal lobe,right angular decreased in PA group before and after acupuncture decreased.The functional connectivity between PCC and left middle fontal gyrus,right middle frontal gyrus,right middle temporal lobe,left cuneus,left precuneus,left supra marginal,right supp motor area,and cerebellar peduncles Crus2 increased,and decreased in left angular in HA group between before and after acupuncture(P<0.05,t>4.35,cluster>10,uncorrected).Conclusions1.Participants with different sensitivity constitutions to acupuncture have different needling sensations,which might lead to disparate analgesia effect.2.The results of brain functional connectivity analysis showed that the significantly different brain regions of the two groups were in default mode network(DMN),limbic-paralimbic-neocortical network(LPNN)and pain matrix.But functional connectivity changed in contrast in temporal lobe,enhanced in HA group and decreased in PA group,functional connectivity between PCC and angular decreased in both PA group and HA group.This clinical phenomenon of nondeterminacy may be explained by various modulation mode of the brain functional connectivity with PCC.