Objective To observe the synchronism difference of brain region activities in response to acupuncture stimulation of Zusanli(ST 36) in healthy volunteer subjects with different acupuncture analgesia sensitivity

so as to study the central factors influencing acupuncture intervention outcomes.Methods Forty-five healthy volunteer subjects with different constitutions(different sensitivities in response to needling stimulation) were divided into insensitive group

normal group and sensitive group(n=15).The pressure pain threshold(PPT) of the Zusanli(ST 36) region before and after acupuncture stimulation of ST 36 was assessed using visual analog scale(VAS).Two weeks later after acupuncture stimulation of ST 36

resting-state fMRI images were acquired by using a nuclear magnetic resonance imaging system and analyzed by using DPARSFV 2.1 software package

software SPM 8 and REST 1.7.The cerebral regional homogeneity(ReHo) of the subjects was then calculated by Resting-State fMRI Data Analysis Toolkit(REST).Results Compared with pre-acupuncture

PPT levels of the normal and sensitive groups were significantly increased after acupuncture of ST 36(P<0.05)

and that of the insensitive group had no significant change(P>0.05).Following acupuncture stimulation of ST 36

the insensitive group only showed a significant decreased ReHo in the left fusiform gyrus

left inferior temporal gyrus

bilateral postcentral gyrus

and left anterior central gyrus.In the normal group

a significantly increased ReHo was found in left brainstem

the right cerebellum posterior lobe

right parahippocampa gyrus

right fusiform gyrus

left angular gyrus

temporal lobe and the left frontal lobe;and a significantly decreased ReHo in the occipital lobes and the right superior temporal gyrus after acupuncture stimulation of ST 36.In the sensitive group

a markedly increased ReHo was found in the left brainstem

bilateral cerebellum posterior lobes

left inferior temporal gyrus

basal ganglia

the left insular lobe

anterior cingutate

frontal lobe

inferior parietal lobule

and the right supplementary motor area

and an obviously decreased ReHo found in the bilateral occipital lobes

fusiform gyrus

posterior central gyrus

the right posterior cingutate

the left temporal lobe and the left paracentral lobule

etc.after acupuncture of ST 36.Conclusion Constitution-associated needling sensation may be an important influential factor for acupuncture analgesia in normal subjects.The change of ReHo in different cerebral areas is probably responsible for the difference of acupuncture analgesia in different constitution people.