Observation Of The Brain Visual Cortex Activation On FMRI By Electroacupuncture Stimulation At LR3 (Taichong)

Purpose:To investigate the brain cortex activation especially the visual cortex application of functional MR imaging during acupuncture stimulation at LR3(taichong) and sham acupoint near LR3 alternatively, to obtain the modern scientific mechanism of acupuncture for treating ophthalmic diseases.Subjects and method:Thirty healthy adult volunteers were enrolled,informed that electroacupuncture stimulation at two acupoints on right foot before experiment .However , the precise locations of needling ,the presumed acupuncture effects and the stimulation paradigm were not divulged. During the experiment , the subjects were requested to keep their eyes closed. fMRI was performed on a 1.5T GE MRI with the sequence :Blood Oxygenation Level Dependent(BOLD) of Echo Planer Imaging(EPI). Electroacupuncture stimulation at right LR3 and a sham acupoint near it alternately in the same sequence employing a block design. The block design was just as follows: off- acupuncture stimulation at LR3-off- acupuncture stimulation at sham acupoint near LR3-off.The individual activation maps and group activation maps were obtained while the functional data were analyzed by SPM2. If the visual cortex was activated in group map, we can figure out the signal intensities in activation point of the two acupuncture tasks , statistical analysis done by SPSS13.0.Results:(1) Bilateral visual cortices activations were observed in group map when acupuncture stimulation at right LR3, these two visual cortices were right inferior occipital gyrus (Broadmann Area (BA)18) and left lingual gyrus (BA 18).Sham acupoint stimulation did not show any activation in group map.(2) In the individual maps ,visual cortices were activated in 9 of 30 volunteers when acupuncture stimulation at right LR3, in 6 of 30 volunteers when acupuncture stimulation at sham acupoint.(3) There were statistically significant differences in the signal intensities of bilateral visual cortices comparison of acupuncture stimulation at right LR3 with sham acupoint near it. The signal intensities of bilateral visual cortices when acupuncture stimulation at LR3 were more intensive than the sham acupoint task . The signal intensities in right visual cortex (acupuncture side) was more intensive than it in left visual cortex of these two acupuncture tasks.(4) Both acupuncture stimulation at right LR3 and sham acupoint near it activated left precentral gyrus .The activated brain regions were different in the two acupuncture tasks , the activated regions when acupuncture stimulation at LR3 were more extensive than acupuncture stimulation at sham acupoint. Acupuncture stimulation at right LR3 activated not only left lingual gyrus and right inferior occipital gyrus ,but also bilateral angular gyrus, bilateral medial frontal gyrus, bilateral inferior frontal gyrus, left superior temporal gyrus, left inferior temporal gyrus ,left cingulate gyrus ,left insula , right superior frontal gyrus and right supramarginal gyrus .However, acupuncture stimulation at sham acupoint near right LR3 only activated left precentral gyrus.Conclusions:(1)Acupuncture stimulation at LR3 activates bilateral occipital visual cortices(BA18) which are both with responsibility for advanced visual disposal. The signal intensity in ipsilateral acupuncture stimulation is more intensive than the signal intensity in contralateral stimulation . The phenomenona might explain the mechanism of acupuncture for treating ophthalmic diseases.(2)Acupuncture stimulation at LR3 activates some brain regions in limbic areas and language system as well , it may be an evidence of acupuncture stimulation at LR3. to treat depression and aphasia.