Objective: To investigate the mechanism of the effects of different stimulus intensities of electroacupuncture (EA) at the same acupoint. Methods: 11 adult Wistar rats were divided into control group (n=3)

moderate EA group (n=4) and strong EA group (n=4). EA (moderate intensity: 2～4 mA

20/ 4 Hz; high intensity: 5～7 mA

20/4 Hz) was applied to “Yanglingquan”(GB 34) and “Zusanli”(ST 36) for 60 min

once every other day

3 times altogether. On the 7 th day

these rats were decapitated for taking brain tissue which was then cut into sections (10 μm) to be mounted to glass slides. The expression of phospho-Akt in hippocampus (CA1)

dentate gyrus and cerebral cortex of the rats was examined by immunohistochemistry and Western blot analysis. Results: Immunohistochemical results showed that the p-Akt expression-positive neurons in CA1

dentate gyrus and cerebral cortex of moderate EA group were significantly more than those of strong EA and control groups (P<0.01). P-Akt positive neurons of the cerebral cortex in strong EA group were significantly more than those of control group (P<0.05)

but no marked differences were found between strong EA and control groups in p-Akt expression positive neurons in CA1 and dentate gyrus (P> 0.05). Results of Western blot were similar to those of immunohisochemical staining. Conclusion: Moderate intensity EA is superior to strong EA in promoting the expression of p-Akt in rat hippocampal CA1

dentate gyrus and cerebral cortex.