OBJECTIVETo observe the effects of auricular acupuncture on the learning and memory abilities of model rats with Alzheimer's disease (AD), and investigate its mechanism.

METHODSThirty SD rats were randomly divided into a control group, a model group and an auricular acupuncture group, 10 rats in each group. The model rats with AD were established by multiple injections with Okadaic Acid into the CA1 region of hippocampus. In the control group, the same quantity injection with Dimethyl Sulfoxide (DMSO) was applied on experimental rats. The auricular acupoints of "Nao" (brain) and "Shen" (kidney) were used for treating in the auricular acupuncture group, in contrast, the auricular region were not treated in the model and the control groups. The learning and memory capabilities of the rats were assessed with Morris Water Maze behavioral test, and the expressions of choline acetyltransferase (ChAT) and glial fibrillary acidic protein (GFAP) were examined by immunohistochemistry.

RESULTSComparing with the model group, the treated AD rats with auricular acupuncture was showed that the average escape latency was obviously shortened in the place navigation test (P<0.01), the movement time in plateform quadrant was obviously prolonged in the spatial probe test (P<0.05), and the number of traversing platform obviously increased (P<0.01) after the platform was taken away. The expression of ChAT increased in the hippocampus and cortex (P<0.01, P<0.05), but the expression of GFAP obviously decreased in the CA1 region of hippocampus (P<0.01).

CONCLUSIONAuricular acupuncture can improve the learning and memory capability of the model rats with AD. Its mechanism might be related with decreasing cholinergic neuron damage and reducing the abnormal activation and hyperplasia of astrocyte.