||OBJECTIVE: To investigate the effect of acupoint Shuigou (GV 26) and non-acupoint on inhibiting the neuronal necrosis induced by the middle cerebral artery obstruction (MCAO) in rats through the morphological observation. METHODS: Forty two healthy adult male Wistar rats were randomly divided into a normal group, false-ope ration group, model control group, non-acupuncture group, Shuigou-acupuncture group and non-acupoint acupuncture group, 7 rats in each group. Besides the normal and false-operation groups, the experimental modal of MCAO was established in the other groups by using the Zea-Longa thread method. Acupoint Shuigou (GV 26) and non-acupoint (below the costal region) were selected respectively in the Shuigou-acupuncture group and non-acupoint acupuncture group for puncturing at 180 times/min for 5 seconds. Its effect was estimated by measuring the rate of the neuronal necrosis at the level of the light microscope and the degree of the neuronal necrosis at the level of the electron microscope. RESULTS: (1) At the level of the light microscope, comparing with the model control group (0.66 +/- 0.18), of the neuronal necrosis there were no significant differences in the rate of neuronal necrosis in the non-acupuncture group (0.67 +/- 0.34) and non-acupoint acupuncture group (0.59 +/- 0.11) (both P > 0.05), while it was significantly decreased in the Shuigou-acupuncture group (0.200 +/- 12) (P < 0.05). It indicates that no intervention and wrong (non-acupoint) intervention could light the damage of the neurons, however, only right intervention (Shuigou, GV 26) can obviously decrease the rate of the neuronal necrosis, showing with the specificity of acupoint. (2) At the level of the electron microscope, the ultrastructure of the involved neurons in the non-acupuncture group and non-acupoint acupuncture group is similar to that of the model control group, showing with the serious edema and structure damage. In contrast, the ultrastructure of the involved neurons in the Shuigou-acupuncture group is similar to that of the normal group and false-operation group, showing with light neuronal damage. CONCLUSION: Acupuncturing Shuigou (GV 26) could protect the involved neurons and inhibit the neuronal necrosis induced by the MCAO in rats, but acupuncturing the non-acupoint couldn't, which imply that there is the specificity of acupoint in the acupuncture.