Influence of Electroacupuncture Preconditioning on Surviving Neuron Density of Cerebral Cortex in Rats with Temporary Cerebral Ischemia-reperfusion

Objective:To observe the effect of electroacupuncture preconditioning (EAP) on neurons of the cerebral cortex in cerebral ischemia-reperfusion (IR) rats. Methods: 95 Wistar rats were randomly divided into normal control group (group A, n=5), sham-ischemia control group (group B, n=15), EAP control group (group C, n=15), cerebral IR control group (group D, n=15), EAP and cerebral IR group (group E, n=45). E group was further evenly divided into 0.5 hr, 1.5 hr and 3 hr subgroups (i.e. IR was conducted 0.5, 1.5 and 3 hours after EA). Temporary cerebral IR injury model was established by using common carotid artery blood drainage method. Shenshu (BL 23) and Baihui (GV 20) were punctured and stimulated electrically with an EA therapeutic apparatus (8～80 Hz, dense-sparse waves, 3 V, 4×10 min). After treatment, these rats of group B, C, D and 3 subgroups of group E survived for 1, 3 and 7 days (i.e. IR-1d, IR-3d and IR-7d) respectively, and were then killed for taking out the brain tissue which was to be cut into sections after perfusion fixation, with the tissue sections being stained with HE method. Then the surviving neurons were counted under microscope. Results: There were no significant differences among group A, B and C at IR-1d and between group B and C at IR-3d and IR-7d in the density of the cerebral surviving neurons, indicating that sham-operation and EAP had no apparent influence on cerebral neurons. Compared with group A, the density values of neurons of group D at IR-1d, IR-3d and IR-7d all reduced significantly (P0.05). Comparison among E 0.5 hr, E 1.5 hr and E 3 hr subgroups of group D,displayed that the density values of E 0.5 hr subgroup at different IR time-courses and E 1.5 hr subgroup at IR-3d and IR-7d all evidently higher than those of group D(P0.05), suggesting that EAP has an apparent anti-IR injury action. But there were no significant differences among E 1.5 hr and E 3 hr and D groups at the 3 time-courses (P0.05).Conclusion: EAP can resist the injury of neurons of the cerebral cortex induced by temporary cerebral ischemia-reperfusion, which is better at 30 min after EAP than at 90 min and 180 min.