BACKGROUND: Delayed neuronal death after total cerebral ischemia may accompany with apoptosis, but acupuncture may play a certain role in protecting nerve through inhibiting ischemic neuronal apoptosis.OBJECTIVE: To observe the effect of acupuncture on neuronal apoptosis in rats after cerebral ischemia and analyze its cerebral protective mechanism.DESIGN: Contrast observation among groups.SETTING: Heilongjiang University of Traditional Chinese Medicine.MATERIALS: A total of 30 male healthy Wistar rats of general grade and weighing (250±20) g were randomly divided into three groups, including sham operation group, cerebral ischemia group and acupuncture group with 10 rats in each group. Apoptosis in situ kit was provided by Baolingman Company,Germany.METHODS: The experiment was carried out in the Laboratory Center, Heilongjiang University of Traditional Chinese Medicine from May to November 2004. ① Rats in the cerebral ischemia group and the acupuncture group were used to establish total cerebral ischemic models with four vessels occlusion; in addition, models in the sham operation group were established with the same method as mentioned above.However, four vessels of rats in the sham operation were exposured and cerebral ischemia did not occur. Rats in the acupuncture group were given acupuncture treatment after operation. Needle of 40 mm in length was used to acupuncture bilateral Zusanli (St 36) and Quchi (LI 11) with the depth of 3 mm, and then bilateral acupoints were connected with KWD-808Ⅱ omnipotenc impulse electro-therapeutic apparatus (frequency: 1 Hz;thin waves; voltage: 2 V) once a day for totally 30 minutes. Meanwhile, needle of 25 mm in length was used to acupuncture Baihui (Du 20) with the depth of 3 mm, and then the needle was twirled once every 5 minutes for 30 minutes in total. The course was 7 days. ② Neuronal injuries in hippocampal CA1 area after cerebral ischemia were observed with Nissl body staining method at 7 days after treatment; neuronal apoptosis was observed with TUNEL staining; manifestations of neuronal apoptosis in cerebral cortex and hippocampal CA1 area were observed with electron microscope.MAIN OUTCOME MEASURES: Neuronal injuries in hippocampal CA1 area after cerebral ischemia;neuronal apoptosis in cerebral cortex and hippocampal CA1 area after cerebral ischemia; morphological changes under electron microscope.RESULTS: Among 30 Wistar rats, 24 rats were involved in the final analysis. ① Expression of positive urons in cerebral cortex and hippocampal CA1 area with Nissl body staining: Neuronal defect was obvious in cerebral cortex and hippocampal CA1 area in the cerebral ischemia group as compared with that in the sham operation group (P ＜ 0.05), and neuronal defect was decreased in hippocampal CA1 area in the cerebral ischemia group as compared with that in the acupuncture group (P ＜ 0.05). ② Expression of positive neurons in cerebral cortex and hippocampal CA1 area with TUNEL staining: Positive neurons with TUNEL staining were not observed in the sham operation group, but positive neurons were increased in the cerebral ischemia group as compared with those in the acupuncture group (P ＜0.05). ③ Observational results of electron microscope: Neuronal apoptosis was not found in the sham operation group; neuronal apoptosis was rarely found in the acupuncture group; neuronal apoptosis was typical in the cerebral ischemia group.CONCLUSION: Delayed neuronal death after total cerebral ischemia may accompany ith apoptosis, but acupuncture may play a certain role in protecting nerve through inhibiting ischemic neuronal apoptosis.