Objective: To observe the effect of electroacupuncture (EA) on hippocampal apoptosis and learning-memory ability in vascular dementia (VD) mice so as to investigate its underlying mechanism in the treatment of VD patients.
Methods: Kunming mice were randomly divided into sham-operation (sham, n = 13), model (n = 15), EA (n = 16) and Nimodipine (intragastric gavage, 30 mg/kg for 15 days, n = 15) groups. VD model was duplicated by occlusion of bilateral carotid arteries and reperfusion. EA (2-80 Hz, 2 mA) was applied to "Dazhui" (GV 14), "Baihui" (GV 20), "Geshu" (BL 17) and "Zusanli" (ST 36) for 10 min, once daily for 15 days. Step-down and step-up tests were performed to assess the animal's memory and learning abilities separately; and the terminal deoxynucleotidyl transferase-mediated dUTP-nick end-labeling (TUNEL) method was used to display the apoptotic cells of the hippocampus tissue.
Results: In comparison with sham group, the animals' reaction time upon electric shock stimulation, both step-up and step-down error times, and hippocampal apoptosis number in model, EA and Nimodipine groups increased significantly (P<0.01), while the reaction latency upon electric shock of model, EA and Nimodipine groups decreased significantly (P<0.01). Compared with model group, the reaction time, both step-up and step-down error times and hippocampal apoptosis number of both EA and Nimodipine groups decreased significantly (P<0.05, P<0.01); while the reaction latency of EA and Nimodipine groups increased considerably (P<0.01). Comparison between EA and Nimodipine groups showed that the reaction latency of EA group was obviously longer than that of the later group (P<0.01), and the step-down error times of EA group was markedly lower than that of Nimodipine group (P<0.05). No significant differences were found between these two groups in other indexes (P>0.05).
Conclusion: EA can ameliorate VD mice's learning-memory ability, which may be closely related to its effect in reducing hippocampal apoptosis.