Objective: To observe the effect of electroacupuncture (EA) of "Xiusanzhen" [bilateral "Yingxiang" (LI 20) + "Yintang" (GV 29)] on learning-memory ability and hippocampal somatostatin (SS) and arginine vasopressin (AVP) contents in vascular dementia (VD) rats.
Methods: Forty SD rats were randomly divided into control, VD model, VD plus olfactory bulb lesion (OBL, destroyed by electro-coagulation) and EA groups, with 10 cases in each. VD model was established by 4-vessel occlusion. Morris maze tests were conducted for evaluating the rats' learning and memory ability. EA (1-3 mA, 80/100 Hz) was applied to bilateral LI 20 and GV 29 in VD + OBL and EA groups for 10 min, once daily (except Saturdays and Sundays) for 6 weeks. The contents of SS and AVP in hippocampus tissue were measured by radioimmunoassay.
Results: In comparison with control group, the average escape latency (AEL) prolonged significantly and the target-platform crossing times (TPCT) decreased remarkably in VD model group (P < 0.01). In comparison with VD model group, the AEL was shortened and TPCT increased remarkably in EA group (P < 0.01). No significant differences were found between VD model and VD + OBL groups in the AEL and the TPCT (P > 0.05). Hippocampal SS and AVP contents in VD model group were significantly lower than those in control group (P < 0.05), while those in EA group were markedly higher than those in VD model group (P < 0.05). No significant differences were found between VD model and VD + OBL groups in SS and AVP contents (P > 0.05).
Conclusion: EA of "Xiusanzhen" can improve VD rats' learning-memory ability, which may be related to its effects in raising hippocampal SS and AVP contents and to the intact olfactory pathway.