[Effect of electroacupuncture on ethology and cytokines of hippocampus in rats with dysmnesy].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on learning and memory impairment and cytokines of hippocampus in aging rats induced by D-galactose for exploring its underlying mechanism in the treatment of dysmnesy. METHODS: A total of 27 SD rats were randomly divided into control group (n = 9), model group (n = 8) and EA group (n = 10). Dysmnesy model was induced by intraperitoneal injection of D-galactose. EA (3 Hz, continuous waves, 1 mA) was applied to "Baihui" (GV 20) and "Zusanli" (ST 36) for 20 min every time and on alternate days, continuously for 21 days. Morris water maze tests were conducted to detect the rat's escape latency, percentage of swimming distance in the original platform quadrant and the total distance (SD/TD) and the percentage of swimming time in the platform quadrant after removal of the platform (spatial probe test) which were used for assessing the animals' learning and memory ability. The contents of IL-1beta, IL-6 and TNF-alpha in the hippocampus tissue were assayed by radioimmunoassay. RESULTS: Location navigation test showed that the escape latencies on the 2nd day and the 3rd day in model group were significantly longer than those of control group (P < 0.05), and the percents of SD/TD and swimming time in the platform quadrant were significantly lower than those of control group (P < 0.05, P < 0.01). In comparison with model group, the escape latency of EA group on the 3rd day was significantly shorter (P < 0.05), and the percent of SD/TD in the platform quadrant of EA group was significantly longer (P < 0.01). Compared with control group, IL-1beta and TNF-alpha contents in the hippocampus increased significantly in model group (P < 0.05, P < 0.01), while IL-6 content in model group decreased significantly (P < 0.01). In comparison with model group, the levels of IL-1beta and TNF-alpha in EA group decreased significantly (P < 0.05). CONCLUSION: EA can improve the learning-memory ability in dysmnesy rats, which may be closely associated with its effects in regulating the levels of cytokines in the hippocampus.