Objective To observe the effect of electroacupuncture(EA) combined with Ginkgo biloba extract(GBE 50) on learning-memory ability and hippocampal cytokine contents in aging rats for exploring its underlying mechanism in the treatment of dysmnesy.Methods Forty-five SD rats were randomly divided into control(n=9)

model(n=8)

EA(n=10)

GBE 50(n=9) and EA+GBE 50(n=9) groups.The dysmnesy model was established by D-galactose intraperitoneal injection for 42 days.EA(3 Hz

1 mA) was applied to "Baihui"(GV 20) and "Zusanli"(ST 36) for 20 min

once every other day for 21 days.The learning-memory ability was detected by Morris water maze tests.The levels of IL-1β

IL-6 and TNF-α in hippocampus were examined by radioimmunoassay.Results Compared with control group

the mean escape latency(MEL) of the rats in model group was significantly greater on the 2nd and 3rd day training(P<0.05

P<0.01)

and the percent of swimming distance(PSD) in the target quadrant was shortened significantly(P<0.01).Compared with model group

the MEL values of the rats in EA

GBE 50 and EA+GBE 50 groups were significantly shortened(P<0.05

P<0.01)

and the PSD values of the later 3 groups increased considerably(P<0.01).Comparison among the EA

GBE 50 and EA+GBE 50 groups showed that the MEL of EA+GBE 50 was obviously shorter than those of EA and GBE 50 groups(P<0.05).Compared with control group

the contents of IL-1β and TNF-α in hippocampus in model group increased significantly

but IL-6 decreased markedly(P<0.05

P<0.01).In comparison with model group

the IL-1β contents of EA

GBE 50 and EA+GBE 50 groups

and TNF-α of EA and EA+GBE 50 groups were reduced significantly(P<0.05

P<0.01);and the contents of IL-6 in GBE 50 and EA+GBE 50 groups increased apparently(P<0.01).No significant differences were found between model and EA groups in IL-6 levels

and between model and EA+GBE 50 groups in hippocampal TNF-α levels(P>0.05).Conclusion Both EA and GBE 50 can improve the dysmnesy rats' learning-memory ability

which may be closely associated with their effects in regulating hippocampal IL-1β

IL-6 and TNF-α levels to relieve the inflammatory reaction.Combined administration of EA and GBE 50 has a synergic effect.