Objective To observe the effect of electrocupuncture(EA)intervention at different time-points of post-modeling on behavior and hippocampal monoamine neurotransmitter noradrenalin(NE)

dopamine(DA)and 5-hydroxytrypamine(5-HT)contents in vascular dementia(VD)mice

so as to study its mechanism underlying improvement of VD.Methods A total of 60Kunming mice were randomized into sham-operation control(n=20)

VD model(n=20)

EA-day(D)-1(EA treatment was given from the 1st day on after modeling

n=10)

EA-D-3(EA was given from the 3rd day on after modeling

n=10)groups. VD model was established by occlusion of the bilateral cervical common arteries and reperfusion.EA(2Hz/80Hz)was applied to "Baihui"(GV 20)

"Dazhui"(GV 14)

"Zusanli"(ST 36)and"Geshu"(BL 17)for 10min

once daily for 15days.Hippocampal NE

DA and 5-HT contents were assayed by fluorospectrophotometry.The mouse's learning-memory ability was assessed by step-down tests.Results In comparison with the sham-operation control group

the learning-memory ability(marked increase of reaction time and error times

decrease of step-down latency)was apparently lowered in the model group(P<0.01).The hippocampal NE

DA and 5-HT contents were significantly lower in the model group than in the sham-operation group(P<0.01). Compared with the model group

the mice's learning-memory ability(marked decrease of reaction time and error times

increase of step-down latency)was significantly increased in EA intervention groups(P<0.01)

and hippocampal NE

DA and 5-HT levels were significantly increased(P<0.01)

and the effect of EA-D-3group was obviously better than that of the EA-D-1group(P<0.05

P<0.01).Conclusion EA can improve the VD mice's learning-memory ability

which is closely related to its effects in up-regulating hippocampal NE

DA and 5-HT contents

and the effect of later EA intervention after modeling is better.