Objective To investigate the effect of manual acupuncture on long-term potentiation(LTP)in CA1 area in hippocampal slices from rats suffered from diabetes mellitus(DM)and cerebral ischemia(CI).Methods A total of 54 female Wistar rats were randomly divided into 5 groups:normal control(Con)

CI

DM+Sham-CI

DM+CI and DM+CI+acupuncture(Acup).DM model was established by i.p.of streptozotocin(60 mg/kg)

and CI model duplicated by bilateral common carotid arteries occlusion and reperfusion."Baihui"(GV 20)

bilateral "Sanyinjiao"(SP 6)and "Pishu"(BL 20)or "Baihui"(GV 20)

bilateral "Shenshu"(BL 23)and "Zusanli"(ST 36)were punctured alternatively and stimulated manually

once every other day for 15 times.Hippocampal slices were taken 40 days after modeling.LTP in hippocampal CA1 induced by high frequency stimulation(100 Hz

100 pulses)of Schaffer collaterals and population spikes(PS)were recorded by using glass micropipettes.Results No significant differences were found between DM+CI and normal control groups in the shape and amplitude of PS(P>0.05).After stimulation of Schaffer collaterals

the amplitude and slope rate of PS in hippocampal CA1 of DM+CI rats were decreased significantly in comparison with normal control group(P<0.05

P<0.01).While compared with DM+CI group

both the amplitude and slope rate of PSin DM+CI +Acup groupincreased significantly(P<0.05

P<0.01)

suggesting basic restoration of LTP after acupuncture.Conclusion Acupuncture can promotethe recovery of DM+CI induced decline of the amplitude and slope rate of PS

which may contributetoits effect ini mproving memory abilityin DM+CI rats through regulating hippocampal neuronal synaptic plasticity.