Objective: To observe the effect of electroacupuncture(EA) on the expression of brain-derived neurotrophic factor(BDNF) in substantia nigra compacta(SNC) of Parkinson's disease(PD) mice so as to study the synaptic plasticity.Methods: Twenty-four male mice(C57BL/6J) were averagely and randomly divided into normal control

EA

model and model +EA groups.PD model was induced by injection(i.p.) of 1-methyl

4-phenyl-1

2

3

6 tetrahydropyridine((30 mg/kg)).EA((2-100 Hz)

2-(4 V)

dense-sparse waves) was applied to "Hegu"(LI 4) and "Taichong"(LR 3) for(20 min)

once daily.After 21 treatments

the mice were killed for sampling SNC tissue which was then cut into sections for detecting the expression of BDNF and BDNF mRNA by immunohistochemical and in situ hybridization techniques respectively.Results: Both immunohistochemical and in situ hybridization assays showed that compared with normal control group

the number of BDNF and BDNF mRNA positive cells and integral optical density(OD) values of model group were significantly lower(P<0.05

0.01);compared with model group

the number of BDNF and BDNF mRNA positive cells and integral OD values in model +EA group were significantly higher(P<0.05

0.01).No significant differences were found among normal control

EA and model +EA groups in these indexes.Conclusion: EA can inhibit the down-regulation of expression of BDNF and BDNF mRNA of SNC in PD mice which maybe contribute to its effect in raising the synaptic plasticity of the degenerative dopaminergic neurons.