Study Of Brain Derived Neurotrophic Factor Expression And Electroacupucture Intervention In Rats With Cerebral Ischemia/Reperfusion

Objective: Brain derived neurotrophic factor (BDNF), a main ingredient of neurotrophic factors family, plays an important role in the recovery of cerebral ischemia, but its expression change with time after MCAO has not been well defined so far, electroacupuncture (EA) can promote the functional rehabilitation of cerebral ischemic injury patients and abate brain damages. However, it is still not clear if EA is involved in the protection mechanisms of ischemic neuronal damages. In the present study, the protection mechanism of BDNF and EA in cerebral ischemic damages is explored by means of experimental observation of BDNF mRNA expression change with time in rats' cortex and corpus striatum after local MCAO and the effect of EA on BDNF mRNA expression after MCAO.Methods: To make Ih for local cerebral ischemia and reperfusion for 2h, 6h, 12h, 24h, 2d, 3d, 7d and 14d animal models by rats MCAO means and to study cerebral ischemia reperfusion injury and the timely change of BDNF mRNA expression with the protection of EA, stimulating the trunks of brachial plexus, in cerebral ischemic changes by means of in situ hybridization.Results: BDNF mRNA expressed in the area of cortex and corpus striatum with the basal level in sham operated control, and expressed mainly in the ischemic sphere and distributed mainly in the area of cortex and corpus striatum. BDNF mRNA expression rapidly increased to a moderate or high level 2h after cerebral ischemia and 24h to maximumlasting to three day, and lowered to basal level in 14d. However, in corpus striatum, BDNF mRNA expressed slowly to maximum in 2d and last to 14d still with significance. 2h after MCAO, BDNF mRNA expression had no increasing in EA intervention team comparing with simple cerebral ischemia team, and after 6 hours a prominent increased BDNF expression emerged and last to 14d still with high expression. Conclusion: Cortex has better BDNF protection mechanism with rapid and high BDNF mRNA expression, but its BDNF mRNA expression course is shorter than corpus striatum. And corpus striatum shows slow BDNF response to neuronal ischemia/reperfusion with long course BDNF protection mechanism. EA can increase BDNF expression 6h after MCAO, and has protection mechanism in the middle and late course of cerebral ischemic damage.