Expression of brain derived neurotrophic factor after nerve trunk stimulation by electroacupuncture in rats with cerebral ischemia/reperfusion

Objective To observe the expression of brain derived neurotrophic factor(BDNF) mRNA after nerve trunk stimulation by electroacupuncture in rats' cortex with cerebral ischemia/reperfusion. Methods The MCAO model was established by ligation of the artery for 1 hour, and then reperfusion was conducted for 2h, 6h, 12h, 24h, 2d, 3d, 7d and 14d.The expression of BDNF mRNA after the cerebral ischemia/reperfusion injury (MCAO group) was observed and comparison was made between the electroacupuncture group and the control group. Results The number of cells with positive expression of BDNF mRNA in the cortex after 2h, 6h, 12h, 24h, 2d and 3d of reperfusion was more than that in the control group (all P0.01), but after 7d and 14d of reperfusion,there had no difference between the two groups (all P0.05). At 2h of reperfusion, the amount of the positive cells peaked and was much more than that at the 6h and 12h time points (P0.05). At 24h reperfusion, the amount of the positive cells had reached another apexes and much more than the other time points respectively (P0.05).In the electroacupuncture group, at 2h reperfusion,the number of the positive cells demonstrated no significant increase when compared with that of the MCAO group (P0.05),but after 6h reperfusion, a significant increase of expression of BDNF mRNA was observed against the MCAO group and control group, and the increase lasted to 14d after reperfusion. Conclusion Nerve trunk stimulation with electroacupuncture could improve and maintain the expression of BDNF mRNA for a long time, and this might contribute to the protection effect of electroacupuncture against the brain ischemia/reperfusion injury.