急、慢性应激对大鼠海马BDNF表达的时序性影响

 摘要：目的 观察急性应激和重复低强度强迫游泳应激后大鼠海马BDNF及BNDF mRNA在不同时间点的动态表达；观察慢性应激条件下动物行为改变。方法 采用反转录－聚合酶链反应（RT-PCR）方法，观察急性和慢性应激对大鼠海马BDNF mRNA的动态表达的影响；采用Western bloting方法检测海马BDNF 蛋白表达量的变化。结果 急性应激导致动物海马BDNF mRNA及其产物表达增加，3小时后表达逐渐降低，与对照组比较差异具有显著性；慢性应激后BDNF蛋白表达呈降低趋势，并在多时点显著低于急性应激组 (p<0.05)。结论 急性应激显著增强大鼠海马BDNF表达；慢性应激组大鼠BNDF mRNA表达存在一定适应现象，且多时点表达量显著低于急性应激组。

Effect of acute and chronic stress on the expression of BDNF and BDNF mRNA in the hippocampus of rats

Objective To study the change of BDNF expression in hippocampus and prefrontal lobe of rats by acute and chronic forced-swimming stress,and to study the effect of different intensity stress on the behaviors of rats.Methods The change of BDNF mRNA expression in hippocampus was observed by RT-PCR,and Western blot was used to explore the expression of BDNF protein in rat hippocampus.Results Acute stress resulted in elevated expression of BDNF mRNA and protein,and the expression of BDNF became lower and lower after 3 hours(P<0.01).Meanwhile the chronic stress led to the lower level expression of the BDNF as compared with acute stress group.Conclusions Acute stress results in the high level expression of BDNF in hippocampus.Chronic and repeated stress lead to the habituation expression of BDNF,which is lower than that of acute stress group.