Decrease of BDNF mRNA expression in cortex of cerebral ischemia-reperfusion injury model rats

Objective To observe brain morphology and brain-derived neurotrophic factor(BDNF) mRNA expression in cortex of cerebral ischemia-reperfusion model rats.Methods Twenty-two male SD rats were randomly divided into three groups,normal group,sham group and model group.Focal cerebral ischemia-reperfusion model was induced for 2h by middle cerebral artery occlusion(MCAO) followed by 3d reperfusion.TTC staining was used to examine brain infarction,HE staining was to examine brain morphology,and RT-PCR was used to detect BDNF mRNA expression in the cerebral cortex.Results Rats in sham-operated group showed no brain infarction,no brain morphological changes and no significant difference in cortex BDNF mRNA expression compared with rats in normal group.Compared with rats in sham group,model group rats showed infarct in the left hemisphere,necrosis of large numbers of nerve cells,osteoporosis of cytoplasm and condensed stained nuclei in the left hemisphere.In addition,BDNF mRNA expression in cortex was significantly reduced.Conclusion Middle cerebral artery occlusion(MCAO) for 2h followed by reperfusion for 3d could cause cerebral ischemia-reperfusion injury,which might be related to the decreasing expression of BDNF mRNA.