Expression of brain-derived neurotrophic factor and TrkB gene in the prefrontal cortex of the post-stroke depression in the rat model

Objective To explore the expression of brain-derived neurotrophic factor(BDNF) mRNA and high-affinity receptor TrkB mRNA in the prefrontal cortex of the post stroke depression in the rats. Methods Focal cerebral ischemic rat models were made with thread embolism method. Post stroke depression(PSD) rat models were established with comprehensive separately breeding and chronic unpredicted mild stress (CUMS) on this basis. Normal control group, depression group and stroke group were used to compare with PSD group. 8 rats were used in each group. RT-PCR was employed to detect gene expression of BDNF and TrkB. GADPH was used as control at 29th day after the CUMS. Results The results showed that the gene level of BNDF in the prefrontal cortex of rat subjected PSD was lowest among all groups(0.75±0.21). And the expression of BNDF mRNA in the normal control rats was (0.83±0.16)and was highest among all groups.While it was(0.77±0.22)in the depression group and(0.80±0.20)in the stroke group.The one-way analysis of variance showed the expression of BDNF mRNA in the prefrontal cortex decreased significantly in the PSD group compared with normal control rats(P 0.05). Conclusion The downregulation of BDNF mRNA in the prefrontal cortex may be responsible for the pathogenesis of PSD. Key words: Post stroke depression; Prefrontal cortex; Brain derived neurotrophic factor; Tyrosine kinase receptor B