After exposure to chronic unpredictable mild stress (CUMS), these rats exhibit anxiety (Zhang et al., 2019a) and depression-like behavior (Zhang et al., 2019b), the mechanism of which mainly involved increasing concentrations of glucocorticoids, imbalance between microglia M1 proinflammatory phenotype and M2 anti-inflammatory phenotype polarization, and decreasing expression of the astrocyte marker glial fibrillary acidic protein (GFAP), the brain-derived neurotrophic factor (BDNF) and the tyrosine kinase B receptor (TrkB). The gene discussed is BDNF; the disease is major depressive disorder.