BDNF and major depressive disorder: Liang et al., 2023 demonstrated that EXD significantly enhanced the protein and mRNA levels of BDNF, TrkB, and CREB in the hippocampus of the MS-RS-induced depression mouse model. Additionally, Zhang et al. (2021a) utilized ovariectomy combined with CUMS to establish a mouse model of menopausal depression and demonstrated that EXD upregulated the BDNF levels in the hippocampus of the perimenopausal depression mouse model.