BDNF and mood disorder: Fortunately, a large number of studies have found that the natural plant metabolite PF could upregulate the expression of plasma BDNF and BDNF mRNA in the hippocampus and frontal cortex (Mu et al., 2020; Mao et al., 2009a; Qingwei, 2018; Mao et al., 2012b), as well as postsynaptic density protein 95 (PSD 95) in model animals with mood disorders (Liu S. C. et al., 2019), thereby preventing CUMS-induced synaptic plasticity defects and providing neuroprotection in animal models of mood disorders.