BDNF, a neurotrophin essential for the survival and function of serotonergic, hippocampal, and cortical neurons (Allen et al., 2013) is often reduced in AD, contributing to Aβ accumulation, tau phosphorylation, neuroinflammation, and neuronal apoptosis (Gao et al., 2022; Wang et al., 2023; Wang et al., 2019). This evidence concerns the gene MAPT and Alzheimer disease.