BDNF and dementia: As a neurotrophic factor, BDNF facilitates neuronal plasticity and survival, which is consistent with reduced levels of BDNF in patients with dementia.48 A33-induced increases in BDNF may rebalance the dynamics in the brain from neurodegeneration toward neural regeneration,49 accounting for the potential mechanism whereby A33 alleviated the behavior impairment in AlD mice.