BDNF and Lewy body dementia: SFN → ↑ Nrf2 → ↑ microglial arginase 1+ phenotype by initiating TREM2 transcription in mPFC, improving DLB in CSDS mice. Nrf2 KO ↓ TREM2 and microglial arginase 1+; both → DBL. Nrf2 KO and ↓ TREM2 expression associated with ↓ BDNF/TrkB signalling pathway