Microglial State Switch Reveals Dual Paths to Alzheimer’s Resilience

A human-brain study identifies six tissue domains and a pivotal transition in microglia from an amyloid-associated inflammatory state to a tau-associated antigen-presenting state; resilience against dementia arises via two routes—octogenarians who block progression and centenarians whose late microglial activation is uncoupled from tau—pointing to therapies that preserve early microglial responses or target pathways like TREM2 to delay cognitive decline.