How microglia age: the brain immunity shift driving neurodegeneration

Microglia, the resident immune cells of the central nervous system, adopt distinct behavioral polarizations depending on their tissue environment. In aging, these cells abandon their maintenance function and shift toward a pro-inflammatory defensive state, a transition that drives cognitive deterioration and accelerates neurodegenerative diseases like Alzheimer's. Researchers have identified consistent alterations in microglial molecular signatures and morphology across both healthy aging and disease pathology, pinpointing oxidative stress and cellular senescence as core mechanisms driving the transition to a chronic reactive state. Understanding these molecular transformations is essential for designing therapeutic interventions that restore the anti-inflammatory microglial phenotype before tissue damage becomes irreversible. For the longevity-focused biohacker and premium wellness consumer, this opens a pathway to strategies aimed at recalibrating microglial function before neuroinflammation locks in age-related cognitive decline.