Your Brain's Caretakers Age Secretly—And We're Finally Reading Their Diary

Microglia are your brain's custodial cells; as we age, they accumulate tiny mutations like a building inspector gradually marking up a decades-old structure, revealing the long, invisible wear of time.

This means we can now trace how aging actually rewrites the brain's immune cells at the genetic level, which could help explain why neurological disease risk climbs with age.