Microglia decline after age 50 as inflammatory blood-derived immune cells infiltrate the hippocampus, potentially driving neuroinflammation and dementia.
https://www.foxnews.com/health/major-brain-changes-occur-around-age-50-could-impact-dementia-risk
https://www.foxnews.com/health/major-brain-changes-occur-around-age-50-could-impact-dementia-risk