Brain cell regulation changes significantly from age 50

A new study published in Science reveals that human brain cells undergo significant changes starting around age 50, particularly regarding genome regulation. This process involves the complex mechanisms by which cells control which genes are active.

Research focused on the hippocampus, a region vital for learning and memory, found that microglia—the brain's immune cells—decrease sharply between the ages of 50 and 75. These cells are increasingly replaced by cells with molecular characteristics similar to immune cells that show higher signs of inflammation, potentially contributing to chronic inflammation in the aging brain.

Additionally, the study noted a significant decline in cells responsible for maintaining the blood-brain barrier, which protects the brain from harmful substances in the bloodstream. These findings suggest that brain aging is a complex process involving simultaneous changes across multiple systems, including immune cells and blood vessels.