Immune Cells Discovered to Flood into the Aging Human Brain, Challenging Prior Beliefs

New research from Stanford University has revealed that large numbers of immune cells from the rest of the body enter the human brain as people age, where they can transform into microglia, the brain's specialized immune cells. This discovery overturns the long-standing assumption that the brain's immune system remains largely separate from the body's immune defenses throughout life. The findings could reshape the understanding of brain aging and open new avenues for treating neurological diseases.