A major Alzheimer’s risk gene may shrink brain cells years before symptoms

Researchers have uncovered a possible reason why the Alzheimer’s risk gene APOE4 can disrupt the brain long before memory problems begin. In mice, APOE4 increased a protein called Nell2, shrinking neurons and making memory circuits unusually active. That early hyperactivity predicted worse memo...

Source: [ScienceDaily](https://www.sciencedaily.com/releases/2026/08/260821012234.htm)