Blood–brain barrier

It begins as a quiet breach so small you’d never notice. Imagine the brain as a city behind high, guarded walls, with sentries carefully screening every visitor. For most of our lives, those gates stand firm, keeping harmful invaders out while letting life-sustaining nutrients in. But in Alzheimer’s disease, those defenses weaken. Tiny gaps form. …

A drug already carrying years of human safety data from trials for Parkinson’s disease and ALS just produced a striking result in a different disease altogether. Researchers at Monash University gave the compound to mice bred to develop Alzheimer’s, then watched what happened inside the animals’ brains over eight weeks of treatment. Numbers from that …