🚨🇺🇸 SCIENTISTS SWAP BRAIN CELLS WITHOUT WIPING OUT IMMUNE SYSTEM Your brain’s microglia - tiny immune cells that clean up debris and protect neurons - are hard to replace if they’re broken. Normally, doctors use full-body stem cell transplants, which require chemo to destroy your immune system. That’s dangerous and can be fatal. Stanford researchers found a shortcut: skip the body, target only the brain. They used Sca1⁺ myeloid progenitors (not full stem cells), cleared space only in brain tissue, and injected the new cells directly. The result? Healthy microglia moved in, fixed genetic problems, and caused no immune rejection. In mice with Sandhoff disease - a fatal disorder where bad microglia can’t clean toxic GM2 ganglioside - the treatment lowered GM2, improved health, and extended lifespan. Human lab-grown cells worked too in animal tests. Think brain “cell swap” without bulldozing the whole neighborhood. Source: Nature