A mouse brain is not supposed to contain human cells. In a study published in Nature on 16 September 2026, a Stanford Medicine team reported a mouse brain that largely does — and the human tissue inside it didn't just survive, it wired itself into the rest of the animal's nervous system. Mice Engineered Without Their Own Cortex The cerebral cortex is the brain's outer … [Read more...] about Scientists Grew Human Brain Tissue Inside Mice — and the Cells Wired Themselves Into the Animals’ Nervous Systems