Why did Stanford scientists put human brain cells in a mouse?

Researchers use human neural cells or organoid-derived tissue in animals to study development and disease in a living system that a dish cannot reproduce. Blood flow, sensory input, and surrounding cells can reveal how human cells mature or malfunction, potentially improving models of neurological disorders. The work raises serious animal-welfare and moral-status questions, so the scientific value depends on independent oversight, clear limits, and avoiding exaggerated claims about consciousness.