Meet a mouse whose brain cortex is made up of human cells

Researchers at Stanford engineered mice lacking most cortical and hippocampal cells, then injected human neural organoids into their brains. The human cells proliferated, occupying up to half the brain volume and improving maze-based memory performance compared to the cell-deficient mice. The study demonstrates that post-natal human neural tissue can integrate and function within a mouse nervous system, offering a model for brain injury research.