Stanford researchers create mice with half human brain tissue using cerebral organoids

Scientists at Stanford have implanted human cerebral organoids into mice whose own brain regions were genetically removed, producing neuro-chimeric animals whose brains are about half human by volume.

The approach aims to give researchers a more realistic model for studying human brain development and neurological diseases, overcoming the long-standing challenge of obtaining human brain tissue for experiments.

The work, reported in Nature, confirmed the presence of human-derived cells in the brains of three-month-old chimeric mouse pups.

However, the creation of mice with substantial human neural tissue raises significant ethical questions about the moral status of such animals and the implications of further advances in brain chimerism.