Science

Stanford researchers grow human brain cells inside genetically altered mice

The Guardian reports that scientists transplanted human brain cells into mice missing key cerebral structures to study neurological disorders.

Updated Sep 16, 2026 · 22:12 UTC6 reports

The short version

Stanford University researchers engineered newborn mice without a cortex and hippocampus, filling the space with millions of human brain cells.[The Guardian]
Three months after transplantation, the human tissue integrated into the blood supply and occupied roughly half of the mice's brain volume.[The Guardian]
The study aims to assist in research and treatment development for psychiatric and neurological conditions like schizophrenia and epilepsy.[The Guardian]
Ethical concerns and scientific questions remain regarding animal welfare and how accurately artificial models reflect natural human brain development.[The Guardian]

Stanford University scientists transplanted human brain cells into mice engineered without a cerebral cortex or hippocampus.[The Guardian]
The mice lacked approximately 14 million native brain cells and gained about 4 million human cells.[The Guardian]
Three months after surgery, the human brain tissue connected to the blood supply and occupied around half of the rodent brain's volume.[The Guardian]

It remains uncertain how accurately this artificial model reflects natural human brain development and whether the tissue raises ethical concerns over animal welfare or consciousness.[The Guardian]

Outlet counts describe coverage, not independent confirmation. Reports may share a wire service or original source.