A small piece of human brain tissue was placed into a newborn mouse. What happened over the next few months was far more extensive than a simple transplant. The tissue grew through the space where the mouse’s cerebral cortex would normally have developed. It formed different types of human cortical neurons.
Some of those neurons sent long projections through the mouse brain and into its spinal cord. By three months, human-derived tissue made up 91.9% of the measured cortical tissue volume in the transplanted animals. The experiment comes from Stanford researchers led by neuroscientist Sergiu Pașca. Their findings were published in Nature on September 16, 2026.
