Neuroscientist explains how his team grew human brain tissue in mice and breaks down what they found

Researchers at Stanford University developed a method to install millions of lab-grown human brain cells into mice, creating animals with partially human cerebral cortexes. The study, published in the journal Nature, aims to better understand and develop treatments for neurodegenerative diseases that are hard to replicate in non-human models. Mice were genetically altered to lack most of their cerebral cortex tissue, then implanted with human cortical organoids—three-dimensional clusters of brain cells grown from reprogrammed skin cells. The transplanted human neurons survived and thrived, forming functional connections within the mice’s brains and spinal cords. Sergiu Pașca, a professor at Stanford University, emphasizes that this breakthrough offers new opportunities to study human-specific neurological conditions such as autism, epilepsy, schizophrenia, and cerebral palsy, but stresses these are not "mice with human-like thoughts." The research was conducted under strict ethical guidelines.