Human neurons inside an animal brain: Stanford's "alien-cortical mice" study

Stanford Medicine researchers have created a new method in which human brain tissue takes root and grows inside mice engineered to lack a cortex. The model, called "alien-cortical mice," is described as an advanced platform for studying brain disorders that arise before birth.

The integration of human neurons into an animal brain has also raised ethical debates about neurohybrid research; researchers say it could become a platform for testing new treatments in vivo.

Why this matters: it opens a new way to study human brain development and disease directly.

At the same time, a debate is needed on the limits of medical research that crosses species.