Thanks to a mouse watching clips from “The Matrix,” scientists have created the largest functional map of a brain to date.

Researchers mapped 84,000 neurons in a mouse brain after it watched video clips. The 3D map links structure and activity.

This image provided by the Allen Institute on April 8, 2025, shows a digital representation of neurons in a section of a mouse's brain, part of a project to create the largest map to date of brain ...

This image shows a digital representation of neurons in a section of a mouse's brain, part of a project to create the largest map to date of brain wiring and function, in Seattle, Wash.