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

A team of over 150 scientists has achieved what once seemed impossible: a complete wiring and activity map of a tiny section of a mammalian brain. This feat, part of the MICrONS Project, rivals the ...

and specific areas within the hippocampus (the part of the brain that helps with learning, memory, and spatial navigation). All participants underwent standardized tests to assess their verbal memory.

In 1979, biologist Francis Crick claimed it would be impossible to create an accurate diagram of the brain’s wiring and neuronal activity—even within just a cubic millimeter of brain tissue. Now, a ...