In a massive scientific effort, hundreds of researchers have helped to map the connections between hundreds of thousands of neurons in the mouse brain and then overlayed their firing patterns in response to visual stimuli.

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 team of more than 150 researchers has proven him wrong by mapping a tiny portion of a mouse’s brain.