Researchers have created the largest and most detailed wiring diagram of a mammalian brain to date, by mapping cells in a cubic millimetre of a mouse’s brain tissue. In a landmark achievement, the diagram also details the activity of individual neurons on a large scale―a neuroscience first.

Scientists say the map of a speck of a mouse's brain could be as transformative as the Human Genome Project. Here's what to know.

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.