Two teams of neuroscientists have reconstructed the wiring of tiny pieces of the brain and related it to the function of individual cells. To understand how the brain works, you need to know what connects to what. But the brain has so many cells, making so many connections, that this is a big challenge. Using a souped-up electron microscope with a sophisticated slicing system, along with lots of computing power, the scientists mapped tiny specks of the mouse visual system. The team at the Max Planck Institute for Medical Research in Germany focused on the retina, while researchers at Harvard University in Boston looked at a bit of the visual cortex, the area of the brain where information from the retina is processed. The teams confirmed previous ideas about how neurons in these areas help mice to see. The pair of papers is published in this week’s Nature.

Marvel at the detail of the brainy reconstructions in this Nature Video. The video also shows how the new technique works, and how the research is part of ‘connectomics’, which aims to map the brain at many different scales.