Envisioning a fly brain

Scientists have painstakingly mapped 379 neurons in a fruit fly’s brain that help the insect detect motion (shown). Dmitri Chklovskii of HHMI’s Janelia Farm Research Campus in Ashburn, Va., and colleagues digitally re-created these cells — and their 8,637 connections — to understand flies’ ability to sense moving objects, a skill that’s obvious to anyone who has ever used a flyswatter. The neurons’ shapes offer clues to how visual information winds from cell to cell through the fly brain. Some of these neurons seem primed to respond to motion in one of four directions, for instance.