How to reroute a broken neural circuit Scientists genetically manipulate worms to bypass damaged neurons — and study how the mind perceives the environment January 19, 2021 • By Sabrina Richards / Fred Hutch News Service Hutch neuroscientist Dr. Jihong Bai explains why he studies tiny worms called nematodes. Video by Robert Hood / Fred Hutch News Service Nematodes, minuscule worms that are partial to rotting fruit, haven't been blessed with a lot of brain cells to rub together. But even with the few neurons they do have, these worms do amazing things: find food, avoid danger. Killing off even a single brain cell can prevent a worm from turning environmental cues into a coherent picture of its surroundings. When scientists damage a neuron at the center of a worm's odor-sensing circuit, it wanders aimlessly, unable to move toward a pleasing scent even though its neuron that detects the smell still works.