Posted on by Dr. Francis Collins
This eerie scene might bring back memories of the computer-generated alien war machines from Steven Spielberg’s War of the Worlds thriller. But what you’re seeing is a computer-generated depiction of a quite different world—the world inside the retina, the light-sensitive tissue that lines the back of the eye. The stilt-legged “creatures” are actually ganglion nerve cells, and what appears to be their long “noses” are fibers that will eventually converge to form the optic nerve that relays visual signals to the brain. The dense, multi-colored mat near the bottom of the image is a region where the ganglia and other types of retinal cells interact to convey visual information.
What I find particularly interesting about this image is that it was produced through the joint efforts of people who played EyeWire, an internet crowdsourcing game developed in the lab of computational neuroscientist Sebastian Seung, now at Princeton University in New Jersey. Seung and his colleagues created EyeWire using a series of high-resolution microscopic images of the mouse retina, which were digitized into 3D cubes containing dense skeins of branching nerve fibers. It’s at this point where the crowdsourcing came in. Online gamers—most of whom aren’t scientists— volunteered for a challenge that involved mapping the 3D structure of individual nerve cells within these 3D cubes. Players literally colored-in the interiors of the cells and progressively traced their long extensions across the image to distinguish them from their neighbors. Sounds easy, but the branches are exceedingly thin and difficult to follow.