Seeking a ‘parts list’ for the retina
As we scan a scene, many types of neurons in our retinas interact to analyze different aspects of what we see and form a cohesive image. Each type is specialized to respond to a particular variety of visual input — for example, light or darkness, the edges of an object, or movement in a certain direction.Neuroscientists believe there are 20 to 30 types of these specialized neurons, known as retinal ganglion cells, but they have yet to come up with a definitive classification system.A new study from MIT neuroscientists has made some headway on this daunting task. Using a computer algorithm that traces the shapes of neurons and groups them based on structural similarity, the researchers sorted more than 350 mouse retinal neurons into 15 types, including six that were previously unidentified.This technique, described in the March 24 online edition of Nature Communications, could also be deployed to help identify...