Brainbow of a Hippocampus Dentate Gyrus This image shows individual neurons in part of the memory system of a mouse brain. Each neuron of this transgenic mouse is a different color because each produces a different combination of red, green and blue fluorescent proteins. Being able to image individual neurons allows researchers to better understand the connections within the brain. Jean Livet, Ryan Draft and Jeff Lichtman 2007 Courtesy of Jeff Lichtman Lab, Harvard University