It's the first complete map of all of the genes in the mouse brain, accessible for free on the web to researchers around the world. Scientists can see in living color where in the brain a certain gene is active, as well as how it interacts with other genes. Okay, so it's a roadmap for a rodent's noggin, but neuroscientists say it's an invaluable foundation for studying and understanding human brain disorders from Alzheimer's to depression and dementia. Turns out that mice and men share many of the same brain genes.