Hover over the image to see two snapshots of the fruit fly brain. In the first, the brain of a sleep-deprived fly glows orange, marking high concentrations of a synaptic protein involved in communication between neurons. The color also lights up three brain areas associated with learning. By contrast, the second image from a well-rested fly has lower levels of the protein. These pictures illustrate the results of a recent study showing that sleep reduces the protein’s levels, suggesting that such “downscaling” resets the brain to normal levels of synaptic activity and makes it ready to learn after a restful night. Courtesy of University of Wisconsin-Madison neuroscientist Chiara Cirelli.