Additionally, a starved fly's brain turns sleepy orange due to Bruchpilot, a communication protein between brain cells. These bright orange areas of the brain are associated with learning. At the bottom, a well-rested fly shows lower levels of Bruchpilot, which could make the fly ready to learn after a good night's rest. These images illustrate the results of an April 2009 study showing that sleep reduces protein levels, suggesting that such downscaling and quot resets the brain to normal levels of synaptic activity and makes it ready to learn after a restful night.