An internal biological clock regulates our sleep-wake cycle, but the mechanism of this rhythm remains elusive. For the first time, researchers at Johns Hopkins, led by Dr. Mark N. Wu, have found a protein in fruit flies that translates timing information from the body's clock and uses it to control sleep by communicating with specific regions in the brain. This study identified the " Wide Awake" gene, which is responsible for delivering the message to the brain that it is time to shut down and sleep. Fruit flies containing a mutation in the Wide Awake gene were unable to receive proper GABA neuronal signals responsible for quieting down the arousal circuits in the brain. The researchers full article, titled WIDE AWAKE Mediates the Circadian Timing of Sleep Onset, can be found in the journal Neuron.