Understanding the neurogenetics of sleep: progress from Drosophila.

Most behaviors manifest themselves through interactions with environments. Sleep, however, is characterized by immobility and reduced responsiveness. Although nearly all animals sleep, the purpose of sleep remains an enduring puzzle. Drosophila melanogaster exhibits all the behavioral characteristics of mammalian sleep, enabling the use of powerful genetic approaches to dissect conserved fundamental neurogenetic aspects of sleep. Drosophila studies over the past four years have identified novel genes and pathways modulating sleep, such as Shaker and sleepless, and candidate brain regions known to function in circadian regulation and learning and memory. Advances in systems genetics coupled with the ability to target specific brain regions enable the characterization of transcriptional networks and neural circuits contributing to phenotypic variation in sleep.