title: Two dopaminergic neurons signal to the dorsal fan-shaped body to promote wakefulness in Drosophila.
abstract: BACKGROUND
  The neuronal circuitry underlying sleep is poorly understood. Although dopamine (DA) is thought to play a key role in sleep/wake regulation, the identities of the individual DA neurons and their downstream targets required for this process are unknown.
  
  
  RESULTS
  Here, we identify a DA neuron in each PPL1 cluster that promotes wakefulness in Drosophila. Imaging data suggest that the activity of these neurons is increased during wakefulness, consistent with a role in promoting arousal. Strikingly, these neurons project to the dorsal fan-shaped body, which has previously been shown to promote sleep. The reduced sleep caused by activation of DA neurons can be blocked by loss of DopR, and restoration of DopR expression in the fan-shaped body can rescue the wake-promoting effects of DA in a DopR mutant background.
  
  
  CONCLUSIONS
  These experiments define a novel arousal circuit at the single-cell level. Because the dorsal fan-shaped body promotes sleep, these data provide a key link between wake and sleep circuits. Furthermore, these findings suggest that inhibition of sleep centers via monoaminergic signaling is an evolutionarily conserved mechanism to promote arousal.
authors.affiliation: Department of Neurology, Johns Hopkins University, Baltimore, MD 21287, USA.
authors.forename: Qili
authors.initials: Q
authors.lastname: Liu
authors.forename: Sha
authors.initials: S
authors.lastname: Liu
authors.forename: Lay
authors.initials: L
authors.lastname: Kodama
authors.forename: Maria R
authors.initials: MR
authors.lastname: Driscoll
authors.forename: Mark N
authors.initials: MN
authors.lastname: Wu
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000502:physiology; D059290:Dopaminergic Neurons / Q000502:physiology*; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D012890:Sleep / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins