RT Journal Article SR Electronic T1 Wakefulness Is Promoted during Day Time by PDFR Signalling to Dopaminergic Neurons in Drosophila melanogaster JF eneuro JO eNeuro FD Society for Neuroscience SP ENEURO.0129-18.2018 DO 10.1523/ENEURO.0129-18.2018 VO 5 IS 4 A1 Sheetal Potdar A1 Vasu Sheeba YR 2018 UL http://www.eneuro.org/content/5/4/ENEURO.0129-18.2018.abstract AB Circadian clocks modulate timing of sleep/wake cycles in animals; however, the underlying mechanisms remain poorly understood. In Drosophila melanogaster, large ventral lateral neurons (l-LNv) are known to promote wakefulness through the action of the neuropeptide pigment dispersing factor (PDF), but the downstream targets of PDF signalling remain elusive. In a screen using downregulation or overexpression (OEX) of the gene encoding PDF receptor (pdfr), we found that a subset of dopaminergic neurons responds to PDF to promote wakefulness during the day. Moreover, we found that small LNv (s-LNv) and dopaminergic neurons form synaptic contacts, and PDFR signalling inhibited dopaminergic neurons specifically during day time. We propose that these dopaminergic neurons that respond to PDFR signalling are sleep-promoting and that during the day when PDF levels are high, they are inhibited, thereby promoting wakefulness. Thus, we identify a novel circadian clock pathway that mediates wake promotion specifically during day time.