title: Widespread receptivity to neuropeptide PDF throughout the neuronal circadian clock network of Drosophila revealed by real-time cyclic AMP imaging.
abstract: The neuropeptide PDF is released by sixteen clock neurons in Drosophila and helps maintain circadian activity rhythms by coordinating a network of approximately 150 neuronal clocks. Whether PDF acts directly on elements of this neural network remains unknown. We address this question by adapting Epac1-camps, a genetically encoded cAMP FRET sensor, for use in the living brain. We find that a subset of the PDF-expressing neurons respond to PDF with long-lasting cAMP increases and confirm that such responses require the PDF receptor. In contrast, an unrelated Drosophila neuropeptide, DH31, stimulates large cAMP increases in all PDF-expressing clock neurons. Thus, the network of approximately 150 clock neurons displays widespread, though not uniform, PDF receptivity. This work introduces a sensitive means of measuring cAMP changes in a living brain with subcellular resolution. Specifically, it experimentally confirms the longstanding hypothesis that PDF is a direct modulator of most neurons in the Drosophila clock network.
authors.affiliation: Department of Anatomy & Neurobiology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA.
authors.forename: Orie T
authors.initials: OT
authors.lastname: Shafer
authors.forename: Dong Jo
authors.initials: DJ
authors.lastname: Kim
authors.forename: Richard
authors.initials: R
authors.lastname: Dunbar-Yaffe
authors.forename: Viacheslav O
authors.initials: VO
authors.lastname: Nikolaev
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Lohse
authors.forename: Paul H
authors.initials: PH
authors.lastname: Taghert
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001522:Behavior, Animal; D001921:Brain / Q000166:cytology; D002940:Circadian Rhythm / Q000502:physiology*; D005576:Colforsin / Q000494:pharmacology; D003199:Computer Systems; D000242:Cyclic AMP / Q000378:metabolism*; D003952:Diagnostic Imaging; D004305:Dose-Response Relationship, Drug; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D007301:Insect Hormones / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D009043:Motor Activity / Q000235:genetics; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000378:metabolism* / Q000494:pharmacology
chemical_list: C434606:Dh31 protein, Drosophila; D029721:Drosophila Proteins; D007301:Insect Hormones; D008164:Luminescent Proteins; D009479:Neuropeptides; C113883:pdf protein, Drosophila; D005576:Colforsin; D000242:Cyclic AMP