title: Electrochemical Measurements of Optogenetically Stimulated Quantal Amine Release from Single Nerve Cell Varicosities in Drosophila Larvae.
abstract: The nerve terminals found in the body wall of Drosophila melanogaster larvae are readily accessible to experimental manipulation. We used the light-activated ion channel, channelrhodopsin-2, which is expressed by genetic manipulation in Type II varicosities to study octopamine release in Drosophila. We report the development of a method to measure neurotransmitter release from exocytosis events at individual varicosities in the Drosophila larval system by amperometry. A microelectrode was placed in a region of the muscle containing a varicosity and held at a potential sufficient to oxidize octopamine and the terminal stimulated by blue light. Optical stimulation of Type II boutons evokes exocytosis of octopamine, which is detected through oxidization at the electrode surface. We observe 22700±4200 molecules of octopamine released per vesicle. This system provides a genetically accessible platform to study the regulation of amine release at an intact synapse.
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology Department, Kemivägen 10, 41296 Gothenburg (Sweden).
authors.forename: Soodabeh
authors.initials: S
authors.lastname: Majdi
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 41296 Gothenburg (Sweden).
authors.forename: E Carina
authors.initials: EC
authors.lastname: Berglund
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology Department, Kemivägen 10, 41296 Gothenburg (Sweden).
authors.forename: Johan
authors.initials: J
authors.lastname: Dunevall
authors.affiliation: Ecole Normale Supérieure-PSL Research University, Département de Chimie, Sorbonne Universités-UPMC Univ Paris 06, CNRS UMR 8640 PASTEUR, 24, rue Lhomond, 75005 Paris (France).
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Oleinick
authors.affiliation: Ecole Normale Supérieure-PSL Research University, Département de Chimie, Sorbonne Universités-UPMC Univ Paris 06, CNRS UMR 8640 PASTEUR, 24, rue Lhomond, 75005 Paris (France).
authors.forename: Christian
authors.initials: C
authors.lastname: Amatore
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, Gonda Center for Neuroscience and Genetics Research, David Geffen School of Medicine at, University of California, Los Angeles, CA (USA).
authors.forename: David E
authors.initials: DE
authors.lastname: Krantz
authors.affiliation: Department of Chemistry and Chemical Engineering, Chalmers University of Technology Department, Kemivägen 10, 41296 Gothenburg (Sweden). andrew.ewing@chem.gu.se.|Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 41296 Gothenburg (Sweden). andrew.ewing@chem.gu.se.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Ewing
mesh_terms: D000588:Amines / Q000378:metabolism*; D000818:Animals; D004331:Drosophila melanogaster / Q000166:cytology* / Q000378:metabolism; D055664:Electrochemical Techniques; D007814:Larva / Q000166:cytology / Q000378:metabolism; D008027:Light; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D062308:Optogenetics; D010775:Photic Stimulation
chemical_list: D000588:Amines
keywords: Drosophila larvae; amperometry; channelrhodopsin; octopamine; varicosity