title: nAChR-induced octopamine release mediates the effect of nicotine on a startle response in Drosophila melanogaster.
abstract: Biogenic amines (BAs) play a central role in the generation of complex behaviors in vertebrates and invertebrates, including the fly Drosophila melanogaster. The comparative advantages of Drosophila as a genetic model to study the contribution of BAs to behaviors stumble upon the difficulty to access the fly brain to ask relevant physiological questions. For instance, it is not known whether the activation of nicotinic acetylcholine receptors (nAChRs) induces the release of BAs in fly brain, a phenomenon associated to several behaviors in vertebrates. Here, we describe a new preparation to study the efflux of BAs in the adult fly brain by in vitro chronoamperometry. Using this preparation we show that nAChR agonists including nicotine induce a fast, transient, dose-dependent efflux of endogenous BAs, an effect mediated by α-bungarotoxin-sensitive nAChRs. By using different genetic tools we demonstrate that the BA whose efflux is induced by nAChR activation is octopamine (Oct). Furthermore, we show that the impairment of a mechanically induced startle response after nicotine exposure is not observed in flies deficient in Oct transmission. Thus, our data show that the efflux of BAs in Drosophila brain is increased by nAChR activation as in vertebrates, and that then AChR-induced Oct release could have implications in a nicotine-induced behavioral response.
authors: Departamento de Biología Celular y Molecular, Pontificia Universidad Católica de Chile, Millennium Nucleus Stress and Addiction (NEDA), Santiago, CHILE.
authors: Nicolás
authors: N
authors: Fuenzalida-Uribe
authors: Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Millennium Nucleus Stress and Addiction (NEDA), Santiago, CHILE.
authors: Rodrigo C
authors: RC
authors: Meza
authors: Facultad de Medicina, Pontificia Universidad Católica de Chile, Millennium Nucleus Stress and Addiction (NEDA), Santiago, CHILE.
authors: Hernán A
authors: HA
authors: Hoffmann
authors: Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Millennium Nucleus Stress and Addiction (NEDA), Santiago, CHILE.
authors: Rodrigo
authors: R
authors: Varas
authors: Departamento de Biología Celular y Molecular, Pontificia Universidad Católica de Chile, Millennium Nucleus Stress and Addiction (NEDA), Santiago, CHILE.
authors: Jorge M
authors: JM
authors: Campusano
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology; D004331:Drosophila melanogaster / Q000378:metabolism*; D055664:Electrochemical Techniques; D008297:Male; D023421:Models, Animal; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D009655:Octopamine / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000378:metabolism*; D013216:Reflex, Startle / Q000502:physiology*
chemical_list: D018722:Nicotinic Agonists; D011978:Receptors, Nicotinic; D009655:Octopamine; D009538:Nicotine
keywords: Drosophila; behavior; biogenic amines; nicotinic receptor; octopamine