title: An automated assay of the behavioral effects of cocaine injections in adult Drosophila.
abstract: Introducing Drosophila models in neuropharmacological research helps to discover new mechanisms of drug action. In fruit flies, the pharmacobehavioral approach has been used to evaluate the effects of drugs of abuse including cocaine. Standard procedures of cocaine administration to flies employ drug vaporization whereas behavior is evaluated either by trained observers or by videotaping followed by analysis via a computer-operated tracking system. Because in mammalian studies cocaine is typically administered by injection, a procedure that ensures precise and timely dose delivery, we developed a method for injecting cocaine into adult Drosophila. To objectively measure the behavioral response of flies to cocaine injections, we adapted the standard Drosophila Activity Monitoring System (Trikinetics). We found that in wild-type Canton S flies, cocaine injections produce a dose-dependent increase in the number of hyperactivity bursts and that repeated injections of cocaine produce behavioral sensitization. Acute responses to cocaine were observed also in period null (per(0)) mutant flies, but in these flies, repeated injections of cocaine did not produce sensitization. In conclusion, we developed a method for accurately measuring the behavioral effects of cocaine in adult fruit flies that can be applied to studies of the mechanisms of behavioral sensitization.
authors.affiliation: Department of Psychiatry, The Psychiatric Institute, University of Illinois at Chicago, 1601 West Taylor Street, MC912, Chicago, IL 60612, USA.
authors.forename: Nikola
authors.initials: N
authors.lastname: Dimitrijevic
authors.forename: Svetlana
authors.initials: S
authors.lastname: Dzitoyeva
authors.forename: Hari
authors.initials: H
authors.lastname: Manev
mesh_terms: D000286:Administration, Sublingual; D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003042:Cocaine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004330:Drosophila / Q000187:drug effects*; D029721:Drosophila Proteins; D001330:Electronic Data Processing / Q000379:methods*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D056950:Period Circadian Proteins
chemical_list: D000779:Anesthetics, Local; D029721:Drosophila Proteins; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; D003042:Cocaine