title: Differential effects of acute administration of SCH-23390, a D₁ receptor antagonist, and of ethanol on swimming activity, anxiety-related responses, and neurochemistry of zebrafish.
abstract: BACKGROUND
  The zebrafish has become an increasingly popular animal model for investigating ethanol's actions in the brain and its effects on behavior. Acute exposure to ethanol in zebrafish has been shown to induce a dose-dependent increase of locomotor activity, to reduce fear- and anxiety-related behavioral responses, and to increase the levels of dopamine and its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC).
  
  
  OBJECTIVE
  The objective of the present study was to investigate the role of dopamine D1 receptors (D1-R) in ethanol-induced locomotor activity in zebrafish.
  
  
  METHODS
  Zebrafish were pre-treated with SCH-23390 (0 or 1 mg/L bath concentration), a D1-R antagonist, and subsequently exposed to ethanol (0, 0.25, 0.5, 1.0 % v/v). To explore potential underlying mechanisms, we quantified levels of dopamine, DOPAC, serotonin, and 5-HIAA from whole-brain tissue using high-precision liquid chromatography.
  
  
  RESULTS
  We found pre-treatment with the D1-R antagonist to attenuate locomotor activity independent of ethanol concentration. Furthermore, unlike ethanol, D1-R antagonism did not alter behavioral responses associated with fear and anxiety. Pre-treatment with SCH-23390 decreased levels of dopamine and DOPAC, but this effect was also independent of ethanol concentration. The D1-R antagonist also reduced serotonin and 5-hydroxyindole acetic acid (5-HIAA) levels.
  
  
  CONCLUSIONS
  These results suggest a multifaceted and at least partially independent role of dopamine D1 receptors in ethanol-induced locomotor activity and anxiety-related responses as well as in the functioning of the dopaminergic and serotoninergic neurotransmitter systems in zebrafish.
authors.affiliation: Department of Cell and Systems Biology, University of Toronto Mississauga, 3359 Mississauga Road North, DV 1022D, Mississauga, ON, L5L 1C6, Canada, stevenhuy.tran@mail.utoronto.ca.
authors.forename: Steven
authors.initials: S
authors.lastname: Tran
authors.forename: Magda
authors.initials: M
authors.lastname: Nowicki
authors.forename: Arrujyan
authors.initials: A
authors.lastname: Muraleetharan
authors.forename: Diptendu
authors.initials: D
authors.lastname: Chatterjee
authors.forename: Robert
authors.initials: R
authors.lastname: Gerlai
mesh_terms: D000818:Animals; D001007:Anxiety / Q000378:metabolism / Q000523:psychology; D001552:Benzazepines / Q000008:administration & dosage*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects* / Q000502:physiology; D018492:Dopamine Antagonists / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage*; D005260:Female; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D009448:Neurochemistry; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013550:Swimming / Q000502:physiology / Q000523:psychology; D015027:Zebrafish
chemical_list: D001552:Benzazepines; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; C534628:SCH 23390; D000431:Ethanol