title: Blocking dopamine d1-like receptors attenuates context-induced renewal of pavlovian-conditioned alcohol-seeking in rats.
abstract: BACKGROUND
  Environmental contexts associated with drug use can trigger craving in humans and the renewal of drug-seeking behaviors in animals. Here, we tested the hypothesis that context-induced renewal of Pavlovian-conditioned alcohol-seeking is mediated by dopamine.
  
  
  METHODS
  Male, Long-Evans rats were trained to discriminate between two, 10-second, auditory conditioned stimuli. One stimulus (CS+) was consistently paired with 15% ethanol (EtOH) (v/v, 0.2 ml per CS+) and the second stimulus (CS-) was not. Each CS occurred 16 times per session, and entries into a fluid port where EtOH was delivered were measured. Pavlovian discrimination training (PDT) occurred in a distinctive context, referred to as Context A. Subsequently, behavior was extinguished by presenting both cues without EtOH in a different context (Context B). At test, rats were injected with a dopamine D1-like receptor antagonist (R)-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH 23390; 0, 3.33, 10 μg/kg; 1 ml/kg; s.c.) and presented with the CS+ and CS- without EtOH in the prior PDT context (Context A).
  
  
  RESULTS
  Across training, rats developed higher response levels to the alcohol-predictive CS+, compared with the CS-. Port entries during the CS+ decreased across extinction. At test, placement into the alcohol-associated context triggered a selective increase in CS+ responses after saline, which was significantly reduced by SCH 23390 pretreatment. In separate studies, SCH 23390 did not affect lever-pressing for sucrose under reinforced or extinction conditions, but decreased port entries relative to saline in both cases.
  
  
  CONCLUSIONS
  These data indicate that dopamine is required for context-induced renewal of Pavlovian-conditioned alcohol-seeking and may also be necessary for preparatory conditioned approach behaviors.
authors.affiliation: Department of Psychology, Center for Studies in Behavioural Neurobiology/Groupe de Recherche en Neurobiologie Comportementale, Concordia University, Montreal, QC, Canada.
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Sciascia
authors.forename: Jose
authors.initials: J
authors.lastname: Mendoza
authors.forename: Nadia
authors.initials: N
authors.lastname: Chaudhri
mesh_terms: D000428:Alcohol Drinking / Q000523:psychology; D000437:Alcoholism / Q000188:drug therapy* / Q000523:psychology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001552:Benzazepines / Q000494:pharmacology*; D003214:Conditioning, Classical / Q000187:drug effects*; D004193:Discrimination Learning / Q000187:drug effects; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D058999:Drug-Seeking Behavior / Q000187:drug effects*; D005108:Extinction, Psychological / Q000187:drug effects; D008297:Male; D051381:Rats; D020318:Rats, Long-Evans; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors*; D012008:Recurrence; D012646:Self Administration; D013395:Sucrose / Q000494:pharmacology
chemical_list: D001552:Benzazepines; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; C534628:SCH 23390; D013395:Sucrose
keywords: Alcoholism; Ethanol; Reinstatement; Relapse; SCH 23390