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Blocking Dopamine D 1‐Like Receptors Attenuates Context‐Induced Renewal of Pavlovian‐Conditioned Alcohol‐Seeking in Rats
Author(s) -
Sciascia Joanna M.,
Mendoza Jose,
Chaudhri Nadia
Publication year - 2014
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/acer.12262
Subject(s) - dopamine , blocking (statistics) , context (archaeology) , dopamine receptor , receptor , blocking effect , neuroscience , psychology , pharmacology , biology , medicine , computer science , developmental psychology , computer network , paleontology
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 D 1‐like receptor antagonist ( R )‐(+)‐7‐chloro‐8‐hydroxy‐3‐methyl‐1‐phenyl‐2,3,4,5‐tetrahydro‐1 H ‐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.