Pavlovian Cue-Driven Alcohol-Seeking: The Role of Dopamine and Impact of Vendor Differences in Long Evans Rats

摘要: Rationale Drug-associated environmental stimuli can acquire incentive and motivational properties through Pavlovian conditioning, come to function as conditioned cues that elicit drug-seeking behavior. Objectives The current experiments tested the hypothesis dopamine mediates alcohol-seeking driven by alcohol-predictive cues. Studies were conducted in Long-Evans rats obtained from two different sources, based on published reports oral alcohol consumption differ within-strain. Method Male, (220-240 g arrival) Charles River (St-Constant, Canada) Harlan Laboratories (Indianapolis, USA) received intermittent, 24-h access ethanol (15%; v/v) water via 2 bottles home cage (21 sessions). Next, trained discriminate between auditory (10-sec each; white noise or clicker); one stimulus (CS+) was paired with (0.2 ml per CS+; 3.2 session; consumption) second (CS-) not ethanol. During 17 daily, 60-min discrimination training (PDT) sessions 16 random presentations each of CS+ CS- delivered according a variable-time 67-sec schedule. Entries made into fluid port consume recorded before, during after CS. Following PDT, habituated (5 sessions; 60-min) different, non-alcohol context where withheld. At test, responding non-extinguished measured second, absence Rats injections D1-like receptor antagonist (SCH 23390; 0, 3.33 10 µg/kg; 1 ml/kg; s.c.) D2-like (eticlopride; 5, 15-min before test. In addition, we examined impact SCH 23390 (10 s.c.); eticlopride PDT when Results gained weight more rapidly attained significantly higher overall weights than Harlan. Across pre-exposure, preference rats. sessions, both vendors responded alcohol-paired CS-. Total port-entry responses decreased across habituation context. test context, saline infused CS-, indicating remained intact despite at Pre-treatment dose-dependently attenuated vendors. However, reduced rats, but River. An infusion 23390, cue Conclusion These results indicate novel differences Long Evans breeders. They also suggest neurotransmission is required for are experienced context. Keywords: Alcohol, cues, dopamine, eticlopride, vendor differences,