Assessing appetitive, aversive, and negative ethanol-mediated reinforcement through an immature rat model

• Published in: Neuroscience and biobehavioral reviews 2009-06, Vol.33 (6), p.953-974
• Main Authors: Pautassi, Ricardo M., Nizhnikov, Michael E., Spear, Norman E.
• Format: Article
• Language: English
• Subjects: Aging; Animals; Animals, Newborn; Anxiolytic effects; Appetitive conditioning; Aversive conditioning; Behavioral psychophysiology; Biological and medical sciences; Central Nervous System Depressants - administration & dosage; Conditioned place preference; Conditioned taste aversion; Conditioning, Psychological - drug effects; Early ethanol exposure; Ethanol - administration & dosage; Ethanol reinforcement; Fundamental and applied biological sciences. Psychology; Infant rat; Medical sciences; Mice; Motivation; Motor Activity - drug effects; Neuropharmacology; Ontogeny; Operant learning; Pharmacology. Drug treatments; Psycholeptics: tranquillizer, neuroleptic; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychopharmacology; Rats; Reinforcement, Psychology; Reward; Second-order conditioning; Spatial Behavior - drug effects; Taste Perception - drug effects
• ISSN: 0149-7634; 1873-7528
• DOI: 10.1016/j.neubiorev.2009.03.008

The motivational effects of drugs play a key role during the transition from casual use to abuse and dependence. Ethanol reinforcement has been successfully studied through Pavlovian and operant conditioning in adult rats and mice genetically selected for their ready acceptance of ethanol. Another model for studying ethanol reinforcement is the immature (preweanling) rat, which consumes ethanol and exhibits the capacity to process tactile, odor and taste cues and transfer information between different sensorial modalities. This review describes the motivational effects of ethanol in preweanling, heterogeneous non-selected rats. Preweanlings exhibit ethanol-mediated conditioned taste avoidance and conditioned place aversion. Ethanol's appetitive effects, however, are evident when using first- and second-order conditioning and operant procedures. Ethanol also devalues the motivational representation of aversive stimuli, suggesting early negative reinforcement. It seems that preweanlings are highly sensitive not only to the aversive motivational effects of ethanol but also to its positive and negative (anti-anxiety) reinforcement potential. The review underscores the advantages of using a developing rat to evaluate alcohol's motivational effects.