| Abstract | The misuse of alcohol is a growing problem in the United States. The scientific study of alcohol use via animal models possesses relevance for translational and theoretical problems in the following domains (1) establishing a rodent model of high-concentration alcohol use to better understand the transition from regular drinking to addictive drinking behavior, (2) exploring the rewarding properties of high-concentration alcohol, (3) assessing the role of motivation on preference for alcohol over water via conditions of food-deprivation and continuous food availability, (4) assessing the pharmacological basis of alcohol consumption by antagonizing the orexin-1 receptor. Throughout testing these problems, we found that rats preferred alcohol to water in concentrations ranging from 6-66% (Experiment 1), and that pharmacologically relevant BAC levels were obtained after access to 10% and 66% alcohol compared to 2% alcohol and water (Experiment 2). Providing rats with continuous access to food eliminated preference for 66% alcohol, but did not cause rats to stop drinking the solution (Experiment 3). Rats learned an operant licking task involving an empty tube to gain access to a tube containing 66% alcohol (Experiments 4 and 5) and were successful at this task under progressive ratio (PR) conditions for 2%, 10%, 66% alcohol and water in a within-subject (Experiment 6) and for 10% and 66% alcohol and water in a between-subject (Experiment 7) design. Individual differences in coping with frustration were observed in a reward downshift task conducted prior to tasks involving 66% alcohol (Experiment 8). A test of emotional self-medication with 66% alcohol revealed no significant differences between recovery from frustration groups (Experiment 9). Finally, antagonism of the orexin-1 receptor was conducted 30-min prior to PR self-administration of 66% alcohol. Rats exhibited the lowest breakpoint for the lowest, 1 mg/kg dose of the antagonist SB-334867 as well as the most suppression of licking behavior. These experiments demonstrate that individual differences can affect the reward value of alcohol solutions, and that pharmacologically relevant BAC levels can be obtained through oral, self-administration methods. |
