REPEATED EXPOSURE TO ALCOHOLIC BEER DOES NOT INDUCE LONG-LASTING CHANGES IN ALCOHOL SELF-ADMINISTRATION AND INTAKE IN SARDINIAN ALCOHOL-PREFERRING AND SARDINIAN NON-PREFERRING RATS

Abstract — Aims: Rats avidly consume non-alcoholic beer, and addition of alcohol to non-alcoholic beer may function as a medium to induce intake of large amounts of alcohol in rats. The present study investigated whether Sardinian alcohol-preferring (sP) and Sardinian non-preferring (sNP) rats, initially exposed to non-alcoholic beer, and subsequently to non-alcoholic beer containing increasing concentrations of alcohol, would develop unusually high alcohol self-administration and drinking behaviours: (i) when alcohol was added to non-alcoholic beer, and (2) once beer was withdrawn and a plain alcohol solution was made available. Methods: In Experiment 1, rats were exposed to operant, 30-min/day self-administration sessions of non-alcoholic beer with increasing concentrations of alcohol [0, 2.5, 5, 7.5, and 10 % (v/v)] for a total of 45 days. After a brief ‘beer-fading ’ phase, the rats were exposed to self-administration sessions of a plain 10 % (v/v) alcohol solution. In Experiment 2, the rats were exposed to non-alcoholic beer with increasing concentrations of alcohol [0, 2.5, 5, 7.5, and 10 % (v/v)] and water under the 2-bottle choice regimen with unlimited access (24 h/day) for a total of 35 days. After a brief ‘beer-fading ’ phase, the rats were exposed to the choice between a plain 10 % (v/v) alcohol solution and water. Results: sP and sNP rats did not differ in self-administration (Experiment 1) and intake (Experiment 2) of non-alcoholic beer. In Experiment 1, as alcohol content increased, the amount of self-administered alcohol increased progressively in sP rats (up to 1–1.2 g/kg) and remained stable in sNP rats (approximately 0.65 g/kg). When the plai