ALCOHOL VS. SACCHARIN: A STUDY ON REWARD CHOICE IN ALCOHOL DEPENDENT AND NON-DEPENDENT ANIMALS

Maladaptive decision-making characterized by drug use despite the availability of many alternative rewards is a key component of substance use disorders. However, the role of changes in decision-making in the enhanced susceptibility to drug dependence has been little studied. The present thesis examined the choice between ethanol and a non-drug reward, saccharin, using the discrete-choice model in ethanol dependent and non-dependent animals. In a separate experiment, rats were trained to self-administer intravenous (i.v.) nicotine and oral saccharin. The two main findings of this thesis are: (1) rats choose oral ethanol and saccharin to a similar degree, in contrast to near-exclusive choice of oral saccharin over i.v. drugs, and (2) ethanol dependence shifts reward preference to exclusive ethanol choice. The increased choice of ethanol over saccharin produced by dependence may be explained by a dependence-induced increase in the positive reinforcing effects of ethanol and a decrease in its negative reinforcing effects.M.Sc