While the initial pursuit of drugs can be characterized as a goal-directed action, in certain individuals following many cycles of drug-taking, this behavior becomes dominated by a behavioral repertoire that is generally characterized as compulsive, perseverative and inflexible. Thus evaluating the psychobiological mechanisms involved in this drug induced transition from goal-directed to habitual behavior is vitally important for understanding how drugs control behavior and for future therapeutic strategies to combat these effects. In this application, we present a novel approach for evaluating the effects of drugs on goal-directed behavior, characterizing goal-directed performance based on the fulfillment of two criteria: (1) a knowledge of the outcome as a goal, (2) knowledge of the contingency between response and the outcome. There is substantial evidence for the occurrence of these processes in animals, which can be assessed via the manipulation of outcome value (reinforcer devaluation) and contingency (contingency degradation). In the current application, we will temporarily inactivate regions known to play a role in goal-directed responding (i.e., PLC, BLA) during cocaine exposure to establish whether this manipulation will prevent cocaine from detrimentally affecting the integrity of these systems and thus allow the animal to behave in a goal-directed manner. Additionally, in a separate series of experiments we will inactivate regions known to be critical for habit-based learning following cocaine exposure to establish whether this will subsequently reinstate goal-directed performance. Collectively, the experiments in this application will advance our understanding of the brain mechanisms that control the transition from goal-directed to habitual behavior following chronic drug use.
Drug addiction is a serious and costly public health problem that is characterized by habitual drug-taking despite adverse consequences associated with this behavior. Using an animal model that distinguishes between goal-directed and habit-based behavior, this novel approach aims to evaluate the neural and psychological factors that govern the drug-induced transition from goal-directed to habitual behavior. As such the proposed studies have substantial potential to increase our understanding of the etiology of addiction.