LONG-TERM WESTERN DIET CONSUMPTION INCREASES THE INTRAVENOUS SELF-ADMINISTRATION OF COCAINE IN MALE SPRAGUE-DAWLEY RATS

Recent literature suggests that dysregulated food and drug intake may result from similar mechanisms that usurp the neural circuits mediating inhibitory control in the brain. Given these physiological and behavioral parallels, it might be predicted that a history with one would affect the likelihood of the other, i.e., animals that display dysregulated consumption of a highly palatable diet would display potentiated levels of compulsive drug intake. Interestingly, the limited research on the topic has only investigated the effects of high fat diet (HFD) consumption on cocaine intravenous self-administration (IVSA) in adult rats rather than the potentially more clinically relevant levels of high saturated fats, simple carbohydrates and refined sugars which characterize the Western diet (WD) in adolescents. In an effort to build upon these preclinical models, the present experiment evaluated whether consumption of a WD initiated and maintained throughout adolescence and adulthood influences cocaine IVSA. Specifically, 60 male Sprague-Dawley rats were maintained on either a WD (n = 42) or chow diet (n = 18) beginning on postnatal day (PND) 21 and underwent cocaine IVSA [Fixed Ratio (FR) 1, FR5, FR10, FR20, Progressive Ratio (PR) and cue- and drug + cue-induced reinstatement] from PNDs 77-126 . Animals maintained on the WD throughout adolescence and adulthood displayed higher rates of cocaine IVSA, greater PR responding, more responding in drug non-available periods and greater reinstatement of drug-taking behaviors than animals maintained on the standard rodent chow diet. This work demonstrates that long-term WD consumption impacts subsequent cocaine intake and implicates deficits in inhibitory control for each excessive behavior.