Ad-libitum high fat diet consumption during adolescence and adulthood impacts the intravenous self-administration of cocaine in male Sprague-Dawley rats.

In preclinical populations, binge consumption of a high-fat diet (HFD) initiated during either adolescence or adulthood increases the intravenous self-administration (IVSA) of cocaine, whereas ad lib HFD consumption initiated during adulthood reduces or fails to influence cocaine intake. From this, it appears that binge exposure is a sufficient condition to increase cocaine IVSA and that such effects occur independent of the exposure period. It is not clear, however, if ad lib exposure would be sufficient to affect the IVSA of cocaine if initiated during adolescence, a developmental period associated with high-risk behavior. To investigate this question, the present experiment evaluated the effects of consumption of a HFD given throughout adolescence and adulthood on cocaine IVSA (0.75 mg/kg/infusion). Specifically, male Sprague-Dawley rats were maintained on either a HFD (n = 24) or chow diet (n = 15) beginning on postnatal day (PND) 21 and as adults underwent cocaine IVSA [Fixed Ratio (FR) 1, FR 5, FR 10, FR 20, Progressive Ratio (PR) and cue- and drug + cue-induced responding] from PNDs 77-126. Under all of these conditions, animals maintained on the HFD displayed higher rates of cocaine IVSA than those given access to chow. The present data demonstrate that under these specific conditions long-term exposure during the risk period of adolescence and extended throughout adulthood is capable of impacting the subsequent likelihood of cocaine self-administration and suggest that diet type and the duration of exposure may be important factors influencing the vulnerability to drug intake. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Ad libitum high fat diet consumption during adolescence and adulthood fails to impact the affective properties of cocaine in male Sprague-Dawley rats.

Recent research from our laboratories has demonstrated that long-term and ad libitum high fat diet (HFD) consumption during adolescence and adulthood increases the intravenous self-administration (IVSA) of cocaine in adult male Sprague-Dawley rats. One possible interpretation of these findings is that this dietary history influences the affective properties of cocaine, that is, cocaine's rewarding and/or aversive effects. In this context, our research and others suggest that the overall affective response to a drug, and its potential for use and abuse, reflects a balance between these properties in which the rewarding effects of a drug maintain its use and the aversive effects limit it. Accordingly, long-term HFD consumption might increase the rewarding effects of cocaine and/or decrease its aversive effects, resulting in greater IVSA. To examine this possibility, male Sprague-Dawley rats were maintained on either a HFD (n = 32) or chow diet (n = 32) beginning on postnatal day (PND) 21 and underwent combined cocaine-induced place preference and taste avoidance conditioning from PNDs 78-102. Under these conditions, cocaine (18 and 32 mg/kg, intraperitoneally [IP]), but not vehicle, was effective in inducing both a place preference and a taste avoidance; however, HFD- and chow-fed animals did not differ on either of these behavioral indices. These data suggest that the ability of ad libitum HFD consumption during adolescence to increase cocaine IVSA is not likely due to changes in the affective properties of cocaine. (PsycInfo Database Record (c) 2020 APA, all rights reserved).