Concurrent access to sucrose pellets decreases methamphetamine-seeking behavior in Lewis rats

Abstract

Investigation of the role of choice between use of drugs of abuse and pursuit of alternative non-drug reinforcers is receiving greater attention. An understanding of the determinants influencing choice between drugs and alternative reinforcers will eventually lead to an understanding to the neural substrates of the drug altered brain. We investigated the impact of concurrent access to sucrose pellets on methamphetamine self-administration and self-regulated reinstatement of methamphetamine seeking following extinction training in Lewis rats. Our results from the self-administration experiment show that rats with concurrent access to sucrose self-administered significantly less methamphetamine compared to the methamphetamine only group. For our extinction/reinstatement experiment, concurrent access to sucrose during self-regulated methamphetamine reinstatement reduced methamphetamine intake and non-reinforced methamphetamine-seeking behavior in rats compared to rats that received access to just methamphetamine. These findings indicate that concurrent access to alternative reinforcers during various stages of methamphetamine-seeking behavior robustly decreased methamphetamine intake and serves as a valid rodent choice paradigm.