Pavlovian drug discrimination with bupropion as a feature positive occasion setter: substitution by methamphetamine and nicotine, but not cocaine.
Bupropion can serve as a discriminative stimulus (S(D)) in an operant drug discrimination task, and a variety of stimulants substitute for the bupropion S(D). There are no reports, however, of bupropion functioning as a Pavlovian occasion setter (i.e. feature positive modulator). The present experiment seeks to fill this gap in the literature by training bupropion in rats as a feature positive modulator that disambiguates when a light will be paired with sucrose. Specifically, on bupropion (10 mg/kg intraperitoneal) sessions, offset of 15-second cue lights were followed by brief delivery of liquid sucrose; saline sessions were similar except no sucrose was available. Rats readily acquired the discrimination with more conditioned responding to the light on bupropion sessions. Bupropion is approved for use as a smoking cessation aid, and more recently has drawn attention as a potential pharmacotherapy for cocaine and methamphetamine abuse. Accordingly, after discrimination training, we tested the ability of cocaine (1-10 mg/kg), methamphetamine (0.1 to 1 mg/kg) and nicotine (0.00625 to 0.2 mg/kg) to substitute for the bupropion feature. Nicotine (0.05 mg/kg) and methamphetamine (0.3 mg/kg) substituted fully for bupropion; cocaine did not substitute. These results extend previous research on shared stimulus properties between bupropion and other stimulants to a Pavlovian occasion setting function. Further, this is the first report of nicotine and methamphetamine substitution for bupropion. The overlap in stimulus properties might explain the effectiveness of bupropion as a smoking cessation aid and highlight the possible utility of bupropion for treatment of stimulant use disorder.
Wilkinson
Jamie L
JL
Department of Psychology, University of Nebraska-Lincoln, USA. rbevins1@unl.edu
Li
Chia
C
Bevins
Rick A
RA
D016642:Bupropion / Q000008:administration & dosage / Q000494:pharmacology*; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D003214:Conditioning, Classical; D004193:Discrimination Learning / Q000187:drug effects*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008694:Methamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology*; D010537:Peritoneum
D018765:Dopamine Uptake Inhibitors; D016642:Bupropion; D008694:Methamphetamine; D009538:Nicotine; D003042:Cocaine