Patrick A Randall1, Brayden Fortino1, Y Wendy Huynh2, Brady M Thompson2, Christopher E Larsen2, Mackenzie P Callen2, Scott T Barrett2, Jennifer E Murray3, Rick A Bevins2, Joyce Besheer4. 1. Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. 2. Department of Psychology, University of Nebraska at Lincoln, Lincoln, NE 68588, USA. 3. Department of Psychology, University of Guelph, Guelph, Ontario, Canada N1G 2W1. 4. Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Curriculum in Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address: jbesheer@med.unc.edu.
Abstract
BACKGROUND: Smoking constitutes a significant public health risk. Alcohol and methamphetamine use disorders are also highly co-morbid with smoking, further increasing negative health outcomes. An important question in determining the underlying neurobiology of nicotine poly-drug use is understanding whether having a positive history with nicotine effects alters later drug-taking behavior. METHODS: The current experiments sought to elucidate whether having an appetitive nicotine conditioning history would affect later alcohol or methamphetamine self-administration. Adult male and female Long-Evans rats were first trained on a discriminated goal-tracking task in which the interoceptive effects of nicotine predicted sucrose reinforcement. As a control, pseudo-conditioned groups were included that had equated nicotine and sucrose experience. Rats were then shifted to either alcohol self-administration or methamphetamine self-administration. RESULTS: Nicotine conditioning history had no effect on acquisition or maintenance of alcohol self-administration in males or females. In contrast, an appetitive nicotine conditioning history decreased methamphetamine self-administration in female rats, but not males. CONCLUSIONS: In female, but not male, rats, an appetitive conditioning history with nicotine decreases methamphetamine, but not alcohol, self-administration. This dissociation suggests that the effects may be due to a specific increase in the reinforcing value of methamphetamine. This may have implications for better understanding the progression of drug use from nicotine to methamphetamine.
BACKGROUND: Smoking constitutes a significant public health risk. Alcohol and methamphetamine use disorders are also highly co-morbid with smoking, further increasing negative health outcomes. An important question in determining the underlying neurobiology of nicotine poly-drug use is understanding whether having a positive history with nicotine effects alters later drug-taking behavior. METHODS: The current experiments sought to elucidate whether having an appetitive nicotine conditioning history would affect later alcohol or methamphetamine self-administration. Adult male and female Long-Evans rats were first trained on a discriminated goal-tracking task in which the interoceptive effects of nicotine predicted sucrose reinforcement. As a control, pseudo-conditioned groups were included that had equated nicotine and sucrose experience. Rats were then shifted to either alcohol self-administration or methamphetamine self-administration. RESULTS:Nicotine conditioning history had no effect on acquisition or maintenance of alcohol self-administration in males or females. In contrast, an appetitive nicotine conditioning history decreased methamphetamine self-administration in female rats, but not males. CONCLUSIONS: In female, but not male, rats, an appetitive conditioning history with nicotine decreases methamphetamine, but not alcohol, self-administration. This dissociation suggests that the effects may be due to a specific increase in the reinforcing value of methamphetamine. This may have implications for better understanding the progression of drug use from nicotine to methamphetamine.
Authors: Zachary R Harmony; Erin M Alderson; Israel Garcia-Carachure; Laurence D Bituin; Cynthia A Crawford Journal: Drug Alcohol Depend Date: 2020-02-19 Impact factor: 4.492