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Marked individual differences in the propensity to select methamphetamine over food reinforcement in a rat preclinical model
Author(s) -
Purpura Mari
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.1040.13
Subject(s) - meth , reinforcement , methamphetamine , addiction , conditioned place preference , psychology , vulnerability (computing) , substance abuse , medicine , clinical psychology , psychiatry , social psychology , chemistry , computer security , computer science , monomer , organic chemistry , acrylate , polymer
Drug abuse and addiction are serious health issues in the US and worldwide. Methamphetamine (METH) abuse remains an extremely serious problem in the United States and the consequences of METH abuse are devastating psychologically, medically, and socially. However, the factors that contribute to METH addiction vulnerability remain largely unknown. Recent preclinical data have demonstrated that there is substantial individual variation in the propensity to select drugs of abuse (cocaine or heroin) over a competing reinforcer (food) with the majority of individual exhibiting a strong preference for one reinforcer. Further, the distribution of individuals that prefer cocaine over food exhibits a marked sex difference with females exhibiting a higher propensity to forgo food reinforcement to obtain cocaine as compared to males. Currently, there is limited information on how subject factors may impact the selection of METH over a competing reinforcer and thus, we have begun to explore individual differences in a rat model of METH versus food choice. Briefly, rats are implanted with an intravenous catheter and then trained for METH or food reinforcement on alternating days followed by assessment of choice between these reinforcers followed by additional tests at higher doses of METH. To date, the data indicate that, like cocaine, there is a high degree of individual difference in the selection of METH over food reinforcement and that this selection is dependent upon METH dose with 12.5% selecting 0.05 mg/kg/infusion METH and 37.5% selecting 0.1 mg/kg/infusion METH over food reinforcement. Our preliminary data also suggest that, in comparison to reports of employing drug‐food choice procedures in male rats, that females exhibit higher and more plastic (i.e. dose dependent) selection between METH over a competing reinforcer. Additional studies will provide a more direct comparison between males and females as well as determine the potential contribution of gonadal hormones. Generally, the results of this pilot study are consistent with the growing body of clinical and preclinical evidence demonstrating that females exhibit a higher addiction vulnerability for stimulant drugs of abuse.