%0 Journal Article
%T Effects of a selectively bred novelty-seeking phenotype on the motivation to take cocaine in male and female rats
%A Jennifer A Cummings
%A Brooke A Gowl
%A Christel Westenbroek
%A Sarah M Clinton
%A Huda Akil
%A Jill B Becker
%J Biology of Sex Differences
%D 2011
%I BioMed Central
%R 10.1186/2042-6410-2-3
%X We examined motivation for taking cocaine in two experiments using a range of doses on a progressive ratio (PR) schedule of responding in bHR or bLR males and females. Additionally, we included a measure of continuing to respond in the absence of reinforcement, a feature of addiction that has been recently incorporated into tests of animal models on the basis of the criteria for substance use disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Statistical analyses were performed using PASW Statistics 18.0 software. Data were analyzed using repeated-measures analysis of variance followed by a Bonferroni correction post hoc test when applicable.We found sex differences as well as effects of novelty reactivity on the motivation to self-administer cocaine. Specifically, females demonstrated higher breaking points on the PR schedule compared with males, regardless of phenotype, and bHR males and females exhibited higher motivation than bLR animals at a number of the doses studied.An individual's sex continues to be a predisposing factor with respect to drug abuse liability and can be compounded by additional individual differences such as reactivity to novelty.Drug abuse vulnerability can vary with an individual's sex, hormone status and personality traits (that is, novelty reactivity), among other factors. In humans, personality traits such as novelty-seeking, reactivity to novelty, sensation-seeking and impulsivity contribute to an enhanced likelihood of substance abuse [1-4]. People who exhibit a heightened response to novelty use more drugs compared with those with an attenuated novelty reactivity response. Thus, novelty responsivity is considered to be a predictor of drug abuse liability.Analogously to humans, individual behavioral traits in rats influence psychostimulant self-administration [5-8]. Indeed, animals that exhibit high novelty-induced locomotor behavior (High Responders (HRs)) have increased sensitivity to the reinforc
%U http://www.bsd-journal.com/content/2/1/3