Per1Brdm1 mice self-administer cocaine and reinstate cocaine-seeking behaviour following extinctionHalbout, Briaca; Perreau-Lenz, Stéphaniea; Dixon, Claire I.b; Stephens, David N.b; Spanagel, RaineraBehavioural Pharmacology: February 2011 - Volume 22 - Issue 1 - p 76–80 doi: 10.1097/FBP.0b013e328341e9ca Short Reports Abstract Author Information A clear interrelationship between biological rhythms and addiction has emerged from recent preclinical and clinical studies. In particular, the manipulation of the so-called ‘clock genes’ interferes with the manifestation of drug-related responses. For instance, Period 1 (Per1Brdm1) mutant mice do not display behavioural sensitization in response to repeated cocaine administration and do not express cocaine conditioned place preference, in contrast to control littermates. To assess the involvement of the mPer1 gene in a robust model of cocaine reinforcement and relapse-like behaviour, we tested Per1Brdm1 mutant mice and their littermates for self-administration of several doses (0.06–0.75 mg/kg/infusion) of cocaine, and for reinstatement of an extinguished cocaine-seeking response. Per1Brdm1 mutant mice did not differ from control littermates in their propensity to self-administer cocaine or to reinstate an extinguished cocaine-seeking behaviour in response to drug-associated cues or cocaine priming. In contrast to our earlier data on Per1Brdm1 mutant mice in cocaine sensitization and conditioned place preference, this finding does not suggest a relationship between the circadian clock gene mPer1 in cocaine self-administration and reinstatement of cocaine-seeking behaviour. This study adds one further example to the notion that various behavioural tests usually used in addiction research rely on different neurobiological substrates. aDepartment of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany bSchool of Psychology, University of Sussex, Brighton, UK Correspondence to Briac Halbout, MSc, Department of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, J5, 68159 Mannheim, Germany e-mail: email@example.com Received July 23, 2010 Accepted October 1, 2010 © 2011 Lippincott Williams & Wilkins, Inc.