title: Influence of sensitization on the discriminative stimulus effects of methylphenidate in mice.
abstract: Methylphenidate (MPH) remains an important therapy for attention-deficit hyperactivity disorder, but aspects of its pharmacology remain unclear. In the present study, we used a regimen of MPH (8 mg/kg daily×14 days) in C57BL/6J mice to determine whether establishing locomotor sensitization to MPH influenced the acquisition and the dose-response function of MPH in a classic drug discrimination procedure. MPH-sensitized mice (SENS group) showed enhanced locomotor activity to the 8 mg/kg exposure dose as well as a 2 mg/kg dose before discrimination training. However, the SENS mice did not acquire discrimination of either a low dose (2 mg/kg) or a higher dose (4 mg/kg) of MPH any more rapidly than the CTRL mice. Further, during generalization testing, the dose-response functions for the SENS and CTRL mice were identical. Therefore, we did not find that previous exposure to MPH, which produced a sensitized locomotor response, facilitated MPH discrimination.
authors.affiliation: Department of Psychiatry and Behavioral Science, Center for Drug and Alcohol Programs, Medical University of South Carolina, Charleston, South Carolina, USA.
authors.forename: Robin
authors.initials: R
authors.lastname: McGovern
authors.forename: Lauryn
authors.initials: L
authors.lastname: Luderman
authors.forename: Kelly
authors.initials: K
authors.lastname: Knecht
authors.forename: William C
authors.initials: WC
authors.lastname: Griffin
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D004192:Discrimination, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005518:Food Preferences / Q000187:drug effects; D008774:Methylphenidate / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects*
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate