title: Positive or negative allosteric modulation of metabotropic glutamate receptor 5 (mGluR5) does not alter expression of behavioral sensitization to methamphetamine.
abstract: We investigated the role of metabotropic glutamate receptor type 5 (mGluR5) in methamphetamine-induced behavioral sensitization. The mGluR5 positive allosteric modulator (3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl) benzamide (CDPPB) and negative allosteric modulator fenobam were tested in separate experiments. Sprague-Dawley rats were repeatedly injected with 1 mg/kg methamphetamine or saline, and then given a locomotor challenge test using a dose of 0.5 mg/kg methamphetamine. Prior to the challenge test session, rats were injected with CDPPB, fenobam, or a vehicle.  Doses from previous studies showed reduced drug-conditioned behavior; however in this study neither CDPPB nor fenobam pretreatment resulted in an altered expression of behavioral sensitization, indicating a lack of mGluR5 involvement in sensitized methamphetamine-induced locomotion. Additionally, the high dose (30 mg/kg) of fenobam resulted in decreased methamphetamine-induced locomotion in rats regardless of drug exposure history, which suggests evidence of nonspecific behavioral inhibition.
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, 85287-1104, USA.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Kufahl
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, 85287-1104, USA.
authors.forename: Natali E
authors.initials: NE
authors.lastname: Nemirovsky
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, 85287-1104, USA.
authors.forename: Lucas R
authors.initials: LR
authors.lastname: Watterson
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, 85287-1104, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Zautra
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, 85287-1104, USA.
authors.forename: M Foster
authors.initials: MF
authors.lastname: Olive