title: mGlu1 receptor blockade attenuates cue- and nicotine-induced reinstatement of extinguished nicotine self-administration behavior in rats.
abstract: Glutamatergic neurotransmission is believed to be critically involved in the acquisition and maintenance of drug addiction. The present study evaluated the role of metabotropic glutamate (mGlu) 1 receptors in the reinstatement of nicotine-seeking behavior. Rats were trained to nose-poke to receive response-contingent intravenous infusions of nicotine (0.01 mg/kg/infusion, free base). Following the subsequent extinction phase, reinstatement tests were conducted in animals that were exposed either to response-contingent presentations of the nicotine-associated discrete light cues or to non-contingent nicotine priming injection (0.3mg/kg, s.c., salt) just prior to the test session. In a separate experiment, rats were subjected to the nearly identical response-reinstatement procedure but operant responding was established using food pellets instead of nicotine infusions. Pretreatment with the mGlu1 receptor antagonist EMQMCM (JNJ16567083, (3-ethyl-2-methyl-quinolin-6-yl)-(4-methoxy-cyclohexyl)-methanone methanesulfonate) significantly inhibited cue-induced reinstatement of nicotine-seeking behavior (5 and 10, but not 2.5 mg/kg). EMQMCM (5 mg/kg) also prevented nicotine priming-induced reinstatement of nicotine-seeking behavior. At the highest tested dose only (10 mg/kg), EMQMCM attenuated cue-induced reinstatement of food-seeking behavior. Taken together with the previous reports, the present findings further suggest that blockade of mGlu1 receptors may be beneficial for preventing relapse to tobacco smoking in nicotine-dependent individuals.
authors.affiliation: Laboratory of Behavioral Pharmacology, Institute of Pharmacology, Pavlov Medical University, 6/8 Lev Tolstoy Street, St. Petersburg 197089, Russia. dorav@spmu.rssi.ru
authors.forename: Olga A
authors.initials: OA
authors.lastname: Dravolina
authors.forename: Elena S
authors.initials: ES
authors.lastname: Zakharova
authors.forename: Elena V
authors.initials: EV
authors.lastname: Shekunova
authors.forename: Edwin E
authors.initials: EE
authors.lastname: Zvartau
authors.forename: Wojciech
authors.initials: W
authors.lastname: Danysz
authors.forename: Anton Y
authors.initials: AY
authors.lastname: Bespalov
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D003216:Conditioning, Operant / Q000187:drug effects; D003463:Cues; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects; D005502:Food; D008297:Male; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage*; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000502:physiology*; D012054:Reinforcement, Psychology; D012646:Self Administration / Q000379:methods
chemical_list: C502015:(3-ethyl-2-methyl-quinolin-6-yl)-(4-methoxycyclohexyl)methanone methanesulfonate; D018722:Nicotinic Agonists; D011804:Quinolines; D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1; D009538:Nicotine