title: Nicotine cue: lack of effect of the alpha 7 nicotinic receptor antagonist methyllycaconitine.
abstract: To assess the role of the alpha 7 neuronal nicotinic acetylcholine receptor in the discriminative stimulus properties of (-)-nicotine, this study investigated the ability of the alpha 7 receptor antagonist methyllycaconitine to modulate the nicotine cue. In rats trained to discriminate (-)-nicotine from saline, intraperitoneal injections of methyllycaconitine neither induced nor blocked the nicotine cue. Intracerebroventricular administration of methyllycaconitine, neither potentiated nor blocked the effect of (-)-nicotine. On the other hand, intracerebroventricular injections of mecamylamine blocked the nicotine cue. The available evidence indicate that the nicotinic acetylcholine receptors in the brain blocked by methyllycaconitine, those presumably containing alpha 7 subunits, do not participate in the expression of the discriminative stimulus properties of (-)-nicotine.
authors.affiliation: Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, IL 60064-3500, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Brioni
authors.forename: D J
authors.initials: DJ
authors.lastname: Kim
authors.forename: A B
authors.initials: AB
authors.lastname: O'Neill
mesh_terms: D000157:Aconitine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects; D003463:Cues; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D018733:Nicotinic Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011978:Receptors, Nicotinic / Q000187:drug effects*
chemical_list: D018722:Nicotinic Agonists; D018733:Nicotinic Antagonists; D011978:Receptors, Nicotinic; C054634:methyllycaconitine; D008464:Mecamylamine; D009538:Nicotine; D000157:Aconitine