title: Modulation of cocaine intravenous self-administration in drug-naive animals by dihydropyridine Ca2+ channel modulators.
abstract: The dihydropyridine Ca2+ channel blocker nimodipine and the dihydropyridine Ca2+ channel activator BayK 8644 (1,4-dihydropyridine-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)-py ridine- 5-carboxylate) were administered to drug-naive mice and rats that were tested for intravenous cocaine self-administration. A range of cocaine doses was tested to investigate the nature of the effect. The results indicate that nimodipine and BayK 8644 shifted the dose-response curve for cocaine's reinforcing action to the right and left, respectively. Thus, the Ca2+ channel blocker nimodipine decreases the sensitivity of mice and rats to the reinforcing effects of cocaine while the Ca2+ channel activator BayK 8644 makes the animals more sensitive to cocaine reward. The results suggest that a dihydropyridine-sensitive mechanism is implicated in the initiation of cocaine self-administration.
authors.affiliation: Pavlov Medical Institute, St.-Petersburg, Russian Federation.
authors.forename: A
authors.initials: A
authors.lastname: Kuzmin
authors.forename: S
authors.initials: S
authors.lastname: Semenova
authors.forename: N F
authors.initials: NF
authors.lastname: Ramsey
authors.forename: E E
authors.initials: EE
authors.lastname: Zvartau
authors.forename: J M
authors.initials: JM
authors.lastname: Van Ree
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003042:Cocaine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007275:Injections, Intravenous; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009553:Nimodipine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012646:Self Administration
chemical_list: D009553:Nimodipine; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D003042:Cocaine