NicotineNicotinic AgonistsTobacco Use DisorderGanglionic StimulantsReceptors, NicotinicMecamylamineCotinineNicotinic AntagonistsChewing GumSubstance Withdrawal SyndromeTobacco Use Cessation ProductsSmoking CessationSmokingAdministration, CutaneousDihydro-beta-ErythroidineProtein BindingTarsalpha7 Nicotinic Acetylcholine ReceptorSelf AdministrationMolecular Sequence DataBinding SitesAzocinesDose-Response Relationship, DrugAmino Acid SequenceAconitineRats, Sprague-DawleyConditioning, OperantQuinolizinesBase SequenceTobacco, SmokelessTobacco ProductsTobaccoRewardBicyclo Compounds, HeterocyclicAnabasineProtein Structure, TertiaryCarbon MonoxideReinforcement (Psychology)Behavior, AnimalSelf StimulationCell LineHexamethoniumBungarotoxinsDNA-Binding ProteinsTime FactorsDopamineBenzazepinesBrainBinding, CompetitiveModels, MolecularHexamethonium CompoundsTobacco Smoke PollutionKineticsQuinoxalinesVentral Tegmental AreaPyridinesNitrosaminesAnalysis of VarianceSmokeTranscription FactorsMotor ActivityRecombinant ProteinsNucleus Accumbens