AconitineAconitumArrhythmias, CardiacTachycardia, VentricularElectrocardiographyDose-Response Relationship, DrugArrhythmia, SinusVeratridineAnti-Arrhythmia AgentsSodium Channel AgonistsAdministration, OralRats, Sprague-DawleyReinforcement ScheduleTime FactorsDose-Response Relationship, RadiationBatrachotoxinsAlkaloidsRats, WistarDrug InteractionsLiverDrug SynergismBehavior, AnimalPharmacologyVentromedial Hypothalamic NucleusDisease Models, AnimalMice, Inbred C57BLTetrodotoxinHeartDrugs, Chinese HerbalVentricular FibrillationCells, CulturedSodium Channels