Vagus Nerve StimulationVagus NerveElectric Stimulation TherapyTranscutaneous Electric Nerve StimulationBlood Gas Monitoring, TranscutaneousElectric StimulationEpilepsyEpilepsy, Complex PartialImplantable NeurostimulatorsElectrodes, ImplantedVagus Nerve DiseasesParasympathetic Fibers, PostganglionicDepressive Disorder, Treatment-ResistantPterygopalatine FossaEarEpilepsy, GeneralizedVagus Nerve InjuriesVagotomyAcetylcholineSeizuresAnticonvulsantsRats, Sprague-DawleyHeart RateTreatment OutcomePeripheral NervesDogsSciatic NerveTime FactorsDrug ResistanceNerve FibersAdministration, CutaneousSympathetic Nervous System