Trigeminal Nucleus, SpinalTrigeminal NucleiTrigeminal Caudal NucleusTrigeminal NerveCentral Nervous System SensitizationFacial PainBrain StemTrigeminal GanglionSubstantia GelatinosaAfferent PathwaysNeurons, AfferentReceptors, Calcitonin Gene-Related PeptideNociceptorsSpinal CordCell NucleusRats, Sprague-DawleyPhysical StimulationElectric StimulationNeuronsVibrissaeDihydroergotamineSumatriptanCapsaicinNerve FibersMeningesWheat Germ Agglutinin-Horseradish Peroxidase ConjugatePonsCalcitonin Gene-Related PeptideMasseter MuscleCochlear NucleusSpinal Cord InjuriesMedulla OblongataDura MaterProto-Oncogene Proteins c-fosStilbamidinesCatsNeural PathwaysDental PulpPeripheral NervesSciatic NerveMechanoreceptors