Trigeminal Nucleus, SpinalTrigeminal NucleiTrigeminal Caudal NucleusTrigeminal NerveCentral Nervous System SensitizationFacial PainBrain StemTrigeminal GanglionSubstantia GelatinosaAfferent PathwaysReceptors, Calcitonin Gene-Related PeptideSpinal CordNociceptorsCell NucleusNeurons, AfferentRats, Sprague-DawleyPhysical StimulationNeuronsDihydroergotamineVibrissaeSumatriptanElectric StimulationMeningesWheat Germ Agglutinin-Horseradish Peroxidase ConjugatePonsMasseter MuscleCochlear NucleusSpinal Cord InjuriesDura MaterMedulla OblongataProto-Oncogene Proteins c-fosStilbamidinesDental PulpNeural Pathways