Raphe NucleiSerotoninPeptostreptococcusNeuronsPeptococcusBrain StemThermoreceptorsPeriaqueductal GrayReticular FormationMedulla OblongataPhysical StimulationEnkephalin, Ala(2)-MePhe(4)-Gly(5)-Periapical AbscessMorphineAfferent PathwaysMicroinjectionsPainRats, Sprague-DawleySuppurationHot TemperatureSpinal CordAnalgesics, OpioidElectric StimulationAction PotentialsSexologyPsychoanalysisTryptophan HydroxylaseBacteria, AnaerobicSerotonergic Neurons8-Hydroxy-2-(di-n-propylamino)tetralinGram-Positive Bacterial InfectionsReceptor, Serotonin, 5-HT1AReceptors, Serotonin, 5-HT1