Wakefulness-Promoting AgentsReceptors, Adrenergic, alpha-2Receptors, Opioid, muReceptors, OpioidAnalgesics, OpioidReceptors, Opioid, deltaReceptors, Opioid, kappaInterleukin 1 Receptor Antagonist ProteinOpioid PeptidesNarcotic AntagonistsNeurokinin-1 Receptor AntagonistsDose-Response Relationship, DrugRats, Sprague-DawleyNaloxonePiperidinesPurinergic P1 Receptor AntagonistsNaltrexoneHistamine H2 AntagonistsSerotonin 5-HT3 Receptor AntagonistsExcitatory Amino Acid AntagonistsDopamine AntagonistsAngiotensin Receptor AntagonistsSerotonin 5-HT2 Receptor AntagonistsAdenosine A2 Receptor AntagonistsHormone AntagonistsRats, WistarMorphineAdenosine A1 Receptor AntagonistsOpioid-Related DisordersPurinergic P2 Receptor AntagonistsEnkephalinsHistamine H1 AntagonistsMuscarinic AntagonistsReceptors, EndothelinEnkephalin, Ala(2)-MePhe(4)-Gly(5)-GABA-A Receptor AntagonistsGABA AntagonistsSerotonin AntagonistsAdrenergic alpha-1 Receptor AntagonistsNarcoticsSialoglycoproteinsHistamine AntagonistsReceptors, Adrenergic, alphaPyrrolidinesDynorphinsRadioligand Assayalpha 1-AntitrypsinReceptors, N-Methyl-D-AspartateReceptors, SerotoninLeukotriene AntagonistsReceptor, Endothelin ADizocilpine MaleateNicotinic AntagonistsSerotonin 5-HT1 Receptor AntagonistsAdrenergic alpha-2 Receptor AntagonistsAdrenergic alpha-AntagonistsAnalgesicsDrug InteractionsEnkephalin, D-Penicillamine (2,5)-Receptors, Interleukin-1Guinea PigsBiphenyl CompoundsPainBenzazepinesEndorphinsBinding, CompetitiveEnkephalin, LeucineTetrazolesPyridinesTime FactorsBehavior, AnimalPeptides, CyclicSerotonin Receptor AgonistsXanthinesPyrazolesNeuronsIndolesSulfonamidesCells, CulturedQuinoxalinesSignal TransductionHistamine H3 AntagonistsPiperazinesBuprenorphineSubstance PAzepinesInjections, IntraventricularReceptors, Neurokinin-1Hypoxia-Inducible Factor 1, alpha SubunitDrug ToleranceSerotoninPain MeasurementElectric StimulationOligopeptidesEnkephalin, Leucine-2-AlanineLosartanEndothelin-1Receptors, BradykininGABA-B Receptor Antagonistsalpha7 Nicotinic Acetylcholine Receptor