BaclofenGABA-B Receptor AgonistsGABA AgonistsReceptors, GABA-BGABA-B Receptor AntagonistsPhosphinic AcidsGABA AntagonistsMuscimolSodium OxybateGABA-A Receptor Agonistsgamma-Aminobutyric AcidGABA AgentsMuscle Relaxants, CentralBicucullineOrganophosphorus CompoundsReceptors, GABA-ANipecotic AcidsReceptors, GABAGABA-A Receptor AntagonistsRats, Sprague-DawleyDose-Response Relationship, DrugSynaptic TransmissionEnkephalin, Ala(2)-MePhe(4)-Gly(5)-NeuronsReceptors, Opioid, muRats, WistarNeural InhibitionMuscle SpasticityPresynaptic TerminalsSelf AdministrationPatch-Clamp TechniquesInfusion Pumps, ImplantableDopamine AgonistsExcitatory Postsynaptic PotentialsDrug InteractionsElectrophysiologyElectric StimulationBehavior, AnimalMembrane PotentialsSynapsesCalcium ChannelsHippocampusInjections, SpinalPurinergic P1 Receptor AgonistsMuscarinic AgonistsNicotinic AgonistsAdrenergic AgonistsAdrenergic alpha-2 Receptor AgonistsSerotonin 5-HT2 Receptor Agonists