AminopyridinesDiynes4-AminopyridineAcetylcholineReceptors, CholinergicReceptors, NicotinicMicrodialysisAtropineNeuromuscular JunctionReceptors, MuscarinicReceptor, Muscarinic M2alpha7 Nicotinic Acetylcholine ReceptorCholineMuscarinic AntagonistsMotor EndplateCholinergic FibersBungarotoxinsElectric StimulationTorpedoGuinea PigsPhysostigmineCD4-Positive T-LymphocytesIleumMyenteric Plexus