Lack of excitability in the internodal membrane of myelinated nerve fiber in frog.
Monophasic action potentials of about 70 and 10 mV were recorded by inserting a microelectrode into the axon and the myelin sheath of an intact myelinated fiber, respectively. When the intra-axonal or the intra-myelinic microelectrode was used for both stimulation and recording, only the anodal current was effective in inducing action potentials. The inter-nodal membrane was, therefore, intrinsically inexitable.
D000200:Action Potentials; D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure; D002462:Cell Membrane / Q000502:physiology; D066298:In Vitro Techniques; D008564:Membrane Potentials; D008839:Microelectrodes; D009186:Myelin Sheath / Q000166:cytology / Q000502:physiology*; D011898:Ranidae; D012584:Sciatic Nerve / Q000166:cytology / Q000502:physiology*