Oscillating repolarization in action potentials of frog sensory myelinated nerve fibres.

Current and voltage clamp experiments were performed in single myelinated sensory nerve fibres of Rana esculenta. The K current was blocked by external tetraethylammonium-chloride and internal CsCl. Negative prepotentials led to the formation of a plateau in the repolarization phase of the action potential, and further regenerative depolarizations emerged from this plateau. A three-state model for Na inactivation based on voltage clamp data was sufficient to simulate these observations.