On the physiological role of internodal potassium channels and the security of conduction in myelinated nerve fibres

Proc R Soc Lond B Biol Sci. 1984 Feb 22;220(1221):415-22. doi: 10.1098/rspb.1984.0010.


A theoretical analysis of the passive electrical properties of normal myelinated nerve suggests that the function of the voltage-dependent potassium channels in the internodal axolemma under the myelin sheath is to permit the generation of an internodal resting potential. Calculation shows that if this internodal potential were not present, the nodal potential would be reduced (by electrotonic short-circuiting) thus impairing the security of conduction. This impairment is particularly pronounced with smaller diameter fibres.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Electrophysiology
  • Ion Channels / physiology*
  • Mammals / physiology
  • Membrane Potentials
  • Nerve Fibers, Myelinated / physiology*
  • Potassium / metabolism*
  • Ranidae / physiology


  • Ion Channels
  • Potassium