Internodal potassium currents can generate ectopic impulses in mammalian myelinated axons

Raju Kapoor, Kenneth J. Smith, Paul A. Felts, Meirion Davies

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33 Citations (Scopus)


Positive clinical symptoms can arise from ectopic action potentials in several disorders of myelinated axons. Here we report that an elevated K+ concentration in the periaxonal, internodal space can cause internodal K+ currents to become excitatory, resulting in slow potential oscillations and associated bursts of ectopic spikes. Ectopic firing may therefore be favoured by conditions in which periaxonal K+ buffering is compromised.

Original languageEnglish
Pages (from-to)165-169
Number of pages5
JournalBrain Research
Issue number1
Publication statusPublished - 14 May 1993



  • 4-Aminopyridine
  • Action potential
  • Ectopic firing
  • Periaxonal space
  • Positive symptom
  • Potassium channel
  • Tetraethylammonium

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