Slow sodium inactivation in Myxicola axons. Evidence for a second inactive state

Biophys J. 1976 Jul;16(7):771-8. doi: 10.1016/S0006-3495(76)85727-X.


Sodium inactivation and reactivation have been examined in voltage-clamped Myxicola axons after long-lasting membrane depolarizations produced either directly by changes in holding potential or indirectly by elevation of external K+ concentration. The results suggest the existence of a second inactivated state of the sodium channel with associated voltage-dependent rate constants at least two orders of magnitude lower than those of the fast inactivation process commonly examined. No specific influence of external [K+] on slow Na+ inactivation could be detected.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Axons / physiology*
  • Electrophysiology
  • Polychaeta
  • Sodium / physiology*


  • Sodium