Skip to main content
NCBI home page
Biophysical Journal logoLink to Biophysical Journal
. 1976 Feb;16(2 Pt 1):171–192. doi: 10.1016/s0006-3495(76)85673-1

A kinetic model for the sodium conductance system in squid axon.

J W Moore, E B Cox
PMCID: PMC1334827  PMID: 1247646

Abstract

We describe a kinetic reaction sequence for the sodium conductance system in the squid axon. It closely matches the original Hodgkin and Huxley model for voltage clamp experiments but it generates an action potential without a bump on the falling phase. When calcium ions are included in the reaction, this model faithfully reproduces the experimental observations of Frankenhaeuser and Hodgkin on the effects of altered calcium in the medium. The fit to experiment is much better than when a voltage shift in rate constants is assumed. The gating currents recently observed by Armstrong and Bezanilla are not compatible with the Hodgkin and Huxley model but can be reprocuced in considerable detail by the kinetic model. Thus it appears that the kinetic model differs from that of Hodgkin and Huxley perhaps in an important and fundamental way that makes it more realistic.

Full text

PDF
171

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Armstrong C. M., Bezanilla F. Charge movement associated with the opening and closing of the activation gates of the Na channels. J Gen Physiol. 1974 May;63(5):533–552. doi: 10.1085/jgp.63.5.533. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Armstrong C. M., Bezanilla F. Currents related to movement of the gating particles of the sodium channels. Nature. 1973 Apr 13;242(5398):459–461. doi: 10.1038/242459a0. [DOI] [PubMed] [Google Scholar]
  3. Armstrong C. M. Inactivation of the potassium conductance and related phenomena caused by quaternary ammonium ion injection in squid axons. J Gen Physiol. 1969 Nov;54(5):553–575. doi: 10.1085/jgp.54.5.553. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bezanilla F., Armstrong C. M. Gating currents of the sodium channels: three ways to block them. Science. 1974 Feb 22;183(4126):753–754. doi: 10.1126/science.183.4126.753. [DOI] [PubMed] [Google Scholar]
  5. FRANKENHAEUSER B., HODGKIN A. L. The action of calcium on the electrical properties of squid axons. J Physiol. 1957 Jul 11;137(2):218–244. doi: 10.1113/jphysiol.1957.sp005808. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Fishman S. N., Chodorov B. I., Volkenstein M. V. Molecular mechanisms of membrane ionic permeability changes. Biochim Biophys Acta. 1971 Jan 5;225(1):1–10. doi: 10.1016/0005-2736(71)90277-x. [DOI] [PubMed] [Google Scholar]
  7. GOLDMAN D. E. GATE CONTROL OF ION FLUX IN AXONS. J Gen Physiol. 1965 May;48:SUPPL–SUPPL:77. doi: 10.1085/jgp.48.5.75. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. GOLDMANN D. E. A MOLECULAR STRUCTURAL BASIS FOR THE EXCITATION PROPERTIES OF AXONS. Biophys J. 1964 May;4:167–188. doi: 10.1016/s0006-3495(64)86776-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Goldman L., Schauf C. L. Inactivation of the sodium current in Myxicola giant axons. Evidence for coupling to the activation process. J Gen Physiol. 1972 Jun;59(6):659–675. doi: 10.1085/jgp.59.6.659. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. HOYT R. C. THE SQUID GIANT AXON. MATHEMATICAL MODELS. Biophys J. 1963 Sep;3:399–431. doi: 10.1016/s0006-3495(63)86829-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. HUXLEY A. F. Ion movements during nerve activity. Ann N Y Acad Sci. 1959 Aug 28;81:221–246. doi: 10.1111/j.1749-6632.1959.tb49311.x. [DOI] [PubMed] [Google Scholar]
  12. Jain M. K., Marks R. H., Cordes E. H. Kinetic model of conduction changes across excitable membranes. Proc Natl Acad Sci U S A. 1970 Oct;67(2):799–806. doi: 10.1073/pnas.67.2.799. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Keynes R. D., Ritchie J. M., Rojas E. The binding of tetrodotoxin to nerve membranes. J Physiol. 1971 Feb;213(1):235–254. doi: 10.1113/jphysiol.1971.sp009379. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Keynes R. D., Rojas E. Kinetics and steady-state properties of the charged system controlling sodium conductance in the squid giant axon. J Physiol. 1974 Jun;239(2):393–434. doi: 10.1113/jphysiol.1974.sp010575. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Meves H. The effect of holding potential on the asymmetry currents in squid gaint axons. J Physiol. 1974 Dec;243(3):847–867. doi: 10.1113/jphysiol.1974.sp010780. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Moore J. W., Ramon F. On numerical integration of the Hodgkin and Huxley equations for a membrane action potential. J Theor Biol. 1974 May;45(1):249–273. doi: 10.1016/0022-5193(74)90054-x. [DOI] [PubMed] [Google Scholar]
  17. Moore L. E., Jakobsson E. Interpretation of the sodium permeability changes of myelinated nerve in terms of linear relaxation theory. J Theor Biol. 1971 Oct;33(1):77–89. doi: 10.1016/0022-5193(71)90217-7. [DOI] [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES