Threshold channels—a novel type of sodium channel in squid giant axon (original) (raw)
- Letter
- Published: 31 May 1984
Nature volume 309, pages 448–450 (1984)Cite this article
- 207 Accesses
- 116 Citations
- 3 Altmetric
- Metrics details
Abstract
Sodium channels in nerve and muscle cells are functionally similar across wide phylogenetic boundaries1 and are usually thought to represent a single, homogeneous population that initiates the .action potential at threshold and unerringly transmits it along the surface membrane. In marked contrast, many cell types are known to have several distinct potassium permeability systems2,3. Distinguishable populations of Na channels have been reported in a few cell types, however, including denervated skeletal muscle4, embryonic cardiac muscle5, Purkinje cell somata6and non-myelinated axons at low temperature7. We report here that in squid giant axon, in standard experimental conditions, there are two functionally distinct populations of Na channels. The newly discovered population accounts for only a few per cent of the total Na permeability. The channels are selectively activated by small depolarizations and have very slow closing kinetics. Because these channels activate at voltages near the resting potential and tend to stay open for long times, they must dominate behaviour of the axon membrane in the threshold region for action potential initiation.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Additional access options:
Similar content being viewed by others
References
- Hagiwara, S. Membrane Potential-dependent Ion Channels in Cell Membranes: Phylogenetic and Developmental Approaches, 118 (Raven, New York, 1983).
Google Scholar - Thompson, S. H. & Aldrich, R. W. in The Cell Surface and Neuronal Function (eds Cotman, C. W., Poste, G. & Nicolson, G. L.) 49–85 (Elsevier, Amsterdam, 1980).
Google Scholar - Dubois, J. M. J. Physiol., Lond. 318, 297–316 (1981).
Article CAS Google Scholar - Pappone, P. A. J. Physiol., Lond. 306, 377–410 (1980).
Article CAS Google Scholar - Ten Eick, R., Yeh, J. & Matsuki, N. Biophys. J. 45, 70–73 (1984).
Article Google Scholar - Llinas, R. & Sugimori, M. J. Physiol., Lond. 305, 197–213 (1980).
Article CAS Google Scholar - Mattesen, D. R. & Armstrong, C. M. J. gen. Physiol. 79, 739–758 (1982).
Article Google Scholar - Armstrong, C. M. & Bezanilla, F. J. gen.Physiol. 63, 533–552 (1974).
Article CAS Google Scholar - Armstrong, C. M. & Gilly, W. F. J. gen. Physiol 74, 691–711 (1979).
Article CAS Google Scholar - Hodgkin, A. L. & Huxley, A. F. J. Physiol, Lond. 117, 500–544 (1952).
Article CAS Google Scholar - Gilly, W. F. & Armstrong, C. M. J. gen. Physiol. 79, 935–964 (1983).
Article Google Scholar - Oxford, G. S. J. gen. Physiol. 77, 1–22 (1981).
Article CAS Google Scholar - Moore, J. W. & Westerfield, M. J. Physiol., Lond. 336, 285–300 (1983).
Article CAS Google Scholar - Moore, J. W., Stockbridge, N. & Westerfield, M. J. Physiol., Lond. 336, 301–311 (1983).
Article CAS Google Scholar
Author information
Authors and Affiliations
- Hopkins Marine Station of Stanford University, Department of Biological Sciences, Pacific Grove, California, 93950, USA
Wm. F. Gilly - Department of Physiology, University of Pennsylvania Medical School, Philadelphia, Pennsylvania, 19104, USA
Clay M. Armstrong
Authors
- Wm. F. Gilly
You can also search for this author inPubMed Google Scholar - Clay M. Armstrong
You can also search for this author inPubMed Google Scholar
Rights and permissions
About this article
Cite this article
Gilly, W., Armstrong, C. Threshold channels—a novel type of sodium channel in squid giant axon.Nature 309, 448–450 (1984). https://doi.org/10.1038/309448a0
- Received: 04 January 1984
- Accepted: 27 March 1984
- Issue Date: 31 May 1984
- DOI: https://doi.org/10.1038/309448a0