Abstract
Horakova et al.1 were the first to observe that the phase of late outward current carried by potassium ions in frog and squid nerve is virtually absent in voltage-clamped rat nodes of Ranvier. This observation has been recently confirmed by Chiu et al.2 in rabbit nodes of Ranvier, suggesting that the nodal membrane in the mammal generally has few if any potassium channels. The present voltage-clamp experiments show that large potassium currents can, however, be produced in normal rabbit nodes of Ranvier by acute treatment designed to loosen the myelin from the axonal membrane. From this we conclude that whereas potassium channels are absent in the mammalian nodal membrane, they are normally present in the internodal axonal membrane at least in the paranodal region.
Similar content being viewed by others
References
Horakova, M., Nonner, W. & Stämpfli, R. Proc. int. Un. physiol. Sci. 7, 198 (1968).
Chiu, S. Y., Ritchie, J. M., Rogart, R. D. & Stagg, D. J. Physiol., Land. 292, 149–166 (1979).
Brismar, T. Acta physiol. scand. 105, 384–386 (1979).
Sherratt, R. M., Bostock, H. & Sears, T. A. Nature 283, 570–572 (1980).
Bostock, H., Sherratt, R. M. & Sears, T. A. Nature 274, 385–387 (1978).
Rogart, R. B. in Abnormal Nerves and Muscles as Impulse Generators (eds Culp, W. Ochoa, J.) (Oxford, New York, in the press).
Hille, B. in Biophysics and Physiology of Excitable Membranes, (ed. Adelman, W. J.) 230–246 (Van Nostrand, New York, 1980).
Ritchie, J. M. & Rogart, R. B. Rev. Physiol. Biochem. Pharmac. 79, 1–50 (1979).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Chiu, S., Ritchie, J. Potassium channels in nodal and internodal axonal membrane of mammalian myelinated fibres. Nature 284, 170–171 (1980). https://doi.org/10.1038/284170a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/284170a0
- Springer Nature Limited
This article is cited by
-
Early Reactive Changes at Myelin Sheaths Gaps (nodes of Ranvier) of Nerve Fibers (a supravital study)
Neuroscience and Behavioral Physiology (2012)
-
Effects of induced hypothermia on somatosensory evoked potentials in patients with chronic spinal cord injury
Spinal Cord (1993)
-
Developmental changes at the node and paranode in human sural nerves: morphometric and fine-structural evaluation
Cell & Tissue Research (1993)
-
Three-dimensional fine structure of cytoskeletal-membrane interactions at nodes of Ranvier
Journal of Neurocytology (1991)
-
Voltage-sensitive Na+ channels in mammalian peripheral nerves detected using Scorpion toxins
Journal of Neurocytology (1990)