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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1985 Feb;82(3):948–952. doi: 10.1073/pnas.82.3.948

Voltage-dependent sodium and potassium channels in mammalian cultured Schwann cells.

P Shrager, S Y Chiu, J M Ritchie
PMCID: PMC397165  PMID: 2579384

Abstract

Cultured Schwann cells from sciatic nerves of newborn rabbits and rats have been examined with patch-clamp techniques. In rabbit cells, single sodium and potassium channels have been detected with single channel conductances of 20 pS and 19 pS, respectively. Single sodium channels have a reversal potential within 15 mV of ENa, are blocked by tetrodotoxin, and have rapid and voltage-independent inactivation kinetics. Single potassium channels show current reversal close to EK and are blocked by 4-aminopyridine. From these results, and from comparisons of single-channel and whole-cell data, we show that these Schwann cells contain voltage-dependent sodium and potassium channels that are similar in most respects to the corresponding channels in mammalian axonal membranes. Cultured rat Schwann cells also have sodium channels, but at a density about 1/10th that of rabbit cells, a result in agreement with saxitoxin binding experiments on axon-free sectioned nerves. Saxitoxin binding to cultured cells suggests that there are up to 25,000 sodium channels in a single rabbit Schwann cell. We speculate that in vivo Schwann cells in myelinated axons might act as a local source for sodium channels at the nodal axolemma.

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Selected References

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

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