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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
. 1971 May;68(5):938–941. doi: 10.1073/pnas.68.5.938

Properties of Squid Axon Membrane as Revealed by a Hydrophobic Probe, 2-p-Toluidinylnaphthalene-6-Sulfonate

I Tasaki 1,2, A Watanabe 1,2, M Hallett 1,2
PMCID: PMC389085  PMID: 4102563

Abstract

A hydrophobic probe, 2-p-toluidinylnaphthalene-6-sulfonate (TNS), was introduced into the interior of a squid giant axon and fluorescene properties of the TNS-stained axon were examined under illumination with polarized ultraviolet light. A transient reduction in fluorescence was observed when the axon was stimulated electrically. The light waves contributing to this fluorescence change were found to be nearly completely polarized, indicating that the probe molecules in the membrane are highly oriented. The emission spectra of these TNS-stained axons were examined at rest and during nerve excitation. The results obtained are considered to support the view that the process of nerve excitation is accompanied by a transition of the axon membrane from a hydrophobic to a hydrophilic state.

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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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