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Effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors
We studied the influence of altered ionic conditions on the recycling of synaptic vesicle membrane in frog retinal photoreceptors using horseradish peroxidase to monitor synaptic activity and trace the fate of internalized membrane. The addition of 1.2 mM barium or 20 mM tetraethylammonium to isolat...
Formato: | Texto |
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Lenguaje: | English |
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The Rockefeller University Press
1982
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2112377/ https://www.ncbi.nlm.nih.gov/pubmed/6292233 |
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collection | PubMed |
description | We studied the influence of altered ionic conditions on the recycling of synaptic vesicle membrane in frog retinal photoreceptors using horseradish peroxidase to monitor synaptic activity and trace the fate of internalized membrane. The addition of 1.2 mM barium or 20 mM tetraethylammonium to isolated retinas maintained in Ringer's solution, changes the usual balance of membrane circulation in the rod cells; the cone cells are much less affected. Retrieval of synaptic vesicle membrane in the rods, which normally regenerates small vesicles, becomes mediated predominantly by large sacs and vacuoles ("cisternae"). Because these cisternae can be labeled with peroxidase, they appear to arise from endocytized membrane. Morphometric analysis suggests strongly that the cisternae are formed of circulating synaptic vesicle membrane. The effects of barium and tetraethylammonium can be inhibited by high extracellular potassium, by high intensity light, and by 5 mM cobalt. They seem likely to depend on potassium channels, though additional more complex mediation may also be involved. The alterations in membrane retrieval that we find are of interest in terms of the multiple pathways of membrane cycling now being uncovered. They open potential experimental approaches to the controls of this circulation. In addition, the findings extend our previous ones demonstrating that rod cells and cone cells differ in their responses to divalent cations in ways that seem likely to be of physiological importance. |
format | Text |
id | pubmed-2112377 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1982 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21123772008-05-01 Effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors J Cell Biol Articles We studied the influence of altered ionic conditions on the recycling of synaptic vesicle membrane in frog retinal photoreceptors using horseradish peroxidase to monitor synaptic activity and trace the fate of internalized membrane. The addition of 1.2 mM barium or 20 mM tetraethylammonium to isolated retinas maintained in Ringer's solution, changes the usual balance of membrane circulation in the rod cells; the cone cells are much less affected. Retrieval of synaptic vesicle membrane in the rods, which normally regenerates small vesicles, becomes mediated predominantly by large sacs and vacuoles ("cisternae"). Because these cisternae can be labeled with peroxidase, they appear to arise from endocytized membrane. Morphometric analysis suggests strongly that the cisternae are formed of circulating synaptic vesicle membrane. The effects of barium and tetraethylammonium can be inhibited by high extracellular potassium, by high intensity light, and by 5 mM cobalt. They seem likely to depend on potassium channels, though additional more complex mediation may also be involved. The alterations in membrane retrieval that we find are of interest in terms of the multiple pathways of membrane cycling now being uncovered. They open potential experimental approaches to the controls of this circulation. In addition, the findings extend our previous ones demonstrating that rod cells and cone cells differ in their responses to divalent cations in ways that seem likely to be of physiological importance. The Rockefeller University Press 1982-10-01 /pmc/articles/PMC2112377/ /pubmed/6292233 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Articles Effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors |
title | Effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors |
title_full | Effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors |
title_fullStr | Effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors |
title_full_unstemmed | Effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors |
title_short | Effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors |
title_sort | effect of barium and tetraethylammonium on membrane circulation in frog retinal photoreceptors |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2112377/ https://www.ncbi.nlm.nih.gov/pubmed/6292233 |