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Discrete Waves and Phototransduction in Voltage-damped Ventral Photoreceptors
Discrete waves in the voltage-clamped photoreceptor of Limulus are remarkably similar in all essential properties to those found in an unclamped cell. The latency distribution of discrete waves is not affected by considerable changes in the holding potential in a voltage-clamped cell. Both large and...
Autores principales: | , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
1974
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2226171/ https://www.ncbi.nlm.nih.gov/pubmed/4846766 |
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author | Behbehani, Michael Srebro, Richard |
author_facet | Behbehani, Michael Srebro, Richard |
author_sort | Behbehani, Michael |
collection | PubMed |
description | Discrete waves in the voltage-clamped photoreceptor of Limulus are remarkably similar in all essential properties to those found in an unclamped cell. The latency distribution of discrete waves is not affected by considerable changes in the holding potential in a voltage-clamped cell. Both large and small waves occur in voltage-clamped and unclamped cells and in approximately the same proportion. Large and small waves also share the same latency distributions and spectral sensitivity. We suggest that small waves may result from the activation of damaged membrane areas. Large waves have an average amplitude of approximately 5 nA in voltage-clamped photoreceptors. It probably requires several square microns of cell membrane to support this much photo-current. Thus the amplification inherent in the discrete wave process may involve spatial spread of activation from unimolecular dimensions to several square microns of cell membrane surface. Neither local current flow, nor pre-packaging of any transmitter substance appears to be involved in the amplification process. The possible mechanisms of the amplification are evaluated with relationship to the properties of discrete waves. |
format | Text |
id | pubmed-2226171 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1974 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22261712008-04-23 Discrete Waves and Phototransduction in Voltage-damped Ventral Photoreceptors Behbehani, Michael Srebro, Richard J Gen Physiol Article Discrete waves in the voltage-clamped photoreceptor of Limulus are remarkably similar in all essential properties to those found in an unclamped cell. The latency distribution of discrete waves is not affected by considerable changes in the holding potential in a voltage-clamped cell. Both large and small waves occur in voltage-clamped and unclamped cells and in approximately the same proportion. Large and small waves also share the same latency distributions and spectral sensitivity. We suggest that small waves may result from the activation of damaged membrane areas. Large waves have an average amplitude of approximately 5 nA in voltage-clamped photoreceptors. It probably requires several square microns of cell membrane to support this much photo-current. Thus the amplification inherent in the discrete wave process may involve spatial spread of activation from unimolecular dimensions to several square microns of cell membrane surface. Neither local current flow, nor pre-packaging of any transmitter substance appears to be involved in the amplification process. The possible mechanisms of the amplification are evaluated with relationship to the properties of discrete waves. The Rockefeller University Press 1974-08-01 /pmc/articles/PMC2226171/ /pubmed/4846766 Text en Copyright © 1974 by The Rockefeller University Press 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 | Article Behbehani, Michael Srebro, Richard Discrete Waves and Phototransduction in Voltage-damped Ventral Photoreceptors |
title | Discrete Waves and Phototransduction in Voltage-damped Ventral Photoreceptors |
title_full | Discrete Waves and Phototransduction in Voltage-damped Ventral Photoreceptors |
title_fullStr | Discrete Waves and Phototransduction in Voltage-damped Ventral Photoreceptors |
title_full_unstemmed | Discrete Waves and Phototransduction in Voltage-damped Ventral Photoreceptors |
title_short | Discrete Waves and Phototransduction in Voltage-damped Ventral Photoreceptors |
title_sort | discrete waves and phototransduction in voltage-damped ventral photoreceptors |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2226171/ https://www.ncbi.nlm.nih.gov/pubmed/4846766 |
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