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Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light

Off-center bipolar cells show hyperpolarizing responses to spot illumination in the receptive field center and depolarization responses to an annulus in the surround. To understand the ionic mechanisms underlying these responses, we examined the current-voltage relationship of these bipolar cells, i...

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Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1983
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2215582/
https://www.ncbi.nlm.nih.gov/pubmed/6854267
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collection PubMed
description Off-center bipolar cells show hyperpolarizing responses to spot illumination in the receptive field center and depolarization responses to an annulus in the surround. To understand the ionic mechanisms underlying these responses, we examined the current-voltage relationship of these bipolar cells, input resistance changes during their light-evoked responses, and the reversal potentials of these responses. Off-center bipolar cells generally showed inward rectification when they were hyperpolarized and outward rectification when they were strongly depolarized. The membrane potential at which the I-V relationship deviated from linearity varied in individual cells. Hyperpolarizing center responses were generally accompanied by a resistance increase, irrespective of signal inputs either from red- sensitive cones or from rods, and the response polarities reversed at greater than +50 mV. Depolarizing surround responses were accompanied by a resistance decrease with a reversal potential at about +28 mV (one case). From the above observations, it is suggested that the center responses are generated by a decrease in sodium conductance (gNa) and the surround response is generated by an increase in gNa.
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spelling pubmed-22155822008-04-23 Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light J Gen Physiol Articles Off-center bipolar cells show hyperpolarizing responses to spot illumination in the receptive field center and depolarization responses to an annulus in the surround. To understand the ionic mechanisms underlying these responses, we examined the current-voltage relationship of these bipolar cells, input resistance changes during their light-evoked responses, and the reversal potentials of these responses. Off-center bipolar cells generally showed inward rectification when they were hyperpolarized and outward rectification when they were strongly depolarized. The membrane potential at which the I-V relationship deviated from linearity varied in individual cells. Hyperpolarizing center responses were generally accompanied by a resistance increase, irrespective of signal inputs either from red- sensitive cones or from rods, and the response polarities reversed at greater than +50 mV. Depolarizing surround responses were accompanied by a resistance decrease with a reversal potential at about +28 mV (one case). From the above observations, it is suggested that the center responses are generated by a decrease in sodium conductance (gNa) and the surround response is generated by an increase in gNa. The Rockefeller University Press 1983-04-01 /pmc/articles/PMC2215582/ /pubmed/6854267 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
Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light
title Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light
title_full Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light
title_fullStr Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light
title_full_unstemmed Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light
title_short Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light
title_sort ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. i. studies on responses evoked by light
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2215582/
https://www.ncbi.nlm.nih.gov/pubmed/6854267