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ERG Responses in Mice with Deletion of the Synaptic Ribbon Component RIBEYE
PURPOSE: To determine the influence of RIBEYE deletion and the resulting absence of synaptic ribbons on retinal light signaling by electroretinography. METHODS: Full-field flash electroretinograms (ERGs) were recorded in RIBEYE knock-out (KO) and wild-type (WT) littermate mice under photopic and sco...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Association for Research in Vision and Ophthalmology
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7405791/ https://www.ncbi.nlm.nih.gov/pubmed/32437548 http://dx.doi.org/10.1167/iovs.61.5.37 |
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author | Fairless, Richard Williams, Sarah K. Katiyar, Rashmi Maxeiner, Stephan Schmitz, Frank Diem, Ricarda |
author_facet | Fairless, Richard Williams, Sarah K. Katiyar, Rashmi Maxeiner, Stephan Schmitz, Frank Diem, Ricarda |
author_sort | Fairless, Richard |
collection | PubMed |
description | PURPOSE: To determine the influence of RIBEYE deletion and the resulting absence of synaptic ribbons on retinal light signaling by electroretinography. METHODS: Full-field flash electroretinograms (ERGs) were recorded in RIBEYE knock-out (KO) and wild-type (WT) littermate mice under photopic and scotopic conditions, with oscillatory potentials (OPs) extracted by digital filtering. Flicker ERGs and ERGs following intravitreal injection of pharmacological agents were also obtained under scotopic conditions. RESULTS: The a-wave amplitudes were unchanged between RIBEYE KO and WT mice; however, the b-wave amplitudes were reduced in KOs under scotopic, but not photopic, conditions. Increasing stimulation frequency led to a greater reduction in RIBEYE KO b-wave amplitudes compared with WTs. Furthermore, we observed prominent, supernormal OPs in RIBEYE KO mice in comparison with WT mice. Following intravitreal injections with l-2 amino-4-phosphonobutyric acid and cis-2,3 piperidine dicarboxylic acid to block ON and OFF responses at photoreceptor synapses, OPs were completely abolished in both mice types, indicating a synaptic origin of the prominent OPs in the KOs. Conversely, tetrodotoxin treatment to block voltage-gated Na(+) channels/spiking neurons did not differentially affect OPs in WT and KO mice. CONCLUSIONS: The decreased scotopic b-wave and decreased responses to increased stimulation frequencies are consistent with signaling malfunctions at photoreceptor and inner retinal ribbon synapses. Because phototransduction in the photoreceptor outer segments is unaffected in the KOs, their supernormal OPs presumably result from a dysfunction in retinal synapses. The relatively mild ERG phenotype in KO mice, particularly in the photopic range, is probably caused by compensatory mechanisms in retinal signaling pathways. |
format | Online Article Text |
id | pubmed-7405791 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | The Association for Research in Vision and Ophthalmology |
record_format | MEDLINE/PubMed |
spelling | pubmed-74057912020-08-19 ERG Responses in Mice with Deletion of the Synaptic Ribbon Component RIBEYE Fairless, Richard Williams, Sarah K. Katiyar, Rashmi Maxeiner, Stephan Schmitz, Frank Diem, Ricarda Invest Ophthalmol Vis Sci Visual Neuroscience PURPOSE: To determine the influence of RIBEYE deletion and the resulting absence of synaptic ribbons on retinal light signaling by electroretinography. METHODS: Full-field flash electroretinograms (ERGs) were recorded in RIBEYE knock-out (KO) and wild-type (WT) littermate mice under photopic and scotopic conditions, with oscillatory potentials (OPs) extracted by digital filtering. Flicker ERGs and ERGs following intravitreal injection of pharmacological agents were also obtained under scotopic conditions. RESULTS: The a-wave amplitudes were unchanged between RIBEYE KO and WT mice; however, the b-wave amplitudes were reduced in KOs under scotopic, but not photopic, conditions. Increasing stimulation frequency led to a greater reduction in RIBEYE KO b-wave amplitudes compared with WTs. Furthermore, we observed prominent, supernormal OPs in RIBEYE KO mice in comparison with WT mice. Following intravitreal injections with l-2 amino-4-phosphonobutyric acid and cis-2,3 piperidine dicarboxylic acid to block ON and OFF responses at photoreceptor synapses, OPs were completely abolished in both mice types, indicating a synaptic origin of the prominent OPs in the KOs. Conversely, tetrodotoxin treatment to block voltage-gated Na(+) channels/spiking neurons did not differentially affect OPs in WT and KO mice. CONCLUSIONS: The decreased scotopic b-wave and decreased responses to increased stimulation frequencies are consistent with signaling malfunctions at photoreceptor and inner retinal ribbon synapses. Because phototransduction in the photoreceptor outer segments is unaffected in the KOs, their supernormal OPs presumably result from a dysfunction in retinal synapses. The relatively mild ERG phenotype in KO mice, particularly in the photopic range, is probably caused by compensatory mechanisms in retinal signaling pathways. The Association for Research in Vision and Ophthalmology 2020-05-21 /pmc/articles/PMC7405791/ /pubmed/32437548 http://dx.doi.org/10.1167/iovs.61.5.37 Text en Copyright 2020 The Authors http://creativecommons.org/licenses/by-nc-nd/4.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. |
spellingShingle | Visual Neuroscience Fairless, Richard Williams, Sarah K. Katiyar, Rashmi Maxeiner, Stephan Schmitz, Frank Diem, Ricarda ERG Responses in Mice with Deletion of the Synaptic Ribbon Component RIBEYE |
title | ERG Responses in Mice with Deletion of the Synaptic Ribbon Component RIBEYE |
title_full | ERG Responses in Mice with Deletion of the Synaptic Ribbon Component RIBEYE |
title_fullStr | ERG Responses in Mice with Deletion of the Synaptic Ribbon Component RIBEYE |
title_full_unstemmed | ERG Responses in Mice with Deletion of the Synaptic Ribbon Component RIBEYE |
title_short | ERG Responses in Mice with Deletion of the Synaptic Ribbon Component RIBEYE |
title_sort | erg responses in mice with deletion of the synaptic ribbon component ribeye |
topic | Visual Neuroscience |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7405791/ https://www.ncbi.nlm.nih.gov/pubmed/32437548 http://dx.doi.org/10.1167/iovs.61.5.37 |
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