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Targeted Deletion of Vesicular GABA Transporter from Retinal Horizontal Cells Eliminates Feedback Modulation of Photoreceptor Calcium Channels123

The cellular mechanisms underlying feedback signaling from horizontal cells to photoreceptors, which are important for the formation of receptive field surrounds of early visual neurons, remain unsettled. Mammalian horizontal cells express a complement of synaptic proteins that are necessary and suf...

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Autores principales: Hirano, Arlene A., Liu, Xue, Boulter, Jim, Grove, James, Pérez de Sevilla Müller, Luis, Barnes, Steven, Brecha, Nicholas C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Society for Neuroscience 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785380/
https://www.ncbi.nlm.nih.gov/pubmed/27022629
http://dx.doi.org/10.1523/ENEURO.0148-15.2016
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author Hirano, Arlene A.
Liu, Xue
Boulter, Jim
Grove, James
Pérez de Sevilla Müller, Luis
Barnes, Steven
Brecha, Nicholas C.
author_facet Hirano, Arlene A.
Liu, Xue
Boulter, Jim
Grove, James
Pérez de Sevilla Müller, Luis
Barnes, Steven
Brecha, Nicholas C.
author_sort Hirano, Arlene A.
collection PubMed
description The cellular mechanisms underlying feedback signaling from horizontal cells to photoreceptors, which are important for the formation of receptive field surrounds of early visual neurons, remain unsettled. Mammalian horizontal cells express a complement of synaptic proteins that are necessary and sufficient for calcium-dependent exocytosis of inhibitory neurotransmitters at their contacts with photoreceptor terminals, suggesting that they are capable of releasing GABA via vesicular release. To test whether horizontal cell vesicular release is involved in feedback signaling, we perturbed inhibitory neurotransmission in these cells by targeted deletion of the vesicular GABA transporter (VGAT), the protein responsible for the uptake of inhibitory transmitter by synaptic vesicles. To manipulate horizontal cells selectively, an iCre mouse line with Cre recombinase expression controlled by connexin57 (Cx57) regulatory elements was generated. In Cx57-iCre mouse retina, only horizontal cells expressed Cre protein, and its expression occurred in all retinal regions. After crossing with a VGAT(flox/flox) mouse line, VGAT was selectively eliminated from horizontal cells, which was confirmed immunohistochemically. Voltage-gated ion channel currents in horizontal cells of Cx57-VGAT(−/−) mice were the same as Cx57-VGAT(+/+) controls, as were the cell responses to the ionotropic glutamate receptor agonist kainate, but the response to the GABA(A) receptor agonist muscimol in Cx57-VGAT(−/−) mice was larger. In contrast, the feedback inhibition of photoreceptor calcium channels, which in control animals is induced by horizontal cell depolarization, was completely absent in Cx57-VGAT(−/−) mice. The results suggest that vesicular release of GABA from horizontal cells is required for feedback inhibition of photoreceptors.
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spelling pubmed-47853802016-03-28 Targeted Deletion of Vesicular GABA Transporter from Retinal Horizontal Cells Eliminates Feedback Modulation of Photoreceptor Calcium Channels123 Hirano, Arlene A. Liu, Xue Boulter, Jim Grove, James Pérez de Sevilla Müller, Luis Barnes, Steven Brecha, Nicholas C. eNeuro New Research The cellular mechanisms underlying feedback signaling from horizontal cells to photoreceptors, which are important for the formation of receptive field surrounds of early visual neurons, remain unsettled. Mammalian horizontal cells express a complement of synaptic proteins that are necessary and sufficient for calcium-dependent exocytosis of inhibitory neurotransmitters at their contacts with photoreceptor terminals, suggesting that they are capable of releasing GABA via vesicular release. To test whether horizontal cell vesicular release is involved in feedback signaling, we perturbed inhibitory neurotransmission in these cells by targeted deletion of the vesicular GABA transporter (VGAT), the protein responsible for the uptake of inhibitory transmitter by synaptic vesicles. To manipulate horizontal cells selectively, an iCre mouse line with Cre recombinase expression controlled by connexin57 (Cx57) regulatory elements was generated. In Cx57-iCre mouse retina, only horizontal cells expressed Cre protein, and its expression occurred in all retinal regions. After crossing with a VGAT(flox/flox) mouse line, VGAT was selectively eliminated from horizontal cells, which was confirmed immunohistochemically. Voltage-gated ion channel currents in horizontal cells of Cx57-VGAT(−/−) mice were the same as Cx57-VGAT(+/+) controls, as were the cell responses to the ionotropic glutamate receptor agonist kainate, but the response to the GABA(A) receptor agonist muscimol in Cx57-VGAT(−/−) mice was larger. In contrast, the feedback inhibition of photoreceptor calcium channels, which in control animals is induced by horizontal cell depolarization, was completely absent in Cx57-VGAT(−/−) mice. The results suggest that vesicular release of GABA from horizontal cells is required for feedback inhibition of photoreceptors. Society for Neuroscience 2016-03-10 /pmc/articles/PMC4785380/ /pubmed/27022629 http://dx.doi.org/10.1523/ENEURO.0148-15.2016 Text en Copyright © 2016 Hirano et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
spellingShingle New Research
Hirano, Arlene A.
Liu, Xue
Boulter, Jim
Grove, James
Pérez de Sevilla Müller, Luis
Barnes, Steven
Brecha, Nicholas C.
Targeted Deletion of Vesicular GABA Transporter from Retinal Horizontal Cells Eliminates Feedback Modulation of Photoreceptor Calcium Channels123
title Targeted Deletion of Vesicular GABA Transporter from Retinal Horizontal Cells Eliminates Feedback Modulation of Photoreceptor Calcium Channels123
title_full Targeted Deletion of Vesicular GABA Transporter from Retinal Horizontal Cells Eliminates Feedback Modulation of Photoreceptor Calcium Channels123
title_fullStr Targeted Deletion of Vesicular GABA Transporter from Retinal Horizontal Cells Eliminates Feedback Modulation of Photoreceptor Calcium Channels123
title_full_unstemmed Targeted Deletion of Vesicular GABA Transporter from Retinal Horizontal Cells Eliminates Feedback Modulation of Photoreceptor Calcium Channels123
title_short Targeted Deletion of Vesicular GABA Transporter from Retinal Horizontal Cells Eliminates Feedback Modulation of Photoreceptor Calcium Channels123
title_sort targeted deletion of vesicular gaba transporter from retinal horizontal cells eliminates feedback modulation of photoreceptor calcium channels123
topic New Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785380/
https://www.ncbi.nlm.nih.gov/pubmed/27022629
http://dx.doi.org/10.1523/ENEURO.0148-15.2016
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