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Subcortical orientation biases explain orientation selectivity of visual cortical cells
The primary visual cortex of carnivores and primates shows an orderly progression of domains of neurons that are selective to a particular orientation of visual stimuli such as bars and gratings. We recorded from single-thalamic afferent fibers that terminate in these domains to address the issue wh...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BlackWell Publishing Ltd
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4425978/ https://www.ncbi.nlm.nih.gov/pubmed/25855249 http://dx.doi.org/10.14814/phy2.12374 |
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author | Vidyasagar, Trichur R Jayakumar, Jaikishan Lloyd, Errol Levichkina, Ekaterina V |
author_facet | Vidyasagar, Trichur R Jayakumar, Jaikishan Lloyd, Errol Levichkina, Ekaterina V |
author_sort | Vidyasagar, Trichur R |
collection | PubMed |
description | The primary visual cortex of carnivores and primates shows an orderly progression of domains of neurons that are selective to a particular orientation of visual stimuli such as bars and gratings. We recorded from single-thalamic afferent fibers that terminate in these domains to address the issue whether the orientation sensitivity of these fibers could form the basis of the remarkable orientation selectivity exhibited by most cortical cells. We first performed optical imaging of intrinsic signals to obtain a map of orientation domains on the dorsal aspect of the anaesthetized cat's area 17. After confirming using electrophysiological recordings the orientation preferences of single neurons within one or two domains in each animal, we pharmacologically silenced the cortex to leave only the afferent terminals active. The inactivation of cortical neurons was achieved by the superfusion of either kainic acid or muscimol. Responses of single geniculate afferents were then recorded by the use of high impedance electrodes. We found that the orientation preferences of the afferents matched closely with those of the cells in the orientation domains that they terminated in (Pearson's r = 0.633, n = 22, P = 0.002). This suggests a possible subcortical origin for cortical orientation selectivity. |
format | Online Article Text |
id | pubmed-4425978 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | BlackWell Publishing Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-44259782015-05-14 Subcortical orientation biases explain orientation selectivity of visual cortical cells Vidyasagar, Trichur R Jayakumar, Jaikishan Lloyd, Errol Levichkina, Ekaterina V Physiol Rep Original Research The primary visual cortex of carnivores and primates shows an orderly progression of domains of neurons that are selective to a particular orientation of visual stimuli such as bars and gratings. We recorded from single-thalamic afferent fibers that terminate in these domains to address the issue whether the orientation sensitivity of these fibers could form the basis of the remarkable orientation selectivity exhibited by most cortical cells. We first performed optical imaging of intrinsic signals to obtain a map of orientation domains on the dorsal aspect of the anaesthetized cat's area 17. After confirming using electrophysiological recordings the orientation preferences of single neurons within one or two domains in each animal, we pharmacologically silenced the cortex to leave only the afferent terminals active. The inactivation of cortical neurons was achieved by the superfusion of either kainic acid or muscimol. Responses of single geniculate afferents were then recorded by the use of high impedance electrodes. We found that the orientation preferences of the afferents matched closely with those of the cells in the orientation domains that they terminated in (Pearson's r = 0.633, n = 22, P = 0.002). This suggests a possible subcortical origin for cortical orientation selectivity. BlackWell Publishing Ltd 2015-04-08 /pmc/articles/PMC4425978/ /pubmed/25855249 http://dx.doi.org/10.14814/phy2.12374 Text en © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society. http://creativecommons.org/licenses/by/4.0/ This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Original Research Vidyasagar, Trichur R Jayakumar, Jaikishan Lloyd, Errol Levichkina, Ekaterina V Subcortical orientation biases explain orientation selectivity of visual cortical cells |
title | Subcortical orientation biases explain orientation selectivity of visual cortical cells |
title_full | Subcortical orientation biases explain orientation selectivity of visual cortical cells |
title_fullStr | Subcortical orientation biases explain orientation selectivity of visual cortical cells |
title_full_unstemmed | Subcortical orientation biases explain orientation selectivity of visual cortical cells |
title_short | Subcortical orientation biases explain orientation selectivity of visual cortical cells |
title_sort | subcortical orientation biases explain orientation selectivity of visual cortical cells |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4425978/ https://www.ncbi.nlm.nih.gov/pubmed/25855249 http://dx.doi.org/10.14814/phy2.12374 |
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