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Circadian Responses to Light-Flash Exposure: Conceptualization and New Data Guiding Future Directions
A growing number of studies document circadian phase-shifting after exposure to millisecond light flashes. When strung together by intervening periods of darkness, these stimuli evoke pacemaker responses rivaling or outmatching those created by steady luminance, suggesting that the circadian system&...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2021
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7905211/ https://www.ncbi.nlm.nih.gov/pubmed/33643205 http://dx.doi.org/10.3389/fneur.2021.627550 |
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author | Wong, Kwoon Y. Fernandez, Fabian-Xosé |
author_facet | Wong, Kwoon Y. Fernandez, Fabian-Xosé |
author_sort | Wong, Kwoon Y. |
collection | PubMed |
description | A growing number of studies document circadian phase-shifting after exposure to millisecond light flashes. When strung together by intervening periods of darkness, these stimuli evoke pacemaker responses rivaling or outmatching those created by steady luminance, suggesting that the circadian system's relationship to light can be contextualized outside the principle of simple dose-dependence. In the current review, we present a brief chronology of this work. We then develop a conceptual model around it that attempts to relate the circadian effects of flashes to a natural integrative process the pacemaker uses to intermittently sample the photic information available at dawn and dusk. Presumably, these snapshots are employed as building blocks in the construction of a coherent representation of twilight the pacemaker consults to orient the next day's physiology (in that way, flash-resetting of pacemaker rhythms might be less an example of a circadian visual illusion and more an example of the kinds of gestalt inferences that the image-forming system routinely makes when identifying objects within the visual field; i.e., closure). We conclude our review with a discussion on the role of cones in the pacemaker's twilight predictions, providing new electrophysiological data suggesting that classical photoreceptors—but not melanopsin—are necessary for millisecond, intermediate-intensity flash responses in ipRGCs (intrinsically photosensitive retinal ganglion cells). Future investigations are necessary to confirm this “Cone Sentinel Model” of circadian flash-integration and twilight-prediction, and to further define the contribution of cones vs. rods in transducing pacemaker flash signals. |
format | Online Article Text |
id | pubmed-7905211 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-79052112021-02-26 Circadian Responses to Light-Flash Exposure: Conceptualization and New Data Guiding Future Directions Wong, Kwoon Y. Fernandez, Fabian-Xosé Front Neurol Neurology A growing number of studies document circadian phase-shifting after exposure to millisecond light flashes. When strung together by intervening periods of darkness, these stimuli evoke pacemaker responses rivaling or outmatching those created by steady luminance, suggesting that the circadian system's relationship to light can be contextualized outside the principle of simple dose-dependence. In the current review, we present a brief chronology of this work. We then develop a conceptual model around it that attempts to relate the circadian effects of flashes to a natural integrative process the pacemaker uses to intermittently sample the photic information available at dawn and dusk. Presumably, these snapshots are employed as building blocks in the construction of a coherent representation of twilight the pacemaker consults to orient the next day's physiology (in that way, flash-resetting of pacemaker rhythms might be less an example of a circadian visual illusion and more an example of the kinds of gestalt inferences that the image-forming system routinely makes when identifying objects within the visual field; i.e., closure). We conclude our review with a discussion on the role of cones in the pacemaker's twilight predictions, providing new electrophysiological data suggesting that classical photoreceptors—but not melanopsin—are necessary for millisecond, intermediate-intensity flash responses in ipRGCs (intrinsically photosensitive retinal ganglion cells). Future investigations are necessary to confirm this “Cone Sentinel Model” of circadian flash-integration and twilight-prediction, and to further define the contribution of cones vs. rods in transducing pacemaker flash signals. Frontiers Media S.A. 2021-02-11 /pmc/articles/PMC7905211/ /pubmed/33643205 http://dx.doi.org/10.3389/fneur.2021.627550 Text en Copyright © 2021 Wong and Fernandez. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Neurology Wong, Kwoon Y. Fernandez, Fabian-Xosé Circadian Responses to Light-Flash Exposure: Conceptualization and New Data Guiding Future Directions |
title | Circadian Responses to Light-Flash Exposure: Conceptualization and New Data Guiding Future Directions |
title_full | Circadian Responses to Light-Flash Exposure: Conceptualization and New Data Guiding Future Directions |
title_fullStr | Circadian Responses to Light-Flash Exposure: Conceptualization and New Data Guiding Future Directions |
title_full_unstemmed | Circadian Responses to Light-Flash Exposure: Conceptualization and New Data Guiding Future Directions |
title_short | Circadian Responses to Light-Flash Exposure: Conceptualization and New Data Guiding Future Directions |
title_sort | circadian responses to light-flash exposure: conceptualization and new data guiding future directions |
topic | Neurology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7905211/ https://www.ncbi.nlm.nih.gov/pubmed/33643205 http://dx.doi.org/10.3389/fneur.2021.627550 |
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