| The effect of controlled photopigment excitations on pupil aperture. | |
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MedLine Citation:
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PMID: 20883331 Owner: NLM Status: In-Process |
Abstract/OtherAbstract:
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In addition to rods and cones, the human retina contains melanopsin which has been identified recently in the body and dendrites of a few ganglion cells. The intrinsically photosensitive retinal ganglion cells (ipRGCs) are good candidates for controlling the tonic pupil aperture but their spectral sensitivity is close to those of rods and S-cones which are other candidates. Our study aims at identifying the stimulus for the pupil response when the luminance is constant and the spectrum of the light changes. A light booth was equipped with five types of coloured light emitting diodes (LEDs): Blue, Cyan, Green, Orange and Red. The intensity of each LED type could be adjusted to control the light spectrum. Illumination pairs were prepared ensuring the exclusive variation of excitation of one receptor type and silent substitution for others. Because the range of the possible controlled changes of excitation was narrow, we also prepared illumination pairs ensuring silent substitution for luminance rather than for L-cones and M-cones independently. Photographs of the observer's eyes were taken following one minute of adaptation to each illumination and the ratio of pupil to iris diameter was measured. No differential pupillary response was observed with a variation of rod, melanopsin or S-cone excitation alone. A differential pupillary response could only be obtained with a variation of the melanopsin stimulus of sufficient high contrast with or without a concurrent variation of rods. |
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Authors:
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Françoise Viénot; Solenne Bailacq; Jean Le Rohellec |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) Volume: 30 ISSN: 1475-1313 ISO Abbreviation: Ophthalmic Physiol Opt Publication Date: 2010 Sep |
Date Detail:
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Created Date: 2010-10-04 Completed Date: - Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8208839 Medline TA: Ophthalmic Physiol Opt Country: England |
Other Details:
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Languages: eng Pagination: 484-91 Citation Subset: IM |
Copyright Information:
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© 2010 The Authors, Ophthalmic and Physiological Optics © 2010 The College of Optometrists. |
Affiliation:
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Muséum national d'histoire naturelle, Centre de Recherche sur la Conservation des Collections, MNHN-CNRS-MCC, Paris, France. vienot@mnhn.fr |
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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