Journal ArticleDOI
Melanopsin (Opn4) Requirement for Normal Light-Induced Circadian Phase Shifting
Satchidananda Panda,Trey K. Sato,Trey K. Sato,Ana Maria de Lauro Castrucci,Mark D. Rollag,Willem J. DeGrip,John B. Hogenesch,Ignacio Provencio,Steve A. Kay,Steve A. Kay +9 more
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TLDR
These mice display severely attenuated phase resetting in response to brief pulses of monochromatic light, highlighting the critical role of melanopsin in circadian photoentrainment in mammals.Abstract:
The master circadian oscillator in the hypothalamic suprachiasmatic nucleus is entrained to the day/night cycle by retinal photoreceptors. Melanopsin (Opn4), an opsin-based photopigment, is a primary candidate for photoreceptor-mediated entrainment. To investigate the functional role of melanopsin in light resetting of the oscillator, we generated melanopsin-null mice (Opn4-/-). These mice entrain to a light/dark cycle and do not exhibit any overt defect in circadian activity rhythms under constant darkness. However, they display severely attenuated phase resetting in response to brief pulses of monochromatic light, highlighting the critical role of melanopsin in circadian photoentrainment in mammals.read more
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Journal ArticleDOI
Molecular components of the mammalian circadian clock
TL;DR: The general mechanisms of the circadian clockwork are reviewed, recent findings that elucidate tissue-specific expression patterns of the clock genes are described and the importance of circadian regulation in peripheral tissues for an organism's overall well-being is addressed.
Journal ArticleDOI
Melanopsin-expressing ganglion cells in primate retina signal colour and irradiance and project to the LGN.
Dennis M. Dacey,Hsi-Wen Liao,Beth B. Peterson,Farrel R. Robinson,Vivianne C. Smith,Joel Pokorny,King Wai Yau,Paul D. Gamlin +7 more
TL;DR: An anatomically distinct population of ‘giant’, melanopsin-expressing ganglion cells in the primate retina that, in addition to being intrinsically photosensitive, are strongly activated by rods and cones, and display a rare, S-Off, (L + M)-On type of colour-opponent receptive field.
Journal ArticleDOI
Epidemiology of the human circadian clock.
Till Roenneberg,Tim Kuehnle,Myriam Juda,Thomas Kantermann,Karla V. Allebrandt,Marijke C. M. Gordijn,Martha Merrow,Martha Merrow +7 more
TL;DR: An algorithm is established which optimises chronotype assessment by incorporating the information on timing of sleep and wakefulness for both work and free days, because sleep duration strongly depends on chronotype.
Journal ArticleDOI
Structure and function of DNA photolyase and cryptochrome blue-light photoreceptors.
TL;DR: This work has shown that the structure and function of the Cryptochromes and the Circadian Clock, as well as their role in the regulation of Photolyase, are fundamentally different than that of the EMTs used in previous studies.
Journal ArticleDOI
Melanopsin and rod/cone photoreceptive systems account for all major accessory visual functions in mice.
Samer Hattar,Robert J. Lucas,Nicholas Mrosovsky,Stewart Thompson,Ronald H. Douglas,Mark W. Hankins,Janis Lem,Martin Biel,Franz Hofmann,Russell G. Foster,King Wai Yau +10 more
TL;DR: The rod–cone and melanopsin systems together seem to provide all of the photic input for these accessory visual functions such as pupillary light reflex and circadian photo-entrainment.
References
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Journal ArticleDOI
Phototransduction by retinal ganglion cells that set the circadian clock.
TL;DR: It is shown that retinal ganglion cells innervating the SCN are intrinsically photosensitive, and depolarized in response to light even when all synaptic input from rods and cones was blocked.
Journal ArticleDOI
Melanopsin-Containing Retinal Ganglion Cells: Architecture, Projections, and Intrinsic Photosensitivity
TL;DR: It is shown that melanopsin is present in cell bodies, dendrites, and proximal axonal segments of a subset of rat RGCs, most likely the visual pigment of phototransducing R GCs that set the circadian clock and initiate other non–image-forming visual functions.
Journal ArticleDOI
A Novel Human Opsin in the Inner Retina
Ignacio Provencio,Ignacio R. Rodriguez,Gui-Sen Jiang,William Pär Hayes,E.F. Moreira,Mark D. Rollag +5 more
TL;DR: The unique inner retinal localization of melanopsin suggests that it is not involved in image formation but rather may mediate nonvisual photoreceptive tasks, such as the regulation of circadian rhythms and the acute suppression of pineal melatonin.
Journal ArticleDOI
The cryb mutation identifies cryptochrome as a circadian photoreceptor in Drosophila
Ralf Stanewsky,Maki Kaneko,Patrick Emery,Bonnie Beretta,Karen Wager-Smith,Steve A. Kay,Michael Rosbash,Michael Rosbash,Jeffrey C. Hall +8 more
TL;DR: Cryb flies are rhythmic in constant darkness, correlating with robust PER and TIM cycling in certain pacemaker neurons, and is an apparent null mutation in a gene encoding Drosophila's version of the blue light receptor cryptochrome.
Journal ArticleDOI
Regulation of Mammalian Circadian Behavior by Non-rod, Non-cone, Ocular Photoreceptors
Melanie S. Freedman,Robert J. Lucas,Bobby G. Soni,Malcolm von Schantz,Marta Muñoz,Zoë K. David-Gray,Russell G. Foster +6 more
TL;DR: Neither rods nor cones are required for photoentrainment, and the murine eye contains additional photoreceptors that regulate the circadian clock.