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https://www.readbyqxmd.com/read/28061512/assessment-of-rod-cone-and-intrinsically-photosensitive-retinal-ganglion-cell-contributions-to-the-canine-chromatic-pupillary-response
#1
Connie Y Yeh, Kristin L Koehl, Christine D Harman, Simone Iwabe, José M Guzman, Simon M Petersen-Jones, Randy H Kardon, András M Komáromy
Purpose: The purpose of this study was to evaluate a chromatic pupillometry protocol for specific functional assessment of rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs) in dogs. Methods: Chromatic pupillometry was tested and compared in 37 dogs in different stages of primary loss of rod, cone, and combined rod/cone and optic nerve function, and in 5 wild-type (WT) dogs. Eyes were stimulated with 1-s flashes of dim (1 cd/m2) and bright (400 cd/m2) blue light (for scotopic conditions) or bright red (400 cd/m2) light with 25-cd/m2 blue background (for photopic conditions)...
January 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28031289/attenuated-pupillary-light-responses-and-downregulation-of-opsin-expression-parallel-decline-in-circadian-disruption-in-two-different-mouse-models-of-huntington-s-disease
#2
Koliane Ouk, Steven Hughes, Carina A Pothecary, Stuart N Peirson, A Jennifer Morton
Circadian deficits in Huntington's disease (HD) are recapitulated in both fragment (R6/2) and full-length (Q175) mouse models of HD. Circadian rhythms are regulated by the suprachiasmatic nuclei (SCN) in the hypothalamus, which are primarily entrained by light detected by the retina. The SCN receives input from intrinsically photosensitive retinal ganglion cells (ipRGCs) that express the photopigment melanopsin, but also receive input from rods and cones. In turn, ipRGCs mediate a range of non-image forming responses to light including circadian entrainment and the pupillary light response (PLR)...
December 27, 2016: Human Molecular Genetics
https://www.readbyqxmd.com/read/27992553/intrinsically-photosensitive-retinal-ganglion-cells-iprgcs-are-necessary-for-light-entrainment-of-peripheral-clocks
#3
Paulo Kofuji, Ludovic S Mure, Logan J Massman, Nicole Purrier, Satchidananda Panda, William C Engeland
Light is a powerful entrainer of circadian clocks in almost all eukaryotic organisms promoting synchronization of internal circadian rhythms with external environmental light-dark (LD) cycles. In mammals, the circadian system is organized in a hierarchical manner, in which a central pacemaker in the suprachiasmatic nucleus (SCN) synchronizes oscillators in peripheral tissues. Recent evidence demonstrates that photoentrainment of the SCN proceeds via signaling from a subpopulation of retinal ganglion cells (RGCs) which are melanopsin-expressing and intrinsically photosensitive (ipRGCs)...
2016: PloS One
https://www.readbyqxmd.com/read/27966269/the-effect-of-blue-blocking-and-neutral-intraocular-lenses-on-circadian-photoentrainment-and-sleep-one-year-after-cataract-surgery
#4
Adam Elias Brøndsted, Birgitte Haargaard, Birgit Sander, Henrik Lund-Andersen, Poul Jennum, Line Kessel
PURPOSE: To compare the long-term effect on circadian photoentrainment and sleep in patients implanted with neutral and blue-blocking intraocular lenses 1 year after cataract surgery. METHODS: Randomized, controlled trial involving 67 patients with age-related cataract. Intervention was cataract surgery with implantation of either a neutral or a blue-blocking intraocular lens (IOL). Main outcome was activation of the intrinsically photosensitive retinal ganglion cells (ipRGC) measured by chromatic pupillometry...
December 14, 2016: Acta Ophthalmologica
https://www.readbyqxmd.com/read/27893096/chemogenetic-activation-of-iprgcs-drives-changes-in-dark-adapted-scotopic-electroretinogram
#5
Nina Milosavljevic, Annette E Allen, Jasmina Cehajic-Kapetanovic, Robert J Lucas
Purpose: The purpose of this study was to investigate the impact of activating melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) on dark-adapted (scotopic) electroretinograms (ERG). Methods: We used mice (Opn4Cre/+) expressing cre recombinase in melanopsin-expressing cells for a targeted gene delivery of a chemogenetic Gq-coupled receptor, hM3Dq, to ipRGCs. Intraperitoneal injection of clozapine N-oxide (CNO) at 5 mg/kg was used for acute activation of hM3Dq and thus excitation of ipRGCs in darkness...
November 1, 2016: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/27789727/horizontal-cells-expressing-melanopsin-x-are-novel-photoreceptors-in-the-avian-inner-retina
#6
Luis P Morera, Nicolás M Díaz, Mario E Guido
In the vertebrate retina, three types of photoreceptors-visual photoreceptor cones and rods and the intrinsically photosensitive retinal ganglion cells (ipRGCs)-converged through evolution to detect light and regulate image- and nonimage-forming activities such as photic entrainment of circadian rhythms, pupillary light reflexes, etc. ipRGCs express the nonvisual photopigment melanopsin (OPN4), encoded by two genes: the Xenopus (Opn4x) and mammalian (Opn4m) orthologs. In the chicken retina, both OPN4 proteins are found in ipRGCs, and Opn4x is also present in retinal horizontal cells (HCs), which connect with visual photoreceptors...
November 15, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27733864/genetic-networks-in-mouse-retinal-ganglion-cells
#7
Felix L Struebing, Richard K Lee, Robert W Williams, Eldon E Geisert
Retinal ganglion cells (RGCs) are the output neuron of the eye, transmitting visual information from the retina through the optic nerve to the brain. The importance of RGCs for vision is demonstrated in blinding diseases where RGCs are lost, such as in glaucoma or after optic nerve injury. In the present study, we hypothesize that normal RGC function is transcriptionally regulated. To test our hypothesis, we examine large retinal expression microarray datasets from recombinant inbred mouse strains in GeneNetwork and define transcriptional networks of RGCs and their subtypes...
2016: Frontiers in Genetics
https://www.readbyqxmd.com/read/27699185/dataset-of-red-light-induced-pupil-constriction-superimposed-on-post-illumination-pupil-response
#8
Shaobo Lei, Herbert C Goltz, Jaime C Sklar, Agnes M F Wong
We collected and analyzed pupil diameter data from of 7 visually normal participants to compare the maximum pupil constriction (MPC) induced by "Red Only" vs. "Blue+Red" visual stimulation conditions. The "Red Only" condition consisted of red light (640±10 nm) stimuli of variable intensity and duration presented to dark-adapted eyes with pupils at resting state. This condition stimulates the cone-driven activity of the intrinsically photosensitive retinal ganglion cells (ipRGC). The "Blue+Red" condition consisted of the same red light stimulus presented during ongoing blue (470±17 nm) light-induced post-illumination pupil response (PIPR), representing the cone-driven ipRGC activity superimposed on the melanopsin-driven intrinsic activity of the ipRGCs ("The Absence of Attenuating Effect of Red light Exposure on Pre-existing Melanopsin-Driven Post-illumination Pupil Response" Lei et al...
September 2016: Data in Brief
https://www.readbyqxmd.com/read/27690169/luminance-and-chromatic-signals-interact-differently-with-melanopsin-activation-to-control-the-pupil-light-response
#9
Pablo A Barrionuevo, Dingcai Cao
Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin. These cells receive afferent inputs from rods and cones, which provide inputs to the postreceptoral visual pathways. It is unknown, however, how melanopsin activation is integrated with postreceptoral signals to control the pupillary light reflex. This study reports human flicker pupillary responses measured using stimuli generated with a five-primary photostimulator that selectively modulated melanopsin, rod, S-, M-, and L-cone excitations in isolation, or in combination to produce postreceptoral signals...
September 1, 2016: Journal of Vision
https://www.readbyqxmd.com/read/27688202/cerebral-neural-correlates-of-differential-melanopic-photic-stimulation-in-humans
#10
Shao-Min Hung, Dan Milea, Annadata Venkata Rukmini, Raymond P Najjar, Joo Huang Tan, Françoise Viénot, Marie Dubail, Sharon Lee Choon Tow, Tin Aung, Joshua J Gooley, Po-Jang Hsieh
Photic stimulation of rods, cones and intrinsically photosensitive melanopsin-containing retinal ganglion cells (ipRGCs) mediates non-visual light responses, including entrainment of circadian rhythms and pupillary light reflex. Unlike visual responses to photic stimulation, the cerebral correlates of non-visual light responses in humans remains elusive. In this study, we used functional magnetic resonance imaging (fMRI) in 14 healthy young participants, to localize cerebral regions which are differentially activated by metameric light that gave rise to different levels of melanopic excitation...
September 26, 2016: NeuroImage
https://www.readbyqxmd.com/read/27669145/a-visual-circuit-uses-complementary-mechanisms-to-support-transient-and-sustained-pupil-constriction
#11
William Thomas Keenan, Alan C Rupp, Rachel A Ross, Preethi Somasundaram, Suja Hiriyanna, Zhijian Wu, Tudor C Badea, Phyllis R Robinson, Bradford B Lowell, Samer S Hattar
Rapid and stable control of pupil size in response to light is critical for vision, but the neural coding mechanisms remain unclear. Here, we investigated the neural basis of pupil control by monitoring pupil size across time while manipulating each photoreceptor input or neurotransmitter output of intrinsically photosensitive retinal ganglion cells (ipRGCs), a critical relay in the control of pupil size. We show that transient and sustained pupil responses are mediated by distinct photoreceptors and neurotransmitters...
September 26, 2016: ELife
https://www.readbyqxmd.com/read/27636197/relationship-between-human-pupillary-light-reflex-and-circadian-system-status
#12
Maria Angeles Bonmati-Carrion, Konstanze Hild, Cheryl Isherwood, Stephen J Sweeney, Victoria L Revell, Debra J Skene, Maria Angeles Rol, Juan Antonio Madrid
Intrinsically photosensitive retinal ganglion cells (ipRGCs), whose photopigment melanopsin has a peak of sensitivity in the short wavelength range of the spectrum, constitute a common light input pathway to the olivary pretectal nucleus (OPN), the pupillary light reflex (PLR) regulatory centre, and to the suprachiasmatic nuclei (SCN), the major pacemaker of the circadian system. Thus, evaluating PLR under short wavelength light (λmax ≤ 500 nm) and creating an integrated PLR parameter, as a possible tool to indirectly assess the status of the circadian system, becomes of interest...
2016: PloS One
https://www.readbyqxmd.com/read/27559310/peripheral-sensory-neurons-expressing-melanopsin-respond-to-light
#13
Anna Matynia, Eileen Nguyen, Xiaoping Sun, Frank W Blixt, Sachin Parikh, Jason Kessler, Luis Pérez de Sevilla Müller, Samer Habib, Paul Kim, Zhe Z Wang, Allen Rodriguez, Andrew Charles, Steven Nusinowitz, Lars Edvinsson, Steven Barnes, Nicholas C Brecha, Michael B Gorin
The ability of light to cause pain is paradoxical. The retina detects light but is devoid of nociceptors while the trigeminal sensory ganglia (TG) contain nociceptors but not photoreceptors. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) are thought to mediate light-induced pain but recent evidence raises the possibility of an alternative light responsive pathway independent of the retina and optic nerve. Here, we show that melanopsin is expressed in both human and mouse TG neurons...
2016: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/27548480/rhodopsin-and-melanopsin-contributions-to-the-early-redilation-phase-of-the-post-illumination-pupil-response-pipr
#14
Prakash Adhikari, Beatrix Feigl, Andrew J Zele
Melanopsin expressing intrinsically photosensitive Retinal Ganglion Cells (ipRGCs) entirely control the post-illumination pupil response (PIPR) from 6 s post-stimulus to the plateau during redilation after light offset. However, the photoreceptor contributions to the early redilation phase of the PIPR (< 6 s post-stimulus) have not been reported. Here, we evaluated the photoreceptor contributions to the early phase PIPR (0.6 s to 5.0 s) by measuring the spectral sensitivity of the criterion PIPR amplitude in response to 1 s light pulses at five narrowband stimulus wavelengths (409, 464, 508, 531 and 592 nm)...
2016: PloS One
https://www.readbyqxmd.com/read/27543383/electrophysiological-responses-from-intrinsically-photosensitive-retinal-ganglion-cells-are-diminished-in-glaucoma-patients
#15
Manami Kuze, Takeshi Morita, Yumi Fukuda, Mineo Kondo, Kazuo Tsubota, Masahiko Ayaki
PURPOSE: To record electroretinograms (ERGs) from intrinsically photosensitive retinal ganglion cells (ipRGCs) of glaucoma patients. METHODS: ERGs were recorded in 10 normal subjects and 15 patients with glaucoma. The ERG illumination system was built to achieve receptor-silent substitution, and comprised an optical diffuser and four-in-one light-emitting diodes. RESULTS: The ERG recordings of ipRGC from normal subjects showed an "on" response and an "off" response...
August 16, 2016: Journal of Optometry
https://www.readbyqxmd.com/read/27464575/blue-and-red-light-evoked-pupil-responses-in-photophobic-subjects-with-tbi
#16
Phillip T Yuhas, Patrick D Shorter, Catherine E McDaniel, Michael J Earley, Andrew T E Hartwick
PURPOSE: Photophobia is a common symptom in individuals suffering from traumatic brain injury (TBI). Recent evidence has implicated blue light-sensitive intrinsically photosensitive retinal ganglion cells (ipRGCs) in contributing to the neural circuitry mediating photophobia in migraine sufferers. The goal of this work is to test the hypothesis that ipRGC function is altered in TBI patients with photophobia by assessing pupillary responses to blue and red light. METHODS: Twenty-four case participants (mean age 43...
January 2017: Optometry and Vision Science: Official Publication of the American Academy of Optometry
https://www.readbyqxmd.com/read/27440795/rev-erb%C3%AE-modulates-retinal-visual-processing-and-behavioral-responses-to-light
#17
Ouafa Ait-Hmyed Hakkari, Niyazi Acar, Elise Savier, Perrine Spinnhirny, Mohammed Bennis, Marie-Paule Felder-Schmittbuhl, Jorge Mendoza, David Hicks
The circadian clock is thought to adjust retinal sensitivity to ambient light levels, yet the involvement of specific clock genes is poorly understood. We explored the potential role of the nuclear receptor subfamily 1, group D, member 1 (REV-ERBα; or NR1D1) in this respect. In light-evoked behavioral tests, compared with wild-type littermates, Rev-Erbα(-/-) mice showed enhanced negative masking at low light levels (0.1 lux). Rev-Erbα(-/-) mouse retinas displayed significantly higher numbers of intrinsically photosensitive retinal ganglion cells (ipRGCs; 62% more compared with wild-type) and more intense melanopsin immunostaining of individual ipRGC cells...
July 20, 2016: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
https://www.readbyqxmd.com/read/27422659/melanopsin-supports-irradiance-driven-changes-in-maintained-activity-in-the-superior-colliculus-of-the-mouse
#18
Miguel Dasilva, Riccardo Storchi, Katherine E Davis, Kenneth L Grieve, Robert J Lucas
Melanopsin phototransduction allows intrinsically photosensitive retinal ganglion cells (ipRGCs) to maintain firing under sustained illumination and to encode irradiance. ipRGCs project to different parts of the visual system, including the superficial superior colliculus (sSC), but to date there is no description of melanopsin contributions to the activity of that nucleus. We sought to fill that gap using extracellular recordings to describe light response in the sSC. We failed to observe light responses in the sSC of mice lacking rod and cone function, in which melanopsin provides the only photoreception...
September 2016: European Journal of Neuroscience
https://www.readbyqxmd.com/read/27383593/m1-iprgcs-influence-visual-function-through-retrograde-signaling-in-the-retina
#19
Cameron L Prigge, Po-Ting Yeh, Nan-Fu Liou, Chi-Chan Lee, Shih-Feng You, Lei-Lei Liu, David S McNeill, Kylie S Chew, Samer Hattar, Shih-Kuo Chen, Dao-Qi Zhang
UNLABELLED: Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs, with five subtypes named M1-M5) are a unique subclass of RGCs with axons that project directly to many brain nuclei involved in non-image-forming functions such as circadian photoentrainment and the pupillary light reflex. Recent evidence suggests that melanopsin-based signals also influence image-forming visual function, including light adaptation, but the mechanisms involved are unclear. Intriguingly, a small population of M1 ipRGCs have intraretinal axon collaterals that project toward the outer retina...
July 6, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27371393/re-evaluating-the-role-of-intrinsically-photosensitive-retinal-ganglion-cells-new-roles-in-image-forming-functions
#20
Takuma Sonoda, Tiffany M Schmidt
Recently, researchers identified a novel ganglion cell photoreceptor in vertebrates, called intrinsically photosensitive retinal ganglion cells (ipRGCs). These ipRGCs are photosensitive due to expression of a photopigment, melanopsin. Although ipRGCs were initially thought to be a uniform population of cells involved solely in subconscious, non-image forming behaviors, recent research points to a role for ipRGCs in pattern vision. Here we highlight the emerging evidence for this influence of ipRGCs on pattern vision and discuss important future directions for understanding this newly appreciated contribution of melanopsin signaling to visual processing...
November 2016: Integrative and Comparative Biology
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