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https://www.readbyqxmd.com/read/28525301/mood-the-circadian-system-and-melanopsin-retinal-ganglion-cells
#1
Lorenzo Lazzerini Ospri, Glen Prusky, Samer Hattar
The discovery of a third type of photoreceptors in the mammalian retina, intrinsically photosensitive retinal ganglion cells (ipRGCs), has had a revolutionary impact on chronobiology. We can now properly account for numerous nonvision-related functions of light, including its effect on the circadian system. Here, we give an overview of ipRGCs and their function as it relates specifically to mood and biological rhythms. Although circadian disruptions have been traditionally hypothesized to be the mediators of light's effects on mood, here we present an alternative model that dispenses with assumptions of causality between the two phenomena and explains mood regulation by light via another ipRGC-dependent mechanism...
May 17, 2017: Annual Review of Neuroscience
https://www.readbyqxmd.com/read/28466070/a-cre-mouse-line-for-probing-irradiance-and-direction-encoding-retinal-networks
#2
Shai Sabbah, Daniel Berg, Carin Papendorp, Kevin L Briggman, David M Berson
Cell type-specific Cre driver lines have revolutionized the analysis of retinal cell types and circuits. We show that the transgenic mouse Rbp4-Cre selectively labels several retinal neuronal types relevant to the encoding of absolute light intensity (irradiance) and visual motion. In the ganglion cell layer (GCL), most marked cells are wide-field spiking polyaxonal amacrine cells (ACs) with sustained irradiance-encoding ON responses that persist during chemical synaptic blockade. Their arbors spread about 1 mm across the retina and are restricted to the inner half of the ON sublamina of the inner plexiform layer (IPL)...
March 2017: ENeuro
https://www.readbyqxmd.com/read/28421205/the-preferential-impairment-of-pupil-constriction-stimulated-by-blue-light-in-patients-with-type-2-diabetes-without-autonomic-neuropathy
#3
Fukashi Ishibashi, Rie Kojima, Miki Taniguchi, Aiko Kosaka, Harumi Uetake, Mitra Tavakoli
The main aim of the present paper is to examine whether the pupillary light reflex (PLR) mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs) is impaired in type 2 diabetic patients. One hundred and three diabetic patients without diabetic autonomic neuropathy (DAN) and 42 age-matched controls underwent a series of detailed neurological examinations. The patients were stratified into three groups: stage I, no neuropathy; stage II, asymptomatic neuropathy; stage III, symptomatic but without DAN...
2017: Journal of Diabetes Research
https://www.readbyqxmd.com/read/28236851/infant-acetylcholine-dopamine-and-melatonin-dysregulation-neonatal-biomarkers-and-causal-factors-for-asd-and-adhd-phenotypes
#4
Kahl Hellmer, Pär Nyström
Autism spectrum disorders (ASD) and ADHD are common neurodevelopmental disorders that benefit from early intervention but currently suffer from late detection and diagnosis: neurochemical dysregulations are extant already at birth but clinical phenotypes are not distinguishable until preschool age or later. The vast heterogeneity between subjects' phenotypes relates to interaction between multiple unknown factors, making research on factor causality insurmountable. To unlock this situation we pose the hypothesis that atypical pupillary light responses from rods, cones, and the recently discovered ipRGC system reflect early acetylcholine, melatonin, and dopamine dysregulation that are sufficient but not necessary factors for developing ASD and/or ADHD disorders...
March 2017: Medical Hypotheses
https://www.readbyqxmd.com/read/28223508/c-terminal-phosphorylation-regulates-the-kinetics-of-a-subset-of-melanopsin-mediated-behaviors-in-mice
#5
Preethi Somasundaram, Glenn R Wyrick, Diego Carlos Fernandez, Alireza Ghahari, Cindy M Pinhal, Melissa Simmonds Richardson, Alan C Rupp, Lihong Cui, Zhijian Wu, R Lane Brown, Tudor Constantin Badea, Samer Hattar, Phyllis R Robinson
Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin and mediate several non-image-forming visual functions, including circadian photoentrainment and the pupillary light reflex (PLR). ipRGCs act as autonomous photoreceptors via the intrinsic melanopsin-based phototransduction pathway and as a relay for rod/cone input via synaptically driven responses. Under low light intensities, where only synaptically driven rod/cone input activates ipRGCs, the duration of the ipRGC response will be determined by the termination kinetics of the rod/cone circuits...
March 7, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28160289/melanopsin-expressing-human-retinal-ganglion-cells-subtypes-distribution-and-intraretinal-connectivity
#6
Jens Hannibal, Anders Tolstrup Christiansen, Steffen Heegaard, Jan Fahrenkrug, Jens Folke Kiilgaard
Intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin belong to a heterogenic population of RGCs which regulate the circadian clock, masking behavior, melatonin suppression, the pupillary light reflex, and sleep/wake cycles. The different functions seem to be associated to different subtypes of melanopsin cells. In rodents, subtype classification has associated subtypes to function. In primate and human retina such classification has so far, not been applied. In the present study using antibodies against N- and C-terminal parts of human melanopsin, confocal microscopy and 3D reconstruction of melanopsin immunoreactive (-ir) RGCs, we applied the criteria used in mouse on human melanopsin-ir RGCs...
June 1, 2017: Journal of Comparative Neurology
https://www.readbyqxmd.com/read/28153865/mechanisms-creating-transient-and-sustained-photoresponses-in-mammalian-retinal-ganglion-cells
#7
Xiwu Zhao, Aaron N Reifler, Melanie M Schroeder, Elizabeth R Jaeckel, Andrew P Chervenak, Kwoon Y Wong
Retinal neurons use sustained and transient light responses to encode visual stimuli of different frequency ranges, but the underlying mechanisms remain poorly understood. In particular, although earlier studies in retinal ganglion cells (RGCs) proposed seven potential mechanisms, all seven have since been disputed, and it remains unknown whether different RGC types use different mechanisms or how many mechanisms are used by each type. Here, we conduct a comprehensive survey in mice and rats of 12 candidate mechanisms that could conceivably produce tonic rod/cone-driven ON responses in intrinsically photosensitive RGCs (ipRGCs) and transient ON responses in three types of direction-selective RGCs (TRHR+, Hoxd10+ ON, and Hoxd10+ ON-OFF cells)...
March 6, 2017: Journal of General Physiology
https://www.readbyqxmd.com/read/28119450/ectopic-expression-of-mouse-melanopsin-in-drosophila-photoreceptors-reveals-fast-response-kinetics-and-persistent-dark-excitation
#8
Bushra Yasin, Elkana Kohn, Maximilian Peters, Rachel Zaguri, Shirley Weiss, Krystina Schopf, Ben Katz, Armin Huber, Baruch Minke
The intrinsically photosensitive M1 retinal ganglion cells (ipRGC) initiate non-image-forming light-dependent activities and express the melanopsin (OPN4) photopigment. Several features of ipRGC photosensitivity are characteristic of fly photoreceptors. However, the light response kinetics of ipRGC is much slower due to unknown reasons. Here we used transgenic Drosophila, in which the mouse OPN4 replaced the native Rh1 photopigment of Drosophila R1-6 photoreceptors, resulting in deformed rhabdomeric structure...
March 3, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28061512/assessment-of-rod-cone-and-intrinsically-photosensitive-retinal-ganglion-cell-contributions-to-the-canine-chromatic-pupillary-response
#9
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
#10
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
#11
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
#12
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
#13
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
#14
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
#15
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
#16
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
#17
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
#18
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...
February 1, 2017: NeuroImage
https://www.readbyqxmd.com/read/27669145/a-visual-circuit-uses-complementary-mechanisms-to-support-transient-and-sustained-pupil-constriction
#19
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
#20
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
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