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https://www.readbyqxmd.com/read/29346496/melanopsin-system-dysfunction-in-smith-magenis-syndrome-patients
#1
Mirella Telles Salgueiro Barboni, Clarissa Bueno, Balázs Vince Nagy, Patrícia Lobo Maia, Kallene Summer Moreira Vidal, Rosana Cardoso Alves, Russel J Reiter, Fernanda Gaspar do Amaral, José Cipolla-Neto, Dora Fix Ventura
Purpose: Smith-Magenis syndrome (SMS) causes sleep disturbance that is related to an abnormal melatonin profile. It is not clear how the genomic disorder leads to a disturbed synchronization of the sleep/wake rhythm in SMS patients. To evaluate the integrity of the intrinsically photosensitive retinal ganglion cell (ipRGC)/melanopsin system, the transducers of the light-inhibitory effect on pineal melatonin synthesis, we recorded pupillary light responses (PLR) in SMS patients. Methods: Subjects were SMS patients (n = 5), with molecular diagnosis and melatonin levels measured for 24 hours and healthy controls (n = 4)...
January 1, 2018: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/29344005/biological-clocks-their-relevance-to-immune-allergic-diseases
#2
REVIEW
Roberto Paganelli, Claudia Petrarca, Mario Di Gioacchino
The 2017 Nobel Prize for Physiology or Medicine, awarded for the discoveries made in the past 15 years on the genetic and molecular mechanisms regulating many physiological functions, has renewed the attention to the importance of circadian rhythms. These originate from a central pacemaker in the suprachiasmatic nucleus in the brain, photoentrained via direct connection with melanopsin containing, intrinsically light-sensitive retinal ganglion cells, and it projects to periphery, thus creating an inner circadian rhythm...
2018: Clinical and Molecular Allergy: CMA
https://www.readbyqxmd.com/read/29336011/decreased-retinal-sensitivity-in-depressive-disorder-a-controlled-study
#3
G Berman, D Muttuvelu, D Berman, J I Larsen, R W Licht, J Ledolter, R H Kardon
OBJECTIVE: To compare pupil responses in depressed patients with a seasonal pattern, depressed patients without a seasonal pattern and healthy controls as a function of daylight hours on the testing day. METHOD: Patients suffering from a major depressive episode were included in wintertime. The pupil light reflex was measured at inclusion and in the following summer using a binocular pupillometer. A protocol of low (1 lux) and high (400 lux) intensity red and blue lights was used to assess rod, cone and melanopsin-containing intrinsic photosensitive retinal ganglion cell input to the pupil reflex...
January 15, 2018: Acta Psychiatrica Scandinavica
https://www.readbyqxmd.com/read/29311335/melanopsin-and-l-cone-induced-pupil-constriction-is-inhibited-by-s-and-m-cones-in-humans
#4
Tom Woelders, Thomas Leenheers, Marijke C M Gordijn, Roelof A Hut, Domien G M Beersma, Emma J Wams
The human retina contains five photoreceptor types: rods; short (S)-, mid (M)-, and long (L)-wavelength-sensitive cones; and melanopsin-expressing ganglion cells. Recently, it has been shown that selective increments in M-cone activation are paradoxically perceived as brightness decrements, as opposed to L-cone increments. Here we show that similar effects are also observed in the pupillary light response, whereby M-cone or S-cone increments lead to pupil dilation whereas L-cone or melanopic illuminance increments resulted in pupil constriction...
January 8, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29304147/the-organization-of-melanopsin-immunoreactive-cells-in-microbat-retina
#5
Mi-Jin Jeong, Hang-Gu Kim, Chang-Jin Jeon
Intrinsically photosensitive retinal ganglion cells (ipRGCs) respond to light and play roles in non-image forming vision, such as circadian rhythms, pupil responses, and sleep regulation, or image forming vision, such as processing visual information and directing eye movements in response to visual clues. The purpose of the present study was to identify the distribution, types, and proportion of melanopsin-immunoreactive (IR) cells in the retina of a nocturnal animal, i.e., the microbat (Rhinolophus ferrumequinum)...
2018: PloS One
https://www.readbyqxmd.com/read/29251688/melanopsin-retinal-ganglion-cells-are-not-labeled-in-thy-1yfp-16-transgenic-mice
#6
Stephanie L Grillo, Salvatore L Stella
Retinal ganglion cells (RGCs) that express the photopigment melanopsin (mRGCs) are photosensitive and initiate the non-image-forming pathway, where the majority of their axons terminate in the suprachiasmatic nucleus (SCN). RGCs only make up approximately half of the cells in the ganglion cell layer of the retina; therefore, it is important to be able to distinguish them from other cell types. The transgenic Thy-1 YFP mouse line 16 (Thy-1 YFP-16) expresses yellow-fluorescent protein (YFP) in projection neurons, including RGCs...
January 17, 2018: Neuroreport
https://www.readbyqxmd.com/read/29251065/the-potential-influence-of-led-lighting-on-mental-illness
#7
Michael Bauer, Tasha Glenn, Scott Monteith, John F Gottlieb, Philipp Ritter, John Geddes, Peter C Whybrow
OBJECTIVES: Two recent scientific breakthroughs may alter the treatment of mental illness, as discussed in this narrative review. First, the invention of white light-emitting diodes (LEDs) enabled an ongoing, rapid transition to energy-efficient LEDs for lighting, and the use of LEDs to backlight digital devices. Second was the discovery of melanopsin-expressing photosensitive retinal ganglion cells, which detect environmental irradiance and mediate non-image forming (NIF) functions including circadian entrainment, melatonin secretion, alertness, sleep regulation and the pupillary light reflex...
December 18, 2017: World Journal of Biological Psychiatry
https://www.readbyqxmd.com/read/29249284/the-m5-cell-a-color-opponent-intrinsically-photosensitive-retinal-ganglion-cell
#8
Maureen E Stabio, Shai Sabbah, Lauren E Quattrochi, Marissa C Ilardi, P Michelle Fogerson, Megan L Leyrer, Jordan M Renna, Min Tae Kim, Inkyu Kim, Matthew Schiel, Kevin L Briggman, David M Berson
Intrinsically photosensitive retinal ganglion cells (ipRGCs) combine direct photosensitivity through melanopsin with synaptically mediated drive from classical photoreceptors through bipolar-cell input. Here, we sought to provide a fuller description of the least understood ipRGC type, the M5 cell, and discovered a distinctive functional characteristic-chromatic opponency (ultraviolet excitatory, green inhibitory). Serial electron microscopic reconstructions revealed that M5 cells receive selective UV-opsin drive from Type 9 cone bipolar cells but also mixed cone signals from bipolar Types 6, 7, and 8...
December 11, 2017: Neuron
https://www.readbyqxmd.com/read/29239123/seeing-the-light-to-change-colour-an-evolutionary-perspective-on-the-role-of-melanopsin-in-neuroendocrine-circuits-regulating-light-mediated-skin-pigmentation
#9
REVIEW
Gabriel E Bertolesi, Sarah McFarlane
Melanopsin photopigments, Opn4x and Opn4m, were evolutionary selected to "see the light" in systems that regulate skin colour change. In this review, we analyse the roles of melanopsins, and how critical evolutionary developments, including the requirement for thermoregulation and ultraviolet protection, the emergence of a background adaptation mechanism in land-dwelling amphibian ancestors and the loss of a photosensitive pineal gland in mammals, may have helped sculpt the mechanisms that regulate light-controlled skin pigmentation...
December 14, 2017: Pigment Cell & Melanoma Research
https://www.readbyqxmd.com/read/29238991/distribution-and-diversity-of-intrinsically-photosensitive-retinal-ganglion-cells-in-tree-shrew
#10
Elizabeth N Johnson, Teleza Westbrook, Rod Shayesteh, Emily L Chen, Joseph W Schumacher, David Fitzpatrick, Greg D Field
Intrinsically photosensitive retinal ganglion cells (ipRGCs) mediate the pupillary light reflex, circadian entrainment, and may contribute to luminance and color perception. The diversity of ipRGCs varies from rodents to primates, suggesting differences in their contributions to retinal output. To further understand the variability in their organization and diversity across species, we used immunohistochemical methods to examine ipRGCs in tree shrew (Tupaia belangeri). Tree shrews share membership in the same clade, or evolutionary branch, as rodents and primates...
December 14, 2017: Journal of Comparative Neurology
https://www.readbyqxmd.com/read/29180820/subcutaneous-white-adipocytes-express-a-light-sensitive-signaling-pathway-mediated-via-a-melanopsin-trpc-channel-axis
#11
Katarina Ondrusova, Mohammad Fatehi, Amy Barr, Zofia Czarnecka, Wentong Long, Kunimasa Suzuki, Scott Campbell, Koenraad Philippaert, Matthew Hubert, Edward Tredget, Peter Kwan, Nicolas Touret, Martin Wabitsch, Kevin Y Lee, Peter E Light
Subcutaneous white adipose tissue (scWAT) is the major fat depot in humans and is a central player in regulating whole body metabolism. Skin exposure to UV wavelengths from sunlight is required for Vitamin D synthesis and pigmentation, although it is plausible that longer visible wavelengths that penetrate the skin may regulate scWAT function. In this regard, we discovered a novel blue light-sensitive current in human scWAT that is mediated by melanopsin coupled to transient receptor potential canonical cation channels...
November 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29102785/melanopsin-expressing-retinal-ganglion-cells-are-relatively-resistant-to-excitotoxicity-induced-by-n-methyl-d-aspartate
#12
Songtao Wang, Dandan Gu, Peng Zhang, Jing Chen, Yan Li, Honglei Xiao, Guomin Zhou
Excitotoxicity plays an important role in neuronal loss in glaucoma. Previous studies indicate melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) are more injury-resistant. However, whether melanopsin-expressing ipRGCs are resistant to N-methyl-d-aspartate (NMDA) induced excitotoxicity is not well understood. In the present study, we investigated the effects of NMDA-induced excitotoxicity in conventional retinal ganglion cells (RGCs) and melanopsin-expressing ipRGCs in adult mice...
November 2, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/29070825/melanopsin-a-canonical-light-receptor-mediates-thermal-activation-of-clock-genes
#13
Maria Nathália Moraes, Leonardo Vinícius Monteiro de Assis, Keila Karoline Magalhães-Marques, Maristela Oliveira Poletini, Leonardo Henrique Ribeiro Graciani de Lima, Ana Maria de Lauro Castrucci
Melanopsin (OPN4) is a photo-pigment found in a small subset of intrinsically photosensitive ganglion cells (ipRGCs) of the mammalian retina. These cells play a role in synchronizing the central circadian pacemaker to the astronomical day by conveying information about ambient light to the hypothalamic suprachiasmatic nucleus, the site of the master clock. We evaluated the effect of a heat stimulus (39.5 °C) on clock gene (Per1 and Bmal1) expression in cultured murine Melan-a melanocytes synchronized by medium changes, and in B16-F10 melanoma cells, in the presence of the selective OPN4 antagonist AA92593, or after OPN4 knockdown by small interfering RNA (siRNA)...
October 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29053761/the-transcription-factor-prdm16-marks-a-single-retinal-ganglion-cell-subtype-in-the-mouse-retina
#14
Sergio Groman-Lupa, Joseph Adewumi, Ko Uoon Park, Joseph A Brzezinski Iv
Purpose: Retinal ganglion cells (RGC) can be categorized into roughly 30 distinct subtypes. How these subtypes develop is poorly understood, in part because few unique subtype markers have been characterized. We tested whether the Prdm16 transcription factor is expressed by RGCs as a class or within particular ganglion cell subtypes. Methods: Embryonic and mature retinal sections and flatmount preparations were examined by immunohistochemistry for Prdm16 and several other cell type-specific markers...
October 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28973921/long-term-restoration-of-visual-function-in-end-stage-retinal-degeneration-using-subretinal-human-melanopsin-gene-therapy
#15
Samantha R De Silva, Alun R Barnard, Steven Hughes, Shu K E Tam, Chris Martin, Mandeep S Singh, Alona O Barnea-Cramer, Michelle E McClements, Matthew J During, Stuart N Peirson, Mark W Hankins, Robert E MacLaren
Optogenetic strategies to restore vision in patients who are blind from end-stage retinal degenerations aim to render remaining retinal cells light sensitive once photoreceptors are lost. Here, we assessed long-term functional outcomes following subretinal delivery of the human melanopsin gene (OPN4) in the rd1 mouse model of retinal degeneration using an adeno-associated viral vector. Ectopic expression of OPN4 using a ubiquitous promoter resulted in cellular depolarization and ganglion cell action potential firing...
October 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28973746/analysis-of-melanopsin-gene-expression-in-the-rabbit-retina-at-different-ages
#16
M M Lira-Carrera, B E Gutiérrez-Amavizca, L J Álvarez-Araujo, M Aguirre-Ramírez, J A Pérez-León
Melanopsin is the photopigment of intrinsically photosensitive retinal ganglion cells that mediate non-visual responses to light. The aim of this study was to describe and analyze melanopsin gene expression in the rabbit retina at different ages and compare its expression with the prototypic gene of retinal ganglion cells (Thy-1 gene). Expression levels of OPN4, Thy-1, and GADPH genes were measured by real-time PCR at 3, 4, 8, 11, 12, 17, 19, 20, 23, 27, 32, and 47 postnatal days. We also regrouped the days before and after day 12 of life (pre-photic and post-photic stage, respectively)...
September 27, 2017: Genetics and Molecular Research: GMR
https://www.readbyqxmd.com/read/28959188/nmda-receptors-contribute-to-retrograde-synaptic-transmission-from-ganglion-cell-photoreceptors-to-dopaminergic-amacrine-cells
#17
Lei-Lei Liu, Nathan J Spix, Dao-Qi Zhang
Recently, a line of evidence has demonstrated that the vertebrate retina possesses a novel retrograde signaling pathway. In this pathway, phototransduction is initiated by the photopigment melanopsin, which is expressed in a small population of retinal ganglion cells. These ganglion cell photoreceptors then signal to dopaminergic amacrine cells (DACs) through glutamatergic synapses, influencing visual light adaptation. We have previously demonstrated that in Mg(2+)-containing solution, α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptors mediate this glutamatergic transmission...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/28955293/melanopsin-mediated-acute-light-responses-measured-in-winter-and-in-summer-seasonal-variations-in-adults-with-and-without-cataracts
#18
Mirjam Münch, Myriam Ladaique, Ségolène Roemer, Kattayoon Hashemi, Aki Kawasaki
Seasonal adaptation is a ubiquitous behavior seen in many species on both global hemispheres and is conveyed by changing photoperiods. In humans this seasonal adaptation is less apparent, in part because changes in daylength are masked by the use of electrical lighting at night. On the other hand, cataracts which reduce light transmission, may compound seasonal changes related to the reduced daylength of winter. To better understand the effects of different photoperiod lengths in healthy adults without and with cataracts, we tested their melanopsin-mediated light responses in summer vs...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28910447/orexin-a-suppresses-signal-transmission-to-dopaminergic-amacrine-cells-from-outer-and-inner-retinal-photoreceptors
#19
Sheng-Nan Qiao, Wei Zhou, Lei-Lei Liu, Dao-Qi Zhang, Yong-Mei Zhong
Purpose: The neuropeptides orexin-A and orexin-B are widely expressed in the vertebrate retina; however, their role in visual function is unclear. This study investigates whether and how orexins modulate signal transmission to dopaminergic amacrine cells (DACs) from both outer retinal photoreceptors (rods and cones) and inner retinal photoreceptors (melanopsin-expressing intrinsically photosensitive retinal ganglion cells [ipRGCs]). Methods: A whole-cell voltage-clamp technique was used to record light-induced responses from genetically labeled DACs in flat-mount mouse retinas...
September 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28882814/opsin-3-and-4-mediate-light-induced-pulmonary-vasorelaxation-that-is-potentiated-by-g-protein-receptor-kinase-2-inhibition
#20
Sebastian Barreto Ortiz, Daijiro Hori, Yohei Nomura, Xin Yun, Haiyang Jiang, Hwanmee Yong, James Chen, Sam Paek, Deepesh Pandey, Gautam Sikka, Anil Bhatta, Andrew Gillard, Jochen Steppan, Jae Hyung Kim, Hideo Adachi, Viachaslau Barodka, Lewis Romer, Steven S An, Larissa A Shimoda, Lakshmi Santhanam, Dan E Berkowitz
We recently demonstrated that blue light induces vasorelaxation in the systemic mouse circulation, a phenomenon mediated by the non-visual G protein-coupled receptor (GPCR) melanopsin (opsin 4; Opn4). Here we tested the hypothesis that non-visual opsins mediate photorelaxation in the pulmonary circulation. We discovered Opsin 3 (Opn3), Opn4, and G-protein coupled receptor kinase 2 (GRK2) in rat pulmonary arteries (PAs) and in pulmonary arterial smooth muscle cells (PASMCs), where the opsins interact directly with GRK2 as demonstrated with a proximity ligation assay...
September 7, 2017: American Journal of Physiology. Lung Cellular and Molecular Physiology
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