Read by QxMD icon Read


Donna Hermawati, Farid Agung Rahmadi, Tanjung Ayu Sumekar, Tri Indah Winarni
Prevalence autism spectrum disorders (ASD) has been on rise, but many studies suggests over-diagnosed. Currently, children have more access to electronic media on the daily basis than those of previous generation. Some studies suggest that increases screen time is associated with melanopsin-expressing neurons and decreasing gamma-aminobutyric acid (GABA) neurotransmitter, and thus results aberrant behavior, decreased cognitive, and language development. Early exposure of electronic media in early life (< 2 years old) gives an impact on language, but it still inconclusive...
February 2018: Intractable & Rare Diseases Research
Andrew J Zele, Beatrix Feigl, Prakash Adhikari, Michelle L Maynard, Dingcai Cao
The visual consequences of melanopsin photoreception in humans are not well understood. Here we studied melanopsin photoreception using a technique of photoreceptor silent substitution with five calibrated spectral lights after minimising the effects of individual differences in optical pre-receptoral filtering and desensitising penumbral cones in the shadow of retinal blood vessels. We demonstrate that putative melanopsin-mediated image-forming vision corresponds to an opponent S-OFF L + M-ON response property, with an average temporal resolution up to approximately 5 Hz, and >10x higher thresholds than red-green colour vision...
March 1, 2018: Scientific Reports
Nils J G Rorsman, Chau M Ta, Hannah Garnett, Pawel Swietach, Paolo Tammaro
BACKGROUND AND PURPOSE: Optogenetic control of electromechanical coupling in vascular smooth muscle cells (VSMCs) is emerging as a powerful research tool with potential applications in drug discovery and therapeutics. However, the precise ionic mechanisms involved in this control remain unclear. EXPERIMENTAL APPROACH: Cell imaging, patch-clamp electrophysiology, and muscle tension recordings were used to define these mechanisms over a wide range of light stimulations...
February 27, 2018: British Journal of Pharmacology
(no author information available yet)
No abstract text is available yet for this article.
February 20, 2018: Proceedings of the National Academy of Sciences of the United States of America
Qinghe Meng, Yuzheng Lian, Jianjun Jiang, Wei Wang, Xiaohong Hou, Yao Pan, Hongqian Chu, Lanqin Shang, Xuetao Wei, Weidong Hao
OBJECTIVES: Ambient light has a vital impact on mood and cognitive functions. Blue light has been previously reported to play a salient role in the antidepressant effect via melanopsin. Whether blue light filtered white light (BFW) affects mood and cognitive functions remains unclear. The present study aimed to investigate whether BFW led to depression-like symptoms and cognitive deficits including spatial learning and memory abilities in rats, and whether they were associated with the light-responsive function in retinal explants...
February 6, 2018: Photochemical & Photobiological Sciences
Leonardo Vinícius Monteiro de Assis, Maria Nathalia Moraes, Keila Karoline Magalhães-Marques, Ana Maria Castrucci
The mammalian skin has a photosensitive system comprised by several opsins, including rhodopsin (OPN2) and melanopsin (OPN4). Recently, our group showed that UVA (4.4 kJ/m2) leads to immediate pigment darkening (IPD) in murine normal and malignant melanocytes. We show the role of OPN2 and OPN4 as UVA sensors: UVA-induced IPD was fully abolished when OPN4 was pharmacologically inhibited by AA9253 or when OPN2 and OPN4 were knocked down by siRNA in both cell lines. Our data, however, demonstrate that phospholipase C/protein kinase C pathway, a classical OPN4 pathway, is not involved in UVA-induced IPD in either cell line...
January 26, 2018: European Journal of Cell Biology
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"