Photic Entrainment of the Circadian System

International Journal of Molecular Sciences, Journal Year: 2022, Volume and Issue: 23(2), P. 729 - 729

Published: Jan. 10, 2022

Circadian rhythms are essential for the survival of all organisms, enabling them to predict daily changes in environment and time their behaviour appropriately. The molecular basis such is circadian clock, a self-sustaining oscillator comprising transcriptional–translational feedback loop. This must be continually readjusted remain alignment with external world through process termed entrainment, which phase master clock suprachiasmatic nuclei (SCN) adjusted response cues. In mammals, primary cue, or “zeitgeber”, light, inputs directly SCN where it integrated additional non-photic zeitgebers. mechanisms underlying photic entrainment complex, number regulatory factors. review will outline photoreception pathways mediating our current understanding that drive SCN.

Language: Английский

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Melanopsin retinal ganglion cells mediate light-promoted brain development

Cell, Journal Year: 2022, Volume and Issue: 185(17), P. 3124 - 3137.e15

Published: Aug. 1, 2022

Language: Английский

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The role of ipRGCs in ocular growth and myopia development

Science Advances, Journal Year: 2022, Volume and Issue: 8(23)

Published: June 8, 2022

The increasing global prevalence of myopia calls for elaboration the pathogenesis this disease. Here, we show that selective ablation and activation intrinsically photosensitive retinal ganglion cells (ipRGCs) in developing mice induced myopic hyperopic refractive shifts by modulating corneal radius curvature (CRC) axial length (AL) an opposite way. Melanopsin- rod/cone-driven signals ipRGCs were found to influence development affecting AL CRC, respectively. role progression is evidenced attenuated form-deprivation magnitudes ipRGC-ablated melanopsin-deficient animals enhanced melanopsin expression/photoresponses form-deprived eyes. Cell subtype–specific showed M1 subtype cells, probably M2/M3 are involved ocular development. Thus, contribute substantially mouse eye growth development, which may inspire novel strategies intervention.

Language: Английский

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Light affects the prefrontal cortex via intrinsically photosensitive retinal ganglion cells

Science Advances, Journal Year: 2024, Volume and Issue: 10(13)

Published: March 29, 2024

The ventromedial prefrontal cortex (vmPFC) is a part of the limbic system engaged in regulation social, emotional, and cognitive states, which are characteristically impaired disorders brain such as schizophrenia depression. Here, we show that intrinsically photosensitive retinal ganglion cells (ipRGCs) modulate, through light, integrity, activity, function vmPFC. This regulatory role, independent circadian mood alterations, mediated by an ipRGC-thalamic-corticolimbic pathway. Lack ipRGC signaling mice causes dendritic degeneration, dysregulation genes involved synaptic plasticity, depressed neuronal activity These alterations primarily undermine ability vmPFC to regulate emotions. Our discovery provides potential light-dependent mechanism for certain PFC-centric humans.

Language: Английский

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Spatial distribution and functional integration of displaced retinal ganglion cells

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: Feb. 28, 2025

Abstract The retina contains distinct types of ganglion cells, which form mosaics with cells each type at position the visual field. Displaced retinal (dRGCs) occur cell bodies in inner nuclear layer (INL), and regularly placed RGCs layer. An example mammalian dRGCs are M1-type intrinsically photosensitive (ipRGCs). Little is known, however, about their relationship ipRGCs. We identified mouse ipRGC M1, M2, M4/sONɑ by immunohistochemistry light microscopy. Reconstruction immunolabeled from M1 sONɑ indicated that tiled regular RGC partners. Multi-electrode array recordings revealed conventional receptive fields displaced fit into mosaic counterparts. distribution analysis showed type-specific dRGC patterns followed neither global density all nor local densities corresponding types. displacement INL occurs a type-dependent manner, where positioned to complete Our data suggest serve same functional role within population RGCs.

Language: Английский

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Chromatic Pupillometry Methods for Assessing Photoreceptor Health in Retinal and Optic Nerve Diseases

Frontiers in Neurology, Journal Year: 2019, Volume and Issue: 10

Published: Feb. 12, 2019

The pupillary light reflex is mediated by melanopsin-containing intrinsically-photosensitive retinal ganglion cells (ipRGCs), which also receive input from rods and cones. Melanopsin-dependent responses are short-wavelength sensitive, have a higher threshold of activation, much slower to activate de-activate compared with rod/cone-mediated responses. Given that rod/cone photoreceptors melanopsin differ in their response properties, stimuli can be designed stimulate preferentially each the different photoreceptor types, providing read-out function. This has given rise chromatic pupillometry methods aim assess health outer ipRGCs measuring blue or red stimuli. Here, we review types protocols been tested patients optic nerve disease, including approaches use short-duration exposures continuous exposure light. Across protocols, disease (e.g., retinitis pigmentosa Leber congenital amaurosis) show reduced absent dim blue-light used rod function, moderately-bright red-light cone By comparison, glaucoma ischemic neuropathy, but not mitochondrial disease) impaired during bright stimuli, post-illumination after offset, These proof-of-concept studies demonstrate damage ipRGCs. In future studies, it will important determine whether for screening early detection diseases. Such may prove useful objectively evaluating degree recovery ipRGC function blind who undergo gene therapy other treatments restore vision.

Language: Английский

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Molecular signatures of retinal ganglion cells revealed through single cell profiling

Scientific Reports, Journal Year: 2019, Volume and Issue: 9(1)

Published: Oct. 31, 2019

Abstract Retinal ganglion cells can be classified into more than 40 distinct subtypes, whether by functional classification or transcriptomics. The examination of these subtypes in relation to their physiology, projection patterns, and circuitry would greatly facilitated through the identification specific molecular identifiers for generation transgenic mice. Advances single cell transcriptomic profiling have enabled signatures cellular that are only rarely found. Therefore, we used combined with hierarchical clustering correlate analyses identify genes expressed populations Parvalbumin-expressing functionally RGCs. RGCs were manually isolated based either upon fluorescence physiological distinction cell-attached recordings. Microarray hybridization RNA-Sequencing employed characterization transcriptomes situ was utilized further characterize gene candidate expression. Gene candidates identified cluster correlation, as well expression specificity within physiologically classes Further, Prph, Ctxn3 , Prkcq potential ipRGC murine retina. use genes, one other newly subset markers, a mouse enable future studies RGC-subtype function, wiring, projection.

Language: Английский

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Crosstalk: The diversity of melanopsin ganglion cell types has begun to challenge the canonical divide between image‐forming and non‐image‐forming vision

The Journal of Comparative Neurology, Journal Year: 2020, Volume and Issue: 528(12), P. 2044 - 2067

Published: Jan. 31, 2020

Melanopsin ganglion cells have defied convention since their discovery almost 20 years ago. In the following, many types of these intrinsically photosensitive retinal (ipRGCs) emerged. mouse retina, there are currently six known (M1-M6) melanopsin cells, each with unique morphology, mosaics, connections, physiology, projections, and functions. While melanopsin-expressing usually associated behaviors like circadian photoentrainment pupillary light reflex, characterization multiple has demonstrated a reach that may extend far beyond non-image-forming vision. fact, studies shown individual potential to impact image-forming functions contrast sensitivity color opponency. Thus, goal this review is summarize morphological functional aspects in retina highlight respective roles Although cell do project brain targets, it important note only first step determining influence on Even so, visual system canonically been divided into two realms begun challenge boundary between them, providing an overlap information complementary rather than redundant. Further photoreceptors will no doubt continue illustrate ever-expanding role for

Language: Английский

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Light Pollution and Oxidative Stress: Effects on Retina and Human Health

Antioxidants, Journal Year: 2024, Volume and Issue: 13(3), P. 362 - 362

Published: March 18, 2024

Visible light refers to the frequencies within electromagnetic spectrum that humans can see, encompassing radiation with wavelengths falling between 380 nm 760 nm. The energy of a single photon increases its frequency. In retina, photoreceptor cells contain light-sensitive pigments absorb and convert it into electrical stimuli through process known as phototransduction. However, since absorption photoreceptors closely aligns blue (ranging from 400 500 nm), exposure high intensities or continuous illumination result in oxidative stress these cells, leading loss their functionality. Apart retina also houses photosensitive ganglion intrinsically retinal (ipRGCs). These relay information suprachiasmatic nucleus brain, playing crucial role modulating melatonin secretion, which turn helps synchronizing body’s circadian rhythms responses seasonal changes. Both, ipRGCs skin possess peak sensitivity wavelengths, rendering them particularly susceptible effects excessive exposure. This study delves consequences and/or prolonged on function explores implications for human health.

Language: Английский

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Photosensitive Melanopsin-Containing Retinal Ganglion Cells in Health and Disease: Implications for Circadian Rhythms

International Journal of Molecular Sciences, Journal Year: 2019, Volume and Issue: 20(13), P. 3164 - 3164

Published: June 28, 2019

Melanopsin-containing retinal ganglion cells (mRGCs) represent a third class of photoreceptors involved in regulating the pupillary light reflex and circadian photoentrainment, among other things. The functional integrity system melanopsin is an essential component well-being health, being both impaired aging disease. Here we review evidence melanopsin-expressing cell alterations neurodegenerative diseases their correlation with development rhythm disorders. In healthy humans, average density melanopsin-positive falls after age 70, accompanied by age-dependent atrophy dendritic arborization. addition to aging, inner outer also involve progressive deterioration loss mRGCs that positively correlates rhythms. Among others, mRGC number plexus complexity are Parkinson's disease patients; changes may explain sleep disorders this pathology. key role photoentrainment endorse importance eye care, even if vision lost, preserve functions maintenance adequate quality life.

Language: Английский

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