scholarly journals Intrinsically Photosensitive Retinal Ganglion Cells

2010 ◽  
Vol 90 (4) ◽  
pp. 1547-1581 ◽  
Author(s):  
Michael Tri Hoang Do ◽  
King-Wai Yau
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Small Population ◽  
Retinal Ganglion ◽  
Visual Functions ◽  
Rods And Cones ◽  
Living Things ◽  
Rotation Of The Earth ◽  
Life On Earth ◽  
And Behavior

Life on earth is subject to alternating cycles of day and night imposed by the rotation of the earth. Consequently, living things have evolved photodetective systems to synchronize their physiology and behavior with the external light-dark cycle. This form of photodetection is unlike the familiar “image vision,” in that the basic information is light or darkness over time, independent of spatial patterns. “Nonimage” vision is probably far more ancient than image vision and is widespread in living species. For mammals, it has long been assumed that the photoreceptors for nonimage vision are also the textbook rods and cones. However, recent years have witnessed the discovery of a small population of retinal ganglion cells in the mammalian eye that express a unique visual pigment called melanopsin. These ganglion cells are intrinsically photosensitive and drive a variety of nonimage visual functions. In addition to being photoreceptors themselves, they also constitute the major conduit for rod and cone signals to the brain for nonimage visual functions such as circadian photoentrainment and the pupillary light reflex. Here we review what is known about these novel mammalian photoreceptors.

scholarly journals Contribution of human melanopsin retinal ganglion cells to steady-state pupil responses

2010 ◽  
Vol 277 (1693) ◽  
pp. 2485-2492 ◽  
Author(s):  
Sei-ichi Tsujimura ◽  
Kazuhiko Ukai ◽  
Daisuke Ohama ◽  
Atsuo Nuruki ◽  
Kazutomo Yunokuchi
Keyword(s):  
Steady State ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Pupil Diameter ◽  
Retinal Ganglion ◽  
Silent Substitution ◽  
Conventional View ◽  
Rods And Cones ◽  
Direct Measurements ◽  
Stimulation System

The recent discovery of melanopsin-containing retinal ganglion cells (mRGCs) has led to a fundamental reassessment of non-image forming processing, such as circadian photoentrainment and the pupillary light reflex. In the conventional view of retinal physiology, rods and cones were assumed to be the only photoreceptors in the eye and were, therefore, considered responsible for non-image processing. However, signals from mRGCs contribute to this non-image forming processing along with cone-mediated luminance signals; although both signals contribute, it is unclear how these signals are summed. We designed and built a novel multi-primary stimulation system to stimulate mRGCs independently of other photoreceptors using a silent-substitution technique within a bright steady background. The system allows direct measurements of pupillary functions for mRGCs and cones. We observed a significant change in steady-state pupil diameter when we varied the excitation of mRGC alone, with no change in luminance and colour. Furthermore, the change in pupil diameter induced by mRGCs was larger than that induced by a variation in luminance alone: that is, for a bright steady background, the mRGC signals contribute to the pupillary pathway by a factor of three times more than the L- and M-cone signals.

Relation of Brightness to Threshold for Light-Adapted and Dark-Adapted Rods and Cones: Effects of Retinal Eccentricity and Target Size

Perception ◽  
1980 ◽  
Vol 9 (6) ◽  
pp. 633-650 ◽  
Author(s):  
Bruce Drum
Keyword(s):  
Retinal Ganglion Cells ◽  
Channel Model ◽  
Ganglion Cells ◽  
The Other ◽  
Target Size ◽  
Retinal Eccentricity ◽  
Retinal Ganglion ◽  
Threshold Functions ◽  
Rods And Cones ◽  
Matching Procedure

‘Equal-brightness' functions of retinal eccentricity and target diameter were measured by a matching procedure, and compared with the corresponding threshold functions for four different adaptation conditions: light-adapted cones (LAC), dark-adapted cones (DAC), light-adapted rods (LAR) and dark-adapted rods (DAR). The separation between log brightness matches and log thresholds decreased with eccentricity and increased with target size for all adaptation conditions, but overall separation was substantially greater for the DAR condition than for the other three. A two-channel model of achromatic brightness is proposed to explain the results. The model assumes ‘strong’ and ‘weak’ channels, which contribute unequally to brightness. These channels are tentatively identified with tonic and phasic classes of retinal ganglion cells.

scholarly journals Functional diversity of human intrinsically photosensitive retinal ganglion cells

Science ◽  
2019 ◽  
Vol 366 (6470) ◽  
pp. 1251-1255 ◽  
Author(s):  
Ludovic S. Mure ◽  
Frans Vinberg ◽  
Anne Hanneken ◽  
Satchidananda Panda
Keyword(s):  
Retinal Ganglion Cells ◽  
Preparation Method ◽  
Ganglion Cells ◽  
Organ Donor ◽  
Retinal Ganglion ◽  
Visual Responses ◽  
Human Organ ◽  
Rods And Cones ◽  
Light Signals ◽  
Human And Mouse

Intrinsically photosensitive retinal ganglion cells (ipRGCs) are a subset of cells that participate in image-forming and non–image-forming visual responses. Although both functional and morphological subtypes of ipRGCs have been described in rodents, parallel functional subtypes have not been identified in primate or human retinas. In this study, we used a human organ donor preparation method to measure human ipRGCs’ photoresponses. We discovered three functional ipRGC subtypes with distinct sensitivities and responses to light. The response of one ipRGC subtype appeared to depend on exogenous chromophore supply, and this response is conserved in both human and mouse retinas. Rods and cones also provided input to ipRGCs; however, each subtype integrated outer retina light signals in a distinct fashion.

scholarly journals Identification of Long Noncoding RNAs in Distinct Subtypes of Mouse Retinal Ganglion Cells 

2021 ◽  
Author(s):  
Ana Ayupe ◽  
Felipe Beckedorff ◽  
Konstantin Levay ◽  
Ramin Shiekhattar ◽  
Kevin Park
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Axonal Injury ◽  
Noncoding Rnas ◽  
Small Population ◽  
Long Noncoding Rnas ◽  
Biological Processes ◽  
Retinal Ganglion ◽  
Sequencing Data ◽  
Specific Expression

Abstract Background: Emerging evidence indicates that long noncoding RNAs (lncRNAs) are important regulators of various biological processes, and their expression can be altered following certain pathological conditions, including central nervous system injury. Retinal ganglion cells (RGCs), whose axons form the optic nerve, are a heterogeneous population of neurons with more than 20 molecularly distinct subtypes. While most RGCs, including the ON-OFF direction-selective RGCs (ooDSGCs), are vulnerable to axonal injury, a small population of RGCs, including the intrinsically photosensitive RGCs (ipRGCs), are more resilient. Results: By performing systematic analyses on RNA-sequencing data, here we identify lncRNAs that are expressed in ooDSGCs and ipRGCs with and without axonal injury. Our results reveal a repertoire of different classes of lncRNAs, including long intergenic noncoding RNAs and antisense ncRNAs that are differentially expressed between these RGC types. Strikingly, we also found dozens of lncRNAs whose expressions are altered markedly in response to axonal injury, some of which are expressed exclusively in either one of the subtypes. Moreover, analyses into these lncRNAs unraveled their neighboring coding genes, many of which encode transcription factors and signaling molecules, suggesting that these lncRNAs may act in cis to regulate important biological processes in these neurons. Lastly, guilt-by-association analysis showed that lncRNAs are correlated with apoptosis associated genes, suggesting potential roles for these lncRNAs in RGC survival.Conclusions: Overall, the results of this study reveal RGC type-specific expression of lncRNAs and provide a foundation for future investigation of the function of lncRNAs in regulating neuronal type specification and survival.

scholarly journals Intrinsically Photosensitive Retinal Ganglion Cells of the Human Retina

2021 ◽  
Vol 12 ◽  
Author(s):  
Ludovic S. Mure
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Life Quality ◽  
Well Being ◽  
Therapeutic Interventions ◽  
Diagnostic Tools ◽  
Human Retina ◽  
Retinal Ganglion ◽  
Rods And Cones ◽  
Light And Gene Expression

Light profoundly affects our mental and physical health. In particular, light, when not delivered at the appropriate time, may have detrimental effects. In mammals, light is perceived not only by rods and cones but also by a subset of retinal ganglion cells that express the photopigment melanopsin that renders them intrinsically photosensitive (ipRGCs). ipRGCs participate in contrast detection and play critical roles in non-image-forming vision, a set of light responses that include circadian entrainment, pupillary light reflex (PLR), and the modulation of sleep/alertness, and mood. ipRGCs are also found in the human retina, and their response to light has been characterized indirectly through the suppression of nocturnal melatonin and PLR. However, until recently, human ipRGCs had rarely been investigated directly. This gap is progressively being filled as, over the last years, an increasing number of studies provided descriptions of their morphology, responses to light, and gene expression. Here, I review the progress in our knowledge of human ipRGCs, in particular, the different morphological and functional subtypes described so far and how they match the murine subtypes. I also highlight questions that remain to be addressed. Investigating ipRGCs is critical as these few cells play a major role in our well-being. Additionally, as ipRGCs display increased vulnerability or resilience to certain disorders compared to conventional RGCs, a deeper knowledge of their function could help identify therapeutic approaches or develop diagnostic tools. Overall, a better understanding of how light is perceived by the human eye will help deliver precise light usage recommendations and implement light-based therapeutic interventions to improve cognitive performance, mood, and life quality.

scholarly journals Melanopic stimulation does not alter psychophysical threshold sensitivity for luminance flicker

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joris Vincent ◽  
Edda B. Haggerty ◽  
David H. Brainard ◽  
Geoffrey K. Aguirre
Keyword(s):  
Circadian Rhythm ◽  
Visual Perception ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Threshold Sensitivity ◽  
Retinal Ganglion ◽  
Pupil Response ◽  
Visual Functions ◽  
Psychophysical Threshold ◽  
Rod And Cone Photoreceptors

AbstractIn addition to the rod and cone photoreceptors the retina contains intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells express the photopigment melanopsin and are known to be involved in reflexive visual functions such as pupil response and photo-entrainment of the circadian rhythm. It is possible that the ipRGCs contribute to conscious visual perception, either by providing an independent signal to the geniculo-striate pathway, or by interacting with and thus modifying signals arising from “classical” retinal ganglion cells that combine and contrast cone input. Here, we tested for the existence of an interaction by asking if a 350% change in melanopsin stimulation alters psychophysical sensitivity for the detection of luminance flicker. In Experiment 1, we tested for a change in the threshold for detecting luminance flicker in three participants after they adapted to backgrounds with different degrees of tonic melanopsin stimulation. In Experiments 2 and 3, this test was repeated, but now for luminance flicker presented on a transient pedestal of melanopsin stimulation. Across the three experiments, no effect of melanopsin stimulation upon threshold flicker sensitivity was found. Our results suggest that even large changes in melanopsin stimulation do not affect near-threshold, cone-mediated visual perception.

scholarly journals Melanopic stimulation does not affect psychophysical threshold sensitivity for luminance flicker

2021 ◽  
Author(s):  
Joris Vincent ◽  
Edda B Haggerty ◽  
David H. Brainard ◽  
Geoffrey Karl Aguirre
Keyword(s):  
Circadian Rhythm ◽  
Visual Perception ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Threshold Sensitivity ◽  
Retinal Ganglion ◽  
Cone Photoreceptors ◽  
Pupil Response ◽  
Visual Functions ◽  
Psychophysical Threshold

In addition to the cone photoreceptors the retina contains intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells express the photopigment melanopsin and are known to be involved in reflexive visual functions such as pupil response and photo-entrainment of the circadian rhythm. It is possible that the ipRGCs contribute to conscious visual perception, either by providing an independent signal to the geniculo-striate pathway, or by interacting with and thus modifying signals arising from "classical" retinal ganglion cells that combine and contrast cone input. Here, we tested for the existence of an interaction by asking if a 350% change in melanopsin stimulation alters psychophysical sensitivity for the detection of luminance flicker. In Experiment 1, we tested for a change in the threshold for detecting luminance flicker in three participants after they adapted to backgrounds with different degrees of tonic melanopsin stimulation. In Experiments 2 and 3, this test was repeated, but now for luminance flicker presented on a transient pedestal of melanopsin stimulation. Across the three experiments, no effect of melanopsin stimulation upon threshold flicker sensitivity was found. Our results suggest that even large changes in melanopsin stimulation do not affect near-threshold, cone-mediated visual perception.

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