Prolonged Inner Retinal Photoreception Depends on the Visual Retinoid Cycle.
Journal of Neuroscience 36(15):4209 (2016)
In addition to rods and cones, mammals have inner retinal photoreceptors called intrinsically photosensitive retinal ganglion cells (ipRGCs), which use the photopigment melanopsin and mediate nonimage-forming visual responses, such as pupil reflexes and circadian entrainment. After photic activa...
Characterization of Three-Dimensional Retinal Tissue Derived from Human Embryonic Stem Cells in Adherent Monolayer Cultures.
Stem Cells and Development 24(23):2778 (2015)
Stem cell-based therapy of retinal degenerative conditions is a promising modality to treat blindness, but requires new strategies to improve the number of functionally integrating cells. Grafting semidifferentiated retinal tissue rather than progenitors allows preservation of tissue structure a...
All spiking, sustained ON displaced amacrine cells receive gap-junction input from melanopsin ganglion cells.
Current Biology 25(21):2763 (2015)
Retinal neurons exhibit sustained versus transient light responses, which are thought to encode low- and high-frequency stimuli, respectively. This dichotomy has been recognized since the earliest intracellular recordings from the 1960s, but the underlying mechanisms are not yet fully understood...
Characterizing and modeling the intrinsic light response of rat ganglion-cell photoreceptors.
Journal of Neurophysiology 114(5):2955 (2015)
Intrinsically photosensitive retinal ganglion cells (ipRGCs) mediate both image-forming vision and non-image-forming visual responses such as pupillary constriction and circadian photoentrainment. Five types of ipRGCs, named M1-M5, have been discovered in rodents. To further investigate their ph...
Inhibition of N-Methyl-D-aspartate-induced Retinal Neuronal Death by Polyarginine Peptides Is Linked to the Attenuation of Stress-induced Hyperpolarization of the Inner Mitochondrial Membrane Potential.
Journal of Biological Chemistry 290(36):22030 (2015)
It is widely accepted that overactivation of NMDA receptors, resulting in calcium overload and consequent mitochondrial dysfunction in retinal ganglion neurons, plays a significant role in promoting neurodegenerative disorders such as glaucoma. Calcium has been shown to initiate a transient hype...
Melatonin Suppression by Light in Humans Is More Sensitive Than Previously Reported.
Journal of Biological Rhythms 30(4):351 (2015)
The retina drives various non-image-forming photoresponses, including circadian photoentrainment and pupil constriction. Previous investigators showed that in humans, photic suppression of the clock-controlled hormone melatonin is most sensitive to 460-nm blue light, with a threshold of ~12 log ...
Using Flickering Light to Enhance Nonimage-Forming Visual Stimulation in Humans.
Investigative Ophthalmology & Visual Science 56(8):4680 (2015)
Intrinsically photosensitive retinal ganglion cells (ipRGCs) mediate nonimage-forming visual functions such as pupillary constriction and circadian photoentrainment. Optimizing daytime nonimage-forming photostimulation has health benefits. We aimed to enhance ipRGC excitation using flickering in...
The rat retina has five types of ganglion-cell photoreceptors.
Experimental Eye Research 130:17 (2015)
Intrinsically photosensitive retinal ganglion cells (ipRGCs) are inner retinal photoreceptors that mediate non-image-forming visual functions, e.g. pupillary constriction, regulation of pineal melatonin release, and circadian photoentrainment. Five types of ipRGCs were recently discovered in mou...
Photoresponse diversity among the five types of intrinsically photosensitive retinal ganglion cells.
Journal of Physiology 592(7):1619 (2014)
Intrinsically photosensitive retinal ganglion cells (ipRGCs) mediate non-image-forming visual responses, including pupillary constriction, circadian photoentrainment and suppression of pineal melatonin secretion. Five morphological types of ipRGCs, M1-M5, have been identified in mice. In order t...
Developmental changes in NMDA receptor subunit composition at ON and OFF bipolar cell synapses onto direction-selective retinal ganglion cells.
Journal of Neuroscience 34(5):1942 (2014)
In the developing mouse retina, spontaneous and light-driven activity shapes bipolar→ganglion cell glutamatergic synapse formation, beginning around the time of eye-opening (P12-P14) and extending through the first postnatal month. During this time, glutamate release can spill outside the synapt...
Intrinsic physiological properties of the five types of mouse ganglion-cell photoreceptors.
Journal of Neurophysiology 109(7):1876 (2013)
In the mammalian retina, some ganglion cells express the photopigment melanopsin and function as photoreceptors. Five morphological types of these intrinsically photosensitive retinal ganglion cells (ipRGCs), M1-M5, have been identified in mice. Whereas M1 specializes in non-image-forming visual...
Apoptosis regulates ipRGC spacing necessary for rods and cones to drive circadian photoentrainment.
Neuron 77(3):503 (2013)
The retina consists of ordered arrays of individual types of neurons for processing vision. Here, we show that such order is necessary for intrinsically photosensitive retinal ganglion cells (ipRGCs) to function as irradiance detectors. We found that during development, ipRGCs undergo proximity-...
A retinal ganglion cell that can signal irradiance continuously for 10 hours.
Journal of Neuroscience 32(33):11478 (2012)
A recently discovered type of mammalian retinal ganglion cell encodes environmental light intensity and mediates non-image-forming visual behaviors, such as the pupillary reflex and circadian photoentrainment. These intrinsically photosensitive retinal ganglion cells (ipRGCs) generate endogenous...
Dopaminergic modulation of ganglion-cell photoreceptors in rat.
European Journal of Neuroscience 35(4):507 (2012)
A novel class of photoreceptors, the intrinsically photosensitive retinal ganglion cells (ipRGCs), express the photopigment melanopsin and drive non-image-forming responses to light such as circadian photoentrainment, the pupillary light reflex and suppression of nocturnal melatonin production i...
Melanopsin-expressing retinal ganglion-cell photoreceptors: cellular diversity and role in pattern vision.
Neuron 67(1):49 (2010)
Using the photopigment melanopsin, intrinsically photosensitive retinal ganglion cells (ipRGCs) respond directly to light to drive circadian clock resetting and pupillary constriction. We now report that ipRGCs are more abundant and diverse than previously appreciated, project more widely within...
Ectopic retinal ON bipolar cell synapses in the OFF inner plexiform layer: contacts with dopaminergic amacrine cells and melanopsin ganglion cells.
Journal of Comparative Neurology 517(2):226 (2009)
A key principle of retinal organization is that distinct ON and OFF channels are relayed by separate populations of bipolar cells to different sublaminae of the inner plexiform layer (IPL). ON bipolar cell axons have been thought to synapse exclusively in the inner IPL (the ON sublamina) onto de...
Circadian modulation of melanopsin-driven light response in rat ganglion-cell photoreceptors.
Journal of Biological Rhythms 24(5):391 (2009)
Intrinsically photosensitive retinal ganglion cells (ipRGCs) project to the suprachiasmatic nucleus (SCN) and are essential for normal photic entrainment of global circadian rhythms in physiology and behavior. The effect of light on the central clock is dependent on circadian phase, and the reti...
Intraretinal signaling by ganglion cell photoreceptors to dopaminergic amacrine neurons.
PNAS 105(37):14181 (2008)
Retinal dopaminergic amacrine neurons (DA neurons) play a central role in reconfiguring retinal function according to prevailing illumination conditions, yet the mechanisms by which light regulates their activity are poorly understood. We investigated the means by which sustained light responses...
Melanopsin ganglion cells use a membrane-associated rhabdomeric phototransduction cascade.
Journal of Neurophysiology 99(5):2522 (2008)
Intrinsically photosensitive retinal ganglion cells (ipRGCs) are photoreceptors of the mammalian eye that drive pupillary responses, synchronization of circadian rhythms, and other reflexive responses to daylight. Melanopsin is the ipRGC photopigment, but the signaling cascade through which this...
OFF ganglion cells cannot drive the optokinetic reflex in zebrafish.
PNAS 104(48):19126 (2007)
Whereas the zebrafish retina has long been an important model system for developmental and genetic studies, little is known about the responses of the inner retinal neurons. Here we report single-unit ganglion cell recordings from 5- to 6-day-old zebrafish larvae. In wild-type larvae we identify...