-
The Journal of Biological Chemistry May 1994
Comparative Study Review
Topics: Animals; Antigens; Arrestin; Calcium; Cell Membrane; Cyclic GMP; Eye Proteins; Inositol 1,4,5-Trisphosphate; Invertebrates; Light; Phosphodiesterase Inhibitors; Phosphorylation; Photoreceptor Cells; Photoreceptor Cells, Invertebrate; Protein Kinase C; Retinal Cone Photoreceptor Cells; Rhodopsin; Rod Cell Outer Segment; Rod Opsins; Signal Transduction; Vertebrates
PubMed: 8182033
DOI: No ID Found -
Optics Letters Sep 2020Noninvasive, objective measurement of rod function is as significant as that of cone function, and for retinal diseases such as retinitis pigmentosa and age-related...
Noninvasive, objective measurement of rod function is as significant as that of cone function, and for retinal diseases such as retinitis pigmentosa and age-related macular degeneration, rod function may be a more sensitive biomarker of disease progression and efficacy of treatment than cone function. Functional imaging of single human rod photoreceptors, however, has proven difficult because their small size and rapid functional response pose challenges for the resolution and speed of the imaging system. Here, we describe light-evoked, functional responses of human rods and cones, measured noninvasively using a synchronized adaptive optics optical coherence tomography (OCT) and scanning light ophthalmoscopy (SLO) system. The higher lateral resolution of the SLO images made it possible to confirm the identity of rods in the corresponding OCT volumes.
Topics: Humans; Light; Ophthalmoscopy; Retinal Cone Photoreceptor Cells; Retinal Rod Photoreceptor Cells
PubMed: 32870829
DOI: 10.1364/OL.398868 -
Current Biology : CB Mar 2002G protein activation by membrane-bound receptors initiates a chain reaction that amplifies cellular responses to external signals. In retinal photoreceptors,... (Review)
Review
G protein activation by membrane-bound receptors initiates a chain reaction that amplifies cellular responses to external signals. In retinal photoreceptors, amplification by the phototransduction cascade is regulated by quickly switching off the visual pigment that acts as the receptor for light.
Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Animals; Cyclic Nucleotide Phosphodiesterases, Type 5; GTP-Binding Proteins; Photoreceptor Cells; Retinal Cone Photoreceptor Cells; Retinal Rod Photoreceptor Cells; Signal Transduction; Transducin; Vision, Ocular
PubMed: 11909550
DOI: 10.1016/s0960-9822(02)00754-6 -
PloS One 2024Retinal detachment (RD) is the separation of the neural layer from the retinal pigmented epithelium thereby preventing the supply of nutrients to the cells within the...
Retinal detachment (RD) is the separation of the neural layer from the retinal pigmented epithelium thereby preventing the supply of nutrients to the cells within the neural layer of the retina. In vertebrates, primary photoreceptor cells consisting of rods and cones undergo daily renewal of their outer segment through the addition of disc-like structures and shedding of these discs at their distal end. When the retina detaches, the outer segment of these cells begins to degenerate and, if surgical procedures for reattachment are not done promptly, the cells can die and lead to blindness. The precise effect of RD on the renewal process is not well understood. Additionally, a time frame within which reattachment of the retina can restore proper photoreceptor cell function is not known. Focusing on rod cells, we propose a mathematical model to clarify the influence of retinal detachment on the renewal process. Our model simulation and analysis suggest that RD stops or significantly reduces the formation of new discs and that an alternative removal mechanism is needed to explain the observed degeneration during RD. Sensitivity analysis of our model parameters points to the disc removal rate as the key regulator of the critical time within which retinal reattachment can restore proper photoreceptor cell function.
Topics: Retinal Detachment; Humans; Models, Biological; Animals; Models, Theoretical; Rod Cell Outer Segment; Retinal Rod Photoreceptor Cells; Retina
PubMed: 38848326
DOI: 10.1371/journal.pone.0297419 -
The Journal of Neuroscience : the... Feb 1996The various classes of photoreceptor cells found in vertebrate retinae are organized in specific patterns, which are important for visual function. It is not known how...
The various classes of photoreceptor cells found in vertebrate retinae are organized in specific patterns, which are important for visual function. It is not known how these patterns are achieved during development. The chick retina provides an excellent model system in which to investigate this issue, containing cone opsins red, green, blue, and violet, as well as the rod-specific opsin rhodopsin. In this study, whole-mount in situ hybridization has revealed striking differences among opsins in both spatial and temporal aspects of expression. The long-wavelength cone opsins, red and green, were first detected in a small spot within the area centralis at embryonic day 14 (E14). In contrast, the short-wavelength cone opsins, blue and violet, were not detected until 2 d later and showed domains of expression both within the area centralis and in temporal retina. The first rhodopsin transcripts were seen at E15 in inferior retina. When opsin expression was first detected, there were differences in the localization of RNA within the inner segment of cone photoreceptors, suggesting that morphological differentiation preceded the expression of photopigment molecules. Marked differences in the distribution of rods and cones were also found. Within the area centralis, a circular rod-free zone bisected by a narrow rod-sparse region along the nasal-temporal axis was evident as soon as rhodopsin RNA could be detected. Such specialized regions appear to be set aside soon after photoreceptor cells become postmitotic, as evidenced by a spatially restricted pattern of visinin RNA observed at E7. The onset of particular opsins in restricted regions of the retina suggest an underlying pattern related to visual function in the chick.
Topics: Animals; Chick Embryo; In Situ Hybridization; Photoreceptor Cells; RNA Probes; Retina; Retinal Rod Photoreceptor Cells; Visual Pathways
PubMed: 8778294
DOI: 10.1523/JNEUROSCI.16-04-01430.1996 -
The Journal of General Physiology Apr 1991The spectral and dynamic properties of cone-driven horizontal cells in carp retina were evaluated with silent substitution stimuli and/or saturating background...
The spectral and dynamic properties of cone-driven horizontal cells in carp retina were evaluated with silent substitution stimuli and/or saturating background illumination. The aim of this study was to describe the wiring underlying the spectral sensitivity of these cells. We will present electrophysiological data that indicate that all cone-driven horizontal cell types receive input from all spectral cone types, and we will present evidence that all cone-driven horizontal cell types feedback to all spectral cone types. These two findings are the basis for a model for the spectral and dynamic behavior of all cone-driven horizontal cells in carp retina. The model can account for the spectral as well as the dynamic behavior of the horizontal cells. It will be shown that the strength of the feedforward and feedback pathways between a horizontal cell and a particular spectral cone type are roughly proportional. This model is in sharp contrast to the Stell model, where the spectral behavior of the three horizontal cell types is explained by a cascade of feedforward and feedback pathways between cones and horizontal cells. The Stell model accounts for the spectral but not for the dynamic behavior of the horizontal cells.
Topics: Animals; Carps; Color; Electrophysiology; Feedback; Ion Channels; Models, Biological; Photic Stimulation; Photoreceptor Cells; Retina; Visual Pathways
PubMed: 1711573
DOI: 10.1085/jgp.97.4.819 -
The Journal of Experimental Biology Aug 2019Among animals with visual processing mechanisms, the leech is a rare example in which all neurons can be identified. However, little is known about its visual system,...
Among animals with visual processing mechanisms, the leech is a rare example in which all neurons can be identified. However, little is known about its visual system, which is composed of several pigmented head eyes and photosensitive non-pigmented sensilla that are distributed across its entire body. Although several interneurons are known to respond to visual stimuli, their response properties are poorly understood. Among these, the S-cell system is especially intriguing: it is multimodal, spans the entire body of the leech and is thought to be involved in sensory integration. To improve our understanding of the role of this system, we tested its spectral sensitivity, spatial integration and adaptation properties. The response of the S-cell system to visual stimuli was found to be strongly dependent on the size of the area stimulated, and adaptation was local. Furthermore, an adaptation experiment demonstrated that at least two color channels contributed to the response, and that their contribution was dependent on the adaptation to the background. The existence of at least two color channels was further supported by transcriptomic evidence, which indicated the existence of at least two distinct groups of putative opsins for leeches. Taken together, our results show that the S-cell system has response properties that could be involved in the processing of spatial and color information of visual stimuli. We propose the leech as a novel system to understand visual processing mechanisms with many practical advantages.
Topics: Animals; Color Vision; Electrophysiological Phenomena; Interneurons; Leeches; Opsins; Photic Stimulation; Photoreceptor Cells; Transcriptome
PubMed: 31262786
DOI: 10.1242/jeb.201764 -
The Journal of Neuroscience : the... May 1997We generated transgenic mice, using 9.5 kilobase pairs of the 5' upstream sequence from the mouse metabotropic glutamate receptor subtype 6 (mGluR6) gene fused to the...
We generated transgenic mice, using 9.5 kilobase pairs of the 5' upstream sequence from the mouse metabotropic glutamate receptor subtype 6 (mGluR6) gene fused to the beta-galactosidase (lacZ) reporter gene, and investigated the promoter function of the cell-specific and developmentally regulated expression of mGluR6. Most of the independent transgenic lines commonly showed the lacZ expression in the defined cell layers of the retina, and four transgenic lines were characterized in detail for cell-specific lacZ expression patterns by X-gal staining and lacZ immunostaining. The lacZ-expressing retinal cells were classified into two cell types. One cell type was identified as rod bipolar cells on the basis of colocalization of protein kinase C (PKC) immunoreactivity and morphological criteria. The other cell type was PKC-immunonegative and resided at the cell layers corresponding precisely to ON-type cone bipolar cells. The latter bipolar cells were found to exist as a large cell population comparable to rod bipolar cells. This observation was confirmed by coimmunostaining of dissociated retinal cells with the lacZ and PKC antibodies. The ontogeny analysis indicated that the lacZ expression completely agrees with a temporal expression pattern of mGluR6 during retinal development. This study demonstrates that the mGluR6 5' upstream genomic sequence is capable of directing a cell-specific and developmentally regulated expression of mGluR6 in ON-type bipolar cells and supports the view that mGluR6 is responsible for ON responses in both the rod and cone systems.
Topics: Animals; Base Sequence; Mice; Mice, Transgenic; Molecular Sequence Data; Photoreceptor Cells; Receptors, Metabotropic Glutamate; Transgenes
PubMed: 9096137
DOI: 10.1523/JNEUROSCI.17-09-03014.1997 -
Visual Neuroscience Mar 2013Eye evolution is driven by the evolution of visually guided behavior. Accumulation of gradually more demanding behaviors have continuously increased the performance...
Eye evolution is driven by the evolution of visually guided behavior. Accumulation of gradually more demanding behaviors have continuously increased the performance requirements on the photoreceptor organs. Starting with nondirectional photoreception, I argue for an evolutionary sequence continuing with directional photoreception, low-resolution vision, and finally, high-resolution vision. Calculations of the physical requirements for these four sensory tasks show that they correlate with major innovations in eye evolution and thus work as a relevant classification for a functional analysis of eye evolution. Together with existing molecular and morphological data, the functional analysis suggests that urbilateria had a simple set of rhabdomeric and ciliary receptors used for directional photoreception, and that organ duplications, positional shifts and functional shifts account for the diverse patterns of eyes and photoreceptors seen in extant animals. The analysis also suggests that directional photoreception evolved independently at least twice before the last common ancestor of bilateria and proceeded several times independently to true vision in different bilaterian and cnidarian groups. This scenario is compatible with Pax-gene expression in eye development in the different animal groups. The whole process from the first opsin to high-resolution vision took about 170 million years and was largely completed by the onset of the Cambrian, about 530 million years ago. Evolution from shadow detectors to multiple directional photoreceptors has further led to secondary cases of eye evolution in bivalves, fan worms, and chitons.
Topics: Animals; Biological Evolution; Eye; Humans; Photoreceptor Cells; Signal Detection, Psychological; Vision, Ocular; Visual Pathways
PubMed: 23578808
DOI: 10.1017/S0952523813000035 -
Neuron Jul 1999
Review
Topics: Animals; Cell Death; Mammals; Retinal Cone Photoreceptor Cells; Retinal Rod Photoreceptor Cells
PubMed: 10433249
DOI: 10.1016/s0896-6273(00)80790-4