scholarly journals Measurement of Diurnal Variation in Rod Outer Segment Length In Vivo in Mice With the OCT Optoretinogram

2020 ◽  
Vol 61 (3) ◽  
pp. 9 ◽  
Author(s):  
Pengfei Zhang ◽  
Bradley Shibata ◽  
Gabriel Peinado ◽  
Robert J. Zawadzki ◽  
Paul FitzGerald ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Outer Segment ◽  
Segment Length ◽  
Rod Outer Segment

Metabolic labeling of normal canine rod outer segment phospholipids in vivo and in vitro

1989 ◽  
Vol 48 (1) ◽  
pp. 149-160 ◽  
Author(s):  
Mary G. Wetzel ◽  
Christian Fahlman ◽  
James P. Alligood ◽  
Paul J. O'Brien ◽  
Gustavo D. Aguirre
Keyword(s):  
Outer Segment ◽  
Metabolic Labeling ◽  
Rod Outer Segment

Evaluation of the electron density profile of the frog rod outer segment disc-membrane in vivo using X-ray diffraction

1981 ◽  
Vol 640 (1) ◽  
pp. 142-158 ◽  
Author(s):  
J. Funk ◽  
W. Welte ◽  
N. Hodapp ◽  
I. Wutschell ◽  
W. Kreutz
Keyword(s):  
Electron Density ◽  
Density Profile ◽  
Outer Segment ◽  
Electron Density Profile ◽  
X Ray Diffraction ◽  
Disc Membrane ◽  
X Ray ◽  
Rod Outer Segment

Rhodopsin content and rod outer segment length in albino rat eyes: Modification by dark adaptation

1978 ◽  
Vol 26 (4) ◽  
pp. 487-497 ◽  
Author(s):  
Barbara-Anne Battelle ◽  
Matthew M. LaVail
Keyword(s):  
Dark Adaptation ◽  
Outer Segment ◽  
Segment Length ◽  
Albino Rat ◽  
Rod Outer Segment

scholarly journals Loss of Pde6a Induces Rod Outer Segment Shrinkage and Visual Alterations in pde6aQ70X Mutant Zebrafish, a Relevant Model of Retinal Dystrophy

2021 ◽  
Vol 9 ◽  
Author(s):  
Lucie Crouzier ◽  
Camille Diez ◽  
Elodie M. Richard ◽  
Nicolas Cubedo ◽  
Clément Barbereau ◽  
...  
Keyword(s):  
Visual Function ◽  
Outer Segment ◽  
Retinal Dystrophy ◽  
Segment Length ◽  
Rod Photoreceptor ◽  
The Novel ◽  
Loss Of Function ◽  
Rod Outer Segment ◽  
Inherited Retinal Degeneration ◽  
Photoreceptor Death

Retinitis pigmentosa (RP) is one of the most common forms of inherited retinal degeneration with 1/4,000 people being affected. The vision alteration primarily begins with rod photoreceptor degeneration, then the degenerative process continues with cone photoreceptor death. Variants in 71 genes have been linked to RP. One of these genes, PDE6a is responsible for RP43. To date no treatment is available and patients suffer from pronounced visual impairment in early childhood. We used the novel zebrafish pde6aQ70X mutant, generated by N-ethyl-N-nitrosourea at the European Zebrafish Resource Centre, to better understand how PDE6a loss of function leads to photoreceptor alteration. Interestingly, zebrafish pde6aQ70X mutants exhibited impaired visual function at 5 dpf as evidenced by the decrease in their visual motor response (VMR) compared to pde6aWT larvae. This impaired visual function progressed with time and was more severe at 21 dpf. These modifications were associated with an alteration of rod outer segment length at 5 and 21 dpf. In summary, these findings suggest that rod outer segment shrinkage due to Pde6a deficiency begins very early in zebrafish, progresses with time. The zebrafish pde6aQ70X mutant represents an ideal model of RP to screen relevant active small molecules that will block the progression of the disease.

scholarly journals Differential spatial and temporal phosphorylation of the visual receptor, rhodopsin, at two primary phosphorylation sites in mice exposed to light

2003 ◽  
Vol 374 (2) ◽  
pp. 537-543 ◽  
Author(s):  
Ryan A. ADAMS ◽  
Xinran LIU ◽  
David S. WILLIAMS ◽  
Alexandra C. NEWTON
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Outer Segment ◽  
Phorbol Esters ◽  
Phosphorylation Sites ◽  
Rod Outer Segment ◽  
Kinase C ◽  
Rhodopsin Kinase

Phosphorylation of rhodopsin critically controls the visual transduction cascade by uncoupling it from the G-protein transducin. The kinase primarily responsible for this phosphorylation is rhodopsin kinase, a substrate-regulated kinase that phosphorylates light-activated rhodopsin. Protein kinase C has been implicated in controlling the phosphorylation of both light-activated and dark-adapted rhodopsin. Two of the major rhodopsin phosphorylation sites in vivo, Ser334 and Ser338, are effective protein kinase C phosphorylation sites in vitro, while the latter is preferentially phosphorylated by rhodopsin kinase in vitro. Using phosphospecific antibodies against each of these two sites, we show that both sites are under differential spatial and temporal regulation. Exposure of mice to light results in rapid phosphorylation of Ser338 that is evenly distributed along the rod outer segment. Phosphorylation of Ser334 is considerably slower, begins at the base of the rod outer segment, and spreads to the top of the photoreceptor over time. In addition, we show that phosphorylation of both sites is abolished in rhodopsin kinase−/− mice, revealing an absolute requirement for rhodopsin kinase to phosphorylate rhodopsin. This requirement may reflect the need for priming phosphorylations at rhodopsin kinase sites allowing for subsequent phosphorylation by protein kinase C at Ser334. In this regard, treatment of mouse retinas with phorbol esters results in a 4-fold increase in phosphorylation on Ser334, with no significant effect on the phosphorylation of Ser338. Our results are consistent with light triggering rapid priming phosphorylations of rhodopsin by rhodopsin kinase, followed by a slower phosphorylation on Ser334, which is regulated by protein kinase C.

scholarly journals Intracellular topography of rhodopsin regeneration in vertebrate rods.

1985 ◽  
Vol 86 (3) ◽  
pp. 413-422 ◽  
Author(s):  
T P Williams ◽  
J S Penn
Keyword(s):  
Retinal Pigment Epithelium ◽  
Epithelial Cells ◽  
Visual Pigment ◽  
Outer Segment ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Rod Outer Segment

The vertebrate visual pigment of rods, rhodopsin, bleaches in light and regenerates in darkness. When the bleaching and regeneration are carried out in vivo, it is found that the regeneration takes place at nonuniform rates along the rod outer segment (ROS): toads and frogs regenerate rhodopsin faster in the proximal ends of the ROS than in the distal ends. Rats do the reverse. These patterns of regeneration persist whether the bleaching is done with flashes or with steady light. They are also independent of the extent to which the retinal pigment epithelium contains melanin. Furthermore, the dichotomy of patterns (proximal faster vs. distal faster) does not seem to depend upon the presence of an excess of stored retinoid in the eye. Instead, it is suggested that the villous processes of the epithelial cells may play an important role in the regeneration patterns. These processes in amphibia extend nearly to the rod inner segment but in the rat they surround only the apical end of the outer segment. If they "funnel" the retinoids back to the ROS, their location and morphology could explain the two different kinds of patterns seen.

High time resolution enzyme cytochemistry of rod outer segment

1990 ◽  
Vol 48 (3) ◽  
pp. 878-879
Author(s):  
Takuma Saito ◽  
Toshihiro Takizawa
Keyword(s):  
Enzyme Activities ◽  
Outer Segment ◽  
Rapid Change ◽  
High Time Resolution ◽  
Visual Cell ◽  
Enzyme Cytochemistry ◽  
Activation Effect ◽  
Rod Outer Segment ◽  
Enzymatic Cascades ◽  
Rapid Drop

Cells and tissues live on a number of dynamic metabolic pathways, which are made up of sequential enzymatic cascades.Recent biochemical and physiological studies of vision research showed the importance of cGMP metabolism in the rod outer segment of visual cell, indicat ing that the photon activated rhodopsin exerts activation effect on the GTP binding protein, transducin, and this act ivated transducin further activates phosphodiesterase (PDEase) to result in a rapid drop in cGMP concentration in the cytoplasm of rod outer segment. This rapid drop of cGMP concentration exerts to close the ion channel on the plasma membrane and to stop of inward current brings hyperpolarization and evokes an action potential.These sequential change of enzyme activities, known as cGMP cascade, proceeds quite rapidly within msec order. Such a rapid change of enzyme activities, such as PDEase in rod outer segment, was not a matter of conventional histochemical invest igations.

Sorbitol, myo-inositol, and rod outer segment phagocytosis in cultured hRPE cells exposed to glucose. In vitro model of myo-inositol depletion hypothesis of diabetic complications

Diabetes ◽  
1991 ◽  
Vol 40 (10) ◽  
pp. 1335-1345 ◽  
Author(s):  
M. A. Del Monte ◽  
R. Rabbani ◽  
T. C. Diaz ◽  
S. A. Lattimer ◽  
J. Nakamura ◽  
...  
Keyword(s):  
Diabetic Complications ◽  
Outer Segment ◽  
In Vitro Model ◽  
Rod Outer Segment ◽  
Vitro Model
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