scholarly journals Development of an optogenetic gene sensitive to daylight and its implications in vision restoration

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yoshito Watanabe ◽  
Eriko Sugano ◽  
Kitako Tabata ◽  
Akito Hatakeyama ◽  
Tetsuya Sakajiri ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Amino Acid ◽  
Royal College ◽  
Visual Function ◽  
Photoreceptor Cells ◽  
Light Sensitivity ◽  
Visual Responses ◽  
Extracellular Loops ◽  
Ion Conducting ◽  
Homologous Amino Acid

AbstractOptogenetic gene-mediated therapy for restoring vision is thought to be a useful treatment for blind patients. However, light sensitivity achieved using this gene therapy is inferior to that of daylight vision. To increase light sensitivity, we designed three mutants using a bioinformatics approach. Nucleotide sequences encoding two sites in the extracellular loops (ex1, ex3) of mVChR1 close to simulated ion-conducting pathways were replaced by homologous amino acid-encoding sequences of ChR1 or ChR2. The light sensitivity of ex3mV1 was higher than that of mVChR1 at 405–617 nm. Visual responses were restored in Royal College of Surgeons rats with genetically degenerating photoreceptor cells transfected with ex3mV1Co, wherein transmembrane of sixth (TM6) in ex3mV1 was additionally replaced with the corresponding domain of CoChR; these rats responded to light in the order of μW/mm2. Thus, ex3mV1Co might be useful for the restoration of advanced visual function.

Age-Dependent Differences in Recovered Visual Responses in Royal College of Surgeons Rats Transduced with the Channelrhodopsin-2 Gene

2011 ◽  
Vol 46 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Hitomi Isago ◽  
Eriko Sugano ◽  
Zhuo Wang ◽  
Namie Murayama ◽  
Eri Koyanagi ◽  
...  
Keyword(s):  
Royal College ◽  
Visual Responses ◽  
Age Dependent

The Visual Hand Display: A Focus on Collaboration

1991 ◽  
Vol 85 (8) ◽  
pp. 338-339
Author(s):  
J.K. Kronheim ◽  
O. Katsumi ◽  
T. Hirose
Keyword(s):  
Young Children ◽  
Retinopathy Of Prematurity ◽  
Visual Function ◽  
Low Vision ◽  
Visual Responses ◽  
Evaluation Tools ◽  
Visual Functioning ◽  
Methods Of Evaluation ◽  
Tools And Techniques

When young children experience subnormal vision, an array of evaluation tools and techniques is used to assess visual function. Some children who have retinopathy of prematurity may require surgery. Post-operatively, at the Children's Low Vision Center in Boston, the pediatric ophthalmologist evaluates the child's visual functioning using a variety of devices. A tool called the Visual Hand Display has been introduced to enhance the physician's methods of evaluation, thereby achieving greater understanding of the child's visual responses. Collaborations among the doctors, educators, therapists, and patients are emphasized.

scholarly journals Evolution and the origin of the visual retinoid cycle in vertebrates

2009 ◽  
Vol 364 (1531) ◽  
pp. 2897-2910 ◽  
Author(s):  
Takehiro G. Kusakabe ◽  
Noriko Takimoto ◽  
Minghao Jin ◽  
Motoyuki Tsuda
Keyword(s):  
Visual Pigment ◽  
Photoreceptor Cells ◽  
Light Sensitivity ◽  
Visual Cycle ◽  
Interphotoreceptor Retinoid Binding Protein ◽  
New Genes ◽  
Ascidian Larva ◽  
Cycle Systems ◽  
Subcellular Compartmentalization ◽  
Cellular Compartments

Absorption of a photon by visual pigments induces isomerization of 11- cis -retinaldehyde (RAL) chromophore to all- trans -RAL. Since the opsins lacking 11- cis -RAL lose light sensitivity, sustained vision requires continuous regeneration of 11- cis -RAL via the process called ‘visual cycle’. Protostomes and vertebrates use essentially different machinery of visual pigment regeneration, and the origin and early evolution of the vertebrate visual cycle is an unsolved mystery. Here we compare visual retinoid cycles between different photoreceptors of vertebrates, including rods, cones and non-visual photoreceptors, as well as between vertebrates and invertebrates. The visual cycle systems in ascidians, the closest living relatives of vertebrates, show an intermediate state between vertebrates and non-chordate invertebrates. The ascidian larva may use retinochrome-like opsin as the major isomerase. The entire process of the visual cycle can occur inside the photoreceptor cells with distinct subcellular compartmentalization, although the visual cycle components are also present in surrounding non-photoreceptor cells. The adult ascidian probably uses RPE65 isomerase, and trans -to- cis isomerization may occur in distinct cellular compartments, which is similar to the vertebrate situation. The complete transition to the sophisticated retinoid cycle of vertebrates may have required acquisition of new genes, such as interphotoreceptor retinoid-binding protein, and functional evolution of the visual cycle genes.

Gene therapy improves brain white matter in aromatic l‐amino acid decarboxylase deficiency

2019 ◽  
Vol 85 (5) ◽  
pp. 644-652 ◽  
Author(s):  
Chih‐Hsien Tseng ◽  
Yin‐Hsiu Chien ◽  
Ni‐Chung Lee ◽  
Yung‐Chin Hsu ◽  
Shinn‐Forng Peng ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Amino Acid ◽  
White Matter ◽  
Acid Decarboxylase ◽  
Amino Acid Decarboxylase ◽  
Brain White Matter ◽  
Decarboxylase Deficiency

Evaluation of visual function in Royal College of Surgeon rats using a depth perception visual cliff test

2019 ◽  
Vol 36 ◽  
Author(s):  
Adi Tzameret ◽  
Ifat Sher ◽  
Victoria Edelstain ◽  
Michael Belkin ◽  
Ofra Kalter-Leibovici ◽  
...  
Keyword(s):  
Royal College ◽  
Depth Perception ◽  
Visual Function ◽  
Light Adaptation ◽  
Visual Cliff ◽  
Spearman's Rho ◽  
Spearman’S Rho ◽  
Rcs Rats ◽  
Old Rats ◽  
Spearman’S Rho Test

AbstractPreserving of vision is the main goal in vision research. The presented research evaluates the preservation of visual function in Royal College of Surgeon (RCS) rats using a depth perception test. Rats were placed on a stage with one side containing an illusory steep drop (“cliff”) and another side with a minimal drop (“table”). Latency of stage dismounting and the percentage of rats that set their first foot on the “cliff” side were determined. Nondystrophic Long–Evans (LE) rats were tested as control. Electroretinogram and histology analysis were used to determine retinal function and structure. Four-week-old RCS rats presented a significantly shorter mean latency to dismount the stage compared with 6-week-old rats (mean ± standard error, 13.7 ± 1.68 vs. 20.85 ± 6.5 s, P = 0.018). Longer latencies were recorded as rats aged, reaching 45.72 s in 15-week-old rats (P < 0.00001 compared with 4-week-old rats). All rats at the age of 4 weeks placed their first foot on the table side. By contrast, at the age of 8 weeks, 28.6% rats dismounted on the cliff side and at the age of 10 and 15 weeks, rats randomly dismounted the stage to either table or cliff side. LE rats dismounted the stage faster than 4-week-old RCS rats, but the difference was not statistically significant (7 ± 1.58 s, P = 0.057) and all LE rats dismounted on the table side. The latency to dismount the stage in RCS rats correlated with maximal electroretinogram b-wave under dark and light adaptation (Spearman’s rho test = −0.603 and −0.534, respectively, all P < 0.0001), outer nuclear layer thickness (Spearman’s rho test = −0.764, P = 0.002), and number of S- and M-cones (Spearman’s rho test = −0.763 [P = 0.002], and −0.733 [P = 0.004], respectively). The cliff avoidance test is an objective, quick, and readily available method for the determination of RCS rats’ visual function.

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