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Pesquisa : A08.675.650.850.625.670.100 [Categoria DeCS]
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[PMID]:29274337
[Au] Autor:Ueda K; Onishi A; Ito SI; Nakamura M; Takahashi M
[Ad] Endereço:Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe, Hyogo, 650-0047, Japan; Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan.
[Ti] Título:Generation of three-dimensional retinal organoids expressing rhodopsin and S- and M-cone opsins from mouse stem cells.
[So] Source:Biochem Biophys Res Commun;495(4):2595-2601, 2018 01 22.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:PURPOSE: Three-dimensional retinal organoids can be differentiated from embryonic stem cells/induced pluripotent stem cells (ES/iPS cells) under defined medium conditions. We modified the serum-free floating culture of embryoid body-like aggregates with quick reaggregation (SFEBq) culture procedure to obtain retinal organoids expressing more rod photoreceptors and S- and M-cone opsins. METHODS: Retinal organoids differentiated from mouse Nrl-eGFP iPS cells were cultured in various mediums during photoreceptor development. To promote rod photoreceptor development, organoids were maintained in media containing 9-cis retinoic acids (9cRA). To obtain retinal organoids with M-opsin expression, we cultured in medium with 1% fetal bovine serum (FBS) supplemented with T3, BMP4, and DAPT. Section immunohistochemistry was performed to visualize the expression of photoreceptor markers. RESULTS: In three-dimensional (3D) retinas exposed to 9cRA, rhodopsin was expressed earlier and S-cone opsins were suppressed. We could maintain 3D retinas up to DD 35 in culture media with 1% FBS. The 3D retinas expressed rhodopsin, S- and M-opsins, but most cone photoreceptors expressed either S- or M-opsins. CONCLUSION: By modifying culture conditions in the SFEBq protocol, we obtained rod-dominated 3D retinas and S- and M-opsin expressing 3D retinas.
[Mh] Termos MeSH primário: Órgãos Bioartificiais
Opsinas dos Cones/metabolismo
Retina/citologia
Retina/crescimento & desenvolvimento
Rodopsina/metabolismo
Células-Tronco/citologia
Engenharia Tecidual/métodos
[Mh] Termos MeSH secundário: Animais
Diferenciação Celular/fisiologia
Células Cultivadas
Camundongos
Organogênese/fisiologia
Impressão Tridimensional
Células Fotorreceptoras Retinianas Cones/metabolismo
Células-Tronco/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cone Opsins); 9009-81-8 (Rhodopsin)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171224
[St] Status:MEDLINE


  2 / 4011 MEDLINE  
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[PMID]:29293603
[Au] Autor:Schori C; Agbaga MP; Brush RS; Ayyagari R; Grimm C; Samardzija M
[Ad] Endereço:Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Zurich, Switzerland.
[Ti] Título:Elovl4 5-bp deletion does not accelerate cone photoreceptor degeneration in an all-cone mouse.
[So] Source:PLoS One;13(1):e0190514, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mutations in the elongation of very long chain fatty acid 4 (ELOVL4) gene cause Stargardt macular dystrophy 3 (STGD3), a rare, juvenile-onset, autosomal dominant form of macular degeneration. Although several mouse models have already been generated to investigate the link between the three identified disease-causing mutations in the ELOVL4 gene, none of these models recapitulates the early-onset cone photoreceptor cell death observed in the macula of STGD3 patients. To address this specifically, we investigated the effect of mutant ELOVL4 in a mouse model with an all-cone retina. Hence, we bred mice carrying the heterozygously mutated Elovl4 gene on the R91W;Nrl-/- all-cone background and analyzed the retinal lipid composition, morphology, and function over the course of 1 year. We observed a reduction of total phosphatidylcholine-containing very long chain-polyunsaturated fatty acids (PC-VLC-PUFAs) by 39% in the R91W;Nrl-/-;Elovl4 mice already at 6 weeks of age with a pronounced decline of the longest forms of PC-VLC-PUFAs. Total levels of shorter-chain fatty acids (< C26) remained unaffected. However, this reduction in PC-VLC-PUFA content in the all-cone retina had no impact on morphology or function and did not accelerate retinal degeneration in the R91W;Nrl-/-;Elovl4 mice. Taken together, mutations in the ELOVL4 gene lead to cone degeneration in humans, whereas mouse models expressing the mutant Elovl4 show predominant rod degeneration. The lack of a phenotype in the all-cone retina expressing the mutant form of the protein supports the view that aberrant function of ELOVL4 is especially detrimental for rods in mice and suggests a more subtle role of VLC-PUFAs for cone maintenance and survival.
[Mh] Termos MeSH primário: Proteínas do Olho/genética
Proteínas de Membrana/genética
Células Fotorreceptoras Retinianas Cones/patologia
Deleção de Sequência
[Mh] Termos MeSH secundário: Animais
Eletrorretinografia
Proteínas do Olho/metabolismo
Ácidos Graxos Insaturados/metabolismo
Proteínas de Membrana/metabolismo
Camundongos
Camundongos Knockout
Mutação
Reação em Cadeia da Polimerase em Tempo Real
Células Fotorreceptoras Retinianas Cones/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Elovl4 protein, mouse); 0 (Eye Proteins); 0 (Fatty Acids, Unsaturated); 0 (Membrane Proteins)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180221
[Lr] Data última revisão:
180221
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180103
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0190514


  3 / 4011 MEDLINE  
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[PMID]:29342178
[Au] Autor:Ma J; Zhou P; Ahmad B; Ren G; Wang C
[Ad] Endereço:School of Science, Chongqing University of Posts and Telecommunications, Chongqing, China.
[Ti] Título:Chaos and multi-scroll attractors in RCL-shunted junction coupled Jerk circuit connected by memristor.
[So] Source:PLoS One;13(1):e0191120, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In this paper, a new four-variable dynamical system is proposed to set chaotic circuit composed of memristor and Josephson junction, and the dependence of chaotic behaviors on nonlinearity is investigated. A magnetic flux-controlled memristor is used to couple with the RCL-shunted junction circuit, and the dynamical behaviors can be modulated by changing the coupling intensity between the memristor and the RCL-shunted junction. Bifurcation diagram and Lyapunov exponent are calculated to confirm the emergence of chaos in the improved dynamical system. The outputs and dynamical behaviors can be controlled by the initial setting and external stimulus as well. As a result, chaos can be suppressed and spiking occurs in the sampled outputs under negative feedback, while applying positive feedback type via memristor can be effective to trigger chaos. Furthermore, it is found that the number of multi-attractors in the Jerk circuit can be modulated when memristor coupling is applied on the circuit. These results indicate that memristor coupling can be effective to control chaotic circuits and it is also useful to reproduce dynamical behaviors for neuronal activities.
[Mh] Termos MeSH primário: Iluminação
Retina/anatomia & histologia
Células Fotorreceptoras Retinianas Cones
[Mh] Termos MeSH secundário: Adulto
Seres Humanos
Meia-Idade
Óptica e Fotônica
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180215
[Lr] Data última revisão:
180215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180118
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0191120


  4 / 4011 MEDLINE  
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[PMID]:29338027
[Au] Autor:Legras R; Gaudric A; Woog K
[Ad] Endereço:Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Paris-Saclay, Université Paris-Saclay, Orsay, France.
[Ti] Título:Distribution of cone density, spacing and arrangement in adult healthy retinas with adaptive optics flood illumination.
[So] Source:PLoS One;13(1):e0191141, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The aim of this article is to analyse cone density, spacing and arrangement using an adaptive optics flood illumination retina camera (rtx1™) on a healthy population. Cone density, cone spacing and packing arrangements were measured on the right retinas of 109 subjects at 2°, 3°, 4°, 5° and 6° of eccentricity along 4 meridians. The effects of eccentricity, meridian, axial length, spherical equivalent, gender and age were evaluated. Cone density decreased on average from 28 884 ± 3 692 cones/mm2, at 2° of eccentricity, to 15 843 ± 1 598 cones/mm2 at 6°. A strong inter-individual variation, especially at 2°, was observed. No important difference of cone density was observed between the nasal and temporal meridians or between the superior and inferior meridians. However, the horizontal and vertical meridians differed by around 14% (T-test, p<0.0001). Cone density, expressed in units of area, decreased as a function of axial length (r2 = 0.60), but remained constant (r2 = 0.05) when cone density is expressed in terms of visual angle supporting the hypothesis that the retina is stretched during the elongation of the eyeball. Gender did not modify the cone distribution. Cone density was slightly modified by age but only at 2°. The older group showed a smaller density (7%). Cone spacing increased from 6,49 ± 0,42 µm to 8,72 ± 0,45 µm respectively between 2° and 6° of eccentricity. The mosaic of the retina is mainly triangularly arranged (i.e. cells with 5 to 7 neighbors) from 2° to 6°. Around half of the cells had 6 neighbors.
[Mh] Termos MeSH primário: Luz
Retina/anatomia & histologia
Células Fotorreceptoras Retinianas Cones
[Mh] Termos MeSH secundário: Adolescente
Adulto
Feminino
Seres Humanos
Masculino
Meia-Idade
Óptica e Fotônica
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180215
[Lr] Data última revisão:
180215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180117
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0191141


  5 / 4011 MEDLINE  
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[PMID]:29264653
[Au] Autor:Nakamura T; Hayashi A; Oiwake T
[Ad] Endereço:Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan. nakatomo@med.u-toyama.ac.jp.
[Ti] Título:Recovery of macular cone photoreceptors in Vogt-Koyanagi-Harada disease.
[So] Source:Graefes Arch Clin Exp Ophthalmol;256(2):387-394, 2018 Feb.
[Is] ISSN:1435-702X
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:PURPOSE: Our purpose was to study changes in macular cone photoreceptors in Vogt-Koyanagi-Harada (VKH) disease patients after high-dose corticosteroid treatment using an adaptive optics (AO) fundus camera. METHODS: We retrospectively analyzed 16 eyes of eight patients with new-onset acute VKH disease that were studied retrospectively. After serous retinal detachment (SRD) had resolved, AO images were obtained using the rtx1™ AO fundus camera over a 12-month course. Cone counting was performed in the nasal, temporal, superior and inferior areas of the macula 0.75 mm from the foveal center. A control group of 30 eyes of 30 healthy subjects was established for comparison. RESULTS: In the eyes with VKH disease, the mean cone densities 0.75 mm from the foveal center were 11,847 at baseline (resolution of SRD), and 15,218, 16,684 and 17,686 cones/mm , at 3, 6, and 12 months later, respectively. The mean cone densities at 3, 6, and 12 months were significantly increased compared to those of baseline (p = 0.007, p < 0.001, and p < 0.001, respectively); however, they were significantly lower than that of the healthy control eyes (p < 0.001). The mean cone densities at areas with a previous presence of cystoid spaces were significantly lower than those without cystoid spaces at the baseline, and at 3, 6, and 12 months (p < 0.001, p = 0.007, p < 0.001, and p = 0.008, respectively). CONCLUSIONS: Cone densities were gradually increased after the resolution of SRD in the eyes of VKH disease patients. The presence of cystoid spaces might be a marker of severe damage to cone photoreceptors.
[Mh] Termos MeSH primário: Macula Lutea/fisiopatologia
Recuperação de Função Fisiológica
Células Fotorreceptoras Retinianas Cones/fisiologia
Síndrome Uveomeningoencefálica/fisiopatologia
[Mh] Termos MeSH secundário: Adulto
Contagem de Células
Corioide/patologia
Feminino
Angiofluoresceinografia
Seguimentos
Fóvea Central/patologia
Fundo de Olho
Glucocorticoides/uso terapêutico
Seres Humanos
Macula Lutea/patologia
Masculino
Meia-Idade
Prognóstico
Células Fotorreceptoras Retinianas Cones/citologia
Estudos Retrospectivos
Fatores de Tempo
Tomografia de Coerência Óptica
Síndrome Uveomeningoencefálica/diagnóstico
Síndrome Uveomeningoencefálica/tratamento farmacológico
Acuidade Visual
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Glucocorticoids)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180214
[Lr] Data última revisão:
180214
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171222
[St] Status:MEDLINE
[do] DOI:10.1007/s00417-017-3869-5


  6 / 4011 MEDLINE  
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[PMID]:29228252
[Au] Autor:Guyon B; Elphege E; Flores M; Gauthier AS; Delbosc B; Saleh M
[Ad] Endereço:Department of Ophthalmology, Besançon University Hospital, Besançon, France.
[Ti] Título:Retinal Reflectivity Measurement for Cone Impairment Estimation and Visual Assessment After Diabetic Macular Edema Resolution (RECOVER-DME).
[So] Source:Invest Ophthalmol Vis Sci;58(14):6241-6247, 2017 Dec 01.
[Is] ISSN:1552-5783
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Purpose: Photoreceptor loss has been suspected of being involved in incomplete visual recovery after diabetic macular edema (DME) resolution. Recent studies have shown that cone density in the perifoveal area could be estimated by in vivo measurements of the outer retinal reflectivity on optical coherence tomography (OCT). The main objective of this study was to assess the photoreceptor layer reflectivity after DME resolution and to determine its relationship with final visual acuity (VA). Methods: In this cross-sectional case-control study, 77 eyes of 58 patients were divided into three groups: a first group (n = 34) encompassed eyes with resolved DME (R-DME), a second group (n = 24) corresponded to diabetic eyes without DME (no-DME), and a third group (n = 19) comprised a control group of nondiabetic healthy eyes. Outer retinal reflectivity was measured on volumetric spectral-domain (SD)-OCT scans acquired 3 months after DME resolution, from the photoreceptor ellipsoid zone (EZ) and the retinal pigment epithelium (RPE). Results: The mean DME duration was 26.5 ± 13.4 months in the R-DME group. EZ reflectivity was 19.8% lower (P < 0.0001) in this group compared to diabetic eyes without DME and 26.5% lower (P < 0.0001) than in nondiabetic control eyes. Reflectivity was 7.8% lower in the no-DME group compared to controls (P < 0.0001). RPE reflectivity was comparable among the three groups (P > 0.05). VA was significantly correlated with EZ reflectivity in diabetic patients (r2 = 0.57; P < 0.0001). Reflectivity tended to decrease with prolonged DME duration without reaching statistical significance (P = 0.10). Conclusions: DME significantly impacts the photoreceptor layer. This impairment can be estimated by measuring outer retinal reflectivity on OCT images after edema resorption. We also provide evidence that in diabetic eyes without a history of DME, there is early photoreceptor loss, or at least outer segment (OS) disorganization, in addition to the inner retinal degeneration reported previously. This suggests the neurodegenerative process in diabetes. This quantitative approach may help monitor neuroprotective strategies to rescue photoreceptor cells in diabetic eyes.
[Mh] Termos MeSH primário: Retinopatia Diabética/diagnóstico
Macula Lutea/patologia
Edema Macular/diagnóstico
Recuperação de Função Fisiológica
Células Fotorreceptoras Retinianas Cones/patologia
Tomografia de Coerência Óptica/métodos
Acuidade Visual
[Mh] Termos MeSH secundário: Estudos Transversais
Retinopatia Diabética/complicações
Retinopatia Diabética/fisiopatologia
Feminino
Angiofluoresceinografia
Fundo de Olho
Seres Humanos
Macula Lutea/fisiopatologia
Edema Macular/etiologia
Edema Macular/fisiopatologia
Masculino
Meia-Idade
Estudos Retrospectivos
[Pt] Tipo de publicação:JOURNAL ARTICLE; OBSERVATIONAL STUDY
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171215
[Lr] Data última revisão:
171215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171212
[St] Status:MEDLINE
[do] DOI:10.1167/iovs.17-22380


  7 / 4011 MEDLINE  
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[PMID]:29049732
[Au] Autor:Wang K; Peng B; Xiao J; Weinreb O; Youdim MBH; Lin B
[Ad] Endereço:Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China.
[Ti] Título:Iron-Chelating Drugs Enhance Cone Photoreceptor Survival in a Mouse Model of Retinitis Pigmentosa.
[So] Source:Invest Ophthalmol Vis Sci;58(12):5287-5297, 2017 Oct 01.
[Is] ISSN:1552-5783
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Purpose: Retinitis pigmentosa (RP) is a group of hereditary retinal degeneration in which mutations commonly result in the initial phase of rod cell death followed by gradual cone cell death. The mechanisms by which the mutations lead to photoreceptor cell death in RP have not been clearly elucidated. There is currently no effective treatment for RP. The purpose of this work was to explore iron chelation therapy for improving cone survival and function in the rd10 mouse model of RP. Methods: Two iron-chelating drugs, 5-(4-(2-hydroxyethyl) piperazin-1-yl (methyl)-8-hydroxyquinoline (VK28) and its chimeric derivative 5-(N-methyl-N-propargyaminomethyl)-quinoline-8-oldihydrochloride (VAR10303), were injected intraperitoneally to rd10 mice every other day starting from postnatal day 14. We investigate the effects of the two compounds on cone rescue at three time points, using a combination of immunocytochemistry, RT-PCR, Western blot analysis, and a series of visual function tests. Results: VK28 and VAR10303 treatments partially rescued cones, and significantly improved visual function in rd10 mice. Moreover, we showed that the neuroprotective effects of VK28 and VAR10303 were correlated to inhibition of neuroinflammation, oxidative stress, and apoptosis. Furthermore, we demonstrated that downregulation of NF-kB and p53 is likely to be the mechanisms by which proinflammatory mediators and apoptosis are reduced in the rd10 retina, respectively. Conclusions: VK28 and VAR10303 provided partial histologic and functional rescue of cones in RD10 mice. Our study demonstrated that iron chelation therapy might represent an effective therapeutic strategy for RP patients.
[Mh] Termos MeSH primário: Modelos Animais de Doenças
Quelantes de Ferro/uso terapêutico
Fármacos Neuroprotetores/uso terapêutico
Células Fotorreceptoras Retinianas Cones/fisiologia
Retinite Pigmentosa/tratamento farmacológico
[Mh] Termos MeSH secundário: Animais
Apoptose/efeitos dos fármacos
Western Blotting
Sobrevivência Celular/fisiologia
Eletrorretinografia
Hidroxiquinolinas/uso terapêutico
Imuno-Histoquímica
Injeções Intraperitoneais
Camundongos
Camundongos Endogâmicos C57BL
NF-kappa B/metabolismo
Estresse Oxidativo/efeitos dos fármacos
Piperazinas/uso terapêutico
Quinolinas/uso terapêutico
Reação em Cadeia da Polimerase em Tempo Real
Retinite Pigmentosa/metabolismo
Retinite Pigmentosa/patologia
Proteína Supressora de Tumor p53/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (5-(2-(methylprop-2-ynylamino)ethyl)quinolin-8-ol); 0 (5-(4-(2-hydroxyethyl)piperazine-1-ylmethyl)quinoline-8-ol); 0 (Hydroxyquinolines); 0 (Iron Chelating Agents); 0 (NF-kappa B); 0 (Neuroprotective Agents); 0 (Piperazines); 0 (Quinolines); 0 (Tumor Suppressor Protein p53)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171020
[St] Status:MEDLINE
[do] DOI:10.1167/iovs.17-22096


  8 / 4011 MEDLINE  
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[PMID]:29049731
[Au] Autor:Kato K; Kondo M; Nagashima R; Sugawara A; Sugimoto M; Matsubara H; McCulloch DL; Ikesugi K
[Ad] Endereço:Department of Ophthalmology, Mie University Graduate School of Medicine, Tsu, Japan.
[Ti] Título:Factors Affecting Mydriasis-Free Flicker ERGs Recorded With Real-Time Correction for Retinal Illuminance: Study of 150 Young Healthy Subjects.
[So] Source:Invest Ophthalmol Vis Sci;58(12):5280-5286, 2017 Oct 01.
[Is] ISSN:1552-5783
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Purpose: A small, full-field flicker electroretinogram (ERG) recording system was recently developed to record flicker ERGs without mydriasis (RETeval). The device delivers a stimulus with constant retinal illuminance by adjusting the retinal luminance to compensate for changes in the pupillary area. The purpose of this study was to determine what factors affect the fundamental components of the flicker ERGs recorded by RETeval in young healthy subjects. Methods: Flicker ERGs were recorded with the RETeval system from 150 eyes of 150 young healthy subjects (age, 20-29 years). Univariate and multivariate linear regression analyses were performed to identify the factors that affected the implicit times and amplitudes of the fundamental component of the flicker ERGs. The independent variables included age, sex, refractive error, axial length, and pupillary area. Results: Multivariate regression analyses indicated that a longer axial length (P = 0.03) and larger pupillary area (P = 0.008) were independent factors that were significantly associated with longer implicit times of the fundamental component of the flicker ERGs. Multivariate regression analyses also showed that the female sex (P = 0.03) was an independent factor, which was significantly associated with larger amplitude fundamental component of the flicker ERGs. Conclusions: These results indicate that the fundamental components of the RETeval flicker ERGs are significantly affected by the axial length, pupillary area, and sex of young healthy subjects. The results also suggest that it would be better to compensate for the Stiles-Crawford effect when flicker ERGs are recorded with natural pupils.
[Mh] Termos MeSH primário: Pupila/fisiologia
Retina/fisiologia
[Mh] Termos MeSH secundário: Adulto
Comprimento Axial do Olho/anatomia & histologia
Eletrorretinografia
Feminino
Voluntários Saudáveis
Seres Humanos
Iluminação
Masculino
Estimulação Luminosa/métodos
Estudos Prospectivos
Retina/efeitos da radiação
Células Fotorreceptoras Retinianas Cones
Fatores Sexuais
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171020
[St] Status:MEDLINE
[do] DOI:10.1167/iovs.17-22587


  9 / 4011 MEDLINE  
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[PMID]:28973563
[Au] Autor:Nunez V; Shapley RM; Gordon J
[Ad] Endereço:Center for Neural Science, New York University, New York, NY, USA.
[Ti] Título:Nonlinear dynamics of cortical responses to color in the human cVEP.
[So] Source:J Vis;17(11):9, 2017 Sep 01.
[Is] ISSN:1534-7362
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The main finding of this paper is that the human visual cortex responds in a very nonlinear manner to the color contrast of pure color patterns. We examined human cortical responses to color checkerboard patterns at many color contrasts, measuring the chromatic visual evoked potential (cVEP) with a dense electrode array. Cortical topography of the cVEPs showed that they were localized near the posterior electrode at position Oz, indicating that the primary cortex (V1) was the major source of responses. The choice of fine spatial patterns as stimuli caused the cVEP response to be driven by double-opponent neurons in V1. The cVEP waveform revealed nonlinear color signal processing in the V1 cortex. The cVEP time-to-peak decreased and the waveform's shape was markedly narrower with increasing cone contrast. Comparison of the linear dynamics of retinal and lateral geniculate nucleus responses with the nonlinear dynamics of the cortical cVEP indicated that the nonlinear dynamics originated in the V1 cortex. The nature of the nonlinearity is a kind of automatic gain control that adjusts cortical dynamics to be faster when color contrast is greater.
[Mh] Termos MeSH primário: Percepção de Cores/fisiologia
Potenciais Evocados Visuais/fisiologia
Células Fotorreceptoras Retinianas Cones/fisiologia
Córtex Visual/fisiologia
[Mh] Termos MeSH secundário: Adulto
Feminino
Corpos Geniculados/fisiologia
Seres Humanos
Masculino
Meia-Idade
Estimulação Luminosa
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171018
[Lr] Data última revisão:
171018
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171004
[St] Status:MEDLINE
[do] DOI:10.1167/17.11.9


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[PMID]:28882401
[Au] Autor:Musser JM; Arendt D
[Ad] Endereço:Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany. Electronic address: jmmusser@gmail.com.
[Ti] Título:Loss and gain of cone types in vertebrate ciliary photoreceptor evolution.
[So] Source:Dev Biol;431(1):26-35, 2017 11 01.
[Is] ISSN:1095-564X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Ciliary photoreceptors are a diverse cell type family that comprises the rods and cones of the retina and other related cell types such as pineal photoreceptors. Ciliary photoreceptor evolution has been dynamic during vertebrate evolution with numerous gains and losses of opsin and phototransduction genes, and changes in their expression. For example, early mammals lost all but two cone opsins, indicating loss of cone receptor types in response to nocturnal lifestyle. Our review focuses on the comparison of specifying transcription factors and cell type-specific transcriptome data in vertebrate retinae to build and test hypotheses on ciliary photoreceptor evolution. Regarding cones, recent data reveal that a combination of factors specific for long-wavelength sensitive opsin (Lws)- cones in non-mammalian vertebrates (Thrb and Rxrg) is found across all differentiating cone photoreceptors in mice. This suggests that mammalian ancestors lost all but one ancestral cone type, the Lws-cone. We test this hypothesis by a correlation analysis of cone transcriptomes in mouse and chick, and find that, indeed, transcriptomes of all mouse cones are most highly correlated to avian Lws-cones. These findings underscore the importance of specifying transcription factors in tracking cell type evolution, and shed new light on the mechanisms of cell type loss and gain in retina evolution.
[Mh] Termos MeSH primário: Evolução Biológica
Células Fotorreceptoras de Vertebrados/citologia
Células Fotorreceptoras de Vertebrados/metabolismo
[Mh] Termos MeSH secundário: Animais
Proteínas Aviárias/genética
Proteínas Aviárias/metabolismo
Galinhas
Evolução Molecular
Duplicação Gênica
Perfilação da Expressão Gênica
Camundongos
Modelos Biológicos
Opsinas/genética
Opsinas/metabolismo
Células Fotorreceptoras Retinianas Cones/citologia
Células Fotorreceptoras Retinianas Cones/metabolismo
Opsinas de Bastonetes/genética
Opsinas de Bastonetes/metabolismo
Fatores de Transcrição/genética
Fatores de Transcrição/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Avian Proteins); 0 (Opsins); 0 (Rod Opsins); 0 (Transcription Factors); 0 (long-wavelength opsin); 0 (short-wavelength opsin)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171111
[Lr] Data última revisão:
171111
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170909
[St] Status:MEDLINE



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