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1.
Sci Data ; 8(1): 27, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33500412

RESUMO

The retina is a key sensory tissue composed of multiple layers of cell populations that work coherently to process and decode visual information. Mass spectrometry-based proteomics approach has allowed high-throughput, untargeted protein identification, demonstrating the presence of these proteins in the retina and their involvement in biological signalling cascades. The comprehensive wild-type mouse retina proteome was prepared using a novel sample preparation approach, the suspension trapping (S-Trap) filter, and further fractionated with high-pH reversed phase chromatography involving a total of 28 injections. This data-dependent acquisition (DDA) approach using a Sciex TripleTOF 6600 mass spectrometer identified a total of 7,122 unique proteins (1% FDR), and generated a spectral library of 5,950 proteins in the normal C57BL/6 mouse retina. Data-independent acquisition (DIA) approach relies on a large and high-quality spectral library to analyse chromatograms, this spectral library would enable access to SWATH-MS acquisition to provide unbiased, multiplexed, and quantification of proteins in the mouse retina, acting as the most extensive reference library to investigate retinal diseases using the C57BL/6 mouse model.


Assuntos
Camundongos Endogâmicos C57BL/genética , Proteoma , Retina , Animais , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos C57BL/fisiologia , Proteômica , Retina/fisiologia
2.
Nat Commun ; 11(1): 5614, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33154382

RESUMO

Adult mammalian central nervous system axons have intrinsically poor regenerative capacity, so axonal injury has permanent consequences. One approach to enhancing regeneration is to increase the axonal supply of growth molecules and organelles. We achieved this by expressing the adaptor molecule Protrudin which is normally found at low levels in non-regenerative neurons. Elevated Protrudin expression enabled robust central nervous system regeneration both in vitro in primary cortical neurons and in vivo in the injured adult optic nerve. Protrudin overexpression facilitated the accumulation of endoplasmic reticulum, integrins and Rab11 endosomes in the distal axon, whilst removing Protrudin's endoplasmic reticulum localization, kinesin-binding or phosphoinositide-binding properties abrogated the regenerative effects. These results demonstrate that Protrudin promotes regeneration by functioning as a scaffold to link axonal organelles, motors and membranes, establishing important roles for these cellular components in mediating regeneration in the adult central nervous system.


Assuntos
Axônios/fisiologia , Sistema Nervoso Central/fisiologia , Retículo Endoplasmático/metabolismo , Regeneração Nervosa , Proteínas de Transporte Vesicular/metabolismo , Animais , Axônios/metabolismo , Células Cultivadas , Retículo Endoplasmático/genética , Endossomos/metabolismo , Feminino , Humanos , Integrinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Regeneração Nervosa/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/fisiologia , Fármacos Neuroprotetores/administração & dosagem , Traumatismos do Nervo Óptico/tratamento farmacológico , Traumatismos do Nervo Óptico/metabolismo , Traumatismos do Nervo Óptico/patologia , Fosforilação , Domínios Proteicos , Ratos , Ratos Sprague-Dawley , Retina/efeitos dos fármacos , Retina/fisiologia , Proteínas de Transporte Vesicular/administração & dosagem , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/genética
3.
PLoS One ; 15(8): e0238246, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866203

RESUMO

Young children exhibit poorer visual performance than adults due to immaturity of the fovea and of the fundamental processing of visual functions such as masking and crowding. Recent studies suggest that masking and crowding are closely related to the size of the fundamental processing unit-the perceptive field (PF). However, while it is known that the retina and basic visual functions develop throughout childhood, it is not clear whether and how changes in the size of the PF affect masking and crowding. Furthermore, no retinal and perceptual development data have been collected from the same cohort and time. Here we explored the developmental process of the PF and the basic visual functions. Psychophysical and imaging methods were used to test visual functions and foveal changes in participants ranging from 3-17 years old. Lateral masking, crowding and contrast sensitivity were tested using computerized tasks. Foveal measurements were obtained from spectral-domain optical coherence tomography (OCT). The children patterns below 6 years exhibited high crowding, while the expected facilitation was found only at a larger target-flanker distance than required for children above 6 years, who exhibited the typical adult. Foveal thickness and macular volume for the children below 6 years were significantly lower than for the older group. Significant correlation was found for contrast sensitivity, foveal thickness and macular volume with age and between contrast sensitivity and foveal thickness. Our data suggest that the developmental processes at the retina and visual cortex occur in the same age range. Thus, in parallel to maturation of the PF, which enables reduction in crowding, foveal development contributes to increasing contrast sensitivity.


Assuntos
Retina/fisiologia , Acuidade Visual/fisiologia , Córtex Visual/fisiologia , Adolescente , Criança , Pré-Escolar , Sensibilidades de Contraste/fisiologia , Aglomeração , Feminino , Fóvea Central/fisiologia , Humanos , Edema Macular/fisiopatologia , Masculino , Tomografia de Coerência Óptica/métodos
4.
PLoS Genet ; 16(9): e1008934, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32870927

RESUMO

Significant association signals from genome-wide association studies (GWAS) point to genomic regions of interest. However, for most loci the causative genetic variant remains undefined. Determining expression quantitative trait loci (eQTL) in a disease relevant tissue is an excellent approach to zoom in on disease- or trait-associated association signals and hitherto on relevant disease mechanisms. To this end, we explored regulation of gene expression in healthy retina (n = 311) and generated the largest cis-eQTL data set available to date. Genotype- and RNA-Seq data underwent rigorous quality control protocols before FastQTL was applied to assess the influence of genetic markers on local (cis) gene expression. Our analysis identified 403,151 significant eQTL variants (eVariants) that regulate 3,007 genes (eGenes) (Q-Value < 0.05). A conditional analysis revealed 744 independent secondary eQTL signals for 598 of the 3,007 eGenes. Interestingly, 99,165 (24.71%) of all unique eVariants regulate the expression of more than one eGene. Filtering the dataset for eVariants regulating three or more eGenes revealed 96 potential regulatory clusters. Of these, 31 harbour 130 genes which are partially regulated by the same genetic signal. To correlate eQTL and association signals, GWAS data from twelve complex eye diseases or traits were included and resulted in identification of 80 eGenes with potential association. Remarkably, expression of 10 genes is regulated by eVariants associated with multiple eye diseases or traits. In conclusion, we generated a unique catalogue of gene expression regulation in healthy retinal tissue and applied this resource to identify potentially pleiotropic effects in highly prevalent human eye diseases. Our study provides an excellent basis to further explore mechanisms of various retinal disease etiologies.


Assuntos
Retina/metabolismo , Retina/fisiologia , Doenças Retinianas/genética , Autopsia , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/genética , Predisposição Genética para Doença/genética , Variação Genética/genética , Estudo de Associação Genômica Ampla/métodos , Genômica/métodos , Genótipo , Voluntários Saudáveis , Humanos , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética
5.
Nat Commun ; 11(1): 4605, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929073

RESUMO

From starlight to sunlight, adaptation alters retinal output, changing both the signal and noise among populations of retinal ganglion cells (RGCs). Here we determine how these light level-dependent changes impact decoding of retinal output, testing the importance of accounting for RGC noise correlations to optimally read out retinal activity. We find that at moonlight conditions, correlated noise is greater and assuming independent noise severely diminishes decoding performance. In fact, assuming independence among a local population of RGCs produces worse decoding than using a single RGC, demonstrating a failure of population codes when correlated noise is substantial and ignored. We generalize these results with a simple model to determine what conditions dictate this failure of population processing. This work elucidates the circumstances in which accounting for noise correlations is necessary to take advantage of population-level codes and shows that sensory adaptation can strongly impact decoding requirements on downstream brain areas.


Assuntos
Retina/fisiologia , Adaptação Ocular/efeitos da radiação , Animais , Teorema de Bayes , Luz , Modelos Lineares , Visão Noturna/fisiologia , Estimulação Luminosa , Ratos Long-Evans , Retina/efeitos da radiação , Células Ganglionares da Retina/fisiologia , Células Ganglionares da Retina/efeitos da radiação
6.
Nat Commun ; 11(1): 3925, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764538

RESUMO

Adaptation is a ubiquitous property of sensory systems. It is typically considered that neurons adapt to dominant energy in the ambient environment to function optimally. However, perceptual representation of the stimulus, often modulated by feedback signals, sometimes do not correspond to the input state of the stimulus, which tends to be more linked with feedforward signals. Here we investigated the relative contributions to cortical adaptation from feedforward and feedback signals, taking advantage of a visual illusion, the Flash-Grab Effect, to disassociate the feedforward and feedback representation of an adaptor. Results reveal that orientation adaptation is exclusively dependent on the perceived rather than the retinal orientation of the adaptor. Combined fMRI and EEG measurements demonstrate that the perceived orientation of the Flash-Grab Effect is indeed supported by feedback signals in the cortex. These findings highlight the important contribution of feedback signals for cortical neurons to recalibrate their sensitivity.


Assuntos
Adaptação Fisiológica , Ilusões/fisiologia , Orientação Espacial/fisiologia , Adulto , Eletroencefalografia , Potenciais Evocados Visuais , Retroalimentação Fisiológica , Feminino , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Ilusões Ópticas/fisiologia , Estimulação Luminosa , Psicofísica , Retina/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto Jovem
7.
PLoS One ; 15(8): e0237403, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790713

RESUMO

Genome duplication leads to an emergence of gene paralogs that are essentially free to undergo the process of neofunctionalization, subfunctionalization or degeneration (gene loss). Onecut1 (Oc1) and Onecut2 (Oc2) transcription factors, encoded by paralogous genes in mammals, are expressed in precursors of horizontal cells (HCs), retinal ganglion cells and cone photoreceptors. Previous studies have shown that ablation of either Oc1 or Oc2 gene in the mouse retina results in a decreased number of HCs, while simultaneous deletion of Oc1 and Oc2 leads to a complete loss of HCs. Here we study the genetic redundancy between Oc1 and Oc2 paralogs and focus on how the dose of Onecut transcription factors influences abundance of individual retinal cell types and overall retina physiology. Our data show that reducing the number of functional Oc alleles in the developing retina leads to a gradual decrease in the number of HCs, progressive thinning of the outer plexiform layer and diminished electrophysiology responses. Taken together, these observations indicate that in the context of HC population, the alleles of Oc1/Oc2 paralogous genes are mutually interchangeable, function additively to support proper retinal function and their molecular evolution does not follow one of the typical routes after gene duplication.


Assuntos
Fator 6 Nuclear de Hepatócito/genética , Proteínas de Homeodomínio/genética , Retina/fisiologia , Fatores de Transcrição/genética , Alelos , Células Amácrinas/metabolismo , Células Amácrinas/patologia , Animais , Células Ependimogliais/metabolismo , Células Ependimogliais/patologia , Olho/crescimento & desenvolvimento , Olho/patologia , Loci Gênicos , Genótipo , Fator 6 Nuclear de Hepatócito/metabolismo , Proteínas de Homeodomínio/metabolismo , Camundongos , Camundongos Transgênicos , Retina/citologia , Retina/patologia , Células Bipolares da Retina/metabolismo , Células Bipolares da Retina/patologia , Células Fotorreceptoras Retinianas Cones/metabolismo , Células Fotorreceptoras Retinianas Cones/patologia , Células Ganglionares da Retina/citologia , Células Ganglionares da Retina/metabolismo , Fatores de Transcrição/metabolismo
8.
J Fr Ophtalmol ; 43(7): 586-597, 2020 Sep.
Artigo em Francês | MEDLINE | ID: mdl-32631695

RESUMO

Major depressive disorder, bipolar disorder and schizophrenia are currently among the most common psychiatric disorders, known to constitute a serious public health issue in terms of morbidity, mortality and functional handicap. Their pathophysiology is still unclear, but there is now increasing evidence supporting the existence of abnormalities of neurotransmission. As the retina is an extension of the central nervous system, it may be an interesting site of study which might provide a better understanding of the pathophysiology of psychiatric disorders. Several studies have demonstrated retinal abnormalities, with abnormal cone and rod responses on electroretinography (ERG), suggesting a process of functional neuronal loss, structurally supported by a decrease in the retinal nerve fiber layer thickness (RNFL) on optical coherence tomography (OCT), which suggests involvement of the molecular signal pathways of neurotransmission. These tests could be useful tools for diagnosing and monitoring psychiatric disorders. This article is an overview of the literature on retinal abnormalities observed in patients with major depressive disorder, bipolar disorder or schizophrenia, and discusses how they could be pathophysiologic markers.


Assuntos
Transtorno Bipolar/fisiopatologia , Transtorno Depressivo Maior/fisiopatologia , Retina/diagnóstico por imagem , Retina/fisiologia , Esquizofrenia/fisiopatologia , Acuidade Visual/fisiologia , Transtorno Bipolar/complicações , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/patologia , Transtorno Depressivo Maior/complicações , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/patologia , Eletrorretinografia , Humanos , Fibras Nervosas/patologia , Fibras Nervosas/fisiologia , Retina/patologia , Células Fotorreceptoras Retinianas Cones/patologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Células Ganglionares da Retina/patologia , Células Ganglionares da Retina/fisiologia , Esquizofrenia/complicações , Esquizofrenia/diagnóstico , Esquizofrenia/patologia , Tomografia de Coerência Óptica
9.
Nat Commun ; 11(1): 3481, 2020 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-32661226

RESUMO

Color vision is essential for an animal's survival. It starts in the retina, where signals from different photoreceptor types are locally compared by neural circuits. Mice, like most mammals, are dichromatic with two cone types. They can discriminate colors only in their upper visual field. In the corresponding ventral retina, however, most cones display the same spectral preference, thereby presumably impairing spectral comparisons. In this study, we systematically investigated the retinal circuits underlying mouse color vision by recording light responses from cones, bipolar and ganglion cells. Surprisingly, most color-opponent cells are located in the ventral retina, with rod photoreceptors likely being involved. Here, the complexity of chromatic processing increases from cones towards the retinal output, where non-linear center-surround interactions create specific color-opponent output channels to the brain. This suggests that neural circuits in the mouse retina are tuned to extract color from the upper visual field, aiding robust detection of predators and ensuring the animal's survival.


Assuntos
Visão de Cores/fisiologia , Retina/fisiologia , Animais , Eletroporação , Feminino , Luz , Masculino , Camundongos , Retina/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo , Campos Visuais/fisiologia , Vias Visuais/fisiologia
10.
PLoS One ; 15(7): e0235926, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645116

RESUMO

PURPOSE: To evaluate the changes in the retinochoroidal vasculature in patients with exogenous obesity using swept-source optical coherence tomography (SS-OCT) and OCT angiography (OCTA). METHODS: In this prospective study, 60 patients diagnosed with obesity (47 males) (mean age: 46.47±10.9 years) were included, of which 30 patients underwent bariatric surgery (Group A), and 30 patients underwent conservative management (exercise/diet) (Group B). Parameters including choroidal thickness (CT), choroidal vascularity index (CVI) and retinal capillary density index (CDI) and arteriovenous ratio (AVR) were measured at the baseline and three months follow up. 30 eyes (30 age and gender-matched) of normal participants were included for comparison. RESULTS: Baseline CT was lower in 60 participants with obesity compared to controls. Compared with normal subjects, subjects with obesity had higher mean CVI (0.66±0.02 versus 0.63±0.04; p<0.01), smaller FAZ area (0.26±0.07 versus 0.45±0.32; p<0.01), higher CDI (superficial plexus: 0.7±0.04 versus 0.68±0.06; p = 0.04, deep plexus: 0.38±0.02 versus 0.35±0.06; p = 0.01), and lower AVR (0.68±0.05 versus 0.70±0.03 versus; p<0.01). At 3-month after intervention, CT showed a significant increase in participants from Group A (329.27±79µm; p<0.01) but not in Group B from baseline. No significant change was noted in CVI or CDI at 3-month in either group compared to baseline. AVR significantly increased in Group B (p = 0.03). CONCLUSION: Subclinical changes in retinochoroidal vasculature occurs in participants with exogenous obesity compared to healthy subjects. Surgical intervention (bariatric surgery) may have a favorable outcome on the choroidal thickness in these patients.


Assuntos
Corioide/fisiologia , Obesidade/patologia , Retina/fisiologia , Adulto , Cirurgia Bariátrica , Estudos de Casos e Controles , Corioide/irrigação sanguínea , Exercício Físico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Vasos Retinianos/fisiologia , Perda de Peso
12.
Med Sci (Paris) ; 36(6-7): 594-599, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32614310

RESUMO

The neuroretina is a functional unit of the central nervous system that converts a light signal into a nerve impulse. Of neuroectodermal origin, derived from the diencephalon, the neuroretina is a layered tissue composed of six types of neuronal cells (two types of photoreceptors: cones and rods, horizontal, bipolar, amacrine and ganglion cells) and three types of glial cells (Müller glial cells, astrocytes and microglial cells). The neuroretina lays on the retinal pigmentary epithelium, that together form the retina. The existence of the internal and external blood-retinal barriers and intra-retinal junctions reflects the fineness of regulation of the retinal exchanges with the circulation and within the retina itself. The central zone of the human retina, which is highly specialized for visual acuity, has anatomical specificities. Recent imaging methods make it possible now to enrich our knowledge of the anatomical and functional characteristics of the retina, which are still imperfectly described.


Assuntos
Retina/anatomia & histologia , Animais , Corioide/irrigação sanguínea , Corioide/citologia , Corioide/fisiologia , Humanos , Neuroglia/citologia , Neuroglia/fisiologia , Retina/citologia , Retina/fisiologia , Retina/ultraestrutura , Células Fotorreceptoras Retinianas Cones/citologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Epitélio Pigmentado da Retina/irrigação sanguínea , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/fisiologia , Células Fotorreceptoras Retinianas Bastonetes/citologia , Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Vasos Retinianos/citologia , Vasos Retinianos/fisiologia
13.
Med Sci (Paris) ; 36(6-7): 626-632, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32614314

RESUMO

Generation of retinal organoids from pluripotent stem cells represents an important advance in the study of retinal development and offer new perspectives for the study of retinal diseases missing suitable animal models. Understanding the key stages of retinal development in vertebrates enabled to design protocols to generate self-organized three-dimensional structures derived from pluripotent stem cells and containing all retinal cell types. In addition to their application in basic research, such as the characterization of molecular and cellular mechanisms in retinal pathophysiology, these miniature organs also open up encouraging prospects in the field of cell therapy or the screening of therapeutic molecules, although some obstacles remain to be overcome.


Assuntos
Organoides/citologia , Retina/citologia , Doenças Retinianas/etiologia , Doenças Retinianas/patologia , Doenças Retinianas/terapia , Animais , Células Cultivadas , Humanos , Modelos Biológicos , Organoides/fisiologia , Retina/patologia , Retina/fisiologia , Terapias em Estudo/métodos , Terapias em Estudo/tendências , Técnicas de Cultura de Tecidos/métodos , Técnicas de Cultura de Tecidos/tendências
14.
PLoS Comput Biol ; 16(7): e1007857, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32667921

RESUMO

In many cases of inherited retinal degenerations, ganglion cells are spared despite photoreceptor cell death, making it possible to stimulate them to restore visual function. Several studies have shown that it is possible to express an optogenetic protein in ganglion cells and make them light sensitive, a promising strategy to restore vision. However the spatial resolution of optogenetically-reactivated retinas has rarely been measured, especially in the primate. Since the optogenetic protein is also expressed in axons, it is unclear if these neurons will only be sensitive to the stimulation of a small region covering their somas and dendrites, or if they will also respond to any stimulation overlapping with their axon, dramatically impairing spatial resolution. Here we recorded responses of mouse and macaque retinas to random checkerboard patterns following an in vivo optogenetic therapy. We show that optogenetically activated ganglion cells are each sensitive to a small region of visual space. A simple model based on this small receptive field predicted accurately their responses to complex stimuli. From this model, we simulated how the entire population of light sensitive ganglion cells would respond to letters of different sizes. We then estimated the maximal acuity expected by a patient, assuming it could make an optimal use of the information delivered by this reactivated retina. The obtained acuity is above the limit of legal blindness. Our model also makes interesting predictions on how acuity might vary upon changing the therapeutic strategy, assuming an optimal use of the information present in the retinal activity. Optogenetic therapy could thus potentially lead to high resolution vision, under conditions that our model helps to determinine.


Assuntos
Cegueira , Optogenética/métodos , Células Ganglionares da Retina/fisiologia , Animais , Cegueira/fisiopatologia , Cegueira/terapia , Terapia Genética , Macaca , Camundongos , Modelos Biológicos , Retina/fisiologia , Acuidade Visual/fisiologia
15.
J Vis Exp ; (159)2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32510482

RESUMO

Recently, the isolated-check visual evoked potential (icVEP) technique was designed and has been reported to detect glaucomatous damage earlier and faster. It creates low spatial frequency/high temporal frequency bright stimuli and records cortical activity initiated primarily by afferents in the magnocellular ON pathway. This pathway contains neurons with larger volumes and axonal diameters, and it is preferentially damaged in early glaucoma, which can result in visual field loss. The study presented here uses standard operative procedures (SOP) of icVEP to obtain reliable results. It can detect visual function loss using a signal-to-noise ratio (SNR) corresponding to the defects of retinal nerve fiber layer (RNFL) in early stage open-angle glaucoma (OAG). A setting of 10 Hz and condition of 15% positive-contrast (bright) are selected to differentiate OAG patients and control subjects, with each check containing eight runs. Each run persists for 2 s (for 20 total cycles). A flowchart is constructed, which consists of pupil size and intraocular pressure over a 30 min rest period before each examination. Additionally, the testing order of eyes is performed to obtain reliable electroencephalographic signals. VEPs are recorded and analyzed automatically by software, and SNRs are derived based on a multivariate statistic. An SNR of ≤ 1 is considered abnormal. A receiver-operating-characteristic (ROC) curve is applied to analyze the accuracy of group classification. Then, the SOP is applied in a cross-sectional study, showing that icVEP can detect glaucomatous visual function abnormality in the central visual field in the form of SNR. This value also correlates with the thickness thinning of RNFL and produces high classification accuracy for early stage OAG. Thus, it serves as a useful and objective diagnostic technology for the early detection of glaucoma.


Assuntos
Glaucoma de Ângulo Aberto/diagnóstico , Adulto , Idoso , Potenciais Evocados Visuais , Feminino , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Retina/fisiologia , Razão Sinal-Ruído , Campos Visuais
16.
J Neurosci ; 40(28): 5431-5442, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32532886

RESUMO

Altered sensory experience in early life often leads to altered response properties of the sensory neurons. This process is mostly thought to happen in the brain, not in the sensory organs. We show that in the mouse retina of both sexes, exposed to a motion-dominated visual environment from eye-opening, the ON-OFF direction selective ganglion cells (ooDSGCs) develop significantly stronger direction encoding ability for motion in all directions. This improvement occurs independent of the motion direction used for training. We demonstrated that this enhanced ability to encode motion direction is mainly attributed to increased response reliability of ooDSGCs. Closer examination revealed that the excitatory inputs from the ON bipolar pathway showed enhanced response reliability after the motion experience training, while other synaptic inputs remain relatively unchanged. Our results demonstrate that retina adapts to the visual environment during neonatal development.SIGNIFICANCE STATEMENT We found that retina, as the first stage of visual sensation, can also be affected by experience dependent plasticity during development. Exposure to a motion enriched visual environment immediately after eye-opening greatly improves motion direction encoding by direction selective retinal ganglion cells (RGCs). These results motivate future studies aimed at understanding how visual experience shapes the retinal circuits and the response properties of retinal neurons.


Assuntos
Potenciais de Ação/fisiologia , Percepção de Movimento/fisiologia , Retina/fisiologia , Células Ganglionares da Retina/fisiologia , Visão Ocular/fisiologia , Animais , Feminino , Masculino , Camundongos , Estimulação Luminosa , Vias Visuais/fisiologia
17.
Proc Natl Acad Sci U S A ; 117(26): 14682-14687, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32546523

RESUMO

We predict and experimentally verify an entoptic phenomenon through which humans are able to perceive and discriminate optical spin-orbit states. Direct perception and discrimination of these particular states of light with polarization-coupled spatial modes is possible through the observation of distinct profiles induced by the interaction between polarization topologies and the radially symmetric dichroic elements that are centered on the foveola in the macula of the human eye. A psychophysical study was conducted where optical states with a superposition of right and left circular polarization coupled to two different orbital angular momentum (OAM) values ([Formula: see text] and [Formula: see text]) were directed onto the retina of participants. The number of azimuthal fringes that a human sees when viewing the spin-orbit states is shown to be equal to the number (N) of radial lines in the corresponding polarization profile of the beam, where [Formula: see text] The participants were able to correctly discriminate between two states carrying OAM [Formula: see text] and differentiated by [Formula: see text] and [Formula: see text], with an average success probability of 77.6% (average sensitivity [Formula: see text], [Formula: see text], [Formula: see text]). These results enable methods of robustly characterizing the structure of the macula, probing retina signaling pathways, and conducting experiments with human detectors and optical states with nonseparable modes.


Assuntos
Fenômenos Fisiológicos Oculares , Retina/fisiologia , Percepção Visual/fisiologia , Humanos , Luz , Estimulação Luminosa , Teoria Quântica
18.
J Vis ; 20(6): 9, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32543649

RESUMO

People routinely perform multiple visual judgments in the real world, yet, intermixing tasks or task variants during training can damage or even prevent learning. This paper explores why. We challenged theories of visual perceptual learning focused on plastic retuning of low-level retinotopic cortical representations by placing different task variants in different retinal locations, and tested theories of perceptual learning through reweighting (changes in readout) by varying task similarity. Discriminating different (but equivalent) and similar orientations in separate retinal locations interfered with learning, whereas training either with identical orientations or sufficiently different ones in different locations released rapid learning. This location crosstalk during learning renders it unlikely that the primary substrate of learning is retuning in early retinotopic visual areas; instead, learning likely involves reweighting from location-independent representations to a decision. We developed an Integrated Reweighting Theory (IRT), which has both V1-like location-specific representations and higher level (V4/IT or higher) location-invariant representations, and learns via reweighting the readout to decision, to predict the order of learning rates in different conditions. This model with suitable parameters successfully fit the behavioral data, as well as some microstructure of learning performance in a new trial-by-trial analysis.


Assuntos
Aprendizagem/fisiologia , Retina/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Cognição , Humanos , Orientação , Baixa Visão
19.
J Vis ; 20(6): 10, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32543650

RESUMO

The human fovea lies at the center of the retina and supports high-acuity vision. In normal visual system development, the highest acuity is correlated with both a high density of cone photoreceptors in the fovea and a magnified retinotopic representation of the fovea in the visual cortex. Both cone density and the cortical area dedicated to each degree of visual space-the latter describing cortical magnification (CM)-steadily decrease with increasing eccentricity from the fovea. In albinism, peak cone density at the fovea and visual acuity are decreased, but seem to be within normal limits in the periphery, thus providing a model to explore the correlation between retinal structure, cortical structure, and behavior. Here, we used adaptive optics scanning light ophthalmoscopy to assess retinal cone density and functional magnetic resonance imaging to measure CM in the primary visual cortex of normal controls and individuals with albinism. We find that retinotopic organization is more varied among individuals with albinism than previously appreciated. Additionally, CM outside the fovea is similar to that in controls, but also more variable. CM in albinism and controls exceeds that which might be predicted based on cone density alone, but is more accurately predicted by retinal ganglion cell density. This finding suggests that decreased foveal cone density in albinism may be partially counteracted by nonuniform connectivity between cones and their downstream signaling partners. Together, these results emphasize that central as well as retinal factors must be included to provide a complete picture of aberrant structure and function in albinism.


Assuntos
Albinismo/fisiopatologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Córtex Visual/fisiologia , Adolescente , Adulto , Contagem de Células , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Oftalmoscopia/métodos , Óptica e Fotônica , Retina/fisiologia , Células Fotorreceptoras Retinianas Cones/citologia , Células Ganglionares da Retina/fisiologia , Acuidade Visual/fisiologia , Adulto Jovem
20.
Invest Ophthalmol Vis Sci ; 61(5): 27, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32421146

RESUMO

Purpose: To determine whether the blood flow in the superior retina is significantly different from that in the inferior retina, and to determine whether the posture affects the blood flow in the superior and inferior retina. Methods: The blood flow in the vessels around the optic nerve head was measured by laser speckle flowgraphy in the sitting position in 68 healthy subjects. The blood flow in the superior peripapillary retina was compared with that in the inferior peripapillary retina. The measurements of the blood flow were performed in the sitting position, and the effect of switching to a supine position was determined at 2, 4, 6, 8, 10, and 30 minutes after the switch. Results: The total relative flow volume (RFV)-all, RFV-artery, and RFV-vein were significantly greater in the superior retina than in the inferior retina (all P < 0.001). The mean diameter-all and mean diameter-artery in the superior retina were significantly larger than that in the inferior retina (all P < 0.05). The mean blur rate (MBR)-all, MBR-artery, and MBR-vein in the superior retina were also greater than that in the inferior retina (P < 0.001, P < 0.01, and P < 0.001, respectively). Although the ocular perfusion pressure was significantly changed with the postural alteration, the total RFV-all remained greater in the superior retina than in the inferior retina after the postural change. Conclusions: Clinicians need to be aware of the differences in the blood flow between the superior and inferior retinal peripapillary area when considering the mechanisms of retinochoroidal diseases.


Assuntos
Fluxo Sanguíneo Regional/fisiologia , Retina/fisiologia , Vasos Retinianos/fisiologia , Adulto , Feminino , Hemodinâmica , Humanos , Fluxometria por Laser-Doppler , Masculino , Microcirculação , Oftalmoscopia , Disco Óptico/irrigação sanguínea , Postura/fisiologia , Microscopia com Lâmpada de Fenda , Acuidade Visual/fisiologia , Adulto Jovem
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