Prevalência de hipertensão arterial em pacientes com oclusão do ramo da veia central da retina

OBJETIVOS: Identificar em pacientes com oclusão do ramo da veia central da retina utilizando a monitorização ambulatorial da pressão arterial e medidas clínicas da pressão arterial: prevalência de hipertensão e o perfil noturno da pressão arterial. MÉTODOS: Prospectivamente, 93 olhos de 83 pacientes com oclusão do ramo da veia central da retina foram submetidos à avaliação oftalmológica. Após, os pacientes foram encaminhados para avaliação clínica e monitorização da pressão arterial. Pacientes sem descenso da pressão durante o sono ("non-dipper") foram definidos como um declínio na pressão arterial sistólica < 10%, e pacientes com descenso presente ("dipper") quando este valor fosse superior. RESULTADOS: A doença acometeu um olho em 73 (88%) pacientes. O ramo temporal superior foi o local da oclusão em 61 (65,6%) olhos, no restante o ramo temporal inferior foi afetado. Setenta e seis (92%) pacientes formam diagnosticados como hipertensos após a avaliação clínica. A monitorização ambulatorial da pressão arterial identificou 76 hipertensos, 5 normotensos, 1 hipertenso do avental branco e 1 hipertenso mascarado. Estes 2 últimos foram excluídos da análise. Dos 81 pacientes, analisados. Quarenta (49%) eram "dippers" e 41 (51%) "non-dippers". Entre os hipertensos (n=76), 36 (47,4%) eram "dippers" e 40 (52,6%) "non-dippers". CONCLUSÃO: Prevalência de hipertensão arterial em nosso estudo foi extremamente elevada (92,8%), que sugere que a fisiopatologia da doença tem íntima relação com as alterações promovidas pela hipertensão. Pouco mais da metade dos hipertensos eram "non-dipper" (n=40; 52,6%). Estas evidências sugerem que um nível sustentado de pressão arterial possa ser um fator de risco adicional para a oclusão do ramo da veia central da retina.

Losses of immunoreactive parvalbumin amacrine and immunoreactive alphaprotein kinase C bipolar cells caused by methylmercury chloride intoxication in the retina of the tropical fish Hoplias malabaricus

To quantify the effects of methylmercury (MeHg) on amacrine and on ON-bipolar cells in the retina, experiments were performed in MeHg-exposed groups of adult trahiras (Hoplias malabaricus) at two dose levels (2 and 6 µg/g, ip). The retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-_aprotein kinase C (_aPKC) immunocytochemistry. Morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (PV-IR) and _aPKC (_aPKC-IR) in wholemount preparations. Cell density, topography and isodensity maps were estimated using confocal images. PV-IR was detected in amacrine cells in the inner nuclear layer and in displaced amacrine cells from the ganglion cell layer, and _aPKC-IR was detected in ON-bipolar cells. The MeHg-treated group (6 µg/g) showed significant reduction of the ON-bipolar _aPKC-IR cell density (mean density = 1306 ± 393 cells/mm²) compared to control (1886 ± 892 cells/mm²; P < 0.001). The mean densities found for amacrine PV-IR cells in MeHg-treated retinas were 1040 ± 56 cells/mm² (2 µg/g) and 845 ± 82 cells/mm² (6 µg/g), also lower than control (1312 ± 31 cells/mm²; P < 0.05), differently from the data observed in displaced PV-IR amacrine cells. These results show that MeHg changed the PV-IR amacrine cell density in a dose-dependent way, and reduced the density of _aKC-IR bipolar cells at the dose of 6 µg/g. Further studies are needed to identify the physiological impact of these findings on visual function.

O fator de crescimento do nervo inibe o edema citotóxico de células de Müller e células bipolares da retina de rato por meio da liberação de citocinas gliais: participação do sistema glutamatérgico e purinérgico

O fator de crescimento do nervo (NGF) pode retardar a degeneração celular na retina de ratos em diferentes injúrias retinianas. O acúmulo de água em células da retina contribui para o desenvolvimento de edema retiniano e degeneração neuronal. Em atribuição ao seu efeito protetor, este trabalho teve por objetivo avaliar se o NGF influencia o edema celular osmótico em células de Müller e células bipolares. Assim, montagens planas, fatias de retina e células isoladas da retina de ratos foram superfundidas com solução hipo-osmótica na presença de BaCl₂. Secções retinianas foram utilizadas para imunomarcações, e a liberação de adenosina foi medida por cromatografia líquida de alta eficácia, em montagens planas. A área de secção transversal celular foi medida antes e após a superfusão em meio hipo-osmótico, em fatias de retina e suspensões celulares. Tanto células de Müller quanto células bipolares foram imunopositivas para TrkA, mas somente células de Müller foram marcadas contra p75^NTR e NGF. A hipo-osmolaridade induziu um rápido e significativo aumento da liberação de adenosina endógena em retinas controle, mas não em retinas perfundidas com BaCl₂. O NGF inibiu o edema citotóxico em células de Müller e em células bipolares em fatias de retina controle e retinas pós-isquêmicas submetidas a condições hipo-osmóticas. Por outro lado, NGF impediu o edema citotóxico da célula de Müller isolada, mas não da célula bipolar isolada (em meio hipo-osmótico contendo íons Ba²⁺). Isto sugere que NGF induz a liberação de fatores por células de Müller, os quais inibem o edema citotóxico de células bipolares em fatias de retina. O efeito inibitório do NGF sobre o edema citotóxico de células de Müller foi mediado pela ativação do receptor TrkA, mas não de p75^NTR, e foi anulado por bloqueadores de receptores metabotrópicos de glutamato, receptores de adenosina A₁, e receptores do fator de crescimento de fibroblasto (FGF). O bFGF evitou o edema citotóxico de células de Müller isoladas, mas inibiu somente em parte o edema citotóxico de células bipolares isoladas. O bloqueio de FGFR impediu o efeito inibidor de edema celular da adenosina, sugerindo que a liberação de bFGF ocorre após à ativação autócrina/parácrina de receptores A_l. Além de bFGF, GDNF e TGF431 reduziram em parte o edema citotóxico da célula bipolar. Estes dados sugerem que o efeito neuroprotetor do NGF é em parte mediado pela prevenção de edema citotóxico de células gliais e bipolares da retina.

Retinopatia diabética experimental: estudo estrutural, ultraestrutural e morfométrico da retina de ratos normais, diabéticos e diabéticos tratados

Pós-graduação em Saúde Coletiva - FMB

ENDO-OLIGOPEPTIDASE-A, A PUTATIVE ENKEPHALIN-GENERATING ENZYME, IN THE VERTEBRATE RETINA

Endo-oligopeptidase A, EC 3.4.22.19, converts small enkephalin-containing peptides into the corresponding enkephalins in vitro. We investigated the presence of endooligopeptidase A in the retina and its possible colocalization with enkephalins in retinal neurons. The specific activity of endo-oligopeptidase A found in pigeon retinae (30.3 +/- 7.3 mU/mg, mean +/- standard deviation) was four times higher than in rabbit retinae (7.0 +/- 1.1 mU/mg). The enzyme activity was not modified by EDTA, but it was enhanced by dithiothreitol and inhibited by zinc and 5,5'-dithiobis(2-nitrobenzoic acid). Immunohistochemical experiments with a purified antiserum against rabbit endo-oligopeptidase A revealed labeled neurons in both the inner nuclear layer and the ganglion cell layer of pigeon and rabbit retinae. Double-labeling immunofluorescence experiments demonstrated that about 90% of neurons containing endo-oligopeptidase A-like immunoreactivity also contained [Leu5]-enkephalin-like immunoreactivity. These colocalization results may represent an important step toward the demonstration of the possible involvement of endo-oligopeptidase A in enkephalin generation in vivo.

Biometria ocular ultrassonográfica e dopplerfluxometria das artérias oftálmica interna e central da retina em macaco-prego (Sapajus spp)

Pós-graduação em Biotecnologia Animal - FMVZ

Twelve chromatically opponent ganglion cell types in turtle retina

The turtle retina has been extensively used for the study of chromatic processing mechanisms. Color opponency has been previously investigated with trichromatic paradigms, but behavioral studies show that the turtle has ail ultraviolet (UV) channel and a tetrachromatic visual system. Our laboratory has been working ill the characterization of neuronal responses in the retina of vertebrates using stimuli in the UV-visible range of the electromagnetic spectrum. In the present investigation, we recorded color-opponent responses from turtle amacrine and ganglion cells to UV and visible stimuli and extended our previous results that UV color-opponency is present at the level of the inner nuclear layer. We recorded from 181 neurons, 36 of which were spectrally opponent. Among these, there were 10 amacrine (5%), and 26 ganglion cells (15%). Morphological identification of color-opponent neurons was possible for two ganglion cell classes (G17 and G22) and two amacrine cell classes (A22 and A23b). There was a variety of cell response types and a potential for complex processing of chromatic stimuli, with intensity- and wavelength-dependent response components. Ten types of color opponency were found in ganglion cells and by adding previous results from our laboratory, 12 types of opponent responses have been found. The majority of the ganglion cells were R+UVBG- and RG+UVB-color-opponents but there were other less frequent types of chromatic opponency. This study confirms the participation of a UV channel in the processing of color opponency in the turtle inner retina and shows that the turtle visual system has the retinal mechanisms to allow many possible chromatic combinations.

No evidence of UV cone input to mono- and biphasic horizontal cells in the goldfish retina

Many animal species make use of ultraviolet (UV) light in a number of behaviors, such as feeding and mating. The goldfish (Carassius auratus) is among those with a UV photoreceptor and pronounced UV sensitivity. Little is known, however, about the retinal processing of this input. We addressed this issue by recording intracellularly from second-order neurons in the adult goldfish retina. In order to test whether cone-driven horizontal cells (HCs) receive UV cone inputs, we performed chromatic adaptation experiments with mono- and biphasic HCs. We found no functional evidence of a projection from the UV-sensitive cones to these neurons in adult animals. This suggests that goldfish UV receptors may contact preferentially triphasic HCs, which is at odds with the hypothesis that all cones contact all cone-driven HC types. However, we did find evidence of direct M-cone input to monophasic HCs, favoring the idea that cone-HC contacts are more promiscuous than originally proposed. Together, our results suggest that either UV cones have a more restricted set of post-synaptic partners than the other three cone types, or that the UV input to mono- and biphasic HCs is not very pronounced in adult animals.

C-Phycocyanin protects SH-SY5Y cells from oxidative injury, rat retina from transient ischemia and rat brain mitochondria from Ca2+/phosphate-induced impairment

Oxidative stress and mitochondrial impairment are essential in the ischemic stroke cascade and eventually lead to tissue injury. C-Phycocyanin (C-PC) has previously been shown to have strong antioxidant and neuroprotective actions. In the present study, we assessed the effects of C-PC on oxidative injury induced by tert-butylhydroperoxide (t-BOOH) in SH-SY5Y neuronal cells, on transient ischemia in rat retinas, and in the calcium/phosphate-induced impairment of isolated rat brain mitochondria (RBM). In SH-SY5Y cells, t-BOOH induced a significant reduction of cell viability as assessed by an MTT assay, and the reduction was effectively prevented by treatment with C-PC in the low micromolar concentration range. Transient ischemia in rat retinas was induced by increasing the intraocular pressure to 120 mmHg for 45 min, which was followed by 15 min of reperfusion. This event resulted in a cell density reduction to lower than 50% in the inner nuclear layer (INL), which was significantly prevented by the intraocular pre-treatment with C-PC for 15 min. In the RBM exposed to 3 mM phosphate and/or 100 mu M Ca2+, C-PC prevented in the low micromolar concentration range, the mitochondrial permeability transition as assessed by mitochondrial swelling, the membrane potential dissipation, the increase of reactive oxygen species levels and the release of the pro-apoptotic cytochrome c. In addition, C-PC displayed a strong inhibitory effect against an electrochemically-generated Fenton reaction. Therefore, C-PC is a potential neuroprotective agent against ischemic stroke, resulting in reduced neuronal oxidative injury and the protection of mitochondria from impairment. (C) 2012 Elsevier Inc. All rights reserved.

Dynamic Range of Vertebrate Retina Ganglion Cells: Importance of Active Dendrites and Coupling by Electrical Synapses

The vertebrate retina has a very high dynamic range. This is due to the concerted action of its diverse cell types. Ganglion cells, which are the output cells of the retina, have to preserve this high dynamic range to convey it to higher brain areas. Experimental evidence shows that the firing response of ganglion cells is strongly correlated with their total dendritic area and only weakly correlated with their dendritic branching complexity. On the other hand, theoretical studies with simple neuron models claim that active and large dendritic trees enhance the dynamic range of single neurons. Theoretical models also claim that electrical coupling between ganglion cells via gap junctions enhances their collective dynamic range. In this work we use morphologically reconstructed multi-compartmental ganglion cell models to perform two studies. In the first study we investigate the relationship between single ganglion cell dynamic range and number of dendritic branches/total dendritic area for both active and passive dendrites. Our results support the claim that large and active dendrites enhance the dynamic range of a single ganglion cell and show that total dendritic area has stronger correlation with dynamic range than with number of dendritic branches. In the second study we investigate the dynamic range of a square array of ganglion cells with passive or active dendritic trees coupled with each other via dendrodendritic gap junctions. Our results suggest that electrical coupling between active dendritic trees enhances the dynamic range of the ganglion cell array in comparison with both the uncoupled case and the coupled case with cells with passive dendrites. The results from our detailed computational modeling studies suggest that the key properties of the ganglion cells that endow them with a large dynamic range are large and active dendritic trees and electrical coupling via gap junctions.

Morphological evidence of neurotoxicity in retina after methylmercury exposure

The visual system is particularly sensitive to methylmercury (MeHg) exposure and, therefore, provides a useful model for investigating the fundamental mechanisms that direct toxic effects. During a period of 70 days, adult of a freshwater fish species Hoplias malabaricus were fed with fish prey previously labeled with two different doses of methylmercury (0.075 and 0.75 mu g g(-1)) to determine the mercury distribution and morphological changes in the retina. Mercury deposits were found in the photoreceptor layer, in the inner plexiform layer and in the outer plexiform layer, demonstrating a dose-dependent bioaccumulation. The ultrastructure analysis of retina revealed a cellular deterioration in the photoreceptor layer, morphological changes in the inner and outer segments of rods, structural changes in the plasma membrane of rods and double cones, changes in the process of removal of membranous discs and a structural discontinuity. These results lead to the conclusion that methylmercury is able to cross the blood-retina barrier, accumulate in the cells and layers of retina and induce changes in photoreceptors of H. malabaricus even under subchronic exposure. (c) 2012 Elsevier Inc. All rights reserved.

Molekulare Charakterisierung der Centrin-Isoformen in der Retina von Säugetieren

Centrine sind Mitglieder einer hoch konservierten Überfamilie von Ca2+-bindenden Proteinen mit EF-Hand Motiven. Bislang sind vier Centrin-Isoformen bei Säugern beschrieben worden, die in diversen Zellen in der Regel mit Centriolen von Centrosomen oder Centrosomen-verwandten Strukturen assoziiert sind. Im Rahmen der vorliegenden Dissertation wurden die vier Centrin-Isoformen bezüglich der Expression in verschiedenen Geweben untersucht. Dabei lag der Hauptfokus auf Untersuchungen der Centrine in den Photorezeptorzellen der Retina. Analysen auf subzellulärer Ebene brachten Klarheit über die differenzielle Lokalisation der verschiedenen Isoformen in der Retina. Mit Hilfe von verschiedenen Methoden konnten Wechselwirkungspartner in der Retina identifiziert werden, die eine Rolle in der visuellen Signaltransduktionskaskade spielen. Dabei könnten Centrine einem Regelmechanismus angehören, der wichtige Translokationsprozesse dieser Proteine regelt. In den Photorezeptorzellen der Säugetierretina werden die vier Isoformen exprimiert, die in den Strukturen des Cilienapparates differenziell lokalisiert sind. Dabei beschränkt sich ihre Lokalisation entweder auf den Basalkörper (Centrin 4), auf das Verbindungscilium (Centrin 1) oder sie sind in beiden Strukturen zu finden (Centrin 2 und 3). In den nicht- Photorezeptorzellen der Retina sind die Isoformen Centrin 2 und 3 zudem an den Centriolen der Centrosomen lokalisiert. In der vorliegenden Arbeit wurde zum ersten Mal gezeigt, dass alle Centrin-Isoformen in ein und derselben Zelle, der Photorezeptorzelle, koexprimiert werden und dabei subzellulär kolokalisiert sind. Im Weiteren konnte die ubiquitäre Expression von Centrin 2 und 3 in allen untersuchten Geweben an Centrosomen bestätigt werden. Centrin 1 und 4 hingegen werden nur in Geweben mit Cilien-tragenden Zellen exprimiert. Die Funktion der Centrine wird nicht nur durch Bindung von Ca2+, sondern auch durch Phosphorylierungen reguliert. Alle Sequenzen der Centrine weisen diverse mögliche Phosphorylierungsstellen für unterschiedliche Proteinkinasen auf. Die Ergebnisse aller durchgeführten in vitro und ex vivo Phosphorylierungs „Assays“ zeigen eine licht-abhängige Phosphorylierung der Centrin-Isoformen in der Retina. Dabei war in der dunkel-adaptierten Retina die Phosphorylierung vor allem von Centrin 1 und 2 erhöht. Weiterführende Experimente mit Kinase-Inhibitoren wiesen darauf hin, dass vor allem die Proteinkinase CKII eine bedeutende Rolle bei der Centrin-Phosphorylierung in der Retina einnimmt. Centrine sind die ersten Cytoskelettkomponenten, deren Phosphorylierungsgrad lichtabhängig moduliert wird. Diese Ergebnisse weisen auf einen Signalweg, der zwischen der visuellen Signaltransduktionskaskade und der Regulation der Centrin-Aktivität vermittelt, hin. Bei der Suche nach Centrin-Bindungspartnern gelang mit Hilfe von Centrin 1 Blot „Overlay Assays“ der Durchbruch. Der neuartige Ansatz zeigte, dass ausschließlich Ca2+-aktiviertes Centrin 1 mit Proteinen aus der Retina interagierte. Nach der Identifikation eines 37 kDa-Proteins als die β-Untereinheit des visuellen G-Proteins Transducin wurden die Untersuchungen auf diesen Interaktionspartner fokussiert. Die Ergebnisse der hier durchgeführten biochemischen und biophysikalischen Protein-Protein Interaktionsexperimente zeigen insgesamt folgendes: ⇒ Alle vier Centrine interagieren mit Transducin, wobei Centrin 3 die geringste Affinität zu Transducin hat. ⇒ Die Assemblierung der Centrin•G-Protein-Komplexe ist strikt Ca2+-abhängig. ⇒ Die Centrine binden sowohl an das isolierte Gtβγ-Heterodimer als auch an den heterotrimeren Gt-holo-Proteinkomplex, nicht aber an Gtα. Die quantitativen immunoelektronenmikroskopischen Analysen zeigen im Weiteren, dass sich die Komplexe aus Transducin und Centrin 1 bis 3 wahrscheinlich in einer Subdomäne des Verbindungsciliums der Photorezeptorzellen ausbilden. Dabei dürfte die Ausbildung der Komplexe an der Regulation der lichtinduzierten Translokation von Transducin zwischen Innen- und Außensegment der Photorezeptorzellen beteiligt sein. Dieser Translokationsmechanismus wird als ein wichtiger Bestandteil der Langzeitadaption der Signaltransduktionskaskade der Säugerretina diskutiert. Der neuartige Regelmechanismus der molekularen Translokationen, in dem Centrine involviert sind, ist außergewöhnlich und dürfte über die speziellen Photorezeptorzellen hinaus von weit reichender Bedeutung sein.

Distacco di retina e lavoro manuale: utilizzo delle schede di dimissione ospedaliera per uno studio di incidenza

Introduzione. La movimentazione manuale di carichi è stata recentemente proposta come un possibile determinante del distacco di retina. Al fine di confortare quest’ipotesi, sono stati analizzati i tassi di incidenza di distacco di retina regmatogeno (DRR) idiopatico, trattato chirurgicamente, tra i residenti in Toscana addetti ad attività lavorative manuali, non manuali e casalinghe. Metodi. Le schede di dimissione ospedaliera (SDO) della Toscana contengono anche informazioni codificate sulla categoria generica di impiego. Sono stati utilizzati i dati di tutti i pazienti residenti in Toscana con una SDO emessa da un qualsiasi ospedale italiano nel periodo 1997-2009, con diagnosi principale di DRR (ICD-9: 361,0-361,07 e 361,9) e con DRG 36 (“interventi sulla retina”). Dopo l’eliminazione dei soggetti che non soddisfacevano i criteri di eligibilità, è stato deciso di restringere la popolazione in studio ai soggetti di età 25-59 anni, successivamente classificati in addetti ad attività lavorative manuali, non manuali o casalinghe. Risultati. Sono stati identificati 1.946 casi. Tra gli uomini, gli addetti ad attività lavorative manuali hanno riportato un tasso di incidenza standardizzato per età 1,8 volte più alto rispetto agli addetti ad attività lavorative non manuali (17,4 [IC95%, 16,1–18,7] vs. 9,8 [IC95%, 8,8–10,8]). Tra le donne, i tassi di incidenza standardizzati per età erano 1,9 volte più alti negli addetti ad attività lavorative manuali (11,1 [IC95%, 9,8–12,3]) e 1,7 volte più alti nelle casalinghe (9,5 [IC95%, 8,3–10,8]) rispetto agli addetti ad attività lavorative non manuali (5,7 [IC95%, 4,8–6,6]). Conclusioni. Lo studio mette in evidenza come gli addetti ad attività lavorative manuali siano maggiormente affetti da DRR idiopatico rispetto agli addetti ad attività lavorative non manuali. Questi risultati supportano l’ipotesi che la movimentazione manuale di carichi, che difficilmente può ritrovarsi come compito di attività lavorative non manuali, possa avere un ruolo causale nella genesi della patologia.

Die organotypische Gewebekultur der adulten Retina als Analysesystem für funktionell intakte Photorezeptorzellen

Photorezeptorzellen der Vertebraten sind hoch spezialisierte, visuell sensorische Neurone in der Retina, die die Lichtinformation in ein neuronales Signal umwandeln. Durch ihre Einbindung in die Retina im Gesamtorgan Auge, sind Photorezeptorzellen im Organismus für zellbiologische Analysen, wie beispielsweise unter Einsatz pharmakologischer Substanzen, nur schwer zugänglich. Demgegenüber ist bei der Nutzung von Zellkulturtechniken eine Beeinflussung oder externe Manipulation von Zellen mit geringem Aufwand möglich. Bei Etablierungsversuchen von Primärkulturen von Photorezeptorzellen zeigte sich jedoch, dass diese rasch ihre spezifische Kompartimentierung und das damit verbundene (lichtsensitive) Funktionsvermögen verlieren. Eine Alternative zur Einzelzellkultur bietet die Kultivierung der Retina als organotypisches Gewebe, in der, durch den überlebenswichtigen Kontakt der retinalen Zellen zu einander, deren Morphologie und Funktionsvermögen erhalten bleibt. In der vorliegenden Arbeit konnte durch Optimierung der Kultivierungstechnik erstmals die adulte Retina für mehrere Tage intakt kultiviert und deren Vitalität und physiologische Aktivität nachgewiesen werden. Nach dem Nachweis der Eignung der organotypischen Retinakultur, stand diese nun für zellbiologische Analysen von Photorezeptorzellen zur Verfügung. Die Langzeitadaptation von Photorezeptorzellen geht einher mit der Translokation der Proteine Arrestin und Transducin. Doch sind die zugrunde liegenden molekularen Mechanismen dieser lichtabhängigen molekularen Bewegungen bislang noch nicht verstanden. Im Kontext der Diskussion um Diffusion oder aktivem Transport der genannten Translokationen, wurden in der vorliegenden Arbeit Experimente zur Abhängigkeit vom Cytoskelett durchgeführt. Die Ergebnisse zeigen, dass die gegensätzlichen Translokationen von Arrestin und Transducin während der Dunkeladaptation vom Aktin-, als auch Mikrotubulicytoskelett abhängig sind. Demgegenüber sind es die während der Helladaptation stattfindenden Translokationen nicht. Diese Befunde verweisen damit auf unterschiedliche Mechanismen für die untersuchten molekularen Bewegungen während der Dunkel- und Helladaptation, und das im Falle des Arrestins auch verschieden Mechanismen zusammen oder in einer Abfolge für die Bewegung durch verschiedene Zellkompartimente notwendig sind. Darüber hinaus konnte in der vorliegenden Arbeit die Eignung der Retinakulturtechnik für Gentransfers in retinale Zellen mittels verschiedener Methoden gezeigt werden. Die organotypische Gewebekultur der adulten Retina erweist sich als ein Analysesystem mit dem zellbiologische Untersuchungen an ausdifferenzierten Photorezeptorzellen durchgeführt werden können, die im lebenden Tier, bzw. der Zellkultur nicht möglich sind. Erfolgreiche Pharmakologische Beeinflussung, sowie Gentransfer in Zellen der Retinakultur prädestinieren die Retinakultur für zellbiologische und Proteinfunktionsanalysen. Dabei kann sie ferner als Modellsystem zur Evaluation von Therapiestrategien zu Retinadystrophien dienen und das ohne, oder zumindest in einer Reduktion von Tierversuchen.