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Sample records for cat retinal ganglion

  1. A new intraretinal recording system with multiple-barreled electrodes for pharmacological studies on cat retinal ganglion cells.

    Science.gov (United States)

    Takao, M; Wang1, Y; Miyoshi, T; Fujita, I; Fukuda, Y

    2000-04-01

    To overcome technical difficulties associated with in vivo intraretinal recordings of cat retinal ganglion cells (RGCs) with multiple-barreled electrodes, we developed a new guide-trocar system that consisted of a small-diameter and large-diameter pipes. We also improved the method to construct tungsten-in-glass multiple-barreled electrodes suitable for intraretinal recording from RGCs. Only the small-diameter pipe was inserted into the eye ball through the sclera, through which only the taper part of a multiple-barreled electrode pass. The large-diameter pipe stably held the electrode at its trunk and remained outside the eye ball. Insertion of only the small-diameter pipe minimized damages in the eye ball and prevented the eye ball movements while positioning the electrode. The system allowed us to keep the recordings stable for more than 1 h. Iontophoretically applied L-glutamate successfully activated RGCs of both X and Y types in the cat retina. PMID:10771079

  2. Intrinsically photosensitive retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    Gary; E.PICKARD; Patricia; J.SOLLARS

    2010-01-01

    A new mammalian photoreceptor was recently discovered to reside in the ganglion cell layer of the inner retina.These intrinsically photosensitive retinal ganglion cells(ipRGCs) express a photopigment,melanopsin,that confers upon them the ability to respond to light in the absence of all rod and cone photoreceptor input.Although relatively few in number,ipRGCs extend their dendrites across large expanses of the retina making them ideally suited to function as irradiance detectors to assess changes in ambient light levels.Phototransduction in ipRGCs appears to be mediated by transient receptor potential channels more closely resembling the phototransduction cascade of invertebrate rather than vertebrate photoreceptors.ipRGCs convey irradiance information centrally via the optic nerve to influence several functions.ipRGCs are the primary retinal input to the hypothalamic suprachiasmatic nucleus(SCN),a circadian oscillator and biological clock,and this input entrains the SCN to the day/night cycle.ipRGCs contribute irradiance signals that regulate pupil size and they also provide signals that interface with the autonomic nervous system to regulate rhythmic gene activity in major organs of the body.ipRGCs also provide excitatory drive to dopaminergic amacrine cells in the retina,providing a novel basis for the restructuring of retinal circuits by light.Here we review the ground-breaking discoveries,current progress and directions for future investigation.

  3. Melanopsin retinal ganglion cell loss in Alzheimer's disease

    DEFF Research Database (Denmark)

    La Morgia, Chiara; Ross-Cisneros, Fred N; Koronyo, Yosef;

    2015-01-01

    OBJECTIVE: Melanopsin retinal ganglion cells (mRGCs) are photoreceptors driving circadian photoentrainment, and circadian dysfunction characterizes Alzheimer's disease (AD). We investigated mRGCs in AD, hypothesizing their contribution to circadian dysfunction. METHODS: We assessed retinal nerve...

  4. Acquired retinal folds in the cat.

    Science.gov (United States)

    MacMillan, A D

    1976-06-01

    Retinal folds were found in 5 cats. The apparent cause of the folding was varied: in 1 cat the folds appeared after a localized retinal detachment; in 2 cats the condition accompanied other intraocular abnormalities associated with feline infectious peritonitis; 1 cat had active keratitis, and the retinal changes were thought to have been injury related; and 1 cat, bilaterally affected, had chronic glomerulonephritis. PMID:945253

  5. Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration

    OpenAIRE

    Nicolas Froger; Lucia Cadetti; Henri Lorach; Joao Martins; Alexis-Pierre Bemelmans; Elisabeth Dubus; Julie Degardin; Dorothée Pain; Valérie Forster; Laurent Chicaud; Ivana Ivkovic; Manuel Simonutti; Stéphane Fouquet; Firas Jammoul; Thierry Léveillard

    2012-01-01

    Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was inc...

  6. Retinal ganglion cell topography in juvenile Pacific bluefin tuna Thunnus orientalis (Temminck and Schlegel).

    Science.gov (United States)

    Miyazaki, Taeko

    2014-02-01

    The retinal ganglion cell distribution, which is known to reflect fish feeding behavior, was investigated in juvenile Pacific bluefin tuna Thunnus orientalis. During the course of examination, regularly arrayed cells with a distinctive larger soma, which may be regarded as motion-sensitive cells, were found. The topographical distribution of ordinary-sized ganglion cells, which is usually utilized to estimate fish visual axis and/or visual field characteristics, showed that the highest-density area, termed the area centralis, was localized in the ventral-temporal retina. The retinal topography of ordinary-sized ganglion cells seems to reflect the bluefin tuna's foraging behavior; while cruising, cells in the area centralis may signal potential prey, such as small schooling pelagic fishes or squids, that are present in the upward-forward direction. Judging from morphological characteristics, the large ganglion cells localized in the small temporal retinal area seem to be equivalent to physiologically categorized off-center Y-cells of cat, which are stimulated by a transient dark spot in a bright visual field. It was inferred that presumed large off-center cells in the temporal retina detect movements of agile prey animals escaping from bluefin tuna as a silhouette against environmental light. PMID:23775518

  7. Retinal glia promote dorsal root ganglion axon regeneration.

    Directory of Open Access Journals (Sweden)

    Barbara Lorber

    Full Text Available Axon regeneration in the adult central nervous system (CNS is limited by several factors including a lack of neurotrophic support. Recent studies have shown that glia from the adult rat CNS, specifically retinal astrocytes and Müller glia, can promote regeneration of retinal ganglion cell axons. In the present study we investigated whether retinal glia also exert a growth promoting effect outside the visual system. We found that retinal glial conditioned medium significantly enhanced neurite growth and branching of adult rat dorsal root ganglion neurons (DRG in culture. Furthermore, transplantation of retinal glia significantly enhanced regeneration of DRG axons past the dorsal root entry zone after root crush in adult rats. To identify the factors that mediate the growth promoting effects of retinal glia, mass spectrometric analysis of retinal glial conditioned medium was performed. Apolipoprotein E and secreted protein acidic and rich in cysteine (SPARC were found to be present in high abundance, a finding further confirmed by western blotting. Inhibition of Apolipoprotein E and SPARC significantly reduced the neuritogenic effects of retinal glial conditioned medium on DRG in culture, suggesting that Apolipoprotein E and SPARC are the major mediators of this regenerative response.

  8. Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells

    International Nuclear Information System (INIS)

    Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

  9. Processing of natural temporal stimuli by macaque retinal ganglion cells

    NARCIS (Netherlands)

    Hateren, J.H. van; Rüttiger, L.; Lee, B.B.

    2002-01-01

    This study quantifies the performance of primate retinal ganglion cells in response to natural stimuli. Stimuli were confined to the temporal and chromatic domains and were derived from two contrasting environments, one typically northern European and the other a flower show. The performance of the

  10. Expression of Aquaporin-6 in Rat Retinal Ganglion Cells.

    Science.gov (United States)

    Jang, Sun Young; Lee, Eung Suk; Ohn, Young-Hoon; Park, Tae Kwann

    2016-08-01

    Several aquaporins (AQPs) have been identified to be present in the eyes, and it has been suggested that they are involved in the movement of water and small solutes. AQP6, which has low water permeability and transports mainly anions, was recently discovered in the eyes. In the present study, we investigate the localization of AQP6 in the rat retina and show that AQP6 is selectively localized to the ganglion cell layer and the outer plexiform layer. Along with the gradual decrease in retinal ganglion cells after a crushing injury of optic nerve, immunofluorescence signals of AQP6 gradually decreased. Confocal microscope images confirmed AQP6 expression in retinal ganglion cells and Müller cells in vitro. Therefore, AQP6 might participate in water and anion transport in these cells. PMID:26526333

  11. Characterization of a transformed rat retinal ganglion cell line.

    Science.gov (United States)

    Krishnamoorthy, R R; Agarwal, P; Prasanna, G; Vopat, K; Lambert, W; Sheedlo, H J; Pang, I H; Shade, D; Wordinger, R J; Yorio, T; Clark, A F; Agarwal, N

    2001-01-31

    The purpose of the present study was to establish a rat retinal ganglion cell line by transformation of rat retinal cells. For this investigation, retinal cells were isolated from postnatal day 1 (PN1) rats and transformed with the psi2 E1A virus. In order to isolate retinal ganglion cells (RGC), single cell clones were chosen at random from the transformed cells. Expression of Thy-1 (a marker for RGC), glial fibrillary acidic protein (GFAP, a positive marker for Muller cells), HPC-1/syntaxin (a marker for amacrine cells), 8A1 (a marker for horizontal and ganglion cells) and neurotrophins was studied using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoblotting and immunocytochemistry. One of the retinal cell clones, designated RGC-5, was positive for Thy-1, Brn-3C, Neuritin, NMDA receptor, GABA-B receptor, and synaptophysin expression and negative for GFAP, HPC-1, and 8A1, suggesting that it represented a putative RGC clone. The results of RT-PCR analysis were confirmed by immunocytochemistry for Thy-1 and GFAP. Upon further characterization by immunoblotting, the RGC-5 clone was positive for Thy-1, negative for GFAP, 8A1 and syntaxin. RGC 5 cells were also positive for the expression of neurotrophins and their cognate receptors. To establish the physiological relevance of RGC-5, the effects of serum/trophic factor deprivation and glutamate toxicity were analyzed to determine if these cells would undergo apoptosis. The protective effects of neurotrophins on RGC-5 after serum deprivation was also investigated. Apoptosis was studied by terminal deoxynucleotidyl transferase-mediated fluoresceinated dUTP nick end labeling (TUNEL). Serum deprivation resulted in apoptosis and supplementation with both BDNF and NT-4 in the growth media, protected the RGC-5 cells from undergoing apoptosis. On differentiation with succinyl concanavalin A (sConA), RGC-5 cells became sensitive to glutamate toxicity, which could be reversed by inclusion of ciplizone (MK801

  12. The functional diversity of retinal ganglion cells in the mouse.

    Science.gov (United States)

    Baden, Tom; Berens, Philipp; Franke, Katrin; Román Rosón, Miroslav; Bethge, Matthias; Euler, Thomas

    2016-01-21

    In the vertebrate visual system, all output of the retina is carried by retinal ganglion cells. Each type encodes distinct visual features in parallel for transmission to the brain. How many such 'output channels' exist and what each encodes are areas of intense debate. In the mouse, anatomical estimates range from 15 to 20 channels, and only a handful are functionally understood. By combining two-photon calcium imaging to obtain dense retinal recordings and unsupervised clustering of the resulting sample of more than 11,000 cells, here we show that the mouse retina harbours substantially more than 30 functional output channels. These include all known and several new ganglion cell types, as verified by genetic and anatomical criteria. Therefore, information channels from the mouse eye to the mouse brain are considerably more diverse than shown thus far by anatomical studies, suggesting an encoding strategy resembling that used in state-of-the-art artificial vision systems. PMID:26735013

  13. The functional diversity of retinal ganglion cells in the mouse.

    Science.gov (United States)

    Baden, Tom; Berens, Philipp; Franke, Katrin; Román Rosón, Miroslav; Bethge, Matthias; Euler, Thomas

    2016-01-21

    In the vertebrate visual system, all output of the retina is carried by retinal ganglion cells. Each type encodes distinct visual features in parallel for transmission to the brain. How many such 'output channels' exist and what each encodes are areas of intense debate. In the mouse, anatomical estimates range from 15 to 20 channels, and only a handful are functionally understood. By combining two-photon calcium imaging to obtain dense retinal recordings and unsupervised clustering of the resulting sample of more than 11,000 cells, here we show that the mouse retina harbours substantially more than 30 functional output channels. These include all known and several new ganglion cell types, as verified by genetic and anatomical criteria. Therefore, information channels from the mouse eye to the mouse brain are considerably more diverse than shown thus far by anatomical studies, suggesting an encoding strategy resembling that used in state-of-the-art artificial vision systems.

  14. Retinal Ganglion Cell Loss in Diabetes Associated with Elevated Homocysteine

    Directory of Open Access Journals (Sweden)

    Kenneth S. Shindler

    2009-11-01

    Full Text Available A number of studies have suggested that homocysteine may be a contributing factor to development of retinopathy in diabetic patients based on observed correlations between elevated homocysteine levels and the presence of retinopathy. The significance of such a correlation remains to be determined, and potential mechanisms by which homocysteine might induce retinopathy have not been well characterized. Ganapathy and colleagues1 used mutant mice that have endogenously elevated homocysteine levels due to heterozygous deletion of the cystathionine-β-synthase gene to examine changes in retinal pathology following induction of diabetes. Their finding that elevated homocysteine levels hastens loss of cells in the retinal ganglion cell layer suggests that toxicity to ganglion cells may warrant further investigation as a potential mechanism of homocysteine enhanced susceptibility to diabetic retinopathy.

  15. Intrinsically photosensitive retinal ganglion cell function in relation to age

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik;

    2012-01-01

    The activity of melanopsin containing intrinsically photosensitive ganglion retinal cells (ipRGC) can be assessed by a means of pupil responses to bright blue (appr.480 nm) light. Due to age related factors in the eye, particularly, structural changes of the lens, less light reaches retina. The aim...... of this study was to examine how age and in vivo measured lens transmission of blue light might affect pupil light responses, in particular, mediated by the ipRGC....

  16. Veratridine increases the survival of retinal ganglion cells in vitro

    Directory of Open Access Journals (Sweden)

    S.P.F. Pereira

    1997-12-01

    Full Text Available Neuronal cell death is an important phenomenon involving many biochemical pathways. This degenerative event has been studied to understand how the cells activate the mechanisms that lead to self-destruction. Target cells and afferent cells play a relevant role in the regulation of natural cell death. We studied the effect of veratridine (1.5, 3.0, 4.5 and 6.0 µM on the survival of neonatal rat retinal ganglion cells in vitro. Veratridine (3.0 µM, a well-known depolarizing agent that opens the Na+ channel, promoted a two-fold increase in the survival of retinal ganglion cells kept in culture for 48 h. This effect was dose-dependent and was blocked by 1.0 µM tetrodotoxin (a classical voltage-dependent Na+ channel blocker and 30.0 µM flunarizine (a Na+ and Ca2+ channel blocker. These results indicate that electrical activity is also important for the maintenance of retinal ganglion cell survival in vitro

  17. Retinal ganglion cell distribution and spatial resolving power in elasmobranchs.

    Science.gov (United States)

    Lisney, Thomas J; Collin, Shaun P

    2008-01-01

    The total number, distribution and peak density of presumed retinal ganglion cells was assessed in 10 species of elasmobranch (nine species of shark and one species of batoid) using counts of Nissl-stained cells in retinal wholemounts. The species sampled include a number of active, predatory benthopelagic and pelagic sharks that are found in a variety of coastal and oceanic habitats and represent elasmobranch groups for which information of this nature is currently lacking. The topographic distribution of cells was heterogeneous in all species. Two benthic species, the shark Chiloscyllium punctatum and the batoid Taeniura lymma, have a dorsal or dorso-central horizontal streak of increased cell density, whereas the majority of the benthopelagic and pelagic sharks examined exhibit a more concentric pattern of increasing cell density, culminating in a central area centralis of higher cell density located close to the optic nerve head. The exception is the shark Alopias superciliosus, which possesses a ventral horizontal streak. Variation in retinal ganglion cell topography appears to be related to the visual demands of different habitats and lifestyles, as well as the positioning of the eyes in the head. The upper limits of spatial resolving power were calculated for all 10 species, using peak ganglion cell densities and estimates of focal length taken from cryo-sectioned eyes in combination with information from the literature. Spatial resolving power ranged from 2.02 to 10.56 cycles deg(-1), which is in accordance with previous studies. Species with a lower spatial resolving power tend to be benthic and/or coastal species that feed on benthic invertebrates and fishes. Active, benthopelagic and pelagic species from more oceanic habitats which feed on larger, more active prey, possess a higher resolving power. Additionally, ganglion cells in a juvenile of C. punctatum, were retrogradely-labeled from the optic nerve with biotinylated dextran amine (BDA). A comparison

  18. Agmatine protects retinal ganglion cells from hypoxia-induced apoptosis in transformed rat retinal ganglion cell line

    Directory of Open Access Journals (Sweden)

    Kim Chan

    2007-10-01

    Full Text Available Abstract Background Agmatine is an endogenous polyamine formed by the decarboxylation of L-arginine. We investigated the protective effects of agmatine against hypoxia-induced apoptosis of immortalized rat retinal ganglion cells (RGC-5. RGC-5 cells were cultured in a closed hypoxic chamber (5% O2 with or without agmatine. Cell viability was determined by lactate dehydrogenase (LDH assay and apoptosis was examined by annexin V and caspase-3 assays. Expression and phosphorylation of mitogen-activated protein kinases (MAPKs; JNK, ERK p44/42, and p38 and nuclear factor-kappa B (NF-κB were investigated by Western immunoblot analysis. The effects of agmatine were compared to those of brain-derived neurotrophic factor (BDNF, a well-known protective neurotrophin for retinal ganglion cells. Results After 48 hours of hypoxic culture, the LDH assay showed 52.3% cell loss, which was reduced to 25.6% and 30.1% when agmatine and BDNF were administered, respectively. This observed cell loss was due to apoptotic cell death, as established by annexin V and caspase-3 assays. Although total expression of MAPKs and NF-κB was not influenced by hypoxic injury, phosphorylation of these two proteins was increased. Agmatine reduced phosphorylation of JNK and NF-κB, while BDNF suppressed phosphorylation of ERK and p38. Conclusion Our results show that agmatine has neuroprotective effects against hypoxia-induced retinal ganglion cell damage in RGC-5 cells and that its effects may act through the JNK and NF-κB signaling pathways. Our data suggest that agmatine may lead to a novel therapeutic strategy to reduce retinal ganglion cell injury related to hypoxia.

  19. Taurine provides neuroprotection against retinal ganglion cell degeneration.

    Science.gov (United States)

    Froger, Nicolas; Cadetti, Lucia; Lorach, Henri; Martins, Joao; Bemelmans, Alexis-Pierre; Dubus, Elisabeth; Degardin, Julie; Pain, Dorothée; Forster, Valérie; Chicaud, Laurent; Ivkovic, Ivana; Simonutti, Manuel; Fouquet, Stéphane; Jammoul, Firas; Léveillard, Thierry; Benosman, Ryad; Sahel, José-Alain; Picaud, Serge

    2012-01-01

    Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases. PMID:23115615

  20. Taurine provides neuroprotection against retinal ganglion cell degeneration.

    Directory of Open Access Journals (Sweden)

    Nicolas Froger

    Full Text Available Retinal ganglion cell (RGC degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats. After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%, whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases.

  1. Taurine provides neuroprotection against retinal ganglion cell degeneration.

    Science.gov (United States)

    Froger, Nicolas; Cadetti, Lucia; Lorach, Henri; Martins, Joao; Bemelmans, Alexis-Pierre; Dubus, Elisabeth; Degardin, Julie; Pain, Dorothée; Forster, Valérie; Chicaud, Laurent; Ivkovic, Ivana; Simonutti, Manuel; Fouquet, Stéphane; Jammoul, Firas; Léveillard, Thierry; Benosman, Ryad; Sahel, José-Alain; Picaud, Serge

    2012-01-01

    Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases.

  2. Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration

    Science.gov (United States)

    Froger, Nicolas; Cadetti, Lucia; Lorach, Henri; Martins, Joao; Bemelmans, Alexis-Pierre; Dubus, Elisabeth; Degardin, Julie; Pain, Dorothée; Forster, Valérie; Chicaud, Laurent; Ivkovic, Ivana; Simonutti, Manuel; Fouquet, Stéphane; Jammoul, Firas; Léveillard, Thierry; Benosman, Ryad; Sahel, José-Alain; Picaud, Serge

    2012-01-01

    Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases. PMID:23115615

  3. Melanopsin retinal ganglion cell loss in Alzheimer disease

    Science.gov (United States)

    Ross‐Cisneros, Fred N.; Koronyo, Yosef; Hannibal, Jens; Gallassi, Roberto; Cantalupo, Gaetano; Sambati, Luisa; Pan, Billy X.; Tozer, Kevin R.; Barboni, Piero; Provini, Federica; Avanzini, Pietro; Carbonelli, Michele; Pelosi, Annalisa; Chui, Helena; Liguori, Rocco; Baruzzi, Agostino; Koronyo‐Hamaoui, Maya; Sadun, Alfredo A.; Carelli, Valerio

    2015-01-01

    Objective Melanopsin retinal ganglion cells (mRGCs) are photoreceptors driving circadian photoentrainment, and circadian dysfunction characterizes Alzheimer disease (AD). We investigated mRGCs in AD, hypothesizing that they contribute to circadian dysfunction. Methods We assessed retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT) in 21 mild‐moderate AD patients, and in a subgroup of 16 we evaluated rest–activity circadian rhythm by actigraphy. We studied postmortem mRGCs by immunohistochemistry in retinas, and axons in optic nerve cross‐sections of 14 neuropathologically confirmed AD patients. We coimmunostained for retinal amyloid β (Aβ) deposition and melanopsin to locate mRGCs. All AD cohorts were compared with age‐matched controls. Results We demonstrated an age‐related optic neuropathy in AD by OCT, with a significant reduction of RNFL thickness (p = 0.038), more evident in the superior quadrant (p = 0.006). Axonal loss was confirmed in postmortem AD optic nerves. Abnormal circadian function characterized only a subgroup of AD patients. Sleep efficiency was significantly reduced in AD patients (p = 0.001). We also found a significant loss of mRGCs in postmortem AD retinal specimens (p = 0.003) across all ages and abnormal mRGC dendritic morphology and size (p = 0.003). In flat‐mounted AD retinas, Aβ accumulation was remarkably evident inside and around mRGCs. Interpretation We show variable degrees of rest–activity circadian dysfunction in AD patients. We also demonstrate age‐related loss of optic nerve axons and specifically mRGC loss and pathology in postmortem AD retinal specimens, associated with Aβ deposition. These results all support the concept that mRGC degeneration is a contributor to circadian rhythm dysfunction in AD. ANN NEUROL 2016;79:90–109 PMID:26505992

  4. Atoh7 promotes the differentiation of retinal stem cells derived from Müller cells into retinal ganglion cells by inhibiting Notch signaling

    OpenAIRE

    Song, Wei-tao; Zhang, Xue-yong; Xia, Xiao-Bo

    2013-01-01

    Introduction Retinal Müller cells exhibit the characteristics of retinal progenitor cells, and differentiate into ganglion cells under certain conditions. However, the number of ganglion cells differentiated from retinal Müller cells falls far short of therapeutic needs. This study aimed to develop a novel protocol to promote the differentiation of retinal Müller cells into ganglion cells and explore the underlying signaling mechanisms. Methods Müller cells were isolated and purified from rat...

  5. Contrast Adaptation Decreases Complexity in Retinal Ganglion Cell Spike Train

    Institute of Scientific and Technical Information of China (English)

    WANG Guang-Li; HUANG Shi-Yong; ZHANG Ying-Ying; LIANG Pei-Ji

    2007-01-01

    @@ The difference in temporal structures of retinal ganglion cell spike trains between spontaneous activity and firing activity after contrast adaptation is investigated. The Lempel-Ziv complexity analysis reveals that the complexity of the neural spike train decreases after contrast adaptation. This implies that the behaviour of the neuron becomes ordered, which may carry relevant information about the external stimulus. Thus, during the neuron activity after contrast adaptation, external information could be encoded in forms of some certain patterns in the temporal structure of spike train that is significantly different, compared to that of the spike train during spontaneous activity, although the firing rates in spontaneous activity and firing activity after contrast adaptation are sometime similar.

  6. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice

    OpenAIRE

    John Martin Barrett; Patrick Degenaar

    2015-01-01

    Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was ...

  7. Enriched retinal ganglion cells derived from human embryonic stem cells.

    Science.gov (United States)

    Gill, Katherine P; Hung, Sandy S C; Sharov, Alexei; Lo, Camden Y; Needham, Karina; Lidgerwood, Grace E; Jackson, Stacey; Crombie, Duncan E; Nayagam, Bryony A; Cook, Anthony L; Hewitt, Alex W; Pébay, Alice; Wong, Raymond C B

    2016-01-01

    Optic neuropathies are characterised by a loss of retinal ganglion cells (RGCs) that lead to vision impairment. Development of cell therapy requires a better understanding of the signals that direct stem cells into RGCs. Human embryonic stem cells (hESCs) represent an unlimited cellular source for generation of human RGCs in vitro. In this study, we present a 45-day protocol that utilises magnetic activated cell sorting to generate enriched population of RGCs via stepwise retinal differentiation using hESCs. We performed an extensive characterization of these stem cell-derived RGCs by examining the gene and protein expressions of a panel of neural/RGC markers. Furthermore, whole transcriptome analysis demonstrated similarity of the hESC-derived RGCs to human adult RGCs. The enriched hESC-RGCs possess long axons, functional electrophysiological profiles and axonal transport of mitochondria, suggestive of maturity. In summary, this RGC differentiation protocol can generate an enriched population of functional RGCs from hESCs, allowing future studies on disease modeling of optic neuropathies and development of cell therapies. PMID:27506453

  8. Imaging retinal ganglion cells: enabling experimental technology for clinical application.

    Science.gov (United States)

    Smith, Corey A; Chauhan, Balwantray C

    2015-01-01

    Recent advances in clinical ophthalmic imaging have enhanced patient care. However, the ability to differentiate retinal neurons, such as retinal ganglion cells (RGCs), would advance many areas within ophthalmology, including the screening and monitoring of glaucoma and other optic neuropathies. Imaging at the single cell level would take diagnostics to the next level. Experimental methods have provided techniques and insight into imaging RGCs, however no method has yet to be translated to clinical application. This review provides an overview of the importance of non-invasive imaging of RGCs and the clinically relevant capabilities. In addition, we report on experimental data from wild-type mice that received an in vivo intravitreal injection of a neuronal tracer that labelled RGCs, which in turn were monitored for up to 100 days post-injection with confocal scanning laser ophthalmoscopy. We were able to demonstrate efficient and consistent RGC labelling with this delivery method and discuss the issue of cell specificity. This type of experimental work is important in progressing towards clinically applicable methods for monitoring loss of RGCs in glaucoma and other optic neuropathies. We discuss the challenges to translating these findings to clinical application and how this method of tracking RGCs in vivo could provide valuable structural and functional information to clinicians. PMID:25448921

  9. Activation of Neuropeptide Y Receptors Modulates Retinal Ganglion Cell Physiology and Exerts Neuroprotective Actions In Vitro

    DEFF Research Database (Denmark)

    Martins, João; Elvas, Filipe; Brudzewsky, Dan;

    2015-01-01

    Neuropeptide Y (NPY) is expressed in mammalian retina but the location and potential modulatory effects of NPY receptor activation remain largely unknown. Retinal ganglion cell (RGC) death is a hallmark of several retinal degenerative diseases, particularly glaucoma. Using purified RGCs and ex vivo...

  10. Caspase-dependent retinal ganglion cell apoptosis in the rat model of acute diabetes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background Neural apoptosis is generally believed to be mediated by two distinct pathways, caspase-dependant and caspase-independent pathways. This study investigated the apoptotic pathways involved in retinal ganglion ceils in acute diabetes in rats. Methods Diabetes was induced in male Wistar rats by a peritoneal injection of streptozotocin (STZ). Expression and localization of caspase-3 and apoptosis-inducing factor (AIF) proteins in the retina of diabetic rats was examined by Western blotting and immunohistochemistry analyses. Terminal transferase dUTP nick end labeling (TUNEL) assay and immunofluorescent staining specific for caspase-3 and AIF were applied to analyze for apoptosis of retinal ganglion cells. In addition, a caspase-3 inhibitor DEVD-CHO was injected intravitreally to further determine the apoptotic pathways of retinal ganglion cells triggered in acute diabetes. Results Two weeks after induction of diabetes, a significant increase in caspase-3 protein expression and localization occurred in the nerve fiber layer, ganglion cell layer, and inner plexiform layer of the retina. Four weeks after the onset of diabetes, the increase in caspase-3 expression was profound eight weeks postinduction of diabetes (P<0.05). Meanwhile, no AIF protein expression was detected in this study. In addition, intravitreal administration of the caspase-3 inhibitor DEVD-CHO reduced apoptosis of retinal ganglion cells by its direct inhibitory action on caspase-3. Conclusion Caspase-dependent apoptotic pathways may be the main stimulant of STZ-induced retinal ganglion cell apoptosis in acute diabetes.

  11. Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    L.D. Loopuijt

    2007-10-01

    Full Text Available To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37 on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 µm ("thin" or "thick" dendrites, respectively. Three cells (4.5% were bistratified, having thick dendrites, and the others (95.5% were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40% and 2 groups with inner (50-100% stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.

  12. Functional Characterization of Retinal Ganglion Cells in the Wild-Type and Mutant Mouse

    OpenAIRE

    Ng, Arash

    2014-01-01

    The retina extracts relevant features from the visual scene and transmits these features to the brain through separate pathways that will eventually result in the perception of sight. The retinal ganglion cells (RGCs) are the only retinal cell type to send an axonal projection to the brain. This indicates that the signals generated by the RGCs are the end result of retinal processing, and the features detected by the RGCs are all that will be transmitted to the brain about the visual environm...

  13. Chicken retinal ganglion cells response characteristics: multi-channel electrode recording study

    Institute of Scientific and Technical Information of China (English)

    陈爱华; 周艺; 龚海庆; 梁培基

    2003-01-01

    The first stage of visual processing occurs in the retina, the function of which is to process the raw information obtained from the outside world. In the present study, the electrical activities of a group of retinal ganglion cells were recorded from a small functioning piece of retina, using multi-electrode array (MEA), and the action potentials were detected by applying nonlinear algorithm. By analyzing the ensemble retinal ganglion output characteristics, it is revealed that both firing rates and correlated activity between adjacent neurons in the retina contribute to visual information encoding.

  14. Can retinal ganglion cell dipoles seed iso-orientation domains in the visual cortex?

    Directory of Open Access Journals (Sweden)

    Manuel Schottdorf

    Full Text Available It has been argued that the emergence of roughly periodic orientation preference maps (OPMs in the primary visual cortex (V1 of carnivores and primates can be explained by a so-called statistical connectivity model. This model assumes that input to V1 neurons is dominated by feed-forward projections originating from a small set of retinal ganglion cells (RGCs. The typical spacing between adjacent cortical orientation columns preferring the same orientation then arises via Moiré-Interference between hexagonal ON/OFF RGC mosaics. While this Moiré-Interference critically depends on long-range hexagonal order within the RGC mosaics, a recent statistical analysis of RGC receptive field positions found no evidence for such long-range positional order. Hexagonal order may be only one of several ways to obtain spatially repetitive OPMs in the statistical connectivity model. Here, we investigate a more general requirement on the spatial structure of RGC mosaics that can seed the emergence of spatially repetitive cortical OPMs, namely that angular correlations between so-called RGC dipoles exhibit a spatial structure similar to that of OPM autocorrelation functions. Both in cat beta cell mosaics as well as primate parasol receptive field mosaics we find that RGC dipole angles are spatially uncorrelated. To help assess the level of these correlations, we introduce a novel point process that generates mosaics with realistic nearest neighbor statistics and a tunable degree of spatial correlations of dipole angles. Using this process, we show that given the size of available data sets, the presence of even weak angular correlations in the data is very unlikely. We conclude that the layout of ON/OFF ganglion cell mosaics lacks the spatial structure necessary to seed iso-orientation domains in the primary visual cortex.

  15. Ganglion cell distribution and retinal resolution in the Florida manatee, Trichechus manatus latirostris.

    Science.gov (United States)

    Mass, Alla M; Ketten, Darlene R; Odell, Daniel K; Supin, Alexander Ya

    2012-01-01

    The topographic organization of retinal ganglion cells was examined in the Florida manatee (Trichechus manatus latirostris) to assess ganglion cell size and distribution and to estimate retinal resolution. The ganglion cell layer of the manatee's retina was comprised primarily of large neurons with broad intercellular spaces. Cell sizes varied from 10 to 60 μm in diameter (mean 24.3 μm). The retinal wholemounts from adult animals measured 446-501 mm(2) in area with total ganglion cell counts of 62,000-81,800 (mean 70,200). The cell density changed across the retina, with the maximum in the area below the optic disc and decreasing toward the retinal edges and in the immediate vicinity of the optic disc. The maximum cell density ranged from 235 to 337 cells per millimeter square in the adult retinae. Two wholemounts obtained from juvenile animals were 271 and 282 mm(2) in area with total cell numbers of 70,900 and 68,700, respectively (mean 69,800), that is, nearly equivalent to those of adults, but juvenile retinae consequently had maximum cell densities that were higher than those of adults: 478 and 491 cells per millimeter square. Calculations indicate a retinal resolution of ∼19' (1.6 cycles per degree) in both adult and juvenile retinae. PMID:21964938

  16. Ganglion cell distribution and retinal resolution in the Florida manatee, Trichechus manatus latirostris.

    Science.gov (United States)

    Mass, Alla M; Ketten, Darlene R; Odell, Daniel K; Supin, Alexander Ya

    2012-01-01

    The topographic organization of retinal ganglion cells was examined in the Florida manatee (Trichechus manatus latirostris) to assess ganglion cell size and distribution and to estimate retinal resolution. The ganglion cell layer of the manatee's retina was comprised primarily of large neurons with broad intercellular spaces. Cell sizes varied from 10 to 60 μm in diameter (mean 24.3 μm). The retinal wholemounts from adult animals measured 446-501 mm(2) in area with total ganglion cell counts of 62,000-81,800 (mean 70,200). The cell density changed across the retina, with the maximum in the area below the optic disc and decreasing toward the retinal edges and in the immediate vicinity of the optic disc. The maximum cell density ranged from 235 to 337 cells per millimeter square in the adult retinae. Two wholemounts obtained from juvenile animals were 271 and 282 mm(2) in area with total cell numbers of 70,900 and 68,700, respectively (mean 69,800), that is, nearly equivalent to those of adults, but juvenile retinae consequently had maximum cell densities that were higher than those of adults: 478 and 491 cells per millimeter square. Calculations indicate a retinal resolution of ∼19' (1.6 cycles per degree) in both adult and juvenile retinae.

  17. Effects of Indocyanine green on cultured retinal ganglion cells in-vitro

    Directory of Open Access Journals (Sweden)

    Murthy Ravi K

    2009-11-01

    Full Text Available Abstract Background Indocyanine green (ICG dye is commonly used to stain the inner limiting membrane during macular surgery. There are reports documenting the toxicity of ICG on retinal pigment epithelial cells, with conflicting results in retinal ganglion cells. In the present study, we evaluated the effect of ICG on retinal ganglion cells in vitro. Cultured rat retinal ganglion cells (RGC-5 were exposed to different concentrations of ICG (0.25, 0.5, 1.0, 1.25, & 5 mg/ml and at various time intervals (1, 5, 15, 30, & 60 minutes. Changes in structural morphology were identified using phase contrast bright field microscopy. Cell viability was quantified using the neutral red assay and cell death was characterized using Annexin-V staining. Findings Significant morphologic changes were observed at the 15 and 60 min intervals for all concentrations, where a reduction in cell size and loss of normal spindle shape was noted. A dose dependent decrease in cell viability was observed with increasing concentration of ICG as well as increasing exposure intervals. Compared to control, 48-74% reduction in neutral red uptake at all concentrations for exposures 5 min or greater (p Conclusion ICG dye exhibits toxicity to retinal ganglion cells at clinically relevant doses following 1 min exposure.

  18. Neuroprotective Effect of Melatonin on Retinal Ganglion Cells in Rats

    Institute of Scientific and Technical Information of China (English)

    TANG Qiongyan; HU Yizhen; CAO Yang

    2006-01-01

    To investigate the neuroprotective effect of melatonin (MT) on retinal ganglion cells (RGCs) in rats with ischemia reperfusion injury (RIR), 24 healthy SD rats were randomly divided into two groups:group A and group B. RIR model was induced in the left eyes by increasing the pressure of the anterior chamber. Group A was treated with 10 % alcohol- normal saline (1 mL/kg/d, ip), while group B was treated with 0.5 % MT (1 mL/kg/d, ip). On the basis of the time interval between the left eyes RIR and the sacrifice, rats in both group A and group B were further divided into 3 subgroups: groups A1 and B1 (days 7), groups A2 and B2 (days 14), groups A3 and B3 (days 30), with4 rats in each subgroup. 7 day before the sacrifice, 3 % fluorogold was bilaterally injected into superior colliculi and geniculate body. The eyes were enucleated after being sacrificed, and mounting of the retina from both eyes was performed on a slide and observed under a fluorescence microscope. Four photos were taken from each of the four quadrants of the retina.The labeled-RGCs were counted by using a computerized image analyzer. The rate of the labeledRGCs was used for statistical analysis. Our results showed that, in group A, the rate of the labeled-RGCs was (77. 16±6.35) %, (65.53±7.01) %, (53.85±4.38) % on day 7, 14 and 30.In group B, the rate of the labeled-RGCs was (81.33±9.27) %, (79.80±8.36) %, (80.34±11.05) % on day 7, 14 and 30. In group B, which was treated with MT after RIR, the rate of labeled-RGCs was significantly higher than that of group A on day 14 and day 30 (P<0.05). It is concluded that, in the RIR rats, MT therapy could increase the survival rate of the RGCs and could rescue and restore the injured RGCs.

  19. Overexpression of Pax6 results in microphthalmia, retinal dysplasia and defective retinal ganglion cell axon guidance

    Directory of Open Access Journals (Sweden)

    Jeffery Glen

    2008-05-01

    Full Text Available Abstract Background The transcription factor Pax6 is expressed by many cell types in the developing eye. Eyes do not form in homozygous loss-of-function mouse mutants (Pax6Sey/Sey and are abnormally small in Pax6Sey/+ mutants. Eyes are also abnormally small in PAX77 mice expressing multiple copies of human PAX6 in addition to endogenous Pax6; protein sequences are identical in the two species. The developmental events that lead to microphthalmia in PAX77 mice are not well-characterised, so it is not clear whether over- and under-expression of Pax6/PAX6 cause microphthalmia through similar mechanisms. Here, we examined the consequences of over-expression for the eye and its axonal connections. Results Eyes form in PAX77+/+ embryos but subsequently degenerate. At E12.5, we found no abnormalities in ocular morphology, retinal cell cycle parameters and the incidence of retinal cell death. From E14.5 on, we observed malformations of the optic disc. From E16.5 into postnatal life there is progressively more severe retinal dysplasia and microphthalmia. Analyses of patterns of gene expression indicated that PAX77+/+ retinae produce a normal range of cell types, including retinal ganglion cells (RGCs. At E14.5 and E16.5, quantitative RT-PCR with probes for a range of molecules associated with retinal development showed only one significant change: a slight reduction in levels of mRNA encoding the secreted morphogen Shh at E16.5. At E16.5, tract-tracing with carbocyanine dyes in PAX77+/+ embryos revealed errors in intraretinal navigation by RGC axons, a decrease in the number of RGC axons reaching the thalamus and an increase in the proportion of ipsilateral projections among those RGC axons that do reach the thalamus. A survey of embryos with different Pax6/PAX6 gene dosage (Pax6Sey/+, Pax6+/+, PAX77+ and PAX77+/+ showed that (1 the total number of RGC axons projected by the retina and (2 the proportions that are sorted into the ipsilateral and

  20. Cellular Origin of Spontaneous Ganglion Cell Spike Activity in Animal Models of Retinitis Pigmentosa

    OpenAIRE

    Margolis, David J.; Detwiler, Peter B.

    2011-01-01

    Here we review evidence that loss of photoreceptors due to degenerative retinal disease causes an increase in the rate of spontaneous ganglion spike discharge. Information about persistent spike activity is important since it is expected to add noise to the communication between the eye and the brain and thus impact the design and effective use of retinal prosthetics for restoring visual function in patients blinded by disease. Patch-clamp recordings from identified types of ON and OFF retina...

  1. Changes in ganglion cell physiology during retinal degeneration influence excitability by prosthetic electrodes

    Science.gov (United States)

    Cho, Alice; Ratliff, Charles; Sampath, Alapakkam; Weiland, James

    2016-04-01

    Objective. Here we investigate ganglion cell physiology in healthy and degenerating retina to test its influence on threshold to electrical stimulation. Approach. Age-related Macular Degeneration and Retinitis Pigmentosa cause blindness via outer retinal degeneration. Inner retinal pathways that transmit visual information to the central brain remain intact, so direct electrical stimulation from prosthetic devices offers the possibility for visual restoration. Since inner retinal physiology changes during degeneration, we characterize physiological properties and responses to electrical stimulation in retinal ganglion cells (RGCs) of both wild type mice and the rd10 mouse model of retinal degeneration. Main results. Our aggregate results support previous observations that elevated thresholds characterize diseased retinas. However, a physiology-driven classification scheme reveals distinct sub-populations of ganglion cells with thresholds either normal or strongly elevated compared to wild-type. When these populations are combined, only a weakly elevated threshold with large variance is observed. The cells with normal threshold are more depolarized at rest and exhibit periodic oscillations. Significance. During degeneration, physiological changes in RGCs affect the threshold stimulation currents required to evoke action potentials.

  2. Detecting Determinism in Firing Activities of Retinal Ganglion Cells during Response to Complex Stimuli

    Institute of Scientific and Technical Information of China (English)

    CAI Chao-Feng; ZHANG Ying-Ying; LIU Xue; LIANG Pei-Ji; ZHANG Pu-Ming

    2008-01-01

    Complex stimuli are used to probe the response properties of the chicken's retinal ganglion cells (GCs). Thecorrelation dimension method and the nonlinear forecasting method are applied to detect the determinism in the firing activities of the retinal GCs during response to complex stimuli.The inter-spike interval (ISI) series and the first difference of the ISI (DISI) series are analysed.Two conclusions are drawn.Firstly,the first difference operation of the ISI series makes it comparatively easier for determinism detection in the firing activities of retinal GCs.Secondly,the nonlinear forecasting method is more efficient and reliable than the correlation dimension method for determinism detection.

  3. Brimonidine prevents axonal and somatic degeneration of retinal ganglion cell neurons

    Directory of Open Access Journals (Sweden)

    Crish Samuel D

    2011-01-01

    Full Text Available Abstract Background Brimonidine is a common drug for lowering ocular pressure and may directly protect retinal ganglion cells in glaucoma. The disease involves early loss of retinal ganglion cell transport to brain targets followed by axonal and somatic degeneration. We examined whether brimonidine preserves ganglion cell axonal transport and abates degeneration in rats with elevated ocular pressure induced by laser cauterization of the episcleral veins. Results Ocular pressure was elevated unilaterally by 90% for a period of 8 weeks post- cauterization. During this time, brimonidine (1mg/kg/day or vehicle (phosphate-buffered saline was delivered systemically and continuously via subcutaneous pump. Animals received bilateral intravitreal injections of fluorescent cholera toxin subunit β (CTB two days before sacrifice to assess anterograde transport. In retinas from the vehicle group, elevated pressure induced a 44% decrease in the fraction of ganglion cells with intact uptake of CTB and a 14-42% reduction in the number of immuno-labelled ganglion cell bodies, with the worst loss occurring nasally. Elevated pressure also caused a 33% loss of ganglion cell axons in vehicle optic nerves and a 70% decrease in CTB transport to the superior colliculus. Each of these components of ganglion cell degeneration was either prevented or significantly reduced in the brimonidine treatment group. Conclusions Continuous and systemic treatment with brimonidine by subcutaneous injection significantly improved retinal ganglion cell survival with exposure to elevated ocular pressure. This effect was most striking in the nasal region of the retina. Brimonidine treatment also preserved ganglion cell axon morphology, sampling density and total number in the optic nerve with elevated pressure. Consistent with improved outcome in the optic projection, brimonidine also significantly reduced the deficits in axonal transport to the superior colliculus associated with

  4. Retinal Ganglion Cell Distribution and Spatial Resolving Power in Deep-Sea Lanternfishes (Myctophidae)

    KAUST Repository

    De Busserolles, Fanny

    2014-01-01

    Topographic analyses of retinal ganglion cell density are very useful in providing information about the visual ecology of a species by identifying areas of acute vision within the visual field (i.e. areas of high cell density). In this study, we investigated the neural cell distribution in the ganglion cell layer of a range of lanternfish species belonging to 10 genera. Analyses were performed on wholemounted retinas using stereology. Topographic maps were constructed of the distribution of all neurons and both ganglion and amacrine cell populations in 5 different species from Nissl-stained retinas using cytological criteria. Amacrine cell distribution was also examined immunohistochemically in 2 of the 5 species using anti-parvalbumin antibody. The distributions of both the total neuron and the amacrine cell populations were aligned in all of the species examined, showing a general increase in cell density toward the retinal periphery. However, when the ganglion cell population was topographically isolated from the amacrine cell population, which comprised up to 80% of the total neurons within the ganglion cell layer, a different distribution was revealed. Topographic maps of the true ganglion cell distribution in 18 species of lanternfishes revealed well-defined specializations in different regions of the retina. Different species possessed distinct areas of high ganglion cell density with respect to both peak density and the location and/or shape of the specialized acute zone (i.e. elongated areae ventro-temporales, areae temporales and large areae centrales). The spatial resolving power was calculated to be relatively low (varying from 1.6 to 4.4 cycles per degree), indicating that myctophids may constitute one of the less visually acute groups of deep-sea teleosts. The diversity in retinal specializations and spatial resolving power within the family is assessed in terms of possible ecological functions and evolutionary history.

  5. Melanopsin retinal ganglion cells are resistant to neurodegeneration in mitochondrial optic neuropathies

    DEFF Research Database (Denmark)

    La Morgia, C; Ross-Cisneros, F.N.; Sadun, A.A.;

    2010-01-01

    Mitochondrial optic neuropathies, that is, Leber hereditary optic neuropathy and dominant optic atrophy, selectively affect retinal ganglion cells, causing visual loss with relatively preserved pupillary light reflex. The mammalian eye contains a light detection system based on a subset of retinal....... We studied the integrity of the retinohypothalamic tract in five patients with Leber hereditary optic neuropathy, in four with dominant optic atrophy and in nine controls by testing the light-induced suppression of nocturnal melatonin secretion. This response was maintained in optic neuropathy...... subjects as in controls, indicating that the retinohypothalamic tract is sufficiently preserved to drive light information detected by melanopsin retinal ganglion cells. We then investigated the histology of post-mortem eyes from two patients with Leber hereditary optic neuropathy and one case...

  6. KR-31378, a potassium-channel opener, induces the protection of retinal ganglion cells in rat retinal ischemic models.

    Science.gov (United States)

    Choi, Anho; Choi, Jun-Sub; Yoon, Yone-Jung; Kim, Kyung-A; Joo, Choun-Ki

    2009-04-01

    KR-31378 is a newly developed K(ATP)-channel opener. To investigate the ability of KR-31378 to protect retinal ganglion cells (RGC), experiments were conducted using two retinal ischemia models. Retinal ischemia was induced by transient high intraocular pressure (IOP) for acute ischemia and by three episcleral vein occlusion for chronic retinal ischemia. KR-31378 was injected intraperitoneally and administered orally in the acute and chronic ischemia models, respectively. Under the condition of chronic ischemia, RGC density in the KR-31378-treated group was statistically higher than that in the non-treated group, and IOP was reduced. In the acute retinal ischemia model, 90% of RGC were degenerated after one week in non-treated retina, but, RGC in KR-31378-treated retina were protected from ischemic damage in a dose-dependent manner and showed inhibited glial fibrillary acidic protein (GFAP) expression. Furthermore, the KR-31378 protective effect was inhibited by glibenclamide treatment in acute ischemia. These findings indicate that systemic KR-31378 treatment may protect against ischemic injury-induced ganglion cell loss in glaucoma.

  7. Intravitreal injection of forskolin, homotaurine, and L-carnosine affords neuroprotection to retinal ganglion cells following retinal ischemic injury

    OpenAIRE

    Russo, Rossella; Adornetto, Annagrazia; Cavaliere, Federica; Varano, Giuseppe Pasquale; Rusciano, Dario; Morrone, Luigi Antonio; Corasaniti, Maria Tiziana; Bagetta, Giacinto; Nucci, Carlo

    2015-01-01

    Purpose Retinal ganglion cell (RGC) death is the final event leading to visual impairment in glaucoma; therefore, identification of neuroprotective strategies able to slow down or prevent the process is one of the main challenges for glaucoma research. The purpose of this study was to evaluate the neuroprotective potential of RGC death induced by the in vivo transient increase in intraocular pressure (IOP) of a combined treatment with forskolin, homotaurine, and L-carnosine. Forskolin (7beta-...

  8. Role of calcium conductance in firing behavior of retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    Dan Wang; Qingli Qiao; Nan Xie

    2011-01-01

    Fohlmeister-Coleman-Miller model of retinal ganglion cells consists of five ion channels; these are sodium channels, calcium channels, and 3 types of potassium channels. An increasing number of studies have investigated sodium channels, voltage-gated potassium channels, and delayed rectifier potassium channels. However, little is known about calcium channels, and in particular the dynamics and computational models of calcium ions. Retinal prostheses have been designed to assist with sight recovery for the blind, and in the present study, the effects of calcium ions in retinal ganglion cell models were analyzed with regard to calcium channel potential and calcium-activated potassium potential. Using MATLAB software, calcium conductance and calcium current from the Fohlmeister-Coleman-Miller model, under clamped voltages, were numerically computed using backward Euler methods. Subsequently, the Fohlmeister-Coleman-Miller model was simulated with the absence of calcium-current (lc,) or calcium-activated potassium current (IK, ca). The model was also analyzed according to the phase plane method.The relationship curve between peak calcium current and clamped potentials revealed an inverted bell shape, and the calcium-activated potassium current increased the frequency of firing and the peak of membrane potential. Results suggested that calcium ion concentrations play an important role in controlling the peak and the magnitude of peak membrane voltage in retinal ganglion cells.

  9. Effects of low level laser treatment on the survival of axotomized retinal ganglion cells in adult Hamsters

    Institute of Scientific and Technical Information of China (English)

    Kwok-Fai So; Mason Chin Pang Leung; Qi Cui

    2014-01-01

    Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the ifrst week with a short period of treatment time (5 minutes) in which 65–66% of retinal ganglion cells survived the optic nerve axotomy whereas 45–47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These ifndings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal gan-glion cells.

  10. Retinal ganglion cell projections to the hamster suprachiasmatic nucleus, intergeniculate leaflet, and visual midbrain: bifurcation and melanopsin immunoreactivity

    Science.gov (United States)

    Morin, Lawrence P.; Blanchard, Jane H.; Provencio, Ignacio

    2003-01-01

    The circadian clock in the suprachiasmatic nucleus (SCN) receives direct retinal input via the retinohypothalamic tract (RHT), and the retinal ganglion cells contributing to this projection may be specialized with respect to direct regulation of the circadian clock. However, some ganglion cells forming the RHT bifurcate, sending axon collaterals to the intergeniculate leaflet (IGL) through which light has secondary access to the circadian clock. The present studies provide a more extensive examination of ganglion cell bifurcation and evaluate whether ganglion cells projecting to several subcortical visual nuclei contain melanopsin, a putative ganglion cell photopigment. The results showed that retinal ganglion cells projecting to the SCN send collaterals to the IGL, olivary pretectal nucleus, and superior colliculus, among other places. Melanopsin-immunoreactive (IR) ganglion cells are present in the hamster retina, and some of these cells project to the SCN, IGL, olivary pretectal nucleus, or superior colliculus. Triple-label analysis showed that melanopsin-IR cells bifurcate and project bilaterally to each SCN, but not to the other visual nuclei evaluated. The melanopsin-IR cells have photoreceptive characteristics optimal for circadian rhythm regulation. However, the presence of moderately widespread bifurcation among ganglion cells projecting to the SCN, and projection by melanopsin-IR cells to locations distinct from the SCN and without known rhythm function, suggest that this ganglion cell type is generalized, rather than specialized, with respect to the conveyance of photic information to the brain. Copyright 2003 Wiley-Liss, Inc.

  11. "Collective coding" of correlated cone signals in the retinal ganglion cell.

    OpenAIRE

    Tsukamoto, Y; R. G. Smith; Sterling, P

    1990-01-01

    The signals in neighboring cones are partially correlated due to local correlations of luminance in the visual scene. By summing these partially correlated signals, the retinal ganglion cell improves its signal/noise ratio (compared to the signal/noise ratio in a cone) and expands the variance of its response to fill its dynamic range. Our computations prove that the optimal weighting function for this summation is dome-shaped. The computations also show that (assuming a particular space cons...

  12. Allogeneic Transplantation of Müller-Derived Retinal Ganglion Cells Improves Retinal Function in a Feline Model of Ganglion Cell Depletion.

    Science.gov (United States)

    Becker, Silke; Eastlake, Karen; Jayaram, Hari; Jones, Megan F; Brown, Robert A; McLellan, Gillian J; Charteris, David G; Khaw, Peng T; Limb, G Astrid

    2016-02-01

    Human Müller glia with stem cell characteristics (hMGSCs) have been shown to improve retinal function upon transplantation into rat models of retinal ganglion cell (RGC) depletion. However, their translational potential may depend upon successful engraftment and improvement of retinal function in experimental models with anatomical and functional features resembling those of the human eye. We investigated the effect of allogeneic transplantation of feline Müller glia with the ability to differentiate into cells expressing RGC markers, following ablation of RGCs by N-methyl-d-aspartate (NMDA). Unlike previous observations in the rat, transplantation of hMGSC-derived RGCs into the feline vitreous formed aggregates and elicited a severe inflammatory response without improving visual function. In contrast, allogeneic transplantation of feline MGSC (fMGSC)-derived RGCs into the vitrectomized eye improved the scotopic threshold response (STR) of the electroretinogram (ERG). Despite causing functional improvement, the cells did not attach onto the retina and formed aggregates on peripheral vitreous remnants, suggesting that vitreous may constitute a barrier for cell attachment onto the retina. This was confirmed by observations that cellular scaffolds of compressed collagen and enriched preparations of fMGSC-derived RGCs facilitated cell attachment. Although cells did not migrate into the RGC layer or the optic nerve, they significantly improved the STR and the photopic negative response of the ERG, indicative of increased RGC function. These results suggest that MGSCs have a neuroprotective ability that promotes partial recovery of impaired RGC function and indicate that cell attachment onto the retina may be necessary for transplanted cells to confer neuroprotection to the retina. Significance: Müller glia with stem cell characteristics are present in the adult human retina, but they do not have regenerative ability. These cells, however, have potential for

  13. Glia-Neuron Interactions in the Retina Can Be Studied in Cocultures of Muller Cells and Retinal Ganglion Cells

    DEFF Research Database (Denmark)

    Skytt, D. M.; Toft-Kehler, A. K.; Braendstrup, C. T.;

    2016-01-01

    Glia-neuron partnership is important for inner retinal homeostasis and any disturbances may result in retinal ganglion cell (RGC) death. Müller cells support RGCs with essential functions such as removing excess glutamate and providing energy sources. The aim was to explore the impact of Müller c...

  14. A Self-Assembling Injectable Biomimetic Microenvironment Encourages Retinal Ganglion Cell Axon Extension in Vitro.

    Science.gov (United States)

    Laughter, Melissa R; Ammar, David A; Bardill, James R; Pena, Brisa; Kahook, Malik Y; Lee, David J; Park, Daewon

    2016-08-17

    Sensory-somatic nervous system neurons, such as retinal ganglion cells (RGCs), are typically thought to be incapable of regenerating. However, it is now known that these cells may be stimulated to regenerate by providing them with a growth permissive environment. We have engineered an injectable microenvironment designed to provide growth-stimulating cues for RGC culture. Upon gelation, this injectable material not only self-assembles into laminar sheets, similar to retinal organization, but also possesses a storage modulus comparable to that of retinal tissue. Primary rat RGCs were grown, stained, and imaged in this three-dimensional scaffold. We were able to show that RGCs grown in this retina-like structure exhibited characteristic long, prominent axons. In addition, RGCs showed a consistent increase in average axon length and neurite-bearing ratio over the 7 day culture period, indicating this scaffold is capable of supporting substantial RGC axon extension. PMID:27434231

  15. Seasonally Changing Cryptochrome 1b Expression in the Retinal Ganglion Cells of a Migrating Passerine Bird.

    Directory of Open Access Journals (Sweden)

    Christine Nießner

    Full Text Available Cryptochromes, blue-light absorbing proteins involved in the circadian clock, have been proposed to be the receptor molecules of the avian magnetic compass. In birds, several cryptochromes occur: Cryptochrome 2, Cryptochrome 4 and two splice products of Cryptochrome 1, Cry1a and Cry1b. With an antibody not distinguishing between the two splice products, Cryptochrome 1 had been detected in the retinal ganglion cells of garden warblers during migration. A recent study located Cry1a in the outer segments of UV/V-cones in the retina of domestic chickens and European robins, another migratory species. Here we report the presence of cryptochrome 1b (eCry1b in retinal ganglion cells and displaced ganglion cells of European Robins, Erithacus rubecula. Immuno-histochemistry at the light microscopic and electron microscopic level showed eCry1b in the cell plasma, free in the cytosol as well as bound to membranes. This is supported by immuno-blotting. However, this applies only to robins in the migratory state. After the end of the migratory phase, the amount of eCry1b was markedly reduced and hardly detectable. In robins, the amount of eCry1b in the retinal ganglion cells varies with season: it appears to be strongly expressed only during the migratory period when the birds show nocturnal migratory restlessness. Since the avian magnetic compass does not seem to be restricted to the migratory phase, this seasonal variation makes a role of eCry1b in magnetoreception rather unlikely. Rather, it could be involved in physiological processes controlling migratory restlessness and thus enabling birds to perform their nocturnal flights.

  16. Cellular Origin of Spontaneous Ganglion Cell Spike Activity in Animal Models of Retinitis Pigmentosa

    Directory of Open Access Journals (Sweden)

    David J. Margolis

    2011-01-01

    Full Text Available Here we review evidence that loss of photoreceptors due to degenerative retinal disease causes an increase in the rate of spontaneous ganglion spike discharge. Information about persistent spike activity is important since it is expected to add noise to the communication between the eye and the brain and thus impact the design and effective use of retinal prosthetics for restoring visual function in patients blinded by disease. Patch-clamp recordings from identified types of ON and OFF retinal ganglion cells in the adult (36–210 d old rd1 mouse show that the ongoing oscillatory spike activity in both cell types is driven by strong rhythmic synaptic input from presynaptic neurons that is blocked by CNQX. The recurrent synaptic activity may arise in a negative feedback loop between a bipolar cell and an amacrine cell that exhibits resonant behavior and oscillations in membrane potential when the normal balance between excitation and inhibition is disrupted by the absence of photoreceptor input.

  17. Spontaneous oscillatory rhythms in the degenerating mouse retina modulate retinal ganglion cell responses to electrical stimulation

    Directory of Open Access Journals (Sweden)

    Yong Sook eGoo

    2016-01-01

    Full Text Available Characterization of the electrical activity of the retina in the animal models of retinal degeneration has been carried out in part to understand the progression of retinal degenerative diseases like age-related macular degeneration (AMD and retinitis pigmentosa (RP, but also to determine optimum stimulus paradigms for use with retinal prosthetic devices. The models most studied in this regard have been the two lines of mice deficient in the β-subunit of phosphodiesterase (rd1 and rd10 mice, where the degenerating retinas exhibit characteristic spontaneous hyperactivity and oscillatory local field potentials (LFPs. Additionally, there is a robust ~10 Hz rhythmic burst of retinal ganglion cell (RGC spikes on the trough of the oscillatory LFP. In rd1 mice, the rhythmic burst of RGC spikes is always phase-locked with the oscillatory LFP and this phase-locking property is preserved regardless of postnatal ages. However, in rd10 mice, the frequency of the oscillatory rhythm changes according to postnatal age, suggesting that this rhythm might be a marker of the stage of degeneration. Furthermore when a biphasic current stimulus is applied to rd10 mice degenerate retina, distinct RGC response patterns that correlate with the stage of degeneration emerge. This review also considers the significance of these response properties.

  18. Alpha B-crystallin improved survival of retinal ganglion cells in a rat model of acute ocular hypertension

    Institute of Scientific and Technical Information of China (English)

    Zhihong Wu; Layi Wang; Shike Hou

    2012-01-01

    Increased endogenous αB-crystallin protein levels have been shown to reduce cell apoptosis,although the effects of exogenous αB-crystallin protein remain poorly understood.The present study established an acute ocular hypertension model in the right eye of Sprague-Dawley rats.Fluorogold retrograde tracing and immunofluorescence methods showed that the number of retinal ganglion cells decreased in the right eyes and caspase-3 expression increased following acute ocular hypertension.Intravitreal injection of αB-crystallin in the right eye increased the number of retinal ganglion cells and reduced caspase-3 expression.Results demonstrated that exogenous αB-crystallin protein inhibited caspase-3 expression and improved retinal ganglion cell survival following acute ocular hypertension.

  19. Caffeine administration prevents retinal neuroinflammation and loss of retinal ganglion cells in an animal model of glaucoma

    Science.gov (United States)

    Madeira, Maria H.; Ortin-Martinez, Arturo; Nadal-Nícolas, Francisco; Ambrósio, António F.; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Santiago, Ana Raquel

    2016-01-01

    Glaucoma is the second leading cause of blindness worldwide, being characterized by progressive optic nerve damage and loss of retinal ganglion cells (RGCs), accompanied by increased inflammatory response involving retinal microglial cells. The etiology of glaucoma is still unknown, and despite elevated intraocular pressure (IOP) being a major risk factor, the exact mechanisms responsible for RGC degeneration remain unknown. Caffeine, which is an antagonist of adenosine receptors, is the most widely consumed psychoactive drug in the world. Several evidences suggest that caffeine can attenuate the neuroinflammatory responses and afford protection upon central nervous system (CNS) injury. We took advantage of a well characterized animal model of glaucoma to investigate whether caffeine administration controls neuroinflammation and elicits neuroprotection. Caffeine or water were administered ad libitum and ocular hypertension (OHT) was induced by laser photocoagulation of the limbal veins in Sprague Dawley rats. Herein, we show that caffeine is able to partially decrease the IOP in ocular hypertensive animals. More importantly, we found that drinking caffeine prevented retinal microglia-mediated neuroinflammatory response and attenuated the loss of RGCs in animals with ocular hypertension (OHT). This study opens the possibility that caffeine or adenosine receptor antagonists might be a therapeutic option to manage RGC loss in glaucoma. PMID:27270337

  20. Role of endoplasmic reticulum stress in the loss of retinal ganglion cells in diabetic retinopathy

    Institute of Scientific and Technical Information of China (English)

    Liping Yang; Lemeng Wu; Dongmei Wang; Ying Li; Hongliang Dou; Mark OMTso; Zhizhong Ma

    2013-01-01

    Endoplasmic reticulum stress is closely involved in the early stage of diabetic retinopathy. In the present study, a streptozotocin-induced diabetic animal model was given an intraperitoneal injection of tauroursodeoxycholic acid. Results from immunofluorescent co-localization experiments showed that both caspase-12 protein and c-Jun N-terminal kinase 1 phosphorylation levels significantly in-creased, which was associated with retinal ganglion celldeath in diabetic retinas. The C/ERB ho-mologous protein pathway directly contributed to glial reactivity, and was subsequently responsible for neuronal loss and vascular abnormalities in diabetic retinopathy. Our experimental findings in-dicate that endoplasmic reticulum stress plays an important role in diabetes-induced retinal neu-ronal loss and vascular abnormalities, and that inhibiting the activation of the endoplasmic reticulum stress pathway provides effective protection against diabetic retinopathy.

  1. Effect of eye NGF administration on two animal models of retinal ganglion cells degeneration

    Directory of Open Access Journals (Sweden)

    Valeria Colafrancesco

    2011-01-01

    Full Text Available The aim of this study was to investigate the effect of nerve growth factor (NGF administration on retinal ganglion cells (RGCs in experimentally induced glaucoma (GL and diabetic retinopathy (DR. GL was induced in adult rats by injection of hypertonic saline into the episcleral vein of the eye and diabetes (DT was induced by administration of streptozoticin. Control and experimental rats were treated daily with either ocular application of NGF or vehicle solution. We found that both animal models present a progressive degeneration of RGCs and changing NGF and VEGF levels in the retina and optic nerve. We then proved that NGF eye drop administration exerts a protective effect on these models of retinal degeneration. In brief, our findings indicate that NGF can play a protective role against RGC degeneration occurring in GL and DR and suggest that ocular NGF administration might be an effective pharmacological approach.

  2. Central projections of intrinsically photosensitive retinal ganglion cells in the macaque monkey

    Science.gov (United States)

    Hannibal, J.; Kankipati, L.; Strang, C.E.; Peterson, B.B.; Dacey, D.; Gamlin, P.D.

    2014-01-01

    Circadian rhythms generated by the suprachiasmatic nucleus (SCN) are entrained to the environmental light/dark cycle via intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin and the neuropeptide PACAP. The ipRGCs regulate other non-image-forming visual functions such as the pupillary light reflex, masking behaviour and light induced melatonin suppression. To evaluate whether PACAP immunoreactive retinal projections are useful as a marker for central projection of ipRGCs in the monkey brain, we characterized the occurrence of PACAP in melanopsin expressing ipRGCs and in the retinal target areas in the brain visualized by the anterograde tracer Cholera Toxin subunit B (CtB) in combination with PACAP staining. In the retina, PACAP and melanopsin were found to be co-stored in 99% of melanopsin expressing cells characterized as inner and outer stratifying melanopsin RGCs. Two macaque monkeys were anesthetized and received a unilateral intravitreal injection of CtB. Bilateral retinal projections containing co-localized CtB and PACAP immunostaining were identified in the SCN, the lateral geniculate complex (LGN) including the pregeniculate nucleus (PrGC), the pretectal olivary nucleus (PON), the nucleus of the optic tract (NOT), the brachium of the superior colliculus (BSC), and the superior colliculus (SC). In conclusion, PACAP immunoreactive projections with co-localized CtB represent retinal projections of ipRGCs in the macaque monkey, and support previous retrograde tracer studies demonstrating that melanopsin containing retinal projections reach areas in the primate brain involved in both image and non-image-forming visual processing. PMID:24752373

  3. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice

    Directory of Open Access Journals (Sweden)

    John Martin Barrett

    2015-08-01

    Full Text Available Retinitis pigmentosa (RP is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity.We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2 in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-ß-glycyrrhetinic acid (18BGA, another gap junction blocker or flupirtine (Flu, a Kv7 potassium channel opener. All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses.Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic

  4. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice.

    Science.gov (United States)

    Barrett, John M; Degenaar, Patrick; Sernagor, Evelyne

    2015-01-01

    Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR) of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity. We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2) in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-β-glycyrrhetinic acid (18BGA, another gap junction blocker) or flupirtine (Flu, a Kv7 potassium channel opener). All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses. Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic prostheses

  5. Chloride channel protein 2 prevents glutamate-induced apoptosis in retinal ganglion cells

    Science.gov (United States)

    Bi, Miao-Miao; Hong, Sen; Ma, Ling-Jun; Zhou, Hong-Yan; Lu, Jia; Zhao, Jing; Zheng, Ya-Juan

    2016-01-01

    Objective(s): The purpose of this study was to investigate the role of chloride channel protein 2 (ClC-2) in glutamate-induced apoptosis in the retinal ganglion cell line (RGC-5). Materials and Methods: RGC-5 cells were treated with 1 mM glutamate for 24 hr. The expression of ClC-2, Bax, and Bcl-2 was detected by western blot analysis. Cell survival and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Caspase-3 and -9 activities were determined by a colorimetric assay. The roles of ClC-2 in glutamate-induced apoptosis were examined by using ClC-2 complementary deoxyribonucleic acid (cDNA) and small inference ribonucleic acid (RNA) transfection technology. Results: Overexpression of ClC-2 in RGC-5 cells significantly decreased glutamate-induced apoptosis and increased cell viability, whereas silencing of ClC-2 with short hairpin (sh) RNA produced opposite effects. ClC-2 overexpression increased the expression of Bcl-2, decreased the expression of Bax, and decreased caspase-3 and -9 activation in RGC-5 cells treated with glutamate, but silencing of ClC-2 produced opposite effects. Conclusion: Our data suggest that ClC-2 chloride channels might play a protective role in glutamate-induced apoptosis in retinal ganglion cells via the mitochondria-dependent apoptosis pathway. PMID:27635193

  6. Muscarinic acetylcholine receptor-mediated stimulation of retinal ganglion cell photoreceptors.

    Science.gov (United States)

    Sodhi, Puneet; Hartwick, Andrew T E

    2016-09-01

    Melanopsin-dependent phototransduction in intrinsically photosensitive retinal ganglion cells (ipRGCs) involves a Gq-coupled phospholipase C (PLC) signaling cascade. Acetylcholine, released in the mammalian retina by starburst amacrine cells, can also activate Gq-PLC pathways through certain muscarinic acetylcholine receptors (mAChRs). Using multielectrode array recordings of rat retinas, we demonstrate that robust spiking responses can be evoked in neonatal and adult ipRGCs after bath application of the muscarinic agonist carbachol. The stimulatory action of carbachol on ipRGCs was a direct effect, as confirmed through calcium imaging experiments on isolated ipRGCs in purified cultures. Using flickering (6 Hz) yellow light stimuli at irradiances below the threshold for melanopsin activation, spiking responses could be elicited in ipRGCs that were suppressed by mAChR antagonism. Therefore, this work identified a novel melanopsin-independent pathway for stimulating sustained spiking in ganglion cell photoreceptors. This mAChR-mediated pathway could enhance ipRGC spiking responses in conditions known to evoke retinal acetylcholine release, such as those involving flickering or moving visual stimuli. Furthermore, this work identifies a pharmacological approach for light-independent ipRGC stimulation that could be targeted by mAChR agonists. PMID:27055770

  7. Matrix metalloproteinase 2 and membrane type 1 matrix metalloproteinase co-regulate axonal outgrowth of mouse retinal ganglion cells

    DEFF Research Database (Denmark)

    Gaublomme, Djoere; Buyens, Tom; De Groef, Lies;

    2014-01-01

    , we were able to show that broad-spectrum MMP inhibition reduces axon outgrowth of mouse retinal ganglion cells (RGCs), implicating MMPs as beneficial factors in axonal regeneration. Additional studies, using more specific MMP inhibitors and MMP-deficient mice, disclosed that both MMP-2 and MT1-MMP...... mouse retinal explants. Our data indicate MMP-2 and MT1-MMP as promising axonal outgrowth-promoting molecules and show a possible link between MMP-2 and β1-integrin in axon outgrowth....

  8. Neuroprotective effects of ClC-3 chloride channel in glutamate-induced retinal ganglion cell RGC-5 apoptosis

    Institute of Scientific and Technical Information of China (English)

    Li Yu; Ning Han; Ligang Jiang; Yajuan Zheng; Lifeng Liu

    2011-01-01

    Transforming growth factor β plays a role in regulation of apoptosis in ClC-3 and the Smads signaling pathway, although the underlying mechanisms remain unclear. The present study determined possible signal transduction mechanisms based on CIC-3 expression, which accordingly affected apoptosis of retinal ganglion cells in a glutamate-induced retinal ganglion cell RGC-5 apoptosis model. Results revealed significantly increased cell survival rate and significantly decreased apoptosis rate following apoptosis of ClC-3 cDNA-transfected glutamate-induced retinal ganglion cells. Following inhibition of the ClC-3 chloride channel using RNAi technology, cell survival and apoptosis rates were reversed. In addition, expression of transforming growth factor β2, Smads2, Smads3, Smads4, and Smads7 increased to varying degrees. These results suggest that ClC-3 chloride channel plays a protective role in glutamate-induced apoptosis of retinal ganglion cells, and transforming growth factor β/Smads signal transduction pathways are involved in this process.

  9. Amacrine cells in the ganglion cell layer of the cat retina.

    Science.gov (United States)

    Wässle, H; Chun, M H; Müller, F

    1987-11-15

    Following transection of the optic nerve, ganglion cells in the cat retina undergo retrograde degeneration. However, many small profiles (less than or equal to 10 micron) survive in the ganglion cell layer. Previously considered to be neuroglia, there is now substantial evidence that they are displaced amacrine cells. Their density increases from approximately 1,000 cells/mm2 in peripheral retina to 7,000 cells/mm2 in the central area. Their total number was found to be 850,000, which is five times the number of ganglion cells and also five times the number of astrocytes. Uptake of 3H-muscimol followed by autoradiography labelled 75% of the displaced amacrine cells; hence, the majority seem to be GABAergic. Immunocytochemistry with an antibody directed against choline-acetyl-transferase labelled approximately 10% of the displaced amacrines in the peripheral retina and 17% in the central area. Uptake of serotonin (5-HT) followed by immunocytochemistry was found in 25-30% of displaced amacrines. NADPH diaphorase histochemistry labelled approximately 5% of displaced amacrine cells. The sum of the various percentages make colocalization likely. Intracellular injection of Lucifer Yellow under microscopic control revealed that displaced amacrine cells constitute several morphological types. PMID:3693612

  10. Specific projection of displaced retinal ganglion cells upon the accessory optic system in the pigeon (Columbia livia).

    Science.gov (United States)

    Karten, J H; Fite, K V; Brecha, N

    1977-04-01

    In the pigeon, the nucleus of the basal optic root, a component of the accessory optic system, projects directly upon the vestibulo-cerebellum. This nucleus receives a prominent projection composed of large-diameter retinal axons, known as the basal optic root. The cells of origin of this tract were identified using horseradish peroxidase (donor:hydrogen-peroxide oxidoreductase, EC 1.11.1.7) as a retrograde marker. Injections of horseradish peroxidase confined primarily to the basal optic root nucleus labeled displaced ganglion cells of the contralateral retina. Cell sizes were 18-30 micronm and the dendrites of these cells were confined to the first stratum of the inner plexiform layer. Approximately 3700 displaced ganglion cells were labeled after injections of horseradish peroxidase into basal optic root. In contrast, no displaced ganglion cells were labeled after injections of horseradish peroxidase into the optic tectum, which labeled only cells in the ganglion cell layer proper. These findings indicate that displaced ganglion cells constitute a unique population of retinal neurons that give rise to a bisynaptic pathway directed to the cerebellum via the nucleus of the basal optic root. These displaced ganglion cells may play a major role inoculomotor reflexes.

  11. A phospholipase A₂ isolated from Lachesis muta snake venom increases the survival of retinal ganglion cells in vitro.

    Science.gov (United States)

    da Silva Cunha, Karinne Cristinne; Fuly, André Lopes; de Araujo, Elizabeth Giestal

    2011-03-15

    We have previously showed that a phospholipase A₂ isolated from Lachesis muta snake venom and named LM-PLA₂-I displayed particular biological activities, as hemolysis, inhibition on platelet aggregation, edema induction and myotoxicity. In the present work, we evaluated the effect of LM-PLA₂-I on the survival of axotomized rat retinal ganglion cells kept in vitro, as well as its mechanism of action. Our results clearly showed that treatment with LM-PLA₂-I increased the survival of ganglion cells (100% when compared to control cultures) and the treatment of LM-PLA₂-I with p-bromophenacyl bromide abolished this effect. This result indicates that the effect of LM-PLA₂-I on ganglion cell survival is entirely dependent on its enzymatic activity and the generation of lysophosphatidylcholine (LPC) may be a prerequisite to the observed survival. In fact, commercial LPC mimicked the effect of LM-PLA₂-I upon ganglion cell survival. To investigate the mechanism of action of LM-PLA₂-I, cultures were treated with chelerythrine chloride, BAPTA-AM, rottlerin and also with an inhibitor of c-junc kinase (JNKi). Our results showed that rottlerin and JNK inhibitor abolished the LM-PLA₂-I on ganglion cell survival. Taken together, our results showed that LM-PLA₂-I and its enzymatic product, LPC promoted survival of retinal ganglion cells through the protein kinase C pathway and strongly suggest a possible role of the PLA₂ enzyme and LPC in controlling the survival of axotomized neuronal cells. PMID:21223976

  12. Protection of retinal ganglion cells and retinal vasculature by Lycium barbarum polysaccharides in a mouse model of acute ocular hypertension.

    Directory of Open Access Journals (Sweden)

    Xue-Song Mi

    Full Text Available Acute ocular hypertension (AOH is a condition found in acute glaucoma. The purpose of this study is to investigate the protective effect of Lycium barbarum polysaccharides (LBP and its protective mechanisms in the AOH insult. LBP has been shown to exhibit neuroprotective effect in the chronic ocular hypertension (COH experiments. AOH mouse model was induced in unilateral eye for one hour by introducing 90 mmHg ocular pressure. The animal was fed with LBP solution (1 mg/kg or vehicle daily from 7 days before the AOH insult till sacrifice at either day 4 or day 7 post insult. The neuroprotective effects of LBP on retinal ganglion cells (RGCs and blood-retinal-barrier (BRB were evaluated. In control AOH retina, loss of RGCs, thinning of IRL thickness, increased IgG leakage, broken tight junctions, and decreased density of retinal blood vessels were observed. However, in LBP-treated AOH retina, there was less loss of RGCs with thinning of IRL thickness, IgG leakage, more continued structure of tight junctions associated with higher level of occludin protein and the recovery of the blood vessel density when compared with vehicle-treated AOH retina. Moreover, we found that LBP provides neuroprotection by down-regulating RAGE, ET-1, Aβ and AGE in the retina, as well as their related signaling pathways, which was related to inhibiting vascular damages and the neuronal degeneration in AOH insults. The present study suggests that LBP could prevent damage to RGCs from AOH-induced ischemic injury; furthermore, through its effects on blood vessel protection, LBP would also be a potential treatment for vascular-related retinopathy.

  13. Retrograde Labeling of Adult Rat Retinal Ganglion Cells with the Flurogold

    Institute of Scientific and Technical Information of China (English)

    Wei Huang; Yannian Hui; Miaoli Zhang

    2000-01-01

    Purpose: To study the densities and distribution of retinal ganglion cells(RGC) in adult rat retinae with flurogold(FG) labeling retogradely.Methods: FG was injected to the superior colliculi(SC) and dorsal lateral geniculate nuclei (dLGN) in adult rats and the retinae were examined by fluorescence microscopy at various periods of time.Results: FG-labelled RGC were observed in the retina as early as 3 days after application of FG. The labelled cells gradually increased in density, reached 95% of the maximal number on days 7 and the maximal number on days 30. The density of labelled cells was higher in the posterior pole than in the peripheral area. The fluorescence intensity in labelled cells maintained up to 60 days.Conclusion: The FG retrograde labeling method is reliable and effective for quantity of RGC. Eye Science 2000; 16:29 ~ 33.

  14. Retrograde Labeling of Adult Rat Retinal Ganglion Cells with the Flurogold

    Institute of Scientific and Technical Information of China (English)

    WeiHuang; YannianHui; 等

    2002-01-01

    Purpose:To study the densities and distribution of retinal ganglion cells(RGC) in adult rat retinae with flurogold(FG) labeling retogradely.Methods:FG was injected to the superior colliculid(SC) and dorsal lateral geniculate nuclei(dLGN) in adult rats and the retinae were examined by fluorescence microscopy at various periods of time.Results:FG-labelled RGC were observed in the retina as early as 3 days after application of FG.The labeled cells gradually increased in density,reached 95% of the maximal number on days 7 and the maximal nuber on days 30.The density of labeled cells was higher in the posterior pole than in the peripheral area.The fluorescence intensity in labeled cells maintained up to 60 days.Conclusion:The FG retrograde labeling method is reliable and effective for quantity of RGC.Eye Science 2000;46:29-33.

  15. Properties of mouse retinal ganglion cell dendritic growth during postnatal development

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The property of dendritic growth dynamics during development is a subject of intense interest.Here,we investigated the dendritic motility of retinal ganglion cells (RGCs) during different developmental stages,using ex vivo mouse retina explant culture,Semliki Forest Virus transfection and time-lapse observations.The results illustrated that during development,the dendritic motility underwent a change from rapid growth to a relatively stable state,i.e.,at P0 (day of birth),RGC dendrites were in a highly active state,whereas at postnatal 13 (P13) they were more stable,and at P3 and P8,the RGCs were in an intermediate state.At any given developmental stage,RGCs of different types displayed the same dendritic growth rate and extent.Since the mouse is the most popular mammalian model for genetic manipulation,this study provided a methodological foundation for further exploring the regulatory mechanisms of dendritic development.

  16. Sulbutiamine counteracts trophic factor deprivation induced apoptotic cell death in transformed retinal ganglion cells.

    Science.gov (United States)

    Kang, Kui Dong; Majid, Aman Shah Abdul; Kim, Kyung-A; Kang, Kyungsu; Ahn, Hong Ryul; Nho, Chu Won; Jung, Sang Hoon

    2010-11-01

    Sulbutiamine is a highly lipid soluble synthetic analogue of vitamin B(1) and is used clinically for the treatment of asthenia. The aim of our study was to demonstrate whether sulbutiamine is able to attenuate trophic factor deprivation induced cell death to transformed retinal ganglion cells (RGC-5). Cells were subjected to serum deprivation for defined periods and sulbutiamine at different concentrations was added to the cultures. Various procedures (e.g. cell viability assays, apoptosis assay, reactive oxygen species analysis, Western blot analysis, flow cytometric analysis, glutathione (GSH) and glutathione-S-transferase (GST) measurement) were used to demonstrate the effect of sulbutiamine. Sulbutiamine dose-dependently attenuated apoptotic cell death induced by serum deprivation and stimulated GSH and GST activity. Moreover, sulbutiamine decreased the expression of cleaved caspase-3 and AIF. This study demonstrates for the first time that sulbutiamine is able to attenuate trophic factor deprivation induced apoptotic cell death in neuronal cells in culture. PMID:20809085

  17. Bone marrow mesenchymal stem cells protect against retinal ganglion cell loss in aged rats with glaucoma

    Directory of Open Access Journals (Sweden)

    Hu Y

    2013-10-01

    Full Text Available Ying Hu,1,2 Hai Bo Tan,1 Xin Mei Wang,3 Hua Rong,1 Hong Ping Cui,1 Hao Cui2 Departments of Ophthalmology, 1Shanghai East Hospital of Tongji University, Shanghai, 2First Affiliated Hospital, 3Fourth Affiliated Hospital, Harbin Medical University, Harbin, People's Republic of China Abstract: Glaucoma is a common eye disease in the aged population and has severe consequences. The present study examined the therapeutic effects of bone marrow mesenchymal stem cell (BMSC transplantation in preventing loss of visual function in aged rats with glaucoma caused by laser-induced ocular hypertension. We found that BMSCs promoted survival of retinal ganglion cells in the transplanted eye as compared with the control eye. Further, in swimming tests guided by visual cues, the rats with a BMSC transplant performed significantly better. We believe that BMSC transplantation therapy is effective in treating aged rats with glaucoma. Keywords: glaucoma, stem cell, transplantation, cell therapy, aging

  18. Rescuing axons from degeneration does not affect retinal ganglion cell death

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    S. de Lima

    2016-01-01

    Full Text Available After a traumatic injury to the central nervous system, the distal stumps of axons undergo Wallerian degeneration (WD, an event that comprises cytoskeleton and myelin breakdown, astrocytic gliosis, and overexpression of proteins that inhibit axonal regrowth. By contrast, injured neuronal cell bodies show features characteristic of attempts to initiate the regenerative process of elongating their axons. The main molecular event that leads to WD is an increase in the intracellular calcium concentration, which activates calpains, calcium-dependent proteases that degrade cytoskeleton proteins. The aim of our study was to investigate whether preventing axonal degeneration would impact the survival of retinal ganglion cells (RGCs after crushing the optic nerve. We observed that male Wistar rats (weighing 200-400 g; n=18 treated with an exogenous calpain inhibitor (20 mM administered via direct application of the inhibitor embedded within the copolymer resin Evlax immediately following optic nerve crush showed a delay in the onset of WD. This delayed onset was characterized by a decrease in the number of degenerated fibers (P<0.05 and an increase in the number of preserved fibers (P<0.05 4 days after injury. Additionally, most preserved fibers showed a normal G-ratio. These results indicated that calpain inhibition prevented the degeneration of optic nerve fibers, rescuing axons from the process of axonal degeneration. However, analysis of retinal ganglion cell survival demonstrated no difference between the calpain inhibitor- and vehicle-treated groups, suggesting that although the calpain inhibitor prevented axonal degeneration, it had no effect on RGC survival after optic nerve damage.

  19. Endothelin B receptors contribute to retinal ganglion cell loss in a rat model of glaucoma.

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    Alena Z Minton

    Full Text Available Glaucoma is an optic neuropathy, commonly associated with elevated intraocular pressure (IOP characterized by optic nerve degeneration, cupping of the optic disc, and loss of retinal ganglion cells which could lead to loss of vision. Endothelin-1 (ET-1 is a 21-amino acid vasoactive peptide that plays a key role in the pathogenesis of glaucoma; however, the receptors mediating these effects have not been defined. In the current study, endothelin B (ET(B receptor expression was assessed in vivo, in the Morrison's ocular hypertension model of glaucoma in rats. Elevation of IOP in Brown Norway rats produced increased expression of ET(B receptors in the retina, mainly in retinal ganglion cells (RGCs, nerve fiber layer (NFL, and also in the inner plexiform layer (IPL and inner nuclear layer (INL. To determine the role of ET(B receptors in neurodegeneration, Wistar-Kyoto wild type (WT and ET(B receptor-deficient (KO rats were subjected to retrograde labeling with Fluoro-Gold (FG, following which IOP was elevated in one eye while the contralateral eye served as control. IOP elevation for 4 weeks in WT rats caused an appreciable loss of RGCs, which was significantly attenuated in KO rats. In addition, degenerative changes in the optic nerve were greatly reduced in KO rats compared to those in WT rats. Taken together, elevated intraocular pressure mediated increase in ET(B receptor expression and its activation may contribute to a decrease in RGC survival as seen in glaucoma. These findings raise the possibility of using endothelin receptor antagonists as neuroprotective agents for the treatment of glaucoma.

  20. Synchronized Firings in Retinal Ganglion Cells in Response to Natural Stimulation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying-Ying; XIAO Lei; LIU Wen-Zhong; GONG Hai-Qing; LIANG Pei-Ji

    2011-01-01

    The response of synchronously firing groups of population retinal ganglion cells (RGCs) to natural movies (NMs)and pseudo-random white-noise checker-board flickering (CB, as control) are investigated using an informationtheoretic algorithm.The main results are: (1) the population RGCs tend to fire in synchrony far more frequently than expected by chance during both NM and CB stimulation; (2) more synchronous groups could be formed and each group contains more neurons under NM than CB stimulation; (3) the individual neurons also participate in more groups and have more distinct partners in NM than CB stimulation.All these results suggest that the synchronized firings in RGCs are more extensive and diverse, which may account for more effective information processing in representing the natural visual environment.%@@ The response of synchronously firing groups of population retinal ganglion cells (RGCs) to natural movies (NMs) and pseudo-random white-noise checker-board flickering (CB, as control) are investigated using an information-theoretic algorithm.The main results are: (1) the population RGCs tend to fire in synchrony far more frequently than expected by chance during both NM and CB stimulation; (2) more synchronous groups could be formed and each group contains more neurons under NM than CB stimulation; (3) the individual neurons also participate in more groups and have more distinct partners in NM than CB stimulation.All these results suggest that the synchronized firings in RGCs are more extensive and diverse, which may account for more effective information processing in representing the natural visual environment.

  1. Autophagy in retinal ganglion cells in a rhesus monkey chronic hypertensive glaucoma model.

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    Shuifeng Deng

    Full Text Available Primary open angle glaucoma (POAG is a neurodegenerative disease characterized by physiological intraocular hypertension that causes damage to the retinal ganglion cells (RGCs. In the past, RGC damage in POAG was suggested to have been attributed to RGC apoptosis. However, in the present study, we applied a model closer to human POAG through the use of a chronic hypertensive glaucoma model in rhesus monkeys to investigate whether another mode of progressive cell death, autophagy, was activated in the glaucomatous retinas. First, in the glaucomatous retinas, the levels of LC3B-II, LC3B-II/LC3B-I and Beclin 1 increased as demonstrated by Western blot analyses, whereas early or initial autophagic vacuoles (AVi and late or degraded autophagic vacuoles (AVd accumulated in the ganglion cell layer (GCL and in the inner plexiform layer (IPL as determined by transmission electron microscopy (TEM analysis. Second, lysosome activity and autophagosome-lysosomal fusion increased in the RGCs of the glaucomatous retinas, as demonstrated by Western blotting against lysosome associated membrane protein-1 (LAMP1 and double labeling against LC3B and LAMP1. Third, apoptosis was activated in the glaucomatous eyes with increased levels of caspase-3 and cleaved caspase-3 and an increased number of TUNEL-positive RGCs. Our results suggested that autophagy was activated in RGCs in the chronic hypertensive glaucoma model of rhesus monkeys and that autophagy may have potential as a new target for intervention in glaucoma treatment.

  2. Implementing dynamic clamp with synaptic and artificial conductances in mouse retinal ganglion cells.

    Science.gov (United States)

    Huang, Jin Y; Stiefel, Klaus M; Protti, Dario A

    2013-05-16

    Ganglion cells are the output neurons of the retina and their activity reflects the integration of multiple synaptic inputs arising from specific neural circuits. Patch clamp techniques, in voltage clamp and current clamp configurations, are commonly used to study the physiological properties of neurons and to characterize their synaptic inputs. Although the application of these techniques is highly informative, they pose various limitations. For example, it is difficult to quantify how the precise interactions of excitatory and inhibitory inputs determine response output. To address this issue, we used a modified current clamp technique, dynamic clamp, also called conductance clamp (1, 2, 3) and examined the impact of excitatory and inhibitory synaptic inputs on neuronal excitability. This technique requires the injection of current into the cell and is dependent on the real-time feedback of its membrane potential at that time. The injected current is calculated from predetermined excitatory and inhibitory synaptic conductances, their reversal potentials and the cell's instantaneous membrane potential. Details on the experimental procedures, patch clamping cells to achieve a whole-cell configuration and employment of the dynamic clamp technique are illustrated in this video article. Here, we show the responses of mouse retinal ganglion cells to various conductance waveforms obtained from physiological experiments in control conditions or in the presence of drugs. Furthermore, we show the use of artificial excitatory and inhibitory conductances generated using alpha functions to investigate the responses of the cells.

  3. Gender difference in the neuroprotective effect of rat bone marrow mesenchymal cells against hypoxia-induced apoptosis of retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    Jing Yuan; Jian-xiong Yu

    2016-01-01

    Bone marrow mesenchymal stem cells can reduce retinal ganglion cell death and effectively prevent vision loss. Previously, we found that during differentiation, female rhesus monkey bone marrow mesenchymal stem cells acquire a higher neurogenic potential compared with male rhesus monkey bone marrow mesenchymal stem cells. This suggests that female bone marrow mesenchymal stem cells have a stron-ger neuroprotective effect than male bone marrow mesenchymal stem cells. Here, we ifrst isolated and cultured bone marrow mesenchymal stem cells from female and male rats by density gradient centrifugation. Retinal tissue from newborn rats was prepared by enzymatic digestion to obtain primary retinal ganglion cells. Using the transwell system, retinal ganglion cells were co-cultured with bone marrow mesenchymal stem cells under hypoxia. Cell apoptosis was detected by lfow cytometry and caspase-3 activity assay. We found a marked increase in apoptotic rate and caspase-3 activity of retinal ganglion cells after 24 hours of hypoxia compared with normoxia. Moreover, apoptotic rate and caspase-3 activity of retinal ganglion cells signiifcantly decreased with both female and male bone marrow mesenchymal stem cell co-culture under hypoxia compared with culture alone, with more signiifcant effects from female bone marrow mesenchymal stem cells. Our results indicate that bone marrow mesenchymal stem cells exert a neuroprotective effect against hypoxia-induced apoptosis of retinal ganglion cells, and also that female cells have greater neuroprotective ability compared with male cells.

  4. Effect of alpha lipoic acid on retinal ganglion cell survival in an optic nerve crush model

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    Liu, Ruixing; Wang, Yanling; Pu, Mingliang

    2016-01-01

    Purpose This study was conducted to determine whether alpha lipoic acid (ALA) promotes the survival of retinal ganglion cells (RGCs) in a rat model of optic nerve crush (ONC) injury and to investigate the neuroprotective mechanisms of ALA in the retina in this ONC injury model. Methods Adult male Sprague-Dawley rats (180–220 g) were subjected to ONC injury surgery. ALA (63 mg/kg) was injected intravenously 1 day before or after the ONC injury. Animals were euthanized after 10 days, and the number of ganglion cells positive for RNA-binding protein with multiple splicing (Rbpms), which is an RGC marker, were counted on the whole mount retinas. In addition, immunofluorescence and immunoblotting were performed to examine the localization and levels of erythropoietin receptor (EPOR) and neurotrophin-4/5 (NT4/5) in the retinas in all experimental groups. To determine whether the EPO/EPOR signaling pathway was involved in the ALA antioxidant pathway, the rats were subjected to ruxolitinib (INCB018424, 0.25 mg/kg, bid, intraperitoneal, i.p.) treatment after the animals were injected intravenously with ALA 1 day before ONC injury. Results The average number of Rbpms-positive cells/mm2 in the control group (sham-operated group), the ONC group, the ALA-ONC group, and the ONC-ALA group retinas was 2219±28, 418±8, 848±22, and 613±18/mm2, respectively. The ALA-ONC and ONC-ALA groups showed a statistically significantly increased RGC survival rate compared to the ONC group. There were statistical differences in the RGC survival rates between the ALA-ONC (39%) and ONC-ALA groups (28%; p<0.05). Immunofluorescent labeling showed that EPOR and NT4/5 expression was significant in the retinal ganglion cell layer (GCL). At the same time, western blot analysis revealed that ALA induced upregulation of EPOR protein and NT4/5 protein expression in the retina after ONC injury. However, INCB018424 reversed the protective effects of ALA on the ONC retinas. Conclusions ALA has

  5. Growth hormone and retinal ganglion cell function: QNR/D cells as an experimental model.

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    Martínez-Moreno, Carlos; Andres, Alexis; Giterman, Daniel; Karpinski, Edward; Harvey, Steve

    2014-01-01

    Retinal ganglion cells (RGCs) have been shown to be sites of growth hormone (GH) production and GH action in the embryonic (embryo day 7, ED7) chick neural retina. Primary RGC cell cultures were previously used to determine autocrine or paracrine actions of GH in the retina, but the antibody used in their immunopanning (anti-Thy-1) is no longer available. We have therefore characterized an immortalized neural retina (QNR/D) cell line derived from ED7 embryonic quail as a replacement experimental model. These cells express the GH gene and have GH receptor (GHR)-immunoreactivity. They are also immunoreactive for RGC markers (islet-1, calretinin, RA4) and neural fibers (neurofilament, GAP 43, vimentin) and they express the genes for Thy-1, neurotrophin 3 (NTF3), neuritin 1 (NRN1) and brn3 (POU4F). These cells are also electrically active and therefore resemble the RGCs in the neural retina. They are also similarly responsive to exogenous GH, which induces overexpression of the neurotrophin 3 and insulin-like growth factor (IGF) 1 genes and stimulates cell survival, as in the chick embryo neural retina. QNR/D cells are therefore a useful experimental model to assess the actions of GH in retinal function. PMID:24239556

  6. Elevated intracranial pressure causes optic nerve and retinal ganglion cell degeneration in mice.

    Science.gov (United States)

    Nusbaum, Derek M; Wu, Samuel M; Frankfort, Benjamin J

    2015-07-01

    The purpose of this study was to develop a novel experimental system for the modulation and measurement of intracranial pressure (ICP), and to use this system to assess the impact of elevated ICP on the optic nerve and retinal ganglion cells (RGCs) in CD1 mice. This system involved surgical implantation of an infusion cannula and a radiowave based pressure monitoring probe through the skull and into the subarachnoid space. The infusion cannula was used to increase ICP, which was measured by the probe and transmitted to a nearby receiver. The system provided robust and consistent ICP waveforms, was well tolerated, and was stable over time. ICP was elevated to approximately 30 mmHg for one week, after which we assessed changes in optic nerve structure with transmission electron microscopy in cross section and RGC numbers with antibody staining in retinal flat mounts. ICP elevation resulted in optic nerve axonal loss and disorganization, as well as RGC soma loss. We conclude that the controlled manipulation of ICP in active, awake mice is possible, despite their small size. Furthermore, ICP elevation results in visual system phenotypes of optic nerve and RGC degeneration, suggesting that this model can be used to study the impact of ICP on the visual system. Potentially, this model can also be used to study the relationship between ICP and IOP, as well diseases impacted by ICP variation such as glaucoma, idiopathic intracranial hypertension, and the spaceflight-related visual impairment intracranial pressure syndrome. PMID:25912998

  7. Neuroprotection by GH against excitotoxic-induced cell death in retinal ganglion cells.

    Science.gov (United States)

    Martínez-Moreno, Carlos G; Ávila-Mendoza, José; Wu, Yilun; Arellanes-Licea, Elvira Del Carmen; Louie, Marcela; Luna, Maricela; Arámburo, Carlos; Harvey, Steve

    2016-08-01

    Retinal growth hormone (GH) has been shown to promote cell survival in retinal ganglion cells (RGCs) during developmental waves of apoptosis during chicken embryonic development. The possibility that it might also against excitotoxicity-induced cell death was therefore examined in the present study, which utilized quail-derived QNR/D cells as an in vitro RGC model. QNR/D cell death was induced by glutamate in the presence of BSO (buthionine sulfoxamide) (an enhancer of oxidative stress), but this was significantly reduced (PGH (rcGH). Similarly, QNR/D cells that had been prior transfected with a GH plasmid to overexpress secreted and non-secreted GH. This treatment reduced the number of TUNEL-labeled cells and blocked their release of lactate dehydrogenase (LDH). In a further experiment with dissected neuroretinal explants from ED (embryonic day) 10 embryos, rcGH treatment of the explants also reduced (PGH-overexpressing QNR/D cells. As rcGH treatment and GH-overexpression cells also increased the content of IGF-1 and IGF-1 mRNA this neuroprotective action of GH is likely to be mediated, at least partially, through an IGF-1 mechanism. This possibility is supported by the fact that the siRNA knockdown of GH or IGF-1 significantly reduced QNR/D cell viability, as did the immunoneutralization of IGF-1. GH is therefore neuroprotective against excitotoxicity-induced RGC cell death by anti-apoptotic actions involving IGF-1 stimulation. PMID:27129619

  8. Effects of p-xylene inhalation on axonal transport in the rat retinal ganglion cells

    International Nuclear Information System (INIS)

    Although the solvent xylene is suspected of producing nervous system dysfunction in animals and humans, little is known regarding the neurochemical consequences of xylene inhalation. The intent of this study was to determine the effect of intermittent, acute, and subchronic p-xylene exposure on the axonal transport of proteins and glycoproteins within the rat retinofugal tract. A number of different exposure regimens were tested ranging from 50 ppm for a single 6-hr exposure to 1600 ppm 6 hr/day, 5 days/week, for a total of 8 exposure days. Immediately following removal from the inhalation chambers rats were injected intraocularly with [35S]methionine and [3H]fucose (to label retinal proteins and glycoproteins, respectively) and the axonal transport of labeled macromolecules to axons (optic nerve and optic tract) and nerve endings (lateral geniculate body and superior colliculus) was examined 20 hr after precursor injection. Only relatively severe exposure regimens (i.e., 800 or 1600 ppm 6 hr/day, 5 days/week, for 1.5 weeks) produced significant reductions in axonal transport; there was a moderate reduction in the axonal transport of 35S-labeled proteins in the 800-ppm-treated group which was more widespread in the 1600 ppm-treated group. Transport of 3H-labeled glycoproteins was less affected. Assessment of retinal metabolism immediately after isotope injection indicated that the rate of precursor uptake was not reduced in either treatment group. Furthermore, rapid transport was still substantially reduced in animals exposed to 1600 ppm p-xylene and allowed a 13-day withdrawal period. These data indicate that p-xylene inhalation decreases rapid axonal transport supplied to the projections of the rat retinal ganglion cells immediately after cessation of inhalation exposure and that this decreased transport is still apparent 13 days after the last exposure

  9. A Purine-Sensitive Pathway Regulates Multiple Genes Involved in Axon Regeneration in Goldfish Retinal Ganglion Cells

    OpenAIRE

    Petrausch, Barbara; Tabibiazar, Raymond; Roser, Timo; Jing, Yun; Goldmann, Daniel; Stürmer, Claudia; Irwin, Nina; Benowitz, Larry I.

    2000-01-01

    In lower vertebrates, retinal ganglion cells (RGCs) can regenerate their axons and reestablish functional connections after optic nerve injury. We show here that in goldfish RGCs, the effects of several trophic factors converge on a purine-sensitive signaling mechanism that controls axonal outgrowth and the expression of multiple growth-associated proteins. In culture, goldfish RGCs regenerate their axons in response to two molecules secreted by optic nerve glia, axogenesis factor-1 (AF-1) an...

  10. Protein Profiling of Human Nonpigmented Ciliary Epithelium Cell Secretome: The Differentiation Factors Characterization for Retinal Ganglion Cell line

    Directory of Open Access Journals (Sweden)

    Ming-Hui Yang

    2011-01-01

    Full Text Available The purpose of this paper was to characterize proteins secreted from the human nonpigmented ciliary epithelial (HNPE cells, which have differentiated a rat retinal ganglion cell line, RGC-5. Undifferentiated RGC-5 cells have been shown to express several marker proteins characteristic of retinal ganglion cells. However, RGC-5 cells do not respond to N-methyl-D aspartate (NMDA, or glutamate. HNPE cells have been shown to secrete numbers of neuropeptides or neuroproteins also found in the aqueous humor, many of which have the ability to influence the activity of neuronal cells. This paper details the profile of HNPE cell-secreted proteins by proteomic approaches. The experimental results revealed the identification of 132 unique proteins from the HNPE cell-conditioned SF-medium. The biological functions of a portion of these identified proteins are involved in cell differentiation. We hypothesized that a differentiation system of HNPE cell-conditioned SF-medium with RGC-5 cells can induce a differentiated phenotype in RGC-5 cells, with functional characteristics that more closely resemble primary cultures of rat retinal ganglion cells. These proteins may replace harsh chemicals, which are currently used to induce cell differentiation.

  11. Inner nuclear layer thickening is inversley proportional to retinal ganglion cell loss in optic neuritis.

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    Megha Kaushik

    Full Text Available AIM: To examine the relationship between retinal ganglion cell loss and changes in the inner nuclear layer (INL in optic neuritis (ON. METHODS: 36 multiple sclerosis (MS patients with a history of ON and 36 age and sex-matched controls underwent Optical Coherence Tomography. The paramacular retinal nerve fiber layer (RNFL, combined ganglion cell and inner plexiform layers (GCL/IPL and inner nuclear layer (INL thickness were measured at 36 points around the fovea. To remove inter-subject variability, the difference in thickness of each layer between the ON and fellow eye of each patient was calculated. A topographic analysis was conducted. RESULTS: The INL of the ON patients was thicker than the controls (42.9µm versus 39.6µm, p=0.002. ON patients also had a thinner RNFL (27.8µm versus 32.2µm, p<0.001 and GCL/IPL (69.3µm versus 98.1µm, p<0.001. Among the controls, there was no correlation between RNFL and GCL/IPL as well as RNFL and INL, but a positive correlation was seen between GCL/IPL and INL (r=0.65, p<0.001. In the ON group, there was a positive correlation between RNFL and GCL/IPL (r=0.80, p<0.001 but a negative correlation between RNFL and INL (r=-0.61, p<0.001 as well as GCL/IPL and INL (r=-0.44, p=0.007. The negative correlation between GCL/IPL and INL strengthened in the ON group when inter-subject variability was removed (r=-0.75, p<0.001. Microcysts within the INL were present in 5 ON patients, mainly in the superior and infero-nasal paramacular regions. While patients with microcysts lay at the far end of the correlation curve between GCL/IPL and INL (i.e. larger INL and smaller GCL/IPL compared to other patients, their exclusion did not affect the correlation (r= -0.76, p<0.001. CONCLUSIONS: INL enlargement in MS-related ON is associated with the severity of GCL loss. This is a continuous relationship and patients with INL microcysts may represent the extreme end of the scale.

  12. The role of intrinsically photosensitive retinal ganglion cells in nonimage-forming responses to light

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    Warthen DM

    2012-09-01

    Full Text Available Daniel M Warthen,1,2 Ignacio Provencio11Department of Biology, University of Virginia, Charlottesville, VA, USA; 2Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, USAAbstract: Light exerts many effects on behavior and physiology. These effects can be characterized as either image-forming or nonimage-forming (NIF visual processes. Image-forming vision refers to the process of detecting objects and organisms in the environment and distinguishing their physical characteristics, such as size, shape, and direction of motion. NIF vision, in contrast, refers to effects of light that are independent of fine spatiotemporal vision. NIF effects are many and varied, ranging from modulation of basal physiology, such as heart rate and body temperature, to changes in higher functions, such as mood and cognitive performance. In mammals, many NIF effects of light are dependent upon the inner retinal photopigment melanopsin and the cells in which melanopsin is expressed, the intrinsically photosensitive retinal ganglion cells (ipRGCs. The ipRGCs project broadly throughout the brain. Many of these projections terminate in areas known to mediate NIF effects, while others terminate in regions whose link to photoreception remains to be established. Additionally, the presence of ipRGC projections to areas of the brain with no known link to photoreception suggests the existence of additional ipRGC-mediated NIF effects. This review summarizes the known NIF effects of light and the role of melanopsin and ipRGCs in driving these effects, with an eye toward stimulating further investigation of the many and varied effects of light on physiology and behavior.Keywords: amygdala, bed nucleus of the stria terminalis, melanopsin, opsin, optic nerve, retina

  13. Losartan Treatment Protects Retinal Ganglion Cells and Alters Scleral Remodeling in Experimental Glaucoma.

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    Harry A Quigley

    Full Text Available To determine if oral losartan treatment decreases the retinal ganglion cell (RGC death caused by experimental intraocular pressure (IOP elevation in mice.We produced IOP increase in CD1 mice and performed unilateral optic nerve crush. Mice received oral losartan, spironolactone, enalapril, or no drug to test effects of inhibiting angiotensin receptors. IOP was monitored by Tonolab, and blood pressure was monitored by tail cuff device. RGC loss was measured in masked axon counts and RGC bodies by β-tubulin labeling. Scleral changes that could modulate RGC injury were measured including axial length, scleral thickness, and retinal layer thicknesses, pressure-strain behavior in inflation testing, and study of angiotensin receptors and pathways by reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry.Losartan treatment prevented significant RGC loss (median loss = 2.5%, p = 0.13, while median loss with water, spironolactone, and enalapril treatments were 26%, 28% and 43%; p < 0.0001. The lower RGC loss with losartan was significantly less than the loss with spironolactone or enalapril (regression model p = 0.001; drug treatment group term p = 0.01. Both losartan and enalapril significantly lowered blood pressure (p< 0.001, but losartan was protective, while enalapril led to worse than water-treated RGC loss. RGC loss after crush injury was unaffected by losartan treatment (difference from control p = 0.9. Survival of RGC in cell culture was not prolonged by sartan treatment. Axonal transport blockade after 3 day IOP elevations was less in losartan-treated than in control glaucoma eyes (p = 0.007. Losartan inhibited effects of glaucoma, including reduction in extracellular signal-related kinase activity and modification of glaucoma-related changes in scleral thickness and creep under controlled IOP.The neuroprotective effect of losartan in mouse glaucoma is associated with adaptive changes in the sclera expressed at

  14. Signaling mechanism for modulation by ATP of glycine receptors on rat retinal ganglion cells.

    Science.gov (United States)

    Zhang, Ping-Ping; Zhang, Gong; Zhou, Wei; Weng, Shi-Jun; Yang, Xiong-Li; Zhong, Yong-Mei

    2016-01-01

    ATP modulates voltage- and ligand-gated channels in the CNS via the activation of ionotropic P2X and metabotropic P2Y receptors. While P2Y receptors are expressed in retinal neurons, the function of these receptors in the retina is largely unknown. Using whole-cell patch-clamp techniques in rat retinal slice preparations, we demonstrated that ATP suppressed glycine receptor-mediated currents of OFF type ganglion cells (OFF-GCs) dose-dependently, and the effect was in part mediated by P2Y1 and P2Y11, but not by P2X. The ATP effect was abolished by intracellular dialysis of a Gq/11 protein inhibitor and phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor, but not phosphatidylcholine (PC)-PLC inhibitor. The ATP effect was accompanied by an increase in [Ca(2+)]i through the IP3-sensitive pathway and was blocked by intracellular Ca(2+)-free solution. Furthermore, the ATP effect was eliminated in the presence of PKC inhibitors. Neither PKA nor PKG system was involved. These results suggest that the ATP-induced suppression may be mediated by a distinct Gq/11/PI-PLC/IP3/Ca(2+)/PKC signaling pathway, following the activation of P2Y1,11 and other P2Y subtypes. Consistently, ATP suppressed glycine receptor-mediated light-evoked inhibitory postsynaptic currents of OFF-GCs. These results suggest that ATP may modify the ON-to-OFF crossover inhibition, thus changing action potential patterns of OFF-GCs. PMID:27357477

  15. Modeling the impact of common noise inputs on the network activity of retinal ganglion cells.

    Science.gov (United States)

    Vidne, Michael; Ahmadian, Yashar; Shlens, Jonathon; Pillow, Jonathan W; Kulkarni, Jayant; Litke, Alan M; Chichilnisky, E J; Simoncelli, Eero; Paninski, Liam

    2012-08-01

    Synchronized spontaneous firing among retinal ganglion cells (RGCs), on timescales faster than visual responses, has been reported in many studies. Two candidate mechanisms of synchronized firing include direct coupling and shared noisy inputs. In neighboring parasol cells of primate retina, which exhibit rapid synchronized firing that has been studied extensively, recent experimental work indicates that direct electrical or synaptic coupling is weak, but shared synaptic input in the absence of modulated stimuli is strong. However, previous modeling efforts have not accounted for this aspect of firing in the parasol cell population. Here we develop a new model that incorporates the effects of common noise, and apply it to analyze the light responses and synchronized firing of a large, densely-sampled network of over 250 simultaneously recorded parasol cells. We use a generalized linear model in which the spike rate in each cell is determined by the linear combination of the spatio-temporally filtered visual input, the temporally filtered prior spikes of that cell, and unobserved sources representing common noise. The model accurately captures the statistical structure of the spike trains and the encoding of the visual stimulus, without the direct coupling assumption present in previous modeling work. Finally, we examined the problem of decoding the visual stimulus from the spike train given the estimated parameters. The common-noise model produces Bayesian decoding performance as accurate as that of a model with direct coupling, but with significantly more robustness to spike timing perturbations.

  16. Differentiation of human ESCs to retinal ganglion cells using a CRISPR engineered reporter cell line.

    Science.gov (United States)

    Sluch, Valentin M; Davis, Chung-ha O; Ranganathan, Vinod; Kerr, Justin M; Krick, Kellin; Martin, Russ; Berlinicke, Cynthia A; Marsh-Armstrong, Nicholas; Diamond, Jeffrey S; Mao, Hai-Quan; Zack, Donald J

    2015-11-13

    Retinal ganglion cell (RGC) injury and cell death from glaucoma and other forms of optic nerve disease is a major cause of irreversible vision loss and blindness. Human pluripotent stem cell (hPSC)-derived RGCs could provide a source of cells for the development of novel therapeutic molecules as well as for potential cell-based therapies. In addition, such cells could provide insights into human RGC development, gene regulation, and neuronal biology. Here, we report a simple, adherent cell culture protocol for differentiation of hPSCs to RGCs using a CRISPR-engineered RGC fluorescent reporter stem cell line. Fluorescence-activated cell sorting of the differentiated cultures yields a highly purified population of cells that express a range of RGC-enriched markers and exhibit morphological and physiological properties typical of RGCs. Additionally, we demonstrate that aligned nanofiber matrices can be used to guide the axonal outgrowth of hPSC-derived RGCs for in vitro optic nerve-like modeling. Lastly, using this protocol we identified forskolin as a potent promoter of RGC differentiation.

  17. Roles of PACAP-containing retinal ganglion cells in circadian timing.

    Science.gov (United States)

    Hannibal, Jens

    2006-01-01

    The brain's biological clock located in the suprachiasmatic nucleus (SCN) generates circadian rhythms in physiology and behavior. The clock-driven rhythms need daily adjustment (entrainment) to be synchronized with the astronomical day of 24 h. The most important stimulus for entrainment of the clock is the light-dark (LD) cycle. In this review functional elements of the light entrainment pathway will be considered with special focus on the neurotransmitter pituitary adenylate cyclase-activating polypeptide (PACAP), which is found exclusively in the monosynaptic neuronal pathway mediating light information to the SCN, the retinohypothalamic tract (RHT). The retinal ganglion cells of the RHT are intrinsically photosensitive due to the expression of melanopsin and seem to constitute a non-image forming photosensitive system in the mammalian eye regulating circadian timing, masking behavior, light-regulated melatonin secretion, and the pupillary light reflex. Evidence from in vitro and in vivo studies and studies of mice lacking PACAP and the specific PACAP receptor (PAC1) indicate that PACAP and glutamate are neurotransmitters in the RHT which in a clock and concentration-dependent manner interact during light entrainment of the clock.

  18. Electrical activity of ON and OFF retinal ganglion cells: a modelling study

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    Guo, Tianruo; Tsai, David; Morley, John W.; Suaning, Gregg J.; Kameneva, Tatiana; Lovell, Nigel H.; Dokos, Socrates

    2016-04-01

    Objective. Retinal ganglion cells (RGCs) demonstrate a large range of variation in their ionic channel properties and morphologies. Cell-specific properties are responsible for the unique way RGCs process synaptic inputs, as well as artificial electrical signals such as that from a visual prosthesis. A cell-specific computational modelling approach allows us to examine the functional significance of regional membrane channel expression and cell morphology. Approach. In this study, an existing RGC ionic model was extended by including a hyperpolarization activated non-selective cationic current as well as a T-type calcium current identified in recent experimental findings. Biophysically-defined model parameters were simultaneously optimized against multiple experimental recordings from ON and OFF RGCs. Main results. With well-defined cell-specific model parameters and the incorporation of detailed cell morphologies, these models were able to closely reconstruct and predict ON and OFF RGC response properties recorded experimentally. Significance. The resulting models were used to study the contribution of different ion channel properties and spatial structure of neurons to RGC activation. The techniques of this study are generally applicable to other excitable cell models, increasing the utility of theoretical models in accurately predicting the response of real biological neurons.

  19. The types of retinal ganglion cells: current status and implications for neuronal classification.

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    Sanes, Joshua R; Masland, Richard H

    2015-07-01

    In the retina, photoreceptors pass visual information to interneurons, which process it and pass it to retinal ganglion cells (RGCs). Axons of RGCs then travel through the optic nerve, telling the rest of the brain all it will ever know about the visual world. Research over the past several decades has made clear that most RGCs are not merely light detectors, but rather feature detectors, which send a diverse set of parallel, highly processed images of the world on to higher centers. Here, we review progress in classification of RGCs by physiological, morphological, and molecular criteria, making a particular effort to distinguish those cell types that are definitive from those for which information is partial. We focus on the mouse, in which molecular and genetic methods are most advanced. We argue that there are around 30 RGC types and that we can now account for well over half of all RGCs. We also use RGCs to examine the general problem of neuronal classification, arguing that insights and methods from the retina can guide the classification enterprise in other brain regions. PMID:25897874

  20. Retinal nerve fiber layer and ganglion cell complex thickness in patients with type 2 diabetes mellitus

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    Mehmet Demir

    2014-01-01

    Full Text Available Aim: The aim of the following study is to evaluate the retinal nerve fiber layer (RNFL and ganglion cell complex (GCC thickness in patients with type 2 diabetes mellitus (DM. Materials and Methods: Average, inferior, and superior values of RNFL and GCC thickness were measured in 123 patients using spectral domain optical coherence tomography. The values of participants with DM were compared to controls. Diabetic patients were collected in Groups 1, 2 and 3. Group 1 = 33 participants who had no diabetic retinopathy (DR; Group 2 = 30 participants who had mild nonproliferative DR and Group 3 = 30 participants who had moderate non-proliferative DR. The 30 healthy participants collected in Group 4. Analysis of variance test and a multiple linear regression analysis were used for statistical analysis. Results: The values of RNFL and GCC in the type 2 diabetes were thinner than controls, but this difference was not statistically significant. Conclusions: This study showed that there is a nonsignificant loss of RNFL and GCC in patients with type 2 diabetes.

  1. Imipramine protects retinal ganglion cells from oxidative stress through the tyrosine kinase receptor B signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Ming-lei Han; Guo-hua Liu; Jin Guo; Shu-juan Yu; Jing Huang

    2016-01-01

    Retinal ganglion cell (RGC) degeneration is irreversible in glaucoma and tyrosine kinase receptor B (TrkB)-associated signaling pathways have been implicated in the process. In this study, we attempted to examine whether imipramine, a tricyclic antidepressant, may protect hydrogen peroxide (H2O2)-induced RGC degeneration through the activation of the TrkB pathway in RGC-5 cell lines. RGC-5 cell lines were pre-treated with imipramine 30 minutes before exposure to H2O2. Western blot assay showed that in H2O2-damaged RGC-5 cells, imipramine activated TrkB pathways through extracellular signal-regulated protein kinase/TrkB phosphorylation. TUNEL staining assay also demonstrated that imipramine ameliorated H2O2-induced apoptosis in RGC-5 cells. Finally, TrkB-IgG intervention was able to reverse the protective effect of imipramine on H2O2-induced RGC-5 apoptosis. Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the TrkB signaling pathway.

  2. KCC2-dependent subcellular ECl difference of ON-OFF retinal ganglion cells in larval zebrafish

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    Rongwei eZhang

    2013-05-01

    Full Text Available Subcellular difference in the reversal potential of Cl- (ECl has been found in many types of neurons. As local ECl largely determines the action of nearby GABAergic/glycinergic synapses, subcellular ECl difference can effectively regulate neuronal computation. The ON-OFF retinal ganglion cell (RGC processes both ON and OFF visual signals via its ON and OFF dendrites, respectively. It is thus interesting to investigate whether the ON and OFF dendrites of single RGCs exhibit different local ECl. Here, using in vivo gramicidin-perforated patch recording in larval zebrafish ON-OFF RGCs, we examine local ECl at the ON and OFF dendrites, and soma through measuring light-evoked ON and OFF inhibitory responses, and GABA-induced response at the soma, respectively. We find there are subcellular ECl differences between the soma and dendrite, as well as between the ON and OFF dendrites of single RGCs. These somato-dendritic and inter-dendritic ECl differences are dependent on the Cl- extruder, K+/Cl- co-transporter (KCC2, because they are largely diminished by down-regulating kcc2 expression with morpholino oligonucleotides or by blocking KCC2 function with furosemide. Thus, our findings indicate that there exists KCC2-dependent ECl difference between the ON and OFF dendrites of individual ON-OFF RGCs that may differentially affect visual processing in the ON and OFF pathways.

  3. Connexin 36 and rod bipolar cell independent rod pathways drive retinal ganglion cells and optokinetic reflexes.

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    Cowan, Cameron S; Abd-El-Barr, Muhammad; van der Heijden, Meike; Lo, Eric M; Paul, David; Bramblett, Debra E; Lem, Janis; Simons, David L; Wu, Samuel M

    2016-02-01

    Rod pathways are a parallel set of synaptic connections which enable night vision by relaying and processing rod photoreceptor light responses. We use dim light stimuli to isolate rod pathway contributions to downstream light responses then characterize these contributions in knockout mice lacking rod transducin-α (Trα), or certain pathway components associated with subsets of rod pathways. These comparisons reveal that rod pathway driven light sensitivity in retinal ganglion cells (RGCs) is entirely dependent on Trα, but partially independent of connexin 36 (Cx36) and rod bipolar cells. Pharmacological experiments show that rod pathway-driven and Cx36-independent RGC ON responses are also metabotropic glutamate receptor 6-dependent. To validate the RGC findings in awake, behaving animals we measured optokinetic reflexes (OKRs), which are sensitive to changes in ON pathways. Scotopic OKR contrast sensitivity was lost in Trα(-/-) mice, but indistinguishable from controls in Cx36(-/-) and rod bipolar cell knockout mice. Mesopic OKRs were also altered in mutant mice: Trα(-/-) mice had decreased spatial acuity, rod BC knockouts had decreased sensitivity, and Cx36(-/-) mice had increased sensitivity. These results provide compelling evidence against the complete Cx36 or rod BC dependence of night vision's ON component. Further, the findings suggest the parallel nature of rod pathways provides considerable redundancy to scotopic light sensitivity but distinct contributions to mesopic responses through complicated interactions with cone pathways. PMID:26718442

  4. Protective effects of triptolide on retinal ganglion cells in a rat model of chronic glaucoma

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    Yang F

    2015-11-01

    Full Text Available Fan Yang, Dongmei Wang, Lingling Wu, Ying Li Ophthalmology Department, Peking University Third Hospital, Beijing, People’s Republic of China Purpose: To study the effects of triptolide, a Chinese herb extract, on retinal ganglion cells (RGCs in a rat model of chronic glaucoma.Methods: Eighty Wistar rats were randomly divided into triptolide group (n=40 and normal saline (NS group (n=40. Angle photocoagulation was used to establish the model of glaucoma, with right eye as laser treated eye and left eye as control eye. Triptolide group received triptolide intraperitoneally daily, while NS group received NS. Intraocular pressure (IOP, anti-CD11b immunofluorescent stain in retina and optic nerve, RGCs count with Nissel stain and microglia count with anti-CD11b immunofluorescence stain in retina flat mounts, retinal tumor necrosis factor (TNF-α mRNA detection by reverse transcription–polymerase chain reaction, and double immunofluorescent labeling with anti-TNF-α and anti-CD11b in retinal frozen section were performed.Results: Mean IOP of the laser treated eyes significantly increased 3 weeks after photocoagulation (P<0.05, with no statistical difference between the two groups (P>0.05. RGCs survival in the laser treated eyes was significantly improved in the triptolide group than the NS group (P<0.05. Microglia count in superficial retina of the laser treated eyes was significantly less in the triptolide group (30.40±4.90 than the NS group (35.06±7.59 (P<0.05. TNF-α mRNA expression in the retina of the laser treated eyes in the triptolide group decreased by 60% compared with that in the NS group (P<0.01. The double immunofluorescent labeling showed that TNF-α was mainly distributed around the microglia.Conclusion: Triptolide improved RGCs survival in this rat model of chronic glaucoma, which did not depend on IOP decrease but might be exerted by inhibiting microglia activities and reducing TNF-α secretion. Keywords: glaucoma, triptolide

  5. Hydrostatic pressure does not cause detectable changes in survival of human retinal ganglion cells.

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    Andrew Osborne

    Full Text Available PURPOSE: Elevated intraocular pressure (IOP is a major risk factor for glaucoma. One consequence of raised IOP is that ocular tissues are subjected to increased hydrostatic pressure (HP. The effect of raised HP on stress pathway signaling and retinal ganglion cell (RGC survival in the human retina was investigated. METHODS: A chamber was designed to expose cells to increased HP (constant and fluctuating. Accurate pressure control (10-100 mmHg was achieved using mass flow controllers. Human organotypic retinal cultures (HORCs from donor eyes (<24 h post mortem were cultured in serum-free DMEM/HamF12. Increased HP was compared to simulated ischemia (oxygen glucose deprivation, OGD. Cell death and apoptosis were measured by LDH and TUNEL assays, RGC marker expression by qRT-PCR (THY-1 and RGC number by immunohistochemistry (NeuN. Activated p38 and JNK were detected by Western blot. RESULTS: Exposure of HORCs to constant (60 mmHg or fluctuating (10-100 mmHg; 1 cycle/min pressure for 24 or 48 h caused no loss of structural integrity, LDH release, decrease in RGC marker expression (THY-1 or loss of RGCs compared with controls. In addition, there was no increase in TUNEL-positive NeuN-labelled cells at either time-point indicating no increase in apoptosis of RGCs. OGD increased apoptosis, reduced RGC marker expression and RGC number and caused elevated LDH release at 24 h. p38 and JNK phosphorylation remained unchanged in HORCs exposed to fluctuating pressure (10-100 mmHg; 1 cycle/min for 15, 30, 60 and 90 min durations, whereas OGD (3 h increased activation of p38 and JNK, remaining elevated for 90 min post-OGD. CONCLUSIONS: Directly applied HP had no detectable impact on RGC survival and stress-signalling in HORCs. Simulated ischemia, however, activated stress pathways and caused RGC death. These results show that direct HP does not cause degeneration of RGCs in the ex vivo human retina.

  6. Quantitative measurement of retinal ganglion cell populations via histology-based random forest classification.

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    Hedberg-Buenz, Adam; Christopher, Mark A; Lewis, Carly J; Fernandes, Kimberly A; Dutca, Laura M; Wang, Kai; Scheetz, Todd E; Abràmoff, Michael D; Libby, Richard T; Garvin, Mona K; Anderson, Michael G

    2016-05-01

    The inner surface of the retina contains a complex mixture of neurons, glia, and vasculature, including retinal ganglion cells (RGCs), the final output neurons of the retina and primary neurons that are damaged in several blinding diseases. The goal of the current work was two-fold: to assess the feasibility of using computer-assisted detection of nuclei and random forest classification to automate the quantification of RGCs in hematoxylin/eosin (H&E)-stained retinal whole-mounts; and if possible, to use the approach to examine how nuclear size influences disease susceptibility among RGC populations. To achieve this, data from RetFM-J, a semi-automated ImageJ-based module that detects, counts, and collects quantitative data on nuclei of H&E-stained whole-mounted retinas, were used in conjunction with a manually curated set of images to train a random forest classifier. To test performance, computer-derived outputs were compared to previously published features of several well-characterized mouse models of ophthalmic disease and their controls: normal C57BL/6J mice; Jun-sufficient and Jun-deficient mice subjected to controlled optic nerve crush (CONC); and DBA/2J mice with naturally occurring glaucoma. The result of these efforts was development of RetFM-Class, a command-line-based tool that uses data output from RetFM-J to perform random forest classification of cell type. Comparative testing revealed that manual and automated classifications by RetFM-Class correlated well, with 83.2% classification accuracy for RGCs. Automated characterization of C57BL/6J retinas predicted 54,642 RGCs per normal retina, and identified a 48.3% Jun-dependent loss of cells at 35 days post CONC and a 71.2% loss of RGCs among 16-month-old DBA/2J mice with glaucoma. Output from automated analyses was used to compare nuclear area among large numbers of RGCs from DBA/2J mice (n = 127,361). In aged DBA/2J mice with glaucoma, RetFM-Class detected a decrease in median and mean nucleus size

  7. Co-expression of two subtypes of melatonin receptor on rat M1-type intrinsically photosensitive retinal ganglion cells.

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    Wen-Long Sheng

    Full Text Available Intrinsically photosensitive retinal ganglion cells (ipRGCs are involved in circadian and other non-image forming visual responses. An open question is whether the activity of these neurons may also be under the regulation mediated by the neurohormone melatonin. In the present work, by double-staining immunohistochemical technique, we studied the expression of MT1 and MT2, two known subtypes of mammalian melatonin receptors, in rat ipRGCs. A single subset of retinal ganglion cells labeled by the specific antibody against melanopsin exhibited the morphology typical of M1-type ipRGCs. Immunoreactivity for both MT1 and MT2 receptors was clearly seen in the cytoplasm of all labeled ipRGCs, indicating that these two receptors were co-expressed in each of these neurons. Furthermore, labeling for both the receptors were found in neonatal M1 cells as early as the day of birth. It is therefore highly plausible that retinal melatonin may directly modulate the activity of ipRGCs, thus regulating non-image forming visual functions.

  8. Signalling mechanism for somatostatin receptor 5-mediated suppression of AMPA responses in rat retinal ganglion cells.

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    Deng, Qin-Qin; Sheng, Wen-Long; Zhang, Gong; Weng, Shi-Jun; Yang, Xiong-Li; Zhong, Yong-Mei

    2016-08-01

    Somatostatin (SRIF) is involved in a variety of physiological functions via the activation of five subtypes of specific receptors (sst1-5). Here, we investigated the effects of SRIF on AMPA receptor (AMPAR)-mediated currents (AMPA currents) in isolated rat retinal ganglion cells (GCs) using patch-clamp techniques. Immunofluorescence double labelling demonstrated the expression of sst5 in rat GCs. Consistent to this, whole cell AMPA currents of GCs were dose-dependently suppressed by SRIF, and the effect was reversed by the sst5 antagonist BIM-23056. Intracellular dialysis of GDP-β-S or pre-incubation with the Gi/o inhibitor pertussis toxin (PTX) abolished the SRIF effect. The SRIF effect was mimicked by the administration of either 8-Br-cAMP or forskolin, but was eliminated by the protein kinase A (PKA) antagonists H-89/KT5720/Rp-cAMP. Moreover, SRIF increased intracellular Ca(2+) levels and did not suppress the AMPA currents when GCs were infused with an intracellular Ca(2+)-free solution or in the presence of ryanodine receptor modulators caffeine/ryanodine. Furthermore, the SRIF effect was eliminated when the activity of calmodulin (CaM), calcineurin and protein phosphatase 1 (PP1) was blocked with W-7, FK-506 and okadaic acid, respectively. SRIF persisted to suppress the AMPA currents when cGMP-protein kinase G (PKG) and phosphatidylinositol (PI)-/phosphatidylcholine (PC)-phospholipase C (PLC) signalling pathways were blocked. In rat flat-mount retinas, SRIF suppressed AMPAR-mediated light-evoked excitatory postsynaptic currents (L-EPSCs) in GCs. We conclude that a distinct Gi/o/cAMP-PKA/ryanodine/Ca(2+)/CaM/calcineurin/PP1 signalling pathway comes into play due to the activation of sst5 to mediate the SRIF effect on GCs. PMID:26969240

  9. Retinal ganglion cell neuroprotection in a rat model of glaucoma following brimonidine, latanoprost or combined treatments.

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    Hernández, María; Urcola, J Haritz; Vecino, Elena

    2008-05-01

    The aim of the present study is to evaluate the neuroprotective effect of two antiglaucomatous substances, regardless of their hypotensive effect in the eye. Brimonidine, which does not reduce IOP when administered intraperitoneally, and latanoprost, which has a renowned hypotensive effect topically. We examined rat retinal ganglion cell (RGC) survival and size distribution in experimental glaucoma in response to different glaucomatous agents. IOP was elevated by episcleral vein cauterization (EVC) prior to the application of different treatments: (I) PBS application (control group), (II) intraperitoneal administration of brimonidine (a general hypotensive agent), (III) topical application of latanoprost (an ocular hypotensive agent), and (IV) latanoprost combined with brimonidine. After 12 weeks, RGCs were retrogradely labeled with fluorogold and RGC density was analyzed. EVC caused a significant increase (42%) in IOP in each group before drug treatment. After 12weeks of EVC, RGC survival in control vs. EVC rats was 78.9+/-3.2%. No IOP reduction was observed in brimonidine injected rats, but RGC survival at 12 weeks was total (103.7+/-2.7%). In latanoprost treated rats, IOP dropped by around 22% and 94.7+/-3.7% of the RGC population survived. Finally in the latanoprost+brimonidine combined group, IOP was significantly reduced by 25% and 94.4+/-2.2% of RGCs survived. Surprisingly, whereas EVC led to a 6% increase in RGC soma size, brimonidine treatment was associated with a 9% reduction in the soma size of RGCs at 12 weeks. We conclude that brimonidine exerts a neuroprotective effect via a mechanism which is independent of IOP reduction. These findings indicate that cell survival in glaucoma may be enhanced by neuroprotective strategies which are independent of IOP reduction. No synergistic neuroprotective effect was observed when both treatments were applied simultaneously.

  10. Mice deficient of glutamatergic signaling from intrinsically photosensitive retinal ganglion cells exhibit abnormal circadian photoentrainment.

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    Nicole Purrier

    Full Text Available Several aspects of behavior and physiology, such as sleep and wakefulness, blood pressure, body temperature, and hormone secretion exhibit daily oscillations known as circadian rhythms. These circadian rhythms are orchestrated by an intrinsic biological clock in the suprachiasmatic nuclei (SCN of the hypothalamus which is adjusted to the daily environmental cycles of day and night by the process of photoentrainment. In mammals, the neuronal signal for photoentrainment arises from a small subset of intrinsically photosensitive retinal ganglion cells (ipRGCs that send a direct projection to the SCN. ipRGCs also mediate other non-image-forming (NIF visual responses such as negative masking of locomotor activity by light, and the pupillary light reflex (PLR via co-release of neurotransmitters glutamate and pituitary adenylate cyclase-activating peptide (PACAP from their synaptic terminals. The relative contribution of each neurotransmitter system for the circadian photoentrainment and other NIF visual responses is still unresolved. We investigated the role of glutamatergic neurotransmission for circadian photoentrainment and NIF behaviors by selective ablation of ipRGC glutamatergic synaptic transmission in mice. Mutant mice displayed delayed re-entrainment to a 6 h phase shift (advance or delay in the light cycle and incomplete photoentrainment in a symmetrical skeleton photoperiod regimen (1 h light pulses between 11 h dark periods. Circadian rhythmicity in constant darkness also was reduced in some mutant mice. Other NIF responses such as the PLR and negative masking responses to light were also partially attenuated. Overall, these results suggest that glutamate from ipRGCs drives circadian photoentrainment and negative masking responses to light.

  11. Neuritin 1 promotes retinal ganglion cell survival and axonal regeneration following optic nerve crush.

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    Sharma, T P; Liu, Y; Wordinger, R J; Pang, I-H; Clark, A F

    2015-01-01

    Neuritin 1 (Nrn1) is an extracellular glycophosphatidylinositol-linked protein that stimulates axonal plasticity, dendritic arborization and synapse maturation in the central nervous system (CNS). The purpose of this study was to evaluate the neuroprotective and axogenic properties of Nrn1 on axotomized retinal ganglion cells (RGCs) in vitro and on the in vivo optic nerve crush (ONC) mouse model. Axotomized cultured RGCs treated with recombinant hNRN1 significantly increased survival of RGCs by 21% (n=6-7, P<0.01) and neurite outgrowth in RGCs by 141% compared to controls (n=15, P<0.05). RGC transduction with AAV2-CAG-hNRN1 prior to ONC promoted RGC survival (450%, n=3-7, P<0.05) and significantly preserved RGC function by 70% until 28 days post crush (dpc) (n=6, P<0.05) compared with the control AAV2-CAG-green fluorescent protein transduction group. Significantly elevated levels of RGC marker, RNA binding protein with multiple splicing (Rbpms; 73%, n=5-8, P<0.001) and growth cone marker, growth-associated protein 43 (Gap43; 36%, n=3, P<0.01) were observed 28 dpc in the retinas of the treatment group compared with the control group. Significant increase in Gap43 (100%, n=5-6, P<0.05) expression was observed within the optic nerves of the AAV2-hNRN1 group compared to controls. In conclusion, Nrn1 exhibited neuroprotective, regenerative effects and preserved RGC function on axotomized RGCs in vitro and after axonal injury in vivo. Nrn1 is a potential therapeutic target for CNS neurodegenerative diseases. PMID:25719245

  12. Neuroprotective effect of peroxiredoxin 6 against hypoxia-induced retinal ganglion cell damage

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    Kumar Anil

    2010-10-01

    Full Text Available Abstract Background The ability to respond to changes in the extra-intracellular environment is prerequisite for cell survival. Cellular responses to the environment include elevating defense systems, such as the antioxidant defense system. Hypoxia-evoked reactive oxygen species (ROS-driven oxidative stress is an underlying mechanism of retinal ganglion cell (RGC death that leads to blinding disorders. The protein peroxiredoxin 6 (PRDX6 plays a pleiotropic role in negatively regulating death signaling in response to stressors, and thereby stabilizes cellular homeostasis. Results We have shown that RGCs exposed to hypoxia (1% or hypoxia mimetic cobalt chloride display reduced expression of PRDX6 with higher ROS expression and activation of NF-κB. These cells undergo apoptosis, while cells with over-expression of PRDX6 demonstrate resistance against hypoxia-driven RGC death. The RGCs exposed to hypoxia either with 1% oxygen or cobalt chloride (0-400 μM, revealed ~30%-70% apoptotic cell death after 48 and 72 h of exposure. Western analysis and real-time PCR showed elevated expression of PRDX6 during hypoxia at 24 h, while PRDX6 protein and mRNA expression declined from 48 h onwards following hypoxia exposure. Concomitant with this, RGCs showed increased ROS expression and activation of NF-κB with IkB phosphorylation/degradation, as examined with H2DCF-DA and transactivation assays. These hypoxia-induced adverse reactions could be reversed by over-expression of PRDX6. Conclusion Because an abundance of PRDX6 in cells was able to attenuate hypoxia-induced RGC death, the protein could possibly be developed as a novel therapeutic agent acting to postpone RGC injury and delay the progression of glaucoma and other disorders caused by the increased-ROS-generated death signaling related to hypoxia.

  13. Comparison of Central Corneal Thickness and Retinal Nerve Fiber Layer Thickness and Ganglion Cell Complex in Patients with Ocular Hypertension

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    Gamze Mumcu Taşlı

    2013-12-01

    Full Text Available Purpose: To evaluate the correlation of retinal nerve fiber layer thickness (RNFLT with ganglion cell complex and central corneal thickness (CCT measurements in patients with ocular hypertension and healthy subjects. Material and Method: Seventy-six eyes of 38 patients with ocular hypertension and 76 eyes of 38 healthy subjects were included in this study. Both groups were stratified by CCT into 579 µm (p0.05. In the control group, there was no significant correlation between CCT and RNFLT (average, superior average, inferior average measurements (p>0.05. There was no significant correlation between CCT and average, superior average, inferior average ganglion cell complex in both groups. Discussion: Ocular hypertension patients with CCT <550 µm may represent patients who have very early undetected glaucoma. This may in part explain the higher risk of these patients for progression to glaucoma. (Turk J Ophthalmol 2013; 43: 385-90

  14. Glaucoma-induced degeneration of retinal ganglion cells prevented by hypoxic preconditioning: a model of glaucoma tolerance.

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    Zhu, Yanli; Zhang, Lihong; Schmidt, Jimena F; Gidday, Jeffrey M

    2012-01-01

    Like all cells, neurons adapt to stress by transient alterations in phenotype, an epigenetic response that forms the basis for preconditioning against acute ischemic injury in the central nervous system. We recently showed that a modified repetitive hypoxic preconditioning (RHP) regimen significantly extends the window of ischemic tolerance to acute retinal ischemic injury from days to months. The present study was undertaken to determine if this uniquely protracted neuroprotective phenotype would also confer resistance to glaucomatous neurodegeneration. Retinal ganglion cell death at somatic and axonal levels was assessed after both 3 and 10 wks of sustained intraocular hypertension in an adult mouse model of inducible, open-angle glaucoma, with or without RHP before intraocular pressure elevation. Loss of brn3-positive ganglion cell soma after 3 wks of experimental glaucoma, along with increases in several apoptotic endpoints, were all significantly and robustly attenuated in mice subjected to RHP. Soma protection by RHP was also confirmed after 10 wks of intraocular hypertension by brn3 and SMI32 immunostaining. In addition, quantification of axon density in the postlaminar optic nerve documented robust preservation in RHP-treated mice, and neurofilament immunostaining also revealed preconditioning-induced improvements in axon integrity/survival in both retina and optic nerve after 10 wks of experimental glaucoma. This uniquely protracted period of phenotypic change, established in retinal ganglion cells by the activation of latent antiapoptotic, prosurvival mechanisms at both somatic and axonal levels, reflects a novel form of inducible neuronal plasticity that may provide innovative therapeutic targets for preventing and treating glaucoma and other neurodegenerative diseases. PMID:22396016

  15. Vaccination for protection of retinal ganglion cells against death from glutamate cytotoxicity and ocular hypertension: Implications for glaucoma

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    Schori, Hadas; Kipnis, Jonathan; Yoles, Eti; Woldemussie, Elizabeth; Ruiz, Guadalupe; Wheeler, Larry A.; Schwartz, Michal

    2001-03-01

    Our group recently demonstrated that autoimmune T cells directed against central nervous system-associated myelin antigens protect neurons from secondary degeneration. We further showed that the synthetic peptide copolymer 1 (Cop-1), known to suppress experimental autoimmune encephalomyelitis, can be safely substituted for the natural myelin antigen in both passive and active immunization for neuroprotection of the injured optic nerve. Here we attempted to determine whether similar immunizations are protective from retinal ganglion cell loss resulting from a direct biochemical insult caused, for example, by glutamate (a major mediator of degeneration in acute and chronic optic nerve insults) and in a rat model of ocular hypertension. Passive immunization with T cells reactive to myelin basic protein or active immunization with myelin oligodendrocyte glycoprotein-derived peptide, although neuroprotective after optic nerve injury, was ineffective against glutamate toxicity in mice and rats. In contrast, the number of surviving retinal ganglion cells per square millimeter in glutamate-injected retinas was significantly larger in mice immunized 10 days previously with Cop-1 emulsified in complete Freund's adjuvant than in mice injected with PBS in the same adjuvant (2,133 ± 270 and 1,329 ± 121, respectively, mean ± SEM; P myelin. The use of Cop-1 apparently circumvents this antigen specificity barrier. In the rat ocular hypertension model, which simulates glaucoma, immunization with Cop-1 significantly reduced the retinal ganglion cell loss from 27.8%±6.8% to 4.3%±1.6%, without affecting the intraocular pressure. This study may point the way to a therapy for glaucoma, a neurodegenerative disease of the optic nerve often associated with increased intraocular pressure, as well as for acute and chronic degenerative disorders in which glutamate is a prominent participant.

  16. Protective effects of Achyranthes bidentata polypeptides on retinal ganglion cells post-optic nerve crush in rats

    Institute of Scientific and Technical Information of China (English)

    Nan Hu; Qi Zhao; Fangling Zhang; Junfang Zhang; Xiaosong Gu

    2011-01-01

    Achyranthes bidentata polypeptides (ABPP) have been reported to inhibit apoptosis of retinal ganglion cells (RGCs).The present study investigated the protective effects of ABPP on RGCs in a rat model of optic nerve injury.With prolonged injury time,RGC densities were gradually decreased.ABPP (5 μg) significantly increased RGC densities and upregulated growth associated protein 43 expression in rats with optic nerve injury.Results demonstrate that ABPP can protect RGCs and promote axonal growth after optic nerve crush.

  17. The intricacies of neurotrophic factor therapy for retinal ganglion cell rescue in glaucoma: a case for gene therapy

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    Foldvari, Marianna; Chen, Ding Wen

    2016-01-01

    Regeneration of damaged retinal ganglion cells (RGC) and their axons is an important aspect of reversing vision loss in glaucoma patients. While current therapies can effectively lower intraocular pressure, they do not provide extrinsic support to RGCs to actively aid in their protection and regeneration. The unmet need could be addressed by neurotrophic factor gene therapy, where plasmid DNA, encoding neurotrophic factors, is delivered to retinal cells to maintain sufficient levels of neurotrophins in the retina. In this review, we aim to describe the intricacies in the design of the therapy including: the choice of neurotrophic factor, the site and route of administration and target cell populations for gene delivery. Furthermore, we also discuss the challenges currently being faced in RGC-related therapy development with special considerations to the existence of multiple RGC subtypes and the lack of efficient and representative in vitro models for rapid and reliable screening in the drug development process.

  18. The intricacies of neurotrophic factor therapy for retinal ganglion cell rescue in glaucoma:a case for gene therapy

    Institute of Scientific and Technical Information of China (English)

    Marianna Foldvari; Ding Wen Chen

    2016-01-01

    Regeneration of damaged retinal ganglion cells (RGC) and their axons is an important aspect of reversing vision loss in glaucoma patients. While current therapies can effectively lower intraocular pressure, they do not provide extrinsic support to RGCs to actively aid in their protection and regeneration. The unmet need could be addressed by neurotrophic factor gene therapy, where plasmid DNA, encoding neurotrophic factors, is delivered to retinal cells to maintain sufifcient levels of neurotrophins in the retina. In this review, we aim to describe the intricacies in the design of the therapy including: the choice of neurotrophic factor, the site and route of administration and target cell populations for gene delivery. Furthermore, we also dis-cuss the challenges currently being faced in RGC-related therapy development with special considerations to the existence of multiple RGC subtypes and the lack of efifcient and representativein vitro models for rapid and reliable screening in the drug development process.

  19. Time Course of Age-dependent Changes in Intraocular Pressure and Retinal Ganglion Cell Death in DBA/2J Mouse

    Institute of Scientific and Technical Information of China (English)

    Xiulan Zhang; Mei Zhang; Marcel Y. Avila; Jian Ge; Alan M. Laties

    2006-01-01

    Purpose: To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure (IOP) and retinal ganglion cells (RGCs) numbers in mice of various ages.Methods: A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs.Results: The baseline IOP for DBA/2J mice at 7 weeks was (16.6 ± 1.2)mm Hg.Then IOP increased extend to 12 months, with the peak of (25.2 ± 1.2)mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age (P=0.006), when the loss was proportionally higher in peripheral regions (P<0.05).Conclusion: The elevation in IOP precedes the loss of RGCs by several months.RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma.

  20. Neuroprotection by α2-Adrenergic Receptor Stimulation after Excitotoxic Retinal Injury: A Study of the Total Population of Retinal Ganglion Cells and Their Distribution in the Chicken Retina

    Science.gov (United States)

    Galindo-Romero, Caridad; Harun-Or-Rashid, Mohammad; Jiménez-López, Manuel; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta

    2016-01-01

    We have studied the effect of α2-adrenergic receptor stimulation on the total excitotoxically injured chicken retinal ganglion cell population. N-methyl-D-aspartate (NMDA) was intraocularly injected at embryonic day 18 and Brn3a positive retinal ganglion cells (Brn3a+ RGCs) were counted in flat-mounted retinas using automated routines. The number and distribution of the Brn3a+ RGCs were analyzed in series of normal retinas from embryonic day 8 to post-hatch day 11 retinas and in retinas 7 or 14 days post NMDA lesion. The total number of Brn3a+ RGCs in the post-hatch retina was approximately 1.9x106 with a density of approximately 9.2x103 cells/mm2. The isodensity maps of normal retina showed that the density decreased with age as the retinal size increased. In contrast to previous studies, we did not find any specific region with increased RGC density, rather the Brn3a+ RGCs were homogeneously distributed over the central retina with decreasing density in the periphery and in the region of the pecten oculli. Injection of 5–10 μg NMDA caused 30–50% loss of Brn3a+ cells and the loss was more severe in the dorsal than in the ventral retina. Pretreatment with brimonidine reduced the loss of Brn3a+ cells both 7 and 14 days post lesion and the protective effect was higher in the dorsal than in the ventral retina. We conclude that α2-adrenergic receptor stimulation reduced the impact of the excitotoxic injury in chicken similarly to what has been shown in mammals. Furthermore, the data show that the RGCs are evenly distributed over in the retina, which challenges previous results that indicate the presence of specific high RGC-density regions of the chicken retina. PMID:27611432

  1. Neuronal injury external to the retina rapidly activates retinal glia, followed by elevation of markers for cell cycle re-entry and death in retinal ganglion cells.

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    Alba Galan

    Full Text Available Retinal ganglion cells (RGCs are neurons that relay visual signals from the retina to the brain. The RGC cell bodies reside in the retina and their fibers form the optic nerve. Full transection (axotomy of the optic nerve is an extra-retinal injury model of RGC degeneration. Optic nerve transection permits time-kinetic studies of neurodegenerative mechanisms in neurons and resident glia of the retina, the early events of which are reported here. One day after injury, and before atrophy of RGC cell bodies was apparent, glia had increased levels of phospho-Akt, phospho-S6, and phospho-ERK1/2; however, these signals were not detected in injured RGCs. Three days after injury there were increased levels of phospho-Rb and cyclin A proteins detected in RGCs, whereas these signals were not detected in glia. DNA hyperploidy was also detected in RGCs, indicative of cell cycle re-entry by these post-mitotic neurons. These events culminated in RGC death, which is delayed by pharmacological inhibition of the MAPK/ERK pathway. Our data show that a remote injury to RGC axons rapidly conveys a signal that activates retinal glia, followed by RGC cell cycle re-entry, DNA hyperploidy, and neuronal death that is delayed by preventing glial MAPK/ERK activation. These results demonstrate that complex and variable neuro-glia interactions regulate healthy and injured states in the adult mammalian retina.

  2. Differential calcium signaling mediated by voltage-gated calcium channels in rat retinal ganglion cells and their unmyelinated axons.

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    Allison Sargoy

    Full Text Available Aberrant calcium regulation has been implicated as a causative factor in the degeneration of retinal ganglion cells (RGCs in numerous injury models of optic neuropathy. Since calcium has dual roles in maintaining homeostasis and triggering apoptotic pathways in healthy and injured cells, respectively, investigation of voltage-gated Ca channel (VGCC regulation as a potential strategy to reduce the loss of RGCs is warranted. The accessibility and structure of the retina provide advantages for the investigation of the mechanisms of calcium signalling in both the somata of ganglion cells as well as their unmyelinated axons. The goal of the present study was to determine the distribution of VGCC subtypes in the cell bodies and axons of ganglion cells in the normal retina and to define their contribution to calcium signals in these cellular compartments. We report L-type Ca channel α1C and α1D subunit immunoreactivity in rat RGC somata and axons. The N-type Ca channel α1B subunit was in RGC somata and axons, while the P/Q-type Ca channel α1A subunit was only in the RGC somata. We patch clamped isolated ganglion cells and biophysically identified T-type Ca channels. Calcium imaging studies of RGCs in wholemounted retinas showed that selective Ca channel antagonists reduced depolarization-evoked calcium signals mediated by L-, N-, P/Q- and T-type Ca channels in the cell bodies but only by L-type Ca channels in the axons. This differential contribution of VGCC subtypes to calcium signals in RGC somata and their axons may provide insight into the development of target-specific strategies to spare the loss of RGCs and their axons following injury.

  3. Impact of Morphometry, Myelinization and Synaptic Current Strength on Spike Conduction in Human and Cat Spiral Ganglion Neurons

    Science.gov (United States)

    Rattay, Frank; Potrusil, Thomas; Wenger, Cornelia; Wise, Andrew K.; Glueckert, Rudolf; Schrott-Fischer, Anneliese

    2013-01-01

    Background Our knowledge about the neural code in the auditory nerve is based to a large extent on experiments on cats. Several anatomical differences between auditory neurons in human and cat are expected to lead to functional differences in speed and safety of spike conduction. Methodology/Principal Findings Confocal microscopy was used to systematically evaluate peripheral and central process diameters, commonness of myelination and morphology of spiral ganglion neurons (SGNs) along the cochlea of three human and three cats. Based on these morphometric data, model analysis reveales that spike conduction in SGNs is characterized by four phases: a postsynaptic delay, constant velocity in the peripheral process, a presomatic delay and constant velocity in the central process. The majority of SGNs are type I, connecting the inner hair cells with the brainstem. In contrast to those of humans, type I neurons of the cat are entirely myelinated. Biophysical model evaluation showed delayed and weak spikes in the human soma region as a consequence of a lack of myelin. The simulated spike conduction times are in accordance with normal interwave latencies from auditory brainstem response recordings from man and cat. Simulated 400 pA postsynaptic currents from inner hair cell ribbon synapses were 15 times above threshold. They enforced quick and synchronous spiking. Both of these properties were not present in type II cells as they receive fewer and much weaker (∼26 pA) synaptic stimuli. Conclusions/Significance Wasting synaptic energy boosts spike initiation, which guarantees the rapid transmission of temporal fine structure of auditory signals. However, a lack of myelin in the soma regions of human type I neurons causes a large delay in spike conduction in comparison with cat neurons. The absent myelin, in combination with a longer peripheral process, causes quantitative differences of temporal parameters in the electrically stimulated human cochlea compared to the cat

  4. Impact of morphometry, myelinization and synaptic current strength on spike conduction in human and cat spiral ganglion neurons.

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    Frank Rattay

    Full Text Available BACKGROUND: Our knowledge about the neural code in the auditory nerve is based to a large extent on experiments on cats. Several anatomical differences between auditory neurons in human and cat are expected to lead to functional differences in speed and safety of spike conduction. METHODOLOGY/PRINCIPAL FINDINGS: Confocal microscopy was used to systematically evaluate peripheral and central process diameters, commonness of myelination and morphology of spiral ganglion neurons (SGNs along the cochlea of three human and three cats. Based on these morphometric data, model analysis reveales that spike conduction in SGNs is characterized by four phases: a postsynaptic delay, constant velocity in the peripheral process, a presomatic delay and constant velocity in the central process. The majority of SGNs are type I, connecting the inner hair cells with the brainstem. In contrast to those of humans, type I neurons of the cat are entirely myelinated. Biophysical model evaluation showed delayed and weak spikes in the human soma region as a consequence of a lack of myelin. The simulated spike conduction times are in accordance with normal interwave latencies from auditory brainstem response recordings from man and cat. Simulated 400 pA postsynaptic currents from inner hair cell ribbon synapses were 15 times above threshold. They enforced quick and synchronous spiking. Both of these properties were not present in type II cells as they receive fewer and much weaker (∼26 pA synaptic stimuli. CONCLUSIONS/SIGNIFICANCE: Wasting synaptic energy boosts spike initiation, which guarantees the rapid transmission of temporal fine structure of auditory signals. However, a lack of myelin in the soma regions of human type I neurons causes a large delay in spike conduction in comparison with cat neurons. The absent myelin, in combination with a longer peripheral process, causes quantitative differences of temporal parameters in the electrically stimulated human cochlea

  5. Both electrical stimulation thresholds and SMI-32-immunoreactive retinal ganglion cell density correlate with age in S334ter line 3 rat retina.

    Science.gov (United States)

    Chan, Leanne L H; Lee, Eun-Jin; Humayun, Mark S; Weiland, James D

    2011-06-01

    Electrical stimulation threshold and retinal ganglion cell density were measured in a rat model of retinal degeneration. We performed in vivo electrophysiology and morphometric analysis on normal and S334ter line 3 (RD) rats (ages 84-782 days). We stimulated the retina in anesthetized animals and recorded evoked responses in the superior colliculus. Current pulses were delivered with a platinum-iridium (Pt-Ir) electrode of 75-μm diameter positioned on the epiretinal surface. In the same animals used for electrophysiology, SMI-32 immunolabeling of the retina enabled ganglion cell counting. An increase in threshold currents positively correlated with age of RD rats. SMI-32-labeled retinal ganglion cell density negatively correlated with age of RD rats. ANOVA shows that RD postnatal day (P)100 and P300 rats have threshold and density similar to normal rats, but RD P500 and P700 rats have threshold and density statistically different from normal rats (P < 0.05). Threshold charge densities were within the safety limits of Pt for all groups and pulse configurations, except at RD P600 and RD P700, where pulses were only safe up to 1- and 0.2-ms duration, respectively. Preservation of ganglion cells may enhance the efficiency and safety of electronic retinal implants.

  6. Frequency-dependent reduction of voltage-gated sodium current modulates retinal ganglion cell response rate to electrical stimulation

    Science.gov (United States)

    Tsai, David; Morley, John W.; Suaning, Gregg J.; Lovell, Nigel H.

    2011-10-01

    The ability to elicit visual percepts through electrical stimulation of the retina has prompted numerous investigations examining the feasibility of restoring sight to the blind with retinal implants. The therapeutic efficacy of these devices will be strongly influenced by their ability to elicit neural responses that approximate those of normal vision. Retinal ganglion cells (RGCs) can fire spikes at frequencies greater than 200 Hz when driven by light. However, several studies using isolated retinas have found a decline in RGC spiking response rate when these cells were stimulated at greater than 50 Hz. It is possible that the mechanism responsible for this decline also contributes to the frequency-dependent 'fading' of electrically evoked percepts recently reported in human patients. Using whole-cell patch clamp recordings of rabbit RGCs, we investigated the causes for the spiking response depression during direct subretinal stimulation of these cells at 50-200 Hz. The response depression was not caused by inhibition arising from the retinal network but, instead, by a stimulus-frequency-dependent decline of RGC voltage-gated sodium current. Under identical experimental conditions, however, RGCs were able to spike at high frequency when driven by light stimuli and intracellular depolarization. Based on these observations, we demonstrated a technique to prevent the spiking response depression.

  7. Heat Shock Protein 72 Protects Retinal Ganglion Cells in Rat Model of Acute Glaucoma

    Institute of Scientific and Technical Information of China (English)

    Guoping Qing; Xuanchu Duan; Youqin Jiang

    2005-01-01

    Purpose: To investigate whether the induction of heat shock protein (HSP)72 by heat stress (HS) or zinc (Zn2+ ) administration can increase survival of retinal ganglion cells (RGC) in rat model of acute experimental glaucoma.Methods: Acute glaucoma model was made by intracameral irrigation with BSS at 102 mmHg for two hours in right eyes of male Wistar rats. Glaucoma model rats were treated with HS once a week (six rats) or intraperitoneal injection of zinc sulfate (24.6 mg/kg) every two weeks (six rats), and were referred to as HS group and zinc group, respectively. Untreated model rats served as damage group (six rats). In control groups, quercetin (400 mg/kg) was intraperitoneally injected to inhibit the induction of heat shock proteins 6 hours before HS or zinc administration, and were referred to as HS+que group (six rats) and zinc+que group (six rats), respectively. Subsequent to 16 days of IOP elevation, the rats were sacrificed. Eyes were quickly enucleated, and the retinas were dissected. RGC were labeled with Nissl staining and counted under microscope.Results: The average RGC density in normal Wistar rats was (2504±181) cells/mm2. In damage group, it decreased to (2015±111 ) cells/mm2. The RGC densities at 1,2, and 3 mm from the center of the optic nerve head were (2716±215), (2496±168), and (2317±171) cells/mm2, respectively, for normal rats and (2211±133), (1969±154),and (1872±68) cells/mm2, respectively, for damage group. The latter was significantly lower at all locations compared with the former (P=0.027 for each, Mann-Whitney test).The average RGC densities were (2207±200) cells/mm2 for HS group, (2272±155) cells/mm2 for zinc group, (1964±188) cells/mm2 for HS+que group, (2051 ±214) cells/mm2 for zinc+que group and (2015±111 ) cells/mm2 for damage group. There were significant differences in density of labeled RGCs among the five groups (P=0.040,Kruskal-Wallis test). Both HS and zinc group had higher RGC densities than damage group (P

  8. Characteristics of retinal reflectance changes induced by transcorneal electrical stimulation in cat eyes.

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    Takeshi Morimoto

    Full Text Available Transcorneal electrical stimulation (TES activates retinal neurons leading to visual sensations. How the retinal cells are activated by TES has not been definitively determined. Investigating the reflectance changes of the retina is an established technique and has been used to determine the mechanism of retinal activation. The purpose of this study was to evaluate the reflectance changes elicited by TES in cat eyes. Eight eyes of Eight cats were studied under general anesthesia. Biphasic electrical pulses were delivered transcornealy. The fundus images observed with near-infrared light (800-880 nm were recorded every 25 ms for 26 s. To improve the signal-to-noise ratio, the images of 10 consecutive recordings were averaged. Two-dimensional topographic maps of the reflective changes were constructed by subtracting images before from those after the TES. The effects of different stimulus parameters, e.g., current intensity, pulse duration, frequency, and stimulus duration, on the reflective changes were studied. Our results showed that after TES, the reflective changes appeared on the retinal vessels and optic disc. The intensity of reflectance changes increased as the current intensity, pulse duration, and stimulation duration increased (P<0.05 for all. The maximum intensity of the reflective change was obtained when the stimulus frequency was 20 Hz. The time course of the reflectance changes was also altered by the stimulation parameters. The response started earlier and returned to the baseline later with higher current intensities, longer pulse durations, but the time of the peak of the response was not changed. These results showed that the reflective changes were due to the activation of retinal neurons by TES and might involve the vascular changes induced by an activation of the retinal neurons.

  9. In vivo evaluation of an episcleral multielectrode array for stimulation of the retina with reduced retinal ganglion cell mass.

    Science.gov (United States)

    Siu, Timothy L; Morley, John W

    2008-05-01

    A visual prosthesis is an experimental device designed to activate residual functional neurons in the visual pathway to generate artificial vision for blind patients. Specifically, for photoreceptor disease, a microelectrode array applied to the surface of the sclera could potentially serve to stimulate the remaining interneurons in the retina to produce topographically mapped visual percepts. However, of those neurons spared in the disease process, the retinal ganglion cells (RGC), which represent the final output neurons of the retina, can be markedly reduced in number. Using an albino rabbit model with RGC deficits, acute recording of cortical electrical evoked potential was performed to ascertain whether such a stimulation strategy is feasible. By analyzing the strength-duration curve (current threshold vs. pulse duration) and cortical activation profiles, our results prove that bioelectrically safe and spatially differentiated stimulation of the retina is feasible notwithstanding the condition of markedly reduced RGC counts.

  10. Chemogenetic Activation of Melanopsin Retinal Ganglion Cells Induces Signatures of Arousal and/or Anxiety in Mice.

    Science.gov (United States)

    Milosavljevic, Nina; Cehajic-Kapetanovic, Jasmina; Procyk, Christopher A; Lucas, Robert J

    2016-09-12

    Functional imaging and psychometric assessments indicate that bright light can enhance mood, attention, and cognitive performance in humans. Indirect evidence links these events to light detection by intrinsically photosensitive melanopsin-expressing retinal ganglion cells (mRGCs) [1-9]. However, there is currently no direct demonstration that mRGCs can have such an immediate effect on mood or behavioral state in any species. We addressed this deficit by using chemogenetics to selectively activate mRGCs, simulating the excitatory effects of bright light on this cell type in dark-housed mice. This specific manipulation evoked circadian phase resetting and pupil constriction (known consequences of mRGC activation). It also induced c-Fos (a marker of neuronal activation) in multiple nuclei in the hypothalamus (paraventricular, dorsomedial, and lateral hypothalamus), thalamus (paraventricular and centromedian thalamus), and limbic system (amygdala and nucleus accumbens). These regions influence numerous aspects of autonomic and neuroendocrine activity and are typically active during periods of wakefulness or arousal. By contrast, c-Fos was absent from the ventrolateral preoptic area (active during sleep). In standard behavioral tests (open field and elevated plus maze), mRGC activation induced behaviors commonly interpreted as anxiety like or as signs of increased alertness. Similar changes in behavior could be induced by bright light in wild-type and rodless and coneless mice, but not melanopsin knockout mice. These data demonstrate that mRGCs drive a light-dependent switch in behavioral motivation toward a more alert, risk-averse state. They also highlight the ability of this small fraction of retinal ganglion cells to realign activity in brain regions defining widespread aspects of physiology and behavior. PMID:27426512

  11. Y-like retinal ganglion cells innervate the dorsal raphe nucleus in the Mongolian gerbil (Meriones unguiculatus.

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    Liju Luan

    Full Text Available BACKGROUND: The dorsal raphe nucleus (DRN of the mesencephalon is a complex multi-functional and multi-transmitter nucleus involved in a wide range of behavioral and physiological processes. The DRN receives a direct input from the retina. However little is known regarding the type of retinal ganglion cell (RGC that innervates the DRN. We examined morphological characteristics and physiological properties of these DRN projecting ganglion cells. METHODOLOGY/PRINCIPAL FINDINGS: The Mongolian gerbils are highly visual rodents with a diurnal/crepuscular activity rhythm. It has been widely used as experimental animals of various studies including seasonal affective disorders and depression. Young adult gerbils were used in the present study. DRN-projecting RGCs were identified following retrograde tracer injection into the DRN, characterized physiologically by extracellular recording and morphologically after intracellular filling. The result shows that DRN-projecting RGCs exhibit morphological characteristics typical of alpha RGCs and physiological response properties of Y-cells. Melanopsin was not detected in these RGCs and they show no evidence of intrinsic photosensitivity. CONCLUSIONS/SIGNIFICANCE: These findings suggest that RGCs with alpha-like morphology and Y-like physiology appear to perform a non-imaging forming function and thus may participate in the modulation of DRN activity which includes regulation of sleep and mood.

  12. The influence of venous blood flow on the retinal ganglion cell complex in patients with primary open angle glaucoma

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    N. I. Kurysheva

    2014-07-01

    Full Text Available Purpose: To study the influence of venous blood flow on the ganglion cell complex (GCC in patients with preperimetric and perimetric open angle glaucoma.Methods: 74 patients were included in the research. 59 eyes and 62 eyes were diagnosed with preperimetric and perimetric open angle glaucoma respectively. The mean age was 56.5±10.5 years. 22 (12 female and 10 male healthy individuals constituted the control group. The ganglion cell complex and retinal nerve fibre layer were evaluated with the help of optical coherence tomography (RTVue-100 OCT, Optovue, Inc., Fremont, CA. Ocular blood flow was measured by Color Doppler Imaging (multifunctional VOLUSON 730 ProSystem. The statistical analysis included correlation between GCC and RNFL thickness in both glaucoma groups.Results: The results showed a statistically significant reduction of venous blood flow velocity in both glaucoma groups compared to the control group. No difference in venous blood flow parameters between two glaucoma groups was found, except resistance index, which was higher in perimetric group in comparison to preperimetric group. A correlation was also obtained between venous blood flow parameters and GCC and RNFL thickness in both glaucoma groups.Conclusion: Early GCC damage in glaucoma might occur due to venous blood flow reduction. This fact may be of great value in understanding glaucoma pathogenesis and search for novel treatment options.

  13. Involvement of two different mechanisms in trigeminal ganglion-evoked vasodilatation in the cat lower lip: role of experimental conditions.

    Science.gov (United States)

    Date, H; Kato, M; Izumi, H

    2000-03-15

    The present study was designed to examine the vasodilator mechanisms elicited by electrical stimulation of trigeminal ganglion (TG) in cat lower lip of the cats. When vago-sympathectomized cats were fixed into a stereotaxic frame by means of ear-bars, etc., the lip blood flow (LBF) increase evoked by lingual nerve (LN) stimulation (parasympathetic reflex response) was almost abolished in 15 out of 34 animals, but unaffected in the other 19. With the animal in the stereotaxic frame, electrical stimulation at sites within the TG evoked an LBF increase whether or not the LN stimulation-induced reflex response was intact. However, hexamethonium abolished the TG stimulation-induced LBF increase in animals whose brainstem parasympathetic reflex was intact, but reduced it by only 50% in animals whose reflex was impaired. This difference was seen in all experiments in which the electrode site was within the TG proper, regardless of its exact position. Although the underlying mechanism is unclear, these data suggest that when the TG is stimulated the LBF increase is entirely mediated via the parasympathetic reflex mechanism in animals whose brainstem reflex is intact, and that an antidromic vasodilatation occurs only in animals whose brainstem parasympathetic reflex is impaired.

  14. Retinal ganglion cell survival and axon regeneration in WldS transgenic rats after optic nerve crush and lens injury

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    Lorber Barbara

    2012-06-01

    Full Text Available Abstract Background We have previously shown that the slow Wallerian degeneration mutation, whilst delaying axonal degeneration after optic nerve crush, does not protect retinal ganglion cell (RGC bodies in adult rats. To test the effects of a combination approach protecting both axons and cell bodies we performed combined optic nerve crush and lens injury, which results in both enhanced RGC survival as well as axon regeneration past the lesion site in wildtype animals. Results As previously reported we found that the WldS mutation does not protect RGC bodies after optic nerve crush alone. Surprisingly, we found that WldS transgenic rats did not exhibit the enhanced RGC survival response after combined optic nerve crush and lens injury that was observed in wildtype rats. RGC axon regeneration past the optic nerve lesion site was, however, similar in WldS and wildtypes. Furthermore, activation of retinal glia, previously shown to be associated with enhanced RGC survival and axon regeneration after optic nerve crush and lens injury, was unaffected in WldS transgenic rats. Conclusions RGC axon regeneration is similar between WldS transgenic and wildtype rats, but WldS transgenic rats do not exhibit enhanced RGC survival after combined optic nerve crush and lens injury suggesting that the neuroprotective effects of lens injury on RGC survival may be limited by the WldS protein.

  15. Inhibiting Matrix Metalloproteinase 3 Ameliorates Neuronal Loss in the Ganglion Cell Layer of Rats in Retinal Ischemia/Reperfusion.

    Science.gov (United States)

    Hu, Tu; You, Qiuting; Chen, Dan; Tong, Jianbin; Shang, Lei; Luo, Jia; Qiu, Yi; Yu, Huimin; Zeng, Leping; Huang, Jufang

    2016-05-01

    It has been demonstrated that matrix metalloproteinase 3 (MMP3) is integrally involved in the neuronal degeneration of the central nervous system by promoting glial activation, neuronal apoptosis and damage to the brain-blood barrier. However, whether MMP3 also contributes to the neuronal degeneration induced by retinal ischemia/reperfusion is still uncertain. In the present study, we detected the cellular localization of MMP3 in adult rat retinae and explored the relationship of its expression with neuronal loss in the ganglion cell layer (GCL) in retinal ischemia/reperfusion. We found that MMP3 was widely expressed in many cells throughout the layers of the rat retinae, including Vertebrate neuron-specific nuclear protein (NeuN)-, parvalbumin-, calbindin-, protein kinase C-α-, glial fibrillary acidic protein-, glutamine synthetase- and CD11b-positive cells. Furthermore, all rats were treated with high intraocular pressure (HIOP) for 1 h (h) and sacrificed at 6 h, 1 day (d), 3 d, and 7 d after HIOP. Compared to the normal control, the expression of both proenzyme MMP3 and active MMP3 were significantly up-regulated after HIOP treatment without alteration of the laminar distribution pattern. Moreover, inhibiting MMP3 ameliorated the loss of NeuN-positive cells in the GCL following HIOP. In summary, our data demonstrates that MMP3 is expressed in multiple types of neurons and glial cells in normal rat retinae. Simultaneously, the up-regulation of its expression and activity are closely involved in neuronal loss in the GCL in retinal ischemia/reperfusion. PMID:26830289

  16. Central projections of intrinsically photosensitive retinal ganglion cells in the macaque monkey

    DEFF Research Database (Denmark)

    Hannibal, J; Kankipati, L; Strang, C E;

    2014-01-01

    ). The ipRGCs regulate other nonimage-forming visual functions such as the pupillary light reflex, masking behavior, and light-induced melatonin suppression. To evaluate whether PACAP-immunoreactive retinal projections are useful as a marker for central projection of ipRGCs in the monkey brain, we...... including the pregeniculate nucleus, the pretectal olivary nucleus, the nucleus of the optic tract, the brachium of the superior colliculus, and the superior colliculus. In conclusion, PACAP-immunoreactive projections with colocalized CtB represent retinal projections of ipRGCs in the macaque monkey......, supporting previous retrograde tracer studies demonstrating that melanopsin-containing retinal projections reach areas in the primate brain involved in both image- and nonimage-forming visual processing....

  17. Comparative study of photoreceptor and retinal ganglion cell topography and spatial resolving power in Dipsadidae snakes.

    Science.gov (United States)

    Hauzman, Einat; Bonci, Daniela M O; Grotzner, Sonia R; Mela, Maritana; Liber, André M P; Martins, Sonia L; Ventura, Dora F

    2014-01-01

    The diurnal Dipsadidae snakes Philodryas olfersii and P. patagoniensis are closely related in their phylogeny but inhabit different ecological niches. P. olfersii is arboreal, whereas P. patagoniensis is preferentially terrestrial. The goal of the present study was to compare the density and topography of neurons, photoreceptors, and cells in the ganglion cell layer in the retinas of these two species using immunohistochemistry and Nissl staining procedures and estimate the spatial resolving power of their eyes based on the ganglion cell peak density. Four morphologically distinct types of cones were observed by scanning electron microscopy, 3 of which were labeled with anti-opsin antibodies: large single cones and double cones labeled by the antibody JH492 and small single cones labeled by the antibody JH455. The average densities of photoreceptors and neurons in the ganglion cell layer were similar in both species (∼10,000 and 7,000 cells·mm(-2), respectively). The estimated spatial resolving power was also similar, ranging from 2.4 to 2.7 cycles·degree(-1). However, the distribution of neurons had different specializations. In the arboreal P. olfersii, the isodensity maps had a horizontal visual streak, with a peak density in the central region and a lower density in the dorsal retina. This organization might be relevant for locomotion and hunting behavior in the arboreal layer. In the terrestrial P. patagoniensis, a concentric pattern of decreasing cell density emanated from an area centralis located in the naso-ventral retina. Lower densities were observed in the dorsal region. The ventrally high density improves the resolution in the superior visual field and may be an important adaptation for terrestrial snakes to perceive the approach of predators from above. PMID:25342570

  18. Temporal properties of network-mediated responses to repetitive stimuli are dependent upon retinal ganglion cell type

    Science.gov (United States)

    Im, Maesoon; Fried, Shelley I.

    2016-04-01

    Objective. To provide artificially-elicited vision that is temporally dynamic, retinal prosthetic devices will need to repeatedly stimulate retinal neurons. However, given the diversity of physiological types of retinal ganglion cells (RGCs) as well as the heterogeneity of their responses to electric stimulation, temporal properties of RGC responses have not been adequately investigated. Here, we explored the cell type dependence of network-mediated RGC responses to repetitive electric stimulation at various stimulation rates. Approach. We examined responses of ON and OFF types of RGCs in the rabbit retinal explant to five consecutive stimuli with varying inter-stimulus intervals (10-1000 ms). Each stimulus was a 4 ms long monophasic sinusoidal cathodal current, which was applied epiretinally via a conical electrode. Spiking activity of targeted RGCs was recorded using a cell-attached patch electrode. Main results. ON and OFF cells had distinct responses to repetitive stimuli. Consistent with earlier studies, OFF cells always generated reduced responses to subsequent stimuli compared to responses to the first stimulus. In contrast, a new stimulus to ON cells suppressed all pending/ongoing responses from previous stimuli and initiated its own response that was remarkably similar to the response from a single stimulus in isolation. This previously unreported ‘reset’ behavior was observed exclusively and consistently in ON cells. These contrasts between ON and OFF cells created a range of stimulation rates (4-7 Hz) that maximized the ratio of the responses arising in ON versus OFF cells. Significance. Previous clinical testing reported that subjects perceive bright phosphenes (ON responses) and also prefer stimulation rates of 5-7 Hz. Our results suggest that responses of ON cells are weak at high rates of stimulation (> ˜7 Hz) due to the reset while responses of OFF cells are strong at low rates (cells more closely match physiological patterns (Im and Fried 2015

  19. Gender difference in the neuroprotective effect of rat bone marrow mesenchymal cells against hypoxia-induced apoptosis of retinal ganglion cells

    OpenAIRE

    Jing Yuan; Jian-xiong Yu

    2016-01-01

    Bone marrow mesenchymal stem cells can reduce retinal ganglion cell death and effectively prevent vision loss. Previously, we found that during differentiation, female rhesus monkey bone marrow mesenchymal stem cells acquire a higher neurogenic potential compared with male rhesus monkey bone marrow mesenchymal stem cells. This suggests that female bone marrow mesenchymal stem cells have a stronger neuroprotective effect than male bone marrow mesenchymal stem cells. Here, we first isolated and...

  20. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells

    OpenAIRE

    Gaub, Benjamin M.; Berry, Michael H.; Holt, Amy E.; Reiner, Andreas; Kienzler, Michael A; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D.; Beltran, William A.; Flannery, John G.; Isacoff, Ehud Y.

    2014-01-01

    We restored visual function to animal models of human blindness using a chemical compound that photosensitizes a mammalian ion channel. Virus-mediated expression of this light sensor in surviving retinal cells of blind mice restored light responses in vitro, reanimated innate light avoidance, and enabled learned visually guided behavior. The treatment also restored light responses to the retina of blind dogs. Patients that might benefit from this treatment would need to have intact ganglion c...

  1. 17β-Estradiol eye drops protect the retinal ganglion cell layer and preserve visual function in an in vivo model of glaucoma

    OpenAIRE

    Tatrai, Katalin Prokai; Xin, Hua; Nguyen, Vien; Szarka, Szabolcs; Blazics, Balazs; Prokai, Laszlo; Koulen, Peter

    2013-01-01

    Neuroprotection in glaucoma as a curative strategy complementary to current therapies to lower intraocular pressure (IOP) is highly desirable. This study was designed to investigate neuroprotection by 17β-estradiol (E2) to prevent retinal ganglion cell (RGC) death in a glaucoma model of surgically elevated IOP in rats. We found that daily treatment with E2 containing eye drops resulted in significant E2 concentration in the retina with concomitant profound neuroprotective therapeutic benefits...

  2. Formalization of the input/output retinal transformation regarding non-standard ganglion cells behavior

    OpenAIRE

    Teftef, Elaa; Viéville, Thierry

    2012-01-01

    National audience; We propose to implement the computational principles raised by the study on the K-cells of the retina using a variational specification of the visual front-end, with an important consequence: In such a framework, the GC are not to be considered individually, but as a network, yielding a mesoscopic view of the retinal processWe consider this visual event detection mechanism to be based on image segmentation and specific natural statistical recognition, including temporal pat...

  3. The polymodal ion channel TRPV4 modulates calcium flux, spiking rate and apoptosis of mouse retinal ganglion cells

    Science.gov (United States)

    Ryskamp, Daniel A.; Witkovsky, Paul; Barabas, Peter; Huang, Wei; Koehler, Christopher; Akimov, Nikolay P.; Lee, Suk Hee; Chauhan, Shiwani; Xing, Wei; Rentería, René C.; Liedtke, Wolfgang; Krizaj, David

    2011-01-01

    Sustained increase in intraocular pressure represents a major risk factor for eye disease yet the cellular mechanisms of pressure transduction in the posterior eye are essentially unknown. Here we show that the mouse retina expresses mRNA and protein for the polymodal TRPV4 cation channel known to mediate osmo- and mechanotransduction. TRPV4 antibodies labeled perikarya, axons and dendrites of retinal ganglion cells (RGCs) and intensely immunostained the optic nerve head. Müller glial cells, but not retinal astrocytes or microglia, also expressed TRPV4 immunoreactivity. The selective TRPV4 agonists 4α-PDD and GSK1016790A elevated [Ca2+]i in dissociated RGCs in a dose-dependent manner whereas the TRPV1 agonist capsaicin had no effect on [Ca2+]RGC. Exposure to hypotonic stimulation evoked robust increases in [Ca2+]RGC. RGC responses to TRPV4-selective agonists and hypotonic stimulation were absent in Ca2+-free saline and were antagonized by the nonselective TRP channel antagonists Ruthenium Red and gadolinium, but were unaffected by the TRPV1 antagonist capsazepine. TRPV4-selective agonists increased the spiking frequency recorded from intact retinas recorded with multielectrode arrays. Sustained exposure to TRPV4 agonists evoked dose-dependent apoptosis of RGCs. Our results demonstrate functional TRPV4 expression in RGCs and suggest that its activation mediates response to membrane stretch leading to elevated [Ca2+]i and augmented excitability. Excessive Ca2+ influx through TRPV4 predisposes RGCs to activation of Ca2+-dependent pro-apoptotic signaling pathways, indicating that TRPV4 is a component of the response mechanism to pathological elevations of intraocular pressure. PMID:21562271

  4. Protection by an oral disubstituted hydroxylamine derivative against loss of retinal ganglion cell differentiation following optic nerve crush.

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    James D Lindsey

    Full Text Available Thy-1 is a cell surface protein that is expressed during the differentiation of retinal ganglion cells (RGCs. Optic nerve injury induces progressive loss in the number of RGCs expressing Thy-1. The rate of this loss is fastest during the first week after optic nerve injury and slower in subsequent weeks. This study was undertaken to determine whether oral treatment with a water-soluble N-hydroxy-2,2,6,6-tetramethylpiperidine derivative (OT-440 protects against loss of Thy-1 promoter activation following optic nerve crush and whether this effect targets the earlier quick phase or the later slow phase. The retina of mice expressing cyan fluorescent protein under control of the Thy-1 promoter (Thy1-CFP mice was imaged using a blue-light confocal scanning laser ophthalmoscope (bCSLO. These mice then received oral OT-440 prepared in cream cheese or dissolved in water, or plain vehicle, for two weeks and were imaged again prior to unilateral optic nerve crush. Treatments and weekly imaging continued for four more weeks. Fluorescent neurons were counted in the same defined retinal areas imaged at each time point in a masked fashion. When the counts at each time point were directly compared, the numbers of fluorescent cells at each time point were greater in the animals that received OT-440 in cream cheese by 8%, 27%, 52% and 60% than in corresponding control animals at 1, 2, 3 and 4 weeks after optic nerve crush. Similar results were obtained when the vehicle was water. Rate analysis indicated the protective effect of OT-440 was greatest during the first two weeks and was maintained in the second two weeks after crush for both the cream cheese vehicle study and water vehicle study. Because most of the fluorescent cells detected by bCSLO are RGCs, these findings suggest that oral OT-440 can either protect against or delay early degenerative responses occurring in RGCs following optic nerve injury.

  5. Increased production of omega-3 fatty acids protects retinal ganglion cells after optic nerve injury in mice.

    Science.gov (United States)

    Peng, Shanshan; Shi, Zhe; Su, Huanxing; So, Kwok-Fai; Cui, Qi

    2016-07-01

    Injury to the central nervous system causes progressive degeneration of injured axons, leading to loss of the neuronal bodies. Neuronal survival after injury is a prerequisite for successful regeneration of injured axons. In this study, we investigated the effects of increased production of omega-3 fatty acids and elevation of cAMP on retinal ganglion cell (RGC) survival and axonal regeneration after optic nerve (ON) crush injury in adult mice. We found that increased production of omega-3 fatty acids in mice enhanced RGC survival, but not axonal regeneration, over a period of 3 weeks after ON injury. cAMP elevation promoted RGC survival in wild type mice, but no significant difference in cell survival was seen in mice over-producing omega-3 fatty acids and receiving intravitreal injections of CPT-cAMP, suggesting that cAMP elevation protects RGCs after injury but does not potentiate the actions of the omega-3 fatty acids. The observed omega-3 fatty acid-mediated neuroprotection is likely achieved partially through ERK1/2 signaling as inhibition of this pathway by PD98059 hindered, but did not completely block, RGC protection. Our study thus enhances our current understanding of neural repair after CNS injury, including the visual system.

  6. Hydrogen-rich saline promotes survival of retinal ganglion cells in a rat model of optic nerve crush.

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    Jing-chuan Sun

    Full Text Available OBJECTIVE: To investigate the effect of molecular hydrogen (H2 in a rat model subjected to optic nerve crush (ONC. METHODS: We tested the hypothesis that after optic nerve crush (ONC, retinal ganglion cell (RGC could be protected by H₂. Rats in different groups received saline or hydrogen-rich saline every day for 14 days after ONC. Retinas from animals in each group underwent measurements of hematoxylin and eosin (H&E staining, cholera toxin beta (CTB tracing, gamma synuclein staining, and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL staining 2 weeks post operation. Flash visual evoked potentials (FVEP and pupillary light reflex (PLR were then tested to evaluate the function of optic nerve. The malondialdehyde (MDA level in retina was evaluated. RESULTS: H&E, gamma synuclein staining and CTB tracing showed that the survival rate of RGCs in hydrogen saline-treated group was significantly higher than that in saline-treated group. Apoptosis of RGCs assessed by TUNEL staining were less observed in hydrogen saline-treated group. The MDA level in retina of H₂ group was much lower than that in placebo group. Furthermore, animals treated with hydrogen saline showed better function of optic nerve in assessments of FVEP and PLR. CONCLUSION: These results demonstrated that H₂ protects RGCs and helps preserve the visual function after ONC and had a neuroprotective effect in a rat model subjected to ONC.

  7. Responses of retinal ganglion cells to extracellular electrical stimulation, from single cell to population: model-based analysis.

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    David Tsai

    Full Text Available Retinal ganglion cells (RGCs, which survive in large numbers following neurodegenerative diseases, could be stimulated with extracellular electric pulses to elicit artificial percepts. How do the RGCs respond to electrical stimulation at the sub-cellular level under different stimulus configurations, and how does this influence the whole-cell response? At the population level, why have experiments yielded conflicting evidence regarding the extent of passing axon activation? We addressed these questions through simulations of morphologically and biophysically detailed computational RGC models on high performance computing clusters. We conducted the analyses on both large-field RGCs and small-field midget RGCs. The latter neurons are unique to primates. We found that at the single cell level the electric potential gradient in conjunction with neuronal element excitability, rather than the electrode center location per se, determined the response threshold and latency. In addition, stimulus positioning strongly influenced the location of RGC response initiation and subsequent activity propagation through the cellular structure. These findings were robust with respect to inhomogeneous tissue resistivity perpendicular to the electrode plane. At the population level, RGC cellular structures gave rise to low threshold hotspots, which limited axonal and multi-cell activation with threshold stimuli. Finally, due to variations in neuronal element excitability over space, following supra-threshold stimulation some locations favored localized activation of multiple cells, while others favored axonal activation of cells over extended space.

  8. Interferon-gamma (IFN-γ-mediated retinal ganglion cell death in human tyrosinase T cell receptor transgenic mouse.

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    Shahid Husain

    Full Text Available We have recently demonstrated the characterization of human tyrosinase TCR bearing h3T-A2 transgenic mouse model, which exhibits spontaneous autoimmune vitiligo and retinal dysfunction. The purpose of current study was to determine the role of T cells and IFN-γ in retina dysfunction and retinal ganglion cell (RGC death using this model. RGC function was measured by pattern electroretinograms (ERGs in response to contrast reversal of patterned visual stimuli. RGCs were visualized by fluorogold retrograde-labeling. Expression of CD3, IFN-γ, GFAP, and caspases was measured by immunohistochemistry and Western blotting. All functional and structural changes were measured in 12-month-old h3T-A2 mice and compared with age-matched HLA-A2 wild-type mice. Both pattern-ERGs (42%, p = 0.03 and RGC numbers (37%, p = 0.0001 were reduced in h3T-A2 mice when compared with wild-type mice. The level of CD3 expression was increased in h3T-A2 mice (h3T-A2: 174 ± 27% vs. HLA-A2: 100%; p = 0.04. The levels of effector cytokine IFN-γ were also increased significantly in h3T-A2 mice (h3T-A2: 189 ± 11% vs. HLA-A2: 100%; p = 0.023. Both CD3 and IFN-γ immunostaining were increased in nerve fiber (NF and RGC layers of h3T-A2 mice. In addition, we have seen a robust increase in GFAP staining in h3T-A2 mice (mainly localized to NF layer, which was substantially reduced in IFN-γ ((-/- knockout h3T-A2 mice. We also have seen an up-regulation of caspase-3 and -9 in h3T-A2 mice. Based on our data we conclude that h3T-A2 transgenic mice exhibit visual defects that are mostly associated with the inner retinal layers and RGC function. This novel h3T-A2 transgenic mouse model provides opportunity to understand RGC pathology and test neuroprotective strategies to rescue RGCs.

  9. Distribution of damage to the entire retinal ganglion cell pathway: quantified using spectral-domain optical coherence tomography analysis in patients with glaucoma.

    Science.gov (United States)

    Lee, Kyungmoo; Kwon, Young H; Garvin, Mona K; Niemeijer, Meindert; Sonka, Milan; Abràmoff, Michael D

    2012-09-01

    OBJECTIVES To test the hypothesis that the amount and distribution of glaucomatous damage along the entire retinal ganglion cell-axonal complex (RGC-AC) can be quantified and to map the RGC-AC connectivity in early glaucoma using automated image analysis of standard spectral-domain optical coherence tomography. METHODS Spectral-domain optical coherence tomography volumes were obtained from 116 eyes in 58 consecutive patients with glaucoma or suspected glaucoma. Layer and optic nerve head (ONH) analysis was performed; the mean regional retinal ganglion cell layer thickness (68 regions), nerve fiber layer (NFL) thickness (120 regions), and ONH rim area (12 wedge-shaped regions) were determined. Maps of RGC-AC connectivity were created using maximum correlation between regions' ganglion cell layer thickness, NFL thickness, and ONH rim area; for retinal nerve fiber bundle regions, the maximum "thickness correlation paths" were determined. RESULTS The mean (SD) NFL thickness and ganglion cell layer thickness across all macular regions were 22.5 (7.5) μm and 33.9 (8.4) μm, respectively. The mean (SD) rim area across all ONH wedge regions was 0.038 (0.004) mm2. Connectivity maps were obtained successfully and showed typical nerve fiber bundle connectivity of the RGC-AC cell body segment to the initial NFL axonal segment, of the initial to the final RGC-AC NFL axonal segments, of the final RGC-AC NFL axonal to the ONH axonal segment, and of the RGC-AC cell body segment to the ONH axonal segment. CONCLUSIONS In early glaucoma, the amount and distribution of glaucomatous damage along the entire RGC-AC can be quantified and mapped using automated image analysis of standard spectral-domain optical coherence tomography. Our findings should contribute to better detection and improved management of glaucoma. PMID:22965586

  10. Retinal nerve fiber layer and ganglion cell complex thickness assessment in patients with Alzheimer disease and mild cognitive impairment. Preliminary results

    Directory of Open Access Journals (Sweden)

    A. S. Tiganov

    2014-07-01

    Full Text Available Purpose: to investigate the retinal nerve fiber layer (RNFL and the macular ganglion cell complex (GCC in patients with Alzheimer`s disease and mild cognitive impairment.Methods: this study included 10 patients (20 eyes with Alzheimer`s disease, 10 patients with mild cognitive impairment and 10 age- and sex-matched healthy controls that had no history of dementia. All the subjects underwent psychiatric examination, including the Mini-Mental State Examination (MMSE, and complete ophthalmological examination, comprising optical coherence tomography and scanning laser polarimetry.Results: there was a significant decrease in GCC thickness in patients with Alzheimer`s disease compared to the control group, global loss volume of ganglion cells was higher than in control group. there was no significant difference among the groups in terms of RNFL thickness. Weak positive correlation of GCC thickness and MMSE results was observed.Conclusion: Our data confirm the retinal involvement in Alzheimer`s disease, as reflected by loss of ganglion cells. Further studies will clear up the role and contribution of dementia in pathogenesis of optic neuropathy.

  11. Lack of genetic association among coat colors, progressive retinal atrophy and polycystic kidney disease in Persian cats.

    Science.gov (United States)

    Rah, HyungChul; Maggs, David J; Lyons, Leslie A

    2006-10-01

    An inherited form of progressive retinal atrophy (PRA) is recognized in Persian cats; however, the prevalence of PRA in the breed has not been determined. Breeders suggest that cats from only brown ('chocolate') or Himalayan ('pointed') lines are at risk for PRA, suggesting the disease is not widespread. This study was designed to evaluate whether PRA in Persian cats is associated with three coat colors, including chocolate, or with a highly prevalent inherited disease in this breed--polycystic kidney disease (PKD). Sixty related cats were evaluated for PRA by ophthalmic examination and genetically typed for PKD and the mutations that cause coat color variants in agouti, brown and color (producing the pointed coloration in Himalayan). No associations were identified among any of the traits, including between PRA and chocolate. These data suggest that PRA is not limited to cats with chocolate coat coloration and breeders and veterinarians should be aware that the prevalence of the disease may be higher than currently claimed.

  12. Erythropoietin protects adult retinal ganglion cells against NMDA-, trophic factor withdrawal-, and TNF-α-induced damage.

    Directory of Open Access Journals (Sweden)

    Zhi-Yang Chang

    Full Text Available PURPOSE: This study aimed to evaluate the neuroprotective effect of EPO in the presence of N-methyl-d-aspartate (NMDA-, trophic factor withdrawal (TFW-, and tumor necrosis factor-alpha (TNF-α-induced toxicity on total, small, and large retinal ganglion cells (RGCs. METHODS: Retinal cells from adult rats were cultured in a medium containing brain-derived neurotrophic factor (BDNF, ciliary neurotrophic factor (CNTF, basic fibroblast growth factor (bFGF, and forskolin. Expression of RGC markers and EPOR was examined using immunocytochemistry. RGCs were classified according to their morphological properties. Cytotoxicity was induced by NMDA, TFW, or TNF-α. RGC survival was assessed by counting thy-1 and neurofilament-l double-positive cells. RESULTS: EPO offered dose-dependent (EC₅₀ = 5.7 ng/mL protection against NMDA toxicity for small RGCs; protection was not significant for large RGCs. Time-course analysis showed that the presence of EPO either before or after NMDA exposure gave effective protection. For both small and large RGCs undergoing trophic factor withdrawal, EPO at concentrations of 1, 10, or 100 ng/mL improved survival. However, EPO had to be administered soon after the onset of injury to provide effective protection. For TNF-α-induced toxicity, survival of small RGCs was seen only for the highest examined concentration (100 ng/mL of EPO, whereas large RGCs were protected at concentrations of 1, 10, or 100 ng/mL of EPO. Time-course analysis showed that pretreatment with EPO provided protection only for large RGCs; early post-treatment with EPO protected both small and large RGCs. Inhibitors of signal transduction and activators of transcription such as (STAT-5, mitogen-activated protein kinases (MAPK/extracellular-regulated kinase (ERK, and phosphatidyl inositol-3 kinase (PI3K/Akt impaired the protective effect of EPO on RGCs exposed to different insults. CONCLUSION: EPO provided neuroprotection to cultured adult rat RGCs

  13. Protection of neurons in the retinal ganglion cell layer against excitotoxicity by the N-acylethanolamine, N-linoleoylethanolamine

    Directory of Open Access Journals (Sweden)

    Duncan RS

    2011-04-01

    Full Text Available R. Scott Duncan1,*, Hua Xin1,*, Daryl L Goad1, Kent D Chapman2,3, Peter Koulen1,31Vision Research Center and Departments of Ophthalmology and Basic Medical Science, School of Medicine, University of Missouri, Kansas City, MO, USA; 2Department of Biological Sciences, University of North Texas, Denton, TX, USA; 3Center for Plant Lipid Research, University of North Texas, Denton, TX, USA *Authors contributed equallyAbstract: Retinal ganglion cell (RGC death is a hallmark of neurodegenerative diseases and disease processes of the eye, including glaucoma. The protection of RGCs has been an important strategy for combating glaucoma, but little clinical success has been reported to date. One pathophysiological consequence of glaucoma is excessive extracellular glutamate subsequently leading to excitotoxicity in the retina. Endocannabinoids, such as the N-acylethanolamine (NAE, arachidonylethanolamine (NAE 20:4, exhibit neuroprotective properties in some models of neurodegenerative disease. The majority of NAEs, however, are not cannabinoids, and their physiological function is not clear. Here, we determined whether the noncannabinoid NAE, linoleoylethanolamine (NAE18:2, protects neurons in the RGC layer against glutamate excitotoxicity in ex-vivo retina cultures. Using a terminal deoxynucleotidyl transferase-mediated dUTP (2´-deoxyuridine 5´-triphosphate nick-end labeling (TUNEL assay, we determined that NAE18:2 reduces the number of apoptotic RGC layer neurons in response to glutamate and conclude that NAE18:2 is a neuroprotective compound with potential for treating glaucomatous retinopathy.Keywords: neuroprotection, glutamate, calcium signaling, immunocytochemistry, eye, vision, glaucoma.

  14. The glial cell modulator ibudilast attenuates neuroinflammation and enhances retinal ganglion cell viability in glaucoma through protein kinase A signaling.

    Science.gov (United States)

    Cueva Vargas, Jorge L; Belforte, Nicolas; Di Polo, Adriana

    2016-09-01

    Glaucoma is a neurodegenerative disease and the leading cause of irreversible blindness worldwide. Vision deficits in glaucoma result from the selective loss of retinal ganglion cells (RGC). Glial cell-mediated neuroinflammation has been proposed to contribute to disease pathophysiology, but whether this response is harmful or beneficial for RGC survival is not well understood. To test this, we characterized the role of ibudilast, a clinically approved cAMP phosphodiesterase (PDE) inhibitor with preferential affinity for PDE type 4 (PDE4). Here, we demonstrate that intraocular administration of ibudilast dampened macroglia and microglia reactivity in the retina and optic nerve hence decreasing production of proinflammatory cytokines in a rat model of ocular hypertension. Importantly, ibudilast promoted robust RGC soma survival, prevented axonal degeneration, and improved anterograde axonal transport in glaucomatous eyes without altering intraocular pressure. Intriguingly, ocular hypertension triggered upregulation of PDE4 subtype A in Müller glia, and ibudilast stimulated cAMP accumulation in these cells. Co-administration of ibudilast with Rp-cAMPS, a cell-permeable and non-hydrolysable cAMP analog that inhibits protein kinase A (PKA), completely blocked ibudilast-induced neuroprotection. Collectively, these data demonstrate that ibudilast, a safe and well-tolerated glial cell modulator, attenuates gliosis, decreases levels of proinflammatory mediators, and enhances neuronal viability in glaucoma through activation of the cAMP/PKA pathway. This study provides insight into PDE4 signaling as a potential target to counter the harmful effects associated with chronic gliosis and neuroinflammation in glaucoma. PMID:27163643

  15. A single nucleotide polymorphism in the Bax gene promoter affects transcription and influences retinal ganglion cell death

    Directory of Open Access Journals (Sweden)

    Sheila J Semaan

    2010-03-01

    Full Text Available Pro-apoptotic Bax is essential for RGC (retinal ganglion cell death. Gene dosage experiments in mice, yielding a single wild-type Bax allele, indicated that genetic background was able to influence the cell death phenotype. DBA/2JBax+/− mice exhibited complete resistance to nerve damage after 2 weeks (similar to Bax−/− mice, but 129B6Bax+/− mice exhibited significant cell loss (similar to wild-type mice. The different cell death phenotype was associated with the level of Bax expression, where 129B6 neurons had twice the level of endogenous Bax mRNA and protein as DBA/2J neurons. Sequence analysis of the Bax promoters between these strains revealed a single nucleotide polymorphism (T129B6 to CDBA/2J at position −515. A 1.5- to 2.5-fold increase in transcriptional activity was observed from the 129B6 promoter in transient transfection assays in a variety of cell types, including RGC5 cells derived from rat RGCs. Since this polymorphism occurred in a p53 half-site, we investigated the requirement of p53 for the differential transcriptional activity. Differential transcriptional activity from either 129B6 or DBA/2J Bax promoters were unaffected in p53−/− cells, and addition of exogenous p53 had no further effect on this difference, thus a role for p53 was excluded. Competitive electrophoretic mobility-shift assays identified two DNA–protein complexes that interacted with the polymorphic region. Those forming Complex 1 bound with higher affinity to the 129B6 polymorphic site, suggesting that these proteins probably comprised a transcriptional activator complex. These studies implicated quantitative expression of the Bax gene as playing a possible role in neuronal susceptibility to damaging stimuli.

  16. Network oscillations drive correlated spiking of ON and OFF ganglion cells in the rd1 mouse model of retinal degeneration.

    Directory of Open Access Journals (Sweden)

    David J Margolis

    Full Text Available Following photoreceptor degeneration, ON and OFF retinal ganglion cells (RGCs in the rd-1/rd-1 mouse receive rhythmic synaptic input that elicits bursts of action potentials at ∼ 10 Hz. To characterize the properties of this activity, RGCs were targeted for paired recording and morphological classification as either ON alpha, OFF alpha or non-alpha RGCs using two-photon imaging. Identified cell types exhibited rhythmic spike activity. Cross-correlation of spike trains recorded simultaneously from pairs of RGCs revealed that activity was correlated more strongly between alpha RGCs than between alpha and non-alpha cell pairs. Bursts of action potentials in alpha RGC pairs of the same type, i.e. two ON or two OFF cells, were in phase, while bursts in dissimilar alpha cell types, i.e. an ON and an OFF RGC, were 180 degrees out of phase. This result is consistent with RGC activity being driven by an input that provides correlated excitation to ON cells and inhibition to OFF cells. A2 amacrine cells were investigated as a candidate cellular mechanism and found to display 10 Hz oscillations in membrane voltage and current that persisted in the presence of antagonists of fast synaptic transmission and were eliminated by tetrodotoxin. Results support the conclusion that the rhythmic RGC activity originates in a presynaptic network of electrically coupled cells including A2s via a Na(+-channel dependent mechanism. Network activity drives out of phase oscillations in ON and OFF cone bipolar cells, entraining similar frequency fluctuations in RGC spike activity over an area of retina that migrates with changes in the spatial locus of the cellular oscillator.

  17. Spatial relationships between GABAergic and glutamatergic synapses on the dendrites of distinct types of mouse retinal ganglion cells across development.

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    Adam Bleckert

    Full Text Available Neuronal output requires a concerted balance between excitatory and inhibitory (I/E input. Like other circuits, inhibitory synaptogenesis in the retina precedes excitatory synaptogenesis. How then do neurons attain their mature balance of I/E ratios despite temporal offset in synaptogenesis? To directly compare the development of glutamatergic and GABAergic synapses onto the same cell, we biolistically transfected retinal ganglion cells (RGCs with PSD95CFP, a marker of glutamatergic postsynaptic sites, in transgenic Thy1-YFPγ2 mice in which GABAA receptors are fluorescently tagged. We mapped YFPγ2 and PSD95CFP puncta distributions on three RGC types at postnatal day P12, shortly before eye opening, and at P21 when robust light responses in RGCs are present. The mature IGABA/E ratios varied among ON-Sustained (S A-type, OFF-S A-type, and bistratified direction selective (DS RGCs. These ratios were attained at different rates, before eye-opening for ON-S and OFF-S A-type, and after eye-opening for DS RGCs. At both ages examined, the IGABA/E ratio was uniform across the arbors of the three RGC types. Furthermore, measurements of the distances between neighboring PSD95CFP and YFPγ2 puncta on RGC dendrites indicate that their local relationship is established early in development, and cannot be predicted by random organization. These close spatial associations between glutamatergic and GABAergic postsynaptic sites appear to represent local synaptic arrangements revealed by correlative light and EM reconstructions of a single RGC's dendrites. Thus, although RGC types have different IGABA/E ratios and establish these ratios at separate rates, the local relationship between excitatory and inhibitory inputs appear similarly constrained across the RGC types studied.

  18. Spatial Relationships between GABAergic and Glutamatergic Synapses on the Dendrites of Distinct Types of Mouse Retinal Ganglion Cells across Development

    Science.gov (United States)

    Bleckert, Adam; Parker, Edward D.; Kang, YunHee; Pancaroglu, Raika; Soto, Florentina; Lewis, Renate; Craig, Ann Marie; Wong, Rachel O. L.

    2013-01-01

    Neuronal output requires a concerted balance between excitatory and inhibitory (I/E) input. Like other circuits, inhibitory synaptogenesis in the retina precedes excitatory synaptogenesis. How then do neurons attain their mature balance of I/E ratios despite temporal offset in synaptogenesis? To directly compare the development of glutamatergic and GABAergic synapses onto the same cell, we biolistically transfected retinal ganglion cells (RGCs) with PSD95CFP, a marker of glutamatergic postsynaptic sites, in transgenic Thy1­YFPγ2 mice in which GABAA receptors are fluorescently tagged. We mapped YFPγ2 and PSD95CFP puncta distributions on three RGC types at postnatal day P12, shortly before eye opening, and at P21 when robust light responses in RGCs are present. The mature IGABA/E ratios varied among ON-Sustained (S) A-type, OFF-S A-type, and bistratified direction selective (DS) RGCs. These ratios were attained at different rates, before eye-opening for ON-S and OFF-S A-type, and after eye-opening for DS RGCs. At both ages examined, the IGABA/E ratio was uniform across the arbors of the three RGC types. Furthermore, measurements of the distances between neighboring PSD95CFP and YFPγ2 puncta on RGC dendrites indicate that their local relationship is established early in development, and cannot be predicted by random organization. These close spatial associations between glutamatergic and GABAergic postsynaptic sites appear to represent local synaptic arrangements revealed by correlative light and EM reconstructions of a single RGC's dendrites. Thus, although RGC types have different IGABA/E ratios and establish these ratios at separate rates, the local relationship between excitatory and inhibitory inputs appear similarly constrained across the RGC types studied. PMID:23922756

  19. Transgenic inhibition of astroglial NF-κB protects from optic nerve damage and retinal ganglion cell loss in experimental optic neuritis

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    Brambilla Roberta

    2012-09-01

    Full Text Available Abstract Background Optic neuritis is an acute, demyelinating neuropathy of the optic nerve often representing the first appreciable symptom of multiple sclerosis. Wallerian degeneration of irreversibly damaged optic nerve axons leads to death of retinal ganglion cells, which is the cause of permanent visual impairment. Although the specific mechanisms responsible for triggering these events are unknown, it has been suggested that a key pathological factor is the activation of immune-inflammatory processes secondary to leukocyte infiltration. However, to date, there is no conclusive evidence to support such a causal role for infiltrating peripheral immune cells in the etiopathology of optic neuritis. Methods To dissect the contribution of the peripheral immune-inflammatory response versus the CNS-specific inflammatory response in the development of optic neuritis, we analyzed optic nerve and retinal ganglion cells pathology in wild-type and GFAP-IκBα-dn transgenic mice, where NF-κB is selectively inactivated in astrocytes, following induction of EAE. Results We found that, in wild-type mice, axonal demyelination in the optic nerve occurred as early as 8 days post induction of EAE, prior to the earliest signs of leukocyte infiltration (20 days post induction. On the contrary, GFAP-IκBα-dn mice were significantly protected and showed a nearly complete prevention of axonal demyelination, as well as a drastic attenuation in retinal ganglion cell death. This correlated with a decrease in the expression of pro-inflammatory cytokines, chemokines, adhesion molecules, as well as a prevention of NAD(PH oxidase subunit upregulation. Conclusions Our results provide evidence that astrocytes, not infiltrating immune cells, play a key role in the development of optic neuritis and that astrocyte-mediated neurotoxicity is dependent on activation of a transcriptional program regulated by NF-κB. Hence, interventions targeting the NF-κB transcription

  20. Vesicular glutamate transporter 2 (VGLUT2) is co-stored with PACAP in projections from the rat melanopsin-containing retinal ganglion cells

    DEFF Research Database (Denmark)

    Engelund, Anna Iversen; Fahrenkrug, Jan; Harrison, Adrian Paul;

    2010-01-01

    The retinal ganglion cell layer of the eye comprises a subtype of cells characterized by their intrinsic photosensitivity and expression of melanopsin (ipRGCs). These cells regulate a variety of non-image-forming (NIF) functions such as light entrainment of circadian rhythms, acute suppression......-localized in their projections in the suprachiasmatic nucleus, the intergeniculate leaflet, and the olivary pretectal nucleus. We conclude that there is evidence to support the use of glutamate and PACAP as neurotransmitters in NIF photoperception by rat ipRGCs, and that these neurotransmitters are co-stored and probably...

  1. RNA-binding protein Hermes/RBPMS inversely affects synapse density and axon arbor formation in retinal ganglion cells in vivo.

    Science.gov (United States)

    Hörnberg, Hanna; Wollerton-van Horck, Francis; Maurus, Daniel; Zwart, Maarten; Svoboda, Hanno; Harris, William A; Holt, Christine E

    2013-06-19

    The RNA-binding protein Hermes [RNA-binding protein with multiple splicing (RBPMS)] is expressed exclusively in retinal ganglion cells (RGCs) in the CNS, but its function in these cells is not known. Here we show that Hermes protein translocates in granules from RGC bodies down the growing axons. Hermes loss of function in both Xenopus laevis and zebrafish embryos leads to a significant reduction in retinal axon arbor complexity in the optic tectum, and expression of a dominant acting mutant Hermes protein, defective in RNA-granule localization, causes similar defects in arborization. Time-lapse analysis of branch dynamics reveals that the decrease in arbor complexity is caused by a reduction in new branches rather than a decrease in branch stability. Surprisingly, Hermes depletion also leads to enhanced early visual behavior and an increase in the density of presynaptic puncta, suggesting that reduced arborization is accompanied by increased synaptogenesis to maintain synapse number. PMID:23785151

  2. Effects of minocycline on apoptosis and neuronal changes in retinal ganglion cells from experimental optic neuritis rats

    Institute of Scientific and Technical Information of China (English)

    Jing Zhang

    2008-01-01

    BACKGROUND: Minocycline, a tetracycline derivative, is neuroprotective in models of various neurological diseases.OBJECTIVE: To investigate the effects of minocycline on retinal ganglion cells (RGCs) in rats with optic neuritis, and to compare with the effects of methylprednisolone.DESIGN, TIME AND SETTING: This neuropathology controlled study was performed at the First Affiliated Hospital, Chongqing Medical University, China in May 2007.MATERIALS: A total of 22 female Wistar rats were randomly assigned into a normal control group (n = 5) and an experimental group (n = 17). The experimental group was composed of a model subgroup (n = 7), a minocycline subgroup (n = 5), and a methylprednisolone subgroup (n = 5). Minocycline was supplied by Sigma, USA.METHODS: Antigen homogenate made from guinea pig spinal cord and complete Freund adjuvant was used to induce autoimmune encephalomyelitis, which could induce demyelinated optic neuritis models. Rats in the minocycline subgroup were intraperitoneally injected with minocycline (45 mg/kg) daily from day 8 following autoimmunity. Rats in the methylprednisolone subgroup were intraperitoneally injected with methylprednisolone (20 mg/kg) daily from day 8 following autoimmunity.MAIN OUTCOME MEASURES: On day 18 after autoimmunity induction, pathological changes in the optic nerve were observed by hematoxylin-eosin staining. The percentage area of axons in the transverse section of the optic nerve was measured by Bielschowsky staining. Apoptosis of RGCs was detected by TUNEL.RESULTS: Under an optical microscope, the optic nerve in rats with demyelinated optic neuritis showed a vacuole-like structure of fibers, irregular swelling of the axons, and infiltration of a large quantity of inflammatory cells. With an electron microscope, the optic nerve presented with vacuole-like structures in the axons, a small percentage area of axons in the transverse section, loose myelin sheaths, and microtubules and microfilaments disappeared. The

  3. Both systemic and local application of Granulocyte-colony stimulating factor (G-CSF is neuroprotective after retinal ganglion cell axotomy

    Directory of Open Access Journals (Sweden)

    Dietz Gunnar PH

    2009-05-01

    Full Text Available Abstract Background The hematopoietic Granulocyte-Colony Stimulating Factor (G-CSF plays a crucial role in controlling the number of neutrophil progenitor cells. Its function is mediated via the G-CSF receptor, which was recently found to be expressed also in the central nervous system. In addition, G-CSF provided neuroprotection in models of neuronal cell death. Here we used the retinal ganglion cell (RGC axotomy model to compare effects of local and systemic application of neuroprotective molecules. Results We found that the G-CSF receptor is robustly expressed by RGCs in vivo and in vitro. We thus evaluated G-CSF as a neuroprotectant for RGCs and found a dose-dependent neuroprotective effect of G-CSF on axotomized RGCs when given subcutaneously. As stem stell mobilization had previously been discussed as a possible contributor to the neuroprotective effects of G-CSF, we compared the local treatment of RGCs by injection of G-CSF into the vitreous body with systemic delivery by subcutaneous application. Both routes of application reduced retinal ganglion cell death to a comparable extent. Moreover, G-CSF enhanced the survival of immunopurified RGCs in vitro. Conclusion We thus show that G-CSF neuroprotection is at least partially independent of potential systemic effects and provide further evidence that the clinically applicable G-CSF could become a treatment option for both neurodegenerative diseases and glaucoma.

  4. Negative impact of AQP-4 channel inhibition on survival of retinal ganglion cells and glutamate metabolism after crushing optic nerve.

    Science.gov (United States)

    Nishikawa, Yuko; Oku, Hidehiro; Morishita, Seita; Horie, Taeko; Kida, Teruyo; Mimura, Masashi; Fukumoto, Masanori; Kojima, Shota; Ikeda, Tsunehiko

    2016-05-01

    The purpose of this study was to determine whether inhibition of aquaporin 4 (AQP4) is neuroprotective or neurodestructive after crushing the optic nerve of rats. The left optic nerves of rats were crushed, and TGN-020 (5.0 mg/kg, crush TGN-020) or its vehicle (DMSO, crush placebo) was injected intraperitoneally just after the crushing. As controls, the left optic nerves were exposed but not touched in other rats (sham controls). The retinal damages were determined by the density of retinal ganglion cells (RGCs) and the ratio of BAX/Bcl-2 on day 7. The glutamate level in the optic nerve on day 1 after the crushing was determined. The expressions of glutamine synthetase, glutamate-aspartate transporter (GLAST), and AQP4 were determined on day 3 by immunoblotting. The effects of AQP4 inhibition on the glutamate-induced changes of AQP4 expression and on the glutamate uptake were determined for optic nerve astrocytes in culture. The results showed that the density of RGCs was 2040 ± 91.3 cells/mm(2) (n = 6) in the sham control, and it was significantly decreased to 1072 ± 134.3 cells/mm(2) after crushing the optic nerve (P crush placebo, n = 7; Fisher). An intraperitoneal injection of TGN-020 led to a further significant (P = 0.02, Fisher) decrease of the density of RGCs to 743 ± 371 cells/mm(2) (crush TGN-020, n = 7). The mRNA level of BAX/Bcl-2 ratio was 0.37 ± 0.05 in the sham control (n = 6) which was significantly increased to 0.88 ± 0.10 after crushing the optic nerve (placebo crush, n = 7; P = 0.0001, Scheffe). TGN-020 also significantly increased the BAX/Bcl-2 ratio to 1.29 ± 0.4 (n = 6) from the crush placebo group (P = 0.04, Scheffe). Immunoblotting showed similar changes in the protein levels. The glutamate level in the optic nerve was significantly increased to 53.7 ± 6.0 μM/mg/protein on day 1 (n = 4) from the sham control level of 45.9 ± 3.1 μM/mg/protein (n = 4; P = 0.04, t test). TGN-020

  5. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells.

    Science.gov (United States)

    Gaub, Benjamin M; Berry, Michael H; Holt, Amy E; Reiner, Andreas; Kienzler, Michael A; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D; Beltran, William A; Flannery, John G; Isacoff, Ehud Y

    2014-12-23

    Most inherited forms of blindness are caused by mutations that lead to photoreceptor cell death but spare second- and third-order retinal neurons. Expression of the light-gated excitatory mammalian ion channel light-gated ionotropic glutamate receptor (LiGluR) in retinal ganglion cells (RGCs) of the retina degeneration (rd1) mouse model of blindness was previously shown to restore some visual functions when stimulated by UV light. Here, we report restored retinal function in visible light in rodent and canine models of blindness through the use of a second-generation photoswitch for LiGluR, maleimide-azobenzene-glutamate 0 with peak efficiency at 460 nm (MAG0(460)). In the blind rd1 mouse, multielectrode array recordings of retinal explants revealed robust and uniform light-evoked firing when LiGluR-MAG0(460) was targeted to RGCs and robust but diverse activity patterns in RGCs when LiGluR-MAG0(460) was targeted to ON-bipolar cells (ON-BCs). LiGluR-MAG0(460) in either RGCs or ON-BCs of the rd1 mouse reinstated innate light-avoidance behavior and enabled mice to distinguish between different temporal patterns of light in an associative learning task. In the rod-cone dystrophy dog model of blindness, LiGluR-MAG0(460) in RGCs restored robust light responses to retinal explants and intravitreal delivery of LiGluR and MAG0(460) was well tolerated in vivo. The results in both large and small animal models of photoreceptor degeneration provide a path to clinical translation. PMID:25489083

  6. Effects of GABA receptor antagonists on thresholds of P23H rat retinal ganglion cells to electrical stimulation of the retina

    Science.gov (United States)

    Jensen, Ralph J.; Rizzo, Joseph F., III

    2011-06-01

    An electronic retinal prosthesis may provide useful vision for patients suffering from retinitis pigmentosa (RP). In animal models of RP, the amount of current needed to activate retinal ganglion cells (RGCs) is higher than in normal, healthy retinas. In this study, we sought to reduce the stimulation thresholds of RGCs in a degenerate rat model (P23H-line 1) by blocking GABA receptor mediated inhibition in the retina. We examined the effects of TPMPA, a GABAC receptor antagonist, and SR95531, a GABAA receptor antagonist, on the electrically evoked responses of RGCs to biphasic current pulses delivered to the subretinal surface through a 400 µm diameter electrode. Both TPMPA and SR95531 reduced the stimulation thresholds of ON-center RGCs on average by 15% and 20% respectively. Co-application of the two GABA receptor antagonists had the greatest effect, on average reducing stimulation thresholds by 32%. In addition, co-application of the two GABA receptor antagonists increased the magnitude of the electrically evoked responses on average three-fold. Neither TPMPA nor SR95531, applied alone or in combination, had consistent effects on the stimulation thresholds of OFF-center RGCs. We suggest that the effects of the GABA receptor antagonists on ON-center RGCs may be attributable to blockage of GABA receptors on the axon terminals of ON bipolar cells.

  7. Retinal vessel diameters decrease with macular ganglion cell layer thickness in autosomal dominant optic atrophy and in healthy subjects

    DEFF Research Database (Denmark)

    Rönnbäck, Cecilia; Grønskov, Karen; Larsen, Michael

    2014-01-01

    PURPOSE: To investigate retinal trunk vessel diameters in subjects with autosomal dominant optic atrophy (ADOA) and mutation-free healthy relatives. METHODS: This cross-sectional study included 52 ADOA patients with the optic atrophy 1 (OPA1) exon 28 (c.2826_2836delinsGGATGCTCCA) mutation (age 8.......6-83.5 years) (best-corrected visual acuity (BCVA) 8-94 Early Treatment Diabetic Retinopathy Study (ETDRS) letters) and 55 mutation-free first-degree healthy relatives (age 8.9-68.7 years, BCVA 80-99). Analysis of fundus photographs provided integrated magnification-corrected measures of retinal vessel...... diameters (central retinal artery equivalent, CRAE, and central retinal vein equivalent, CRVE). Statistical analysis was corrected for age, gender, spherical equivalent refraction, axial length and mean arterial blood pressure (MABP) in a mixed model analysis. RESULTS: Retinal arteries and veins were...

  8. The CORM ALF-186 Mediates Anti-Apoptotic Signaling via an Activation of the p38 MAPK after Ischemia and Reperfusion Injury in Retinal Ganglion Cells

    Science.gov (United States)

    Ulbrich, Felix; Kaufmann, Kai B.; Meske, Alexander; Lagrèze, Wolf A.; Augustynik, Michael; Buerkle, Hartmut; Ramao, Carlos C.; Biermann, Julia

    2016-01-01

    Purpose Ischemia and reperfusion injury may induce apoptosis and lead to sustained tissue damage and loss of function, especially in neuronal organs. While carbon monoxide is known to exert protective effects after various harmful events, the mechanism of carbon monoxide releasing molecules in neuronal tissue has not been investigated yet. We hypothesize that the carbon monoxide releasing molecule (CORM) ALF-186, administered after neuronal ischemia-reperfusion injury (IRI), counteracts retinal apoptosis and its involved signaling pathways and consecutively reduces neuronal tissue damage. Methods IRI was performed in rat´s retinae for 1 hour. The water-soluble CORM ALF-186 (10 mg/kg) was administered intravenously via a tail vein after reperfusion. After 24 and 48 hours, retinal tissue was harvested to analyze mRNA and protein expression of Bcl-2, Bax, Caspase-3, ERK1/2, p38 and JNK. Densities of fluorogold pre-labeled retinal ganglion cells (RGC) were analyzed 7 days after IRI. Immunohistochemistry was performed on retinal cross sections. Results ALF-186 significantly reduced IRI mediated loss of RGC. ALF-186 treatment differentially affected mitogen-activated protein kinases (MAPK) phosphorylation: ALF-186 activated p38 and suppressed ERK1/2 phosphorylation, while JNK remained unchanged. Furthermore, ALF-186 treatment affected mitochondrial apoptosis, decreasing pro-apoptotic Bax and Caspase-3-cleavage, but increasing anti-apoptotic Bcl-2. Inhibition of p38-MAPK using SB203580 reduced ALF-186 mediated anti-apoptotic effects. Conclusion In this study, ALF-186 mediated substantial neuroprotection, affecting intracellular apoptotic signaling, mainly via MAPK p38. CORMs may thus represent a promising therapeutic alternative treating neuronal IRI. PMID:27764224

  9. Bioactive compounds in green tea leaves attenuate the injury of retinal ganglion RGC-5 cells induced by H2O2 and ultraviolet radiation.

    Science.gov (United States)

    Jin, Jianchang; Ying, Hao; Huang, Meirong; Du, Qizhen

    2015-11-01

    The Chinese commonly believe that tea helps maintain clear vision. This viewpoint has been recorded in Chinese medical books also. The key bioactive compounds in green tea leaves, (-)-epigallocatechin gallate (EGCG), L-theanine (theanine) and caffeine, were investigated for their abilities to attenuate the injury of retinal ganglion cells (RGC-5) induced by H2O2 and ultraviolet radiation. Theanine and caffeine promoted cell growth while concentrations of EGCG greater than 10μg/ml inhibited cell growth. The nine and caffeine both protected RGC-5 cells from injury as well as enhanced their recovery, while EGCG only protected the cells from injury and did not help them to recover. Tea is a unique drink, which is simultaneously enriched with EGCG, theanine and caffeine. The role of these compounds in optic nerve protection may partially explain why some tea drinkers feel enhanced vision. PMID:26687755

  10. Activation of the sigma receptor 1 modulates AMPA receptor-mediated light-evoked excitatory postsynaptic currents in rat retinal ganglion cells.

    Science.gov (United States)

    Liu, Lei-Lei; Deng, Qin-Qin; Weng, Shi-Jun; Yang, Xiong-Li; Zhong, Yong-Mei

    2016-09-22

    Sigma receptor (σR), a unique receptor family, is classified into three subtypes: σR1, σR2 and σR3. It was previously shown that σR1 activation induced by 1μM SKF10047 (SKF) suppressed N-methyl-d-aspartate (NMDA) receptor-mediated responses of rat retinal ganglion cells (GCs) and the suppression was mediated by a distinct Ca(2+)-dependent phospholipase C (PLC)-protein kinase C (PKC) pathway. In the present work, using whole-cell patch-clamp techniques in rat retinal slice preparations, we further demonstrate that SKF of higher dosage (50μM) significantly suppressed AMPA receptor (AMPAR)-mediated light-evoked excitatory postsynaptic currents (L-EPSCs) of retinal ON-type GCs (ON GCs), and the effect was reversed by the σR1 antagonist BD1047, suggesting the involvement of σR1. The SKF (50μM) effect was unlikely due to a change in glutamate release from bipolar cells, as suggested by the unaltered paired-pulse ratio (PPR) of AMPAR-mediated EPSCs of ON GCs. SKF (50μM) did not change L-EPSCs of ON GCs when the G protein inhibitor GDP-β-S or the protein kinase G (PKG) inhibitor KT5823 was intracellularly infused. Calcium imaging further revealed that SKF (50μM) did not change intracellular calcium concentration in GCs and persisted to suppress L-EPSCs when intracellular calcium was chelated by BAPTA. The SKF (50μM) effect was intact when protein kinase A (PKA) and phosphatidylinostiol (PI)-PLC signaling pathways were both blocked. We conclude that the SKF (50μM) effect is Ca(2+)-independent, PKG-dependent, but not involving PKA, PI-PLC pathways. PMID:27373906

  11. Neuronal Nogo-A in New-born Retinal Ganglion Cells: Implication for the Formation of the Age-related Fiber Order in the Optic Tract.

    Science.gov (United States)

    Su, Dongqiang; Liu, Huaicun; Chan, Sun-On; Wang, Jun

    2016-08-01

    Nogo-A is highly expressed in oligodendrocytes in the adult central nervous system (CNS). Recently it was found that Nogo-A is also expressed in some neuronal types during development. Here, we examined the expression pattern of Nogo-A in both the retina and optic tract (OT) of mouse embryos from E12 to E15. After perturbation of its function in the OT for 5 hr in the brain slice culture system using a Nogo-A specific antibody or antagonist of its receptor (NEP1-40), the optic nerve fibers and growth cones were traced with DiI. We showed that most Tuj-1 positive new-born neurons at E12 were Nogo-A positive. At E15, retinal neurons reduced the Nogo-A expression. It was worth noting that some projecting axons expressed Nogo-A along the retinofugal pathway. On the basis of their specific locations within the superficial half of the OT and the colocalization with GAP-43 (a marker for the newly born growth cones and axons), we concluded that those Nogo-A positive axons were the newly arrived retinal fibers. Blocking the function of Nogo-A with Nogo-A antibody or NEP1-40 resulted in the shift of DiI labeled axons and growth cones from the superficial half to the whole depth of the OT. These results indicate that Nogo-A in the newly born retinal ganglion cells (RGCs) and their axons are involved in sorting out the newly arrived axons to the subpial region of the OT. Anat Rec, 299:1027-1036, 2016. © 2016 Wiley Periodicals, Inc. PMID:27273864

  12. Neuroprotective effects of Argon are mediated via an ERK-1/2 dependent regulation of heme-oxygenase-1 in retinal ganglion cells.

    Science.gov (United States)

    Ulbrich, Felix; Kaufmann, Kai B; Coburn, Mark; Lagrèze, Wolf Alexander; Roesslein, Martin; Biermann, Julia; Buerkle, Hartmut; Loop, Torsten; Goebel, Ulrich

    2015-08-01

    Retinal ischemia and reperfusion injuries (R-IRI) damage neuronal tissue permanently. Recently, we demonstrated that Argon exerts anti-apoptotic and protective properties. The molecular mechanism remains unclear. We hypothesized that Argon inhalation exert neuroprotective effects in rats retinal ganglion cells (RGC) via an ERK-1/2 dependent regulation of heat-shock proteins. Inhalation of Argon (75 Vol%) was performed after R-IRI on the rats' left eyes for 1 h immediately or with delay. Retinal tissue was harvested after 24 h to analyze mRNA and protein expression of heat-shock proteins -70, -90 and heme-oxygenase-1, mitogen-activated protein kinases (p38, JNK, ERK-1/2) and histological changes. To analyze ERK dependent effects, the ERK inhibitor PD98059 was applicated prior to Argon inhalation. RGC count was analyzed 7 days after injury. Statistics were performed using anova. Argon significantly reduced the R-IRI-affected heat-shock protein expression (p ERK-1/2 expression (p ERK-1/2 before Argon inhalation resulted in significantly lower vital RGCs (p ERK-1/2 activation in Müller cells. We conclude, that Argon treatment protects R-IRI-induced apoptotic loss of RGC via an ERK-1/2 dependent regulation of heme-oxygenase-1. We proposed the following possible mechanism for Argon-mediated neuroprotection: Argon exerts its protective effects via an induction of an ERK with subsequent suppression of the heat shock response. In conclusion, ischemia and reperfusion injuries and subsequent neuronal apoptosis are attenuated. These novel findings may open up new opportunities for Argon as a therapeutic option, especially since Argon is not toxic.

  13. Differentiation of retinal ganglion cells and photoreceptor precursors from mouse induced pluripotent stem cells carrying an Atoh7/Math5 lineage reporter.

    Directory of Open Access Journals (Sweden)

    Bin-Bin Xie

    Full Text Available The neural retina is a critical component of the visual system, which provides the majority of sensory input in humans. Various retinal degenerative diseases can result in the permanent loss of retinal neurons, especially the light-sensing photoreceptors and the centrally projecting retinal ganglion cells (RGCs. The replenishment of lost RGCs and the repair of optic nerve damage are particularly challenging, as both RGC specification and their subsequent axonal growth and projection involve complex and precise regulation. To explore the developmental potential of pluripotent stem cell-derived neural progenitors, we have established mouse iPS cells that allow cell lineage tracing of progenitors that have expressed Atoh7/Math5, a bHLH transcription factor required for RGC production. These Atoh7 lineage reporter iPS cells encode Cre to replace one copy of the endogenous Atoh7 gene and a Cre-dependent YFP reporter in the ROSA locus. In addition, they express pluripotent markers and are capable of generating teratomas in vivo. Under anterior neural induction and neurogenic conditions in vitro, the Atoh7-Cre/ROSA-YFP iPS cells differentiate into neurons that co-express various RGC markers and YFP, indicating that these neurons are derived from Atoh7-expressing progenitors. Consistent with previous in vivo cell lineage studies, the Atoh7-Cre/ROSA-YFP iPS cells also give rise to a subset of Crx-positive photoreceptor precursors. Furthermore, inhibition of Notch signaling in the iPSC cultures results in a significant increase of YFP-positive RGCs and photoreceptor precursors. Together, these results show that Atoh7-Cre/ROSA-YFP iPS cells can be used to monitor the development and survival of RGCs and photoreceptors from pluripotent stem cells.

  14. Excitatory Synaptic Inputs to Mouse On-Off Direction-Selective Retinal Ganglion Cells Lack Direction Tuning

    OpenAIRE

    Park, Silvia J.H.; Kim, In-Jung; Loren L Looger; Demb, Jonathan B; Borghuis, Bart G.

    2014-01-01

    Direction selectivity represents a fundamental visual computation. In mammalian retina, On-Off direction-selective ganglion cells (DSGCs) respond strongly to motion in a preferred direction and weakly to motion in the opposite, null direction. Electrical recordings suggested three direction-selective (DS) synaptic mechanisms: DS GABA release during null-direction motion from starburst amacrine cells (SACs) and DS acetylcholine and glutamate release during preferred direction motion from SACs ...

  15. Brain-Derived Neurotrophic Factor (BDNF) Promotes Cochlear Spiral Ganglion Cell Survival and Function in Deafened, Developing Cats

    OpenAIRE

    Leake, Patricia A.; Hradek, Gary T.; Hetherington, Alexander M.; Stakhovskaya, Olga

    2011-01-01

    Postnatal development and survival of spiral ganglion (SG) neurons depend upon both neural activity and neurotrophic support. Our previous studies showed that electrical stimulation from a cochlear implant only partly prevents SG degeneration after early deafness. Thus, neurotrophic agents that might be combined with an implant to improve neural survival are of interest. Recent studies reporting that BDNF promotes SG survival after deafness, have been conducted in rodents and limited to relat...

  16. In vivowide-field multispectral scanning laser ophthalmoscopy-optical coherence tomography mouse retinal imager: longitudinal imaging of ganglion cells, microglia, and Müller glia, and mapping of the mouse retinal and choroidal vasculature

    Science.gov (United States)

    Zhang, Pengfei; Zam, Azhar; Jian, Yifan; Wang, Xinlei; Li, Yuanpei; Lam, Kit S.; Burns, Marie E.; Sarunic, Marinko V.; Pugh, Edward N., Jr.; Zawadzki, Robert J.

    2015-12-01

    Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) provide complementary views of the retina, with the former collecting fluorescence data with good lateral but relatively low-axial resolution, and the latter collecting label-free backscattering data with comparable lateral but much higher axial resolution. To take maximal advantage of the information of both modalities in mouse retinal imaging, we have constructed a compact, four-channel, wide-field (˜50 deg) system that simultaneously acquires and automatically coregisters three channels of confocal SLO and Fourier domain OCT data. The scanner control system allows "zoomed" imaging of a region of interest identified in a wide-field image, providing efficient digital sampling and localization of cellular resolution features in longitudinal imaging of individual mice. The SLO is equipped with a "flip-in" spectrometer that enables spectral "fingerprinting" of fluorochromes. Segmentation of retina layers and en face display facilitate spatial comparison of OCT data with SLO fluorescence patterns. We demonstrate that the system can be used to image an individual retinal ganglion cell over many months, to simultaneously image microglia and Müller glia expressing different fluorochromes, to characterize the distinctive spatial distributions and clearance times of circulating fluorochromes with different molecular sizes, and to produce unequivocal images of the heretofore uncharacterized mouse choroidal vasculature.

  17. Delayed administration of glial cell line-derived neurotrophic factor (GDNF) protects retinal ganglion cells in a pig model of acute retinal ischemia

    DEFF Research Database (Denmark)

    Kyhn, Maria Voss; Klassen, Henry; Johansson, Ulrica Englund;

    2009-01-01

    This study investigates whether intravitreal administration of glial cell line-derived neurotrophic factor (GDNF) enhances survival of NeuN positive retinal cells in a porcine model of retinal ischemia. 16 pigs were subjected to an ischemic insult where intraocular pressure was maintained at 5 mm......Hg below mean arterial blood pressure for 2 h. The mean IOP during the ischemic insult was 79.5 mmHg (s.e.m. 2.1 mmHg, n = 15). Three days after the insult the pigs received an intravitreal injection of GDNF microspheres or blank microspheres. The pigs were evaluated by way of multifocal.......04-0.16) in eyes treated with blank microspheres, and 0.24 (95% CI: 0.18-0.32) and 0.23 (95% CI: 0.15-0.33) in eyes treated with GDNF microspheres. These differences were statistically significant (P

  18. Progress in stem cell transplantation for treatment of retinal ganglion cell damage diseases%干细胞移植治疗视网膜神经节细胞损伤性疾病的研究进展

    Institute of Scientific and Technical Information of China (English)

    孙颖健; 郑雅娟

    2015-01-01

    视网膜神经节细胞是视觉形成的重要参与者。视网膜神经节细胞损伤或死亡往往会导致视功能不可逆转的损害。青光眼、糖尿病视网膜病变、高血压、视网膜变性等致盲性疾病,均会引起视网膜神经节细胞损伤或进行性大量凋亡。目前此类疾病在临床上尚无明确的治疗方法。为了恢复患者视网膜神经节细胞功能,国内外学者将研究焦点集中在干细胞移植上。干细胞移植主要指两大类,一类是基于干细胞的替代治疗,另一类则是通过干细胞移植促进某些因子分泌来保护视网膜神经节细胞。我们旨在对干细胞移植治疗视网膜神经节细胞损伤疾病的潜力进行综述,并着重讨论不同种干细胞分化为视网膜神经节细胞的研究进展。%Retinal ganglion cells are crucial in the formation of vision. Injury or death of retinal ganglion cells may lead to irreversibly damage of visual function. Glaucoma, diabetic retinopathy, hypertension, and other blind leading diseases can cause the damage or progressively apoptosis of retinal ganglion cells. Currently, there is no specific treatment to restore vision damage caused by those diseases. Scholars at home and abroad focus on stem cells transplantation in order to recover the visual function of patients. Two categories are mainly involved in stem cell transplantation, one is the replacement therapy based on stem cells, the other is to promote the secretion of some factors to protect ganglion cells through stem cell transplantation. In this review, we aim to summarize the potential of stems cell transplantation to treat retinal ganglion cells related diseases, and discuss the differentiation of different types of stem cells to retinal ganglion cells.

  19. Retinal ganglion cells survive and maintain normal dendritic morphology in a mouse model of inherited photoreceptor degeneration

    OpenAIRE

    Mazzoni, Francesca; Novelli, Elena; Strettoi, Enrica

    2008-01-01

    Retinitis Pigmentosa (RP), a family of inherited disorders characterized by progressive photoreceptor death, is a leading cause of blindness with no available cure. Despite the genetic heterogeneity underlying the disease, recent data on animal models show that the degeneration of photoreceptors triggers stereotyped remodeling among their postsynaptic partners. In particular, bipolar and horizontal cells might undergo dendritic atrophy and secondary death. The aim of this study was to investi...

  20. Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe.

    Directory of Open Access Journals (Sweden)

    Xudong Qiu

    Full Text Available Peptide probes for imaging retinal ganglion cell (RGC apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in

  1. Minocycline protects retinal ganglion cells after optic nerve crush injury in mice by delaying autophagy and upregulating nuclear factor-κB2

    Institute of Scientific and Technical Information of China (English)

    Jiao Xiaoling; Peng Yuan; Yang Liu

    2014-01-01

    Background Currently,no medicine is available that can prevent or treat neural damage associated with optic nerve injury.Minocycline is recently reported to have a neuroprotective function.The aims of this study were to exarmine the neuroprotective effect of minocycline on retinal ganglion cells (RGCs) and determine its underlying mechanisms,using a mouse model of optic nerve crush (ONC).Methods ONC was performed in the left eye of adult male mice,and the mice were randomly divided into minocycline-treated group and saline-treated control group.The mice without receiving ONC injury were used as positive controls.RGC densities were assessed in retinal whole mounts with immunofluorescence labeling of βⅢ-tubulin.Transmission electron microscopy was used to detect RGC morphologies,and Western blotting and real-time PCR were applied to investigate the expression of autophagy markers LC3-Ⅰ,LC3-Ⅱ,and transcriptional factors nuclear factor-κB1 (NF-κB1),NF-κB2.Results In the early stage after ONC (at Days 4 and 7),the density of RGCs in the minocycline-treated group was higher than that of the saline-treated group.Electron micrographs showed that minocycline prevented nuclei and mitochondria injuries at Day 4.Western blotting analysis demonstrated that the conversion of LC3-Ⅰ to LC3-Ⅱ was reduced in the minocycline-treated group at Days 4 and 7,which meant autophagy process was inhibited by minocycline.In addition,the gene expression of NF-κB2 was upregulated by minocycline at Day 4.Conclusion The neuroprotective effect of minocycline is generated in the early stage after ONC in mice,partly through delaying autophagy process and regulating NF-κB2 pathway.

  2. Evaluation of Macular Retinal Ganglion Cell-Inner Plexiform Layer Thickness after Vitrectomy with Internal Limiting Membrane Peeling for Idiopathic Macular Holes

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    Alfonso L. Sabater

    2014-01-01

    Full Text Available Purpose. To evaluate macular retinal ganglion cell-inner plexiform layer (GCIPL thickness changes after Brilliant Blue G-assisted internal limiting membrane peeling for idiopathic macular hole repair using a high-resolution spectral-domain optical coherence tomography (SD-OCT. Methods. 32 eyes from 32 patients with idiopathic macular holes who underwent vitrectomy with internal limiting membrane peeling between January 2011 and July 2012 were retrospectively analyzed. GCIPL thickness was measured before surgery, and at one month and at six months after surgery. Values obtained from automated and semimanual SD-OCT segmentation analysis were compared (Cirrus HD-OCT, Carl Zeiss Meditec, Dublin, CA. Results. No significant differences were found between average GCIPL thickness values between preoperative and postoperative analysis. However, statistical significant differences were found in GCIPL thickness at the temporal macular quadrants at six months after surgery. Quality measurement analysis performed by automated segmentation revealed a significant number of segmentation errors. Semimanual segmentation slightly improved the quality of the results. Conclusion. SD-OCT analysis of GCIPL thickness found a significant reduction at the temporal macular quadrants at 6 months after Brilliant Blue G-assisted internal limiting membrane peeling for idiopathic macular hole.

  3. Cats

    Science.gov (United States)

    ... those experienced by humans. Cats that hunt wild rodents and rabbits in the western, particularly the southwestern, ... caused by a fungus that can infect skin, hair, and nails of both people and animals. Ringworm ...

  4. Effects of brain-derived neurotrophic factor (BDNF) and electrical stimulation on survival and function of cochlear spiral ganglion neurons in deafened, developing cats.

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    Leake, Patricia A; Stakhovskaya, Olga; Hetherington, Alexander; Rebscher, Stephen J; Bonham, Ben

    2013-04-01

    Both neurotrophic support and neural activity are required for normal postnatal development and survival of cochlear spiral ganglion (SG) neurons. Previous studies in neonatally deafened cats demonstrated that electrical stimulation (ES) from a cochlear implant can promote improved SG survival but does not completely prevent progressive neural degeneration. Neurotrophic agents combined with an implant may further improve neural survival. Short-term studies in rodents have shown that brain-derived neurotrophic factor (BDNF) promotes SG survival after deafness and may be additive to trophic effects of stimulation. Our recent study in neonatally deafened cats provided the first evidence of BDNF neurotrophic effects in the developing auditory system over a prolonged duration Leake et al. (J Comp Neurol 519:1526-1545, 2011). Ten weeks of intracochlear BDNF infusion starting at 4 weeks of age elicited significant improvement in SG survival and larger soma size compared to contralateral. In the present study, the same deafening and BDNF infusion procedures were combined with several months of ES from an implant. After combined BDNF + ES, a highly significant increase in SG numerical density (>50 % improvement re: contralateral) was observed, which was significantly greater than the neurotrophic effect seen with ES-only over comparable durations. Combined BDNF + ES also resulted in a higher density of myelinated radial nerve fibers within the osseous spiral lamina. However, substantial ectopic and disorganized sprouting of these fibers into the scala tympani also occurred, which may be deleterious to implant function. EABR thresholds improved (re: initial thresholds at time of implantation) on the chronically stimulated channels of the implant. Terminal electrophysiological studies recording in the inferior colliculus (IC) revealed that the basic cochleotopic organization was intact in the midbrain in all studied groups. In deafened controls or after ES-only, lower IC

  5. Evaluation of the percentage of ganglion cells in the ganglion cell layer of the rodent retina

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    Schlamp, Cassandra L.; Montgomery, Angela D.; Mac Nair, Caitlin E.; Schuart, Claudia; Willmer, Daniel J.; Nickells, Robert W

    2013-01-01

    Purpose Retinal ganglion cells comprise a percentage of the neurons actually residing in the ganglion cell layer (GCL) of the rodent retina. This estimate is useful to extrapolate ganglion cell loss in models of optic nerve disease, but the values reported in the literature are highly variable depending on the methods used to obtain them. Methods We tested three retrograde labeling methods and two immunostaining methods to calculate ganglion cell number in the mouse retina (C57BL/6). Addition...

  6. Etanercept, a widely used inhibitor of tumor necrosis factor-α (TNF-α, prevents retinal ganglion cell loss in a rat model of glaucoma.

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    Miin Roh

    Full Text Available BACKGROUND: Visual loss in glaucoma is associated with pathological changes in retinal ganglion cell (RGC axons and a slow decline in the RGC population. Age and elevated intraocular pressure (IOP are the main risk factors for glaucomatous loss of vision. Several studies have implicated the proinflammatory cytokine tumor necrosis factor-α (TNF-α as a link between elevated IOP and RGC death, but the cellular source of TNF-α and its causative role in RGC death remain uncertain. Here, using a rat model of glaucoma, we investigated the source of elevated TNF-α and examined whether Etanercept, a TNF-α blocker that is in common clinical use for other indications, is protective against RGC death. METHODOLOGY/PRINCIPAL FINDINGS: Episcleral vein cauterization (EVC caused intraocular pressure (IOP to be elevated for at least 28 days. IOP elevation resulted in a dramatic increase in TNF-α levels within a few days, axonal degeneration, and a 38% loss of RGCs by 4 weeks. Immunostaining coupled with confocal microscopy showed that OHT induced robust induction of TNF-α in Iba-1-positive microglia around the optic nerve head (ONH. Despite persistent elevation of IOP, Etanercept reduced microglial activation, TNF-α levels, axon degeneration in the optic nerve, and the loss of RGCs. CONCLUSIONS/SIGNIFICANCE: Ocular hypertension (OHT triggers an inflammatory response characterized by the appearance of activated microglia around the ONH that express TNF-α. Blocking TNF-α activity with a clinically approved agent inhibits this microglial response and prevents axonal degeneration and loss of RGCs. These findings suggest a new treatment strategy for glaucoma using TNF-α antagonists or suppressors of inflammation.

  7. Ganglion cell complex and retinal nerve fiber layer measured by fourier-domain optical coherence tomography for early detection of structural damage in patients with preperimetric glaucoma

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    Rolle T

    2011-07-01

    Full Text Available Teresa Rolle, Cristina Briamonte, Daniela Curto, Federico Maria GrignoloEye Clinic, Section of Ophthalmology, Department of Clinical Physiopathology, University of Torino, Torino, ItalyAims: To evaluate the capability of Fourier-domain optical coherence tomography (FD-OCT to detect structural damage in patients with preperimetric glaucoma.Methods: A total of 178 Caucasian subjects were enrolled in this cohort study: 116 preperimetric glaucoma patients and 52 healthy subjects. Using three-dimensional FD-OCT, the participants underwent imaging of the ganglion cell complex (GCC and the optic nerve head. Sensitivity, specificity, likelihood ratios, and predictive values were calculated for all parameters at the first and fifth percentiles. Areas under the curves (AUCs were generated for all parameters and were compared (Delong test. For both the GCC and the optic nerve head protocols, the OR logical disjunction (Boolean logic operator was calculated.Results: The AUCs didn’t significantly differ. Macular global loss volume had the largest AUC (0.81. Specificities were high at both the fifth and first percentiles (up to 97%, but sensitivities were low, especially at the first percentile (55%–27%.Conclusion: Macular and papillary diagnostic accuracies did not differ significantly based on the 95% confidence interval. The computation of the Boolean OR operator has been found to boost diagnostic accuracy. Using the software-provided classification, sensitivity and diagnostic accuracy were low for both the retinal nerve fiber layer and the GCC scans. FD-OCT does not seem to be decisive for early detection of structural damage in patients with no functional impairment. This suggests that there is a need for analysis software to be further refined to enhance glaucoma diagnostic capability.Keywords: OCT, RNFL, GCC, diagnostic accuracy 

  8. Sulphur antioxidants inhibit oxidative stress induced retinal ganglion cell death by scavenging reactive oxygen species but influence nuclear factor (erythroid-derived 2)-like 2 signalling pathway differently.

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    Majid, Aman Shah Abdul; Yin, Zheng Qin; Ji, Dan

    2013-01-01

    This study aimed to show if two different sulphur containing drugs sulbutiamine and acetylcysteine (NAC) could attenuate the effects of two different insults being serum deprivation and glutamate/buthionine sulfoximine (GB)-induced death to transformed retinal ganglion cell line (RGC-5) in culture. Cells were exposed to either 5 mM of GB for 24 h or serum deprivation for 48 h with inclusion of either NAC or sulbutiamine. Cell viability, microscopic evidence for apoptosis, caspase 3 activity, reactive oxygen species (ROS), glutathione (GSH), catalase and gluthathione-S-transferase (GST) were determined. The effects of NAC and sulbutiamine on the oxidative stress related transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) levels and its dependent phase II enzyme haemeoxygenase-1 (HO-1) were carried out using Western blot and quantitative-polymerase chain reaction (PCR). NAC and sulbutiamine dose-dependently attenuated serum deprivation-induced cell death. However NAC but not sulbutiamine attenuated GB-induced cell death. NAC and sulbutiamine both independently stimulated the GSH and GST production but scavenged different types of ROS with different efficacy. Moreover only sulbutiamine stimulated catalase and significantly increased Nrf-2 and HO-1 levels. In addition, the pan caspase inhibitor, benzoylcarbonyl-Val-Ala-Asp-fluoromethyl ketone (z-VAD-fmk) attenuated the negative effect of serum deprivation while the necroptosis inhibitor (necrostatin-1) counteracted solely an insult of GB. The neuroprotective actions of NAC and sulbutiamine in GB or serum-deprivation insult are therefore different. PMID:23811559

  9. Roles of PI3K and JAK pathways in viability of retinal ganglion cells after acute elevation of intraocular pressure in rats with different autoimmune backgrounds

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    Wang Ningli

    2008-08-01

    Full Text Available Abstract Background We recently showed that whereas inhibition of PI3K/akt or JAK/STAT pathway promoted retinal ganglion cell (RGC survival after optic nerve (ON injury in Fischer 344 (F344 rats, the same inhibition resulted in aggravated RGC loss after acute intraocular pressure (IOP elevation in Sprague Dawley (SPD rats. In addition, the responses of macrophages to ON injury and acute IOP elevation were different between F344 and Lewis rats, i.e., different autoimmune profiles. Using an acute IOP elevation paradigm in this study, we investigated 1 whether autoimmune background influences PI3K/akt and JAK/STAT functions by examining the effect of PI3K/akt and JAK/STAT pathway inhibition on RGC survival in F344 and Lewis rats, and 2 whether differential actions of macrophages occur in PI3K/akt and JAK/STAT pathways-dependent modulation of RGC survival. IOP elevation was performed at 110 mmHg for 2 hours. PI3K/akt and JAK/STAT pathway inhibitors were applied intravitreally to block their respective pathway signaling transduction. Because macrophage invasion was seen in the eye after the pathway inhibition, to examine the role of these pathways independent of macrophages, macrophages in the retina were removed by intravitreal application of clodronate liposomes. Viable RGCs were retrogradely labelled by FluoroGold 40 hours before animal sacrifice. Results Similar to what was previously observed, significantly more RGCs were lost in Lewis than F344 rats 3 weeks after acute IOP elevation. As in SPD rats, inhibition of the PI3K/akt or JAK/STAT pathway increased the loss of RGCs in both F344 and Lewis rats. Removal of macrophages in the eye by clodronate liposomes reduced RGC loss due to pathway inhibition in both strains. Conclusion This study demonstrates that following acute IOP elevation 1 PI3K/akt and JAK/STAT pathways mediate RGC survival in both F344 and Lewis rats, 2 autoimmune responses do not influence the functions of these two pathways

  10. Comparison of diagnostic capability of macular ganglion cell complex and retinal nerve fiber layer among primary open angle glaucoma, ocular hypertension, and normal population using Fourier-domain optical coherence tomography and determining their functional correlation in Indian population

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    Nabanita Barua

    2016-01-01

    Full Text Available Context: Analysis of diagnostic ability of macular ganglionic cell complex and retinal nerve fiber layer (RNFL in glaucoma. Aim: To correlate functional and structural parameters and comparing predictive value of each of the structural parameters using Fourier-domain (FD optical coherence tomography (OCT among primary open angle glaucoma (POAG and ocular hypertension (OHT versus normal population. Setting and Design: Single centric, cross-sectional study done in 234 eyes. Materials and Methods: Patients were enrolled in three groups: POAG, ocular hypertensive and normal (40 patients in each group. After comprehensive ophthalmological examination, patients underwent standard automated perimetry and FD-OCT scan in optic nerve head and ganglion cell mode. The relationship was assessed by correlating ganglion cell complex (GCC parameters with mean deviation. Results were compared with RNFL parameters. Statistical Analysis: Data were analyzed with SPSS, analysis of variance, t-test, Pearson′s coefficient, and receiver operating curve. Results: All parameters showed strong correlation with visual field (P 0.5 when compared with other parameters. None of the parameters showed significant diagnostic capability to detect OHT from normal population. In diagnosing early glaucoma from OHT and normal population, only inferior GCC had statistically significant AUC value (0.715. Conclusion: In this study, GCC and RNFL parameters showed equal predictive capability in perimetric versus normal group. In early stage, inferior GCC was the best parameter. In OHT population, single day cross-sectional imaging was not valuable.

  11. Comparative Diagnostic Accuracy of Ganglion Cell-Inner Plexiform and Retinal Nerve Fiber Layer Thickness Measures by Cirrus and Spectralis Optical Coherence Tomography in Relapsing-Remitting Multiple Sclerosis

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    Julio J. González-López

    2014-01-01

    Full Text Available Objective. To estimate sensitivity and specificity of several optical coherence tomography (OCT measurements for detecting retinal thickness changes in patients with relapsing-remitting multiple sclerosis (RRMS, such as macular ganglion cell-inner plexiform layer (GCIPL thickness measured with Cirrus (OCT and peripapillary retinal nerve fiber layer (pRNFL thickness measured with Cirrus and Spectralis OCT. Methods. Seventy patients (140 eyes with RRMS and seventy matched healthy subjects underwent pRNFL and GCIPL thickness analysis using Cirrus OCT and pRNFL using Spectralis OCT. A prospective, cross-sectional evaluation of sensitivities and specificities was performed using latent class analysis due to the absence of a gold standard. Results. GCIPL measures had higher sensitivity and specificity than temporal pRNFL measures obtained with both OCT devices. Average GCIPL thickness was significantly more sensitive than temporal pRNFL by Cirrus (96.34% versus 58.41% and minimum GCIPL thickness was significantly more sensitive than temporal pRNFL by Spectralis (96.41% versus 69.69%. Generalised estimating equation analysis revealed that age (P=0.030, optic neuritis antecedent (P=0.001, and disease duration (P=0.002 were significantly associated with abnormal results in average GCIPL thickness. Conclusion. Average and minimum GCIPL measurements had significantly better sensitivity to detect retinal thickness changes in RRMS than temporal pRNFL thickness measured by Cirrus and Spectralis OCT, respectively.

  12. Modulation of cannabinoid to GABA currents in retinal ganglion cells in human and mice%大麻素对人和小鼠视网膜神经节细胞GABA电流的调控差异

    Institute of Scientific and Technical Information of China (English)

    罗雪; 刘诗亮; 江梦南; 沈雨濛; 胡单萍; 沈吟

    2015-01-01

    目的 比较人和小鼠视网膜内源性大麻素类受体1(cannabinoid receptor,CB1)的表达差异,观察大麻素受体激动剂WIN55212-2对不同种属视网膜神经节细胞GABA电流的调控作用.方法 采用冰冻切片免疫荧光染色,观察CB1受体在视网膜中的表达.制备视网膜薄片,行全细胞膜片钳记录.在神经节细胞上给予100 μmol/L GABA快速加药诱导出电流I GABA,而后观察孵育大麻素受体激动剂WIN55212-2时GABA诱导的IGABA及同时孵育WIN 55212-2和大麻素受体拮抗剂SR141716A的电流IGABA.结果 人和小鼠视网膜CB1受体的分布有所不同,人的内核层、外核层、神经节细胞层有显著的CB1表达,但小鼠CB1受体主要表达在内网状层、外网状层上;膜片钳结果显示不管是在人还是在小鼠的视网膜上,孵育WIN55212-2后的GABA诱导电流幅度均有显著减小.不同的是,在人视网膜神经节细胞上,WIN55212-2明显减慢了GABA电流的反应速度,表现在电流达峰时间明显延长,恢复时间缩短(P<0.05).WIN55212-2对小鼠视网膜神经节细胞GABA的反应速度无明显差别(P>0.05).结论 CB1受体在人和小鼠视网膜中有差异性分布,对神经节细胞的GABA电流影响也不同.孵育WIN55212-2可抑制人和小鼠神经节细胞GABA电流幅度,但仅对人的神经节细胞的GABA电流的动力学速度有影响.%Objective To compare the expression of endogenous cannabinoid receptor 1 (CB1) in human and mouse retinal ganglion cells and observe the modulation of CB1 receptor agonist WIN55212-2 to γ-aminobutyric acid (GABA) currents.Methods Immunofluorescence assay was applied to study the expression pattern of CB1 receptors in the retina.Whole-cell patch-clamp technology was used to record GABA currents in the retinal ganglion cells after applying 2 μmol/L WIN55212-2 or 2 μmol/L WIN55212-2 + 4 μmol/L SR141716A (CB1 receptor antagonist).Results CB1 receptors were expressed in the human outer nuclear

  13. Protection of zinc against pig retinal ganglion cells' damage induced by microwave%锌对微波致猪视网膜神经节细胞损伤的防护作用

    Institute of Scientific and Technical Information of China (English)

    杨瑞华; 陈景元; 邓中荣; 刘秀红; 郑刚; 赵瑞刚

    2001-01-01

    目的 探讨微波对体外培养的猪视网膜神经节细胞的脂质过氧化损伤作用及耐受剂量,为进一步研究微波的眼底损伤机制及其防护提供一定的实验依据. 方法 体外培养猪视网膜神经节细胞,按微波辐照强度分为对照组,30 mW*cm-2组,60 mW*cm-2组及各辐照剂量加锌组,微波理疗机于微波屏蔽室内辐照1 h,辐照后立即于光镜及电镜观察细胞形态变化,测定超氧化物歧化酶(SOD)和丙二醛(MDA)活性. 结果 微波辐照后,细胞有聚集现象,部分细胞轴突消失,电镜可见线粒体及内质网肿胀,细胞MDA活性明显增高,SOD降低,加锌各组光镜下细胞形态变化不明显,电镜显示线粒体轻度肿胀,嵴完整,MDA活性有所恢复,SOD活性增高. 结论 微波可引起视网膜神经节细胞脂质过氧化损伤,锌可提高细胞的抗氧化能力,在一定程度上减轻微波对视网膜神经节细胞的过氧化损伤.%AIM To determine the lipid peroxidation damage in the primary cultured pig retinal ganglion cells induced by microwave and cells' tolerance to microwave in order to provide some experiment foundation for study of mechanism of microwave damage and its protection. METHODS Pig retinal ganglion cells were cultured in vitro and divided into 3 groups of different radiation intensities (control group, 30 mW*cm-2 group, 60 mW*cm-2 group) and 2 more radiated groups with zinc added. The activity of intracellular superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were assayed after they had been radiated for 1h in a shielded room by 2450 MHz continuous wave physiotherapy machine. The morphological variation of cells was observed immediately after radiation by optics microscope and transmission electronic microscope. RESULTS After radiation, some cells congregated and their axon disappeared. Mitochondria and endoplasmic reticulum were detected swelling by transmission

  14. Size of the Optic Nerve Head and Its Relationship with the Thickness of the Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer in Patients with Primary Open Angle Glaucoma

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    Nobuko Enomoto

    2015-01-01

    Full Text Available Purpose. To evaluate the relationships among the optic nerve head (ONH area, macular ganglion cell complex (mGCC thickness, circumpapillary retinal nerve fiber layer (cpRNFL thickness, and visual field defects in patients with primary open angle glaucoma (POAG. Methods. This retrospective study included 90 eyes of 90 patients with POAG. The ONH area, rim area, mGCC thickness, and cpRNFL thickness were measured using optical coherence tomography. Mean deviation (MD was measured using standard automated perimetry. The relationships among clinical factors including age, refraction, the ONH area, the rim area, the mGCC thickness, the cpRNFL thickness, and MD were evaluated using correlation coefficients and multiple regression analyses. Results. The significant correlation of the ONH area with refraction (r=0.362, P<0.001, the mGCC thickness (r=0.225, P=0.033, and the cpRNFL thickness (r=0.253, P=0.016 was found. Multiple regression analysis showed that the ONH area, rim area, and MD were selected as significant contributing factors to explain the mGCC thickness and cpRNFL thickness. No factor was selected to explain MD. Conclusions. The ONH area, in other words, the disc size itself may affect the mGCC thickness and cpRNFL thickness in POAG patients.

  15. Methane attenuates retinal ischemia/reperfusion injury via anti-oxidative and anti-apoptotic pathways.

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    Liu, Lin; Sun, Qinglei; Wang, Ruobing; Chen, Zeli; Wu, Jiangchun; Xia, Fangzhou; Fan, Xian-Qun

    2016-09-01

    Retinal ischemia/reperfusion injury (IRI) may cause incurable visual impairment due to neural regeneration limits. Methane was shown to exert a protective effect against IRI in many organs. This study aims to explore the possible protective effects of methane-rich saline against retinal IRI in rat. Retinal IRI was performed on the right eyes of male Sprague-Dawley rats, which were immediately injected intraperitoneally with methane-saturated saline (25ml/kg). At one week after surgery, the number of retinal ganglion cells (RGCs), total retinal thickness, visual function were measured by hematoxylin and eosin staining, FluoroGold anterograde labeling and flash visual evoked potentials. The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), 4-Hydroxy-2-nonenal (4-HNE), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), caspase-3, caspase-9, B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in retinas were assessed by immunofluorescence staining, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. As expected, methane treatment significantly improved the retinal IRI-induced RGC loss, total retinal layer thinning and visual dysfunction. Moreover, methane treatment significantly reduced the levels of oxidative stress biomarkers (8-OHdG, 4-HNE, MDA) and increased the antioxidant enzyme activities (SOD, CAT, GPx) in the retinas with IRI. Meanwhile, methane treatment significantly increased the anti-apoptotic gene (Bcl-2) expression and decreased the pro-apoptotic gene (Bax) expression, accompanied by the suppression of caspase-3 and caspase-9 activity. Thus, these data demonstrated that methane can exert a neuroprotective role against retinal IRI through anti-oxidative and anti-apoptotic pathways. PMID:27208496

  16. Excessive retinal ganglion cell loss after optic nerve crushed with forceps in rats%钳夹法造成大鼠视网膜神经节细胞过量丢失

    Institute of Scientific and Technical Information of China (English)

    廖良; 徐铭谦; 韦企平; 周剑; 孔莹莹; 孙艳红

    2011-01-01

    Objective To evaluate the injury degree of retinal ganglion cells (RGCs) after optic nerve crushed with forceps. Methods A total of 38 male Wistar rats were divided into forceps groups, which was subdivided into group A to group E, with crushing time of 12 seconds,9 seconds,6 seconds,3 seconds and 1 second, the group F was the forceps group at reverse direction,5 rats in each group. The optic nerve at temple side of rat eyeball was exposed. Optic nerves at 2 mm behind the eyeball were crushed with 90 g micro forceps and then with the 40 g forceps at reverse direction. Left eye of each rat was taken operation, and right eye was treated as normal control. Left eyes of rats in shame operation group were taken treatment to expose optic nerve behind the eyeball,but not with crush. Amount and survival rate of RGCs were calculated with fluorogold regressive labeling RGCs and retinal stretched preparation. Results Cell densities of left and right eyes of rats in shame operation group were (2 679 ± 67) mm-2 and(2 689 ±53)mm-2,there was no significant difference(P = 0. 8%) ,and were (220±167)mm-2,(265 ±232)mm-2, (298 ±239)mm-2, (478 ±682)mm -2, (769 ±615) mm-2 and (974 ±476) mm-2 in forceps groups, which were obviously decreased. There was negative correlation between impulse of forceps(force of forceps multiply time) and survival rate of RGCs. Conclusions Crush with forceps can make definite and quantitative optic injury,but the injury is serious and stability is poor. There is still a marked gap between our experiment and the actual pathogenesis of traumatic optic neuropathy.%目的 评估钳夹视神经对视网膜神经节细胞(retinal ganglion cells,RGCs)的损伤程度.方法 取38只雄性Wistar大鼠,夹持组(n=30)按夹持时间12 s、9 s、6 s,3 s、1 s分为A-E组,F为反身夹持组,每组各5只大鼠.沿大鼠眼球颞侧暴露视神经,于球后2 mm处用90 g微型视神经夹夹持视神经,另有40 g反向镊在球后2 mm处夹持视神经,每

  17. 早期糖尿病大鼠视网膜神经节细胞树突形态异常的研究%Study on abnormal dendrite of retinal ganglion cells in diabetic rats

    Institute of Scientific and Technical Information of China (English)

    徐格致; 秦要武; 王文吉

    2008-01-01

    Objective To observe the morphological changes of dendrite and soma in retinal ganglion cells (RGCs) which subsisted in early diabetic rats. Methods The RGCs of 3-months-course diabetic rats and coeval normal rats were marked by gene gun techniques. To collect RGCs photographs by Leica microscope with Z axis and CCD camera;to observe the changes of diameter, variance of structural features in dendritic field and somata after classification which according to the size and morphology. Thy-1 antibody marks on the retinal RGCs, taking a photograph under fluorescent microscope, counting the changes of retinal RGCs density in early diabetic rat. Results In three-month diabetic rats, the density of retinal RGCs was decreased obviously. Morphological changes of RGCs in the dendritic fields were observed with gene gun technique. There was no severe variation in all kinds of the bole of cell dendrite,in which some only showed crispation partially and sparseness also twisting in the dendritic ramus. The mean diameter of dendritic field and soma in class A of diabetic rats was (401±86)μm, the mean diameter of dendritic field in control group was (315±72) μm,compared with each other, there is statistically significant differences (t=21. 249, P0.05); the mean diameter of dendritic field and soma in class B of diabetic rats were (170±36). (14±2) μm respectively, in control group were (165±36), (16±2) μm, the mean diameter of dendritic field and soma in class C of diabetic group were (265±78),(17±5) μm respectively, in control group were (251±57),(17±4) μm , compared with each other,there are on statistically significant differences (t=1.357,0.798,0. 835,1.104 ,P>0.05). ConclusionsIn short-term diabetes, the survived RGCs show good plasticity in adult diabetic rats, especially in class A. The changes of dendrites were more sensitive than the soma, which could be the leading index of themorphologic changes of RGCs in the early stage. The good plasticity showed by

  18. Effects of progesterone on the expression of MAP-1B in retinal ganglion cells of ar ts with optic nerve injury%黄体酮对视神经损伤大鼠视网膜神经节细胞微管相关蛋白-1B的影响

    Institute of Scientific and Technical Information of China (English)

    白瑜; 杜丽敏; 赵平

    2016-01-01

    Objective To observe the effects of progesterone on the expression of microtubule associated protein-1B ( MAP-1B) in retinal ganglion cells of rats with optic nerve injury in order to provide experimental evidence of progesterone’ s protective effects on optic nerve.Methods Sixty rats were randomly divided into 3 groups,with 20 rats in each group.The rats in control group were not treated,however,the optic nerve injury models in right eye of rats were established in injury group 1, with 0.9%sodium chloride solution intraperitoneal injection,and the animal models were also established in injury group 2, with progesterone intraperitoneal injection.On 3d,7d,14d and 28d after injury, the right eyeballs of rats were excised, and retinal tissues were taken out, the morphological changes of retina were observed by HE staining, and the survival numbers of retinal ganglion cell were calculated, furthermore,the expression levels of MAP-1B in retinal ganglion cell were detected by immunohistochemistry.Results After optic nerve injury, the retinal nerve fiber layer appeared obvious edema, and the numbers of retinal ganglion cells were quickly decreased in injury group 1,however, the retinal morphological changes were alleviated,retinal nerve fiber layer appeared slight edema and the numbers of retinal ganglion cells were decreased slowly after treatment with progesterone in injury group 2.There was a significant difference in the optical density value at different time points between injury group 1 and injury group 2 ( P <0.05).Conclusion Progesterone can relieve the damage of retinal ganglion cells at early period of optic nerve injury through increasing the expression levels of cytoskeleton protein-MAP-1b, thus,which has protective effects on optic nerve and retina.%目的:观察并探讨黄体酮对视神经损伤早期视网膜神经节细胞微管相关蛋白-1B的影响,以期为黄体酮在视神经保护方面的作用提供实验依据。方法60

  19. Immunohistochemical and electrophysiological characterization of the mouse model for Retinitis Pigmentosa, rd10

    OpenAIRE

    Biswas, Sonia

    2014-01-01

    In the human disease retinitis pigmentosa (RP) the photoreceptors degenerate over time but the retinal network, in particular the retinal output neurons, the ganglion cells (RGCs) persist, providing a target for electrical stimulation by retinal prostheses. However, remodelling of the retinal network might interfere with this therapeutic approach. In the widely used mouse model of retinal degeneration, rd1, the loss of photoreceptors leads to rhythmic electrical activity of 10 to 16 Hz in the...

  20. 银杏叶提取物对培养的人眼视网膜神经节细胞的保护作用%The protective effects of ginkgo biloba extract on cultured human retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    王云松; 徐亮; 马科; 王津津

    2011-01-01

    目的 探讨银杏叶提取物(EGb761)对培养的人眼视网膜神经节细胞(RGC)的保护作用。方法 对照实验研究。将培养的人眼视网膜细胞分为对照组、谷氨酸组、EGb761组及谷氨酸+EGb761组,用Thy-1作为RGC特异性荧光抗体,以免疫流式细胞技术评价EGb761对人眼RGC的保护作用。多组间细胞存活率比较采用重复测量的方差分析,组间两两比较采用LSD t检验。结果 在不同干预因素作用下,RGC存活率呈现不同变化,对照组为(61.94±7.75)%,谷氨酸组为(44.59 +4.19)%,EGb761组为(75.05 +3.90)%,EGb761+谷氨酸组为(63.19±9.44)%;各组间RGC存活率比较差异有统计学意义(F=13.329,P<0.01)。各组与对照组RGC存活率两两比较,显示谷氨酸组RGC存活率降低(P =0.010),EGb761组RGC存活率升高(P=0.019),EGb761+谷氨酸组与对照组RGC存活率差异无统计学意义(P =0.801);与谷氨酸组相比EGb761组和EGb761+谷氨酸组RGC存活率明显升高(P=0.000,0.020)。死亡RGC中大RGC所占百分比,EGb761组为(24.63+7.21)%,EGb761+谷氨酸组为(25.99±5.05)%,与对照组(36.69±2.92)%比较,两组死亡RGC中大RGC所占百分比均降低(P=0.001,0.002);与谷氨酸组(40.78±3.34)%相比,两组大RGC死亡百分比亦降低(P =0.000,0.000)。结论 EGb761可对抗谷氨酸兴奋性毒性造成的RGC损伤,对体外培养的人眼RGC具有明显的保护作用。%Objective This study was designed to investigate the protective effects of ginkgo biloba extract (EGb)761 on human retinal ganglion cells(RGC). Methods It was an experimental study.Cultured human retinal cells were separated for four groups: control group, glutamate group, EGb761 group and EGb761 + glutamate group. RGC survival rate was determined by immune Flow cytometry using Thy-1 as a special fluorescent antibody of RGC. RGC survival rate in Multi groups were analysed by repetitive measure analysis of variance

  1. 血管内皮生长因子B对小鼠视神经保护作用的研究%Effect of VEGF-B on neuroprotection in mouse retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    张水华; 曲毅

    2009-01-01

    目的 探讨血管内皮生长因子B(VEGF-B)在视网膜组织的表达及其对视网膜神经节细胞的保护作用.方法 对照实验研究.35只成年雌性健康C57BL/6小鼠,分为正常对照组,视神经损伤后6 h、1 d、1周、2周组.其中10只鼠用于原位杂交,每组2只鼠;25只鼠用于实时定量逆转录聚合酶链反应(real time RT-PCR),每组5只鼠.采用原位杂交法观察实验鼠视网膜组织VEGF-B的mRNA表达;用real time RT-PCR法观察视网膜组织损伤后不同时间VEGF-B的mRNA定量表达;从双侧上丘行荧光金逆行标记和视网膜神经节细胞计数,评估玻璃体腔内注射重组人VEGF-B(450 mg/L)对视网膜神经节细胞的保护作用.应用SAS统计学软件进行数据分析.对组间real timeRT-PCR检测结果比较采用方差分析,对组间视网膜神经节细胞计数的计量资料比较采用秩和检验.以P<0.05作为差异有统计学意义.结果 小鼠视神经损伤后的视网膜组织VEGF-B表达显著增强,损伤后1周达高峰.玻璃体腔内注射重组人VEGF-B蛋白,可显著增加视网膜神经节细胞的存活数量,分别是单纯视神经损伤组和损伤加玻璃体腔内注射的阴性对照组的1.7倍(t=0.1301,P<0.01)和1.9倍(t=0.001,P<0.01).结论 VEGF-B参与小鼠视神经损伤后的修复,并对视网膜神经节细胞有保护作用.(中华眼科杂志,2009,45:38-42)%Objective To investigate the expression of vascular endothelial growth factor-B (VEGF-B) in retina and its effect on neuroprotection in mouse retinal ganglion cells (RGCs). Methods It was a experimental study. 35 of C57BL/6 mice (adult male) were used. Optic nerve crush injury was made in 28 mice, 7 as control.Expression of VEGF-B in retina was detected by hybridization in situ in each group of 2 at 6 hours, 1 day, 1 and 2 weeks after optic nerve crush. A quantitative analysis of VEGF-B mRNA was determined by real time reverse transcription polymerase chain reaction (RT-PCR) in each group

  2. c-Jun N-terminal kinase 3 expression in the retina of ocular hypertension mice: a possible target to reduce ganglion cell apoptosis

    Directory of Open Access Journals (Sweden)

    Yue He

    2015-01-01

    Full Text Available Glaucoma, a type of optic neuropathy, is characterized by the loss of retinal ganglion cells. It remains controversial whether c-Jun N-terminal kinase (JNK participates in the apoptosis of retinal ganglion cells in glaucoma. This study sought to explore a possible mechanism of action of JNK signaling pathway in glaucoma-induced retinal optic nerve damage. We established a mouse model of chronic ocular hypertension by reducing the aqueous humor followed by photocoagulation using the laser ignition method. Results showed significant pathological changes in the ocular tissues after the injury. Apoptosis of retinal ganglion cells increased with increased intraocular pressure, as did JNK3 mRNA expression in the retina. These data indicated that the increased expression of JNK3 mRNA was strongly associated with the increase in intraocular pressure in the retina, and correlated positively with the apoptosis of retinal ganglion cells.

  3. c-Jun N-terminal kinase 3 expression in the retina of ocular hypertension mice:a possible target to reduce ganglion cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    Yue He; Jie Chen; Shu-guang Zhang; Yuan-sheng Yuan; Yan Li; Hong-bin Lv; Jin-hua Gan

    2015-01-01

    Glaucoma, a type of optic neuropathy, is characterized by the loss of retinal ganglion cells. It remains controversial whether c-Jun N-terminal kinase (JNK) participates in the apoptosis of retinal ganglion cells in glaucoma. This study sought to explore a possible mechanism of action of JNK signaling pathway in glaucoma-induced retinal optic nerve damage. We established a mouse model of chronic ocular hypertension by reducing the aqueous humor followed by pho-tocoagulation using the laser ignition method. Results showed signiifcant pathological changes in the ocular tissues after the injury. Apoptosis of retinal ganglion cells increased with increased intraocular pressure, as did JNK3 mRNA expression in the retina. These data indicated that the increased expression of JNK3 mRNA was strongly associated with the increase in intraocular pressure in the retina, and correlated positively with the apoptosis of retinal ganglion cells.

  4. Comparative retinal physiology in anthropoids.

    Science.gov (United States)

    Kremers, J; Lee, B B

    1998-11-01

    During the last decade it has become clear that colour vision in platyrrhines (New World monkeys) differs from the uniform trichromatic pattern normally found in catarrhines (Old World monkeys, apes and human). Colour vision in most platyrrhine species is polymorphic, with many dichromatic individuals. The comparison of response properties in retinal ganglion cells and lateral geniculate cells between catarrhines and playrrhines elucidates how the evolution of trichromatic colour vision influenced the post-receptoral processing. We find that spatial and temporal processing is very similar in the platyrrhine and catarrhine retina, strongly suggesting that the retinal structure and function, found in living anthropoids, was already present in their common ancestor. PMID:9893846

  5. Fractal features of dark, maintained, and driven neural discharges in the cat visual system

    CERN Document Server

    Lowen, S B; Kaplan, E; Saleh, B E A; Teich, M C; Lowen, Steven B.; Ozaki, Tsuyoshi; Kaplan, Ehud; Saleh, Bahaa E. A.; Teich, Malvin C.

    1999-01-01

    We employ a number of statistical measures to characterize neural discharge activity in cat retinal ganglion cells (RGCs) and in their target lateral geniculate nucleus (LGN) neurons under various stimulus conditions, and we develop a new measure to examine correlations in fractal activity between spike-train pairs. In the absence of stimulation (i.e., in the dark), RGC and LGN discharges exhibit similar properties. The presentation of a constant, uniform luminance to the eye reduces the fractal fluctuations in the RGC maintained discharge but enhances them in the target LGN discharge, so that neural activity in the pair no longer mirror each other. A drifting-grating stimulus yields RGC and LGN driven spike trains similar in character to those observed in the maintained discharge, with two notable distinctions: action potentials are reorganized along the time axis so that they occur only during certain phases of the stimulus waveform, and fractal activity is suppressed. Under both uniform-luminance and drift...

  6. 白蒺藜皂苷对慢性高眼压兔视网膜神经节细胞的保护作用%Protective effect of gross saponins from tribulus terrestris L on retinal ganglion cells in rabbits with chronic high intraocular pressure

    Institute of Scientific and Technical Information of China (English)

    李诺; 黄丽娜; 曾平; 刘军

    2010-01-01

    目的:观察白蒺藜皂苷(gross saponins from tribulus terrestris L,GSTT)及灯盏细辛注射液\\对慢性高眼压模型兔视网膜神经节细胞(retinal ganglion cells,RGCs)的保护作用. 方法:健康新西兰白兔24只,随机分为对照组、高眼压组、EBHM治疗组和GSTT治疗组,高眼压组和EBHM治疗组及GSTT治疗组的兔眼前房内注射20g/L甲基纤维素制成慢性高眼压模型,EBHM治疗组的兔每日耳缘ivEBHM注射液4.5mg/kg,GSTT治疗组的兔每日耳缘iv GSTT注射液5mg/kg,高眼压持续4wk时,处死实验兔,摘取眼球,做RGCs电镜检查.结果:造模后各组眼压均升高,电镜下高眼压组相对于GSTT治疗组及EBHM注射液治疗组,RGCs超微结构有明显损伤.结论:GSTT及EBHM注射液对慢性高眼压兔RGCs均具有保护作用.

  7. Intravitreal injection of erythropoietin sustained-release microspheres protects damaged retinal ganglion cells in rats%促红细胞生成素缓释微球玻璃体腔注射对视网膜神经节细胞的保护作用

    Institute of Scientific and Technical Information of China (English)

    荣先芳; 莫晓芬; 任甜甜; 袁伟恩; 王艳; 王鑫

    2010-01-01

    目的 探讨乳酸/羟基乙酸共聚物(PLGA)装载的促红细胞生成素(EPO)缓释微球(EPO-PLGA微球)经玻璃体腔注射对大鼠视神经挫伤模型中受损视网膜神经节细胞(RGC)的保护作用.方法 选取成年SD大鼠,建立视神经挫伤模型.建模后分别经玻璃体腔内注射含10 IU EPO的PLGA微球(EPO-PLGA组)、10 IU EPO(EPO组)、5 μl空白PLGA(PLGA组)、5 μl PBS(PBS组),另设未治疗组不予玻璃体腔注药.术后5 d和2周,做视网膜切片,对各组RGC凋亡情况行TUNEL检测;术后23 d,DiI上丘逆标RGC,并于术后4周处死大鼠,视网膜铺片观察各组RGC存活情况;每组各个时间点分别处死6只SD大鼠.采用方差分析对结果进行比较.结果 TUNEL检测显示,术后5 d和2周,各组均可见TUNEL阳性细胞,其中EPO-PLGA组和EPO组TUNEL阳性细胞显著减少,其细胞凋亡率明显少于PLGA组、PBS组及未治疗组.术后4周,视网膜铺片RGC计数显示,正常SD大鼠RGC密度为(2387.7±164.9)个/mm2,未治疗组为(748.3±58.8)个/mm2,EPO-PLGA组为(1296.7±157.6)个/mm2,EPO组为(1418.5±154.9)个/mm2,PLGA组为(821.7±52.1)个/mm2,PBS组为(804.4±86.4)个/mm2;可见EPO-PLGA组和EPO组较未治疗组细胞密度显著增高,具有明显的RGC保护作用(P均<0.01),而EPO-PLGA组和EPO组间差异无统计学意义(P=0.065).结论 EPO-PLGA缓释微球与EPO具有等效的RGC保护作用,这为进一步观察EPO-PLGA缓释微球的长效神经保护作用奠定了基础.%Objective To investigate the protective effect of erythropoietin (EPO) encapsulated in poly (L-lactic-co-glycolic acid) (PLGA) microspheres on damaged retinal ganglion cell (RGC) by intravitreal injection after optic nerve crush. Methods Adult SD rats were selected to establish an optic nerve crush model. Immediately after the crush, the animals received intravitreal doses of 10 IU EPO of EPO-PLGA microspheres (EPO-PLGA group), 10 IU EPO (EPO group), blank PLGA microshperes (PLGA group), and PBS (PBS

  8. 大鼠轴索损伤后视网膜神经节细胞和少突胶质细胞内Tau蛋白的表达%Expression changes of Tau protein in retinal ganglion cells and oligodendrocytes following axonal injury in rats

    Institute of Scientific and Technical Information of China (English)

    何朝晖; 孙晓川; 李峰; 江涌; 郑履平

    2009-01-01

    Objective To investigate expression changes of Tau protein in retinal ganglion cells (RGCs) and oligodendrocytes (Ols) after stretch injury in rats and explore the relationship of Tau protein with pathological changes after axonal injury. Methods Morphological changes of optic nerves, RGCs and OLs after stretch injury were examined under light microscope in control group, stretch only group, heat stress only group and heat stress pretreatment plus stretch group. The expressions of Tau protein in RGCs and OLs after heat stress and/or stretch injury were observed by using immunohistechemical stai-ning. Results Pathological changes of axons, RGCs and OLs were identified morphologically or quan-titatively after stretch injury to the optic nerves, which was significantly ameliorated through pretreatment with heat stress plus stretch injury. The expressions of Tau protein in RGCs and OLs were increased in stretch only group. There was no significant expression change of Tau protein in heat stress only group. Expression of Tan protein was obviously decreased in heat stress pretreatment plus stretch group. Con-clusions Both neurons and glial cells are involved in pathological process after axonal injury. The ex-pression changes of Tau protein are probably related to delayed axotomy and neuron apoptosis. Heat stress can relieve the impairment of cystoskeleton through decreasing and delaying the expression of Tau protein.%目的 观察大鼠轴索损伤后视网膜神经节细胞(retinal ganglion cells,RGCs)及少突胶质细胞(oligodendrocytes,OLs)内Tau蛋白表达的变化,探讨Tau蛋白与轴索损伤后病理变化的关系. 方法 光镜下观察正常对照组、单纯视神经牵拉伤组、单纯热应激处理组和热应激预处理牵拉伤组大鼠视神经、RGCs、OLs的形态学变化,免疫组化染色检测各组大鼠RGCs及OLs中Tau蛋白的表达情况. 结果 牵拉伤后视神经轴索、RGCs及OLs的形态发生明显的病理变化,热应激预处

  9. Cell type-specific bipolar cell input to ganglion cells in the mouse retina.

    Science.gov (United States)

    Neumann, S; Hüser, L; Ondreka, K; Auler, N; Haverkamp, S

    2016-03-01

    Many distinct ganglion cell types, which are the output elements of the retina, were found to encode for specific features of a visual scene such as contrast, color information or movement. The detailed composition of retinal circuits leading to this tuning of retinal ganglion cells, however, is apart from some prominent examples, largely unknown. Here we aimed to investigate if ganglion cell types in the mouse retina receive selective input from specific bipolar cell types or if they sample their synaptic input non-selectively from all bipolar cell types stratifying within their dendritic tree. To address this question we took an anatomical approach and immunolabeled retinae of two transgenic mouse lines (GFP-O and JAM-B) with markers for ribbon synapses and type 2 bipolar cells. We morphologically identified all green fluorescent protein (GFP)-expressing ganglion cell types, which co-stratified with type 2 bipolar cells and assessed the total number of bipolar input synapses and the proportion of synapses deriving from type 2 bipolar cells. Only JAM-B ganglion cells received synaptic input preferentially from bipolar cell types other than type 2 bipolar cells whereas the other analyzed ganglion cell types sampled their bipolar input most likely from all bipolar cell terminals within their dendritic arbor.

  10. Imaging retinal mosaics in the living eye.

    Science.gov (United States)

    Rossi, E A; Chung, M; Dubra, A; Hunter, J J; Merigan, W H; Williams, D R

    2011-03-01

    Adaptive optics imaging of cone photoreceptors has provided unique insight into the structure and function of the human visual system and has become an important tool for both basic scientists and clinicians. Recent advances in adaptive optics retinal imaging instrumentation and methodology have allowed us to expand beyond cone imaging. Multi-wavelength and fluorescence imaging methods with adaptive optics have allowed multiple retinal cell types to be imaged simultaneously. These new methods have recently revealed rod photoreceptors, retinal pigment epithelium (RPE) cells, and the smallest retinal blood vessels. Fluorescence imaging coupled with adaptive optics has been used to examine ganglion cells in living primates. Two-photon imaging combined with adaptive optics can evaluate photoreceptor function non-invasively in the living primate retina.

  11. Axonal transmission in the retina introduces a small dispersion of relative timing in the ganglion cell population response.

    Directory of Open Access Journals (Sweden)

    Günther Zeck

    Full Text Available BACKGROUND: Visual stimuli elicit action potentials in tens of different retinal ganglion cells. Each ganglion cell type responds with a different latency to a given stimulus, thus transforming the high-dimensional input into a temporal neural code. The timing of the first spikes between different retinal projection neurons cells may further change along axonal transmission. The purpose of this study is to investigate if intraretinal conduction velocity leads to a synchronization or dispersion of the population signal leaving the eye. METHODOLOGY/PRINCIPAL FINDINGS: We 'imaged' the initiation and transmission of light-evoked action potentials along individual axons in the rabbit retina at micron-scale resolution using a high-density multi-transistor array. We measured unimodal conduction velocity distributions (1.3±0.3 m/sec, mean ± SD for axonal populations at all retinal eccentricities with the exception of the central part that contains myelinated axons. The velocity variance within each piece of retina is caused by ganglion cell types that show narrower and slightly different average velocity tuning. Ganglion cells of the same type respond with similar latency to spatially homogenous stimuli and conduct with similar velocity. For ganglion cells of different type intraretinal conduction velocity and response latency to flashed stimuli are negatively correlated, indicating that differences in first spike timing increase (up to 10 msec. Similarly, the analysis of pair-wise correlated activity in response to white-noise stimuli reveals that conduction velocity and response latency are negatively correlated. CONCLUSION/SIGNIFICANCE: Intraretinal conduction does not change the relative spike timing between ganglion cells of the same type but increases spike timing differences among ganglion cells of different type. The fastest retinal ganglion cells therefore act as indicators of new stimuli for postsynaptic neurons. The intraretinal dispersion

  12. Retinal cartography.

    Science.gov (United States)

    Mosier, M A

    1982-10-01

    This paper analyses retinal cartography in terms of its reflection of anatomic data and its relation to several forms of geographic methods of map-making. It shows that the distances between anatomic landmarks of the eye are reasonably similar to the relative distances on the retinal drawing chart currently used. Two forms of geographic cartography--azimuth equidistant and orthographic--are described and compared with retinal cartography. The retinal drawing chart currently used most closely approximates an azimuth equidistant projection, which suffers from circumferential distortion, a fact that retinal surgeons must keep in mind. It is therefore recommended that the chart be modified to have equally spaced concentric circles and clearer identification of the ora serrata; the present accurate marking of anatomic landmarks, such as the equator and the posterior border of the ciliary body, should be preserved.

  13. A semi-automated technique for labeling and counting of apoptosing retinal cells

    OpenAIRE

    Bizrah, M.; Dakin, S C; Guo, L.; F. Rahman1; Parnell, M.; Normando, E.; Nizari, S; Davis, B; Younis, A.; Cordeiro, M F

    2014-01-01

    Background Retinal ganglion cell (RGC) loss is one of the earliest and most important cellular changes in glaucoma. The DARC (Detection of Apoptosing Retinal Cells) technology enables in vivo real-time non-invasive imaging of single apoptosing retinal cells in animal models of glaucoma and Alzheimer’s disease. To date, apoptosing RGCs imaged using DARC have been counted manually. This is time-consuming, labour-intensive, vulnerable to bias, and has considerable inter- and intra-operator varia...

  14. An excitatory amacrine cell detects object motion and provides feature-selective input to ganglion cells in the mouse retina

    Science.gov (United States)

    Kim, Tahnbee; Soto, Florentina; Kerschensteiner, Daniel

    2015-01-01

    Retinal circuits detect salient features of the visual world and report them to the brain through spike trains of retinal ganglion cells. The most abundant ganglion cell type in mice, the so-called W3 ganglion cell, selectively responds to movements of small objects. Where and how object motion sensitivity arises in the retina is incompletely understood. In this study, we use 2-photon-guided patch-clamp recordings to characterize responses of vesicular glutamate transporter 3 (VGluT3)-expressing amacrine cells (ACs) to a broad set of visual stimuli. We find that these ACs are object motion sensitive and analyze the synaptic mechanisms underlying this computation. Anatomical circuit reconstructions suggest that VGluT3-expressing ACs form glutamatergic synapses with W3 ganglion cells, and targeted recordings show that the tuning of W3 ganglion cells' excitatory input matches that of VGluT3-expressing ACs' responses. Synaptic excitation of W3 ganglion cells is diminished, and responses to object motion are suppressed in mice lacking VGluT3. Object motion, thus, is first detected by VGluT3-expressing ACs, which provide feature-selective excitatory input to W3 ganglion cells. DOI: http://dx.doi.org/10.7554/eLife.08025.001 PMID:25988808

  15. Mechanism of retinal ganglion cells apoptosis in the diet -induced obese C57 BL/6 mice%膳食诱导的肥胖型 C57 BL/6小鼠视网膜神经节细胞凋亡的机制

    Institute of Scientific and Technical Information of China (English)

    白霞; 赵剑; 赵文青; 陈玉玲

    2014-01-01

    AIM:To investigate the mechanism of retinal ganglion cells (RGCs) apoptosis in the diet-induced obese C57BL/6 mice. METHODS: Mice were fed high-fat diet. After 19 weeks of feeding, the mice were divided into diet induced obesity-resistant ( DIO-R ) group and diet induced obesity ( DIO) group, while mice of the control ( CON) group were fed a basal diet at the same time. The apoptosis of RGCs was detected by TUNEL.Laser scanning confocal microscope was used to detect the intracellular calcium ion concentration. RESULTS: TUNEL staining showed apoptosis cells in ganglion cell layer ( GCL) in DIO group increased and the percentage of apoptotic cells was (6.7±1.2)%which was much higher than in CON and DIO-R groups ( P0.05 ).Laser scanning confocal microscope detection showed Ca2+ staining intensity of RGCs in DIO group increased and its staining intensity was significantly higher than in CON and DIO-R mice (P0.05 ) . CONCLUSION:Intracellular calcium ion overload might be involved in the RGCs apoptosis in the diet-induced obese C57BL/6 mice.%目的:探讨高脂饮食诱导的C57 BL/6肥胖小鼠视网膜神经节细胞( RGCs)凋亡的机制。  方法:高脂饲料喂养19 wk后,小鼠分为肥胖抵抗( DIO-R)组和肥胖倾向( DIO)组,同时对照组( CON)小鼠给予基础饲料。 TUNEL法检测各组小鼠RGCs的凋亡情况,并应用激光共聚焦显微镜检测RGCs内钙离子的浓度。  结果:TUNEL法凋亡检测结果显示,DIO组小鼠视网膜神经节细胞层可见较多黄色着染的凋亡细胞,其凋亡指数为(6.7±1.2)%,显著高于对照组和DIO-R组(P<0.01, P<0.05);对照组和DIO-R组间比较无显著差异( P>0.05)。激光共聚焦结果显示,与对照组和DIO-R组比较,DIO组小鼠视网膜神经节细胞内Ca2+荧光染色明显增强,其荧光染色强度比值显著升高(均P<0.01);对照组和DIO-R组视网膜神经节细胞内Ca2+荧

  16. Increased aqueous flare is associated with thickening of inner retinal layers in eyes with retinitis pigmentosa

    Science.gov (United States)

    Nagasaka, Yosuke; Ito, Yasuki; Ueno, Shinji; Terasaki, Hiroko

    2016-01-01

    Retinitis pigmentosa(RP) is a hereditary retinal disease that causes photoreceptor, outer retinal, degeneration. Although the pathogenesis is still unclear, there have been numerous reports regarding inner retinal changes in RP eyes. The aim of this study is to retrospectively evaluate the changes in the thicknesses of different retinal layers of RP eyes, and its association with aqueous flare, which is used for measuring the intensity of intraocular inflammation. A total of 125 eyes of 64 patients with RP and 13 normal eyes were studied. The thicknesses of total neural retina,nerve fiber layer(NFL),ganglion cell layer(GCL),inner plexiform layer(IPL),inner nuclear layer(INL),outer layers and foveal thickness were measured in the optical coherence tomographic images. Aqueous flare was measured with a laser flare-cell meter. The associations between those parameters, visual acuity and visual field were determined in RP eyes using multivariate analysis. The results of this study showed the significant thickening of NFL, GCL and INL, the significant thinning of outer layers and the association of them with increased aqueous flare, whereas NFL and INL thickening associated with outer retinal thinning. These results can suggest the involvement of intraocular inflammation in the pathogenesis of inner retinal thickening as a secondary change following outer retinal degeneration. PMID:27653207

  17. 大麻素CB1受体对大鼠视网膜神经节细胞诱发动作电位的作用%Activation of cannabinoid CB1 receptors modulates evoked action potentials in rat retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    蒋淑霞; 李倩; 王霄汉; 李芳; 王中峰

    2013-01-01

    Activation of cannabinoid CB1 receptors (CB 1Rs) regulates a variety of physiological functions in the vertebrate retina through modulating various types of ion channels.The aim of the present study was to investigate the effects of this receptor on cell excitability of rat retinal ganglion cells (RGCs) in retinal slices using whole-cell patch-clamp techniques.The results showed that under current-clamped condition perfusing WIN55212-2 (WIN,5 μmol/L),a CB1R agonist,did not significantly change the spontaneous firing frequency and resting membrane potential of RGCs.In the presence of cocktail synaptic blockers,including excitatory postsynaptic receptor blockers CNQX and D-APV,and inhibitory receptor blockers bicuculline and strychnine,perfusion of WIN (5 μmol/L)hardly changed the frequencies of evoked action potentials by a series of positive current injection (from +10 to +100 pA).Phaseplane plot analysis showed that both average threshold voltage for triggering action potential and delay time to reach threshold voltage were not affected by WIN.However,WIN significantly decreased +dV/dtmax and-dV/dtmax of action potentials,suggestive of reduced rising and descending velocities of action potentials.The effects of WIN were reversed by co-application of SR141716,a CB1R selective antagonist.Moreover,WIN did not influence resting membrane potential of RGCs with synaptic inputs being blocked.These results suggest that activation of CB1Rs may regulate intrinsic excitability of rat RGCs through modulating evoked action potentials.%激活大麻素CB1受体(CB1Rs)通过调控多种离子通道,从而调节脊椎动物视网膜的功能.本文旨在利用膜片钳全细胞记录技术,在大鼠视网膜薄片上研究CB1Rs对神经节细胞兴奋性的作用.结果显示,在电流钳制状态下,灌流CB1R激动剂WIN55212-2 (WIN,5μmol/L)对神经节细胞的自发动作电位发放频率和静息膜电位均没有显著影响.在灌流液中加入CNQX,D-APV,bicuculline

  18. Neuroprotective effects of lomerizine on retinal ganglion cellsin the diet-induced obese C57BL/6J mice%洛美利嗪对膳食诱导的C57BL/6J肥胖小鼠视网膜神经节细胞凋亡的保护作用

    Institute of Scientific and Technical Information of China (English)

    白霞; 赵剑; 赵文青; 陈玉玲

    2014-01-01

    electron microscope.The cellular apoptosis was detected by TUNEL. The laser scanning confocal microscope was used to measure intracellular calcium ion concentration. RESULTS:Compared with the CON group , the RGCs in DIO group showed smaller and condensation of nuclear chromatin and increased electron density of the cytoplasm, whereas the changes in DIO+LOM mice were obviously diminished.TUNEL staining showed that the number of apoptosis cells in the ganglion cell layer ( GCL ) increased in DIO group and the percentage of apoptotic cells was much higher than that in the CON groups(P CONCLUSION: Lomerizine has neuroprotective effects on damage of retinal ganglion cells in diet-induced obesity mice, which may be related tothe attenuatio n of intracellular Ca2+overload.

  19. 补肾活血中药血清对高糖状态下纯化培养的视网膜神经节细胞活力的影响%Effect of Serum Contained Chinese Drugs for Nourishing Shen and Activating Blood on Activity of Purified Retinal Ganglion Cells Cultured in High Glucose Medium

    Institute of Scientific and Technical Information of China (English)

    马荣; 谢学军; 万李; 马殿伟

    2009-01-01

    目的 探讨补肾活血中药血清对体外高糖状态下纯化培养的视网膜神经节细胞活力的影响.方法 体外纯化SD大鼠视网膜神经节细胞(retinal ganglion cells,RGCs),模拟稳定高糖(50 mmol/L)及糖波动环境进行培养,以补肾活血中药血清进行干预,检测RGCs乳酸脱氢酶(lactate dehydrogenase,LDH)漏出量,以推测RGCs活力.结果 RGCs的LDH漏出量(U/L)稳定高糖组24 h(1 349.17±215.50)、48 h(1 220.24±124.53)及72 h(1 982.14±219.03)均较正常对照组(1 628.10±122.10、1 484.13±127.55及2 155.75±140.44)降低(P<0.05);而糖波动组的LDH漏出量在72 h(2 299.60±88.35)较正常对照组增加(P<0.05),且糖波动组各时段的LDH漏出量均较稳定高糖组增加(P<0.05);稳定高糖中药干预组的LDH漏出量在72 h(1 797.62±146.40)时较稳定高糖组减少(P<0.05);糖波动中药干预组的LDH漏出量在48 h(1 259.92±87.74)和72 h(1 940.40±155.47)时均较糖波动组减少(P<0.05).结论 糖波动能明显降低RGCs细胞膜的稳定性,增加细胞膜通透性,降低细胞活力;补肾活血中药血清能降低本实验中稳定高糖及糖波动条件下RGCs的细胞膜通透性,提高细胞膜稳定性,增强其细胞活力,这可能是补肾活血中药复方防治糖尿病视网膜病变(diabetic retinopathy,DRP)的药物干预途径之一.%Objective To investigate the effect of serum contained Chinese drugs for nourishing Shen and activating blood(S-NSAB)on activity of purified retinal ganglion cells(RGCs)cultured in high glucose medium.Methods Purified RGCs of SD rats were cultured in simulative stable high glucose(50 mmol/L)condition(SHG)and fluctuated glucose condition(FGC)separately,they were intervened with S-NSAB,and the lactate dehydrogenase(LDH)leakage was detected by spectrophotometer for estimating the activity of RGCs.Results LDH leakage(U/L)in SHG culture was 1 349.17±215.50 at 24 h,1 220.24±124.53 at 48 h and 1 982.14±219.03 at 72 h,all significantly lower

  20. Numerical simulation of neuronal spike patterns in a retinal network model

    Institute of Scientific and Technical Information of China (English)

    Lei Wang; Shenquan Liu; Shanxing Ou

    2011-01-01

    This study utilized a neuronal compartment model and NEURON software to study the effects of external light stimulation on retinal photoreceptors and spike patterns of neurons in a retinal network. Following light stimulation of different shapes and sizes, changes in the spike features of ganglion cells indicated that different shapes of light stimulation elicited different retinal responses. By manipulating the shape of light stimulation, we investigated the effects of the large number of electrical synapses existing between retinal neurons. Model simulation and analysis suggested that interplexiform cells play an important role in visual signal information processing in the retina, and the findings indicated that our constructed retinal network model was reliable and feasible. In addition, the simulation results demonstrated that ganglion cells exhibited a variety of spike patterns under different light stimulation sizes and different stimulation shapes, which reflect the functions of the retina in signal transmission and processing.

  1. ON and OFF channels in human retinal ganglion cells.

    Science.gov (United States)

    Hashimoto, Takao; Katai, Satoshi; Saito, Yasunori; Kobayashi, Fumitoshi; Goto, Tetsuya

    2013-01-01

    The ON and OFF channels are basic functional elements in parallel processing in the visual system in vertebrates including primates. We analysed the responses of the optic tract fibre activity in response to switching a flashlight on or off in 25 awake patients with Parkinson's disease who underwent stereotactic surgery targeting the internal globus pallidus. The responses were evoked in a darkened room by a light with a luminance of approximately 4 × 10(4) cd m(-2) at the eye and a wide-spectrum wavelength. Most of the responses at the light on event were excitatory (38 out of 41 sites, 93%). Thirty-five sites with increase in activity at the light on event showed reciprocal responses or no responses to light off, and these sites were classified as containing ON fibres. In single-fibre analysis, all of 14 ON fibres were recorded at the sites of multi-fibre excitatory responses. Six sites showed multi-fibre excitatory responses at the light off event; three sites showed sustained reduction in activity at the light on event, and these three sites were classified as containing OFF fibres. In single-fibre analysis, two OFF fibres were recorded at the sites of multi-fibre suppressive responses at the light on event, and the other two OFF fibres were recorded at the sites of multi-fibre excitatory responses at the light on event. We found that all excitatory responses to light on were transient, while all but one excitatory responses to light off were sustained. Reduction in activity tended to be smaller than increase in activity at the light on event. These results demonstrate that the ON and OFF channels, and their transient and sustained features function in visual processing in humans. PMID:23070704

  2. Melanopsin-expressing retinal ganglion cells: implications for human diseases

    DEFF Research Database (Denmark)

    La Morgia, Chiara; Ross-Cisneros, Fred N; Hannibal, Jens;

    2011-01-01

    .e. Leber hereditary optic neuropathy and dominant optic atrophy. The mechanism leading to mRGCs sparing in these blinding disorders, characterized by extensive and selective loss of RGCs, is currently unknown and under investigation. Other studies reported on mRGCs in glaucoma, on genetic variation...

  3. Ganglion cell and displaced amacrine cell density distribution in the retina of the howler monkey (Alouatta caraya.

    Directory of Open Access Journals (Sweden)

    José Augusto Pereira Carneiro Muniz

    Full Text Available Unlike all other New World (platyrrine monkeys, both male and female howler monkeys (Alouatta sp. are obligatory trichromats. In all other platyrrines, only females can be trichromats, while males are always dichromats, as determined by multiple behavioral, electrophysiological, and genetic studies. In addition to obligatory trichromacy, Alouatta has an unusual fovea, with substantially higher peak cone density in the foveal pit than every other diurnal anthropoid monkey (both platyrrhines and catarrhines and great ape yet examined, including humans. In addition to documenting the general organization of the retinal ganglion cell layer in Alouatta, the distribution of cones is compared to retinal ganglion cells, to explore possible relationships between their atypical trichromacy and foveal specialization. The number and distribution of retinal ganglion cells and displaced amacrine cells were determined in six flat-mounted retinas from five Alouatta caraya. Ganglion cell density peaked at 0.5 mm between the fovea and optic nerve head, reaching 40,700-45,200 cells/mm2. Displaced amacrine cell density distribution peaked between 0.5-1.75 mm from the fovea, reaching mean values between 2,050-3,100 cells/mm2. The mean number of ganglion cells was 1,133,000±79,000 cells and the mean number of displaced amacrine cells was 537,000±61,800 cells, in retinas of mean area 641±62 mm2. Ganglion cell and displaced amacrine cell density distribution in the Alouatta retina was consistent with that observed among several species of diurnal Anthropoidea, both platyrrhines and catarrhines. The principal alteration in the Alouatta retina appears not to be in the number of any retinal cell class, but rather a marked gradient in cone density within the fovea, which could potentially support high chromatic acuity in a restricted central region.

  4. 优视胶囊对急性高眼压家兔眼压及神经节细胞的影响%Effects of Youshi capsule on the intraocular pressure(IOP) and retinal ganglion cells (RGC) of rabbits under artificial acute intraocular hypertension

    Institute of Scientific and Technical Information of China (English)

    张宗端; 段俊国

    2001-01-01

    目的:观察优视胶囊对急性高眼压兔眼压的影响及对视网膜视神经的保护作用。方法:采用自行设计的上巩膜静脉结扎法建立18只兔眼急性高眼压动物模型,于造模前1周至造模后3天共10天内给予具活血化瘀、开窍明目功效的优视胶囊灌胃,18只造模眼随机分为模型组、低剂量组和高剂量组,每组6眼,与18只正常眼进行对照。实验过程中测量眼压并行视网膜神经节细胞计数。结果:①造模后即可获得平均眼压高于6.83kPa并能持续3天以上的高眼压动物模型,优视胶囊高、低剂量组表现出轻微的降眼压作用。②持续性的高眼压可造成视网膜神经节细胞减少,但高、低剂量组经优视胶囊治疗后高眼压模型眼神经节细胞数高于模型组,提示优视胶囊具有保护或改善急性高眼压后兔眼视网膜神经节细胞的作用。结论:优视胶囊对急性高眼压兔眼视网膜视神经具有保护的作用。%Objective:To observe the effects of Youshi capsule on the intraocular pressure(IOP) and retinal ganglion cells(RGC) of rabbits under artificial acute intraocular hypertension.Methods:We used episcleral veins ligation on rabbit to establish an acute intraocular hypertension animal model devised by ourselves. Between one week before and 3 days after the models were induced, Youshi capsule was irrigated into the stomachs, having the function of promoting blood circulation and removing blood stasis,opening porus and improving vision. 18 model-established eyes were randomly divided into model group, high and low dosage group(6 eyes each group) and compared with other 18 normal eyes. Then examined IOP and counted RGC.Results:①Acute intraocular hypertension animal model was produced just after model was established and its average IOP above 6.83kPa could maintain 3 days. High and low dosage Youshi capsule showed slight effect on the reduction of IOP in intraocluar

  5. Focal electrical stimulation of major ganglion cell types in the primate retina for the design of visual prostheses.

    Science.gov (United States)

    Jepson, Lauren H; Hottowy, Pawel; Mathieson, Keith; Gunning, Deborah E; Dabrowski, Wladyslaw; Litke, Alan M; Chichilnisky, E J

    2013-04-24

    Electrical stimulation of retinal neurons with an advanced retinal prosthesis may eventually provide high-resolution artificial vision to the blind. However, the success of future prostheses depends on the ability to activate the major parallel visual pathways of the human visual system. Electrical stimulation of the five numerically dominant retinal ganglion cell types was investigated by simultaneous stimulation and recording in isolated peripheral primate (Macaca sp.) retina using multi-electrode arrays. ON and OFF midget, ON and OFF parasol, and small bistratified ganglion cells could all be activated directly to fire a single spike with submillisecond latency using brief pulses of current within established safety limits. Thresholds for electrical stimulation were similar in all five cell types. In many cases, a single cell could be specifically activated without activating neighboring cells of the same type or other types. These findings support the feasibility of direct electrical stimulation of the major visual pathways at or near their native spatial and temporal resolution.

  6. Cat Scan

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> A man takes his motionless dog to the vet."Doc,I think my dog is dead.”The vet looks the dog over, goes into a backroom,and comes out with a cat.He places the caton the table next to the dog.The cat walks aroundand sniffs at the dog.The dog does not move.The

  7. Dendritic field size and morphology of midget and parasol ganglion cells of the human retina.

    OpenAIRE

    Dacey, D M; Petersen, M R

    1992-01-01

    The visual system of the macaque monkey has provided a useful model for understanding the neural basis of human vision, yet, there are few detailed comparisons of neural populations other than photoreceptors for the two species. Using intracellular staining in an in vitro preparation of the isolated and intact human retina, we have characterized the relationship of dendritic field size to retinal eccentricity for the two major ganglion cell classes, the midget and the parasol cells. We report...

  8. Imaging Light Responses of Foveal Ganglion Cells in the Living Macaque Eye

    OpenAIRE

    Yin, Lu; Masella, Benjamin; Dalkara, Deniz; Zhang, Jie; Flannery, John G.; Schaffer, David V; Williams, David R.; Merigan, William H.

    2014-01-01

    The fovea dominates primate vision, and its anatomy and perceptual abilities are well studied, but its physiology has been little explored because of limitations of current physiological methods. In this study, we adapted a novel in vivo imaging method, originally developed in mouse retina, to explore foveal physiology in the macaque, which permits the repeated imaging of the functional response of many retinal ganglion cells (RGCs) simultaneously. A genetically encoded calcium indicator, G-C...

  9. [Optogenetics and prosthetic treatment of retinal degeneration].

    Science.gov (United States)

    Kirpichnikov, M P; Ostrovskiy, M A

    2015-01-01

    This is a review of the current state of optogenetics-based research in the field of ophthalmology and physiology of vision. Optogenetics employs an interdisciplinary approach that amalgamates gene engineering, optics, and physiology. It involves exogenous expression of a light-activated protein in a very particular retinal cell enabling regulation (stimulation vs. inhibition) of its physiological activity. The experience with gene therapy came in very useful for optogenetics. However, unlike gene therapy, which is aimed at repairing damaged genes or replacing them with healthy ones, optogenetics is focused on protein genes delivery for further molecular control of the cell. In retina, the loss of photoreceptors is not necessarily followed by neuronal loss (at least ganglion cells remain intact), which determines the practicability of prosthetic treatment. Clinical trials can now be considered, owing to the first successful conversion of ganglion cells of mouse degenerative retinas into artificial photoreceptive cells with ON and OFF receptive fields, which is crucial for spatial vision. The following issues are reviewed here in detail: 1. Choice of cell targets within the degenerative retina. 2. Strategy of utilizing the existing light-sensitive agents and development of new optogenetic tools. 3. Gene delivery and expression in retinal cells. 4. Methods of evaluating the treatment success. 5. Selection criteria for optogenetic prosthetics. The conclusion discusses currently unsolved problems and prospects for optogenetic approaches to retinal prosthetics.

  10. Retinal Remodeling: Concerns, Emerging Remedies, and Future Prospects

    Directory of Open Access Journals (Sweden)

    Vidhyasankar eKrishnamoorthy

    2016-02-01

    Full Text Available Deafferentation results not only in sensory loss, but also in a variety of alterations in the postsynaptic circuitry. These alterations may have detrimental impact on potential treatment strategies. Progressive loss of photoreceptors in retinal degenerative diseases, such as retinitis pigmentosa and age-related macular degeneration, leads to several changes in the remnant retinal circuitry. Müller glial cells undergo hypertrophy and form a glial seal. The second- and third-order retinal neurons undergo morphological, biochemical and physiological alterations. A result of these alterations is that retinal ganglion cells (RGCs, the output neurons of the retina, become hyperactive and exhibit spontaneous, oscillatory bursts of spikes. This aberrant electrical activity degrades the signal-to-noise ratio in RGC responses, and thus the quality of information they transmit to the brain. These changes in the remnant retina, collectively termed retinal remodeling, pose challenges for genetic, cellular and bionic approaches to restore vision. It is therefore crucial to understand the nature of retinal remodeling, how it affects the ability of remnant retina to respond to novel therapeutic strategies, and how to ameliorate its effects. In this article, we discuss these topics, and suggest that the pathological state of the retinal output following photoreceptor loss is reversible, and therefore, amenable to restorative strategies.

  11. Production of Retinal Cells from Confluent Human iPS Cells.

    Science.gov (United States)

    Reichman, Sacha; Goureau, Olivier

    2016-01-01

    Human induced pluripotent stem (hiPS) cells could be used as an unlimited source of retinal cells for the treatment of retinal degenerative diseases. Although much progress has been made in the differentiation of pluripotent stem cells towards different retinal lineages, the production of retinal cells from hiPS cells for therapeutic approaches require the development of easy and standardized protocols. In this chapter, we describe a simple and effective protocol for retinal differentiation of hiPS cells bypassing embryoid body formation and the use of exogenous molecules and substrates. In 2 weeks, confluent hiPS cells cultured in pro-neural medium can generate both retinal pigmented epithelial cells and self-forming neural retina-like structures containing retinal progenitor cells. These progenitors can be differentiated into all retinal cell types, including retinal ganglion cells and precursors of photoreceptors, which could find important applications in regenerative medicine. This differentiation system and the resulting hiPS-derived retinal cells will also offer opportunity to study the molecular and cellular mechanisms underlying human retinal development, and the establishment of in vitro models of human retinal degenerative diseases.

  12. Mosaic properties of midget and parasol ganglion cells in the marmoset retina.

    Science.gov (United States)

    Szmajda, Brett A; Grünert, Ulrike; Martin, Paul R

    2005-01-01

    We measured mosaic properties of midget and parasol ganglion cells in the retina of a New World monkey, the common marmoset Callithrix jacchus . We addressed the functional specialization of these populations for color and spatial vision, by comparing the mosaic of ganglion cells in dichromatic ("red-green color blind") and trichromatic marmosets. Ganglion cells were labelled by photolytic amplification of retrograde marker ("photofilling") following injections into the lateral geniculate nucleus, or by intracellular injection in an in vitro retinal preparation. The dendritic-field size, shape, and overlap of neighboring cells were measured. We show that in marmosets, both midget and parasol cells exhibit a radial bias, so that the long axis of the dendritic field points towards the fovea. The radial bias is similar for parasol cells and midget cells, despite the fact that midget cell dendritic fields are more elongated than are those of parasol cells. The dendritic fields of midget ganglion cells from the same (ON or OFF) response-type array show very little overlap, consistent with the low coverage of the midget mosaic in humans. No large differences in radial bias, or overlap, were seen on comparing retinae from dichromatic and trichromatic animals. These data suggest that radial bias in ganglion cell populations is a consistent feature of the primate retina. Furthermore, they suggest that the mosaic properties of the midget cell population are associated with high spatial resolution rather than being specifically associated with trichromatic color vision. PMID:16212698

  13. 3D-OCT对早期原发性青光眼黄斑区视网膜神经节细胞复合体及神经纤维层结构变化的评估%Evaluation of macular ganglion cell complex and peripheral retinal nerve fiber layer structural damage in early primary glaucomous eyes by 3D-OCT

    Institute of Scientific and Technical Information of China (English)

    严钰洁; 孙心铨; 陈术; 施爱群; 王志军

    2016-01-01

    常或轻微变薄.结论 原发性青光眼mGCC层厚度变薄早于视盘周围RNFL的变薄,提示青光眼视神经结构的损害始于RGCs的细胞体并早于轴突的损伤或丢失.%Background In previous study,peripheral retinal nerve fiber layer (RNFL) thickness is considered to be the earliest structural changes which can be detected.3D-OCT can measure the thickness of macular ganglion cell complex (mGCC),which makes the detection of primary glaucoma possible in the early stage.Objective This study was to measure the thickness of mGCC and disc-peripheral RNFL in early stage of primary glaucomous eyes by 3D-OCT and assess the anatomic basis of glaucoma-induced optical nerve damage.Methods 3D-OCT images from 10 patients with advanced stage primary glaucoma in one lateral eye and early stage glaucoma in fellow eye from December 2010 to December 2012 were prospectively analyzed in China-Japan Friendship Hospital.The patients were diagnosed based on the recommended standard of National glaucoma group (1987 version) and received routine eye examination.3D-OCT scanning was performed using 3D-macular mode,3D-macular Wide mode and 3D-disc mode with TOPCON 3D-OCT 2000 system,and the images at macular 6 mm×6 mm area were analyzed.The posterior pole area was divided into 5 concentric rings from fovea toward periphery and equally subdivided into 100 small checks,with the area of 0.6 mm×0.6 mm for each.The probable values in each check were calculated as the ratio of each figure and corresponding normal value.The probable values were expressed as red color (P< 1%),yellow color (P<5%) and gray color (P≥ 5%).Then the disc-periphery RNFL thickness and disc cup were evaluated.Results No evident abnormality was found in the thicknesses of photoreceptors layer and bipolar cell layer in both advanced glaucomous eyes and the early stage of glaucomous eyes in the 10 patients.Serious damage of visual field was seen in the advanced glaucomous eyes and presented with red color in the

  14. Cat Scratch Disease

    Science.gov (United States)

    Cat scratch disease (CSD) is an illness caused by the bacterium Bartonella henselae. Almost half of all cats carry ... infection does not make cats sick. However, the scratch or bite of an infected cat can cause ...

  15. Retinal abnormalities in multiple sclerosis patients with associated chronic cerebrospinal venous insufficiency

    OpenAIRE

    Aneta Adamczyk-Ludyga; Justyna Wróbeł; Marian Simka; Tomasz Ludyga; Paweł Latacz; Marek Kazibudzki

    2012-01-01

    Optical coherence tomography (OCT) is a non-invasive method for the assessment of optic nerve fibers and retinal ganglion cells. This study was aimed at the assessment of retinal abnormalities in multiple sclerosis patients in the context of chronic cerebrospinal venous insufficiency using OCT of the retina and the optic nerve. We examined 239 multiple sclerosis (MS) patients, including 220 patients with associated chronic cerebrospinal venous insufficiency and 19 MS patients without venous p...

  16. Visual Responses in Mice Lacking Critical Components of All Known Retinal Phototransduction Cascades

    OpenAIRE

    Annette E Allen; Cameron, Morven A.; Timothy M Brown; Vugler, Anthony A.; Lucas, Robert J.

    2010-01-01

    The mammalian visual system relies upon light detection by outer-retinal rod/cone photoreceptors and melanopsin-expressing retinal ganglion cells. Gnat1(-/-); Cnga3(-/-); Opn4(-/-) mice lack critical elements of each of these photoreceptive mechanisms via targeted disruption of genes encoding rod alpha transducin (Gnat1); the cone-specific alpha 3 cyclic nucleotide gated channel subunit (Cnga3); and melanopsin (Opn4). Although assumed blind, we show here that these mice retain sufficiently wi...

  17. Retinal vessel diameter changes induced by transient high perfusion pressure

    Institute of Scientific and Technical Information of China (English)

    Yin-Ying; Zhao; Ping-Jun; Chang; Fang; Yu; Yun-E; Zhao

    2014-01-01

    ·AIM: To investigate the effects of transient high perfusion pressure on the retinal vessel diameter and retinal ganglion cells.·METHODS: The animals were divided into four groups according to different infusion pressure and infusion time(60 mm Hg-3min, 60 mm Hg-5min, 100 mm Hg-3min, 100 mm Hg-5min). Each group consisted of six rabbits. The left eye was used as the experimental eye and the right as a control. Retinal vascular diameters were evaluated before, during infusion, immediately after infusion, 5min, 10 min and 30 min after infusion based on the fundus photographs. Blood pressure was monitored during infusion. The eyes were removed after 24 h.Damage to retinal ganglion cell(RGC) was analyzed by histology.·RESULTS: Retina became whiten and papilla optic was pale during perfusion. Measurements showed significant decrease in retinal artery and vein diameter during perfusion in all of the four groups at the proximal of the edge of the optic disc. The changes were significant in the 100 mm Hg-3min group and 100 mm Hg-5min group compared with 60 mm Hg-3min group(P 1=0.025, P 2=0.000).The diameters in all the groups recovered completely after 30 min of reperfusion. The number of RGC)showed no significant changes at the IOP in 100 mm Hg with5 min compared with contralateral untreated eye(P >0.05).·CONCLUSION: Transient fluctuations during infusion lead to temporal changes of retinal vessels, which could affect the retinal blood circulation. The RGCs were not affected by this transient fluctuation. Further studies are necessary to evaluate the effect of pressure during realtime phacoemusification on retinal blood circulation.

  18. Mutation Discovered in a Feline Model of Human Congenital Retinal Blinding Disease

    OpenAIRE

    Menotti-Raymond, Marilyn; Deckman, Koren Holland; David, Victor; Myrkalo, Jaimie; O'Brien, Stephen J.; Narfström, Kristina

    2010-01-01

    The authors report on the genetic characterization of a deletion in the feline CRX gene in the Rdy cat, defining a new large-animal model for Leber congenital amaurosis, retinitis pigmentosa, and cone–rod dystrophy.

  19. Retinal hypoxia induces vascular endothelial growth factor through induction of estrogen-related receptor γ

    Energy Technology Data Exchange (ETDEWEB)

    Do, Ji Yeon; Choi, Young Keun [Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University School of Medicine, Kyungpook National University, Daegu (Korea, Republic of); Kook, Hyun [Department of Pharmacology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Suk, Kyoungho [Department of Pharmacology, Brain Science & Engineering Institute, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Lee, In-Kyu [Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University School of Medicine, Kyungpook National University, Daegu (Korea, Republic of); Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Aging and Metabolism, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Park, Dong Ho, E-mail: sarasate2222@gmail.com [Department of Ophthalmology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

    2015-05-01

    Ischemic retinopathies causing overexpression of pro-angiogenic factors, including vascular endothelial growth factor (VEGF), are the most common cause of blindness. Thus, understanding the pathophysiology of targetable pathways that regulate retinal VEGF is of great interest. A conserved binding site for estrogen-related receptor γ (ERRγ) has been identified in the promoter of the Vegfa gene. ERRγ is a constitutively active orphan nuclear receptor and its expression is increased by hypoxic stimuli in metabolically active tissues. This study evaluated the role of ERRγ in the ischemic retina and the anti-VEGF potential of GSK5182, a selective inverse agonist of ERRγ. In an oxygen-induced retinopathy (OIR) mouse model, immunohistochemistry showed significantly increased ERRγ expression in the ganglion cell layer at postnatal day (P) 17. In a ganglion cell line (RGC-5), mRNA and protein levels of ERRγ were increased by desferrioxamine treatment and hypoxic conditions (1% O{sub 2}). Transient transfection of RGC-5 cells revealed that ERRγ regulated Vegfa expression and this was inhibited by GSK5182. Intravitreal injection of GSK5182 into the OIR model at P14 inhibited retinal Vegfa mRNA expression at P17. GSK5182 suppresses hypoxia-induced VEGF expression via ERRγ; therefore, ERRγ could be a treatment target for ischemic retinopathies. - Highlights: • OIR mice exhibited increased ERRγ expression in the ganglion cell layer. • Hypoxia-induced ERRγ expression was observed in retinal ganglion cells. • ERRγ overexpression increased VEGFA expression in retinal ganglion cells. • An ERRγ inverse agonist suppressed VEGFA expression in retinal ganglion cells. • Intravitreal injection of an ERRγ inverse agonist suppressed VEGFA in OIR mice.

  20. Cat's Claw

    Science.gov (United States)

    ... R S T U V W X Y Z Cat's Claw Share: On This Page Introduction What the ... More Information Key References © Steven Foster Common Names: cat’s claw, uña de gato Latin Name: Uncaria tomentosa, ...

  1. My Cat

    Institute of Scientific and Technical Information of China (English)

    王悦; 李成梅

    2002-01-01

    The name of my cat is Naty. This year he is one year old. He isvery fat, but he is very nice. He has a big round white head. His mouth and nose are small. His eyes are interesting. In the day,they are small and black,but at night they are big and blue.

  2. Heat shock protein 27 and its role in retinal ganglion cell apoptosis in rat high intraocular pressure model%大鼠高眼压模型中热休克蛋白27抗体及视网膜神经节细胞凋亡的研究

    Institute of Scientific and Technical Information of China (English)

    欧阳科; 袁援生

    2012-01-01

    .05).结论 随着眼压的升高以及高眼压持续时间的延长,大鼠血清中的HSP27抗体水平逐渐升高,视网膜在高眼压状态下HSP27表达上调.逐渐升高的HSP27抗体水平与RGCs凋亡增加的趋势一致.%Background Glaucoma is common blinding eye diseases characterized by chronic loss of retinal ganglion cells(RGCs).Currently glaucoma pathogenesis is not completely understood,heat shock protein 27 ( HSP27 )may be associated with the pathogenesis of glaucomatous optic neuropathy. Objective Through the establishment of a rat model of high intraocular pressure,detection of the expression of HSP27 antibody in serum and RGCs apoptosis to investigate the role of HSP27 in RGCs apoptosis. Methods Fifty-one clean Wistar rats were divided into high intraocular pressure group (34 rats)and sham operation group( 17 rats)using a random number table.An animal model of high intraocular pressure was established in the right eye by the application of bipolar underwater electrocoagulation on vein of sclera surface in the experimental group,and rats with conjunctiva incision only without electric coagulation were served as sham operation (control).The intraocular pressure of rats of the both groups including experimental and control rats was measured 1,2,4,6,8 weeks after operation and then the rats were sacrificed.1 ml serum was collected from these rats to determine the concentration of HSP27 antibody.The retinas of the rats were isolated and homogenated for the extraction and analysis of the retinal protein by Western blot.Apoptosis of RGCs were assayed by TUNEL.The use of the experimental animals followed the Regulations for the Administration of Affair Concerning Experimental Animals by Kunming Medical Collegc. Results Intraocular pressure was elevated significantly after modeling and remained a high value during the expcrimental duration,showing a significant difference among the different groups ( F =318.502,P<0.01 ).However,no significant change in

  3. Long-term Fluorometholone Topical Use Induces Ganglion Cell Damage in Rats Analyzed With Optical Coherence Tomography.

    Science.gov (United States)

    Lin, Cheng-Hui; Liao, Po-Lin; Hsiao, George; Li, Ching-Hao; Huang, Shih-Hsuan; Tsai, Chi-Hao; Wu, Man-Ru; Lin, Fan-Li; Ho, Jau-Der; Cheng, Hui-Wen; Cheng, Yu-Wen

    2015-10-01

    To determine the toxic effects of long-term topical usage of fluorometholone (FLM) on ganglion cells using a direct in vivo retinopathological Brown Norway (BN) rat model. The BN rat retinal model was investigated with a minimum of 3 rats and a maximum of 4 rats per group. Rats received vehicle and 0.02% FLM suspension via topical administration 3 times a day for 28 days. The fundus images and retinal vessels were detected on days 1, 14, and 28 using Micron III retinal imaging microscope and fundus fluorescein angiography (FFA). For retinal structures, spectral-domain optical coherence tomography (SD-OCT) images were taken after FFA on days 1, 14, and 28 using an SD-OCT Imaging System. For retinal function, electrical signal transduction of photoreceptors and bipolar cells was determined by electroretinographic (ERG) recording on days 1 and 28 and IOP detection. At the end of the experiment on day 28, immunohistochemistry and TUNEL assay were performed to investigate apoptosis in ganglion cells. Total retina and nerve fiber layer (NFL) to the inner plexiform layer (IPL) were significantly thinner following 28 days of FLM treatment. Hematoxylin and eosin stain showed that there were NFL and ganglion cell layer deformations in the FLM group. With FLM treatment, TUNEL assay showed approximately a 4.68-fold increase in apoptotic cells. Moreover, FLM decreased ERG b-wave amplitude by about 56%. Using ophthalmofundoscopy devices, after 28 days of topical administration, FLM decreased NFL-IPL and total retina thickness. This suggests that long-term FLM induces adverse effects with respect to ganglion cell apoptosis. PMID:26141393

  4. Sphenopalatine ganglion neuromodulation in migraine

    DEFF Research Database (Denmark)

    Khan, Sabrina; Schoenen, Jean; Ashina, Messoud

    2014-01-01

    OBJECTIVE: The objective of this article is to review the prospect of treating migraine with sphenopalatine ganglion (SPG) neurostimulation. BACKGROUND: Fuelled by preliminary studies showing a beneficial effect in cluster headache patients, the potential of treating migraine with neurostimulation...... has gained increasing interest within recent years, as current treatment strategies often fail to provide adequate relief from this debilitating headache. Common migraine symptoms include lacrimation, nasal congestion, and conjunctival injection, all parasympathetic manifestations. In addition......, studies have suggested that parasympathetic activity may also contribute to the pain of migraineurs. The SPG is the largest extracranial parasympathetic ganglion of the head, innervating the meninges, lacrimal gland, nasal mucosa, and conjunctiva, all structures involved in migraine with cephalic...

  5. Transfection of brain-derived neurotrophic factor gene by recombinant adeno-associated virus vector in retinal ganglion cells in vitro%腺伴随病毒介导的脑源性神经营养因子对体外培养的鼠视网膜神经节细胞转染及生长特性的影响

    Institute of Scientific and Technical Information of China (English)

    李海燕; 赵家良; 张华

    2008-01-01

    目的 探讨重组腺伴随病毒载体介导的脑源性神经营养因子(rAAV-BDNF)对体外培养的鼠视网膜神经节细胞(RGCs)转染及其生长活性的影响.方法 实验研究.(1)应用rAAV-BDNF对体外培养2 d的RGCs进行转染;(2)应用逆转录聚合酶链反应(RT-PCR)技术,检测外源性BDNF基因在RGCs细胞mRNA水平的表达情况;(3)应用酶联免疫吸附测定(ELISA)法,对细胞培养液中BDNF含量进行检测;(4)对rAAV-BDNF转染细胞、未转染细胞及加入BDNF的培养细胞进行MTT比色分析;(5)应用Annexin V-FITC凋亡检测试剂盒和流式细胞仪,检测rAAV-BDNF转染细胞、未转染细胞及加入BDNF培养细胞的凋亡比率.结果 (1)RT-PCR检测结果:转染细胞表达外源性BDNF基因,而未转染细胞不表达BDNF基因.(2)ELISA法检测结果:rAAV-BDNF转染细胞的培养液中BDNF含量:转染7 d后为(616.1±40.0)ng/L,转染14 d后为(1075.1±48.7)ng/L.(3)MTT比色结果:转染3和6 d后,rAAV-BDNF转染细胞与未转染细胞间的吸光度(A)值差异无统计学意义(t=1.084,1.582;P=0.284,0.120);转染9 d后,转染细胞的A值高于未转染细胞(t=4.854,P=0.000).(4)流式细胞仪检测结果:rAAV-BDNF转染细胞和加入BDNF培养细胞的凋亡率明显低于未转染细胞的凋亡率,差异有统计学意义(P=0.015,0.017).结论 rAAV-BDNF可有效转染体外培养的鼠RGCs,转染细胞可在转录水平和翻译水平表达外源性BDNF基因,且生长活性改善,凋亡细胞减少.这为青光眼视神经保护的基因治疗提供了理论和技术支持.%Objective To determine whether rat retinal ganglion cells(RGCs)could be infected by rAAV-BDNF in vitro and to evaluate the influence of rAAV-BDNF transfection on the survival and apoptosis of rat RGCs.Methods It Was a experimental study.(1)RGCs were isolated from neonatal Sprague-Dawley rats(postnatal within 24 h).(2)Two days after the cultivation,the RGCs were transfected with rAAV- BDNF at a dosage of MOI=103 and then

  6. Loss of Synaptic Connectivity, Particularly in Second Order Neurons Is a Key Feature of Diabetic Retinal Neuropathy in the Ins2Akita Mouse

    OpenAIRE

    Hombrebueno, Jose R.; Mei Chen; Penalva, Rosana G.; Heping Xu

    2014-01-01

    Retinal neurodegeneration is a key component of diabetic retinopathy (DR), although the detailed neuronal damage remains ill-defined. Recent evidence suggests that in addition to amacrine and ganglion cell, diabetes may also impact on other retinal neurons. In this study, we examined retinal degenerative changes in Ins2Akita diabetic mice. In scotopic electroretinograms (ERG), b-wave and oscillatory potentials were severely impaired in 9-month old Ins2Akita mice. Despite no obvious pathology ...

  7. Exploring the retinal connectome

    Science.gov (United States)

    Anderson, James R.; Jones, Bryan W.; Watt, Carl B.; Shaw, Margaret V.; Yang, Jia-Hui; DeMill, David; Lauritzen, James S.; Lin, Yanhua; Rapp, Kevin D.; Mastronarde, David; Koshevoy, Pavel; Grimm, Bradley; Tasdizen, Tolga; Whitaker, Ross

    2011-01-01

    Purpose A connectome is a comprehensive description of synaptic connectivity for a neural domain. Our goal was to produce a connectome data set for the inner plexiform layer of the mammalian retina. This paper describes our first retinal connectome, validates the method, and provides key initial findings. Methods We acquired and assembled a 16.5 terabyte connectome data set RC1 for the rabbit retina at ≈2 nm resolution using automated transmission electron microscope imaging, automated mosaicking, and automated volume registration. RC1 represents a column of tissue 0.25 mm in diameter, spanning the inner nuclear, inner plexiform, and ganglion cell layers. To enhance ultrastructural tracing, we included molecular markers for 4-aminobutyrate (GABA), glutamate, glycine, taurine, glutamine, and the in vivo activity marker, 1-amino-4-guanidobutane. This enabled us to distinguish GABAergic and glycinergic amacrine cells; to identify ON bipolar cells coupled to glycinergic cells; and to discriminate different kinds of bipolar, amacrine, and ganglion cells based on their molecular signatures and activity. The data set was explored and annotated with Viking, our multiuser navigation tool. Annotations were exported to additional applications to render cells, visualize network graphs, and query the database. Results Exploration of RC1 showed that the 2 nm resolution readily recapitulated well known connections and revealed several new features of retinal organization: (1) The well known AII amacrine cell pathway displayed more complexity than previously reported, with no less than 17 distinct signaling modes, including ribbon synapse inputs from OFF bipolar cells, wide-field ON cone bipolar cells and rod bipolar cells, and extensive input from cone-pathway amacrine cells. (2) The axons of most cone bipolar cells formed a distinct signal integration compartment, with ON cone bipolar cell axonal synapses targeting diverse cell types. Both ON and OFF bipolar cells receive

  8. Retinal oscillations carry visual information to cortex

    Directory of Open Access Journals (Sweden)

    Kilian Koepsell

    2009-04-01

    Full Text Available Thalamic relay cells fire action potentials that transmit information from retina to cortex. The amount of information that spike trains encode is usually estimated from the precision of spike timing with respect to the stimulus. Sensory input, however, is only one factor that influences neural activity. For example, intrinsic dynamics, such as oscillations of networks of neurons, also modulate firing pattern. Here, we asked if retinal oscillations might help to convey information to neurons downstream. Specifically, we made whole-cell recordings from relay cells to reveal retinal inputs (EPSPs and thalamic outputs (spikes and then analyzed these events with information theory. Our results show that thalamic spike trains operate as two multiplexed channels. One channel, which occupies a low frequency band (<30 Hz, is encoded by average firing rate with respect to the stimulus and carries information about local changes in the visual field over time. The other operates in the gamma frequency band (40-80 Hz and is encoded by spike timing relative to retinal oscillations. At times, the second channel conveyed even more information than the first. Because retinal oscillations involve extensive networks of ganglion cells, it is likely that the second channel transmits information about global features of the visual scene.

  9. black cat

    Institute of Scientific and Technical Information of China (English)

    杜铁梅

    2016-01-01

    The black cat is a masterpiece of short fiction of Poe. He successfully solved the problem of creating of the horror effect by using scene description, symbol, repetition and first-person narrative methods. And created a complete and unified mysterious terror, achieved the effect of shocking. This paper aims to discuss the mystery in-depth and to enrich the research system in Poe’s novels.

  10. Expression of hermes gene is restricted to the ganglion cells in the retina.

    Science.gov (United States)

    Piri, Natik; Kwong, Jacky M K; Song, Min; Caprioli, Joseph

    2006-09-11

    The RNA binding protein with multiple splicing 2, or hermes, is a member of the RRM (RNA recognition motif) family of RNA-binding proteins. In this study, we show that the hermes gene is expressed in the rat retina, and its expression is restricted to the ganglion cell layer. Double in situ hybridization with riboprobes corresponding to the hermes gene and Thy-1, the RGC marker in the retina, showed that the majority of the Thy-1 positive cells in the ganglion cell layer were also hermes positive. This was also shown by co-localization of the hermes in situ hybridization signals with the retrogradely labeled RGCs. Our observations suggest that hermes is expressed in the majority, if not all, of RGCs and is not restricted to only certain RGC types. Hermes in situ hybridization signals were not detected in the retinal sections of optic nerve transected animals, which are characterized by rapid and specific RGC degeneration. The dramatic reduction of the hermes mRNA level in axotomized retinas was also observed by semi-quantitative RT-PCR. The specific expression of hermes in retinal ganglion cells qualifies this gene as a potential RGC marker in the retina. Outside the retina, hermes is expressed in the heart, liver, and kidney, and to a lesser degree in the cerebellum, cortex, lung, and small intestine. PMID:16870336

  11. Inner retinal change in a novel rd1-FTL mouse model of retinal degeneration

    Directory of Open Access Journals (Sweden)

    Ursula eGreferath

    2015-07-01

    Full Text Available While photoreceptor loss is the most devastating result of inherited retinal degenerations such as retinitis pigmentosa, inner retinal neurons also undergo significant alteration. Detailing these changes has become important as many vision restorative therapies target the remaining neurons. In this study, the rd1-Fos-Tau-LacZ (rd1-FTL mouse model was used to explore inner retinal change at a late stage of retinal degeneration, after the loss of photoreceptor nuclei. The rd1-FTL model carries a mutation in the phosphodiesterase gene, Pde6b, and an axonally targeted transgenic beta galactosidase reporter system under the control of the c-fos promoter. Retinae of transgenic rd1-FTL mice and control FTL animals aged 2 to 12 months were processed for indirect fluorescence immunocytochemistry. At 2 months of age, a time when the majority of photoreceptor nuclei are lost, there was negligible c-fos reporter (FTL expression, however, from 4 months, reporter expression was observed to increase within subpopulations of amacrine and ganglion cells within the central retina. These areas of inner retinal FTL expression coincided with regions that contained aberrant Müller cells. Specifically, these cells exhibited reduced glutamine synthetase and Kir4.1 immunolabelling, whilst showing evidence of proliferative gliosis (increased cyclinD1 and GFAP expression. These changes were limited to distinct regions where cone photoreceptor terminals were absent. Overall, these results highlight that distinct areas of the rd1-FTL central retina undergo significant glial alterations after cone photoreceptor loss. These areas coincide with up-regulation of the c-fos reporter in the inner retina, which may represent a change in neuronal function/plasticity. The rd1-FTL mouse is a useful model system to probe changes that occur in the inner retina at later stages of retinal degeneration.

  12. Inner retinal change in a novel rd1-FTL mouse model of retinal degeneration.

    Science.gov (United States)

    Greferath, Ursula; Anderson, Emily E; Jobling, Andrew I; Vessey, Kirstan A; Martinez, Gemma; de Iongh, Robb U; Kalloniatis, Michael; Fletcher, Erica L

    2015-01-01

    While photoreceptor loss is the most devastating result of inherited retinal degenerations such as retinitis pigmentosa, inner retinal neurons also undergo significant alteration. Detailing these changes has become important as many vision restorative therapies target the remaining neurons. In this study, the rd1-Fos-Tau-LacZ (rd1-FTL) mouse model was used to explore inner retinal change at a late stage of retinal degeneration, after the loss of photoreceptor nuclei. The rd1-FTL model carries a mutation in the phosphodiesterase gene, Pde6b, and an axonally targeted transgenic beta galactosidase reporter system under the control of the c-fos promoter. Retinae of transgenic rd1-FTL mice and control FTL animals aged 2-12 months were processed for indirect fluorescence immunocytochemistry. At 2 months of age, a time when the majority of photoreceptor nuclei are lost, there was negligible c-fos reporter (FTL) expression, however, from 4 months, reporter expression was observed to increase within subpopulations of amacrine and ganglion cells within the central retina. These areas of inner retinal FTL expression coincided with regions that contained aberrant Müller cells. Specifically, these cells exhibited reduced glutamine synthetase and Kir4.1 immunolabelling, whilst showing evidence of proliferative gliosis (increased cyclinD1 and glial fibrillary acidic protein expression). These changes were limited to distinct regions where cone photoreceptor terminals were absent. Overall, these results highlight that distinct areas of the rd1-FTL central retina undergo significant glial alterations after cone photoreceptor loss. These areas coincide with up-regulation of the c-fos reporter in the inner retina, which may represent a change in neuronal function/plasticity. The rd1-FTL mouse is a useful model system to probe changes that occur in the inner retina at later stages of retinal degeneration. PMID:26283925

  13. Suppressed retinal degeneration in aged wild type and APPswe/PS1ΔE9 mice by bone marrow transplantation.

    Directory of Open Access Journals (Sweden)

    Yue Yang

    Full Text Available Alzheimer's disease (AD is an age-related condition characterized by accumulation of neurotoxic amyloid β peptides (Aβ in brain and retina. Because bone marrow transplantation (BMT results in decreased cerebral Aβ in experimental AD, we hypothesized that BMT would mitigate retinal neurotoxicity through decreased retinal Aβ. To test this, we performed BMT in APPswe/PS1ΔE9 double transgenic mice using green fluorescent protein expressing wild type (wt mice as marrow donors. We first examined retinas from control, non-transplanted, aged AD mice and found a two-fold increase in microglia compared with wt mice, prominent inner retinal Aβ and paired helical filament-tau, and decreased retinal ganglion cell layer neurons. BMT resulted in near complete replacement of host retinal microglia with BMT-derived cells and normalized total AD retinal microglia to non-transplanted wt levels. Aβ and paired helical filament-tau were reduced (61.0% and 44.1% respectively in BMT-recipient AD mice, which had 20.8% more retinal ganglion cell layer neurons than non-transplanted AD controls. Interestingly, aged wt BMT recipients also had significantly more neurons (25.4% compared with non-transplanted aged wt controls. Quantitation of retinal ganglion cell layer neurons in young mice confirmed age-related retinal degeneration was mitigated by BMT. We found increased MHC class II expression in BMT-derived microglia and decreased oxidative damage in retinal ganglion cell layer neurons. Thus, BMT is neuroprotective in age-related as well as AD-related retinal degeneration, and may be a result of alterations in innate immune function and oxidative stress in BMT recipient mice.

  14. Protective effect of neuroglobin on retinal ganglion cell in glaucoma mice model%神经球蛋白对慢性高眼压小鼠视网膜神经节细胞损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    魏欣; 刘旭阳; 邓应平; 陈晓明

    2012-01-01

    .05).1周时,Ngb-Tg小鼠微球单次注射组视网膜中DHE含量明显低于WT小鼠微球单次注射组(t=3.212,P=0.008),而ATP的含量则明显高于WT小鼠微球单次注射组(t=2.864,P<0.01). 结论 Ngb可能是青光眼损伤的内源性神经保护因子,对高眼压所致RGCs损伤有保护作用,其机制可能是通过降低氧化应激和改善线粒体功能实现的.%Background Neuroglobin (Ngb) is a newly discovered member of globin superfamily.It is thought to regulate cell survival under hypoxia or oxidative stress condition.Ngb is expressed at a high level in retinal neuron,suggesting that retina may be one of important functional sites of Ngb.Objective The aim of this study was to investigate the protective role of endogenous Ngb on retina ganglion cells (RGCs) following chronic high intraocular pressure(IOP)in mice and the underlying mechanisms.Methods This study included the in vitro and in vivo experiment.RGCs derived from adult C57BL/6J wild type(WT) mice and Ngb-transgenic(Ngb-Tg) mice which cultivated by our laboratory were incubated with 5.0,7.5,10.0 mmol/L glutamic acid for 3 days.RGCs survival rate was calculated for the ration of dead and survival cells using a double labeling kit to evaluate the influence of Ngb on RGCs survival rate in the addition of glutamic acid.Chronic ocular hypertension models were established by injection of fluorescent microballon(MB) (10 μm)into the anterior chamber of WT mice and Ngb-Tg mice,The mice were divided into WT control group(n=18),Ngb-Tg control group(n=30),WT+MB single injection group(n=38),Ngb-Tg+MB single injection group (n =38),WT+MB twice injection group (n =6) and Ngb-Tg + twice injection group (n=6).In addition,WT+PBS injection group (n =6) and Ngb-Tg+ PBS injection group (n =6) were designed as negative controls to identify if it can affect IOP or not.The mice were sacrificed on 0 day(control group),3 days and 1,4,8 weeks followed the MB anterior chamber injection.Real-time PCR

  15. Virtual electrode design for increasing spatial resolution in retinal prosthesis.

    Science.gov (United States)

    Loizos, Kyle; Cela, Carlos; Marc, Robert; Lazzi, Gianluca

    2016-06-01

    Retinal prostheses systems are currently used to restore partial vision to patients blinded by degenerative diseases by electrically stimulating surviving retinal cells. To obtain likely maximum resolution, electrode size is minimised, allowing for a large quantity on an array and localised stimulation regions. Besides the small size leading to fabrication difficulties and higher electrochemical charge density, there are challenges associated with the number of drivers needed for a large electrode count as well as the strategies to deliver sufficient power to these drivers wirelessly. In hopes to increase electrode resolution while avoiding these issues, the authors propose a new 'virtual electrode' design to increase locations of likely stimulation. Passive metallisation strategically placed between disk electrodes, combined with alternating surrounding stimuli, channel current into a location between electrodes, producing a virtual stimulation site. A computational study was conducted to optimise the passive metal element geometry, quantify the expected current density output, and simulate retinal ganglion cell activity due to virtual electrode stimulation. Results show that this procedure leads to array geometry that focuses injected current and achieves retinal ganglion cell stimulation in a region beneath the 'virtual electrode,' creating an alternate stimulation site without additional drivers. PMID:27382477

  16. Mouse Ganglion-Cell Photoreceptors Are Driven by the Most Sensitive Rod Pathway and by Both Types of Cones

    OpenAIRE

    Shijun Weng; Estevez, Maureen E.; Berson, David M.

    2013-01-01

    Intrinsically photosensitive retinal ganglion cells (iprgcs) are depolarized by light by two mechanisms: directly, through activation of their photopigment melanopsin; and indirectly through synaptic circuits driven by rods and cones. To learn more about the rod and cone circuits driving ipRGCs, we made multielectrode array (MEA) and patch-clamp recordings in wildtype and genetically modified mice. Rod-driven ON inputs to ipRGCs proved to be as sensitive as any reaching the conventional gangl...

  17. Retinal projection to the pretectal nucleus lentiformis mesencephali in pigeons (Columba livia).

    Science.gov (United States)

    Wylie, Douglas R; Kolominsky, Jeffrey; Graham, David J; Lisney, Thomas J; Gutierrez-Ibanez, Cristian

    2014-12-01

    In birds, the nucleus of the basal optic root (nBOR) and the nucleus lentiformis mesencephali (LM) are retinal-recipient nuclei involved in the analysis of optic flow and the generation of the optokinetic response. The nBOR receives retinal input from displaced ganglion cells (DGCs), which are found at the margin of the inner nuclear and inner plexiform layers, rather than the ganglion cell layer. The LM receives afferents from retinal ganglion cells, but whether DGCs also project to LM remains unclear. To resolve this issue, we made small injections of retrograde tracer into LM and examined horizontal sections through the retina. For comparison, we also had cases with injections in nBOR, the optic tectum, and the anterior dorsolateral thalamus (the equivalent to the mammalian lateral geniculate nucleus). From all LM injections both retinal ganglion cells and DGCs were labeled. The percentage of DGCs, as a proportion of all labeled cells, varied from 2-28%, and these were not different in morphology or size compared to those labeled from nBOR, in which the proportion of DGCs was much higher (84-93%). DGCs were also labeled after injections into the anterior dorsolateral thalamus. The proportion was small (2-3%), and these DGCs were smaller in size than those projecting to the nBOR and LM. No DGCs were labeled from an injection in the optic tectum. Based on an analysis of size, we suggest that different populations of retinal ganglion cells are involved in the projections to LM, nBOR, the optic tectum, and the anterior dorsolateral thalamus.

  18. Brazilian Green Propolis Protects against Retinal Damage In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Yuta Inokuchi

    2006-01-01

    Full Text Available Propolis, a honeybee product, has gained popularity as a food and alternative medicine. Its constituents have been shown to exert pharmacological (anticancer, antimicrobial and anti-inflammatory effects. We investigated whether Brazilian green propolis exerts neuroprotective effects in the retina in vitro and/or in vivo. In vitro, retinal damage was induced by 24 h hydrogen peroxide (H2O2 exposure, and cell viability was measured by Hoechst 33342 and YO-PRO-1 staining or by a resazurin–reduction assay. Propolis inhibited the neurotoxicity and apoptosis induced in cultured retinal ganglion cells (RGC-5, a rat ganglion cell line transformed using E1A virus by 24 h H2O2 exposure. Propolis also inhibited the neurotoxicity induced in RGC-5 cultures by staurosporine. Regarding the possible underlying mechanism, in pig retina homogenates propolis protected against oxidative stress (lipid peroxidation, as also did trolox (water-soluble vitamin E. In mice in vivo, propolis (100 mg kg−1; intraperitoneally administered four times reduced the retinal damage (decrease in retinal ganglion cells and in thickness of inner plexiform layer induced by intravitreal in vivo N-methyl-d-aspartate injection. These findings indicate that Brazilian green propolis has neuroprotective effects against retinal damage both in vitro and in vivo, and that a propolis-induced inhibition of oxidative stress may be partly responsible for these neuroprotective effects.

  19. Dark rearing maintains tyrosine hydroxylase expression in retinal amacrine cells following optic nerve transection

    Institute of Scientific and Technical Information of China (English)

    Wei Wan; Zhenghai Liu; Xiaosheng Wang; Xuegang Luo

    2012-01-01

    The present study examined changes in retinal tyrosine hydroxylase (TH) expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigate the effects of amacrine cells on axonal regeneration in retinal ganglion cells and on the synapses that transmit visual signals. The results revealed that retinal TH expression gradually decreased following optic nerve transection in rats housed under a normal day/night cycle, reaching a minimum at 5 days. In contrast, retinal TH expression decreased to a minimum at 1 day following optic nerve transection in dark reared rats, gradually increasing afterward and reaching a normal level at 5-7 days. The number of TH-positive synaptic particles correlated with the TH levels, indicating that dark rearing can help maintain TH expression during the synaptic degeneration stage (5-7 days after optic nerve injury) in retinal amacrine cells.

  20. Astrocytes and Müller cells changes during retinal degeneration in a transgenic rat model of retinitis pigmentosa.

    Directory of Open Access Journals (Sweden)

    Laura eFernández-Sánchez

    2015-12-01

    Full Text Available Purpose: Retinitis pigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer of P23H versus SD rat retinas. Conclusions: In the P23H rat model of retinitis pigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina.

  1. Schroedinger's cat

    International Nuclear Information System (INIS)

    The issue is to seek quantum interference effects in an arbitrary field, in particular in psychology. For this a digest of quantum mechanics over finite-n-dimensional Hilbert space is invented. In order to match crude data not only von Neumann's mixed states are used but also a parallel notion of unsharp tests. The mathematically styled text (and earlier work on multibin tests, designated MB) deals largely with these new tests. Quantum psychology itself is only given a foundation. It readily engenders objections; its plausibility is developed gradually, in interlocking essays. There is also the empirically definite proposal that (state, test, outcome)-indexed counts be gathered to record data, then fed to a 'matrix format' (MF) search for quantum models. A previously proposed experiment in visual perception which has since failed to find significant quantum correlations, is discussed. The suspicion that quantum mechanics is all around goes beyond MF, and 'Schroedinger's cat' symbolizes this broader perspective. (author)

  2. Non-Coding RNAs in Retinal Development

    Directory of Open Access Journals (Sweden)

    Robert Hindges

    2012-01-01

    Full Text Available Retinal development is dependent on an accurately functioning network of transcriptional and translational regulators. Among the diverse classes of molecules involved, non-coding RNAs (ncRNAs play a significant role. Members of this family are present in the cell as transcripts, but are not translated into proteins. MicroRNAs (miRNAs are small ncRNAs that act as post-transcriptional regulators. During the last decade, they have been implicated in a variety of biological processes, including the development of the nervous system. On the other hand, long-ncRNAs (lncRNAs represent a different class of ncRNAs that act mainly through processes involving chromatin remodeling and epigenetic mechanisms. The visual system is a prominent model to investigate the molecular mechanisms underlying neurogenesis or circuit formation and function, including the differentiation of retinal progenitor cells to generate the seven principal cell classes in the retina, pathfinding decisions of retinal ganglion cell axons in order to establish the correct connectivity from the eye to the brain proper, and activity-dependent mechanisms for the functionality of visual circuits. Recent findings have associated ncRNAs in several of these processes and uncovered a new level of complexity for the existing regulatory mechanisms. This review summarizes and highlights the impact of ncRNAs during the development of the vertebrate visual system, with a specific focus on the role of miRNAs and a synopsis regarding recent findings on lncRNAs in the retina.

  3. Tickling the retina: integration of subthreshold electrical pulses can activate retinal neurons

    Science.gov (United States)

    Sekhar, S.; Jalligampala, A.; Zrenner, E.; Rathbun, D. L.

    2016-08-01

    Objective. The field of retinal prosthetics has made major progress over the last decade, restoring visual percepts to people suffering from retinitis pigmentosa. The stimulation pulses used by present implants are suprathreshold, meaning individual pulses are designed to activate the retina. In this paper we explore subthreshold pulse sequences as an alternate stimulation paradigm. Subthreshold pulses have the potential to address important open problems such as fading of visual percepts when patients are stimulated at moderate pulse repetition rates and the difficulty in preferentially stimulating different retinal pathways. Approach. As a first step in addressing these issues we used Gaussian white noise electrical stimulation combined with spike-triggered averaging to interrogate whether a subthreshold sequence of pulses can be used to activate the mouse retina. Main results. We demonstrate that the retinal network can integrate multiple subthreshold electrical stimuli under an experimental paradigm immediately relevant to retinal prostheses. Furthermore, these characteristic stimulus sequences varied in their shape and integration window length across the population of retinal ganglion cells. Significance. Because the subthreshold sequences activate the retina at stimulation rates that would typically induce strong fading (25 Hz), such retinal ‘tickling’ has the potential to minimize the fading problem. Furthermore, the diversity found across the cell population in characteristic pulse sequences suggests that these sequences could be used to selectively address the different retinal pathways (e.g. ON versus OFF). Both of these outcomes may significantly improve visual perception in retinal implant patients.

  4. Cat and Dog Bites

    Science.gov (United States)

    MENU Return to Web version Cat and Dog Bites Cat and Dog Bites How should I take care of a bite from a cat or a dog? Whether from a family pet or a neighborhood stray, cat and dog bites are common. Here are some things you ...

  5. Imaging light responses of foveal ganglion cells in the living macaque eye.

    Science.gov (United States)

    Yin, Lu; Masella, Benjamin; Dalkara, Deniz; Zhang, Jie; Flannery, John G; Schaffer, David V; Williams, David R; Merigan, William H

    2014-05-01

    The fovea dominates primate vision, and its anatomy and perceptual abilities are well studied, but its physiology has been little explored because of limitations of current physiological methods. In this study, we adapted a novel in vivo imaging method, originally developed in mouse retina, to explore foveal physiology in the macaque, which permits the repeated imaging of the functional response of many retinal ganglion cells (RGCs) simultaneously. A genetically encoded calcium indicator, G-CaMP5, was inserted into foveal RGCs, followed by calcium imaging of the displacement of foveal RGCs from their receptive fields, and their intensity-response functions. The spatial offset of foveal RGCs from their cone inputs makes this method especially appropriate for fovea by permitting imaging of RGC responses without excessive light adaptation of cones. This new method will permit the tracking of visual development, progression of retinal disease, or therapeutic interventions, such as insertion of visual prostheses. PMID:24806684

  6. Stimulus-specific oscillations in a retinal model.

    Science.gov (United States)

    Kenyon, Garrett T; Travis, Bryan J; Theiler, James; George, John S; Stephens, Gregory J; Marshak, David W

    2004-09-01

    High-frequency oscillatory potentials (HFOPs) in the vertebrate retina are stimulus specific. The phases of HFOPs recorded at any given retinal location drift randomly over time, but regions activated by the same stimulus tend to remain phase locked with approximately zero lag, whereas regions activated by spatially separate stimuli are typically uncorrelated. Based on retinal anatomy, we previously postulated that HFOPs are mediated by feedback from a class of axon-bearing amacrine cells that receive excitation from neighboring ganglion cells-via gap junctions-and make inhibitory synapses back onto the surrounding ganglion cells. Using a computer model, we show here that such circuitry can account for the stimulus specificity of HFOPs in response to both high- and low-contrast features. Phase locking between pairs of model ganglion cells did not depend critically on their separation distance, but on whether the applied stimulus created a continuous path between them. The degree of phase locking between spatially separate stimuli was reduced by lateral inhibition, which created a buffer zone around strongly activated regions. Stimulating the inhibited region between spatially separate stimuli increased their degree of phase locking proportionately. Our results suggest several experimental strategies for testing the hypothesis that stimulus-specific HFOPs arise from axon-mediated feedback in the inner retina.

  7. Interconnection between brain and retinal neurodegenerations.

    Science.gov (United States)

    Jindal, Vishal

    2015-01-01

    The eye is a special sensory organ, which is basically an extension of the brain. Both are derived from neural tube and consist of neurons. Therefore, diseases of both the brain and eye should have some similarity. Neurodegenerative disorders like Alzheimer's disease (AD) is the major cause of dementia in the world. Amyloid deposition in the cerebral cortex and hippocampal region is the basic pathology in AD. But along with it, there are various changes that take place in the eye, i.e., abnormal pupillary reaction, decreased vision, decreased contrast sensitivity, visual field changes, loss of retinal ganglionic cells and retinal fiber layer, peripapillary atrophy, increased cup-disk ratio, retinal thinning, tortuosity of blood vessels, and deposition of Aβ-like substance in the retina. And these changes are present in the early part of the disease when only mild cognitive impairment is there. As the brain is covered by a hard bony skull which makes it difficult to directly visualize the changes occurring in the brain at molecular levels, finer details of disease progression are not available with us. But the eye is the window of the brain; with advanced modern techniques, we can directly visualize the changes in the retina at a very fine level. Therefore, by depicting neurodegenerative changes in the eye, we can diagnose and manage AD at very early stages. Along with it, retinal neurodegenerations like glaucoma and age-related macular degeneration (ARMD) are the major cause of loss of vision, and still, there are no effective treatment modalities for these blinding conditions. So if we can understand its pathogenesis and progression by correlating with brain neurodegenerations, we can come up with a better therapy for glaucoma and ARMD.

  8. Retinal prosthetics, optogenetics, and chemical photoswitches.

    Science.gov (United States)

    Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

    2014-10-15

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream

  9. Ganglion block. When and how?

    International Nuclear Information System (INIS)

    Increasing understanding of the anatomy and physiology of neural structures has led to the development of surgical and percutaneous neurodestructive methods in order to target and destroy various components of afferent nociceptive pathways. The dorsal root ganglia and in particular the ganglia of the autonomous nervous system are targets for radiological interventions. The autonomous nervous system is responsible for the regulation of organ functions, sweating, visceral and blood vessel-associated pain. Ganglia of the sympathetic chain and non-myelinized autonomous nerves can be irreversibly destroyed by chemical and thermal ablation. Computed tomography (CT)-guided sympathetic nerve blocks are well established interventional radiological procedures which lead to vasodilatation, reduction of sweating and reduction of pain associated with the autonomous nervous system. Sympathetic blocks are applied for the treatment of various vascular diseases including critical limb ischemia. Other indications for thoracic and lumbar sympathectomy include complex regional pain syndrome (CRPS), chronic tumor associated pain and hyperhidrosis. Neurolysis of the celiac plexus is an effective palliative pain treatment particularly in patients suffering from pancreatic cancer. Percutaneous dorsal root ganglion rhizotomy can be performed in selected patients with radicular pain that is resistant to conventional pharmacological and interventional treatment. (orig.)

  10. Postnatal visual deprivation in rats regulates several retinal genes and proteins, including differentiation-associated fibroblast growth factor-2.

    Science.gov (United States)

    Prokosch-Willing, Verena; Meyer zu Hoerste, Melissa; Mertsch, Sonja; Stupp, Tobias; Thanos, Solon

    2015-01-01

    Little is known about the retinal cellular basis of amblyopia, which is a developmental disease characterized by impaired visual acuity. This study examined the retinal transcripts associated with experimentally induced unilateral amblyopia in rats. Surgical tarsorrhaphy of the eyelids on one side was performed in pups prior to eye opening at postnatal day 14, thereby preventing any visual experience. This condition was maintained for over 2 months, after which electroretinograms (ERGs) were recorded, the retinal ganglion cell (RGC) arrangement and number were determined using neuroanatomical tracing, the retinal transcripts were studied using microarray analysis, regulated mRNAs were confirmed with quantitative reverse-transcriptase PCR, and proteins were stained using Western blotting and immunohistochemistry. An attenuated ERG was found in eyes that were deprived of visual experience. Retrograde neuroanatomical staining disclosed a larger number of RGCs within the retina on the visually deprived side compared to the non-deprived, control side, and a multilayered distribution of RGCs. At the retinomic level, several transcripts associated with retinal differentiation, such as fibroblast growth factor 2 (FGF-2), were either up- or downregulated. Most of the transcripts could be verified at the mRNA level. To unravel the role of a differentiation-associated protein, we tested FGF-2 in dissociated postnatal retinal cell cultures and found that FGF-2 is a potent factor triggering ganglion cell differentiation. The data suggest that visual experience shapes the postnatal retinal differentiation, whereas visual deprivation induces changes at the functional, cellular and molecular levels within the retina.

  11. Beta-adrenoceptor-mediated vasodilation of retinal blood vessels is reduced in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Nakazawa, Taisuke; Sato, Ayumi; Mori, Asami; Saito, Maki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2008-01-01

    We investigated the effects of epinephrine and dopamine on retinal blood vessels in streptozotocin (STZ, 80 mg/kg, i.p.)-treated rats and age-matched control rats to determine whether diabetes mellitus alters the retinal vascular responses to circulating catecholamines. Experiments were performed 6-8 weeks after treatment with STZ or the vehicle. The fundus images were captured with the digital fundus camera system for small animals we developed and diameters of retinal blood vessels contained in the digital images were measured. Epinephrine increased the diameters of retinal blood vessels, but the vasodilator responses were reduced in diabetic rats. Dopamine produced a biphasic retinal vascular response with an initial vasoconstriction followed by a vasodilation. The vasoconstrictor effects of dopamine on retinal arterioles were enhanced in diabetic rats, whereas the difference between the two groups was abolished by treatment with propranolol. The vasodilator effect of isoproterenol, but not of the activator of adenylyl cyclase colforsin, on retinal blood vessels was reduced in diabetic rats. No difference in vasoconstriction of retinal blood vessels to phenylephrine between non-diabetic and diabetic rats was observed. The vasodilator responses of retinal blood vessels to 1,1-dimethyl-4-phenylpiperazinium, a ganglionic nicotinic receptor agonist, were also attenuated in diabetic rats. These results suggest that diabetes mellitus alters the retinal vascular responses to circulating catecholamines and the impairment of vasodilator responses mediated by beta-adrenoceptors contributes to the alteration.

  12. Physiological variation of segmented OCT retinal layer thicknesses is short-lasting.

    Science.gov (United States)

    Balk, Lisanne; Mayer, Markus; Uitdehaag, Bernard M J; Petzold, Axel

    2013-12-01

    The application of spectral domain optical coherence tomography as a surrogate for neurodegeneration in a range of neurological disorders demands better understanding of the physiological variation of retinal layer thicknesses, which may mask any value of this emerging outcome measure. A prospective study compared retinal layer thicknesses between control subjects (n = 15) and runners (n = 27) participating in a 10-km charity run. Three scans were performed using an eye-tracking function (EBF) and automated scan registration for optimal precision at (1) baseline, (2) directly after the run, and (3) following a rehydration period. Retinal layer segmentation was performed with suppression of axial retinal vessel signal artifacts. Following the run, there was an increase in the relative retinal nerve fibre layer (p = 0.018), the combined inner plexiform/ganglion cell layer (p = 0.038), and the outer nuclear layer (p = 0.018) in runners compared to controls. The initial increase of thickness in the outer nuclear layer of runners (p < 0.0001) was likely related to (noncompliant) rehydration during exercise. Following a period of rest and rehydration, the difference in thickness change for all retinal layers, except the retinal nerve fibre layer (RNFL) (p < 0.05), disappeared between the two groups. There is a quantifiable change in the axial thickness of retinal layersthat which can be explained by an increase in the cellular volume. This effect may potentially be caused by H2O volume shifts.

  13. Modern retinal laser therapy

    OpenAIRE

    Kozak, Igor; Luttrull, Jeffrey K.

    2014-01-01

    Medicinal lasers are a standard source of light to produce retinal tissue photocoagulation to treat retinovascular disease. The Diabetic Retinopathy Study and the Early Treatment Diabetic Retinopathy Study were large randomized clinical trials that have shown beneficial effect of retinal laser photocoagulation in diabetic retinopathy and have dictated the standard of care for decades. However, current treatment protocols undergo modifications. Types of lasers used in treatment of retinal dise...

  14. Stereotyped initiation of retinal waves by bipolar cells via presynaptic NMDA autoreceptors.

    Science.gov (United States)

    Zhang, Rong-Wei; Li, Xiao-Quan; Kawakami, Koichi; Du, Jiu-Lin

    2016-01-01

    Glutamatergic retinal waves, the spontaneous patterned neural activities propagating among developing retinal ganglion cells (RGCs), instruct the activity-dependent refinement of visuotopic maps. However, its initiation and underlying mechanism remain largely elusive. Here using larval zebrafish and multiple in vivo approaches, we discover that bipolar cells (BCs) are responsible for the generation of glutamatergic retinal waves. The wave originates from BC axon terminals (ATs) and propagates laterally to nearby BCs and vertically to downstream RGCs and the optic tectum. Its initiation is triggered by the activation of and consequent glutamate release from BC ATs, and is mediated by the N-methyl-D-aspartate subtype of glutamate receptors (NMDARs) expressed at these ATs. Intercellular asymmetry of NMDAR expression at BC ATs enables the preferential initiation of waves at the temporal retina, where BC ATs express more NMDARs. Thus, our findings indicate that glutamatergic retinal waves are initiated by BCs through a presynaptic NMDA autoreceptor-dependent process. PMID:27586999

  15. The retinal ciliopathies.

    Science.gov (United States)

    Adams, N A; Awadein, Ahmed; Toma, Hassanain S

    2007-09-01

    While the functions of many of the proteins located in or associated with the photoreceptor cilia are poorly understood, disruption of the function of these proteins may result in a wide variety of phenotypes ranging from isolated retinal degeneration to more pleiotropic phenotypes. Systemic findings include neurosensory hearing loss, developmental delay, situs-inversus, infertility, disorders of limb and digit development, obesity, kidney disease, liver disease, and respiratory disease. The concept of "retinal ciliopathies" brings to attention the importance of further molecular analysis of this organelle as well as provides a potential common target for therapies for these disorders. The retinal ciliopathies include retinitis pigmentosa, macular degeneration, cone-dystrophy, cone-rod dystrophy, Leber congenital amaurosis, as well as retinal degenerations associated with Usher syndrome, primary ciliary dyskinesia, Senior-Loken syndrome, Joubert syndrome, Bardet-Biedl syndrome, Laurence-Moon syndrome, McKusick-Kaufman syndrome, and Biemond syndrome. Mutations for these disorders have been found in retinitis pigmentosa-1 (RP1), retinitis pigmentosa GTPase regulator (RPGR), retinitis pigmentosa GTPase regulator interacting protein (RPGR-IP), as well as the Usher, Bardet-Biedl, and nephronophthisis genes. Other systemic disorders associated with retinal degenerations that may also involve ciliary abnormalities include: Alstrom, Edwards-Sethi, Ellis-van Creveld, Jeune, Meckel-Gruber, Orofaciodigital Type 9, and Gurrieri syndromes. Understanding these conditions as ciliopathies may help the ophthalmologist to recognize associations between seemingly unrelated diseases and have a high degree of suspicion that a systemic finding may be present. PMID:17896309

  16. Cat Scratch Disease

    Science.gov (United States)

    Cat scratch disease (CSD) is an illness caused by the bacterium Bartonella henselae. Almost half of all cats carry the infection ... symptoms of CSD, call your doctor. Centers for Disease Control and Prevention

  17. Ectopic ganglion in cauda equina: case report.

    Science.gov (United States)

    Conner, Andrew K; Fung, Kar-Ming; Peterson, Jo Elle G; Glenn, Chad A; Martin, Michael D

    2016-06-01

    Macroscopic ectopic or heterotopic ganglionic tissue within the cauda equina is a very rare pathological finding and is usually associated with spinal dysraphism. However, it may mimic genuine neoplasms of the cauda equina. The authors describe a 29-year-old woman with a history of back pain, right leg pain, and urinary incontinence in whom imaging demonstrated an enhancing mass located in the cauda equina at the L1-2 interspace. The patient subsequently underwent biopsy and was found to have a focus of ectopic ganglionic tissue that was 1.3 cm in greatest dimension. To the authors' knowledge, ectopic or heterotopic ganglionic tissue within the cauda equina in a patient without evidence of spinal dysraphism has never been reported. This patient presented with imaging and clinical findings suggestive of a neoplasm, and an open biopsy proved the lesion to be ectopic ganglionic tissue. The authors suggest that ectopic ganglionic tissue be added to the list of differential diagnoses of a space-occupying lesion arising from the cauda equina. PMID:26871650

  18. Ultrasound findings of ganglions of the wrist.

    Science.gov (United States)

    Päivänsalo, M; Jalovaara, P

    1991-01-01

    Fifty-one patients with a palpable swelling of a wrist or finger of suspected ganglion origin were examined by ultrasound (US). Forty-five were operated on, and a ganglion was found in 35. The ganglions took the form of cysts 0.4-4 cm in diameter (mean 1.4 cm) with a projection into the joint or tendon in 19 cases. Two patients had multiple ganglia, and two a wrist lipoma, one echo-rich and the other echo-poor with a thick wall. One patient had a giant cell tumour of the tendon sheath which was moderately echogenic in appearance, one had carpal tunnel syndrome and a ganglion-like finding at US, one had tenosynovitis and negative US and one had a prominent tendon due to postoperative sequelae, with US showing a longish echo-poor lesion. Two had hypertrophied muscle forming a long echo-poor structure, one had an exostosis and one had no abnormality in the wrist at operation. Our experiences suggest that ultrasound is useful in many cases with impression of a ganglion at palpation showing multiplicity of a lesion or for assisting in differential diagnosis, although a physical examination is mostly sufficient for diagnostic purposes. PMID:1756743

  19. Lycium barbarum polysaccharides reduce neuronal damage, blood-retinal barrier disruption and oxidative stress in retinal ischemia/reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Suk-Yee Li

    Full Text Available Neuronal cell death, glial cell activation, retinal swelling and oxidative injury are complications in retinal ischemia/reperfusion (I/R injuries. Lycium barbarum polysaccharides (LBP, extracts from the wolfberries, are good for "eye health" according to Chinese medicine. The aim of our present study is to explore the use of LBP in retinal I/R injury. Retinal I/R injury was induced by surgical occlusion of the internal carotid artery. Prior to induction of ischemia, mice were treated orally with either vehicle (PBS or LBP (1 mg/kg once a day for 1 week. Paraffin-embedded retinal sections were prepared. Viable cells were counted; apoptosis was assessed using TUNEL assay. Expression levels of glial fibrillary acidic protein (GFAP, aquaporin-4 (AQP4, poly(ADP-ribose (PAR and nitrotyrosine (NT were investigated by immunohistochemistry. The integrity of blood-retinal barrier (BRB was examined by IgG extravasations. Apoptosis and decreased viable cell count were found in the ganglion cell layer (GCL and the inner nuclear layer (INL of the vehicle-treated I/R retina. Additionally, increased retinal thickness, GFAP activation, AQP4 up-regulation, IgG extravasations and PAR expression levels were observed in the vehicle-treated I/R retina. Many of these changes were diminished or abolished in the LBP-treated I/R retina. Pre-treatment with LBP for 1 week effectively protected the retina from neuronal death, apoptosis, glial cell activation, aquaporin water channel up-regulation, disruption of BRB and oxidative stress. The present study suggests that LBP may have a neuroprotective role to play in ocular diseases for which I/R is a feature.

  20. PROPERTIES OF PROLIFERATION AND DIFFERENTIATION OF NEONATAL RAT RETINAL PROGENITOR CELLS IN VITRO

    Institute of Scientific and Technical Information of China (English)

    Kang Qianyan; Liu Yong; Zhao Jianjun; Qiu Fen; Chen Xinlin; Tian Yumei; Hu Ming

    2006-01-01

    Objective To investigate the properties of proliferation and differentiation of neonatal rat retinal progenitor cells (RPCs) in vitro. Methods RPCs were isolated from neonatal SD rats neural retina and cultured in DMEM/F12+N2 with EGF and bFGF (suspension medium )or 10%FBS without EGF and bFGF (differentiation medium). The cells grew as suspended spheres or adherent monolayers, depending on different culture conditions. The neural stem cells or retinal progenitors, neurons, astrocytes, retinal ganglion cells, rod photoreceptors and the proliferating cells were evaluated with immunofluorescence analysis by Nestin or Pax6, Map2, GFAP, Thy-1, Rhodopsin and BrdU antibodies respectively. Results RPCs could propagate and differentiate in suspension or differentiation medium and express the markers of Nestin (92.86%) or Pax6 (86.75%), Map2 (38.54%), GFAP (20.93%), Thy-1 (27.66%) and Rhodopsin(13.33%)in suspension medium; however, Nestin (60.27%), Pax6 (52%), Map2 (34.94%), GFAP (38.17%), Thy-1(30.84%) and Rhodopsin (34.67%) in differentiation medium. 96.4% of the population in the neurospheres was BrdU-positive cells. The cells could spontaneously adherent forming some subspheres and retinal specific cell types. Conclusion Neonatal rat RPCs possess the high degree of proliferation and can differentiate into neurons, astrocytes, retinal ganglion cells and rod photoreceptors in vitro. There are different proportions for RPCs to differentiate into specific cell types.

  1. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that ...

  2. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Here's Help White House Lunch Recipes Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  3. Discospondylitis in a cat

    International Nuclear Information System (INIS)

    The incidence and causative agents of discospondylitis in cats are unknown. This report describes a cat with radiologic changes consistent with discospondylitis and concurrent urinary tract infection. As in dogs, discospondylitis should be the primary rule out for vertebral end plate lysis in cats

  4. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Snowboarding, Skating Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  5. Chitosan oligosaccharides attenuates oxidative-stress related retinal degeneration in rats.

    Directory of Open Access Journals (Sweden)

    I-Mo Fang

    Full Text Available This study investigated the therapeutic potential and mechanisms of chitosan oligosaccharides (COS for oxidative stress-induced retinal diseases. Retinal oxidative damage was induced in Sprague-Dawley rats by intravitreal injection of paraquat (PQ. Low-dose (5 mg/kg or high-dose (10 mg/kg COS or PBS was intragastrically given for 14 days after PQ injection. Electroretinograms were performed to determine the functionality of the retinas. The surviving neurons in the retinal ganglion cell layer and retinal apoptosis were determined by counting Neu N-positive cells in whole-mounted retinas and TUNEL staining, respectively. The generation of reactive oxygen species (ROS was determined by lucigenin- and luminol-enhanced chemiluminescence. Retinal oxidative damages were assessed by staining with nitrotyrosine, acrolein, and 8-hydroxy-2'-deoxyguanosine (8-OHdG. Immunohistochemical studies were used to demonstrate the expression of nuclear factor-kappa B (NF-κB p65 in retinas. An in vitro study using RGC-5 cells was performed to verify the results. We demonstrated COS significantly enhanced the recovery of retinal function, preserved inner retinal thickness, and decreased retinal neurons loss in a dose-dependent manner. COS administration demonstrated anti-oxidative effects by reducing luminol- and lucigenin-dependent chemiluminenscense levels and activating superoxide dismutase and catalase, leading to decreased retinal apoptosis. COS markedly reduced retinal NF-κB p65. An in vitro study demonstrated COS increased IκB expression, attenuated the increase of p65 and thus decreased NF-κB/DNA binding activity in PQ-stimulated RGC-5 cells. In conclusion, COS attenuates oxidative stress-induced retinal damages, probably by decreasing free radicals, maintaining the activities of anti-oxidative enzymes, and inhibiting the activation of NF-κB.

  6. Ganglion cell like cells, diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Anand Shankar Ammanagi

    2013-01-01

    Full Text Available We report a case of cutaneous swelling found on the left anterior axillary fold of a 41-year-old man. Gross examination of specimen excised from the dermis showed a well-circumscribed nodule histologically composed of spindle cells with interspersed ganglion cell like cells. On hematoxylin and eosine (H and E staining it was diagnosed as ganglioneuroma. Ganglioneuromas are rare, benign, fully differentiated tumors that contain mature schwann cells, ganglion cells, fibrous tissue, and nerve fibers. They are commonly found along the paravertebral sympathetic ganglia and sometimes in the adrenal medulla. However primary cutaneous ganglioneuroma is an extremely rare tumor. Immunohistochemical workup revealed a fibroblastic origin and hence the case was diagnosed as fibromatosis with ganglion cell like fibroblasts. This case report suggests that the features considered diagnostic of ganglioneuromas can occur in other cutaneous lesions and, therefore, this diagnosis cannot be offered only on the basis of H and E.

  7. Age-Related Vitamin D Deficiency Is Associated with Reduced Macular Ganglion Cell Complex: A Cross-Sectional High-Definition Optical Coherence Tomography Study

    OpenAIRE

    Mathieu Uro; Olivier Beauchet; Mehdi Cherif; Alix Graffe; Dan Milea; Cedric Annweiler

    2015-01-01

    Background Vitamin D deficiency is associated with smaller volume of optic chiasm in older adults, indicating a possible loss of the visual axons and their cellular bodies. Our objective was to determine whether vitamin D deficiency in older adults is associated with reduced thickness of the ganglion cell complex(GCC) and of the retinal nerve fibre layer(RNFL), as measured with high-definition optical coherence tomography(HD-OCT). Methods Eighty-five French older community-dwellers without op...

  8. Retinal oximetry in patients with ischaemic retinal diseases

    DEFF Research Database (Denmark)

    Rilvén, Sandra; Torp, Thomas Lee; Grauslund, Jakob

    2016-01-01

    The retinal oximeter is a new tool for non-invasive measurement of retinal oxygen saturation in humans. Several studies have investigated the associations between retinal oxygen saturation and retinal diseases. In the present systematic review, we examine whether there are associations between...

  9. Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion

    DEFF Research Database (Denmark)

    Noergaard, Michael Hove; Bach-Holm, Daniella; Scherfig, Erik;

    2008-01-01

    To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.......To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs....

  10. Polymer optoelectronic structures for retinal prosthesis.

    Science.gov (United States)

    Gautam, Vini; Narayan, K S

    2014-01-01

    This commentary highlights the effectiveness of optoelectronic properties of polymer semiconductors based on recent results emerging from our laboratory, where these materials are explored as artificial receptors for interfacing with the visual systems. Organic semiconductors based polymer layers in contact with physiological media exhibit interesting photophysical features, which mimic certain natural photoreceptors, including those in the retina. The availability of such optoelectronic materials opens up a gateway to utilize these structures as neuronal interfaces for stimulating retinal ganglion cells. In a recently reported work entitled "A polymer optoelectronic interface provides visual cues to a blind retina," we utilized a specific configuration of a polymer semiconductor device structure to elicit neuronal activity in a blind retina upon photoexcitation. The elicited neuronal signals were found to have several features that followed the optoelectronic response of the polymer film. More importantly, the polymer-induced retinal response resembled the natural response of the retina to photoexcitation. These observations open up a promising material alternative for artificial retina applications.

  11. Pulmonary thromboembolism in cats.

    Science.gov (United States)

    Schermerhorn, Thomas; Pembleton-Corbett, Julie R; Kornreich, Bruce

    2004-01-01

    Pulmonary thromboembolism (PTE) is rarely diagnosed in cats, and the clinical features of the disease are not well known. PTE was diagnosed at postmortem examination in 17 cats, a prevalence of 0.06% over a 24-year period. The age of affected cats ranged from 10 months to 18 years, although young (10 years) cats were more commonly affected than were middle-aged cats. Males and females were equally affected. The majority of cats with PTE (n = 16) had concurrent disease, which was often severe. The most common diseases identified in association with PTE were neoplasia, anemia of unidentified cause, and pancreatitis. Cats with glomerulonephritis, encephalitis, pneumonia, heart disease, and hepatic lipidosis were also represented in this study. Most cats with PTE demonstrated dyspnea and respiratory distress before death or euthanasia, but PTE was not recognized ante mortem in any cat studied. In conclusion, PTE can affect cats of any age and is associated with a variety of systemic and inflammatory disorders. It is recommended that the same clinical criteria used to increase the suspicion of PTE in dogs should also be applied to cats. PMID:15320593

  12. Defective FGF signaling causes coloboma formation and disrupts retinal neurogenesis

    Institute of Scientific and Technical Information of China (English)

    Shuyi Chen; Hua Li; Karin Gaudenz; Ariel Paulson; Fengli Guo; Rhonda Trimble; Allison Peak

    2013-01-01

    The optic fissure (OF) is a transient opening on the ventral side of the developing vertebrate eye that closes before nearly all retinal progenitor cell differentiation has occurred.Failure to close the OF results in coloboma,a congenital disease that is a major cause of childhood blindness.Although human genetic studies and animal models have linked a number of genes to coloboma,the cellular and molecular mechanisms driving the closure of the OF are still largely unclear.In this study,we used Cre-LoxP-mediated conditional removal of fibroblast growth factor (FGF) receptors,Fgfr1 and Fgfr2,from the developing optic cup (OC) to show that FGF signaling regulates the closing of the OF.Our molecular,cellular and transcriptome analyses of Fgfr1 and Fgfr2 double conditional knockout OCs suggest that FGF signaling controls the OF closure through modulation of retinal progenitor cell proliferation,fate specification and morphological changes.Furthermore,Fgfr1 and Fgfr2 double conditional mutant retinal progenitor cells fail to initiate retinal ganglion cell (RGC) genesis.Taken together,our mouse genetic studies reveal that FGF signaling is essential for OF morphogenesis and RGC development.

  13. Retinal development in the gilthead seabream Sparus aurata.

    Science.gov (United States)

    Pavón-Muñoz, T; Bejarano-Escobar, R; Blasco, M; Martín-Partido, G; Francisco-Morcillo, J

    2016-02-01

    The retinal development of the gilthead seabream Sparus aurata has been analysed from late embryonic development to juvenile stages using classical histological and immunohistological methods. Five significant phases were established. Phases 1 and 2 comprise the late embryonic and hatching stages, respectively. The results indicate that during these early stages the retina is composed of a single neuroblastic layer that consists of undifferentiated retinal progenitor cells. Phase 3 (late prolarval stage) is characterized by the emergence of the retinal layers and the appearance of neurochemical profiles in differentiating photoreceptors, amacrine and ganglion cells. Phases 4 and 5 comprise the late larval and juvenile stages. In these stages, all the retinal cell types can be detected immunohistochemically. All the maturational events described are first detected in the central retina and, as development progresses, spread to the rest of the retina following a central-to-peripheral gradient. The results of this study suggest that S. aurata is an altricial teleost species that hatches with a morphologically undifferentiated retina. The most relevant processes involved in retinogenesis occur during the late prolarval stage (phase 3). PMID:26507100

  14. Retinal cross talk in the mammalian visual system.

    Science.gov (United States)

    Tang, Xiaolan; Tzekov, Radouil; Passaglia, Christopher L

    2016-06-01

    The existence and functional relevance of efferent optic nerve fibers in mammals have long been debated. While anatomical evidence for cortico-retinal and retino-retinal projections is substantial, physiological evidence is lacking, as efferent fibers are few in number and are severed in studies of excised retinal tissue. Here we show that interocular connections contribute to retinal bioelectrical activity in adult mammals. Full-field flash electroretinograms (ERGs) were recorded from one or both eyes of Brown-Norway rats under dark-adapted (n = 16) and light-adapted (n = 11) conditions. Flashes were confined to each eye by an opaque tube that blocked stray light. Monocular flashes evoked a small (5-15 μV) signal in the nonilluminated eye, which was named "crossed ERG" (xERG). The xERG began under dark-adapted conditions with a positive (xP1) wave that peaked at 70-90 ms and ended with slower negative (xN1) and positive (xP2) waves from 200 to 400 ms. xN1 was absent under light-adapted conditions. Injection of tetrodotoxin in either eye (n = 15) eliminated the xERG. Intraocular pressure elevation of the illuminated eye (n = 6) had the same effect. The treatments also altered the ERG b-wave in both eyes, and the alterations correlated with xERG disappearance. Optic nerve stimulation (n = 3) elicited a biphasic compound action potential in the nonstimulated nerve with 10- to 13-ms latency, implying that the xERG comes from slow-conducting (W type) fibers. Monocular dye application (n = 7) confirmed the presence of retino-retinal ganglion cells in adult rats. We conclude that mammalian eyes communicate directly with each other via a handful of optic nerve fibers. The cross talk alters retinal activity in rats, and perhaps other animals. PMID:26984426

  15. Differential Diagnosis of Retinal Vasculitis

    Science.gov (United States)

    Abu El-Asrar, Ahmed M.; Herbort, Carl P.; Tabbara, Khalid F.

    2009-01-01

    Retinal vaculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein angiographic findings. PMID:20404987

  16. Differential Diagnosis of Retinal Vasculitis

    OpenAIRE

    Abu El-Asrar Ahmed; Herbort Carl; Tabbara Khalid

    2009-01-01

    Retinal vaculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein a...

  17. Differential diagnosis of retinal vasculitis

    Directory of Open Access Journals (Sweden)

    Abu El-Asrar Ahmed

    2009-01-01

    Full Text Available Retinal vaculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein angiographic findings.

  18. Genotype-phenotype heterogeneity of ganglion cell and inner plexiform layer deficit in autosomal-dominant optic atrophy

    DEFF Research Database (Denmark)

    Rönnbäck, Cecilia; Nissen, Claus; Almind, Gitte J;

    2015-01-01

    PURPOSE: To describe the thickness of the combined ganglion cell and inner plexiform layers (GC-IPL) and the peripapillary retinal nerve fibre layer (RNFL) in patients with OPA1 c.983A>G or c.2708_2711delTTAG autosomal-dominant optic atrophy (ADOA). METHODS: The study included 20 individuals with c...... measurement and high-definition optical coherence tomography. RESULTS: There was overlap in GC-IPL thickness in subjects younger than 20-30 years between the two new groups of ADOA patients and controls. Numerical decreases in GC-IPL thickness with age did not reach statistical significance in individuals...

  19. A tortoiseshell male cat

    DEFF Research Database (Denmark)

    Pedersen, A. S.; Berg, Lise Charlotte; Almstrup, Kristian;

    2014-01-01

    Tortoiseshell coat color is normally restricted to female cats due to X-linkage of the gene that encodes the orange coat color. Tortoiseshell male cats do, however, occur at a low frequency among tortoiseshell cats because of chromosome aberrations similar to the Klinefelter syndrome in man...... tissue from a tortoiseshell male cat referred to us. Chromosome analysis using RBA-banding consistently revealed a 39,XXY karyotype. Histological examinations of testis biopsies from this cat showed degeneration of the tubules, hyperplasia of the interstitial tissue, and complete loss of germ cells....... Immunostaining using anti-vimentin and anti-VASA (DDX4) showed that only Sertoli cells and no germ cells were observed in the testicular tubules. As no sign of spermatogenesis was detected, we conclude that this is a classic case of a sterile, male tortoiseshell cat with a 39,XXY chromosome complement. © 2013 S...

  20. Intraocular retinal prosthesis.

    OpenAIRE

    Humayun, M. S.

    2001-01-01

    PURPOSE: An electronic implant that can bypass the damaged photoreceptors and electrically stimulate the remaining retinal neurons to restore useful vision has been proposed. A number of key questions remain to make this approach feasible. The goal of this thesis is to address the following 2 specific null hypotheses: (1) Stimulus parameters make no difference in the electrically elicited retinal responses. (2) Just as we have millions of photoreceptors, so it will take a device that can gene...

  1. Adaptive optics retinal imaging in the living mouse eye.

    Science.gov (United States)

    Geng, Ying; Dubra, Alfredo; Yin, Lu; Merigan, William H; Sharma, Robin; Libby, Richard T; Williams, David R

    2012-04-01

    Correction of the eye's monochromatic aberrations using adaptive optics (AO) can improve the resolution of in vivo mouse retinal images [Biss et al., Opt. Lett. 32(6), 659 (2007) and Alt et al., Proc. SPIE 7550, 755019 (2010)], but previous attempts have been limited by poor spot quality in the Shack-Hartmann wavefront sensor (SHWS). Recent advances in mouse eye wavefront sensing using an adjustable focus beacon with an annular beam profile have improved the wavefront sensor spot quality [Geng et al., Biomed. Opt. Express 2(4), 717 (2011)], and we have incorporated them into a fluorescence adaptive optics scanning laser ophthalmoscope (AOSLO). The performance of the instrument was tested on the living mouse eye, and images of multiple retinal structures, including the photoreceptor mosaic, nerve fiber bundles, fine capillaries and fluorescently labeled ganglion cells were obtained. The in vivo transverse and axial resolutions of the fluorescence channel of the AOSLO were estimated from the full width half maximum (FWHM) of the line and point spread functions (LSF and PSF), and were found to be better than 0.79 μm ± 0.03 μm (STD)(45% wider than the diffraction limit) and 10.8 μm ± 0.7 μm (STD)(two times the diffraction limit), respectively. The axial positional accuracy was estimated to be 0.36 μm. This resolution and positional accuracy has allowed us to classify many ganglion cell types, such as bistratified ganglion cells, in vivo.

  2. Neuroprotective effect of minocycline in a rat model of branch retinal vein occlusion.

    Science.gov (United States)

    Sun, Chuan; Li, Xiao-Xin; He, Xiang-Jun; Zhang, Qi; Tao, Yong

    2013-08-01

    minocycline treatment upregulated Bcl-2 expression and inhibits TNF α expression since early stage of BRVO. We also performed Hematoxylin-Eosin (HE) and immunostaining for Iba 1 (a microgilal marker), active caspase-3, Bax, Bcl-2, IL-1 β, TNF α and found that minocycline inhibits retinal microglial activation, prevents retinal ganglion cell loss, and inhibits retinal caspase-3 activation. Thus, our study indicates that systemic administration of minocycline ameliorates retinal edema and preserves retinal function in the early stage of BRVO possibly via inhibiting microglia activation and protecting RGC from apoptosis. PMID:23748101

  3. Partial mitochondrial complex I inhibition induces oxidative damage and perturbs glutamate transport in primary retinal cultures. Relevance to Leber Hereditary Optic Neuropathy (LHON).

    Science.gov (United States)

    Beretta, Simone; Wood, John P M; Derham, Barry; Sala, Gessica; Tremolizzo, Lucio; Ferrarese, Carlo; Osborne, Neville N

    2006-11-01

    Leber Hereditary Optic Neuropathy (LHON) is a maternally inherited form of visual loss, due to selective degeneration of retinal ganglion cells. Despite the established aetiological association between LHON and mitochondrial DNA mutations affecting complex I of the electron transport chain, the pathophysiology of this disorder remains obscure. Primary rat retinal cultures were exposed to increasing concentrations of rotenone to titrate complex I inhibition. Neural cells were more sensitive than Müller glial cells to rotenone toxicity. Rotenone induced an increase in mitochondrial-derived free radicals and lipid peroxidation. Sodium-dependent glutamate uptake, which is mostly mediated by the glutamate transporter GLAST expressed by Müller glial cells, was reduced dose-dependently by rotenone with no changes in GLAST expression. Our findings suggest that complex I-derived free radicals and disruption of glutamate transport might represent key elements for explaining the selective retinal ganglion cell death in LHON.

  4. Progressive outer retinal necrosis-like retinitis in immunocompetent hosts.

    Science.gov (United States)

    Chawla, Rohan; Tripathy, Koushik; Gogia, Varun; Venkatesh, Pradeep

    2016-08-10

    We describe two young immunocompetent women presenting with bilateral retinitis with outer retinal necrosis involving posterior pole with centrifugal spread and multifocal lesions simulating progressive outer retinal necrosis (PORN) like retinitis. Serology was negative for HIV and CD4 counts were normal; however, both women were on oral steroids at presentation for suspected autoimmune chorioretinitis. The retinitis in both eyes responded well to oral valaciclovir therapy. However, the eye with the more fulminant involvement developed retinal detachment with a loss of vision. Retinal atrophy was seen in the less involved eye with preservation of vision. Through these cases, we aim to describe a unique evolution of PORN-like retinitis in immunocompetent women, which was probably aggravated by a short-term immunosuppression secondary to oral steroids.

  5. Progressive outer retinal necrosis-like retinitis in immunocompetent hosts.

    Science.gov (United States)

    Chawla, Rohan; Tripathy, Koushik; Gogia, Varun; Venkatesh, Pradeep

    2016-01-01

    We describe two young immunocompetent women presenting with bilateral retinitis with outer retinal necrosis involving posterior pole with centrifugal spread and multifocal lesions simulating progressive outer retinal necrosis (PORN) like retinitis. Serology was negative for HIV and CD4 counts were normal; however, both women were on oral steroids at presentation for suspected autoimmune chorioretinitis. The retinitis in both eyes responded well to oral valaciclovir therapy. However, the eye with the more fulminant involvement developed retinal detachment with a loss of vision. Retinal atrophy was seen in the less involved eye with preservation of vision. Through these cases, we aim to describe a unique evolution of PORN-like retinitis in immunocompetent women, which was probably aggravated by a short-term immunosuppression secondary to oral steroids. PMID:27511757

  6. Comparison of eye morphology and retinal topography in two species of new world vultures (Aves: Cathartidae)

    DEFF Research Database (Denmark)

    Lisney, Thomas J.; Stecyk, Karyn; Kolominsky, Jeffrey;

    2013-01-01

    Vultures are highly reliant on their sensory systems for the rapid detection and localization of carrion before other scavengers can exploit the resource. In this study, we compared eye morphology and retinal topography in two species of New World vultures (Cathartidae), turkey vultures (Cathartes...... aura), with a highly developed olfactory sense, and black vultures (Coragyps atratus), with a less developed sense of olfaction. We found that eye size relative to body mass was the same in both species, but that black vultures have larger corneas relative to eye size than turkey vultures. However......, the overall retinal topography, the total number of cells in the retinal ganglion cell layer, peak and average cell densities, cell soma area frequency distributions, and the theoretical peak anatomical spatial resolving power were the same in both species. This suggests that the visual systems of these two...

  7. That Fat Cat

    Science.gov (United States)

    Lambert, Phyllis Gilchrist

    2012-01-01

    This activity began with a picture book, Nurit Karlin's "Fat Cat On a Mat" (HarperCollins; 1998). The author and her students started their project with a 5-inch circular template for the head of their cats. They reviewed shapes as they drew the head and then added the ears and nose, which were triangles. Details to the face were added when…

  8. Cat Scratch Colon

    Directory of Open Access Journals (Sweden)

    M. Lourdes Ruiz-Rebollo

    2011-01-01

    Full Text Available Over the past few years, we have read several publications regarding the term “cat scratch colon.” This neologism was developed to define some bright red linear markings seen in the colonic mucosa that resemble scratches made by a cat. We would like to communicate a recent case attended at our institution.

  9. Hyperadrenocorticism in a cat.

    Science.gov (United States)

    Zerbe, C A; Nachreiner, R F; Dunstan, R W; Dalley, J B

    1987-03-01

    A diabetic cat with hyperadrenocorticism had polydipsia, polyuria, ventral abdominal alopecia, thin dry skin, and a pendulous abdomen. Results of laboratory testing indicated persistent resting hypercortisolemia, hyperresponsiveness of the adrenal glands (increased cortisol concentration) to ACTH gel, and no suppression of cortisol concentrations after administration of dexamethasone at 0.01 or 1.0 mg/kg of body weight. Necropsy revealed a pituitary gland tumor, bilateral adrenal hyperplasia, hepatic neoplasia, and demodicosis. Adrenal gland function was concurrently assessed in 2 cats with diabetes mellitus. One cat had resting hypercortisolemia, and both had hyperresponsiveness to ACTH gel (increased cortisol concentration) at one hour. After administration of dexamethasone (0.01 and 1.0 mg/kg), the diabetic cats appeared to have normal suppression of cortisol concentrations. The effects of mitotane were investigated in 4 clinically normal cats. Adrenocortical suppression of cortisol production occurred in 2 of 4 cats after dosages of 25, 37, and 50 mg/kg. Three cats remained clinically normal throughout the study. One cat experienced vomiting, diarrhea, and anorexia.

  10. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System Winter Sports: Sledding, ... Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A ...

  11. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Skiing, Snowboarding, Skating Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de ...

  12. Obesity in show cats.

    Science.gov (United States)

    Corbee, R J

    2014-12-01

    Obesity is an important disease with a high prevalence in cats. Because obesity is related to several other diseases, it is important to identify the population at risk. Several risk factors for obesity have been described in the literature. A higher incidence of obesity in certain cat breeds has been suggested. The aim of this study was to determine whether obesity occurs more often in certain breeds. The second aim was to relate the increased prevalence of obesity in certain breeds to the official standards of that breed. To this end, 268 cats of 22 different breeds investigated by determining their body condition score (BCS) on a nine-point scale by inspection and palpation, at two different cat shows. Overall, 45.5% of the show cats had a BCS > 5, and 4.5% of the show cats had a BCS > 7. There were significant differences between breeds, which could be related to the breed standards. Most overweight and obese cats were in the neutered group. It warrants firm discussions with breeders and cat show judges to come to different interpretations of the standards in order to prevent overweight conditions in certain breeds from being the standard of beauty. Neutering predisposes for obesity and requires early nutritional intervention to prevent obese conditions. PMID:24612018

  13. Learning LM Specificity for Ganglion Cells

    Science.gov (United States)

    Ahumada, Albert J.

    2015-01-01

    Unsupervised learning models have been proposed based on experience (Ahumada and Mulligan, 1990;Wachtler, Doi, Lee and Sejnowski, 2007) that allow the cortex to develop units with LM specific color opponent receptive fields like the blob cells reported by Hubel and Wiesel on the basis of visual experience. These models used ganglion cells with LM indiscriminate wiring as inputs to the learning mechanism, which was presumed to occur at the cortical level.

  14. Endoscopic sphenopalatine ganglion block for pain relief

    OpenAIRE

    Murty, P. S. N.; Prasanna, Atma

    1998-01-01

    The anaesthetic effect of the sphenopalatine (SPG) block has been well utilized for intranasal topical anaesthesia but the analgesic efficacy of (SPG) block, though well documented in literature, has not been put into practice. The methods available for SPG block till date were blind as they do not visualize the foramen. Nasal endoscopies have been used to visualize the foramen for an effective block. The authors present their experience with the endoscopic sphenopalatine ganglion block for p...

  15. Optical Coherence Tomography Reveals Distinct Patterns of Retinal Damage in Neuromyelitis Optica and Multiple Sclerosis.

    Directory of Open Access Journals (Sweden)

    Elisa Schneider

    Full Text Available Neuromyelitis optica (NMO and relapsing-remitting multiple sclerosis (RRMS are difficult to differentiate solely on clinical grounds. Optical coherence tomography (OCT studies investigating retinal changes in both diseases focused primarily on the retinal nerve fiber layer (RNFL while rare data are available on deeper intra-retinal layers.To detect different patterns of intra-retinal layer alterations in patients with NMO spectrum disorders (NMOSD and RRMS with focus on the influence of a previous optic neuritis (ON.We applied spectral-domain OCT in eyes of NMOSD patients and compared them to matched RRMS patients and healthy controls (HC. Semi-automatic intra-retinal layer segmentation was used to quantify intra-retinal layer thicknesses. In a subgroup low contrast visual acuity (LCVA was assessed.NMOSD-, MS- and HC-groups, each comprising 17 subjects, were included in analysis. RNFL thickness was more severely reduced in NMOSD compared to MS following ON. In MS-ON eyes, RNFL thinning showed a clear temporal preponderance, whereas in NMOSD-ON eyes RNFL was more evenly reduced, resulting in a significantly lower ratio of the nasal versus temporal RNFL thickness. In comparison to HC, ganglion cell layer thickness was stronger reduced in NMOSD-ON than in MS-ON, accompanied by a more severe impairment of LCVA. The inner nuclear layer and the outer retinal layers were thicker in NMOSD-ON patients compared to NMOSD without ON and HC eyes while these differences were primarily driven by microcystic macular edema.Our study supports previous findings that ON in NMOSD leads to more pronounced retinal thinning and visual function impairment than in RRMS. The different retinal damage patterns in NMOSD versus RRMS support the current notion of distinct pathomechanisms of both conditions. However, OCT is still insufficient to help with the clinically relevant differentiation of both conditions in an individual patient.

  16. CAT questions and answers

    International Nuclear Information System (INIS)

    This document, prepared in February 1993, addresses the most common questions asked by APS Collaborative Access Teams (CATs). The answers represent the best judgment on the part of the APS at this time. In some cases, details are provided in separate documents to be supplied by the APS. Some of the answers are brief because details are not yet available. The questions are separated into five categories representing different aspects of CAT interactions with the APS: (1) Memorandum of Understanding (MOU), (2) CAT Beamline Review and Construction, (3) CAT Beamline Safety, (4) CAT Beamline Operations, and (5) Miscellaneous. The APS plans to generate similar documents as needed to both address new questions and clarify answers to present questions

  17. State of cat genomics.

    Science.gov (United States)

    O'Brien, Stephen J; Johnson, Warren; Driscoll, Carlos; Pontius, Joan; Pecon-Slattery, Jill; Menotti-Raymond, Marilyn

    2008-06-01

    Our knowledge of cat family biology was recently expanded to include a genomics perspective with the completion of a draft whole genome sequence of an Abyssinian cat. The utility of the new genome information has been demonstrated by applications ranging from disease gene discovery and comparative genomics to species conservation. Patterns of genomic organization among cats and inbred domestic cat breeds have illuminated our view of domestication, revealing linkage disequilibrium tracks consequent of breed formation, defining chromosome exchanges that punctuated major lineages of mammals and suggesting ancestral continental migration events that led to 37 modern species of Felidae. We review these recent advances here. As the genome resources develop, the cat is poised to make a major contribution to many areas in genetics and biology.

  18. Edaravone protect against retinal damage in streptozotocin-induced diabetic mice.

    Directory of Open Access Journals (Sweden)

    Dongqing Yuan

    Full Text Available Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one, a free radical scavenger, is used for the clinical treatment of retinal injury. In this study, we investigated the protective effects of edaravone against diabetic retinal damage in the mouse. Diabetic retinopathy in the mouse was induced by injection of streptozotocin. Edaravone was given once-daily and was intraperitoneally (i.p. treated at a dose of 3 mg/kg from streptozotocin injection to 4 weeks after onset of diabetes. Retinal ganglion cells (RGCs damage was evaluated by recording the pattern electroretinogram (ERG. RGCs damage was also detected by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL staining, and the levels of reactive oxygen species (ROS were determined fluorometrically. The expressions of phosporylated-ERK1/2, BDNF, and caspase-3 were determined by Western blot analysis. Retinal levels of ROS, phosphorylated ERK1/2, and cleaved caspase-3 were significantly increased, whereas the expression of BDNF was significantly decreased in the retinas of diabetic mice, compared to nondiabetic mice. Administration of edaravone significantly attenuated diabetes induced RGCs death, upregulation of ROS, ERK1/2 phosphorylation, and cleaved caspase-3 and downregulation of BDNF. These findings suggest that oxidative stress plays a pivotal role in diabetic retinal damage and that systemic administration of edaravone may slow the progression of retinal neuropathy induced by diabetes.

  19. The intrinsic vasculature of the cat facial nerve.

    Science.gov (United States)

    Balkany, T

    1986-01-01

    Treatment of facial nerve disorders is based in part on assumptions regarding the intrinsic blood supply of the nerve. This study was designed to comprehensively delineate the intrinsic facial nerve microcirculation and its relation to the extrinsic circulation in an animal model. Twenty-eight cat facial nerves were removed intact from brain stem to stylomastoid foramen following intravital fixation. Specimens were studied by gross dissection, silicone injection and tissue clearing, complete vessel counts on serial cross sections of individual nerves, and scanning electron microscopy or transmission electron microscopy. The labyrinthine segment of the cat facial nerve contains strikingly fewer intrinsic blood vessels than the mastoid and tympanic segments. The geniculate ganglion, however, has a distinct, rich vascular plexus. The ultrastructure of the intrinsic facial nerve vessels is similar to other small vessels of the body with tight junctions of the endothelium and overlapping spiral smooth muscle fibers of arterioles, as well as surrounding pericytes. PMID:3510355

  20. Visual Advantage in Deaf Adults Linked to Retinal Changes

    Science.gov (United States)

    Codina, Charlotte; Pascalis, Olivier; Mody, Chris; Toomey, Peter; Rose, Jill; Gummer, Laura; Buckley, David

    2011-01-01

    The altered sensory experience of profound early onset deafness provokes sometimes large scale neural reorganisations. In particular, auditory-visual cross-modal plasticity occurs, wherein redundant auditory cortex becomes recruited to vision. However, the effect of human deafness on neural structures involved in visual processing prior to the visual cortex has never been investigated, either in humans or animals. We investigated neural changes at the retina and optic nerve head in profoundly deaf (N = 14) and hearing (N = 15) adults using Optical Coherence Tomography (OCT), an in-vivo light interference method of quantifying retinal micro-structure. We compared retinal changes with behavioural results from the same deaf and hearing adults, measuring sensitivity in the peripheral visual field using Goldmann perimetry. Deaf adults had significantly larger neural rim areas, within the optic nerve head in comparison to hearing controls suggesting greater retinal ganglion cell number. Deaf adults also demonstrated significantly larger visual field areas (indicating greater peripheral sensitivity) than controls. Furthermore, neural rim area was significantly correlated with visual field area in both deaf and hearing adults. Deaf adults also showed a significantly different pattern of retinal nerve fibre layer (RNFL) distribution compared to controls. Significant correlations between the depth of the RNFL at the inferior-nasal peripapillary retina and the corresponding far temporal and superior temporal visual field areas (sensitivity) were found. Our results show that cross-modal plasticity after early onset deafness may not be limited to the sensory cortices, noting specific retinal adaptations in early onset deaf adults which are significantly correlated with peripheral vision sensitivity. PMID:21673805

  1. Visual advantage in deaf adults linked to retinal changes.

    Directory of Open Access Journals (Sweden)

    Charlotte Codina

    Full Text Available The altered sensory experience of profound early onset deafness provokes sometimes large scale neural reorganisations. In particular, auditory-visual cross-modal plasticity occurs, wherein redundant auditory cortex becomes recruited to vision. However, the effect of human deafness on neural structures involved in visual processing prior to the visual cortex has never been investigated, either in humans or animals. We investigated neural changes at the retina and optic nerve head in profoundly deaf (N = 14 and hearing (N = 15 adults using Optical Coherence Tomography (OCT, an in-vivo light interference method of quantifying retinal micro-structure. We compared retinal changes with behavioural results from the same deaf and hearing adults, measuring sensitivity in the peripheral visual field using Goldmann perimetry. Deaf adults had significantly larger neural rim areas, within the optic nerve head in comparison to hearing controls suggesting greater retinal ganglion cell number. Deaf adults also demonstrated significantly larger visual field areas (indicating greater peripheral sensitivity than controls. Furthermore, neural rim area was significantly correlated with visual field area in both deaf and hearing adults. Deaf adults also showed a significantly different pattern of retinal nerve fibre layer (RNFL distribution compared to controls. Significant correlations between the depth of the RNFL at the inferior-nasal peripapillary retina and the corresponding far temporal and superior temporal visual field areas (sensitivity were found. Our results show that cross-modal plasticity after early onset deafness may not be limited to the sensory cortices, noting specific retinal adaptations in early onset deaf adults which are significantly correlated with peripheral vision sensitivity.

  2. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  3. Bioelectronic retinal prosthesis

    Science.gov (United States)

    Weiland, James D.

    2016-05-01

    Retinal prosthesis have been translated to clinical use over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa and one device is in clinical trials for treatment of age-related macular degeneration. These devices provide partial sight restoration and patients use this improved vision in their everyday lives to navigate and to detect large objects. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. In particular, current retinal prostheses do not provide peripheral visions due to technical and surgical limitations, thus limiting the effectiveness of the treatment. This paper reviews recent results from human implant patients and presents technical approaches for peripheral vision.

  4. IndexCat

    Data.gov (United States)

    U.S. Department of Health & Human Services — IndexCat provides access to the digitized version of the printed Index-Catalogue of the Library of the Surgeon General's Office; eTK for medieval Latin texts; and...

  5. StreamCat

    Data.gov (United States)

    U.S. Environmental Protection Agency — The StreamCat Dataset provides summaries of natural and anthropogenic landscape features for ~2.65 million streams, and their associated catchments, within the...

  6. Longitudinal live imaging of retinal α-synuclein::GFP deposits in a transgenic mouse model of Parkinson’s Disease/Dementia with Lewy Bodies

    Science.gov (United States)

    Price, Diana L.; Rockenstein, Edward; Mante, Michael; Adame, Anthony; Overk, Cassia; Spencer, Brian; Duong-Polk, Karen X.; Bonhaus, Douglas; Lindsey, James; Masliah, Eliezer

    2016-01-01

    Abnormal α-synuclein (α-syn) accumulation in the CNS may underlie neuronal cell and synaptic dysfunction leading to motor and cognitive deficits in synucleinopathies including Parkinson’s disease (PD) and Dementia with Lewy Bodies (DLB). Multiple groups demonstrated α-syn accumulation in CNS accessory structures, including the eyes and olfactory terminals, as well as in peripheral organs of Parkinsonian patients. Retinal imaging studies of mice overexpressing fused α-syn::GFP were conducted to evaluate the presence and progression of retinal pathology in a PD/DLB transgenic mouse model. Bright-field image retinal maps and fluorescent images were acquired at 1-month intervals for 3 months. Retinal imaging revealed the accumulation of GFP-tagged α-syn in retinal ganglion cell layer and in the edges of arterial blood vessels in the transgenic mice. Double labeling studies confirmed that the α-syn::GFP-positive cells were retinal ganglion cells containing α-syn. Accumulation of α-syn persisted in the same cells and increased with age. Accumulation of α-syn::GFP was reduced by immunization with single chain antibodies against α-syn. In conclusion, longitudinal live imaging of the retina in the PDGF-α-syn::GFP mice might represent a useful, non-invasive tool to monitor the fate of α-syn accumulation in the CNS and to evaluate the therapeutic effects of compounds targeting α-syn. PMID:27389831

  7. Resolving Schrodinger's cat

    OpenAIRE

    Hobson, Art

    2016-01-01

    Schrodinger's famous cat has long been misunderstood. According to quantum theory and experiments with entangled systems, an entangled state such as the Schrodinger's cat state is neither a superposition of states of either subsystem nor a superposition of compound states of the composite system, but rather a nonlocal superposition of correlations between pairs of states of the two subsystems. The entangled post-measurement state that results from an ideal measurement is not paradoxical, but ...

  8. Haemobartonellosis in Van Cats

    OpenAIRE

    AKKAN, Hasan Altan; Karaca, Mehmet; TÜTÜNCÜ, Mehmet

    2005-01-01

    The present study was conducted to determine prevalence of Haemobartonella felis in Van cats. 121 Van cats (82 female, 39 male, aged 1-9 years) were the materials of the study. To determine biochemical and haematological parameters, 2 ml blood with and without anticoagulant were taken according to technique from vena cephalica antebrachii. H. felis was detected in blood smears preparations of 18 (14.88%) by Papenheim staining. Among biochemical parameters aspartate amino transferase (AST), al...

  9. Matrix metalloproteinase 14 in the zebrafish: an eye on retinal and retinotectal development.

    Directory of Open Access Journals (Sweden)

    Els Janssens

    Full Text Available BACKGROUND: Matrix metalloproteinases (MMPs are members of the metzincin superfamily of proteinases that cleave structural elements of the extracellular matrix and many molecules involved in signal transduction. Although there is evidence that MMPs promote the proper development of retinotectal projections, the nature and working mechanisms of specific MMPs in retinal development remain to be elucidated. Here, we report a role for zebrafish Mmp14a, one of the two zebrafish paralogs of human MMP14, in retinal neurogenesis and retinotectal development. RESULTS: Whole mount in situ hybridization and immunohistochemical stainings for Mmp14a in developing zebrafish embryos reveal expression in the optic tectum, in the optic nerve and in defined retinal cell populations, including retinal ganglion cells (RGCs. Furthermore, Mmp14a loss-of-function results in perturbed retinoblast cell cycle kinetics and consequently, in a delayed retinal neurogenesis, differentiation and lamination. These Mmp14a-dependent retinal defects lead to microphthalmia and a significantly reduced innervation of the optic tectum (OT by RGC axons. Mmp14b, on the contrary, does not appear to alter retinal neurogenesis or OT innervation. As mammalian MMP14 is known to act as an efficient MMP2-activator, we also explored and found a functional link and a possible co-involvement of Mmp2 and Mmp14a in zebrafish retinotectal development. CONCLUSION: Both the Mmp14a expression in the developing visual system and the Mmp14a loss-of-function phenotype illustrate a critical role for Mmp14a activity in retinal and retinotectal development.

  10. Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.

    Directory of Open Access Journals (Sweden)

    Kelly E O'Quin

    Full Text Available The retina is the light-sensitive tissue of the eye that facilitates vision. Mutations within genes affecting eye development and retinal function cause a host of degenerative visual diseases, including retinitis pigmentosa and anophthalmia/microphthalmia. The characin fish Astyanax mexicanus includes both eyed (surface fish and eyeless (cavefish morphs that initially develop eyes with normal retina; however, early in development, the eyes of cavefish degenerate. Since both surface and cave morphs are members of the same species, they serve as excellent evolutionary mutant models with which to identify genes causing retinal degeneration. In this study, we crossed the eyed and eyeless forms of A. mexicanus and quantified the thickness of individual retinal layers among 115 F(2 hybrid progeny. We used next generation sequencing (RAD-seq and microsatellite mapping to construct a dense genetic map of the Astyanax genome, scan for quantitative trait loci (QTL affecting retinal thickness, and identify candidate genes within these QTL regions. The map we constructed for Astyanax includes nearly 700 markers assembled into 25 linkage groups. Based on our scans with this map, we identified four QTL, one each associated with the thickness of the ganglion, inner nuclear, outer plexiform, and outer nuclear layers of the retina. For all but one QTL, cavefish alleles resulted in a clear reduction in the thickness of the affected layer. Comparative mapping of genetic markers within each QTL revealed that each QTL corresponds to an approximately 35 Mb region of the zebrafish genome. Within each region, we identified several candidate genes associated with the function of each affected retinal layer. Our study is the first to examine Astyanax retinal degeneration in the context of QTL mapping. The regions we identify serve as a starting point for future studies on the genetics of retinal degeneration and eye disease using the evolutionary mutant model Astyanax.

  11. Cardiac Biomarkers in Hyperthyroid Cats

    OpenAIRE

    Sangster, Jodi Kirsten

    2013-01-01

    Background: Hyperthyroidism has substantial effects on the circulatory system. The cardiac biomarkers NT-proBNP and troponin I (cTNI) have proven useful in identifying cats with myocardial disease but have not been as extensively investigated in hyperthyroidism.Hypothesis: Plasma NT-proBNP and cTNI concentrations are higher in cats with primary cardiac disease than in cats with hyperthyroidism and higher in cats with hyperthyroidism than in healthy control cats.Animals: Twenty-three hyperthyr...

  12. Cardiac Biomarkers in Hyperthyroid Cats

    OpenAIRE

    Sangster, J.K.; Panciera, D L; Abbott, J.A.; Zimmerman, K.C.; Lantis, A.C.

    2013-01-01

    Background Hyperthyroidism has substantial effects on the circulatory system. The cardiac biomarkers NT‐proBNP and troponin I (cTNI) have proven useful in identifying cats with myocardial disease but have not been extensively investigated in hyperthyroidism. Hypothesis Plasma NT‐proBNP and cTNI concentrations are higher in cats with primary myocardial disease than in cats with hyperthyroidism and higher in cats with hyperthyroidism than in healthy control cats. Animals Twenty‐three hyperthyro...

  13. Dissection, culture, and analysis of Xenopus laevis embryonic retinal tissue.

    Science.gov (United States)

    McDonough, Molly J; Allen, Chelsea E; Ng-Sui-Hing, Ng-Kwet-Leok A; Rabe, Brian A; Lewis, Brittany B; Saha, Margaret S

    2012-01-01

    The process by which the anterior region of the neural plate gives rise to the vertebrate retina continues to be a major focus of both clinical and basic research. In addition to the obvious medical relevance for understanding and treating retinal disease, the development of the vertebrate retina continues to serve as an important and elegant model system for understanding neuronal cell type determination and differentiation(1-16). The neural retina consists of six discrete cell types (ganglion, amacrine, horizontal, photoreceptors, bipolar cells, and Müller glial cells) arranged in stereotypical layers, a pattern that is largely conserved among all vertebrates (12,14-18). While studying the retina in the intact developing embryo is clearly required for understanding how this complex organ develops from a protrusion of the forebrain into a layered structure, there are many questions that benefit from employing approaches using primary cell culture of presumptive retinal cells (7,19-23). For example, analyzing cells from tissues removed and dissociated at different stages allows one to discern the state of specification of individual cells at different developmental stages, that is, the fate of the cells in the absence of interactions with neighboring tissues (8,19-22,24-33). Primary cell culture also allows the investigator to treat the culture with specific reagents and analyze the results on a single cell level (5,8,21,24,27-30,33-39). Xenopus laevis, a classic model system for the study of early neural development (19,27,29,31-32,40-42), serves as a particularly suitable system for retinal primary cell culture (10,38,43-45). Presumptive retinal tissue is accessible from the earliest stages of development, immediately following neural induction (25,38,43). In addition, given that each cell in the embryo contains a supply of yolk, retinal cells can be cultured in a very simple defined media consisting of a buffered salt solution, thus removing the confounding

  14. Retinal vein occlusion

    Science.gov (United States)

    ... decrease the risk of retinal vein occlusion. These measures include: Eating a low-fat diet Getting regular exercise Maintaining an ideal weight Not smoking Aspirin or other blood thinners may help prevent blockages in the other eye. Controlling diabetes may ...

  15. Retinal artery occlusion

    Science.gov (United States)

    ... artery occlusion; Branch retinal artery occlusion; CRAO; BRAO Images Retina References Sanborn GE, Magargal LE. Arterial obstructive disease ... A.M. Editorial team. Related MedlinePlus Health Topics ... audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among ...

  16. An Optimized Culture Method of Rat Dorsal Root Ganglion Neurons

    Institute of Scientific and Technical Information of China (English)

    LIUYin; CHENJing-Hong; GONGZe-Hui

    2004-01-01

    AIM: To establish a primary culture technique of acutely isolated dorsal root ganglion (DRG) neurons, and provide a simple & useful in vitro model for study of analgesia. Methods: Acutely isolated dorsal root ganglion (DRG) neurons were planted and cultured; the configuration and growth characters of DRG neurons were observed through inverted microscope.

  17. Aldose reductase mediates retinal microglia activation.

    Science.gov (United States)

    Chang, Kun-Che; Shieh, Biehuoy; Petrash, J Mark

    2016-04-29

    Retinal microglia (RMG) are one of the major immune cells in charge of surveillance of inflammatory responses in the eye. In the absence of an inflammatory stimulus, RMG reside predominately in the ganglion layer and inner or outer plexiform layers. However, under stress RMG become activated and migrate into the inner nuclear layer (INL) or outer nuclear layer (ONL). Activated RMG in cell culture secrete pro-inflammatory cytokines in a manner sensitive to downregulation by aldose reductase inhibitors. In this study, we utilized CX3CR1(GFP) mice carrying AR mutant alleles to evaluate the role of AR on RMG activation and migration in vivo. When tested on an AR(WT) background, IP injection of LPS induced RMG activation and migration into the INL and ONL. However, this phenomenon was largely prevented by AR inhibitors or in AR null mice, or was exacerbated in transgenic mice that over-express AR. LPS-induced increases in ocular levels of TNF-α and CX3CL-1 in WT mice were substantially lower in AR null mice or were reduced by AR inhibitor treatment. These studies demonstrate that AR expression in RMG may contribute to the proinflammatory phenotypes common to various eye diseases such as uveitis and diabetic retinopathy.

  18. Ultrastructure of the retinal synapses in cubozoans.

    Science.gov (United States)

    Gray, G Clark; Martin, Vicki J; Satterlie, Richard A

    2009-08-01

    Cubomedusae (box jellyfish) are well known for strong directional swimming, rapid responses to visual stimuli, and complex lensed eyes comparable to those of more advanced multicellular animals. They possess a total of 24 eyes that are of four morphologically different types, yet little is known about the neural organization of their eyes. The eyes are located on ganglion-like structures called rhopalia. Each of the four rhopalia contains an upper and a lower lensed eye (with a cornea, lens, and retina), two pit ocelli, and two slit ocelli. Transmission electron microscopy was used to examine the synaptic morphology of the eyes and pacemaker region of four species of cubozoans (Tamoya haplonema, Carybdea marsupialis, Tripedalia cystophora, and Chiropsalmus quadrumanus). Invaginated synapses were found in all four species, but only in the upper and lower lensed eyes. Density measurements indicated that the invaginated synapses were located close to the basal region of photoreceptor cells, and size differences of invaginated synapses were observed between the upper and lower lensed eyes, as well as between species. Four additional types of chemical synapses-clear unidirectional, dense-core unidirectional, clear bidirectional, and clear and dense-core bidirectional-were also observed in the rhopalia. The invaginated synapses of the lensed eyes may be useful as markers to help sort out the neural circuitry in the retinal region of these complex cubomedusan eyes. PMID:19679721

  19. Cell-type specific roles for PTEN in establishing a functional retinal architecture.

    Directory of Open Access Journals (Sweden)

    Robert Cantrup

    Full Text Available BACKGROUND: The retina has a unique three-dimensional architecture, the precise organization of which allows for complete sampling of the visual field. Along the radial or apicobasal axis, retinal neurons and their dendritic and axonal arbors are segregated into layers, while perpendicular to this axis, in the tangential plane, four of the six neuronal types form patterned cellular arrays, or mosaics. Currently, the molecular cues that control retinal cell positioning are not well-understood, especially those that operate in the tangential plane. Here we investigated the role of the PTEN phosphatase in establishing a functional retinal architecture. METHODOLOGY/PRINCIPAL FINDINGS: In the developing retina, PTEN was localized preferentially to ganglion, amacrine and horizontal cells, whose somata are distributed in mosaic patterns in the tangential plane. Generation of a retina-specific Pten knock-out resulted in retinal ganglion, amacrine and horizontal cell hypertrophy, and expansion of the inner plexiform layer. The spacing of Pten mutant mosaic populations was also aberrant, as were the arborization and fasciculation patterns of their processes, displaying cell type-specific defects in the radial and tangential dimensions. Irregular oscillatory potentials were also observed in Pten mutant electroretinograms, indicative of asynchronous amacrine cell firing. Furthermore, while Pten mutant RGC axons targeted appropriate brain regions, optokinetic spatial acuity was reduced in Pten mutant animals. Finally, while some features of the Pten mutant retina appeared similar to those reported in Dscam-mutant mice, PTEN expression and activity were normal in the absence of Dscam. CONCLUSIONS/SIGNIFICANCE: We conclude that Pten regulates somal positioning and neurite arborization patterns of a subset of retinal cells that form mosaics, likely functioning independently of Dscam, at least during the embryonic period. Our findings thus reveal an unexpected

  20. Retinal abnormalities in multiple sclerosis patients with associated chronic cerebrospinal venous insufficiency

    Directory of Open Access Journals (Sweden)

    Aneta Adamczyk-Ludyga

    2012-06-01

    Full Text Available Optical coherence tomography (OCT is a non-invasive method for the assessment of optic nerve fibers and retinal ganglion cells. This study was aimed at the assessment of retinal abnormalities in multiple sclerosis patients in the context of chronic cerebrospinal venous insufficiency using OCT of the retina and the optic nerve. We examined 239 multiple sclerosis (MS patients, including 220 patients with associated chronic cerebrospinal venous insufficiency and 19 MS patients without venous pathology. The following OCT parameters were assessed: average ganglion cell complex thickness, global loss volume, focal loss volume and average retinal nerve fibre layer thickness. Abnormalities in the azygous and internal jugular veins were evaluated using catheter venography. We found a higher prevalence of abnormal OCT parameters in the patients with previous history of optic neuritis, not only on the side of inflammatory event, but also in the contralateral eye, which is in line with already existing body of evidence. The new and intriguing discovery is that we found statistically significant higher prevalence of abnormal OCT values in multiple sclerosis patients with unilateral stenosis of internal jugular vein. Patients who were not found venous abnormalities, as well as those presenting with pathologic azygous or bilateral internal jugular venous outflows, did not demonstrate a changed frequency of abnormal OCT parameters. Potential association between venous malformations and eye manifestations of multiple sclerosis, as has been demonstrated in this report, justifies further studies on this topic.

  1. Edaravone (MCI-186), a free radical scavenger, attenuates retinal ischemia/reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Yi SONG; Yuan-yuan GONG; Zheng-gao XIE; Cai-hong LI; Qing GU; Xing-wei WU

    2008-01-01

    Aim: To investigate the effect of edaravone (MCI-186), a free radical scavenger, against ischemia/reperfusion (I/R) injury in the rat retina. Methods: Retinal is-chemia was induced in male Sprague-Dawley rats by elevating intraocular pres-sure to 110 mmHg for 60 min. The rats were intraperitoneally injected with edaravone at a dose of 3 mg/kg at 30 min before ischemia, and then treated with edaravone (3 mg/kg, ip) twice daffy for 1 or 5 d after I/R. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the retinal tissues were determined on d 1 after I/R injury. The apoptosis of retinal neurons was detected on d 1 after I/R injury by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling staining. The electroretinogram (ERG) was recorded on d 5 after reperfusion. Results: Edaravone lowered MDA levels, raised SOD activity, and attenuated I/R-induced apoptosis of retinal neurons within the inner nuclear, gan-glion cell, and outer nuclear layers of the rat retina. Moreover, edaravone sup-pressed I/R-induced reduction in a- and b-wave amplitudes of ERG. Conclusion: Edaravone can protect the retina from I/R injury in rats through reducing oxidative stress and inhibiting apoptosis of retinal neurons, which suggests that edaravone might be a potential choice for the treatment of I/R-induced eye disorders.

  2. Cats protecting birds revisited.

    Science.gov (United States)

    Fan, Meng; Kuang, Yang; Feng, Zhilan

    2005-09-01

    In this paper, we revisit the dynamical interaction among prey (bird), mesopredator (rat), and superpredator (cat) discussed in [Courchamp, F., Langlais, M., Sugihara, G., 1999. Cats protecting birds: modelling the mesopredator release effect. Journal of Animal Ecology 68, 282-292]. First, we develop a prey-mesopredator-superpredator (i.e., bird-rat-cat, briefly, BRC) model, where the predator's functional responses are derived based on the classical Holling's time budget arguments. Our BRC model overcomes several model construction problems in Courchamp et al. (1999), and admits richer, reasonable and realistic dynamics. We explore the possible control strategies to save or restore the bird by controlling or eliminating the rat or the cat when the bird is endangered. We establish the existence of two types of mesopredator release phenomena: severe mesopredator release, where once superpredators are suppressed, a burst of mesopredators follows which leads their shared prey to extinction; and mild mesopredator release, where the mesopredator release could assert more negative impact on the endemic prey but does not lead the endemic prey to extinction. A sharp sufficient criterion is established for the occurrence of severe mesopredator release. We also show that, in a prey-mesopredator-superpredator trophic food web, eradication of introduced superpredators such as feral domestic cats in the BRC model, is not always the best solution to protect endemic insular prey. The presence of a superpredator may have a beneficial effect in such systems. PMID:15998496

  3. The Feline Mystique: Dispelling the Myth of the Independent Cat.

    Science.gov (United States)

    Soltow, Willow

    1984-01-01

    Describes learning activities about cats for primary and intermediate grades. Primary grade activity subjects include cat behavior, needs, breeds, storybook cats, and celestial cats. Intermediate grade activity subjects include cat history, care, language, literary cats, and cats in art. (BC)

  4. Moniliform Deformation of Retinal Ganglion Cells by Formaldehyde-Based Fixatives

    OpenAIRE

    Stradleigh, Tyler W.; Greenberg, Kenneth P; Partida, Gloria J.; Pham, Aaron; Ishida, Andrew T.

    2014-01-01

    Protocols for characterizing cellular phenotypes commonly use chemical fixatives to preserve anatomical features, mechanically stabilize tissue, and stop physiological responses. Formaldehyde, diluted in either phosphate-buffered saline or phosphate buffer, has been widely used in studies of neurons, especially in conjunction with dyes and antibodies. However, previous studies have reported that these fixatives induce the formation of bead-like varicosities in the dendrites and axons of brain...

  5. Relationship between Daytime Sleepiness and Intrinsically Photosensitive Retinal Ganglion Cells in Glaucomatous Disease

    Directory of Open Access Journals (Sweden)

    Carolina P. B. Gracitelli

    2016-01-01

    Full Text Available Patients with glaucoma showed to have higher daytime sleepiness measured by Epworth sleepiness scale. In addition, this symptom was associated with pupillary reflex and polysomnography parameters. These ipRGC functions might be impaired in patients with glaucoma, leading to worse quality of life.

  6. Bone marrow mesenchymal stem cells protect against retinal ganglion cell loss in aged rats with glaucoma

    OpenAIRE

    Hu Y; Tan HB; Wang XM; Rong H; Cui HP; Cui H

    2013-01-01

    Ying Hu,1,2 Hai Bo Tan,1 Xin Mei Wang,3 Hua Rong,1 Hong Ping Cui,1 Hao Cui2 Departments of Ophthalmology, 1Shanghai East Hospital of Tongji University, Shanghai, 2First Affiliated Hospital, 3Fourth Affiliated Hospital, Harbin Medical University, Harbin, People's Republic of China Abstract: Glaucoma is a common eye disease in the aged population and has severe consequences. The present study examined the therapeutic effects of bone marrow mesenchymal stem cell (BMSC) transplantation i...

  7. Idebenone protects against retinal damage and loss of vision in a mouse model of Leber's hereditary optic neuropathy.

    Directory of Open Access Journals (Sweden)

    Fabrice D Heitz

    Full Text Available Leber's hereditary optic neuropathy (LHON is an inherited disease caused by mutations in complex I of the mitochondrial respiratory chain. The disease is characterized by loss of central vision due to retinal ganglion cell (RGC dysfunction and optic nerve atrophy. Despite progress towards a better understanding of the disease, no therapeutic treatment is currently approved for this devastating disease. Idebenone, a short-chain benzoquinone, has shown promising evidence of efficacy in protecting vision loss and in accelerating recovery of visual acuity in patients with LHON. It was therefore of interest to study suitable LHON models in vitro and in vivo to identify anatomical correlates for this protective activity. At nanomolar concentrations, idebenone protected the rodent RGC cell line RGC-5 against complex I dysfunction in vitro. Consistent with the reported dosing and observed effects in LHON patients, we describe that in mice, idebenone penetrated into the eye at concentrations equivalent to those which protected RGC-5 cells from complex I dysfunction in vitro. Consequently, we next investigated the protective effect of idebenone in a mouse model of LHON, whereby mitochondrial complex I dysfunction was caused by exposure to rotenone. In this model, idebenone protected against the loss of retinal ganglion cells, reduction in retinal thickness and gliosis. Furthermore, consistent with this protection of retinal integrity, idebenone restored the functional loss of vision in this disease model. These results support the pharmacological activity of idebenone and indicate that idebenone holds potential as an effective treatment for vision loss in LHON patients.

  8. Idebenone protects against retinal damage and loss of vision in a mouse model of Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Heitz, Fabrice D; Erb, Michael; Anklin, Corinne; Robay, Dimitri; Pernet, Vincent; Gueven, Nuri

    2012-01-01

    Leber's hereditary optic neuropathy (LHON) is an inherited disease caused by mutations in complex I of the mitochondrial respiratory chain. The disease is characterized by loss of central vision due to retinal ganglion cell (RGC) dysfunction and optic nerve atrophy. Despite progress towards a better understanding of the disease, no therapeutic treatment is currently approved for this devastating disease. Idebenone, a short-chain benzoquinone, has shown promising evidence of efficacy in protecting vision loss and in accelerating recovery of visual acuity in patients with LHON. It was therefore of interest to study suitable LHON models in vitro and in vivo to identify anatomical correlates for this protective activity. At nanomolar concentrations, idebenone protected the rodent RGC cell line RGC-5 against complex I dysfunction in vitro. Consistent with the reported dosing and observed effects in LHON patients, we describe that in mice, idebenone penetrated into the eye at concentrations equivalent to those which protected RGC-5 cells from complex I dysfunction in vitro. Consequently, we next investigated the protective effect of idebenone in a mouse model of LHON, whereby mitochondrial complex I dysfunction was caused by exposure to rotenone. In this model, idebenone protected against the loss of retinal ganglion cells, reduction in retinal thickness and gliosis. Furthermore, consistent with this protection of retinal integrity, idebenone restored the functional loss of vision in this disease model. These results support the pharmacological activity of idebenone and indicate that idebenone holds potential as an effective treatment for vision loss in LHON patients.

  9. Small Animal Retinal Imaging

    Science.gov (United States)

    Choi, WooJhon; Drexler, Wolfgang; Fujimoto, James G.

    Developing and validating new techniques and methods for small animal imaging is an important research area because there are many small animal models of retinal diseases such as diabetic retinopathy, age-related macular degeneration, and glaucoma [1-6]. Because the retina is a multilayered structure with distinct abnormalities occurring in different intraretinal layers at different stages of disease progression, there is a need for imaging techniques that enable visualization of these layers individually at different time points. Although postmortem histology and ultrastructural analysis can be performed for investigating microscopic changes in the retina in small animal models, this requires sacrificing animals, which makes repeated assessment of the same animal at different time points impossible and increases the number of animals required. Furthermore, some retinal processes such as neurovascular coupling cannot be fully characterized postmortem.

  10. Inherited Retinal Degenerative Disease Registry

    Science.gov (United States)

    2016-03-21

    Eye Diseases Hereditary; Retinal Disease; Achromatopsia; Bardet-Biedl Syndrome; Bassen-Kornzweig Syndrome; Batten Disease; Best Disease; Choroidal Dystrophy; Choroideremia; Cone Dystrophy; Cone-Rod Dystrophy; Congenital Stationary Night Blindness; Enhanced S-Cone Syndrome; Fundus Albipunctatus; Goldmann-Favre Syndrome; Gyrate Atrophy; Juvenile Macular Degeneration; Kearns-Sayre Syndrome; Leber Congenital Amaurosis; Refsum Syndrome; Retinitis Pigmentosa; Retinitis Punctata Albescens; Retinoschisis; Rod-Cone Dystrophy; Rod Dystrophy; Rod Monochromacy; Stargardt Disease; Usher Syndrome

  11. Retinal Thickening and Photoreceptor Loss in HIV Eyes without Retinitis.

    Directory of Open Access Journals (Sweden)

    Cheryl A Arcinue

    Full Text Available To determine the presence of structural changes in HIV retinae (i.e., photoreceptor density and retinal thickness in the macula compared with age-matched HIV-negative controls.Cohort of patients with known HIV under CART (combination Antiretroviral Therapy treatment were examined with a flood-illuminated retinal AO camera to assess the cone photoreceptor mosaic and spectral-domain optical coherence tomography (SD-OCT to assess retinal layers and retinal thickness.Twenty-four eyes of 12 patients (n = 6 HIV-positive and 6 HIV-negative were imaged with the adaptive optics camera. In each of the regions of interest studied (nasal, temporal, superior, inferior, the HIV group had significantly less mean cone photoreceptor density compared with age-matched controls (difference range, 4,308-6,872 cones/mm2. A different subset of forty eyes of 20 patients (n = 10 HIV-positive and 10 HIV-negative was included in the retinal thickness measurements and retinal layer segmentation with the SD-OCT. We observed significant thickening in HIV positive eyes in the total retinal thickness at the foveal center, and in each of the three horizontal B-scans (through the macular center, superior, and inferior to the fovea. We also noted that the inner retina (combined thickness from ILM through RNFL to GCL layer was also significantly thickened in all the different locations scanned compared with HIV-negative controls.Our present study shows that the cone photoreceptor density is significantly reduced in HIV retinae compared with age-matched controls. HIV retinae also have increased macular retinal thickness that may be caused by inner retinal edema secondary to retinovascular disease in HIV. The interaction of photoreceptors with the aging RPE, as well as possible low-grade ocular inflammation causing diffuse inner retinal edema, may be the key to the progressive vision changes in HIV-positive patients without overt retinitis.

  12. Acute retinal ischemia caused by controlled low ocular perfusion pressure in a porcine model. Electrophysiological and histological characterisation

    DEFF Research Database (Denmark)

    Kyhn, Maria Voss; Warfvinge, Karin; Scherfig, Erik;

    2009-01-01

    The purpose of this study was to establish, and characterize a porcine model of acute, controlled retinal ischemia. The controlled retinal ischemia was produced by clamping the ocular perfusion pressure (OPP) in the left eye to 5 mm Hg for 2 h. The OPP was defined as mean arterial blood pressure...... (MAP) minus the intraocular pressure (IOP). It was clamped to 0-30 mm Hg by continuous monitoring of MAP and adjustment of the IOP, which was controlled by cannulation of the anterior chamber. Inner retinal function was assessed by induced multifocal electroretinography (mfERG) with comparisons...... of the amplitudes obtained in the experimental, left eye, and the control, right eye. Quantitative histology was performed to measure the survival of ganglion cells, amacrine cells and horizontal cells 2-6 weeks after the ischemic insult. An OPP of 5 mm Hg for 2h induced significant reductions in the amplitudes...

  13. Profile and Determinants of Retinal Optical Intensity in Normal Eyes with Spectral Domain Optical Coherence Tomography.

    Directory of Open Access Journals (Sweden)

    Binyao Chen

    Full Text Available To investigate the profile and determinants of retinal optical intensity in normal subjects using 3D spectral domain optical coherence tomography (SD OCT.A total of 231 eyes from 231 healthy subjects ranging in age from 18 to 80 years were included and underwent a 3D OCT scan. Forty-four eyes were randomly chosen to be scanned by two operators for reproducibility analysis. Distribution of optical intensity of each layer and regions specified by the Early Treatment of Diabetic Retinopathy Study (ETDRS were investigated by analyzing the OCT raw data with our automatic graph-based algorithm. Univariate and multivariate analyses were performed between retinal optical intensity and sex, age, height, weight, spherical equivalent (SE, axial length, image quality, disc area and rim/disc area ratio (R/D area ratio.For optical intensity measurements, the intraclass correlation coefficient of each layer ranged from 0.815 to 0.941, indicating good reproducibility. Optical intensity was lowest in the central area of retinal nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer and photoreceptor layer, except for the retinal pigment epithelium (RPE. Optical intensity was positively correlated with image quality in all retinal layers (0.5530.05. There was no relationship between retinal optical intensity and sex, height, weight, SE, axial length, disc area and R/D area ratio.There was a specific pattern of distribution of retinal optical intensity in different regions. The optical intensity was affected by image quality and age. Image quality can be used as a reference for normalization. The effect of age needs to be taken into consideration when using OCT for diagnosis.

  14. ServCat Sensitivity Guidelines

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This guide covers sensitivity in ServCat. This document provides technical guidance on how sensitivity fields work in ServCat, and provides suggestions on what...

  15. [Application of retinal oximeter in ophthalmology].

    Science.gov (United States)

    Li, Jing; Ma, Jianmin; Wang, Ningli

    2015-11-01

    Retinal oximeter is a new machine which has been used in the diagnose, treatment and research of several ophthalmic diseases for recent years. It allows ophthalmologists to gain retinal oxygen saturation directly. Therefore, retinal oximeter might be useful for ophthalmologists to understand ophthalmic diseases more deeper and clarify the impact of ischemia on retinal function. It has been reported in the literatures that retinal oximeter has potentially useful diagnostic and therapeutic indications in various eye diseases such as diabetic retinopathy, central retinal vein and artery occlusion, retinitis pigmentosa, glaucomatous optic neuropathy, et al. In this thesis, the application of retinal oximeter in ophthalmology is reviewed.

  16. Stellate ganglion blockade for analgesia following upper limb surgery.

    LENUS (Irish Health Repository)

    McDonnell, J G

    2012-01-31

    We report the successful use of a stellate ganglion block as part of a multi-modal postoperative analgesic regimen. Four patients scheduled for orthopaedic surgery following upper limb trauma underwent blockade of the stellate ganglion pre-operatively under ultrasound guidance. Patients reported excellent postoperative analgesia, with postoperative VAS pain scores between 0 and 2, and consumption of morphine in the first 24 h ranging from 0 to 14 mg. While these are preliminary findings, and must be confirmed in a clinical trial, they highlight the potential for stellate ganglion blockade to provide analgesia following major upper limb surgery.

  17. Adenosine A(2A receptor up-regulates retinal wave frequency via starburst amacrine cells in the developing rat retina.

    Directory of Open Access Journals (Sweden)

    Pin-Chien Huang

    Full Text Available BACKGROUND: Developing retinas display retinal waves, the patterned spontaneous activity essential for circuit refinement. During the first postnatal week in rodents, retinal waves are mediated by synaptic transmission between starburst amacrine cells (SACs and retinal ganglion cells (RGCs. The neuromodulator adenosine is essential for the generation of retinal waves. However, the cellular basis underlying adenosine's regulation of retinal waves remains elusive. Here, we investigated whether and how the adenosine A(2A receptor (A(2AR regulates retinal waves and whether A(2AR regulation of retinal waves acts via presynaptic SACs. METHODOLOGY/PRINCIPAL FINDINGS: We showed that A(2AR was expressed in the inner plexiform layer and ganglion cell layer of the developing rat retina. Knockdown of A(2AR decreased the frequency of spontaneous Ca²⁺ transients, suggesting that endogenous A(2AR may up-regulate wave frequency. To investigate whether A(2AR acts via presynaptic SACs, we targeted gene expression to SACs by the metabotropic glutamate receptor type II promoter. Ca²⁺ transient frequency was increased by expressing wild-type A(2AR (A2AR-WT in SACs, suggesting that A(2AR may up-regulate retinal waves via presynaptic SACs. Subsequent patch-clamp recordings on RGCs revealed that presynaptic A(2AR-WT increased the frequency of wave-associated postsynaptic currents (PSCs or depolarizations compared to the control, without changing the RGC's excitability, membrane potentials, or PSC charge. These findings suggest that presynaptic A(2AR may not affect the membrane properties of postsynaptic RGCs. In contrast, by expressing the C-terminal truncated A(2AR mutant (A(2AR-ΔC in SACs, the wave frequency was reduced compared to the A(2AR-WT, but was similar to the control, suggesting that the full-length A(2AR in SACs is required for A(2AR up-regulation of retinal waves. CONCLUSIONS/SIGNIFICANCE: A(2AR up-regulates the frequency of retinal waves via

  18. Protective effects of the compounds isolated from the seed of Psoralea corylifolia on oxidative stress-induced retinal damage

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung-A [Functional Food Center, Korea Institute of Science and Technology (KIST) Gangneung Institute, Gangneung 210-340 (Korea, Republic of); Shim, Sang Hee [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Ahn, Hong Ryul [Functional Food Center, Korea Institute of Science and Technology (KIST) Gangneung Institute, Gangneung 210-340 (Korea, Republic of); Jung, Sang Hoon, E-mail: shjung507@gmail.com [Functional Food Center, Korea Institute of Science and Technology (KIST) Gangneung Institute, Gangneung 210-340 (Korea, Republic of)

    2013-06-01

    The mechanism underlying glaucoma remains controversial, but apoptosis caused by increased levels of reactive oxygen species (ROS) is thought to play a role in its pathogenesis. We investigated the effects of compounds isolated from Psoralea corylifolia on oxidative stress-induced cell death in vitro and in vivo. Transformed retinal ganglion cells (RGC-5) were treated with L-buthione-(S,R)-sulfoximine (BSO) and glutamate in the presence or with pre-treatment with compound 6, bakuchiol isolated from P. corylifolia. We observed reduced cell death in cells pre-treated with bakuchiol. Moreover, bakuchiol inhibited the oxidative stress-induced decrease of mitochondrial membrane potential (MMP, ΔΨm). Furthermore, while intracellular Ca{sup 2+} was high in RGC-5 cells after exposure to oxidative stress, bakuchiol reduced these levels. In an in vivo study, in which rat retinal damage was induced by intravitreal injection of N-methyl-D-aspartate (NMDA), bakuchiol markedly reduced translocation of AIF and release of cytochrome c, and inhibited up-regulation of cleaved caspase-3, cleaved caspase-9, and cleaved PARP. The survival rate of retinal ganglion cells (RGCs) 7 days after optic nerve crush (ONC) in mice was significantly decreased; however, bakuchiol attenuated the loss of RGCs. Moreover, bakuchiol attenuated ONC-induced up-regulation of apoptotic proteins, including cleaved PARP, cleaved caspase-3, and cleaved caspase-9. Bakuchiol also significantly inhibited translocation of mitochondrial AIF into the nuclear fraction and release of mitochondrial cytochrome c into the cytosol. These results demonstrate that bakuchiol isolated from P. corylifolia has protective effects against oxidative stress-induced retinal damage, and may be considered as an agent for treating or preventing retinal degeneration. - Highlights: • Psoralea corylifolia have neuroprotective effects in vitro and in vivo. • Bakuchiol attenuated the increase of apoptotic proteins induced by oxidative

  19. Getting a CAT Scan

    Medline Plus

    Full Text Available ... More Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading Back-to-School ... Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands ...

  20. Getting a CAT Scan

    Medline Plus

    Full Text Available ... More Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System ... Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands ...

  1. Chemodectoma in a cat

    International Nuclear Information System (INIS)

    A 10-year-old, spayed female, domestic shorthair cat was presented for evaluation of a thoracic mass. Radiographs demonstrated a 4 by 5-cm mass dorsal to the heart. Cytology of specimens obtained by ultrasound-guided needle aspiration was compatible with a neuroendocrine tumor. Scintigraphy, thoracic exploratory, and histology were used to identify the mass as an aortic body chemodectoma

  2. Coxofemoral luxations in cats

    International Nuclear Information System (INIS)

    In a retrospective study, 79 untreated luxations of the coxofemoral joint in cats were recorded over a 12-year period. Twenty-nine of these cases were available for follow-up, of which 13 were re-examined clinically and radiologically. It was found that the maximum incidence of the injury occurred from one to three years of age. Follow-up radiographs showed that the cats had developed nearthroses of various degrees located dorsally on the ilium. The degree of nearthrosis formation was not consistently correlated with the length of the observation time. Radiological signs of decreased bone density of the proximal femur may be caused by reduced weightbearing related to changes in biomechanical function and altered blood supply in the luxated limb. Almost two-thirds of the re-examined animals presented some kind of locomotor dysfunction on clinical examination. Limb function improved with time. The best clinical results appeared to be in cats that were immature at the time of injury and developed nearthrosis similar to a normal coxofemoral joint. All the cats available to this study showed acceptable functional results and had a normal level of activity according to the owners

  3. Oligopsonistic Cats and Dogs

    OpenAIRE

    Dewit, Dr. Gerda; Leahy, Dr. Dermot

    2005-01-01

    We study the strategic investment behaviour of oligopsonistic rivals in the labour market. Under wage competition, firms play "puppy dog" with productivityaugmenting investment and "fat cat" with supply-enhancing investment. Under employment competition, investing strategically always involves playing "top dog".

  4. The Fishing Cat

    Institute of Scientific and Technical Information of China (English)

    孙雅飞; 乐伟国

    2008-01-01

    @@ 一、故事内容 A cat goes fishing every day. He wants to eat fish, but he can't catch any fish. One day, he goes to the river as usual. Suddenly, a fish comes out. He catches the fish and putsthe fish in the basket. He's very happy, but he forgest to put the lid on the basket.

  5. Membranous nephropathy in sibling cats.

    Science.gov (United States)

    Nash, A S; Wright, N G

    1983-08-20

    Membranous nephropathy was diagnosed in two sibling cats from the same household. Both cases presented with the nephrotic syndrome but 33 months elapsed before the second cat became ill, by which time the first cat had been in full clinical remission for over a year. PMID:6623883

  6. Loss of synaptic connectivity, particularly in second order neurons is a key feature of diabetic retinal neuropathy in the Ins2Akita mouse.

    Directory of Open Access Journals (Sweden)

    Jose R Hombrebueno

    Full Text Available Retinal neurodegeneration is a key component of diabetic retinopathy (DR, although the detailed neuronal damage remains ill-defined. Recent evidence suggests that in addition to amacrine and ganglion cell, diabetes may also impact on other retinal neurons. In this study, we examined retinal degenerative changes in Ins2Akita diabetic mice. In scotopic electroretinograms (ERG, b-wave and oscillatory potentials were severely impaired in 9-month old Ins2Akita mice. Despite no obvious pathology in fundoscopic examination, optical coherence tomography (OCT revealed a progressive thinning of the retina from 3 months onwards. Cone but not rod photoreceptor loss was observed in 3-month-old diabetic mice. Severe impairment of synaptic connectivity at the outer plexiform layer (OPL was detected in 9-month old Ins2Akita mice. Specifically, photoreceptor presynaptic ribbons were reduced by 25% and postsynaptic boutons by 70%, although the density of horizontal, rod- and cone-bipolar cells remained similar to non-diabetic controls. Significant reductions in GABAergic and glycinergic amacrine cells and Brn3a+ retinal ganglion cells were also observed in 9-month old Ins2Akita mice. In conclusion, the Ins2Akita mouse develops cone photoreceptor degeneration and the impairment of synaptic connectivity at the OPL, predominately resulting from the loss of postsynaptic terminal boutons. Our findings suggest that the Ins2Akita mouse is a good model to study diabetic retinal neuropathy.

  7. Genetics Home Reference: retinitis pigmentosa

    Science.gov (United States)

    ... by the combination of vision loss and hearing loss beginning early in life. Retinitis pigmentosa is also a feature of several other genetic syndromes, including Bardet-Biedl syndrome ; Refsum disease ; and neuropathy, ... for retinitis pigmentosa lead to a gradual loss of rods and cones in the retina. The ...

  8. New Wrinkles in Retinal Densitometry

    OpenAIRE

    Masella, Benjamin D.; Hunter, Jennifer J.; Williams, David R.

    2014-01-01

    Retinal densitometry has the potential to provide objective information about the function of the retina. However, a number of factors complicate the interpretation of retinal reflectance. We have discovered additional sources of reflectance change and have defined a method to minimize their impact.

  9. Health and Behavioral Survey of over 8000 Finnish Cats.

    Science.gov (United States)

    Vapalahti, Katariina; Virtala, Anna-Maija; Joensuu, Tara A; Tiira, Katriina; Tähtinen, Jaana; Lohi, Hannes

    2016-01-01

    A comprehensive feline health survey was conducted to reveal breed-specific inheritable diseases in Finnish pedigree cats for genetic research. Prevalence of 19 disease categories and 227 feline diseases were defined in a study population of 8175 cats belonging to 30 breeds. Dental and oral diseases, with a prevalence of 28%, and dental calculus and gingivitis (21 and 8%, respectively) were the most prevalent disease category and diseases among all cats and in most of the breeds. An exception was Korats, which were more often affected by the diseases of the respiratory tract (23%) and asthma (19%). Other prevalent disease categories affected various organ systems, such as the skin (12%), the urinary system (12%), the digestive tract (11%), eyes (10%), the musculoskeletal system (10%), and genitals of female cats (17%). Prevalent health or developmental issues included repetitive vomiting (4%), tail kink (4%), feline odontoclastic resorption lesion (4%), urinary tract infections (4%), as well as cesarean section (6%) and stillborn kittens (6%) among female cats. We found 57 breed-specific conditions by Fisher's exact tests and logistic regression analyses, including 32 previously described and 19 new breed-specific diseases. The genetic defect has already been found in six of them: polycystic kidney disease, progressive retinal atrophy, hypertrophic cardiomyopathy, and three types of tail malformations. Behavioral profiling revealed breed-specific traits, such as an increased human avoidance in British Short and Longhairs and a higher level of aggression in Turkish vans. Our epidemiological study reveals the overall health profile in Finnish pure and mixed breed cats and identifies many breed-specific conditions without molecular identity for genetic research. PMID:27622188

  10. Health and behavioral survey of over 8000 Finnish cats

    Directory of Open Access Journals (Sweden)

    Katariina Vapalahti

    2016-08-01

    Full Text Available A comprehensive feline health survey was conducted to reveal breed-specific inheritable diseases in Finnish pedigree cats for genetic research. Prevalences of 19 disease categories and 227 feline diseases were defined in a study population of 8175 cats belonging to 30 breeds. Dental and oral diseases with a prevalence of 28% and dental calculus and gingivitis (21% and 8%, respectively were the most prevalent disease category and diseases among all cats and in most of the breeds. An exception was Korats, which were more often affected by the diseases of the respiratory tract (23% and asthma (19%. Other prevalent disease categories affected various organ systems such as the skin (12%, the urinary system (12%, the digestive tract (11%, eyes, (10%, the musculoskeletal system (10%, and genitals of female cats (17%. Prevalent health or developmental issues included repetitive vomiting (4%, tail kink (4%, feline odontoclastic resorption lesion (FORL (4%, urinary tract infections (4%, as well as caesarean section (6% and stillborn kittens (6% among female cats. We found 57 breed-specific conditions by Fisher’s exact tests and logistic regression analyses, including 32 previously described and 19 new breed-specific diseases. The genetic defect has already been found in six of them: polycystic kidney disease (PKD, progressive retinal atrophy (PRA, hypertrophic cardiomyopathy (HCM and three types of tail malformations. Behavioral profiling revealed breed-specific traits, such as an increased human avoidance in British Short and Longhairs and a higher level of aggression in Turkish vans. Our epidemiological study reveals the overall health profile in Finnish pure and mixed breed cats and identifies many breed-specific conditions without molecular identity for genetic research.

  11. Health and Behavioral Survey of over 8000 Finnish Cats

    Science.gov (United States)

    Vapalahti, Katariina; Virtala, Anna-Maija; Joensuu, Tara A.; Tiira, Katriina; Tähtinen, Jaana; Lohi, Hannes

    2016-01-01

    A comprehensive feline health survey was conducted to reveal breed-specific inheritable diseases in Finnish pedigree cats for genetic research. Prevalence of 19 disease categories and 227 feline diseases were defined in a study population of 8175 cats belonging to 30 breeds. Dental and oral diseases, with a prevalence of 28%, and dental calculus and gingivitis (21 and 8%, respectively) were the most prevalent disease category and diseases among all cats and in most of the breeds. An exception was Korats, which were more often affected by the diseases of the respiratory tract (23%) and asthma (19%). Other prevalent disease categories affected various organ systems, such as the skin (12%), the urinary system (12%), the digestive tract (11%), eyes (10%), the musculoskeletal system (10%), and genitals of female cats (17%). Prevalent health or developmental issues included repetitive vomiting (4%), tail kink (4%), feline odontoclastic resorption lesion (4%), urinary tract infections (4%), as well as cesarean section (6%) and stillborn kittens (6%) among female cats. We found 57 breed-specific conditions by Fisher’s exact tests and logistic regression analyses, including 32 previously described and 19 new breed-specific diseases. The genetic defect has already been found in six of them: polycystic kidney disease, progressive retinal atrophy, hypertrophic cardiomyopathy, and three types of tail malformations. Behavioral profiling revealed breed-specific traits, such as an increased human avoidance in British Short and Longhairs and a higher level of aggression in Turkish vans. Our epidemiological study reveals the overall health profile in Finnish pure and mixed breed cats and identifies many breed-specific conditions without molecular identity for genetic research. PMID:27622188

  12. Health and Behavioral Survey of over 8000 Finnish Cats.

    Science.gov (United States)

    Vapalahti, Katariina; Virtala, Anna-Maija; Joensuu, Tara A; Tiira, Katriina; Tähtinen, Jaana; Lohi, Hannes

    2016-01-01

    A comprehensive feline health survey was conducted to reveal breed-specific inheritable diseases in Finnish pedigree cats for genetic research. Prevalence of 19 disease categories and 227 feline diseases were defined in a study population of 8175 cats belonging to 30 breeds. Dental and oral diseases, with a prevalence of 28%, and dental calculus and gingivitis (21 and 8%, respectively) were the most prevalent disease category and diseases among all cats and in most of the breeds. An exception was Korats, which were more often affected by the diseases of the respiratory tract (23%) and asthma (19%). Other prevalent disease categories affected various organ systems, such as the skin (12%), the urinary system (12%), the digestive tract (11%), eyes (10%), the musculoskeletal system (10%), and genitals of female cats (17%). Prevalent health or developmental issues included repetitive vomiting (4%), tail kink (4%), feline odontoclastic resorption lesion (4%), urinary tract infections (4%), as well as cesarean section (6%) and stillborn kittens (6%) among female cats. We found 57 breed-specific conditions by Fisher's exact tests and logistic regression analyses, including 32 previously described and 19 new breed-specific diseases. The genetic defect has already been found in six of them: polycystic kidney disease, progressive retinal atrophy, hypertrophic cardiomyopathy, and three types of tail malformations. Behavioral profiling revealed breed-specific traits, such as an increased human avoidance in British Short and Longhairs and a higher level of aggression in Turkish vans. Our epidemiological study reveals the overall health profile in Finnish pure and mixed breed cats and identifies many breed-specific conditions without molecular identity for genetic research.

  13. Intra-articular ganglion cysts of the cruciate ligaments

    Energy Technology Data Exchange (ETDEWEB)

    Tyrrell, P.N.M.; Cassar-Pullicino, V.N.; McCall, I.W. [Department of Diagnostic Imaging and The Institute of Orthopaedics, The Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Oswestry, Shropshire (United Kingdom)

    2000-08-01

    Intra-articular ganglion cysts of the cruciate ligaments are associated with non-specific clinical signs and symptoms. Familiarity with the MR appearances in particular is important to make an accurate diagnosis, exclude associated abnormalities, and avoid misdiagnosis. (orig.)

  14. Ganglion cysts of the cruciate ligaments detected by MRI

    OpenAIRE

    Sumen, Y.; Ochi, M.; Deie, M.; Adachi, N.; Ikuta, Y.

    1999-01-01

     Eight patients with ganglion cysts arising from the cruciate ligaments of the knee joint underwent arthroscopic excision after the MR examination. The MR findings, clinical features and arthroscopic findings were evaluated comparatively.

  15. Ganglion cyst of the posterior cruciate ligament in a child.

    Science.gov (United States)

    Hameed, Shamsi Abdul; Sujir, Premjit; Naik, Monappa A; Rao, Sharath K

    2012-04-01

    Ganglion cysts are more commonly associated with the anterior cruciate ligament than the posterior cruciate ligament (PCL). A literature review showed that all reported cases of ganglion cysts to date involved adults. We report a rare case of ganglion cyst in the PCL of a four-year-old boy, and discuss its aetiology, clinical presentation, imaging features and management. Ganglion cysts of the PCL may be confused with meniscal cysts arising from tears of the posterior horn of the medial meniscus on magnetic resonance (MR) imaging. Hence, the posterior horn of the medial meniscus has to be carefully evaluated to rule out a tear. MR imaging is the method of choice to confirm diagnosis, and arthroscopic resection is a safe treatment modality even in children. PMID:22511069

  16. Visual responses of ganglion cells of a New-World primate, the capuchin monkey, Cebus apella.

    Science.gov (United States)

    Lee, B B; Silveira, L C; Yamada, E S; Hunt, D M; Kremers, J; Martin, P R; Troy, J B; da Silva-Filho, M

    2000-11-01

    1. The genetic basis of colour vision in New-World primates differs from that in humans and other Old-World primates. Most New-World primate species show a polymorphism; all males are dichromats and most females trichromats. 2. In the retina of Old-World primates such as the macaque, the physiological correlates of trichromacy are well established. Comparison of the retinae in New- and Old-World species may help constrain hypotheses as to the evolution of colour vision and the pathways associated with it. 3. Ganglion cell behaviour was recorded from trichromatic and dichromatic members of a New-World species (the capuchin monkey, Cebus apella) and compared with macaque data. Despite some differences in quantitative detail (such as a temporal response extended to higher frequencies), results from trichromatic animals strongly resembled those from the macaque. 4. In particular, cells of the parvocellular (PC) pathway showed characteristic frequency-dependent changes in responsivity to luminance and chromatic modulation, cells of the magnocellular (MC) pathway showed frequency-doubled responses to chromatic modulation, and the surround of MC cells received a chromatic input revealed on changing the phase of heterochromatically modulated lights. 5. Ganglion cells of dichromats were colour-blind versions of those of trichromats. 6. This strong physiological homology is consistent with a common origin of trichromacy in New- and Old-World monkeys; in the New-World primate the presence of two pigments in the middle-to-long wavelength range permits full expression of the retinal mechanisms of trichromatic vision. PMID:11432364

  17. The Cat nRules

    CERN Document Server

    Mould, R A

    2004-01-01

    The nRules that are developed in another paper are applied to two versions of the Schrodinger cat experiment. In version I the initially conscious cat is made unconscious by a mechanism that is initiated by a radioactive decay. In version II the initially unconscious cat is awakened by a mechanism that is initiated by a radioactive decay. In both cases an observer is permitted to check the statues of the cat at any time during the experiment. In all cases the nRules correctly and unambiguously predict the conscious experience of the cat and the observer. Keywords: brain states of observer, stochastic choice, state reduction, wave collapse.

  18. Prostatic carcinoma in two cats

    International Nuclear Information System (INIS)

    Clinical, radiological and pathological features of two cats with prostatic carcinoma are reported. In both cats the presenting history included signs of lower urinary tract disease with haematuria and dysuria. Prostatomegaly was visible radiographically in one cat; an irregular intraprostatic urethra was seen on retrograde contrast urethrography in both cats. In one of the cats, neoplasia was suspected on the basis of a transurethral catheter biopsy. Following a poor response to palliative treatment in both cases, euthanasia was performed with histological confirmation of the diagnosis

  19. Retinal characteristics of the ornate dragon lizard, Ctenophorus ornatus.

    Science.gov (United States)

    Barbour, Helen R; Archer, Michael A; Hart, Nathan S; Thomas, Nicole; Dunlop, Sarah A; Beazley, Lyn D; Shand, Julia

    2002-09-01

    The retina of a diurnal insectivorous lizard, Ctenophorus ornatus (Agamidae) was investigated using microspectrophotometry and light and electron microscopy. A prominent broad yellow band was observed that extended across the mid-retina. The yellow coloration was found to originate from both oil droplets and diffuse pigmentation within cone inner segments. Microspectrophotometric analysis revealed yellow oil droplets with variable absorption of wavelengths below 520 nm and transparent oil droplets with no detectable absorptance between 350 and 750 nm. Cones with transparent oil droplets lacked the diffuse yellow pigmentation. The mean wavelengths of maximum absorbance of visual pigments in the isolated cone outer segments were at 440, 493, and 571 nm. The retina was found to possess a deep convexiclivate fovea located within the yellow band, slightly dorsotemporal of the retinal midpoint. The topography of the retinal ganglion cells revealed that the fovea was contained within an area centralis. Photoreceptors were either single (80%) or unequal double (20%) cones. Within the region of the fovea, the cones were approximately 20% the diameter of those in the peripheral retina. Colored oil droplets and yellow pigment may increase visual acuity by absorbing short wavelength light scattered either by the atmosphere or the optical structures of the eye. The presence of a fovea containing slender cone photoreceptors and three visual pigments suggests that the lizard has high acuity and the potential for color vision. PMID:12209847

  20. Probing the functional impact of sub-retinal prosthesis

    Science.gov (United States)

    Roux, Sébastien; Matonti, Frédéric; Dupont, Florent; Hoffart, Louis; Takerkart, Sylvain; Picaud, Serge; Pham, Pascale; Chavane, Frédéric

    2016-01-01

    Retinal prostheses are promising tools for recovering visual functions in blind patients but, unfortunately, with still poor gains in visual acuity. Improving their resolution is thus a key challenge that warrants understanding its origin through appropriate animal models. Here, we provide a systematic comparison between visual and prosthetic activations of the rat primary visual cortex (V1). We established a precise V1 mapping as a functional benchmark to demonstrate that sub-retinal implants activate V1 at the appropriate position, scalable to a wide range of visual luminance, but with an aspect-ratio and an extent much larger than expected. Such distorted activation profile can be accounted for by the existence of two sources of diffusion, passive diffusion and activation of ganglion cells’ axons en passant. Reverse-engineered electrical pulses based on impedance spectroscopy is the only solution we tested that decreases the extent and aspect-ratio, providing a promising solution for clinical applications. DOI: http://dx.doi.org/10.7554/eLife.12687.001 PMID:27549126

  1. Nyctalopin Expression in Retinal Bipolar Cells Restores Visual Function in a Mouse Model of Complete X-Linked Congenital Stationary Night Blindness

    OpenAIRE

    Gregg, Ronald G; Kamermans, Maarten; Klooster, Jan; Lukasiewicz, Peter D.; PEACHEY, NEAL S.; Kirstan A Vessey; McCall, Maureen A.

    2007-01-01

    Mutations in the NYX gene that encodes the protein nyctalopin cause congenital stationary night blindness type 1. In no b-wave (nob) mice, a mutation in Nyx results in a functional phenotype that includes the absence of the electroretinogram b-wave and abnormal spontaneous and light-evoked activity in retinal ganglion cells (RGCs). In contrast, there is no morphological abnormality in the retina at either the light or electron microscopic levels. These functional deficits suggest that nyctalo...

  2. Genetic testing in domestic cats.

    Science.gov (United States)

    Lyons, Leslie A

    2012-12-01

    Varieties of genetic tests are currently available for the domestic cat that support veterinary health care, breed management, species identification, and forensic investigations. Approximately thirty-five genes contain over fifty mutations that cause feline health problems or alterations in the cat's appearance. Specific genes, such as sweet and drug receptors, have been knocked-out of Felidae during evolution and can be used along with mtDNA markers for species identification. Both STR and SNP panels differentiate cat race, breed, and individual identity, as well as gender-specific markers to determine sex of an individual. Cat genetic tests are common offerings for commercial laboratories, allowing both the veterinary clinician and the private owner to obtain DNA test results. This article will review the genetic tests for the domestic cat, and their various applications in different fields of science. Highlighted are genetic tests specific to the individual cat, which are a part of the cat's genome.

  3. Retinal neurodegeneration in Wilson's disease revealed by spectral domain optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    Philipp Albrecht

    Full Text Available BACKGROUND/OBJECTIVE: In addition to cirrhosis of the liver, Wilson's disease leads to copper accumulation and widespread degeneration of the nervous system. Delayed visual evoked potentials (VEPs suggest changes to the visual system and potential structural changes of the retina. METHODS: We used the latest generation of spectral domain optical coherence tomography to assess the retinal morphology of 42 patients with Wilson's disease and 76 age- and sex-matched controls. We measured peripapillary retinal nerve fiber layer (RNFL thickness and total macular thickness and manually segmented all retinal layers in foveal scans of 42 patients with Wilson's disease and 76 age- and sex-matched controls. The results were compared with VEPs and clinical parameters. RESULTS: The mean thickness of the RNFL, paramacular region, retinal ganglion cell/inner plexiform layer and inner nuclear layer was reduced in Wilson's disease. VEPs were altered with delayed N75 and P100 latencies, but the N140 latency and amplitude was unchanged. An analysis of the laboratory parameters indicated that the serum concentrations of copper and caeruloplasmin positively correlated with the thickness of the outer plexiform layer and with N75 and P100 VEP latencies. CONCLUSION: Neuronal degeneration in Wilson's disease involves the retina and changes can be quantified by optical coherence tomography. While the VEPs and the thickness of the outer plexiform layer appear to reflect the current copper metabolism, the thicknesses of the RNFL, ganglion cell/inner plexiform layer, inner nuclear layer and the total paramacular thickness may be the best indicators of chronic neuronal degeneration.

  4. Antibodies against Pax6 immunostain amacrine and ganglion cells and neuronal progenitors, but not rod precursors, in the normal and regenerating retina of the goldfish.

    Science.gov (United States)

    Hitchcock, P F; Macdonald, R E; VanDeRyt, J T; Wilson, S W

    1996-03-01

    Pax6 is a developmental regulatory gene that plays a key role in the development of the embryonic brain, eye, and retina. This gene is also expressed in discrete groups of neurons within the adult brain. In this study, antibodies raised against a fusion protein from a zebra fish pax6 cDNA were used to investigate the expression of the pax6 gene in the mature, growing, and regenerating retina of the goldfish. On western blots of retinal proteins, the pax6 antibodies recognize a single band at the approximate size of the zebra fish pax6 protein. In retinal sections, the antibodies label the nuclei of mature amacrine and some ganglion cells. At the retinal margin, where neurogenesis and cellular differentiation continually occur in goldfish, the antibodies label neuronal progenitors and the newly postmitotic neurons. Following injury and during neuronal regeneration, the antibodies label mitotically active progenitors of regenerating neurons. Rod precursors, proliferating cells that normally give rise solely to rod photoreceptors and are the presumed antecedents of the injury-stimulated neuronal progenitors, are not immunostained by antibodies to the pax6 protein. The results of this study document the identity of pax6-expressing cells in the mature retina and demonstrate that in the goldfish pax6 is expressed in neuronal progenitors during both retinal growth and regeneration.

  5. The Cheshire Cat revisited

    CERN Document Server

    Vento, V

    1998-01-01

    The concept of effective field theory leads in a natural way to a construction principle for phenomenological sensible models known under the name of the Cheshire Cat Principle. We review its formulation in the chiral bag scenario and discuss its realization for the flavor singlet axial charge. Quantum effects inside the chiral bag induce a color anomaly which requires a compensating surface term to prevent breakdown of color gauge invariance. The presence of this surface term allows one to derive in a gauge-invariant way a chiral-bag version of the Shore-Veneziano two-component formula for the flavor-singlet axial charge of the proton. We show that one can obtain a striking Cheshire-Cat phenomenon with a negligibly small singlet axial charge.

  6. Acute retinal necrosis

    Directory of Open Access Journals (Sweden)

    Hugo Hernán Ocampo

    2009-12-01

    Full Text Available Purpose: Clinical features in a case of acute retinal necrosis are described as well as its diagnostic approach and response to early treatment. Methods: This is a descriptive and retrospective study case report of a 26 year old male patient who arrived to the emergency room with a three day history of sudden visual loss in the right eye (RE. At initial evaluation a visual acuity of hand movements in the RE, 20/15 in the left eye (LE and a right relative afferent pupillary defect were found. Fundoscopy revealed profuse soft exudates and hemorrhages involving posterior pole, inferior hemiretina and superotemporal periphery. Infectious workup and fluoresceinic angiography were made and positive serologies for herpes virus types 1 and 2, without HIV, were found. A diagnosis of acute retinal necrosis was made and treatment with intravenous valgancyclovir for two weeks and intra-vitreous triamcinolone for severe vasculitis, was given. Then a 3 months treatment with oral antiviral agents was prescribed. Results: Patient’s evolution showed improvement with treatment and at two and a half months of follow up, visual acuity was 20/50 in the right eye, normal slit lamp examination, tonometry of 12 mm Hg and fundoscopy improved when compared to initial pictures.Conclusions: A high index of suspicion is needed for diagnosing ARN taking into account clinical findings. Prompt intravenous and intra-vitreous treatments are needed to achieve good clinical and functional outcomes and to avoid central nervous system complications.

  7. Evaluation of micro Electroretinograms Recorded with Multiple Electrode Array to Assess Focal Retinal Function

    Science.gov (United States)

    Fujii, Momo; Sunagawa, Genshiro A.; Kondo, Mineo; Takahashi, Masayo; Mandai, Michiko

    2016-01-01

    Full-field electroretinograms (ERGs) are used to objectively assess the mass function of the retina, whereas focal ERGs are used to evaluate the focal retinal function. The purpose of this study was to determine the usefulness of a multiple electrode array (MEA) system for recording ex vivo micro ERGs (mERGs) together with multiunit spike responses of the retinal ganglion cells (RGCs) to assess focal retinal function in isolated mouse retinas. The a- and b-waves of the full-field ERGs were present in the mERG. The b-wave was blocked by L-AP4, an inhibitor of the mGluR6 receptor, and the OFF-component was blocked by exposure to PDA, an antagonist of ionotropic glutamate receptors, with a corresponding RGC responses. mERGs were also recorded from mice with progressive retinal degeneration, the C57BL/6J-Pde6brd1-2J/J (rd1) mice, from which conventional full-field ERGs are non-recordable. A blockade of the glutamate receptors indicated that the negative wave of rd1 mice do not originate from the photoreceptors but from the second or third order neurons. This technique of recording mERGs will be useful in assessing the focal properties of the retinas obtained from eyes with pathology and also to follow the recovery of the physiology of the retina in regenerative studies. PMID:27480484

  8. Bone marrow mesenchymal stem cells stimulate proliferation and neuronal differentiation of retinal progenitor cells.

    Directory of Open Access Journals (Sweden)

    Jing Xia

    Full Text Available During retina development, retinal progenitor cell (RPC proliferation and differentiation are regulated by complex inter- and intracellular interactions. Bone marrow mesenchymal stem cells (BMSCs are reported to express a variety of cytokines and neurotrophic factors, which have powerful trophic and protective functions for neural tissue-derived cells. Here, we show that the expanded RPC cultures treated with BMSC-derived conditioned medium (CM which was substantially enriched for bFGF and CNTF, expressed clearly increased levels of nuclear receptor TLX, an essential regulator of neural stem cell (NSC self-renewal, as well as betacellulin (BTC, an EGF-like protein described as supporting NSC expansion. The BMSC CM- or bFGF-treated RPCs also displayed an obviously enhanced proliferation capability, while BMSC CM-derived bFGF knocked down by anti-bFGF, the effect of BMSC CM on enhancing RPC proliferation was partly reversed. Under differentiation conditions, treatment with BMSC CM or CNTF markedly favoured RPC differentiation towards retinal neurons, including Brn3a-positive retinal ganglion cells (RGCs and rhodopsin-positive photoreceptors, and clearly diminished retinal glial cell differentiation. These findings demonstrate that BMSCs supported RPC proliferation and neuronal differentiation which may be partly mediated by BMSC CM-derived bFGF and CNTF, reveal potential limitations of RPC culture systems, and suggest a means for optimizing RPC cell fate determination in vitro.

  9. Physiological variation of retinal layer thickness is not caused by hydration: a randomised trial.

    Science.gov (United States)

    Balk, Lisanne J; Oberwahrenbrock, Timm; Uitdehaag, Bernard M J; Petzold, Axel

    2014-09-15

    There is evidence for physiological variation of retinal thicknesses as determined by optical coherence tomography (OCT). We tested if such changes could be explained by hydration and would exceed what may be expected from normal ageing. Subjects (n=26) of a previous study were re-assessed and were randomised to 3 groups of a hydration escalation trial (no hydration, 1× hydration, 2× hydration). Automated retinal layer segmentations were performed for the macular retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL) and outer nuclear layer (ONL). The averaged volumes were calculated for the central foveola, 3 mm and 6 mm circles of the ETDRS grid. Following oral hydration there were no significant differences of retinal layer thicknesses between the three randomised groups in any of the ETDRS regions at any time-point. Ageing related changes were significant over an 18 month period for the GCL. The negative outcome of this trial implies that, until the causes for the observed variation are resolved, investigators may need to accept, and include into trial power calculations, a small degree of variation (<1%) of quantitative SD-OCT imaging either due to human physiology or instrument/software related factors.

  10. Neuroprotection, Growth Factors and BDNF-TrkB Signalling in Retinal Degeneration

    Science.gov (United States)

    Kimura, Atsuko; Namekata, Kazuhiko; Guo, Xiaoli; Harada, Chikako; Harada, Takayuki

    2016-01-01

    Neurotrophic factors play key roles in the development and survival of neurons. The potent neuroprotective effects of neurotrophic factors, including brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), glial cell-line derived neurotrophic factor (GDNF) and nerve growth factor (NGF), suggest that they are good therapeutic candidates for neurodegenerative diseases. Glaucoma is a neurodegenerative disease of the eye that causes irreversible blindness. It is characterized by damage to the optic nerve, usually due to high intraocular pressure (IOP), and progressive degeneration of retinal neurons called retinal ganglion cells (RGCs). Current therapy for glaucoma focuses on reduction of IOP, but neuroprotection may also be beneficial. BDNF is a powerful neuroprotective agent especially for RGCs. Exogenous application of BDNF to the retina and increased BDNF expression in retinal neurons using viral vector systems are both effective in protecting RGCs from damage. Furthermore, induction of BDNF expression by agents such as valproic acid has also been beneficial in promoting RGC survival. In this review, we discuss the therapeutic potential of neurotrophic factors in retinal diseases and focus on the differential roles of glial and neuronal TrkB in neuroprotection. We also discuss the role of neurotrophic factors in neuroregeneration. PMID:27657046

  11. Optical coherence tomography angiography of stimulus evoked hemodynamic responses in individual retinal layers.

    Science.gov (United States)

    Son, Taeyoon; Wang, Benquan; Thapa, Damber; Lu, Yiming; Chen, Yanjun; Cao, Dingcai; Yao, Xincheng

    2016-08-01

    Blood flow changes are highly related to neural activities in the retina. It has been reported that neural activity increases when flickering light stimulation of the retina is used. It is known that blood flow changes with flickering light stimulation can be altered in patients with vascular disease and that measurement of flicker-induced vasodilatation is an easily applied tool for monitoring functional microvascular alterations. However, details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood due to the limitation of existing techniques. In this study, flickering light stimulation was applied to mouse retinas to investigate stimulus evoked hemodynamic responses in individual retinal layers. A spectral domain optical coherence tomography (OCT) angiography imaging system was developed to provide dynamic mapping of hemodynamic responses in the ganglion cell layer, inner plexiform layer, outer plexiform layer and choroid layer before, during and after flickering light stimulation. Experimental results showed hemodynamic responses with different magnitudes and time courses in individual retinal layers. We anticipate that the dynamic OCT angiography of stimulus evoked hemodynamic responses can greatly foster the study of neurovascular coupling mechanisms in the retina, promising new biomarkers for retinal disease detection and diagnosis. PMID:27570706

  12. Ecomorphology of eye shape and retinal topography in waterfowl (Aves: Anseriformes: Anatidae) with different foraging modes.

    Science.gov (United States)

    Lisney, Thomas J; Stecyk, Karyn; Kolominsky, Jeffrey; Schmidt, Brian K; Corfield, Jeremy R; Iwaniuk, Andrew N; Wylie, Douglas R

    2013-05-01

    Despite the large body of literature on ecomorphological adaptations to foraging in waterfowl, little attention has been paid to their sensory systems, especially vision. Here, we compare eye shape and retinal topography across 12 species representing 4 different foraging modes. Eye shape was significantly different among foraging modes, with diving and pursuit-diving species having relatively smaller corneal diameters compared to non-diving species. This may be associated with differences in ambient light intensity while foraging or an ability to tightly constrict the pupil in divers in order to facilitate underwater vision. Retinal topography was similar across all species, consisting of an oblique visual streak, a central area of peak cell density, and no discernible fovea. Because the bill faces downwards when the head is held in the normal posture in waterfowl, the visual streak will be held horizontally, allowing the horizon to be sampled with higher visual acuity. Estimates of spatial resolving power were similar among species with only the Canada goose having a higher spatial resolution. Overall, we found no evidence of ecomorphological adaptations to different foraging modes in the retinal ganglion cell layer in waterfowl. Rather, retinal topography in these birds seems to reflect the 'openness' of their habitats. PMID:23475299

  13. Retinal hemorrhages as one of complications of optic disc drusen during pregnancy

    Directory of Open Access Journals (Sweden)

    Trenkić-Božinović Marija

    2014-01-01

    Full Text Available Introduction. Drusen of the optic nerve head are relatively benign and asymptomatic. They represent retinal hyaline corpuscles resulting from impaired axoplasmic transport of the retinal ganglion cells of optic nerve in front of the lamina cribrosa. They are usually detected accidentally, during a routine ophthalmologic examination. Most patients with optic disc drusen are not aware of the deterioration of their eyesight because of the slow progression of visual field defects. Damage in visual acuity due to optic disc drusen is rare. Case Report. A 27-year-old female patient in the sixth month of pregnancy visited an ophthalmologist because of a visual impairment described as the appearance of mist and shadows over her right eye. When first examined, her visual acuity in both eyes was 20/20. The retinal hemorrhages framing the bottom half of the optic nerve were seen. Complete laboratory and clinical testing as well as specific ophthalmic examinations (photofundus, computerized visual field, optical coherence tomography, and ultrasound were performed to exclude systemic causes and they presented no risk for the pregnancy. Echosonographic examination confirmed the presence of bilateral optic nerve head drusen. Conclusion. Hemodynamic changes during pregnancy are possible factors for the development of optical disc and retinal hemorrhages. Since treatment of optic disc drusen is limited, recognition of optic nerve drusen as a cause of hemorrhage during pregnancy prevents unnecessary diagnostic and therapeutic interventions.

  14. Bimatoprost protects retinal neuronal damage via Akt pathway.

    Science.gov (United States)

    Takano, Norihito; Tsuruma, Kazuhiro; Ohno, Yuta; Shimazawa, Masamitsu; Hara, Hideaki

    2013-02-28

    Worldwide, prostaglandin analogs, such as bimatoprost, have become the major therapeutic class for medical treatment of glaucoma because of their efficacy and generally well tolerated systemic safety profile. However, the detailed mechanism of the direct action of bimatoprost on retinal ganglion cells (RGC) has rarely been understood. Thus, in this study, we elucidated the mechanism of the protective effects of bimatoprost on RGC against oxidative stress. To examine the protective effects of bimatoprost, cultured RGC with various concentrations of bimatoprost (in both free acid and amide form) were exposed to l-buthionin-(S,R)-sulfoximine (BSO) plus glutamate or serum depletion in vitro and intravitreal injection of N-methyl-D-aspartate (NMDA) was used to induce retinal damage in vivo. To elucidate the protective mechanism of bimatoprost, we used western blot analysis to investigate the phosphorylation of Akt and extracellular signal-regulated kinase (ERK). Bimatoprost significantly reduced BSO plus glutamate- and serum deprivation-induced death in concentration-dependent manners. Bimatoprost induced activation of Akt and ERK, and a phosphatidylinositol 3-kinase inhibitor, LY294002, attenuated the protective effect of bimatoprost. On the other hand, a mitogen-activated protein kinase kinase inhibitor, U0126, exhibited protective effect unexpectedly. Moreover, ERK was more phosphorylated by attenuation of Akt activity in cultured RGC. In an in vivo study, bimatoprost reduced NMDA-induced RGC death. Taken together, these findings indicate that bimatoprost has protective effects on in vitro and in vivo retinal damage, suggesting that the mechanism underlying may be via the Akt pathway, which may modulate the ERK pathway.

  15. Non-invasive detection of early retinal neuronal degeneration by ultrahigh resolution optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    Debbie Tudor

    Full Text Available Optical coherence tomography (OCT has revolutionises the diagnosis of retinal disease based on the detection of microscopic rather than subcellular changes in retinal anatomy. However, currently the technique is limited to the detection of microscopic rather than subcellular changes in retinal anatomy. However, coherence based imaging is extremely sensitive to both changes in optical contrast and cellular events at the micrometer scale, and can generate subtle changes in the spectral content of the OCT image. Here we test the hypothesis that OCT image speckle (image texture contains information regarding otherwise unresolvable features such as organelle changes arising in the early stages of neuronal degeneration. Using ultrahigh resolution (UHR OCT imaging at 800 nm (spectral width 140 nm we developed a robust method of OCT image analyses, based on spatial wavelet and texture-based parameterisation of the image speckle pattern. For the first time we show that this approach allows the non-invasive detection and quantification of early apoptotic changes in neurons within 30 min of neuronal trauma sufficient to result in apoptosis. We show a positive correlation between immunofluorescent labelling of mitochondria (a potential source of changes in cellular optical contrast with changes in the texture of the OCT images of cultured neurons. Moreover, similar changes in optical contrast were also seen in the retinal ganglion cell- inner plexiform layer in retinal explants following optic nerve transection. The optical clarity of the explants was maintained throughout in the absence of histologically detectable change. Our data suggest that UHR OCT can be used for the non-invasive quantitative assessment of neuronal health, with a particular application to the assessment of early retinal disease.

  16. Retinal synaptic regeneration via microfluidic guiding channels

    OpenAIRE

    Ping-Jung Su; Zongbin Liu; Kai Zhang; Xin Han; Yuki Saito; Xiaojun Xia; Kenji Yokoi; Haifa Shen; Lidong Qin

    2015-01-01

    In vitro culture of dissociated retinal neurons is an important model for investigating retinal synaptic regeneration (RSR) and exploring potentials in artificial retina. Here, retinal precursor cells were cultured in a microfluidic chip with multiple arrays of microchannels in order to reconstruct the retinal neuronal synapse. The cultured retinal cells were physically connected through microchannels. Activation of electric signal transduction by the cells through the microchannels was demon...

  17. Retinal Image Preprocessing: Background and Noise Segmentation

    OpenAIRE

    Usman Akram

    2012-01-01

    Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse ...

  18. Flexible retinal electrode array

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  19. Hypereosinophilic syndrome in two cats.

    Science.gov (United States)

    Takeuchi, Yoshinori; Matsuura, Shinobu; Fujino, Yasuhito; Nakajima, Mayumi; Takahashi, Masashi; Nakashima, Ko; Sakai, Yusuke; Uetsuka, Koji; Ohno, Koichi; Nakayama, Hiroyuki; Tsujimoto, Hajime

    2008-10-01

    Two cats showing chronic vomiting, diarrhea and weight loss were found to have leukocytosis with marked eosinophilia. Both cats were diagnosed with hypereosinophilic syndrome by the findings of increased eosinophils and their precursors in the bone marrow, eosinophilic infiltration into multiple organs, and exclusion of other causes for eosinophilia. Although cytoreductive chemotherapy with hydroxycarbamide and prednisolone was performed, these two cats died 48 days and 91 days after the initial presentation. PMID:18981665

  20. Primary hyperaldosteronism, a mediator of progressive renal disease in cats.

    Science.gov (United States)

    Javadi, S; Djajadiningrat-Laanen, S C; Kooistra, H S; van Dongen, A M; Voorhout, G; van Sluijs, F J; van den Ingh, T S G A M; Boer, W H; Rijnberk, A

    2005-01-01

    In recent years, there has been renewed interest in primary hyperaldosteronism, particularly because of its possible role in the progression of kidney disease. While most studies have concerned humans and experimental animal models, we here report on the occurrence of a spontaneous form of (non-tumorous) primary hyperaldosteronism in cats. At presentation, the main physical features of 11 elderly cats were hypokalemic paroxysmal flaccid paresis and loss of vision due to retinal detachment with hemorrhages. Primary hyperaldosteronism was diagnosed on the basis of plasma concentrations of aldosterone (PAC) and plasma renin activity (PRA), and the calculation of the PAC:PRA ratio. In all animals, PACs were at the upper end or higher than the reference range. The PRAs were at the lower end of the reference range, and the PAC:PRA ratios exceeded the reference range. Diagnostic imaging by ultrasonography and computed tomography revealed no or only very minor changes in the adrenals compatible with nodular hyperplasia. Adrenal gland histopathology revealed extensive micronodular hyperplasia extending from zona glomerulosa into the zona fasciculata and reticularis. In three cats, plasma urea and creatinine concentrations were normal when hyperaldosteronism was diagnosed but thereafter increased to above the upper limit of the respective reference range. In the other eight cats, urea and creatinine concentrations were raised at first examination and gradually further increased. Even in end-stage renal insufficiency, there was a tendency to hypophosphatemia rather than to hyperphosphatemia. The histopathological changes in the kidneys mimicked those of humans with hyperaldosteronism: hyaline arteriolar sclerosis, glomerular sclerosis, tubular atrophy and interstitial fibrosis. The non-tumorous form of primary hyperaldosteronism in cats has many similarities with "idiopathic" primary hyperaldosteronism in humans. The condition is associated with progressive renal disease

  1. The Cat oRules

    CERN Document Server

    Mould, R A

    2004-01-01

    The oRules of state reduction are applied to the case of the Schrodinger cat experiment. It is shown that these rules can unambiguously describe the conscious state of the cat, as well as an outside observer at any time during the experiment. Two versions of the experiment are considered. In version I, the conscious cat is made unconscious by a mechanism that is triggered by a radioactive decay. In version II, the sleeping cat is made conscious by an alarm clock that is triggered by a radioactive decay.

  2. The Cat nRules

    OpenAIRE

    Mould, Richard A

    2004-01-01

    The nRules that are developed in another paper are applied to two versions of the Schrodinger cat experiment. In version I the initially conscious cat is made unconscious by a mechanism that is initiated by a radioactive decay. In version II the initially unconscious cat is awakened by a mechanism that is initiated by a radioactive decay. In both cases an observer is permitted to check the statues of the cat at any time during the experiment. In all cases the nRules correctly and unambiguousl...

  3. Ganglion cysts in the paediatric wrist: magnetic resonance imaging findings

    International Nuclear Information System (INIS)

    The majority of published literature on ganglion cysts in children has been from a surgical perspective, with no dedicated radiologic study yet performed. Our aim was to assess the magnetic resonance (MR) imaging appearance of ganglion cysts in a series of paediatric MR wrist examinations. Ninety-seven consecutive paediatric MR wrist examinations were retrospectively reviewed for the presence of ganglion cysts. Only those studies with wrist ganglia were included. Cysts were assessed for location, size, internal characteristics and secondary effect(s). Forty-one ganglion cysts (2-32 mm in size) were seen in 35/97 (36%) patients (24 female, 11 male), mean age: 13 years 11 months (range: 6 years 3 months-18 years). The majority were palmar (63.4%) with the remainder dorsal. Of the cysts, 43.9% were related to a wrist ligament(s), 36.6% to a joint and 17.1% to the triangular fibrocartilage complex. Of the patients, 91.4% had wrist symptoms: pain (n=29, 82.9%), swelling (n=7, 20%) and/or palpable mass (n=4, 11.4%); 71.4% patients had significant additional wrist abnormalities. Ganglion cysts were frequently found in children referred for wrist MRI. (orig.)

  4. Ganglion cysts in the paediatric wrist: magnetic resonance imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Bracken, Jennifer; Bartlett, Murray [Royal Children' s Hospital, Medical Imaging Department, Melbourne, VIC (Australia)

    2013-12-15

    The majority of published literature on ganglion cysts in children has been from a surgical perspective, with no dedicated radiologic study yet performed. Our aim was to assess the magnetic resonance (MR) imaging appearance of ganglion cysts in a series of paediatric MR wrist examinations. Ninety-seven consecutive paediatric MR wrist examinations were retrospectively reviewed for the presence of ganglion cysts. Only those studies with wrist ganglia were included. Cysts were assessed for location, size, internal characteristics and secondary effect(s). Forty-one ganglion cysts (2-32 mm in size) were seen in 35/97 (36%) patients (24 female, 11 male), mean age: 13 years 11 months (range: 6 years 3 months-18 years). The majority were palmar (63.4%) with the remainder dorsal. Of the cysts, 43.9% were related to a wrist ligament(s), 36.6% to a joint and 17.1% to the triangular fibrocartilage complex. Of the patients, 91.4% had wrist symptoms: pain (n=29, 82.9%), swelling (n=7, 20%) and/or palpable mass (n=4, 11.4%); 71.4% patients had significant additional wrist abnormalities. Ganglion cysts were frequently found in children referred for wrist MRI. (orig.)

  5. Cytomegalovirus retinitis mimicking intraocular lymphoma

    Directory of Open Access Journals (Sweden)

    Patrick Gooi

    2008-12-01

    Full Text Available Patrick Gooi1, James Farmer2, Bernard Hurley3, Elliott Brodbaker41Department of Ophthalmology, University of Calgary, Calgary, Alberta, Canada; 2Department of Pathology and Lab Medicine University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada; 3Department of Ophthalmology, University of Ottawa Eye Institute and The Ottawa Hospital, Ottawa, Ontario, Canada; 4Faculty of Medicine, University of Ottawa, Ottawa, Ontario, CanadaAbstract: We present a case of an unusual retinal infiltrate requiring retinal biopsy for definitive diagnosis. A 62-year-old man with treated lymphoma presented with decreased vision in the right eye associated with a white retinal lesion, which extended inferonasally from an edematous disc. Intraocular lymphoma was considered as a diagnosis; thus, the patient was managed with vitrectomy and retinal biopsy. Cytological analysis of the vitreous aspirate could not rule out a lymphoproliferative disorder. The microbial analysis was negative. Histology of the lesion showed extensive necrosis and large cells with prominent nucleoli. To rule out lymphoma, a battery of immunostains was performed and all were negative. However the limited amount of tissue was exhausted in the process. Subsequently, a hematoxylin and eosin (H/E slide was destained, on which a CMV immunostain was performed. This revealed positivity in the nuclei and intranuclear inclusions within the large atypical cells. A diagnosis of CMV retinitis was made. Retinal biopsy may provide a definitive diagnosis and direct patient care toward intravenous gancyclovir in the case of CMV or toward radiation and chemotherapy for intraocular lymphoma. When faced with a limited amount of tissue, destaining regular H/E slides is a possible avenue to performing additional immunohistochemical studies.Keywords: CMV retinitis, retinal biopsy, immunohistochemistry, destaining

  6. Microsystems Technology for Retinal Implants

    Science.gov (United States)

    Weiland, James

    2005-03-01

    The retinal prosthesis is targeted to treat age-related macular degeneration, retinitis pigmentosa, and other outer retinal degenerations. Simulations of artificial vision have predicted that 600-1000 individual pixels will be needed if a retinal prosthesis is to restore function such as reading large print and face recognition. An implantable device with this many electrode contacts will require microsystems technology as part of its design. An implantable retinal prosthesis will consist of several subsystems including an electrode array and hermetic packaging. Microsystems and microtechnology approaches are being investigated as possible solutions for these design problems. Flexible polydimethylsiloxane (PDMS) substrate electrode arrays and silicon micromachined electrode arrays are under development. Inactive PDMS electrodes have been implanted in 3 dogs to assess mechanical biocompatibility. 3 dogs were followed for 6 months. The implanted was securely fastened to the retina with a single retinal tack. No post-operative complications were evident. The array remained within 100 microns of the retinal surface. Histological evaluation showed a well preserved retina underneath the electrode array. A silicon device with electrodes suspended on micromachined springs has been implanted in 4 dogs (2 acute implants, 2 chronic implants). The device, though large, could be inserted into the eye and positioned on the retina. Histological analysis of the retina from the spring electrode implants showed that spring mounted posts penetrated the retina, thus the device will be redesigned to reduce the strength of the springs. These initial implants will provide information for the designers to make the next generation silicon device. We conclude that microsystems technology has the potential to make possible a retinal prosthesis with 1000 individual contacts in close proximity to the retina.

  7. cats and dogs

    Institute of Scientific and Technical Information of China (English)

    颜玉秀

    2003-01-01

    有这样一则英语成语:“To rain cats anddogs.”如果望文生义,则会被译为“下猫下狗”,因而会弄出许多笑话来,这应当是值得引以为戒的。其实这句成语的真正含义是:“下倾盆大雨”。那么下雨为什么会与cats和dogs联系在一起呢?

  8. Characterizing and modeling the intrinsic light response of rat ganglion-cell photoreceptors.

    Science.gov (United States)

    Walch, Olivia J; Zhang, L Samantha; Reifler, Aaron N; Dolikian, Michael E; Forger, Daniel B; Wong, Kwoon Y

    2015-11-01

    Intrinsically photosensitive retinal ganglion cells (ipRGCs) mediate both image-forming vision and non-image-forming visual responses such as pupillary constriction and circadian photoentrainment. Five types of ipRGCs, named M1-M5, have been discovered in rodents. To further investigate their photoresponse properties, we made multielectrode array spike recordings from rat ipRGCs, classified them into M1, M2/M4, and M3/M5 clusters, and measured their intrinsic, melanopsin-based responses to single and flickering light pulses. Results showed that ipRGC spiking can track flickers up to ∼0.2 Hz in frequency and that flicker intervals between 5 and 14 s evoke the most spikes. We also learned that melanopsin's integration time is intensity and cluster dependent. Using these data, we constructed a mathematical model for each cluster's intrinsic photoresponse. We found that the data for the M1 cluster are best fit by a model that assumes a large photoresponse, causing the cell to enter depolarization block. Our models also led us to hypothesize that the M2/M4 and M3/M5 clusters experience comparable photoexcitation but that the M3/M5 cascade decays significantly faster than the M2/M4 cascade, resulting in different response waveforms between these clusters. These mathematical models will help predict how each ipRGC cluster might respond to stimuli of any waveform and could inform the invention of lighting technologies that promote health through melanopsin stimulation.

  9. Physiological and morphological characterization of ganglion cells in the salamander retina.

    Science.gov (United States)

    Wang, Jing; Jacoby, Roy; Wu, Samuel M

    2016-02-01

    Retinal ganglion cells (RGCs) integrate visual information from the retina and transmit collective signals to the brain. A systematic investigation of functional and morphological characteristics of various types of RGCs is important to comprehensively understand how the visual system encodes and transmits information via various RGC pathways. This study evaluated both physiological and morphological properties of 67 RGCs in dark-adapted flat-mounted salamander retina by examining light-evoked cation and chloride current responses via voltage-clamp recordings and visualizing morphology by Lucifer yellow fluorescence with a confocal microscope. Six groups of RGCs were described: asymmetrical ON-OFF RGCs, symmetrical ON RGCs, OFF RGCs, and narrow-, medium- and wide-field ON-OFF RGCs. Dendritic field diameters of RGCs ranged 102-490 μm: narrow field (300 μm, 24%). Dendritic ramification patterns of RGCs agree with the sublamina A/B rule. 34% of RGCs were monostratified, 24% bistratified and 42% diffusely stratified. 70% of ON RGCs and OFF RGCs were monostratified. Wide-field RGCs were diffusely stratified. 82% of RGCs generated light-evoked ON-OFF responses, while 11% generated ON responses and 7% OFF responses. Response sensitivity analysis suggested that some RGCs obtained separated rod/cone bipolar cell inputs whereas others obtained mixed bipolar cell inputs. 25% of neurons in the RGC layer were displaced amacrine cells. Although more types may be defined by more refined classification criteria, this report is to incorporate more physiological properties into RGC classification. PMID:26731645

  10. Infrared neural stimulation (INS) inhibits electrically evoked neural responses in the deaf white cat

    Science.gov (United States)

    Richter, Claus-Peter; Rajguru, Suhrud M.; Robinson, Alan; Young, Hunter K.

    2014-03-01

    Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.

  11. Accelerator programme at CAT

    International Nuclear Information System (INIS)

    The Accelerator Programme at the Centre for Advanced Technology (CAT), Indore, has very broad based concept under which all types of accelerators are to be taken up for design and fabrication. This centre will be housing a wide variety of accelerators to serve as a common facility for the universities, national laboratories in addition to laboratories under the Department of Atomic Energy. In the first phase of the programme, a series of electron accelerators are designed and fabricated. They are synchrotron radiation sources of 450 MeV (INDUS-I) and of 2 GeV (INDUS-II), microtron upto energy of 20 MeV, linear accelerator upto 20 MeV, and DC Accelerator for industrial irradiation upto 750 KeV and 20 KW. A proton accelerator of 300 MeV with 20 MeV linac injector is also designed. CAT is also developing a strong base for support technologies like ultra high vacuum, radio frequency and microwaves, DC pulsed and superconducting magnets, power supplies and controls etc. These technologies are very useful for other industrial applications also. To develop user groups to utilise INDUS-II synchrotron radiation source, a batch production of rotating Anode X-ray generators with power supplies has been initiated. So also, the sputter ion pumps, electron guns, turbo molecular pumps are brought into batch production. (author)

  12. [Glomerulonephritis in dogs and cats].

    Science.gov (United States)

    Reinacher, M; Frese, K

    1991-04-01

    Immunohistology and special staining of plastic sections allow diagnosis and differentiation of subtypes of glomerulonephritis in dogs. Frequency and clinical importance of these forms of glomerulonephritis vary significantly. In cats, glomerulonephritis occurs frequently in FIV-positive cats but is rare in animals suffering from persistent FeLV infection or FIP. PMID:2068715

  13. Lumbosacral agenesis in a cat

    Directory of Open Access Journals (Sweden)

    Gabrielle C Hybki

    2016-01-01

    Full Text Available Case summary Lumbosacral agenesis is a rare congenital condition reported in children. We report a 17-week-old female domestic shorthair cat with lumbosacral agenesis on whole-body radiographs. The cat was euthanized shortly thereafter presentation. A necropsy was not permitted. Relevance and novel information This is the first reported feline case of lumbosacral agenesis.

  14. CONTRACT ADMINISTRATIVE TRACKING SYSTEM (CATS)

    Science.gov (United States)

    The Contract Administrative Tracking System (CATS) was developed in response to an ORD NHEERL, Mid-Continent Ecology Division (MED)-recognized need for an automated tracking and retrieval system for Cost Reimbursable Level of Effort (CR/LOE) Contracts. CATS is an Oracle-based app...

  15. College Students and Their Cats

    Science.gov (United States)

    Weinstein, Lawrence; Alexander, Ralph

    2010-01-01

    Twenty-two Siamese and 32 mixed breed cats' personalities were rated by their respective college student owners and compared. Further, the owners' self rated personality traits were correlated with the pets'; significant Siamese and Mixed differences and correlations were obtained. These are the first data to examine breed of cat on a personality…

  16. Feline leukemia virus and feline immunodeficiency virus infections in a cat with lymphoma.

    Science.gov (United States)

    Shelton, G H; McKim, K D; Cooley, P L; Dice, P F; Russell, R G; Grant, C K

    1989-01-15

    Lymphoma was diagnosed in a 7-year-old domestic cat found to be infected with FeLV and feline immunodeficiency virus (FIV). The cat was affected by chronic disorders suggestive of immunosuppression, including gingivitis, periodontitis, keratitis, and abscesses. Despite treatment, peripheral keratitis of the left eye progressed, resulting in uveitis, chronic glaucoma, and eventual corneal rupture. Microscopic retinal and optic disk pathologic processes also were suspected. Abnormal jaw movements that were believed to be indicative of neurologic disease were observed. Approximately 17 months later, the cat developed generalized lymphadenopathy, hepatosplenomegaly, and bilateral renomegaly. Lymphoblastic lymphoma and glomerulonephritis were diagnosed histologically. Manganese- and magnesium-dependent reverse transcriptase activity were detected in supernatants from lymph node and spleen mononuclear cell cultures, suggesting T-lymphocyte infection with FeLV and FIV. PMID:2537274

  17. Aquaporin 4-specific T cells and NMO-IgG cause primary retinal damage in experimental NMO/SD.

    Science.gov (United States)

    Zeka, Bleranda; Hastermann, Maria; Kaufmann, Nathalie; Schanda, Kathrin; Pende, Marko; Misu, Tatsuro; Rommer, Paulus; Fujihara, Kazuo; Nakashima, Ichiro; Dahle, Charlotte; Leutmezer, Fritz; Reindl, Markus; Lassmann, Hans; Bradl, Monika

    2016-01-01

    Neuromyelitis optica/spectrum disorder (NMO/SD) is a severe, inflammatory disease of the central nervous system (CNS). In the majority of patients, it is associated with the presence of pathogenic serum autoantibodies (the so-called NMO-IgGs) directed against the water channel aquaporin 4 (AQP4), and with the formation of large, astrocyte-destructive lesions in spinal cord and optic nerves. A large number of recent studies using optical coherence tomography (OCT) demonstrated that damage to optic nerves in NMO/SD is also associated with retinal injury, as evidenced by retinal nerve fiber layer (RNFL) thinning and microcystic inner nuclear layer abnormalities. These studies concluded that retinal injury in NMO/SD patients results from secondary neurodegeneration triggered by optic neuritis.However, the eye also contains cells expressing AQP4, i.e., Müller cells and astrocytes in the retina, epithelial cells of the ciliary body, and epithelial cells of the iris, which raised the question whether the eye can also be a primary target in NMO/SD. Here, we addressed this point in experimental NMO/SD (ENMO) induced in Lewis rat by transfer of AQP4268-285-specific T cells and NMO-IgG.We show that these animals show retinitis and subsequent dysfunction/damage of retinal axons and neurons, and that this pathology occurs independently of the action of NMO-IgG. We further show that in the retinae of ENMO animals Müller cell side branches lose AQP4 reactivity, while retinal astrocytes and Müller cell processes in the RNFL/ganglionic cell layers are spared. These changes only occur in the presence of both AQP4268-285-specific T cells and NMO-IgG.Cumulatively, our data show that damage to retinal cells can be a primary event in NMO/SD. PMID:27503347

  18. Peritoneopericardial diaphragmatic hernia in cats

    International Nuclear Information System (INIS)

    Peritoneopericardial diaphragmatic hernia in a cat is often an incidental finding on a routine thoracic or abdominal radiograph. Clinical signs are nonspecific-usually respiratory (dyspnea) or gastrointestinal(vomiting or diarrhea). Some of the cats with this anomaly are asymptomatic. The physical examination may be normal: muffled heart sounds are the most common abnormality noted during a physical examination. Cats of many breeds are affected, although 26% of reported cases were inPersians. Age of the cat at diagnosis ranged from 6 days to 14 years. Thirty of the 52 reported cases were in females. Diagnostic studies used to confirm the diagnosis included echocardiography, upper gastrointestinal study, ultrasonography, angiography, positive-contrast peritoneography, and laparotomy. Surgical correction was reportedly successful in 22 of 25 cats

  19. CAT-generation of ideals

    CERN Document Server

    Ueckerdt, Torsten

    2010-01-01

    We consider the problem of generating all ideals of a poset. It is a long standing open problem, whether or not the ideals of any poset can be generated in constant amortized time, CAT for short. We refine the tree traversal, a method introduced by Pruesse and Ruskey in 1993, to obtain a CAT-generator for two large classes of posets: posets of interval dimension at most two and so called locally planar posets. This includes all posets for which a CAT-generator was known before. Posets of interval dimension at most two generalize both, interval orders and 2-dimensional posets. Locally planar posets generalize for example posets with a planar cover graph. We apply our results to CAT-generate all $c$-orientations of a planar graph. As a special case this is a CAT-generator for many combinatorial objects like domino and lozenge tilings, planar spanning trees, planar bipartite perfect matchings, Schnyder woods, and others.

  20. Retinal detachment in paediatric patients

    International Nuclear Information System (INIS)

    Objective: To assess the causes of retinal detachment in children and the various operative procedures requiring vitreoretinal surgical intervention for the same. Study Design: Case series. Place and Duration of Study: Department of Ophthalmology, Al-Shifa Trust Eye Hospital, Rawalpindi, from January 2006 to May 2009. Methodology: A total of 281 eyes of 258 patients, (aged 0 - 18 years) who underwent vitreo-retinal surgical intervention for retinal detachment were included. Surgical log was searched for the type of retinal detachment and its causes. Frequencies of various interventions done in these patients viz. vitrectomy, scleral buckle, use of tamponading agents, laser photocoagulation and cryotherapy were noted. Results were described as descriptive statistics. Results: Myopia was the cause in 62 (22.1%) and trauma in 51 (18.1%) of the eyes. Total retinal detachment (RD) was treated in 94 (33.5%) eyes, sub total RD in 36 (12.8%), recurrent RD in 32 (11.4%), giant retinal tear in 28 (10%), tractional RD in 15 (5.3%) and exudative RD in 2 (0.7%). Prophylactic laser or cryotherapy was applied in 74 (26.3%) of the eyes. Pars plana vitrectomy (PPV) was carried out in 159 (56.6%) eyes while scleral buckle procedure was done in 129 (45.9%) eyes. Silicon oil was used in 149 (53%), perfluorocarbon liquid in 32 (11.4%) and gas tamponade in 20 (7.1%) eyes. Conclusion: The most common cause of retinal detachment in paediatric patients was myopia, followed by trauma. Total RD was more common as compared to the other types. The most common procedure adopted was pars plana vitrectomy followed by scleral buckle procedure. (author)

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  3. File list: Unc.Neu.05.AllAg.Superior_Cervical_Ganglion [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Neu.05.AllAg.Superior_Cervical_Ganglion mm9 Unclassified Neural Superior Cervic...al Ganglion http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.05.AllAg.Superior_Cervical_Ganglion.bed ...

  4. Diabetes Accelerates Retinal Neuronal Cell Death In A Mouse Model of Endogenous Hyperhomocysteinemia

    Directory of Open Access Journals (Sweden)

    Preethi S. Ganapathy

    2009-07-01

    Full Text Available Hyperhomocysteinemia has been implicated in visual dysfunction. We reported recently that mice with endogenous hyperhomocysteinemia, due to mutation of the cystathionine-β-synthase (cbs gene, demonstrate loss of neurons in the retinal ganglion cell (RGC layer and other retinal layers as homocysteine levels increase. Some clinical studies implicate hyperhomocysteinemia in the pathogenesis of diabetic retinopathy, which is also characterized by RGC loss. The present study used cbs+/- mice to determine whether modest elevation of plasma homocysteine, in the presence of diabetes, accelerates neuronal cell loss. Diabetes (DB was induced in 3 wk old cbs+/- and wildtype mice using streptozotocin; four groups of mice were studied: DB cbs+/-; non-DB cbs+/-; DB cbs+/+; non-DB cbs+/+. One group of diabetic cbs+/- mice was maintained on a high methionine diet (HMD, 0.5% methionine drinking water to increase plasma homocysteine slightly. Eyes were harvested at 5, 10 and 15 weeks post-onset of diabetes; retinal cryosections were examined by light microscopy and subjected to systematic morphometric analysis. Diabetic cbs+/- had significantly fewer RGCs at 5 weeks compared to age-matched, non-diabetic cbs+/- and wildtype controls (10.0 ± 0.5 versus 14.9 ± 0.5 and 15.8 ± 0.6 cells/100 µm retina length, respectively. Significant differences in retinas of DB/high homocysteine versus controls were obtained 15 wks post-onset of diabetes including fewer RGCS and decreased thickness of inner nuclear and plexiform layers. Moderate increases in plasma homocysteine coupled with diabetes cause a more dramatic alteration of retinal phenotype than elevated homocysteine or diabetes alone and suggest that diabetes accelerates the retinal neuronal death in hyperhomocysteinemic mice.

  5. Expression patterns of the retinal development-related genes in the fetal and adult retina

    Institute of Scientific and Technical Information of China (English)

    LI Hui-ming; WANG Feng; QIU Wei; LIU Yan; HUANG Qian

    2007-01-01

    Background Retina is important in converting light into neural signals, but little is known about the regulatory genes essential for the retinal morphological formation, development and functional differentiation. This study aimed to investigate the mRNA expression patterns and cellular or subcellular distribution of 33 differentially expressed genes in the retina belonging to the early and middle-late embryogenesis stages as well as the early adult stage during human development.Methods In situ hybridization and real-time fluorescent quantitative reverse transcription polymerase chain reaction (FQ-RT-PCR) were used to assay 33 differentially expressed genes which were screened out using microarray analysis and were not present in the retinal cDNA or the Expressed Sequence Tags (EST) database of the National Eye Institute (NEI) Genebank.Results Nine of the 33 genes belonged to EST or the unknown cDNA fragments, and the remaining belonged to the novel genes in the retina. During the human retinal development 17 genes were down-regulated, 6 were up-regulated and the remaining 10 were relatively unchanged. Most of the genes expressed in all layers of the retina at the gestation stage, and in the fully developed retina some genes examined did show higher expression level in certain specific cells and structures such as retinal ganglion cells or the outer segment of photoreceptor cells.Conclusion The gene expression profile during retinal development possesses temporal and spatial distribution features, which can provide experimental evidence for further research of the functions of those genes.

  6. How cats lap

    Science.gov (United States)

    Stocker, Roman; Reis, Pedro; Jung, Sunghwan; Aristoff, Jeffrey

    2010-11-01

    We studied the lapping of the domestic cat (Felis catus) by combining high-speed photography with a laboratory model of lapping. We found that Felis catus laps by a subtle mechanism based on water adhesion to the dorsal side of the tongue and the creation of a liquid column, exploiting inertia to defeat gravity and pull liquid into the mouth. The competition between inertia and gravity controls the pinch-off time of the column, determining the optimal lapping frequency, f. Felis catus was found to operate near the optimum and theoretical analysis yielded a scaling, f ˜M-1/6, of lapping frequency with animal mass, M. This prediction was verified by measuring lapping frequency across felids, from ocelots to lions, suggesting that the lapping mechanism is conserved among felines.

  7. Cat Ownership Perception and Caretaking Explored in an Internet Survey of People Associated with Cats

    OpenAIRE

    Zito, Sarah; Vankan, Dianne; Bennett, Pauleen; Paterson, Mandy; Phillips, Clive J. C.

    2015-01-01

    People who feed cats that they do not perceive they own (sometimes called semi-owners) are thought to make a considerable contribution to unwanted cat numbers because the cats they support are generally not sterilized. Understanding people’s perception of cat ownership and the psychology underlying cat semi-ownership could inform approaches to mitigate the negative effects of cat semi-ownership. The primary aims of this study were to investigate cat ownership perception and to examine its ass...

  8. Vascular malformation (so-called hemangioma) of Scarpa's ganglion

    NARCIS (Netherlands)

    Bernardeschi, D; Dunnebier, EA; Sauvaget, E; Herman, P; Wassef, M; Huy, PTB

    2004-01-01

    Vascular malformations of the cerebello-pontine angle (CPA) arising from the capillary plexus surrounding Scarpa's ganglion are rare tumors. We report a case of so-called "hemangioma" of the CPA which was operated on via a trans-labyrinthine approach based on a preoperative diagnosis of vestibular s

  9. Metrizamide demonstration of the subarachnoid space surrounding the Gasserian ganglion

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, D.; Babin, E.

    1980-05-01

    The chance opacification of the subarachnoid space surrounding the Gasserian ganglion, observed during metrizamide basal cisternography, is reported. This is compared to similar demonstrations of the optic subarachnoid space. Such infrequently observed images should be known because they may be related to the occurrence of trigeminal neuralgia.

  10. Magnetic resonance imaging of lacunar infarcts in the basal ganglionic area

    International Nuclear Information System (INIS)

    During the previous 2 years, 88 patients have been diagnosed as having lacunar infarcts in the basal ganglioa ( a total of 157 lesions) on magnetic resonance imaging (MRI):42 patients had a single lesion and 46 patients had multiple lesions (2 lesions in 25 patients, 3 lesions in 14, and 4 or more lesions in 7). Seventy-seven lesions (49%) were smaller than 5 mm in diameter, and the others ranged from 5 mm to 15 mm. According to the regional relations to the internal capsule, the lesions were classified as lateral (57 lesions), anterior (36), superior (34), posterior (26), and inferior (4). Lesions of posterior, anterior, superior, and inferior types were associated with severer hemisparetic state, an abnormally slow gait, a sensory disturbance of numbness, and a depressive state, respectively. Forty five lesions (28%) were asymptomatic. Cat scanning failed to deliniate 47 lesions (30%) that were detected on MRI. Twenty three lesions were both asymptomatic and undistinguished on CT, which consisted of the superior type (10), anteior type (7), lateral type (5), and posterior type (one). Twenty four lesions were symptomatic, but were undistinguished on CT, suggesting that MRI is superior to CT in detecting the lacunar infarcts in the basal ganglionic area. Lacunar infarcts in both acute and chronic stages tended to be larger on T2-weighted images than T1-weighted images. In 7 patients who had neither history of hypertension, diabetes mellitus, or cardiac emboli nor CT evidence, MRI was capable of detecting lacunar infarcts. (N.K.)

  11. Ischemic Retinal Vasculitis and Its Management

    Directory of Open Access Journals (Sweden)

    Lazha Talat

    2014-01-01

    Full Text Available Ischemic retinal vasculitis is an inflammation of retinal blood vessels associated with vascular occlusion and subsequent retinal hypoperfusion. It can cause visual loss secondary to macular ischemia, macular edema, and neovascularization leading to vitreous hemorrhage, fibrovascular proliferation, and tractional retinal detachment. Ischemic retinal vasculitis can be idiopathic or secondary to systemic disease such as in Behçet’s disease, sarcoidosis, tuberculosis, multiple sclerosis, and systemic lupus erythematosus. Corticosteroids with or without immunosuppressive medication are the mainstay treatment in retinal vasculitis together with laser photocoagulation of retinal ischemic areas. Intravitreal injections of bevacizumab are used to treat neovascularization secondary to systemic lupus erythematosus but should be timed with retinal laser photocoagulation to prevent further progression of retinal ischemia. Antitumor necrosis factor agents have shown promising results in controlling refractory retinal vasculitis excluding multiple sclerosis. Interferon has been useful to control inflammation and induce neovascular regression in retinal vasculitis secondary to Behçet’s disease and multiple sclerosis. The long term effect of these management strategies in preventing the progression of retinal ischemia and preserving vision is not well understood and needs to be further studied.

  12. Short colon in a cat

    International Nuclear Information System (INIS)

    An 11-year-old male Japanese domestic cat was referred to the veterinary hospital with a chronic diarrhea and signs of pain and vocalization when defecating. The cat has discharged unformed feces throughout his life. Morphological diagnosis of short colon was made radiographically after barium enema. The ileocolic junction and cecum was located to the left of the midline at the proximal end of the descending colon. Additional endoscopic examination demonstrated the difference in visual structures of the mucosal surface and in histological structures on mucosal biopsy specimens, between the colon and ileum. This is the first report of short colon in a cat in Japan

  13. Long non-coding RNA MALAT1 regulates retinal neurodegeneration through CREB signaling.

    Science.gov (United States)

    Yao, Jin; Wang, Xiao-Qun; Li, Yu-Jie; Shan, Kun; Yang, Hong; Wang, Yang-Ning-Zhi; Yao, Mu-Di; Liu, Chang; Li, Xiu-Miao; Shen, Yi; Liu, Jing-Yu; Cheng, Hong; Yuan, Jun; Zhang, Yang-Yang; Jiang, Qin; Yan, Biao

    2016-01-01

    The nervous and vascular systems, although functionally different, share many common regulators of function maintenance. Long non-coding RNAs (lncRNAs) are important players in many biological processes and human disorders. We previously identified a role of MALAT1 in microvascular dysfunction. However, its role in neurodegeneration is still unknown. Here, we used the eye as the model to investigate the role of MALAT1 in retinal neurodegeneration. We show that MALAT1 expression is significantly up-regulated in the retinas, Müller cells, and primary retinal ganglion cells (RGCs) upon stress. MALAT1 knockdown reduces reactive gliosis, Müller cell activation, and RGC survival in vivo and in vitro MALAT1-CREB binding maintains CREB phosphorylation by inhibiting PP2A-mediated dephosphorylation, which leads to continuous CREB signaling activation. Clinical and animal experimentation suggests that MALAT1 dysfunction is implicated in neurodegenerative processes and several human disorders. Collectively, this study reveals that MALAT1 might regulate the development of retinal neurodegeneration through CREB signaling. PMID:26964565

  14. AAV-mediated Gene Therapy Halts Retinal Degeneration in PDE6β-deficient Dogs.

    Science.gov (United States)

    Pichard, Virginie; Provost, Nathalie; Mendes-Madeira, Alexandra; Libeau, Lyse; Hulin, Philippe; Tshilenge, Kizito-Tshitoko; Biget, Marine; Ameline, Baptiste; Deschamps, Jack-Yves; Weber, Michel; Le Meur, Guylène; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

    2016-05-01

    We previously reported that subretinal injection of AAV2/5 RK.cpde6β allowed long-term preservation of photoreceptor function and vision in the rod-cone dysplasia type 1 (rcd1) dog, a large animal model of naturally occurring PDE6β deficiency. The present study builds on these earlier findings to provide a detailed assessment of the long-term effects of gene therapy on the spatiotemporal pattern of retinal degeneration in rcd1 dogs treated at 20 days of age. We analyzed the density distribution of the retinal layers and of particular photoreceptor cells in 3.5-year-old treated and untreated rcd1 dogs. Whereas no rods were observed outside the bleb or in untreated eyes, gene transfer halted rod degeneration in all vector-exposed regions. Moreover, while gene therapy resulted in the preservation of cones, glial cells and both the inner nuclear and ganglion cell layers, no cells remained in vector-unexposed retinas, except in the visual streak. Finally, the retinal structure of treated 3.5-year-old rcd1 dogs was identical to that of unaffected 4-month-old rcd1 dogs, indicating near complete preservation. Our findings indicate that gene therapy arrests the degenerative process even if intervention is initiated after the onset of photoreceptor degeneration, and point to significant potential of this therapeutic approach in future clinical trials.

  15. Angiographic results of retinal-retinal anastomosis and retinal-choroidal anastomosis after treatments in eyes with retinal angiomatous proliferation

    Directory of Open Access Journals (Sweden)

    Saito M

    2012-08-01

    Full Text Available Masaaki Saito,1 Tomohiro Iida,1,2 Mariko Kano,1 Kanako Itagaki11Department of Ophthalmology, Fukushima Medical University School of Medicine, Fukushima, 2Department of Ophthalmology, Tokyo Women's Medical University School of Medicine, Tokyo, JapanBackground: The purpose of this study was to evaluate the angiographic results of retinal-retinal anastomosis (RRA and retinal-choroidal anastomosis (RCA for eyes with retinal angiomatous proliferation (RAP after treatment with intravitreal bevacizumab injections as monotherapy or intravitreal bevacizumab combined with photodynamic therapy.Methods: In this interventional, consecutive case series, we retrospectively reviewed five naïve eyes from four patients (mean age 80 years treated with three consecutive monthly intravitreal bevacizumab (1.25 mg/0.05 mL injections as initial treatment, and followed up for at least 3 months. In cases with over 3 months of follow-up and having recurrence of RAP or leakage by fluorescein angiography, retreatment was performed with a single intravitreal bevacizumab injection and photodynamic therapy.Results: Indocyanine green angiography showed RRA in three eyes with subretinal neovascularization and RCA in two eyes with choroidal neovascularization at baseline. At 3 months after baseline (month 3, neither the RRA nor RCA was occluded in any eye on indocyanine green angiography. Retreatment with intravitreal bevacizumab plus photodynamic therapy was performed in three eyes at months 3 (persistent leakage on fluorescein angiography, 6, and 7 (recurrence of RAP lesion, which achieved obvious occlusion of the RRA and RCA. Mean best-corrected visual acuity improved from 0.13 to 0.21 at month 3 (P = 0.066. No complications or systemic adverse events were noted.Conclusion: Although intravitreal bevacizumab for RAP was effective in improving visual acuity during short-term follow-up, intravitreal bevacizumab could not achieve complete occlusion of RRA and RCA, which could

  16. Fundamentals of ServCat

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This training manual for the U.S. Fish and Wildlife Service Catalog (ServCat) provides detailed instructions on searching for records, creating records, and...

  17. Seizures and epilepsy in cats

    OpenAIRE

    Moore SA

    2014-01-01

    Sarah A Moore Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, USA Abstract: Seizures are a common presenting complaint in cats, although causes and options for the treatment of seizures in this species have been historically poorly described in the veterinary literature. Seizure manifestation in cats may be different than what is typically seen in dogs, but the underlying causes of seizure activity are the same. These include primary epilepsies, structura...

  18. Food hypersensitivity in a cat.

    Science.gov (United States)

    Medleau, L; Latimer, K S; Duncan, J R

    1986-09-15

    Food hypersensitivity was diagnosed in a 4-year-old Siamese cat. Clinical signs included intense erythema, with alopecia, excoriations, erosions, and crusts involving the ventral portion of the abdomen, inguinal region, medial aspect of each thigh, and cranial and lateral aspects of all 4 limbs. The cat was intensely pruritic. Histologically, there was cutaneous mast cell hyperplasia and diffuse infiltration of eosinophils in the dermis. Blood eosinophilia also was found. Clinical signs resolved after exclusive feeding of a hypoallergenic diet.

  19. Properties of squeezed Schroedinger cats

    International Nuclear Information System (INIS)

    In this article we investigate some statistical properties of the even and odd squeezed (squeezed Schroedinger cat) states. The quasi-probability distribution functions especially W(α) and Q(α) are calculated and discussed for these states. The phase distribution function is discussed. A generation scheme is proposed for either the squeezed generalized Schroedinger cat, or the squeezed number state. (author). 35 refs, 5 figs

  20. Utility of MR imaging in cat-scratch neuroretinitis

    International Nuclear Information System (INIS)

    About 80% of cat-scratch disease (CSD) infections occur in children, and CSD neuroretinitis (optic neuropathy with retinal exudates in a ''macular star'' pattern) mostly occurs in children and young adults. A recent study suggested that CSD optic neuropathy has specific features on MR imaging. However, MR imaging findings in CSD neuroretinitis are not well described in the pediatric literature. We present a patient with CSD neuroretinitis in whom these specific MR imaging features preceded the macular star, a funduscopic finding strongly suggestive of neuroretinitis. This case demonstrates how knowledge of these features is important in the appropriate diagnostic work-up of optic neuropathy. MR imaging also incidentally revealed neuritis of another cranial nerve in the auditory canal - a rare manifestation of CSD. (orig.)

  1. [Progress of research in retinal image registration].

    Science.gov (United States)

    Yu, Lun; Wei, Lifang; Pan, Lin

    2011-10-01

    The retinal image registration has important applications in the processes of auxiliary diagnosis and treatment for a variety of diseases. The retinal image registration can be used to measure the disease process and the therapeutic effect. A variety of retinal image registration techniques have been studied extensively in recent years. However, there are still many problems existing and there are numerous research possibilities. Based on extensive investigation of existing literatures, the present paper analyzes the feature of retinal image and current challenges of retinal image registration, and reviews the transformation models of the retinal image registration technology and the main research algorithms in current retinal image registration, and analyzes the advantages and disadvantages of various types of algorithms. Some research challenges and future developing trends are also discussed.

  2. Echocardiographic Findings in 11 Cats with Acromegaly

    OpenAIRE

    Myers, J A; Lunn, K.F.; Bright, J.M.

    2014-01-01

    Background Information regarding cardiac changes in domestic cats with acromegaly is limited. Hypothesis/Objectives The objective of this study was to describe the echocardiographic findings in cats with acromegaly. Animals Eighteen cats diagnosed with acromegaly at Colorado State University between 2008 and 2012. Of these 18 cats, 11 had echocardiography performed. Methods A retrospective review of medical records was made to identify cats with acromegaly that also had echocardiography perfo...

  3. Schrodinger's cat: much ado about nothing

    CERN Document Server

    Ionicioiu, Radu

    2016-01-01

    In this note I briefly discuss the Schrodinger's cat Gedankenexperiment. By analysing the information flow in the system I show that no entanglement exists between the atom and the cat. The atom and the cat are connected only through a classical information channel (detector clicks $\\rightarrow$ poison is released $\\rightarrow$ cat is dead). No amount of local operations and classical communication can entangle the atom and the cat. Consequently, the paradox disappears.

  4. Cyclin D1 fine-tunes the neurogenic output of embryonic retinal progenitor cells

    Directory of Open Access Journals (Sweden)

    Choi Yoon

    2009-05-01

    Full Text Available Abstract Background Maintaining the correct balance of proliferation versus differentiation in retinal progenitor cells (RPCs is essential for proper development of the retina. The cell cycle regulator cyclin D1 is expressed in RPCs, and mice with a targeted null allele at the cyclin D1 locus (Ccnd1-/- have microphthalmia and hypocellular retinas, the latter phenotype attributed to reduced RPC proliferation and increased photoreceptor cell death during the postnatal period. How cyclin D1 influences RPC behavior, especially during the embryonic period, is unclear. Results In this study, we show that embryonic RPCs lacking cyclin D1 progress through the cell cycle at a slower rate and exit the cell cycle at a faster rate. Consistent with enhanced cell cycle exit, the relative proportions of cell types born in the embryonic period, such as retinal ganglion cells and photoreceptor cells, are increased. Unexpectedly, cyclin D1 deficiency decreases the proportions of other early born retinal neurons, namely horizontal cells and specific amacrine cell types. We also found that the laminar positioning of horizontal cells and other cell types is altered in the absence of cyclin D1. Genetically replacing cyclin D1 with cyclin D2 is not efficient at correcting the phenotypes due to the cyclin D1 deficiency, which suggests the D-cyclins are not fully redundant. Replacement with cyclin E or inactivation of cyclin-dependent kinase inhibitor p27Kip1 restores the balance of RPCs and retinal cell types to more normal distributions, which suggests that regulation of the retinoblastoma pathway is an important function for cyclin D1 during embryonic retinal development. Conclusion Our findings show that cyclin D1 has important roles in RPC cell cycle regulation and retinal histogenesis. The reduction in the RPC population due to a longer cell cycle time and to an enhanced rate of cell cycle exit are likely to be the primary factors driving retinal hypocellularity

  5. Retinal imaging and image analysis

    NARCIS (Netherlands)

    Abramoff, M.D.; Garvin, Mona K.; Sonka, Milan

    2010-01-01

    Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of blindne

  6. Sentinel Ganglions in Malignant Tumors of the Oral Cavity

    International Nuclear Information System (INIS)

    Full text: Objectives: The use of lymphoscintigraphy in order to show lymphatic invasion, for a better precision of the surgical act as well as for the delimitation of the volumes-target to settle the radio therapeutic treatment. Material And Method: A group of 20 patients (18 men and 2 women) diagnosed with malign tumors of the oral cavity with no clinical adenopathy (N0), investigated clinically and para clinically (laboratory examinations and lymphoscintigraphy associated with bone scintigraphy). The lymphoscintigraphy was performed by the pritumoral injection of 18.5MBq 99m Tc-Nanocoll in 4 points. Before the lymphoscintigraphy was performed each patient had been injected with 750MBq Medronat. The images were taken with a GE eNTEGRA 2.5202. system. Pre-operatory (20 min.) intra vital coloring was performed with metilen blue by peritumoral injection. The surgery addressed to the primary tumor was completed by a supraomohioidian cervical vacuuming. Results: The lymphoscintigraphy showed the lymphatic drain of the malign tumors in 95% of the cases. All malign tumors of the oral cavity drain in the latero-cervical lymphatic ganglions (bilateral), most frequently the sentinel ganglions being found at the level IIb (48%), followed by level III (32%), level I-a (16%) and others (4%).The identification of the lymphatic ganglions pre-operatory by inter vital coloration was of 90.62%. The morphology of the satellite lymphoganglions is closely related to the histological type and the degree of differentiation of the tumors. In the invasive forms the frequency of the nodal metastases varies with the clinical stage of the tumor. In a single case multiple bone metastases were found by scintigraphy fact that led to the change of therapeutic attitude. Conclusions: Lymphoscintigraphy is essential for the settling of the therapeutic attitude towards the malign tumors of the oral cavity, due to: - the early detection of the invaded lymphatic ganglions (83 sentinel ganglions found

  7. Infrared laser stimulation of retinal and vestibular neurons

    Science.gov (United States)

    Bardin, Fabrice; Bec, Jean-Michel; Albert, Emmanuelle S.; Hamel, Christian; Dupeyron, Gérard; Chabbert, Christian; Marc, Isabelle; Dumas, Michel

    2011-03-01

    The study of laser-neuron interaction has gained interest over the last few years not only for understanding of fundamental mechanisms but also for medical applications such as prosthesis because of the non-invasive characteristic of the laser stimulation. Several authors have shown that near infrared lasers are able to stimulate neurons. It is suggested that a thermal gradient induced by the absorption of the laser radiation on cells is the primary effect but the exact mechanism remains unclear. We show in this work that infrared laser radiations provide a possible way for stimulating retinal and vestibular ganglion cells. We describe relevant physical characteristics allowing safe and reproducible neuron stimulations by single infrared pulses. Calcium fluorescence imaging and electrophysiological recordings have been used to measure ionic exchanges at the neuron membrane. The stimulation system is based on a pulsed laser diode beam of a few mW. Effects of three different wavelengths (from 1470 to 1875 nm) and stimulation durations have been investigated. Variations of the stimulation energy thresholds suggest that the main physical parameter is the water optical absorption. Measurements of the temperature at the cell membrane show that a constant temperature rise is required to stimulate neurons, suggesting a photothermal process.

  8. Reported cat bites in Dallas: characteristics of the cats, the victims, and the attack events.

    OpenAIRE

    Wright, J C

    1990-01-01

    Associated with the increased popularity of cats as pets in American households has been an increase in the number of cat bites reported to health departments. Bite reports from Dallas, TX, for 1985 were analyzed for different aspects of the cat bite event, including characteristics of the cats, the people bitten, the wounds, and the attack events. Cat bites and scratches constituted 25 percent of the 2,494 reported animal bites. Biting cats were typically stray females. People 21 to 35 years...

  9. Cat Ownership Perception and Caretaking Explored in an Internet Survey of People Associated with Cats.

    Directory of Open Access Journals (Sweden)

    Sarah Zito

    Full Text Available People who feed cats that they do not perceive they own (sometimes called semi-owners are thought to make a considerable contribution to unwanted cat numbers because the cats they support are generally not sterilized. Understanding people's perception of cat ownership and the psychology underlying cat semi-ownership could inform approaches to mitigate the negative effects of cat semi-ownership. The primary aims of this study were to investigate cat ownership perception and to examine its association with human-cat interactions and caretaking behaviours. A secondary aim was to evaluate a definition of cat semi-ownership (including an association time of ≥1 month and frequent feeding, revised from a previous definition proposed in the literature to distinguish cat semi-ownership from casual interactions with unowned cats. Cat owners and semi-owners displayed similar types of interactions and caretaking behaviours. Nevertheless, caretaking behaviours were more commonly displayed towards owned cats than semi-owned cats, and semi-owned cats were more likely to have produced kittens (p<0.01. All interactions and caretaking behaviours were more likely to be displayed towards cats in semi-ownership relationships compared to casual interaction relationships. Determinants of cat ownership perception were identified (p<0.05 and included association time, attachment, perceived cat friendliness and health, and feelings about unowned cats, including the acceptability of feeding unowned cats. Encouraging semi-owners to have the cats they care for sterilized may assist in reducing the number of unwanted kittens and could be a valuable alternative to trying to prevent semi-ownership entirely. Highly accessible semi-owner "gatekeepers" could help to deliver education messages and facilitate the provision of cat sterilization services to semi-owners. This research enabled semi-ownership to be distinguished from casual interaction relationships and can assist

  10. Melanopsin-expressing ganglion cells on macaque and human retinas form two morphologically distinct populations.

    Science.gov (United States)

    Liao, Hsi-Wen; Ren, Xiaozhi; Peterson, Beth B; Marshak, David W; Yau, King-Wai; Gamlin, Paul D; Dacey, Dennis M

    2016-10-01

    The long-term goal of this research is to understand how retinal ganglion cells that express the photopigment melanopsin, also known as OPN4, contribute to vision in humans and other primates. Here we report the results of anatomical studies using our polyclonal antibody specifically against human melanopsin that confirm and extend previous descriptions of melanopsin cells in primates. In macaque and human retina, two distinct populations of melanopsin cells were identified based on dendritic stratification in either the inner or the outer portion of the inner plexiform layer (IPL). Variation in dendritic field size and cell density with eccentricity was confirmed, and dendritic spines, a new feature of melanopsin cells, were described. The spines were the sites of input from DB6 diffuse bipolar cell axon terminals to the inner stratifying type of melanopsin cells. The outer stratifying melanopsin type received inputs from DB6 bipolar cells via a sparse outer axonal arbor. Outer stratifying melanopsin cells also received inputs from axon terminals of dopaminergic amacrine cells. On the outer stratifying melanopsin cells, ribbon synapses from bipolar cells and conventional synapses from amacrine cells were identified in electron microscopic immunolabeling experiments. Both inner and outer stratifying melanopsin cell types were retrogradely labeled following tracer injection in the lateral geniculate nucleus (LGN). In addition, a method for targeting melanopsin cells for intracellular injection using their intrinsic fluorescence was developed. This technique was used to demonstrate that melanopsin cells were tracer coupled to amacrine cells and would be applicable to electrophysiological experiments in the future. J. Comp. Neurol. 524:2845-2872, 2016. © 2016 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26972791

  11. Rac1 selective activation improves retina ganglion cell survival and regeneration.

    Directory of Open Access Journals (Sweden)

    Erika Lorenzetto

    Full Text Available In adult mammals, after optic nerve injury, retinal ganglion cells (RGCs do not regenerate their axons and most of them die by apoptosis within a few days. Recently, several strategies that activate neuronal intracellular pathways were proposed to prevent such degenerative processes. The rho-related small GTPase Rac1 is part of a complex, still not fully understood, intracellular signaling network, mediating in neurons many effects, including axon growth and cell survival. However, its role in neuronal survival and regeneration in vivo has not yet been properly investigated. To address this point we intravitreally injected selective cell-penetrating Rac1 mutants after optic nerve crush and studied the effect on RGC survival and axonal regeneration. We injected two well-characterized L61 constitutively active Tat-Rac1 fusion protein mutants, in which a second F37A or Y40C mutation confers selectivity in downstream signaling pathways. Results showed that, 15 days after crush, both mutants were able to improve survival and to prevent dendrite degeneration, while the one harboring the F37A mutation also improved axonal regeneration. The treatment with F37A mutant for one month did not improve the axonal elongation respect to 15 days. Furthermore, we found an increase of Pak1 T212 phosphorylation and ERK1/2 expression in RGCs after F37A treatment, whereas ERK1/2 was more activated in glial cells after Y40C administration. Our data suggest that the selective activation of distinct Rac1-dependent pathways could represent a therapeutic strategy to counteract neuronal degenerative processes in the retina.

  12. Exogenous BDNF rescues rat spiral ganglion neurons in vivo

    OpenAIRE

    Sarah L. McGuinness; Shepherd, Robert K.

    2005-01-01

    The loss of hair cells resulting in a sensorineural hearing loss (SNHL) also leads to the secondary degeneration of spiral ganglion neurons (SGNs). The effectiveness of cochlear implantation in patients with a profound SNHL relies, in part, upon the survival of SGNs; therefore any therapy that can prevent or halt the loss of these neurons would be of potential clinical benefit. Previous research has shown that intracochlear infusion with neurotrophins can provide trophic support to SGNs in de...

  13. Characteristics of sodium currents in rat geniculate ganglion neurons

    OpenAIRE

    NAKAMURA, SHIRO; Bradley, Robert M.

    2011-01-01

    Geniculate ganglion (GG) cell bodies of chorda tympani (CT), greater superficial petrosal (GSP), and posterior auricular (PA) nerves transmit orofacial sensory information to the rostral nucleus of the solitary tract. We have used whole cell recording to investigate the characteristics of the Na+ channels in isolated Fluorogold-labeled GG neurons that innervate different peripheral receptive fields. GG neurons expressed two classes of Na+ channels, TTX sensitive (TTX-S) and TTX resistant (TTX...

  14. Retinal vasculature classification using novel multifractal features

    International Nuclear Information System (INIS)

    Retinal blood vessels have been implicated in a large number of diseases including diabetic retinopathy and cardiovascular diseases, which cause damages to retinal blood vessels. The availability of retinal vessel imaging provides an excellent opportunity for monitoring and diagnosis of retinal diseases, and automatic analysis of retinal vessels will help with the processes. However, state of the art vascular analysis methods such as counting the number of branches or measuring the curvature and diameter of individual vessels are unsuitable for the microvasculature. There has been published research using fractal analysis to calculate fractal dimensions of retinal blood vessels, but so far there has been no systematic research extracting discriminant features from retinal vessels for classifications. This paper introduces new methods for feature extraction from multifractal spectra of retinal vessels for classification. Two publicly available retinal vascular image databases are used for the experiments, and the proposed methods have produced accuracies of 85.5% and 77% for classification of healthy and diabetic retinal vasculatures. Experiments show that classification with multiple fractal features produces better rates compared with methods using a single fractal dimension value. In addition to this, experiments also show that classification accuracy can be affected by the accuracy of vessel segmentation algorithms. (paper)

  15. Cytomegalovirus retinitis associated with acquired immunodeficiency syndrome

    Institute of Scientific and Technical Information of China (English)

    GENG Shuang; YE Jun-jie; ZHAO Jia-liang; LI Tai-sheng; HAN Yang

    2011-01-01

    Background Cytomegalovirus (CMV) retinitis is the most severe intraocular complication that results in total retinal destruction and loss of visual acuity in patients with acquired immunodeficiency syndrome (AIDS). This study aimed to investigate the fundus characteristics, systemic manifestations and therapeutic outcomes of CMV retinitis associated with AIDS.Methods It was a retrospective case series. CMV retinitis was present in 39 eyes (25 patients). Best corrected visual acuities, anterior segment, fundus features, fundus fluorescence angiography (FFA) and CD4+ T-lymphocyte counts of the patients with CMV retinitis associated with AIDS were analyzed. Intravitreal injections of ganciclovir (400 μg) were performed in 4 eyes (2 patients).Results Retinal vasculitis, dense, full-thickness, yellow-white lesions along vascular distribution with irregular granules at the border, and hemorrhage on the retinal surface were present in 28 eyes. The vitreous was clear or mildly opaque.Late stage of the retinopathy was demonstrated in 8 eyes characterized as atrophic retina, sclerotic and attenuated vessels, retinal pigment epithelium (RPE) atrophy, and optic nerve atrophy. Retinal detachment was found in 3 eyes. The average CD4+ T-lymphocyte count in peripheral blood of the patients with CMV retinitis was (30.6±25.3) ×106/L (range,(0-85) × 106/L). After intravitreal injections of ganciclovir, visual acuity was improved and fundus lesions regressed.Conclusions CMV retinitis is the most severe and the most common intraocular complication in patients with AIDS. For the patients with yellow-white retinal lesions, hemorrhage and retinal vasculitis without clear cause, human immunodeficiency virus (HIV) serology should be performed. Routine eye examination is also indicated in HIV positive patients.

  16. Activation of autophagy in a rat model of retinal ischemia following high intraocular pressure.

    Directory of Open Access Journals (Sweden)

    Antonio Piras

    Full Text Available Acute primary open angle glaucoma is an optic neuropathy characterized by the elevation of intraocular pressure, which causes retinal ischemia and neuronal death. Rat ischemia/reperfusion enhances endocytosis of both horseradish peroxidase (HRP or fluorescent dextran into ganglion cell layer (GCL neurons 24 h after the insult. We investigated the activation of autophagy in GCL-neurons following ischemia/reperfusion, using acid phosphatase (AP histochemistry and immunofluorescence against LC3 and LAMP1. Retinal I/R lead to the appearance of AP-positive granules and LAMP1-positive vesicles 12 and 24 h after the insult, and LC3 labelling at 24 h, and induced a consistent retinal neuron death. At 48 h the retina was negative for autophagic markers. In addition, Western Blot analysis revealed an increase of LC3 levels after damage: the increase in the conjugated, LC3-II isoform is suggestive of autophagic activity. Inhibition of autophagy by 3-methyladenine partially prevented death of neurons and reduces apoptotic markers, 24 h post-lesion. The number of neurons in the GCL decreased significantly following I/R (I/R 12.21±1.13 vs controls 19.23±1.12 cells/500 µm; this decrease was partially prevented by 3-methyladenine (17.08±1.42 cells/500 µm, which potently inhibits maturation of autophagosomes. Treatment also prevented the increase in glial fibrillary acid protein immunoreactivity elicited by I/R. Therefore, targeting autophagy could represent a novel and promising treatment for glaucoma and retinal ischemia.

  17. A novel retinal oscillation mechanism in an autosomal dominant photoreceptor degeneration mouse model

    Directory of Open Access Journals (Sweden)

    Hung-Ya eTu

    2016-01-01

    Full Text Available It has been shown in rd1 and rd10 models of photoreceptor degeneration (PD that inner retinal neurons display spontaneous and rhythmic activities. Furthermore, the rhythmic activity has been shown to require the gap junction protein connexin 36, which is likely located in AII amacrine cells (AII-ACs. In the present study, an autosomal dominant PD model called rhoΔCTA, whose rods overexpress a C-terminally truncated mutant rhodopsin and degenerate with a rate similar to that of rd1, was used to investigate the generality and mechanisms of heightened inner retinal activity following PD. To fluorescently identify cholinergic starburst amacrine cells (SACs, the rhoΔCTA mouse was introduced into a combined ChAT-IRES-Cre and Ai9 background. In this mouse, we observed large amplitude excitatory postsynaptic currents (EPSCs oscillations and non-rhythmic inhibitory postsynaptic currents (IPSCs in both ON- and OFF-SACs. The IPSCs were more noticeable in OFF- than in ON-SACs. Similar to reported retinal ganglion cell (RGC oscillation in rd1 mice, EPSC oscillation was synaptically driven by glutamate and sensitive to blockade of NaV channels and gap junctions. These data suggest that akin to rd1 mice, AII-AC is a prominent oscillator in rhoΔCTA mice. Surprisingly, OFF-SAC but not ON-SAC EPSC oscillation could readily be enhanced by GABAergic blockade. More importantly, weakening the AII-AC gap junction network by activating retinal dopamine receptors abolished oscillations in ON-SACs but not in OFF-SACs. Furthermore, the latter persisted in the presence of flupirtine, an M-type potassium channel activator recently reported to dampen intrinsic AII-AC bursting. These data suggest the existence of a novel oscillation mechanism in mice with PD.

  18. A Novel Retinal Oscillation Mechanism in an Autosomal Dominant Photoreceptor Degeneration Mouse Model.

    Science.gov (United States)

    Tu, Hung-Ya; Chen, Yu-Jiun; McQuiston, Adam R; Chiao, Chuan-Chin; Chen, Ching-Kang

    2015-01-01

    It has been shown in rd1 and rd10 models of photoreceptor degeneration (PD) that inner retinal neurons display spontaneous and rhythmic activities. Furthermore, the rhythmic activity has been shown to require the gap junction protein connexin 36, which is likely located in AII amacrine cells (AII-ACs). In the present study, an autosomal dominant PD model called rhoΔCTA, whose rods overexpress a C-terminally truncated mutant rhodopsin and degenerate with a rate similar to that of rd1, was used to investigate the generality and mechanisms of heightened inner retinal activity following PD. To fluorescently identify cholinergic starburst amacrine cells (SACs), the rhoΔCTA mouse was introduced into a combined ChAT-IRES-Cre and Ai9 background. In this mouse, we observed excitatory postsynaptic current (EPSC) oscillation and non-rhythmic inhibitory postsynaptic current (IPSC) in both ON- and OFF-SACs. The IPSCs were more noticeable in OFF- than in ON-SACs. Similar to reported retinal ganglion cell (RGC) oscillation in rd1 mice, EPSC oscillation was synaptically driven by glutamate and sensitive to blockade of NaV channels and gap junctions. These data suggest that akin to rd1 mice, AII-AC is a prominent oscillator in rhoΔCTA mice. Surprisingly, OFF-SAC but not ON-SAC EPSC oscillation could readily be enhanced by GABAergic blockade. More importantly, weakening the AII-AC gap junction network by activating retinal dopamine receptors abolished oscillations in ON-SACs but not in OFF-SACs. Furthermore, the latter persisted in the presence of flupirtine, an M-type potassium channel activator recently reported to dampen intrinsic AII-AC bursting. These data suggest the existence of a novel oscillation mechanism in mice with PD. PMID:26793064

  19. Diabetes and overexpression of proNGF cause retinal neurodegeneration via activation of RhoA pathway.

    Directory of Open Access Journals (Sweden)

    Mohammed M H Al-Gayyar

    Full Text Available Our previous studies showed positive correlation between accumulation of proNGF, activation of RhoA and neuronal death in diabetic models. Here, we examined the neuroprotective effects of selective inhibition of RhoA kinase in the diabetic rat retina and in a model that stably overexpressed the cleavage-resistance proNGF plasmid in the retina. Male Sprague-Dawley rats were rendered diabetic using streptozotocin or stably express cleavage-resistant proNGF plasmid. The neuroprotective effects of the intravitreal injection of RhoA kinase inhibitor Y27632 were examined in vivo. Effects of proNGF were examined in freshly isolated primary retinal ganglion cell (RGC cultures and RGC-5 cell line. Retinal neurodegeneration was assessed by counting TUNEL-positive and Brn-3a positive retinal ganglion cells. Expression of proNGF, p75(NTR, cleaved-PARP, caspase-3 and p38MAPK/JNK were examined by Western-blot. Activation of RhoA was assessed by pull-down assay and G-LISA. Diabetes and overexpression of proNGF resulted in retinal neurodegeneration as indicated by 9- and 6-fold increase in TUNEL-positive cells, respectively. In vitro, proNGF induced 5-fold cell death in RGC-5 cell line, and it induced >10-fold cell death in primary RGC cultures. These effects were associated with significant upregulation of p75(NTR and activation of RhoA. While proNGF induced TNF-α expression in vivo, it selectively activated RhoA in primary RGC cultures and RGC-5 cell line. Inhibiting RhoA kinase with Y27632 significantly reduced diabetes- and proNGF-induced activation of proapoptotic p38MAPK/JNK, expression of cleaved-PARP and caspase-3 and prevented retinal neurodegeneration in vivo and in vitro. Taken together, these results provide compelling evidence for a causal role of proNGF in diabetes-induced retinal neurodegeneration through enhancing p75(NTR expression and direct activation of RhoA and p38MAPK/JNK apoptotic pathways.

  20. Reliability of retinal vessel calibre measurements using a retinal oximeter

    OpenAIRE

    Heitmar, Rebekka; Kalitzeos, Angelos A.

    2015-01-01

    Background Summarised retinal vessel diameters are linked to systemic vascular pathology. Monochromatic images provide best contrast to measure vessel calibres. However, when obtaining images with a dual wavelength oximeter the red-free image can be extracted as the green channel information only which in turn will reduce the number of photographs taken at a given time. This will reduce patient exposure to the camera flash and could provide sufficient quality images to reliably measure vessel...

  1. Automatic diagnosis of retinal diseases from color retinal images

    OpenAIRE

    Jayanthi, D.; N. Devi; SwarnaParvathi, S.

    2010-01-01

    Teleophthalmology holds a great potential to improve the quality, access, and affordability in health care. For patients, it can reduce the need for travel and provide the access to a superspecialist. Ophthalmology lends itself easily to telemedicine as it is a largely image based diagnosis. The main goal of the proposed system is to diagnose the type of disease in the retina and to automatically detect and segment retinal diseases without human supervision or interaction. The proposed system...

  2. Energy requirements of adult cats.

    Science.gov (United States)

    Bermingham, Emma N; Thomas, David G; Morris, Penelope J; Hawthorne, Amanda J

    2010-04-01

    A meta-analysis was carried out in order to establish the energy requirements of adult cats. Publications that identified cat body weight (BW) were used to generate allometric relationships between energy requirements and BW of healthy adult cats, using log-log linear regression. Energy requirements were expressed in kcal/kg BW to be consistent with those reported by the National Research Council. Mean maintenance energy requirements were 55.1 (se 1.2) kcal/kg BW (115 treatment groups). Three allometric equations were identified to predict the energy requirements for maintenance of BW in the cat based on BW: light (53.7 kcal/kg BW- 1.061), normal (46.8 kcal/kg BW- 1.115) and heavy (131.8 kcal/kg BW- 0 .366). When reported on lean mass, the allometric equation revealed maintenance requirements were 58.4 kcal/kg lean mass- 1.140 (adjusted R2 0.694; thirty-six treatment groups). The present review suggests that values for maintenance energy requirements based on BW alone may not be an accurate prediction and more detailed information on the age, sex and neuter status, BW and composition would enhance the ability to interpret the maintenance energy requirements of cats.

  3. Role of retinal metabolism in methanol-induced retinal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Garner, C.D. [General Motors Corp., Warren, MI (United States)]|[Wayne State Univ., Detroit, MI (United States); Lee, E.W.; Terzo, T.S. [General Motors Corp., Warren, MI (United States); Louis-Ferdinand, R.T. [Wayne State Univ., Detroit, MI (United States)

    1995-08-01

    Methanol is a toxicant that causes systemic and ocular toxicity after acute exposure. The folate-reduced (FR) rat is an excellent animal model that mimics characteristic human methanol toxic responses. The present study examines the role of the methanol metabolites formaldehyde and formate in the initiation of methanol-induced retinal toxicity. After a single oral dose of 3.0 g/kg methanol, blood methanol concentrations were not significantly different in FR rats compared with folate-sufficient (FS) (control) rats. However, FR rats treated with 3.0 g/kg methanol displayed elevated blood (14.6 mM) and vitreous humor (19.5 mM) formate levels and abnormal electroretinograms (loss of b-wave) 48 h postdose. FR rats pretreated with disulfiram (DSF) prior to 3.0 g/kg methanol treatment failed to display these symptoms. Formaldehyde was not detected in blood or vitreous humor with or without DSF treatment, suggesting that formate is the toxic metabolite in methanol-induced retinal toxicity. Additionally, creating a blood formate profile (14.2 mM at 48 h) similar to that observed in methanol-treated rats by iv infusion of pH-buffered formate does not alter the electroretinogram as is observed with methanol treatment. These data suggest that intraretinal metabolism of methanol is necessary for the formate-mediated initiation of methanol-induced retinal toxicity. 31 refs., 5 figs., 2 tabs.

  4. Synergistic protective effects of escin and low‑dose glucocorticoids on blood‑retinal barrier breakdown in a rat model of retinal ischemia.

    Science.gov (United States)

    Zhang, Fenglan; Li, Yuanbin; Zhang, Leiming; Mu, Guoying

    2013-05-01

    Escin, a natural mixture of triterpenoid saponins isolated from the seed of the horse chestnut (Aesculus hippocastanum), has been demonstrated to possess glucocorticoid (GC)‑like anti‑edematous and anti‑inflammatory effects. The aim of the present study was to investigate whether escin exhibits synergistic protective effects on blood‑retinal barrier (BRB) breakdown when combined with GCs in a rat model of retinal ischemia. Low concentrations of escin and triamcinolone acetonide (TA) alone did not affect BRB permeability. However, when administered together, low‑dose escin and TA significantly reduced BRB permeability following ischemia. Furthermore, low‑dose escin and TA alone did not affect the expression of occludin in the ischemic retina; however, when administered together, they significantly increased occludin expression in the ganglion cell layer of the ischemic retina. This indicates that escin and GCs have synergistic protective effects on BRB breakdown and the molecular mechanisms may be correlated with the upregulation of occludin. Therefore, the administration of escin may allow a reduction in the dose of GCs for the treatment of macular edema. The combination of escin with GCs is potentially a beneficial treatment method for BRB breakdown and warrants further investigation. PMID:23525122

  5. Wavefront sensorless adaptive optics fluorescence biomicroscope for in vivo retinal imaging in mice.

    Science.gov (United States)

    Wahl, Daniel J; Jian, Yifan; Bonora, Stefano; Zawadzki, Robert J; Sarunic, Marinko V

    2016-01-01

    Cellular-resolution in vivo fluorescence imaging is a valuable tool for longitudinal studies of retinal function in vision research. Wavefront sensorless adaptive optics (WSAO) is a developing technology that enables high-resolution imaging of the mouse retina. In place of the conventional method of using a Shack-Hartmann wavefront sensor to measure the aberrations directly, WSAO uses an image quality metric and a search algorithm to drive the shape of the adaptive element (i.e. deformable mirror). WSAO is a robust approach to AO and it is compatible with a compact, low-cost lens-based system. In this report, we demonstrated a hill-climbing algorithm for WSAO with a variable focus lens and deformable mirror for non-invasive in vivo imaging of EGFP (enhanced green fluorescent protein) labelled ganglion cells and microglia cells in the mouse retina.

  6. Wavefront sensorless adaptive optics fluorescence biomicroscope for in vivo retinal imaging in mice.

    Science.gov (United States)

    Wahl, Daniel J; Jian, Yifan; Bonora, Stefano; Zawadzki, Robert J; Sarunic, Marinko V

    2016-01-01

    Cellular-resolution in vivo fluorescence imaging is a valuable tool for longitudinal studies of retinal function in vision research. Wavefront sensorless adaptive optics (WSAO) is a developing technology that enables high-resolution imaging of the mouse retina. In place of the conventional method of using a Shack-Hartmann wavefront sensor to measure the aberrations directly, WSAO uses an image quality metric and a search algorithm to drive the shape of the adaptive element (i.e. deformable mirror). WSAO is a robust approach to AO and it is compatible with a compact, low-cost lens-based system. In this report, we demonstrated a hill-climbing algorithm for WSAO with a variable focus lens and deformable mirror for non-invasive in vivo imaging of EGFP (enhanced green fluorescent protein) labelled ganglion cells and microglia cells in the mouse retina. PMID:26819812

  7. Retinal Image Preprocessing: Background and Noise Segmentation

    Directory of Open Access Journals (Sweden)

    Usman Akram

    2012-07-01

    Full Text Available Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse segmentation and fine segmentation. Standard retinal images databases Diaretdb0, Diaretdb1, DRIVE and STARE are used to test the validation of our preprocessing technique. The experimental results show the validity of proposed preprocessing technique.

  8. Current perspectives of herpesviral retinitis and choroiditis.

    Science.gov (United States)

    Madhavan, H N; Priya, K; Biswas, J

    2004-10-01

    Vision-threatening viral retinitis are primarily caused by members of the herpesvirus family. The biology and molecular characterization of herpesviruses, clinical presentations of retinopathies, pathology and pathogenesis including the host responses, epidemiology and the laboratory methods of aetiological diagnosis of these diseases are described. Clinical syndromes are acute retinal necrosis (ARN), progressive outer retinal necrosis (PORN), cytomegalovirus (CMV) retinitis, multifocal choroiditis and serpiginous choroiditis besides other viral retinopathies. Herpes simplex virus (HSV) retinitis is more common in immunocompetent persons while varicella zoster virus (VZV) affects both immunocompetent and immunosuppressed patients equally. CMV retinitis is most common among patients with AIDS. The currently employed laboratory methods of antigen detection, virus isolation and antibody detection by enzyme linked immuno-sorbent assay (ELISA) have low sensitivity. Polymerase chain reaction (PCR) has increased the value of diagnosis due to its high clinical sensitivity and absolute specificity in detection of herpesviruses in intraocular specimens. PMID:16295367

  9. Advances in Retinal Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    Andrea S Viczian

    2013-01-01

    Full Text Available Tremendous progress has been made in recent years to generate retinal cells from pluripotent cell sources. These advances provide hope for those suffering from blindness due to lost retinal cells. Understanding the intrinsic genetic network in model organisms, like fly and frog, has led to a better understanding of the extrinsic signaling pathways necessary for retinal progenitor cell formation in mouse and human cell cultures. This review focuses on the culture methods used by different groups, which has culminated in the generation of laminated retinal tissue from both embryonic and induced pluripotent cells. The review also briefly describes advances made in transplantation studies using donor retinal progenitor and cultured retinal cells.

  10. On Schr\\"odinger's cat

    CERN Document Server

    de Silva, Nalin

    2010-01-01

    Schr\\"odinger's cat appears to have been harassed in a chamber during the past eighty years or so by interpreting the role of the observer as a person, who sets an experiment and then observes results, may be after some time. The realist position tells us that the physical processes would take place independent of the observer with well defined properties, whereas the positivist position wants us to believe that nothing can be said of a system when it is not being observed. In this paper we question both these positions and also the assumption that the atom and the cat are entangled and further whether the atom could be considered to be in a state of decay and not decay. We let the cat either out of the bag (chamber) or rest in peace with or without the atom or the observer.

  11. Spectrophotometric retinal oximetry in pigs

    DEFF Research Database (Denmark)

    Traustason, Sindri; Kiilgaard, Jens Folke; Karlsson, Robert;

    2013-01-01

    PURPOSE: To assess the validity of spectrophotometric retinal oximetry, by comparison to blood gas analysis and intra-vitreal measurements of partial pressure of oxygen (pO2). METHODS: Female domestic pigs were used for all experiments (n=8). Oxygen fraction in inspired air was changed using......, Reykjavik, Iceland). The device simultaneously acquires images at two wavelengths (570 nm and 600 nm) and specialized software automatically detects retinal blood vessels. In three pigs, invasive pO2-measurements were performed after the initial non-invasive measurements. RESULTS: Comparison of femoral......-measurements in three pigs. This relationship was approximately linear (R(2) = 0.45, p = 0.04). CONCLUSIONS: Non-invasive spectrophotometric oximetry is sensitive to changes in oxygen saturation in pigs and correlated with intravitreal pO2-measurements and with femoral artery pO2. Pigs present a higher intra...

  12. Retinal vein occlusion: current treatment.

    Science.gov (United States)

    Lattanzio, Rosangela; Torres Gimeno, Ana; Battaglia Parodi, Maurizio; Bandello, Francesco

    2011-01-01

    Retinal vein occlusion (RVO) is a pathology noted for more than 150 years. Although a lot has been written on the matter, it is still a frequent condition with multifactorial etiopathogenesis with many unclear aspects. The RVO pathogenesis has varied systemic and local implications that make it difficult to elaborate treatment guidelines. The management of the patient with RVO is very complex and a multidisciplinary approach is required in order to identify and correct the associated risk factors. Laser therapy remains the gold standard in RVO, but only modest functional improvement has been shown in branch retinal occlusion forms. Multicenter studies of intravitreal drugs present them as an option to combine with laser. Anti-vascular endothelial growth factor, corticosteroids and sustained-release implants are the future weapons to stop disease progression and get a better visual outcome. Consequently, it is useful to clarify some aspects of the pathology that allow a better patient management. PMID:20938213

  13. Cat Ownership Perception and Caretaking Explored in an Internet Survey of People Associated with Cats.

    Science.gov (United States)

    Zito, Sarah; Vankan, Dianne; Bennett, Pauleen; Paterson, Mandy; Phillips, Clive J C

    2015-01-01

    People who feed cats that they do not perceive they own (sometimes called semi-owners) are thought to make a considerable contribution to unwanted cat numbers because the cats they support are generally not sterilized. Understanding people's perception of cat ownership and the psychology underlying cat semi-ownership could inform approaches to mitigate the negative effects of cat semi-ownership. The primary aims of this study were to investigate cat ownership perception and to examine its association with human-cat interactions and caretaking behaviours. A secondary aim was to evaluate a definition of cat semi-ownership (including an association time of ≥1 month and frequent feeding), revised from a previous definition proposed in the literature to distinguish cat semi-ownership from casual interactions with unowned cats. Cat owners and semi-owners displayed similar types of interactions and caretaking behaviours. Nevertheless, caretaking behaviours were more commonly displayed towards owned cats than semi-owned cats, and semi-owned cats were more likely to have produced kittens (pcats in semi-ownership relationships compared to casual interaction relationships. Determinants of cat ownership perception were identified (pcat friendliness and health, and feelings about unowned cats, including the acceptability of feeding unowned cats. Encouraging semi-owners to have the cats they care for sterilized may assist in reducing the number of unwanted kittens and could be a valuable alternative to trying to prevent semi-ownership entirely. Highly accessible semi-owner "gatekeepers" could help to deliver education messages and facilitate the provision of cat sterilization services to semi-owners. This research enabled semi-ownership to be distinguished from casual interaction relationships and can assist welfare and government agencies to identify cat semi-owners in order to develop strategies to address this source of unwanted cats. PMID:26218243

  14. Cytomegalovirus retinitis mimicking intraocular lymphoma

    OpenAIRE

    Gooi, Patrick

    2008-01-01

    Patrick Gooi1, James Farmer2, Bernard Hurley3, Elliott Brodbaker41Department of Ophthalmology, University of Calgary, Calgary, Alberta, Canada; 2Department of Pathology and Lab Medicine University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada; 3Department of Ophthalmology, University of Ottawa Eye Institute and The Ottawa Hospital, Ottawa, Ontario, Canada; 4Faculty of Medicine, University of Ottawa, Ottawa, Ontario, CanadaAbstract: We present a case of an unusual retinal infiltra...

  15. Retinal Vascular Fractals and Cognitive Impairment

    OpenAIRE

    Ong, Yi-Ting; Hilal, Saima; Cheung, Carol Yim-Lui; Xu, Xin; Chen, Christopher; Venketasubramanian, Narayanaswamy; Wong, Tien Yin; Ikram, Mohammad Kamran

    2014-01-01

    Background Retinal microvascular network changes have been found in patients with age-related brain diseases such as stroke and dementia including Alzheimer's disease. We examine whether retinal microvascular network changes are also present in preclinical stages of dementia. Methods This is a cross-sectional study of 300 Chinese participants (age: ≥60 years) from the ongoing Epidemiology of Dementia in Singapore study who underwent detailed clinical examinations including retinal photography...

  16. Retinal Vascular Fractals and Cognitive Impairment

    OpenAIRE

    Yi-Ting Ong; Saima Hilal; Carol Yim-lui Cheung; Xin Xu; Christopher Chen; Narayanaswamy Venketasubramanian; Tien Yin Wong; Mohammad Kamran Ikram

    2014-01-01

    Background: Retinal microvascular network changes have been found in patients with age-related brain diseases such as stroke and dementia including Alzheimer's disease. We examine whether retinal microvascular network changes are also present in preclinical stages of dementia. Methods: This is a cross-sectional study of 300 Chinese participants (age: ≥60 years) from the ongoing Epidemiology of Dementia in Singapore study who underwent detailed clinical examinations including retinal photograp...

  17. The morphology, topography and cytoarchitectonics of the ciliary ganglion in the domestic turkey (Meleagris gallopavo domesticus).

    Science.gov (United States)

    Radzimirska, Małgorzata

    2003-11-01

    The ciliary ganglion of the domestic turkey (Meleagris gallopavo domesticus) is located between the posterior wall of the eyeball and the optic nerve. It is closely connected with the oculomotor nerve; in particular with its inferior branch. The ganglion has a cask-like shape and is adjacent to the inferior branch of the oculomotor nerve. From this ganglion postganglionic fibres emerge which are arranged in two fasciculi. These are termed the long ciliary nerves and the short ciliary nerves. A cross-section of the ciliary ganglion revealed two populations of cells: small ones - choroid cells and large ones - ciliary cells.

  18. Large Ganglion Cyst with Unusual Location on the Back-A Case Report

    DEFF Research Database (Denmark)

    Schoellhammer, Liv; Nielsen, Thomas Wagner; Berg, Jais Oliver

    2016-01-01

    A ganglion cyst is a soft tissue tumor-like lesion filled with colloid material commonly located on the hand and wrist. We report a case of a large ganglion cyst with an unusual location on the back. The patient presented with a mass growing over 2 months measuring 11.2 × 4.7 × 7.2 cm on magnetic...... resonance imaging. Ultrasound and puncture was attempted twice without achieving drainage. After surgical removal, histologic examination diagnosed the tumor as a ganglion cyst. We conclude that when evaluating a subcutaneous soft tissue mass, regardless of localization, a ganglion cyst may...

  19. Retinal Macroglial Responses in Health and Disease

    Directory of Open Access Journals (Sweden)

    Rosa de Hoz

    2016-01-01

    Full Text Available Due to their permanent and close proximity to neurons, glial cells perform essential tasks for the normal physiology of the retina. Astrocytes and Müller cells (retinal macroglia provide physical support to neurons and supplement them with several metabolites and growth factors. Macroglia are involved in maintaining the homeostasis of extracellular ions and neurotransmitters, are essential for information processing in neural circuits, participate in retinal glucose metabolism and in removing metabolic waste products, regulate local blood flow, induce the blood-retinal barrier (BRB, play fundamental roles in local immune response, and protect neurons from oxidative damage. In response to polyetiological insults, glia cells react with a process called reactive gliosis, seeking to maintain retinal homeostasis. When malfunctioning, macroglial cells can become primary pathogenic elements. A reactive gliosis has been described in different retinal pathologies, including age-related macular degeneration (AMD, diabetes, glaucoma, retinal detachment, or retinitis pigmentosa. A better understanding of the dual, neuroprotective, or cytotoxic effect of macroglial involvement in retinal pathologies would help in treating the physiopathology of these diseases. The extensive participation of the macroglia in retinal diseases points to these cells as innovative targets for new drug therapies.

  20. Hop/STI1 modulates retinal proliferation and cell death independent of PrPC

    International Nuclear Information System (INIS)

    Hop/STI1 is a co-chaperone adaptor protein for Hsp70/Hsp90 complexes. Hop/STI1 is found extracellularly and modulates cell death and differentiation through interaction with the prion protein (PrPC). Here, we investigated the expression of hop/STI1 and its role upon cell proliferation and cell death in the developing retina. Hop/STI1 is more expressed in developing rat retina than in the mature tissue. Hop/STI1 blocks retinal cell death in the neuroblastic layer (NBL) in a PrPC dependent manner, but failed to protect ganglion cells against axotomy-induced cell death. An antibody raised against hop/STI1 (α-STI1) blocked both ganglion cell and NBL cell death independent of PrPC. cAMP/PKA, ERK, PI3K and PKC signaling pathways were not involved in these effects. Hop/STI1 treatment reduced proliferation, while α-STI1 increased proliferation in the developing retina, both independent of PrPC. We conclude that hop/STI1 can modulate both proliferation and cell death in the developing retina independent of PrPC