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Sample records for cat retinal ganglion

  1. Adaptation and dynamics of cat retinal ganglion cells.

    Science.gov (United States)

    Enroth-Cugell, C; Shapley, R M

    1973-09-01

    1. The impulse/quantum (I/Q) ratio was measured as a function of background illumination for rod-dominated, pure central, linear square-wave responses of retinal ganglion cells in the cat.2. The I/Q ratio was constant at low backgrounds (dark adapted state) and inversely proportional to the 0.9 power of the background at high backgrounds (the light adapted state). There was an abrupt transition from the dark-adapted state to the light-adapted state.3. It was possible to define the adaptation level at a particular background as the ratio (I/Q ratio at that background)/(dark adapted I/Q ratio).4. The time course of the square-wave response was correlated with the adaptation level. The response was sustained in the dark-adapted state, partially transient at the transition level, and progressively more transient the lower the impulse/quantum ratio of the ganglion cell became. This was true both for on-centre and off-centre cells.5. The frequency response of the central response mechanism at different adaptation levels was measured. It was a low-pass characteristic in the dark-adapted state and became progressively more of a bandpass characteristic as the cell became more light-adapted.6. The rapidity of onset of adaptation was measured with a time-varying adapting light. The impulse/quantum ratio is reset within 100 msec of the onset of the conditioning light, and is kept at the new value throughout the time the conditioning light is on.7. These results can be explained by a nonlinear feedback model. In the model, it is postulated that the exponential function of the horizontal cell potential controls transmission from rods to bipolars. This model has an abrupt transition from dark- to light-adapted states, and its response dynamics are correlated with adaptation level. PMID:4747229

  2. Morphology of Retinal Ganglion Cells in the Ferret (Mustela putorius furo)

    OpenAIRE

    ISAYAMA, TOMOKI; O’Brien, Brendan J.; Ugalde, Irma; Muller, Jay F.; Frenz, Aaron; Aurora, Vikas; Tsiaras, William; Berson, David M.

    2009-01-01

    The ferret is the premiere mammalian model of retinal and visual system development, but the spectrum and properties of its retinal ganglion cells are less well understood than in another member of the Carnivora, the domestic cat. Here, we have extensively surveyed the dendritic architecture of ferret ganglion cells and report that the classification scheme previously developed for cat ganglion cells can be applied with few modifications to the ferret retina.

  3. 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.

  4. Topography of ganglion cell production in the cat's retina

    International Nuclear Information System (INIS)

    The ganglion cells of the cat's retina form several classes distinguishable in terms of soma size, axon diameter, dendritic morphology, physiological properties, and central connections. Labeling with [3H]thymidine shows that the ganglion cells which survive in the adult are produced as several temporally shifted, overlapping waves: medium-sized cells are produced before large cells, whereas the smallest ganglion cells are produced throughout the period of ganglion cell generation. Large cells and medium-sized cells show the same distinctive pattern of production, forming rough spirals around the area centralis. The oldest cells tend to lie superior and nasal to the area centralis, whereas cells in the inferior nasal retina and inferior temporal retina are, in general, progressively younger. Within each retinal quadrant, cells nearer the area centralis tend to be older than cells in the periphery, but there is substantial overlap. The retinal raphe divides the superior temporal quadrant into two zones with different patterns of cell addition. Superior temporal retina near the vertical meridian adds cells only slightly later than superior nasal retina, whereas superior temporal retina near the horizontal meridian adds cells very late, contemporaneously with inferior temporal retina. The broader wave of production of smaller ganglion cells seems to follow this same spiral pattern at its beginning and end. The presence of the area centralis as a nodal point about which ganglion cell production in the retinal quadrants pivots suggests that the area centralis is already an important retinal landmark even at the earliest stages of retinal development

  5. Changes in ganglion cells during retinal degeneration.

    Science.gov (United States)

    Saha, Susmita; Greferath, Ursula; Vessey, Kirstan A; Grayden, David B; Burkitt, Anthony N; Fletcher, Erica L

    2016-08-01

    Inherited retinal degeneration such as retinitis pigmentosa (RP) is associated with photoreceptor loss and concomitant morphological and functional changes in the inner retina. It is not known whether these changes are associated with changes in the density and distribution of synaptic inputs to retinal ganglion cells (RGCs). We quantified changes in ganglion cell density in rd1 and age-matched C57BL/6J-(wildtype, WT) mice using the immunocytochemical marker, RBPMS. Our data revealed that following complete loss of photoreceptors, (∼3months of age), there was a reduction in ganglion cell density in the peripheral retina. We next examined changes in synaptic inputs to A type ganglion cells by performing double labeling experiments in mice with the ganglion cell reporter lines, rd1-Thy1 and age-matched wildtype-Thy1. Ribbon synapses were identified by co-labelling with CtBP2 (RIBEYE) and conventional synapses with the clustering molecule, gephyrin. ON RGCs showed a significant reduction in RIBEYE-immunoreactive synapse density while OFF RGCs showed a significant reduction in the gephyrin-immmunoreactive synapse density. Distribution patterns of both synaptic markers across the dendritic trees of RGCs were unchanged. The change in synaptic inputs to RGCs was associated with a reduction in the number of immunolabeled rod bipolar and ON cone bipolar cells. These results suggest that functional changes reported in ganglion cells during retinal degeneration could be attributed to loss of synaptic inputs. PMID:27132232

  6. 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

  7. 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...

  8. Advances in retinal ganglion cell imaging.

    Science.gov (United States)

    Balendra, S I; Normando, E M; Bloom, P A; Cordeiro, M F

    2015-10-01

    Glaucoma is one of the leading causes of blindness worldwide and will affect 79.6 million people worldwide by 2020. It is caused by the progressive loss of retinal ganglion cells (RGCs), predominantly via apoptosis, within the retinal nerve fibre layer and the corresponding loss of axons of the optic nerve head. One of its most devastating features is its late diagnosis and the resulting irreversible visual loss that is often predictable. Current diagnostic tools require significant RGC or functional visual field loss before the threshold for detection of glaucoma may be reached. To propel the efficacy of therapeutics in glaucoma, an earlier diagnostic tool is required. Recent advances in retinal imaging, including optical coherence tomography, confocal scanning laser ophthalmoscopy, and adaptive optics, have propelled both glaucoma research and clinical diagnostics and therapeutics. However, an ideal imaging technique to diagnose and monitor glaucoma would image RGCs non-invasively with high specificity and sensitivity in vivo. It may confirm the presence of healthy RGCs, such as in transgenic models or retrograde labelling, or detect subtle changes in the number of unhealthy or apoptotic RGCs, such as detection of apoptosing retinal cells (DARC). Although many of these advances have not yet been introduced to the clinical arena, their successes in animal studies are enthralling. This review will illustrate the challenges of imaging RGCs, the main retinal imaging modalities, the in vivo techniques to augment these as specific RGC-imaging tools and their potential for translation to the glaucoma clinic. PMID:26293138

  9. Polymodal Sensory Integration in Retinal Ganglion Cells.

    Science.gov (United States)

    Križaj, David

    2016-01-01

    An animal's ability to perceive the external world is conditioned by its capacity to extract and encode specific features of the visual image. The output of the vertebrate retina is not a simple representation of the 2D visual map generated by photon absorptions in the photoreceptor layer. Rather, spatial, temporal, direction selectivity and color "dimensions" of the original image are distributed in the form of parallel output channels mediated by distinct retinal ganglion cell (RGC) populations. We propose that visual information transmitted to the brain includes additional, light-independent, inputs that reflect the functional states of the retina, anterior eye and the body. These may include the local ion microenvironment, glial metabolism and systemic parameters such as intraocular pressure, temperature and immune activation which act on ion channels that are intrinsic to RGCs. We particularly focus on light-independent mechanical inputs that are associated with physical impact, cell swelling and intraocular pressure as excessive mechanical stimuli lead to the counterintuitive experience of "pressure phosphenes" and/or debilitating blinding disease such as glaucoma and diabetic retinopathy. We point at recently discovered retinal mechanosensitive ion channels as examples through which molecular physiology brings together Greek phenomenology, modern neuroscience and medicine. Thus, RGC output represents a unified picture of the embodied context within which vision takes place. PMID:26427477

  10. Retinal Ganglion Cell Dendritic Atrophy in DBA/2J Glaucoma

    OpenAIRE

    Williams, Pete A.; Howell, Gareth R.; Barbay, Jessica M.; Braine, Catherine E.; Sousa, Gregory L.; John, Simon W. M.; Morgan, James E.

    2013-01-01

    Glaucoma is a complex disease affecting an estimated 70 million people worldwide, characterised by the progressive degeneration of retinal ganglion cells and accompanying visual field loss. The common site of damage to retinal ganglion cells is thought to be at the optic nerve head, however evidence from other optic neuropathies and neurodegenerative disorders suggests that dendritic structures undergo a prolonged period of atrophy that may accompany or even precede soma loss and neuronal cel...

  11. 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...

  12. Melanopsin Ganglion Cells Are the Most Resistant Retinal Ganglion Cell Type to Axonal Injury in the Rat Retina

    OpenAIRE

    Pérez de Sevilla Müller, Luis; SARGOY, ALLISON; Rodriguez, Allen R.; Brecha, Nicholas C.

    2014-01-01

    We report that the most common retinal ganglion cell type that remains after optic nerve transection is the M1 melanopsin ganglion cell. M1 ganglion cells are members of the intrinsically photosensitive retinal ganglion cell population that mediates non-image-forming vision, comprising ∼2.5% of all ganglion cells in the rat retina. In the present study, M1 ganglion cells comprised 1.7±1%, 28±14%, 55±13% and 82±8% of the surviving ganglion cells 7, 14, 21 and 60 days after optic nerve transect...

  13. The retinal ganglion cell classes of New World primates.

    Science.gov (United States)

    Yamada, E S; Silveira, L C; Gomes, F L; Lee, B B

    1996-12-01

    In the primate retina there are distinct ganglion cell classes, exhibiting particular morphologies and central projections, each responsible for conveying particular types of visual information to the brain. The chief retinal inputs to the cortex arise from specific ganglion cell classes, M-ganglion cells, responsible for carrying the luminance signal, and P-ganglion cells, that convey the red-green color opponent signal, as well as high contrast luminance signal. There are other ganglion cell classes, such as small-field bistratified cells, exhibiting dendrites that stratify at two different levels in the inner plexiform layer, which convey the blue-yellow color opponent signal. Most published data concerning primate retinal ganglion cell anatomy and physiology have been obtained from Old World species. Studies on New World monkeys have recently become of interest since they differ from the Old World monkeys with respect to the color vision inheritance pattern. On reviewing retinal ganglion cell layer organization in New World monkeys, it seems that there are more similarities than differences in relation to the Old World monkeys. Diurnal genera of New World monkeys exhibit a well-developed fovea centralis and ganglion cell density peak, as well as peripheral density values which are in the range reported for Old World monkeys and human. Moreover, all the major ganglion cell classes identified in Old World monkeys are also present in New World primates. Up to now, no obvious anatomical differences between dichromats and trichromats have been reported. The only genus that is significantly different from the others is the Aotus. It exhibits lower ganglion cell density in the central retina, and apparently lacks the small-field bistratified cells. PMID:9394516

  14. Directional summation in non-direction selective retinal ganglion cells.

    Directory of Open Access Journals (Sweden)

    Syed Y Abbas

    Full Text Available Retinal ganglion cells receive inputs from multiple bipolar cells which must be integrated before a decision to fire is made. Theoretical studies have provided clues about how this integration is accomplished but have not directly determined the rules regulating summation of closely timed inputs along single or multiple dendrites. Here we have examined dendritic summation of multiple inputs along On ganglion cell dendrites in whole mount rat retina. We activated inputs at targeted locations by uncaging glutamate sequentially to generate apparent motion along On ganglion cell dendrites in whole mount retina. Summation was directional and dependent13 on input sequence. Input moving away from the soma (centrifugal resulted in supralinear summation, while activation sequences moving toward the soma (centripetal were linear. Enhanced summation for centrifugal activation was robust as it was also observed in cultured retinal ganglion cells. This directional summation was dependent on hyperpolarization activated cyclic nucleotide-gated (HCN channels as blockade with ZD7288 eliminated directionality. A computational model confirms that activation of HCN channels can override a preference for centripetal summation expected from cell anatomy. This type of direction selectivity could play a role in coding movement similar to the axial selectivity seen in locust ganglion cells which detect looming stimuli. More generally, these results suggest that non-directional retinal ganglion cells can discriminate between input sequences independent of the retina network.

  15. Directional summation in non-direction selective retinal ganglion cells.

    Science.gov (United States)

    Abbas, Syed Y; Hamade, Khaldoun C; Yang, Ellen J; Nawy, Scott; Smith, Robert G; Pettit, Diana L

    2013-01-01

    Retinal ganglion cells receive inputs from multiple bipolar cells which must be integrated before a decision to fire is made. Theoretical studies have provided clues about how this integration is accomplished but have not directly determined the rules regulating summation of closely timed inputs along single or multiple dendrites. Here we have examined dendritic summation of multiple inputs along On ganglion cell dendrites in whole mount rat retina. We activated inputs at targeted locations by uncaging glutamate sequentially to generate apparent motion along On ganglion cell dendrites in whole mount retina. Summation was directional and dependent13 on input sequence. Input moving away from the soma (centrifugal) resulted in supralinear summation, while activation sequences moving toward the soma (centripetal) were linear. Enhanced summation for centrifugal activation was robust as it was also observed in cultured retinal ganglion cells. This directional summation was dependent on hyperpolarization activated cyclic nucleotide-gated (HCN) channels as blockade with ZD7288 eliminated directionality. A computational model confirms that activation of HCN channels can override a preference for centripetal summation expected from cell anatomy. This type of direction selectivity could play a role in coding movement similar to the axial selectivity seen in locust ganglion cells which detect looming stimuli. More generally, these results suggest that non-directional retinal ganglion cells can discriminate between input sequences independent of the retina network. PMID:23516351

  16. 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

  17. Dorsal raphe nucleus projecting retinal ganglion cells: Why Y cells?

    Science.gov (United States)

    Pickard, Gary E; So, Kwok-Fai; Pu, Mingliang

    2015-10-01

    Retinal ganglion Y (alpha) cells are found in retinas ranging from frogs to mice to primates. The highly conserved nature of the large, fast conducting retinal Y cell is a testament to its fundamental task, although precisely what this task is remained ill-defined. The recent discovery that Y-alpha retinal ganglion cells send axon collaterals to the serotonergic dorsal raphe nucleus (DRN) in addition to the lateral geniculate nucleus (LGN), medial interlaminar nucleus (MIN), pretectum and the superior colliculus (SC) has offered new insights into the important survival tasks performed by these cells with highly branched axons. We propose that in addition to its role in visual perception, the Y-alpha retinal ganglion cell provides concurrent signals via axon collaterals to the DRN, the major source of serotonergic afferents to the forebrain, to dramatically inhibit 5-HT activity during orientation or alerting/escape responses, which dis-facilitates ongoing tonic motor activity while dis-inhibiting sensory information processing throughout the visual system. The new data provide a fresh view of these evolutionarily old retinal ganglion cells. PMID:26363667

  18. 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)

  19. 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.

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

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik; Broendsted, Adam Elias; Kessel, Line; Hansen, Michael Stormly; Kawasaki, Aki

    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...

  1. 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

  2. Hypoxia-ischemia and retinal ganglion cell damage

    Directory of Open Access Journals (Sweden)

    Charanjit Kaur

    2008-08-01

    Full Text Available Charanjit Kaur1, Wallace S Foulds2, Eng-Ang Ling11Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore Eye Research Institute, SingaporeAbstract: Retinal hypoxia is the potentially blinding mechanism underlying a number of sight-threatening disorders including central retinal artery occlusion, ischemic central retinal vein thrombosis, complications of diabetic eye disease and some types of glaucoma. Hypoxia is implicated in loss of retinal ganglion cells (RGCs occurring in such conditions. RGC death occurs by apoptosis or necrosis. Hypoxia-ischemia induces the expression of hypoxia inducible factor-1α and its target genes such as vascular endothelial growth factor (VEGF and nitric oxide synthase (NOS. Increased production of VEGF results in disruption of the blood retinal barrier leading to retinal edema. Enhanced expression of NOS results in increased production of nitric oxide which may be toxic to the cells resulting in their death. Excess glutamate release in hypoxic-ischemic conditions causes excitotoxic damage to the RGCs through activation of ionotropic and metabotropic glutamate receptors. Activation of glutamate receptors is thought to initiate damage in the retina by a cascade of biochemical effects such as neuronal NOS activation and increase in intracellular Ca2+ which has been described as a major contributing factor to RGC loss. Excess production of proinflammatory cytokines also mediates cell damage. Besides the above, free-radicals generated in hypoxic-ischemic conditions result in RGC loss because of an imbalance between antioxidant- and oxidant-generating systems. Although many advances have been made in understanding the mediators and mechanisms of injury, strategies to improve the damage are lacking. Measures to prevent neuronal injury have to be developed.Keywords: retinal hypoxia, retinal ganglion cells, glutamate receptors, neuronal injury, retina

  3. 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.

  4. Origin of correlated activity between parasol retinal ganglion cells

    OpenAIRE

    Khuc-Trong, Philipp; Rieke, Fred

    2008-01-01

    Cells throughout the central nervous system exhibit synchronous activity patterns - i.e. a cell’s probability of generating an action potential depends both on its firing rate and on the occurrence of action potentials in surrounding cells. The mechanisms producing synchronous or correlated activity are poorly understood despite its prevalence and potential impact on neural coding. We find that neighboring parasol retinal ganglion cells receive strongly correlated synaptic input in the absenc...

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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

  10. Astrocyte Reactivity: A Biomarker for Retinal Ganglion Cell Health in Retinal Neurodegeneration

    OpenAIRE

    Formichella, Cathryn R; Abella, Simone K; Sims, Stephanie M; Cathcart, Heather M; Sappington, Rebecca M.

    2014-01-01

    Retinal ganglion cell (RGC) loss in glaucoma is sectorial in nature and preceded by deficits in axonal transport. Neuroinflammation plays an important role in the pathophysiology of glaucoma in the retina, optic nerve and visual centers of the brain, where it similarly appears to be regulated spatially. In a murine model, we examined the spatial characteristics of astrocyte reactivity (migration/proliferation, hypertrophy and GFAP expression) in healthy retina, retina with two glaucoma-relate...

  11. 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...

  12. 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.

  13. 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 ...

  14. An open-source computational tool to automatically quantify immunolabeled retinal ganglion cells.

    Science.gov (United States)

    Dordea, Ana C; Bray, Mark-Anthony; Allen, Kaitlin; Logan, David J; Fei, Fei; Malhotra, Rajeev; Gregory, Meredith S; Carpenter, Anne E; Buys, Emmanuel S

    2016-06-01

    A fully automated and robust method was developed to quantify β-III-tubulin-stained retinal ganglion cells, combining computational recognition of individual cells by CellProfiler and a machine-learning tool to teach phenotypic classification of the retinal ganglion cells by CellProfiler Analyst. In animal models of glaucoma, quantification of immunolabeled retinal ganglion cells is currently performed manually and remains time-consuming. Using this automated method, quantifications of retinal ganglion cell images were accelerated tenfold: 1800 images were counted in 3 h using our automated method, while manual counting of the same images took 72 h. This new method was validated in an established murine model of microbead-induced optic neuropathy. The use of the publicly available software and the method's user-friendly design allows this technique to be easily implemented in any laboratory. PMID:27119563

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

    DEFF Research Database (Denmark)

    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 pituitary adenylate cyclase-activating polypeptide (PACAP...

  16. 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

  17. 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

  18. Inner Nuclear Layer Thickening Is Inversley Proportional to Retinal Ganglion Cell Loss in Optic Neuritis

    OpenAIRE

    Kaushik, Megha; Wang, Chen Yu; Barnett, Michael H; Garrick, Raymond; Parratt, John; GRAHAM, STUART L.; Sriram, Prema; Yiannikas, Con; Klistorner, Alexandr

    2013-01-01

    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 v...

  19. An Optic Nerve Crush Injury Murine Model to Study Retinal Ganglion Cell Survival

    OpenAIRE

    Tang, Zhongshu; Zhang, Shuihua; Lee, Chunsik; Kumar, Anil; Arjunan, Pachiappan; LI Yang; Zhang, Fan; Li, Xuri

    2011-01-01

    Injury to the optic nerve can lead to axonal degeneration, followed by a gradual death of retinal ganglion cells (RGCs), which results in irreversible vision loss. Examples of such diseases in human include traumatic optic neuropathy and optic nerve degeneration in glaucoma. It is characterized by typical changes in the optic nerve head, progressive optic nerve degeneration, and loss of retinal ganglion cells, if uncontrolled, leading to vision loss and blindness.

  20. 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.

  1. 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.

  2. 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...

  3. Tetrandrine protects mouse retinal ganglion cells from ischemic injury

    Directory of Open Access Journals (Sweden)

    Li WY

    2014-03-01

    Full Text Available Weiyi Li,1,2 Chen Yang,2 Jing Lu,2 Ping Huang,1 Colin J Barnstable,2 Chun Zhang,1 Samuel S Zhang2,3 1Department of Ophthalmology, Peking University Third Hospital, Peking University Eye Center, Beijing, People's Republic of China; 2Department of Neural and Behavioral Sciences, Penn State University, Hershey, PA, USA; 3Singapore Eye Research Institute, Singapore National Eye Centre, Singapore Abstract: This study aimed to determine the protective effects of tetrandrine (Tet on murine ischemia-injured retinal ganglion cells (RGCs. For this, we used serum deprivation cell model, glutamate and hydrogen peroxide (H2O2-induced RGC-5 cell death models, and staurosporine-differentiated neuron-like RGC-5 in vitro. We also investigated cell survival of purified primary-cultured RGCs treated with Tet. An in vivo retinal ischemia/reperfusion model was used to examine RGC survival after Tet administration 1 day before ischemia. We found that Tet affected RGC-5 survival in a dose- and time-dependent manner. Compared to dimethyl sulfoxide treatment, Tet increased the numbers of RGC-5 cells by 30% at 72 hours. After 48 hours, Tet protected staurosporine-induced RGC-5 cells from serum deprivation-induced cell death and significantly increased the relative number of cells cultured with 1 mM H2O2 (P<0.01. Several concentrations of Tet significantly prevented 25-mM-glutamate-induced cell death in a dose-dependent manner. Tet also increased primary RGC survival after 72 and 96 hours. Tet administration (10 µM, 2 µL 1 day before retinal ischemia showed RGC layer loss (greater survival, which was less than those in groups with phosphate-buffered saline intravitreal injection plus ischemia in the central (P=0.005, n=6, middle (P=0.018, n=6, and peripheral (P=0.017, n=6 parts of the retina. Thus, Tet conferred protective effects on serum deprivation models of staurosporine-differentiated neuron-like RGC-5 cells and primary cultured murine RGCs. Furthermore, Tet showed

  4. Retinal ganglion cells are autonomous circadian oscillators synthesizing N-acetylserotonin during the day.

    Science.gov (United States)

    Garbarino-Pico, Eduardo; Carpentieri, Agata R; Contin, Maria A; Sarmiento, María I Keller; Brocco, Marcela A; Panzetta, Pedro; Rosenstein, Ruth E; Caputto, Beatriz L; Guido, Mario E

    2004-12-01

    Retinal ganglion cells send visual and circadian information to the brain regarding the environmental light-dark cycles. We investigated the capability of retinal ganglion cells of synthesizing melatonin, a highly reliable circadian marker that regulates retinal physiology, as well as the capacity of these cells to function as autonomous circadian oscillators. Chick retinal ganglion cells presented higher levels of melatonin assessed by radioimmunoassay during both the subjective day in constant darkness and the light phase of a light-dark cycle. Similar changes were observed in mRNA levels and activity of arylalkylamine N-acetyltransferase, a key enzyme in melatonin biosynthesis, with the highest levels of both parameters during the subjective day. These daily variations were preceded by the elevation of cyclic-AMP content, the second messenger involved in the regulation of melatonin biosynthesis. Moreover, cultures of immunopurified retinal ganglion cells at embryonic day 8 synchronized by medium exchange synthesized a [3H]melatonin-like indole from [3H]tryptophan. This [3H]indole was rapidly released to the culture medium and exhibited a daily variation, with levels peaking 8 h after synchronization, which declined a few hours later. Cultures of embryonic retinal ganglion cells also showed self-sustained daily rhythms in arylalkylamine N-acetyltransferase mRNA expression during at least three cycles with a period near 24 h. These rhythms were also observed after the application of glutamate. The results demonstrate that chick retinal ganglion cells may function as autonomous circadian oscillators synthesizing a melatonin-like indole during the day. PMID:15448149

  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.; Hannibal, Jens; Munarini, A; Mantovani, V; Bardoni, P; Cantalupo, G; Tozer, K.R.; Sancisi, E; Salomao, S.R.; Moraes, M.N.; Moraes-Filho, M.N.; Heegaard, Steffen; Milea, Dan; Kjer, Poul; Montagna, P; Carelli, V

    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...... ganglion cells containing the photopigment melanopsin. These cells give origin to the retinohypothalamic tract and support the non-image-forming visual functions of the eye, which include the photoentrainment of circadian rhythms, light-induced suppression of melatonin secretion and pupillary light reflex...... 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 with...

  6. 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.

  7. 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

  8. 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.

  9. Mitochondrial Uncoupling Protein 2 (UCP2) Regulates Retinal Ganglion Cell Number and Survival.

    Science.gov (United States)

    Barnstable, Colin J; Reddy, Rajini; Li, Hong; Horvath, Tamas L

    2016-04-01

    In the brain, mitochondrial uncoupling protein 2 (UCP2) has emerged as a stress signal associated with neuronal survival. In the retina, UCP2 is expressed primarily by retinal ganglion cells. Here, we investigated the functional relevance of UCP2 in the mouse retina. Increased expression of UCP2 significantly reduced apoptosis during the critical developmental period resulting in elevated numbers of retinal ganglion cells in the adult. Elevated UCP2 levels also protected against excitotoxic cell death induced by intraocular injection of either NMDA or kainic acid. In monolayer cultures of retinal cells, elevated UCP2 levels increased cell survival and rendered the cells independent of the survival-promoting effects of the neurotrophic factors BDNF and CNTF. Taken together, these data implicate UCP2 as an important regulator of retinal neuron survival both during development and in adult animals. PMID:26846222

  10. 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...

  11. A dedicated circuit linking direction selective retinal ganglion cells to primary visual cortex

    OpenAIRE

    Cruz-Martín, Alberto; El-Danaf, Rana N.; Osakada, Fumitaka; Sriram, Balaji; Dhande, Onkar S.; Nguyen, Phong L.; Callaway, Edward M.; Ghosh, Anirvan; Huberman, Andrew D.

    2014-01-01

    How specific features in the environment are represented within the brain is an important unanswered question in neuroscience. A subset of retinal neurons, called direction selective ganglion cells (DSGCs) are specialized for detecting motion along specific axes of the visual field 1 . Despite extensive study of the retinal circuitry that endows DSGCs with their unique tuning properties 2,3 , their downstream circuitry in the brain and thus their contribution to visual processing has remained...

  12. Uptake of Retrograde Tracers by Intact Optic Nerve Axons: A New Way to Label Retinal Ganglion Cells

    OpenAIRE

    Liang, Yu-Xiang; Yang, Jian; Yuan, Ti-Fei; So, Kwok-Fai

    2015-01-01

    Retrograde labelling of retinal ganglion cells with optic nerve transection often leads to degeneration of ganglion cells in prolonged experiments. Here we report that an intact optic nerve could uptake retrograde tracers applied onto the surface of the nerve, leading to high efficiency labelling of ganglion cells in the retina with long-term survival of cells. This method labelled a similar number of ganglion cells (2289±174 at 2 days) as the retrograde labeling technique from the superior c...

  13. 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.

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

    International Nuclear Information System (INIS)

    Complex stimuli are used to probe the response properties of the chicken's retinal ganglion cells (GCs). The correlation 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. (general)

  15. Hypoxia-ischemia and retinal ganglion cell damage

    OpenAIRE

    Charanjit Kaur; Foulds, Wallace S.; Eng-Ang Ling

    2008-01-01

    Charanjit Kaur1, Wallace S Foulds2, Eng-Ang Ling11Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore Eye Research Institute, SingaporeAbstract: Retinal hypoxia is the potentially blinding mechanism underlying a number of sight-threatening disorders including central retinal artery occlusion, ischemic central retinal vein thrombosis, complications of diabetic eye disease and some types of glaucoma. Hypoxia is implicated in loss of re...

  16. 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.

  17. Msx2 alters the timing of retinal ganglion cells fate commitment and differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shao-Yun, E-mail: jiangshaoyun@yahoo.com [School of Dentistry, Tianjin Medical University, 12 Qi Xiang Tai Street, Tianjin 300070 (China); Wang, Jian-Tao, E-mail: wangjiantao65@hotmail.com [Eye Center, Tianjin Medical University, 64 Tongan Road, Tianjin 300070 (China); Dohney Eye Institute, Keck School of Medicine, University of Southern California, 1355 San Pablo Street, DOH 314, Los Angeles, CA 90033 (United States)

    2010-05-14

    Timing of cell fate commitment determines distinct retinal cell types, which is believed to be controlled by a tightly coordinated regulatory program of proliferation, cell cycle exit and differentiation. Although homeobox protein Msx2 could induce apoptosis of optic vesicle, it is unclear whether Msx2 regulates differentiation and cell fate commitment of retinal progenitor cells (RPCs) to retinal ganglion cells (RGCs). In this study, we show that overexpression of Msx2 transiently suppressed the expression of Cyclin D1 and blocked cell proliferation. Meanwhile, overexpression of Msx2 delayed the expression of RGC-specific differentiation markers (Math5 and Brn3b), which showed that Msx2 could affect the timing of RGCs fate commitment and differentiation by delaying the timing of cell cycle exit of retinal progenitors. These results indicate Msx2 possesses dual regulatory functions in controlling cell cycle progression of retinal RPCs and timing of RGCs differentiation.

  18. Msx2 alters the timing of retinal ganglion cells fate commitment and differentiation

    International Nuclear Information System (INIS)

    Timing of cell fate commitment determines distinct retinal cell types, which is believed to be controlled by a tightly coordinated regulatory program of proliferation, cell cycle exit and differentiation. Although homeobox protein Msx2 could induce apoptosis of optic vesicle, it is unclear whether Msx2 regulates differentiation and cell fate commitment of retinal progenitor cells (RPCs) to retinal ganglion cells (RGCs). In this study, we show that overexpression of Msx2 transiently suppressed the expression of Cyclin D1 and blocked cell proliferation. Meanwhile, overexpression of Msx2 delayed the expression of RGC-specific differentiation markers (Math5 and Brn3b), which showed that Msx2 could affect the timing of RGCs fate commitment and differentiation by delaying the timing of cell cycle exit of retinal progenitors. These results indicate Msx2 possesses dual regulatory functions in controlling cell cycle progression of retinal RPCs and timing of RGCs differentiation.

  19. 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-...

  20. Ocular anatomy, ganglion cell distribution and retinal resolution of a killer whale (Orcinus orca).

    Science.gov (United States)

    Mass, Alla M; Supin, Alexander Y; Abramov, Andrey V; Mukhametov, Lev M; Rozanova, Elena I

    2013-01-01

    Retinal topography, cell density and sizes of ganglion cells in the killer whale (Orcinus orca) were analyzed in retinal whole mounts stained with cresyl violet. A distinctive feature of the killer whale's retina is the large size of ganglion cells and low cell density compared to terrestrial mammals. The ganglion cell diameter ranged from 8 to 100 µm, with the majority of cells within a range of 20-40 µm. The topographic distribution of ganglion cells displayed two spots of high cell density located in the temporal and nasal quadrants, 20 mm from the optic disk. The high-density areas were connected by a horizontal belt-like area passing below the optic disk of the retina. Peak cell densities in these areas were evaluated. Mean peak cell densities were 334 and 288 cells/mm(2) in the temporal and nasal high-density areas, respectively. With a posterior nodal distance of 19.5 mm, these high-density data predict a retinal resolution of 9.6' (3.1 cycles/deg.) and 12.6' (2.4 cycles/deg.) in the temporal and nasal areas, respectively, in water. PMID:23018493

  1. 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.

  2. 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.

  3. 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.

  4. The neuroprotective effect of resveratrol on retinal ganglion cells after optic nerve transection

    OpenAIRE

    Kim, Seok Hwan; Park, Joo Hyun; Kim, Yu Jeong; Park, Ki Ho

    2013-01-01

    Purpose This study aimed to investigate the neuroprotective effect of resveratrol in an optic nerve transection (ONT) model and to identify the neuroprotective mechanism of resveratrol in retinal ganglion cells (RGCs). Methods ONT and retrograde labeling were performed in Sprague-Dawley rats. Various concentrations of resveratrol were injected intravitreally immediately after ONT. The number of labeled RGCs was determined at 1 and 2 weeks after ONT. The effect of resveratrol and sirtinol (a s...

  5. Xenopus laevis retinal ganglion cell dendritic arbors develop independently of visual stimulation

    OpenAIRE

    Barbara Lom; Rebecca L. Rigel

    2004-01-01

    Newly formed neurons must locate their appropriate target cells and then form synaptic connections with these targets in order to establish a functional nervous system. In the vertebrate retina, retinal ganglion cell (RGC) dendrites extend from the cell body and form synapses with nearby amacrine and bipolar cells. RGC axons, however, exit the retina and synapse with the dendrites of midbrain neurons in the optic tectum. We examined how visual stimulation influenced Xenopus RGC dendritic arbo...

  6. Teneurin-3 Specifies Morphological and Functional Connectivity of Retinal Ganglion Cells in the Vertebrate Visual System

    OpenAIRE

    Paride Antinucci; Nikolas Nikolaou; Martin P. Meyer; Robert Hindges

    2013-01-01

    Summary A striking feature of the CNS is the precise wiring of its neuronal connections. During vertebrate visual system development, different subtypes of retinal ganglion cells (RGCs) form specific connections with their corresponding synaptic partners. However, the underlying molecular mechanisms remain to be fully elucidated. Here, we report that the cell-adhesive transmembrane protein Teneurin-3 (Tenm3) is required by zebrafish RGCs for acquisition of their correct morphological and func...

  7. "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...

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

    OpenAIRE

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

    2011-01-01

    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 ...

  9. Network Variability Limits Stimulus-Evoked Spike Timing Precision in Retinal Ganglion Cells

    OpenAIRE

    Murphy, Gabe J.; Rieke, Fred

    2006-01-01

    Visual, auditory, somatosensory, and olfactory stimuli generate temporally precise patterns of action potentials (spikes). It is unclear, however, how the pattern and variability of synaptic input elicited by physiological stimuli governs the precision of spike generation. We determined how synaptic conductances evoked by light stimuli that activate the rod bipolar pathway control spike generation in three identified types of mouse retinal ganglion cells (RGCs). The relative amplitude, timing...

  10. 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; Martins, Tânia; Kolomiets, Bogdan; Tralhão, Pedro; Gøtzsche, Casper R; Cavadas, Cláudia; Castelo-Branco, Miguel; Woldbye, David P D; Picaud, Serge; Santiago, Ana R; Ambrósio, António F

    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...

  11. Ganglion

    OpenAIRE

    Sevda Söker

    2006-01-01

    The celebrated 2nd century Greek physician Galen who lived and worked in Rome first used the word ganglion to denote a nerve complex. Ganglion still is used to refer to an aggregation of peripheric nerve cell bodies. In this article, structures and functions of ganglion is reviewed.

  12. 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

  13. Origin of correlated activity between parasol retinal ganglion cells.

    Science.gov (United States)

    Trong, Philipp Khuc; Rieke, Fred

    2008-11-01

    Cells throughout the CNS have synchronous activity patterns; that is, a cell's probability of generating an action potential depends both on its firing rate and on the occurrence of action potentials in surrounding cells. The mechanisms producing synchronous or correlated activity are poorly understood despite its prevalence and potential effect on neural coding. We found that neighboring parasol ganglion cells in primate retina received strongly correlated synaptic input in the absence of modulated light stimuli. This correlated variability appeared to arise through the same circuits that provide uncorrelated synaptic input. In addition, ON, but not OFF, parasol cells were coupled electrically. Correlated variability in synaptic input, however, dominated correlations in the parasol spike outputs and shared variability in the timing of action potentials generated by neighboring cells. These results provide a mechanistic picture of how correlated activity is produced in a population of neurons that are critical for visual perception. PMID:18820692

  14. 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.

  15. Effect of stimulation of trigeminal ganglion on regional cerebral blood flow in cats

    International Nuclear Information System (INIS)

    Regional cerebral blood flow was studied in the cat, with and without trigeminal ganglion stimulation, by the intravenous injection of the tracer [14C]iodoantipyrine and subsequent regional brain dissection. Electrical activation of the trigeminal ganglion led to a selective increase in regional blood flow in the frontal and parietal cortex that was bilateral without change in the posterior cortex, deep cerebral nuclei, white matter, or brain stem. Unilateral intracranial section of the facial nerve blocked the response in the ipsilateral frontal and parietal cortex, whereas bilateral facial nerve section blocked the contralateral frontal cortical response. The contralateral parietal cortical increase in blood flow was not affected by facial nerve section and may thus represent the result of metabolic activation of sensory cortex

  16. 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

  17. 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.

  18. 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.

  19. Gene delivery into mouse retinal ganglion cells by in utero electroporation

    Directory of Open Access Journals (Sweden)

    Herrera Eloisa

    2007-09-01

    Full Text Available Abstract Background The neural retina is a highly structured tissue of the central nervous system that is formed by seven different cell types that are arranged in layers. Despite much effort, the genetic mechanisms that underlie retinal development are still poorly understood. In recent years, large-scale genomic analyses have identified candidate genes that may play a role in retinal neurogenesis, axon guidance and other key processes during the development of the visual system. Thus, new and rapid techniques are now required to carry out high-throughput analyses of all these candidate genes in mammals. Gene delivery techniques have been described to express exogenous proteins in the retina of newborn mice but these approaches do not efficiently introduce genes into the only retinal cell type that transmits visual information to the brain, the retinal ganglion cells (RGCs. Results Here we show that RGCs can be targeted for gene expression by in utero electroporation of the eye of mouse embryos. Accordingly, using this technique we have monitored the morphology of electroporated RGCs expressing reporter genes at different developmental stages, as well as their projection to higher visual targets. Conclusion Our method to deliver ectopic genes into mouse embryonic retinas enables us to follow the course of the entire retinofugal pathway by visualizing RGC bodies and axons. Thus, this technique will permit to perform functional studies in vivo focusing on neurogenesis, axon guidance, axon projection patterning or neural connectivity in mammals.

  20. 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

  1. 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

  2. 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

  3. Characterization of Ca2+ Signalling in Postnatal Mouse Retinal Ganglion Cells: Involvement of OPA1 in Ca2+ Clearance

    Czech Academy of Sciences Publication Activity Database

    Dayanithi, Govindan; Chen-Kuo-Chang, M.; Viero, C.; Hamel, C.; Muller, A.; Lenaers, G.

    2010-01-01

    Roč. 31, č. 2 (2010), s. 53-65. ISSN 1381-6810 Institutional research plan: CEZ:AV0Z50390703 Keywords : retinal ganglion cells * Ca2+ homeostasis * Ca2+ clearance Subject RIV: FH - Neurology Impact factor: 1.333, year: 2010

  4. 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

  5. Xenopus laevis retinal ganglion cell dendritic arbors develop independently of visual stimulation

    Directory of Open Access Journals (Sweden)

    Rebecca L. Rigel

    2004-06-01

    Full Text Available Newly formed neurons must locate their appropriate target cells and then form synaptic connections with these targets in order to establish a functional nervous system. In the vertebrate retina, retinal ganglion cell (RGC dendrites extend from the cell body and form synapses with nearby amacrine and bipolar cells. RGC axons, however, exit the retina and synapse with the dendrites of midbrain neurons in the optic tectum. We examined how visual stimulation influenced Xenopus RGC dendritic arborization. Neuronal activity is known to be an important factor in shaping dendritic and axonal arborization. Thus, we reared tadpoles in dark and light environments then used rhodamine dextran retrograde labeling to identify RGCs in the retina. When we compared RGC dendritic arbors from tadpoles reared in dark and light environments, we found no morphological differences, suggesting that physiological visual activity did not contribute to the morphological development of Xenopus RGC dendritic arbors.

  6. Xenopus laevis Retinal Ganglion Cell Dendritic Arbors Develop Independently of Visual Stimulation

    Directory of Open Access Journals (Sweden)

    Barbara Lom

    2004-01-01

    Full Text Available Newly formed neurons must locate their appropriate target cells and then form synaptic connections with these targets in order to establish a functional nervous system. In the vertebrate retina, retinal ganglion cell (RGC dendrites extend from the cell body and form synapses with nearby amacrine and bipolar cells. RGC axons, however, exit the retina and synapse with the dendrites of midbrain neurons in the optic tectum. We examined how visual stimulation influenced Xenopus RGC dendritic arborization. Neuronal activity is known to be an important factor in shaping dendritic and axonal arborization. Thus, we reared tadpoles in dark and light environments then used rhodamine dextran retrograde labeling to identify RGCs in the retina. When we compared RGC dendritic arbors from tadpoles reared in dark and light environments, we found no morphological differences, suggesting that physiological visual activity did not contribute to the morphological development of Xenopus RGC dendritic arbors.

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

    International Nuclear Information System (INIS)

    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. (cross-disciplinary physics and related areas of science and technology)

  8. Role of HDACs in optic nerve damage-induced nuclear atrophy of retinal ganglion cells.

    Science.gov (United States)

    Schmitt, Heather M; Schlamp, Cassandra L; Nickells, Robert W

    2016-06-20

    Optic neuropathies are characterized by retinal ganglion cell (RGC) death, resulting in the loss of vision. In glaucoma, the most common optic neuropathy, RGC death is initiated by axonal damage, and can be modeled by inducing acute axonal trauma through procedures such as optic nerve crush (ONC) or optic nerve axotomy. One of the early events of RGC death is nuclear atrophy, and is comprised of RGC-specific gene silencing, histone deacetylation, heterochromatin formation, and nuclear shrinkage. These early events appear to be principally regulated by epigenetic mechanisms involving histone deacetylation. Class I histone deacetylases HDACs 1, 2, and 3 are known to play important roles in the process of early nuclear atrophy in RGCs, and studies using both inhibitors and genetic ablation of Hdacs also reveal a critical role in the cell death process. Select inhibitors, such as those being developed for cancer therapy, may also provide a viable secondary treatment option for optic neuropathies. PMID:26733303

  9. 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.

  10. 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

  11. 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

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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

  17. 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

  18. A dedicated circuit links direction-selective retinal ganglion cells to the primary visual cortex

    Science.gov (United States)

    Cruz-Martín, Alberto; El-Danaf, Rana N.; Osakada, Fumitaka; Sriram, Balaji; Dhande, Onkar S.; Nguyen, Phong L.; Callaway, Edward M.; Ghosh, Anirvan; Huberman, Andrew D.

    2014-03-01

    How specific features in the environment are represented within the brain is an important unanswered question in neuroscience. A subset of retinal neurons, called direction-selective ganglion cells (DSGCs), are specialized for detecting motion along specific axes of the visual field. Despite extensive study of the retinal circuitry that endows DSGCs with their unique tuning properties, their downstream circuitry in the brain and thus their contribution to visual processing has remained unclear. In mice, several different types of DSGCs connect to the dorsal lateral geniculate nucleus (dLGN), the visual thalamic structure that harbours cortical relay neurons. Whether direction-selective information computed at the level of the retina is routed to cortical circuits and integrated with other visual channels, however, is unknown. Here we show that there is a di-synaptic circuit linking DSGCs with the superficial layers of the primary visual cortex (V1) by using viral trans-synaptic circuit mapping and functional imaging of visually driven calcium signals in thalamocortical axons. This circuit pools information from several types of DSGCs, converges in a specialized subdivision of the dLGN, and delivers direction-tuned and orientation-tuned signals to superficial V1. Notably, this circuit is anatomically segregated from the retino-geniculo-cortical pathway carrying non-direction-tuned visual information to deeper layers of V1, such as layer 4. Thus, the mouse harbours several functionally specialized, parallel retino-geniculo-cortical pathways, one of which originates with retinal DSGCs and delivers direction- and orientation-tuned information specifically to the superficial layers of the primary visual cortex. These data provide evidence that direction and orientation selectivity of some V1 neurons may be influenced by the activation of DSGCs.

  19. Differential responses to high-frequency electrical stimulation in ON and OFF retinal ganglion cells

    Science.gov (United States)

    Twyford, Perry; Cai, Changsi; Fried, Shelley

    2014-04-01

    Objective. The field of retinal prosthetics for artificial vision has advanced considerably in recent years, however clinical outcomes remain inconsistent. The performance of retinal prostheses is likely limited by the inability of electrical stimuli to preferentially activate different types of retinal ganglion cell (RGC). Approach. Here we examine the response of rabbit RGCs to high-frequency stimulation, using biphasic pulses applied at 2000 pulses per second. Responses were recorded using cell-attached patch clamp methods, and stimulation was applied epiretinally via a small cone electrode. Main results. When prolonged stimulus trains were applied to OFF-brisk transient (BT) RGCs, the cells exhibited a non-monotonic relationship between response strength and stimulus amplitude; this response pattern was different from those elicited previously by other electrical stimuli. When the amplitude of the stimulus was modulated transiently from a non-zero baseline amplitude, ON-BT and OFF-BT cells exhibited different activity patterns: ON cells showed an increase in activity while OFF cells exhibited a decrease in activity. Using a different envelope to modulate the amplitude of the stimulus, we observed the opposite effect: ON cells exhibited a decrease in activity while OFF cells show an increase in activity. Significance. As ON and OFF RGCs often exhibit opposing activity patterns in response to light stimulation, this work suggests that high-frequency electrical stimulation of RGCs may be able to elicit responses that are more physiological than traditional pulsatile stimuli. Additionally, the prospect of an electrical stimulus capable of cell-type specific selective activation has broad applications throughout the fields of neural stimulation and neuroprostheses.

  20. 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

  1. Retinal Ganglion Cell Atrophy in Homonymous Hemianopia due to Acquired Occipital Lesions Observed Using Cirrus High-Definition-OCT

    OpenAIRE

    Yamashita, Tsutomu; Miki, Atsushi; Goto, Katsutoshi; Araki, Syunsuke; Takizawa, Go; Ieki, Yoshiaki; Kiryu, Junichi; Tabuchi, Akio; Iguchi, Yasuyuki; Kimura, Kazumi; Yagita, Yoshiki

    2016-01-01

    Purpose. To report a reduction in macular ganglion cell layer and inner plexiform layer (GCL+IPL) thickness and circumpapillary retinal nerve fiber layer (cpRNFL) thickness using spectral-domain optical coherence tomography in patients with homonymous hemianopia due to posterior cerebral artery (PCA) stroke. Methods. Seven patients with PCA stroke were examined using Cirrus high-definition-OCT. The GCL+IPL thicknesses were divided into the hemianopic and unaffected sides. The relationship bet...

  2. Cortical-Thalamic Axons are Required for Retinal Ganglion Cell Targeting to the Mouse Dorsal Lateral Geniculate Nucleus

    OpenAIRE

    Shanks, James Alexander

    2015-01-01

    AbstractJames A. ShanksCortical-Thalamic Axons are Required for Retinal Ganglion Cell Targeting to the Mouse Dorsal Lateral Geniculate Nucleus The human brain contains over 85 billion neurons, which make trillions of synapses in a very ordered and stereotypical manner (Williams and Herrup, 1988). The human cerebral cortex, which contains over 20 percent of the total number of neurons within the brain, is responsible for critical functions such as memory, attention, perception, awareness, lan...

  3. Astaxanthin Attenuates the Apoptosis of Retinal Ganglion Cells in db/db Mice by Inhibition of Oxidative Stress

    OpenAIRE

    Xiao-Li Kang; Gao Lu; Ling-Yan Dong; Jie Jin

    2013-01-01

    Diabetic retinopathy is a common diabetic eye disease caused by changes in retinal ganglion cells (RGCs). It is an ocular manifestation of systemic disease, which affects up to 80% of all patients who have had diabetes for 10 years or more. The genetically diabetic db / db mouse, as a model of type-2 diabetes, shows diabetic retinopathy induced by apoptosis of RGCs. Astaxanthin is a carotenoid with powerful antioxidant properties that exists naturally in various plants, algae and seafood. Her...

  4. Neuroprotective effect of astaxanthin against rat retinal ganglion cell death under various stresses that induce apoptosis and necrosis

    OpenAIRE

    Yamagishi, Reiko; Aihara, Makoto

    2014-01-01

    Purpose Astaxanthin is a type of carotenoid known to have strong antioxidant effects. The purpose of this study was to investigate whether astaxanthin confers a neuroprotective effect against glutamate stress, oxidative stress, and hypoxia-induced apoptotic or necrotic cell death in primary cultures of rat retinal ganglion cells (RGCs). Methods Purified rat RGCs were exposed to three kinds of stressors induced by 25 μM glutamate for 72 h, B27 medium without an antioxidant for 4 h, and a reduc...

  5. 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...

  6. 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.

  7. 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

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

    Directory of Open Access Journals (Sweden)

    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

  9. 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

  10. Glycyl-L-glutamine opposes the fall in choline acetyltransferase in the denervated superior cervical ganglion of the cat.

    OpenAIRE

    Koelle, G B; O'Neill, J J; Thampi, N S; Han, M S; Caccese, R

    1989-01-01

    Intracarotid infusion of 3 microM glycyl-L-glutamine was found to oppose the fall in the choline acetyl-transferase content of the preganglionically denervated cat superior cervical ganglion; this same effect has been demonstrated previously for acetylcholinesterase content. Because choline acetyltransferase, in contrast to acetylcholinesterase, occurs exclusively in the preganglionic axons and their terminals, this finding raises the possibility that glycyl-L-glutamine opposes postsectional ...

  11. The role of NgR-Rhoa-Rock signal pathway in retinal ganglion cell apoptosis of early diabetic rats

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    Yun-Jie Fu

    2014-09-01

    Full Text Available AIM: To study the function and mechanism of the NgR-Rhoa-Rock signal pathways which exists in the retinal ganglion cells apoptosis in diabetes mellitus(DMrats. METHODS: Some healthy SD rats were operated by means of single intraperitoneal injection of 1% streptozotocin based on the standard of 50mg/kg wight, after that the blood sugar value was greater than 16.7mmol/L as DM model, then randomly divided into 3 groups, each group was 10 rats. In addition to take 10 healthy SD rats as control group. Four groups of rats were bilaterally eyeball intravitreal injection in turn with NgR-siRNA virus 10μL(siRNA group, NgR-siRNA virus diluted 10μL(DM group, NgR-siRNA virus-negative-control solution 10μL(siRNA blank group, NgR-siRNA virus diluted 10μL(normal control group, and fed normally. During that time, some life indexes like blood glucose, body mass, etc. were measured and recorded. After 12wk, the expression of NgR and Rhoa, HE staining, and TUNNEL staining were detected by Western blot analysis. RESULTS: Western blot analysis: compared with normal control group, the expression of NgR and Rhoa in DM group and siRNA blank group increased significantly(PP>0.05; compared with DM group and siRNA blank group, the expression of those proteins significantly lowered in siRNA group. HE staining: compared with normal control group, some extent ganglion cells arranged disorder, irregular shape, spacing not consistent were all found in three groups of model rats; compared with DM group and siRNA blank group, there was some improvement in siRNA group of ganglion cells about the order and shape size. TUNEL staining: compared with normal control group, there were retinal ganglion cells apoptosis in all of three groups of model rats. Compared with DM group and siRNA blank group, the number of retinal ganglion cells apoptotic cells was less, and the shape of cells had improved significantly in siRNA group. CONCLUSION: In the DM phase, the expression of NgR and

  12. 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

    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...... thinner in ADOA than in healthy controls (CRAE (mean ± 2 standard deviations (SD)) 153.9 ± 41.0 μm and CRVE 236.1 ± 42.0 μm in ADOA, CRAE 172.5 ± 25.0 μm (p = 0.0004) and CRVE 254.2 ± 37.6 μm (p = 0.0019) in healthy controls). MABP was comparable in the two groups (p = 0.18), and in both groups, CRAE...... ganglion cell-inner plexiform layer (GC-IPL) thickness (p = 0.0017 and p = 0.0057, respectively). CONCLUSION: Narrow retinal arteries and veins were associated not only with the severity of ADOA but with ganglion cell volume in patients with ADOA and in healthy subjects. This suggests that narrow vessels...

  13. Nuclear translocation and overexpression of GAPDH by the hyper-pressure in retinal ganglion cell

    International Nuclear Information System (INIS)

    To investigate the effect of hyper-pressure on retinal ganglion cells (RGC-5), RGC-5 cells were exposed to an ambient hydrostatic pressure of 100 mm Hg. Upon treatment, the proliferation of RGC-5 cells was inhibited and neuronal apoptosis was detected by specific apoptosis marker TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling). To probe into the mechanism mediating the apoptosis of RGC-5 cells in 100 mm Hg, protein profile alterations following hyper-pressure treatment were examined using two-dimensional gel electrophoresis (2-DE) followed by MALDI-TOF. Out of the 400 protein spots of RGC-5 cells detected on 2-DE gels, 37 differentially expressed protein spots were further identified using in gel tryptic digestion and mass spectrometry. Among these proteins, glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) was significantly expressed 10 times more in 100 mm Hg than in normal pressure. The accumulation of GAPDH in the nucleus and its translocation from the cytosol to the nucleus in 100 mm Hg were observed using a microscope. These results suggest that the hyper-pressure-induced apoptosis in RGC-5 cells may be involved with not only the increase of GAPDH expression, but also the accumulation and the translocalization of GAPDH to the nucleus

  14. Teneurin-3 Specifies Morphological and Functional Connectivity of Retinal Ganglion Cells in the Vertebrate Visual System

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    Paride Antinucci

    2013-11-01

    Full Text Available A striking feature of the CNS is the precise wiring of its neuronal connections. During vertebrate visual system development, different subtypes of retinal ganglion cells (RGCs form specific connections with their corresponding synaptic partners. However, the underlying molecular mechanisms remain to be fully elucidated. Here, we report that the cell-adhesive transmembrane protein Teneurin-3 (Tenm3 is required by zebrafish RGCs for acquisition of their correct morphological and functional connectivity in vivo. Teneurin-3 is expressed by RGCs and their presynaptic amacrine and postsynaptic tectal cell targets. Knockdown of Teneurin-3 leads to RGC dendrite stratification defects within the inner plexiform layer, as well as mistargeting of dendritic processes into outer portions of the retina. Moreover, a subset of RGC axons exhibits tectal laminar arborization errors. Finally, functional analysis of RGCs targeting the tectum reveals a selective deficit in the development of orientation selectivity after Teneurin-3 knockdown. These results suggest that Teneurin-3 plays an instructive role in the functional wiring of the vertebrate visual system.

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

    Science.gov (United States)

    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.

  16. Optic neuritis and retinal ganglion cell loss in a chronic murine model of multiple sclerosis

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    KennethS.Shindler

    2011-08-01

    Full Text Available Multiple sclerosis (MS and its animal model experimental autoimmune encephalomyelitis (EAE are neurodegenerative diseases with characteristic inflammatory demyelination in the central nervous system, including the optic nerve. Neuronal and axonal damage is considered to be the main cause of long-term disability in patients with MS. Neuronal loss, including retinal ganglion cell (RGC apoptosis in eyes with optic neuritis, also occurs in EAE. However, there is significant variability in the clinical course and level of neuronal damage in MS and EAE. The current studies examine the mechanisms and kinetics of RGC loss in C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein to induce a chronic EAE disease. Clinical progression of EAE was scored daily and vision was assessed by optokinetic responses. At various time points, RGCs were counted and optic nerves were examined for inflammatory cell infiltration. Almost all EAE mice develop optic neuritis by day 15 post-immunization; however, RGC loss is delayed in these mice. No RGC loss is detected 25 days post-immunization, whereas RGC numbers in EAE mice significantly and progressively decrease compared to controls from 35-50 days post-immunization. The delayed time course of RGC loss is in stark contrast to that reported in relapsing EAE, as well as in rats with chronic EAE. Results suggest that different clinical disease courses of optic nerve inflammation may trigger distinct mechanisms of neuronal damage, or RGCs in different rodent strains may have variable resistance to neuronal degeneration.

  17. 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.

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

    Science.gov (United States)

    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

  19. 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. PMID:22203465

  20. 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.

  1. Adult rat retinal ganglion cells and glia can be printed by piezoelectric inkjet printing

    International Nuclear Information System (INIS)

    We have investigated whether inkjet printing technology can be extended to print cells of the adult rat central nervous system (CNS), retinal ganglion cells (RGC) and glia, and the effects on survival and growth of these cells in culture, which is an important step in the development of tissue grafts for regenerative medicine, and may aid in the cure of blindness. We observed that RGC and glia can be successfully printed using a piezoelectric printer. Whilst inkjet printing reduced the cell population due to sedimentation within the printing system, imaging of the printhead nozzle, which is the area where the cells experience the greatest shear stress and rate, confirmed that there was no evidence of destruction or even significant distortion of the cells during jet ejection and drop formation. Importantly, the viability of the cells was not affected by the printing process. When we cultured the same number of printed and non-printed RGC/glial cells, there was no significant difference in cell survival and RGC neurite outgrowth. In addition, use of a glial substrate significantly increased RGC neurite outgrowth, and this effect was retained when the cells had been printed. In conclusion, printing of RGC and glia using a piezoelectric printhead does not adversely affect viability and survival/growth of the cells in culture. Importantly, printed glial cells retain their growth-promoting properties when used as a substrate, opening new avenues for printed CNS grafts in regenerative medicine. (paper)

  2. 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

  3. 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.

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

    Science.gov (United States)

    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

  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. 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

  7. Protection of pattern electroretinogram and retinal ganglion cells by oncostatin M after optic nerve injury.

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    Xin Xia

    Full Text Available Injury to retinal ganglion cell (RGC axons leads to selective loss of RGCs and vision. Previous studies have shown that exogenous neurotrophic factors promote RGC survival. We investigated the neuroprotective effects of oncostatin M (OSM, a member of the IL-6 family of cytokines, on pattern electroretinogram (PERG and RGC survival after optic nerve crush (ON-crush in the mouse. BALB/C mice received ON-crush in the left eyes for either 4-second or 1-second duration (4-s or 1-s. Fluoro-gold retrograde labeling was used to identify RGCs. RGC function was assessed by PERG measurement. OSM or CNTF protein was injected intravitreally immediately after ON-crush. OSM responsive cells were identified by localization of increased STAT3 phosphorylation. Significant higher RGC survival (46% of untreated control was seen in OSM-treated eyes when assessed 2 weeks after 4-s ON-crush as compared to that (14% of untreated control of the PBS-treated eyes (P<0.001. In addition, PERG amplitude was significantly higher in eyes treated with OSM or CNTF 1 week after 1-s ON-crush (36% of baseline as compared with the amplitude of PBS-treated eyes (19% of the baseline, P = 0.003. An increase in STAT3 phosphorylation was localized in Müller layer after OSM treatment, suggesting that Müller cells mediate the effect of OSM. Our results demonstrate that one single injection of either OSM or CNTF after ON-crush improves RGC survival together with their electrophysiological activity. These data provide proof-of-concept for using neurotrophic factors OSM and CNTF for RGC degenerative diseases, including glaucoma and acute optic nerve trauma.

  8. 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.

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

    Science.gov (United States)

    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

  10. 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.

  11. Analysis of the Spike Timing Precision in Retinal Ganglion Cells by the Stochastic Model

    OpenAIRE

    Yoshimi Kamiyama

    2010-01-01

    The ganglion cells of the vertebrate retina form the pathway by which the retina communicates with the visual cortex. The ganglion cells convert the graded potentials into a pattern of spikes whose characteristics is modulated by the synaptic and membrane currents. The ganglion cells respond with precise and reliable spikes to randomly flickering light (Keat et al., 2001). This feature could not be reproduced by the previous models, described with the deterministic differential equations simi...

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

    Science.gov (United States)

    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.

  13. Selectivity of direct and network-mediated stimulation of the retinal ganglion cells with epi-, sub- and intraretinal electrodes

    Science.gov (United States)

    Boinagrov, David; Pangratz-Fuehrer, Susanne; Goetz, Georges; Palanker, Daniel

    2014-04-01

    Objective. Intra-retinal placement of stimulating electrodes can provide close and stable proximity to target neurons. We assessed improvement in stimulation thresholds and selectivity of the direct and network-mediated retinal stimulation with intraretinal electrodes, compared to epiretinal and subretinal placements. Approach. Stimulation thresholds of the retinal ganglion cells (RGCs) in wild-type rat retina were measured using the patch-clamp technique. Direct and network-mediated responses were discriminated using various synaptic blockers. Main results. Three types of RGC responses were identified: short latency (SL, τ 40 ms) originating in photoreceptors. Cathodic epiretinal stimulation exhibited the lowest threshold for direct RGC response and the highest direct selectivity (network/direct thresholds ratio), exceeding a factor of 3 with pulse durations below 0.5 ms. For network-mediated stimulation, the lowest threshold was obtained with anodic pulses in OPL position, and its network selectivity (direct/network thresholds ratio) increased with pulse duration, exceeding a factor of 4 at 10 ms. Latency of all three types of responses decreased with increasing strength of the stimulus. Significance. These results define the optimal range of pulse durations, pulse polarities and electrode placement for the retinal prostheses aiming at direct or network-mediated stimulation of RGCs.

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

    Directory of Open Access Journals (Sweden)

    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

  15. 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.

  16. 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.

  17. AMPA receptor desensitization is the determinant of AMPA receptor mediated excitotoxicity in purified retinal ganglion cells.

    Science.gov (United States)

    Park, Yong H; Mueller, Brett H; McGrady, Nolan R; Ma, Hai-Ying; Yorio, Thomas

    2015-03-01

    The ionotropic glutamate receptors (iGLuR) have been hypothesized to play a role in neuronal pathogenesis by mediating excitotoxic death. Previous studies on iGluR in the retina have focused on two broad classes of receptors: NMDA and non-NMDA receptors including the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic receptor (AMPAR) and kainate receptor. In this study, we examined the role of receptor desensitization on the specific excitotoxic effects of AMPAR activation on primary retinal ganglion cells (RGCs). Purified rat RGCs were isolated from postnatal day 4-7 Sprague-Dawley rats. Calcium imaging was used to identify the functionality of the AMPARs and selectivity of the s-AMPA agonist. Phosphorylated CREB and ERK1/2 expression were performed following s-AMPA treatment. s-AMPA excitotoxicity was determined by JC-1 mitochondrial membrane depolarization assay, caspase 3/7 luciferase activity assay, immunoblot analysis for α-fodrin, and Live (calcein AM)/Dead (ethidium homodimer-1) assay. RGC cultures of 98% purity, lacking Iba1 and GFAP expression were used for the present studies. Isolated prenatal RGCs expressed calcium permeable AMPAR and s-AMPA (100 μM) treatment of cultured RGCs significantly increased phosphorylation of CREB but not that of ERK1/2. A prolonged (6 h) AMPAR activation in purified RGCs using s-AMPA (100 μM) did not depolarize the RGC mitochondrial membrane potential. In addition, treatment of cultured RGCs with s-AMPA, both in the presence and absence of trophic factors (BDNF and CNTF), did not increase caspase 3/7 activities or the cleavage of α-fodrin (neuronal apoptosis marker), as compared to untreated controls. Lastly, a significant increase in cell survival of RGCs was observed after s-AMPA treatment as compared to control untreated RGCs. However, preventing the desensitization of AMPAR with the treatment with either kainic acid (100 μM) or the combination of s-AMPA and cyclothiazide (50 μM) significantly reduced cell

  18. Developmental maturation of passive electrical properties in retinal ganglion cells of rainbow trout.

    Science.gov (United States)

    Picones, Arturo; Chung, S Clare; Korenbrot, Juan I

    2003-04-01

    We investigated the electrotonic and anatomical features of the dendritic arbor in developing retinal ganglion cells (RGCs). Cell anatomy was studied by filling individual cells with fluorescent, membrane-bound dyes and using computer-assisted image reconstruction. Electrotonic properties were characterized through an analysis of charging membrane currents measured with tight-seal electrodes in the whole-cell mode. We studied developing RGCs in the peripheral growth zone (PGZ) of a fish retina. The PGZ presents a developmental time-line ranging from pluripotent, proliferating cells at the extreme edge, to mature, fully developed retina more centrally. In the PGZ, RGCs mature through three histologically distinct zones (in developmental sequence): bulge, transition and mature zones. In the most peripheral three-quarters of the bulge zone, cells have rounded somas, lack dendritic extensions and some are coupled so that membrane-bound dyes traverse from one cell to its immediate neighbours. In the more central quarter of the bulge, cells' dendrites are few, short and of limited branching. In the transition zone dendritic arbors becomes progressively more expansive and branched and we present a morphometric analysis of these changes. Regardless of the size and branching pattern of the developing RGC dendritic arbor, the ratio of the diameters of parent and progeny dendrites at any branching nodes is well described by Rall's 3/2 power law. Given this anatomical feature, the RGC passive electrical properties are well described by an equivalent electrical circuit consisting of an isopotential cell body in parallel with a single equivalent cylinder of finite length. We measured the values of the electrical parameters that define this equivalent circuit in bulge, transition and mature RGCs. As RGCs develop the electrical properties of their dendritic arbor change in an orderly and tightly regulated manner, not randomly. Electrically, dendritic arbors develop along either of

  19. Assessment of retinal ganglion cell damage in glaucomatous optic neuropathy: Axon transport, injury and soma loss.

    Science.gov (United States)

    Nuschke, Andrea C; Farrell, Spring R; Levesque, Julie M; Chauhan, Balwantray C

    2015-12-01

    Glaucoma is a disease characterized by progressive axonal pathology and death of retinal ganglion cells (RGCs), which causes structural changes in the optic nerve head and irreversible vision loss. Several experimental models of glaucomatous optic neuropathy (GON) have been developed, primarily in non-human primates and, more recently and commonly, in rodents. These models provide important research tools to study the mechanisms underlying glaucomatous damage. Moreover, experimental GON provides the ability to quantify and monitor risk factors leading to RGC loss such as the level of intraocular pressure, axonal health and the RGC population. Using these experimental models we are able to gain a better understanding of GON, which allows for the development of potential neuroprotective strategies. Here we review the advantages and disadvantages of the relevant and most often utilized methods for evaluating axonal degeneration and RGC loss in GON. Axonal pathology in GON includes functional disruption of axonal transport (AT) and structural degeneration. Horseradish peroxidase (HRP), rhodamine-B-isothiocyanate (RITC) and cholera toxin-B (CTB) fluorescent conjugates have proven to be effective reporters of AT. Also, immunohistochemistry (IHC) for endogenous AT-associated proteins is often used as an indicator of AT function. Similarly, structural degeneration of axons in GON can be investigated via changes in the activity and expression of key axonal enzymes and structural proteins. Assessment of axonal degeneration can be measured by direct quantification of axons, qualitative grading, or a combination of both methods. RGC loss is the most frequently quantified variable in studies of experimental GON. Retrograde tracers can be used to quantify RGC populations in rodents via application to the superior colliculus (SC). In addition, in situ IHC for RGC-specific proteins is a common method of RGC quantification used in many studies. Recently, transgenic mouse models

  20. 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.

  1. GABAergic and glycinergic pathways to goldfish retinal ganglion cells: an ultrastructural double label study

    International Nuclear Information System (INIS)

    An ultrastructural double label has been employed to compare GABAergic and glycinergic systems in the inner plexiform layer (IPL) of the goldfish retina. Electron microscope autoradiography of 3H-GABA and 3H-glycine uptake was combined with retrograde HRP-labeling of ganglion cells. When surveyed for distribution, GABAergic and glycinergic synapses were found onto labeled ganglion cells throughout the IPL. This reinforces previous physiological work that described GABAergic and glycinergic influences on a variety of ganglion cells in goldfish and carp; These physiological effects often reflect direct inputs

  2. Ionic mechanisms involved in the release of 3H-norepinephrine from the cat superior cervical ganglion

    International Nuclear Information System (INIS)

    It has previously been reported that in the isolated cat superior cervical ganglion (SCG) labeled with tritiated norepinephrine (3H-NE), the stimulation of the preganglionic trunk at 10 Hz as well as the exposure to 100 μM exogenous acetylcholine (ACh), produced a Ca++-dependent release of 3H-NE. The present results show that a Ca++-dependent release of 3H-NE was produced also by exposure to either 50 μM veratridine or 60 mM KCl. Tetrodotoxin (0.5 μM) abolished the release of 3H-NE induced by preganglionic stimulation, ACh and veratridine but did not modify the release evoked by KCl. The metabolic distribution of the radioactivity released by the different depolarizing stimuli showed that the 3H-NE was collected mainly unmetabolized. In the cat SCG neither the release of 3H-NE evoked by KCl nor the endogenous content of NE was modified by pretreatment with 6-OH-dopamine (6-OH-DA). On the other hand, this chemical sympathectomy depleted the endogenous content of NE in the cat nictitating membrane, whose nerve terminals arise from the SCG. The data presented suggest that the depolarization-coupled release of NE from the cat SCG involves structures that are different to nerve terminals and that contain Na+ channels as well as Ca++

  3. Light adaptation in the primate retina: analysis of changes in gain and dynamics of monkey retinal ganglion cells.

    Science.gov (United States)

    Purpura, K; Tranchina, D; Kaplan, E; Shapley, R M

    1990-01-01

    The responses of monkey retinal ganglion cells to sinusoidal stimuli of various temporal frequencies were measured and analyzed at a number of mean light levels. Temporal modulation tuning functions (TMTFs) were measured at each mean level by varying the drift rate of a sine-wave grating of fixed spatial frequency and contrast. The changes seen in ganglion cell temporal responses with changes in adaptation state were similar to those observed in human subjects and in turtle horizontal cells and cones tested with sinusoidally flickering stimuli; "Weber's Law" behavior was seen at low temporal frequencies but not at higher temporal frequencies. Temporal responses were analyzed in two ways: (1) at each light level, the TMTFs were fit by a model consisting of a cascade of low- and high-pass filters; (2) the family of TMTFs collected over a range of light levels for a given cell was fit by a linear negative feedback model in which the gain of the feedback was proportional to the mean light level. Analysis (1) revealed that the temporal responses of one class of monkey ganglion cells (M cells) were more phasic at both photopic and mesopic light levels than the responses of P ganglion cells. In analysis (2), the linear negative feedback model accounted reasonably well for changes in gain and dynamics seen in three P cells and one M cell. From the feedback model, it was possible to estimate the light level at which the dark-adapted gain of the cone pathways in the primate retina fell by a factor of two. This value was two to three orders of magnitude lower than the value estimated from recordings of isolated monkey cones. Thus, while a model which includes a single stage of negative feedback can account for the changes in gain and dynamics associated with light adaptation in the photopic and mesopic ranges of vision, the underlying physical mechanisms are unknown and may involve elements in the primate retina other than the cone. PMID:2176096

  4. Activation and inhibition of retinal ganglion cells in response to epiretinal electrical stimulation: a computational modelling study

    Science.gov (United States)

    Abramian, Miganoosh; Lovell, Nigel H.; Morley, John W.; Suaning, Gregg J.; Dokos, Socrates

    2015-02-01

    Objective. Retinal prosthetic devices aim to restore sight in visually impaired people by means of electrical stimulation of surviving retinal ganglion cells (RGCs). This modelling study aims to demonstrate that RGC inhibition caused by high-intensity cathodic pulses greatly influences their responses to epiretinal electrical stimulation and to investigate the impact of this inhibition on spatial activation profiles as well as their implications for retinal prosthetic device design. Another aim is to take advantage of this inhibition to reduce axonal activation in the nerve fibre layer. Approach. A three-dimensional finite-element model of epiretinal electrical stimulation was utilized to obtain RGC activation and inhibition threshold profiles for a range of parameters. Main results. RGC activation and inhibition thresholds were highly dependent on cell and stimulus parameters. Activation thresholds were 1.5, 3.4 and 11.3 μA for monopolar electrodes with 5, 20 and 50 μm radii, respectively. Inhibition to activation threshold ratios were mostly within the range 2-10. Inhibition significantly altered spatial patterns of RGC activation. With concentric electrodes and appropriately high levels of stimulus amplitudes, activation of passing axons was greatly reduced. Significance. RGC inhibition significantly impacts their spatial activation profiles, and therefore it most likely influences patterns of perceived phosphenes induced by retinal prosthetic devices. Thus this inhibition should be taken into account in future studies concerning retinal prosthesis development. It might be possible to utilize this inhibitory effect to bypass activation of passing axons and selectively stimulate RGCs near their somas and dendrites to achieve more localized phosphenes.

  5. Neuroglobin Is an Endogenous Neuroprotectant for Retinal Ganglion Cells against Glaucomatous Damage

    OpenAIRE

    Wei, Xin; Yu, Zhanyang; Cho, Kin-Sang; Chen, Huihui; Malik, Muhammad Taimur A.; Chen, Xiaoming; Lo, Eng H.; Wang, Xiaoying; Chen, Dong F.

    2011-01-01

    Neuroglobin (NGB), a newly discovered member of the globin superfamily, may regulate neuronal survival under hypoxia or oxidative stress. Although NGB is greatly expressed in retinal neurons, the biological functions of NGB in retinal diseases remain largely unknown. We investigated the role of NGB in an experimental model of glaucoma, a neurodegenerative disorder that usually involves elevation of intraocular pressure (IOP). Elevated IOP is thought to induce oxidative stress in retinal gangl...

  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. Spatially restricted electrical activation of retinal ganglion cells in the rabbit retina by hexapolar electrode return configuration

    Science.gov (United States)

    Habib, Amgad G.; Cameron, Morven A.; Suaning, Gregg J.; Lovell, Nigel H.; Morley, John W.

    2013-06-01

    Objective. Visual prostheses currently in development aim to restore some form of vision to patients suffering from diseases such as age-related macular degeneration and retinitis pigmentosa. Most rely on electrically stimulating inner retinal cells via electrodes implanted on or near the retina, resulting in percepts of light termed ‘phosphenes’. Activation of spatially distinct populations of cells in the retina is key for pattern vision to be produced. To achieve this, the electrical stimulation must be localized, activating cells only in the direct vicinity of the stimulating electrode(s). With this goal in mind, a hexagonal return (hexapolar) configuration has been proposed as an alternative to the traditional monopolar or bipolar return configurations for electrically stimulating the retina. This study investigated the efficacy of the hexapolar configuration in localizing the activation of retinal ganglion cells (RGCs), compared to a monopolar configuration. Approach. Patch-clamp electrophysiology was used to measure the activation thresholds of RGCs in whole-mount rabbit retina to monopolar and hexapolar electrical stimulation, applied subretinally. Main results. Hexapolar activation thresholds for RGCs located outside the hex guard were found to be significantly (>2 fold) higher than those located inside the area of tissue bounded by the hex guard. The hexapolar configuration localized the activation of RGCs more effectively than its monopolar counterpart. Furthermore, no difference in hexapolar thresholds or localization was observed when using cathodic-first versus anodic-first stimulation. Significance. The hexapolar configuration may provide an improved method for electrically stimulating spatially distinct populations of cells in retinal tissue.

  9. Monte Carlo methods for localization of cones given multielectrode retinal ganglion cell recordings.

    Science.gov (United States)

    Sadeghi, K; Gauthier, J L; Field, G D; Greschner, M; Agne, M; Chichilnisky, E J; Paninski, L

    2013-01-01

    It has recently become possible to identify cone photoreceptors in primate retina from multi-electrode recordings of ganglion cell spiking driven by visual stimuli of sufficiently high spatial resolution. In this paper we present a statistical approach to the problem of identifying the number, locations, and color types of the cones observed in this type of experiment. We develop an adaptive Markov Chain Monte Carlo (MCMC) method that explores the space of cone configurations, using a Linear-Nonlinear-Poisson (LNP) encoding model of ganglion cell spiking output, while analytically integrating out the functional weights between cones and ganglion cells. This method provides information about our posterior certainty about the inferred cone properties, and additionally leads to improvements in both the speed and quality of the inferred cone maps, compared to earlier "greedy" computational approaches. PMID:23194406

  10. 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; Stakenborg, Michelle; Janssens, Els; Ingvarsen, Signe; Porse, Astrid; Behrendt, Niels; Moons, Lieve

    2014-01-01

    , but not MMP-9, are involved in this process. Furthermore, administration of a novel antibody to MT1-MMP that selectively blocks pro-MMP-2 activation revealed a functional co-involvement of these proteinases in determining RGC axon outgrowth. Subsequent immunostainings showed expression of both MMP-2......, 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...... and MT1-MMP in RGC axons and glial cells. Finally, results from combined inhibition of MMP-2 and β1-integrin were suggestive for a functional interaction between these molecules. Overall, our data indicate MMP-2 and MT1-MMP as promising axonal outgrowth-promoting molecules. Axonal regeneration in the...

  11. Distal retinal ganglion cell axon transport loss and activation of p38 MAPK stress pathway following VEGF-A antagonism.

    Science.gov (United States)

    Foxton, R; Osborne, A; Martin, K R; Ng, Y-S; Shima, D T

    2016-01-01

    There is increasing evidence that VEGF-A antagonists may be detrimental to neuronal health following ocular administration. Here we investigated firstly the effects of VEGF-A neutralization on retinal neuronal survival in the Ins2(Akita) diabetic and JR5558 spontaneous choroidal neovascularization (CNV) mice, and then looked at potential mechanisms contributing to cell death. We detected elevated apoptosis in the ganglion cell layer in both these models following VEGF-A antagonism, indicating that even when vascular pathologies respond to treatment, neurons are still vulnerable to reduced VEGF-A levels. We observed that retinal ganglion cells (RGCs) seemed to be the cells most susceptible to VEGF-A antagonism, so we looked at anterograde transport in these cells, due to their long axons requiring optimal protein and organelle trafficking. Using cholera toxin B-subunit tracer studies, we found a distal reduction in transport in the superior colliculus following VEGF-A neutralization, which occurred prior to net RGC loss. This phenomenon of distal transport loss has been described as a feature of early pathological changes in glaucoma, Alzheimer's and Parkinson's disease models. Furthermore, we observed increased phosphorylation of p38 MAPK and downstream Hsp27 stress pathway signaling in the retinas from these experiments, potentially providing a mechanistic explanation for our findings. These experiments further highlight the possible risks of using VEGF-A antagonists to treat ocular neovascular disease, and suggest that VEGF-A may contribute to the maintenance and function of axonal transport in neurons of the retina. PMID:27148685

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Classifying the motion of visual stimuli from the spike response of a population of retinal ganglion cells.

    Science.gov (United States)

    Cerquera, Alexander; Greschner, Martin; Freund, Jan A

    2008-01-01

    We present an analysis of the spike response of a retinal ganglion cell ensemble. The retina of a turtle was stimulated in vitro by moving light patterns. Its non-steady motion was specified by two features: changes of direction and changes of speed. The spike response of a ganglion cell population was recorded extracellularly with a multielectrode array and responding neurons were identified through spike sorting. Restricting further analysis to a time window of greatest firing activity, we selected a subset of cells with reliable firing patterns, excluding cells that were not selective to the stimulus. The reliability of a firing pattern was assessed on the single cell level in terms of two measures: temporal precision (jitter) of the first spike and the fraction of trials in which a spike was generated. We then condensed the spike response of the extracted group by merging the multivariate spike trains into a single spike train. Finally, we compared different coding hypotheses that are based on the timing of the first and the second spike of the population or the spike count in the preselected time window. We found that the second spike of the population significantly increases the classification efficiency beyond that of the first spike. Moreover, the combination of first plus second spike is comparably efficient as the combination of the first spike plus the spike count but allows for a classification that is much faster. PMID:19163609

  14. Control of Retinal Ganglion Cell Positioning and Neurite Growth: Combining 3D Printing with Radial Electrospun Scaffolds.

    Science.gov (United States)

    Kador, Karl E; Grogan, Shawn P; Dorthé, Erik W; Venugopalan, Praseeda; Malek, Monisha F; Goldberg, Jeffrey L; D'lima, Darryl D

    2016-02-01

    Retinal ganglion cells (RGCs) are responsible for the transfer of signals from the retina to the brain. As part of the central nervous system, RGCs are unable to regenerate following injury, and implanted cells have limited capacity to orient and integrate in vivo. During development, secreted guidance molecules along with signals from extracellular matrix and the vasculature guide cell positioning, for example, around the fovea, and axon outgrowth; however, these changes are temporally regulated and are not the same in the adult. Here, we combine electrospun cell transplantation scaffolds capable of RGC neurite guidance with thermal inkjet 3D cell printing techniques capable of precise positioning of RGCs on the scaffold surface. Optimal printing parameters are developed for viability, electrophysiological function and, neurite pathfinding. Different media, commonly used to promote RGC survival and growth, were tested under varying conditions. When printed in growth media containing both brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF), RGCs maintained survival and normal electrophysiological function, and displayed radial axon outgrowth when printed onto electrospun scaffolds. These results demonstrate that 3D printing technology may be combined with complex electrospun surfaces in the design of future retinal models or therapies. PMID:26729061

  15. Transient requirement for ganglion cells during assembly of retinal synaptic layers

    OpenAIRE

    Kay, J N; Roeser, T; Mumm, J S; L. Godinho; Mrejeru, A; Wong, ROL; Baier, Herwig

    2004-01-01

    The inner plexiform layer (IPL) of the vertebrate retina comprises functionally specialized sublaminae, representing connections between bipolar, amacrine and ganglion cells with distinct visual functions. Developmental mechanisms that target neurites to the correct synaptic sublaminae are largely unknown. Using transgenic zebrafish expressing GFP in subsets of amacrine cells, we imaged IPL formation and sublamination. in vivo and asked whether the major postsynaptic cells in this circuit, th...

  16. Caspase dependence of the death of neonatal retinal ganglion cells induced by axon damage and induction of autophagy as a survival mechanism

    Directory of Open Access Journals (Sweden)

    C. Sternberg

    2010-10-01

    Full Text Available We examined the degeneration of post-mitotic ganglion cells in ex-vivo neonatal retinal explants following axon damage. Ultrastructural features of both apoptosis and autophagy were detected. Degenerating cells reacted with antibodies specific for activated caspase-3 or -9, consistent with the presence of caspase activity. Furthermore, peptidic inhibitors of caspase-9, -6 or -3 prevented cell death (100 µM Ac-LEDH-CHO, 50 µM Ac-VEID-CHO and 10 µM Z-DEVD-fmk, respectively. Interestingly, inhibition of autophagy by 7-10 mM 3-methyl-adenine increased the rate of cell death. Immunohistochemistry data, caspase activation and caspase inhibition data suggest that axotomy of neonatal retinal ganglion cells triggers the intrinsic apoptotic pathway, which, in turn, is counteracted by a pro-survival autophagic response, demonstrated by electron microscopy profiles and pharmacological autophagy inhibitor.

  17. 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...

  18. 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...

  19. Receptive field center size decreases and firing properties mature in ON and OFF retinal ganglion cells after eye opening in the mouse

    OpenAIRE

    Koehler, Christopher L.; Akimov, Nikolay P.; Rentería, René C.

    2011-01-01

    Development of the mammalian visual system is not complete at birth but continues postnatally well after eye opening. Although numerous studies have revealed changes in the development of the thalamus and visual cortex during this time, less is known about the development of response properties of retinal ganglion cells (RGCs). Here, we mapped functional receptive fields of mouse RGCs using a Gaussian white noise checkerboard stimulus and a multielectrode array to record from retinas at eye o...

  20. 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 (< ˜4 Hz) due to reduced desensitization, both reducing the ratio

  1. 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

  2. Cytoskeleton proteins previously considered exclusive to Ganglion Cells are transiently expressed by all retinal neuronal precursors

    OpenAIRE

    Canto-Soler M Valeria; McNally Minda; Gutierrez Christian

    2011-01-01

    Abstract Background Understanding the mechanisms governing cell fate specification remains one of the main challenges in the study of retinal development. In this context, molecular markers that identify specific cell types become crucial tools for the analysis and interpretation of these phenomena. In studies using the developing chick retina, expression of the mid-size neurofilament (NF-M) and a chick-specific microtubule associated protein recognized by the RA4 antibody (MAP(RA4)), have be...

  3. Substituting mouse transcription factor Pou4f2 with a sea urchin orthologue restores retinal ganglion cell development

    Science.gov (United States)

    Mocko-Strand, Julie A.; Wang, Jing; Ullrich-Lüter, Esther; Pan, Ping; Wang, Steven W.; Arnone, Maria Ina; Frishman, Laura J.; Klein, William H.

    2016-01-01

    Pou domain transcription factor Pou4f2 is essential for the development of retinal ganglion cells (RGCs) in the vertebrate retina. A distant orthologue of Pou4f2 exists in the genome of the sea urchin (class Echinoidea) Strongylocentrotus purpuratus (SpPou4f1/2), yet the photosensory structure of sea urchins is strikingly different from that of the mammalian retina. Sea urchins have no obvious eyes, but have photoreceptors clustered around their tube feet disc. The mechanisms that are associated with the development and function of photoreception in sea urchins are largely unexplored. As an initial approach to better understand the sea urchin photosensory structure and relate it to the mammalian retina, we asked whether SpPou4f1/2 could support RGC development in the absence of Pou4f2. To answer this question, we replaced genomic Pou4f2 with an SpPou4f1/2 cDNA. In Pou4f2-null mice, retinas expressing SpPou4f1/2 were outwardly identical to those of wild-type mice. SpPou4f1/2 retinas exhibited dark-adapted electroretinogram scotopic threshold responses, indicating functionally active RGCs. During retinal development, SpPou4f1/2 activated RGC-specific genes and in S. purpuratus, SpPou4f2 was expressed in photoreceptor cells of tube feet in a pattern distinct from Opsin4 and Pax6. Our results suggest that SpPou4f1/2 and Pou4f2 share conserved components of a gene network for photosensory development and they maintain their conserved intrinsic functions despite vast morphological differences in mouse and sea urchin photosensory structures. PMID:26962139

  4. Differential progression of structural and functional alterations in distinct retinal ganglion cell types in a mouse model of glaucoma.

    Science.gov (United States)

    Della Santina, Luca; Inman, Denise M; Lupien, Caroline B; Horner, Philip J; Wong, Rachel O L

    2013-10-30

    Intraocular pressure (IOP) elevation is a principal risk factor for glaucoma. Using a microbead injection technique to chronically raise IOP for 15 or 30 d in mice, we identified the early changes in visual response properties of different types of retinal ganglion cells (RGCs) and correlated these changes with neuronal morphology before cell death. Microbead-injected eyes showed reduced optokinetic tracking as well as cell death. In such eyes, multielectrode array recordings revealed that four RGC types show diverse alterations in their light responses upon IOP elevation. OFF-transient RGCs exhibited a more rapid decline in both structural and functional organizations compared with other RGCs. In contrast, although the light-evoked responses of OFF-sustained RGCs were perturbed, the dendritic arbor of this cell type remained intact. ON-transient and ON-sustained RGCs had normal functional receptive field sizes but their spontaneous and light-evoked firing rates were reduced. ON- and OFF-sustained RGCs lost excitatory synapses across an otherwise structurally normal dendritic arbor. Together, our observations indicate that there are changes in spontaneous activity and light-evoked responses in RGCs before detectable dendritic loss. However, when dendrites retract, we found corresponding changes in receptive field center size. Importantly, the effects of IOP elevation are not uniformly manifested in the structure and function of diverse RGC populations, nor are distinct RGC types perturbed within the same time-frame by such a challenge. PMID:24174678

  5. Action potentials in retinal ganglion cells are initiated at the site of maximal curvature of the extracellular potential

    Science.gov (United States)

    Eickenscheidt, Max; Zeck, Günther

    2014-06-01

    Objective. The initiation of an action potential by extracellular stimulation occurs after local depolarization of the neuronal membrane above threshold. Although the technique shows remarkable clinical success, the site of action and the relevant stimulation parameters are not completely understood. Approach. Here we identify the site of action potential initiation in rabbit retinal ganglion cells (RGCs) interfaced to an array of extracellular capacitive stimulation electrodes. We determine which feature of the extracellular potential governs action potential initiation by simultaneous stimulation and recording RGCs interfaced in epiretinal configuration. Stimulation electrodes were combined to areas of different size and were presented at different positions with respect to the RGC. Main results. Based on stimulation by electrodes beneath the RGC soma and simultaneous sub-millisecond latency measurement we infer axonal initiation at the site of maximal curvature of the extracellular potential. Stimulation by electrodes at different positions along the axon reveals a nearly constant threshold current density except for a narrow region close to the cell soma. These findings are explained by the concept of the activating function modified to consider a region of lower excitability close to the cell soma. Significance. We present a framework how to estimate the site of action potential initiation and the stimulus required to cross threshold in neurons tightly interfaced to capacitive stimulation electrodes. Our results underscore the necessity of rigorous electrical characterization of the stimulation electrodes and of the interfaced neural tissue.

  6. 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.

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

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    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.

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

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    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

  9. Long-term gene therapy causes transgene-specific changes in the morphology of regenerating retinal ganglion cells.

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    Jennifer Rodger

    Full Text Available Recombinant adeno-associated viral (rAAV vectors can be used to introduce neurotrophic genes into injured CNS neurons, promoting survival and axonal regeneration. Gene therapy holds much promise for the treatment of neurotrauma and neurodegenerative diseases; however, neurotrophic factors are known to alter dendritic architecture, and thus we set out to determine whether such transgenes also change the morphology of transduced neurons. We compared changes in dendritic morphology of regenerating adult rat retinal ganglion cells (RGCs after long-term transduction with rAAV2 encoding: (i green fluorescent protein (GFP, or (ii bi-cistronic vectors encoding GFP and ciliary neurotrophic factor (CNTF, brain-derived neurotrophic factor (BDNF or growth-associated protein-43 (GAP43. To enhance regeneration, rats received an autologous peripheral nerve graft onto the cut optic nerve of each rAAV2 injected eye. After 5-8 months, RGCs with regenerated axons were retrogradely labeled with fluorogold (FG. Live retinal wholemounts were prepared and GFP positive (transduced or GFP negative (non-transduced RGCs injected iontophoretically with 2% lucifer yellow. Dendritic morphology was analyzed using Neurolucida software. Significant changes in dendritic architecture were found, in both transduced and non-transduced populations. Multivariate analysis revealed that transgenic BDNF increased dendritic field area whereas GAP43 increased dendritic complexity. CNTF decreased complexity but only in a subset of RGCs. Sholl analysis showed changes in dendritic branching in rAAV2-BDNF-GFP and rAAV2-CNTF-GFP groups and the proportion of FG positive RGCs with aberrant morphology tripled in these groups compared to controls. RGCs in all transgene groups displayed abnormal stratification. Thus in addition to promoting cell survival and axonal regeneration, vector-mediated expression of neurotrophic factors has measurable, gene-specific effects on the morphology of injured

  10. 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.

  11. 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

  12. 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

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

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    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.

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

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    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.

  15. Retinal ganglion cells: mechanisms underlying depolarization block and differential responses to high frequency electrical stimulation of ON and OFF cells

    Science.gov (United States)

    Kameneva, T.; Maturana, M. I.; Hadjinicolaou, A. E.; Cloherty, S. L.; Ibbotson, M. R.; Grayden, D. B.; Burkitt, A. N.; Meffin, H.

    2016-02-01

    Objective. ON and OFF retinal ganglion cells (RGCs) are known to have non-monotonic responses to increasing amplitudes of high frequency (2 kHz) biphasic electrical stimulation. That is, an increase in stimulation amplitude causes an increase in the cell’s spike rate up to a peak value above which further increases in stimulation amplitude cause the cell to decrease its activity. The peak response for ON and OFF cells occurs at different stimulation amplitudes, which allows differential stimulation of these functional cell types. In this study, we investigate the mechanisms underlying the non-monotonic responses of ON and OFF brisk-transient RGCs and the mechanisms underlying their differential responses. Approach. Using in vitro patch-clamp recordings from rat RGCs, together with simulations of single and multiple compartment Hodgkin-Huxley models, we show that the non-monotonic response to increasing amplitudes of stimulation is due to depolarization block, a change in the membrane potential that prevents the cell from generating action potentials. Main results. We show that the onset for depolarization block depends on the amplitude and frequency of stimulation and reveal the biophysical mechanisms that lead to depolarization block during high frequency stimulation. Our results indicate that differences in transmembrane potassium conductance lead to shifts of the stimulus currents that generate peak spike rates, suggesting that the differential responses of ON and OFF cells may be due to differences in the expression of this current type. We also show that the length of the axon’s high sodium channel band (SOCB) affects non-monotonic responses and the stimulation amplitude that leads to the peak spike rate, suggesting that the length of the SOCB is shorter in ON cells. Significance. This may have important implications for stimulation strategies in visual prostheses.

  16. Retinal Ganglion Cell Protection Via Topical and Systemic Alpha-Tocopherol Administration in Optic Nerve Crush Model of Rat

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    Zeynep Aktaş

    2013-06-01

    Full Text Available Pur po se: The aim of our study was to investigate the neuroprotective effects of topical α-tocopherol in optic nerve crush model of rat and to compare its efficacy with that of systemic α -tocopherol. Ma te ri al and Met hod: 50 eyes of 25 Wistar albino rats were included. The eyes were divided into six groups. Optic nerve crush was performed in Groups 1, 3, 5. Additionally, systemic and topical α-tocopherol therapies were given to Groups 1 and 3, respectively. No treatment was applied in Group 5. Groups 2, 4, and 6 were the fellow eyes of the animals comprising Groups 1, 3, and 5. Eyes were enucleated at day 45 of the study. Retinal ganglion cells (RGCs were counted with light microscopy. Re sults: Mean RGC numbers were 14.5±3.7 (10.3-20 and 27.5±2.6 (24-30 in Groups 5 and 6, respectively (p: 0.001 They were measured to be 26.6±7.8 (19-45 and 24.6±3.9 (20-32 in Groups 1 and 2 and 21.1±7.1 (11-34 and 27±7.5 (18-42 in Groups 3 and 4 (p:0.659, p:0.094, respectively. There was no difference in Groups 2 and 4 compared with Group 6 (p:0.210, p:0.299, respectively. Dis cus si on: Topical α-tocopherol has a significant neuroprotective effects in optic nerve crush model of rat and may be used in the future for the treatment of optic neuropathies such as glaucoma. (Turk J Ophthalmol 2013; 43: 161-6

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

    Directory of Open Access Journals (Sweden)

    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

  18. Brain-derived neurotrophic factor promotes cochlear spiral ganglion cell survival and function in deafened, developing cats.

    Science.gov (United States)

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

    2011-06-01

    Postnatal development and survival of spiral ganglion (SG) neurons depend on both neural activity and neurotrophic support. Our previous studies showed that electrical stimulation from a cochlear implant only partially 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 brain-derived neurotrophic factor (BDNF) promotes SG survival after deafness have been conducted in rodents and limited to relatively short durations. Our study examined longer duration BDNF treatment in deafened cats that may better model the slow progression of SG degeneration in human cochleae, and this is the first study of BDNF in the developing auditory system. Kittens were deafened neonatally, implanted at 4-5 weeks with intracochlear electrodes containing a drug-delivery cannula, and BDNF or artificial perilymph was infused for 10 weeks from a miniosmotic pump. In BDNF-treated cochleae, SG cells grew to normal size and were significantly larger than cells on the contralateral side. However, their morphology was not completely normal, and many neurons lacked or had thinned perikaryl myelin. Unbiased stereology was employed to estimate SG cell density, independent of cell size. BDNF was effective in promoting significantly improved survival of SG neurons in these developing animals. BDNF treatment also resulted in higher density and larger size of myelinated radial nerve fibers, sprouting of fibers into the scala tympani, and improvement of electrically evoked auditory brainstem response thresholds. BDNF may have potential therapeutic value in the developing auditory system, but many serious obstacles currently preclude clinical application. PMID:21452221

  19. Molecular events associated with increased regenerative capacity of the goldfish retinal ganglion cells following X-irradiation: decreased level of axonal growth inhibitors

    International Nuclear Information System (INIS)

    In our previous work we established conditions to study the contribution of non-neuronal cells to the process of goldfish optic nerve regeneration. This issue has been studied successfully by adapting the use of X-irradiation to manipulate division of non-neuronal cells associated with the injured nerve. The regenerative capacity of the goldfish retinal ganglion cells was determined subsequent to the X-ray treatment. The authors present an analysis of the molecular events associated with regeneration and enhanced regenerative capacity which follows X-irradiation. (Auth.)

  20. 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

  1. 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.

  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. 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

  4. Effects of the concomitant activation of ON and OFF retinal ganglion cells on the visual thalamus: evidence for an enhanced recruitment of GABAergic cells

    Directory of Open Access Journals (Sweden)

    Giovanni Montesano

    2015-11-01

    Full Text Available A fundamental question in vision neuroscience is how parallel processing of Retinal Ganglion Cell (RGC signals is integrated at the level of the visual thalamus. It is well known that parallel ON-OFF pathways generate output signals from the retina that are conveyed to the dorsal lateral geniculate nucleus (dLGN. However, it is unclear how these signals distribute onto thalamic cells and how these two pathways interact. Here, by electrophysiological recordings and c-Fos expression analysis, we characterized the effects of pharmacological manipulations of the retinal circuit aimed at inducing either a selective activation of a single pathway, OFF RGCs (intravitreal L-(+-2-Amino-4-phosphonobutyric, L-AP4 or an unregulated activity of all classes of retinal ganglion cells (intravitreal 4-Aminopyridine, 4-AP. In in vivo experiments, the analysis of c-Fos expression in the dLGN showed that these two manipulations recruited active cells from the same area, the lateral edge of the dLGN. Despite this similarity, the unregulated co-activation of both ON and OFF pathways by 4-AP yielded a much stronger recruitment of GABAergic interneurons in the dLGN when compared to L-AP4 pure OFF activation. The increased activation of an inhibitory thalamic network by a high level of unregulated discharge of ON and OFF RGCs might suggest that cross-inhibitory pathways between opposing visual channels are presumably replicated at multiple levels in the visual pathway, thus increasing the filtering ability for non-informative or noisy visual signals.

  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. 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; Warfvinge, Karin; Lavik, Erin; Kiilgaard, Jens F; Prause, Jan Ulrik; Scherfig, Erik; Young, Michael; la Cour, Morten

    2009-01-01

    eyes injected with GDNF microspheres compared to eyes injected with blank microspheres. In eyes injected with GDNF microspheres the ganglion cell count was 9.5/field (s.e.m.: 2.1, n = 8), in eyes injected with blank microspheres it was 3.5/field (s.e.m.: 1.2, n = 7). This difference was statistically...

  8. 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

  9. 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...

  10. 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.

  11. 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

  12. 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

  13. 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 ...

  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. 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.

  16. 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...

  17. 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

  18. 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.

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

    OpenAIRE

    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...

  20. 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

    Directory of Open Access Journals (Sweden)

    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 

  1. Autocrine protective mechanisms of human granulocyte colony-stimulating factor (G-CSF) on retinal ganglion cells after optic nerve crush.

    Science.gov (United States)

    Huang, Shun-Ping; Fang, Kan-Tang; Chang, Chung-Hsing; Huang, Tzu-Lun; Wen, Yao-Tseng; Tsai, Rong-Kung

    2016-02-01

    This study investigated the role of autocrine mechanisms in the anti-apoptotic effects of human granulocyte colony-stimulating factor (G-CSF) on retinal ganglion cells (RGCs) after optic nerve (ON) crush. We observed that both G-CSF and G-CSF receptor (G-CSFR) are expressed in normal rat retina. Further dual immunofluorescence staining showed G-CSFR immunoreactive cells were colocalized with RGCs, Müller cells, horizontal and amacrine cells. These results confirm that G-CSF is an endogenous ligand in the retina. The semi-quantitative RT-PCR finding demonstrated the transcription levels of G-CSF and G-CSFR were up-regulated after ON crush injury. G-CSF treatment further increased and prolonged the expression level of G-CSFR in the retina. G-CSF has been shown to enhance transdifferentiation of the mobilized hematopoietic stem cells into tissue to repair central nervous system injury. We test the hypothesis that the hematopoietic stem cells recruited by G-CSF treatment can transdifferentiate into RGCs after ON crush by performing sublethal irradiation of the rats 5 days before ON crush. The flow cytometric analysis showed the number of CD34 positive cells in the peripheral blood is significantly lower in the irradiated, crushed and G-CSF-treated group than the sham control group or crush and G-CSF treated group. Nevertheless, the G-CSF treatment enhances the RGC survival after sublethal irradiation and ON crush injury. These data indicate that G-CSF seems unlikely to induce hematopoietic stem cell transdifferentiation into RGCs after ON crush injury. In conclusion, G-CSF may serve an endogenous protective signaling in the retina through direct activation of intrinsic G-CSF receptors and downstream signaling pathways to rescue RGCs after ON crush injury, exogenous G-CSF administration can enhance the anti-apoptotic effects on RGCs. PMID:26518178

  2. 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.

    Science.gov (United States)

    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

  3. Ganglion Cysts

    Science.gov (United States)

    ... a Hand Therapist? Media Find a Hand Surgeon Ganglion Cysts Email to a friend * required fields From * ... in to name and customize your collection. DESCRIPTION Ganglion cysts are very common lumps within the hand ...

  4. 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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

    Science.gov (United States)

    Barua, Nabanita; Sitaraman, Chitra; Goel, Sonu; Chakraborti, Chandana; Mukherjee, Sonai; Parashar, Hemandra

    2016-01-01

    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. PMID:27221682

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

    Directory of Open Access Journals (Sweden)

    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

  7. Intrinsically photosensitive retinal ganglion cell function in relation to age: A pupillometric study in humans with special reference to the age-related optic properties of the lens

    Directory of Open Access Journals (Sweden)

    Herbst Kristina

    2012-04-01

    Full Text Available Abstract Background 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. Methods Consensual pupil responses were explored in 44 healthy subjects aged between 26 and 68 years. A pupil response was recorded to a continuous 20 s light stimulus of 660 nm (red or 470 nm (blue both at 300 cd/m2 intensity (14.9 and 14.8 log photons/cm2/s, respectively. Additional recordings were performed using four 470 nm stimulus intensities of 3, 30, 100 and 300 cd/m2. The baseline pupil size was measured in darkness and results were adjusted for the baseline pupil and gender. The main outcome parameters were maximal and sustained pupil contraction amplitudes and the postillumination response assessed as area under the curve (AUC over two time-windows: early (0–10 s after light termination and late (10–30 s after light termination. Lens transmission was measured with an ocular fluorometer. Results The sustained pupil contraction and the early poststimulus AUC correlated positively with age (p = 0.02, p = 0.0014, respectively for the blue light stimulus condition only. The maximal pupil contraction amplitude did not correlate to age either for bright blue or red light stimulus conditions. Lens transmission decreased linearly with age (p 2 light (p = 0.02. Conclusions Age did not reduce, but rather enhance pupil responses mediated by ipRGC. The age related decrease of blue light transmission led to similar results, however, the effect of age was greater on these pupil responses than that of the lens transmission. Thus there must

  8. 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

    Directory of Open Access Journals (Sweden)

    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.

  9. Demonstration of a neurotrophic factor for the maintenance of acetylcholinesterase and butyrylcholinesterase in the preganglionically denervated superior cervical ganglion of the cat.

    OpenAIRE

    Koelle, G B; Ruch, G A

    1983-01-01

    Under sodium pentobarbital anesthesia, the superior cervical ganglia of cats were preganglionically denervated bilaterally. The following day cats were reanesthetized, the external carotid and lingual arteries were ligated bilaterally, and the right common carotid artery was infused for 24 hr with an extract prepared from cat brain, spinal cord, and sciatic nerves, with and without the incorporation of aprotinin, an inhibitor of proteases. They were sacrificed 48 hr after denervation, and the...

  10. Effects of sodium pentobarbital anesthesia and neurotrophic factor on the maintenance of acetylcholinesterase and butyrylcholinesterase in the preganglionically denervated superior cervical ganglion of the cat.

    OpenAIRE

    Koelle, G B; Ruch, G A; Uchida, E

    1983-01-01

    In continuation of a previously reported study, the superior cervical ganglia of cats were preganglionically denervated bilaterally under sodium pentobarbital anesthesia. The following day cats were reanesthetized and infused via the common carotid artery with an aqueous extract of cat brain, spinal cord, and sciatic nerves for periods of 24, 12, 6, and 3 hr, without ligation of the external carotid or lingual arteries as was done previously. Values for acetylcholinesterase and butyrylcholine...

  11. 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

  12. Effects of glycyl-L-glutamine in vitro on the molecular forms of acetylcholinesterase in the preganglionically denervated superior cervical ganglion of the cat.

    OpenAIRE

    Koelle, G B; Massoulié, J; Eugène, D; Melone, M.A.

    1988-01-01

    Normal and preganglionically denervated cat superior cervical ganglia were sectioned and cultured for 24 or 48 hr, with or without preliminary inactivation of acetylcholinesterase, and in the presence or absence of 10(-5) M glycyl-L-glutamine. They were then homogenized, and the molecular forms of acetylcholinesterase were analyzed by sucrose gradient sedimentation. We observed an increased proportion of the globular monomeric G1 form, and to a lesser extent of the dimeric G2 and tetrameric m...

  13. 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

    Directory of Open Access Journals (Sweden)

    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.

  14. Periosteal ganglion

    International Nuclear Information System (INIS)

    Ganglionic cysts are a common myxomatous degenerative disorder in periarticular connective tissues particularly in the hand and foot as well as within the subchondral bone adjacent to osteoarthritic joints. Compared with them, periosteal ganglia are only rarely reported in the literature. Their radiologic features are quite typical as documented by the following observation. (orig.)

  15. Periosteal ganglion

    Energy Technology Data Exchange (ETDEWEB)

    Kolar, J.; Zidkova, H.; Matejovsky, Z.

    1986-02-01

    Ganglionic cysts are a common myxomatous degenerative disorder in periarticular connective tissues particularly in the hand and foot as well as within the subchondral bone adjacent to osteoarthritic joints. Compared with them, periosteal ganglia are only rarely reported in the literature. Their radiologic features are quite typical as documented by the following observation.

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

    Science.gov (United States)

    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

  17. Repeatability of Perimacular Ganglion Cell Complex Analysis with Spectral-Domain Optical Coherence Tomography

    OpenAIRE

    Ng, Dorothy S. K.; Preeti Gupta; Yih Chung Tham; Chye Fong Peck; Tien Yin Wong; Mohammad Kamran Ikram; Cheung, Carol Y.

    2015-01-01

    Purpose. To assess the repeatability of spectral-domain optical coherence tomography to measure macular and perimacular ganglion cell complex thicknesses and compare retinal ganglion cell parameters between algorithms. Methods. Ninety-two nonglaucomatous eyes from 92 participants underwent macular and perimacular ganglion cell complex thickness measurement using OCT-HS100 Glaucoma 3D algorithm and these measurements were repeated for 34 subjects. All subjects also had macular ganglion cell-in...

  18. Dopaminergic modulation of tracer coupling in a ganglion-amacrine cell network

    OpenAIRE

    Mills, Stephen L.; XIA, XIAO-BO; HOSHI, HIDEO; Firth, Sally I.; Rice, Margaret E.; Frishman, Laura J.; MARSHAK, DAVID W.

    2007-01-01

    Many retinal ganglion cells are coupled via gap junctions with neighboring amacrine cells and ganglion cells. We investigated the extent and dynamics of coupling in one such network, the OFF α ganglion cell of rabbit retina and its associated amacrine cells. We also observed the relative spread of Neurobiotin injected into a ganglion cell in the presence of modulators of gap junctional permeability. We found that gap junctions between amacrine cells were closed via stimulation of a D1 dopamin...

  19. Ocular morphology, topography of ganglion cell distribution and visual resolution of the pilot whale (Globicephala melas)

    OpenAIRE

    Mengual Molina, Rosa María; García Irles, Magdalena; Segovia Huertas, Yolanda; Pertusa, José Francisco

    2015-01-01

    The ocular morphology, morphological characteristics and topography of ganglion cell distribution were studied in four eyes of Globicephala melas to estimate the retinal resolution. The ganglion cell layer was composed of a single row of ganglion cells with a primarily round shape and a cell size which varied from 10 to 75 µm (mean 33.5 µm) in diameter. The typical feature was that 65 % of ganglion cells had a diameter larger than 25 µm, with a similar average size in all regions of the retin...

  20. 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...

  1. 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

  2. Retinal oximetry

    OpenAIRE

    Sveinn Hákon Harðarson 1978

    2012-01-01

    Purpose Malfunction of retinal blood flow or oxygenation is believed to be involved in various diseases. Among them are retinal vessel occlusions, diabetic retinopathy and glaucoma. Reliable, non-invasive technology for retinal oxygen measurements has been scarce and most of the knowledge on retinal oxygenation comes from animal studies. This thesis describes human retinal oximetry, performed with novel retinal oximetry technology. The thesis describes studies on retinal vessel oxygen satu...

  3. Axonal Transmission in the Retina Introduces a Small Dispersion of Relative Timing in the Ganglion Cell Population Response

    OpenAIRE

    Zeck, G; Lambacher, A.; Fromherz, P

    2011-01-01

    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 dispersio...

  4. 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...

  5. 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.

  6. Lumbar Intraspinal Extradural Ganglion Cysts

    OpenAIRE

    Cho, Sung Min; Rhee, Woo Tack; Choi, Soo Jung; Eom, Dae Woon

    2009-01-01

    The lumbar intraspinal epidural ganglion cyst has been a rare cause of the low back pain or leg pain. Ganglion cysts and synovial cysts compose the juxtafacet cysts. Extensive studies have been performed about the synovial cysts, however, very little has been known about the ganglion cyst. Current report is about two ganglion cysts associated with implicative findings in young male patients. We discuss about the underlying pathology of the ganglion cyst based on intraoperative evidences, asso...

  7. 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.

  8. Retinitis Pigmentosa

    Science.gov (United States)

    ... Congenital Amaurosis Macular Degeneration Retinitis Pigmentosa Stargardt Disease Usher Syndrome Other Retinal Diseases Glossary News & Research News & ... die. Forms of RP and related diseases include Usher syndrome, Leber’s congenital amaurosis, rod-cone disease, Bardet- ...

  9. W-cells in the cat retina: correlated morphological and physiological evidence for two distinct classes.

    Science.gov (United States)

    Stanford, L R

    1987-01-01

    Intracellular recording and iontophoresis of horseradish peroxidase were used to study the morphology of physiologically characterized W-cells in the cat retina. The recording experiments were performed in an in vivo preparation to allow the responses of these retinal ganglion cells to be compared with previous functional studies of these neurons. The physiological and morphological characteristics of 16 injected and recovered retinal W-cells were compared with similar data from 14 retinal X-cells injected in the same preparations. The soma sizes of retinal W-cells were found to fall into two distinct groups. The somata of the phasic W-cells, at every eccentricity, were smaller than the somata of tonic W-cells, with no overlap between the two distributions. Soma sizes of the tonic W-cells fell into the previously described "medium-sized" range of retinal ganglion cell soma sizes and were similar to, although slightly larger than, the soma sizes of physiologically identified beta- or X-cells. The dendritic arbors of all of the cells physiologically classified as tonic W-cells were similar. Every example of this type had four to five primary dendrites that branched a short distance from the soma to form a circular or cruciate dendritic arbor. The dendritic arrays of these cells were easily distinguishable from the compact dendritic arbors of the physiologically identified X-cells. The dendritic arbors of the phasic W-cells were much more heterogeneous, ranging from sparse, wide dendritic arbors to very compact dendritic arbors with many fine branches. No significant correlation was found between the extent of the dendritic arbor and the distance from the area centralis for either the tonic W-cells or the phasic W-cells. The axons of the tonic and phasic W-cells differed from one another and from X-cells on a number of different morphological and physiological measures. The intraretinal segments of the axons of the phasic W-cells had the smallest diameters of the

  10. One case of intraosseous ganglion

    International Nuclear Information System (INIS)

    Intraosseous ganglion is a rare disease and identified as a cystic lesion on plain radiograph. One case of intraosseous ganglion is examined by plain radiography and computed tomography and findings are analyzed.

  11. One case of intraosseous ganglion

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sun Seob; Shim, Hyung Jin; Lee, Yong Chul [Chung Ang University College of Medicine, Seoul (Korea, Republic of)

    1983-09-15

    Intraosseous ganglion is a rare disease and identified as a cystic lesion on plain radiograph. One case of intraosseous ganglion is examined by plain radiography and computed tomography and findings are analyzed.

  12. Semimembranosus ganglion cyst

    OpenAIRE

    Ananthi Kumarasamy, Suba; Kannadath, Bijun Sai; Soundamourthy, Sandosh; Subramanian, Aruna; Sankappa P Sinhasan; Ramachandra V. Bhat

    2014-01-01

    Ganglion cysts are tumor-like lesions in the soft tissues, generated by mucoid degeneration of the joint capsule, tendon or tendon sheaths on the dorsum of hand, wrist and foot. However, an intratendinous origin for a ganglion cyst is extremely rare. During dissection of the popliteal fossa, a cyst of 2.5 cm×2 cm×0.5 cm was observed in the tendon of right semimembranosus, 3.5 cm above the insertion of the muscle. Contrast X-ray revealed the cyst as not communicating with the knee joint or any...

  13. Calcitonin gene-related peptide and nitric oxide in the trigeminal ganglion

    DEFF Research Database (Denmark)

    Edvinsson, L; Mulder, H; Goadsby, P J; Uddman, R

    ganglion of the cat, a moderate number of NOS immunoreactive nerve cell bodies was seen, of which the major part also expressed calcitonin gene-related peptide (CGRP). The nerve cell bodies expressing NOS in the trigeminal ganglion were predominantly of small to medium size; while numerous cell bodies of...... flow. However, the nasociliary nerve response was reduced by 50% after h-CGRP (8-37), with a general shift to the right of the frequency-response curve. These data suggest that although NOS is seen in several trigeminal ganglion cells and coexists with CGRP in a subpopulation of the sensory neurons...

  14. 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

  15. Selective wavelength pupillometry to evaluate outer and inner retinal photoreception

    OpenAIRE

    Kawasaki, Aki

    2013-01-01

    Purpose Intrinsically photosensitive retinal ganglion cells (ipRGCs) express a unique photopigment called melanopsin. Capable of direct phototransduction, the ipRGCs are also influenced by rods and cones via synaptic inputs.  Thus, the photoinput that mediates the pupil light reflex derives from both outer (rods and cones) and inner (melanopsin-mediated) retinal photoreception. This thesis has aimed to develop a pupillometric test that provides quantitative information about the functional st...

  16. The smooth monostratified ganglion cell: evidence for spatial diversity in the Y-cell pathway to the lateral geniculate nucleus and superior colliculus in the macaque monkey.

    Science.gov (United States)

    Crook, Joanna D; Peterson, Beth B; Packer, Orin S; Robinson, Farrel R; Gamlin, Paul D; Troy, John B; Dacey, Dennis M

    2008-11-26

    In the primate visual system approximately 20 morphologically distinct pathways originate from retinal ganglion cells and project in parallel to the lateral geniculate nucleus (LGN) and/or the superior colliculus. Understanding of the properties of these pathways and the significance of such extreme early pathway diversity for later visual processing is limited. In a companion study we found that the magnocellular LGN-projecting parasol ganglion cells also projected to the superior colliculus and showed Y-cell receptive field structure supporting the hypothesis that the parasol cells are analogous to the well studied alpha-Y cell of the cat's retina. We here identify a novel ganglion cell class, the smooth monostratified cells, that share many properties with the parasol cells. Smooth cells were retrogradely stained from tracer injections made into either the LGN or superior colliculus and formed inner-ON and outer-OFF populations with narrowly monostratified dendritic trees that surprisingly appeared to perfectly costratify with the dendrites of parasol cells. Also like parasol cells, smooth cells summed input from L- and M-cones, lacked measurable S-cone input, showed high spike discharge rates, high contrast and temporal sensitivity, and a Y-cell type nonlinear spatial summation. Smooth cells were distinguished from parasol cells however by smaller cell body and axon diameters but approximately 2 times larger dendritic tree and receptive field diameters that formed a regular but lower density mosaic organization. We suggest that the smooth and parasol populations may sample a common presynaptic circuitry but give rise to distinct, parallel achromatic spatial channels in the primate retinogeniculate pathway. PMID:19036959

  17. Retinal Detachment

    Science.gov (United States)

    ... are three different types of retinal detachment: Rhegmatogenous [reg-ma-TAH-jenous]—A tear or break in the retina allows fluid to get under the retina and separate it from the retinal pigment epithelium (RPE), the pigmented cell layer that nourishes the retina. These types of ...

  18. The Human Spiral Ganglion

    OpenAIRE

    Tylstedt, Sven

    2003-01-01

    Our knowledge of the fine structure of the Human Spiral Ganglion (HSG) is still inadequate and new treatment techniques for deafness using electric stimulation, call for further information and studies on the neuronal elements of the human cochlea. This thesis presents results of analyses of human cochlear tissue and specimens obtained during neurosurgical transpetrosal removal of life-threatening meningeomas. The use of surgical biopsies produced a well-preserved material suitable for ultras...

  19. Establishing an experimental rat model of photodynamically-induced retinal vein occlusion using erythrosin B

    OpenAIRE

    Wei Chen; Ying Wu; Mi Zheng; Qing Gu; Zhi Zheng; Xin Xia

    2014-01-01

    AIM:To develop a reliable, reproducible rat model of retinal vein occlusion (RVO) with a novel photosensitizer (erythrosin B) and study the cellular responses in the retina.METHODS:Central and branch RVOs were created in adult male rats via photochemically-induced ischemia. Retinal changes were monitored via color fundus photography and fluorescein angiography at 1 and 3h, and 1, 4, 7, 14, and 21d after irradiation. Tissue slices were evaluated histopathologically. Retinal ganglion cell survi...

  20. 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...

  1. Retinal circadian clocks and non-visual photoreceptors: light input to the circadian system.

    OpenAIRE

    Ouria Dkhissi-Benyahya

    2013-01-01

    The mammalian retina contains an endogenous pacemaker that regulates retinal physiology and adjusts daily the temporal phase of the central circadian timing system with environmental time. This entrainment process involves rods, cones and melanopsin-expressing retinal ganglion cells. In contrast with non mammalian retinas, in which the clock has been identified in photoreceptors, the location of the retinal circadian clock in mammals is still controversial. In addition, the impact of specific...

  2. 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

  3. Ganglion Cyst of the Wrist and Hand

    Science.gov (United States)

    .org Ganglion Cyst of the Wrist and Hand Page ( 1 ) Ganglion cysts are the most common mass or lump ... can quickly appear, disappear, and change size. Many ganglion cysts do not require treatment. However, if the ...

  4. 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

  5. [Vision engineering--photoelectric dye-based retinal prostheses: Okayama University model].

    Science.gov (United States)

    Matsuo, Toshihiko

    2007-04-01

    Patients with retinitis pigmentosa lose photoreceptor cells by genetic abnormalities and hence become blind. Neurons such as bipolar cells and ganglion cells still remain alive even in the retina of these patients, and ganglion cells send axons to the brain as the optic nerve. The replacement of dead photoreceptor cells with something artificial is the basic concept of retinal prostheses. The remaining retinal neurons can be stimulated by either electric current or electric potential. Photodiode array and electrode array are two main ways to stimulate retinal neurons as retinal prostheses. These retinal prostheses have problems such as low sensitivity and requiring outer electric sources (batteries). To overcome the problems, we are developing photoelectric dye-based retinal prostheses which absorb light and convert photon energy to electric potentials. The prototype, photoelectric dye-coupled polyethylene film, could generate intracellular calcium elevation in photoreceptor-lacking retinal tissues and also in cultured retinal neurons. The photoelectric dye-based retinal prostheses are thin and soft, and therefore, a sheet of the film in a large size, corresponding to wide visual field, can be inserted into the vitreous and then to the subretinal space through a small opening by rolling up the film. After the production control and the quality control have been established, clinical trials of the photoelectric dye-based retinal prostheses would be planned in concordance with the Drugs and Medical Devices Law to prove the safety and the efficacy. PMID:17447519

  6. 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

  7. Amyloidomas of the Gasserian Ganglion

    OpenAIRE

    van Lindert, Erik; Bornemann, Antje; Hey, Otto; Perneczky, Axel; Müller-Forell, Wibke

    1995-01-01

    An amyloidoma is a local deposition of amyloid that becomes a space-occupying lesion. Amyloidomas of the central nervous system are very uncommon lesions and only four amyloidomas of the gasserian ganglion have been reported so far. We present the neuroradiologic and surgical characteristics of three more amyloidomas of the gasserian ganglion seen at one neurosurgical department in 11 years.

  8. Other Retinal Diseases

    Science.gov (United States)

    ... Congenital Amaurosis Macular Degeneration Retinitis Pigmentosa Stargardt Disease Usher Syndrome Other Retinal Diseases Glossary News & Research News & ... affected by retinitis pigmentosa, age-related macular degeneration, Usher syndrome and the entire spectrum of retinal diseases. ...

  9. Retinal topography of the harp seal Pagophilus groenlandicus.

    Science.gov (United States)

    Mass, Alla M; Supin, A Y

    2003-01-01

    The total number, size, topographic distribution, and cell density of ganglion cells were studied in retinal wholemounts of the harp seal Pagophilus groenlandicus. Ganglion cell size varied from 10 to 60 mum. A distinct group were large ganglion cells more than 30-35 mum in diameter which were similar to alpha-cells known in terrestrial mammals. The number of alpha-cells constituted 5.3-5.9% of the total ganglion cell population. The cell size distribution was bimodal, with the second mode composed of alpha-cells. The topographic distribution of ganglion cells showed a definite area of high cell density similar to area centralis of terrestrial carnivores. This area was located in the temporal retinal quadrant, 7-8 mm (16-18 degrees ) from the optic disk. In this area, the peak cell densities in two wholemounts were 2,500 and 1,650 (mean 2,075) cells/mm(2). With a posterior nodal distance of 25.5 mm (underwater), this density corresponded to 495 and 327 (mean 411) cells/deg(2). These values predict a retinal resolution of 2.7-3.3' (11.1-9.0 cycles/deg) in water and 3.6-4.4' (8.3-6.8 cycles/deg) in air. Topographic distributions of alpha-cells was qualitatively similar to that of the total ganglion cell population, but the density of alpha-cells constituted only a few percent (mostly 3-7.5%) of the total ganglion cell density. PMID:14573995

  10. 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.

  11. Block of gap junctions eliminates aberrant activity and restores light responses during retinal degeneration.

    Science.gov (United States)

    Toychiev, Abduqodir H; Ivanova, Elena; Yee, Christopher W; Sagdullaev, Botir T

    2013-08-28

    Retinal degeneration leads to progressive photoreceptor cell death, resulting in vision loss. Subsequently, inner retinal neurons develop aberrant synaptic activity, compounding visual impairment. In retinal ganglion cells, light responses driven by surviving photoreceptors are obscured by elevated levels of aberrant spiking activity. Here, we demonstrate in rd10 mice that targeting disruptive neuronal circuitry with a gap junction antagonist can significantly reduce excessive spiking. This treatment increases the sensitivity of the degenerated retina to light stimuli driven by residual photoreceptors. Additionally, this enhances signal transmission from inner retinal neurons to ganglion cells, potentially allowing the retinal network to preserve the fidelity of signals either from prosthetic electronic devices, or from cells optogenetically modified to transduce light. Thus, targeting maladaptive changes to the retina allows for treatments to use existing neuronal tissue to restore light sensitivity, and to augment existing strategies to replace lost photoreceptors. PMID:23986234

  12. Acetylcholinesterase-positive afferent axons in mucosa of urinary bladder of adult cats: retrograde tracing and degeneration studies

    OpenAIRE

    Wakabayashi, Y.; Kojima, Y.; Makiura, Y.; Tomoyoshi, T.; Maeda, T.

    1995-01-01

    Acetylcholinesterase (AchE)-positive afferent axons in the mucosa of the cat urinary bladder were examined in the present experiments. Smallsized dorsal root ganglion cells containing AchE enzyme activity were labelled by injection of retrograde tracer (wheat germ agglutinin conjugated to enzymatically inactive horseradish peroxidase gold complex) into the bladder mucosa of adult cats. Results show that 48.9% (901184) of the labelled ganglion cells possesse...

  13. 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

  14. 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

  15. 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

  16. 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.

  17. The human superior cervical ganglion

    DEFF Research Database (Denmark)

    Tajti, J; Möller, S; Uddman, R; Bodi, I; Edvinsson, L

    Noradrenaline (NA)- and neuropeptide Y (NPY)-containing cell bodies were found to occur in high numbers (>75% of all cells were positive) in the human superior cervical ganglion and distributed homogeneously throughout the ganglion and showed colocalisation. A few cell bodies were VIP......-immunoreactive (-ir) (less than 5%) but none of them showed NOS-, CGRP- or SP-ir. Receptor mRNA expression was studied with RT-PCR. Total RNA from the superior cervical ganglion was successfully extracted. By using appropriate sense and antisense oligonucleotides designed from the published human sequences, we could...

  18. Symptomatic Elbow Ganglion Causing Pronator Syndrome

    OpenAIRE

    Ross Blagg, MD; W. Bradford Rockwell, MD

    2014-01-01

    Summary: Descriptions of ganglion cysts date back to 400 BC. Ganglions causing peripheral nerve compression have been described most notably at the wrist. Ganglion compression of the median nerve at the elbow is rare. We report a case of a palmar elbow ganglion causing median nerve compression and the clinical presentation of pronator syndrome. After removal of the ganglion and median nerve decompression, the patient’s symptoms fully resolved.

  19. Symptomatic Elbow Ganglion Causing Pronator Syndrome

    Directory of Open Access Journals (Sweden)

    Ross Blagg, MD

    2014-02-01

    Full Text Available Summary: Descriptions of ganglion cysts date back to 400 BC. Ganglions causing peripheral nerve compression have been described most notably at the wrist. Ganglion compression of the median nerve at the elbow is rare. We report a case of a palmar elbow ganglion causing median nerve compression and the clinical presentation of pronator syndrome. After removal of the ganglion and median nerve decompression, the patient’s symptoms fully resolved.

  20. 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; Grønskov, Karen; Milea, Dan; Larsen, Michael

    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...

  1. Cat scratch disease (image)

    Science.gov (United States)

    Cat scratch disease is an infectious illness associated with cat scratches, bites, or exposure to cat saliva, causing chronic swelling of the lymph nodes. Cat scratch disease is possibly the most common cause of ...

  2. 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

  3. 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

    interest on these cells, mainly focused on animal models. Only recently, a few studies have started to address the relevance of the mRGC system in humans and related diseases. We recently discovered that mRGCs resist neurodegeneration in two inherited mitochondrial disorders that cause blindness, i...

  4. 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.

  5. 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, ...

  6. A Catalogue of Anatomical Fugitive Sheets: Cat. 49-62

    OpenAIRE

    1999-01-01

    Images Cat. 50 Cat. 51 Cat. 53 Cat. 54 Cat. 55 (a) Cat. 55 (b) Cat. 56 Cat. 57: 1 Cat. 57: 2 Cat. 57: 3 Cat. 57: 4 Cat. 59: 1 Cat. 59: 2 Cat. 59: 3 Cat. 59: 4 Cat. 60 Cat. 61 Cat. 62: 1 (a) Cat. 62: 1 (b) Cat. 62: 2 (a) Cat. 62: 2 (b)

  7. A Catalogue of Anatomical Fugitive Sheets: Cat. 26-48

    OpenAIRE

    1999-01-01

    Images Cat. 26: 1 (a) Cat. 26: 1 (b) Cat. 26: 2 (a) Cat. 26: 2(b) Cat. 27: 1 (a) Cat. 27: 1 (b) Cat. 27: 2 (a) Cat. 27: 2 (b) Cat. 28 Cat. 29: 2 (a) Cat. 29: 2 (b) Cat. 30: 1 Cat. 30: 2 Cat. 30: 3 Cat. 33 Cat. 34: 1 Cat. 34: 2 Cat. 35: 1 Cat. 35: 2 Cat. 35: 3 Cat. 36 Cat. 37 Cat. 38: 1 Cat. 38: 2 Cat. 40 Cat. 42 Cat. 43 Cat. 44 Cat. 45: 1 Cat. 45: 2 Cat. 46 Cat. 47: 1 Cat. 47: 2 Cat. 47: 3 Cat. 48: 1 Cat. 48: 2 Cat. 48: 3

  8. 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.

  9. 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...

  10. 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...

  11. 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.

  12. Retinal vein occlusion

    Science.gov (United States)

    Central retinal vein occlusion; Branch retinal vein occlusion; CRVO; BRVO ... Retinal vein occlusion is most often caused by hardening of the arteries ( atherosclerosis ) and the formation of a blood clot. Blockage ...

  13. Retinitis pigmentosa

    Directory of Open Access Journals (Sweden)

    Hamel Christian

    2006-10-01

    Full Text Available Abstract Retinitis pigmentosa (RP is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visual acuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms. Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema, and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis.

  14. 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...

  15. IPLaminator: an ImageJ plugin for automated binning and quantification of retinal lamination

    OpenAIRE

    LI, SHUAI; Woodfin, Michael; Long, Seth S.; Fuerst, Peter G.

    2016-01-01

    Background Information in the brain is often segregated into spatially organized layers that reflect the function of the embedded circuits. This is perhaps best exemplified in the layering, or lamination, of the retinal inner plexiform layer (IPL). The neurites of the retinal ganglion, amacrine and bipolar cell subtypes that form synapses in the IPL are precisely organized in highly refined strata within the IPL. Studies focused on developmental organization and cell morphology often use this...

  16. The retinal clock is altered in a mouse model of diabetic retinopathy

    OpenAIRE

    HASNA LAHOUAOUI; Christine Coutanson; Mohamed BENNIS

    2013-01-01

    The mammalian retina contains an endogenous pacemaker that regulates retinal physiology and adjusts daily the temporal phase of the central circadian timing system with environmental time. This entrainment process involves rods, cones and melanopsin-expressing retinal ganglion cells. Diabetic retinopathy is a major cause of blindness and visual impairment that affects up to 90% of patients with diabetes. Although vascular damage is considered the first clinical sign of retinopathy, several ...

  17. Neural remodeling in retinal degeneration.

    Science.gov (United States)

    Marc, Robert E; Jones, Bryan W; Watt, Carl B; Strettoi, Enrica

    2003-09-01

    Mammalian retinal degenerations initiated by gene defects in rods, cones or the retinal pigmented epithelium (RPE) often trigger loss of the sensory retina, effectively leaving the neural retina deafferented. The neural retina responds to this challenge by remodeling, first by subtle changes in neuronal structure and later by large-scale reorganization. Retinal degenerations in the mammalian retina generally progress through three phases. Phase 1 initiates with expression of a primary insult, followed by phase 2 photoreceptor death that ablates the sensory retina via initial photoreceptor stress, phenotype deconstruction, irreversible stress and cell death, including bystander effects or loss of trophic support. The loss of cones heralds phase 3: a protracted period of global remodeling of the remnant neural retina. Remodeling resembles the responses of many CNS assemblies to deafferentation or trauma, and includes neuronal cell death, neuronal and glial migration, elaboration of new neurites and synapses, rewiring of retinal circuits, glial hypertrophy and the evolution of a fibrotic glial seal that isolates the remnant neural retina from the surviving RPE and choroid. In early phase 2, stressed photoreceptors sprout anomalous neurites that often reach the inner plexiform and ganglion cell layers. As death of rods and cones progresses, bipolar and horizontal cells are deafferented and retract most of their dendrites. Horizontal cells develop anomalous axonal processes and dendritic stalks that enter the inner plexiform layer. Dendrite truncation in rod bipolar cells is accompanied by revision of their macromolecular phenotype, including the loss of functioning mGluR6 transduction. After ablation of the sensory retina, Müller cells increase intermediate filament synthesis, forming a dense fibrotic layer in the remnant subretinal space. This layer invests the remnant retina and seals it from access via the choroidal route. Evidence of bipolar cell death begins in

  18. 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.

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

    International Nuclear Information System (INIS)

    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% O2). 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

  1. 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 ...

  2. Visual cortex controls retinal output in the rat.

    Science.gov (United States)

    Molotchnikoff, S; Tremblay, F

    1986-07-01

    The first objective of the present investigation was to shed more light on corticofugal influences on the retina by providing an analysis of the type and proportion of retinal ganglion cells that are affected by cooling the visual cortex in rats. The second question was to determine if the pretectum participates in functional cortico-retinal relationships. In urethane-anesthetized and paralyzed hooded rats, axonal activity of retinal ganglion cells was recorded with glass micropipettes at optic chiasm level. Units were classified as ON, OFF, suppressed-by-light and concentric. The visual cortex was inactivated by cooling its surface with a 4 mm2 steel probe using the Peltier effect. The pretectum was blocked with microinjections of 50 to 100 nanoliters of cobalt ions, lidocaine hydrochloride or KCl. The inactivations and recoveries at both sites were monitored by simultaneously recording evoked field potentials. Interrupting corticofugal impulses caused modifications of the evoked discharge pattern in all types of cells. The concentric type was the group least affected by cortical cooling. A common trend emerged suggesting that cooling of the visual cortex led to an enhancement of the initial evoked excitation. This was often followed by an enhanced post-excitatory inhibition. The Pearson coefficient allowed us to measure the degree of similarity between two histograms. When all data were pooled, a weak correlation between control and test histograms (r = 0.29, N = 56) was found, while the control and recovery patterns averaged a correlation of more than twice that size (r = 0.68). In a second series of experiments, the pretectum and visual cortex (VC) were simultaneously inactivated. It is shown that both sites summed their influence and acted synergistically upon the pattern of ganglion cell responses. The results strongly suggest that the visual cortex exerts a major control over the response pattern of thirty percent of retinal ganglion cells, and that the

  3. Intraosseous ganglion of the patella

    International Nuclear Information System (INIS)

    Osteolytic cystic lesions of the patella are rare lesions. A review of the literature revealed only one previously reported example. The pathogenesis and radiological and pathological features of intraosseous ganglion cysts are discussed. In addition, the differential diagnosis of lytic patellar lesions is discussed. (orig.). With 5 figs

  4. Intraosseous ganglion of the patella

    Energy Technology Data Exchange (ETDEWEB)

    Tam, W. [Department of Radiology, Veterans Administration Medical Center, 3350 La Jolla Village Drive, San Diego, CA 92161 (United States); Resnick, D. [Department of Radiology, Veterans Administration Medical Center, 3350 La Jolla Village Drive, San Diego, CA 92161 (United States); Haghighi, P. [Department of Pathology, Veterans Administration Medical Center, San Diego, California (United States); Vaughan, L. [Department of Orthopedic Surgery, Scripps Green Clinic and Research Center, La Jolla, California (United States)

    1996-08-01

    Osteolytic cystic lesions of the patella are rare lesions. A review of the literature revealed only one previously reported example. The pathogenesis and radiological and pathological features of intraosseous ganglion cysts are discussed. In addition, the differential diagnosis of lytic patellar lesions is discussed. (orig.). With 5 figs.

  5. 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

  6. 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)

  7. 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.

  8. Neuroprotective Effects of Low-Dose Statins in the Retinal Ultrastructure of Hypercholesterolemic Rabbits

    Science.gov (United States)

    de Hoz, Rosa; Salazar, Juan J; Ramírez, Ana I; Rojas, Blanca; Gallego, Beatriz I.; Triviño, Alberto; Tejerina, Teresa

    2016-01-01

    To evaluate the pleiotropic effects to statins, we analyze the qualitative and quantitative retinal changes in hypercholesterolemic rabbits after a low-dosage statin treatment. For this purpose, New Zealand rabbits were split into three groups: control (G0; n = 10), fed a standard diet; hypercholesterolemic (G1; n = 8), fed a 0.5% cholesterol-enriched diet for 8 months; and statins (G2; n = 8), fed a 0.5% cholesterol-enriched diet for 8 months, together with the administration of statin (pravastatin or fluvastatin sodium) at a dose of 2 mg / kg / day each diet. The retinas were analyzed by transmission electron microscopy and immunohistochemistry (glial fibrillary acidic protein). The retinal thickness of nuclear and plexiform layers were quantified in semi-thin sections. The results revealed that the low-statin-treated rabbits in comparison with the hypercholesterolemic group showed: i) a more preserved structure in all retinal layers; ii) a significant reduction in retinal thickness; iii) a decrease in cell death in the nuclear-and ganglion-cell layers; iv) a reduction of hydropic degeneration in the plexiform and nerve-fiber layers; v) a preservation of astrocytes and of the retinal area occupied by them; and vi) a better-preserved retinal vascular structure. Our findings indicate that low doses of statins can prevent retinal degeneration, acting on retinal macroglia, neurons and retinal vessels, despite that hypercholesterolemia remained unchanged. Thus, the pleiotropic effects of the statins may help safeguard the retinal ultrastructure. PMID:27144842

  9. 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

  10. 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...

  11. 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.

  12. Types of Parvalbumin-Containing Retinotectal Ganglion Cells in Mouse

    International Nuclear Information System (INIS)

    The calcium-binding protein parvalbumin (PV) occurs in the retinal ganglion cells (RGCs) of various vertebrate species. In the present study, we aimed to identify the types of PV-containing RGCs that project to the superior colliculus (SC) in the mouse. We injected retrograde tracer dextran into the mouse SC to label RGCs. PV-containing RGCs were first identified by immunocytochemistry and then neurons double-labeled with dextran and PV were iontophoretically injected with a lipophilic dye, DiI. Subsequently, confocal microscopy was used to characterize the morphologic classification of the PV-immunoreactive (IR) retinotectal ganglion cells on the basis of dendritic field size, branching pattern, and stratification within the inner plexiform layer. Among the 8 different types of PV-containing RGCs in the mouse retina, we found all 8 types of RGCs projecting to the SC. The RGCs were heterogeneous in morphology. The combined approach of using tracer injection and a single cell injection after immunocytochemistry on a particular protein will provide valuable data to further understand the functional features of the RGCs which constitute the retinotectal pathway

  13. 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 ...

  14. 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

  15. Identification of the probable site of synthesis of butyrylcholinesterase in the superior cervical and ciliary ganglia of the cat.

    OpenAIRE

    Uchida, E; Koelle, G B

    1983-01-01

    The source of butyrylcholinesterase (acylcholine acylhydrolase, EC 3.1.1.8) in the ganglion cells of the cat superior cervical and ciliary ganglia has been elusive, inasmuch as the enzyme is present in high concentrations in the neuropil, where it is confined largely to the dendritic and perikaryonal plasma membranes, but appears to be absent from the perikarya. In the present study, ganglionic butyrylcholinesterase was near-totally inactivated by the injection of tetramonoisopropyl pyyrophos...

  16. 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.

  17. Proximal Sciatic Nerve Intraneural Ganglion Cyst

    OpenAIRE

    Fee, Dominic B.; Swartz, Karin R.; Michael Boland; Dianne Wilson

    2009-01-01

    Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009.

  18. Intratendinous ganglion cyst of the semimembranosus tendon

    OpenAIRE

    Kim, S K; Park, J. M.; Choi, J E; Rhee, S K; Shim, S. I.

    2010-01-01

    Intratendinous ganglion cyst is a very rare lesion with an unknown aetiology that originates within the tendon. We encountered a case of 43-year-old woman who complained of a palpable, non-tender mass in the thigh with increasing swelling. An intratendinous ganglion cyst in the semimembranosus tendon of the lower extremity was diagnosed and located by ultrasound and MRI. Nine months after a surgical excision, there were recurrent ganglion cysts along the semimembranosus tendon. We describe th...

  19. Ganglions of the proximal interphalangeal joint.

    Science.gov (United States)

    Cheng, C A; Rockwell, W B

    1999-08-01

    Ganglion cysts-the most common hand tumors-usually affect women in their twenties and thirties. The cause of these cysts is unknown, although trauma has been postulated as an inciting factor. Ganglions occur most commonly at the dorsal and palmar wrist. However, ganglions of the proximal interphalangeal (PIP) joint are rare. Four patients with PIP joint ganglions were recently treated at our institution. Three received aspiration and one received operative therapy, all with good results. All four patients were older than 65 years. PMID:10470671

  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. 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...

  2. Stratification of alpha ganglion cells and ON/OFF directionally selective ganglion cells in the rabbit retina

    OpenAIRE

    Zhang, Jian; Li, Wei; HOSHI, HIDEO; Mills, Stephen L.; MASSEY, STEPHEN C.

    2005-01-01

    The correlation between cholinergic sensitivity and the level of stratification for ganglion cells was examined in the rabbit retina. As examples, we have used ON or OFF α ganglion cells and ON/OFF directionally selective (DS) ganglion cells. Nicotine, a cholinergic agonist, depolarized ON/OFF DS ganglion cells and greatly enhanced their firing rates but it had modest excitatory effects on ON or OFF α ganglion cells. As previously reported, we conclude that DS ganglion cells are the most sens...

  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 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

  5. 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 at some ... Poor appetite For people with weak immune systems, CSD may cause more serious problems. The best way ...

  6. Homonymous Hemianopic Hyporeflective Retinal Abnormality on Infrared Confocal Scanning Laser Photography: A Novel Sign of Optic Tract Lesion.

    Science.gov (United States)

    Monteiro, Mario L R; Araújo, Rafael B; Suzuki, Ana C F; Cunha, Leonardo P; Preti, Rony C

    2016-03-01

    Infrared confocal scanning laser photography of a patient with long-standing optic tract lesion revealed a homonymous hemianopic hyporeflective image contralateral to the visual field defect. Spectral domain optical coherence tomography showed thinning of the retinal nerve fiber and retinal ganglion cell layer and thickening of the inner nuclear layer (with microcystic degeneration) in the macular area, matching the infrared image. Hyporeflective image on infrared laser photography is associated with retinal degeneration secondary to anterior visual pathway disease and, when located in homonymous hemianopic retinas, may represent a new sign of an optic tract lesion. PMID:26172159

  7. 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 ...

  8. 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 ...

  9. 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

  10. 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 ...

  11. 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

  12. Histogenesis of retinal dysplasia in trisomy 13

    Directory of Open Access Journals (Sweden)

    Gonzalez-Fernandez Federico

    2007-12-01

    Full Text Available Abstract Background Although often associated with holoprosencephaly, little detail of the histopathology of cyclopia is available. Here, we describe the ocular findings in a case of trisomy 13 to better understand the histogenesis of the rosettes, or tubules, characteristic of the retinal dysplasia associated with this condition. Methods A full pediatric autopsy was performed of a near term infant who died shortly after birth from multiple congenital anomalies including fused facial-midline structures. A detailed histopathological study of the ocular structures was performed. The expression of interphotoreceptor retinoid-binding protein (IRBP, cellular retinal-binding protein (CRALBP, rod opsin, and Sonic Hedgehog (Shh were studied by immunohistochemistry. Results Holoprosencephaly, and a spectrum of anatomical findings characteristic of Patau's syndrome, were found. Cytogenetic studies demonstrated trisomy 13 [47, XY, +13]. The eyes were fused but contained two developed separate lenses. In contrast, the cornea, and angle structures were hypoplastic, and the anterior chamber had failed to form. The retina showed areas of normally laminated neural retina, whereas in other areas it was replaced by numerous neuronal rosettes. Histological and immunohistochemical studies revealed that the rosettes were composed of differentiated retinal neurons and Müller cell glia. In normally laminated retina, Shh expression was restricted to retinal-ganglion cells, and to a population of neurons in the inner zone of the outer nuclear layer. In contrast, Shh could not be detected in the dysplastic rosettes. Conclusion The histopathology of cyclopia appears to be more complex than what may have been previously appreciated. In fact, the terms "cyclopia" and "synophthalmia" are misnomers as the underlying mechanism is a failure of the eyes to form separately during development. The rosettes found in the dysplastic retina are fundamentally different than those of

  13. 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

  14. A Catalogue of Anatomical Fugitive Sheets: Cat. 1-10

    OpenAIRE

    1999-01-01

    Images Cat. 1 Cat. 2 (a) Cat. 2 (b) Cat. 2 (c) Cat. 2 (d) Cat. 2 (e) Cat. 2 (f) Cat. 3: 1 (a) Cat. 3: 1 (b) Cat. 3: 2 (a) Cat. 3: 2 (b) Cat. 4: 1 Cat. 4: 2 Cat. 6: 1 (a) Cat. 6: 1 (b) Cat. 6: 2 (a) Cat. 6: 2 (b) Cat. 7: 1 (a) Cat. 7: 1 (b) Cat. 7: 2 (a) Cat. 7: 2 (b) Cat. 8: 1 Cat. 9: 1 Cat. 9: 2 Cat. 10: 1 Cat. 10: 2

  15. Intramuscular Ganglion of the Quadriceps Femoris

    OpenAIRE

    Kim, Yeung Jin; Chae, Soo Uk; Choi, Byong San; Kim, Jong Yun; Jo, Hyang Jeong

    2013-01-01

    Ganglion cysts are common lesions that are most often found around the joints of the hands and feet. Ganglia around the distal femur usually occur within the synovial membrane or tendon sheath, but rarely within muscles. Several cases of intramuscular ganglions in the hand and wrist have been reported, but a ganglion cyst in the quadriceps muscle has rarely been addressed in studies. In this report, we present a 17-year-old patient with a painful movable mass in the intramuscular area of the ...

  16. Dorsal wrist ganglion: Current review of literature.

    Science.gov (United States)

    Meena, Sanjay; Gupta, Ajay

    2014-06-01

    Ganglion cyst is the most common soft tissue tumour of hand. Sixty to seventy percent of ganglion cysts are found in the dorsal aspect of the wrist. They may affect any age group; however they are more common in the twenties to forties. Its origin and pathogenesis remains enigmatic. Non-surgical treatment is unreliable with a high recurrence rates. Open surgical excision leads to unsightly scar and poor outcome. Arthroscopy excision has shown very promising result with very low recurrence rate. We reviewed the current literature available on dorsal wrist ganglion. PMID:25983472

  17. 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

  18. 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...

  19. 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

  20. Infraspinatus paralysis due to spinoglenoid notch ganglion.

    Science.gov (United States)

    Skirving, A P; Kozak, T K; Davis, S J

    1994-07-01

    We describe five patients, seen since 1984, with posterior shoulder pain and isolated wasting and weakness of the infraspinatus. In four of these a ganglion in the spinoglenoid notch was demonstrated by MRI and in one recent case ultrasound scans were positive. Three patients have been treated by operation, but there was recurrence in one after five years. In each confirmed case, the ganglion straddled the base of the spine of the scapula, extending into both supraspinatus and infraspinatus fossae. The nerve was either compressed against the spine or stretched over the posterior aspect of the ganglion. Adequate surgical exposure is essential to preserve the nerve to the infraspinatus and to allow complete removal of the ganglion. This is difficult because of the location and thin-walled nature of the cysts. PMID:8027146

  1. A Catalogue of Anatomical Fugitive Sheets: Cat. 11-25

    OpenAIRE

    1999-01-01

    Images Cat. 11 (a) Cat. 11 (b) Cat. 11 (c) Cat. 11 (d) Cat. 12: 1 (a) Cat. 12: 1 (b) Cat. 12: 2 (a) Cat. 12: 2 (b) Cat. 13 Cat. 14 (a) Cat. 14 (b) Cat. 14 (c) Cat. 15 (a) Cat. 15 (b) Cat. 17: 1 Cat. 17: 2 Cat. 18: 1 Cat. 18: 2 Cat. 19: 1 (a) Cat. 19: 1 (b) Cat. 19: 2 (a) Cat. 19: 2 (b) Cat. 20: 1 Cat. 20: 2 (a) Cat. 20: 2 (b) Cat. 21 (a) Cat. 21 (b) Cat. 21 (c) Cat. 21 (d) Cat. 21 (e) Cat. 22 Cat. 24: 1 and 2 Cat. 25: 1 Cat. 25: 2 Cat. 25: 3 Cat. 25: 4

  2. 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.

  3. Dorsal wrist ganglion: Current review of literature

    OpenAIRE

    Meena, Sanjay; Gupta, Ajay

    2014-01-01

    Ganglion cyst is the most common soft tissue tumour of hand. Sixty to seventy percent of ganglion cysts are found in the dorsal aspect of the wrist. They may affect any age group; however they are more common in the twenties to forties. Its origin and pathogenesis remains enigmatic. Non-surgical treatment is unreliable with a high recurrence rates. Open surgical excision leads to unsightly scar and poor outcome. Arthroscopy excision has shown very promising result with very low recurrence rat...

  4. Ganglions of the hand and wrist.

    Science.gov (United States)

    Young, L; Bartell, T; Logan, S E

    1988-06-01

    The ganglion is the most common soft tissue tumor of the hand and wrist, originating from the joint capsule or tendon sheath. Accurate diagnosis and proper treatment of these entities require a thorough knowledge of the anatomy of the wrist and hand as well as of the ganglion itself. Definitive therapy is based on total surgical removal of the cyst and its connections to the joint or tendon sheath. PMID:3287641

  5. 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.

  6. 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.

  7. 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...

  8. 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....

  9. Synchronizing retinal activity in both eyes disrupts binocular map development in the optic tectum

    OpenAIRE

    Brickley, S.; Dawes, E.; Keating, M; Grant, S

    1998-01-01

    Spatiotemporal correlations in the pattern of spontaneous and evoked retinal ganglion cell (RGC) activity are believed to influence the topographic organization of connections throughout the developing visual system. We have tested this hypothesis by examining the effects of interfering with these potential activity cues during development on the functional organization of binocular maps in the Xenopus frog optic tectum. Paired recordings combined with cross-correlation analyses demonstrated ...

  10. RNA Sequence Reveals Mouse Retinal Transcriptome Changes Early after Axonal Injury

    OpenAIRE

    Yasuda, Masayuki; Tanaka, Yuji; Ryu, Morin; Tsuda, Satoru; Nakazawa, Toru

    2014-01-01

    Glaucoma is an ocular disease characterized by progressive retinal ganglion cell (RGC) death caused by axonal injury. However, the underlying mechanisms involved in RGC death remain unclear. In this study, we investigated changes in the transcriptome profile following axonal injury in mice (C57BL/6) with RNA sequencing (RNA-seq) technology. The experiment group underwent an optic nerve crush (ONC) procedure to induce axonal injury in the right eye, and the control group underwent a sham proce...

  11. 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.)

  12. Relationship between dorsal ganglion cysts of the wrist and intraosseous ganglion cysts of the carpal bones.

    Science.gov (United States)

    Van den Dungen, Sophie; Marchesi, Simona; Ezzedine, Rabih; Bindou, David; Lorea, Patrick

    2005-10-01

    Soft tissue ganglion cysts are the most common benign tumours of the wrist; their pathogenesis remains controversial. We prospectively screened the radiographic appearance of the wrists of 51 patients presenting to a single surgeon with dorsal wrist ganglions during a one-year period. Postero-anterior and lateral radiographs were systematically performed looking for possible associated intraosseous ganglion cysts. There were 51 dorsal soft tissue ganglion cysts in 51 patients. We detected 29 associated intraosseous ganglia in 24 patients (47%): 16 ganglia in the lunate bone (55%), 5 in the capitate bone, 7 in the scaphoid and 1 in the trapezoid. Mean size of the intraosseous ganglia was 3 mm (range, 2 to 5 mm). This high prevalence of intraosseous ganglia in association with soft tissue ganglia has to our knowledge never been reported previously. A common aetiology for these two types of ganglion cysts may explain this high association rate. PMID:16305077

  13. Effect of axonal micro-tubules on the morphology of retinal nerve fibers studied by second-harmonic generation

    Science.gov (United States)

    Lim, Hyungsik; Danias, John

    2012-11-01

    Many studies suggest that the degradation of microtubules in the retinal ganglion cells may be an early event in the progression of glaucoma. Because reflectance and birefringence of the retinal nerve fibers arise primarily from microtubules, the optical properties have been intensively studied for early detection of the disease. We previously reported a novel nonlinear optical signal from axonal microtubules for visualizing the retinal nerve fibers, namely second-harmonic generation (SHG). We demonstrate the use of axonal SHG to investigate the effect of microtubules on the morphology of the retinal nerve fiber bundles. Time-lapse SHG imaging of ex vivo rat retinal flat mounts was performed during pharmacological treatment of nocodazole, and the intensity of axonal SHG and the changes in nerve fiber bundle morphology were monitored. We found that the microtubule disruption does not lead to immediate modification in the morphology of the nerve fibers. Our results indicate that microtubular SHG may provide a useful means for sensitive detection of axonal injuries. Since the intrinsic radiation depends on the regular architecture of the cytoskeleton element as maintained by active cellular regulations, the intensity of signal reflects the health of the retinal ganglion cell axons.

  14. Molecular Mechanisms Mediating Retinal Reactive Gliosis Following Bone Marrow Mesenchymal Stem Cell Transplantation

    Science.gov (United States)

    Tassoni, Alessia; Gutteridge, Alex; Barber, Amanda C.; Osborne, Andrew

    2015-01-01

    abstract A variety of diseases lead to degeneration of retinal ganglion cells (RGCs) and their axons within the optic nerve resulting in loss of visual function. Although current therapies may delay RGC loss, they do not restore visual function or completely halt disease progression. Regenerative medicine has recently focused on stem cell therapy for both neuroprotective and regenerative purposes. However, significant problems remain to be addressed, such as the long‐term impact of reactive gliosis occurring in the host retina in response to transplanted stem cells. The aim of this work was to investigate retinal glial responses to intravitreally transplanted bone marrow mesenchymal stem cells (BM‐MSCs) to help identify factors able to modulate graft‐induced reactive gliosis. We found in vivo that intravitreal BM‐MSC transplantation is associated with gliosis‐mediated retinal folding, upregulation of intermediate filaments, and recruitment of macrophages. These responses were accompanied by significant JAK/STAT3 and MAPK (ERK1/2 and JNK) cascade activation in retinal Muller glia. Lipocalin‐2 (Lcn‐2) was identified as a potential new indicator of graft‐induced reactive gliosis. Pharmacological inhibition of STAT3 in BM‐MSC cocultured retinal explants successfully reduced glial fibrillary acidic protein expression in retinal Muller glia and increased BM‐MSC retinal engraftment. Inhibition of stem cell‐induced reactive gliosis is critical for successful transplantation‐based strategies for neuroprotection, replacement, and regeneration of the optic nerve. Stem Cells 2015;33:3006–3016 PMID:26175331

  15. 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...

  16. 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

  17. 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

  18. Retinal profile and structural differences between myopes and emmetropes

    Science.gov (United States)

    Clark, Christopher Anderson

    Refractive development has been shown to be influenced by optical defocus in the eye and the interpretation of this signal appears to be localized in the retina. Optical defocus is not uniform across the retina and has been suggested as a potential cause of myopia development. Specifically hyperopic focus, i.e. focusing light behind the retina, may signal the eye to elongate, causing myopia. This non-uniform hyperopic signal appears to be due to the retinal shape. Ultimately, these signals are detected by the retina in an as yet undetermined manner. The purpose of this thesis is to examine the retinal profile using a novel method developed at Indiana University and then to examine retinal structural changes across the retina associated with myopia. Myopes exhibited more prolate retinas than hyperopes/emmetropes using the SD OCT. Using the SD OCT, this profile difference was detectable starting at 5 degrees from the fovea, which was closer than previously reported in the literature. These results agreed significantly with results found from peripheral refraction and peripheral axial length at 10 degrees. Overall, the total retina was thinner for myopes than hyperopes/emmetropes. It was also statistically significantly thinner for the Outer Nuclear Layer (ONL), Inner Nuclear Layer (INL) and Outer Plexiform Layer (OPL) but not for other retinal layers such as the Ganglion Layer. Thinning generally occurred outside of 5 degrees. The SD OCT method provided a nearly 10 fold increase in sensitivity which allowed for detection of profile changes closer to the fovea. The location of the retinal changes may be interesting as the layers that showed significant differences in thickness are also layers that contain cells believed to be associated with refractive development (amacrine, bipolar, and photoreceptor cells.) The reason for the retinal changes cannot be determined with this study, but possible theories include stretch due to axial elongation, neural remodeling due to

  19. 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…

  20. 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 ...

  1. 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 ...

  2. 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

  3. 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...

  4. 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.

  5. 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

  6. 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

  7. Post-traumatic extensive knee ganglion cyst

    Directory of Open Access Journals (Sweden)

    Mehran Mahvash

    2011-08-01

    Full Text Available A rare case of a posttraumatic extensive ganglion cyst of the anterolateral thigh with connection to the knee joint is presented. A 54- year-old man presented a palpable mass in the anterolateral region of his right thigh with a 15 months existing sense of fullness and tightness. He had an accident with his bicycle 21 months ago. Magnetic resonance imaging (MRI was performed showing a cyst inside the quadriceps femoris muscle between vastus lateralis and intermedius with connection to recessus suprapatellaris and knee joint. In addition MRI detected a traumatic lesion in the quadriceps femoris tendon in the near of the knee joint. The ganglion cyst was 18 cm long and was excised completely. Intraope - ratively, the knee joint connection was confirmed and excised as well. The ganglion cyst was filled with a gelatinous and viscous fluid.

  8. 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

  9. Two Case Report on Wrist Ganglion Treated with Scolopendrid Pharmacopuncture

    OpenAIRE

    Min-Seop Shin; Jin-Bok Lee; Beom-yong Song

    2010-01-01

    Object : This study was to investigate the clinical effect of Scolopendrid Pharmacopuncture on two patients suffering from Wrist Ganglion. Methods : We treated two patients suffering from Wrist Ganglion with both acupuncture and injection of Scolopendrid Pharmacopuncture. Then we measured the sizes of Wrist Ganglion and Visual Analogue Scale(VAS). Results and Conclusions : We found that the sizes of Wrist Ganglion of the two patients were significantly reduced. Moreover, the pain and di...

  10. [Acute retinal necrosis].

    Science.gov (United States)

    Lucke, K; Reinking, U; el-Hifnawi, E; Dennin, R H; Laqua, H

    1988-12-01

    The authors report on three patients with acute retinal necrosis who were treated with the virostatic agent Acyclovir and who underwent vitreoretinal surgery with silicone oil filling for total retinal detachment. In two eyes the retina was reattached, but useful vision was only preserved in one patient. Titers from blood and the vitreous, as well as microscopic findings in retinal biopsies, support the view that the necrosis is caused by a herpes simplex virus infection. After therapy with Acyclovir was instituted no further progression on the necrosis was observed. However, the development of retinal detachment could not be prevented. Early diagnosis and antiviral therapy are essential to improve the otherwise poor prognosis in this rare syndrome. PMID:3221657

  11. Retinal laser optical aids

    Directory of Open Access Journals (Sweden)

    Das Traprasad

    1991-01-01

    Full Text Available Knowledge of optics, comparative magnification and working field of view is essential for rational use of ophthalmoscopic contact lenses for retinal photocoagulation. The three commonly used contact lenses are described and compared.

  12. Retinal Tears and Detachments

    Science.gov (United States)

    ... does not cause retinal damage. However, inflammation or myopia (nearsightedness) may cause the vitreous to pull away ... repaired? If your retina is only torn, prompt treatment may prevent detachment. Your eye surgeon will discuss ...

  13. [Ganglion cysts of the hand and wrist].

    Science.gov (United States)

    Sarig, Oren; Hass, Avraham; Oron, Amir

    2013-10-01

    Ganglion cysts are considered the most common tumor of the wrist and hand. They are most common between the second and fourth decades of life. The most common anatomical location is the dorsal wrist. This article includes a general review of these cysts including symptoms, pathology and methods of diagnosis, as well as a review of these cysts in specific anatomic locations. The article also includes an updated review of the literature comparing open surgery vs. arthroscopic treatment. The authors believe that arthroscopic surgery of ganglion cysts will gain an important role in the treatment of these cysts. PMID:24450035

  14. 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...

  15. Simultaneous cell death in the trigeminal ganglion and in ganglion neurons present in the oculomotor nerve of the bovine fetus.

    OpenAIRE

    Bortolami, R; Lucchi, M L; Callegari, E; Barazzoni, A M; Costerbosa, G L; Scapolo, P A

    1990-01-01

    A well-developed ganglion and scattered ganglion cells are present in the intracranial portion of the oculomotor nerve during the first half of fetal life in the ox. In the second half of fetal life a dramatic reduction of the ganglion cells associated with the oculomotor nerve occurs because of spontaneous cell death. Concomitantly, the same phenomenon of cell death is found in the trigeminal ganglion, especially in its rostromedial portion. Free degenerating perikarya can be found in the ca...

  16. 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

  17. 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...

  18. 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

  19. 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...

  20. 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 ...

  1. Ganglion cyst of the posterior cruciate ligament

    OpenAIRE

    Ahmed, F.; Ibrahim, S A; Soliman, A.; Khirat, S

    2010-01-01

    A ganglion is a fluid cyst with a myxoid matrix that arises close to the tendons and joints. Its occurrence inside a joint is rare. Among the various pathological conditions producing impairment of the knee function, ganglia of the cruciate ligaments are quite rare.

  2. Ganglions of the hand and wrist.

    Science.gov (United States)

    Thornburg, L E

    1999-01-01

    Ganglions of the hand and wrist are common benign lesions. They most frequently arise adjacent to joints and tendons, but may also be intratendinous or intraosseous. Treatment options include observation, aspiration, and surgical excision. Observation is acceptable in most instances. Indications for more aggressive treatment include pain, interference with activity, nerve compression, and imminent ulceration (in the case of some mucous cysts). The recurrence rate after puncture and aspiration is greater than 50% for cysts in most locations, but is less than 30% for cysts in the flexor tendon sheath. Surgical excision is effective, with a recurrence rate of only 5% if care is taken to completely excise the stalk of the cyst along with a small portion of joint capsule. Surgical treatment of occult ganglions is successful with accurate assessment of the source of the pain. Arthroscopic treatment of dorsal wrist ganglions is still experimental, but early results are encouraging. Ganglion surgery requires a formal operative environment and careful technique in order to minimize injury to adjacent structures and minimize the likelihood of recurrence. PMID:10434077

  3. 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...

  4. 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...

  5. 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.

  6. VEGF-B inhibits hyperglycemia- and Macugen-induced retinal apoptosis

    Science.gov (United States)

    Huang, Delong; Zhao, Chen; Ju, Rong; Kumar, Anil; Tian, Geng; Huang, Lijuan; Zheng, Lei; Li, Xianglin; Liu, Lixian; Wang, Shasha; Ren, Xiangrong; Ye, Zhimin; Chen, Wei; Xing, Liying; Chen, Qishan; Gao, Zhiqin; Mi, Jia; Tang, Zhongshu; Wang, Bin; Zhang, Shuping; Lee, Chunsik; Li, Xuri

    2016-01-01

    Vascular endothelial growth factor B (VEGF-B) was discovered a long time ago. However, its role in hyperglycemia- and VEGF-A inhibition-induced retinal apoptosis remains unknown thus far. Yet, drugs that can block VEGF-B are being used to treat patients with diabetic retinopathy and other ocular neovascular diseases. It is therefore urgent to have a better understanding of the function of VEGF-B in these pathologies. Here, we report that both streptozotocin (STZ)-induced diabetes in rats and Macugen intravitreal injection in mice leads to retinal apoptosis in retinal ganglion cell and outer nuclear layers respectively. Importantly, VEGF-B treatment by intravitreal injection markedly reduced retinal apoptosis in both models. We further reveal that VEGF-B and its receptors, vascular endothelial growth factor 1 (VEGFR1) and neuropilin 1 (NP1), are abundantly expressed in rat retinae and choroids and are upregulated by high glucose with concomitant activation of Akt and Erk. These data highlight an important function of VEGF-B in protecting retinal cells from apoptosis induced by hyperglycemia and VEGF-A inhibition. VEGF-B may therefore have a therapeutic potential in treating various retinal degenerative diseases, and modulation of VEGF-B activity in the eye needs careful consideration. PMID:27189805

  7. VEGF-B inhibits hyperglycemia- and Macugen-induced retinal apoptosis.

    Science.gov (United States)

    Huang, Delong; Zhao, Chen; Ju, Rong; Kumar, Anil; Tian, Geng; Huang, Lijuan; Zheng, Lei; Li, Xianglin; Liu, Lixian; Wang, Shasha; Ren, Xiangrong; Ye, Zhimin; Chen, Wei; Xing, Liying; Chen, Qishan; Gao, Zhiqin; Mi, Jia; Tang, Zhongshu; Wang, Bin; Zhang, Shuping; Lee, Chunsik; Li, Xuri

    2016-01-01

    Vascular endothelial growth factor B (VEGF-B) was discovered a long time ago. However, its role in hyperglycemia- and VEGF-A inhibition-induced retinal apoptosis remains unknown thus far. Yet, drugs that can block VEGF-B are being used to treat patients with diabetic retinopathy and other ocular neovascular diseases. It is therefore urgent to have a better understanding of the function of VEGF-B in these pathologies. Here, we report that both streptozotocin (STZ)-induced diabetes in rats and Macugen intravitreal injection in mice leads to retinal apoptosis in retinal ganglion cell and outer nuclear layers respectively. Importantly, VEGF-B treatment by intravitreal injection markedly reduced retinal apoptosis in both models. We further reveal that VEGF-B and its receptors, vascular endothelial growth factor 1 (VEGFR1) and neuropilin 1 (NP1), are abundantly expressed in rat retinae and choroids and are upregulated by high glucose with concomitant activation of Akt and Erk. These data highlight an important function of VEGF-B in protecting retinal cells from apoptosis induced by hyperglycemia and VEGF-A inhibition. VEGF-B may therefore have a therapeutic potential in treating various retinal degenerative diseases, and modulation of VEGF-B activity in the eye needs careful consideration. PMID:27189805

  8. Role of Connexin Channels in the Retinal Light Response of a Diurnal Rodent

    Directory of Open Access Journals (Sweden)

    Jose Hurtado

    2014-08-01

    Full Text Available Several studies have shown that connexin channels play an important role in retinal neural coding in nocturnal rodents. However, the contribution of these channels to signal processing in the retina of diurnal rodents remains unclear. To gain insight into this problem, we studied connexin expression and the contribution of connexin channels to the retinal light response in the diurnal rodent Octodon degus (degu compared to rat, using in vivo ERG recording under scotopic and photopic light adaptation. Analysis of the degu genome showed that the common retinal connexins present a high degree of homology to orthologs expressed in other mammals, and expression of Cx36 and Cx43 was confirmed in degu retina. Cx36 localized mainly to the outer and inner plexiform layers, while Cx43 was expressed mostly in cells of the retinal pigment epithelium. Under scotopic conditions, the b-wave response amplitude was strongly reduced by 18-β-glycyrrhetinic acid (β-GA (-45.1% in degu, compared to -52.2% in rat, suggesting that connexins are modulating this response. Remarkably, under photopic adaptation, β-GA increased the ERG b-wave amplitude in degu (+107.2% while reducing it in rat (-62.3%. Moreover, β-GA diminished the spontaneous action potential firing rate in ganglion cells and increased the response latency of ON and OFF ganglion cells. Our results support the notion that connexins exert a fine-tuning control of the retinal light response and have an important role in retinal neural coding.

  9. 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

  10. 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.

  11. Lysophospholipid receptors LPA1–3 are not required for the inhibitory effects of LPA on mouse retinal growth cones

    Directory of Open Access Journals (Sweden)

    Eric Birgbauer

    2010-02-01

    Full Text Available Eric Birgbauer, Jerold ChunDepartment of Molecular Biology, Helen L Dorris Institute for Neurological and Psychiatric Disorders, The Scripps Research Institute, La Jolla, CA, USA Abstract: One of the major requirements in the development of the visual system is axonal guidance of retinal ganglion cells toward correct targets in the brain. A novel class of extracellular lipid signaling molecules, lysophospholipids, may serve as potential axon guidance cues. They signal through cognate G protein-coupled receptors, at least some of which are expressed in the visual system. Here we show that in the mouse visual system, a lysophospholipid known as lysophosphatidic acid (LPA is inhibitory to retinal neurites in vitro when delivered extracellularly, causing growth cone collapse and neurite retraction. This inhibitory effect of LPA is both active in the nanomolar range and specific compared to the related lysophospholipid, sphingosine 1-phosphate (S1P. Knockout mice lacking three of the five known LPA receptors, LPA1–3, continue to display retinal growth cone collapse and neurite retraction in response to LPA, demonstrating that these three receptors are not required for these inhibitory effects and indicating the existence of one or more functional LPA receptors expressed on mouse retinal neurites that can mediate neurite retraction.Keywords: retinal ganglion cells, lysophosphatidic acid, axon guidance

  12. Retinal vein and artery occlusions

    DEFF Research Database (Denmark)

    Christiansen, Christine Benn; Lip, Gregory Y. H.; Lamberts, Morten;

    2013-01-01

    Retinal vascular occlusions may constitute an independent risk factor for stroke in patients with atrial fibrillation.......Retinal vascular occlusions may constitute an independent risk factor for stroke in patients with atrial fibrillation....

  13. Retinal oxygen extraction in humans

    OpenAIRE

    René M. Werkmeister; Doreen Schmidl; Gerold Aschinger; Veronika Doblhoff-Dier; Stefan Palkovits; Magdalena Wirth; Gerhard Garhöfer; Linsenmeier, Robert A.; Rainer A. Leitgeb; Leopold Schmetterer

    2015-01-01

    Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measurements were done on 8 healthy subjects while breathing ambient room air and 100% oxygen. Total retinal b...

  14. Staurosporine induces ganglion cell differentiation in part by stimulating urokinase-type plasminogen activator expression and activation in the developing chick retina

    International Nuclear Information System (INIS)

    Highlights: ► Staurosporine mediates stimulation of RGC differentiation in vitro cultured retinal neuroblasts. ► Staurosporine mediates uPA activation during RGC differentiation in vitro. ► Inhibition of uPA blocks the staurosporine mediated RGC differentiation both in vitro and in ovo. ► Thus, uPA may play a role in the staurosporine-mediated stimulation of RGC differentiation. -- Abstract: Here, we investigated whether staurosporine-mediated urokinase-type plasminogen activator (uPA) activation is involved in retinal ganglion cell (RGC) differentiation. Retinal cells were isolated from developing chick retinas at embryonic day 6 (E6). Relatively few control cells grown in serum-free medium started to form processes by 12 h. In contrast, staurosporine-treated cells had processes within 3 h, and processes were evident at 8 h. Immunofluorescence staining showed that Tuj-1-positive cells with shorter neurites could be detected in control cultures at 18 h, whereas numerous Tuj-1 positive ganglion cells with longer neuritic extensions were seen in staurosporine-treated cultures. BrdU-positive proliferating cells were more numerous in control cultures than in staurosporine-treated cultures, and the BrdU staining was not detected in post-mitotic Tuj-1 positive ganglion cells. Western blotting of cell lysates showed that staurosporine induced high levels of the active form of uPA. The staurosporine-induced uPA signal was localized predominantly in the soma, neurites and axons of Tuj-1-positive ganglion cells. Amiloride, an inhibitor of uPA, markedly reduced staurosporine-induced Tuj-1 staining, neurite length, neurite number, and uPA staining versus controls. In developing retinas in ovo, amiloride administration remarkably reduced the staurosporine-induced uPA staining and RGC differentiation. Taken together, our in vitro and in vivo data collectively indicate that uPA plays a role in the staurosporine-mediated stimulation of RGC differentiation.

  15. 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.

  16. Lysophospholipid receptors LPA1–3 are not required for the inhibitory effects of LPA on mouse retinal growth cones

    OpenAIRE

    Birgbauer, Eric; Chun, Jerold

    2010-01-01

    One of the major requirements in the development of the visual system is axonal guidance of retinal ganglion cells toward correct targets in the brain. A novel class of extracellular lipid signaling molecules, lysophospholipids, may serve as potential axon guidance cues. They signal through cognate G protein-coupled receptors, at least some of which are expressed in the visual system. Here we show that in the mouse visual system, a lysophospholipid known as lysophosphatidic acid (LPA) is inhi...

  17. Risk factor profile in retinal detachment

    OpenAIRE

    Azad Raj; Nayak B; Sharma Y; Tiwari Hem; Khosla P

    1988-01-01

    150 cases of retinal detachment comprising 50 patients each of bilateral retinal detachment, unilateral retinal detachment without any retinal lesions in the fellow eve and unilateral retinal detachment with retinal lesions in the fellow eye were studied and the various associated risk factors were statistically analysed. The findings are discussed in relation to their aetiological and prognostic significance in the different types of retinal detachment. Based on these observations certain gu...

  18. Microsurgical principles related to excision of intraneural ganglion at the elbow

    OpenAIRE

    Xu, Qintong; Chen, Zenggan; Dellon, A Lee; Zhang, Feng

    2013-01-01

    We describe the treatment of a ganglion within the ulnar nerve at the elbow and apply the concept that an intraneural ganglion arises from the joint adjacent to the nerve in which the ganglion is located. Successful treatment of nerve compression and prevention of recurrence of the ganglion require disconnection of the nerve from the joint and deflation, not excision, of the ganglion.

  19. 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

  20. Eye Histology and Ganglion Cell Topography of Northern Elephant Seals (Mirounga angustirostris).

    Science.gov (United States)

    Smodlaka, Hrvoje; Khamas, Wael A; Palmer, Lauren; Lui, Bryan; Borovac, Josip A; Cohn, Brian A; Schmitz, Lars

    2016-06-01

    Northern elephant seals are one of the deepest diving marine mammals. As northern elephant seals often reach the bathypelagic zone, it is usually assumed that their eyes possess evolutionary adaptations that provide better ability to see in dim or scotopic environments. The purpose of this study was to carefully describe anatomical and histological traits of the eye that may improve light sensitivity. Northern elephant seals have large, somewhat elliptical eyes, with equatorial and anteroposterior diameters of 5.03 and 4.4 cm, respectively. The cornea is large in diameter and the lens is completely spherical. The iris has pronounced constrictor and dilator muscles, whereas the ciliary muscle is notably less developed. The tapetum lucidum is more prominent than in other pinnipeds, making up about 63% of retinal thickness in the posterior aspect of the globe. Within the retina, the pigmented epithelium lacks pigment except for the region close to the ora serrata. Parts of the photoreceptor and outer nuclear layers are folded. Although the photoreceptor layer is composed predominantly of rods, cone photoreceptors were also observed. Cells within the retinal ganglion cell layer are arranged in a single level. Ganglion cells reach their maximum density (∼1,300 cells per mm(2) ) dorsal to the optic disc, whereas the periphery of the retina is sparsely populated (<100 cells per mm(2) ). All above mentioned features are consistent with the predicted evolutionary adaptations to the photic environment of the bathypelagic zone. Anat Rec, 299:798-805, 2016. © 2016 Wiley Periodicals, Inc. PMID:26950409

  1. Protective effect of magnesium acetyltaurate against endothelin-induced retinal and optic nerve injury.

    Science.gov (United States)

    Arfuzir, N N N; Lambuk, L; Jafri, A J A; Agarwal, R; Iezhitsa, I; Sidek, S; Agarwal, P; Bakar, N S; Kutty, M K; Yusof, A P Md; Krasilnikova, A; Spasov, A; Ozerov, A; Mohd Ismail, N

    2016-06-14

    Vascular dysregulation has long been recognized as an important pathophysiological factor underlying the development of glaucomatous neuropathy. Endothelin-1 (ET1) has been shown to be a key player due to its potent vasoconstrictive properties that result in retinal ischemia and oxidative stress leading to retinal ganglion cell (RGC) apoptosis and optic nerve (ON) damage. In this study we investigated the protective effects of magnesium acetyltaurate (MgAT) against retinal cell apoptosis and ON damage. MgAT was administered intravitreally prior to, along with or after administration of ET1. Seven days post-injection, animals were euthanized and retinae were subjected to morphometric analysis, TUNEL and caspase-3 staining. ON sections were stained with toluidine blue and were graded for neurodegenerative effects. Oxidative stress was also estimated in isolated retinae. Pre-treatment with MgAT significantly lowered ET1-induced retinal cell apoptosis as measured by retinal morphometry and TUNEL staining. This group of animals also showed significantly lesser caspase-3 activation and significantly reduced retinal oxidative stress compared to the animals that received intravitreal injection of only ET1. Additionally, the axonal degeneration in ON was markedly reduced in MgAT pretreated animals. The animals that received MgAT co- or post-treatment with ET1 also showed improvement in all parameters; however, the effects were not as significant as observed in MgAT pretreated animals. The current study showed that the intravitreal pre-treatment with MgAT reduces caspase-3 activation and prevents retinal cell apoptosis and axon loss in ON induced by ET1. This protective effect of ET1 was associated with reduced retinal oxidative stress. PMID:27012609

  2. Telocytes of the human adult trigeminal ganglion.

    Science.gov (United States)

    Rusu, Mugurel Constantin; Cretoiu, Dragos; Vrapciu, Alexandra Diana; Hostiuc, Sorin; Dermengiu, Dan; Manoiu, Vasile Sorin; Cretoiu, Sanda Maria; Mirancea, Nicolae

    2016-06-01

    Telocytes (TCs) are typically defined as cells with telopodes by their ultrastructural features. Their presence was reported in various organs, however little is known about their presence in human trigeminal ganglion. To address this issue, samples of trigeminal ganglia were tested by immunocytochemistry for CD34 and examined by transmission electron microscopy (TEM). We found that TCs are CD34 positive and form networks within the ganglion in close vicinity to microvessels and nerve fibers around the neuronal-glial units (NGUs). TEM examination confirmed the existence of spindle-shaped and bipolar TCs with one or two telopodes measuring between 15 to 53 μm. We propose that TCs are cells with stemness capacity which might contribute in regeneration and repair processes by: modulation of the stem cell activity or by acting as progenitors of other cells present in the normal tissue. In addition, further studies are needed to establish if they might influence the neuronal circuits. PMID:27147447

  3. From connected pathway flow to ganglion dynamics

    Science.gov (United States)

    Rücker, M.; Berg, S.; Armstrong, R. T.; Georgiadis, A.; Ott, H.; Schwing, A.; Neiteler, R.; Brussee, N.; Makurat, A.; Leu, L.; Wolf, M.; Khan, F.; Enzmann, F.; Kersten, M.

    2015-05-01

    During imbibition, initially connected oil is displaced until it is trapped as immobile clusters. While initial and final states have been well described before, here we image the dynamic transient process in a sandstone rock using fast synchrotron-based X-ray computed microtomography. Wetting film swelling and subsequent snap off, at unusually high saturation, decreases nonwetting phase connectivity, which leads to nonwetting phase fragmentation into mobile ganglia, i.e., ganglion dynamics regime. We find that in addition to pressure-driven connected pathway flow, mass transfer in the oil phase also occurs by a sequence of correlated breakup and coalescence processes. For example, meniscus oscillations caused by snap-off events trigger coalescence of adjacent clusters. The ganglion dynamics occurs at the length scale of oil clusters and thus represents an intermediate flow regime between pore and Darcy scale that is so far dismissed in most upscaling attempts.

  4. Ganglion cysts in a juvenile dog.

    Science.gov (United States)

    Cho, K O; Park, N Y; Kang, M I; Umemura, K; Itakura, C

    2000-07-01

    Ganglion cysts were diagnosed in a 4-month-old male Afghan Hound. Grossly, the subcutaneous ovoid cysts around the caudal right elbow joint and left ischiatic tuberosity had abundant mucinous fluid and internal folding. The lesions recurred twice around the elbow joint after surgical removal. Neither cyst communicated with the joint cavity. Histologically, the cyst wall consisted of inner myxomatous and outer immature connective tissue. Some parts of the cyst wall had various stages of myxoid metaplasia of collagen tissue leading to new cyst formation. Ultrastructural study revealed that cells in the myxoid metaplastic lesion had well-developed cytoplasmic secretory elements, including abundant rough endoplasmic reticulum, Golgi apparatus, and many smooth-walled vesicles. These ganglion cysts apparently resulted from the metaplasia of fibroblasts to secreting cells. PMID:10896396

  5. Ganglion cysts and carpal tunnel syndrome.

    Science.gov (United States)

    Kerrigan, J J; Bertoni, J M; Jaeger, S H

    1988-09-01

    We review 12 cases of ganglion cyst with carpal tunnel syndrome in 11 patients seen at the Hand Rehabilitation Center. Mean age was 42 years (range, 28 to 60 years). One half of the cysts were associated with direct trauma, usually with wrist hyperextension. Symptoms usually developed after the appearance or sudden growth of the cyst. Motor conduction or distal sensory latency was abnormal in seven of eight studied cases. Tinel's sign on tapping the cyst may be pathognomonic for this syndrome. Cyst removal and incision of the flexor retinaculum relieved the symptoms in 11 cases. The other case had total resolution after spontaneous cyst rupture. This syndrome is successfully treated with cyst decompression with release of the carpal canal and has an excellent prognosis. To our knowledge this represents the largest operative series of carpal tunnel syndrome and ganglion cyst. PMID:3241055

  6. 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

  7. E-Z-CAT

    International Nuclear Information System (INIS)

    A new barium sulphate suspension, E-Z-CAT, for use as an oral contrast medium at computed tomography of the abdomen has been compared with the commonly used water-soluble iodinated contrast medium Gastrografin as regards patient tolerance and diagnostic information. The investigation was conducted as an unpaired randomized single-blind study in 100 consecutive patients. E-Z-CAT seems to be preferred because of its better taste, its lesser tendency to cause diarrhoea, and for usage in patients who are known to be hypersensitive to iodinated contrast media. The diagnostic information was the same for both contrast media. (Auth.)

  8. 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.

  9. 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...

  10. Post-traumatic extensive knee ganglion cyst

    OpenAIRE

    Mehran Mahvash; Majid Hashemi; Homajoun Maslehaty; Alexandros Doukas; Petridis, Athanasios K.; Hubertus Maximilian Mehdorn

    2011-01-01

    A rare case of a posttraumatic extensive ganglion cyst of the anterolateral thigh with connection to the knee joint is presented. A 54- year-old man presented a palpable mass in the anterolateral region of his right thigh with a 15 months existing sense of fullness and tightness. He had an accident with his bicycle 21 months ago. Magnetic resonance imaging (MRI) was performed showing a cyst inside the quadriceps femoris muscle between vastus lateralis and intermedius with connection to recess...

  11. Intraosseous Ganglion Cyst of the Lunate

    OpenAIRE

    Nazerani, Shahram; Ebrahimpour, Adel; Najafi, Arvin; Shams Koushki, Ehsan

    2012-01-01

    Intraosseous ganglia can affect the carpal bones of the hand and must be considered in the differential diagnosis of wrist pain. A 38-year-old female presented with a 14-month history of left wrist pain and a radiolucent cystic lesion was seen computed tomography (CT) scanning. Characteristic radiographic findings of a cyst in association with a fine sclerotic rim was apparent. We report an unusual presentation of a ganglion cyst in the lunate bone with excellent treatment outcome.

  12. Retinal tolerance to dyes

    OpenAIRE

    Lüke, C; Lüke, M; Dietlein, T S; Hueber, A; Jordan, J; Sickel, W.; Kirchhof, B

    2005-01-01

    Background: Dye solutions for intraoperative staining of epiretinal membranes and the internal limiting membrane improve the visualisation of these thin structures and facilitate their removal. In the present study the authors investigated the effects of indocyanine green 0.05%, trypan blue 0.15%, and patent blue 0.48% on bovine retinal function.

  13. 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 ...

  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. The image appearances of intraosseous ganglion of the wrist

    International Nuclear Information System (INIS)

    Objective: To observe the imaging features of intraosseous ganglion of the wrist. Methods: The radiographs (6 cases), CT (4 cases), and MR (1 case) in 6 cases (7 lesions) of surgically confirmed intraosseous ganglion were retrospectively reviewed. Results: Typical intraosseous ganglion was seen as sharp margined and cystic lesion with the size of approximately 0.5 cm in diameter. All but one lesion showed no communication with joint. No degenerative changes were seen in the joints nearby. CT was able to depict the lesions better than radiographs in 4 cases. Intraosseous ganglion was seen as slight low signal on T1WI and slight high signal on T2WI MR images. Conclusion: Intraosseous ganglion was typically seen as sharp-margined and cystic lesion on radiographs, and it could be better demonstrated with CT and MR. With typical imaging appearance, a suggestion to the diagnosis of intraosseous ganglion could be made

  16. Simultaneous bilateral ganglion cysts of the anterior cruciate ligaments.

    Science.gov (United States)

    Demircay, Emre; Ofluoglu, Demet; Ozel, Omer; Oztop, Pinar

    2015-04-01

    Intra-articular ganglion cysts of the anterior cruciate ligament (ACL) are rare, and bilateral ganglion cysts are even rarer. These cysts may cause intermittent or chronic nonspecific knee discomfort. Although three cases of bilateral ganglion cysts have been reported in the literature, the knees were not simultaneously affected in those cases. Herein, we report the case of a 56-year-old woman who presented with simultaneous bilateral ganglion cysts of the ACL that were symptomatic. She was successfully treated with arthroscopic resection and debridement. We also present a brief review of the literature, highlighting the aetiology, diagnosis and management of ganglion cysts of the ACL. To the best of our knowledge, this is the first report of simultaneous bilateral intra-articular ganglion cysts of the ACL. PMID:25917477

  17. Retinal projections in the Tasmanian devil, Sarcophilus harrisii.

    Science.gov (United States)

    Sanderson, K J; Pearson, L J; Haight, J R

    1979-11-15

    Retinal projections were mapped in Tasmanian devils which had one eye injected with 3H-proline. The retinal fibers terminate in seven regions in the brain. These are (1) dorsal lateral geniculate nucleus (LGNd), (2) ventral lateral geniculate nucleus, (3) lateral posterior nucleus, (4) pretectum, (5) superior colliculus, (6) hypothalamus and (7) accessory optic system. The pattern of retinal input to six of these regions is similar to that seen in other marsupials. The pattern of retinal projections to the LGNd, while basically similar to that observed in other polyprotodont marsupials, is much simpler than that seen in the related native cat, Dasyurus viverrinus. The LGNd of Sarcophilus presents the simplest cytoarchitectural organisation of any marsupial examined so far. Each LGNd receives overlapping projections from both eyes. Suggestions of an intermittent lamination are seen in the LGNd contralateral to an eye injection of 3H-proline. On the ipsilateral side there are two patches of label, a large lateral patch and a smaller medial patch, both of which occupy areas receiving contralateral input. The monocular segment, occupying the ventral 40% of the nucleus, is more extensive than has been reported in any other polyprotodont marsupial. PMID:500862

  18. 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. PMID:27033597

  19. Case report 551: Intraosseous ganglion of olecranon with vacuum phenomenon

    International Nuclear Information System (INIS)

    Intraosseous ganglion of the ulna in a 52-year-old woman is reported. Gas (vacuum phenomenon) in the lesion was documented on CT scan. Vacuum phenomenon may be observed in intraosseous ganglion even if there is no communication with the joint. The clinical, radiological and pathological features of intraosseous ganglion were discussed and the reasons for a vacuum phenomenon were considered. (orig./GDG)

  20. A Ganglion Cyst in the Second Lumbar Intervertebral Foramen

    OpenAIRE

    Kim, Sang Woo; Choi, Joon Hyuk; Kim, Min Su; Chang, Chul Hoon

    2011-01-01

    Ganglion cysts usually arise from the tendon sheaths and tissues around the joints. It is usually associated with degenerative arthritic changes in older people. Ganglion cyst in the spine is rare and there is no previous report on case that located in the intervertebral foramen and compressed dorsal root ganglion associated severe radiculopathy. A 29-year-old woman presented with severe left thigh pain and dysesthesia for a month. Magnetic resonance imaging revealed a dumbbell like mass in t...

  1. Cat Scratch Disease (For Parents)

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth Cat Scratch Disease KidsHealth > For Parents > Cat Scratch Disease Print A A A Text Size ... Doctor en español Enfermedad por arañazo de gato Cat scratch disease is a bacterial infection that a ...

  2. Tracheal collapse in two cats

    International Nuclear Information System (INIS)

    Two cats examined bronchoscopically to discover the cause of tracheal collapse were found to have tracheal obstruction cranial to the collapse. Cats with this unusual sign should be examined bronchoscopically to ascertain whether there is an obstruction, as the cause in these 2 cats was distinct from the diffuse airway abnormality that causes tracheal collapse in dogs

  3. 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

  4. Taxonomy Icon Data: domestic cat [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available domestic cat ... Felis silvestris cat us Chordata/Vertebrata/Mammalia/Theria/Eutheria/Carnivora Felis ... _silvestris_cat us_L.png Felis_silvestris_cat us_NL.png Felis_silves ... tris_cat us_S.png Felis_silvestris_cat us_NS.png http://biosc ...

  5. 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

  6. 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 ...

  7. 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

  8. 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

  9. 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 ...

  10. 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.

  11. 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".

  12. Amyloid β accumulation and inner retinal degenerative changes in Alzheimer's disease transgenic mouse.

    Science.gov (United States)

    Gupta, Vivek K; Chitranshi, Nitin; Gupta, Veer B; Golzan, Mojtaba; Dheer, Yogita; Wall, Roshana Vander; Georgevsky, Dana; King, Anna E; Vickers, James C; Chung, Roger; Graham, Stuart

    2016-06-01

    The APP-PS1ΔE9 mouse model of Alzheimer's disease (AD) exhibits age dependent amyloid β (Aβ) plaque formation in their central nervous system due to high expression of mutated human APP and PSEN1 transgenes. Here we evaluated Aβ deposition and changes in soluble Aβ accumulation in the retinas of aged APP-PS1 mice using a combination of immunofluorescence, retinal flat mounts and western blotting techniques. Aβ accumulation in the retina has previously been shown to be associated with retinal ganglion cell apoptosis in animal models of glaucoma. This study investigated changes in the inner retinal function and structure in APP-PS1 mice using electrophysiology and histological approaches respectively. We report for the first time a significant decline in scotopic threshold response (STR) amplitudes which represents inner retinal function in transgenic animals compared to the wild type counterparts (p<0.0001). Thinning of the retina particularly involving inner retinal layers and reduction in axonal density in the optic nerve was also observed. TUNEL staining was performed to examine neuronal apoptosis in the inner retina. Intraocular pressure (IOP) measurements showed that APP-PS1ΔE9 mice had a slightly elevated IOP, but the significance of this finding is not yet known. Together, these results substantiate previous observations and highlight that APP-PS1ΔE9 mice show evidence of molecular, functional and morphological degenerative changes in the inner retina. PMID:27133194

  13. 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.

  14. 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

  15. 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.

  16. MRI of ganglion cysts in uncommon sites or with atypical appearance

    International Nuclear Information System (INIS)

    Ganglion cysts are common lesions which are most often found around the hands and feet. Magnetic resonance (MR) imaging is seldom performed; cysts are identified incidentally on MR images obtained for the purpose of evaluating other disorders. Clinically complicated ganglions are often confused with other more serious tumors, and MR examination is thus requested. Ganglions arising from uncommon sites or showing unusual MR findings can lead to wrong diagnosis. Thus, a thorough knowledge of potential sites and of the MR findings of unusual ganglion cysts, including complicated ganglions, cruciate ligament ganglion cysts, meniscal cysts, labral cysts, ganglions in shoulder notches and tarsal tunnels, and intermuscular ganglion cysts

  17. MRI of ganglion cysts in uncommon sites or with atypical appearance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Uk; Kook, Shin Ho; Chung, Eun Chul; Youn, Eun Kyung; Park, Jun Yong [Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of)

    1999-08-01

    Ganglion cysts are common lesions which are most often found around the hands and feet. Magnetic resonance (MR) imaging is seldom performed; cysts are identified incidentally on MR images obtained for the purpose of evaluating other disorders. Clinically complicated ganglions are often confused with other more serious tumors, and MR examination is thus requested. Ganglions arising from uncommon sites or showing unusual MR findings can lead to wrong diagnosis. Thus, a thorough knowledge of potential sites and of the MR findings of unusual ganglion cysts, including complicated ganglions, cruciate ligament ganglion cysts, meniscal cysts, labral cysts, ganglions in shoulder notches and tarsal tunnels, and intermuscular ganglion cysts.

  18. 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. PMID:22546621

  19. 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.

  20. 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

  1. Retinal flow cytometer

    OpenAIRE

    Alt, C.; Veilleux, I.; Lee, H; Pitsillides, C. M.; D. Côté; Lin, C.P.

    2007-01-01

    The in vivo flow cytometer is an instrument capable of continuous, real-time monitoring of fluorescently labeled cells in the circulation without the need to draw blood samples. However, the original system probes a single vessel in the mouse ear; the small sample volume limits the sensitivity of the technique. We describe an in vivo retinal flow cytometer that simultaneously probes five artery–vein pairs in the mouse eye by circularly scanning a small laser spot rapidly around the optic nerv...

  2. Aphakic retinal detachment.

    OpenAIRE

    Le Mesurier, R; Vickers, S; Booth-Mason, S; Chignell, A H

    1985-01-01

    A study of 132 cases of aphakic retinal detachment (ARD) following mainly intracapsular cataract surgery has been made. Forty-nine cases (37%) were found to have vitreous incarcerated into the cataract section out of a total of 54 (41%) cases who had suffered a vitreous complication during cataract surgery. A study of the characteristics of ARD reveals that those cases having had a vitreous complication in the management of their cataracts are more likely to develop detachment within three mo...

  3. 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.

  4. 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.

  5. Peroneal nerve palsy caused by intraneural ganglion

    International Nuclear Information System (INIS)

    A case of peroneal nerve palsy caused by an intraneural ganglion is presented. The cystic mass was located posterolateral to the lateral femoral condyle and extended along the common peroneal nerve distal to the origin of the peroneus longus muscle. The nerve was compressed in the narrow fibro-osseous tunnel against the fibula neck and the tight origin of the peroneus longus muscle. The nerve was decompressed by complete tumor excision and transection of the origin of the peroneus longus muscle. Full recovery of nerve function was obtained in 6 months. (orig.)

  6. Intraosseous ganglion in the first metacarpal bone

    International Nuclear Information System (INIS)

    Intraosseous ganglia occur most frequently in the long bones of the lower limbs, particularly in the medial malleolus of the tibia. They usually appear as radiographically well circumscribed juxta-articular cystic lesions, containing myxoid fibrous tissue histologically. Intraosseous ganglia in the hand are very rare. Most reported cases have involved the carpal bones, in particular the lunate and scaphoid. To our knowledge, the present case is the third report of an intraosseous ganglion appearing in the first metacarpal bone; it arose in a patient who had been on dialysis for 25 years, mimicking amyloidosis of bone. (orig.)

  7. Subchondral synovial cysts (intra-osseous ganglion)

    Energy Technology Data Exchange (ETDEWEB)

    Graf, L.; Freyschmidt, J.

    1988-04-01

    Twelve cases of subchondral synovial cysts (intra-osseous ganglion) have been seen and their clinical features, radiological findings and differential diagnosis are described. The lesion is a benign cystic tumour-like mass in the subchondral portion of a synovial joint. Our findings in respect of age, sex and localisation are compared with those of other authors. The aetiology and pathogenesis of the lesion is not completely understood. There is an increased incidence in middle life and joints with high dynamic and static stress are favoured, particularly in the lower extremities. Chronic stress or microtrauma, causing damage to the involved joint, therefore appears to be a plausible explanation.

  8. Subchondral synovial cysts (intra-osseous ganglion)

    International Nuclear Information System (INIS)

    Twelve cases of subchondral synovial cysts (intra-osseous ganglion) have been seen and their clinical features, radiological findings and differential diagnosis are described. The lesion is a benign cystic tumour-like mass in the subchondral portion of a synovial joint. Our findings in respect of age, sex and localisation are compared with those of other authors. The aetiology and pathogenesis of the lesion is not completely understood. There is an increased incidence in middle life and joints with high dynamic and static stress are favoured, particularly in the lower extremities. Chronic stress or microtrauma, causing damage to the involved joint, therefore appears to be a plausible explanation. (orig.)

  9. 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.

  10. 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.

  11. Radiographically ossified ganglion cyst of finger in a swimmer

    International Nuclear Information System (INIS)

    Ganglion cysts are fibrous-walled cystic lesions closely associated with joint or tendon sheaths and contain gelatinous mucinous fluid. The radiographic appearance is usually normal. Calcification or ossification in these cysts is extremely unusual. We report on an unusual appearing ganglion cyst of the little finger in a swimmer with ossification resembling myositis ossificans. (orig.)

  12. The successful arthroscopic treatment of suprascapular intraneural ganglion cysts.

    Science.gov (United States)

    Prasad, Nikhil K; Spinner, Robert J; Smith, Jay; Howe, Benjamin M; Amrami, Kimberly K; Iannotti, Joseph P; Dahm, Diane L

    2015-09-01

    OBJECT High-resolution magnetic resonance imaging (MRI) can distinguish between intraneural ganglion cysts and paralabral (extraneural) cysts at the glenohumeral joint. Suprascapular intraneural ganglion cysts share the same pathomechanism as their paralabral counterparts, emanating from a tear in the glenoid labrum. The authors present 2 cases to demonstrate that the identification and arthroscopic repair of labral tears form the cornerstone of treatment for intraneural ganglion cysts of the suprascapular nerve. METHODS Two patients with suprascapular intraneural ganglion cysts were identified: 1 was recognized and treated prospectively, and the other, previously reported as a paralabral cyst, was identified retrospectively through the reinter-pretation of high-resolution MR images. RESULTS Both patients achieved full functional recovery and had complete radiological involution of the intraneural ganglion cysts at the 3-month and 12-month follow-ups, respectively. CONCLUSIONS Previous reports of suprascapular intraneural ganglion cysts described treatment by an open approach to decompress the cysts and resect the articular nerve branch to the glenohumeral joint. The 2 cases in this report demonstrate that intraneural ganglion cysts, similar to paralabral cysts, can be treated with arthroscopic repair of the glenoid labrum without resection of the articular branch. This approach minimizes surgical morbidity and directly addresses the primary etiology of intraneural and extraneural ganglion cysts. PMID:26323813

  13. Radiographically ossified ganglion cyst of finger in a swimmer

    Energy Technology Data Exchange (ETDEWEB)

    Tehranzadeh, J.; Anavim, A. [Department of Radiological Sciences, University of California, Orange (United States); Lin, F. [Department of Pathology, University of California, Irvine Medical Center, Orange (Canada)

    1998-12-01

    Ganglion cysts are fibrous-walled cystic lesions closely associated with joint or tendon sheaths and contain gelatinous mucinous fluid. The radiographic appearance is usually normal. Calcification or ossification in these cysts is extremely unusual. We report on an unusual appearing ganglion cyst of the little finger in a swimmer with ossification resembling myositis ossificans. (orig.) With 3 figs., 8 refs.

  14. 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

  15. 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.

  16. 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...

  17. 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.

  18. EFFECTS OF P-XYLENE INHALATION ON AXONAL TRANSPORT IN THE RAT RETINAL GANGLION CELLS

    Science.gov (United States)

    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. he intent of this study was to determine the effect of intermittent, acute, and subchronic p-xyle...

  19. 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...

  20. Local cloning of CAT states

    International Nuclear Information System (INIS)

    In this Letter we analyze the (im)possibility of the exact cloning of orthogonal three-qubit CAT states under local operation and classical communication (LOCC) with the help of a restricted entangled state. We also classify the three-qubit CAT states that can (not) be cloned under LOCC restrictions and extend the results to the n-qubit case. -- Highlights: → We analyze the (im)possibility of exact cloning of orthogonal CAT states under LOCC. → We also classify the set of CAT states that can(not) be cloned by LOCC. → No set of orthogonal CAT states can be cloned by LOCC with help of similar CAT state. → Any two orthogonal n-qubit GHZ-states can be cloned by LOCC with help of a GHZ state.

  1. 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.

  2. 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 ...

  3. Retinal detachment surgery without cryotherapy.

    OpenAIRE

    Chignell, A H; Markham, R H

    1981-01-01

    A series of cases of retinal detachment treated without the application of cryotherapy at the time of surgery has been studied. The omission of cryotherapy while not interfering with retinal reattachment, carries the risk of redetachment at a later date. Macular pucker may still occur in spite of the absence of cryotherapy.

  4. Environmental Enrichment for Indoor Cats

    OpenAIRE

    Herron, Meghan E.; Buffington, C. A. Tony

    2010-01-01

    Recommendations to cat owners to house their cats indoors confer the responsibility to provide conditions that ensure good health and welfare. Cats maintain their natural behaviors, such as scratching, chewing, and elimination, while living indoors, and they may develop health and behavior problems when deprived of appropriate environmental outlets for these behaviors. This article divides the environment into five basic “systems” to enable identification of features that may benefit from imp...

  5. 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

  6. Environmental enrichment for indoor cats.

    Science.gov (United States)

    Herron, Meghan E; Buffington, C A Tony

    2010-12-01

    Recommendations to cat owners to house their cats indoors confer the responsibility to provide conditions that ensure good health and welfare. Cats maintain their natural behaviors, such as scratching, chewing, and elimination, while living indoors, and they may develop health and behavior problems when deprived of appropriate environmental outlets for these behaviors. This article divides the environment into five basic "systems" to enable identification of features that may benefit from improvement. It also addresses practical means of meeting cats' needs in each of these systems. PMID:21882164

  7. 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...

  8. 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

  9. 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

  10. 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...

  11. 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

  12. Tendoscopic Excision of an Intratendinous Ganglion in the Flexor Hallucis Longus Tendon: A Case Report.

    Science.gov (United States)

    Endo, Jun; Yamaguchi, Satoshi; Sasho, Takahisa

    2016-01-01

    Intratendinous ganglion cysts are rare lesions of unknown etiology that originate within a tendon. We report the case of a 34-year-old female with an intratendinous ganglion in the plantar portion of the flexor hallucis longus tendon. The intratendinous ganglion recurred after ultrasound-guided needle aspiration. Tendoscopic excision of the intratendinous ganglion cyst achieved a satisfactorily result without recurrence. PMID:25456345

  13. 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?

  14. Methylene blue-enhanced arthroscopic resection of dorsal wrist ganglions.

    Science.gov (United States)

    Lee, Byung Joo; Sawyer, Gregory A; Dasilva, Manuel F

    2011-12-01

    The ganglion is the most common soft tissue mass of the hand and wrist. Over the past 10 to 15 years, there has been a growing interest in arthroscopic treatment of dorsal wrist ganglions. Proposed advantages of arthroscopy include greater motion (particularly wrist flexion), improved cosmesis, and potential to identify/treat other intra-articular pathology. Despite the documented clinical success of arthroscopic ganglion excision, limitations include inconsistent identification of the ganglion stalk. Our described technique offers a means by which to improve visualization of the ganglion stalk intra-articularly to produce a more effective and efficient arthroscopic ganglion excision. During the procedure, a small volume of methylene blue solution is injected into the cyst. Its communication with the joint is apparent arthroscopically, thus identifying the location of the stalk. With the ability to precisely identify the ganglion stalk using an injection of methylene blue, the surgeon can direct the arthroscopic debridement toward the appropriate pathologic tissue. Unnecessary debridement of uninvolved tissue can be avoided with the technique. This also allows for optimal portal placement and, in particular, indicates whether a midcarpal portal should be employed. This should result in fewer recurrences, decreased operative time, and less iatrogenic injury. PMID:22105637

  15. EzCatDB: M00143 [EzCatDB

    Lifescience Database Archive (English)

    Full Text Available http://ezcatdb.cbrc.jp/EzCatDB/search/get.do?dbcode=M00143 EzCatDB M00143 0) { response = "?" + ... 1995 Volume 34 Pages 955-64 Authors Mimeault M, De Lean ... A, Lafleur M, Bonenfant D, Fournier A Title Evalua ...

  16. Toxoplasmosis: An Important Message for Cat Owners

    Science.gov (United States)

    ... role do cats play in the spread of toxoplasmosis? Cats get Toxoplasma infection by eating infected rodents, ... an infected cat may have defecated. What is toxoplasmosis? Toxoplasmosis is an infection caused by a microscopic ...

  17. 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.

  18. Simultaneous Segmentation of Retinal Surfaces and Microcystic Macular Edema in SDOCT Volumes

    Science.gov (United States)

    Antony, Bhavna J.; Lang, Andrew; Swingle, Emily K.; Al-Louzi, Omar; Carass, Aaron; Solomon, Sharon; Calabresi, Peter A.; Saidha, Shiv; Prince, Jerry L.

    2016-01-01

    Optical coherence tomography (OCT) is a noninvasive imaging modality that has begun to find widespread use in retinal imaging for the detection of a variety of ocular diseases. In addition to structural changes in the form of altered retinal layer thicknesses, pathological conditions may also cause the formation of edema within the retina. In multiple sclerosis, for instance, the nerve fiber and ganglion cell layers are known to thin. Additionally, the formation of pseudocysts called microcystic macular edema (MME) have also been observed in the eyes of about 5% of MS patients, and its presence has been shown to be correlated with disease severity. Previously, we proposed separate algorithms for the segmentation of retinal layers and MME, but since MME mainly occurs within specific regions of the retina, a simultaneous approach is advantageous. In this work, we propose an automated globally optimal graph-theoretic approach that simultaneously segments the retinal layers and the MME in volumetric OCT scans. SD-OCT scans from one eye of 12 MS patients with known MME and 8 healthy controls were acquired and the pseudocysts manually traced. The overall precision and recall of the pseudocyst detection was found to be 86.0% and 79.5%, respectively.

  19. Retinal neurodegeneration may precede microvascular changes characteristic of diabetic retinopathy in diabetes mellitus.

    Science.gov (United States)

    Sohn, Elliott H; van Dijk, Hille W; Jiao, Chunhua; Kok, Pauline H B; Jeong, Woojin; Demirkaya, Nazli; Garmager, Allison; Wit, Ferdinand; Kucukevcilioglu, Murat; van Velthoven, Mirjam E J; DeVries, J Hans; Mullins, Robert F; Kuehn, Markus H; Schlingemann, Reinier Otto; Sonka, Milan; Verbraak, Frank D; Abràmoff, Michael David

    2016-05-10

    Diabetic retinopathy (DR) has long been recognized as a microvasculopathy, but retinal diabetic neuropathy (RDN), characterized by inner retinal neurodegeneration, also occurs in people with diabetes mellitus (DM). We report that in 45 people with DM and no to minimal DR there was significant, progressive loss of the nerve fiber layer (NFL) (0.25 μm/y) and the ganglion cell (GC)/inner plexiform layer (0.29 μm/y) on optical coherence tomography analysis (OCT) over a 4-y period, independent of glycated hemoglobin, age, and sex. The NFL was significantly thinner (17.3 μm) in the eyes of six donors with DM than in the eyes of six similarly aged control donors (30.4 μm), although retinal capillary density did not differ in the two groups. We confirmed significant, progressive inner retinal thinning in streptozotocin-induced "type 1" and B6.BKS(D)-Lepr(db)/J "type 2" diabetic mouse models on OCT; immunohistochemistry in type 1 mice showed GC loss but no difference in pericyte density or acellular capillaries. The results suggest that RDN may precede the established clinical and morphometric vascular changes caused by DM and represent a paradigm shift in our understanding of ocular diabetic complications. PMID:27114552

  20. 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

  1. 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.

  2. 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.

  3. Dual ACL Ganglion Cysts: Significance of Detailed Arthroscopy

    OpenAIRE

    Samarth Mittal; Amit Singla; Nag, H. L.; Sanjay Meena; Ramprakash Lohiya; Abhinav Agarwal

    2014-01-01

    Intra-articular ganglion cysts of the knee joint are rare and most frequently are an incidental finding on MRI and arthroscopy. Most of the previous studies have reported a single ganglion cyst in the knee. There have been previous reports of more than one cyst in the same knee but not in the same structure within the knee. We are reporting a case of dual ACL (anterior cruciate ligament) ganglion cysts one of which was missed on radiological examination but later detected during arthroscopy. ...

  4. Ulnar Nerve Compression in Guyon's Canal by Ganglion Cyst.

    Science.gov (United States)

    Kwak, Kyung-Woo; Kim, Min-Su; Chang, Chul-Hoon; Kim, Seong-Ho

    2011-02-01

    Compression of the ulnar nerve in Guyon's canal can result from repeated blunt trauma, fracture of the hamate's hook, and arterial thrombosis or aneurysm. In addition, conditions such as ganglia, rheumatoid arthritis and ulnar artery disease can rapidly compress the ulnar nerve in Guyon's canal. A ganglion cyst can acutely protrude or grow, which also might compress the ulnar nerve. So, clinicians should consider a ganglion cyst in Guyon's canal as a possible underlying cause of ulnar nerve compression in patients with a sudden decrease in hand strength. We believe that early decompression with removal of the ganglion is very important to promote complete recovery. PMID:21519507

  5. Dual ACL Ganglion Cysts: Significance of Detailed Arthroscopy

    Directory of Open Access Journals (Sweden)

    Samarth Mittal

    2014-01-01

    Full Text Available Intra-articular ganglion cysts of the knee joint are rare and most frequently are an incidental finding on MRI and arthroscopy. Most of the previous studies have reported a single ganglion cyst in the knee. There have been previous reports of more than one cyst in the same knee but not in the same structure within the knee. We are reporting a case of dual ACL (anterior cruciate ligament ganglion cysts one of which was missed on radiological examination but later detected during arthroscopy. To the best of our knowledge, no such case has been reported in the indexed English literature till date.

  6. Diagnostic imaging of tibial periosteal ganglion

    International Nuclear Information System (INIS)

    A case of a soft tissue tumor situated in the anterior surface of the proximal end of the tibia in an adult patient is demonstrated by conventional radiographs, CT, and MRI. The lesion was well defined with respect to the adjacent soft tissue. The CT exam showed a soft tissue mass with external cortical erosion and thick spicules by periosteal reaction. On T1-weighted images the mass was homogeneous and of low signal intensity, whereas on T2-weighted images it showed a high signal intensity, with some septa in the mass. The differential considerations include a periosteal chondroma, a lipoma, a subperiosteal hematoma, an inflammatory process, a giant cell tumor of tendon sheath, and a parosteal osteosarcoma. The CT and MR features of these entities are reviewed as an aid in differential diagnosis of the periosteal ganglion. (orig.). With 4 figs

  7. Magnetic resonance imaging of ganglion cell tumours

    International Nuclear Information System (INIS)

    The MRI and CT studies of four patients with ganglion cell tumours, one with a cerebellar gangliocytoma (Lhermitte-Duclos disease), and three with gangliogliomas are reported. MRI in Lhermitte-Duclos disease clearly demonstrated a mass of low signal intensity in the left cerebellum on T1-weighted spin-echo (SE) images and an area of high signal intensity with a blurred margin on T2-weighted SE images. These MRI studies were useful for delineating the lesion, which was verified at surgery. In the ganglioglioma, MRI demonstrated two isointense solid masses on T1-weighted SE images, which enhanced clearly with Gd-DTPA. The enhancement study was advantageous in planning surgery. (orig.)

  8. 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.

  9. 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)

  10. Chemical stimulation of rat retinal neurons: feasibility of an epiretinal neurotransmitter-based prosthesis

    Science.gov (United States)

    Inayat, Samsoon; Rountree, Corey M.; Troy, John B.; Saggere, Laxman

    2015-02-01

    Objective. No cure currently exists for photoreceptor degenerative diseases, which cause partial or total blindness in millions of people worldwide. Electrical retinal prostheses have been developed by several groups with the goal of restoring vision lost to these diseases, but electrical stimulation has limitations. It excites both somas and axons, activating retinal pathways nonphysiologically, and limits spatial resolution because of current spread. Chemical stimulation of retinal ganglion cells (RGCs) using the neurotransmitter glutamate has been suggested as an alternative to electrical stimulation with some significant advantages. However, sufficient scientific data to support developing a chemical-based retinal prosthesis is lacking. The goal of this study was to investigate the feasibility of a neurotransmitter-based retinal prosthesis and determine therapeutic stimulation parameters. Approach. We injected controlled amounts of glutamate into rat retinas from the epiretinal side ex vivo via micropipettes using a pressure injection system and recorded RGC responses with a multielectrode array. Responsive units were identified using a spike rate threshold of 3 Hz. Main results. We recorded both somal and axonal units and demonstrated successful glutamatergic stimulation across different RGC subtypes. Analyses show that exogenous glutamate acts on RGC synapses similar to endogenous glutamate and, unlike electrical prostheses, stimulates only RGC somata. The spatial spread of glutamate stimulation was ˜ 290 μm from the injection site, comparable to current electrical prostheses. Further, the glutamate injections produced spatially differential responses in OFF, ON, and ON-OFF RGC subtypes, suggesting that differential stimulation of the OFF and ON systems may be possible. A temporal resolution of 3.2 Hz was obtained, which is a rate suitable for spatial vision. Significance. We provide strong support for the feasibility of an epiretinal neurotransmitter

  11. 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.

  12. Characterizing retinal structure injury in African-Americans with multiple sclerosis.

    Science.gov (United States)

    Seraji-Bozorgzad, Navid; Reed, Sheridan; Bao, Fen; Santiago, Carla; Tselis, Alexandros; Bernitsas, Evanthia; Caon, Christina; Frohman, Elliot; Bhatti, M Tariq; Cree, Bruce A C; Khan, Omar

    2016-05-01

    To examine retinal structure injury in African-Americans (AA) with Multiple Sclerosis (MS) compared to Caucasians (CA) with MS, we used spectral domain optical-coherence tomography (OCT) in this cross sectional study. The peripapillary retinal nerve fiber layer (pRNFL) and macular volume of 234 MS patients (149 CA; 85 AA) and 74 healthy controls (60 CA; 17 AA) were measured. Intra-retinal segmentation was performed to obtain retinal nerve fiber (RNFL), ganglion cell (GCL), inner plexiform (IPL), inner nuclear (INL), outer plexiform (OPL), outer nuclear (ONL), retinal pigment epithelium (RPE), and photoreceptor (PR) layer volumes. Study was approved by IRB, and informed consent obtained from all participants. We found that pRNFL was thicker in AA v. CA healthy controls (100.9 vs 97.00μm, p=0.004). Compared to HC, MS patients demonstrated thinner pRNFL (pIPL (p<0.0001). AAMS patients had thinner pRNFL (87.2 vs 90.0μm, and lower TMV (8.2 vs 8.4mm(3), p=0.0001), RNFL (0.73 vs 0.79mm(3), p=0.0001), and GCL (0.94 vs 0.98mm(3), p=0.007) than CAMS patients. Sub-analysis of patients without history of AON showed thinner pRNFL (88.9 vs 93.1µm) and TMV (8.2 vs. 8.5mm(3), p<0.0001) in AAMS compared to CAMS patients. In conclusion, this cross-sectional study provides evidence supporting greater retinal structure injury in AAMS compared to CAMS patients, irrespective of history of AON. Our findings are consistent with other studies demonstrating a more severe CNS tissue injury in AAMS patients. PMID:27237751

  13. Role of connexin channels in the retinal light response of a diurnal rodent

    Science.gov (United States)

    Palacios-Muñoz, Angelina; Escobar, Maria J.; Vielma, Alex; Araya, Joaquín; Astudillo, Aland; Valdivia, Gonzalo; García, Isaac E.; Hurtado, José; Schmachtenberg, Oliver; Martínez, Agustín D.; Palacios, Adrian G.

    2014-01-01

    Several studies have shown that connexin channels play an important role in retinal neural coding in nocturnal rodents. However, the contribution of these channels to signal processing in the retina of diurnal rodents remains unclear. To gain insight into this problem, we studied connexin expression and the contribution of connexin channels to the retinal light response in the diurnal rodent Octodon degus (degu) compared to rat, using in vivo ERG recording under scotopic and photopic light adaptation. Analysis of the degu genome showed that the common retinal connexins present a high degree of homology to orthologs expressed in other mammals, and expression of Cx36 and Cx43 was confirmed in degu retina. Cx36 localized mainly to the outer and inner plexiform layers (IPLs), while Cx43 was expressed mostly in cells of the retinal pigment epithelium. Under scotopic conditions, the b-wave response amplitude was strongly reduced by 18-β-glycyrrhetinic acid (β-GA) (−45.1% in degu, compared to −52.2% in rat), suggesting that connexins are modulating this response. Remarkably, under photopic adaptation, β-GA increased the ERG b-wave amplitude in degu (+107.2%) while reducing it in rat (−62.3%). Moreover, β-GA diminished the spontaneous action potential firing rate in ganglion cells (GCs) and increased the response latency of ON and OFF GCs. Our results support the notion that connexins exert a fine-tuning control of the retinal light response and have an important role in retinal neural coding. PMID:25202238

  14. CRB1 mutations in inherited retinal dystrophies.

    OpenAIRE

    Bujakowska, Kinga; Audo, Isabelle; Mohand-Saïd, Saddek; Lancelot, Marie-Elise; Antonio, Aline; Germain, Aurore; Léveillard, Thierry; Letexier, Mélanie; Saraiva, Jean-Paul; Lonjou, Christine; Carpentier, Wassila; Sahel, José-Alain; Bhattacharya, Shomi; Zeitz, Christina

    2012-01-01

    Mutations in the CRB1 gene are associated with variable phenotypes of severe retinal dystrophies, ranging from leber congenital amaurosis (LCA) to rod-cone dystrophy, also called retinitis pigmentosa (RP). Moreover, retinal dystrophies resulting from CRB1 mutations may be accompanied by specific fundus features: preservation of the para-arteriolar retinal pigment epithelium (PPRPE) and retinal telangiectasia with exudation (also referred to as Coats-like vasculopathy). In this publication, we...

  15. 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...

  16. 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 ...

  17. 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...

  18. 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…

  19. [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

  20. 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

  1. 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

  2. Retinal detachment following excimer laser

    OpenAIRE

    Charteris, D; Cooling, R; Lavin, M; McLeod, D

    1997-01-01

    AIMS—To report the clinical presentation, surgical management, and outcome of retinal detachment following excimer laser.
METHODS—Retrospective analysis of retinal detachments observed in 11 eyes of 10 myopic patients who had previously undergone photorefractive keratectomy (PRK) or phototherapeutic keratectomy (PTK) by excimer laser.
RESULTS—Symptoms of visual loss in two eyes were initially attributed to corneal haze. In 10 of 11 eyes visualisation of the retinal detachment and causative br...

  3. 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.)

  4. 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.

  5. 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

  6. Intra-articular ganglion cysts of the cruciate ligaments

    International Nuclear Information System (INIS)

    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.)

  7. Macroanatomical Studies on the Cranial Cervical Ganglion in Sheep

    OpenAIRE

    Türkmenoğlu, İsmail

    2003-01-01

    In this study, the location and relations of the cranial cervical ganglion were investigated. A total of six sheep of different ages and both sexes were used. The cranial cervical ganlion lies medial to the occipitohyoid muscle, ventral to the jugular foramen, lateral to the longissimus capitis muscle and craniomedial to a common mass constituted by the glossopharyngeal, vagal, accessory and hypoglossal nerves and the condyloid artery. The colour and shape of the ganglion are light brown and ...

  8. Ulnar Nerve Compression in Guyon's Canal by Ganglion Cyst

    OpenAIRE

    Kwak, Kyung-Woo; Kim, Min-Su; Chang, Chul-Hoon; Kim, Seong-Ho

    2011-01-01

    Compression of the ulnar nerve in Guyon's canal can result from repeated blunt trauma, fracture of the hamate's hook, and arterial thrombosis or aneurysm. In addition, conditions such as ganglia, rheumatoid arthritis and ulnar artery disease can rapidly compress the ulnar nerve in Guyon's canal. A ganglion cyst can acutely protrude or grow, which also might compress the ulnar nerve. So, clinicians should consider a ganglion cyst in Guyon's canal as a possible underlying cause of ulnar nerve c...

  9. Bilateral Thoracic Ganglion Cyst : A Rare Case Report

    OpenAIRE

    Kazanci, Burak; Tehli, Ozkan; Türkoglu, Erhan; Guclu, Bulent

    2013-01-01

    Ganglion cysts usually arise from the tissues around the facet joints. It is usually associated with degenerative cahanges in facet joints. Bilateral thoracic ganglion cysts are very rare and there is no previous case that located in bilateral intervertebral foramen compressing the L1 nerve root associated with severe radiculopathy. We report a 53 years old woman who presented with bilateral groin pain and severe numbness. Magnetic resonance imaging revealed bilateral cystic mass in the inter...

  10. A rare case of intraosseous ganglion of the triquetrum

    OpenAIRE

    Luben Stokov; Georgi P. Georgiev; Boris Matev

    2012-01-01

    Carpal intraosseous ganglia are one of the rarely seenpathologic conditions in the hand. In this report we presenta rare case of an intraosseous ganglion cyst in a16-year-old girl located in the triquetrum bone as an uncommoncause of wrist pain. Radiographic and magneticresonance imaging demonstrated the cystic lesion intothe triquetrum. The patient was successfully treated byexcision of the ganglion cyst and curettage of the bone.Clinical aspects, radiological findings and treatment modaliti...

  11. A case of lumbar ganglion cyst causing radiculopathy

    OpenAIRE

    Milcan, Abdullah; Ozdemir, Cengiz; Karabacak, Tuba; Duce, Meltem Nas; Bagdatoglu, Celal

    2004-01-01

    Ganglion cysts represent a rare pathology mostly encountered in the lumbar region of the spinal column. Magnetic resonance imaging revealed a ganglion cyst at the L4-5 level in a 46-year-old woman who had a complaint of long-standing pain in her right leg. The cyst was completely excised following total laminectomy at L4. After surgery, her symptoms and neurological signs completely disappeared.

  12. GANGLION CYST IN THE ROOT OF THE LEFT INDEX FINGER

    OpenAIRE

    Manoj; Prem Charles; Shyamala

    2014-01-01

    Ganglion cyst is a condition where there is herniation of synovium from the joint space to the exterior and presents as a cystic mass. The cyst can maintain the connection to the joint space. There is potential risk of injury and infection due to even a trivial trauma leading to complications like arthritis and septicemia. The ganglion cysts normally observed in major and weight bearing joints. The incidence in small joints are uncommon. The present patient presented with a cy...

  13. A rare case of intraosseous ganglion of the triquetrum

    OpenAIRE

    Matev, Boris; Georgi P. Georgiev; Stokov, Luben

    2012-01-01

    Carpal intraosseous ganglia are one of the rarely seen pathologic conditions in the hand. In this report we present a rare case of an intraosseous ganglion cyst in a 16-year-old girl located in the triquetrum bone as an uncommon cause of wrist pain. Radiographic and magnetic resonance imaging demonstrated the cystic lesion into the triquetrum. The patient was successfully treated by excision of the ganglion cyst and curettage of the bone. Clinical aspects, radiological findings and treatment ...

  14. Therapeutic Approach of Wrist Ganglion Using Electroacupuncture: Two Case Reports

    OpenAIRE

    Kim, Kyoung Min; Kang, Eun Young; Lee, Sung Hoon; Jung, A Young; Nam, Doo Hyoun; Cheon, Ji Hwan

    2014-01-01

    A ganglion cyst is a relatively common benign tumor on the wrist. Conservative and surgical approaches have been used for its treatment. Various conservative treatment methods have been suggested such as reassurance, aspiration, sclerosant injection, and direct compression. But, there is no acceptable treatment of choice yet because each suggested method has a relatively high recurrence rate. We want to report two cases in which the size of the wrist ganglion was decreased by using electroacu...

  15. Ganglion Cyst of the Posterior Longitudinal Ligament Causing Lumbar Radiculopathy

    OpenAIRE

    Cho, Sung-Min; Rhee, Woo-Tack; Lee, Sang-Youl; Lee, Sang-Bok

    2010-01-01

    Degenerated conditions such as herniated disc or spinal stenosis are common etiologies of lumbar radiculopathy. Less common etiologies include spinal extradural cyst such as synovial cysts and ganglion cysts. Ganglion cyst of the posterior longitudinal ligament (PLL) of the spine is a rare entity that can result in classical sciatica. Posterior longitudinal ligament cyst has no continuity with the facet joint and has no epithelial lining. Two young male patients presented with unilateral scia...

  16. 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.

  17. Like herding cats.

    Science.gov (United States)

    Muller-Smith, P

    1997-12-01

    In an effort to be a good manager, it is easy to lose sight of the fact that knowledge workers require a unique approach from their manager. Because nurses are independent and capable individuals that prosper in an environment that recognizes them as knowledge workers, nurse managers often find that traditional management techniques are not sufficient. Trying to manage all of the nurses on a unit as a single group is much like trying to herd cats. It might be less frustrating for the nurse manager to lead gently rather than manage with a firm hand. Warren Bennis suggests that this approach may provide a valuable key to successfully managing in a world of constant change. PMID:9464034

  18. 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...

  19. Adult retinal stem cells revisited.

    OpenAIRE

    Bhatia, B; Singhal, S; Jayaram, H.; Khaw, P T; Limb, G A

    2010-01-01

    Recent advances in retinal stem cell research have raised the possibility that these cells have the potential to be used to repair or regenerate diseased retina. Various cell sources for replacement of retinal neurons have been identified, including embryonic stem cells, the adult ciliary epithelium, adult Müller stem cells and induced pluripotent stem cells (iPS). However, the true stem cell nature of the ciliary epithelium and its possible application in cell therapies has now been question...

  20. Light and inherited retinal degeneration

    OpenAIRE

    Paskowitz, D M; LaVail, M.M.; Duncan, J. L.

    2006-01-01

    Light deprivation has long been considered a potential treatment for patients with inherited retinal degenerative diseases, but no therapeutic benefit has been demonstrated to date. In the few clinical studies that have addressed this issue, the underlying mutations were unknown. Our rapidly expanding knowledge of the genes and mechanisms involved in retinal degeneration have made it possible to reconsider the potential value of light restriction in specific genetic contexts. This review summ...