Four alpha ganglion cell types in mouse retina: Function, structure, and molecular signatures

PubMed Central

Sanes, Joshua R.

2017-01-01

The retina communicates with the brain using ≥30 parallel channels, each carried by axons of distinct types of retinal ganglion cells. In every mammalian retina one finds so-called "alpha" ganglion cells (αRGCs), identified by their large cell bodies, stout axons, wide and mono-stratified dendritic fields, and high levels of neurofilament protein. In the mouse, three αRGC types have been described based on responses to light steps: On-sustained, Off-sustained, and Off-transient. Here we employed a transgenic mouse line that labels αRGCs in the live retina, allowing systematic targeted recordings. We characterize the three known types and identify a fourth, with On-transient responses. All four αRGC types share basic aspects of visual signaling, including a large receptive field center, a weak antagonistic surround, and absence of any direction selectivity. They also share a distinctive waveform of the action potential, faster than that of other RGC types. Morphologically, they differ in the level of dendritic stratification within the IPL, which accounts for their response properties. Molecularly, each type has a distinct signature. A comparison across mammals suggests a common theme, in which four large-bodied ganglion cell types split the visual signal into four channels arranged symmetrically with respect to polarity and kinetics. PMID:28753612

Protecting retinal ganglion cells.

PubMed

Khatib, T Z; Martin, K R

2017-02-01

Retinal ganglion cell degeneration underlies several conditions which give rise to significant visual compromise, including glaucoma, hereditary optic neuropathies, ischaemic optic neuropathies, and demyelinating disease. In this review, we discuss the emerging strategies for neuroprotection specifically in the context of glaucoma, including pharmacological neuroprotection, mesenchymal stem cells, and gene therapy approaches. We highlight potential pitfalls that need to be considered when developing these strategies and outline future directions, including the prospects for clinical trials.

Protecting retinal ganglion cells

PubMed Central

Khatib, T Z; Martin, K R

2017-01-01

Retinal ganglion cell degeneration underlies several conditions which give rise to significant visual compromise, including glaucoma, hereditary optic neuropathies, ischaemic optic neuropathies, and demyelinating disease. In this review, we discuss the emerging strategies for neuroprotection specifically in the context of glaucoma, including pharmacological neuroprotection, mesenchymal stem cells, and gene therapy approaches. We highlight potential pitfalls that need to be considered when developing these strategies and outline future directions, including the prospects for clinical trials. PMID:28085136

Regenerating reptile retinas: a comparative approach to restoring retinal ganglion cell function.

PubMed

Williams, D L

2017-02-01

Transection or damage to the mammalian optic nerve generally results in loss of retinal ganglion cells by apoptosis. This cell death is seen less in fish or amphibians where retinal ganglion cell survival and axon regeneration leads to recovery of sight. Reptiles lie somewhere in the middle of this spectrum of nerve regeneration, and different species have been reported to have a significant variation in their retinal ganglion cell regenerative capacity. The ornate dragon lizard Ctenophoris ornatus exhibits a profound capacity for regeneration, whereas the Tenerife wall lizard Gallotia galloti has a more variable response to optic nerve damage. Some individuals regain visual activity such as the pupillomotor responses, whereas in others axons fail to regenerate sufficiently. Even in Ctenophoris, although the retinal ganglion cell axons regenerate adequately enough to synapse in the tectum, they do not make long-term topographic connections allowing recovery of complex visually motivated behaviour. The question then centres on where these intraspecies differences originate. Is it variation in the innate ability of retinal ganglion cells from different species to regenerate with functional validity? Or is it variances between different species in the substrate within which the nerves regenerate, the extracellular environment of the damaged nerve or the supporting cells surrounding the regenerating axons? Investigations of retinal ganglion cell regeneration between different species of lower vertebrates in vivo may shed light on these questions. Or perhaps more interesting are in vitro studies comparing axon regeneration of retinal ganglion cells from various species placed on differing substrates.

Changes in morphology of retinal ganglion cells with eccentricity in retinal degeneration.

PubMed

Anderson, E E; Greferath, U; Fletcher, E L

2016-05-01

Ganglion cells are the output neurons of the retina and are known to remodel during the subtle plasticity changes that occur following the death of photoreceptors in inherited retinal degeneration. We examine the influence of retinal eccentricity on anatomical remodelling and ganglion cell morphology well after photoreceptor loss. Rd1 mice that have a mutation in the β subunit of phosphodiesterase 6 were used as a model of retinal degeneration and gross remodelling events were examined by processing serial sections for immunocytochemistry. Retinal wholemounts from rd1-Thy1 and control Thy1 mice that contained a fluorescent protein labelling a subset of ganglion cells were processed for immunohistochemistry at 11 months of age. Ganglion cells were classified based on their soma size, dendritic field size and dendritic branching pattern and their dendritic fields were analysed for their length, area and quantity of branching points. Overall, more remodelling was found in the central compared with the peripheral retina. In addition, the size and complexity of A2, B1, C1 and D type ganglion cells located in the central region of the retina decreased. We propose that the changes in ganglion cell morphology are correlated with remodelling events in these regions and impact the function of retinal circuitry in the degenerated retina.

Retinal ganglion cell distribution and spatial resolving power in elasmobranchs.

PubMed

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

Features and functions of nonlinear spatial integration by retinal ganglion cells.

PubMed

Gollisch, Tim

2013-11-01

Ganglion cells in the vertebrate retina integrate visual information over their receptive fields. They do so by pooling presynaptic excitatory inputs from typically many bipolar cells, which themselves collect inputs from several photoreceptors. In addition, inhibitory interactions mediated by horizontal cells and amacrine cells modulate the structure of the receptive field. In many models, this spatial integration is assumed to occur in a linear fashion. Yet, it has long been known that spatial integration by retinal ganglion cells also incurs nonlinear phenomena. Moreover, several recent examples have shown that nonlinear spatial integration is tightly connected to specific visual functions performed by different types of retinal ganglion cells. This work discusses these advances in understanding the role of nonlinear spatial integration and reviews recent efforts to quantitatively study the nature and mechanisms underlying spatial nonlinearities. These new insights point towards a critical role of nonlinearities within ganglion cell receptive fields for capturing responses of the cells to natural and behaviorally relevant visual stimuli. In the long run, nonlinear phenomena of spatial integration may also prove important for implementing the actual neural code of retinal neurons when designing visual prostheses for the eye. Copyright © 2012 Elsevier Ltd. All rights reserved.

Strychnine blocks transient but not sustained inhibition in mudpuppy retinal ganglion cells.

PubMed Central

Belgum, J H; Dvorak, D R; McReynolds, J S

1984-01-01

Transient and sustained inhibitory synaptic inputs to on-centre, off-centre, and on-off ganglion cells in the mudpuppy retina were studied using intracellular recording in the superfused eye-cup preparation. When chemical transmission was blocked with 4 mM-Co2+, application of either glycine or gamma-aminobutyric acid (GABA) caused a hyperpolarization and conductance increase in all ganglion cells. For both amino acids, the responses were dose dependent in the range 0.05-10 mM, with a half-maximal response at about 0.7 mM. Glycine and GABA sensitivities were very similar in all three types of ganglion cells. The response to applied glycine was selectively antagonized by 10(-5) M-strychnine and the response to applied GABA was selectively antagonized by 10(-5) M-picrotoxin. In all ganglion cells, 10(-5) M-strychnine eliminated the transient inhibitory events which occur at the onset and termination of a light stimulus. The block of transient inhibition was associated with a relative depolarization of membrane potential and decrease in conductance at these times. Strychnine had no effect on membrane potential or conductance in darkness or during sustained inhibitory responses to light. Picrotoxin (10(-5) M) did not block transient inhibitory events in any ganglion cells, but did affect other components of their responses. The results suggest that in all three classes of ganglion cells transient inhibition, but not sustained inhibition, may be mediated by glycine or a closely related substance. PMID:6481635

Thresholds for activation of rabbit retinal ganglion cells with an ultrafine, extracellular microelectrode.

PubMed

Jensen, Ralph J; Rizzo, Joseph F; Ziv, Ofer R; Grumet, Andrew; Wyatt, John

2003-08-01

To determine electrical thresholds required for extracellular activation of retinal ganglion cells as part of a project to develop an epiretinal prosthesis. Retinal ganglion cells were recorded extracellularly in retinas isolated from adult New Zealand White rabbits. Electrical current pulses of 100- micro s duration were delivered to the inner surface of the retina from a 5- micro m long electrode. In about half of the cells, the point of lowest threshold was found by searching with anodal current pulses; in the other cells, cathodal current pulses were used. Threshold measurements were obtained near the cell bodies of 20 ganglion cells and near the axons of 19 ganglion cells. Both cathodal and anodal stimuli evoked a neural response in the ganglion cells that consisted of a single action potential of near-constant latency that persisted when retinal synaptic transmission was blocked with cadmium chloride. For cell bodies, but not axons, thresholds for both cathodal and anodal stimulation were dependent on the search method used to find the point of lowest threshold. With search and stimulation of matching polarity, cathodal stimuli evoked a ganglion cell response at lower currents (approximately one seventh to one tenth axonal threshold) than did anodal stimuli for both cell bodies and axons. With cathodal search and stimulation, cell body median thresholds were somewhat lower (approximately one half) than the axonal median thresholds. With anodal search and stimulation, cell body median thresholds were approximately the same as axonal median thresholds. The results suggest that cathodal stimulation should produce lower thresholds, more localized stimulation, and somewhat better selectivity for cell bodies over axons than would anodal stimulation.

Ganglion Cell and Displaced Amacrine Cell Density Distribution in the Retina of the Howler Monkey (Alouatta caraya)

PubMed Central

Muniz, José Augusto Pereira Carneiro; de Athaide, Luana Modesto; Gomes, Bruno Duarte; Finlay, Barbara L.; Silveira, Luiz Carlos de Lima

2014-01-01

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. PMID:25546077

Berberine exerts antioxidant effects via protection of spiral ganglion cells against cytomegalovirus-induced apoptosis.

PubMed

Zhuang, Wei; Li, Ting; Wang, Caiji; Shi, Xi; Li, Yalan; Zhang, Shili; Zhao, Zeqi; Dong, Hongyan; Qiao, Yuehua

2018-06-01

Cytomegalovirus (CMV) is the leading cause of sensorineural hearing loss (SNHL) in children because of its damage to the cochlea and spiral ganglion cells. Therefore, it has become a top priority to devise new methods to effectively protect spiral ganglion cells from damage. Berberine (BBR) has gained attention for its vast beneficial biological effects through immunomodulation, and its anti-inflammatory and anti-apoptosis properties. However, the effect of BBR on spiral ganglion cells and molecular mechanisms are still unclear. This study aims to investigate whether BBR has an anti-apoptosis effect in CMV-induced apoptosis in cultured spiral ganglion cells and explore the possible mechanism. In this study, TUNEL and MTT assays significantly demonstrated that low doses of BBR did not promote cell apoptosis and they also inhibited the CMV-induced cultured spiral ganglion cell apoptosis. Immunofluorescence and Western blot assays indicated that the anti-apoptosis effect of BBR was related to Nox3. Mitochondrial calcium and Western blot assays revealed that NMDAR1 mediated this anti-apoptosis effect. Our results demonstrated that BBR exerted an anti-apoptosis effect against CMV in cultured spiral ganglion cells, and the mechanism is related to NMDAR1/Nox3-mediated mitochondrial reactive oxygen species (ROS) generation. Copyright © 2018 Elsevier Inc. All rights reserved.

Accelerated retinal ganglion cell death in mice deficient in the Sigma-1 receptor.

PubMed

Mavlyutov, Timur A; Nickells, Robert W; Guo, Lian-Wang

2011-04-26

The sigma-1 receptor (σR1), a ligand-operated chaperone, has been inferred to be neuroprotective in previous studies using σR1 ligands. The σR1 specificity of the protective function, however, has yet to be firmly established, due to the existence of non-σR1 targets of the ligands. Here, we used the σR1-knockout mouse (Sigmar1(-/-)) to demonstrate unambiguously the role of the σR1 in protecting the retinal ganglion cells against degeneration after acute damage to the optic nerve. Retinal σR binding sites were labeled with radioiodinated σR ligands and analyzed by autoradiography. Localization of the σR1 was performed by indirect immunofluorescence on frozen retinal sections. Retinal ganglion cell death was induced by acute optic nerve crush in wild-type and Sigmar1(-/-) mice. Surviving cells in the ganglion cell layer were counted on Nissl-stained retinal whole mounts 7 days after the crush surgery. Photoaffinity labeling indicated the presence of the σR1 in the retina, in concentrations equivalent to those in liver tissue. Immunolabeling detected this receptor in cells of both the ganglion cell layer and the photoreceptor cell layer in wild-type retinas. Quantification of cells remaining after optic nerve crush showed that 86.8±7.9% cells remained in the wild-type ganglion cell layer, but only 68.3±3.4% survived in the Sigmar1(-/-), demonstrating a significant difference between the wild-type and the Sigmar1(-/-) in crush-induced ganglion cell loss. Our data indicated faster retinal ganglion cell death in Sigmar1(-/-) than in wild-type mice under the stresses caused by optic nerve crush, providing direct evidence for a role of the σR1 in alleviating retinal degeneration. This conclusion is consistent with the previous pharmacological studies using σR1 agonists. Thus, our study supports the idea that the σR1 is a promising therapeutic target for neurodegenerative retinal diseases, such as glaucoma.

Intrinsically photosensitive retinal ganglion cells.

PubMed

Do, Michael Tri Hoang; Yau, King-Wai

2010-10-01

Life on earth is subject to alternating cycles of day and night imposed by the rotation of the earth. Consequently, living things have evolved photodetective systems to synchronize their physiology and behavior with the external light-dark cycle. This form of photodetection is unlike the familiar "image vision," in that the basic information is light or darkness over time, independent of spatial patterns. "Nonimage" vision is probably far more ancient than image vision and is widespread in living species. For mammals, it has long been assumed that the photoreceptors for nonimage vision are also the textbook rods and cones. However, recent years have witnessed the discovery of a small population of retinal ganglion cells in the mammalian eye that express a unique visual pigment called melanopsin. These ganglion cells are intrinsically photosensitive and drive a variety of nonimage visual functions. In addition to being photoreceptors themselves, they also constitute the major conduit for rod and cone signals to the brain for nonimage visual functions such as circadian photoentrainment and the pupillary light reflex. Here we review what is known about these novel mammalian photoreceptors.

A decay of gap junctions associated with ganglion cell differentiation during retinal regeneration of the adult newt.

PubMed

Oi, Hanako; Chiba, Chikafumi; Saito, Takehiko

2003-12-01

Changes in the gap junctional coupling and maturation of voltage-activated Na(+) currents during regeneration of newt retinas were examined by whole-cell patch-clamping in slice preparations. Progenitor cells in regenerating retinas did not exhibit Na(+) currents but showed prominent electrical and tracer couplings. Cells identified by LY-fills were typically slender. Na(+) currents were detected in premature ganglion cells with round somata in the 'intermediate-II' regenerating retina. No electrical and tracer couplings were observed between these cells. Mature ganglion cells did not exhibit electrical coupling, but showed tracer coupling. On average, the maximum Na(+) current amplitude recorded from premature ganglion cells was roughly 2.5-fold smaller than that of mature ganglion cells. In addition, the activation threshold of the Na(+) current was nearly 11 mV more positive than that of mature cells. We provide morphological and physiological evidence showing that loss of gap junctions between progenitor cells is associated with ganglion cell differentiation during retinal regeneration and that new gap junctions are recreated between mature ganglion cells. Also we provide evidence suggesting that the loss of gap junctions correlates with the appearance of voltage-activated Na(+) currents in ganglion cells.

Broad Thorny Ganglion Cells: A Candidate for Visual Pursuit Error Signaling in the Primate Retina

PubMed Central

Manookin, Michael B.; Neitz, Jay; Rieke, Fred

2015-01-01

Functional analyses exist only for a few of the morphologically described primate ganglion cell types, and their correlates in other mammalian species remain elusive. Here, we recorded light responses of broad thorny cells in the whole-mounted macaque retina. They showed ON-OFF-center light responses that were strongly suppressed by stimulation of the receptive field surround. Spike responses were delayed compared with parasol ganglion cells and other ON-OFF cells, including recursive bistratified ganglion cells and A1 amacrine cells. The receptive field structure was shaped by direct excitatory synaptic input and strong presynaptic and postsynaptic inhibition in both ON and OFF pathways. The cells responded strongly to dark or bright stimuli moving either in or out of the receptive field, independent of the direction of motion. However, they did not show a maintained spike response either to a uniform background or to a drifting plaid pattern. These properties could be ideally suited for guiding movements involved in visual pursuit. The functional characteristics reported here permit the first direct cross-species comparison of putative homologous ganglion cell types. Based on morphological similarities, broad thorny ganglion cells have been proposed to be homologs of rabbit local edge detector ganglion cells, but we now show that the two cells have quite distinct physiological properties. Thus, our data argue against broad thorny cells as the homologs of local edge detector cells. PMID:25834063

[Met]- and [Leu]enkephalin-like immunoreactive cell bodies and nerve fibres in the coeliac ganglion of the cat.

PubMed

Julé, Y; Clerc, N; Niel, J P; Condamin, M

1986-06-01

The occurrence and distribution of methionine- and leucine-enkephalin-like immunoreactivity were investigated in the cat coeliac ganglion using either the indirect immunoperoxidase method or the peroxidase-antiperoxidase technique. Several antisera raised to methionine- and leucine-enkephalin were used. Their specificity was assessed by incubating sections of the coeliac ganglion with increasing dilutions of antisera and with antisera saturated with their respective antigen. The present study was performed both in untreated and in colchicine-treated cats. Immunoreactive methionine- and leucine-enkephalin-like cell bodies were only visualized in colchicine-treated cats. Two types of labeled cells were observed. The first type had a size similar to that of unlabeled principal ganglion cells. These labeled cells were numerous and scattered throughout the ganglion; they probably represented enkephalin-containing ganglion cells. The second type of immunoreactive cells were of a much smaller size. They were always gathered in small clusters of about 5-15 cells and were not numerous; they presumably represented enkephalin-containing small intensely fluorescent cells. Immunoreactive nerve fibres were mainly observed in untreated cats and accessorily in colchicine-treated cats. In untreated animals dense networks of methionine- and leucine-enkephalin-like immunoreactive fibres were found in the coeliac ganglion. These fibres had numerous varicosities which often closely surrounded unlabeled principal ganglion cells. In colchicine-treated cats some immunoreactive fibres surrounded labeled principal ganglion cell bodies. The present results establish for the first time the presence of enkephalin-like immunoreactive principal ganglion cells in a mammalian sympathetic prevertebral ganglion. The presence of enkephalin-containing principal ganglion cells, small intensely fluorescent cells and nerve terminals, supports an important role of enkephalins in the integrative synaptic

Learning LM Specificity for Ganglion Cells

NASA Technical Reports Server (NTRS)

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.

Accelerated retinal ganglion cell death in mice deficient in the Sigma-1 receptor

PubMed Central

Mavlyutov, Timur A.; Nickells, Robert W.

2011-01-01

Purpose The sigma-1 receptor (σR1), a ligand-operated chaperone, has been inferred to be neuroprotective in previous studies using σR1 ligands. The σR1 specificity of the protective function, however, has yet to be firmly established, due to the existence of non-σR1 targets of the ligands. Here, we used the σR1-knockout mouse (Sigmar1−/−) to demonstrate unambiguously the role of the σR1 in protecting the retinal ganglion cells against degeneration after acute damage to the optic nerve. Methods Retinal σR binding sites were labeled with radioiodinated σR ligands and analyzed by autoradiography. Localization of the σR1 was performed by indirect immunofluorescence on frozen retinal sections. Retinal ganglion cell death was induced by acute optic nerve crush in wild-type and Sigmar1−/− mice. Surviving cells in the ganglion cell layer were counted on Nissl-stained retinal whole mounts 7 days after the crush surgery. Results Photoaffinity labeling indicated the presence of the σR1 in the retina, in concentrations equivalent to those in liver tissue. Immunolabeling detected this receptor in cells of both the ganglion cell layer and the photoreceptor cell layer in wild-type retinas. Quantification of cells remaining after optic nerve crush showed that 86.8±7.9% cells remained in the wild-type ganglion cell layer, but only 68.3±3.4% survived in the Sigmar1−/−, demonstrating a significant difference between the wild-type and the Sigmar1−/− in crush-induced ganglion cell loss. Conclusions Our data indicated faster retinal ganglion cell death in Sigmar1−/− than in wild-type mice under the stresses caused by optic nerve crush, providing direct evidence for a role of the σR1 in alleviating retinal degeneration. This conclusion is consistent with the previous pharmacological studies using σR1 agonists. Thus, our study supports the idea that the σR1 is a promising therapeutic target for neurodegenerative retinal diseases, such as glaucoma. PMID

Pou4f2-GFP knock-in mouse line: A model for studying retinal ganglion cell development.

PubMed

Zheng, Dongwang; Yang, Xiaoyan; Sheng, Donglai; Yu, Dongliang; Liang, Guoqing; Guo, Luming; Xu, Mei; Hu, Xu; He, Daqiang; Yang, Yang; Wang, Yuying

2016-10-01

Pou4f2 acts as a key node in the comprehensive and step-wise gene regulatory network (GRN) and regulates the development of retinal ganglion cells (RGCs). Accordingly, deletion of Pou4f2 results in RGC axon defects and apoptosis. To investigate the GRN involved in RGC regeneration, we generated a mouse line with a POU4F2-green fluorescent protein (GFP) fusion protein expressed in RGCs. Co-localization of POU4F2 and GFP in the retina and brain of Pou4f2-GFP/+ heterozygote mice was confirmed using immunofluorescence analysis. Compared with those in wild-type mice, the expression patterns of POU4F2 and POU4F1 and the co-expression patterns of ISL1 and POU4F2 were unaffected in Pou4f2-GFP/GFP homozygote mice. Moreover, the quantification of RGCs showed no significant difference between Pou4f2-GFP/GFP homozygote and wild-type mice. These results demonstrated that the development of RGCs in Pou4f2-GFP/GFP homozygote mice was the same as in wild-type mice. Thus, the present Pou4f2-GFP knock-in mouse line is a useful tool for further studies on the differentiation and regeneration of RGCs. © 2016 Wiley Periodicals, Inc.

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

NASA Technical Reports Server (NTRS)

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.

Visual Field Defects and Retinal Ganglion Cell Losses in Human Glaucoma Patients

PubMed Central

Harwerth, Ronald S.; Quigley, Harry A.

2007-01-01

Objective The depth of visual field defects are correlated with retinal ganglion cell densities in experimental glaucoma. This study was to determine whether a similar structure-function relationship holds for human glaucoma. Methods The study was based on retinal ganglion cell densities and visual thresholds of patients with documented glaucoma (Kerrigan-Baumrind, et al.) The data were analyzed by a model that predicted ganglion cell densities from standard clinical perimetry, which were then compared to histologic cell counts. Results The model, without free parameters, produced accurate and relatively precise quantification of ganglion cell densities associated with visual field defects. For 437 sets of data, the unity correlation for predicted vs. measured cell densities had a coefficient of determination of 0.39. The mean absolute deviation of the predicted vs. measured values was 2.59 dB, the mean and SD of the distribution of residual errors of prediction was -0.26 ± 3.22 dB. Conclusions Visual field defects by standard clinical perimetry are proportional to neural losses caused by glaucoma. Clinical Relevance The evidence for quantitative structure-function relationships provides a scientific basis of interpreting glaucomatous neuropathy from visual thresholds and supports the application of standard perimetry to establish the stage of the disease. PMID:16769839

A Learning Model for L/M Specificity in Ganglion Cells

NASA Technical Reports Server (NTRS)

Ahumada, Albert J.

2016-01-01

An unsupervised learning model for developing LM specific wiring at the ganglion cell level would support the research indicating LM specific wiring at the ganglion cell level (Reid and Shapley, 2002). Removing the contributions to the surround from cells of the same cone type improves the signal-to-noise ratio of the chromatic signals. The unsupervised learning model used is Hebbian associative learning, which strengthens the surround input connections according to the correlation of the output with the input. Since the surround units of the same cone type as the center are redundant with the center, their weights end up disappearing. This process can be thought of as a general mechanism for eliminating unnecessary cells in the nervous system.

Digital Museum of Retinal Ganglion Cells with Dense Anatomy and Physiology.

PubMed

Bae, J Alexander; Mu, Shang; Kim, Jinseop S; Turner, Nicholas L; Tartavull, Ignacio; Kemnitz, Nico; Jordan, Chris S; Norton, Alex D; Silversmith, William M; Prentki, Rachel; Sorek, Marissa; David, Celia; Jones, Devon L; Bland, Doug; Sterling, Amy L R; Park, Jungman; Briggman, Kevin L; Seung, H Sebastian

2018-05-17

When 3D electron microscopy and calcium imaging are used to investigate the structure and function of neural circuits, the resulting datasets pose new challenges of visualization and interpretation. Here, we present a new kind of digital resource that encompasses almost 400 ganglion cells from a single patch of mouse retina. An online "museum" provides a 3D interactive view of each cell's anatomy, as well as graphs of its visual responses. The resource reveals two aspects of the retina's inner plexiform layer: an arbor segregation principle governing structure along the light axis and a density conservation principle governing structure in the tangential plane. Structure is related to visual function; ganglion cells with arbors near the layer of ganglion cell somas are more sustained in their visual responses on average. Our methods are potentially applicable to dense maps of neuronal anatomy and physiology in other parts of the nervous system. Copyright © 2018 Elsevier Inc. All rights reserved.

Spontaneous Discharge Patterns in Cochlear Spiral Ganglion Cells Prior to the Onset of Hearing in Cats

PubMed Central

Jones, Timothy A.; Leake, Patricia A.; Snyder, Russell L.; Stakhovskaya, Olga; Bonham, Ben

2008-01-01

Spontaneous neural activity has been recorded in the auditory nerve of cats as early as 2 days postnatal (P2 ), yet individual auditory neurons do not respond to ambient sound levels below 90–100 dB SPL until about P10. Significant refinement of the central projections from the spiral ganglion to the cochlear nucleus occurs during this neonatal period. This refinement may be dependent on peripheral spontaneous discharge activity. We recorded from single spiral ganglion cells in kittens aged P3 to P9. The spiral ganglion was accessed via the round window through the spiral lamina. A total of 112 ganglion cells were isolated for study in 9 animals. Spike rates in neonates were very low, ranging from 0.06 to 56 sp/s with a mean of 3.09 +/− 8.24 sp/s. Ganglion cells in neonatal kittens exhibited remarkable repetitive spontaneous bursting discharge patterns. The unusual patterns were evident in the large mean interval coefficient of variation (CVi = 2.9 +/−1.6) and burst index of 5.2 +/− 3.5 across ganglion cells. Spontaneous bursting patterns in these neonatal mammals were similar to those reported for cochlear ganglion cells of the embryonic chicken suggesting this may be a general phenomenon that is common across animal classes. Rhythmic spontaneous discharge of retinal ganglion cells has been shown to be important in the development of central retinotopic projections and normal binocular vision (Shatz, 1996, Proc Natl Acad Sci 93). Bursting rhythms in cochlear ganglion cells may play a similar role in the auditory system during pre-hearing periods. PMID:17686914

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

PubMed

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. Copyright © 2012 S. Karger AG, Basel.

Diagnostic ability of macular ganglion cell asymmetry for glaucoma.

PubMed

Hwang, Young Hoon; Ahn, Sang Il; Ko, Sung Ju

2015-11-01

Using spectral-domain optical coherence tomography (OCT), this study aims to investigate the glaucoma diagnostic ability of macular ganglion cell asymmetry analysis. A cross-sectional study was conducted. This study was performed to investigate glaucoma diagnostic ability of macular ganglion cell asymmetry analysis in eyes with various degrees of glaucoma. We enrolled 181 healthy eyes and 265 glaucomatous eyes. Glaucomatous eyes were subdivided into pre-perimetric, early, moderate and advanced-to-severe glaucoma based on visual field test results. For each eye, macular ganglion cell-inner plexiform layer (GCIPL) thickness was measured using OCT. Average GCIPL thickness, GCIPL thicknesses in superior and inferior hemispheres, absolute difference in GCIPL thickness between superior and inferior hemispheres and GCIPL asymmetry index calculated as the absolute value of log10 (inferior hemisphere thickness/superior hemisphere thickness) were analysed. Areas under the receiver operating characteristics curves (AUCs) of GCIPL parameter were calculated and compared. All of the GCIPL parameters showed good glaucoma diagnostic ability (AUCs ≥ 0.817, P < 0.01). AUCs of average, superior and inferior GCIPL thickness increased as the severity of glaucoma increased. GCIPL thickness difference and asymmetry index showed the highest AUCs in early and moderate glaucoma and lower AUCs in pre-perimetric and advanced-to-severe glaucoma. GCIPL thickness difference and asymmetry index showed better glaucoma diagnostic ability than other GCIPL parameters only in early stage of glaucoma (P < 0.05); in other stages, these parameters had similar to or worse glaucoma diagnostic ability than other GCIPL parameters. Macular ganglion cell asymmetry analysis showed good glaucoma diagnostic ability, especially in early-stage glaucoma. However, it has limited usefulness in other stages of glaucoma. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

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

PubMed

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. Copyright © 2011 Wiley Periodicals, Inc.

Central Projections of Melanopsin-Expressing Retinal Ganglion Cells in the Mouse

PubMed Central

HATTAR, SAMER; KUMAR, MONICA; PARK, ALEXANDER; TONG, PATRICK; TUNG, JONATHAN; YAU, KING-WAI; BERSON, DAVID M.

2010-01-01

A rare type of ganglion cell in mammalian retina is directly photosensitive. These novel retinal photoreceptors express the photopigment melanopsin. They send axons directly to the suprachiasmatic nucleus (SCN), intergeniculate leaflet (IGL), and olivary pretectal nucleus (OPN), thereby contributing to photic synchronization of circadian rhythms and the pupillary light reflex. Here, we sought to characterize more fully the projections of these cells to the brain. By targeting tau-lacZ to the melanopsin gene locus in mice, ganglion cells that would normally express melanopsin were induced to express, instead, the marker enzyme β-galactosidase. Their axons were visualized by X-gal histochemistry or anti-β-galactosidase immunofluorescence. Established targets were confirmed, including the SCN, IGL, OPN, ventral division of the lateral geniculate nucleus (LGv), and preoptic area, but the overall projections were more widespread than previously recognized. Targets included the lateral nucleus, peri-supraoptic nucleus, and subparaventricular zone of the hypothalamus, medial amygdala, margin of the lateral habenula, posterior limitans nucleus, superior colliculus, and periaqueductal gray. There were also weak projections to the margins of the dorsal lateral geniculate nucleus. Co-staining with the cholera toxin B subunit to label all retinal afferents showed that melanopsin ganglion cells provide most of the retinal input to the SCN, IGL, and lateral habenula and much of that to the OPN, but that other ganglion cells do contribute at least some retinal input to these targets. Staining patterns after monocular enucleation revealed that the projections of these cells are overwhelmingly crossed except for the projection to the SCN, which is bilaterally symmetrical. PMID:16736474

Retinal ganglion cells in diabetes

PubMed Central

Kern, Timothy S; Barber, Alistair J

2008-01-01

Diabetic retinopathy has long been recognized as a vascular disease that develops in most patients, and it was believed that the visual dysfunction that develops in some diabetics was due to the vascular lesions used to characterize the disease. It is becoming increasingly clear that neuronal cells of the retina also are affected by diabetes, resulting in dysfunction and even degeneration of some neuronal cells. Retinal ganglion cells (RGCs) are the best studied of the retinal neurons with respect to the effect of diabetes. Although investigations are providing new information about RGCs in diabetes, including therapies to inhibit the neurodegeneration, critical information about the function, anatomy and response properties of these cells is yet needed to understand the relationship between RGC changes and visual dysfunction in diabetes. PMID:18565995

Relationship between macular ganglion cell complex thickness and macular outer retinal thickness: a spectral-domain optical coherence tomography study.

PubMed

Kita, Yoshiyuki; Kita, Ritsuko; Takeyama, Asuka; Anraku, Ayako; Tomita, Goji; Goldberg, Ivan

2013-01-01

To assess the relationship between macular ganglion cell complex and macular outer retinal thicknesses. Case-control study. Forty-two normal eyes and 91 eyes with primary open-angle glaucoma were studied. Spectral-domain optical coherence tomography (RTVue-100) was used to measure the macular ganglion cell complex and macular outer retinal thickness. Ganglion cell complex to outer retinal thickness ratio was also calculated. The relationships between the ganglion cell complex and outer retinal thicknesses and between the ganglion cell complex to outer retinal thickness ratio and outer retinal thickness were evaluated. There was a positive correlation between ganglion cell complex and outer retinal thicknesses in the normal group and the glaucoma group (r = 0.53, P < 0.001 and r = 0.42, P < 0.001, respectively). In that respect, there was no correlation between ganglion cell complex to outer retinal thickness ratio and outer retinal thickness in the both groups (r = -0.07, P = 0.657, and r = 0.04, P = 0.677, respectively). The ganglion cell complex to outer retinal thickness ratio was 55.65% in the normal group, 45.07% in the glaucoma group. This difference was statistically significant. The ganglion cell complex thickness may be affected by outer retinal thickness, and there is individual variation in the outer retinal thickness. Therefore, when determining the ganglion cell complex, it seems necessary to consider the outer retinal thickness as well. We propose the ratio as a suitable parameter to account for individual variations in outer retinal thickness. © 2013 The Authors. Clinical and Experimental Ophthalmology © 2013 Royal Australian and New Zealand College of Ophthalmologists.

TRPC1 is required for survival and proliferation of cochlear spiral ganglion stem/progenitor cells.

PubMed

Chen, Hsin-Chien; Wang, Chih-Hung; Shih, Cheng-Ping; Chueh, Sheau-Huei; Liu, Shu-Fan; Chen, Hang-Kang; Lin, Yi-Chun

2015-12-01

The present studies were designed to test the hypothesis that canonical transient receptor potential channel 1 (TRPC1) is required for the proliferation of cochlear spiral ganglion stem/progenitor cells (SPCs). TRPC1 were detected and evaluated in postnatal day 1 CBA/CaJ mice pups derived-cochlear spiral ganglion SPCs by reverse transcription-polymerase chain reaction, Western blot, immunocytochemistry, and calcium imaging. The cell viability and proliferation of the spiral ganglion SPCs following si-RNA mediated knockdown of TRPC1 or addition of TRPC channel blocker SKF9635 were compared to controls. In spiral ganglion SPCs, TRPC1 was found to be the most abundantly expressed TRPC subunit and shown to contribute to store-operated calcium entry. Silencing of TRPC1 or addition of TRPC channel blockers significantly decreased the rate of cell proliferation. The results suggest that TRPC1 might serve as an essential molecule in regulating the proliferation of spiral ganglion SPCs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The ciliary margin zone of the mammalian retina generates retinal ganglion cells

PubMed Central

Marcucci, Florencia; Murcia-Belmonte, Veronica; Coca, Yaiza; Ferreiro-Galve, Susana; Wang, Qing; Kuwajima, Takaaki; Khalid, Sania; Ross, M. Elizabeth; Herrera, Eloisa; Mason, Carol

2016-01-01

Summary The retina of lower vertebrates grows continuously by integrating new neurons generated from progenitors in the ciliary margin zone (CMZ). Whether the mammalian CMZ provides the neural retina with retinal cells is controversial. Live-imaging of embryonic retina expressing eGFP in the CMZ shows that cells migrate laterally from the CMZ to the neural retina where differentiated retinal ganglion cells (RGCs) reside. As Cyclin D2, a cell-cycle regulator, is enriched in ventral CMZ, we analyzed Cyclin D2−/− mice to test whether the CMZ is a source of retinal cells. Neurogenesis is diminished in Cyclin D2 mutants, leading to a reduction of RGCs in the ventral retina. In line with these findings, in the albino retina, the decreased production of ipsilateral RGCs is correlated with fewer Cyclin D2+ cells. Together, these results implicate the mammalian CMZ as a neurogenic site that produces RGCs and whose proper generation depends on Cyclin D2 activity. PMID:28009286

Enhanced Stem Cell Differentiation and Immunopurification of Genome Engineered Human Retinal Ganglion Cells.

PubMed

Sluch, Valentin M; Chamling, Xitiz; Liu, Melissa M; Berlinicke, Cynthia A; Cheng, Jie; Mitchell, Katherine L; Welsbie, Derek S; Zack, Donald J

2017-11-01

Human pluripotent stem cells have the potential to promote biological studies and accelerate drug discovery efforts by making possible direct experimentation on a variety of human cell types of interest. However, stem cell cultures are generally heterogeneous and efficient differentiation and purification protocols are often lacking. Here, we describe the generation of clustered regularly-interspaced short palindromic repeats(CRISPR)-Cas9 engineered reporter knock-in embryonic stem cell lines in which tdTomato and a unique cell-surface protein, THY1.2, are expressed under the control of the retinal ganglion cell (RGC)-enriched gene BRN3B. Using these reporter cell lines, we greatly improved adherent stem cell differentiation to the RGC lineage by optimizing a novel combination of small molecules and established an anti-THY1.2-based protocol that allows for large-scale RGC immunopurification. RNA-sequencing confirmed the similarity of the stem cell-derived RGCs to their endogenous human counterparts. Additionally, we developed an in vitro axonal injury model suitable for studying signaling pathways and mechanisms of human RGC cell death and for high-throughput screening for neuroprotective compounds. Using this system in combination with RNAi-based knockdown, we show that knockdown of dual leucine kinase (DLK) promotes survival of human RGCs, expanding to the human system prior reports that DLK inhibition is neuroprotective for murine RGCs. These improvements will facilitate the development and use of large-scale experimental paradigms that require numbers of pure RGCs that were not previously obtainable. Stem Cells Translational Medicine 2017;6:1972-1986. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Prevention of Excitotoxicity in Primary Retinal Ganglion Cells by (+)-Pentazocine, a Sigma Receptor-1-Specific Ligand

PubMed Central

Dun, Ying; Thangaraju, Muthusamy; Prasad, Puttur; Ganapathy, Vadivel; Smith, Sylvia B.

2013-01-01

Purpose σRs are non-opioid, non-phencyclidine binding sites with robust neuroprotective properties. Previously, we induced death in the RGC-5 cell line using very high concentrations (1 mM) of the excitatory amino acids glutamate (Glu) and homocysteine (Hcy) and demonstrated that the σR1 ligand (+)-pentazocine ((+)-PTZ) could protect against cell death. The purpose of the present study was to establish a physiologically relevant paradigm for testing the neuroprotective effect of (+)-PTZ in retinal ganglion cells. Methods Primary ganglion cells (1°GCs) were isolated by immunopanning from retinas of 1-day-old mice, maintained in culture for 3 days and then exposed to 10, 20, 25 or 50 µM Glu or 10, 25, 50 or 100 µM Hcy for 6 or 18 h in the presence or absence of (+)-PTZ (0.5, 1, 3 µM). Cell viability was measured using the Live/Dead and ApopTag Fluorescein In Situ Assays. Expression of σR1 was assessed by immunocytochemistry, RT-PCR and western blotting. Morphological appearance of live ganglion cells and their processes was examined over time (0, 3, 6, 18 h) by differential interference contrast (DIC) microscopy following exposure to excitotoxins in the presence or absence of (+)-PTZ. Results 1°GCs showed robust σR1 expression. The cells are exquisitely sensitive to Glu or Hcy toxicity (6 h treatment with 25 or 50 µM Glu or 50 or 100 µM Hcy induced marked cell death). 1°GCs pre-treated 1 h with (+)-PTZ followed by 18 h co-treatment with 25 µM Glu and (+)-PTZ showed a marked decrease in cell death: (25 µM Glu alone: 50%; 25 µM Glu/0.5 µM (+)-PTZ: 38%; 25 µM Glu/1 µM (+)-PTZ: 20%; 25 µM Glu/3 µM (+)-PTZ: 18%). Similar results were obtained with Hcy. σR1 mRNA and protein levels did not change in the presence of the excitotoxins. DIC examination of cells exposed to excitotoxins revealed substantial disruption of neuronal processes; co-treatment with (+)-PTZ revealed marked preservation of these processes. The stereoselective effect of (+)-PTZ for �

Atypical fibrosarcomas derived from cutaneous ganglion cell-like cells in 2 domestic Djungarian hamsters (Phodopus sungorus).

PubMed

Kondo, Hirotaka; Onuma, Mamoru; Shibuya, Hisashi; Sato, Tsuneo; Abbott, Jeffrey R

2011-07-01

Androgen-dependent atypical fibromas are benign tumors derived from ganglion-cell-like cells that are particular to Djungarian hamsters (Phodopus sungorus). Masses excised from 2 hamsters were composed of pleomorphic ganglion cell-like cells supported by small to moderate amounts of collagenous matrix. Intracytoplasmic fibrils were present in silver-stained sections, and immunohistochemistry showed that the cells expressed vimentin, androgen receptor, and, in one case, estrogen receptor α. In contrast to previously reported atypical fibromas, these tumors had features of anaplasia and were locally invasive. We diagnosed the tumors as atypical fibrosarcomas and consider them an unusual malignant counterpart of atypical fibroma. Copyright 2011 by the American Association for Laboratory Animal Science

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

PubMed Central

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. The optic nerve crush (ONC) injury mouse model is an important experimental disease model for traumatic optic neuropathy, glaucoma, etc. In this model, the crush injury to the optic nerve leads to gradual retinal ganglion cells apoptosis. This disease model can be used to study the general processes and mechanisms of neuronal death and survival, which is essential for the development of therapeutic measures. In addition, pharmacological and molecular approaches can be used in this model to identify and test potential therapeutic reagents to treat different types of optic neuropathy. Here, we provide a step by step demonstration of (I) Baseline retrograde labeling of retinal ganglion cells (RGCs) at day 1, (II) Optic nerve crush injury at day 4, (III) Harvest the retinae and analyze RGC survival at day 11, and (IV) Representative result. PMID:21540827

Effects of cholinergic drugs on receptive field properties of rabbit retinal ganglion cells

PubMed Central

Ariel, M.; Daw, N. W.

1982-01-01

1. Retinal ganglion cells were recorded extracellularly from the rabbit's eye in situ to study the effects of cholinergic drugs on receptive field properties. Physostigmine, an acetylcholinesterase inhibitor, and nicotine increased the spontaneous activity of nearly all retinal ganglion cell types. The effectiveness of physostigmine was roughly correlated with the neurone's inherent level of spontaneous activity. Brisk cells, having high rates of spontaneous firing, showed large increases in their maintained discharge, whereas sluggish cells, with few or no spontaneous spikes, showed small and sometimes transient increases in spontaneous activity during physostigmine. 2. The sensitivity of ganglion cells to spots of optimal size and position did not change substantially during the infusion of physostigmine. However, the responsiveness to light (number of spikes per stimulus above the spontaneous level) increased. This effect occurred with sluggish and more complex cells, rarely with brisk cells. 3. Another effect of physostigmine on sluggish and more complex cells was to make these cells `on—off'. The additional response to the inappropriate change in contrast had a long latency and lacked an initial transient burst. 4. Complex receptive field properties such as orientation sensitivity, radial grating inhibition, speed tuning and size specificity were also examined. These inhibitory properties were still present during infusion of physostigmine and, in most cases, the trigger feature of each cell type remained. 5. These results are consistent with pharmacological results on ACh release from the retina. There appear to be two types of release of ACh, having their most powerful influences on separate classes of cells. One release (transient), occurs at light onset and offset and acts primarily on sluggish and more complex ganglion cells; the other release (tonic) is not light-modulated and acts primarily on brisk cells. A wiring diagram for the ACh cells is

Spatial resolution, contrast sensitivity, and sensitivity to defocus of chicken retinal ganglion cells in vitro.

PubMed

Diedrich, Erich; Schaeffel, Frank

2009-11-01

The chicken has been extensively studied as an animal model for myopia because its eye growth is tightly controlled by visual experience. It has been found that the retina controls the axial eye growth rates depending on the amount and the sign of defocus imposed in the projected image. Glucagonergic amacrine cells were discovered that appear to encode for the sign of imposed defocus. It is not clear whether the downstream neurons, the retinal ganglion cells, still have access to this information-and whether it ultimately reaches the brain. We have analyzed the spike rates of chicken retinal ganglion cells in vitro using a microelectrode array. For this purpose, we initially defined spatial resolution and contrast sensitivity in vitro. Two classes of chicken retinal ganglions were found, depending on the linearity of their responses with increasing contrast. Responses generally declined with increasing defocus of the visual stimulus. These responses were well predicted by the modulation transfer function for a diffraction-limited defocused optical system, the first Bessel function. Thus, the studied retinal ganglion cells did not distinguish between a loss of contrast at a given spatial frequency due to reduced contrast of the stimulus pattern or because the pattern was presented out of focus. Furthermore, there was no indication that the retinal ganglion cells responded differently to defocus of either sign, at least for the cells that were recorded in this study.

Progranulin deficiency causes the retinal ganglion cell loss during development.

PubMed

Kuse, Yoshiki; Tsuruma, Kazuhiro; Mizoguchi, Takahiro; Shimazawa, Masamitsu; Hara, Hideaki

2017-05-10

Astrocytes are glial cells that support and protect neurons in the central nervous systems including the retina. Retinal ganglion cells (RGCs) are in contact with the astrocytes and our earlier findings showed the reduction of the number of cells in the ganglion cell layer in adult progranulin deficient mice. In the present study, we focused on the time of activation of the astrocytes and the alterations in the number of RGCs in the retina and optic nerve in progranulin deficient mice. Our findings showed that the number of Brn3a-positive cells was reduced and the expression of glial fibrillary acidic protein (GFAP) was increased in progranulin deficient mice. The progranulin deficient mice had a high expression of GFAP on postnatal day 9 (P9) but not on postnatal day 1. These mice also had a decrease in the number of the Brn3a-positive cells on P9. Taken together, these findings indicate that the absence of progranulin can affect the survival of RGCs subsequent the activation of astrocytes during retinal development.

Electrical Interaction of Paired Ganglion Cells in the Leech

PubMed Central

Eckert, Roger

1963-01-01

The two paired giant ganglion cells (PGC's) found in each ganglion of the leech central nervous system fire synchronously in response to certain sensory input. Polarizing current passed into either of these cells is seen to displace the membrane potentials of both cells, the voltage attenuation between the two somata ranging from 2 to 5 times. This attenuation factor remains unchanged when the direction of the polarizing current is reversed, and remains about the same when the other cell of the pair is directly polarized. When one of the PGC's is partially depolarized with outward current, a repetitive train of impulses is generated. Each spike is followed by a spike in the other cell. Occasionally, a small subspike potential is seen in place of a follower spike. This potential appears to differ in shape and time course from synaptic potentials elicited by afferent input to these cells, and appears rather to be an electrotonic potential derived from the prejunctional impulse in the stimulated PGC. It is proposed that transmission between these cells is electrical, being accomplished by a flow of local circuit current across a non-rectifying junction or connection to the spike-initiating region of the other PGC. PMID:19873553

The retina of the shovel-nosed ray, Rhinobatos batillum (Rhinobatidae): morphology and quantitative analysis of the ganglion, amacrine and bipolar cell populations.

PubMed

Collin, S P

1988-01-01

A light microscopy study of the retina of the shovel-nosed ray, Rhinobatos batillum (Rhinobatidae) has revealed a duplex retina with a rod to cone ratio between 4:1 and 6:1. The inner nuclear layer consists of three layers of large horizontal cells, tightly packed, stellate bipolar cells, and up to three substrata of amacrine cells. The collaterals of the many supporting Müller cells project from the inner to the outer limiting membrane and divide the retina into many subunits. The cells of the ganglion cell layer are distributed into two layers, although a large proportion of ganglion cells are also displaced into the inner plexiform and inner nuclear layers. Topographic analysis of the cells in the ganglion cell layer, inner plexiform and inner nuclear layers reveals a number of regional specializations or "areae centrales". Ganglion cells were retrogradely-labelled with cobalt-lysine from the optic nerve, and three sub-populations of neurons characterized on their soma size and position. Small (20-50 microns2), large (80-300 microns2) and giant (greater than 300 microns2) sub-populations of ganglion cells each revealed distinct retinal specializations with peak densities of 3 x 10(3), 1.25 x 10(3) and 1.57 x 10(3) cells per mm2, respectively. Topographical comparison between Nissl-stained and retrogradely-labelled ganglion cell populations have established that a maximum of 20% in the "area centralis", and 75% in unspecialized, peripheral regions of the retina are non-ganglion cells. Out of a total of 210,566 cells in the ganglion cell layer, 49% were found to be non-ganglion cells. Iso-density contour maps of amacrine and bipolar cell distributions also reveal some specializations. These cell concentrations lie in corresponding regions to areas of increased density in the large and giant ganglion cell populations, suggesting some functional association.

Neuroprotection of a Novel Cyclopeptide C*HSDGIC* from the Cyclization of PACAP (1–5) in Cellular and Rodent Models of Retinal Ganglion Cell Apoptosis

PubMed Central

Cheng, Huanhuan; Ding, Yong; Yu, Rongjie; Chen, Jiansu; Wu, Chunyun

2014-01-01

Purpose To investigate the protective effects of a novel cyclopeptide C*HSDGIC* (CHC) from the cyclization of Pituitary adenylate cyclase-activating polypeptide (PACAP) (1–5) in cellular and rodent models of retinal ganglion cell apoptosis. Methodology/Principal Findings Double-labeling immunohistochemistry was used to detect the expression of Thy-1 and PACAP receptor type 1 in a retinal ganglion cell line RGC-5. The apoptosis of RGC-5 cells was induced by 0.02 J/cm2 Ultraviolet B irradiation. MTT assay, flow cytometry, fluorescence microscopy were used to investigate the viability, the level of reactive oxygen species (ROS) and apoptosis of RGC-5 cells respectively. CHC attenuated apoptotic cell death induced by Ultraviolet B irradiation and inhibited the excessive generation of ROS. Moreover, CHC treatment resulted in decreased expression of Bax and concomitant increase of Bcl-2, as was revealed by western-blot analysis. The in vivo apoptosis of retinal ganglion cells was induced by injecting 50 mM N-methyl-D-aspartate (NMDA) (100 nmol in a 2 µL saline solution) intravitreally, and different dosages of CHC were administered. At day 7, rats in CHC+ NMDA-treated groups showed obvious aversion to light when compared to NMDA rats. Electroretinogram recordings revealed a marked decrease in the amplitudes of a-wave, b-wave, and photopic negative response due to NMDA damage. In retina receiving intravitreal NMDA and CHC co-treatment, these values were significantly increased. CHC treatment also resulted in less NMDA-induced cell loss and a decrease in the proportion of dUTP end-labeling-positive cells in ganglion cell line. Conclusions C*HSDGIC*, a novel cyclopeptide from PACAP (1–5) attenuates apoptosis in RGC-5 cells and inhibits NMDA-induced retinal neuronal death. The beneficial effects may occur via the mitochondria pathway. PACAP derivatives like CHC may serve as a promising candidate for neuroprotection in glaucoma. PMID:25286089

Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration

PubMed Central

Fernández-Sánchez, Laura; Rondón, Netxibeth; Esquiva, Gema; Germain, Francisco; de la Villa, Pedro; Cuenca, Nicolás

2015-01-01

Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA)-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss. PMID:26379056

In vivo fluorescence imaging of primate retinal ganglion cells and retinal pigment epithelial cells

NASA Astrophysics Data System (ADS)

Gray, Daniel C.; Merigan, William; Wolfing, Jessica I.; Gee, Bernard P.; Porter, Jason; Dubra, Alfredo; Twietmeyer, Ted H.; Ahamd, Kamran; Tumbar, Remy; Reinholz, Fred; Williams, David R.

2006-08-01

The ability to resolve single cells noninvasively in the living retina has important applications for the study of normal retina, diseased retina, and the efficacy of therapies for retinal disease. We describe a new instrument for high-resolution, in vivo imaging of the mammalian retina that combines the benefits of confocal detection, adaptive optics, multispectral, and fluorescence imaging. The instrument is capable of imaging single ganglion cells and their axons through retrograde transport in ganglion cells of fluorescent dyes injected into the monkey lateral geniculate nucleus (LGN). In addition, we demonstrate a method involving simultaneous imaging in two spectral bands that allows the integration of very weak signals across many frames despite inter-frame movement of the eye. With this method, we are also able to resolve the smallest retinal capillaries in fluorescein angiography and the mosaic of retinal pigment epithelium (RPE) cells with lipofuscin autofluorescence.

The Ciliary Margin Zone of the Mammalian Retina Generates Retinal Ganglion Cells.

PubMed

Marcucci, Florencia; Murcia-Belmonte, Veronica; Wang, Qing; Coca, Yaiza; Ferreiro-Galve, Susana; Kuwajima, Takaaki; Khalid, Sania; Ross, M Elizabeth; Mason, Carol; Herrera, Eloisa

2016-12-20

The retina of lower vertebrates grows continuously by integrating new neurons generated from progenitors in the ciliary margin zone (CMZ). Whether the mammalian CMZ provides the neural retina with retinal cells is controversial. Live imaging of embryonic retina expressing eGFP in the CMZ shows that cells migrate laterally from the CMZ to the neural retina where differentiated retinal ganglion cells (RGCs) reside. Because Cyclin D2, a cell-cycle regulator, is enriched in ventral CMZ, we analyzed Cyclin D2 -/- mice to test whether the CMZ is a source of retinal cells. Neurogenesis is diminished in Cyclin D2 mutants, leading to a reduction of RGCs in the ventral retina. In line with these findings, in the albino retina, the decreased production of ipsilateral RGCs is correlated with fewer Cyclin D2 + cells. Together, these results implicate the mammalian CMZ as a neurogenic site that produces RGCs and whose proper generation depends on Cyclin D2 activity. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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.

The morphology and classification of α ganglion cells in the rat retinae: a fractal analysis study.

PubMed

Jelinek, Herbert F; Ristanović, Dušan; Milošević, Nebojša T

2011-09-30

Rat retinal ganglion cells have been proposed to consist of a varying number of subtypes. Dendritic morphology is an essential aspect of classification and a necessary step toward understanding structure-function relationships of retinal ganglion cells. This study aimed at using a heuristic classification procedure in combination with the box-counting analysis to classify the alpha ganglion cells in the rat retinae based on the dendritic branching pattern and to investigate morphological changes with retinal eccentricity. The cells could be divided into two groups: cells with simple dendritic pattern (box dimension lower than 1.390) and cells with complex dendritic pattern (box dimension higher than 1.390) according to their dendritic branching pattern complexity. Both were further divided into two subtypes due to the stratification within the inner plexiform layer. In the present study we have shown that the alpha rat RCGs can be classified further by their dendritic branching complexity and thus extend those of previous reports that fractal analysis can be successfully used in neuronal classification, particularly that the fractal dimension represents a robust and sensitive tool for the classification of retinal ganglion cells. A hypothesis of possible functional significance of our classification scheme is also discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of duration and severity of migraine on retinal nerve fiber layer, ganglion cell layer, and choroidal thickness.

PubMed

Abdellatif, Mona K; Fouad, Mohamed M

2018-03-01

To investigate the factors in migraine that have the highest significance on retinal and choroidal layers' thickness. Ninety patients with migraine and 40 age-matched healthy participants were enrolled in this observational, cross-sectional study. After full ophthalmological examination, spectral domain-optical coherence tomography was done for all patients measuring the thickness of ganglion cell layer and retinal nerve fiber layer. Enhanced depth imaging technique was used to measure the choroidal thickness. There was significant thinning in the superior and inferior ganglion cell layers, all retinal nerve fiber layer quadrants, and all choroidal quadrants (except for the central subfield) in migraineurs compared to controls. The duration of migraine was significantly correlated with ganglion cell layer, retinal nerve fiber layer, and all choroidal quadrants, while the severity of migraine was significantly correlated with ganglion cell layer and retinal nerve fiber layer only. Multiregression analysis showed that the duration of migraine is the most important determinant factor of the superior retinal nerve fiber layer quadrant (β = -0.375, p = 0.001) and in all the choroidal quadrants (β = -0.531, -0.692, -0.503, -0.461, -0.564, respectively, p  < 0.001), while severity is the most important determinant factor of inferior, nasal, and temporal retinal nerve fiber layer quadrants (β = -0.256, -0.335, -0.308; p  = 0.036, 0.005, 0.009, respectively) and the inferior ganglion cell layer hemisphere (β = -0.377 and p = 0.001). Ganglion cell layer, retinal nerve fiber layer, and choroidal thickness are significantly thinner in patients with migraine. The severity of migraine has more significant influence in the thinning of ganglion cell layer and retinal nerve fiber layer, while the duration of the disease affected the choroidal thickness more.

[Effects on survival of shRNA mediated APE/Ref1 gene silencing in rat spiral ganglion cells in oxidative stress].

PubMed

Jiang, Zhendong; Zhong, Cheng; Li, Taijun; Xiang, Zhaolan; Zhang, Xueyuan

2014-02-01

To investigate the effects of reducing APE/Ref1 expression in the cultures of rat spiral ganglion cells with oxidative damage induced by H(2)O(2). Primary cultured rat spiral ganglion cells were infected with small interfering RNA to APE/Ref1 (Ape1siRNA) for 72 h, followed by treating with H(2)O(2) (0, 10, 25, 50, 100 and 300 µmol/L) for 1 h , and then cultured in normal medium for 24 h. Western blot were used to detect the level of APE/Ref1 protein and phosphorylation of histone protein H2AX in the infected cells. The caspase3 activation was tested by spectrophotometric method . The cell viability was determined by MTT and the apoptosis of spiral ganglion cells was determined by terminal-deoxynucleotidyl transferase mediated nick and labeling (TUNEL). Western blot showed that infection with Ape1siRNA resulted in APE/Ref1 reduced expression in the spiral ganglion cells. Exposing spiral ganglion cultures with reduced expression of APE/Ref1 to H(2)O(2) (50, 100, 300 µmol/L) for 1 h resulted in increasing in the phosphorylation of histone protein H2AX. The reduction in APE/Ref1 significantly reduced cell viability in cultures 24 h after 1 h expression to 50-300 µmol/L H(2)O(2). The apoptosis of cells and caspase 3 activity was detected significantly improved. The induced of APE/Ref1 results in significantly decrease in spiral ganglion cells viability in oxidative stress. The repairing function of APE/Ref1 is necessary for optimal levels of neuronal rat spiral ganglion cells survival.

Nanotopography induced contact guidance of the F11 cell line during neuronal differentiation: a neuronal model cell line for tissue scaffold development

NASA Astrophysics Data System (ADS)

Wieringa, Paul; Tonazzini, Ilaria; Micera, Silvestro; Cecchini, Marco

2012-07-01

The F11 hybridoma, a dorsal root ganglion-derived cell line, was used to investigate the response of nociceptive sensory neurons to nanotopographical guidance cues. This established this cell line as a model of peripheral sensory neuron growth for tissue scaffold design. Cells were seeded on substrates of cyclic olefin copolymer (COC) films imprinted via nanoimprint lithography (NIL) with a grating pattern of nano-scale grooves and ridges. Different ridge widths were employed to alter the focal adhesion formation, thereby changing the cell/substrate interaction. Differentiation was stimulated with forskolin in culture medium consisting of either 1 or 10% fetal bovine serum (FBS). Per medium condition, similar neurite alignment was achieved over the four day period, with the 1% serum condition exhibiting longer, more aligned neurites. Immunostaining for focal adhesions found the 1% FBS condition to also have fewer, less developed focal adhesions. The robust response of the F11 to guidance cues further builds on the utility of this cell line as a sensory neuron model, representing a useful tool to explore the design of regenerative guidance tissue scaffolds.

Melanopsin-expressing retinal ganglion-cell photoreceptors: cellular diversity and role in pattern vision

PubMed Central

Ecker, Jennifer L.; Dumitrescu, Olivia N.; Wong, Kwoon Y.; Alam, Nazia M.; Chen, Shih-Kuo; LeGates, Tara; Renna, Jordan M.; Prusky, Glen T.; Berson, David M.; Hattar, Samer

2010-01-01

Using the photopigment melanopsin, intrinsically photosensitive retinal ganglion cells (ipRGCs) respond directly to light to drive circadian clock resetting and pupillary constriction. We now report that ipRGCs are more abundant and diverse than previously appreciated, project more widely within the brain, and can support spatial visual perception. A Cre-based melanopsin reporter mouse line revealed at least five subtypes of ipRGCs with distinct morphological and physiological characteristics. Collectively, these cells project beyond the known brain targets of ipRGCs to heavily innervate the superior colliculus and dorsal lateral geniculate nucleus, retinotopically-organized nuclei mediating object localization and discrimination. Mice lacking classical rod-cone photoreception, and thus entirely dependent on melanopsin for light detection, were able to discriminate grating stimuli from equiluminant gray, and had measurable visual acuity. Thus, non-classical retinal photoreception occurs within diverse cell types, and influences circuits and functions encompassing luminance as well as spatial information. PMID:20624591

Nanosecond laser pulse stimulation of spiral ganglion neurons and model cells.

PubMed

Rettenmaier, Alexander; Lenarz, Thomas; Reuter, Günter

2014-04-01

Optical stimulation of the inner ear has recently attracted attention, suggesting a higher frequency resolution compared to electrical cochlear implants due to its high spatial stimulation selectivity. Although the feasibility of the effect is shown in multiple in vivo experiments, the stimulation mechanism remains open to discussion. Here we investigate in single-cell measurements the reaction of spiral ganglion neurons and model cells to irradiation with a nanosecond-pulsed laser beam over a broad wavelength range from 420 nm up to 1950 nm using the patch clamp technique. Cell reactions were wavelength- and pulse-energy-dependent but too small to elicit action potentials in the investigated spiral ganglion neurons. As the applied radiant exposure was much higher than the reported threshold for in vivo experiments in the same laser regime, we conclude that in a stimulation paradigm with nanosecond-pulses, direct neuronal stimulation is not the main cause of optical cochlea stimulation.

Strychnine, but not PMBA, inhibits neuronal nicotinic acetylcholine receptors expressed by rabbit retinal ganglion cells.

PubMed

Renna, J M; Strang, C E; Amthor, F R; Keyser, K T

2007-01-01

Strychnine is considered a selective competitive antagonist of glycine gated Cl- channels (Saitoh et al., 1994) and studies have used strychnine at low micromolar concentrations to study the role of glycine in rabbit retina (Linn, 1998; Protti et al., 2005). However, other studies have shown that strychnine, in the concentrations commonly used, is also a potent competitive antagonist of alpha7 nicotinic acetylcholine receptors (nAChRs; Matsubayashi et al., 1998). We tested the effects of low micromolar concentrations of strychnine and 3-[2'-phosphonomethyl[1,1'-biphenyl]-3-yl] alanine (PMBA), a specific glycine receptor blocker (Saitoh et al., 1994; Hosie et al., 1999) on the activation of both alpha7 nAChRs on retinal ganglion cells and on ganglion cell responses to a light flash. Extracellular recordings were obtained from ganglion cells in an isolated retina/choroid preparation and 500 microM choline was used as an alpha7 agonist (Alkondon et al., 1997). We recorded from brisk sustained and brisk transient OFF cells, many of which have been previously shown to have alpha7 receptors (Strang et al., 2005). Further, we tested the effect of strychnine, PMBA and alpha-bungarotoxin on the binding of tetramethylrhodamine alpha-bungarotoxin in the inner plexiform layer. Our data indicates that strychnine, at doses as low as 1.0 microM, can inhibit the alpha7 nAChR-mediated response to choline, but PMBA at concentrations as high as 0.4 microM does not. Binding studies show strychnine and alpha-bungarotoxin inhibit binding of labeled alpha-bungarotoxin in the IPL. Thus, the effects of strychnine application may be to inhibit glycine receptors expressed by ganglion cell or to inhibit amacrine cell alpha7 nAChRs, both of which would result in an increase in the ganglion cell responses. Further research will be required to disentangle the effects of strychnine previously believed to be caused by a single mechanism of glycine receptor inhibition.

Calcium channels in solitary retinal ganglion cells from post-natal rat.

PubMed Central

Karschin, A; Lipton, S A

1989-01-01

1. Calcium currents from identified, post-natal retinal ganglion cell neurones from rat were studied with whole-cell and single-channel patch-clamp techniques. Na+ and K+ currents were suppressed with pharmacological agents, allowing isolation of current carried by either 10 mM-Ca2+ or Ba2- during whole-cell recordings. For cell-attached patch recordings, the recording pipette contained 96-110 mM-BaCl2 while the bath solution consisted of isotonic potassium aspartate in order to zero the neuronal membrane potential. 2. A transient component, present in approximately one-third of the whole-cell recordings resembles closely the T-type calcium current observed previously in other tissues. This component activates at low voltages (-40 to -50 mV from holding potentials negative to -80 mV), inactivates with a time constant of 10-30 ms at 35 degrees C, and is carried equally well by Ba2+ or Ca2+. In single-channel recordings small (8 pS) channels are observed whose aggregate microscopic kinetics correspond well to the macroscopic current obtained during whole-cell measurements. 3. During whole-cell recordings, a more prolonged component activates in all retinal ganglion cells at -40 to -20 mV from a holding potential of -90 mV. This component is substantially larger when equimolar Ba2+ replaces Ca2+ as the charge carrier, and is sensitive to the dihydropyridine agonist Bay K8644 (5 microM) and antagonists nifedipine (1-10 microM) and nimodipine (1-10 microM). Thus, the dihydropyridine pharmacology of this prolonged component resembles that of the L-type calcium current found in dorsal root ganglion neurones and in heart cells. Also reminiscent of the L-current, the prolonged component in this preparation is less inactivated at depolarized holding potentials (-60 to -40 mV) than the transient component. In cell-attached recordings, large (20 pS) channels are observed with activation properties similar to those of the prolonged portion of the whole-cell current. 4. omega

Spontaneous cell death in the semilunar ganglion during fetal and postnatal life in the ox, sheep, goat and guinea pig.

PubMed

Bortolami, R; Lucchi, M L; Callegari, E; De Pasquale, V; Lalatta Costerbosa, G

1979-07-15

A massive cell loss occurs in the semilunar ganglion. It is the result of either a casting-off of the semilunar ganglion cells into the cavernous sinus or a transformation of several cells into polyhedral cells with an epithelial-like organization, a process which immediately precedes their further degeneration.

Localization of laminin B1 mRNA in retinal ganglion cells by in situ hybridization

PubMed Central

1990-01-01

In the nervous system, neuronal migration and axonal growth are dependent on specific interactions with extracellular matrix proteins. During development of the vertebrate retina, ganglion cell axons extend along the internal limiting (basement) membrane and form the optic nerve. Laminin, a major component of basement membranes, is known to be present in the internal limiting membrane, and might be involved in the growth of ganglion cell axons. The identity of the cells that produce retinal laminin, however, has not been established. In the present study, we have used in situ hybridization to localize the sites of laminin B1 mRNA synthesis in the developing mouse retina. Our results show that there are at least two principal sites of laminin B1 mRNA synthesis: (a) the hyaloid vessels and the lens during the period of major axonal outgrowth, and (b) the retinal ganglion cells at later development stages. Muller (glial) cells, the major class of nonneuronal cells in the retina, do not appear to express laminin B1 mRNA either during development or in the adult retina. In Northern blots, we found a single transcript of approximately 6-kb size that encodes the laminin B1 chain in the retina. Moreover, laminin B1 mRNA level was four- to fivefold higher in the postnatal retina compared to that in the adult. Our results show that in addition to nonneuronal cells, retinal ganglion cells also synthesize laminin. The function of laminin in postnatal retinas, however, remains to be elucidated. Nevertheless, our findings raise the possibility that neurons in other parts of the nervous system might also synthesize extracellular matrix proteins. PMID:2351694

Adult Human Nasal Mesenchymal-Like Stem Cells Restore Cochlear Spiral Ganglion Neurons After Experimental Lesion

PubMed Central

Bas, Esperanza; Van De Water, Thomas R.; Lumbreras, Vicente; Rajguru, Suhrud; Goss, Garrett; Hare, Joshua M.

2014-01-01

A loss of sensory hair cells or spiral ganglion neurons from the inner ear causes deafness, affecting millions of people. Currently, there is no effective therapy to repair the inner ear sensory structures in humans. Cochlear implantation can restore input, but only if auditory neurons remain intact. Efforts to develop stem cell-based treatments for deafness have demonstrated progress, most notably utilizing embryonic-derived cells. In an effort to bypass limitations of embryonic or induced pluripotent stem cells that may impede the translation to clinical applications, we sought to utilize an alternative cell source. Here, we show that adult human mesenchymal-like stem cells (MSCs) obtained from nasal tissue can repair spiral ganglion loss in experimentally lesioned cochlear cultures from neonatal rats. Stem cells engraft into gentamicin-lesioned organotypic cultures and orchestrate the restoration of the spiral ganglion neuronal population, involving both direct neuronal differentiation and secondary effects on endogenous cells. As a physiologic assay, nasal MSC-derived cells engrafted into lesioned spiral ganglia demonstrate responses to infrared laser stimulus that are consistent with those typical of excitable cells. The addition of a pharmacologic activator of the canonical Wnt/β-catenin pathway concurrent with stem cell treatment promoted robust neuronal differentiation. The availability of an effective adult autologous cell source for inner ear tissue repair should contribute to efforts to translate cell-based strategies to the clinic. PMID:24172073

Heteromerization and colocalization of TrpV1 and TrpV2 in mammalian cell lines and rat dorsal root ganglia.

PubMed

Rutter, A Richard; Ma, Qing-Ping; Leveridge, Mathew; Bonnert, Timothy P

2005-11-07

Coassociation of the vanilloid transient receptor potential (Trp) ion channels, TrpV1 and TrpV2, was investigated by immunoprecipitation and immunofluorescence in transfected mammalian cell lines, rat dorsal root ganglia and spinal cord. TrpV1/TrpV2 heteromeric complexes were coimmunoprecipitated from human embryonic kidney cells and F-11 dorsal root ganglion hybridoma cells following their transient coexpression. Immunofluorescent labelling of transfected F-11 cells revealed colocalization of TrpV1 and TrpV2 at the cell surface. Immunoprecipitation from rat dorsal root ganglion lysates identified a minor population of receptor complexes composed of TrpV1/TrpV2 heteromers, consistent with a small proportion of cells double-labelled with TrpV1 and TrpV2 antibodies in rat dorsal root ganglion sections. TrpV1/TrpV2 receptor complexes may represent a functionally distinct ion channel complex that may increase the diversity observed within the Trp ion channel family.

Retinal Astrocytes and GABAergic Wide-Field Amacrine Cells Express PDGFRα: Connection to Retinal Ganglion Cell Neuroprotection by PDGF-AA.

PubMed

Takahama, Shokichi; Adetunji, Modupe O; Zhao, Tantai; Chen, Shan; Li, Wei; Tomarev, Stanislav I

2017-09-01

Our previous experiments demonstrated that intravitreal injection of platelet-derived growth factor-AA (PDGF-AA) provides retinal ganglion cell (RGC) neuroprotection in a rodent model of glaucoma. Here we used PDGFRα-enhanced green fluorescent protein (EGFP) mice to identify retinal cells that may be essential for RGC protection by PDGF-AA. PDGFRα-EGFP mice expressing nuclear-targeted EGFP under the control of the PDGFRα promoter were used. Localization of PDGFRα in the neural retina was investigated by confocal imaging of EGFP fluorescence and immunofluorescent labeling with a panel of antibodies recognizing different retinal cell types. Primary cultures of mouse RGCs were produced by immunopanning. Neurobiotin injection of amacrine cells in a flat-mounted retina was used for the identification of EGFP-positive amacrine cells in the inner nuclear layer. In the mouse neural retina, PDGFRα was preferentially localized in the ganglion cell and inner nuclear layers. Immunostaining of the retina demonstrated that astrocytes in the ganglion cell layer and a subpopulation of amacrine cells in the inner nuclear layer express PDGFRα, whereas RGCs (in vivo or in vitro) did not. PDGFRα-positive amacrine cells are likely to be Type 45 gamma-aminobutyric acidergic (GABAergic) wide-field amacrine cells. These data indicate that the neuroprotective effect of PDGF-AA in a rodent model of glaucoma could be mediated by astrocytes and/or a subpopulation of amacrine cells. We suggest that after intravitreal injection of PDGF-AA, these cells secrete factors protecting RGCs.

The trophic effect of ouabain on retinal ganglion cells is mediated by IL-1β and TNF-α

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salles von-Held-Ventura, Juliana; Mázala-de-Oliveira, Thalita; Cândida da Rocha Oliveira, Amanda

Ouabain is a steroid hormone that binds to the enzyme Na{sup +}, K{sup +} – ATPase and stimulates different intracellular pathways controlling growth, proliferation and cell survival. IL-1β and TNF-α are pleiotropic molecules, conventionally regarded as pro-inflammatory cytokines with well-known effects in the immune system. In addition, IL-1β and TNF-α also play important roles in the nervous system including neuroprotective effects. Previous data from our group showed that ouabain treatment is able to induce an increase in retinal ganglion cell survival kept in mixed retinal cell cultures. The aim of this work was to investigate if IL-1β and TNF-α couldmore » be mediating the trophic effect of ouabain on retinal ganglion cells. Our results show that the trophic effect of ouabain on retinal ganglion cell was inhibited by either anti-IL-1β or anti-TNF-α antibodies. In agreement, IL-1β or TNF-α increased the retinal ganglion cells survival in a dose-dependent manner. Accordingly, ouabain treatment induces a temporal release of TNF-α and IL-1β from retinal cell cultures. Interestingly, TNF-α and IL-1β regulate each other intracellular levels. Our results suggest that ouabain treatment triggers the activation of TNF-α and IL-1β signaling pathways leading to an increase in retinal ganglion cell survival. - Highlights: • Pro-inflammatory cytokines regulates the ouabain effect on RGC survival. • Ouabain treatment modulates the intracellular levels of TNF-α and IL-1β. • Ouabain induces the release of TNF-α and IL-1β in retinal cell cultures.« less

Distinguishing ischaemic optic neuropathy from optic neuritis by ganglion cell analysis.

PubMed

Erlich-Malona, Natalie; Mendoza-Santiesteban, Carlos E; Hedges, Thomas R; Patel, Nimesh; Monaco, Caitlin; Cole, Emily

2016-12-01

To determine whether a pattern of altitudinal ganglion cell loss, as detected and measured by optical coherence tomography (OCT), can be used to distinguish non-arteritic ischaemic optic neuropathy (NAION) from optic neuritis (ON) during the acute phase, and whether the rate or severity of ganglion cell loss differs between the two diseases. We performed a retrospective, case-control study of 44 patients (50 eyes) with ON or NAION and 44 age-matched controls. Non-arteritic ischaemic optic neuropathy and ON patients had OCT at presentation and four consecutive follow-up visits. Controls had OCT at one point in time. The ganglion cell complex (GCC) was evaluated in the macula, and the retinal nerve fibre layer (RNFL) was evaluated in the peripapillary region. Ganglion cell complex thickness, RNFL thickness and GCC mean superior and inferior hemispheric difference were compared between NAION and ON patients at each time-point using unpaired t-tests and between disease and control subjects at first measurement using paired t-tests. Mean time from onset of symptoms to initial presentation was 10.7 ± 6.6 days in NAION and 11.7 ± 8.6 days in ON (p = 0.67). There was a significantly greater vertical hemispheric difference in GCC thickness in NAION patients than ON patients at all time-points (5.5-10.7 μm versus 3.1-3.6 μm, p = 0.01-0.049). Mean GCC thickness was significantly decreased at less than 2 weeks after onset in NAION compared to age-matched controls (72.1 μm versus 82.1 μm, p < 0.001), as well as in ON compared to age-matched controls (74.3 μm versus 84.5 μm, p < 0.001). Progression and severity of GCC and RNFL loss did not differ significantly between NAION and ON. A quantitative comparison of mean superior and inferior hemispheric GCC thickness with OCT may be used to distinguish NAION from ON. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Topographic specializations of catecholaminergic cells and ganglion cells and distribution of calcium binding proteins in the crepuscular rock cavy (Kerodon rupestris) retina.

PubMed

Oliveira, Francisco Gilberto; Nascimento-Júnior, Expedito Silva do; Cavalcante, Judney Cley; Guzen, Fausto Pierdoná; Cavalcante, Jeferson de Souza; Soares, Joacil Germano; Cavalcanti, José Rodolfo Lopes de Paiva; Freitas, Leandro Moura de; Costa, Miriam Stela Maris de Oliveira; Andrade-da-Costa, Belmira Lara da Silveira

2018-07-01

The rock cavy (Kerodon rupestris) is a crepuscular Hystricomorpha rodent that has been used in comparative analysis of retinal targets, but its retinal organization remains to be investigated. In order to better characterize its visual system, the present study analyzed neurochemical features related to the topographic organization of catecholaminergic cells and ganglion cells, as well the distribution of calcium-binding proteins in the outer and inner retina. Retinal sections and/or wholemounts were processed using tyrosine hydroxylase (TH), GABA, calbindin, parvalbumin and calretinin immunohistochemistry or Nissl staining. Two types of TH-immunoreactive (TH-IR) cells were found which differ in soma size, dendritic arborization, intensity of TH immunoreactivity and stratification pattern in the inner plexiform layer. The topographic distribution of all TH-IR cells defines a visual streak along the horizontal meridian in the superior retina. The ganglion cells are also distributed in a visual streak and the visual acuity estimated considering their peak density is 4.13 cycles/degree. A subset of TH-IR cells express GABA or calbindin. Calretinin is abundant in most of retinal layers and coexists with calbindin in horizontal cells. Parvalbumin is less abundant and expressed by presumed amacrine cells in the INL and some ganglion cells in the GCL. The topographic distribution of TH-IR cells and ganglion cells in the rock cavy retina indicate a suitable adaptation for using a broad extension of its inferior visual field in aspects that involve resolution, adjustment to ambient light intensity and movement detection without specialized eye movements. Copyright © 2017 Elsevier B.V. All rights reserved.

Ganglion Cell Loss and Age-Related Visual Loss: A Cortical Pooling Analysis

PubMed Central

SCHMIDT, LAURA A.; LY-SCHROEDER, EMILY; SWANSON, WILLIAM H.

2006-01-01

Purpose To evaluate the ability of the cortical pooling model to predict the effects of random, mild ganglion cell loss, we compared the predictions of the model with the age-related loss and variability in achromatic and chromatic contrast sensitivity. Methods The relative sensitivity to small (0.5°) and large (3.0°) stimuli was compared in older (mean = 67 years, n = 27) and younger (mean = 23 years, n = 32) adults. Contrast sensitivity for modulations along the luminance, equiluminant L-cone, and equiluminant S-cone axes was assessed at the fovea and at four peripheral locations (12°). Results When the stimuli were large, threshold measurements obtained from all participants were reliable and well within the range of modulations along the chromatic axes that could be produced by the phosphors of the CRT. For the large stimuli, neither long- nor short-term variability increased as a function of age. Increasing the size of the stimulus did not decrease the magnitude of the age-related losses when the stimulus was chromatic, and visual losses observed with large chromatic stimuli were not different from those obtained with small achromatic stimuli. Moreover, chromatic contrast sensitivity assessments identified significant visual losses in four individuals who were not identified by achromatic contrast sensitivity assessments and only missed identifying one individual with significant losses in achromatic contrast sensitivity. Conclusions The declines in achromatic and chromatic sensitivity as a function of age (0.4 – 0.7 dB per decade) were similar to those obtained in previous studies of achromatic and chromatic perimetry and are consistent with the loss of retinal ganglion cells reported in histologic studies. The results of this study are consistent with the predictions the cortical pooling model makes for both variability and contrast sensitivity. These findings emphasize that selective visual impairments do not necessarily reflect preferential damage to

Ouabain-Induced Apoptosis in Cochlear Hair Cells and Spiral Ganglion Neurons In Vitro

PubMed Central

Fu, Yong; Ding, Dalian; Jiang, Haiyan; Salvi, Richard

2013-01-01

Ouabain is a common tool to explore the pathophysiological changes in adult mammalian cochlea in vivo. In prior studies, locally administering ouabain via round window membrane demonstrated that the ototoxic effects of ouabain in vivo varied among mammalian species. Little is known about the ototoxic effects in vitro. Thus, we prepared cochlear organotypic cultures from postnatal day-3 rats and treated these cultures with ouabain at 50, 500, and 1000 μM for different time to elucidate the ototoxic effects of ouabain in vitro and to provide insights that could explain the comparative ototoxic effects of ouabain in vivo. Degeneration of cochlear hair cells and spiral ganglion neurons was evaluated by hair-cell staining and neurofilament labeling, respectively. Annexin V staining was used to detect apoptotic cells. A quantitative RT-PCR apoptosis-focused gene array determined changes in apoptosis-related genes. The results showed that ouabain-induced damage in vitro was dose and time dependent. 500 μM ouabain and 1000 μM ouabain were destructively traumatic to both spiral ganglion neurons and cochlear hair cells in an apoptotic signal-dependent pathway. The major apoptotic pathways in ouabain-induced spiral ganglion neuron apoptosis culminated in the stimulation of the p53 pathway and triggering of apoptosis by a network of proapoptotic signaling pathways. PMID:24228256

Spatial segregation of adaptation and predictive sensitization in retinal ganglion cells

PubMed Central

Kastner, David B.; Baccus, Stephen A.

2014-01-01

Sensory systems change their sensitivity based upon recent stimuli to adjust their response range to the range of inputs, and to predict future sensory input. Here we report the presence of retinal ganglion cells that have antagonistic plasticity, showing central adaptation and peripheral sensitization. Ganglion cell responses were captured by a spatiotemporal model with independently adapting excitatory and inhibitory subunits, and sensitization requires GABAergic inhibition. Using a simple theory of signal detection we show that the sensitizing surround conforms to an optimal inference model that continually updates the prior signal probability. This indicates that small receptive field regions have dual functionality—to adapt to the local range of signals, but sensitize based upon the probability of the presence of that signal. Within this framework, we show that sensitization predicts the location of a nearby object, revealing prediction as a new functional role for adapting inhibition in the nervous system. PMID:23932000

Synaptology of physiologically identified ganglion cells in the cat retina: a comparison of retinal X- and Y-cells.

PubMed

Weber, A J; Stanford, L R

1994-05-15

It has long been known that a number of functionally different types of ganglion cells exist in the cat retina, and that each responds differently to visual stimulation. To determine whether the characteristic response properties of different retinal ganglion cell types might reflect differences in the number and distribution of their bipolar and amacrine cell inputs, we compared the percentages and distributions of the synaptic inputs from bipolar and amacrine cells to the entire dendritic arbors of physiologically characterized retinal X- and Y-cells. Sixty-two percent of the synaptic input to the Y-cell was from amacrine cell terminals, while the X-cells received approximately equal amounts of input from amacrine and bipolar cells. We found no significant difference in the distributions of bipolar or amacrine cell inputs to X- and Y-cells, or ON-center and OFF-center cells, either as a function of dendritic branch order or distance from the origin of the dendritic arbor. While, on the basis of these data, we cannot exclude the possibility that the difference in the proportion of bipolar and amacrine cell input contributes to the functional differences between X- and Y-cells, the magnitude of this difference, and the similarity in the distributions of the input from the two afferent cell types, suggest that mechanisms other than a simple predominance of input from amacrine or bipolar cells underlie the differences in their response properties. More likely, perhaps, is that the specific response features of X- and Y-cells originate in differences in the visual responses of the bipolar and amacrine cells that provide their input, or in the complex synaptic arrangements found among amacrine and bipolar cell terminals and the dendrites of specific types of retinal ganglion cells.

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

PubMed Central

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

2016-01-01

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

Separability of stimulus parameter encoding by on-off directionally selective rabbit retinal ganglion cells

PubMed Central

Nowak, Przemyslaw; Dobbins, Allan C.; Gawne, Timothy J.; Grzywacz, Norberto M.

2011-01-01

The ganglion cell output of the retina constitutes a bottleneck in sensory processing in that ganglion cells must encode multiple stimulus parameters in their responses. Here we investigate encoding strategies of On-Off directionally selective retinal ganglion cells (On-Off DS RGCs) in rabbits, a class of cells dedicated to representing motion. The exquisite axial discrimination of these cells to preferred vs. null direction motion is well documented: it is invariant with respect to speed, contrast, spatial configuration, spatial frequency, and motion extent. However, these cells have broad direction tuning curves and their responses also vary as a function of other parameters such as speed and contrast. In this study, we examined whether the variation in responses across multiple stimulus parameters is systematic, that is the same for all cells, and separable, such that the response to a stimulus is a product of the effects of each stimulus parameter alone. We extracellularly recorded single On-Off DS RGCs in a superfused eyecup preparation while stimulating them with moving bars. We found that spike count responses of these cells scaled as independent functions of direction, speed, and luminance. Moreover, the speed and luminance functions were common across the whole sample of cells. Based on these findings, we developed a model that accurately predicted responses of On-Off DS RGCs as products of separable functions of direction, speed, and luminance (r = 0.98; P < 0.0001). Such a multiplicatively separable encoding strategy may simplify the decoding of these cells' outputs by the higher visual centers. PMID:21325684

Curcumin Attenuates Staurosporine-Mediated Death of Retinal Ganglion Cells

PubMed Central

Burugula, Balabharathi; Ganesh, Bhagyalaxmi S.

2011-01-01

Purpose. Staurosporine (SS) causes retinal ganglion cell (RGC) death in vivo, but the underlying mechanisms have been unclear. Since previous studies on RGC-5 cells indicated that SS induces cell death by elevating proteases, this study was undertaken to investigate whether SS induces RGC loss by elevating proteases in the retina, and curcumin prevents SS-mediated death of RGCs. Methods. Transformed mouse retinal ganglion-like cells (RGC-5) were treated with 2.0 μM SS and various doses of curcumin. Two optimal doses of SS (12.5 and 100 nM) and curcumin (2.5 and 10 μM) were injected into the vitreous of C57BL/6 mice. Matrix metalloproteinase (MMP)-9, tissue plasminogen activator (tPA), and urokinase plasminogen activator (uPA) activities were assessed by zymography assays. Viability of RGC-5 cells was assessed by MTT assays. RGC and amacrine cell loss in vivo was assessed by immunostaining with Brn3a and ChAT antibodies, respectively. Frozen retinal cross sections were immunostained for nuclear factor-κB (NF-κB). Results. Staurosporine induced uPA and tPA levels in RGC-5 cells, and MMP-9, uPA, and tPA levels in the retinas and promoted the death of RGC-5 cells in vitro and RGCs and amacrine cells in vivo. In contrast, curcumin attenuated RGC and amacrine cell loss, despite elevated levels of proteases. An NF-κB inhibitory peptide reversed curcumin-mediated protective effect on RGC-5 cells, but did not inhibit protease levels. Curcumin did not inhibit protease levels in vivo, but attenuated RGC and amacrine cell loss by restoring NF-κB expression. Conclusions. The results show that curcumin attenuates RGC and amacrine cell death despite elevated levels of proteases and raises the possibility that it may be used as a plausible adjuvant therapeutic agent to prevent the loss of these cells in retinal degenerative conditions. PMID:21498608

Nervus terminalis ganglion of the bonnethead shark (Sphyrna tiburo): evidence for cholinergic and catecholaminergic influence on two cell types distinguished by peptide immunocytochemistry.

PubMed

White, J; Meredith, M

1995-01-16

The nervus terminalis is a ganglionated vertebrate cranial nerve of unknown function that connects the brain and the peripheral nasal structures. To investigate its function, we have studied nervus terminalis ganglion morphology and physiology in the bonnethead shark (Sphyrna tiburo), where the nerve is particularly prominent. Immunocytochemistry for gonadotropin-releasing hormone (GnRH) and Leu-Pro-Leu-Arg-Phe-NH2 (LPLRFamide) revealed two distinct populations of cells. Both were acetylcholinesterase positive, but LPLR-Famide-immunoreactive cells consistently stained more darkly for acetylcholinesterase activity. Tyrosine hydroxylase immunocytochemistry revealed fibers and terminal-like puncta in the ganglion, primarily in areas containing GnRH-immunoreactive cells. Consistent with the anatomy, in vitro electrophysiological recordings provided evidence for cholinergic and catecholaminergic actions. In extracellular recordings, acetylcholine had a variable effect on baseline ganglion cell activity, whereas norepinephrine consistently reduced activity. Electrical stimulation of the nerve trunks suppressed ganglion activity, as did impulses from the brain in vivo. During electrical suppression, acetylcholine consistently increased activity, and norepinephrine decreased activity. Muscarinic and, to a lesser extent, alpha-adrenergic antagonists both increased activity during the electrical suppression, suggesting involvement of both systems. Intracellular recordings revealed two types of ganglion cells that were distinguishable pharmacologically and physiologically. Some cells were hyperpolarized by cholinergic agonists and unaffected by norepinephrine; these cells did not depolarize with peripheral nerve trunk stimulation. Another group of cells did depolarize with peripheral trunk stimulation; a representative of this group was depolarized by carbachol and hyperpolarized by norepinephrine. These and other data suggest that the bonnethead nervus terminalis ganglion

Functional expression of ionotropic glutamate receptors in the rabbit retinal ganglion cells.

PubMed

Chen, Yin-Peng; Chiao, Chuan-Chin

2012-01-03

It has been known that retinal ganglion cells (RGCs) with distinct morphologies have different physiological properties. It was hypothesized that different functions of RGCs may in part result from various expressions of N-methyl-d-aspartate (NMDA), α-amino-3-hydroxyl-5-methyl-isoxazole-4-propinoic acid (AMPA), and kainic acid (KA) receptors on their dendrites. In the present study, we aimed to characterize the functional expression of AMPA and NMDA receptors of morphologically identified RGCs in the wholemount rabbit retina. The agmatine (AGB) activation assay was used to reveal functional expression of ionotropic glutamate receptors after the RGCs were targeted by injecting Neurobiotin. To examine the excitability of these glutamate receptors in an agonist specific manner, the lower concentrations of AMPA (2 μM) and NMDA (100 μM) were chosen to examine G7 (ON-OFF direction selective ganglion cells) and G11 (alpha ganglion cells) types of RGCs. We found that less than 40% of G7 type RGCs had salient AGB activation when incubated with 2 μM AMPA or 100 μM NMDA. The G11 type RGCs also showed similar activation frequencies, except that all of the OFF subtype examined had no AGB permeation under the same AMPA concentration. These results suggest that RGCs with large somata (G7 and G11 types) may express various heterogeneous functional ionotropic glutamate receptors, thus in part rendering their functional diversity. Copyright © 2011 Elsevier B.V. All rights reserved.

Mechanisms regulating plasminogen activators in transformed retinal ganglion cells

PubMed Central

Rock, Nathan; Chintala, Shravan K.

2008-01-01

Irreversible loss of retinal ganglion cells (RGCs) is a major clinical issue in glaucoma, but the mechanisms that lead to RGC death are currently unclear. We have previously reported that elevated levels of tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) cause the death of RGCs in vivo and transformed retinal ganglion cells (RGC-5) in vitro. Yet, it is unclear how secreted proteases such as tPA and uPA directly cause RGCs' death. In this study, by employing RGC-5 cells, we report that tPA and uPA elicit their direct effect through the low-density lipoprotein-related receptor-1 (LRP-1). We also show that blockade of protease-LRP-1 interaction leads to a compete reduction in autocrine synthesis of tPA and uPA, and prevents protease-mediated death of RGC-5 cells. RGC-5 cells were cultured in serum-free medium and treated with 2.0 uM Staurosporine to induce their differentiation. Neurite outgrowth was observed by a phase contrast microscope and quantified by NeuroJ imaging software. Proteolytic activities of tPA and uPA were determined by zymography assays. Cell viability was determined by MTT assays. Compared to untreated RGC-5 cells, cells treated with Staurosporine differentiated, synthesized and secreted elevated levels of tPA and uPA, and underwent cell death. In contrast, when RGC-5 cells were treated with Staurosporine along with the receptor associated protein (RAP), proteolytic activities of both tPA and uPA were significantly reduced. Under these conditions, a significant number of RGC-5 cells survived and showed increased neurite outgrowth. These results indicate that LRP-1 regulates autocrine synthesis of tPA and uPA in RGC-5 cells and suggest that the use of RAP to antagonize the effect of proteases may be a way to prevent RGC death in glaucoma. PMID:18243176

Diagnostic accuracy of ganglion cell complex substructures in different stages of primary open-angle glaucoma.

PubMed

Elbendary, Amal M; Abd El-Latef, Mohamed Hafez; Elsorogy, Hisham I; Enaam, Kamal M

2017-08-01

To evaluate diagnostic accuracy of substructure of ganglion cell complex versus peripapillary nerve fiber layer (NFL) thickness using spectral domain optical coherence tomography (SD-OCT) in different stages of glaucoma. Thirty eyes were normal, 120 were glaucomatous. Glaucomatous eyes were classified into: early glaucoma (46), moderate glaucoma (48), and severe glaucoma (26). Perimetry and SD-OCT were done. Peripapillary NFL thickness, ganglion cell layer (GCL), macular NFL thickness, combined GCL and macular ganglion cell complex (GCC), were recorded. Area under receiver operating characteristic curves (AUCs) was used to verify performance of different OCT parameters. Peripapillary NFL, GCL, and GCC thickness values were significantly different in all stages of glaucoma. All comparisons were significantly different; normal versus early, early versus moderate and moderate versus severe. The best parameters that distinguished normal from early stage were: peripapillary NFL (AUC: 0.90), GCC (AUC: 0.75), early from moderate stage were: peripapillary NFL thickness (AUC: 0.85), GCL (0.81),GCC (0.81), moderate from severe stage were: GCC (AUC:0.95), macular NFL (AUC:0.91), GCL (AUC:0.89), and peripapillary NFL (AUC:0.88). Peripapllary NFL and GCC thinning showed paradoxical course. The most diagnosed parameter in early glaucoma was peripapillary NFL and in severe glaucoma was GCC. In severe glaucoma, macular NFL showed higher diagnostic power than GCL and peripapillary NFL. Ganglion cell complex mapping may provide good alternative to optic disc imaging in advanced glaucoma with poor fixation. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Retinal ganglion cells with distinct directional preferences differ in molecular identity, structure, and central projections.

PubMed

Kay, Jeremy N; De la Huerta, Irina; Kim, In-Jung; Zhang, Yifeng; Yamagata, Masahito; Chu, Monica W; Meister, Markus; Sanes, Joshua R

2011-05-25

The retina contains ganglion cells (RGCs) that respond selectively to objects moving in particular directions. Individual members of a group of ON-OFF direction-selective RGCs (ooDSGCs) detect stimuli moving in one of four directions: ventral, dorsal, nasal, or temporal. Despite this physiological diversity, little is known about subtype-specific differences in structure, molecular identity, and projections. To seek such differences, we characterized mouse transgenic lines that selectively mark ooDSGCs preferring ventral or nasal motion as well as a line that marks both ventral- and dorsal-preferring subsets. We then used the lines to identify cell surface molecules, including Cadherin 6, CollagenXXVα1, and Matrix metalloprotease 17, that are selectively expressed by distinct subsets of ooDSGCs. We also identify a neuropeptide, CART (cocaine- and amphetamine-regulated transcript), that distinguishes all ooDSGCs from other RGCs. Together, this panel of endogenous and transgenic markers distinguishes the four ooDSGC subsets. Patterns of molecular diversification occur before eye opening and are therefore experience independent. They may help to explain how the four subsets obtain distinct inputs. We also demonstrate differences among subsets in their dendritic patterns within the retina and their axonal projections to the brain. Differences in projections indicate that information about motion in different directions is sent to different destinations.

Fractalkine Signaling Regulates Macrophage Recruitment into the Cochlea and Promotes the Survival of Spiral Ganglion Neurons after Selective Hair Cell Lesion.

PubMed

Kaur, Tejbeer; Zamani, Darius; Tong, Ling; Rubel, Edwin W; Ohlemiller, Kevin K; Hirose, Keiko; Warchol, Mark E

2015-11-11

Macrophages are recruited into the cochlea in response to injury caused by acoustic trauma or ototoxicity, but the nature of the interaction between macrophages and the sensory structures of the inner ear remains unclear. The present study examined the role of fractalkine signaling in regulating the injury-evoked behavior of macrophages following the selective ablation of cochlear hair cells. We used a novel transgenic mouse model in which the human diphtheria toxin receptor (huDTR) is selectively expressed under the control of Pou4f3, a hair cell-specific transcription factor. Administration of diphtheria toxin (DT) to these mice resulted in nearly complete ablation of cochlear hair cells, with no evident pathology among supporting cells, spiral ganglion neurons, or cells of the cochlear lateral wall. Hair cell death led to an increase in macrophages associated with the sensory epithelium of the cochlea. Their numbers peaked at 14 days after DT and then declined at later survival times. Increased macrophages were also observed within the spiral ganglion, but their numbers remained elevated for (at least) 56 d after DT. To investigate the role of fractalkine signaling in macrophage recruitment, we crossed huDTR mice to a mouse line that lacks expression of the fractalkine receptor (CX3CR1). Disruption of fractalkine signaling reduced macrophage recruitment into both the sensory epithelium and spiral ganglion and also resulted in diminished survival of spiral ganglion neurons after hair cell death. Our results suggest a fractalkine-mediated interaction between macrophages and the neurons of the cochlea. It is known that damage to the inner ear leads to recruitment of inflammatory cells (macrophages), but the chemical signals that initiate this recruitment and the functions of macrophages in the damaged ear are unclear. Here we show that fractalkine signaling regulates macrophage recruitment into the cochlea and also promotes the survival of cochlear afferents after

The release of acetylcholine from post-ganglionic cell bodies in response to depolarization.

PubMed Central

Johnson, D A; Pilar, G

1980-01-01

1. Acetylcholine (Ach) release from parasympathetic ganglia cell somata was investigated in denervated avian ciliary ganglia. Three days after the input to the ganglion (the oculomotor nerve) was sectioned, all presynaptic nerve terminals had degenerated. 2. Denervated ganglia were shown to contain endogenous ACh and to be capable of synthesizing [3H]ACh from [3H]choline added to the incubation medium. 3. In response to depolarization induced by incubation in 50 mM-[K+]o, denervated ganglia released [3H]ACh into bath effluents in amounts approximately 15% of the non-denervated contralateral control. This release was shown to be Ca2+ dependent in both intact and denervated ganglia. 4. Antidromic electrical stimulation of ciliary nerves also elicited [3H]ACh release. Nicotine (1 microgram/microliter.) depolarized denervated ciliary ganglion cells and evoked release of the transmitter and this release was antagonized by curare. 5. It is concluded that the ganglionic cell bodies sysnthesized ACh and released the transmitter in response to K+ depolarization, antidromic stimulation and cholinergic agonists, despite the lack of morphological specializations usually associated with stimulus-induced release of neurotransmitter. The evidence suggests the existence of a mechanism of transmitter release which is Ca2+ dependent, probably from a cytoplasmic pool and therefore distinct from the usual vesicular release at the nerve terminal. Images Plate 1 Plate 2 PMID:6247485

Expression and function of system N glutamine transporters (SN1/SN2 or SNAT3/SNAT5) in retinal ganglion cells.

PubMed

Umapathy, Nagavedi S; Dun, Ying; Martin, Pamela M; Duplantier, Jennifer N; Roon, Penny; Prasad, Puttur; Smith, Sylvia B; Ganapathy, Vadivel

2008-11-01

Glutamine transport is essential for the glutamate-glutamine cycle, which occurs between neurons and glia. System N, consisting of SN1 (SNAT3) and SN2 (SNAT5), is the principal mediator of glutamine transport in retinal Müller cells. Mediators of glutamine transport in retinal ganglion cells were investigated. The relative contributions of various transport systems for glutamine uptake (systems N, A, L, y+L, ASCT, and ATB(0,+)) were examined in RGC-5 cells based on differential features of the individual transport systems. mRNA for the genes encoding members of these transport systems were analyzed by RT-PCR. Based on these data, SN1 and SN2 were analyzed in mouse retina, RGC-5 cells, and primary mouse ganglion cells (GCs) by in situ hybridization (ISH), immunofluorescence (IF), and Western blotting. Three transport systems--N, A, and L--participated in glutamine uptake in RGC-5 cells. System N was the principal contributor; systems A and L contributed considerably less. ISH and IF revealed SN1 and SN2 expression in the ganglion, inner nuclear, and photoreceptor cell layers. SN1 and SN2 colocalized with the ganglion cell marker Thy 1.2 and with the Müller cell marker vimentin, confirming their presence in both retinal cell types. SN1 and SN2 proteins were detected in primary mouse GCs. These findings suggest that in addition to its role in glutamine uptake in retinal glial cells, system N contributes significantly to glutamine uptake in ganglion cells and, hence, contributes to the retinal glutamate-glutamine cycle.

Ganglion cell-inner plexiform layer and retinal nerve fibre layer changes within the macula in retinitis pigmentosa: a spectral domain optical coherence tomography study.

PubMed

Yoon, Chang Ki; Yu, Hyeong Gon

2018-03-01

To investigate how macular ganglion cell-inner plexiform layer (GCIPL) and retinal nerve fibre layer (RNFL) thicknesses within the macula change with retinitis pigmentosa (RP) severity. Spectral domain optical coherence tomography (SD-OCT) was used to examine 177 patients with RP and 177 normal controls. An optical coherence tomography (OCT) line scan was used to grade RP severity. Retinitis pigmentosa (RP) was categorized as more advanced if there was no identifiable inner segment ellipsoid (ISe) band (NISE) and as less advanced if an ISe band could be identified and peripheral loss of ISe was apparent (IISE). Ganglion cell-inner plexiform layer (GCIPL) and RNFL thicknesses were manually measured on OCT images and analysed. Pearson's correlation analyses were used to examine correlations between GCIPL thickness, RNFL thickness, visual acuity (VA) and visual field extent in patients and controls. Ganglion cell-inner plexiform layer (GCIPL) was significantly thicker in IISE than in control eyes (p < 0.001), but significantly thinner in NISE than in IISE eyes (p < 0.001) in both horizontal and vertical OCT scans. Retinal nerve fibre layer (RNFL) was significantly thicker in eyes with IISE and NISE than in control eyes in both horizontal and vertical meridians (all p < 0.001). Ganglion cell-inner plexiform layer (GCIPL) thickness showed a weak positive correlation with vision, and RNFL thickness showed a weak negative correlation with vision and visual field extent. Based on these results, the inner retina, including the GCIPL and RNFL, maintains its gross integrity longer than the photoreceptor layer in RP. Additionally, thickening of the inner retina may have some functional implications in patients with RP. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Cell Motility and Invasiveness of Neurofibromin-Deficient Neural Crest Cells and Malignant Triton Tumor Lines

DTIC Science & Technology

2005-06-01

derived cells, we isolated first branchial arch mesenchymal populations, as well as trigeminal ganglion non-neuronal cells, from mouse embryos and measured...demonstrate that loss of neurofibromin affects the invasiveness of neural crest-derived (trigeminal ganglion) and cranial mesenchymal ( branchial arch) cell...trigeminal and branchial arch cells between El0 and El 2 indicates that the roles of neurofibromin in controlling motility may become increasingly

Delayed rectifier K channels contribute to contrast adaptation in mammalian retinal ganglion cells

PubMed Central

Weick, Michael; Demb, Jonathan B.

2011-01-01

SUMMARY Retinal ganglion cells adapt by reducing their sensitivity during periods of high contrast. Contrast adaptation in the firing response depends on both presynaptic and intrinsic mechanisms. Here, we investigated intrinsic mechanisms for contrast adaptation in OFF Alpha ganglion cells in the in vitro guinea pig retina. Using either visual stimulation or current injection, we show that brief depolarization evoked spiking and suppressed firing during subsequent depolarization. The suppression could be explained by Na channel inactivation, as shown in salamander cells. However, brief hyperpolarization in the physiological range (5–10 mV) also suppressed firing during subsequent depolarization. This suppression was sensitive selectively to blockers of delayed-rectifier K channels (KDR). Somatic membrane patches showed TEA-sensitive KDR currents with activation near −25 mV and removal of inactivation at voltages negative to Vrest. Brief periods of hyperpolarization apparently remove KDR inactivation and thereby increase the channel pool available to suppress excitability during subsequent depolarization. PMID:21745646

Expression and Function of System N Glutamine Transporters (SN1/SN2 or SNAT3/SNAT5) in Retinal Ganglion Cells

PubMed Central

Umapathy, Nagavedi S.; Dun, Ying; Martin, Pamela M.; Duplantier, Jennifer N.; Roon, Penny; Prasad, Puttur; Smith, Sylvia B.; Ganapathy, Vadivel

2008-01-01

Purpose Glutamine transport is essential for the glutamate-glutamine cycle, which occurs between neurons and glia. System N, consisting of SN1 (SNAT3) and SN2 (SNAT5), is the principal mediator of glutamine transport in retinal Müller cells. Mediators of glutamine transport in retinal ganglion cells were investigated. Methods The relative contributions of various transport systems for glutamine uptake (systems N, A, L, y+L, ASCT, and ATB0,+) were examined in RGC-5 cells based on differential features of the individual transport systems. mRNA for the genes encoding members of these transport systems were analyzed by RT-PCR. Based on these data, SN1 and SN2 were analyzed in mouse retina, RGC-5 cells, and primary mouse ganglion cells (GCs) by in situ hybridization (ISH), immunofluorescence (IF), and Western blotting. Results Three transport systems—N, A, and L—participated in glutamine uptake in RGC-5 cells. System N was the principal contributor; systems A and L contributed considerably less. ISH and IF revealed SN1 and SN2 expression in the ganglion, inner nuclear, and photoreceptor cell layers. SN1 and SN2 colocalized with the ganglion cell marker Thy 1.2 and with the Müller cell marker vimentin, confirming their presence in both retinal cell types. SN1 and SN2 proteins were detected in primary mouse GCs. Conclusions These findings suggest that in addition to its role in glutamine uptake in retinal glial cells, system N contributes significantly to glutamine uptake in ganglion cells and, hence, contributes to the retinal glutamate-glutamine cycle. PMID:18689705

Expression of polysialylated neural cell adhesion molecules on adult stem cells after neuronal differentiation of inner ear spiral ganglion neurons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Kyoung Ho; Yeo, Sang Won, E-mail: swyeo@catholic.ac.kr; Troy, Frederic A., E-mail: fatroy@ucdavis.edu

Highlights: • PolySia expressed on neurons primarily during early stages of neuronal development. • PolySia–NCAM is expressed on neural stem cells from adult guinea pig spiral ganglion. • PolySia is a biomarker that modulates neuronal differentiation in inner ear stem cells. - Abstract: During brain development, polysialylated (polySia) neural cell adhesion molecules (polySia–NCAMs) modulate cell–cell adhesive interactions involved in synaptogenesis, neural plasticity, myelination, and neural stem cell (NSC) proliferation and differentiation. Our findings show that polySia–NCAM is expressed on NSC isolated from adult guinea pig spiral ganglion (GPSG), and in neurons and Schwann cells after differentiation of the NSC withmore » epidermal, glia, fibroblast growth factors (GFs) and neurotrophins. These differentiated cells were immunoreactive with mAb’s to polySia, NCAM, β-III tubulin, nestin, S-100 and stained with BrdU. NSC could regenerate and be differentiated into neurons and Schwann cells. We conclude: (1) polySia is expressed on NSC isolated from adult GPSG and on neurons and Schwann cells differentiated from these NSC; (2) polySia is expressed on neurons primarily during the early stage of neuronal development and is expressed on Schwann cells at points of cell–cell contact; (3) polySia is a functional biomarker that modulates neuronal differentiation in inner ear stem cells. These new findings suggest that replacement of defective cells in the inner ear of hearing impaired patients using adult spiral ganglion neurons may offer potential hope to improve the quality of life for patients with auditory dysfunction and impaired hearing disorders.« less

Morphological patterns in children with ganglion related enteric neuronal abnormalities.

PubMed

Henna, Nausheen; Nagi, Abdul H; Sheikh, Muhammad A; Shaukat, Mahmood

2011-01-01

Hirschsprung's Disease (HD) is a developmental disorder of enteric nervous system characterised by the absence of ganglion cells in submucosal (Meissner's) and myenteric (Aurbach's) plexuses of distal bowel. The purpose of the present study was to observe and report the morphological patterns of ganglion related enteric neuronal abnormalities in children presented with clinical features of (HD) in a Pakistani population. A total of 92 patients with clinical presentation of HD were enrolled between March 2009 and October 2009. Among them, 8 were excluded according to the exclusion criteria. After detailed history and physical examination, paraffin embedded H and E stained sections were prepared from the serial open biopsies from colorectum. The data was analysed using SPSS-17. Frequencies and percentages are given for qualitative variables. Non-parametric Binomial Chi-Square test was applied to observe within group associations and p<0.05 was considered statistically significant. Among 84 patients, 13 (15.5%) proved to be normally ganglionic whereas 71 (84.5%) showed ganglion related enteric neuronal abnormalities namely isolated hypoganglionosis 9 (12.7%), immaturity of ganglion cells 9 (12.7%), isolated hyperganglionosis (IND Type B) 2 (2.8%) and Hirschsprung's disease 51 (71.8%). Among HD group, 34 (66.7%) belonged to isolated form and 17 (33.3%) showed combined ganglion related abnormalities. Hirschsprung's disease is common in Pakistani population, followed by hypoganglionosis, immaturity of ganglion cells and IND type B. The presence of hypertrophic nerve fibres was significant in HD, hyperganglionosis and hypoganglionosis, whereas, no hypertrophic nerve fibres were appreciated in immaturity of ganglion cell group.

Ganglion Cysts

MedlinePlus

... Ganglion Cysts Find a hand surgeon near you. Videos Ganglion Cysts Close Popup Figures Figure 1 - Ganglion ... or "in." Also, avoid using media types like "video," "article," and "picture." Tip 4: Your results can ...

Soluble Adenylyl Cyclase Is Required for Retinal Ganglion Cell and Photoreceptor Differentiation

PubMed Central

Shaw, Peter X.; Fang, Jiahua; Sang, Alan; Wang, Yan; Kapiloff, Michael S.; Goldberg, Jeffrey L.

2016-01-01

Purpose We have previously demonstrated that soluble adenylyl cyclase (sAC) is necessary for retinal ganglion cell (RGC) survival and axon growth. Here, we further investigate the role of sAC in neuronal differentiation during retinal development. Methods Chx10 or Math5 promoter-driven Cre-Lox recombination were used to conditionally delete sAC from early and intermediate retinal progenitor cells during retinal development. We examined cell type–specific markers expressed by retinal cells to estimate their relative numbers and characterize retinal laminar morphology by immunofluorescence in adult and newborn mice. Results Retinal ganglion cell and amacrine cell markers were significantly lower in the retinas of adult Math5cre/sACfl/fl and Chx10cre/sACfl/fl mice than in those of wild-type controls. The effect on RGC development was detectable as early as postnatal day 1 and deleting sAC in either Math5- or Chx10-expressing retinal progenitor cells also reduced nerve fiber layer thickness into adulthood. The thickness of the photoreceptor layer was slightly but statistically significantly decreased in both the newborn Chx10cre/sACfl/fl and Math5cre/sACfl/fl mice, but this reduction and abnormal morphology persisted in the adults in only the Chx10cre/sACfl/fl mice. Conclusions sAC plays an important role in the early retinal development of RGCs as well as in the development of amacrine cells and to a lesser degree photoreceptors. PMID:27679853

Receptive Field Vectors of Genetically-Identified Retinal Ganglion Cells Reveal Cell-Type-Dependent Visual Functions

PubMed Central

Katz, Matthew L.; Viney, Tim J.; Nikolic, Konstantin

2016-01-01

Sensory stimuli are encoded by diverse kinds of neurons but the identities of the recorded neurons that are studied are often unknown. We explored in detail the firing patterns of eight previously defined genetically-identified retinal ganglion cell (RGC) types from a single transgenic mouse line. We first introduce a new technique of deriving receptive field vectors (RFVs) which utilises a modified form of mutual information (“Quadratic Mutual Information”). We analysed the firing patterns of RGCs during presentation of short duration (~10 second) complex visual scenes (natural movies). We probed the high dimensional space formed by the visual input for a much smaller dimensional subspace of RFVs that give the most information about the response of each cell. The new technique is very efficient and fast and the derivation of novel types of RFVs formed by the natural scene visual input was possible even with limited numbers of spikes per cell. This approach enabled us to estimate the 'visual memory' of each cell type and the corresponding receptive field area by calculating Mutual Information as a function of the number of frames and radius. Finally, we made predictions of biologically relevant functions based on the RFVs of each cell type. RGC class analysis was complemented with results for the cells’ response to simple visual input in the form of black and white spot stimulation, and their classification on several key physiological metrics. Thus RFVs lead to predictions of biological roles based on limited data and facilitate analysis of sensory-evoked spiking data from defined cell types. PMID:26845435

Effects of alpha-lipoic acid on retinal ganglion cells, retinal thicknesses, and VEGF production in an experimental model of diabetes.

PubMed

Kan, Emrah; Alici, Ömer; Kan, Elif Kılıç; Ayar, Ahmet

2017-12-01

The purpose of the present study was to investigate the effect of alpha-lipoic acid (ALA) on the thicknesses of various retinal layers and on the numbers of retinal ganglion cells and vascular endothelial growth factor levels in experimental diabetic mouse retinas. Twenty-one male BALB/C mice were made diabetic by the intraperitoneal administration of streptozotocin (200 mg/kg). One week after the induction of diabetes, the mice were divided randomly into three groups: control group (non-diabetic mice treated with alpha-lipoic acid, n = 7), diabetic group (diabetic mice without treatment, n = 7), and alpha-lipoic acid treatment group (diabetic mice with alpha-lipoic acid treatment, n = 7). At the end of the 8th week, the thicknesses of the inner nuclear layer (INL), outer nuclear layer (ONL), and full-length retina were measured; also retinal ganglion cells and VEGF expressions were counted on the histological sections of the mouse retinas and compared with each other. The thicknesses of the full-length retina, ONL, and INL were significantly reduced in the diabetic group compared to the control and ALA treatment groups (p = 0.001), whereas the thicknesses of these layers did not show a significant difference between ALA treatment and control groups. The number of ganglion cells in the diabetic group was significantly lower than those in the control and ALA treatment groups (p = 0.001). The VEGF expression was significantly higher in the diabetic group and mostly observed in the ganglion cell and inner nuclear layers compared to the control and ALA treatment groups (p = 0.001). Therefore, the number of ganglion cells and VEGF levels did not show significant differences between the ALA treatment and control groups (p = 0.7). Our results show that alpha-lipoic acid treatment may have an impact on reducing VEGF levels, protecting ganglion cells, and preserving the thicknesses of the inner and outer layers in diabetic mouse retinas.

Delayed-rectifier K channels contribute to contrast adaptation in mammalian retinal ganglion cells.

PubMed

Weick, Michael; Demb, Jonathan B

2011-07-14

Retinal ganglion cells adapt by reducing their sensitivity during periods of high contrast. Contrast adaptation in the firing response depends on both presynaptic and intrinsic mechanisms. Here, we investigated intrinsic mechanisms for contrast adaptation in OFF Alpha ganglion cells in the in vitro guinea pig retina. Using either visual stimulation or current injection, we show that brief depolarization evoked spiking and suppressed firing during subsequent depolarization. The suppression could be explained by Na channel inactivation, as shown in salamander cells. However, brief hyperpolarization in the physiological range (5-10 mV) also suppressed firing during subsequent depolarization. This suppression was selectively sensitive to blockers of delayed-rectifier K channels (K(DR)). In somatic membrane patches, we observed tetraethylammonium-sensitive K(DR) currents that activated near -25 mV. Recovery from inactivation occurred at potentials hyperpolarized to V(rest). Brief periods of hyperpolarization apparently remove K(DR) inactivation and thereby increase the channel pool available to suppress excitability during subsequent depolarization. Copyright © 2011 Elsevier Inc. All rights reserved.

Association Between Regular Cannabis Use and Ganglion Cell Dysfunction.

PubMed

Schwitzer, Thomas; Schwan, Raymund; Albuisson, Eliane; Giersch, Anne; Lalanne, Laurence; Angioi-Duprez, Karine; Laprevote, Vincent

2017-01-01

Because cannabis use is a major public health concern and cannabis is known to act on central neurotransmission, studying the retinal ganglion cells in individuals who regularly use cannabis is of interest. To determine whether the regular use of cannabis could alter the function of retinal ganglion cells in humans. For this case-control study, individuals who regularly use cannabis, as well as healthy controls, were recruited, and data were collected from February 11 to October 28, 2014. Retinal function was used as a direct marker of brain neurotransmission abnormalities in complex mental phenomena. Amplitude and implicit time of the N95 wave on results of pattern electroretinography. Twenty-eight of the 52 participants were regular cannabis users (24 men and 4 women; median age, 22 years [95% CI, 21-24 years]), and the remaining 24 were controls (20 men and 4 women; median age, 24 years [95% CI, 23-27 years]). There was no difference between groups in terms of age (P = .13) or sex (P = .81). After adjustment for the number of years of education and alcohol use, there was a significant increase for cannabis users of the N95 implicit time on results of pattern electroretinography (median, 98.6 milliseconds [95% CI, 93.4-99.5]) compared with controls (median, 88.4 milliseconds [95% CI, 85.0-91.1]), with 8.4 milliseconds as the median of the differences (95% CI, 4.9-11.5; P < .001, Wald logistic regression). A receiver operating characteristic curve analysis (area under the curve, 0.84 [95% CI, 0.73-0.95]; P < .001) revealed, for a cutoff value of 91.13 milliseconds, a sensitivity of 78.6% (95% CI, 60.5%-89.8%) and a specificity of 75.0% (95% CI, 55.1%-88.0%) for correctly classifying both cannabis users and controls in their corresponding group. The positive predictive value was 78.6% (95% CI, 60.5%-89.8%), and the negative predictive value was 75.0% (95% CI, 55.1%-88.0%). Our results demonstrate a delay in transmission of action potentials by the

Satellite glial cells in the trigeminal ganglion as a determinant of orofacial neuropathic pain

PubMed Central

VIT, JEAN-PHILIPPE; JASMIN, LUC; BHARGAVA, ADITI; OHARA, PETER T.

2008-01-01

Satellite glial cells (SGCs) tightly envelop the perikarya of primary sensory neurons in peripheral ganglion and are identified by their morphology and the presence of proteins not found in ganglion neurons. These SGC-unique proteins include the inwardly rectifying K+ channel Kir4.1, the connexin-43 (Cx43) subunit of gap junctions, the purinergic receptor P2Y4 and soluble guanylate cyclase. We also present evidence that the small-conductance Ca2+-activated K+ channel SK3 is present only in SGCs and that SGCs divide following nerve injury. All the above proteins are involved, either directly or indirectly, in potassium ion (K+) buffering and, thus, can influence the level of neuronal excitability, which, in turn, has been associated with neuropathic pain conditions. We used in vivo RNA interference to reduce the expression of Cx43 (present only in SGCs) in the rat trigeminal ganglion and show that this results in the development of spontaneous pain behavior. The pain behavior is present only when Cx43 is reduced and returns to normal when Cx43 concentrations are restored. This finding shows that perturbation of a single SGC-specific protein is sufficient to induce pain responses and demonstrates the importance of PNS glial cell activity in the pathophysiology of neuropathic pain. PMID:18568096

[The neurotrophic effect of endogenous NT-3 from adult cat spared dorsal root ganglion on ganglionic neurons].

PubMed

Zhang, Wei; Zhou, Xue; Wang, Ting-hua; Wang, Te-wei; Liu, Su; Chen, Si-xiu; Ou, Ke-qun

2004-01-01

To investigate the neurotrophic effect of endogenous NT-3 from adult cat dorsal root ganglion (DRG) on ganglionic neurons. Rhizotomy of bilateral L1, L3, L5 and L7 dorsal roots of cats was performed, leaving L2, L4 and L6 DRG as spared DRGs. The separate neurons of normal (control) DRG, spared DRG and anti-NT-3 antibody blocking DRG were cultured in vitro respectively. The number of survival neurons and the length of neurites were measured and used for comparison in the control, spared DRG, and block groups. There were survival neurons and cell clusters in every group. The number of survival neurons and cell clusters of spared DRG group were much larger than those of the control and block groups. The neurite length of neurons, the neurite number and the length of cell clusters of spared DRG group were much greater than those of control and block groups. Endogenous NT-3 from spared DRG may act on ganglionic neurons to maintain survival of neuron and stimulate growth of neurite.

GDF15 is elevated in mice following retinal ganglion cell death and in glaucoma patients

PubMed Central

Ban, Norimitsu; Siegfried, Carla J.; Lin, Jonathan B.; Shui, Ying-Bo; Sein, Julia; Pita-Thomas, Wolfgang; Sene, Abdoulaye; Santeford, Andrea; Gordon, Mae; Lamb, Rachel; Dong, Zhenyu; Kelly, Shannon C.; Cavalli, Valeria; Yoshino, Jun

2017-01-01

Glaucoma is the second leading cause of blindness worldwide. Physicians often use surrogate endpoints to monitor the progression of glaucomatous neurodegeneration. These approaches are limited in their ability to quantify disease severity and progression due to inherent subjectivity, unreliability, and limitations of normative databases. Therefore, there is a critical need to identify specific molecular markers that predict or measure glaucomatous neurodegeneration. Here, we demonstrate that growth differentiation factor 15 (GDF15) is associated with retinal ganglion cell death. Gdf15 expression in the retina is specifically increased after acute injury to retinal ganglion cell axons and in a murine chronic glaucoma model. We also demonstrate that the ganglion cell layer may be one of the sources of secreted GDF15 and that GDF15 diffuses to and can be detected in aqueous humor (AH). In validating these findings in human patients with glaucoma, we find not only that GDF15 is increased in AH of patients with primary open angle glaucoma (POAG), but also that elevated GDF15 levels are significantly associated with worse functional outcomes in glaucoma patients, as measured by visual field testing. Thus, GDF15 maybe a reliable metric of glaucomatous neurodegeneration, although further prospective validation studies will be necessary to determine if GDF15 can be used in clinical practice. PMID:28469085

Primary culture of glial cells from mouse sympathetic cervical ganglion: a valuable tool for studying glial cell biology.

PubMed

de Almeida-Leite, Camila Megale; Arantes, Rosa Maria Esteves

2010-12-15

Central nervous system glial cells as astrocytes and microglia have been investigated in vitro and many intracellular pathways have been clarified upon various stimuli. Peripheral glial cells, however, are not as deeply investigated in vitro despite its importance role in inflammatory and neurodegenerative diseases. Based on our previous experience of culturing neuronal cells, our objective was to standardize and morphologically characterize a primary culture of mouse superior cervical ganglion glial cells in order to obtain a useful tool to study peripheral glial cell biology. Superior cervical ganglia from neonatal C57BL6 mice were enzymatically and mechanically dissociated and cells were plated on diluted Matrigel coated wells in a final concentration of 10,000cells/well. Five to 8 days post plating, glial cell cultures were fixed for morphological and immunocytochemical characterization. Glial cells showed a flat and irregular shape, two or three long cytoplasm processes, and round, oval or long shaped nuclei, with regular outline. Cell proliferation and mitosis were detected both qualitative and quantitatively. Glial cells were able to maintain their phenotype in our culture model including immunoreactivity against glial cell marker GFAP. This is the first description of immunocytochemical characterization of mouse sympathetic cervical ganglion glial cells in primary culture. This work discusses the uses and limitations of our model as a tool to study many aspects of peripheral glial cell biology. Copyright © 2010 Elsevier B.V. All rights reserved.

Muscarinic acetylcholine receptor subtype expression in avian vestibular hair cells, nerve terminals and ganglion cells.

PubMed

Li, G Q; Kevetter, G A; Leonard, R B; Prusak, D J; Wood, T G; Correia, M J

2007-04-25

Muscarinic acetylcholine receptors (mAChRs) are widely expressed in the CNS and peripheral nervous system and play an important role in modulating the cell activity and function. We have shown that the cholinergic agonist carbachol reduces the pigeon's inwardly rectifying potassium channel (pKir2.1) ionic currents in native vestibular hair cells. We have cloned and sequenced pigeon mAChR subtypes M2-M5 and we have studied the expression of all five mAChR subtypes (M1-M5) in the pigeon vestibular end organs (semicircular canal ampullary cristae and utricular maculae), vestibular nerve fibers and the vestibular (Scarpa's) ganglion using tissue immunohistochemistry (IH), dissociated single cell immunocytochemistry (IC) and Western blotting (WB). We found that vestibular hair cells, nerve fibers and ganglion cells each expressed all five (M1-M5) mAChR subtypes. Two of the three odd-numbered mAChRs (M1, M5) were present on the hair cell cilia, supporting cells and nerve terminals. And all three odd numbered mAChRs (M1, M3 and M5) were expressed on cuticular plates, myelin sheaths and Schwann cells. Even-numbered mAChRs were seen on the nerve terminals. M2 was also shown on the cuticular plates and supporting cells. Vestibular efferent fibers and terminals were not identified in our studies. Results from WB of the dissociated vestibular epithelia, nerve fibers and vestibular ganglia were consistent with the results from IH and IC. Our findings suggest that there is considerable co-expression of the subtypes on the neural elements of the labyrinth. Further electrophysiological and pharmacological studies should delineate the mechanisms of action of muscarinic acetylcholine receptors on structures in the labyrinth.

The Sigma Receptor Ligand (+)-Pentazocine Prevents Apoptotic Retinal Ganglion Cell Death induced in vitro by Homocysteine and Glutamate

PubMed Central

Martin, Pamela Moore; Ola, Mohammad S.; Agarwal, Neeraj; Ganapathy, Vadivel; Smith, Sylvia B.

2013-01-01

Recent studies demonstrated that the excitotoxic amino acid homocysteine induces apoptotic death of retinal ganglion cells in vivo. In the present study, an in vitro rat retinal ganglion cell (RGC-5) culture system was used to analyze the toxicity of acute exposure to high levels of homocysteine, the mechanism of homocysteine-induced toxicity and the usefulness of σR1 ligands as neuroprotectants. When cultured RGC-5 cells were subjected to treatment with 1 mM D, L- homocysteine, a significant increase in cell death was detected by TUNEL analysis and analysis of activated caspase. When cells were treated with homocysteine- or glutamate in the presence of MK-801, an antagonist of the NMDA receptor, the cell death was inhibited significantly. In contrast, NBQX, an antagonist of the AMPA/Kainate receptor, and nifedipine, a calcium channel blocker, did not prevent the homocysteine- or glutamate-induced cell death. Semi-quantitative RT-PCR and immunocytochemical analysis demonstrated that RGC-5 cells exposed to homocysteine or glutamate express type 1 sigma receptor at levels similar to control cells. Treatment of RGC-5 cells with 3 µM or 10 µM concentrations of the σR1-specific ligand (+)-pentazocine inhibited significantly the apoptotic cell death induced by homocysteine or glutamate. The results suggest that homocysteine is toxic to ganglion cells in vitro, that the toxicity is mediated via NMDA receptor activation, and that the σR1-specific ligand (+)-pentazocine can block the RGC-5 cell death induced by homocysteine and glutamate. PMID:15046867

Melanopsin-expressing retinal ganglion cells are resistant to cell injury, but not always.

PubMed

Georg, Birgitte; Ghelli, Anna; Giordano, Carla; Ross-Cisneros, Fred N; Sadun, Alfredo A; Carelli, Valerio; Hannibal, Jens; La Morgia, Chiara

2017-09-01

Melanopsin retinal ganglion cells (mRGCs) are intrinsically photosensitive RGCs deputed to non-image forming functions of the eye such as synchronization of circadian rhythms to light-dark cycle. These cells are characterized by unique electrophysiological, anatomical and biochemical properties and are usually more resistant than conventional RGCs to different insults, such as axotomy and different paradigms of stress. We also demonstrated that these cells are relatively spared compared to conventional RGCs in mitochondrial optic neuropathies (Leber's hereditary optic neuropathy and Dominant Optic Atrophy). However, these cells are affected in other neurodegenerative conditions, such as glaucoma and Alzheimer's disease. We here review the current evidences that may underlie this dichotomy. We also present our unpublished data on cell experiments demonstrating that melanopsin itself does not explain the robustness of these cells and some preliminary data on immunohistochemical assessment of mitochondria in mRGCs. Copyright © 2017 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

The relationship between neurotrophic factors and CaMKII in the death and survival of retinal ganglion cells.

PubMed

Cooper, N G F; Laabich, A; Fan, W; Wang, X

2008-01-01

The scientific discourse relating to the causes and treatments for glaucoma are becoming reflective of the need to protect and preserve retinal neurons from degenerative changes, which result from the injurious environment associated with this disease. Knowledge, in particular, of the signal transduction pathways which affect death and survival of the retinal ganglion cells is critical to this discourse and to the development of a suitable neurotherapeutic strategy for this disease. The goal of this chapter is to review what is known of the chief suspects involved in initiating the cell death/survival pathways in these cells, and what still remains to be uncovered. The least controversial aspect of the subject relates to the potential role of neurotrophic factors in the protection of the retinal ganglion cells. On the other hand, the postulated triggers for signaling cell death in glaucoma remain controversial. Certainly, the restricted flow of neurotrophic factors has been cited as one possible trigger. However, the connections between glaucoma and other factors present in the retina, such as glutamate, long held to be a prospective culprit in retinal ganglion cell death are still being questioned. Whatever the outcome of this particular debate, it is clear that the downstream intersections between the cell death and survival pathways should provide important foci for future studies whose goal is to protect retinal neurons, situated as they are, in the stressful environment of a cell destroying disease. The evidence for CaMKII being one of these intersecting points is discussed.

Macular ganglion cell imaging study: glaucoma diagnostic accuracy of spectral-domain optical coherence tomography.

PubMed

Jeoung, Jin Wook; Choi, Yun Jeong; Park, Ki Ho; Kim, Dong Myung

2013-07-01

We evaluated the diagnostic accuracy of macular ganglion cell-inner plexiform layer (GCIPL) measurements using a high-definition optical coherence tomography (Cirrus HD-OCT) ganglion cell analysis algorithm for detecting early and moderate-to-severe glaucoma. Totals of 119 normal subjects and 306 glaucoma patients (164 patients with early glaucoma and 142 with moderate-to-severe glaucoma) were enrolled from the Macular Ganglion Cell Imaging Study. Macular GCIPL, peripapillary retinal nerve fiber layer (RNFL) thickness, and optic nerve head (ONH) parameters were measured in each subject. Areas under the receiver operating characteristic curves (AUROCs) were calculated and compared. Based on the internal normative database, the sensitivity and specificity for detecting early and moderate-to-severe glaucoma were calculated. There was no statistically significant difference between the AUROCs for the best OCT parameters. For detecting early glaucoma, the sensitivity of the Cirrus GCIPL parameters ranged from 26.8% to 73.2% and that of the Cirrus RNFL parameters ranged from 6.1% to 61.6%. For the early glaucoma group, the best parameter from the GCIPL generally had a higher sensitivity than those of the RNFL and ONH parameters with comparable specificity (P < 0.05, McNemar's test). There were no significant differences between the AUROCs for Cirrus GCIPL, RNFL, and ONH parameters, indicating that these maps have similar diagnostic potentials for glaucoma. The minimum GCIPL showed better glaucoma diagnostic performance than the other parameters at comparable specificities. However, other GCIPL parameters showed performances comparable to those of the RNFL parameters.

Empirical Derivation of Correction Factors for Human Spiral Ganglion Cell Nucleus and Nucleolus Count Units.

PubMed

Robert, Mark E; Linthicum, Fred H

2016-01-01

Profile count method for estimating cell number in sectioned tissue applies a correction factor for double count (resulting from transection during sectioning) of count units selected to represent the cell. For human spiral ganglion cell counts, we attempted to address apparent confusion between published correction factors for nucleus and nucleolus count units that are identical despite the role of count unit diameter in a commonly used correction factor formula. We examined a portion of human cochlea to empirically derive correction factors for the 2 count units, using 3-dimensional reconstruction software to identify double counts. The Neurotology and House Histological Temporal Bone Laboratory at University of California at Los Angeles. Using a fully sectioned and stained human temporal bone, we identified and generated digital images of sections of the modiolar region of the lower first turn of cochlea, identified count units with a light microscope, labeled them on corresponding digital sections, and used 3-dimensional reconstruction software to identify double-counted count units. For 25 consecutive sections, we determined that double-count correction factors for nucleus count unit (0.91) and nucleolus count unit (0.92) matched the published factors. We discovered that nuclei and, therefore, spiral ganglion cells were undercounted by 6.3% when using nucleolus count units. We determined that correction factors for count units must include an element for undercounting spiral ganglion cells as well as the double-count element. We recommend a correction factor of 0.91 for the nucleus count unit and 0.98 for the nucleolus count unit when using 20-µm sections. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

Inhibition of mTOR by Rapamycin Results in Auditory Hair Cell Damage and Decreased Spiral Ganglion Neuron Outgrowth and Neurite Formation In Vitro

PubMed Central

Leitmeyer, Katharina; Glutz, Andrea; Radojevic, Vesna; Setz, Cristian; Huerzeler, Nathan; Bumann, Helen; Bodmer, Daniel; Brand, Yves

2015-01-01

Rapamycin is an antifungal agent with immunosuppressive properties. Rapamycin inhibits the mammalian target of rapamycin (mTOR) by blocking the mTOR complex 1 (mTORC1). mTOR is an atypical serine/threonine protein kinase, which controls cell growth, cell proliferation, and cell metabolism. However, less is known about the mTOR pathway in the inner ear. First, we evaluated whether or not the two mTOR complexes (mTORC1 and mTORC2, resp.) are present in the mammalian cochlea. Next, tissue explants of 5-day-old rats were treated with increasing concentrations of rapamycin to explore the effects of rapamycin on auditory hair cells and spiral ganglion neurons. Auditory hair cell survival, spiral ganglion neuron number, length of neurites, and neuronal survival were analyzed in vitro. Our data indicates that both mTOR complexes are expressed in the mammalian cochlea. We observed that inhibition of mTOR by rapamycin results in a dose dependent damage of auditory hair cells. Moreover, spiral ganglion neurite number and length of neurites were significantly decreased in all concentrations used compared to control in a dose dependent manner. Our data indicate that the mTOR may play a role in the survival of hair cells and modulates spiral ganglion neuronal outgrowth and neurite formation. PMID:25918725

Inhibition of mTOR by Rapamycin Results in Auditory Hair Cell Damage and Decreased Spiral Ganglion Neuron Outgrowth and Neurite Formation In Vitro.

PubMed

Leitmeyer, Katharina; Glutz, Andrea; Radojevic, Vesna; Setz, Cristian; Huerzeler, Nathan; Bumann, Helen; Bodmer, Daniel; Brand, Yves

2015-01-01

Rapamycin is an antifungal agent with immunosuppressive properties. Rapamycin inhibits the mammalian target of rapamycin (mTOR) by blocking the mTOR complex 1 (mTORC1). mTOR is an atypical serine/threonine protein kinase, which controls cell growth, cell proliferation, and cell metabolism. However, less is known about the mTOR pathway in the inner ear. First, we evaluated whether or not the two mTOR complexes (mTORC1 and mTORC2, resp.) are present in the mammalian cochlea. Next, tissue explants of 5-day-old rats were treated with increasing concentrations of rapamycin to explore the effects of rapamycin on auditory hair cells and spiral ganglion neurons. Auditory hair cell survival, spiral ganglion neuron number, length of neurites, and neuronal survival were analyzed in vitro. Our data indicates that both mTOR complexes are expressed in the mammalian cochlea. We observed that inhibition of mTOR by rapamycin results in a dose dependent damage of auditory hair cells. Moreover, spiral ganglion neurite number and length of neurites were significantly decreased in all concentrations used compared to control in a dose dependent manner. Our data indicate that the mTOR may play a role in the survival of hair cells and modulates spiral ganglion neuronal outgrowth and neurite formation.

Combined application of BDNF to the eye and brain enhances ganglion cell survival and function in the cat after optic nerve injury.

PubMed

Weber, Arthur J; Viswanáthan, Suresh; Ramanathan, Chidambaram; Harman, Christine D

2010-01-01

To determine whether application of BDNF to the eye and brain provides a greater level of neuroprotection after optic nerve injury than treatment of the eye alone. Retinal ganglion cell survival and pattern electroretinographic responses were compared in normal cat eyes and in eyes that received (1) a mild nerve crush and no treatment, (2) a single intravitreal injection of BDNF at the time of the nerve injury, or (3) intravitreal treatment combined with 1 to 2 weeks of continuous delivery of BDNF to the visual cortex, bilaterally. Relative to no treatment, administration of BDNF to the eye alone resulted in a significant increase in ganglion cell survival at both 1 and 2 weeks after nerve crush (1 week, 79% vs. 55%; 2 weeks, 60% vs. 31%). Combined treatment of the eye and visual cortex resulted in a modest additional increase (17%) in ganglion cell survival in the 1-week eyes, a further significant increase (55%) in the 2-week eyes, and ganglion cell survival levels for both that were comparable to normal (92%-93% survival). Pattern ERG responses for all the treated eyes were comparable to normal at 1 week after injury; however, at 2 weeks, only the responses of eyes receiving the combined BDNF treatment remained so. Although treatment of the eye alone with BDNF has a significant impact on ganglion cell survival after optic nerve injury, combined treatment of the eye and brain may represent an even more effective approach and should be considered in the development of future optic neuropathy-related neuroprotection strategies.

Ganglion cyst of the temporomandibular joint.

PubMed

Heng-Kun, W; Yan-Ling, G; Wen-Feng, Z; Zhe, S; Ren-Xin, W; Xiao-Tao, Z

2014-02-01

Ganglion cyst of the temporomandibular joint is a rare disease, which may arise from myxoid degeneration of the collagenous tissue of the temporomandibular joint capsule, without epithelial or endothelial lining. We report a case of cystic lesion in a 40-year-old female patient. The patient had a left pre-auricular oval-shaped swelling without any articular symptoms. The pathological analysis after surgical removal allowed diagnosing the lesion as a ganglion cyst of the left temporomandibular joint. We made a literature review and noted that this condition was predominant in female patients. We recommend using MRI for diagnostic purposes and surgery as the best therapeutic alternative. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

EFFECT OF INTRAVITREAL RANIBIZUMAB ON GANGLION CELL COMPLEX AND PERIPAPILLARY RETINAL NERVE FIBER LAYER IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION USING SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

PubMed

Zucchiatti, Ilaria; Cicinelli, Maria V; Parodi, Maurizio Battaglia; Pierro, Luisa; Gagliardi, Marco; Accardo, Agostino; Bandello, Francesco

2017-07-01

To analyze the changes in ganglion cell complex and peripapillary retinal nerve fiber layer thickness, in central macular thickness and choroidal thickness on spectral domain optical coherence tomography in patients with neovascular age-related macular degeneration treated with intravitreal ranibizumab injections. All consecutive patients with untreated neovascular age-related macular degeneration received loading phase of three monthly intravitreal ranibizumab, followed by retreatments on a pro re nata protocol for 12 months. changes in ganglion cell complex and retinal nerve fiber layer at the end of follow-up. Secondary outcome: changes in best-corrected visual acuity, central macular thickness, and choroidal thickness at the end of follow-up. Choroidal thickness was measured at 500 μm, 1000 μm, and 1,500 μm intervals nasally, temporally, superiorly, and inferiorly to the fovea, respectively, on horizontal and vertical line scans centered on the fovea. Twenty-four eyes were included. Ganglion cell complex and peripapillary retinal nerve fiber layer thickness did not show statistically significant changes through 12 months (55.6 ± 18.5 and 81.9 ± 9.9 μm at baseline, 52.7 ± 19.3 and 84.6 ± 15.5 μm at month 12, P > 0.05). Central macular thickness showed progressive decrease from baseline to month 12, with maximum reduction at month 3 (P < 0.001). Statistically significant reduction in choroidal thickness was registered in the nasal 500, 1000, and 1,500 μm from the fovea, corresponding to the papillomacular region (from 169.6 ± 45.3 to 153.9 ± 46.9, P < 0.001). Intravitreal ranibizumab injections did not affect retinal nerve fiber layer and ganglion cell complex thickness in 1-year follow-up. Choroidal thickness in papillomacular area and central macular thickness was significantly reduced at the end of treatment. Further studies, with larger sample, longer follow-up, and greater number of injections, are warranted.

Inhibitory masking controls the threshold sensitivity of retinal ganglion cells

PubMed Central

Pan, Feng; Toychiev, Abduqodir; Zhang, Yi; Atlasz, Tamas; Ramakrishnan, Hariharasubramanian; Roy, Kaushambi; Völgyi, Béla; Akopian, Abram

2016-01-01

Key points Retinal ganglion cells (RGCs) in dark‐adapted retinas show a range of threshold sensitivities spanning ∼3 log units of illuminance.Here, we show that the different threshold sensitivities of RGCs reflect an inhibitory mechanism that masks inputs from certain rod pathways.The masking inhibition is subserved by GABAC receptors, probably on bipolar cell axon terminals.The GABAergic masking inhibition appears independent of dopaminergic circuitry that has been shown also to affect RGC sensitivity.The results indicate a novel mechanism whereby inhibition controls the sensitivity of different cohorts of RGCs. This can limit and thereby ensure that appropriate signals are carried centrally in scotopic conditions when sensitivity rather than acuity is crucial. Abstract The responses of rod photoreceptors, which subserve dim light vision, are carried through the retina by three independent pathways. These pathways carry signals with largely different sensitivities. Retinal ganglion cells (RGCs), the output neurons of the retina, show a wide range of sensitivities in the same dark‐adapted conditions, suggesting a divergence of the rod pathways. However, this organization is not supported by the known synaptic morphology of the retina. Here, we tested an alternative idea that the rod pathways converge onto single RGCs, but inhibitory circuits selectively mask signals so that one pathway predominates. Indeed, we found that application of GABA receptor blockers increased the sensitivity of most RGCs by unmasking rod signals, which were suppressed. Our results indicate that inhibition controls the threshold responses of RGCs under dim ambient light. This mechanism can ensure that appropriate signals cross the bottleneck of the optic nerve in changing stimulus conditions. PMID:27350405

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

PubMed

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.

Frequency Responses of Rat Retinal Ganglion Cells

PubMed Central

Cloherty, Shaun L.; Hung, Yu-Shan; Kameneva, Tatiana; Ibbotson, Michael R.

2016-01-01

There are 15–20 different types of retinal ganglion cells (RGC) in the mammalian retina, each encoding different aspects of the visual scene. The mechanism by which post-synaptic signals from the retinal network generate spikes is determined by each cell’s intrinsic electrical properties. Here we investigate the frequency responses of morphologically identified rat RGCs using intracellular injection of sinusoidal current waveforms, to assess their intrinsic capabilities with minimal contributions from the retinal network. Recorded cells were classified according to their morphological characteristics (A, B, C or D-type) and their stratification (inner (i), outer (o) or bistratified) in the inner plexiform layer (IPL). Most cell types had low- or band-pass frequency responses. A2, C1 and C4o cells were band-pass with peaks of 15–30 Hz and low-pass cutoffs above 56 Hz (A2 cells) and ~42 Hz (C1 and C4o cells). A1 and C2i/o cells were low-pass with peaks of 10–15 Hz (cutoffs 19–25 Hz). Bistratified D1 and D2 cells were also low-pass with peaks of 5–10 Hz (cutoffs ~16 Hz). The least responsive cells were the B2 and C3 types (peaks: 2–5 Hz, cutoffs: 8–11 Hz). We found no difference between cells stratifying in the inner and outer IPL (i.e., ON and OFF cells) or between cells with large and small somas or dendritic fields. Intrinsic physiological properties (input resistance, spike width and sag) had little impact on frequency response at low frequencies, but account for 30–40% of response variability at frequencies >30 Hz. PMID:27341669

Quantifying Spiral Ganglion Neurite and Schwann Behavior on Micropatterned Polymer Substrates.

PubMed

Cheng, Elise L; Leigh, Braden; Guymon, C Allan; Hansen, Marlan R

2016-01-01

The first successful in vitro experiments on the cochlea were conducted in 1928 by Honor Fell (Fell, Arch Exp Zellforsch 7(1):69-81, 1928). Since then, techniques for culture of this tissue have been refined, and dissociated primary culture of the spiral ganglion has become a widely accepted in vitro model for studying nerve damage and regeneration in the cochlea. Additionally, patterned substrates have been developed that facilitate and direct neural outgrowth. A number of automated and semi-automated methods for quantifying this neurite outgrowth have been utilized in recent years (Zhang et al., J Neurosci Methods 160(1):149-162, 2007; Tapias et al., Neurobiol Dis 54:158-168, 2013). Here, we describe a method to study the effect of topographical cues on spiral ganglion neurite and Schwann cell alignment. We discuss our microfabrication process, characterization of pattern features, cell culture techniques for both spiral ganglion neurons and spiral ganglion Schwann cells. In addition, we describe protocols for reducing fibroblast count, immunocytochemistry, and methods for quantifying neurite and Schwann cell alignment.

Recovery of cat retinal ganglion cell sensitivity following pigment bleaching.

PubMed Central

Bonds, A B; Enroth-Cugell, C

1979-01-01

1. The threshold illuminance for small spot stimulation of on-centre cat retinal ganglion cells was plotted vs. time after exposure to adapting light sufficiently strong to bleach significant amounts of rhodopsin. 2. When the entire receptive field of an X- or Y-type ganglion cell is bleached by at most 40%, recovery of the cell's rod-system proceeds in two phases: an early relatively fast one during which the response appears transient, and a late, slower one during which responses become more sustained. Log threshold during the later phase is well fit by an exponential in time (tau = 11.5-38 min). 3. After bleaches of 90% of the underlying pigment, threshold is cone-determined for as long as 40 min. Rod threshold continues to decrease for at least 85 min after the bleach. 4. The rate of recovery is slower after strong than after weak bleaches; 10 and 90% bleaches yield time constants for the later phase of 11.5 and 38 min, respectively. This contrasts with an approximate time constant of 11 min for rhodopsin regeneration following any bleach. 5. The relationship between the initial elevation of log rod threshold extrapolated from the fitted exponential curves and the initial amount of pigment bleached is monotonic, but nonlinear. 6. After a bleaching exposure, the maintained discharge is initially very regular. The firing rate first rises, then falls to the pre-bleach level, with more extended time courses of change in firing rate after stronger exposures. The discharge rate is restored before threshold has recovered fully. 7. The change in the response vs. log stimulus relationship after bleaching is described as a shift of the curve to the right, paired with a decrease in slope of the linear segment of the curve. PMID:521963

Tibial periosteal ganglion cyst: The ganglion in disguise.

PubMed

Reghunath, Anjuna; Mittal, Mahesh K; Khanna, Geetika; Anil, V

2017-01-01

Soft tissue ganglions are commonly encountered cystic lesions around the wrist presumed to arise from myxomatous degeneration of periarticular connective tissue. Lesions with similar pathology in subchondral location close to joints, and often simulating a geode, is the less common entity called intraosseous ganglion. Rarer still is a lesion produced by mucoid degeneration and cyst formation of the periostium of long bones, rightly called the periosteal ganglion. They are mostly found in the lower extremities at the region of pes anserinus, typically limited to the periosteum and outer cortex without any intramedullary component. We report the case of a 62 year-old male who presented with a tender swelling on the mid shaft of the left tibia, which radiologically suggested a juxtacortical lesion extending to the soft tissue or a soft tissue neoplasm eroding the bony cortex of tibia. It was later diagnosed definitively as a periosteal ganglion in an atypical location, on further radiologic work-up and histopathological correlation.

Tibial periosteal ganglion cyst: The ganglion in disguise

PubMed Central

Reghunath, Anjuna; Mittal, Mahesh K; Khanna, Geetika; Anil, V

2017-01-01

Soft tissue ganglions are commonly encountered cystic lesions around the wrist presumed to arise from myxomatous degeneration of periarticular connective tissue. Lesions with similar pathology in subchondral location close to joints, and often simulating a geode, is the less common entity called intraosseous ganglion. Rarer still is a lesion produced by mucoid degeneration and cyst formation of the periostium of long bones, rightly called the periosteal ganglion. They are mostly found in the lower extremities at the region of pes anserinus, typically limited to the periosteum and outer cortex without any intramedullary component. We report the case of a 62 year-old male who presented with a tender swelling on the mid shaft of the left tibia, which radiologically suggested a juxtacortical lesion extending to the soft tissue or a soft tissue neoplasm eroding the bony cortex of tibia. It was later diagnosed definitively as a periosteal ganglion in an atypical location, on further radiologic work-up and histopathological correlation. PMID:28515597

The nervus terminalis ganglion in Anguilla rostrata: an immunocytochemical and HRP histochemical analysis.

PubMed

Grober, M S; Bass, A H; Burd, G; Marchaterre, M A; Segil, N; Scholz, K; Hodgson, T

1987-12-08

Immunocytochemistry and retrograde horseradish peroxidase (HRP) transport were used to study the ganglion of the nervus terminalis in the American eel, Anguilla rostrata. Luteinizing hormone releasing hormone (LHRH) like immunoreactivity was found in large, ganglion-like cells located ventromedially at the junction of the telencephalon and olfactory bulb and in fibers within the retina and olfactory epithelium. HRP transport from the retina demonstrated direct connections with both the ipsi- and contralateral populations of these ganglion-like cells. Given the well-documented role of both olfaction and vision during migratory and reproductive phases of the life cycle of eels, the robust nature of a nervus terminalis system in these fish may present a unique opportunity to study the behavioral correlates of structure-function organization in a discrete population of ganglion-like cells.

RdgB2 is required for dim-light input into intrinsically photosensitive retinal ganglion cells

PubMed Central

Walker, Marquis T.; Rupp, Alan; Elsaesser, Rebecca; Güler, Ali D.; Sheng, Wenlong; Weng, Shijun; Berson, David M.; Hattar, Samer; Montell, Craig

2015-01-01

A subset of retinal ganglion cells is intrinsically photosensitive (ipRGCs) and contributes directly to the pupillary light reflex and circadian photoentrainment under bright-light conditions. ipRGCs are also indirectly activated by light through cellular circuits initiated in rods and cones. A mammalian homologue (RdgB2) of a phosphoinositide transfer/exchange protein that functions in Drosophila phototransduction is expressed in the retinal ganglion cell layer. This raised the possibility that RdgB2 might function in the intrinsic light response in ipRGCs, which depends on a cascade reminiscent of Drosophila phototransduction. Here we found that under high light intensities, RdgB2−/− mutant mice showed normal pupillary light responses and circadian photoentrainment. Consistent with this behavioral phenotype, the intrinsic light responses of ipRGCs in RdgB2−/− were indistinguishable from wild-type. In contrast, under low-light conditions, RdgB2−/− mutants displayed defects in both circadian photoentrainment and the pupillary light response. The RdgB2 protein was not expressed in ipRGCs but was in GABAergic amacrine cells, which provided inhibitory feedback onto bipolar cells. We propose that RdgB2 is required in a cellular circuit that transduces light input from rods to bipolar cells that are coupled to GABAergic amacrine cells and ultimately to ipRGCs, thereby enabling ipRGCs to respond to dim light. PMID:26269578

Retinal ganglion cell dendritic fields in old-world monkeys are oriented radially.

PubMed

Schall, J D; Perry, V H; Leventhal, A G

1986-03-12

We analyzed the dendritic field morphology of 297 ganglion cells from peripheral regions of monkey retina. Most of the dendritic fields were elongated, and there was a significant tendency for the dendritic fields to be oriented radially, i.e., like the spokes of a wheel with the fovea at the hub. An overrepresentation of radial orientations in the peripheral retina of primates might explain why humans are best able to detect stimuli which are oriented radially using peripheral vision.

Photopolymerized microfeatures for directed spiral ganglion neurite and Schwann cell growth.

PubMed

Tuft, Bradley W; Li, Shufeng; Xu, Linjing; Clarke, Joseph C; White, Scott P; Guymon, Bradley A; Perez, Krystian X; Hansen, Marlan R; Guymon, C Allan

2013-01-01

Cochlear implants (CIs) provide auditory perception to individuals with severe hearing impairment. However, their ability to encode complex auditory stimuli is limited due, in part, to poor spatial resolution caused by electrical current spread in the inner ear. Directing nerve cell processes towards target electrodes may reduce the problematic current spread and improve stimulatory specificity. In this work, photopolymerization was used to fabricate micro- and nano-patterned methacrylate polymers to probe the extent of spiral ganglion neuron (SGN) neurite and Schwann cell (SGSC) contact guidance based on variations in substrate topographical cues. Micropatterned substrates are formed in a rapid, single-step reaction by selectively blocking light with photomasks which have parallel line-space gratings with periodicities of 10-100 μm. Channel amplitudes of 250 nm-10 μm are generated by modulating UV exposure time, light intensity, and photoinitiator concentration. Gradual transitions are observed between ridges and grooves using scanning electron and atomic force microscopy. The transitions stand in contrast to vertical features generated via etching lithographic techniques. Alignment of neural elements increases significantly with increasing feature amplitude and constant periodicity, as well as with decreasing periodicity and constant amplitude. SGN neurite alignment strongly correlates (r = 0.93) with maximum feature slope. Multiple neuronal and glial types orient to the patterns with varying degrees of alignment. This work presents a method to fabricate gradually-sloping micropatterns for cellular contact guidance studies and demonstrates spatial control of inner ear neural elements in response to micro- and nano-scale surface topography. Copyright © 2012 Elsevier Ltd. All rights reserved.

Spiral ganglion cell site of excitation I: comparison of scala tympani and intrameatal electrode responses.

PubMed

Cartee, Lianne A; Miller, Charles A; van den Honert, Chris

2006-05-01

To determine the site of excitation on the spiral ganglion cell in response to electrical stimulation similar to that from a cochlear implant, single-fiber responses to electrical stimuli delivered by an electrode positioned in the scala tympani were compared to responses from stimuli delivered by an electrode placed in the internal auditory meatus. The response to intrameatal stimulation provided a control set of data with a known excitation site, the central axon of the spiral ganglion cell. For both intrameatal and scala tympani stimuli, the responses to single-pulse, summation, and refractory stimulus protocols were recorded. The data demonstrated that summation pulses, as opposed to single pulses, are likely to give the most insightful measures for determination of the site of excitation. Single-fiber summation data for both scala tympani and intrameatally stimulated fibers were analyzed with a clustering algorithm. Combining cluster analysis and additional numerical modeling data, it was hypothesized that the scala tympani responses corresponded to central excitation, peripheral excitation adjacent to the cell body, and peripheral excitation at a site distant from the cell body. Fibers stimulated by an intrameatal electrode demonstrated the greatest range of jitter measurements indicating that greater fiber independence may be achieved with intrameatal stimulation.

TGF-β signaling is required for maintenance of retinal ganglion cell differentiation and survival.

PubMed

Walshe, T E; Leach, L L; D'Amore, P A

2011-08-25

To determine the role of TGF-β1 in the maintenance of retinal ganglion cell line (RGC-5) differentiation and integrity. RGC-5 cells were differentiated in media conditioned by human non-pigmented ciliary epithelial cells (HNPE) for 4 days before treatment with TGF-β1 for 24 h. Cells were examined for morphological changes and harvested for western blot and real-time PCR analysis. For study of apoptosis, differentiated RGC-5 cells were grown in serum-free medium for 24 h in the presence or absence of TGF-β1 and collected for Annexin V/Propidium iodide FACs analysis. The role of MAPK pathways in TGF-β1-dependent signaling was determined by treatment with specific inhibitors of ERK, JNK and p38. Differentiation of RGC-5 cells in HNPE-conditioned media (CM) increased the neural cell markers, Brn-3c, NF-160, Thy1.2, Tau and PGP9.5. Treatment with TGF-β1 significantly increased the length of neurites extended by differentiated RGC-5s, concomitant with increased expression of NF-160 and PGP9.5, but not Brn-3c, Thy1.2 or Tau. TGF-β1 also decreased RGC-5 cell apoptosis in serum-free medium. p38 phosphorylation, but not smad2/3, JNK or ERK phosphorylation, was increased in TGF-β1 treated cells. Specific inhibition of p38 signaling reversed TGF-β1 induced neurite growth. These findings demonstrate the induction of RGC-5 cell differentiation by HNPE-derived CM and illustrate a role for TGF-β1 in maintaining RGC-5 cell survival and promoting neurite outgrowth through p38 MAPK. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Caspases in retinal ganglion cell death and axon regeneration

PubMed Central

Thomas, Chloe N; Berry, Martin; Logan, Ann; Blanch, Richard J; Ahmed, Zubair

2017-01-01

Retinal ganglion cells (RGC) are terminally differentiated CNS neurons that possess limited endogenous regenerative capacity after injury and thus RGC death causes permanent visual loss. RGC die by caspase-dependent mechanisms, including apoptosis, during development, after ocular injury and in progressive degenerative diseases of the eye and optic nerve, such as glaucoma, anterior ischemic optic neuropathy, diabetic retinopathy and multiple sclerosis. Inhibition of caspases through genetic or pharmacological approaches can arrest the apoptotic cascade and protect a proportion of RGC. Novel findings have also highlighted a pyroptotic role of inflammatory caspases in RGC death. In this review, we discuss the molecular signalling mechanisms of apoptotic and inflammatory caspase responses in RGC specifically, their involvement in RGC degeneration and explore their potential as therapeutic targets. PMID:29675270

Muscarinic Acetylcholine Receptor Localization and Activation Effects on Ganglion Response Properties

PubMed Central

Renna, Jordan M.; Amthor, Franklin R.; Keyser, Kent T.

2010-01-01

Purpose. The activation and blockade of muscarinic acetylcholine receptors (mAChRs) affects retinal ganglion cell light responses and firing rates. This study was undertaken to identify the full complement of mAChRs expressed in the rabbit retina and to assess mAChR distribution and the functional effects of mAChR activation and blockade on retinal response properties. Methods. RT-PCR, Western blot analysis, and immunohistochemistry were used to identify the complement and distribution of mAChRs in the rabbit retina. Extracellular electrophysiology was used to determine the effects of the activation or blockade of mAChRs on ganglion cell response properties. Results. RT-PCR of whole neural retina resulted in the amplification of mRNA transcripts for the m1 to m5 mAChR subtypes. Western blot and immunohistochemical analyses confirmed that all five mAChR subtypes were expressed by subpopulations of bipolar, amacrine, and ganglion cells in the rabbit retina, including subsets of cells in cholinergic and glycinergic circuits. Nonspecific muscarinic activation and blockade resulted in the class-specific modulation of maintained ganglion cell firing rates and light responses. Conclusions. The expression of mAChR subtypes on subsets of bipolar, amacrine, and ganglion cells provides a substrate for both enhancement and suppression of retinal responses via activation by cholinergic agents. Thus, the muscarinic cholinergic system in the retina may contribute to the modulation of complex stimuli. Understanding the distribution and function of mAChRs in the retina has the potential to provide important insights into the visual changes that are caused by decreased ACh in the retinas of Alzheimer's patients and the potential visual effects of anticholinergic treatments for ocular diseases. PMID:20042645

Comparative anatomy of the accessory ciliary ganglion in mammals.

PubMed

Kuchiiwa, S; Kuchiiwa, T; Suzuki, T

1989-01-01

The orbits of 13 mammalian species (pig, sika deer, domestic sheep, horse, cat, fox, racoon dog, marten, rat, rabbit, crab-eating macaque, japanese macaque and man) were stained with silver nitrate and dissected under a dissecting microscope with special attention to the presence and location of the accessory ciliary ganglion. Some preparations were stained with thionin and examined as whole-mounts in a transmission microscope. The accessory ciliary ganglion was present in all 13 species, although the number and degree of development varied greatly from species to species. The accessory ciliary ganglion could be readily differentiated from the main ciliary ganglion in the following respects: it was located on the short ciliary nerve, and it had no root derived directly from the inferior trunk of the oculomotor nerve and it never attaches to this nerve. In many species, ganglion cells were also scattered in the short ciliary nerves in the stained whole preparations. In a few species, there were one or more small ganglia on the nerve to the inferior oblique muscle.

Rhythmic ganglion cell activity in bleached and blind adult mouse retinas.

PubMed

Menzler, Jacob; Channappa, Lakshmi; Zeck, Guenther

2014-01-01

In retinitis pigmentosa--a degenerative disease which often leads to incurable blindness--the loss of photoreceptors deprives the retina from a continuous excitatory input, the so-called dark current. In rodent models of this disease this deprivation leads to oscillatory electrical activity in the remaining circuitry, which is reflected in the rhythmic spiking of retinal ganglion cells (RGCs). It remained unclear, however, if the rhythmic RGC activity is attributed to circuit alterations occurring during photoreceptor degeneration or if rhythmic activity is an intrinsic property of healthy retinal circuitry which is masked by the photoreceptor's dark current. Here we tested these hypotheses by inducing and analysing oscillatory activity in adult healthy (C57/Bl6) and blind mouse retinas (rd10 and rd1). Rhythmic RGC activity in healthy retinas was detected upon partial photoreceptor bleaching using an extracellular high-density multi-transistor-array. The mean fundamental spiking frequency in bleached retinas was 4.3 Hz; close to the RGC rhythm detected in blind rd10 mouse retinas (6.5 Hz). Crosscorrelation analysis of neighbouring wild-type and rd10 RGCs (separation distance <200 µm) reveals synchrony among homologous RGC types and a constant phase shift (∼70 msec) among heterologous cell types (ON versus OFF). The rhythmic RGC spiking in these retinas is driven by a network of presynaptic neurons. The inhibition of glutamatergic ganglion cell input or the inhibition of gap junctional coupling abolished the rhythmic pattern. In rd10 and rd1 retinas the presynaptic network leads to local field potentials, whereas in bleached retinas additional pharmacological disinhibition is required to achieve detectable field potentials. Our results demonstrate that photoreceptor bleaching unmasks oscillatory activity in healthy retinas which shares many features with the functional phenotype detected in rd10 retinas. The quantitative physiological differences advance the

Processing of central and reflex vagal drives by rat cardiac ganglion neurones: an intracellular analysis

PubMed Central

McAllen, Robin M; Salo, Lauren M; Paton, Julian F R; Pickering, Anthony E

2011-01-01

Abstract Cardiac vagal tone is an important indicator of cardiovascular health, and its loss is an independent risk factor for arrhythmias and mortality. Several studies suggest that this loss of vagal tone can occur at the cardiac ganglion but the factors affecting ganglionic transmissionin vivoare poorly understood. We have employed a novel approach allowing intracellular recordings from functionally connected cardiac vagal ganglion cells in the working heart–brainstem preparation. The atria were stabilisedin situpreserving their central neural connections, and ganglion cells (n = 32) were impaled with sharp microelectrodes. Cardiac ganglion cells with vagal synaptic inputs (spontaneous, n = 10; or electrically evoked from the vagus, n = 3) were identified as principal neurones and showed tonic firing responses to current injected to their somata. Cells lacking vagal inputs (n = 19, presumed interneurones) were quiescent but showed phasic firing responses to depolarising current. In principal cells the ongoing action potentials and EPSPs exhibited respiratory modulation, with peak frequency in post-inspiration. Action potentials arose from unitary EPSPs and autocorrelation of those events showed that each ganglion cell received inputs from a single active preganglionic source. Peripheral chemoreceptor, arterial baroreceptor and diving response activation all evoked high frequency synaptic barrages in these cells, always from the same single preganglionic source. EPSP amplitudes showed frequency dependent depression, leading to more spike failures at shorter inter-event intervals. These findings indicate that rather than integrating convergent inputs, cardiac vagal postganglionic neurones gate preganglionic inputs, so regulating the proportion of central parasympathetic tone that is transmitted on to the heart. PMID:22005679

Sex-, stress-, and sympathetic post-ganglionic-dependent changes in identity and proportions of immune cells in the dura.

PubMed

McIlvried, Lisa A; Cruz, J Agustin; Borghesi, Lisa A; Gold, Michael S

2017-01-01

Aim of investigation Due to compelling evidence in support of links between sex, stress, sympathetic post-ganglionic innervation, dural immune cells, and migraine, our aim was to characterize the impacts of these factors on the type and proportion of immune cells in the dura. Methods Dural immune cells were obtained from naïve or stressed adult male and female Sprague Dawley rats for flow cytometry. Rats with surgical denervation of sympathetic post-ganglionic neurons of the dura were also studied. Results Immune cells comprise ∼17% of all cells in the dura. These included: macrophages/granulocytes ("Macs"; 63.2% of immune cells), dendritic cells (0.88%), T-cells (4.51%), natural killer T-cells (0.51%), natural killer cells (3.08%), and B-cells (20.0%). There were significantly more Macs and fewer B- and natural killer T-cells in the dura of females compared with males. Macs and dendritic cells were significantly increased by stress in males, but not females. In contrast, T-cells were significantly increased in females with a 24-hour delay following stress. Lastly, Macs, dendritic cells, and T-cells were significantly higher in sympathectomized-naïve males, but not females. Conclusions It may not only be possible, but necessary to use different strategies for the most effective treatment of migraine in men and women.

Selective labeling of retinal ganglion cells with calcium indicators by retrograde loading in vitro

PubMed Central

Behrend, Matthew R.; Ahuja, Ashish K.; Humayun, Mark S.; Weiland, James D.; Chow, Robert H.

2012-01-01

Here we present a retrograde loading technique that makes it possible for the first time to rapidly load a calcium indicator in the majority of retinal ganglion cells (RGCs) in salamander retina, and then to observe physiological activity of these dye-loaded cells. Dextran-conjugated calcium indicator, dissolved in water, was applied to the optic nerve stump. Following dye loading, the isolated retina was mounted on a microelectrode array to demonstrate that electrical activity and calcium activity were preserved, as the retina responded to electrical stimuli. PMID:19428523

Visual responses of ganglion cells of a New-World primate, the capuchin monkey, Cebus apella.

PubMed

Lee, B B; Silveira, L C; Yamada, E S; Hunt, D M; Kremers, J; Martin, P R; Troy, J B; da Silva-Filho, M

2000-11-01

1. The genetic basis of colour vision in New-World primates differs from that in humans and other Old-World primates. Most New-World primate species show a polymorphism; all males are dichromats and most females trichromats. 2. In the retina of Old-World primates such as the macaque, the physiological correlates of trichromacy are well established. Comparison of the retinae in New- and Old-World species may help constrain hypotheses as to the evolution of colour vision and the pathways associated with it. 3. Ganglion cell behaviour was recorded from trichromatic and dichromatic members of a New-World species (the capuchin monkey, Cebus apella) and compared with macaque data. Despite some differences in quantitative detail (such as a temporal response extended to higher frequencies), results from trichromatic animals strongly resembled those from the macaque. 4. In particular, cells of the parvocellular (PC) pathway showed characteristic frequency-dependent changes in responsivity to luminance and chromatic modulation, cells of the magnocellular (MC) pathway showed frequency-doubled responses to chromatic modulation, and the surround of MC cells received a chromatic input revealed on changing the phase of heterochromatically modulated lights. 5. Ganglion cells of dichromats were colour-blind versions of those of trichromats. 6. This strong physiological homology is consistent with a common origin of trichromacy in New- and Old-World monkeys; in the New-World primate the presence of two pigments in the middle-to-long wavelength range permits full expression of the retinal mechanisms of trichromatic vision.

Lack of early pattern stimulation prevents normal development of the alpha (Y) retinal ganglion cell population in the cat.

PubMed

Burnat, Kalina; Van Der Gucht, Estelle; Waleszczyk, Wioletta J; Kossut, Malgorzata; Arckens, Lutgarde

2012-08-01

Binocular deprivation of pattern vision (BD) early in life permanently impairs global motion perception. With the SMI-32 antibody against neurofilament protein (NFP) as a marker of the motion-sensitive Y-cell pathway (Van der Gucht et al. [2001] Cereb. Cortex 17:2805-2819), we analyzed the impact of early BD on the retinal circuitry in adult, perceptually characterized cats (Burnat et al. [2005] Neuroreport 16:751-754). In controls, large retinal ganglion cells exhibited a strong NFP signal in the soma and in the proximal parts of the dendritic arbors. The NFP-immunoreactive dendrites typically branched into sublamina a of the inner plexiform layer (IPL), i.e., the OFF inner plexiform sublamina. In the retina of adult BD cats, however, most of the NFP-immunoreactive ganglion cell dendrites branched throughout the entire IPL. The NFP-immunoreactive cell bodies were less regularly distributed, often appeared in pairs, and had a significantly larger diameter compared with NFP-expressing cells in control retinas. These remarkable differences in the immunoreactivity pattern were typically observed in temporal retina. In conclusion, we show that the anatomical organization typical of premature Y-type retinal ganglion cells persists into adulthood even if normal visual experience follows for years upon an initial 6-month period of BD. Binocular pattern deprivation possibly induces a lifelong OFF functional domination, normally apparent only during development, putting early high-quality vision forward as a premise for proper ON-OFF pathway segregation. These new observations for pattern-deprived animals provide an anatomical basis for the well-described motion perception deficits in congenital cataract patients. Copyright © 2012 Wiley Periodicals, Inc.

Cochlear implants and ex vivo BDNF gene therapy protect spiral ganglion neurons.

PubMed

Rejali, Darius; Lee, Valerie A; Abrashkin, Karen A; Humayun, Nousheen; Swiderski, Donald L; Raphael, Yehoash

2007-06-01

Spiral ganglion neurons often degenerate in the deaf ear, compromising the function of cochlear implants. Cochlear implant function can be improved by good preservation of the spiral ganglion neurons, which are the target of electrical stimulation by the implant. Brain derived neurotrophic factor (BDNF) has previously been shown to enhance spiral ganglion survival in experimentally deafened ears. Providing enhanced levels of BDNF in human ears may be accomplished by one of several different methods. The goal of these experiments was to test a modified design of the cochlear implant electrode that includes a coating of fibroblast cells transduced by a viral vector with a BDNF gene insert. To accomplish this type of ex vivo gene transfer, we transduced guinea pig fibroblasts with an adenovirus with a BDNF gene cassette insert, and determined that these cells secreted BDNF. We then attached BDNF-secreting cells to the cochlear implant electrode via an agarose gel, and implanted the electrode in the scala tympani. We determined that the BDNF expressing electrodes were able to preserve significantly more spiral ganglion neurons in the basal turns of the cochlea after 48 days of implantation when compared to control electrodes. This protective effect decreased in the higher cochlear turns. The data demonstrate the feasibility of combining cochlear implant therapy with ex vivo gene transfer for enhancing spiral ganglion neuron survival.

Upper stimulation threshold for retinal ganglion cell activation.

PubMed

Meng, Kevin; Fellner, Andreas; Rattay, Frank; Ghezzi, Diego; Meffin, Hamish; Ibbotson, Michael R; Kameneva, Tatiana

2018-08-01

The existence of an upper threshold in electrically stimulated retinal ganglion cells (RGCs) is of interest because of its relevance to the development of visual prosthetic devices, which are designed to restore partial sight to blind patients. The upper threshold is defined as the stimulation level above which no action potentials (direct spikes) can be elicited in electrically stimulated retina. We collected and analyzed in vitro recordings from rat RGCs in response to extracellular biphasic (anodic-cathodic) pulse stimulation of varying amplitudes and pulse durations. Such responses were also simulated using a multicompartment model. We identified the individual cell variability in response to stimulation and the phenomenon known as upper threshold in all but one of the recorded cells (n  =  20/21). We found that the latencies of spike responses relative to stimulus amplitude had a characteristic U-shape. In silico, we showed that the upper threshold phenomenon was observed only in the soma. For all tested biphasic pulse durations, electrode positions, and pulse amplitudes above lower threshold, a propagating action potential was observed in the distal axon. For amplitudes above the somatic upper threshold, the axonal action potential back-propagated in the direction of the soma, but the soma's low level of hyperpolarization prevented action potential generation in the soma itself. An upper threshold observed in the soma does not prevent spike conductance in the axon.

Clustering is a feature of the spiral ganglion in the basal turn.

PubMed

Gacek, Richard R

2012-01-01

To demonstrate the organization of the spiral ganglion in the mammalian species. Temporal bone (TB) specimens from man (n = 2), monkey (n = 2), lion (n = 2) and cat (n = 20) were stained, decalcified and dissected according to the Sudan black B method of Rasmussen. These TB specimens were examined under a Zeiss operating microscope and photographed with a Canon 100 camera interfaced with the microscope. Spiral ganglion cells occurred in clusters within Rosenthal's canal in all four species. The location of the clusters was marked by the interface between axon and dendritic bundles as well as groups of ganglion cells. In monkey and man the clusters were more separated than in lion and cat. These observations indicate that the spiral ganglion forms clusters of neurons within Rosenthal's canal at the basal cochlear turn in the mammals investigated here. The formation of clusters may be related to the principles of neurogenesis. Copyright © 2011 S. Karger AG, Basel.

Molecular Responses of the Spiral Ganglion to Aminoglycosides

ERIC Educational Resources Information Center

Balaban, Carey D.

2005-01-01

Aminoglycosides are toxic to both the inner ear hair cells and the ganglion cells that give rise to the eighth cranial nerve. According to recent studies, these cells have a repertoire of molecular responses to aminoglycoside exposure that engages multiple neuroprotective mechanisms. The responses appear to involve regulation of ionic homeostasis,…

Archer fish fast hunting maneuver may be guided by directionally selective retinal ganglion cells.

PubMed

Tsvilling, Vadim; Donchin, Opher; Shamir, Maoz; Segev, Ronen

2012-02-01

Archer fish are known for their unique hunting method, where one fish in a group shoots down an insect with a jet of water while all the other fish are observing the prey's motion. To reap its reward, the archer fish must reach the prey before its competitors. This requires fast computation of the direction of motion of the prey, which enables the fish to initiate a turn towards the prey with an accuracy of 99%, at about 100 ms after the prey is shot. We explored the hypothesis that direction-selective retinal ganglion cells may underlie this rapid processing. We quantified the degree of directional selectivity of ganglion cells in the archer fish retina. The cells could be categorized into three groups: sharply (5%), broadly (37%) and non-tuned (58%) directionally selective cells. To relate the electrophysiological data to the behavioral results we studied a computational model and estimated the time required to accumulate sufficient directional information to match the decision accuracy of the fish. The computational model is based on two direction-selective populations that race against each other until one reaches the threshold and drives the decision. We found that this competition model can account for the observed response time at the required accuracy. Thus, our results are consistent with the hypothesis that the fast response behavior of the archer fish relies on retinal identification of movement direction. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

RdgB2 is required for dim-light input into intrinsically photosensitive retinal ganglion cells.

PubMed

Walker, Marquis T; Rupp, Alan; Elsaesser, Rebecca; Güler, Ali D; Sheng, Wenlong; Weng, Shijun; Berson, David M; Hattar, Samer; Montell, Craig

2015-10-15

A subset of retinal ganglion cells is intrinsically photosensitive (ipRGCs) and contributes directly to the pupillary light reflex and circadian photoentrainment under bright-light conditions. ipRGCs are also indirectly activated by light through cellular circuits initiated in rods and cones. A mammalian homologue (RdgB2) of a phosphoinositide transfer/exchange protein that functions in Drosophila phototransduction is expressed in the retinal ganglion cell layer. This raised the possibility that RdgB2 might function in the intrinsic light response in ipRGCs, which depends on a cascade reminiscent of Drosophila phototransduction. Here we found that under high light intensities, RdgB2(-/-) mutant mice showed normal pupillary light responses and circadian photoentrainment. Consistent with this behavioral phenotype, the intrinsic light responses of ipRGCs in RdgB2(-/-) were indistinguishable from wild-type. In contrast, under low-light conditions, RdgB2(-/-) mutants displayed defects in both circadian photoentrainment and the pupillary light response. The RdgB2 protein was not expressed in ipRGCs but was in GABAergic amacrine cells, which provided inhibitory feedback onto bipolar cells. We propose that RdgB2 is required in a cellular circuit that transduces light input from rods to bipolar cells that are coupled to GABAergic amacrine cells and ultimately to ipRGCs, thereby enabling ipRGCs to respond to dim light. © 2015 Walker et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Adenovector GAD65 gene delivery into the rat trigeminal ganglion produces orofacial analgesia

PubMed Central

Vit, Jean-Philippe; Ohara, Peter T; Sundberg, Christopher; Rubi, Blanca; Maechler, Pierre; Liu, Chunyan; Puntel, Mariana; Lowenstein, Pedro; Castro, Maria; Jasmin, Luc

2009-01-01

Background Our goal is to use gene therapy to alleviate pain by targeting glial cells. In an animal model of facial pain we tested the effect of transfecting the glutamic acid decarboxylase (GAD) gene into satellite glial cells (SGCs) of the trigeminal ganglion by using a serotype 5 adenovector with high tropisms for glial cells. We postulated that GABA produced from the expression of GAD would reduce pain behavior by acting on GABA receptors on neurons within the ganglion. Results Injection of adenoviral vectors (AdGAD65) directly into the trigeminal ganglion leads to sustained expression of the GAD65 isoform over the 4 weeks observation period. Immunohistochemical analysis showed that adenovirus-mediated GAD65 expression and GABA synthesis were mainly in SGCs. GABAA and GABAB receptors were both seen in sensory neurons, yet only GABAA receptors decorated the neuronal surface. GABA receptors were not found on SGCs. Six days after injection of AdGAD65 into the trigeminal ganglion, there was a statistically significant decrease of pain behavior in the orofacial formalin test, a model of inflammatory pain. Rats injected with control virus (AdGFP or AdLacZ) had no reduction in their pain behavior. AdGAD65-dependent analgesia was blocked by bicuculline, a selective GABAA receptor antagonist, but not by CGP46381, a selective GABAB receptor antagonist. Conclusion Transfection of glial cells in the trigeminal ganglion with the GAD gene blocks pain behavior by acting on GABAA receptors on neuronal perikarya. PMID:19656360

Adenovector GAD65 gene delivery into the rat trigeminal ganglion produces orofacial analgesia.

PubMed

Vit, Jean-Philippe; Ohara, Peter T; Sundberg, Christopher; Rubi, Blanca; Maechler, Pierre; Liu, Chunyan; Puntel, Mariana; Lowenstein, Pedro; Castro, Maria; Jasmin, Luc

2009-08-05

Our goal is to use gene therapy to alleviate pain by targeting glial cells. In an animal model of facial pain we tested the effect of transfecting the glutamic acid decarboxylase (GAD) gene into satellite glial cells (SGCs) of the trigeminal ganglion by using a serotype 5 adenovector with high tropisms for glial cells. We postulated that GABA produced from the expression of GAD would reduce pain behavior by acting on GABA receptors on neurons within the ganglion. Injection of adenoviral vectors (AdGAD65) directly into the trigeminal ganglion leads to sustained expression of the GAD65 isoform over the 4 weeks observation period. Immunohistochemical analysis showed that adenovirus-mediated GAD65 expression and GABA synthesis were mainly in SGCs. GABAA and GABAB receptors were both seen in sensory neurons, yet only GABAA receptors decorated the neuronal surface. GABA receptors were not found on SGCs. Six days after injection of AdGAD65 into the trigeminal ganglion, there was a statistically significant decrease of pain behavior in the orofacial formalin test, a model of inflammatory pain. Rats injected with control virus (AdGFP or AdLacZ) had no reduction in their pain behavior. AdGAD65-dependent analgesia was blocked by bicuculline, a selective GABAA receptor antagonist, but not by CGP46381, a selective GABAB receptor antagonist. Transfection of glial cells in the trigeminal ganglion with the GAD gene blocks pain behavior by acting on GABAA receptors on neuronal perikarya.

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

PubMed

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 (P<0.01) in the presence of exogenous recombinant chicken GH (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 (P<0.01) the number of glutamate-BSO-induced apoptotic cells and blocked the explant release of LDH. This neuroprotective action was likely mediated by increased STAT5 phosphorylation and increased bcl-2 production, as induced by exogenous rcGH treatment and the media from GH-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. Copyright © 2016 Elsevier Inc. All rights reserved.

Color vision impairment in multiple sclerosis points to retinal ganglion cell damage.

PubMed

Lampert, E J; Andorra, M; Torres-Torres, R; Ortiz-Pérez, S; Llufriu, S; Sepúlveda, M; Sola, N; Saiz, A; Sánchez-Dalmau, B; Villoslada, P; Martínez-Lapiscina, Elena H

2015-11-01

Multiple Sclerosis (MS) results in color vision impairment regardless of optic neuritis (ON). The exact location of injury remains undefined. The objective of this study is to identify the region leading to dyschromatopsia in MS patients' NON-eyes. We evaluated Spearman correlations between color vision and measures of different regions in the afferent visual pathway in 106 MS patients. Regions with significant correlations were included in logistic regression models to assess their independent role in dyschromatopsia. We evaluated color vision with Hardy-Rand-Rittler plates and retinal damage using Optical Coherence Tomography. We ran SIENAX to measure Normalized Brain Parenchymal Volume (NBPV), FIRST for thalamus volume and Freesurfer for visual cortex areas. We found moderate, significant correlations between color vision and macular retinal nerve fiber layer (rho = 0.289, p = 0.003), ganglion cell complex (GCC = GCIP) (rho = 0.353, p < 0.001), thalamus (rho = 0.361, p < 0.001), and lesion volume within the optic radiations (rho = -0.230, p = 0.030). Only GCC thickness remained significant (p = 0.023) in the logistic regression model. In the final model including lesion load and NBPV as markers of diffuse neuroaxonal damage, GCC remained associated with dyschromatopsia [OR = 0.88 95 % CI (0.80-0.97) p = 0.016]. This association remained significant when we also added sex, age, and disease duration as covariates in the regression model. Dyschromatopsia in NON-eyes is due to damage of retinal ganglion cells (RGC) in MS. Color vision can serve as a marker of RGC damage in MS.

Rhythmic Ganglion Cell Activity in Bleached and Blind Adult Mouse Retinas

PubMed Central

Menzler, Jacob; Channappa, Lakshmi; Zeck, Guenther

2014-01-01

In retinitis pigmentosa – a degenerative disease which often leads to incurable blindness- the loss of photoreceptors deprives the retina from a continuous excitatory input, the so-called dark current. In rodent models of this disease this deprivation leads to oscillatory electrical activity in the remaining circuitry, which is reflected in the rhythmic spiking of retinal ganglion cells (RGCs). It remained unclear, however, if the rhythmic RGC activity is attributed to circuit alterations occurring during photoreceptor degeneration or if rhythmic activity is an intrinsic property of healthy retinal circuitry which is masked by the photoreceptor’s dark current. Here we tested these hypotheses by inducing and analysing oscillatory activity in adult healthy (C57/Bl6) and blind mouse retinas (rd10 and rd1). Rhythmic RGC activity in healthy retinas was detected upon partial photoreceptor bleaching using an extracellular high-density multi-transistor-array. The mean fundamental spiking frequency in bleached retinas was 4.3 Hz; close to the RGC rhythm detected in blind rd10 mouse retinas (6.5 Hz). Crosscorrelation analysis of neighbouring wild-type and rd10 RGCs (separation distance <200 µm) reveals synchrony among homologous RGC types and a constant phase shift (∼70 msec) among heterologous cell types (ON versus OFF). The rhythmic RGC spiking in these retinas is driven by a network of presynaptic neurons. The inhibition of glutamatergic ganglion cell input or the inhibition of gap junctional coupling abolished the rhythmic pattern. In rd10 and rd1 retinas the presynaptic network leads to local field potentials, whereas in bleached retinas additional pharmacological disinhibition is required to achieve detectable field potentials. Our results demonstrate that photoreceptor bleaching unmasks oscillatory activity in healthy retinas which shares many features with the functional phenotype detected in rd10 retinas. The quantitative physiological differences advance the

Macular retinal ganglion cell-inner plexiform layer thickness in patients on hydroxychloroquine therapy.

PubMed

Lee, Min Gyu; Kim, Sang Jin; Ham, Don-Il; Kang, Se Woong; Kee, Changwon; Lee, Jaejoon; Cha, Hoon-Suk; Koh, Eun-Mi

2014-11-25

We evaluated macular ganglion cell-inner plexiform layer (GC-IPL) thickness using spectral-domain optical coherence tomography (SD-OCT) in patients with chronic exposure to hydroxychloroquine (HCQ). This study included 130 subjects, who were divided into three groups: Group 1A, 55 patients with HCQ use ≥5 years; Group 1B, 46 patients with HCQ use <5 years; and Group 2, 29 normal controls. In all patients with exposure to HCQ, fundus examination, automated threshold perimetry, fundus autofluorescence photography, SD-OCT, and GC-IPL thickness measurement using the Cirrus HD-OCT ganglion cell analysis algorithm were performed. Average and minimum macular GC-IPL thickness were compared between subjects groups, and correlations between GC-IPL thickness and duration or total dose of HCQ use were analyzed. Among the 101 patients of Group 1, six patients who showed clinically evident HCQ retinopathy also showed markedly thin macular GC-IPL. In addition, weak but significant negative correlations were observed between the average and minimum GC-IPL thickness of Group 1 patients and cumulative dose of HCQ, even when analyzing without the six patients with HCQ retinopathy. However, when analyzing after exclusion of patients with high cumulative doses (>1000 g), significant correlations were not observed. This study revealed that macular GC-IPL thickness did not show definite correlations with HCQ use. However, some patients, especially with HCQ retinopathy or high cumulative doses, showed thin GC-IPL. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

THE NISSL SUBSTANCE OF LIVING AND FIXED SPINAL GANGLION CELLS

PubMed Central

Deitch, Arline D.; Moses, Montrose J.

1957-01-01

Living chick spinal ganglion neurons grown for 19 to 25 days in vitro were photographed with a color-translating ultraviolet microscope (UV-91) at 265, 287, and 310 mµ. This instrument was unique in permitting rapid accumulation of ultraviolet information with minimal damage to the cell. In the photographs taken at 265 mµ of the living neurons, discrete ultraviolet-absorbing cytoplasmic masses were observed which were found to be virtually unchanged in appearance after formalin fixation. These were identical with the Nissl bodies of the same cells seen after staining with basic dyes. The correlation of ultraviolet absorption, ribonuclease extraction, and staining experiments with acid and basic dyes confirmed the ribonucleoprotein nature of these Nissl bodies in the living and fixed cells. No change in distribution or concentration of ultraviolet-absorbing substance was observed in the first 12 ultraviolet photographs of a neuron, and it is concluded that the cells had not been subjected to significant ultraviolet damage during the period of photography. On the basis of these observations, as well as previous findings with phase contrast microscopy, it is concluded that Nissl bodies preexist in the living neuron as discrete aggregates containing high concentrations of nucleoprotein. PMID:13438929

Identification of ganglion cell neurites in human subretinal and epiretinal membranes

PubMed Central

Lewis, Geoffrey P; Betts, Kellen E; Sethi, Charanjit S; Charteris, David G; Lesnik‐Oberstein, Sarit Y; Avery, Robert L; Fisher, Steven K

2007-01-01

Aim To determine whether neural elements are present in subretinal and epiretinal proliferative vitreoretinopathy (PVR) membranes as well as in diabetic, fibrovascular membranes removed from patients during vitrectomy surgery. Methods Human subretinal and epiretinal membranes of varying durations were immunolabelled with different combinations of antibodies to glial fibrillary acidic protein, vimentin, neurofilament protein and laminin. Results Anti‐neurofilament‐labelled neurites from presumptive ganglion cells were frequently found in epiretinal membranes and occasionally found in subretinal membranes. In addition, the neurites were only observed in regions that also contained glial processes. Conclusions These data demonstrate that neuronal processes are commonly found in human peri‐retinal cellular membranes similar to that demonstrated in animal models. These data also suggest that glial cells growing out of the neural retina form a permissive substrate for neurite growth and thus may hold clues to factors that support this growth. PMID:17108012

Threshold setting by the surround of cat retinal ganglion cells.

PubMed

Barlow, H B; Levick, W R

1976-08-01

1. The slope of curves relating the log increment threshold to log background luminance in cat retinal ganglion cells is affected by the area and duration of the test stimulus, as it is in human pyschophysical experiments. 2. Using large area, long duration stimuli the slopes average 0-82 and approach close to 1 (Weber's Law) in the steepest cases. Small stimuli gave an average of 0-53 for on-centre units using brief stimuli, and 0-56 for off-centre units, using long stimuli. Slopes under 0-5 (square root law) were not found over an extended range of luminances. 3. On individual units the slope was generally greater for larger and longer test stimulus, but no unit showed the full extent of change from slope of 0-5 to slope of 1. 4. The above differences hold for objective measures of quantum/spike ratio, as well as for thresholds either judged by ear or assessed by calculation. 5. The steeper slope of the curves for large area, long duration test stimuli compared with small, long duration stimuli, is associated with the increased effectiveness of antagonism from the surround at high backgrounds. This change may be less pronounced in off-centre units, one of which (probably transient Y-type) showed no difference of slope, and gave parallel area-threshold curves at widely separated background luminances, confirming the importance of differential surround effectiveness in changing the slope of the curves. 6. In on-centre units, the increased relative effectiveness of the surround is associated with the part of the raised background light that falls on the receptive field centre. 7. It is suggested that the variable surround functions as a zero-offset control that sets the threshold excitation required for generating impulses, and that this is separate from gain-setting adaptive mechanisms. This may be how ganglion cells maintain high incremental sensitivity in spite of a strong maintained excitatory drive that would otherwise cause compressive response non-linearities.

Zinc oxide nanoparticles decrease the expression and activity of plasma membrane calcium ATPase, disrupt the intracellular calcium homeostasis in rat retinal ganglion cells.

PubMed

Guo, Dadong; Bi, Hongsheng; Wang, Daoguang; Wu, Qiuxin

2013-08-01

Zinc oxide nanoparticle is one of the most important materials with diverse applications. However, it has been reported that zinc oxide nanoparticles are toxic to organisms, and that oxidative stress is often hypothesized to be an important factor in cytotoxicity mediated by zinc oxide nanoparticles. Nevertheless, the mechanism of toxicity of zinc oxide nanoparticles has not been completely understood. In this study, we investigated the cytotoxic effect of zinc oxide nanoparticles and the possible molecular mechanism involved in calcium homeostasis mediated by plasma membrane calcium ATPase in rat retinal ganglion cells. Real-time cell electronic sensing assay showed that zinc oxide nanoparticles could exert cytotoxic effect on rat retinal ganglion cells in a concentration-dependent manner; flow cytometric analysis indicated that zinc oxide nanoparticles could lead to cell damage by inducing the overproduction of reactive oxygen species. Furthermore, zinc oxide nanoparticles could also apparently decrease the expression level and their activity of plasma membrane calcium ATPase, which finally disrupt the intracellular calcium homeostasis and result in cell death. Taken together, zinc oxide nanoparticles could apparently decrease the plasma membrane calcium ATPase expression, inhibit their activity, cause the elevated intracellular calcium ion level and disrupt the intracellular calcium homeostasis. Further, the disrupted calcium homeostasis will trigger mitochondrial dysfunction, generate excessive reactive oxygen species, and finally initiate cell death. Thus, the disrupted calcium homeostasis is involved in the zinc oxide nanoparticle-induced rat retinal ganglion cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

BAX to basics: How the BCL2 gene family controls the death of retinal ganglion cells

PubMed Central

Maes, Margaret E.; Schlamp, Cassandra L.; Nickells, Robert W.

2017-01-01

Retinal ganglion cell (RGC) death is the principal consequence of injury to the optic nerve. For several decades, we have understood that the RGC death process was executed by apoptosis, suggesting that there may be ways to therapeutically intervene in this cell death program and provide a more direct treatment to the cells and tissues affected in diseases like glaucoma. A major part of this endeavor has been to elucidate the molecular biological pathways active in RGCs from the point of axonal injury to the point of irreversible cell death. A major component of this process is the complex interaction of members of the BCL2 gene family. Three distinct family members of proteins orchestrate the most critical junction in the apoptotic program of RGCs, culminating in the activation of pro-apoptotic BAX. Once active, BAX causes irreparable damage to mitochondria, while precipitating downstream events that finish off a dying ganglion cell. This review is divided into two major parts. First, we summarize the extent of knowledge of how BCL2 gene family proteins interact to facilitate the activation and function of BAX. This area of investigation has rapidly changed over the last few years and has yielded a dramatically different mechanistic understanding of how the intrinsic apoptotic program is run in mammalian cells. Second, we provided a comprehensive analysis of nearly two decades of investigation of the role of BAX in the process of RGC death, much of which has provided many important insights into the overall pathophysiology of diseases like glaucoma. PMID:28064040

BAX to basics: How the BCL2 gene family controls the death of retinal ganglion cells.

PubMed

Maes, Margaret E; Schlamp, Cassandra L; Nickells, Robert W

2017-03-01

Retinal ganglion cell (RGC) death is the principal consequence of injury to the optic nerve. For several decades, we have understood that the RGC death process was executed by apoptosis, suggesting that there may be ways to therapeutically intervene in this cell death program and provide a more direct treatment to the cells and tissues affected in diseases like glaucoma. A major part of this endeavor has been to elucidate the molecular biological pathways active in RGCs from the point of axonal injury to the point of irreversible cell death. A major component of this process is the complex interaction of members of the BCL2 gene family. Three distinct family members of proteins orchestrate the most critical junction in the apoptotic program of RGCs, culminating in the activation of pro-apoptotic BAX. Once active, BAX causes irreparable damage to mitochondria, while precipitating downstream events that finish off a dying ganglion cell. This review is divided into two major parts. First, we summarize the extent of knowledge of how BCL2 gene family proteins interact to facilitate the activation and function of BAX. This area of investigation has rapidly changed over the last few years and has yielded a dramatically different mechanistic understanding of how the intrinsic apoptotic program is run in mammalian cells. Second, we provided a comprehensive analysis of nearly two decades of investigation of the role of BAX in the process of RGC death, much of which has provided many important insights into the overall pathophysiology of diseases like glaucoma. Copyright © 2017 Elsevier Ltd. All rights reserved.

Glaucoma Diagnostic Capability of Global and Regional Measurements of Isolated Ganglion Cell Layer and Inner Plexiform Layer.

PubMed

Chien, Jason L; Ghassibi, Mark P; Patthanathamrongkasem, Thipnapa; Abumasmah, Ramiz; Rosman, Michael S; Skaat, Alon; Tello, Celso; Liebmann, Jeffrey M; Ritch, Robert; Park, Sung Chul

2017-03-01

To compare glaucoma diagnostic capability of global/regional macular layer parameters in different-sized grids. Serial horizontal spectral-domain optical coherence tomography scans of macula were obtained. Automated macular grids with diameters of 3, 3.45, and 6 mm were used. For each grid, 10 parameters (total volume; average thicknesses in 9 regions) were obtained for 5 layers: macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), ganglion cell-inner plexiform layer (GCIPL; GCL+IPL), and ganglion cell complex (GCC; mRNFL+GCL+IPL). Sixty-nine normal eyes (69 subjects) and 87 glaucomatous eyes (87 patients) were included. For the total volume parameter, the area under the receiver operating characteristic curves (AUCs) in 6-mm grid were larger than the AUCs in 3- and 3.45-mm grids for GCL, GCC, GCIPL, and mRNFL (all P<0.020). For the average thickness parameters, the best AUC in 6-mm grid (T2 region for GCL, IPL, and GCIPL; I2 region for mRNFL and GCC) was greater than the best AUC in 3-mm grid for GCL, GCC, and mRNFL (P<0.045). The AUC of GCL volume (0.920) was similar to those of GCC (0.920) and GCIPL (0.909) volume. The AUC of GCL T2 region thickness (0.942) was similar to those of GCC I2 region (0.942) and GCIPL T2 region (0.934) thickness. Isolated macular GCL appears to be as good as GCC and GCIPL in glaucoma diagnosis, while IPL does not. Larger macular grids may be better at detecting glaucoma. Each layer has a characteristic region with the best glaucoma diagnostic capability.

Can Retinal Ganglion Cell Dipoles Seed Iso-Orientation Domains in the Visual Cortex?

PubMed Central

Schottdorf, Manuel; Eglen, Stephen J.; Wolf, Fred; Keil, Wolfgang

2014-01-01

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. PMID:24475081

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

PubMed

Schottdorf, Manuel; Eglen, Stephen J; Wolf, Fred; Keil, Wolfgang

2014-01-01

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.

Visual Acuity and the Balance between Receptor Density and Ganglion Cell Receptive Field Overlap.

DTIC Science & Technology

1980-07-01

Physiol. 229:719-731. Cleland, B . G., Dubin, M. W. and Levick , W. R. (1971) Sustained and transient neurones in the cat’s retina and lateral...NOOOIQ.79C-0370 NLASSIFIED IA. EEEEEEEEEEinnuunuuuuuu ’mLuuuu~ 4,0 111 12. 11111IL25 1.4I 111111.6 MICROCOPY RESOLUTION TEST CHART LEVEt 9 70 b *tm...1970; Burke and Hayhow, 1968; Barlow and Levick , 1969). As far as they affect the ganglion cell, these sources of noise are equivalent so they have been

Establishment of a long-term spiral ganglion neuron culture with reduced glial cell number: Effects of AraC on cell composition and neurons.

PubMed

Schwieger, Jana; Esser, Karl-Heinz; Lenarz, Thomas; Scheper, Verena

2016-08-01

Sensorineural deafness is mainly caused by damage to hair cells and degeneration of the spiral ganglion neurons (SGN). Cochlear implants can functionally replace lost hair cells and stimulate the SGN electrically. The benefit from cochlear implantation depends on the number and excitability of these neurons. To identify potential therapies for SGN protection, in vitro tests are carried out on spiral ganglion cells (SGC). A glial cell-reduced and neuron-enhanced culture of neonatal rat SGC under mitotic inhibition (cytarabine (AraC)) for up to seven days is presented. Serum containing and neurotrophin-enriched cultures with and without AraC-addition were analyzed after 4 and 7 days. The total number of cells was significantly reduced, while the proportion of neurons was greatly increased by AraC-treatment. Cell type-specific labeling demonstrated that nearly all fibroblasts and most of the glial cells were removed. Neither the neuronal survival, nor the neurite outgrowth or soma diameter were negatively affected. Additionally neurites remain partly free of surrounding non-neuronal cells. Recent culture conditions allow only for short-term cultivation of neonatal SGC and lack information on the influence of non-neuronal cells on SGN and of direct contact of neurites with test-materials. AraC-addition reduces the number of non-neuronal cells and increases the ratio of SGN in culture, without negative impact on neuronal viability. This treatment allows longer-term cultivation of SGC and provides deeper insight into SGN-glial cell interaction and the attachment of neurites on test-material surfaces. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Protective effects of brain-derived neurotrophic factor on the noise-damaged cochlear spiral ganglion.

PubMed

Zhai, S-Q; Guo, W; Hu, Y-Y; Yu, N; Chen, Q; Wang, J-Z; Fan, M; Yang, W-Y

2011-05-01

To explore the protective effects of brain-derived neurotrophic factor on the noise-damaged cochlear spiral ganglion. Recombinant adenovirus brain-derived neurotrophic factor vector, recombinant adenovirus LacZ and artificial perilymph were prepared. Guinea pigs with audiometric auditory brainstem response thresholds of more than 75 dB SPL, measured seven days after four hours of noise exposure at 135 dB SPL, were divided into three groups. Adenovirus brain-derived neurotrophic factor vector, adenovirus LacZ and perilymph were infused into the cochleae of the three groups, variously. Eight weeks later, the cochleae were stained immunohistochemically and the spiral ganglion cells counted. The auditory brainstem response threshold recorded before and seven days after noise exposure did not differ significantly between the three groups. However, eight weeks after cochlear perfusion, the group receiving brain-derived neurotrophic factor had a significantly decreased auditory brainstem response threshold and increased spiral ganglion cell count, compared with the adenovirus LacZ and perilymph groups. When administered via cochlear infusion following noise damage, brain-derived neurotrophic factor appears to improve the auditory threshold, and to have a protective effect on the spiral ganglion cells.

Metabotropic and ionotropic glutamate receptors regulate calcium channel currents in salamander retinal ganglion cells

PubMed Central

Shen, Wen; Slaughter, Malcolm M

1998-01-01

Glutamate suppressed high-voltage-activated barium currents (IBa,HVA) in tiger salamander retinal ganglion cells. Both ionotropic (iGluR) and metabotropic (mGluR) receptors contributed to this calcium channel inhibition. Trans-ACPD (1-aminocyclopentane-trans-1S,3R-dicarboxylic acid), a broad-spectrum metabotropic glutamate receptor agonist, suppressed a dihydropyridine-sensitive barium current. Kainate, an ionotropic glutamate receptor agonist, reduced an ω-conotoxin GVIA-sensitive current. The relative effectiveness of selective agonists indicated that the predominant metabotropic receptor was the L-2-amino-4-phosphonobutyrate (l-AP4)-sensitive, group III receptor. This receptor reversed the action of forskolin, but this was not responsible for calcium channel suppression. l-AP4 raised internal calcium concentration. Antagonists of phospholipase C, inositol trisphosphate (IP3) receptors and ryanodine receptors inhibited the action of metabotropic agonists, indicating that group III receptor transduction was linked to this pathway. The action of kainate was partially suppressed by BAPTA, by calmodulin antagonists and by blockers of calmodulin-dependent phosphatase. Suppression by kainate of the calcium channel current was more rapid when calcium was the charge carrier, instead of barium. The results indicate that calcium influx through kainate-sensitive glutamate receptors can activate calmodulin, which stimulates phosphatases that may directly suppress voltage-sensitive calcium channels. Thus, ionotropic and metabotropic glutamate receptors inhibit distinct calcium channels. They could act synergistically, since both increase internal calcium. These pathways provide negative feedback that can reduce calcium influx when ganglion cells are depolarized. PMID:9660896

The protective effect of olfactory ensheathing cells on post-injury spiral ganglion cells.

PubMed

Dai, Qi; Zhang, Zhicun; Liu, Quan; Yu, Hongmeng

2016-11-01

Transplantation of OECs into the cochlea may protect and increase the survival of SGCs. To investigate the protective effect of the transplantation of olfactory ensheathing cells (OECs) on injured spiral ganglion cells (SGCs) in rats. OECs were transplanted into the cochlea in rats with SGCs that were injured by kanamycin sulfate (KM). An equal volume of D-Hanks was injected into the cochlea of control rats. Auditory brainstem responses (ABRs) were recorded from the rats in both groups to monitor changes in hearing thresholds. Immunofluorescence was employed to examine the density and morphology of SGCs to assess the ototoxic condition of the cochlea. There was no significant difference in the ABR threshold at each frequency between the control and experimental groups. Notably, in the experimental group, a number of Hoechst 3334-labeled nuclei were detected from the apex to the basal turn of the cochlea, demonstrating that the OECs were successfully transplanted and survived in the cochlea. In the experimental group, most of the SGCs were tightly arranged, and the nuclear membrane, chromatin, and nucleolus were all clear. The SGCs in the control group were loosely arranged, and only a few normal SGCs were observed in this group.

Macular Ganglion Cell Imaging Study: Covariate Effects on the Spectral Domain Optical Coherence Tomography for Glaucoma Diagnosis.

PubMed

Jeong, Jae Hoon; Choi, Yun Jeong; Park, Ki Ho; Kim, Dong Myung; Jeoung, Jin Wook

2016-01-01

To evaluate the effect of multiple covariates on the diagnostic performance of the Cirrus high-definition optical coherence tomography (HD-OCT) for glaucoma detection. A prospective case-control study was performed and included 173 recently diagnosed glaucoma patients and 63 unaffected individuals from the Macular Ganglion Cell Imaging Study. Regression analysis of receiver operating characteristic were conducted to evaluate the influence of age, spherical equivalent, axial length, optic disc size, and visual field index on the macular ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) measurements. Disease severity, as measured by visual field index, had a significant effect on the diagnostic performance of all Cirrus HD-OCT parameters. Age, axial length and optic disc size were significantly associated with diagnostic accuracy of average peripapillary RNFL thickness, whereas axial length had a significant effect on the diagnostic accuracy of average GCIPL thickness. Diagnostic performance of the Cirrus HD-OCT may be more accurate in the advanced stages of glaucoma than at earlier stages. A smaller optic disc size was significantly associated with improved the diagnostic ability of average RNFL thickness measurements; however, GCIPL thickness may be less affected by age and optic disc size.

Retinal ganglion cell maps in the brain: implications for visual processing.

PubMed

Dhande, Onkar S; Huberman, Andrew D

2014-02-01

Everything the brain knows about the content of the visual world is built from the spiking activity of retinal ganglion cells (RGCs). As the output neurons of the eye, RGCs include ∼20 different subtypes, each responding best to a specific feature in the visual scene. Here we discuss recent advances in identifying where different RGC subtypes route visual information in the brain, including which targets they connect to and how their organization within those targets influences visual processing. We also highlight examples where causal links have been established between specific RGC subtypes, their maps of central connections and defined aspects of light-mediated behavior and we suggest the use of techniques that stand to extend these sorts of analyses to circuits underlying visual perception. Copyright © 2013. Published by Elsevier Ltd.

Reliable, responsive pacemaking and pattern generation with minimal cell numbers: the crustacean cardiac ganglion.

PubMed

Cooke, Ian M

2002-04-01

Investigations of the electrophysiology of crustacean cardiac ganglia over the last half-century are reviewed for their contributions to elucidating the cellular mechanisms and interactions by which a small (as few as nine cells) neuronal network accomplishes extremely reliable, rhythmical, patterned activation of muscular activity-in this case, beating of the neurogenic heart. This ganglion is thus a model for pacemaking and central pattern generation. Favorable anatomy has permitted voltage- and space-clamp analyses of voltage-dependent ionic currents that endow each neuron with the intrinsic ability to respond with rhythmical, patterned impulse activity to nonpatterned stimulation. The crustacean soma and initial axon segment do not support impulse generation but integrate input from stretch-sensitive dendrites and electrotonic and chemically mediated synapses on axonal processes in neuropils. The soma and initial axon produce a depolarization-activated, calcium-mediated, sustained potential, the "driver potential," so-called because it drives a train of impulses at the "trigger zone" of the axon. Extreme reliability results from redundancy and the electrotonic coupling and synaptic interaction among all the neurons. Complex modulation by central nervous system inputs and by neurohormones to adjust heart pumping to physiological demands has long been demonstrated, but much remains to be learned about the cellular and molecular mechanisms of action. The continuing relevance of the crustacean cardiac ganglion as a relatively simple model for pacemaking and central pattern generation is confirmed by the rapidly widening documentation of intrinsic potentials such as plateau potentials in neurons of all major animal groups. The suite of ionic currents (a slowly inactivating calcium current and various potassium currents, with variations) observed for the crustacean cardiac ganglion have been implicated in or proven to underlie a majority of the intrinsic potentials

Electric stimulus duration alters network-mediated responses depending on retinal ganglion cell type

NASA Astrophysics Data System (ADS)

Im, Maesoon; Werginz, Paul; Fried, Shelley I.

2018-06-01

Objective. To improve the quality of artificial vision that arises from retinal prostheses, it is important to bring electrically-elicited neural activity more in line with the physiological signaling patterns that arise normally in the healthy retina. Our previous study reported that indirect activation produces a closer match to physiological responses in ON retinal ganglion cells (RGCs) than in OFF cells (Im and Fried 2015 J. Physiol. 593 3677-96). This suggests that a preferential activation of ON RGCs would shape the overall retinal response closer to natural signaling. Recently, we found that changes to the rate at which stimulation was delivered could bias responses towards a stronger ON component (Im and Fried 2016a J. Neural Eng. 13 025002), raising the possibility that changes to other stimulus parameters can similarly bias towards stronger ON responses. Here, we explore the effects of changing stimulus duration on the responses in ON and OFF types of brisk transient (BT) and brisk sustained (BS) RGCs. Approach. We used cell-attached patch clamp to record RGC spiking in the isolated rabbit retina. Targeted RGCs were first classified as ON or OFF type by their light responses, and further sub-classified as BT or BS types by their responses to both light and electric stimuli. Spiking in targeted RGCs was recorded in response to electric pulses with durations varying from 5 to100 ms. Stimulus amplitude was adjusted at each duration to hold total charge constant for all experiments. Main results. We found that varying stimulus durations modulated responses differentially for ON versus OFF cells: in ON cells, spike counts decreased significantly with increasing stimulus duration while in OFF cells the changes were more modest. The maximum ratio of ON versus OFF responses occurred at a duration of ~10 ms. The difference in response strength for BT versus BS cells was much larger in ON cells than in OFF cells. Significance. The stimulation rates preferred by

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

NASA Astrophysics Data System (ADS)

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

2001-03-01

Our group recently demonstrated that autoimmune T cells directed against central nervous system-associated myelin antigens protect neurons from secondary degeneration. We further showed that the synthetic peptide copolymer 1 (Cop-1), known to suppress experimental autoimmune encephalomyelitis, can be safely substituted for the natural myelin antigen in both passive and active immunization for neuroprotection of the injured optic nerve. Here we attempted to determine whether similar immunizations are protective from retinal ganglion cell loss resulting from a direct biochemical insult caused, for example, by glutamate (a major mediator of degeneration in acute and chronic optic nerve insults) and in a rat model of ocular hypertension. Passive immunization with T cells reactive to myelin basic protein or active immunization with myelin oligodendrocyte glycoprotein-derived peptide, although neuroprotective after optic nerve injury, was ineffective against glutamate toxicity in mice and rats. In contrast, the number of surviving retinal ganglion cells per square millimeter in glutamate-injected retinas was significantly larger in mice immunized 10 days previously with Cop-1 emulsified in complete Freund's adjuvant than in mice injected with PBS in the same adjuvant (2,133 ± 270 and 1,329 ± 121, respectively, mean ± SEM; P < 0.02). A similar pattern was observed when mice were immunized on the day of glutamate injection (1,777 ± 101 compared with 1,414 ± 36; P <0.05), but not when they were immunized 48h later. These findings suggest that protection from glutamate toxicity requires reinforcement of the immune system by antigens that are different from those associated with myelin. The use of Cop-1 apparently circumvents this antigen specificity barrier. In the rat ocular hypertension model, which simulates glaucoma, immunization with Cop-1 significantly reduced the retinal ganglion cell loss from 27.8%±6.8% to 4.3%±1.6%, without affecting the intraocular pressure

Coatings of Different Carbon Nanotubes on Platinum Electrodes for Neuronal Devices: Preparation, Cytocompatibility and Interaction with Spiral Ganglion Cells.

PubMed

Burblies, Niklas; Schulze, Jennifer; Schwarz, Hans-Christoph; Kranz, Katharina; Motz, Damian; Vogt, Carla; Lenarz, Thomas; Warnecke, Athanasia; Behrens, Peter

2016-01-01

Cochlear and deep brain implants are prominent examples for neuronal prostheses with clinical relevance. Current research focuses on the improvement of the long-term functionality and the size reduction of neural interface electrodes. A promising approach is the application of carbon nanotubes (CNTs), either as pure electrodes but especially as coating material for electrodes. The interaction of CNTs with neuronal cells has shown promising results in various studies, but these appear to depend on the specific type of neurons as well as on the kind of nanotubes. To evaluate a potential application of carbon nanotube coatings for cochlear electrodes, it is necessary to investigate the cytocompatibility of carbon nanotube coatings on platinum for the specific type of neuron in the inner ear, namely spiral ganglion neurons. In this study we have combined the chemical processing of as-delivered CNTs, the fabrication of coatings on platinum, and the characterization of the electrical properties of the coatings as well as a general cytocompatibility testing and the first cell culture investigations of CNTs with spiral ganglion neurons. By applying a modification process to three different as-received CNTs via a reflux treatment with nitric acid, long-term stable aqueous CNT dispersions free of dispersing agents were obtained. These were used to coat platinum substrates by an automated spray-coating process. These coatings enhance the electrical properties of platinum electrodes, decreasing the impedance values and raising the capacitances. Cell culture investigations of the different CNT coatings on platinum with NIH3T3 fibroblasts attest an overall good cytocompatibility of these coatings. For spiral ganglion neurons, this can also be observed but a desired positive effect of the CNTs on the neurons is absent. Furthermore, we found that the well-established DAPI staining assay does not function on the coatings prepared from single-wall nanotubes.

Coatings of Different Carbon Nanotubes on Platinum Electrodes for Neuronal Devices: Preparation, Cytocompatibility and Interaction with Spiral Ganglion Cells

PubMed Central

Schwarz, Hans-Christoph; Kranz, Katharina; Motz, Damian; Vogt, Carla; Lenarz, Thomas; Warnecke, Athanasia; Behrens, Peter

2016-01-01

Cochlear and deep brain implants are prominent examples for neuronal prostheses with clinical relevance. Current research focuses on the improvement of the long-term functionality and the size reduction of neural interface electrodes. A promising approach is the application of carbon nanotubes (CNTs), either as pure electrodes but especially as coating material for electrodes. The interaction of CNTs with neuronal cells has shown promising results in various studies, but these appear to depend on the specific type of neurons as well as on the kind of nanotubes. To evaluate a potential application of carbon nanotube coatings for cochlear electrodes, it is necessary to investigate the cytocompatibility of carbon nanotube coatings on platinum for the specific type of neuron in the inner ear, namely spiral ganglion neurons. In this study we have combined the chemical processing of as-delivered CNTs, the fabrication of coatings on platinum, and the characterization of the electrical properties of the coatings as well as a general cytocompatibility testing and the first cell culture investigations of CNTs with spiral ganglion neurons. By applying a modification process to three different as-received CNTs via a reflux treatment with nitric acid, long-term stable aqueous CNT dispersions free of dispersing agents were obtained. These were used to coat platinum substrates by an automated spray-coating process. These coatings enhance the electrical properties of platinum electrodes, decreasing the impedance values and raising the capacitances. Cell culture investigations of the different CNT coatings on platinum with NIH3T3 fibroblasts attest an overall good cytocompatibility of these coatings. For spiral ganglion neurons, this can also be observed but a desired positive effect of the CNTs on the neurons is absent. Furthermore, we found that the well-established DAPI staining assay does not function on the coatings prepared from single-wall nanotubes. PMID:27385031

Visual pattern recognition based on spatio-temporal patterns of retinal ganglion cells’ activities

PubMed Central

Jing, Wei; Liu, Wen-Zhong; Gong, Xin-Wei; Gong, Hai-Qing

2010-01-01

Neural information is processed based on integrated activities of relevant neurons. Concerted population activity is one of the important ways for retinal ganglion cells to efficiently organize and process visual information. In the present study, the spike activities of bullfrog retinal ganglion cells in response to three different visual patterns (checker-board, vertical gratings and horizontal gratings) were recorded using multi-electrode arrays. A measurement of subsequence distribution discrepancy (MSDD) was applied to identify the spatio-temporal patterns of retinal ganglion cells’ activities in response to different stimulation patterns. The results show that the population activity patterns were different in response to different stimulation patterns, such difference in activity pattern was consistently detectable even when visual adaptation occurred during repeated experimental trials. Therefore, the stimulus pattern can be reliably discriminated according to the spatio-temporal pattern of the neuronal activities calculated using the MSDD algorithm. PMID:21886670

Functional engraftment of the medial ganglionic eminence cells in experimental stroke model.

PubMed

Daadi, Marcel M; Lee, Sang Hyung; Arac, Ahmet; Grueter, Brad A; Bhatnagar, Rishi; Maag, Anne-Lise; Schaar, Bruce; Malenka, Robert C; Palmer, Theo D; Steinberg, Gary K

2009-01-01

Currently there are no effective treatments targeting residual anatomical and behavioral deficits resulting from stroke. Evidence suggests that cell transplantation therapy may enhance functional recovery after stroke through multiple mechanisms. We used a syngeneic model of neural transplantation to explore graft-host communications that enhance cellular engraftment.The medial ganglionic eminence (MGE) cells were derived from 15-day-old transgenic rat embryos carrying green fluorescent protein (GFP), a marker, to easily track the transplanted cells. Adult rats were subjected to transient intraluminal occlusion of the medial cerebral artery. Two weeks after stroke, the grafts were deposited into four sites, along the rostro-caudal axis and medially to the stroke in the penumbra zone. Control groups included vehicle and fibroblast transplants. Animals were subjected to motor behavioral tests at 4 week posttransplant survival time. Morphological analysis demonstrated that the grafted MGE cells differentiated into multiple neuronal subtypes, established synaptic contact with host cells, increased the expression of synaptic markers, and enhanced axonal reorganization in the injured area. Initial patch-clamp recording demonstrated that the MGE cells received postsynaptic currents from host cells. Behavioral analysis showed reduced motor deficits in the rotarod and elevated body swing tests. These findings suggest that graft-host interactions influence the fate of grafted neural precursors and that functional recovery could be mediated by neurotrophic support, new synaptic circuit elaboration, and enhancement of the stroke-induced neuroplasticity.

Intrinsic physiological properties of rat retinal ganglion cells with a comparative analysis.

PubMed

Wong, Raymond C S; Cloherty, Shaun L; Ibbotson, Michael R; O'Brien, Brendan J

2012-10-01

Mammalian retina contains 15-20 different retinal ganglion cell (RGC) types, each of which is responsible for encoding different aspects of the visual scene. The encoding is defined by a combination of RGC synaptic inputs, the neurotransmitter systems used, and their intrinsic physiological properties. Each cell's intrinsic properties are defined by its morphology and membrane characteristics, including the complement and localization of the ion channels expressed. In this study, we examined the hypothesis that the intrinsic properties of individual RGC types are conserved among mammalian species. To do so, we measured the intrinsic properties of 16 morphologically defined rat RGC types and compared these data with cat RGC types. Our data demonstrate that in the rat different morphologically defined RGC types have distinct patterns of intrinsic properties. Variation in these properties across cell types was comparable to that found for cat RGC types. When presumed morphological homologs in rat and cat retina were compared directly, some RGC types had very similar properties. The rat A2 cell exhibited patterns of intrinsic properties nearly identical to the cat alpha cell. In contrast, rat D2 cells (ON-OFF directionally selective) had a very different pattern of intrinsic properties than the cat iota cell. Our data suggest that the intrinsic properties of RGCs with similar morphology and suspected visual function may be subject to variation due to the behavioral needs of the species.

Synaptic potentials recorded by the sucrosegap method from the rabbit superior cervical ganglion

PubMed Central

Kosterlitz, H. W.; Lees, G. M.; Wallis, D. I.

1970-01-01

1. Compound ganglionic potentials evoked by stimulation of the preganglionic nerves to the superior cervical ganglion of the rabbit were recorded by the sucrose-gap method. 2. When the distal part of the ganglion was bathed in flowing isotonic sucrose solution or sodium-deficient solutions, ganglionic action potentials were no longer evoked, only large synaptic potentials. 3. The compound synaptic potential, which remained unaltered for more than 1 h, originated in a population of cells at the interface between the Krebs and sucrose solutions. Hexamethonium reduced the size but did not alter the time course of the synaptic potential. 4. It is suggested that a higher concentration of sodium ions is required for the generation of ganglionic action potentials than for either conduction in the postganglionic axons or production of synaptic potentials. 5. When lithium replaced sodium in the solution bathing the distal part of the ganglion, the synaptic potential was greatly reduced in amplitude. Impulse propagation in the postganglionic axons was only slightly impaired when lithium replaced sodium in the solution bathing the axons. 6. A quantitative assessment of the potency of the ganglion-blocking drugs nicotine, pentolinium, hexamethonium and pempidine was made by measuring the depression of the synaptic potentials produced by bathing the distal part of the ganglion in flowing isotonic sucrose solution. The concentrations which produced a 50% depression were 8·1 μM nicotine, 26·5 μM pentolinium, 111 μM hexamethonium and 22·2 μM pempidine. PMID:5492898

The spiral ganglion: connecting the peripheral and central auditory systems

PubMed Central

Nayagam, Bryony A; Muniak, Michael A; Ryugo, David K

2011-01-01

In mammals, the initial bridge between the physical world of sound and perception of that sound is established by neurons of the spiral ganglion. The cell bodies of these neurons give rise to peripheral processes that contact acoustic receptors in the organ of Corti, and the central processes collect together to form the auditory nerve that projects into the brain. In order to better understand hearing at this initial stage, we need to know the following about spiral ganglion neurons: (1) their cell biology including cytoplasmic, cytoskeletal, and membrane properties, (2) their peripheral and central connections including synaptic structure; (3) the nature of their neural signaling; and (4) their capacity for plasticity and rehabilitation. In this report, we will update the progress on these topics and indicate important issues still awaiting resolution. PMID:21530629

Chandipura virus growth kinetics in vertebrate cell lines, insect cell lines & embryonated eggs.

PubMed

Jadi, R S; Sudeep, A B; Kumar, Satyendra; Arankalle, V A; Mishra, A C

2010-08-01

Since not much information on Chandipura virus is available, an attempt was made to study the growth kinetics of the virus in certain vertebrate, invertebrate cell lines and embryonated chicken eggs. Comparative study of Chandipura virus (CHPV) growth kinetics in three vertebrate cell lines [Vero E6, Rhabdo myosarcoma (RD), Porcine stable kidney (PS) cell lines], two insect cell lines [Aedes aegypti (AA) and Phlebotomus papatasi (PP-9) cell lines] and embryonated pathogen free chicken eggs was conducted, by tissue culture infective dose 50 per cent (TCID(50)) and indirect immunofluorescence assay (IFA). All the cell lines and embryonated egg supported the growth of CHPV and yielded high virus titre. The vertebrate cell lines showed distinct cytopathic effect (CPE) within 4-6 h post infection (PI), while no CPE was observed in insect cell lines. PP-9 cell line was the most sensitive system to CHPV as viral antigen could be detected at 1 h PI by IFA. Our results demonstrated that all the systems were susceptible to CHPV and achieved high yield of virus. However, the PP-9 cell line had an edge over the others due to its high sensitivity to the virus which might be useful for detection and isolation of the virus during epidemics.

Transplantation of Human Neural Progenitor Cells Expressing IGF-1 Enhances Retinal Ganglion Cell Survival

PubMed Central

Guo, Caiwei; Sun, Yu; Liao, Tiffany; Beattie, Ursula; López, Francisco J.; Chen, Dong Feng; Lashkari, Kameran

2015-01-01

We have previously characterized human neuronal progenitor cells (hNP) that can adopt a retinal ganglion cell (RGC)-like morphology within the RGC and nerve fiber layers of the retina. In an effort to determine whether hNPs could be used a candidate cells for targeted delivery of neurotrophic factors (NTFs), we evaluated whether hNPs transfected with an vector that expresses IGF-1 in the form of a fusion protein with tdTomato (TD), would increase RGC survival in vitro and confer neuroprotective effects in a mouse model of glaucoma. RGCs co-cultured with hNPIGF-TD cells displayed enhanced survival, and increased neurite extension and branching as compared to hNPTD or untransfected hNP cells. Application of various IGF-1 signaling blockers or IGF-1 receptor antagonists abrogated these effects. In vivo, using a model of glaucoma we showed that IOP elevation led to reductions in retinal RGC count. In this model, evaluation of retinal flatmounts and optic nerve cross sections indicated that only hNPIGF-TD cells effectively reduced RGC death and showed a trend to improve optic nerve axonal loss. RT-PCR analysis of retina lysates over time showed that the neurotrophic effects of IGF-1 were also attributed to down-regulation of inflammatory and to some extent, angiogenic pathways. This study shows that neuronal progenitor cells that hone into the RGC and nerve fiber layers may be used as vehicles for local production and delivery of a desired NTF. Transplantation of hNPIGF-TD cells improves RGC survival in vitro and protects against RGC loss in a rodent model of glaucoma. Our findings have provided experimental evidence and form the basis for applying cell-based strategies for local delivery of NTFs into the retina. Application of cell-based delivery may be extended to other disease conditions beyond glaucoma. PMID:25923430

Y-cell receptive field and collicular projection of parasol ganglion cells in macaque monkey retina

PubMed Central

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

2009-01-01

The distinctive parasol ganglion cell of the primate retina transmits a transient, spectrally non-opponent signal to the magnocellular layers of the lateral geniculate nucleus (LGN). Parasol cells show well-recognized parallels with the alpha-Y cell of other mammals, yet two key alpha-Y cell properties, a collateral projection to the superior colliculus and nonlinear spatial summation, have not been clearly established for parasol cells. Here we show by retrograde photodynamic staining that parasol cells project to the superior colliculus. Photostained dendritic trees formed characteristic spatial mosaics and afforded unequivocal identification of the parasol cells among diverse collicular-projecting cell types. Loose-patch recordings were used to demonstrate for all parasol cells a distinct Y-cell receptive field ‘signature’ marked by a non-linear mechanism that responded to contrast-reversing gratings at twice the stimulus temporal frequency (second Fourier harmonic, F2) independent of stimulus spatial phase. The F2 component showed high contrast gain and temporal sensitivity and appeared to originate from a region coextensive with that of the linear receptive field center. The F2 spatial frequency response peaked well beyond the resolution limit of the linear receptive field center, showing a Gaussian center radius of ~15 μm. Blocking inner retinal inhibition elevated the F2 response, suggesting that amacrine circuitry does not generate this non-linearity. Our data are consistent with a pooled-subunit model of the parasol-Y cell receptive field in which summation from an array of transient, partially rectifying cone bipolar cells accounts for both linear and non-linear components of the receptive field. PMID:18971470

Macular Ganglion Cell Imaging Study: Covariate Effects on the Spectral Domain Optical Coherence Tomography for Glaucoma Diagnosis

PubMed Central

Jeong, Jae Hoon; Choi, Yun Jeong; Park, Ki Ho; Kim, Dong Myung

2016-01-01

Purpose To evaluate the effect of multiple covariates on the diagnostic performance of the Cirrus high-definition optical coherence tomography (HD-OCT) for glaucoma detection. Methods A prospective case-control study was performed and included 173 recently diagnosed glaucoma patients and 63 unaffected individuals from the Macular Ganglion Cell Imaging Study. Regression analysis of receiver operating characteristic were conducted to evaluate the influence of age, spherical equivalent, axial length, optic disc size, and visual field index on the macular ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) measurements. Results Disease severity, as measured by visual field index, had a significant effect on the diagnostic performance of all Cirrus HD-OCT parameters. Age, axial length and optic disc size were significantly associated with diagnostic accuracy of average peripapillary RNFL thickness, whereas axial length had a significant effect on the diagnostic accuracy of average GCIPL thickness. Conclusions Diagnostic performance of the Cirrus HD-OCT may be more accurate in the advanced stages of glaucoma than at earlier stages. A smaller optic disc size was significantly associated with improved the diagnostic ability of average RNFL thickness measurements; however, GCIPL thickness may be less affected by age and optic disc size. PMID:27490718

CLO: The cell line ontology

PubMed Central

2014-01-01

Background Cell lines have been widely used in biomedical research. The community-based Cell Line Ontology (CLO) is a member of the OBO Foundry library that covers the domain of cell lines. Since its publication two years ago, significant updates have been made, including new groups joining the CLO consortium, new cell line cells, upper level alignment with the Cell Ontology (CL) and the Ontology for Biomedical Investigation, and logical extensions. Construction and content Collaboration among the CLO, CL, and OBI has established consensus definitions of cell line-specific terms such as ‘cell line’, ‘cell line cell’, ‘cell line culturing’, and ‘mortal’ vs. ‘immortal cell line cell’. A cell line is a genetically stable cultured cell population that contains individual cell line cells. The hierarchical structure of the CLO is built based on the hierarchy of the in vivo cell types defined in CL and tissue types (from which cell line cells are derived) defined in the UBERON cross-species anatomy ontology. The new hierarchical structure makes it easier to browse, query, and perform automated classification. We have recently added classes representing more than 2,000 cell line cells from the RIKEN BRC Cell Bank to CLO. Overall, the CLO now contains ~38,000 classes of specific cell line cells derived from over 200 in vivo cell types from various organisms. Utility and discussion The CLO has been applied to different biomedical research studies. Example case studies include annotation and analysis of EBI ArrayExpress data, bioassays, and host-vaccine/pathogen interaction. CLO’s utility goes beyond a catalogue of cell line types. The alignment of the CLO with related ontologies combined with the use of ontological reasoners will support sophisticated inferencing to advance translational informatics development. PMID:25852852

Generation of Functional Human Retinal Ganglion Cells with Target Specificity from Pluripotent Stem Cells by Chemically Defined Recapitulation of Developmental Mechanism.

PubMed

Teotia, Pooja; Chopra, Divyan A; Dravid, Shashank Manohar; Van Hook, Matthew J; Qiu, Fang; Morrison, John; Rizzino, Angie; Ahmad, Iqbal

2017-03-01

Glaucoma is a complex group of diseases wherein a selective degeneration of retinal ganglion cells (RGCs) lead to irreversible loss of vision. A comprehensive approach to glaucomatous RGC degeneration may include stem cells to functionally replace dead neurons through transplantation and understand RGCs vulnerability using a disease in a dish stem cell model. Both approaches require the directed generation of stable, functional, and target-specific RGCs from renewable sources of cells, that is, the embryonic stem cells and induced pluripotent stem cells. Here, we demonstrate a rapid and safe, stage-specific, chemically defined protocol that selectively generates RGCs across species, including human, by recapitulating the developmental mechanism. The de novo generated RGCs from pluripotent cells are similar to native RGCs at the molecular, biochemical, functional levels. They also express axon guidance molecules, and discriminate between specific and nonspecific targets, and are nontumorigenic. Stem Cells 2017;35:572-585. © 2016 AlphaMed Press.

Hypoxia Induces a Metabolic Shift and Enhances the Stemness and Expansion of Cochlear Spiral Ganglion Stem/Progenitor Cells

PubMed Central

Chao, Ting-Ting; Sytwu, Huey-Kang; Li, Shiue-Li; Fang, Mei-Cho; Chen, Hang-Kang; Lin, Yi-Chun; Kuo, Chao-Yin

2015-01-01

Previously, we demonstrated that hypoxia (1% O2) enhances stemness markers and expands the cell numbers of cochlear stem/progenitor cells (SPCs). In this study, we further investigated the long-term effect of hypoxia on stemness and the bioenergetic status of cochlear spiral ganglion SPCs cultured at low oxygen tensions. Spiral ganglion SPCs were obtained from postnatal day 1 CBA/CaJ mouse pups. The measurement of oxygen consumption rate, extracellular acidification rate (ECAR), and intracellular adenosine triphosphate levels corresponding to 20% and 5% oxygen concentrations was determined using a Seahorse XF extracellular flux analyzer. After low oxygen tension cultivation for 21 days, the mean size of the hypoxia-expanded neurospheres was significantly increased at 5% O2; this correlated with high-level expression of hypoxia-inducible factor-1 alpha (Hif-1α), proliferating cell nuclear antigen (PCNA), cyclin D1, Abcg2, nestin, and Nanog proteins but downregulated expression of p27 compared to that in a normoxic condition. Low oxygen tension cultivation tended to increase the side population fraction, with a significant difference found at 5% O2 compared to that at 20% O2. In addition, hypoxia induced a metabolic energy shift of SPCs toward higher basal ECARs and higher maximum mitochondrial respiratory capacity but lower proton leak than under normoxia, where the SPC metabolism was switched toward glycolysis in long-term hypoxic cultivation. PMID:26236724

Ganglion Cyst

MedlinePlus

... with aspiration and injection therapy, there are nevertheless cases in which the ganglion cyst returns. Find an ACFAS Physician Search Search Tools Find an ACFAS Physician: Search by Mail Address ...

The Pattern of Visual Fixation Eccentricity and Instability in Optic Neuropathy and Its Spatial Relationship to Retinal Ganglion Cell Layer Thickness.

PubMed

Mallery, Robert M; Poolman, Pieter; Thurtell, Matthew J; Wang, Jui-Kai; Garvin, Mona K; Ledolter, Johannes; Kardon, Randy H

2016-07-01

The purpose of this study was to assess whether clinically useful measures of fixation instability and eccentricity can be derived from retinal tracking data obtained during optical coherence tomography (OCT) in patients with optic neuropathy (ON) and to develop a method for relating fixation to the retinal ganglion cell complex (GCC) thickness. Twenty-nine patients with ON underwent macular volume OCT with 30 seconds of confocal scanning laser ophthalmoscope (cSLO)-based eye tracking during fixation. Kernel density estimation quantified fixation instability and fixation eccentricity from the distribution of fixation points on the retina. Preferred ganglion cell layer loci (PGCL) and their relationship to the GCC thickness map were derived, accounting for radial displacement of retinal ganglion cell soma from their corresponding cones. Fixation instability was increased in ON eyes (0.21 deg2) compared with normal eyes (0.06982 deg2; P < 0.001), and fixation eccentricity was increased in ON eyes (0.48°) compared with normal eyes (0.24°; P = 0.03). Fixation instability and eccentricity each correlated moderately with logMAR acuity and were highly predictive of central visual field loss. Twenty-six of 35 ON eyes had PGCL skewed toward local maxima of the GCC thickness map. Patients with bilateral dense central scotomas had PGCL in homonymous retinal locations with respect to the fovea. Fixation instability and eccentricity measures obtained during cSLO-OCT assess the function of perifoveal retinal elements and predict central visual field loss in patients with ON. A model relating fixation to the GCC thickness map offers a method to assess the structure-function relationship between fixation and areas of preserved GCC in patients with ON.

Denervation does not alter the number of neuronal bungarotoxin binding sites on autonomic neurons in the frog cardiac ganglion.

PubMed

Sargent, P B; Bryan, G K; Streichert, L C; Garrett, E N

1991-11-01

The binding of neuronal bungarotoxin (n-BuTX; also known as bungarotoxin 3.1, kappa-bungarotoxin, and toxin F) was analyzed in normal and denervated parasympathetic cardiac ganglia of the frog Rana pipiens, n-BuTX blocks both EPSPs and ACh potentials at 5-20 nM, as determined by intracellular recording techniques. Scatchard analysis on homogenates indicates that cardiac ganglia have two classes of binding sites for 125I-n-BuTX: a high-affinity site with an apparent dissociation constant (Kd,app) of 1.7 nM and a Bmax (number of binding sites) of 3.8 fmol/ganglion and a low-affinity site with a Kd,app of 12 microM and a Bmax of 14 pmol/ganglion. alpha-Bungarotoxin does not appear to interfere with the binding of 125I-n-BuTX to either site. The high-affinity binding site is likely to be the functional nicotinic ACh receptor (AChR), given the similarity between its affinity for 125I-n-BuTX and the concentration of n-BuTX required to block AChR function. Light microscopic autoradiographic analysis of 125I-n-BuTX binding to the ganglion cell surface reveals that toxin binding is concentrated at synaptic sites, which were identified using a synaptic vesicle-specific antibody. Scatchard analysis of autoradiographic data reveals that 125I-n-BuTX binding to the neuronal surface is saturable and has a Kd,app similar to that of the high-affinity binding site characterized in homogenates. Surface binding of 125I-n-BuTX is blocked by nicotine, carbachol, and d-tubocurarine (IC50 less than 20 microM), but not by atropine (IC50 greater than 10 mM). Denervation of the heart increases the ACh sensitivity of cardiac ganglion cells but has no effect upon the number of high-affinity binding sites for 125I-n-BuTX in tissue homogenates. Moreover, autoradiographic analysis indicates that denervation does not alter the number of 125I-n-BuTX binding sites on the ganglion cell surface. n-BuTX is as effective in reducing ganglion cell responses to ACh in denervated ganglia as it is in

Changes in intrinsic excitability of ganglion cells in degenerated retinas of RCS rats

PubMed Central

Ren, Yi-Ming; Weng, Chuan-Huang; Zhao, Cong-Jian; Yin, Zheng-Qin

2018-01-01

AIM To evaluate the intrinsic excitability of retinal ganglion cells (RGCs) in degenerated retinas. METHODS The intrinsic excitability of various morphologically defined RGC types using a combination of patch-clamp recording and the Lucifer yellow tracer in retinal whole-mount preparations harvested from Royal College of Surgeons (RCS) rats, a common retinitis pigmentosa (RP) model, in a relatively late stage of retinal degeneration (P90) were investigated. Several parameters of RGC morphologies and action potentials (APs) were measured and compared to those of non-dystrophic control rats, including dendritic stratification, dendritic field diameter, peak amplitude, half width, resting membrane potential, AP threshold, depolarization to threshold, and firing rates. RESULTS Compared with non-dystrophic control RGCs, more depolarizations were required to reach the AP threshold in RCS RGCs with low spontaneous spike rates and in RCS OFF cells (especially A2o cells), and RCS RGCs maintained their dendritic morphologies, resting membrane potentials and capabilities to generate APs. CONCLUSION RGCs are relatively well preserved morphologically and functionally, and some cells are more susceptible to decreased excitability during retinal degeneration. These findings provide valuable considerations for optimizing RP therapeutic strategies. PMID:29862172

Changes in intrinsic excitability of ganglion cells in degenerated retinas of RCS rats.

PubMed

Ren, Yi-Ming; Weng, Chuan-Huang; Zhao, Cong-Jian; Yin, Zheng-Qin

2018-01-01

To evaluate the intrinsic excitability of retinal ganglion cells (RGCs) in degenerated retinas. The intrinsic excitability of various morphologically defined RGC types using a combination of patch-clamp recording and the Lucifer yellow tracer in retinal whole-mount preparations harvested from Royal College of Surgeons (RCS) rats, a common retinitis pigmentosa (RP) model, in a relatively late stage of retinal degeneration (P90) were investigated. Several parameters of RGC morphologies and action potentials (APs) were measured and compared to those of non-dystrophic control rats, including dendritic stratification, dendritic field diameter, peak amplitude, half width, resting membrane potential, AP threshold, depolarization to threshold, and firing rates. Compared with non-dystrophic control RGCs, more depolarizations were required to reach the AP threshold in RCS RGCs with low spontaneous spike rates and in RCS OFF cells (especially A2o cells), and RCS RGCs maintained their dendritic morphologies, resting membrane potentials and capabilities to generate APs. RGCs are relatively well preserved morphologically and functionally, and some cells are more susceptible to decreased excitability during retinal degeneration. These findings provide valuable considerations for optimizing RP therapeutic strategies.

Enkephalin-containing neurons in the inferior mesenteric ganglion projecting to the distal colon of cat: evidence from combined retrograde tracing by fluorescent microspheres and immunohistochemistry.

PubMed

Bagnol, D; Jule, Y; Kirchner, G; Cupo, A; Roman, C

1993-02-01

Retrograde tracing with rhodamine fluorescent microspheres combined with fluorescein immunolabelling of methionine-enkephalin showed the presence of enkephalin-like material in neurons of the inferior mesenteric ganglion (sympathetic prevertebral ganglion) projecting to the distal colon in cat. Two weeks after injecting the microspheres into the wall of the distal colon, the inferior mesenteric ganglion was dissected out and incubated for 24 hours in a colchicine-containing culture medium in order to facilitate the detection of enkephalins in the soma of ganglion neurons. It was observed that retrogradely labelled ganglion cells contained enkephalin-like immunoreactive material. These ganglion cells corresponded to enkephalin-like postganglionic neurons, the terminals of which were located inside the wall of the distal colon. These enkephalin-like neurons were numerous and scattered throughout the ganglion. Sometimes enkephalin-like immunoreactive fibers, probably originating from spinal preganglionic neurons, ran close to immunoreactive and non-immunoreactive retrogradely labelled ganglion cells. This suggests that enkephalin-like immunoreactive fibers may make synaptic connections with enkephalin-like and non-enkephalin-like postganglionic neurons projecting to the distal colon. The present study establishes for the first time the existence of an enkephalin-like postganglionic pathway to the digestive tract originating from a sympathetic prevertebral ganglion. This finding indicates that the enkephalinergic innervation of the cat digestive tract may have at least two possible sources: (i) the sympathetic prevertebral ganglia; and (ii) the enteric nervous ganglia.

Retinal ganglion cell damage in an experimental rodent model of blast-mediated traumatic brain injury.

PubMed

Mohan, Kabhilan; Kecova, Helga; Hernandez-Merino, Elena; Kardon, Randy H; Harper, Matthew M

2013-05-15

To evaluate retina and optic nerve damage following experimental blast injury. Healthy adult mice were exposed to an overpressure blast wave using a custom-built blast chamber. The effects of blast exposure on retina and optic nerve function and structure were evaluated using the pattern electroretinogram (pERG), spectral domain optical coherence tomography (OCT), and the chromatic pupil light reflex. Assessment of the pupil response to light demonstrated decreased maximum pupil constriction diameter in blast-injured mice using red light or blue light stimuli 24 hours after injury compared with baseline in the eye exposed to direct blast injury. A decrease in the pupil light reflex was not observed chronically following blast exposure. We observed a biphasic pERG decrease with the acute injury recovering by 24 hours postblast and the chronic injury appearing at 4 months postblast injury. Furthermore, at 3 months following injury, a significant decrease in the retinal nerve fiber layer was observed using OCT compared with controls. Histologic analysis of the retina and optic nerve revealed punctate regions of reduced cellularity in the ganglion cell layer and damage to optic nerves. Additionally, a significant upregulation of proteins associated with oxidative stress was observed acutely following blast exposure compared with control mice. Our study demonstrates that decrements in retinal ganglion cell responses can be detected after blast injury using noninvasive functional and structural tests. These objective responses may serve as surrogate tests for higher CNS functions following traumatic brain injury that are difficult to quantify.

Retinal Ganglion Cell Damage in an Experimental Rodent Model of Blast-Mediated Traumatic Brain Injury

PubMed Central

Mohan, Kabhilan; Kecova, Helga; Hernandez-Merino, Elena; Kardon, Randy H.; Harper, Matthew M.

2013-01-01

Purpose. To evaluate retina and optic nerve damage following experimental blast injury. Methods. Healthy adult mice were exposed to an overpressure blast wave using a custom-built blast chamber. The effects of blast exposure on retina and optic nerve function and structure were evaluated using the pattern electroretinogram (pERG), spectral domain optical coherence tomography (OCT), and the chromatic pupil light reflex. Results. Assessment of the pupil response to light demonstrated decreased maximum pupil constriction diameter in blast-injured mice using red light or blue light stimuli 24 hours after injury compared with baseline in the eye exposed to direct blast injury. A decrease in the pupil light reflex was not observed chronically following blast exposure. We observed a biphasic pERG decrease with the acute injury recovering by 24 hours postblast and the chronic injury appearing at 4 months postblast injury. Furthermore, at 3 months following injury, a significant decrease in the retinal nerve fiber layer was observed using OCT compared with controls. Histologic analysis of the retina and optic nerve revealed punctate regions of reduced cellularity in the ganglion cell layer and damage to optic nerves. Additionally, a significant upregulation of proteins associated with oxidative stress was observed acutely following blast exposure compared with control mice. Conclusions. Our study demonstrates that decrements in retinal ganglion cell responses can be detected after blast injury using noninvasive functional and structural tests. These objective responses may serve as surrogate tests for higher CNS functions following traumatic brain injury that are difficult to quantify. PMID:23620426

Melanopsin expressing human retinal ganglion cells: Subtypes, distribution, and intraretinal connectivity.

PubMed

Hannibal, Jens; Christiansen, Anders Tolstrup; Heegaard, Steffen; Fahrenkrug, Jan; Kiilgaard, Jens Folke

2017-06-01

Intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin belong to a heterogenic population of RGCs which regulate the circadian clock, masking behavior, melatonin suppression, the pupillary light reflex, and sleep/wake cycles. The different functions seem to be associated to different subtypes of melanopsin cells. In rodents, subtype classification has associated subtypes to function. In primate and human retina such classification has so far, not been applied. In the present study using antibodies against N- and C-terminal parts of human melanopsin, confocal microscopy and 3D reconstruction of melanopsin immunoreactive (-ir) RGCs, we applied the criteria used in mouse on human melanopsin-ir RGCs. We identified M1, displaced M1, M2, and M4 cells. We found two other subtypes of melanopsin-ir RGCs, which were named "gigantic M1 (GM1)" and "gigantic displaced M1 (GDM1)." Few M3 cells and no M5 subtypes were labeled. Total cell counts from one male and one female retina revealed that the human retina contains 7283 ± 237 melanopsin-ir (0.63-0.75% of the total number of RGCs). The melanopsin subtypes were unevenly distributed. Most significant was the highest density of M4 cells in the nasal retina. We identified input to the melanopsin-ir RGCs from AII amacrine cells and directly from rod bipolar cells via ribbon synapses in the innermost ON layer of the inner plexiform layer (IPL) and from dopaminergic amacrine cells and GABAergic processes in the outermost OFF layer of the IPL. The study characterizes a heterogenic population of human melanopsin-ir RGCs, which most likely are involved in different functions. © 2017 Wiley Periodicals, Inc.

No dramatic age-related loss of hair cells and spiral ganglion neurons in Bcl-2 over-expression mice or Bax null mice

PubMed Central

2010-01-01

Age-related decline of neuronal function is associated with age-related structural changes. In the central nervous system, age-related decline of cognitive performance is thought to be caused by synaptic loss instead of neuronal loss. However, in the cochlea, age-related loss of hair cells and spiral ganglion neurons (SGNs) is consistently observed in a variety of species, including humans. Since age-related loss of these cells is a major contributing factor to presbycusis, it is important to study possible molecular mechanisms underlying this age-related cell death. Previous studies suggested that apoptotic pathways were involved in age-related loss of hair cells and SGNs. In the present study, we examined the role of Bcl-2 gene in age-related hearing loss. In one transgenic mouse line over-expressing human Bcl-2, there were no significant differences between transgenic mice and wild type littermate controls in their hearing thresholds during aging. Histological analysis of the hair cells and SGNs showed no significant conservation of these cells in transgenic animals compared to the wild type controls during aging. These data suggest that Bcl-2 overexpression has no significant effect on age-related loss of hair cells and SGNs. We also found no delay of age-related hearing loss in mice lacking Bax gene. These findings suggest that age-related hearing loss is not through an apoptotic pathway involving key members of Bcl-2 family. PMID:20637089

Asymmetry between ON and OFF α ganglion cells of mouse retina: integration of signal and noise from synaptic inputs.

PubMed

Freed, Michael A

2017-11-15

Bipolar and amacrine cells presynaptic to the ON sustained α cell of mouse retina provide currents with a higher signal-to-noise power ratio (SNR) than those presynaptic to the OFF sustained α cell. Yet the ON cell loses proportionately more SNR from synaptic inputs to spike output than the OFF cell does. The higher SNR of ON bipolar cells at the beginning of the ON pathway compensates for losses incurred by the ON ganglion cell, and improves the processing of positive contrasts. ON and OFF pathways in the retina include functional pairs of neurons that, at first glance, appear to have symmetrically similar responses to brightening and darkening, respectively. Upon careful examination, however, functional pairs exhibit asymmetries in receptive field size and response kinetics. Until now, descriptions of how light-adapted retinal circuitry maintains a preponderance of signal over the noise have not distinguished between ON and OFF pathways. Here I present evidence of marked asymmetries between members of a functional pair of sustained α ganglion cells in the mouse retina. The ON cell exhibited a proportionately greater loss of signal-to-noise power ratio (SNR) from its presynaptic arrays to its postsynaptic currents. Thus the ON cell combines signal and noise from its presynaptic arrays of bipolar and amacrine cells less efficiently than the OFF cell does. Yet the inefficiency of the ON cell is compensated by its presynaptic arrays providing a higher SNR than the arrays presynaptic to the OFF cell, apparently to improve visual processing of positive contrasts. Dynamic clamp experiments were performed that introduced synaptic conductances into ON and OFF cells. When the amacrine-modulated conductance was removed, the ON cell's spike train exhibited an increase in SNR. The OFF cell, however, showed the opposite effect of removing amacrine input, which was a decrease in SNR. Thus ON and OFF cells have different modes of synaptic integration with direct effects on

CellLineNavigator: a workbench for cancer cell line analysis

PubMed Central

Krupp, Markus; Itzel, Timo; Maass, Thorsten; Hildebrandt, Andreas; Galle, Peter R.; Teufel, Andreas

2013-01-01

The CellLineNavigator database, freely available at http://www.medicalgenomics.org/celllinenavigator, is a web-based workbench for large scale comparisons of a large collection of diverse cell lines. It aims to support experimental design in the fields of genomics, systems biology and translational biomedical research. Currently, this compendium holds genome wide expression profiles of 317 different cancer cell lines, categorized into 57 different pathological states and 28 individual tissues. To enlarge the scope of CellLineNavigator, the database was furthermore closely linked to commonly used bioinformatics databases and knowledge repositories. To ensure easy data access and search ability, a simple data and an intuitive querying interface were implemented. It allows the user to explore and filter gene expression, focusing on pathological or physiological conditions. For a more complex search, the advanced query interface may be used to query for (i) differentially expressed genes; (ii) pathological or physiological conditions; or (iii) gene names or functional attributes, such as Kyoto Encyclopaedia of Genes and Genomes pathway maps. These queries may also be combined. Finally, CellLineNavigator allows additional advanced analysis of differentially regulated genes by a direct link to the Database for Annotation, Visualization and Integrated Discovery (DAVID) Bioinformatics Resources. PMID:23118487

Spatial consequences of bleaching adaptation in cat retinal ganglion cells.

PubMed Central

Bonds, A B; Enroth-Cugell, C

1981-01-01

1. Experiments were conducted to study the effects of localized bleaching on the centre responses of rod-driven cat retinal ganglion cells. 2. Stimulation as far as 2 degrees from the bleaching site yielded responses which were reduced nearly as much as those generated at the bleaching site. Bleaching in the receptive field middle reduced responsiveness at a site 1 degrees peripheral more than bleaching at that peripheral site itself. 3. The effectiveness of a bleach in reducing centre responsiveness is related to the sensitivity of the region in which the bleach is applied. 4. Response reduction after a 0.2 degree bleach followed the same temporal pattern for concentric test spots of from 0.2 to 1.8 degrees in diameter, implying a substantially uniform spread of adaptation within these bounds. 5. A linear trade-off between fraction of rhodopsin and area bleached over a range of 8:1 yields the same pattern of response reduction, implying that the non-linear nature of bleaching adaptation is a property of the adaptation pool rather than independent photoreceptors. PMID:7320894

The novel cyclophilin D inhibitor compound 19 protects retinal pigment epithelium cells and retinal ganglion cells from UV radiation.

PubMed

Xie, Laiqing; Cheng, Long; Xu, Guoxu; Zhang, Ji; Ji, Xiaoyan; Song, E

2017-06-10

Excessive Ultra violet (UV) radiation induces injuries to retinal pigment epithelium (RPE) cells (RPEs) and retinal ganglion cells (RGCs), causing retinal degeneration. Cyclophilin D (Cyp-D)-dependent mitochondrial permeability transition pore (mPTP) opening mediates UV-induced cell death. In this study, we show that a novel Cyp-D inhibitor compound 19 efficiently protected RPEs and RGCs from UV radiation. Compound 19-mediated cytoprotection requires Cyp-D, as it failed to further protect RPEs/RGCs from UV when Cyp-D was silenced by targeted shRNAs. Compound 19 almost blocked UV-induced p53-Cyp-D mitochondrial association, mPTP opening and subsequent cytochrome C release. Further studies showed that compound 19 inhibited UV-induced reactive oxygen species (ROS) production, lipid peroxidation and DNA damage. Together, compound 19 protects RPEs and RGCs from UV radiation, possibly via silencing Cyp-D-regulated intrinsic mitochondrial death pathway. Compound 19 could a lead compound for treating UV-associated retinal degeneration diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Modeling activity and target-dependent developmental cell death of mouse retinal ganglion cells ex vivo.

PubMed

Voyatzis, Sylvie; Muzerelle, Aude; Gaspar, Patricia; Nicol, Xavier

2012-01-01

Programmed cell death is widespread during the development of the central nervous system and serves multiple purposes including the establishment of neural connections. In the mouse retina a substantial reduction of retinal ganglion cells (RGCs) occurs during the first postnatal week, coinciding with the formation of retinotopic maps in the superior colliculus (SC). We previously established a retino-collicular culture preparation which recapitulates the progressive topographic ordering of RGC projections during early post-natal life. Here, we questioned whether this model could also be suitable to examine the mechanisms underlying developmental cell death of RGCs. Brn3a was used as a marker of the RGCs. A developmental decline in the number of Brn3a-immunolabelled neurons was found in the retinal explant with a timing that paralleled that observed in vivo. In contrast, the density of photoreceptors or of starburst amacrine cells increased, mimicking the evolution of these cell populations in vivo. Blockade of neural activity with tetrodotoxin increased the number of surviving Brn3a-labelled neurons in the retinal explant, as did the increase in target availability when one retinal explant was confronted with 2 or 4 collicular slices. Thus, this ex vivo model reproduces the developmental reduction of RGCs and recapitulates its regulation by neural activity and target availability. It therefore offers a simple way to analyze developmental cell death in this classic system. Using this model, we show that ephrin-A signaling does not participate to the regulation of the Brn3a population size in the retina, indicating that eprhin-A-mediated elimination of exuberant projections does not involve developmental cell death.

Cortical-basal ganglionic degeneration.

PubMed

Riley, D E; Lang, A E; Lewis, A; Resch, L; Ashby, P; Hornykiewicz, O; Black, S

1990-08-01

We report our experience with 15 patients believed to have cortical-basal ganglionic degeneration. The clinical picture is distinctive, comprising features referable to both cortical and basal ganglionic dysfunction. Characteristic manifestations include cortical sensory loss, focal reflex myoclonus, "alien limb" phenomena, apraxia, rigidity and akinesia, a postural-action tremor, limb dystonia, hyperreflexia, and postural instability. The asymmetry of symptoms and signs is often striking. Brain imaging may demonstrate greater abnormalities contralateral to the more affected side. Postmortem studies in 2 patients revealed the characteristic pathologic features of swollen, poorly staining (achromatic) neurons and degeneration of cerebral cortex and substantia nigra. Biochemical analysis of 1 brain showed a severe, diffuse loss of dopamine in the striatum. This condition is more frequent than previously believed, and the diagnosis can be predicted during life on the basis of clinical findings. However, as with other "degenerative" diseases of the nervous system, a definitive diagnosis of cortical-basal ganglionic degeneration requires confirmation by autopsy.

The Pattern of Visual Fixation Eccentricity and Instability in Optic Neuropathy and Its Spatial Relationship to Retinal Ganglion Cell Layer Thickness

PubMed Central

M. Mallery, Robert; Poolman, Pieter; J. Thurtell, Matthew; Wang, Jui-Kai; K. Garvin, Mona; Ledolter, Johannes; Kardon, Randy H.

2016-01-01

Purpose The purpose of this study was to assess whether clinically useful measures of fixation instability and eccentricity can be derived from retinal tracking data obtained during optical coherence tomography (OCT) in patients with optic neuropathy (ON) and to develop a method for relating fixation to the retinal ganglion cell complex (GCC) thickness. Methods Twenty-nine patients with ON underwent macular volume OCT with 30 seconds of confocal scanning laser ophthalmoscope (cSLO)-based eye tracking during fixation. Kernel density estimation quantified fixation instability and fixation eccentricity from the distribution of fixation points on the retina. Preferred ganglion cell layer loci (PGCL) and their relationship to the GCC thickness map were derived, accounting for radial displacement of retinal ganglion cell soma from their corresponding cones. Results Fixation instability was increased in ON eyes (0.21 deg2) compared with normal eyes (0.06982 deg2; P < 0.001), and fixation eccentricity was increased in ON eyes (0.48°) compared with normal eyes (0.24°; P = 0.03). Fixation instability and eccentricity each correlated moderately with logMAR acuity and were highly predictive of central visual field loss. Twenty-six of 35 ON eyes had PGCL skewed toward local maxima of the GCC thickness map. Patients with bilateral dense central scotomas had PGCL in homonymous retinal locations with respect to the fovea. Conclusions Fixation instability and eccentricity measures obtained during cSLO-OCT assess the function of perifoveal retinal elements and predict central visual field loss in patients with ON. A model relating fixation to the GCC thickness map offers a method to assess the structure–function relationship between fixation and areas of preserved GCC in patients with ON. PMID:27409502

Topographic prominence discriminator for the detection of short-latency spikes of retinal ganglion cells

NASA Astrophysics Data System (ADS)

Choi, Myoung-Hwan; Ahn, Jungryul; Park, Dae Jin; Lee, Sang Min; Kim, Kwangsoo; Cho, Dong-il Dan; Senok, Solomon S.; Koo, Kyo-in; Goo, Yong Sook

2017-02-01

Objective. Direct stimulation of retinal ganglion cells in degenerate retinas by implanting epi-retinal prostheses is a recognized strategy for restoration of visual perception in patients with retinitis pigmentosa or age-related macular degeneration. Elucidating the best stimulus-response paradigms in the laboratory using multielectrode arrays (MEA) is complicated by the fact that the short-latency spikes (within 10 ms) elicited by direct retinal ganglion cell (RGC) stimulation are obscured by the stimulus artifact which is generated by the electrical stimulator. Approach. We developed an artifact subtraction algorithm based on topographic prominence discrimination, wherein the duration of prominences within the stimulus artifact is used as a strategy for identifying the artifact for subtraction and clarifying the obfuscated spikes which are then quantified using standard thresholding. Main results. We found that the prominence discrimination based filters perform creditably in simulation conditions by successfully isolating randomly inserted spikes in the presence of simple and even complex residual artifacts. We also show that the algorithm successfully isolated short-latency spikes in an MEA-based recording from degenerate mouse retinas, where the amplitude and frequency characteristics of the stimulus artifact vary according to the distance of the recording electrode from the stimulating electrode. By ROC analysis of false positive and false negative first spike detection rates in a dataset of one hundred and eight RGCs from four retinal patches, we found that the performance of our algorithm is comparable to that of a generally-used artifact subtraction filter algorithm which uses a strategy of local polynomial approximation (SALPA). Significance. We conclude that the application of topographic prominence discrimination is a valid and useful method for subtraction of stimulation artifacts with variable amplitudes and shapes. We propose that our algorithm

Light might directly affect retinal ganglion cell mitochondria to potentially influence function.

PubMed

del Olmo-Aguado, Susana; Manso, Alberto G; Osborne, Neville N

2012-01-01

Visible light (360-760 nm) entering the eye impinges on the many ganglion cell mitochondria in the non-myelinated part of their axons. The same light also disrupts isolated mitochondrial function in vitro and kills cells in culture with the blue light component being particularly lethal whereas red light has little effect. Significantly, a defined light insult only affects the survival of fibroblasts in vitro that contain functional mitochondria supporting the view that mitochondrial photosensitizers are influenced by light. Moreover, a blue light insult to cells in culture causes a change in mitochondrial structure and membrane potential and results in a release of cytochrome c. Blue light also causes an alteration in mitochondria located components of the OXPHOS (oxidative phosphorylation system). Complexes III and IV as well as complex V are significantly upregulated whereas complexes I and II are slightly but significantly up- and downregulated, respectively. Also, blue light causes Dexras1 and reactive oxygen species to be upregulated and for mitochondrial located apoptosis-inducing factor to be activated. A blue light detrimental insult to cells in culture does not involve the activation of caspases but is known to be attenuated by necrostatin-1, typical of a death mechanism named necroptosis. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

Heterogeneous transgene expression in the retinas of the TH-RFP, TH-Cre, TH-BAC-Cre and DAT-Cre mouse lines

PubMed Central

Vuong, Helen E.; de Sevilla Müller, Luis Pérez; Hardi, Claudia N.; McMahon, Douglas G.; Brecha, Nicholas C.

2015-01-01

Transgenic mouse lines are essential tools for understanding the connectivity, physiology and function of neuronal circuits, including those in the retina. This report compares transgene expression in the retina of a tyrosine hydroxylase (TH)-red fluorescent protein (RFP) line with three catecholamine-related Cre recombinase lines [TH-bacterial artificial chromosome (BAC)-, TH-, and dopamine transporter (DAT)-Cre] that were crossed with a ROSA26-tdTomato reporter line. Retinas were evaluated and immunostained with commonly used antibodies including those directed to TH, GABA and glycine to characterize the RFP or tdTomato fluorescent-labeled amacrine cells, and an antibody directed to RNA-binding protein with multiple splicing to identify ganglion cells. In TH-RFP retinas, types 1 and 2 dopamine (DA) amacrine cells were identified by their characteristic cellular morphology and type 1 DA cells by their expression of TH immunoreactivity. In the TH-BAC-, TH-, and DAT-tdTomato retinas, less than 1%, ~6%, and 0%, respectively, of the fluorescent cells were the expected type 1 DA amacrine cells. Instead, in the TH-BAC-tdTomato retinas, fluorescently labeled AII amacrine cells were predominant, with some medium somal diameter ganglion cells. In TH-tdTomato retinas, fluorescence was in multiple neurochemical amacrine cell types, including four types of polyaxonal amacrine cells. In DAT-tdTomato retinas, fluorescence was in GABA immunoreactive amacrine cells, including two types of bistratified and two types of monostratified amacrine cells. Although each of the Cre lines were generated with the intent to specifically label DA cells, our findings show a cellular diversity in Cre expression in the adult retina and indicate the importance of careful characterization of transgene labeling patterns. These mouse lines with their distinctive cellular labeling patterns will be useful tools for future studies of retinal function and visual processing. PMID:26335381

Heterogeneous transgene expression in the retinas of the TH-RFP, TH-Cre, TH-BAC-Cre and DAT-Cre mouse lines.

PubMed

Vuong, H E; Pérez de Sevilla Müller, L; Hardi, C N; McMahon, D G; Brecha, N C

2015-10-29

Transgenic mouse lines are essential tools for understanding the connectivity, physiology and function of neuronal circuits, including those in the retina. This report compares transgene expression in the retina of a tyrosine hydroxylase (TH)-red fluorescent protein (RFP) mouse line with three catecholamine-related Cre recombinase mouse lines [TH-bacterial artificial chromosome (BAC)-, TH-, and dopamine transporter (DAT)-Cre] that were crossed with a ROSA26-tdTomato reporter line. Retinas were evaluated and immunostained with commonly used antibodies including those directed to TH, GABA and glycine to characterize the RFP or tdTomato fluorescent-labeled amacrine cells, and an antibody directed to RNA-binding protein with multiple splicing to identify ganglion cells. In TH-RFP retinas, types 1 and 2 dopamine (DA) amacrine cells were identified by their characteristic cellular morphology and type 1 DA cells by their expression of TH immunoreactivity. In the TH-BAC-, TH-, and DAT-tdTomato retinas, less than 1%, ∼ 6%, and 0%, respectively, of the fluorescent cells were the expected type 1 DA amacrine cells. Instead, in the TH-BAC-tdTomato retinas, fluorescently labeled AII amacrine cells were predominant, with some medium diameter ganglion cells. In TH-tdTomato retinas, fluorescence was in multiple neurochemical amacrine cell types, including four types of polyaxonal amacrine cells. In DAT-tdTomato retinas, fluorescence was in GABA immunoreactive amacrine cells, including two types of bistratified and two types of monostratified amacrine cells. Although each of the Cre lines was generated with the intent to specifically label DA cells, our findings show a cellular diversity in Cre expression in the adult retina and indicate the importance of careful characterization of transgene labeling patterns. These mouse lines with their distinctive cellular labeling patterns will be useful tools for future studies of retinal function and visual processing. Published by Elsevier

Distribution of TRPV1 and TRPV2 in the human stellate ganglion and spinal cord.

PubMed

Kokubun, Souichi; Sato, Tadasu; Ogawa, Chikara; Kudo, Kai; Goto, Koju; Fujii, Yuki; Shimizu, Yoshinaka; Ichikawa, Hiroyuki

2015-03-17

Immunohistochemistry for the transient receptor potential cation channel subfamily V member 1 (TRPV1) and 2 (TRPV2) was performed on the stellate ganglion and spinal cord in human cadavers. In the stellate ganglion, 25.3% and 16.2% of sympathetic neurons contained TRPV1- and TRPV2-immunoreactivity, respectively. The cell size analysis also demonstrated that proportion of TRPV1- or TRPV2-immunoreactive (-IR) neurons among large (>600 μm(2)) sympathetic neurons (TRPV1, 30.7%; TRPV2, 27.0%) was higher than among small (<600 μm(2)) sympathetic neurons (TRPV1, 22.0%; TRPV2, 13.6%). The present study also demonstrated that 10.0% of sympathetic neurons in the stellate ganglion had pericellular TRPV2-IR nerve fibers. Fourteen percent of large neurons and 7.8% of small neurons were surrounded by TRPV2-IR nerve fibers. TRPV2-immunoreactivity was also detected in about 40% of neuronal cell bodies with pericellular TRPV2-IR nerve fibers. In the lateral horn of the human thoracic spinal cord, TRPV2-immunoreactivity was expressed by some neurons and many varicose fibers surrounding TRPV2-immunonegative neurons. TRPV2-IR pericellular fibers in the stellate ganglion may originate from the lateral horn of the spinal cord. There appears to be TRPV1- or TRPV2-IR sympathetic pathway in the human stellate ganglion and spinal cord. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Analysis of renal cancer cell lines from two major resources enables genomics-guided cell line selection

NASA Astrophysics Data System (ADS)

Sinha, Rileen; Winer, Andrew G.; Chevinsky, Michael; Jakubowski, Christopher; Chen, Ying-Bei; Dong, Yiyu; Tickoo, Satish K.; Reuter, Victor E.; Russo, Paul; Coleman, Jonathan A.; Sander, Chris; Hsieh, James J.; Hakimi, A. Ari

2017-05-01

The utility of cancer cell lines is affected by the similarity to endogenous tumour cells. Here we compare genomic data from 65 kidney-derived cell lines from the Cancer Cell Line Encyclopedia and the COSMIC Cell Lines Project to three renal cancer subtypes from The Cancer Genome Atlas: clear cell renal cell carcinoma (ccRCC, also known as kidney renal clear cell carcinoma), papillary (pRCC, also known as kidney papillary) and chromophobe (chRCC, also known as kidney chromophobe) renal cell carcinoma. Clustering copy number alterations shows that most cell lines resemble ccRCC, a few (including some often used as models of ccRCC) resemble pRCC, and none resemble chRCC. Human ccRCC tumours clustering with cell lines display clinical and genomic features of more aggressive disease, suggesting that cell lines best represent aggressive tumours. We stratify mutations and copy number alterations for important kidney cancer genes by the consistency between databases, and classify cell lines into established gene expression-based indolent and aggressive subtypes. Our results could aid investigators in analysing appropriate renal cancer cell lines.

Hyperexcitable neurons and altered non-neuronal cells in the compressed spinal ganglion

PubMed Central

LaMotte, Robert H.; Chao, MA

2009-01-01

The cell body or soma in the dosal root ganglion (DRG) is normally excitable and this excitability can increase and persist after an injury of peripheral sensory neurons. In a rat model of radicular pain, an intraforaminal implantation of a rod that chronically compressed the lumbar DRG (“CCD” model) resulted in neuronal somal hyperexcitability and spontaneous activity that was accompanied by hyperalgesia in the ipsilateral hind paw. By the 5th day after onset of CCD, there was a novel upregulation in neuronal expression of the chemokine, monocyte chemoattractant protein-1 (MCP-1 or CCL2) and also its receptor, CCR2. The neurons developed, in response to topically applied MCP-1, an excitatory response that they normally do not have. CCD also activated non-neuronal cells including, for example, the endothelial cells as evidenced by angiogenesis in the form of an increased number of capillaries in the DRG after 7 days. A working hypothesis is that the CCD induced changes in neurons and non-neuronal cells that may act together to promote the survival of the injured tissue. The release of ligands such as CCL2, in addition to possibly activating nociceptive neurons (maintaining the pain), may also act to preserve injured cells in the face of ischemia and hypoxia, for example, by promoting angiogenesis. Thus, somal hyperexcitability, as often said of inflammation, may represent a double edged sword. PMID:18958366

Why do hair cells and spiral ganglion neurons in the cochlea die during aging?

PubMed Central

Perez, Philip; Bao, Jianxin

2011-01-01

Age-related decline of cochlear function is mainly due to the loss of hair cells and spiral ganglion neurons (SGNs). Recent findings clearly indicate that survival of these two cell types during aging depends on genetic and environmental interactions, and this relationship is seen at the systemic, tissue, cellular, and molecular levels. At cellular and molecular levels, age-related loss of hair cells and SGNs can occur independently, suggesting distinct mechanisms for the death of each during aging. This mechanistic independence is also observed in the loss of medial olivocochlear efferent innervation and outer hair cells during aging, pointing to a universal independent cellular mechanism for age-related neuronal death in the peripheral auditory system. While several molecular signaling pathways are implicated in the age-related loss of hair cells and SGNs, studies with the ability to locally modify gene expression in these cell types are needed to address whether these signaling pathways have direct effects on hair cells and SGNs during aging. Finally, the issue of whether age-related loss of these cells occurs via typical apoptotic pathways requires further examination. As new studies in the field of aging reshape the framework for exploring these underpinnings, understanding of the loss of hair cells and SGNs associated with age and the interventions that can treat and prevent these changes will result in dramatic benefits for an aging population. PMID:22396875

Mechanisms creating transient and sustained photoresponses in mammalian retinal ganglion cells

PubMed Central

Zhao, Xiwu; Jaeckel, Elizabeth R.; Chervenak, Andrew P.

2017-01-01

Retinal neurons use sustained and transient light responses to encode visual stimuli of different frequency ranges, but the underlying mechanisms remain poorly understood. In particular, although earlier studies in retinal ganglion cells (RGCs) proposed seven potential mechanisms, all seven have since been disputed, and it remains unknown whether different RGC types use different mechanisms or how many mechanisms are used by each type. Here, we conduct a comprehensive survey in mice and rats of 12 candidate mechanisms that could conceivably produce tonic rod/cone-driven ON responses in intrinsically photosensitive RGCs (ipRGCs) and transient ON responses in three types of direction-selective RGCs (TRHR+, Hoxd10+ ON, and Hoxd10+ ON-OFF cells). We find that the tonic kinetics of ipRGCs arises from their substantially above-threshold resting potentials, input from sustained ON bipolar cells, absence of amacrine cell inhibition of presynaptic ON bipolar cells, and mGluR7-mediated maintenance of light-evoked glutamatergic input. All three types of direction-selective RGCs receive input from transient ON bipolar cells, and each type uses additional strategies to promote photoresponse transience: presynaptic inhibition and dopaminergic modulation for TRHR+ cells, center/surround antagonism and relatively negative resting potentials for Hoxd10+ ON cells, and presynaptic inhibition for Hoxd10+ ON-OFF cells. We find that the sustained nature of ipRGCs’ rod/cone-driven responses depends neither on melanopsin nor on N-methyl-d-aspartate (NMDA) receptors, whereas the transience of the direction-selective cells’ responses is influenced neither by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptor desensitization nor by glutamate uptake. For all cells, we further rule out spike frequency adaptation and intracellular Ca2+ as determinants of photoresponse kinetics. In conclusion, different RGC types use diverse mechanisms to produce sustained or

Cobalamin C Deficiency Shows a Rapidly Progressing Maculopathy With Severe Photoreceptor and Ganglion Cell Loss.

PubMed

Bonafede, Lucas; Ficicioglu, Can H; Serrano, Leona; Han, Grace; Morgan, Jessica I W; Mills, Monte D; Forbes, Brian J; Davidson, Stefanie L; Binenbaum, Gil; Kaplan, Paige B; Nichols, Charles W; Verloo, Patrick; Leroy, Bart P; Maguire, Albert M; Aleman, Tomas S

2015-12-01

To describe in detail the retinal structure and function of a group of patients with cobalamin C (cblC) disease. Patients (n = 11, age 4 months to 15 years) with cblC disease (9/11, early onset) diagnosed by newborn screening underwent complete ophthalmic examinations, fundus photography, near-infrared reflectance imaging, and spectral-domain optical coherence tomography (SD-OCT). Electroretinograms (ERGs) were performed in a subset of patients. Patients carried homozygous or compound heterozygote mutations in the methylmalonic aciduria and homocystinuria type C (MMACHC) gene. Late-onset patients had a normal exam. All early-onset patients showed a maculopathy; older subjects had a retina-wide degeneration (n = 4; >7 years of age). In general, retinal changes were first observed before 1 year of age and progressed within months to a well-established maculopathy. Pseudocolobomas were documented in three patients. Measurable visual acuities ranged from 20/200 to 20/540. Nystagmus was present in 8/11 patients; 5/6 patients had normal ERGs; 1/6 had reduced rod-mediated responses. Spectral-domain OCT showed macular thinning, with severe ganglion cell layer (GCL) and outer nuclear layer (ONL) loss. Inner retinal thickening was observed in areas of total GCL/ONL loss. A normal lamination pattern in the peripapillary nasal retina was often seen despite severe central and/or retina-wide disease. Patients with early-onset cblC and MMACHC mutations showed an early-onset, unusually fast-progressing maculopathy with severe central ONL and GCL loss. An abnormally thickened inner retina supports a remodeling response to both photoreceptor and ganglion cell degeneration and/or an interference with normal development in early-onset cblC.

Cobalamin C Deficiency Shows a Rapidly Progressing Maculopathy With Severe Photoreceptor and Ganglion Cell Loss

PubMed Central

Bonafede, Lucas; Ficicioglu, Can H.; Serrano, Leona; Han, Grace; Morgan, Jessica I. W.; Mills, Monte D.; Forbes, Brian J.; Davidson, Stefanie L.; Binenbaum, Gil; Kaplan, Paige B.; Nichols, Charles W.; Verloo, Patrick; Leroy, Bart P.; Maguire, Albert M.; Aleman, Tomas S.

2015-01-01

Purpose To describe in detail the retinal structure and function of a group of patients with cobalamin C (cblC) disease. Methods Patients (n = 11, age 4 months to 15 years) with cblC disease (9/11, early onset) diagnosed by newborn screening underwent complete ophthalmic examinations, fundus photography, near-infrared reflectance imaging, and spectral-domain optical coherence tomography (SD-OCT). Electroretinograms (ERGs) were performed in a subset of patients. Results Patients carried homozygous or compound heterozygote mutations in the methylmalonic aciduria and homocystinuria type C (MMACHC) gene. Late-onset patients had a normal exam. All early-onset patients showed a maculopathy; older subjects had a retina-wide degeneration (n = 4; >7 years of age). In general, retinal changes were first observed before 1 year of age and progressed within months to a well-established maculopathy. Pseudocolobomas were documented in three patients. Measurable visual acuities ranged from 20/200 to 20/540. Nystagmus was present in 8/11 patients; 5/6 patients had normal ERGs; 1/6 had reduced rod-mediated responses. Spectral-domain OCT showed macular thinning, with severe ganglion cell layer (GCL) and outer nuclear layer (ONL) loss. Inner retinal thickening was observed in areas of total GCL/ONL loss. A normal lamination pattern in the peripapillary nasal retina was often seen despite severe central and/or retina-wide disease. Conclusions Patients with early-onset cblC and MMACHC mutations showed an early-onset, unusually fast-progressing maculopathy with severe central ONL and GCL loss. An abnormally thickened inner retina supports a remodeling response to both photoreceptor and ganglion cell degeneration and/or an interference with normal development in early-onset cblC. PMID:26658511

Physiological and morphological characterization of ganglion cells in the salamander retina

PubMed Central

Wang, Jing; Jacoby, Roy; Wu, Samuel M.

2016-01-01

Retinal ganglion cells (RGCs) integrate visual information from the retina and transmit collective signals to the brain. A systematic investigation of functional and morphological characteristics of various types of RGCs is important to comprehensively understand how the visual system encodes and transmits information via various RGC pathways. This study evaluated both physiological and morphological properties of 67 RGCs in dark-adapted flat-mounted salamander retina by examining light-evoked cation and chloride current responses via voltage-clamp recordings and visualizing morphology by Lucifer yellow fluorescence with a confocal microscope. Six groups of RGCs were described: asymmetrical ON–OFF RGCs, symmetrical ON RGCs, OFF RGCs, and narrow-, medium- and wide-field ON–OFF RGCs. Dendritic field diameters of RGCs ranged 102–490 µm: narrow field (<200 µm, 31% of RGCs), medium field (200–300 µm, 45%) and wide field (>300 µm, 24%). Dendritic ramification patterns of RGCs agree with the sub-lamina A/B rule. 34% of RGCs were monostratified, 24% bistratified and 42% diffusely stratified. 70% of ON RGCs and OFF RGCs were monostratified. Wide-field RGCs were diffusely stratified. 82% of RGCs generated light-evoked ON–OFF responses, while 11% generated ON responses and 7% OFF responses. Response sensitivity analysis suggested that some RGCs obtained separated rod/cone bipolar cell inputs whereas others obtained mixed bipolar cell inputs. 25% of neurons in the RGC layer were displaced amacrine cells. Although more types may be defined by more refined classification criteria, this report is to incorporate more physiological properties into RGC classification. PMID:26731645

Electrical receptive fields of retinal ganglion cells: Influence of presynaptic neurons

PubMed Central

Apollo, Nicholas V.; Garrett, David J.

2018-01-01

Implantable retinal stimulators activate surviving neurons to restore a sense of vision in people who have lost their photoreceptors through degenerative diseases. Complex spatial and temporal interactions occur in the retina during multi-electrode stimulation. Due to these complexities, most existing implants activate only a few electrodes at a time, limiting the repertoire of available stimulation patterns. Measuring the spatiotemporal interactions between electrodes and retinal cells, and incorporating them into a model may lead to improved stimulation algorithms that exploit the interactions. Here, we present a computational model that accurately predicts both the spatial and temporal nonlinear interactions of multi-electrode stimulation of rat retinal ganglion cells (RGCs). The model was verified using in vitro recordings of ON, OFF, and ON-OFF RGCs in response to subretinal multi-electrode stimulation with biphasic pulses at three stimulation frequencies (10, 20, 30 Hz). The model gives an estimate of each cell’s spatiotemporal electrical receptive fields (ERFs); i.e., the pattern of stimulation leading to excitation or suppression in the neuron. All cells had excitatory ERFs and many also had suppressive sub-regions of their ERFs. We show that the nonlinearities in observed responses arise largely from activation of presynaptic interneurons. When synaptic transmission was blocked, the number of sub-regions of the ERF was reduced, usually to a single excitatory ERF. This suggests that direct cell activation can be modeled accurately by a one-dimensional model with linear interactions between electrodes, whereas indirect stimulation due to summated presynaptic responses is nonlinear. PMID:29432411

Dose-dependent effects of ouabain on spiral ganglion neurons and Schwann cells in mouse cochlea.

PubMed

Zhang, Zhi-Jian; Guan, Hong-Xia; Yang, Kun; Xiao, Bo-Kui; Liao, Hua; Jiang, Yang; Zhou, Tao; Hua, Qing-Quan

2017-10-01

This study aimed in fully investigating the toxicities of ouabain to mouse cochlea and the related cellular environment, and providing an optimal animal model system for cell transplantation in the treatment of auditory neuropathy (AN) and sensorineural hearing loss (SNHL). Different dosages of ouabain were applied to mouse round window. The auditory brainstem responses and distortion product otoacoustic emissions were used to evaluate the cochlear function. The immunohistochemical staining and cochlea surface preparation were performed to detect the spiral ganglion neurons (SGNs), Schwann cells and hair cells. Ouabain at the dosages of 0.5 mM, 1 mM and 3 mM selectively and permanently destroyed SGNs and their functions, while leaving the hair cells relatively intact. Ouabain at 3 mM resulted in the most severe SGNs loss and induced significant loss of Schwann cells started as early as 7 days and with further damages at 14 and 30 days after ouabain exposure. The application of ouabain to mouse round window induces damages of SGNs and Schwann cells in a dose- and time-dependent manner, this study established a reliable and accurate animal model system of AN and SNHL.

Type I intrinsically photosensitive retinal ganglion cells of early post-natal development correspond to the M4 subtype.

PubMed

Sexton, Timothy J; Bleckert, Adam; Turner, Maxwell H; Van Gelder, Russell N

2015-06-21

Intrinsically photosensitive retinal ganglion cells (ipRGCs) mediate circadian light entrainment and the pupillary light response in adult mice. In early development these cells mediate different processes, including negative phototaxis and the timing of retinal vascular development. To determine if ipRGC physiologic properties also change with development, we measured ipRGC cell density and light responses in wild-type mouse retinas at post-natal days 8, 15 and 30. Melanopsin-positive cell density decreases by 17% between post-natal days 8 and 15 and by 25% between days 8 and 30. This decrease is due specifically to a decrease in cells co-labeled with a SMI-32, a marker for alpha-on ganglion cells (corresponding to adult morphologic type M4 ipRGCs). On multi-electrode array recordings, post-natal day 8 (P8) ipRGC light responses show more robust firing, reduced adaptation and more rapid recovery from short and extended light pulses than do the light responses of P15 and P30 ipRGCs. Three ipRGC subtypes - Types I-III - have been defined in early development based on sensitivity and latency on multielectrode array recordings. We find that Type I cells largely account for the unique physiologic properties of P8 ipRGCs. Type I cells have previously been shown to have relatively short latencies and high sensitivity. We now show that Type I cells show have rapid and robust recovery from long and short bright light exposures compared with Type II and III cells, suggesting differential light adaptation mechanisms between cell types. By P15, Type I ipRGCs are no longer detectable. Loose patch recordings of P8 M4 ipRGCs demonstrate Type I physiology. Type I ipRGCs are found only in early development. In addition to their previously described high sensitivity and rapid kinetics, these cells are uniquely resistant to adaptation and recover quickly and fully to short and prolonged light exposure. Type I ipRGCs correspond to the SMI-32 positive, M4 subtype and largely lose

Human amniotic fluid promotes retinal pigmented epithelial cells' trans-differentiation into rod photoreceptors and retinal ganglion cells.

PubMed

Ghaderi, Shima; Soheili, Zahra-Soheila; Ahmadieh, Hamid; Davari, Maliheh; Jahromi, Fatemeh Sanie; Samie, Shahram; Rezaie-Kanavi, Mozhgan; Pakravesh, Jalil; Deezagi, Abdolkhalegh

2011-09-01

To evaluate the effect of human amniotic fluid (HAF) on retinal pigmented epithelial cells growth and trans-differentiation into retinal neurons, retinal pigmented epithelium (RPE) cells were isolated from neonatal human cadaver eye globes and cultured in Dulbecco's modified Eagle's medium-F12 supplemented with 10% fetal bovine serum (FBS). Confluent monolayer cultures were trypsinized and passaged using FBS-containing or HAF-containing media. Amniotic fluid samples were received from pregnant women in the first trimester of gestation. Cell proliferation and death enzyme-linked immunosorbent assays were performed to assess the effect of HAF on RPE cell growth. Trans-differentiation into rod photoreceptors and retinal ganglion cells was also studied using immunocytochemistry and real-time polymerase chain reaction techniques. Primary cultures of RPE cells were successfully established under FBS-containing or HAF-containing media leading to rapid cell growth and proliferation. When RPE cells were moved to in vitro culture system, they began to lose their differentiation markers such as pigmentation and RPE65 marker and trans-differentiated neural-like cells followed by spheroid colonies pertaining to stem/progenitor cells were morphologically detected. Immunocytochemistry (ICC) analysis of HAF-treated cultures showed a considerable expression of Rhodopsin gene (30% Rhodopsin-positive cells) indicating trans-differentiation of RPE cells to rod photoreceptors. Real-time polymerase chain reaction revealed an HAF-dose-dependant expression of Thy-1 gene (RGC marker) and significant promoting effect of HAF on RGCs generation. The data presented here suggest that HAF possesses invaluable stimulatory effect on RPE cells growth and trans-differentiation into retinal neurons. It can be regarded as a newly introduced enriched supplement in serum-free kinds of media used in neuro-retinal regeneration studies.

Imaging of single retinal ganglion cell with differential interference contrast microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Oh, Juyeong; Kim, Yu Jeong; Kim, Chul-Ki; Lee, Taik Jin; Seo, Mina; Lee, Seok; Woo, Deok Ha; Jun, Seong Chan; Park, Ki-Ho; Kim, Seok Hwan; Kim, Jae Hun

2017-02-01

Glaucoma is a progressive optic neuropathy, characterized by the selective loss of retinal ganglion cells (RGCs). Therefore, monitoring the change of number or morphology of RGC is essential for the early detection as well as investigation of pathophysiology of glaucoma. Since RGC layer is transparent and hyporeflective, the direct optical visualization of RGCs has not been successful so far. Therefore, glaucoma evaluation mostly depends on indirect diagnostic methods such as the evaluation of optic disc morphology or retinal nerve fiber layer thickness measurement by optical coherence tomography. We have previously demonstrated single photoreceptor cell imaging with differential interference contrast (DIC) microscopy. Herein, we successfully visualized single RGC using DIC microscopy. Since RGC layer is much less reflective than photoreceptor layer, various techniques including the control of light wavelength and bandwidth using a tunable band pass filter were adopted to reduce the chromatic aberration in z-axis for higher and clearer resolution. To verify that the imaged cells were the RGCs, the flat-mounted retina of Sprague-Dawley rat, in which the RGCs were retrogradely labeled with fluorescence, was observed by both fluorescence and DIC microscopies for direct comparison. We have confirmed that the cell images obtained by fluorescence microscopy were perfectly matched with cell images by DIC microscopy. As conclusion, we have visualized single RGC with DIC microscopy, and confirmed with fluorescence microscopy.

Cell lines authentication and mycoplasma detection as minimun quality control of cell lines in biobanking.

PubMed

Corral-Vázquez, C; Aguilar-Quesada, R; Catalina, P; Lucena-Aguilar, G; Ligero, G; Miranda, B; Carrillo-Ávila, J A

2017-06-01

Establishment of continuous cell lines from human normal and tumor tissues is an extended and useful methodology for molecular characterization of cancer pathophysiology and drug development in research laboratories. The exchange of these cell lines between different labs is a common practice that can compromise assays reliability due to contamination with microorganism such as mycoplasma or cells from different flasks that compromise experiment reproducibility and reliability. Great proportions of cell lines are contaminated with mycoplasma and/or are replaced by cells derived for a different origin during processing or distribution process. The scientific community has underestimated this problem and thousand of research experiment has been done with cell lines that are incorrectly identified and wrong scientific conclusions have been published. Regular contamination and authentication tests are necessary in order to avoid negative consequences of widespread misidentified and contaminated cell lines. Cell banks generate, store and distribute cell lines for research, being mandatory a consistent and continuous quality program. Methods implementation for guaranteeing both, the absence of mycoplasma and authentication in the supplied cell lines, has been performed in the Andalusian Health System Biobank. Specifically, precise results were obtained using real time PCR detection for mycoplasma and 10 STRs identification by capillary electrophoresis for cell line authentication. Advantages and disadvantages of these protocols are discussed.

Complex distribution patterns of voltage-gated calcium channel α-subunits in the spiral ganglion

PubMed Central

Chen, Wei Chun; Xue, Hui Zhong; Hsu, Yun (Lucy); Liu, Qing; Patel, Shail; Davis, Robin L.

2011-01-01

As with other elements of the peripheral auditory system, spiral ganglion neurons display specializations that vary as a function of location along the tonotopic axis. Previous work has shown that voltage-gated K+ channels and synaptic proteins show graded changes in their density that confers rapid responsiveness to neurons in the high frequency, basal region of the cochlea and slower, more maintained responsiveness to neurons in the low frequency, apical region of the cochlea. In order to understand how voltage-gated calcium channels (VGCCs) may contribute to these diverse phenotypes, we identified the VGCC α-subunits expressed in the ganglion, investigated aspects of Ca2+-dependent neuronal firing patterns, and mapped the intracellular and intercellular distributions of seven VGCC α-subunits in the spiral ganglion in vitro. Initial experiments with qRT-PCR showed that eight of the ten known VGCC α-subunits were expressed in the ganglion and electrophysiological analysis revealed firing patterns that were consistent with the presence of both LVA and HVA Ca2+ channels. Moreover, we were able to study seven of the α-subunits with immunocytochemistry, and we found that all were present in spiral ganglion neurons, and that three of them were neuron-specific (CaV1.3, CaV2.2, and CaV3.3). Further characterization of neuron-specific α-subunits showed that CaV1.3 and CaV3.3 were tonotopically-distributed, whereas CaV2.2 was uniformly distributed in apical and basal neurons. Multiple VGCC α-subunits were also immunolocalized to Schwann cells, having distinct intracellular localizations, and, significantly, appearing to distinguish putative compact0 (CaV2.3, CaV3.1) from loose (CaV1.2) myelin. Electrophysiological evaluation of spiral ganglion neurons in the presence of TEA revealed Ca2+ plateau potentials with slopes that varied proportionately with the cochlear region from which neurons were isolated. Because afterhyperpolarizations were minimal or absent under

Amyloid-beta mediates the receptor of advanced glycation end product-induced pro-inflammatory response via toll-like receptor 4 signaling pathway in retinal ganglion cell line RGC-5.

PubMed

Lee, Jong-Jer; Wang, Pei-Wen; Yang, I-Hui; Wu, Chia-Lin; Chuang, Jiin-Haur

2015-07-01

Patients with diabetes mellitus have an increased risk of developing Alzheimer's disease. Amyloid-β, a product of amyloid precursor protein, is associated with neuro-inflammation in patients with Alzheimer's diseases. The correlation between amyloid-beta and advanced glycation end products, which accumulate in tissue of diabetic patients, is not clear. The aims of this study were to determine the effect of advanced glycation end product on the expression of amyloid precursor protein/amyloid-beta and associated pro-inflammatory responses in retinal ganglion cell line RGC-5. Treatment with advanced glycation end product produced upregulation of amyloid precursor protein and increased secretion of amyloid-β(1-40). Additionally, amyloid-β(1-40) induced toll-like receptor 4-dependent phosphorylation of tyrosine in myeloid differentiation primary response gene (88). We found that N-[N-(3,5-Difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester, a γ-secretase inhibitor, reduced the secretion of amyloid-β(1-40) and inhibited the advanced glycation end product-induced activation of myeloid differentiation primary response gene (88). Amyloid-β(1-40) induced the activation of NF-κB and the expression of TNFα mRNA. Knockdown of toll-like receptor 4 inhibited the amyloid-β(1-40)-induced phosphorylation of p65 in NF-κB. Additionally, the nuclear translocation of p65 and transcriptions of TNFα were inhibited by siRNA knockdown of receptor of advanced glycation end product or toll-like receptor 4. The advanced glycation end product-induced secretion of VEGF-A was also reduced by knockdown of toll-like receptor 4. Taken together, our data suggested that amyloid-β(1-40) mediates the interaction between receptor of advanced glycation end product and toll-like receptor 4. Inhibition of the toll-like receptor 4 is an effective method for suppressing the amyloid-β(1-40)-induced pro-inflammatory responses in RGC-5 cells. Copyright © 2015 Elsevier Ltd. All rights

Vascular Leiomyoma and Geniculate Ganglion

PubMed Central

Magliulo, Giuseppe; Iannella, Giannicola; Valente, Michele; Greco, Antonio; Appiani, Mario Ciniglio

2013-01-01

Objectives Discussion of a rare case of angioleiomyoma involving the geniculate ganglion and the intratemporal facial nerve segment and its surgical treatment. Design Case report. Setting Presence of an expansive lesion englobing the geniculate ganglion without any lesion to the cerebellopontine angle. Participants A 45-year-old man with a grade III facial paralysis according to the House-Brackmann scale of evaluation. Main Outcomes Measure Surgical pathology, radiologic appearance, histological features, and postoperative facial function. Results Removal of the entire lesion was achieved, preserving the anatomic integrity of the nerve; no nerve graft was necessary. Postoperative histology and immunohistochemical studies revealed features indicative of solid vascular leiomyoma. Conclusion Angioleiomyoma should be considered in the differential diagnosis of geniculate ganglion lesions. Optimal postoperative facial function is possible only by preserving the anatomical and functional integrity of the facial nerve. PMID:23943721

Glaucoma-Diagnostic Ability of Ganglion Cell-Inner Plexiform Layer Thickness Difference Across Temporal Raphe in Highly Myopic Eyes.

PubMed

Kim, Young Kook; Yoo, Byeong Wook; Jeoung, Jin Wook; Kim, Hee Chan; Kim, Hae Jin; Park, Ki Ho

2016-11-01

To evaluate the glaucoma-diagnostic ability of the ganglion cell-inner plexiform layer (GCIPL) thickness difference across the temporal raphe in highly myopic eyes. We consecutively enrolled a total of 195 highly myopic eyes (axial length [AL] >26.5 mm) of 195 subjects: 93 glaucoma patients along with and 102 nonglaucomatous subjects. Cirrus high-definition optical coherence tomography (OCT) was employed to scan all of the subjects' macular and optic discs. Using a MATLAB-based customized program (the GCIPL hemifield test), a positive test result was automatically declared if the following two conditions were met: (1) the horizontal line is detected for longer than one-half of the distance from the temporal inner elliptical annulus to the outer elliptical annulus, and (2) the average GCIPL thickness difference within 10 pixels of the reference line, both above and below, is 5 μm or more. The glaucoma-diagnostic ability was computed using the area under the receiver operating characteristic curve (AUC). Among the glaucomatous eyes, GCIPL hemifield test positivity was shown in 92.5% (86 of 93), significantly higher than that for the nonglaucomatous eyes (4.90%, 5 of 102; P <0.001). The value of AUC for the GCIPL hemifield test was excellent (0.938; sensitivity 92.50%, specificity 95.10%) and was the best compared with those for any of OCT parameters. In highly myopic eyes, determination of the presence or absence of GCIPL thickness difference across the temporal raphe via OCT macula scan can be a useful means of distinguishing the glaucomatous damage.

Role of the immune modulator programmed cell death-1 during development and apoptosis of mouse retinal ganglion cells

PubMed Central

Chen, Ling; Sham, Caroline W.; Chan, Ann M.; Francisco, Loise M.; Wu, Yin; Mareninov, Sergey; Sharpe, Arlene H.; Freeman, Gordon J.; Yang, Xian-Jie; Braun, Jonathan; Gordon, Lynn K.

2011-01-01

PURPOSE Mammalian programmed cell death-1 (PD-1) is a membrane-associated receptor regulating the balance between T cell activation, tolerance and immunopathology, however its role in neurons has not yet been defined. We investigate the hypothesis that PD-1 signaling actively promotes retinal ganglion cell (RGC) death within the developing mouse retina. METHODS Mature retinal cell types expressing PD-1 were identified by immunofluorescence staining of vertical retina sections; developmental expression was localized by immunostaining and quantified by Western analysis. PD-1 involvement in developmental RGC survival was assessed in vitro using retina explants and in vivo using PD-1 knockout mice. PD-1 ligand gene expression was detected by RT-PCR. RESULTS PD-1 is expressed in most adult RGCs, and undergoes dynamic upregulation during the early postnatal window of retinal cell maturation and physiological programmed cell death (PCD). In vitro blockade of PD-1 signaling during this time selectively increases survival of RGCs. Furthermore, PD-1 deficient mice show a selective increase in RGC number in the neonatal retina at the peak of developmental RGC death. Lastly, throughout postnatal retina maturation, we find gene expression of both immune PD-1 ligand genes, PD-L1 and PD-L2. CONCLUSIONS These findings collectively support a novel role for a PD-1-mediated signaling pathway in developmental PCD during postnatal RGC maturation. PMID:19420345

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

PubMed

Hannibal, Jens

2006-01-01

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

Simultaneous recording of mouse retinal ganglion cells during epiretinal or subretinal stimulation

PubMed Central

Sim, S.L.; Szalewski, R.J.; Johnson, L.J.; Akah, L.E.; Shoemaker, L.E.; Thoreson, W.B.; Margalit, E.

2015-01-01

We compared response patterns and electrical receptive fields (ERF) of retinal ganglion cells (RGCs) during epiretinal and subretinal electrical stimulation of isolated mouse retina. Retinas were stimulated with an array of 3200 independently controllable electrodes. Four response patterns were observed: a burst of activity immediately after stimulation (Type I cells, Vision Research (2008), 48, 1562–1568), delayed bursts beginning >25 ms after stimulation (Type II), a combination of both (Type III), and inhibition of ongoing spike activity. Type I responses were produced more often by epiretinal than subretinal stimulation whereas delayed and inhibitory responses were evoked more frequently by subretinal stimulation. Response latencies were significantly shorter with epiretinal than subretinal stimulation. These data suggest that subretinal stimulation is more effective at activating intraretinal circuits than epiretinal stimulation. There was no significant difference in charge threshold between subretinal and epiretinal configurations. ERFs were defined by the stimulating array surface area that successfully stimulated spikes in an RGC. ERFs were complex in shape, similar to receptive fields mapped with light. ERF areas were significantly smaller with subretinal than epiretinal stimulation. This may reflect the greater distance between stimulating electrodes and RGCs in the subretinal configuration. ERFs for immediate and delayed responses mapped within the same Type III cells differed in shape and size, consistent with different sites and mechanisms for generating these two response types. PMID:24863584

Molluscan cells in culture: primary cell cultures and cell lines

PubMed Central

Yoshino, T. P.; Bickham, U.; Bayne, C. J.

2013-01-01

In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as biomonitors for environmental contaminants, as models for gene transfer technologies, and for studies of innate immunity and neoplastic disease. Despite efforts to isolate proliferative cell lines from molluscs, the snail Biomphalaria glabrata Say, 1818 embryonic (Bge) cell line is the only existing cell line originating from any molluscan species. Taking an organ systems approach, this review summarizes efforts to establish molluscan cell cultures and describes the varied applications of primary cell cultures in research. Because of the unique status of the Bge cell line, an account is presented of the establishment of this cell line, and of how these cells have contributed to our understanding of snail host-parasite interactions. Finally, we detail the difficulties commonly encountered in efforts to establish cell lines from molluscs and discuss how these difficulties might be overcome. PMID:24198436

Methane rescues retinal ganglion cells and limits retinal mitochondrial dysfunction following optic nerve crush.

PubMed

Wang, Ruobing; Sun, Qinglei; Xia, Fangzhou; Chen, Zeli; Wu, Jiangchun; Zhang, Yuelu; Xu, Jiajun; Liu, Lin

2017-06-01

Secondary degeneration is a common event in traumatic central nervous system disorders, which involves neuronal apoptosis and mitochondrial dysfunction. Exogenous methane exerts the therapeutic effects in many organ injury. Our study aims to investigate the potential neuroprotection of methane in a rat model of optic nerve crush (ONC). Adult male Sprague-Dawley rats were subjected to ONC and administrated intraperitoneally with methane-saturated or normal saline (10 ml/kg) once per day for one week after ONC. The retinal ganglion cells (RGCs) density was assessed by hematoxylin and eosin staining and Fluoro-Gold retrogradely labeling. Visual function was evaluated by flash visual evoked potentials (FVEP). The retinal apoptosis was measured by terminal-deoxy-transferase-mediated dUTP nick end labeling (TUNEL) assay and the expression of apoptosis-related factors, such as phosphorylated Bcl-2-associated death promoter (pBAD), phosphorylated glycogen synthase kinase-3β (pGSK-3β), Bcl-2 associated X protein (Bax) and Bcl-2 extra large (Bcl-xL). Retinal mitochondrial function was assessed by the mRNA expressions of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), the mitochondrial DNA (mtDNA) copy number, citrate synthase activity and ATP content. Methane treatment significantly improved the RGC loss and visual dysfunction following ONC. As expected, methane also remarkably inhibited the retinal neural apoptosis, such as the fewer TUNEL-positive cells in ganglion cell layer, accompanied by the up-regulations of anti-apoptotic factors (pGSK-3β, pBAD, Bcl-xL) and the down-regulation of pro-apoptotic factor (Bax). Furthermore, methane treatment suppressed up-regulations of critical mitochondrial components (PGC-1α, NRF1 and TFAM) mRNA and mtDNA copy number, as well as improved the reduction of functional mitochondria markers, including citrate synthase

Report on the National Eye Institute Audacious Goals Initiative: Replacement of Retinal Ganglion Cells from Endogenous Cell Sources.

PubMed

Vetter, Monica L; Hitchcock, Peter F

2017-03-01

This report emerges from a workshop convened by the National Eye Institute (NEI) as part of the "Audacious Goals Initiative" (AGI). The workshop addressed the replacement of retinal ganglion cells (RGCs) from exogenous and endogenous sources, and sought to identify the gaps in our knowledge and barriers to progress in devising cellular replacement therapies for diseases where RGCs die. Here, we briefly review relevant literature regarding common diseases associated with RGC death, the genesis of RGCs in vivo, strategies for generating transplantable RGCs in vitro, and potential endogenous cellular sources to regenerate these cells. These topics provided the clinical and scientific context for the discussion among the workshop participants and are relevant to efforts that may lead to therapeutic approaches for replacing RGCs. This report also summarizes the content of the workshop discussion, which focused on: (1) cell sources for RGC replacement and regeneration, (2) optimizing integration, survival, and synaptogenesis of new RGCs, and (3) approaches for assessing the outcomes of RGC replacement therapies. We conclude this report with a summary of recommendations, based on the workshop discussions, which may guide vision scientists seeking to develop therapies for replacing RGCs in humans.

Cell Line Data Base: structure and recent improvements towards molecular authentication of human cell lines

PubMed Central

Romano, Paolo; Manniello, Assunta; Aresu, Ottavia; Armento, Massimiliano; Cesaro, Michela; Parodi, Barbara

2009-01-01

The Cell Line Data Base (CLDB) is a well-known reference information source on human and animal cell lines including information on more than 6000 cell lines. Main biological features are coded according to controlled vocabularies derived from international lists and taxonomies. HyperCLDB (http://bioinformatics.istge.it/hypercldb/) is a hypertext version of CLDB that improves data accessibility by also allowing information retrieval through web spiders. Access to HyperCLDB is provided through indexes of biological characteristics and navigation in the hypertext is granted by many internal links. HyperCLDB also includes links to external resources. Recently, an interest was raised for a reference nomenclature for cell lines and CLDB was seen as an authoritative system. Furthermore, to overcome the cell line misidentification problem, molecular authentication methods, such as fingerprinting, single-locus short tandem repeat (STR) profile and single nucleotide polymorphisms validation, were proposed. Since this data is distributed, a reference portal on authentication of human cell lines is needed. We present here the architecture and contents of CLDB, its recent enhancements and perspectives. We also present a new related database, the Cell Line Integrated Molecular Authentication (CLIMA) database (http://bioinformatics.istge.it/clima/), that allows to link authentication data to actual cell lines. PMID:18927105

Cell Line Data Base: structure and recent improvements towards molecular authentication of human cell lines.

PubMed

Romano, Paolo; Manniello, Assunta; Aresu, Ottavia; Armento, Massimiliano; Cesaro, Michela; Parodi, Barbara

2009-01-01

The Cell Line Data Base (CLDB) is a well-known reference information source on human and animal cell lines including information on more than 6000 cell lines. Main biological features are coded according to controlled vocabularies derived from international lists and taxonomies. HyperCLDB (http://bioinformatics.istge.it/hypercldb/) is a hypertext version of CLDB that improves data accessibility by also allowing information retrieval through web spiders. Access to HyperCLDB is provided through indexes of biological characteristics and navigation in the hypertext is granted by many internal links. HyperCLDB also includes links to external resources. Recently, an interest was raised for a reference nomenclature for cell lines and CLDB was seen as an authoritative system. Furthermore, to overcome the cell line misidentification problem, molecular authentication methods, such as fingerprinting, single-locus short tandem repeat (STR) profile and single nucleotide polymorphisms validation, were proposed. Since this data is distributed, a reference portal on authentication of human cell lines is needed. We present here the architecture and contents of CLDB, its recent enhancements and perspectives. We also present a new related database, the Cell Line Integrated Molecular Authentication (CLIMA) database (http://bioinformatics.istge.it/clima/), that allows to link authentication data to actual cell lines.

Neuronal couplings between retinal ganglion cells inferred by efficient inverse statistical physics methods

PubMed Central

Cocco, Simona; Leibler, Stanislas; Monasson, Rémi

2009-01-01

Complexity of neural systems often makes impracticable explicit measurements of all interactions between their constituents. Inverse statistical physics approaches, which infer effective couplings between neurons from their spiking activity, have been so far hindered by their computational complexity. Here, we present 2 complementary, computationally efficient inverse algorithms based on the Ising and “leaky integrate-and-fire” models. We apply those algorithms to reanalyze multielectrode recordings in the salamander retina in darkness and under random visual stimulus. We find strong positive couplings between nearby ganglion cells common to both stimuli, whereas long-range couplings appear under random stimulus only. The uncertainty on the inferred couplings due to limitations in the recordings (duration, small area covered on the retina) is discussed. Our methods will allow real-time evaluation of couplings for large assemblies of neurons. PMID:19666487

Selective Vulnerability of Specific Retinal Ganglion Cell Types and Synapses after Transient Ocular Hypertension.

PubMed

Ou, Yvonne; Jo, Rebecca E; Ullian, Erik M; Wong, Rachel O L; Della Santina, Luca

2016-08-31

Key issues concerning ganglion cell type-specific loss and synaptic changes in animal models of experimental glaucoma remain highly debated. Importantly, changes in the structure and function of various RGC types that occur early, within 14 d after acute, transient intraocular pressure elevation, have not been previously assessed. Using biolistic transfection of individual RGCs and multielectrode array recordings to measure light responses in mice, we examined the effects of laser-induced ocular hypertension on the structure and function of a subset of RGCs. Among the α-like RGCs studied, αOFF-transient RGCs exhibited higher rates of cell death, with corresponding reductions in dendritic area, dendritic complexity, and synapse density. Functionally, OFF-transient RGCs displayed decreases in spontaneous activity and receptive field size. In contrast, neither αOFF-sustained nor αON-sustained RGCs displayed decreases in light responses, although they did exhibit a decrease in excitatory postsynaptic sites, suggesting that synapse loss may be one of the earliest signs of degeneration. Interestingly, presynaptic ribbon density decreased to a greater degree in the OFF sublamina of the inner plexiform layer, corroborating the hypothesis that RGCs with dendrites stratifying in the OFF sublamina may be damaged early. Indeed, OFF arbors of ON-OFF RGCs lose complexity more rapidly than ON arbors. Our results reveal type-specific differences in RGC responses to injury with a selective vulnerability of αOFF-transient RGCs, and furthermore, an increased susceptibility of synapses in the OFF sublamina. The selective vulnerability of specific RGC types offers new avenues for the design of more sensitive functional tests and targeted neuroprotection. Conflicting reports regarding the selective vulnerability of specific retinal ganglion cell (RGC) types in glaucoma exist. We examine, for the first time, the effects of transient intraocular pressure elevation on the structure

Retinal ganglion cells in the eastern newt Notophthalmus viridescens: topography, morphology, and diversity.

PubMed

Pushchin, Igor I; Karetin, Yuriy A

2009-10-20

The topography and morphology of retinal ganglion cells (RGCs) in the eastern newt were studied. Cells were retrogradely labeled with tetramethylrhodamine-conjugated dextran amines or horseradish peroxidase and examined in retinal wholemounts. Their total number was 18,025 +/- 3,602 (mean +/- SEM). The spatial density of RGCs varied from 2,100 cells/mm(2) in the retinal periphery to 4,500 cells/mm(2) in the dorsotemporal retina. No prominent retinal specializations were found. The spatial resolution estimated from the spatial density of RGCs varied from 1.4 cycles per degree in the periphery to 1.95 cycles per degree in the region of the peak RGC density. A sample of 68 cells was camera lucida drawn and subjected to quantitative analysis. A total of 21 parameters related to RGC morphology and stratification in the retina were estimated. Partitionings obtained by using different clustering algorithms combined with automatic variable weighting and dimensionality reduction techniques were compared, and an effective solution was found by using silhouette analysis. A total of seven clusters were identified and associated with potential cell types. Kruskal-Wallis ANOVA-on-Ranks with post hoc Mann-Whitney U tests showed significant pairwise between-cluster differences in one or more of the clustering variables. The average silhouette values of the clusters were reasonably high, ranging from 0.52 to 0.79. Cells assigned to the same cluster displayed similar morphology and stratification in the retina. The advantages and limitations of the methodology adopted are discussed. The present classification is compared with known morphological and physiological RGC classifications in other salamanders.

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

PubMed

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

2014-05-07

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.

Prickle1 regulates neurite outgrowth of apical spiral ganglion neurons but not hair cell polarity in the murine cochlea

PubMed Central

Kersigo, Jennifer; Wu, Shu; Fritzsch, Bernd; Bassuk, Alexander G.

2017-01-01

In the mammalian organ of Corti (OC), the stereocilia on the apical surface of hair cells (HCs) are uniformly organized in a neural to abneural axis (or medial-laterally). This organization is regulated by planar cell polarity (PCP) signaling. Mutations of PCP genes, such as Vangl2, Dvl1/2, Celsr1, and Fzd3/6, affect the formation of HC orientation to varying degrees. Prickle1 is a PCP signaling gene that belongs to the prickle / espinas / testin family. Prickle1 protein is shown to be asymmetrically localized in the HCs of the OC, and this asymmetric localization is associated with loss of PCP in Smurf mutants, implying that Prickle1 is involved in HC PCP development in the OC. A follow-up study found no PCP polarity defects after loss of Prickle1 (Prickle1-/-) in the cochlea. We show here strong Prickle1 mRNA expression in the spiral ganglion by in situ hybridization and β-Gal staining, and weak expression in the OC by β-Gal staining. Consistent with this limited expression in the OC, cochlear HC PCP is unaffected in either Prickle1C251X/C251X mice or Prickle1f/f; Pax2-cre conditional null mice. Meanwhile, type II afferents of apical spiral ganglion neurons (SGN) innervating outer hair cells (OHC) have unusual neurite growth. In addition, afferents from the apex show unusual collaterals in the cochlear nuclei that overlap with basal turn afferents. Our findings argue against the role of Prickle1 in regulating hair cell polarity in the cochlea. Instead, Prickle1 regulates the polarity-related growth of distal and central processes of apical SGNs. PMID:28837644

Radiation sensitivity of Merkel cell carcinoma cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leonard, J.H.; Ramsay, J.R.; Birrell, G.W.

1995-07-30

Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions. Some of the MCC lines grew as suspension cultures and could not be single cell cloned; therefore, it was not possible to use clonogenic survival for all cell lines. A tetrazolium based (MTT)more » assay was used for these lines, to estimate cell growth after {gamma} irradiation. Control experiments were conducted on lymphoblastoid cell lines (LCL) and the adherent MCC line, MCC13, to demonstrate that the two assays were comparable under the conditions used. We have examined cell lines from MCC, small cell lung cancer (SCLC), malignant melanomas, Epstein Barr virus (EBV) transformed lymphocytes (LCL), and skin fibroblasts for their sensitivity to {gamma} irradiation using both clonogenic cell survival and MTT assays. The results show that the tumor cell lines have a range of sensitivities, with melanoma being more resistant (surviving fraction at 2 Gy (SF2) 0.57 and 0.56) than the small cell carcinoma lines, MCC (SF2 range 0.21-0.45, mean SF2 0.30, n = 8) and SCLC (SF2 0.31). Fibroblasts were the most sensitive (SF2 0.13-0.20, mean 0.16, n = 5). The MTT assay, when compared to clonogenic assay for the MCC13 adherent line and the LCL, gave comparable results under the conditions used. Both assays gave a range of SF2 values for the MCC cell lines, suggesting that these cancers would give a heterogeneous response in vivo. The results with the two derivative clones of MCC14 (SF2 for MCC14/1 0.38, MCC14/2 0.45) would further suggest that some of them may develop resistance during clonogenic evolution. 25 refs., 3 figs., 1 tab.« less

Diagnostic ability of macular ganglion cell inner plexiform layer measurements in glaucoma using swept source and spectral domain optical coherence tomography.

PubMed

Yang, Zhiyong; Tatham, Andrew J; Weinreb, Robert N; Medeiros, Felipe A; Liu, Ting; Zangwill, Linda M

2015-01-01

To evaluate the diagnostic ability of macular ganglion cell and inner plexiform layer measurements in glaucoma, obtained using swept source (SS) and spectral domain (SD) optical coherence tomography (OCT) and to compare to circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements. The study included 106 glaucomatous eyes of 80 subjects and 41 eyes of 22 healthy subjects from the Diagnostic Innovations in Glaucoma Study. Macular ganglion cell and inner plexiform layer (mGCIPL), macular ganglion cell complex (mGCC) and cpRNFL thickness were assessed using SS-OCT and SD-OCT, and area under the receiver operating characteristic curves (AUCs) were calculated to determine ability to differentiate glaucomatous and healthy eyes and between early glaucomatous and healthy eyes. Mean (± standard deviation) mGCIPL and mGCC thickness were thinner in both healthy and glaucomatous eyes using SS-OCT compared to using SD-OCT. Fixed and proportional biases were detected between SS-OCT and SD-OCT measures. Diagnostic accuracy (AUCs) for differentiating between healthy and glaucomatous eyes for average and sectoral mGCIPL was similar in SS-OCT (0.65 to 0.81) and SD-OCT (0.63 to 0.83). AUCs for average cpRNFL acquired using SS-OCT and SD-OCT tended to be higher (0.83 and 0.85, respectively) than for average mGCC (0.82 and 0.78, respectively), and mGCIPL (0.73 and 0.75, respectively) but these differences did not consistently reach statistical significance. Minimum SD-OCT mGCIPL and mGCC thickness (unavailable in SS-OCT) had the highest AUC (0.86) among macular measurements. Assessment of mGCIPL thickness using SS-OCT or SD-OCT is useful for detecting glaucomatous damage, but measurements are not interchangeable for patient management decisions. Diagnostic accuracies of mGCIPL and mGCC from both SS-OCT and SD-OCT were similar to that of cpRNFL for glaucoma detection.

Diagnostic Ability of Macular Ganglion Cell Inner Plexiform Layer Measurements in Glaucoma Using Swept Source and Spectral Domain Optical Coherence Tomography

PubMed Central

Yang, Zhiyong; Tatham, Andrew J.; Weinreb, Robert N.; Medeiros, Felipe A.; Liu, Ting; Zangwill, Linda M.

2015-01-01

Purpose To evaluate the diagnostic ability of macular ganglion cell and inner plexiform layer measurements in glaucoma, obtained using swept source (SS) and spectral domain (SD) optical coherence tomography (OCT) and to compare to circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements. Methods The study included 106 glaucomatous eyes of 80 subjects and 41 eyes of 22 healthy subjects from the Diagnostic Innovations in Glaucoma Study. Macular ganglion cell and inner plexiform layer (mGCIPL), macular ganglion cell complex (mGCC) and cpRNFL thickness were assessed using SS-OCT and SD-OCT, and area under the receiver operating characteristic curves (AUCs) were calculated to determine ability to differentiate glaucomatous and healthy eyes and between early glaucomatous and healthy eyes. Results Mean (± standard deviation) mGCIPL and mGCC thickness were thinner in both healthy and glaucomatous eyes using SS-OCT compared to using SD-OCT. Fixed and proportional biases were detected between SS-OCT and SD-OCT measures. Diagnostic accuracy (AUCs) for differentiating between healthy and glaucomatous eyes for average and sectoral mGCIPL was similar in SS-OCT (0.65 to 0.81) and SD-OCT (0.63 to 0.83). AUCs for average cpRNFL acquired using SS-OCT and SD-OCT tended to be higher (0.83 and 0.85, respectively) than for average mGCC (0.82 and 0.78, respectively), and mGCIPL (0.73 and 0.75, respectively) but these differences did not consistently reach statistical significance. Minimum SD-OCT mGCIPL and mGCC thickness (unavailable in SS-OCT) had the highest AUC (0.86) among macular measurements. Conclusion Assessment of mGCIPL thickness using SS-OCT or SD-OCT is useful for detecting glaucomatous damage, but measurements are not interchangeable for patient management decisions. Diagnostic accuracies of mGCIPL and mGCC from both SS-OCT and SD-OCT were similar to that of cpRNFL for glaucoma detection. PMID:25978420

Mesenchymal stromal cell-mediated neuroprotection and functional preservation of retinal ganglion cells in a rodent model of glaucoma.

PubMed

Mead, Ben; Hill, Lisa J; Blanch, Richard J; Ward, Kelly; Logan, Ann; Berry, Martin; Leadbeater, Wendy; Scheven, Ben A

2016-04-01

Glaucoma is a leading cause of irreversible blindness involving loss of retinal ganglion cells (RGC). Mesenchymal stromal cells (MSC) have shown promise as a paracrine-mediated therapy for compromised neurons. It is, however, unknown whether dental pulp stem cells (DPSC) are effective as a cellular therapy in glaucoma and how their hypothesized influence compares with other more widely researched MSC sources. The present study aimed to compare the efficacy of adipose-derived stem cells, bone marrow-derived MSC (BMSC) and DPSC in preventing the loss of RGC and visual function when transplanted into the vitreous of glaucomatous rodent eyes. Thirty-five days after raised intraocular pressure (IOP) and intravitreal stem cell transplantation, Brn3a(+) RGC numbers, retinal nerve fibre layer thickness (RNFL) and RGC function were evaluated by immunohistochemistry, optical coherence tomography and electroretinography, respectively. Control glaucomatous eyes that were sham-treated with heat-killed DPSC had a significant loss of RGC numbers, RNFL thickness and function compared with intact eyes. BMSC and, to a greater extent, DPSC provided significant protection from RGC loss and RNFL thinning and preserved RGC function. The study supports the use of DPSC as a neuroprotective cellular therapy in retinal degenerative disease such as glaucoma. Copyright © 2016 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

A ganglion-cell-based primary image representation method and its contribution to object recognition

NASA Astrophysics Data System (ADS)

Wei, Hui; Dai, Zhi-Long; Zuo, Qing-Song

2016-10-01

A visual stimulus is represented by the biological visual system at several levels: in the order from low to high levels, they are: photoreceptor cells, ganglion cells (GCs), lateral geniculate nucleus cells and visual cortical neurons. Retinal GCs at the early level need to represent raw data only once, but meet a wide number of diverse requests from different vision-based tasks. This means the information representation at this level is general and not task-specific. Neurobiological findings have attributed this universal adaptation to GCs' receptive field (RF) mechanisms. For the purposes of developing a highly efficient image representation method that can facilitate information processing and interpretation at later stages, here we design a computational model to simulate the GC's non-classical RF. This new image presentation method can extract major structural features from raw data, and is consistent with other statistical measures of the image. Based on the new representation, the performances of other state-of-the-art algorithms in contour detection and segmentation can be upgraded remarkably. This work concludes that applying sophisticated representation schema at early state is an efficient and promising strategy in visual information processing.

Sex-, stress-, and sympathetic post-ganglionic neuron-dependent changes in the expression of pro- and anti-inflammatory mediators in rat dural immune cells

PubMed Central

McIlvried, Lisa A; Borghesi, Lisa A; Gold, Michael S

2015-01-01

Background Migraine attacks are associated with sterile inflammation of the dura. Immune cells are a primary source of inflammatory mediators, and we therefore sought to further explore the link between dural immune cells and migraine. Objective Based on the observations that migraine is more common in women than in men, stress is the most common trigger for a migraine attack, and sympathetic post-ganglionic innervation of the dura enables local control of dural immune cells, we hypothesized that stress shifts the balance of inflammatory mediator expression in dural immune cells toward those that trigger a migraine attack, where these changes are larger in females and dependent, at least in part, on sympathetic post-ganglionic innervation of the dura. Our objective was to test this hypothesis. Methods Dura were obtained from naïve or stressed, intact or surgically sympathectomized, adult male and female rats. Dura were assessed immediately or 24 hrs after termination of four continuous days of unpredictable, mild stressors. Following enzymatic digestion of each dura, myeloid and lymphoid derived dural immune cells were isolated by fluorescence activated cell sorting for semi-quantitative polymerase chain reaction analysis. Results In myeloid derived dural immune cells there was an increase in pro-inflammatory mediator mRNA following stress, particularly in females, which remained elevated with a 24 hr delay after stress. There was a stress-induced decrease in anti-inflammatory mediator mRNA immediately after stress in females, but not males. The stress-induced changes were attenuated in sympathectomized females. In lymphoid derived dural immune cells, there was a persistent increase in pro-inflammatory mediator mRNA following stress, particularly in females. A stress-induced increase in anti-inflammatory mediator mRNA was also observed in both males and females, and was further attenuated in sympathectomized females. Conclusions Consistent with our hypothesis

Parkin overexpression protects retinal ganglion cells against glutamate excitotoxicity.

PubMed

Hu, Xinxin; Dai, Yi; Sun, Xinghuai

2017-01-01

To investigate the role of parkin in regulating mitochondrial homeostasis of retinal ganglion cells (RGCs) under glutamate excitotoxicity. Rat RGCs were purified from dissociated retinal tissue with a modified two-step panning protocol. Cultured RGCs were transfected with parkin using an adenovirus system. The distribution and morphology of mitochondria in the RGCs were assessed with MitoTracker. The expression and distribution of parkin and optineurin proteins were measured with western blot analysis and immunofluorescence. Cytotoxicity of RGCs was evaluated by measuring lactate dehydrogenase (LDH) activity. Mitochondrial membrane potential was determined with the JC-1 assay. The expression of Bax and Bcl-2 were measured with western blot analysis. In the presence of glutamate-induced excitotoxicity, the number of mitochondria in the axons of the RGCs was predominantly increased, and the mitochondrial membrane potential in RGCs was depolarized. The expression of the parkin and optineurin proteins was upregulated and distributed mostly in the axons of the RGCs. Overexpression of parkin stabilized the mitochondrial membrane potential of RGCs, decreased cytotoxicity and apoptosis, attenuated the expression of Bax, and promoted the expression of optineurin under glutamate excitotoxicity. Overexpression of parkin exerted a significant protective effect on cultured RGCs against glutamate excitotoxicity. Interventions to alter the parkin-mediated mitochondria pathway may be useful in protecting RGCs against excitotoxic RGC damage.

Genetically Identified Suppressed-by-Contrast Retinal Ganglion Cells Reliably Signal Self-Generated Visual Stimuli

PubMed Central

Tien, Nai-Wen; Pearson, James T.; Heller, Charles R.; Demas, Jay

2015-01-01

Spike trains of retinal ganglion cells (RGCs) are the sole source of visual information to the brain; and understanding how the ∼20 RGC types in mammalian retinae respond to diverse visual features and events is fundamental to understanding vision. Suppressed-by-contrast (SbC) RGCs stand apart from all other RGC types in that they reduce rather than increase firing rates in response to light increments (ON) and decrements (OFF). Here, we genetically identify and morphologically characterize SbC-RGCs in mice, and target them for patch-clamp recordings under two-photon guidance. We find that strong ON inhibition (glycine > GABA) outweighs weak ON excitation, and that inhibition (glycine > GABA) coincides with decreases in excitation at light OFF. These input patterns explain the suppressive spike responses of SbC-RGCs, which are observed in dim and bright light conditions. Inhibition to SbC-RGC is driven by rectified receptive field subunits, leading us to hypothesize that SbC-RGCs could signal pattern-independent changes in the retinal image. Indeed, we find that shifts of random textures matching saccade-like eye movements in mice elicit robust inhibitory inputs and suppress spiking of SbC-RGCs over a wide range of texture contrasts and spatial frequencies. Similarly, stimuli based on kinematic analyses of mouse blinking consistently suppress SbC-RGC spiking. Receiver operating characteristics show that SbC-RGCs are reliable indicators of self-generated visual stimuli that may contribute to central processing of blinks and saccades. SIGNIFICANCE STATEMENT This study genetically identifies and morphologically characterizes suppressed-by-contrast retinal ganglion cells (SbC-RGCs) in mice. Targeted patch-clamp recordings from SbC-RGCs under two-photon guidance elucidate the synaptic mechanisms mediating spike suppression to contrast steps, and reveal that SbC-RGCs respond reliably to stimuli mimicking saccade-like eye movements and blinks. The similarity of

BHD Tumor Cell Line and Renal Cell Carcinoma Line | NCI Technology Transfer Center | TTC

Cancer.gov

Scientists at the National Cancer Institute  have developed a novel renal cell carcinoma (RCC) cell line designated UOK257, which was derived from the surgical kidney tissue of a patient with hereditary Birt-Hogg-Dube''''(BHD) syndrome and companion cell line UOK257-2 in which FLCN expression has been restored by lentivirus infection. The NCI Urologic Oncology Branch seeks parties interested in licensing or collaborative research to co-develop, evaluate, or commercialize kidney cancer tumor cell lines.

Piriformis ganglion: An uncommon cause of sciatica.

PubMed

Park, J H; Jeong, H J; Shin, H K; Park, S J; Lee, J H; Kim, E

2016-04-01

Sciatica can occur due to a spinal lesion, intrapelvic tumor, diabetic neuropathy, and rarely piriformis syndrome. The causes of piriformis syndrome vary by a space-occupying lesion. A ganglionic cyst can occur in various lesions in the body but seldom around the hip joint. In addition, sciatica due to a ganglionic cyst around the hip joint has been reported in one patient in Korea who underwent surgical treatment. We experienced two cases of sciatica from a piriformis ganglionic cyst and we report the clinical characterics and progress after non-operative treatment by ultrasonography-guided aspiration. The two cases were diagnosed by magnetic resonance imaging and were treated by ultrasonography-guided aspiration. We followed the patients for more than 6months. The symptoms of piriformis syndrome from the ganglion improved following aspiration and this conservative treatment is a treatment method that can be used without extensive incision or cyst excision. Level IV historical case. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Ganglion cell loss in relation to visual disability in multiple sclerosis.

PubMed

Walter, Scott D; Ishikawa, Hiroshi; Galetta, Kristin M; Sakai, Reiko E; Feller, Daniel J; Henderson, Sam B; Wilson, James A; Maguire, Maureen G; Galetta, Steven L; Frohman, Elliot; Calabresi, Peter A; Schuman, Joel S; Balcer, Laura J

2012-06-01

We used high-resolution spectral-domain optical coherence tomography (SD-OCT) with retinal segmentation to determine how ganglion cell loss relates to history of acute optic neuritis (ON), retinal nerve fiber layer (RNFL) thinning, visual function, and vision-related quality of life (QOL) in multiple sclerosis (MS). Cross-sectional study. A convenience sample of patients with MS (n = 122; 239 eyes) and disease-free controls (n = 31; 61 eyes). Among MS eyes, 87 had a history of ON before enrollment. The SD-OCT images were captured using Macular Cube (200×200 or 512×128) and ONH Cube 200×200 protocols. Retinal layer segmentation was performed using algorithms established for glaucoma studies. Thicknesses of the ganglion cell layer/inner plexiform layer (GCL+IPL), RNFL, outer plexiform/inner nuclear layers (OPL+INL), and outer nuclear/photoreceptor layers (ONL+PRL) were measured and compared in MS versus control eyes and MS ON versus non-ON eyes. The relation between changes in macular thickness and visual disability was also examined. The OCT measurements of GCL+IPL and RNFL thickness; high contrast visual acuity (VA); low-contrast letter acuity (LCLA) at 2.5% and 1.25% contrast; on the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and 10-Item Neuro-Ophthalmic Supplement composite score. Macular RNFL and GCL+IPL were significantly decreased in MS versus control eyes (P<0.001 and P = 0.001) and in MS ON versus non-ON eyes (P<0.001 for both measures). Peripapillary RNFL, macular RNFL, GCL+IPL, and the combination of macular RNFL+GCL+IPL were significantly correlated with VA (P≤0.001), 2.5% LCLA (P<0.001), and 1.25% LCLA (P≤0.001). Among OCT measurements, reductions in GCL+IPL (P<0.001), macular RNFL (P = 0.006), and the combination (macular RNFL+GCL+IPL; P<0.001) were most strongly associated with lower (worse) NEI-VFQ-25 and 10-Item Supplement QOL scores; GCL+IPL thinning was significant even accounting for macular RNFL thickness (P

Authentication of M14 melanoma cell line proves misidentification of MDA‐MB‐435 breast cancer cell line

PubMed Central

Korch, Christopher; Hall, Erin M.; Dirks, Wilhelm G.; Ewing, Margaret; Faries, Mark; Varella‐Garcia, Marileila; Robinson, Steven; Storts, Douglas; Turner, Jacqueline A.; Wang, Ying; Burnett, Edward C.; Healy, Lyn; Kniss, Douglas; Neve, Richard M.; Nims, Raymond W.; Reid, Yvonne A.; Robinson, William A.

2017-01-01

A variety of analytical approaches have indicated that melanoma cell line UCLA‐SO‐M14 (M14) and breast carcinoma cell line MDA‐MB‐435 originate from a common donor. This indicates that at some point in the past, one of these cell lines became misidentified, meaning that it ceased to correspond to the reported donor and instead became falsely identified (through cross‐contamination or other means) as a cell line from a different donor. Initial studies concluded that MDA‐MB‐435 was the misidentified cell line and M14 was the authentic cell line, although contradictory evidence has been published, resulting in further confusion. To address this question, we obtained early samples of the melanoma cell line (M14), a lymphoblastoid cell line from the same donor (ML14), and donor serum preserved at the originator's institution. M14 samples were cryopreserved in December 1975, before MDA‐MB‐435 cells were established in culture. Through a series of molecular characterizations, including short tandem repeat (STR) profiling and cytogenetic analysis, we demonstrated that later samples of M14 and MDA‐MB‐435 correspond to samples of M14 frozen in 1975, to the lymphoblastoid cell line ML14, and to the melanoma donor's STR profile, sex and blood type. This work demonstrates conclusively that M14 is the authentic cell line and MDA‐MB‐435 is misidentified. With clear provenance information and authentication testing of early samples, it is possible to resolve debates regarding the origins of problematic cell lines that are widely used in cancer research. PMID:28940260

Effects of delayed treatment with combined GDNF and continuous electrical stimulation on spiral ganglion cell survival in deafened guinea pigs.

PubMed

Scheper, Verena; Paasche, Gerrit; Miller, Josef M; Warnecke, Athanasia; Berkingali, Nurdanat; Lenarz, Thomas; Stöver, Timo

2009-05-01

Electrical stimulation (ES) of spiral ganglion cells (SGC) via a cochlear implant is the standard treatment for profound sensor neural hearing loss. However, loss of hair cells as the morphological correlate of sensor neural hearing loss leads to deafferentation and death of SGC. Although immediate treatment with ES or glial cell line-derived neurotrophic factor (GDNF) can prevent degeneration of SGC, only few studies address the effectiveness of delayed treatment. We hypothesize that both interventions have a synergistic effect and that even delayed treatment would protect SGC. Therefore, an electrode connected to a pump was implanted into the left cochlea of guinea pigs 3 weeks after deafening. The contralateral untreated cochleae served as deafened intraindividual controls. Four groups were set up. Control animals received intracochlear infusion of artificial perilymph (AP/-). The experimental groups consisted of animals treated with AP in addition to continuous ES (AP/ES) or treated with GDNF alone (GDNF/-) or GDNF combined with continuous ES (GDNF/ES). Acoustically and electrically evoked auditory brain stem responses were recorded. All animals were killed 48 days after deafening; their cochleae were histologically evaluated. Survival of SGC increased significantly in the GDNF/- and AP/ES group compared with the AP/- group. A highly significant increase in SGC density was observed in the GDNF/ES group compared with the control group. Additionally, animals in the GDNF/ES group showed reduced EABR thresholds. Thus, delayed treatment with GDNF and ES can protect SGC from degeneration and may improve the benefits of cochlear implants.

Thyroid cell lines in research on goitrogenesis.

PubMed

Gerber, H; Peter, H J; Asmis, L; Studer, H

1991-12-01

Thyroid cell lines have contributed a lot to the understanding of goitrogenesis. The cell lines mostly used in thyroid research are briefly discussed, namely the rat thyroid cell lines FRTL and FRTL-5, the porcine thyroid cell lines PORTHOS and ARTHOS, The sheep thyroid cell lines OVNIS 5H and 6H, the cat thyroid cell lines PETCAT 1 to 4 and ROMCAT, and the human thyroid cell lines FTC-133 and HTh 74. Chinese hamster ovary (CHO) cells and COS-7 cells, stably transfected with TSH receptor cDNA and expressing a functional TSH receptor, are discussed as examples for non-thyroidal cells, transfected with thyroid genes.

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

NASA Astrophysics Data System (ADS)

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.

Edaravone suppresses retinal ganglion cell death in a mouse model of normal tension glaucoma

PubMed Central

Akaiwa, Kei; Namekata, Kazuhiko; Azuchi, Yuriko; Guo, Xiaoli; Kimura, Atsuko; Harada, Chikako; Mitamura, Yoshinori; Harada, Takayuki

2017-01-01

Glaucoma, one of the leading causes of irreversible blindness, is characterized by progressive degeneration of optic nerves and retinal ganglion cells (RGCs). In the mammalian retina, excitatory amino-acid carrier 1 (EAAC1) is expressed in neural cells, including RGCs. Loss of EAAC1 leads to RGC degeneration without elevated intraocular pressure (IOP) and exhibits glaucomatous pathology including glutamate neurotoxicity and oxidative stress. In the present study, we found that edaravone, a free radical scavenger that is used for treatment of acute brain infarction and amyotrophic lateral sclerosis (ALS), reduces oxidative stress and prevents RGC death and thinning of the inner retinal layer in EAAC1-deficient (KO) mice. In addition, in vivo electrophysiological analyses demonstrated that visual impairment in EAAC1 KO mice was ameliorated with edaravone treatment, clearly establishing that edaravone beneficially affects both histological and functional aspects of the glaucomatous retina. Our findings raise intriguing possibilities for the management of glaucoma by utilizing a widely prescribed drug for the treatment of acute brain infarction and ALS, edaravone, in combination with conventional treatments to lower IOP. PMID:28703795

Spontaneous voltage and current fluctuations in tissue cultured mouse dorsal root ganglion cells.

PubMed

Mathers, D A; Barker, J L

1984-02-13

Fetal mouse dorsal root ganglion (DRG) neurons were maintained in primary dissociated cell culture for periods of 7 days to 3 months. Intracellular recordings from these cells revealed the presence of spontaneous subthreshold potentials in 101/177 neurons studied. When measured at the resting membrane potential, these spontaneous voltage events took two forms: (a) high frequency potential fluctuations several millivolts in peak-to-peak amplitude and (b) small, discrete hyperpolarizations. Neurons exhibiting either type of event were designated as 'active' DRG cells. No spontaneous potentials were seen in DRG cells hyperpolarized to membrane voltages more negative than -64 +/- 11.5 mV (n = 5 cells). Under voltage-clamp conditions, the subthreshold potentials of active DRG cells were replaced by fluctuations in outward current. The power spectral density, S(f) of these current fluctuations was approximated by an equation of the form S(f) = (S(o)/[1 + (f/fc) alpha] where 2 less than or equal to a less than or equal to 3 and the half-power frequency fc = 11.3 +/- 3.1 Hz at 23 degrees C (n = 17 cells). The spontaneous voltage fluctuations of active DRG cells were abolished in Ca2+-free saline, and of the divalent metal cations Sr2+, Mg2+, Ba2+, Co2+ and Mn2+, only Sr2+ could substitute for Ca2+ in the maintenance of this activity. Tetraethylammonium ions (1-10 mM) reversibly blocked the spontaneous potentials, while caffeine (10 mM) increased the frequency of these events. The spontaneous voltage fluctuations were not dependent on the presence of spinal cord neurons in the culture plate, and they were also observed in cultured DRG cells derived from adult mice.

A novel model for rapid induction of apoptosis in spiral ganglions of mice.

PubMed

Lee, Ji Eun; Nakagawa, Takayuki; Kim, Tae Soo; Iguchi, Fukuichiro; Endo, Tsuyoshi; Dong, Youyi; Yuki, Kazuo; Naito, Yasushi; Lee, Sang Heun; Ito, Juichi

2003-06-01

The survival of the spiral ganglion (SG) is a critical issue in preservation of hearing. Research on topics related to this issue requires a mouse experimental model because such a model has advantages including use of genetic information and knockout or "knockin" mice. Thus, the aim of the study was to establish a mouse model for induction of apoptosis of SG neurons with a definite time course. Laboratory study using experimental animals. C57BL/6 mice were used as experimental animals and were subjected to direct application of cisplatin into the inner ear. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay and immunostaining for Neurofilament 200-kD (NF) and peripherin were used for analysis of SG degeneration. In addition, generation of peroxynitrite in affected spiral ganglions was examined by immunostaining for nitrotyrosine. Cellular location of activated caspase-9 and cytochrome-c in dying SG neurons were examined for analysis of cell death pathway. The TUNEL assay and immunohistochemical analysis for NF and peripherin indicated that type I neurons in spiral ganglions were deleted through the apoptotic pathway over time. Spiral ganglion neurons treated with cisplatin exhibited expression of nitrotyrosine, indicating induction of peroxynitrite by cisplatin. In dying SG neurons, expression of activated caspase-9 and translocation of cytochrome-c from mitochondria to cytoplasm were observed, indicating the mitochondrial pathway of apoptosis. The predictable fashion of induction of apoptosis in SG neurons over a well-defined time course in the model in the study will aid studies of the molecular mechanism of cell death and elucidation of a strategy for prevention of SG degeneration.

Vesicular glutamate transporters, VGluT1 and VGluT2, in the trigeminal ganglion neurons of the rat, with special reference to coexpression.

PubMed

Li, Jin-Lian; Xiong, Kang-Hui; Dong, Yu-Lin; Fujiyama, Fumino; Kaneko, Takeshi; Mizuno, Noboru

2003-08-18

Vesicular glutamate transporters are responsible for glutamate transport into synaptic vesicles. In the present study, we examined immunohistochemically the expression of vesicular glutamate transporters, VGluT1 and VGluT2, in trigeminal ganglion neurons of the rat. Immunohistochemistry for VGluT1 and VGluT2 indicated that more than 80% of trigeminal ganglion neurons express VGluT1 and/or VGluT2 in their cell bodies. It also indicated that large and small trigeminal ganglion neurons express VGluT2 more frequently than VGluT1. Dual immunofluorescence histochemistry for VGluT1 and VGluT2 indicated that trigeminal ganglion neurons express VGluT2 more frequently than VGluT1 and that more than 80% of VGluT-expressing trigeminal ganglion neurons express VGluT1 and VGluT2. Many axon terminals in the superficial layers of the medullary dorsal horn also showed VGluT1 and VGluT2 immunoreactivities. Some of these axon terminals were confirmed to form the central core of the synaptic glomerulus. These results indicated that VGluT1 and VGluT2 are coexpressed in the cell bodies and axon terminals in most trigeminal ganglion neurons. Copyright 2003 Wiley-Liss, Inc.

Human Periodontal Ligament-Derived Stem Cells Promote Retinal Ganglion Cell Survival and Axon Regeneration After Optic Nerve Injury.

PubMed

Cen, Ling-Ping; Ng, Tsz Kin; Liang, Jia-Jian; Zhuang, Xi; Yao, Xiaowu; Yam, Gary Hin-Fai; Chen, Haoyu; Cheung, Herman S; Zhang, Mingzhi; Pang, Chi Pui

2018-06-01

Optic neuropathies are the leading cause of irreversible blindness and visual impairment in the developed countries, affecting more than 80 million people worldwide. While most optic neuropathies have no effective treatment, there is intensive research on retinal ganglion cell (RGC) protection and axon regeneration. We previously demonstrated potential of human periodontal ligament-derived stem cells (PDLSCs) for retinal cell replacement. Here, we report the neuroprotective effect of human PDLSCs to ameliorate RGC degeneration and promote axonal regeneration after optic nerve crush (ONC) injury. Human PDLSCs were intravitreally injected into the vitreous chamber of adult Fischer rats after ONC in vivo as well as cocultured with retinal explants in vitro. Human PDLSCs survived in the vitreous chamber and were maintained on the RGC layer even at 3 weeks after ONC. Immunofluorescence analysis of βIII-tubulin and Gap43 showed that the numbers of surviving RGCs and regenerating axons were significantly increased in the rats with human PDLSC transplantation. In vitro coculture experiments confirmed that PDLSCs enhanced RGC survival and neurite regeneration in retinal explants without inducing inflammatory responses. Direct cell-cell interaction and elevated brain-derived neurotrophic factor secretion, but not promoting endogenous progenitor cell regeneration, were the RGC protective mechanisms of human PDLSCs. In summary, our results revealed the neuroprotective role of human PDLSCs by strongly promoting RGC survival and axonal regeneration both in vivo and in vitro, indicating a therapeutic potential for RGC protection against optic neuropathies. Stem Cells 2018;36:844-855. © AlphaMed Press 2018.

A morphometric study of the endocytosis of wheat germ agglutinin-horseradish peroxidase conjugates by retinal ganglion cells in the rat.

PubMed

Trojanowski, J Q; Gonatas, N K

1983-08-08

In order to elucidate the sequence for the intraneuronal translocation of ligands after internalization in vivo, the adsorptive endocytosis of horseradish peroxidase (HRP) conjugates of the lectin wheat germ agglutinin (WGHRP) by retinal ganglion cells of the rat was studied by ultrastructural morphometry after intravitreal injections of this probe. Retinas were harvested at post-injection survival times of 15 min to 7 days and processed for the electron microscopic visualization of WGHRP in subcellular organelles. The labeled organelles included vesicles, tubules, lysosomes and the cisterns and coated as well as uncoated vesicles of GERL (Golgi Apparatus-Endoplasmic-Reticulum-Lysosomes). For quantitation, labeled organelles were classed as vesicles, lysosomes and GERL. From 15 min to 3 h the number of labeled GERL and vesicles progressively increased to a maximum at 3 h and then declined to zero by 7 days. In contrast, the number of labeled lysosomes continued to increase beyond 3 h to reach a maximum at 24 h before declining to near zero by 7 days. These results are consistent with the hypothesis that the adsorptive endocytosis of WGHRP entails the passage of the ligand through GERL prior to being deposited in lysosomes. They do not exclude the possibility that other endocytic pathways for WGHRP and possible WGHRP-membrane complexes may exist in retinal ganglion cells including a plasma membrane to lysosome route.

Drug/Cell-line Browser: interactive canvas visualization of cancer drug/cell-line viability assay datasets.

PubMed

Duan, Qiaonan; Wang, Zichen; Fernandez, Nicolas F; Rouillard, Andrew D; Tan, Christopher M; Benes, Cyril H; Ma'ayan, Avi

2014-11-15

Recently, several high profile studies collected cell viability data from panels of cancer cell lines treated with many drugs applied at different concentrations. Such drug sensitivity data for cancer cell lines provide suggestive treatments for different types and subtypes of cancer. Visualization of these datasets can reveal patterns that may not be obvious by examining the data without such efforts. Here we introduce Drug/Cell-line Browser (DCB), an online interactive HTML5 data visualization tool for interacting with three of the recently published datasets of cancer cell lines/drug-viability studies. DCB uses clustering and canvas visualization of the drugs and the cell lines, as well as a bar graph that summarizes drug effectiveness for the tissue of origin or the cancer subtypes for single or multiple drugs. DCB can help in understanding drug response patterns and prioritizing drug/cancer cell line interactions by tissue of origin or cancer subtype. DCB is an open source Web-based tool that is freely available at: http://www.maayanlab.net/LINCS/DCB CONTACT: avi.maayan@mssm.edu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Isolated dorsal root ganglion neurones inhibit receptor-dependent adenylyl cyclase activity in associated glial cells

PubMed Central

Ng, KY; Yeung, BHS; Wong, YH; Wise, H

2013-01-01

Background and Purpose Hyper-nociceptive PGE2 EP4 receptors and prostacyclin (IP) receptors are present in adult rat dorsal root ganglion (DRG) neurones and glial cells in culture. The present study has investigated the cell-specific expression of two other Gs-protein coupled hyper-nociceptive receptor systems: β-adrenoceptors and calcitonin gene-related peptide (CGRP) receptors in isolated DRG cells and has examined the influence of neurone–glial cell interactions in regulating adenylyl cyclase (AC) activity. Experimental Approach Agonist-stimulated AC activity was determined in mixed DRG cell cultures from adult rats and compared with activity in DRG neurone-enriched cell cultures and pure DRG glial cell cultures. Key Results Pharmacological analysis showed the presence of Gs-coupled β2-adrenoceptors and CGRP receptors, but not β1-adrenoceptors, in all three DRG cell preparations. Agonist-stimulated AC activity was weakest in DRG neurone-enriched cell cultures. DRG neurones inhibited IP receptor-stimulated glial cell AC activity by a process dependent on both cell–cell contact and neurone-derived soluble factors, but this is unlikely to involve purine or glutamine receptor activation. Conclusions and Implications Gs-coupled hyper-nociceptive receptors are readily expressed on DRG glial cells in isolated cell cultures and the activity of CGRP, EP4 and IP receptors, but not β2-adrenoceptors, in glial cells is inhibited by DRG neurones. Studies using isolated DRG cells should be aware that hyper-nociceptive ligands may stimulate receptors on glial cells in addition to neurones, and that variable numbers of neurones and glial cells will influence absolute measures of AC activity and affect downstream functional responses. PMID:22924655

Electrophysiological effects of tachykinin analogues on ganglion cell activity in cyprinid fish retina.

PubMed

Downing, J E; Djamgoź, M B

1993-02-01

Electrical spike activity of ganglion cells has been recorded extracellularly in the teleost (roach) retina, and effects of a variety of tachykinins studied at a working concentration of 1 microM. Application of substance P mostly caused a slow and prolonged increase in background activity. In contrast, the response to carbachol was very brisk and short-lasting. Substance P and physalaemin predominantly induced an enhancement of 'On' and 'Off' components of light-evoked responses, whilst eledoisin and neurokinin A were mostly inhibitory. All effects were independent of chromatic and spatial aspects of the responses. Interestingly, in the presence of a tachykinin antagonist, 'Spantide' [D-Arg1,D-Pro2, D-Trp7.9, Leu11]SP, the profile of the effect of substance P reversed, inhibitory actions becoming much more common. Taken together, the results suggest that a tachykinin system utilising two subtypes of the receptor may be active in the roach retina and these may be involved in differential control of visual sensitivity.

History of leukemia-lymphoma cell lines.

PubMed

Drexler, Hans G; Macleod, Roderick A F

2010-08-01

We outline the near 50-year history of leukemia-lymphoma (LL) cell lines - a key model system in biomedicine. Due to the detailed documentation of their oncogenomic and transcriptional alterations via recent advances in molecular medicine, LL cell lines may be fitted to parent tumors with a degree of precision unattainable in other cancers. We have surveyed the corpus of published LL cell lines and found 637 examples that meet minimum standards of authentication and characterization. Alarmingly, the rate of establishment of new LL cell lines has plummeted over the last decade. Although the main hematopoietic developmental cell types are represented by cell lines, some LL categories stubbornly resist establishment in vitro. The advent of engineering techniques for immortalizing primary human cells that maintain differentiation means the time is ripe for renewed search for in vitro models from un(der)represented hematologic entities. Given their manifold applications in biomedicine, there is little doubt that LL-derived cell lines will continue to play a vital part well into the next half-century as well. © 2010 The Authors. Human Cell © 2010 Japan Human Cell Society.

Involvement of P2X7 receptors in retinal ganglion cell apoptosis induced by activated Müller cells.

PubMed

Xue, Bo; Xie, Yuting; Xue, Ying; Hu, Nan; Zhang, Guowei; Guan, Huaijin; Ji, Min

2016-12-01

Müller cell reactivation (gliosis) is an early response in glaucomatous retina. Previous studies have demonstrated that activation of P2X 7 receptors results in retinal ganglion cell (RGC) apoptosis. Here, the issues of whether and how activated Müller cells may contribute to RGC apoptosis through P2X 7 receptors were investigated. Either intravitreal injection of (S)-3,5-dihydroxyphenylglycine (DHPG), a group I metabotropic glutamate receptor (mGluR I) agonist, in normal rat retinas, or DHPG treatment of purified cultured rat retinal Müller cells induced an increase in glial fibrillary acidic protein (GFAP) expression, indicative of Müller cell gliosis. In addition, an increase in adenosine triphosphate (ATP) release from purified cultured Müller cells was detected during DHPG treatment (for 10 min to 48 h), which was mediated by the intracellular mGluR5/Gq/PI-PLC/PKC signaling pathway. Intravitreal injection of DHPG mimicked the reduction in the number of fluorogold retrogradely labeled RGCs in chronic ocular hypertension (COH) rats. Treatment with the conditioned culture medium (CM) obtained from the DHPG-activated Müller cell medium induced an increase in the number of TUNEL-positive cells in cultured RGCs, which was mimicked by benzoylbenzoyl adenosine triphosphate (BzATP), a P2X 7 receptor agonist, but was partially blocked by brilliant blue G (BBG), a P2X 7 receptor antagonist. Moreover, the CM treatment of cultured RGCs significantly increased Bax protein level and decreased Bcl-2 protein level, which was also mimicked by BzATP and partially blocked by BBG, respectively. These results suggest that reactivated Müller cells may release excessive ATP, in turn leading to RGC apoptosis through activating P2X 7 receptors in these cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Retinal ganglion cells survival in a glaucoma model by GDNF/Vit E PLGA microspheres prepared according to a novel microencapsulation procedure.

PubMed

Checa-Casalengua, Patricia; Jiang, Caihui; Bravo-Osuna, Irene; Tucker, Budd A; Molina-Martínez, Irene T; Young, Michael J; Herrero-Vanrell, Rocío

2011-11-30

The present experimental work describes the use of a novel protein encapsulation method to achieve protection of the biological factor during the microencapsulation procedure. With this aim, the protein is included in poly(lactic-co-glycolic acid) (PLGA) microspheres without any preliminary manipulation, in contrast to the traditional S/O/W (solid-in-oil-in-water) method where the bioactive substance is first dissolved and then freeze-dried in the presence of lyoprotectors. Furthermore, the presented technique involves the use of an oily additive, vitamin E (Vit E), useful from a technological point of view, by promoting additional protein protection and also from a pharmacological point of view, because of its antioxidant and antiproliferative properties. Application of this microencapsulation technique has been performed for GDNF (glial cell line-derived neurotrophic factor) designed for the treatment of optic nerve degenerative diseases, such as glaucoma, the second leading cause of blindness in the western world. The protein was released in vitro in its bioactive form for more than three months, demonstrated by the survival of their potential target cells (photoreceptors and retinal ganglion cells (RGC)). Moreover, the intravitreal injection of GDNF/Vit E PLGA microspheres in an experimental animal model of glaucoma significantly increased RGC survival compared with GDNF, Vit E or blank microspheres (p<0.01). This effect was present for at least eleven weeks, which suggests that the formulation prepared may be clinically useful as a neuroprotective tool in the treatment of glaucomatous optic neuropathy. Copyright © 2011 Elsevier B.V. All rights reserved.

Retrograde and Wallerian Axonal Degeneration Occur Synchronously after Retinal Ganglion Cell Axotomy

PubMed Central

Kanamori, Akiyasu; Catrinescu, Maria-Magdalena; Belisle, Jonathan M.; Costantino, Santiago; Levin, Leonard A.

2013-01-01

Axonal injury and degeneration are pivotal pathological events in diseases of the nervous system. In the past decade, it has been recognized that the process of axonal degeneration is distinct from somal degeneration and that axoprotective strategies may be distinct from those that protect the soma. Preserving the cell body via neuroprotection cannot improve function if the axon is damaged, because the soma is still disconnected from its target. Therefore, understanding the mechanisms of axonal degeneration is critical for developing new therapeutic interventions for axonal disease treatment. We combined in vivo imaging with a multilaser confocal scanning laser ophthalmoscope and in vivo axotomy with a diode-pumped solid-state laser to assess the time course of Wallerian and retrograde degeneration of unmyelinated retinal ganglion cell axons in living rats for 4 weeks after intraretinal axotomy. Laser injury resulted in reproducible axon loss both distal and proximal to the site of injury. Longitudinal polarization-sensitive imaging of axons demonstrated that Wallerian and retrograde degeneration occurred synchronously. Neurofilament immunostaining of retinal whole-mounts confirmed axonal loss and demonstrated sparing of adjacent axons to the axotomy site. In vivo fluorescent imaging of axonal transport and photobleaching of labeled axons demonstrated that the laser axotomy model did not affect adjacent axon function. These results are consistent with a shared mechanism for Wallerian and retrograde degeneration. PMID:22642911

Pyroglutamic acid promotes survival of retinal ganglion cells after optic nerve injury.

PubMed

Oono, Shinichirou; Kurimoto, Takuji; Nakazawa, Toru; Miyoshi, Tomomitsu; Okamoto, Norio; Kashimoto, Ryosuke; Tagami, Yuichi; Ito, Yoshimasa; Mimura, Osamu

2009-07-01

To determine whether pyroglutamic acid (PGA) enhances the survival of retinal ganglion cells (RGCs) after optic nerve (ON) transection in vivo and RGCs in culture. The RGCs of rats were retrogradely labeled by Fluorogold (FG)-soaked sponges placed on both superior colliculi. Seven days later, the ON was transected, and PGA was immediately injected into the vitreous. Seven or fourteen days later, the number of FG-labeled RGCs was counted on flat-mounted retinas to obtain the mean densities of FG-labeled RGCs. To determine whether the survival effect of PGA was related to excitatory amino acid transporter (EAAT), L-trans-pyrrolidine-2,4 dicarboxylate (PDC), a nonselective glutamate transport inhibitor, was injected into vitreous with the PGA. In primary retinal cultures, RGCs were identified as cells that were immunopositive to beta III tubulin three days after beginning the culture with and without PDC. The mean density of FG-labeled RGCs was reduced from 2249 +/- 210 to 920 +/- 202 cells/mm(2) (p < 0.001) on day 7 after the ON transection. The mean density RGCs was significantly higher at 1213 +/- 159 cells/mm(2) after 0.5% PGA injection immediately after the ON transaction than eyes injected with the vehicle at 1007 +/- 122 cells/mm(2) (p = 0.035). One percent PGA was the most effective concentration for survival-promoting effects on RGCs, and the mean density of the RGCs was 1464 +/- 102/mm(2) (p < 0.001). Fourteen days after 1% PGA, the mean density of FG-labeled RGCs was significantly higher than that with vehicle (204 +/- 23/mm(2) versus 145 +/- 17 cells/mm(2); p < 0.01). Simultaneous application of 1% PGA and PDC blocked the survival effects of PGA on day 7 after ON transection. The presence of PGA increased the number of beta III tubulin-positive cells. PGA promotes the survival of axotomized RGCs in adult mammalian retinas possibly mediated by the EAATs.

Depicting the pterygopalatine ganglion on 3 Tesla magnetic resonance images.

PubMed

Bratbak, Daniel Fossum; Folvik, Mari; Nordgård, Ståle; Stovner, Lars Jacob; Dodick, David W; Matharu, Manjit; Tronvik, Erling

2018-06-01

The pterygopalatine ganglion has yet not been identified on medical images in living humans. The primary aim of this study was to evaluate whether the pterygopalatine ganglion could be identified on 3 T MR imaging. This study was performed on medical images of 20 Caucasian subjects on both sides (n = 40 ganglia) with an exploratory design. 3 T MR images were assessed by two physicians for the presence and size of the pterygopalatine ganglion. The distance from the pterygopalatine ganglion to four bony landmarks was registered from fused MR and CT images. In an equivalence analysis, the distances were compared to those obtained in an anatomical cadaveric study serving as historical controls (n = 50). A structure assumed to be the pterygopalatine ganglion was identified on MR images in all patients on both sides by both physicians. The mean size was depth 2.1 ± 0.5 mm, width 4.2 ± 1.1 mm and height 5.1 ± 1.4 mm, which is in accordance with formerly published data. Equivalence of the measurements on MR images and the historical controls was established, suggesting that the structure identified on the MR images is the pterygopalatine ganglion. Our findings suggest that the pterygopalatine ganglion can be detected on 3 T MR images. Identification of the pterygopalatine ganglion may be important for image-guided interventions targeting the pterygopalatine ganglion, and has the potential to increase the efficacy, safety and reliability for these treatments.

Laminin γ3 plays an important role in retinal lamination, photoreceptor organisation and ganglion cell differentiation.

PubMed

Dorgau, Birthe; Felemban, Majed; Sharpe, Alexander; Bauer, Roman; Hallam, Dean; Steel, David H; Lindsay, Susan; Mellough, Carla; Lako, Majlinda

2018-05-23

Laminins are heterotrimeric glycoproteins of the extracellular matrix. Eleven different laminin chains have been identified in vertebrates. They are ubiquitously expressed in the human body, with a distinct tissue distribution. Laminin expression in neural retina and their functional role during human retinogenesis is still unknown. This study investigated the laminin expression in human developing and adult retina, showing laminin α1, α5, β1, β2 and γ1 to be predominantly expressed in Bruch's membrane and the inner limiting membrane. Laminin-332 and laminin γ3 expression were mainly observed in the neural retina during retinal histogenesis. These expression patterns were largely conserved in pluripotent stem cell-derived retinal organoids. Blocking of laminin γ3 function in retinal organoids resulted in the disruption of laminar organisation and synapse formation, the loss of photoreceptor organisation and retinal ganglion cells. Our data demonstrate a unique temporal and spatial expression for laminins and reveal a novel role for laminin γ3 during human retinogenesis.

Intracerebroventricular gene therapy that delays neurological disease progression is associated with selective preservation of retinal ganglion cells in a canine model of CLN2 disease.

PubMed

Whiting, Rebecca E H; Jensen, Cheryl A; Pearce, Jacqueline W; Gillespie, Lauren E; Bristow, Daniel E; Katz, Martin L

2016-05-01

CLN2 disease is one of a group of lysosomal storage disorders called the neuronal ceroid lipofuscinoses (NCLs). The disease results from mutations in the TPP1 gene that cause an insufficiency or complete lack of the soluble lysosomal enzyme tripeptidyl peptidase-1 (TPP1). TPP1 is involved in lysosomal protein degradation, and lack of this enzyme results in the accumulation of protein-rich autofluorescent lysosomal storage bodies in numerous cell types including neurons throughout the central nervous system and the retina. CLN2 disease is characterized primarily by progressive loss of neurological functions and vision as well as generalized neurodegeneration and retinal degeneration. In children the progressive loss of neurological functions typically results in death by the early teenage years. A Dachshund model of CLN2 disease with a null mutation in TPP1 closely recapitulates the human disorder with a progression from disease onset at approximately 4 months of age to end-stage at 10-11 months. Delivery of functional TPP1 to the cerebrospinal fluid (CSF), either by periodic infusion of the recombinant protein or by a single administration of a TPP1 gene therapy vector to the CSF, significantly delays the onset and progression of neurological signs and prolongs life span but does not prevent the loss of vision or modest retinal degeneration that occurs by 11 months of age. In this study we found that in dogs that received the CSF gene therapy treatment, the degeneration of the retina and loss of retinal function continued to progress during the prolonged life spans of the treated dogs. Eventually the normal cell layers of the retina almost completely disappeared. An exception was the ganglion cell layer. In affected dogs that received TPP1 gene therapy to the CSF and survived an average of 80 weeks, ganglion cell axons were present in numbers comparable to those of normal Dachshunds of similar age. The selective preservation of the retinal ganglion cells suggests

Analysis of Sigma Receptor (σR1) expression in retinal ganglion cells cultured under hyperglycemic conditions and in diabetic mice

PubMed Central

Ola, M. Shamsul; Moore, Pamela; Maddox, Dennis; El-Sherbeny, Amira; Huang, Wei; Roon, Penny; Agarwal, Neeraj; Ganapathy, Vadivel; Smith, Sylvia B.

2013-01-01

Summary The type 1 sigma receptor (σR1) is a nonopiate and nonphencyclidine binding site that has numerous pharmacological and physiological functions. In some studies, agonists for σR1 have been shown to afford neuroprotective against overstimulation of the NMDA receptor. σR1 expression has been demonstrated recently in retinal ganglion cells (RGC). RGCs undergo apoptosis early in diabetic retinopathy via NMDA receptor overstimulation. In the present study we asked whether RGCs cultured under hyperglycemic conditions and RGCs of diabetic mice continue to express σ1. RGCs were cultured 48 h in RPMI medium containing either 45 mM glucose or 11 mM glucose plus 34 mM mannitol (osmolar control). C57BL/6 mice were made diabetic using streptozotocin. The retina was dissected from normal and streptozotocin-induced diabetic mice 3, 6 and 12 weeks post-onset of diabetes. σR1 was analyzed in cells using semiquantitative RT-PCR and in tissues σR1 by semiquantitative RT-PCR, in situ hybridization, western blot analysis and immunolocalization. The RT-PCR analysis of cultured RGCs showed that σR1 mRNA is expressed under hyperglycemic conditions at levels similar to control cells. Similarly, analysis of retinas of diabetic mice showed no difference in levels of mRNA encoding σR1 compared to retinas of control mice. In situ hybridization analysis showed that expression patterns of σR1 mRNA in the ganglion cell layer were similar between diabetic and control mice. Western blot analysis suggested that levels of σR1 in retina were similar between diabetic and control retinas. Immunohistochemical analysis of σR1 showed a similar pattern of σR1 protein expression between control and diabetic retina. These studies demonstrate that σR1 is expressed under hyperglycemic conditions in vitro and in vivo. PMID:12425939

Analysis of sigma receptor (sigmaR1) expression in retinal ganglion cells cultured under hyperglycemic conditions and in diabetic mice.

PubMed

Ola, M Shamsul; Moore, Pamela; Maddox, Dennis; El-Sherbeny, Amira; Huang, Wei; Roon, Penny; Agarwal, Neeraj; Ganapathy, Vadivel; Smith, Sylvia B

2002-11-15

The type 1 sigma receptor (sigmaR1) is a nonopiate and nonphencyclidine binding site that has numerous pharmacological and physiological functions. In some studies, agonists for sigmaR1 have been shown to afford neuroprotection against overstimulation of the NMDA receptor. sigmaR1 expression has been demonstrated recently in retinal ganglion cells (RGC). RGCs undergo apoptosis early in diabetic retinopathy via NMDA receptor overstimulation. In the present study we asked whether RGCs cultured under hyperglycemic conditions and RGCs of diabetic mice continue to express sigmaR1. RGCs were cultured 48 h in RPMI medium containing either 45 mM glucose or 11 mM glucose plus 34 mM mannitol (osmolar control). C57BL/6 mice were made diabetic using streptozotocin. The retina was dissected from normal and streptozotocin-induced diabetic mice 3, 6 and 12 weeks post-onset of diabetes. sigmaR1 was analyzed in cells using semiquantitative RT-PCR and in tissues by semiquantitative RT-PCR, in situ hybridization, Western blot analysis and immunolocalization. The RT-PCR analysis of cultured RGCs showed that sigmaR1 mRNA is expressed under hyperglycemic conditions at levels similar to control cells. Similarly, analysis of retinas of diabetic mice showed no difference in levels of mRNA encoding sigmaR1 compared to retinas of control mice. In situ hybridization analysis showed that expression patterns of sigmaR1 mRNA in the ganglion cell layer were similar between diabetic and control mice. Western blot analysis suggested that levels of sigmaR1 in retina were similar between diabetic and control retinas. Immunohistochemical analysis of sigmaR1 showed a similar pattern of sigmaR1 protein expression between control and diabetic retina. These studies demonstrate that sigmaR1 is expressed under hyperglycemic conditions in vitro and in vivo.

Arthroscopic excision of ganglion cysts.

PubMed

Bontempo, Nicholas A; Weiss, Arnold-Peter C

2014-02-01

Arthroscopy is an advancing field in orthopedics, the applications of which have been expanding over time. Traditionally, excision of ganglion cysts has been done in an open fashion. However, more recently, studies show outcomes following arthroscopic excision to be as good as open excision. Cosmetically, the incisions are smaller and heal faster following arthroscopy. In addition, there is the suggested benefit that patients will regain function and return to work faster following arthroscopic excision. More prospective studies comparing open and arthroscopic excision of ganglion cysts need to be done in order to delineate if there is a true functional benefit. Copyright © 2014 Elsevier Inc. All rights reserved.

Cancer stem cell-like cells from a single cell of oral squamous carcinoma cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Felthaus, O.; Department of Oral and Maxillofacial Surgery, University of Regensburg; Ettl, T.

2011-04-01

Research highlights: {yields} Four oral squamous cancer cell lines (OSCCL) were analyzed for cancer stem cells (CSCs). {yields} Single cell derived colonies of OSCCL express CSC-marker CD133 differentially. {yields} Monoclonal cell lines showed reduced sensitivity for Paclitaxel. {yields} In situ CD133{sup +} cells are slow cycling (Ki67-) indicating a reduced drug sensitivity. {yields} CD133{sup +} and CSC-like cells can be obtained from single colony forming cells of OSCCL. -- Abstract: Resistance of oral squamous cell carcinomas (OSCC) to conventional chemotherapy or radiation therapy might be due to cancer stem cells (CSCs). The development of novel anticancer drugs requires a simplemore » method for the enrichment of CSCs. CSCs can be enriched from OSCC cell lines, for example, after cultivation in serum-free cell culture medium (SFM). In our study, we analyzed four OSCC cell lines for the presence of CSCs. CSC-like cells could not be enriched with SFM. However, cell lines obtained from holoclone colonies showed CSC-like properties such as a reduced rate of cell proliferation and a reduced sensitivity to Paclitaxel in comparison to cells from the parental lineage. Moreover, these cell lines differentially expressed the CSC-marker CD133, which is also upregulated in OSCC tissues. Interestingly, CD133{sup +} cells in OSCC tissues expressed little to no Ki67, the cell proliferation marker that also indicates reduced drug sensitivity. Our study shows a method for the isolation of CSC-like cell lines from OSCC cell lines. These CSC-like cell lines could be new targets for the development of anticancer drugs under in vitro conditions.« less

The molecular basis of retinal ganglion cell death in glaucoma.

PubMed

Almasieh, Mohammadali; Wilson, Ariel M; Morquette, Barbara; Cueva Vargas, Jorge Luis; Di Polo, Adriana

2012-03-01

Glaucoma is a group of diseases characterized by progressive optic nerve degeneration that results in visual field loss and irreversible blindness. A crucial element in the pathophysiology of all forms of glaucoma is the death of retinal ganglion cells (RGCs), a population of CNS neurons with their soma in the inner retina and axons in the optic nerve. Strategies that delay or halt RGC loss have been recognized as potentially beneficial to preserve vision in glaucoma; however, the success of these approaches depends on an in-depth understanding of the mechanisms that lead to RGC dysfunction and death. In recent years, there has been an exponential increase in valuable information regarding the molecular basis of RGC death stemming from animal models of acute and chronic optic nerve injury as well as experimental glaucoma. The emerging landscape is complex and points at a variety of molecular signals - acting alone or in cooperation - to promote RGC death. These include: axonal transport failure, neurotrophic factor deprivation, toxic pro-neurotrophins, activation of intrinsic and extrinsic apoptotic signals, mitochondrial dysfunction, excitotoxic damage, oxidative stress, misbehaving reactive glia and loss of synaptic connectivity. Collectively, this body of work has considerably updated and expanded our view of how RGCs might die in glaucoma and has revealed novel, potential targets for neuroprotection. Copyright © 2011. Published by Elsevier Ltd.

Relation Between Macular Retinal Ganglion Cell/Inner Plexiform Layer Thickness and Multifocal Electroretinogram Measures in Experimental Glaucoma

PubMed Central

Luo, Xunda; Patel, Nimesh B.; Rajagopalan, Lakshmi P.; Harwerth, Ronald S.; Frishman, Laura J.

2014-01-01

Purpose. We investigated relations between macular retinal ganglion cell plus inner plexiform layer (RGC+IPL) thickness and macular retinal function revealed by multifocal electroretinonography (mfERG) in a nonhuman primate model of experimental glaucoma. Methods. Retinal ganglion cell (RGC) structure and function were followed with spectral-domain optical coherence tomography (SD-OCT) and ERGs in five macaques with unilateral experimental glaucoma. Linear regression was used to study correlations in control (Con) and experimental (Exp) eyes between peripapillary retinal nerve fiber layer (RNFL) thickness, macular RGC+IPL thickness, multifocal photopic negative response (mfPhNR) and high-frequency multifocal oscillatory potentials (mfOP) in slow-sequence mfERG, and low-frequency component (mfLFC) in global-flash mfERG. We used ANOVA and paired t-tests to compare glaucoma-related mfERG changes between superior and inferior hemifields, foveal hexagon, inner three rings, and four quadrants of macula. Results. Average macular RGC+IPL and temporal RNFL thickness were strongly correlated (r2 = 0.90, P < 0.001). In hexagon-by-hexagon analysis, all three mfERG measures were correlated (P < 0.001) with RGC+IPL thickness for Con (r2, 0.33–0.51) and Exp eyes (r2, 0.17–0.35). The RGC structural and functional metrics decreased as eccentricity increased. The reduction in amplitude of mfERG measures in Exp eyes relative to Con eyes was proportionally greater, in general, than the relative thinning of RGC+IPL at the same location for eyes in which structural loss was not evident, or mild to moderate. Although not statistically significant, percent amplitude reduction of mfERG measures was greatest in the inferior temporal quadrant. Conclusions. Macular RGC+IPL thickness and mfERG measures of RGC function can be complementary tools in assessing glaucomatous neuropathy. PMID:24970256

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

PubMed Central

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

2013-01-01

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 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

Excitatory synaptic inputs to mouse on-off direction-selective retinal ganglion cells lack direction tuning.

PubMed

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

2014-03-12

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 and bipolar cells. However, evidence for DS acetylcholine and glutamate release has been inconsistent and at least one bipolar cell type that contacts another DSGC (On-type) lacks DS release. Here, whole-cell recordings in mouse retina showed that cholinergic input to On-Off DSGCs lacked DS, whereas the remaining (glutamatergic) input showed apparent DS. Fluorescence measurements with the glutamate biosensor intensity-based glutamate-sensing fluorescent reporter (iGluSnFR) conditionally expressed in On-Off DSGCs showed that glutamate release in both On- and Off-layer dendrites lacked DS, whereas simultaneously recorded excitatory currents showed apparent DS. With GABA-A receptors blocked, both iGluSnFR signals and excitatory currents lacked DS. Our measurements rule out DS release from bipolar cells onto On-Off DSGCs and support a theoretical model suggesting that apparent DS excitation in voltage-clamp recordings results from inadequate voltage control of DSGC dendrites during null-direction inhibition. SAC GABA release is the apparent sole source of DS input onto On-Off DSGCs.

LINE-1 Cultured Cell Retrotransposition Assay

PubMed Central

Kopera, Huira C.; Larson, Peter A.; Moldovan, John B.; Richardson, Sandra R.; Liu, Ying; Moran, John V.

2016-01-01

Summary The Long INterspersed Element-1 (LINE-1 or L1) retrotransposition assay has facilitated the discovery and characterization of active (i.e., retrotransposition-competent) LINE-1 sequences from mammalian genomes. In this assay, an engineered LINE-1 containing a retrotransposition reporter cassette is transiently transfected into a cultured cell line. Expression of the reporter cassette, which occurs only after a successful round of retrotransposition, allows the detection and quantification of the LINE-1 retrotransposition efficiency. This assay has yielded insight into the mechanism of LINE-1 retrotransposition. It also has provided a greater understanding of how the cell regulates LINE-1 retrotransposition and how LINE-1 retrotransposition impacts the structure of mammalian genomes. Below, we provide a brief introduction to LINE-1 biology and then detail how the LINE-1 retrotransposition assay is performed in cultured mammalian cells. PMID:26895052

Silencing the Kir4.1 potassium channel subunit in satellite glial cells of the rat trigeminal ganglion results in pain-like behavior in the absence of nerve injury.

PubMed

Vit, Jean-Philippe; Ohara, Peter T; Bhargava, Aditi; Kelley, Kanwar; Jasmin, Luc

2008-04-16

Growing evidence suggests that changes in the ion buffering capacity of glial cells can give rise to neuropathic pain. In the CNS, potassium ion (K+) buffering is dependent on the glia-specific inward rectifying K+ channel Kir4.1. We recently reported that the satellite glial cells that surround primary sensory neurons located in sensory ganglia of the peripheral nervous system also express Kir4.1, whereas the neurons do not. In the present study, we show that, in the rat trigeminal ganglion, the location of the primary sensory neurons for face sensation, specific silencing of Kir4.1 using RNA interference leads to spontaneous and evoked facial pain-like behavior in freely moving rats. We also show that Kir4.1 in the trigeminal ganglion is reduced after chronic constriction injury of the infraorbital nerve. These findings suggests that neuropathic pain can result from a change in expression of a single K+ channel in peripheral glial cells, raising the possibility of targeting Kir4.1 to treat pain in general and particularly neuropathic pain that occurs in the absence of nerve injury.

Soluble Tumor Necrosis Factor Alpha Promotes Retinal Ganglion Cell Death in Glaucoma via Calcium-Permeable AMPA Receptor Activation.

PubMed

Cueva Vargas, Jorge L; Osswald, Ingrid K; Unsain, Nicolas; Aurousseau, Mark R; Barker, Philip A; Bowie, Derek; Di Polo, Adriana

2015-09-02

Loss of vision in glaucoma results from the selective death of retinal ganglion cells (RGCs). Tumor necrosis factor α (TNFα) signaling has been linked to RGC damage, however, the mechanism by which TNFα promotes neuronal death remains poorly defined. Using an in vivo rat glaucoma model, we show that TNFα is upregulated by Müller cells and microglia/macrophages soon after induction of ocular hypertension. Administration of XPro1595, a selective inhibitor of soluble TNFα, effectively protects RGC soma and axons. Using cobalt permeability assays, we further demonstrate that endogenous soluble TNFα triggers the upregulation of Ca(2+)-permeable AMPA receptor (CP-AMPAR) expression in RGCs of glaucomatous eyes. CP-AMPAR activation is not caused by defects in GluA2 subunit mRNA editing, but rather reflects selective downregulation of GluA2 in neurons exposed to elevated eye pressure. Intraocular administration of selective CP-AMPAR blockers promotes robust RGC survival supporting a critical role for non-NMDA glutamate receptors in neuronal death. Our study identifies glia-derived soluble TNFα as a major inducer of RGC death through activation of CP-AMPARs, thereby establishing a novel link between neuroinflammation and cell loss in glaucoma. Tumor necrosis factor α (TNFα) has been implicated in retinal ganglion cell (RGC) death, but how TNFα exerts this effect is poorly understood. We report that ocular hypertension, a major risk factor in glaucoma, upregulates TNFα production by Müller cells and microglia. Inhibition of soluble TNFα using a dominant-negative strategy effectively promotes RGC survival. We find that TNFα stimulates the expression of calcium-permeable AMPA receptors (CP-AMPAR) in RGCs, a response that does not depend on abnormal GluA2 mRNA editing but on selective downregulation of the GluA2 subunit by these neurons. Consistent with this, CP-AMPAR blockers promote robust RGC survival supporting a critical role for non-NMDA glutamate receptors

Postconditioning with inhaled hydrogen promotes survival of retinal ganglion cells in a rat model of retinal ischemia/reperfusion injury.

PubMed

Wang, Ruobing; Wu, Jiangchun; Chen, Zeli; Xia, Fangzhou; Sun, Qinglei; Liu, Lin

2016-02-01

Retinal ischemia/reperfusion (I/R) injury plays a crucial role in the pathophysiology of various ocular diseases. Intraperitoneal injection or ocular instillation with hydrogen (H2)-rich saline was recently shown to be neuroprotective in the retina due to its anti-oxidative and anti-inflammatory effects. Our study aims to explore whether postconditioning with inhaled H2 can protect retinal ganglion cells (RGCs) in a rat model of retinal I/R injury. Retinal I/R injury was performed on the right eyes of rats and was followed by inhalation of 67% H2 mixed with 33% oxygen immediately after ischemia for 1h daily for one week. RGC density was counted using haematoxylin and eosin (HE) staining and retrograde labeling with cholera toxin beta (CTB). Visual function was assessed using flash visual evoked potentials (FVEP) and pupillary light reflex (PLR). Potential biomarkers of retinal oxidative stress and inflammatory responses were measured, including the expression of 4-Hydroxynonenalv (4-HNE), interleukin-1 beta (IL1-β) and tumor necrosis factor alpha (TNF-α). HE and CTB tracing showed that the survival rate of RGCs in the H2-treated group was significantly higher than the rate in the I/R group. Rats with H2 inhalation showed better visual function in assessments of FVEP and PLR. Moreover, H2 treatment significantly decreased the number of 4-HNE-stained cells in the ganglion cell layer and inhibited the retinal overexpression of IL1-β and TNF-α that was induced by retinal I/R injury. Our results demonstrate that postconditioning with inhaled high-dose H2 appears to confer neuroprotection against retinal I/R injury via anti-oxidative, anti-inflammatory and anti-apoptosis pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of intravitreally delivered capsid mutant AAV2-Cre vector to induce tissue-specific mutations in murine retinal ganglion cells.

PubMed

Langouet-Astrie, Christophe J; Yang, Zhiyong; Polisetti, Sraavya M; Welsbie, Derek S; Hauswirth, William W; Zack, Donald J; Merbs, Shannath L; Enke, Raymond A

2016-10-01

Targeted expression of Cre recombinase in murine retinal ganglion cells (RGCs) by viral vector is an effective strategy for creating tissue-specific gene knockouts for investigation of genetic contribution to RGC degeneration associated with optic neuropathies. Here we characterize dosage, efficacy and toxicity for sufficient intravitreal delivery of a capsid mutant Adeno-associated virus 2 (AAV2) vector encoding Cre recombinase. Wild type and Rosa26 (R26) LacZ mice were intravitreally injected with capsid mutant AAV2 viral vectors. Murine eyes were harvested at intervals ranging from 2 weeks to 15 weeks post-injection and were assayed for viral transduction, transgene expression and RGC survival. 10(9) vector genomes (vg) were sufficient for effective in vivo targeting of murine ganglion cell layer (GCL) retinal neurons. Transgene expression was observed as early as 2 weeks post-injection of viral vectors and persisted to 11 weeks. Early expression of Cre had no significant effect on RGC survival, while significant RGC loss was detected beginning 5 weeks post-injection. Early expression of viral Cre recombinase was robust, well-tolerated and predominantly found in GCL neurons suggesting this strategy can be effective in short-term RGC-specific mutation studies in experimental glaucoma models such as optic nerve crush and transection experiments. RGC degeneration with Cre expression for more than 4 weeks suggests that Cre toxicity is a limiting factor for targeted mutation strategies in RGCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modelling the spatio-temporal modulation response of ganglion cells with difference-of-Gaussians receptive fields: relation to photoreceptor response kinetics.

PubMed

Donner, K; Hemilä, S

1996-01-01

Difference-of-Gaussians (DOG) models for the receptive fields of retinal ganglion cells accurately predict linear responses to both periodic stimuli (typically moving sinusoidal gratings) and aperiodic stimuli (typically circular fields presented as square-wave pulses). While the relation of spatial organization to retinal anatomy has received considerable attention, temporal characteristics have been only loosely connected to retinal physiology. Here we integrate realistic photoreceptor response waveforms into the DOG model to clarify how far a single set of physiological parameters predict temporal aspects of linear responses to both periodic and aperiodic stimuli. Traditional filter-cascade models provide a useful first-order approximation of the single-photon response in photoreceptors. The absolute time scale of these, plus a time for retinal transmission, here construed as a fixed delay, are obtained from flash/step data. Using these values, we find that the DOG model predicts the main features of both the amplitude and phase response of linear cat ganglion cells to sinusoidal flicker. Where the simplest model formulation fails, it serves to reveal additional mechanisms. Unforeseen facts are the attenuation of low temporal frequencies even in pure center-type responses, and the phase advance of the response relative to the stimulus at low frequencies. Neither can be explained by any experimentally documented cone response waveform, but both would be explained by signal differentiation, e.g. in the retinal transmission pathway, as demonstrated at least in turtle retina.

Melanopsin retinal ganglion cell loss in Alzheimer disease

PubMed Central

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

2015-01-01

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

Characterization of spontaneous excitatory synaptic currents in salamander retinal ganglion cells.

PubMed Central

Taylor, W R; Chen, E; Copenhagen, D R

1995-01-01

1. Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded under voltage-clamp conditions. Consistent with activation of non-NMDA-type glutamate receptors, the sEPSCs reversed at potentials above 0 mV, were blocked by 1 microM CNQX and prolonged by 2 mM aniracetam. 2. The peak conductance of the averaged sEPSCs (n = 70-400) was 130 +/- 60 pS (mean +/- S.D.; 17 cells, ranging from 70 to 290 pS). Amplitude distributions were skewed towards larger amplitudes. 3. The decay of individual and mean sEPSCs was exponential with a mean time constant (tau d) of 3.75 +/- 0.84 ms (n = 13), which was voltage independent. The 10-90% rise time of the sEPSCs was 1.30 +/- 0.44 ms (n = 13). There was no correlation between sEPSC rise time and tau d suggesting that dendritic filtering alone did not shape the time course of sEPSCs. 4. Light-evoked EPSCs in these retinal ganglion cells are mediated by concomitant activation of NMDA and non-NMDA receptors; however, no NMDA component was discerned in the sEPSCs, even when recording at -96 mV in Mg(2+)-free solutions. The decay time course was not altered by 20 microM AP7, an NMDA antagonist, nor was an NMDA component unmasked by adding glycine or D-serine. These results suggest that NMDA and non-NMDA receptors are not coactivated by a single vesicle of transmitter during spontaneous release, and thus are probably not colocalized in the postsynaptic membrane at the sites of spontaneous release. 5. The sEPSCs were an order of magnitude faster than the non-NMDA receptor-mediated EPSCs evoked by light stimuli, and it is proposed that the EPSC time course is determined largely by the extended time course of release of synaptic vesicles from bipolar cells. The quantal content of a light-evoked non-NMDA receptor-mediated EPSC in an on-off cell is about 200 quanta. Images Figure 6 PMID:7562636

Immunocytochemical localization of metabotropic (mGluR2/3 and mGluR4a) and ionotropic (GluR2/3) glutamate receptors in adrenal medullary ganglion cells.

PubMed

Sarría, R; Díez, J; Losada, J; Doñate-Oliver, F; Kuhn, R; Grandes, P

2006-02-01

The localization of metabotropic glutamate receptors of groups II (mGluR2/3) and III (mGluR4a) and the subunits 2 and 3 of alfa-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) ionotropic glutamate receptors (GluR2/3) was investigated with immunocytochemical methods in the rat adrenal gland. MGluR2/3, mGluR4a and GluR2/3 immunoreactivities were observed in large-sized, centrally located type I adrenal medullary ganglion neurons. Furthermore, the small-sized type II adrenal ganglion neurons identified by their immunoreactivity to brain nitric oxide synthase (bNOS), also expressed mGluR2/3, mGluR4a and GluR2/3. These cells were disposed in the peripheral portion of the adrenal medulla. None of the type I neurons were positively labeled for bNOS. These morphological observations suggest that activation of glutamate receptors in ganglion neurons may be instrumental in the control of adrenal endocrine systems as well as blood regulation.

Method to investigate temporal dynamics of ganglion and other retinal cells in the living human eye

NASA Astrophysics Data System (ADS)

Kurokawa, Kazuhiro; Liu, Zhuolin; Crowell, James; Zhang, Furu; Miller, Donald T.

2018-02-01

The inner retina is critical for visual processing, but much remains unknown about its neural circuitry and vulnerability to disease. A major bottleneck has been our inability to observe the structure and function of the cells composing these retinal layers in the living human eye. Here, we present a noninvasive method to observe both structural and functional information. Adaptive optics optical coherence tomography (AO-OCT) is used to resolve the inner retinal cells in all three dimensions and novel post processing algorithms are applied to extract structure and physiology down to the cellular level. AO-OCT captured the 3D mosaic of individual ganglion cell somas, retinal nerve fiber bundles of micron caliber, and microglial cells, all in exquisite detail. Time correlation analysis of the AO-OCT videos revealed notable temporal differences between the principal layers of the inner retina. The GC layer was more dynamic than the nerve fiber and inner plexiform layers. At the cellular level, we applied a customized correlation method to individual GCL somas, and found a mean time constant of activity of 0.57 s and spread of +/-0.1 s suggesting a range of physiological dynamics even in the same cell type. Extending our method to slower dynamics (from minutes to one year), time-lapse imaging and temporal speckle contrast revealed appendage and soma motion of resting microglial cells at the retinal surface.

Parallel Inhibition of Dopamine Amacrine Cells and Intrinsically Photosensitive Retinal Ganglion Cells in a Non-Image-Forming Visual Circuit of the Mouse Retina

PubMed Central

Vuong, Helen E.; Hardi, Claudia N.; Barnes, Steven

2015-01-01

An inner retinal microcircuit composed of dopamine (DA)-containing amacrine cells and melanopsin-containing, intrinsically photosensitive retinal ganglion cells (M1 ipRGCs) process information about the duration and intensity of light exposures, mediating light adaptation, circadian entrainment, pupillary reflexes, and other aspects of non-image-forming vision. The neural interaction is reciprocal: M1 ipRGCs excite DA amacrine cells, and these, in turn, feed inhibition back onto M1 ipRGCs. We found that the neuropeptide somatostatin [somatotropin release inhibiting factor (SRIF)] also inhibits the intrinsic light response of M1 ipRGCs and postulated that, to tune the bidirectional interaction of M1 ipRGCs and DA amacrine cells, SRIF amacrine cells would provide inhibitory modulation to both cell types. SRIF amacrine cells, DA amacrine cells, and M1 ipRGCs form numerous contacts. DA amacrine cells and M1 ipRGCs express the SRIF receptor subtypes sst2A and sst4 respectively. SRIF modulation of the microcircuit was investigated with targeted patch-clamp recordings of DA amacrine cells in TH–RFP mice and M1 ipRGCs in OPN4–EGFP mice. SRIF increases K+ currents, decreases Ca2+ currents, and inhibits spike activity in both cell types, actions reproduced by the selective sst2A agonist L-054,264 (N-[(1R)-2-[[[(1S*,3R*)-3-(aminomethyl)cyclohexyl]methyl]amino]-1-(1H-indol-3-ylmethyl)-2-oxoethyl]spiro[1H-indene-1,4′-piperidine]-1′-carboxamide) in DA amacrine cells and the selective sst4 agonist L-803,087 (N2-[4-(5,7-difluoro-2-phenyl-1H-indol-3-yl)-1-oxobutyl]-l-arginine methyl ester trifluoroacetate) in M1 ipRGCs. These parallel actions of SRIF may serve to counteract the disinhibition of M1 ipRGCs caused by SRIF inhibition of DA amacrine cells. This allows the actions of SRIF on DA amacrine cells to proceed with adjusting retinal DA levels without destabilizing light responses by M1 ipRGCs, which project to non-image-forming targets in the brain. SIGNIFICANCE

Transcriptome of Atoh7 retinal progenitor cells identifies new Atoh7-dependent regulatory genes for retinal ganglion cell formation.

PubMed

Gao, Zhiguang; Mao, Chai-An; Pan, Ping; Mu, Xiuqian; Klein, William H

2014-11-01

The bHLH transcription factor ATOH7 (Math5) is essential for establishing retinal ganglion cell (RGC) fate. However, Atoh7-expressing retinal progenitor cells (RPCs) can give rise to all retinal cell types, suggesting that other factors are involved in specifying RGCs. The basis by which a subpopulation of Atoh7-expressing RPCs commits to an RGC fate remains uncertain but is of critical importance to retinal development since RGCs are the earliest cell type to differentiate. To better understand the regulatory mechanisms leading to cell-fate specification, a binary genetic system was generated to specifically label Atoh7-expressing cells with green fluorescent protein (GFP). Fluorescence-activated cell sorting (FACS)-purified GFP(+) and GFP(-) cells were profiled by RNA-seq. Here, we identify 1497 transcripts that were differentially expressed between the two RPC populations. Pathway analysis revealed diminished growth factor signaling in Atoh7-expressing RPCs, indicating that these cells had exited the cell cycle. In contrast, axon guidance signals were enriched, suggesting that axons of Atoh7-expressing RPCs were already making synaptic connections. Notably, many genes enriched in Atoh7-expressing RPCs encoded transcriptional regulators, and several were direct targets of ATOH7, including, and unexpectedly, Ebf3 and Eya2. We present evidence for a Pax6-Atoh7-Eya2 pathway that acts downstream of Atoh7 but upstream of differentiation factor Pou4f2. EYA2 is a protein phosphatase involved in protein-protein interactions and posttranslational regulation. These properties, along with Eya2 as an early target gene of ATOH7, suggest that EYA2 functions in RGC specification. Our results expand current knowledge of the regulatory networks operating in Atoh7-expressing RPCs and offer new directions for exploring the earliest aspects of retinogenesis. © 2014 Wiley Periodicals, Inc.

One-day high-fat diet induces inflammation in the nodose ganglion and hypothalamus of mice.

PubMed

Waise, T M Zaved; Toshinai, Koji; Naznin, Farhana; NamKoong, Cherl; Md Moin, Abu Saleh; Sakoda, Hideyuki; Nakazato, Masamitsu

2015-09-04

A high-fat diet (HFD) induces inflammation in systemic organs including the hypothalamus, resulting in obesity and diabetes. The vagus nerve connects the visceral organs and central nervous system, and the gastric-derived orexigenic peptide ghrelin transmits its starvation signals to the hypothalamus via the vagal afferent nerve. Here we investigated the inflammatory response in vagal afferent neurons and the hypothalamus in mice following one day of HFD feeding. This treatment increased the number of macrophages/microglia in the nodose ganglion and hypothalamus. Furthermore, one-day HFD induced expression of Toll-like receptor 4 in the goblet cells of the colon and upregulated mRNA expressions of the proinflammatory biomarkers Emr1, Iba1, Il6, and Tnfα in the nodose ganglion and hypothalamus. Both subcutaneous administration of ghrelin and celiac vagotomy reduced HFD-induced inflammation in these tissues. HFD intake triggered inflammatory responses in the gut, nodose ganglion, and subsequently in the hypothalamus within 24 h. These findings suggest that the vagal afferent nerve may transfer gut-derived inflammatory signals to the hypothalamus via the nodose ganglion, and that ghrelin may protect against HFD-induced inflammation. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Complete adult neurogenesis within a Wallerian degenerating nerve expressed as an ectopic ganglion.

PubMed

Nakano, Tomonori; Kurimoto, Shigeru; Kato, Shuichi; Asano, Kenichi; Hirata, Takuma; Kiyama, Hiroshi; Hirata, Hitoshi

2018-06-01

Neurogenesis in the adult peripheral nervous system remains to be demonstrated. We transplanted embryonic neural stem cells into a Wallerian degenerating nerve graft and observed development of a nodular structure consisting of neurons, glia, and Schwann cells. Histological analysis revealed a structure loosely resembling the spinal cord, including a synaptic network that formed along the neuron. Furthermore, the new axons reinnervated the paralysed muscle, forming both de novo and revived neuromuscular junctions. Reinnervation of the paralysed muscle resulted in significantly greater mean wet muscle weight and muscle fibre cross-sectional area on the cell transplantation side than on the surgical control side (body weight 0.071 ± 0.011% vs. 0.051 ± 0.007%, p = .006; area 355.6 ± 345.2 vs. 114.0 ± 132.0 μm 2 , p < .001). Electrophysiological experiments demonstrated a functional connection between the neurons and muscle; hence, we identified this nodule as an ectopic ganglion. Surprisingly, in green rat experiments, most of these glial cells, but none of the neurons, expressed enhanced green fluorescent protein, suggesting that the cells constituting the ectopic ganglion were derived from both transplanted stem cells and endogenous stem cells. Such adult neurogenesis in a peripheral nerve related to neural stem cell transplantation has not been reported previously, and these results form the basis for a novel regenerative medicine approach in paralysed muscle. Copyright © 2018 John Wiley & Sons, Ltd.

Reprogramming of single-cell derived mesenchymal stem cells into hair cell-like cells

PubMed Central

Lin, Zhaoyu; Perez, Philip; Sun, Zhenyu; Liu, Jan-Jan; Shin, June Ho; Hyrc, Krzysztof L.; Samways, Damien; Egan, Terry; Holley, Matthew C.; Bao, Jianxin

2012-01-01

Hypothesis Adult mesenchymal stem cells (MSCs) can be converted into hair cell-like cells by transdetermination. Background Given the fundamental role sensory hair cells play in sound detection and the irreversibility of their loss in mammals, much research has focused on developing methods to generate new hair cells as a means of treating permanent hearing loss. Although MSCs can differentiate into multiple cell lineages, no efficient means of reprogramming them into sensory hair cells exists. Earlier work has shown that the transcription factor Atoh1 is necessary for early development of hair cells, but it is not clear whether Atoh1 can be used to convert MSCs into hair cells. Methods Clonal MSC cell lines were established and reprogrammed into hair cell-like cells by a combination of protein transfer, adenoviral based gene transfer and co-culture with neurons. During transdetermination, inner ear molecular markers were analyzed by RT-PCR, and cell structures were examined by immunocytochemistry. Results Atoh1 overexpression in MSCs failed to convert MSCs into hair cell-like cells, suggesting that the ability of Atoh1 to induce hair cell differentiation is context dependent. Because Atoh1 overexpression successfully transforms VOT-E36 cells into hair cell-like cells, we modified the cell context of MSCs by performing a total protein transfer from VOT-E36 cells prior to overexpressing Atoh1. The modified MSCs were transformed into hair cell-like cells and attracted contacts from spiral ganglion neurons in a co-culture model. Conclusion We established a new procedure, consisting of VOT-E36 protein transfer, Atoh1 overexpression, and co-culture with spiral ganglion neurons, which can transform MSCs into hair cell-like cells. PMID:23111404

Who's lost first? Susceptibility of retinal ganglion cell types in experimental glaucoma.

PubMed

Della Santina, Luca; Ou, Yvonne

2017-05-01

The purpose of this article is to summarize our current knowledge about the susceptibility of specific retinal ganglion cell (RGC) types in experimental glaucoma, and to delineate the initial morphological and functional alterations that occur in response to intraocular pressure (IOP) elevation. There has been debate in the field as to whether RGCs with large somata and axons are more vulnerable, with definitive conclusions still in progress because of the wide diversity of RGC types. Indeed, it is now estimated that there are greater than 30 different RGC types, and while we do not yet understand the complete details, we discuss a growing body of work that supports the selective vulnerability hypothesis of specific RGC types in experimental glaucoma. Specifically, structural and functional degeneration of various RGC types have been examined across different rodent models of experimental glaucoma (acute vs. chronic) and different strains, and an emerging consensus is that OFF RGCs appear to be more vulnerable to IOP elevation compared to ON RGCs. Understanding the mechanisms by which this selective vulnerability manifests across different RGC types should lead to novel and improved strategies for neuroprotection and neuroregeneration in glaucoma. Copyright © 2016 Elsevier Ltd. All rights reserved.

Generating mammalian stable cell lines by electroporation.

PubMed

A Longo, Patti; Kavran, Jennifer M; Kim, Min-Sung; Leahy, Daniel J

2013-01-01

Expression of functional, recombinant mammalian proteins often requires expression in mammalian cells (see Single Cell Cloning of a Stable Mammalian Cell Line). If the expressed protein needs to be made frequently, it can be best to generate a stable cell line instead of performing repeated transient transfections into mammalian cells. Here, we describe a method to generate stable cell lines via electroporation followed by selection steps. This protocol will be limited to the CHO dhfr-Urlaub et al. (1983) and LEC1 cell lines, which in our experience perform the best with this method. Copyright © 2013 Elsevier Inc. All rights reserved.

Characterization of a Merkel Cell Polyomavirus-Positive Merkel Cell Carcinoma Cell Line CVG-1.

PubMed

Velásquez, Celestino; Amako, Yutaka; Harold, Alexis; Toptan, Tuna; Chang, Yuan; Shuda, Masahiro

2018-01-01

Merkel cell polyomavirus (MCV) plays a causal role in ∼80% of Merkel cell carcinomas (MCC). MCV is clonally integrated into the MCC tumor genome, which results in persistent expression of large T (LT) and small T (sT) antigen oncoproteins encoded by the early locus. In MCV-positive MCC tumors, LT is truncated by premature stop codons or deletions that lead to loss of the C-terminal origin binding (OBD) and helicase domains important for replication. The N-terminal Rb binding domain remains intact. MCV-positive cell lines derived from MCC explants have been valuable tools to study the molecular mechanism of MCV-induced Merkel cell carcinogenesis. Although all cell lines have integrated MCV and express truncated LT antigens, the molecular sizes of the LT proteins differ between cell lines. The copy number of integrated viral genome also varies across cell lines, leading to significantly different levels of viral protein expression. Nevertheless, these cell lines share phenotypic similarities in cell morphology, growth characteristics, and neuroendocrine marker expression. Several low-passage MCV-positive MCC cell lines have been established since the identification of MCV. We describe a new MCV-positive MCV cell line, CVG-1, with features distinct from previously reported cell lines. CVG-1 tumor cells grow in more discohesive clusters in loose round cell suspension, and individual cells show dramatic size heterogeneity. It is the first cell line to encode an MCV sT polymorphism resulting in a unique leucine (L) to proline (P) substitution mutation at amino acid 144. CVG-1 possesses a LT truncation pattern near identical to that of MKL-1 cells differing by the last two C-terminal amino acids and also shows an LT protein expression level similar to MKL-1. Viral T antigen knockdown reveals that, like other MCV-positive MCC cell lines, CVG-1 requires T antigen expression for cell proliferation.

Single-Cell Resolution Imaging of Retinal Ganglion Cell Apoptosis In Vivo Using a Cell-Penetrating Caspase-Activatable Peptide Probe

PubMed Central

Qiu, Xudong; Johnson, James R.; Wilson, Bradley S.; Gammon, Seth T.; Piwnica-Worms, David; Barnett, Edward M.

2014-01-01

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 vivo imaging

Response properties of ON-OFF retinal ganglion cells to high-order stimulus statistics.

PubMed

Xiao, Lei; Gong, Han-Yan; Gong, Hai-Qing; Liang, Pei-Ji; Zhang, Pu-Ming

2014-10-17

The visual stimulus statistics are the fundamental parameters to provide the reference for studying visual coding rules. In this study, the multi-electrode extracellular recording experiments were designed and implemented on bullfrog retinal ganglion cells to explore the neural response properties to the changes in stimulus statistics. The changes in low-order stimulus statistics, such as intensity and contrast, were clearly reflected in the neuronal firing rate. However, it was difficult to distinguish the changes in high-order statistics, such as skewness and kurtosis, only based on the neuronal firing rate. The neuronal temporal filtering and sensitivity characteristics were further analyzed. We observed that the peak-to-peak amplitude of the temporal filter and the neuronal sensitivity, which were obtained from either neuronal ON spikes or OFF spikes, could exhibit significant changes when the high-order stimulus statistics were changed. These results indicate that in the retina, the neuronal response properties may be reliable and powerful in carrying some complex and subtle visual information. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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.

PubMed

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.

Optimal voltage stimulation parameters for network-mediated responses in wild type and rd10 mouse retinal ganglion cells

NASA Astrophysics Data System (ADS)

Jalligampala, Archana; Sekhar, Sudarshan; Zrenner, Eberhart; Rathbun, Daniel L.

2017-04-01

To further improve the quality of visual percepts elicited by microelectronic retinal prosthetics, substantial efforts have been made to understand how retinal neurons respond to electrical stimulation. It is generally assumed that a sufficiently strong stimulus will recruit most retinal neurons. However, recent evidence has shown that the responses of some retinal neurons decrease with excessively strong stimuli (a non-monotonic response function). Therefore, it is necessary to identify stimuli that can be used to activate the majority of retinal neurons even when such non-monotonic cells are part of the neuronal population. Taking these non-monotonic responses into consideration, we establish the optimal voltage stimulation parameters (amplitude, duration, and polarity) for epiretinal stimulation of network-mediated (indirect) ganglion cell responses. We recorded responses from 3958 mouse retinal ganglion cells (RGCs) in both healthy (wild type, WT) and a degenerating (rd10) mouse model of retinitis pigmentosa—using flat-mounted retina on a microelectrode array. Rectangular monophasic voltage-controlled pulses were presented with varying voltage, duration, and polarity. We found that in 4-5 weeks old rd10 mice the RGC thresholds were comparable to those of WT. There was a marked response variability among mouse RGCs. To account for this variability, we interpolated the percentage of RGCs activated at each point in the voltage-polarity-duration stimulus space, thus identifying the optimal voltage-controlled pulse (-2.4 V, 0.88 ms). The identified optimal voltage pulse can activate at least 65% of potentially responsive RGCs in both mouse strains. Furthermore, this pulse is well within the range of stimuli demonstrated to be safe and effective for retinal implant patients. Such optimized stimuli and the underlying method used to identify them support a high yield of responsive RGCs and will serve as an effective guideline for future in vitro investigations of

The Cellosaurus, a Cell-Line Knowledge Resource

PubMed Central

Bairoch, Amos

2018-01-01

The Cellosaurus is a knowledge resource on cell lines. It aims to describe all cell lines used in biomedical research. Its scope encompasses both vertebrates and invertebrates. Currently, information for >100,000 cell lines is provided. For each cell line, it provides a wealth of information, cross-references, and literature citations. The Cellosaurus is available on the ExPASy server (https://web.expasy.org/cellosaurus/) and can be downloaded in a variety of formats. Among its many uses, the Cellosaurus is a key resource to help researchers identify potentially contaminated/misidentified cell lines, thus contributing to improving the quality of research in the life sciences. PMID:29805321

Gymnopilin--a substance produced by the hallucinogenic mushroom, Gymnopilus junonius--mobilizes intracellular Ca(2+) in dorsal root ganglion cells.

PubMed

Miyazaki, Shunsuke; Kitamura, Naoki; Nishio, Aiko; Tanaka, Saki; Kayano, Tomohiko; Moriya, Taiki; Ichiyanagi, Tsuyoshi; Shimomura, Norihiro; Shibuya, Izumi; Aimi, Tadanori

2012-04-01

Gymnopilus junonius is a widely spread mushroom in Japan and well known as a hallucinogenic mushroom. Gymnopilin was purified from the fruiting body of G. junonius and was reported to act on the spinal cord and depolarize motoneurons. This is the only evidence that gymnopilin has a biological effect on animals and no mechanism of the action has been determined at all. In this study, we examined effects of gymnopilin on intracellular Ca(2+) concentrations ([Ca(2+)](i)) of cultured cells isolated from the dorsal root ganglion (DRG) of the rat. The cell culture consisted of neurons and non-neuronal cells. Gymnopilin increased [Ca(2+)](i) in both the types of cells. The gymnopilinevoked [Ca(2+)](i) rise in the non-neuronal cells was inhibited by cyclopiazonic acid and U-73122, inhibitors of Ca(2+)-ATPase of the intracellular Ca(2+) store and phospholipase C, respectively, but not by removal of extracellular Ca(2+). These results indicate that gymnopilin activated phospholipase C and mobilize Ca(2+) from the intracellular Ca(2+) store in non-neuronal cells from the DRG. This is the first report to show that gymnopilin directly acts on cells isolated from the mammalian nervous system.

Transplantation of cells from eye-like structures differentiated from embryonic stem cells in vitro and in vivo regeneration of retinal ganglion-like cells.

PubMed

Aoki, Hitomi; Hara, Akira; Niwa, Masayuki; Motohashi, Tsutomu; Suzuki, Takashi; Kunisada, Takahiro

2008-02-01

An embryonic stem (ES) cell-derived eye-like structure, made up of neural retinal lineage cells, retinal pigment epithelial (RPE) cells, and lens cells was constructed in our laboratory. We have shown that cells from these eye-like structures can be integrated into the developing optic vesicle of chicks. The purpose of this study was to determine whether the cells from these eye-like structures can differentiate into retinal ganglion cells (RGCs) when transplanted into the vitreous of an injured adult mouse retina. ES cells were induced to differentiate into eye-like structures in vitro for 6 or 11 days. Recipient mouse eyes were injected with NMDA to injure the RGCs prior to the transplantation. Sham-treated eyes received the same amount of carrier vehicle. Cells were extracted from the eye-like structures and transplanted into the vitreous of damaged and control eyes. The host eyes were analyzed both qualitatively and quantitatively by immunohistochemistry 10 days or 8 weeks after transplantation. Cells from the ES cell-derived eye-like structures were integrated into the RGC layer, and differentiated into neurons when transplanted into control (non-NMDA-treated) adult eyes. However, they rarely expressed RGC markers. When they were transplanted into NMDA-treated eyes, the cells spread on the surface of the retina and covered a relatively large area of the host RGC layer that had been injured by the NMDA. The cells from the ES cell-derived eye cells frequently differentiated into cells expressing RGC-specific markers, and formed a new RGC layer. In addition, a small number of these ES cell-derived cells were observed to extend axon-like processes toward the optic disc of the host. However, visually evoked responses could not be recorded from the visual cortex. These findings suggest that ES cell-derived eye-like structures contain cells that can differentiate into RG-like cells and regenerate a new RGC layer. These cells also appeared to be integrated into the

Crocin prevents retinal ischaemia/reperfusion injury-induced apoptosis in retinal ganglion cells through the PI3K/AKT signalling pathway.

PubMed

Qi, Yun; Chen, Li; Zhang, Lei; Liu, Wen-Bo; Chen, Xiao-Yan; Yang, Xin-Guang

2013-02-01

Crocin is a pharmacologically active component of Crocus sativus L. (saffron) and has been reported to be useful in the treatment of neuronal damage. In the present study, we investigated the neuroprotective effect of crocin on retinal ganglion cells (RGCs) after retinal ischaemia/reperfusion (IR) injury, and our results show that crocin acts through the PI3K/AKT signalling pathway. Retinal IR injury was induced by raising the intraocular pressure of Sprague-Dawley rats to 110 mmHg for 60 min. The neuroprotective effect of crocin was determined by quantifying the surviving RGCs and apoptotic RGCs following IR injury by means of retrograde labelling and TUNEL staining, respectively. The phosphorylated AKT protein level was determined by western blot and immunohistochemical analysis. To determine the extent to which the PI3K/AKT pathway contributes to the neuroprotective effect of crocin, experiments were also performed using the PI3K inhibitor LY294002. Compared with the IR + vehicle group, crocin (50 mg/kg) treatment enhanced RGC survival by approximately 36% and decreased RGC apoptosis by 44% after retinal IR injury. Western blot and immunohistochemical analysis demonstrated that the PI3K/AKT pathway was activated by crocin in the ganglion cell layer after retinal IR injury. Intravitreal injection of LY294002 blocked the neuroprotective effect of crocin on IR-induced RGC death. In conclusion, crocin prevents retinal IR-induced apoptosis of RGCs by activating the PI3K/AKT signalling pathway. Copyright © 2012 Elsevier Ltd. All rights reserved.

Differences in Optic Nerve Head, Retinal Nerve Fiber Layer, and Ganglion Cell Complex Parameters Between Caucasian and Chinese Subjects.

PubMed

Chansangpetch, Sunee; Huang, Guofu; Coh, Paul; Oldenburg, Catherine; Amoozgar, Behzad; He, Mingguang; Lin, Shan C

2018-04-01

To compare optic nerve head, peripapillary retinal nerve fiber layer (pRNFL), and ganglion cell complex (GCC) parameters between Caucasian and ethnic Chinese. Normal subjects above 40 years old and self-identified as being Caucasian and Chinese were recruited. They were evaluated with spectral-domain optical coherence tomography (RTVue-100). Parameters related to the optic nerve head, pRNFL, and GCC analysis protocols were acquired. Multivariable linear regression was performed adjusting for potential confounders. Data from 116 Caucasian and 130 Chinese subjects were available for analysis. Mean age of all participants was 66.72 (SD 10.82) years. There were statistically significant differences for disc area (DA), area cup-to-disc, vertical cup-to-disc, and cup volume (P=0.02, 0.004, 0.02, and 0.03, respectively), greater in Chinese. After adjusting for age, sex, axial length (AL), intraocular pressure (IOP), DA, and GCC thickness, Chinese subjects had significantly greater thickness in all pRNFL parameters (mean differences ranged between 4.29 and 9.93 μm; all P<0.001) except the nasal quadrant. GCC outcomes were also adjusted for DA and pRNFL; Caucasians had significantly higher average GCC and inferior GCC (mean difference 2.97 and 3.45 μm, respectively; P<0.01), whereas the Chinese group had significantly higher ganglion cell global loss volume (mean difference 2.47 %, P<0.001). This study suggests there is significantly greater pRNFL thickness in Chinese, which were independent of age, AL, IOP, and DA, and possibly greater GCC in Caucasians after adjustment for age, AL, IOP, DA, and pRNFL thickness.

Intravitreally transplanted dental pulp stem cells promote neuroprotection and axon regeneration of retinal ganglion cells after optic nerve injury.

PubMed

Mead, Ben; Logan, Ann; Berry, Martin; Leadbeater, Wendy; Scheven, Ben A

2013-11-15

To investigate the potential therapeutic benefit of intravitreally implanted dental pulp stem cells (DPSCs) on axotomized adult rat retinal ganglion cells (RGCs) using in vitro and in vivo neural injury models. Conditioned media collected from cultured rat DPSCs and bone marrow-derived mesenchymal stem cells (BMSCs) were assayed for nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) secretion using ELISA. DPSCs or BMSCs were cocultured with retinal cells, with or without Fc-TrK inhibitors, in a Transwell system, and the number of surviving βIII-tubulin⁺ retinal cells and length/number of βIII-tubulin⁺ neurites were quantified. For the in vivo study, DPSCs or BMSCs were transplanted into the vitreous body of the eye after a surgically induced optic nerve crush injury. At 7, 14, and 21 days postlesion (dpl), optical coherence tomography (OCT) was used to measure the retinal nerve fiber layer thickness as a measure of axonal atrophy. At 21 dpl, numbers of Brn-3a⁺ RGCs in parasagittal retinal sections and growth-associated protein-43⁺ axons in longitudinal optic nerve sections were quantified as measures of RGC survival and axon regeneration, respectively. Both DPSCs and BMSCs secreted NGF, BDNF, and NT-3, with DPSCs secreting significantly higher titers of NGF and BDNF than BMSCs. DPSCs, and to a lesser extent BMSCs, promoted statistically significant survival and neuritogenesis/axogenesis of βIII-tubulin⁺ retinal cells in vitro and in vivo where the effects were abolished after TrK receptor blockade. Intravitreal transplants of DPSCs promoted significant neurotrophin-mediated RGC survival and axon regeneration after optic nerve injury.

Development of a new canine osteosarcoma cell line.

PubMed

Séguin, B; Zwerdling, T; McCallan, J L; DeCock, H E V; Dewe, L L; Naydan, D K; Young, A E; Bannasch, D L; Foreman, O; Kent, M S

2006-12-01

Establishing a canine osteosarcoma (OSA) cell line can be useful to develop in vivo and in vitro models of OSA. The goal of this study was to develop, characterize and authenticate a new canine OSA cell line and a clone. A cell line and a clone were developed with standard cell culture techniques from a naturally occurring OSA in a dog. The clonal cell line induced a tumour after injection in RAG 1-deficient mouse. Histology was consistent with OSA. The original tumour from the dog and the tumour induced in the mouse were both reactive with vimentin and osteonectin (ON). The parent cell line and clonal cell line were reactive with ON, osteocalcin and alkaline phosphatase. Loss of heterozygosity was found in the same three microsatellite markers in the parent and clonal cell lines, and the tumour tissue grown in the mouse.

Pressure wave injuries to rat dorsal root ganglion cells in culture caused by high-energy missiles.

PubMed

Suneson, A; Hansson, H A; Lycke, E; Seeman, T

1989-01-01

A high-energy missile impact in an extremity of an animal creates a shock wave which is rapidly dispersed as a burst of oscillating pressure waves that traverses the entire body causing local, regional, and distant injuries. The present study was performed on dorsal root ganglion (DRG) cells, cultured for 3 weeks, to elucidate the cellular mechanism for damage of nerve cells, using a simplified test system. A model system was developed allowing exposure of DRG cultures to a burst of high-frequency oscillating pressure waves, comparable to those recorded in animals after high-energy missile extremity impact. The pressure waves were induced by impact of a high-energy missile in a rubber tube filled with water, in which nerve cell cultures were kept in a closed rubber glove filled with tissue culture medium. The pressure waves had a duration of 0.5-1.5 ms and a frequency spectrum ranging from 0-250 kHz. Within minutes the neurites showed changes in their microtubules. In addition, varicosities, enriched with tubulin immunoreactive material, became irregularly studded along the nerve cell processes. Scattered DRG cells were initially permeable to the marker complex Evans-blue albumin (EBA), used as an indicator of the ability of the plasma membranes to exclude proteins. After 6 hr, however, almost every DRG neuron was intensely stained by EBA. Concomitantly, there was swelling of the nerve cell cytoplasm and organelles, and, to a variable extent, neurofilament tangles were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Silencing the Kir4.1 potassium channel subunit in satellite glial cells of the rat trigeminal ganglion results in pain-like behavior in the absence of nerve injury

PubMed Central

Vit, Jean-Philippe; Ohara, Peter T.; Bhargava, Aditi; Kelley, Kanwar; Jasmin, Luc

2008-01-01

Growing evidence suggests that changes in the ion buffering capacity of glial cells can give rise to neuropathic pain. In the CNS, potassium ion (K+) buffering is dependent on the glia-specific inward rectifying K+ channel Kir4.1. We recently reported that the satellite glial cells (SGCs) that surround primary sensory neurons located in sensory ganglia of the peripheral nervous system also express Kir4.1 while the neurons do not. In the present study we show that in the rat trigeminal ganglion, the location of the primary sensory neurons for face sensation, specific silencing of Kir4.1 using RNA interference leads to spontaneous and evoked facial pain-like behavior in freely moving rats. We also show that Kir4.1 in the trigeminal ganglion is reduced following chronic constriction injury of the infraorbital nerve. These findings suggests that neuropathic pain can result from a change in expression of a single K+ channel in peripheral glial cells, raising the possibility of targeting Kir4.1 to treat pain in general, and particularly neuropathic pain that occurs in the absence of nerve injury. PMID:18417695

Characterization of Ganglionic Acetylcholine Receptor Autoantibodies

PubMed Central

Vernino, Steven; Lindstrom, Jon; Hopkins, Steve; Wang, Zhengbei; Low, Phillip A.

2008-01-01

In myasthenia gravis (MG), autoantibodies bind to the α1 subunit and other subunits of the muscle nicotinic acetylcholine receptor (AChR). Autoimmune autonomic ganglionopathy (AAG) is an antibody-mediated neurological disorder caused by antibodies against neuronal AChRs in autonomic ganglia. Subunits of muscle and neuronal AChR are homologous. We examined the specificity of AChR antibodies in patients with MG and AAG. Ganglionic AChR autoantibodies found in AAG patients are specific for AChRs containing the α3 subunit. Muscle and ganglionic AChR antibody specificities are distinct. Antibody crossreactivity between AChRs with different α subunits is uncommon but can occur. PMID:18485491

JUN regulates early transcriptional responses to axonal injury in retinal ganglion cells.

PubMed

Fernandes, Kimberly A; Harder, Jeffrey M; Kim, Jessica; Libby, Richard T

2013-07-01

The AP1 family transcription factor JUN is an important molecule in the neuronal response to injury. In retinal ganglion cells (RGCs), JUN is upregulated soon after axonal injury and disrupting JUN activity delays RGC death. JUN is known to participate in the control of many different injury response pathways in neurons, including pathways controlling cell death and axonal regeneration. The role of JUN in regulating genes involved in cell death, ER stress, and regeneration was tested to determine the overall importance of JUN in regulating RGC response to axonal injury. Genes from each of these pathways were transcriptionally controlled following axonal injury and Jun deficiency altered the expression of many of these genes. The differentially expressed genes included, Atf3, Ddit3, Ecel1, Gadd45α, Gal, Hrk, Pten, Socs3, and Sprr1a. Two of these genes, Hrk and Atf3, were tested for importance in RGC death using null alleles of each gene. Disruption of the prodeath Bcl2 family member Hrk did not affect the rate or amount of RGC death after axonal trauma. Deficiency in the ATF/CREB family transcription factor Atf3 did lessen the amount of RGC death after injury, though it did not provide long term protection to RGCs. Since JUN's dimerization partner determines its transcriptional targets, the expression of several candidate AP1 family members were examined. Multiple AP1 family members were induced by axonal injury and had a different expression profile in Jun deficient retinas compared to wildtype retinas (Fosl1, Fosl2 and Jund). Overall, JUN appears to play a multifaceted role in regulating RGC response to axonal injury. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ganglionic adrenergic action modulates ovarian steroids and nitric oxide in prepubertal rat.

PubMed

Delgado, Silvia Marcela; Casais, Marilina; Sosa, Zulema; Rastrilla, Ana María

2006-08-01

Both peripheral innervation and nitric oxide (NO) participate in ovarian steroidogenesis. The purpose of this work was to analyse the ganglionic adrenergic influence on the ovarian release of steroids and NO and the possible steroids/NO relationship. The experiments were carried out in the ex vivo coeliac ganglion-superior ovarian nerve (SON)-ovary system of prepubertal rats. The coeliac ganglion-SON-ovary system was incubated in Krebs Ringer-bicarbonate buffer in presence of adrenergic agents in the ganglionic compartment. The accumulation of progesterone, androstenedione, oestradiol and NO in the ovarian incubation liquid was measured. Norepinephrine in coeliac ganglion inhibited the liberation of progesterone and increased androstenedione, oestradiol and NO in ovary. The addition of alpha and beta adrenergic antagonists also showed different responses in the liberation of the substances mentioned before, which, from a physiological point of view, reveals the presence of adrenergic receptors in coeliac ganglion. In relation to propranolol, it does not revert the effect of noradrenaline on the liberation of progesterone, which leads us to think that it might also have a "per se" effect on the ganglion, responsible for the ovarian response observed for progesterone. Finally, we can conclude that the ganglionic adrenergic action via SON participates on the regulation of the prepubertal ovary in one of two ways: either increasing the NO, a gaseous neurotransmitter with cytostatic characteristics, to favour the immature follicles to remain dormant or increasing the liberation of androstenedione and oestradiol, the steroids necessary for the beginning of the near first estral cycle.

Diagnostic utility of combined retinal ganglion cell count estimates in Japanese glaucoma patients.

PubMed

Sakamoto, Mari; Mori, Sotaro; Ueda, Kaori; Akashi, Azusa; Inoue, Yukako; Kurimoto, Takuji; Kanamori, Akiyasu; Yamada, Yuko; Nakamura, Makoto

2018-01-01

To assess the combined estimate of retinal ganglion cell (RGC) count developed by Medeiros et al. as a tool for diagnosis of glaucoma in Japanese patients. Cross-sectional study. Thirty-one eyes of 19 healthy controls and 106 eyes of 70 glaucoma patients underwent standard automated perimetry (SAP) and three types of spectral domain optical coherence tomography (SD-OCT) imaging using the Cirrus, RTVue, and 3D-OCT instruments. RGC counts derived from SAP and SD-OCT data were estimated using the Harwerth model (SAPrgc and OCTrgc, respectively), from which the combined RGC count estimates (CRGC) were calculated using the formula developed by Medeiros et al. Receiver operating characteristic curve (ROC) analyses were conducted for mean deviation (MD), retinal nerve fiber layer thickness (RNFLT), and CRGC. The mean OCTrgc derived from the Cirrus, RTVue, and 3D-OCT instruments were 1150, 1245, and 1316 (× 1000 cells), respectively, for the control group and 463, 519, and 516 (× 1000 cells), respectively, for the patient group. SAPrgc of the controls' group was 1526 and the patients' group, 731 (× 1000 cells), and were consistently greater than OCTrgc in both groups (a generalized estimating equation model, p < 0.001). Partial area under the curve (pAUC) of MD was 0.178, and that of RNFLT and CRGC for the three OCT instruments were 0.185, 0.18, 0.189 and 0.196, 0.196, 0.197, respectively. CRGC had larger pAUC than MD, whereas there was no or marginal difference in pAUC between CRGC and cpRNFLT, irrespective of OCT device used or glaucoma severity. CRGC proved well suited to discriminate glaucoma patients from controls. However, its clinical utility did not seem to overwhelm isolated structural measures in the tested Japanese patients.

[Establishment of Z-HL16C cell line.].

PubMed

Chen, J P; Li, J; Zhao, S L; Tian, J Y; Ye, F

2006-09-01

To establish and study the nature and the application of Z-HL16C cell line. The cell line was continuously passed, frozen stored and recovered. Its application was expanded and the cell type was identified. The cell line had an epithelial-cell-like shape, the size appeared uniform, the cell boundary was distinct. It has been continuously passed, frozen stored and recovered for ten years. Its recovery rate was about 90%. It has been proved to be sensitive to the tested viruses which were enteroviruses (Polio, Cox, Echo), influenza viruses, parainfluenzaviruses, adenoviruses, measles virus. This cell line has been identified as a cancerization cell. The cell line Z-HL16C has been stably established, it has a broad spectrum in sensitivity for culturing viruses.

Zinc oxide nanoparticles induce rat retinal ganglion cell damage through bcl-2, caspase-9 and caspase-12 pathways.

PubMed

Guo, Dadong; Bi, Hongsheng; Wu, Qiuxin; Wang, Daoguang; Cui, Yan

2013-06-01

Nanomaterials, including zinc oxide (ZnO) nanoparticles, are being developed for a variety of commercial products. Recent reports showed that cells exposed to ZnO nanoparticles produced severe cytotoxicity accompanied by oxidative stress and genotoxicity. To understand the possible mechanism underlying oxidative stress of ZnO nanoparticles, the present investigation focused on the direct bioactivity of ZnO nanoparticles using a rat retinal ganglion cell (RGC-5) culture. At concentrations relevant to those used in vitro exposure of RGC-5 cells to ZnO nanoparticles, it was found that ZnO nanoparticles could inhibit cell proliferation in time- and concentration-dependent manners. Meanwhile, cell cycle arrest of S and G2/M phases occurred in RGC-5 cells induced by ZnO nanoparticles. Moreover, our results also demonstrated that the overproduction of reactive oxygen species (ROS) and elevated level of caspase-12 as well as decreased levels of bcl-2 and caspase-9 occurred after treatment with different concentrations of ZnO nanoparticles when compared to those in untreated cells. In summary, our findings suggest that ZnO nanoparticles could lead to the over generations of ROS and caspase-12 as well as decreased levels of bcl-2 and caspase-9. These results indicate that bcl-2, caspase-9 and caspase-12 may play significant roles in ZnO nanoparticle-induced RGC-5 cell damage.

A Cell Culture Model of Latent and Lytic Herpes Simplex Virus Type 1 Infection in Spiral Ganglion.

PubMed

Liu, Yuehong; Li, Shufeng

2015-01-01

Reactivation of latent herpes simplex virus type 1 (HSV-1) in spiral ganglion neurons (SGNs) is supposed to be one of the causes of idiopathic sudden sensorineural hearing loss. This study aims to establish a cell culture model of latent and lytic HSV-1 infection in spiral ganglia. In the presence of acyclovir, primary cultures of SGNs were latently infected with HSV-1 expressing green fluorescent protein. Four days later, these cells were treated with trichostatin A (TSA), a known chemical reactivator of HSV-1. TCID50 was used to measure the titers of virus in cultures on Vero cells. RNA from cultures was detected for the presence of transcripts of ICP27 and latency-associated transcript (LAT) using reverse transcription polymerase chain reaction. There is no detectable infectious HSV-1 in latently infected cultures, whereas they could be observed in both lytically infected and latently infected/TSA-treated cultures. LAT was the only detectable transcript during latent infection, whereas lytic ICP27 transcript was detected in lytically infected and latently infected/TSA-treated cultures. Cultured SGNs can be both latently and lytically infected with HSV-1. Furthermore, latently infected SGNs can be reactivated using TSA, yielding infectious virus.

Sphenopalatine ganglion: block, radiofrequency ablation and neurostimulation - a systematic review.

PubMed

Ho, Kwo Wei David; Przkora, Rene; Kumar, Sanjeev

2017-12-28

Sphenopalatine ganglion is the largest collection of neurons in the calvarium outside of the brain. Over the past century, it has been a target for interventional treatment of head and facial pain due to its ease of access. Block, radiofrequency ablation, and neurostimulation have all been applied to treat a myriad of painful syndromes. Despite the routine use of these interventions, the literature supporting their use has not been systematically summarized. This systematic review aims to collect and summarize the level of evidence supporting the use of sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Medline, Google Scholar, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were reviewed for studies on sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Studies included in this review were compiled and analyzed for their treated medical conditions, study design, outcomes and procedural details. Studies were graded using Oxford Center for Evidence-Based Medicine for level of evidence. Based on the level of evidence, grades of recommendations are provided for each intervention and its associated medical conditions. Eighty-three publications were included in this review, of which 60 were studies on sphenopalatine ganglion block, 15 were on radiofrequency ablation, and 8 were on neurostimulation. Of all the studies, 23 have evidence level above case series. Of the 23 studies, 19 were on sphenopalatine ganglion block, 1 study on radiofrequency ablation, and 3 studies on neurostimulation. The rest of the available literature was case reports and case series. The strongest evidence lies in using sphenopalatine ganglion block, radiofrequency ablation and neurostimulation for cluster headache. Sphenopalatine ganglion block also has evidence in treating trigeminal neuralgia, migraines, reducing the needs of analgesics after endoscopic sinus surgery and reducing pain associated with nasal packing

Alteration of the fast excitatory postsynaptic current by barium in voltage-clamped amphibian sympathetic ganglion cells.

PubMed Central

Connor, E. A.; Parsons, R. L.

1984-01-01

Barium-induced alterations in fast excitatory postsynaptic currents (e.p.s.cs) have been studied in voltage-clamped bullfrog sympathetic ganglion B cells. In the presence of 2-8 mM barium, e.p.s.c. decay was prolonged and in many cells the e.p.s.c. decay phase deviated from a single exponential function. The decay phase in these cases was more accurately described as the sum of two exponential functions. The frequency of occurrence of a complex decay increased both with increasing barium concentration and with hyperpolarization. Miniature e.p.s.c. decay also was prolonged in barium-treated cells. E.p.s.c. amplitude was not markedly affected by barium (2-8 mM) in cells voltage-clamped to -50 mV whereas at -90 mV there was a progressive increase in peak size with increasing barium concentration. In control cells the e.p.s.c.-voltage relationship was linear between -20 and -100 mV; however, this relationship became progressively non-linear with membrane hyperpolarization in barium-treated cells. The e.p.s.c. reversal potential was shifted to a more negative value in the presence of barium. There was a voltage-dependent increase in charge movement during the e.p.s.c. in barium-treated cells which was not present in control cells. We conclude that the voltage-dependent alteration in e.p.s.c. decay time course, peak amplitude and charge movement in barium-treated cells is due to a direct postsynaptic action of barium on the kinetics of receptor-channel gating in postganglionic sympathetic neurones. PMID:6333261

Making connections in the inner ear: recent insights into the development of spiral ganglion neurons and their connectivity with sensory hair cells

PubMed Central

Coate, Thomas M.; Kelley, Matthew W.

2013-01-01

In mammals, auditory information is processed by the hair cells (HCs) located in the cochlea and then rapidly transmitted to the CNS via a specialized cluster of bipolar afferent connections known as the spiral ganglion neurons (SGNs). Although many anatomical aspects of SGNs are well described, the molecular and cellular mechanisms underlying their genesis, how they are precisely arranged along the cochlear duct, and the guidance mechanisms that promote the innervation of their hair cell targets are only now being understood. Building upon foundational studies of neurogenesis and neurotrophins, we review here new concepts and technologies that are helping to enrich our understanding of the development of the nervous system within the inner ear. PMID:23660234

Charge-balanced biphasic electrical stimulation inhibits neurite extension of spiral ganglion neurons.

PubMed

Shen, Na; Liang, Qiong; Liu, Yuehong; Lai, Bin; Li, Wen; Wang, Zhengmin; Li, Shufeng

2016-06-15

Intracochlear application of exogenous or transgenic neurotrophins, such as neurotrophin-3 (NT-3) and brain derived neurotrophic factor (BDNF), could promote the resprouting of spiral ganglion neuron (SGN) neurites in deafened animals. These resprouting neurites might reduce the gap between cochlear implant electrodes and their targeting SGNs, allowing for an improvement of spatial resolution of electrical stimulation. This study is to investigate the impact of electrical stimulation employed in CI on the extension of resprouting SGN neurites. We established an in vitro model including the devices delivering charge-balanced biphasic electrical stimulation, and spiral ganglion (SG) dissociated culture treated with BDNF and NT-3. After electrical stimulation with varying durations and intensities, we quantified neurite lengths and Schwann cell densities in SG cultures. Stimulations that were greater than 50μA or longer than 8h significantly decreased SG neurite length. Schwann cell density under 100μA electrical stimulation for 48h was significantly lower compared to that in non-stimulated group. These electrical stimulation-induced decreases of neurite extension and Schwann cell density were attenuated by various types of voltage-dependent calcium channel (VDCC) blockers, or completely prevented by their combination, cadmium or calcium-free medium. Our study suggested that charge-balanced biphasic electrical stimulation inhibited the extension of resprouting SGN neurites and decreased Schwann cell density in vitro. Calcium influx through multiple types of VDCCs was involved in the electrical stimulation-induced inhibition. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The transcriptional diversity of 25 Drosophila cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherbas, Lucy; Willingham, Aarron; Zhang, Dayu

2010-12-22

Drosophila melanogaster cell lines are important resources for cell biologists. In this article, we catalog the expression of exons, genes, and unannotated transcriptional signals for 25 lines. Unannotated transcription is substantial (typically 19% of euchromatic signal). Conservatively, we identify 1405 novel transcribed regions; 684 of these appear to be new exons of neighboring, often distant, genes. Sixty-four percent of genes are expressed detectably in at least one line, but only 21% are detected in all lines. Each cell line expresses, on average, 5885 genes, including a common set of 3109. Expression levels vary over several orders of magnitude. Major signalingmore » pathways are well represented: most differentiation pathways are ‘‘off’’ and survival/growth pathways ‘‘on.’’ Roughly 50% of the genes expressed by each line are not part of the common set, and these show considerable individuality. Thirty-one percent are expressed at a higher level in at least one cell line than in any single developmental stage, suggesting that each line is enriched for genes characteristic of small sets of cells. Most remarkable is that imaginal disc-derived lines can generally be assigned, on the basis of expression, to small territories within developing discs. These mappings reveal unexpected stability of even fine-grained spatial determination. No two cell lines show identical transcription factor expression. We conclude that each line has retained features of an individual founder cell superimposed on a common ‘‘cell line‘‘ gene expression pattern. We report the transcriptional profiles of 25 Drosophila melanogaster cell lines, principally by whole-genome tiling microarray analysis of total RNA, carried out as part of the modENCODE project. The data produced in this study add to our knowledge of the cell lines and of the Drosophila transcriptome in several ways. We summarize the expression of previously annotated genes in each of the 25 lines

Ketorolac Administration Attenuates Retinal Ganglion Cell Death After Axonal Injury.

PubMed

Nadal-Nicolás, Francisco M; Rodriguez-Villagra, Esther; Bravo-Osuna, Irene; Sobrado-Calvo, Paloma; Molina-Martínez, Irene; Villegas-Pérez, Maria Paz; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Herrero-Vanrell, Rocío

2016-03-01

To assess the neuroprotective effects of ketorolac administration, in solution or delivered from biodegradable microspheres, on the survival of axotomized retinal ganglion cells (RGCs). Retinas were treated intravitreally with a single injection of tromethamine ketorolac solution and/or with ketorolac-loaded poly(D,L-lactide-co-glycolide) (PLGA) microspheres. Ketorolac treatments were administered either 1 week before optic nerve crush (pre-ONC) or right after the ONC (simultaneous). In all cases, animals were euthanized 7 days after the ONC. As control, nonloaded microspheres or vehicle (balanced salt solution, BSS) were administered in parallel groups. All retinas were dissected as flat mounts; RGCs were immunodetected with brain-specific homeobox/POU domain protein 3A (Brn3a), and their number was automatically quantified. The percentage of Brn3a+RGCs was 36% to 41% in all control groups (ONC with or without BSS or nonloaded microparticles). Ketorolac solution administered pre-ONC resulted in 63% survival of RGCs, while simultaneous administration promoted a 53% survival. Ketorolac-loaded microspheres were not as efficient as ketorolac solution (43% and 42% of RGC survival pre-ONC or simultaneous, respectively). The combination of ketorolac solution and ketorolac-loaded microspheres did not have an additive effect (54% and 55% survival pre-ONC and simultaneous delivery, respectively). Treatment with the nonsteroidal anti-inflammatory drug ketorolac delays RGC death triggered by a traumatic axonal insult. Pretreatment seems to elicit a better output than simultaneous administration of ketorolac solution. This may be taken into account when performing procedures resulting in RGC axonal injury.

Nitric oxide (NO.) stabilizes whereas nitrosonium (NO+) enhances filopodial outgrowth by rat retinal ganglion cells in vitro.

PubMed

Cheung, W S; Bhan, I; Lipton, S A

2000-06-16

Recent observations suggest that nitric oxide (NO(.)) can increase or decrease growth cone motility. Here, these apparently paradoxical results are explained by distinct actions of different NO-related species. Filopodial morphology of 223 rat retinal ganglion cells was monitored under computer-enhanced video microscopy in the presence of NO synthase (NOS) substrates or inhibitors, donors of specific NO-related species, and membrane-permeant cyclic nucleotide analogs. Physiological NOS activity induced filopodial outgrowth, whereas inhibition of NOS stabilized filopodia. Similar to NOS, nitrosonium (NO(+) transfer) and peroxynitrite (ONOO(-)), which can regulate the activity of growth-associated proteins by S-nitrosylation and oxidation, respectively, induced filopodial outgrowth. In contrast, NO(.), which stimulates guanylate cyclase to increase cGMP, stabilized filopodial activity. Thus disparate NO-related species may offer a dynamic process of filopodial growth regulation.

Rapid and coordinated processing of global motion images by local clusters of retinal ganglion cells.

PubMed

Matsumoto, Akihiro; Tachibana, Masao

2017-01-01

Even when the body is stationary, the whole retinal image is always in motion by fixational eye movements and saccades that move the eye between fixation points. Accumulating evidence indicates that the brain is equipped with specific mechanisms for compensating for the global motion induced by these eye movements. However, it is not yet fully understood how the retina processes global motion images during eye movements. Here we show that global motion images evoke novel coordinated firing in retinal ganglion cells (GCs). We simultaneously recorded the firing of GCs in the goldfish isolated retina using a multi-electrode array, and classified each GC based on the temporal profile of its receptive field (RF). A moving target that accompanied the global motion (simulating a saccade following a period of fixational eye movements) modulated the RF properties and evoked synchronized and correlated firing among local clusters of the specific GCs. Our findings provide a novel concept for retinal information processing during eye movements.

Comparison of steroid receptors from the androgen responsive DDT1 cell line and the nonresponsive HVP cell line.

PubMed

Norris, J S; Kohler, P O

1978-01-01

Two hamster cell lines have been isolated from androgen target tissue. The DDT1 cells derived from ductus deferens tissue exhibit a growth response to androgens, while the HVP cells derived from ventral prostate are androgen unresponsive. Both cell lines contain androgen receptors, that are similar when compared by kinetic methods, sedimentation velocity, chromatographic procedures or nuclear translocation ability. The forms of the high salt extracted nuclear receptors are indistinguishable chromatographically. Therefore, we postulate that the lesion preventing androgen induced growth in the HVP cell line is subseqent to nuclear translocation of the steroid receptor complex.

Allicin protects auditory hair cells and spiral ganglion neurons from cisplatin - Induced apoptosis.

PubMed

Wu, Xianmin; Li, Xiaofei; Song, Yongdong; Li, He; Bai, Xiaohui; Liu, Wenwen; Han, Yuechen; Xu, Lei; Li, Jianfeng; Zhang, Daogong; Wang, Haibo; Fan, Zhaomin

2017-04-01

Cisplatin is a broad-spectrum anticancer drug that is commonly used in the clinic. Ototoxicity is one of the major side effects of this drug, which caused irreversible sensorineural hearing loss. Allicin, the main biologically active compound derived from garlic, has been shown to exert various anti-apoptotic and anti-oxidative activities in vitro and in vivo studies. We took advantage of C57 mice intraperitoneally injected with cisplatin alone or with cisplatin and allicin combined, to investigate whether allicin plays a protective role in vivo against cisplatin ototoxicity. The result showed that C57 mice in cisplatin group exhibited increased shift in auditory brainstem response, whereas the auditory fuction of mice in allicin + cisplatin group was protected in most frequencies, which was accordance with observed damages of outer hair cells (OHCs) and spiral ganglion neurons (SGNs) in the cochlea. Allicin markedly protected SGN mitochondria from damage and releasing cytochrome c, and significantly reduced pro-apoptosis factor expressions activated by cisplatin, including Bax, cleaved-caspase-9, cleaved-caspase-3and p53. Furthermore, allicin reduced the level of Malondialdehyde (MDA), but increased the level of superoxide dismutase (SOD). All data suggested that allicin could prevent hearing loss induced by cisplatin effectively, of which allicin protected SGNs from apoptosis via mitochondrial pathway while protected OHCs and supporting cells (SCs) from apoptosis through p53 pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immunohistochemical localization of cyclooxygenase isoforms in the organ of Corti and the spiral ganglion cells of guinea pig cochlea.

PubMed

Ziegler, E A; Brieger, J; Heinrich, U R; Mann, W J

2004-01-01

Prostaglandins have been used in experimental models and clinical studies for the therapy of sudden hearing loss and tinnitus with conflicting results. However, little is known about the rate-limiting enzymes of prostaglandin synthesis in the inner ear, the generally constitutively expressed cyclooxygenase 1 (COX-1) and the distress-inducible cyclooxygenase 2 (COX-2). To extend our knowledge concerning the physiological expression and localization of these two enzymes, immunohistochemical stainings of the guinea pig cochlea were performed. Light microscopical analysis revealed a homogenous distribution of COX-1 within nearly all cell types of the organ of Corti, but no COX-1 expression in the cuticular plates of pillar cells. COX-2 was found to be expressed in all cell types, with much stronger expression in Hensen cells, neighboring Deiters cells and cuticular plates of outer hair cells. Both COX-1 and COX-2 immunoreactions were also found in the spiral ganglion. We conclude that both COX subtypes are expressed in the guinea pig cochlea under physiological conditions. The prominent expression of the distress-inducible COX-2 isoform in cell types under mechanical stress during noise reception might support the hypothesis of a cytoprotective function of COX products in hearing and in cellular stress situations like intense noise exposure. Copyright (c) 2004 S. Karger AG, Basel.

Pan-retinal characterisation of Light Responses from Ganglion Cells in the Developing Mouse Retina.

PubMed

Hilgen, Gerrit; Pirmoradian, Sahar; Pamplona, Daniela; Kornprobst, Pierre; Cessac, Bruno; Hennig, Matthias H; Sernagor, Evelyne

2017-02-10

We have investigated the ontogeny of light-driven responses in mouse retinal ganglion cells (RGCs). Using a large-scale, high-density multielectrode array, we recorded from hundreds to thousands of RGCs simultaneously at pan-retinal level, including dorsal and ventral locations. Responses to different contrasts not only revealed a complex developmental profile for ON, OFF and ON-OFF responses, but also unveiled differences between dorsal and ventral RGC responses. At eye-opening, dorsal RGCs of all types were more responsive to light, perhaps indicating an environmental priority to nest viewing for pre-weaning pups. The developmental profile of ON and OFF responses exhibited antagonistic behaviour, with the strongest ON responses shortly after eye-opening, followed by an increase in the strength of OFF responses later on. Further, we found that with maturation receptive field (RF) center sizes decrease, spike-triggered averaged responses to white noise become stronger, and centers become more circular while maintaining differences between RGC types. We conclude that the maturation of retinal functionality is not spatially homogeneous, likely reflecting ecological requirements that favour earlier maturation of the dorsal retina.

Sox11 Expression Promotes Regeneration of Some Retinal Ganglion Cell Types but Kills Others.

PubMed

Norsworthy, Michael W; Bei, Fengfeng; Kawaguchi, Riki; Wang, Qing; Tran, Nicholas M; Li, Yi; Brommer, Benedikt; Zhang, Yiming; Wang, Chen; Sanes, Joshua R; Coppola, Giovanni; He, Zhigang

2017-06-21

At least 30 types of retinal ganglion cells (RGCs) send distinct messages through the optic nerve to the brain. Available strategies of promoting axon regeneration act on only some of these types. Here we tested the hypothesis that overexpressing developmentally important transcription factors in adult RGCs could reprogram them to a "youthful" growth-competent state and promote regeneration of other types. From a screen of transcription factors, we identified Sox11 as one that could induce substantial axon regeneration. Transcriptome profiling indicated that Sox11 activates genes involved in cytoskeletal remodeling and axon growth. Remarkably, α-RGCs, which preferentially regenerate following treatments such as Pten deletion, were killed by Sox11 overexpression. Thus, Sox11 promotes regeneration of non-α-RGCs, which are refractory to Pten deletion-induced regeneration. We conclude that Sox11 can reprogram adult RGCs to a growth-competent state, suggesting that different growth-promoting interventions promote regeneration in distinct neuronal types. Copyright © 2017 Elsevier Inc. All rights reserved.

KYNA analogue SZR72 modifies CFA-induced dural inflammation- regarding expression of pERK1/2 and IL-1β in the rat trigeminal ganglion.

PubMed

Lukács, M; Warfvinge, K; Kruse, L S; Tajti, J; Fülöp, F; Toldi, J; Vécsei, L; Edvinsson, L

2016-12-01

Neurogenic inflammation has for decades been considered an important part of migraine pathophysiology. In the present study, we asked the question if administration of a novel kynurenic acid analogue (SZR72), precursor of an excitotoxin antagonist and anti-inflammatory substance, can modify the neurogenic inflammatory response in the trigeminal ganglion. Inflammation in the trigeminal ganglion was induced by local dural application of Complete Freunds Adjuvant (CFA). Levels of phosphorylated MAP kinase pERK1/2 and IL-1β expression in V1 region of the trigeminal ganglion were investigated using immunohistochemistry and Western blot. Pretreatment with one dose of SZR72 abolished the CFA-induced pERK1/2 and IL-1β activation in the trigeminal ganglion. No significant change was noted in case of repeated treatment with SZR72 as compared to a single dose. This is the first study that demonstrates that one dose of KYNA analog before application of CFA can give anti-inflammatory response in a model of trigeminal activation, opening a new line for further investigations regarding possible effects of KYNA derivates.

Transgenic mice expressing cyan fluorescent protein as a reporter strain to detect the effects of rotenone toxicity on retinal ganglion cells.

PubMed

Hayworth, C R; Rojas, J C; Gonzalez-Lima, F

2008-01-01

This is the first study using a reporter transgenic model to investigate the effects of an environmental toxin on the retina. Rotenone is a widely used pesticide that inhibits mitochondrial complex I and produces neurotoxicity. Previous studies demonstrated the time course and dose response of rotenone toxicity on retinal ganglion cells (RGC). However, previous analyses of rotenone-induced retinotoxicity provided little detail of the optic nerve axons and cellular pathology. These limitations were successfully surmounted by using a transgenic mouse line shown to express cyan fluorescent protein (CFP) in neurons, including RGC, under regulatory elements of the human the thy1.1 promoter (thy-CFP). Data showed that CFP expression is limited to RGC and their processes in the retina of thy-CFP mice. Eyes exposed to the pesticide rotenone displayed marked alterations in RGC morphology, inner plexiform layer, optic disc, and optic nerves. After 24 h, the number of CFP-labeled RGC was reduced 50%. Correlated with a loss of RGC bodies was an approximate 50% reduction in CFP fluorescence intensity at the optic disc. The findings showed that rotenone-induced degeneration of RGC and their processes can be visualized with exquisite detail in thy-CFP mice, and that this approach may provide a novel and effective way to monitor the association between environmental toxins and neurodegeneration in living animals.

Effect of Tissue Heterogeneity on the Transmembrane Potential of Type-1 Spiral Ganglion Neurons: A Simulation Study.

PubMed

Sriperumbudur, Kiran Kumar; Pau, Hans Wilhelm; van Rienen, Ursula

2018-03-01

Electric stimulation of the auditory nerve by cochlear implants has been a successful clinical intervention to treat the sensory neural deafness. In this pathological condition of the cochlea, type-1 spiral ganglion neurons in Rosenthal's canal play a vital role in the action potential initiation. Various morphological studies of the human temporal bones suggest that the spiral ganglion neurons are surrounded by heterogeneous structures formed by a variety of cells and tissues. However, the existing simulation models have not considered the tissue heterogeneity in the Rosenthal's canal while studying the electric field interaction with spiral ganglion neurons. Unlike the existing models, we have implemented the tissue heterogeneity in the Rosenthal's canal using a computationally inexpensive image based method in a two-dimensional finite element model. Our simulation results suggest that the spatial heterogeneity of surrounding tissues influences the electric field distribution in the Rosenthal's canal, and thereby alters the transmembrane potential of the spiral ganglion neurons. In addition to the academic interest, these results are especially useful to understand how the latest tissue regeneration methods such as gene therapy and drug-induced resprouting of peripheral axons, which probably modify the density of the tissues in the Rosenthal's canal, affect the cochlear implant functionality.

Celastrol supports survival of retinal ganglion cells injured by optic nerve crush.

PubMed

Kyung, Haksu; Kwong, Jacky M K; Bekerman, Vlad; Gu, Lei; Yadegari, Daniel; Caprioli, Joseph; Piri, Natik

2015-06-03

The present study evaluates the effect of celastrol on the survival of retinal ganglion cells (RGCs) injured by optic nerve crush (ONC). Celastrol, a quinine methide triterpene extracted from the perennial vine Tripterygium wilfordii (Celastraceae), has been identified as a potential neuroprotective candidate in a comprehensive drug screen against various neurodegenerative diseases. Two weeks after ONC, the average density of remaining RGCs in retinas of animals treated with daily intraperitoneal (i.p.) injections of celastrol (1mg/kg) was approximately 1332 cells/mm(2), or 40.8% of the Celastrol/Control group. In retinas of the Vehicle/ONC group about 381 RGCs/mm(2) were counted, which is 9.6% of the total number of RGCs in the DMSO/Control group. This corresponds to approximately a 250% increase in RGC survival mediated by celastrol treatment compared to Vehicle/ONC group. Furthermore, the average RGC number in retinas of ONC animals treated with a single intravitreal injection of 1mg/kg or 5mg/kg of celastrol was increased by approximately 80% (760 RGCs/mm(2)) and 78% (753 RGCs/mm(2)), respectively, compared to Vehicle/ONC controls (422 cells/mm(2)). Injection of 0.2mg/kg of celastrol had no significant effect on cell survival, with the average number of RGCs being 514 cells/mm(2) in celastrol-treated animals versus 422 cells/mm(2) in controls. The expression levels of Hsp70, Hsf1, Hsf2, HO-1 and TNF-alpha in the retina were analyzed to evaluate the roles of these proteins in the celastrol-mediated protection of injured RGCs. No statistically significant change in HO-1, Hsf1 and Hsp70 levels was seen in animals with ONC. An approximately 2 fold increase in Hsf2 level was observed in celastrol-treated animals with or without injury. Hsf2 level was also increased 1.8 fold in DMSO-treated animals with ONC injury compared to DMSO-treated animals with no injury suggesting that Hsf2 induction has an injury-induced component. Expression of TNF-alpha in retinas of

Segmented inner plexiform layer thickness as a potential biomarker to evaluate open-angle glaucoma: Dendritic degeneration of retinal ganglion cell.

PubMed

Kim, Eun Kyoung; Park, Hae-Young Lopilly; Park, Chan Kee

2017-01-01

To evaluate the changes of retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and ganglion cell-inner plexiform layer (GCIPL) thicknesses and compare structure-function relationships of 4 retinal layers using spectral-domain optical coherence tomography (SD-OCT) in macular region of glaucoma patients. In cross-sectional study, a total of 85 eyes with pre-perimetric to advanced glaucoma and 26 normal controls were enrolled. The glaucomatous eyes were subdivided into three groups according to the severity of visual field defect: a preperimetric glaucoma group, an early glaucoma group, and a moderate to advanced glaucoma group. RNFL, GCL, IPL, and GCIPL thicknesses were measured at the level of the macula by the Spectralis (Heidelberg Engineering, Heidelberg, Germany) SD-OCT with automated segmentation software. For functional evaluation, corresponding mean sensitivity (MS) values were measured using 24-2 standard automated perimetry (SAP). RNFL, GCL, IPL, and GCIPL thicknesses were significantly different among 4 groups (P < .001). Macular structure losses were positively correlated with the MS values of the 24-2 SAP for RNFL, GCL, IPL, and GCIPL (R = 0.553, 0.636, 0.648 and 0.646, respectively, P < .001). In regression analysis, IPL and GCIPL thicknesses showed stronger association with the corresponding MS values of 24-2 SAP compared with RNFL and GCL thicknesses (R2 = 0.420, P < .001 for IPL; R2 = 0.417, P< .001 for GCIPL thickness). Segmented IPL thickness was significantly associated with the degree of glaucoma. Segmental analysis of the inner retinal layer including the IPL in macular region may provide valuable information for evaluating glaucoma.

Characterization of stem-like cells in a new astroblastoma cell line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coban, Esra Aydemir; Kasikci, Ezgi; Karatas, Omer Faruk

Cell lines established from tumors are the most commonly used models in cancer research, and their use in recent years has enabled a greater understanding of the biology of cancer and the means to develop effective treatment strategies. Astroblastomas are uncommon neuroepithelial tumors of glial origin, predominantly affecting young people, mainly teenagers and children, predominantly females. To date, only a single study has reported that astroblastomas contain a large number of neural stem-like cells, which had only a partial proliferation capacity and differentiation. Our objective was to establish an astroblastoma cell line to investigate the presence of astroblastic cells andmore » cancer stem-like cells. The migratory and invasion abilities of the cells were quantified with invasion and migration assays and compared to a glioblastoma cell line. The presence of stem cells was detected with surface-marker analysis by using flow cytometry, and measuring the differentiation ability with a differentiation assay and the self-renewal capacity with a sphere-forming assay. These characteristics may determine whether this novel cell line is a model for astroblastomas that may have stem-cell characteristics. With this novel cell line, scientists can investigate the molecular pathways underlying astroblastomas and develop new therapeutic strategies for patients with these tumors. - Highlights: • An establishment of a novel astroblastoma cell line was proposed. • The presence of astroblastic cells and cancer stem-like cells was investigated. • The molecular pathways underlying astroblastomas may be investigated. • New therapeutic strategies for patients with astroblastoma may be developed.« less

Ontological representation, integration, and analysis of LINCS cell line cells and their cellular responses.

PubMed

Ong, Edison; Xie, Jiangan; Ni, Zhaohui; Liu, Qingping; Sarntivijai, Sirarat; Lin, Yu; Cooper, Daniel; Terryn, Raymond; Stathias, Vasileios; Chung, Caty; Schürer, Stephan; He, Yongqun

2017-12-21

Aiming to understand cellular responses to different perturbations, the NIH Common Fund Library of Integrated Network-based Cellular Signatures (LINCS) program involves many institutes and laboratories working on over a thousand cell lines. The community-based Cell Line Ontology (CLO) is selected as the default ontology for LINCS cell line representation and integration. CLO has consistently represented all 1097 LINCS cell lines and included information extracted from the LINCS Data Portal and ChEMBL. Using MCF 10A cell line cells as an example, we demonstrated how to ontologically model LINCS cellular signatures such as their non-tumorigenic epithelial cell type, three-dimensional growth, latrunculin-A-induced actin depolymerization and apoptosis, and cell line transfection. A CLO subset view of LINCS cell lines, named LINCS-CLOview, was generated to support systematic LINCS cell line analysis and queries. In summary, LINCS cell lines are currently associated with 43 cell types, 131 tissues and organs, and 121 cancer types. The LINCS-CLO view information can be queried using SPARQL scripts. CLO was used to support ontological representation, integration, and analysis of over a thousand LINCS cell line cells and their cellular responses.

An anatomic and morphometric study of C2 nerve root ganglion and its corresponding foramen.

PubMed

Bilge, Okan

2004-03-01

Exposing and measuring the dorsal root ganglion of the second cervical spinal nerve (C2 ganglion) and the second intervertebral space, which is present between posterior arch of atlas (APA) and lamina of axis (LA). This study aims to investigate the shape, size, and relation of the C2 ganglion with the adjacent structures that limits the corresponding intervertebral space and the alterations of relation between C2 ganglion and APA and between C2 ganglion and LA with the movements of the head bilaterally. In previous studies, the position and the heights of the C2 ganglion have been described. But the shape of the C2 ganglion and its relation to APA and LA by the movement of the head had not been considered previously. Upper cervical spines of 20 cadavers were dissected posteriorly. The muscles attaching to the atlas and axis were resected to ease the head movements. The heights of the C2 ganglion and space were measured in anatomic position and in hyperextension with opposite rotation position of the head. Originally in this study, plastic dough casts were used to obtain reliable outcomes. The shape of the ganglions was defined in three types: 70% were oval, 20% were spindle-like, and 10% were spherical. The height of the C2 ganglion was 4.97 +/- 0.92 mm on the right side and 4.6 +/- 0.84 mm on the left side. The height of the intervertebral space in anatomic position and in hyperextension with rotation to the opposite position of the head were, respectively, 9.74 +/- 1.77 mm and 7.48 +/- 1.44 mm on the right side and 9.64 +/- 1.47 mm and 7.12 +/- 0.96 mm on the left side. There was no bone contact or impact to the ganglion in each position of the head. The C2 ganglions are confident in their place between APA and LA. No bone contact to the C2 ganglion was detected in either normal limited or in forced head motions.

The neuronal EGF-related gene Nell2 interacts with Macf1 and supports survival of retinal ganglion cells after optic nerve injury.

PubMed

Munemasa, Yasunari; Chang, Chang-Sheng; Kwong, Jacky M K; Kyung, Haksu; Kitaoka, Yasushi; Caprioli, Joseph; Piri, Natik

2012-01-01

Nell2 is a neuron-specific protein containing six epidermal growth factor-like domains. We have identified Nell2 as a retinal ganglion cell (RGC)-expressed gene by comparing mRNA profiles of control and RGC-deficient rat retinas. The aim of this study was to analyze Nell2 expression in wild-type and optic nerve axotomized retinas and evaluate its potential role in RGCs. Nell2-positive in situ and immunohistochemical signals were localized to irregularly shaped cells in the ganglion cell layer (GCL) and colocalized with retrogradely-labeled RGCs. No Nell2-positive cells were detected in 2 weeks optic nerve transected (ONT) retinas characterized with approximately 90% RGC loss. RT-PCR analysis showed a dramatic decrease in the Nell2 mRNA level after ONT compared to the controls. Immunoblot analysis of the Nell2 expression in the retina revealed the presence of two proteins with approximate MW of 140 and 90 kDa representing glycosylated and non-glycosylated Nell2, respectively. Both products were almost undetectable in retinal protein extracts two weeks after ONT. Proteome analysis of Nell2-interacting proteins carried out with MALDI-TOF MS (MS) identified microtubule-actin crosslinking factor 1 (Macf1), known to be critical in CNS development. Strong Macf1 expression was observed in the inner plexiform layer and GCL where it was colocalizied with Thy-1 staining. Since Nell2 has been reported to increase neuronal survival of the hippocampus and cerebral cortex, we evaluated the effect of Nell2 overexpression on RGC survival. RGCs in the nasal retina were consistently more efficiently transfected than in other areas (49% vs. 13%; n = 5, p<0.05). In non-transfected or pEGFP-transfected ONT retinas, the loss of RGCs was approximately 90% compared to the untreated control. In the nasal region, Nell2 transfection led to the preservation of approximately 58% more cells damaged by axotomy compared to non-transfected (n = 5, p<0.01) or pEGFP-transfected controls (n = 5, p<0.01).

The Neuronal EGF-Related Gene Nell2 Interacts with Macf1 and Supports Survival of Retinal Ganglion Cells after Optic Nerve Injury

PubMed Central

Munemasa, Yasunari; Chang, Chang-Sheng; Kwong, Jacky M. K.; Kyung, Haksu; Kitaoka, Yasushi; Caprioli, Joseph; Piri, Natik

2012-01-01

Nell2 is a neuron-specific protein containing six epidermal growth factor-like domains. We have identified Nell2 as a retinal ganglion cell (RGC)-expressed gene by comparing mRNA profiles of control and RGC-deficient rat retinas. The aim of this study was to analyze Nell2 expression in wild-type and optic nerve axotomized retinas and evaluate its potential role in RGCs. Nell2-positive in situ and immunohistochemical signals were localized to irregularly shaped cells in the ganglion cell layer (GCL) and colocalized with retrogradely-labeled RGCs. No Nell2-positive cells were detected in 2 weeks optic nerve transected (ONT) retinas characterized with approximately 90% RGC loss. RT-PCR analysis showed a dramatic decrease in the Nell2 mRNA level after ONT compared to the controls. Immunoblot analysis of the Nell2 expression in the retina revealed the presence of two proteins with approximate MW of 140 and 90 kDa representing glycosylated and non-glycosylated Nell2, respectively. Both products were almost undetectable in retinal protein extracts two weeks after ONT. Proteome analysis of Nell2-interacting proteins carried out with MALDI-TOF MS (MS) identified microtubule-actin crosslinking factor 1 (Macf1), known to be critical in CNS development. Strong Macf1 expression was observed in the inner plexiform layer and GCL where it was colocalizied with Thy-1 staining. Since Nell2 has been reported to increase neuronal survival of the hippocampus and cerebral cortex, we evaluated the effect of Nell2 overexpression on RGC survival. RGCs in the nasal retina were consistently more efficiently transfected than in other areas (49% vs. 13%; n = 5, p<0.05). In non-transfected or pEGFP-transfected ONT retinas, the loss of RGCs was approximately 90% compared to the untreated control. In the nasal region, Nell2 transfection led to the preservation of approximately 58% more cells damaged by axotomy compared to non-transfected (n = 5, p<0.01) or pEGFP-transfected controls (n�

Organ of Corti explants direct tonotopically graded morphology of spiral ganglion neurons in vitro.

PubMed

Smith, Felicia L; Davis, Robin L

2016-08-01

The spiral ganglion is a compelling model system to examine how morphological form contributes to sensory function. While the ganglion is composed mainly of a single class of type I neurons that make simple one-to-one connections with inner hair cell sensory receptors, it has an elaborate overall morphological design. Specific features, such as soma size and axon outgrowth, are graded along the spiral contour of the cochlea. To begin to understand the interplay between different regulators of neuronal morphology, we cocultured neuron explants with peripheral target tissues removed from distinct cochlear locations. Interestingly, these "hair cell microisolates" were capable of both increasing and decreasing neuronal somata size, without adversely affecting survival. Moreover, axon characteristics elaborated de novo by the primary afferents in culture were systematically regulated by the sensory endorgan. Apparent peripheral nervous system (PNS)-like and central nervous system (CNS)-like axonal profiles were established in our cocultures allowing an analysis of putative PNS/CNS axon length ratios. As predicted from the in vivo organization, PNS-like axon bundles elaborated by apical cocultures were longer than their basal counterparts and this phenotype was methodically altered when neuron explants were cocultured with microisolates from disparate cochlear regions. Thus, location-dependent signals within the organ of Corti may set the "address" of neurons within the spiral ganglion, allowing them to elaborate the appropriate tonotopically associated morphological features in order to carry out their signaling function. J. Comp. Neurol. 524:2182-2207, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Diabetes accelerates retinal ganglion cell dysfunction in mice lacking sigma receptor 1

PubMed Central

Ha, Yonju; Saul, Alan; Tawfik, Amany; Zorrilla, Eric P.; Ganapathy, Vadivel

2012-01-01

Purpose Sigma receptor 1 (σR1) is a non-opioid transmembrane protein that may act as a molecular chaperone at the endoplasmic reticulum–mitochondrial membrane. Ligands for σR1, such as (+)-pentazocine [(+)-PTZ], confer marked retinal neuroprotection in vivo and in vitro. Recently we analyzed the retinal phenotype of mice lacking σR1 (σR1 KO) and observed normal retinal morphology and function in young mice (5–30 weeks) but diminished negative scotopic threshold responses (nSTRs), retinal ganglion cell (RGC) loss, and disruption of optic nerve axons consistent with inner retinal dysfunction by 1 year. These data led us to test the hypothesis that σR1 may be critical in forestalling chronic retinal stress; diabetes was used as the model of chronic stress. Methods To determine whether σR1 is required for (+)-PTZ neuroprotective effects, primary RGCs isolated from wild-type (WT) and σR1 KO mice were exposed to xanthine–xanthine oxidase (10 µM:2 mU/ml) to induce oxidative stress in the presence or absence of (+)-PTZ. Cell death was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. To assess effects of chronic stress on RGC function, diabetes was induced in 3-week C57BL/6 (WT) and σR1 KO mice, using streptozotocin to yield four groups: WT nondiabetic (WT non-DB), WT diabetic (WT-DB), σR1 KO non-DB, and σR1 KO-DB. After 12 weeks of diabetes, when mice were 15-weeks old, intraocular pressure (IOP) was recorded, electrophysiologic testing was performed (including detection of nSTRs), and the number of RGCs was counted in retinal histological sections. Results In vitro studies showed that (+)-PTZ could not prevent oxidative stress-induced death of RGCs harvested from σR1 KO mice but afforded robust protection against death of RGCs harvested from WT mice. In the studies of chronic stress induced by diabetes, the IOP measured in the four mouse groups was within the normal range; however, there was a significant

Diabetes accelerates retinal ganglion cell dysfunction in mice lacking sigma receptor 1.

PubMed

Ha, Yonju; Saul, Alan; Tawfik, Amany; Zorrilla, Eric P; Ganapathy, Vadivel; Smith, Sylvia B

2012-01-01

Sigma receptor 1 (σR1) is a non-opioid transmembrane protein that may act as a molecular chaperone at the endoplasmic reticulum-mitochondrial membrane. Ligands for σR1, such as (+)-pentazocine [(+)-PTZ], confer marked retinal neuroprotection in vivo and in vitro. Recently we analyzed the retinal phenotype of mice lacking σR1 (σR1 KO) and observed normal retinal morphology and function in young mice (5-30 weeks) but diminished negative scotopic threshold responses (nSTRs), retinal ganglion cell (RGC) loss, and disruption of optic nerve axons consistent with inner retinal dysfunction by 1 year. These data led us to test the hypothesis that σR1 may be critical in forestalling chronic retinal stress; diabetes was used as the model of chronic stress. To determine whether σR1 is required for (+)-PTZ neuroprotective effects, primary RGCs isolated from wild-type (WT) and σR1 KO mice were exposed to xanthine-xanthine oxidase (10 µM:2 mU/ml) to induce oxidative stress in the presence or absence of (+)-PTZ. Cell death was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. To assess effects of chronic stress on RGC function, diabetes was induced in 3-week C57BL/6 (WT) and σR1 KO mice, using streptozotocin to yield four groups: WT nondiabetic (WT non-DB), WT diabetic (WT-DB), σR1 KO non-DB, and σR1 KO-DB. After 12 weeks of diabetes, when mice were 15-weeks old, intraocular pressure (IOP) was recorded, electrophysiologic testing was performed (including detection of nSTRs), and the number of RGCs was counted in retinal histological sections. In vitro studies showed that (+)-PTZ could not prevent oxidative stress-induced death of RGCs harvested from σR1 KO mice but afforded robust protection against death of RGCs harvested from WT mice. In the studies of chronic stress induced by diabetes, the IOP measured in the four mouse groups was within the normal range; however, there was a significant increase in the IOP of σR1 KO

Surface receptors on human haematopoietic cell lines.

PubMed Central

Huber, C; Sundström, C; Nilsson, K; Wigzell, H

1976-01-01

The expression of complement receptors, of Fc receptors, of SRBC receptors and of S-Ig was investigated on human haematopoietic cell lines of proved malignant derivation. According to their origin and to a panel of phenotypic markers these lines have been classified into lymphoma lines, myeloma lines and leukemia lines. Results were compared with those obtained on non-malignant EBV carrying lymphoblastoid cell lines (LCL). Among the lymphoid cell lines the LCL showed a pattern of B-lymphocyte surface markers, i.e. surface immunoglobulins, C3 receptors but low density of Fc receptors. The non-Burkitt lymphoma lines bore in varying degree these B-lymphocyte markers. The lines U-698 M and DG-75 were exceptional in having only surface immunoglobulin. The Burkitt lymphoma lines had all B-lymphocyte markers. The myeloma lines differed from the lymphoid lines in lacking C3 and Fc receptors and showed only trace amounts of surface immunoglobulins. In contrast to lymphoid and myeloma lines, the leukaemia lines were completely lacking surface immunoglobulins, but showed C3 and Fc receptors in variable densities. On line, the ALL derived line MOLT-3 showed the capacity to spontaneous rosette formation with SRBC. The findings that LCL presented a homogeneous pattern of B-lymphocyte surface markers may be of value in order to discriminate between these lines and lines derived from haematopoietic malignancies other than Burkitt lymphomas. PMID:963908

A Case Report of an Acromioclavicular Joint Ganglion Associated with a Rotator Cuff Tear.

PubMed

Tanaka, Suguru; Gotoh, Masafumi; Mitsui, Yasuhiro; Shirachi, Isao; Okawa, Takahiro; Higuchi, Fujio; Shiba, Naoto

2017-04-13

We report a case of subcutaneous ganglion adjacent to the acromioclavicular joint with massive rotator cuff tear [1-7]. An 81-year-old woman presented with a ganglion adjacent to the acromioclavicular joint that had first been identified 9 months earlier. The ganglion had recurred after having been aspirated by her local physician, so she was referred to our hospital. The puncture fluid was yellowish, clear and viscous. Magnetic resonance imaging identified a massive rotator cuff tear with multi- lobular cystic lesions continuous to the acromioclavicular joint, presenting the "geyser sign". During arthroscopy, distal clavicular resection and excision of the ganglion were performed together with joint debridement. At present, the ganglion has not recurred and the patient has returned to normal daily activity. In this case, the ganglion may have developed subsequent to the concomitant massive cuff tear, due to subcutaneous fluid flow through the damaged acromioclavicular joint.

Petrosal ganglion: a more complex role than originally imagined.

PubMed

Retamal, Mauricio A; Reyes, Edison P; Alcayaga, Julio

2014-01-01

The petrosal ganglion (PG) is a peripheral sensory ganglion, composed of pseudomonopolar sensory neurons that innervate the posterior third of the tongue and the carotid sinus and body. According to their electrical properties PG neurons can be ascribed to one of two categories: (i) neurons with action potentials presenting an inflection (hump) on its repolarizing phase and (ii) neurons with fast and brisk action potentials. Although there is some correlation between the electrophysiological properties and the sensory modality of the neurons in some species, no general pattern can be easily recognized. On the other hand, petrosal neurons projecting to the carotid body are activated by several transmitters, with acetylcholine and ATP being the most conspicuous in most species. Petrosal neurons are completely surrounded by a multi-cellular sheet of glial (satellite) cells that prevents the formation of chemical or electrical synapses between neurons. Thus, PG neurons are regarded as mere wires that communicate the periphery (i.e., carotid body) and the central nervous system. However, it has been shown that in other sensory ganglia satellite glial cells and their neighboring neurons can interact, partly by the release of chemical neuro-glio transmitters. This intercellular communication can potentially modulate the excitatory status of sensory neurons and thus the afferent discharge. In this mini review, we will briefly summarize the general properties of PG neurons and the current knowledge about the glial-neuron communication in sensory neurons and how this phenomenon could be important in the chemical sensory processing generated in the carotid body.

A Cre Mouse Line for Probing Irradiance- and Direction-Encoding Retinal Networks

PubMed Central

Sabbah, Shai

2017-01-01

Abstract Cell type-specific Cre driver lines have revolutionized the analysis of retinal cell types and circuits. We show that the transgenic mouse Rbp4-Cre selectively labels several retinal neuronal types relevant to the encoding of absolute light intensity (irradiance) and visual motion. In the ganglion cell layer (GCL), most marked cells are wide-field spiking polyaxonal amacrine cells (ACs) with sustained irradiance-encoding ON responses that persist during chemical synaptic blockade. Their arbors spread about 1 mm across the retina and are restricted to the inner half of the ON sublamina of the inner plexiform layer (IPL). There, they costratify with dendrites of M2 intrinsically photosensitive retinal ganglion cells (ipRGCs), to which they are tracer coupled. We propose that synaptically driven and intrinsic photocurrents of M2 cells pass through gap junctions to drive AC light responses. Also marked in this mouse are two types of RGCs. R-cells have a bistratified dendritic arbor, weak directional tuning, and irradiance-encoding ON responses. However, they also receive excitatory OFF input, revealed during ON-channel blockade. Serial blockface electron microscopic (SBEM) reconstruction confirms OFF bipolar input, and reveals that some OFF input derives from a novel type of OFF bipolar cell (BC). R-cells innervate specific layers of the dorsal lateral geniculate nucleus (dLGN) and superior colliculus (SC). The other marked RGC type (RDS) is bistratified, transient, and ON-OFF direction selective (DS). It apparently innervates the nucleus of the optic tract (NOT). The Rbp4-Cre mouse will be valuable for targeting these cell types for further study and for selectively manipulating them for circuit analysis. PMID:28466070

Ectopic transgene expression in the retina of four transgenic mouse lines

PubMed Central

Gábriel, Robert; Erdélyi, Ferenc; Szabó, Gábor; Lawrence, J. Josh

2017-01-01

Retinal expression of transgenes was examined in four mouse lines. Two constructs were driven by the choline acetyltransferase (ChAT) promoter: green fluorescent protein conjugated to tau protein (tau-GFP) or cytosolic yellow fluorescent protein (YFP) generated through CRE recombinase-induced expression of Rosa26 (ChAT-CRE/ Rosa26YFP). Two other constructs targeted inhibitory interneurons: GABAergic horizontal and amacrine cells identified by glutamic acid decarboxylase (GAD65-GFP) or parvalbumin (PV) cells (PV-CRE/Rosa26YFP). Animals were transcardially perfused and retinal sections prepared. Antibodies against PV, calretinin (CALR), calbindin (CALB), and tyrosine hydroxylase (TH) were used to counterstain transgene-expressing cells. In PVxRosa and ChAT-tauGFP constructs, staining appeared in vertically oriented row of processes resembling Müller cells. In the ChATxRosa construct, populations of amacrine cells and neurons in the ganglion cell layer were labeled. Some cones also exhibited GFP fluorescence. CALR, PV and TH were found in none of these cells. Occasionally, we found GFP/ CALR and GFP/PV double-stained cells in the ganglion cell layer (GCL). In the GAD65-GFP construct, all layers of the neuroretina were labeled, except photoreceptors. Not all horizontal cells expressed GFP. We did not find GFP/TH double-labeled cells and GFP was rarely present in CALR-and CALB-containing cells. Many PV-positive neurons were also labeled for GFP, including small diameter amacrines. In the GCL, single labeling for GFP and PV was ascertained, as well as several CALR/PV double-stained neurons. In the GCL, cells triple labeled with GFP/CALR/ CALB were sparse. In conclusion, only one of the four transgenic constructs exhibited an expression pattern consistent with endogenous retinal protein expression, while the others strongly suggested ectopic gene expression. PMID:26563404

77 FR 5489 - Identification of Human Cell Lines Project

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-03

...-01] Identification of Human Cell Lines Project AGENCY: National Institute of Standards and Technology... cell line samples as part of the Identification of Human Cell Lines Project. All data and corresponding... cell lines accepted on the NIST Applied Genetics Group Web site at http://www.nist.gov/mml/biochemical...

Use of “MGE Enhancers” for Labeling and Selection of Embryonic Stem Cell-Derived Medial Ganglionic Eminence (MGE) Progenitors and Neurons

PubMed Central

Chen, Ying-Jiun J.; Vogt, Daniel; Wang, Yanling; Visel, Axel; Silberberg, Shanni N.; Nicholas, Cory R.; Danjo, Teruko; Pollack, Joshua L.; Pennacchio, Len A.; Anderson, Stewart; Sasai, Yoshiki; Baraban, Scott C.; Kriegstein, Arnold R.; Alvarez-Buylla, Arturo; Rubenstein, John L. R.

2013-01-01

The medial ganglionic eminence (MGE) is an embryonic forebrain structure that generates the majority of cortical interneurons. MGE transplantation into specific regions of the postnatal central nervous system modifies circuit function and improves deficits in mouse models of epilepsy, Parkinson's disease, pain, and phencyclidine-induced cognitive deficits. Herein, we describe approaches to generate MGE-like progenitor cells from mouse embryonic stem (ES) cells. Using a modified embryoid body method, we provided gene expression evidence that mouse ES-derived Lhx6+ cells closely resemble immature interneurons generated from authentic MGE-derived Lhx6+ cells. We hypothesized that enhancers that are active in the mouse MGE would be useful tools in detecting when ES cells differentiate into MGE cells. Here we demonstrate the utility of enhancer elements [422 (DlxI12b), Lhx6, 692, 1056, and 1538] as tools to mark MGE-like cells in ES cell differentiation experiments. We found that enhancers DlxI12b, 692, and 1538 are active in Lhx6-GFP+ cells, while enhancer 1056 is active in Olig2+ cells. These data demonstrate unique techniques to follow and purify MGE-like derivatives from ES cells, including GABAergic cortical interneurons and oligodendrocytes, for use in stem cell-based therapeutic assays and treatments. PMID:23658702

Development of a cell-based treatment for long-term neurotrophin expression and spiral ganglion neuron survival.

PubMed

Zanin, M P; Hellström, M; Shepherd, R K; Harvey, A R; Gillespie, L N

2014-09-26

Spiral ganglion neurons (SGNs), the target cells of the cochlear implant, undergo gradual degeneration following loss of the sensory epithelium in deafness. The preservation of a viable population of SGNs in deafness can be achieved in animal models with exogenous application of neurotrophins such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3. For translation into clinical application, a suitable delivery strategy that provides ongoing neurotrophic support and promotes long-term SGN survival is required. Cell-based neurotrophin treatment has the potential to meet the specific requirements for clinical application, and we have previously reported that Schwann cells genetically modified to express BDNF can support SGN survival in deafness for 4 weeks. This study aimed to investigate various parameters important for the development of a long-term cell-based neurotrophin treatment to support SGN survival. Specifically, we investigated different (i) cell types, (ii) gene transfer methods and (iii) neurotrophins, in order to determine which variables may provide long-term neurotrophin expression and which, therefore, may be the most effective for supporting long-term SGN survival in vivo. We found that fibroblasts that were nucleofected to express BDNF provided the most sustained neurotrophin expression, with ongoing BDNF expression for at least 30 weeks. In addition, the secreted neurotrophin was biologically active and elicited survival effects on SGNs in vitro. Nucleofected fibroblasts may therefore represent a method for safe, long-term delivery of neurotrophins to the deafened cochlea to support SGN survival in deafness. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Heat Shock Proteins In The Retina: Focus On Hsp70 and Alpha Crystallins In Ganglion Cell Survival

PubMed Central

Piri, Natik; Kwong, Jacky MK; Gu, Lei; Caprioli, Joseph

2016-01-01

Heat shock proteins (HSPs) belong to a superfamily of stress proteins that are critical constituents of a complex defense mechanism that enhances cell survival under adverse environmental conditions. Cell protective roles of HSPs are related to their chaperone functions, antiapoptotic and antinecrotic effects. HSPs' antiapoptotic and cytoprotective characteristics, their ability to protect cells from a variety of stressful stimuli, and the possibility of their pharmacological induction in cells under pathological stress make these proteins an attractive therapeutic target for various neurodegenerative diseases; these include Alzheimer's, Parkinson's, Huntington's, prion disease, and others. This review discusses the possible roles of HSPs, particularly HSP70 and small HSPs (alpha A and alpha B crystallins) in enhancing the survival of retinal ganglion cells (RGCs) in optic neuropathies such as glaucoma, which is characterized by progressive loss of vision caused by degeneration of RGCs and their axons in the optic nerve. Studies in animal models of RGC degeneration induced by ocular hypertension, optic nerve crush and axotomy show that upregulation of HSP70 expression by hyperthermia, zinc, geranyl-geranyl acetone, 17-AAG (a HSP90 inhibitor), or through transfection of retinal cells with AAV2-HSP70 effectively supports the survival of injured RGCs. RGCs survival was also stimulated by overexpression of alpha A and alpha B crystallins. These findings provide support for translating the HSP70- and alpha crystallin-based cell survival strategy into therapy to protect and rescue injured RGCs from degeneration associated with glaucomatous and other optic neuropathies. PMID:27017896

Ganglion cell complex scan in the early prediction of glaucoma.

PubMed

Ganekal, S

2012-01-01

To compare the macular ganglion cell complex (GCC) with peripapillary retinal fiber layer (RNFL) thickness map in glaucoma suspects and patients. Forty participants (20 glaucoma suspects and 20 glaucoma patients) were enrolled. Macular GCC and RNFL thickness maps were performed in both eyes of each participant in the same visit. The sensitivity and specificity of a color code less than 5% (red or yellow) for glaucoma diagnosis were calculated. Standard Automated Perimetry was performed with the Octopus 3.1.1 Dynamic 24-2 program. The statistical analysis was performed with the SPSS 10.1 (SPSS Inc. Chicago, IL, EUA). Results were expressed as mean +/- standard deviation and a p value of 0.05 or less was considered significant. Provide absolute numbers of these findings with their units of measurement. There was a statistically significant difference in average RNFL thickness (p=0.004), superior RNFL thickness (p=0.006), inferior RNFL thickness (p=0.0005) and average GCC (p=0.03) between the suspects and glaucoma patients. There was no difference in optic disc area (p=0.35) and vertical cup/disc ratio (p=0.234) in both groups. While 38% eyes had an abnormal GCC and 13% had an abnormal RNFL thickness in the glaucoma suspect group, 98% had an abnormal GCC and 90% had an abnormal RNFL thickness in the glaucoma group. The ability to diagnose glaucoma with macular GCC thickness is comparable to that with peripapillary RNFL thickness . Macular GCC thickness measurements may be a good alternative or a complementary measurement to RNFL thickness assessment in the clinical evaluation of glaucoma. © NEPjOPH.

Spiral ganglion cells and macrophages initiate neuro-inflammation and scarring following cochlear implantation

PubMed Central

Bas, Esperanza; Goncalves, Stefania; Adams, Michelle; Dinh, Christine T.; Bas, Jose M.; Van De Water, Thomas R.; Eshraghi, Adrien A.

2015-01-01

Conservation of a patient's residual hearing and prevention of fibrous tissue/new bone formation around an electrode array are some of the major challenges in cochlear implant (CI) surgery. Although it is well-known that fibrotic tissue formation around the electrode array can interfere with hearing performance in implanted patients, and that associated intracochlear inflammation can initiate loss of residual hearing, little is known about the molecular and cellular mechanisms that promote this response in the cochlea. In vitro studies in neonatal rats and in vivo studies in adult mice were performed to gain insight into the pro-inflammatory, proliferative, and remodeling phases of pathological wound healing that occur in the cochlea following an electrode analog insertion. Resident Schwann cells (SC), macrophages, and fibroblasts had a prominent role in the inflammatory process in the cochlea. Leukocytes were recruited to the cochlea following insertion of a nylon filament in adult mice, where contributed to the inflammatory response. The reparative stages in wound healing are characterized by persistent neuro-inflammation of spiral ganglion neurons (SGN) and expression of regenerative monocytes/macrophages in the cochlea. Accordingly, genes involved in extracellular matrix (ECM) deposition and remodeling were up-regulated in implanted cochleae. Maturation of scar tissue occurs in the remodeling phase of wound healing in the cochlea. Similar to other damaged peripheral nerves, M2 macrophages and de-differentiated SC were observed in damaged cochleae and may play a role in cell survival and axonal regeneration. In conclusion, the insertion of an electrode analog into the cochlea is associated with robust early and chronic inflammatory responses characterized by recruitment of leukocytes and expression of pro-inflammatory cytokines that promote intracochlear fibrosis and loss of the auditory hair cells (HC) and SGN important for hearing after CI surgery. PMID

Feeder-cell-independent culture of the pig-embryonic-stem-cell-derived exocrine pancreatic cell line, PICM-31

USDA-ARS?s Scientific Manuscript database

The adaptation to feeder-independent growth of a pig embryonic stem cell-derived pancreatic cell line is described. The parental PICM-31 cell line, previously characterized as an exocrine pancreas cell line, was colony-cloned two times in succession resulting in the subclonal cell line, PICM-31A1. P...

Representation of the visual field in the primary visual area of the marmoset monkey: magnification factors, point-image size, and proportionality to retinal ganglion cell density.

PubMed

Chaplin, Tristan A; Yu, Hsin-Hao; Rosa, Marcello G P

2013-04-01