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Retinal ganglion cell

Timm Oberwahrenbrock, Ghislaine L Traber, Sebastian Lukas, Iñigo Gabilondo, Rachel Nolan, Christopher Songster, Lisanne Balk, Axel Petzold, Friedemann Paul, Pablo Villoslada, Alexander U Brandt, Ari J Green, Sven Schippling
Objective: To evaluate the inter-rater reliability of semiautomated segmentation of spectral domain optical coherence tomography (OCT) macular volume scans. Methods: Macular OCT volume scans of left eyes from 17 subjects (8 patients with MS and 9 healthy controls) were automatically segmented by Heidelberg Eye Explorer (v1.9.3.0) beta-software (Spectralis Viewing Module v6.0.0.7), followed by manual correction by 5 experienced operators from 5 different academic centers...
May 2018: Neurology® Neuroimmunology & Neuroinflammation
Dawei Lei, Zhengbo Shao, Xinrong Zhou, Huiping Yuan
Retinal ischemia-reperfusion (RIR) injury causes neuronal degeneration and initiates various optic nerve diseases. This study aimed to investigate the synergistic neuroprotective effect of rasagiline and idebenone against RIR injury. A combination of rasagiline and idebenone was administered intraperitoneally immediately after establishment of the RIR model. Treatment with the combination of the two drugs resulted in a significant restoration of retinal thickness and retinal ganglion cells. Apoptosis of cells in ganglion cell layers was also ameliorated, suggesting that the effect of the two drugs was synergistic and the expression of brain-derived neurotrophic factor increased...
February 23, 2018: Oncotarget
Berkeley K Fahrenthold, Kimberly A Fernandes, Richard T Libby
Excitotoxicity leads to the activation of a cytotoxic cascade that causes neuronal death. In the retina, retinal ganglion cells (RGCs) die after an excitotoxic insult. Multiple pathways have been proposed to contribute to RGC death after an excitotoxic insult, including TNF signaling, JNK activation, and ER stress. To test the importance of these pathways in RGC death after excitotoxic injury, the excitotoxin N-methyl-D-aspartate (NMDA) was intravitreally injected into mice deficient in components of these pathways...
March 15, 2018: Scientific Reports
Kaitlyn A Sapoznik, Ting Luo, Alberto de Castro, Lucie Sawides, Raymond L Warner, Stephen A Burns
In adaptive optics scanning laser ophthalmoscope (AOSLO) systems, capturing multiply scattered light can increase the contrast of the retinal microvasculature structure, cone inner segments, and retinal ganglion cells. Current systems generally use either a split detector or offset aperture approach to collect this light. We tested the ability of a spatial light modulator (SLM) as a rapidly configurable aperture to use more complex shapes to enhance the contrast of retinal structure. Particularly, we varied the orientation of a split detector aperture and explored the use of a more complex shape, the half annulus, to enhance the contrast of the retinal vasculature...
March 1, 2018: Biomedical Optics Express
Alon Poleg-Polsky, Huayu Ding, Jeffrey S Diamond
Dendrites in many neurons actively compute information. In retinal starburst amacrine cells, transformations from synaptic input to output occur within individual dendrites and mediate direction selectivity, but directional signal fidelity at individual synaptic outputs and correlated activity among neighboring outputs on starburst dendrites have not been examined systematically. Here, we record visually evoked calcium signals simultaneously at many individual synaptic outputs within single starburst amacrine cells in mouse retina...
March 13, 2018: Cell Reports
Adam DeBusk, Mark L Moster
PURPOSE OF REVIEW: Highlight some of the recent advances in gene therapy and gene modification for optic nerve disease to promote axon regeneration, neuroprotection, and increased visual functioning. RECENT FINDINGS: Visual loss secondary to optic nerve damage occurs in numerous ophthalmologic and neurologic conditions. Damaged retinal ganglion cells (RGCs) do not regenerate once they undergo apoptosis after injury. Gene therapy has been studied to replace gene mutations in disorders affecting the optic nerve as well as to alter genes responsible for suppressing or activating pathways of optic nerve growth and regeneration...
March 13, 2018: Current Opinion in Ophthalmology
Ji-Yeon Lee, Su-Ja Oh
The retinal degeneration resulting from elevated intraocular pressure was evaluated through functional and morphological analyses, for better understanding of the pathophysiology of glaucoma. Ocular hypertension was induced via unilateral episcleral venous cauterization in rats. Experimental time was set at 1 and 3 days, and 1, 2, 4, and 8 weeks post-operation. Retinal function was analyzed using electroretinography. For morphological analysis, retinal tissues were processed for immunochemistry by using antibodies against the calcium-sensing receptor and calcium-binding proteins...
February 2018: Experimental Neurobiology
Shandiz Tehrani, R Katherine Delf, William O Cepurna, Lauren Davis, Elaine C Johnson, John C Morrison
Small molecule delivery to the optic nerve would allow for exploration of molecular and cellular pathways involved in normal physiology and optic neuropathies such as glaucoma, and provide a tool for screening therapeutics in animal models. We report a novel surgical method for small molecule drug delivery to the optic nerve head (ONH) in a rodent model. In proof-of-principle experiments, we delivered cytochalasin D (Cyt D; a filamentous actin inhibitor) to the junction of the superior optic nerve and globe in rats to target the actin-rich astrocytic cytoskeleton of the ONH...
March 13, 2018: Scientific Reports
Daniela Aneta Starosta, Birgit Lorenz
BACKGROUND: Neurofibromatosis type 2 (NF2) is a genetic condition with an autosomal dominant pattern of inheritance and incomplete penetrance. It is characterized by multiple benign tumors of the central and peripheral nervous system including astrocytomas, ependymomas, meningeomas, and schwannomas, among which bilateral vestibular schwannomas are the most frequent. Among ocular manifestations of NF2, juvenile subcapsular cataract is the most common followed by epiretinal membranes and combined hamartomas of the retina and retinal pigment epithelium...
March 2018: Klinische Monatsblätter Für Augenheilkunde
Christophe Gardella, Olivier Marre, Thierry Mora
The brain has no direct access to physical stimuli but only to the spiking activity evoked in sensory organs. It is unclear how the brain can learn representations of the stimuli based on those noisy, correlated responses alone. Here we show how to build an accurate distance map of responses solely from the structure of the population activity of retinal ganglion cells. We introduce the Temporal Restricted Boltzmann Machine to learn the spatiotemporal structure of the population activity and use this model to define a distance between spike trains...
March 12, 2018: Proceedings of the National Academy of Sciences of the United States of America
Kenji Sakamoto, Taishi Suzuki, Kosuke Takahashi, Takumi Koguchi, Tasuku Hirayama, Asami Mori, Tsutomu Nakahara, Hideko Nagasawa, Kunio Ishii
Excitoneurotoxicity is regarded as one of the mechanisms of the death of retinal ganglion cells induced by retinal central artery occlusion and glaucoma. Oxidative stress is at least in part involved in excitoneurotoxicity. Fenton reaction, which is catalyzed by Fe2+ , is known to cause formation of hydroxyl radical, one of reactive oxygen species, suggesting that chelation of iron may be protective against excitoneurotoxicity. In the present study, we histologically evaluated whether zinc-deferoxamine (Zn-DFO) and deferasirox (DFX), common iron-chelating agents, were protective against N-methyl-D-aspartate (NMDA)-induced retinal injury in the rat in vivo...
March 9, 2018: Experimental Eye Research
Rosa de Hoz, Ana I Ramírez, Rosa González-Martín, Daniel Ajoy, Blanca Rojas, Elena Salobrar-Garcia, Francisco J Valiente-Soriano, Marcelino Avilés-Trigueros, Maria P Villegas-Pérez, Manuel Vidal-Sanz, Alberto Triviño, José M Ramírez, Juan J Salazar
The immune system plays an important role in glaucomatous neurodegeneration. Retinal microglial reactivation associated with ganglion cell loss could reportedly contribute to the glaucoma progression. Recently we have described signs of microglia activation both in contralateral and ocular hypertension (OHT) eyes involving all retinal layers 15 days after OHT laser induction in mice. However, no works available have analyzed the microglial activation at earliest time points after OHT induction (24 h) in this experimental model...
March 9, 2018: Experimental Eye Research
Kimberly A Fernandes, Katherine L Mitchell, Amit Patel, Olivia J Marola, Peter Shrager, Donald J Zack, Richard T Libby, Derek S Welsbie
Optic neuropathies such as glaucoma are characterized by the degeneration of retinal ganglion cells (RGCs) and the irreversible loss of vision. In these diseases, focal axon injury triggers a propagating axon degeneration and, eventually, cell death. Previous work by us and others identified dual leucine zipper kinase (DLK) and JUN N-terminal kinase (JNK) as key mediators of somal cell death signaling in RGCs following axonal injury. Moreover, others have shown that activation of the DLK/JNK pathway contributes to distal axonal degeneration in some neuronal subtypes and that this activation is dependent on the adaptor protein, sterile alpha and TIR motif containing 1 (SARM1)...
March 8, 2018: Experimental Eye Research
Nahla Reda Sarhan, Nesreen Moustafa Omar
Tadalafil (Cialis) is one of the most commonly used phosphodiesterase type5 (PDE5) inhibitors. This work aimed to analyze the histological and ultrastructural changes provoked by chronic tadalafil administration in the rat retina, correlate between such changes and PDE5 immunoexpression and to evaluate the possible reversibility of these changes. Thirty Sprague Dawley male rats were randomly distributed into 3 groups. Control group; given 1 ml distilled water daily for 6 weeks. Tadalafil group; given tadalafil in a daily dose of 2...
March 8, 2018: Acta Histochemica
Pengcheng Sun, Heng Li, Zhuofan Lu, Xiaofan Su, Zengguang Ma, Jianpin Chen, Liming Li, Chuanqing Zhou, Yao Chen, Xinyu Chai
BACKGROUND: Electrical stimulation has been widely used in many ophthalmic diseases to modulate neuronal activities or restore partial visual function. Due to the different processing pathways and mechanisms, responses to visual and electrical stimulation in the primary visual cortex and higher visual areas might be different. This differences would shed some light on the properties of cortical responses evoked by electrical stimulation. OBJECTIVE: This study's goal was to directly compare the cortical responses evoked by visual and electrical stimulation and investigate the cortical processing of visual information and extrinsic electrical signal...
February 21, 2018: Brain Stimulation
Florian S M Edlinger, Laura M Schrems-Hoesl, Christian Y Mardin, Robert Laemmer, Friedrich E Kruse, Wolfgang A Schrems
PURPOSE: Assessment of the diagnostic ability of segmented macular inner retinal layer thickness and peripapillary retinal nerve fiber layer (pRNFL) measured by spectral-domain optical coherence tomography (SD-OCT) in patients with normal-tension (NT) and high-tension (HT) perimetric and preperimetric glaucoma. METHODS: The 212 participants included 45 healthy subjects, 55 patients with ocular hypertension, 56 patients with preperimetric glaucoma, and 56 patients with perimetric glaucoma...
March 9, 2018: Graefe's Archive for Clinical and Experimental Ophthalmology
María Nieves-Moreno, José M Martínez-de-la-Casa, Laura Morales-Fernández, Rubén Sánchez-Jean, Federico Sáenz-Francés, Julián García-Feijoó
OBJECTIVE: To examine differences in individual retinal layer thicknesses measured by spectral domain optical coherence tomography (SD-OCT) (Spectralis®) produced with age and according to sex. DESIGN: Cross-sectional, observational study. METHODS: The study was conducted in 297 eyes of 297 healthy subjects aged 18 to 87 years. In one randomly selected eye of each participant the volume and mean thicknesses of the different macular layers were measured by SD-OCT using the instrument's macular segmentation software...
2018: PloS One
Luciano S Pereira, Marcos P Ávila, Luciana X Salustiano, Alcio C Paula, Emmanuel Arnhold, Timothy J McCulley
INTRODUCTION: The management of nonarteritic anterior ischemic optic neuropathy centers around prevention of second eye involvement, without a uniformly accepted therapy for the involved eye. Several researchers have assessed the benefit of steroids with conflicting results. This experimental study was designed to evaluate the efficacy of a single intravitreal triamcinolone acetonide injection (IVTA) in preserving retinal ganglion cells (RGCs) in a rodent model of anterior ischemic optic neuropathy (rAION)...
March 6, 2018: Journal of Neuro-ophthalmology: the Official Journal of the North American Neuro-Ophthalmology Society
Mancino Raffaele, Massimo Cesareo, Alessio Martucci, Emiliano Di Carlo, Elena Ciuffoletti, Clarissa Giannini, Luigi Antonio Morrone, Carlo Nucci, Francesco Garaci
Recent literature agrees that neurodegenerative processes involve both the retina and the central nervous system, which are two strictly related anatomical structures. However, the causal mechanisms of this dual involvement are still uncertain. To date, anterograde transynaptic neurodegeneration, triggered by retinal ganglion cells' death, and retrograde transynaptic neurodegeneration, induced by neurodegenerative processes of the central nervous system, have been considered the major possible causal mechanisms...
March 6, 2018: Current Medicinal Chemistry
Henry J Alitto, Daniel L Rathbun, Tucker G Fisher, Prescott C Alexander, W Martin Usrey
Visual information processed in the retina is transmitted to primary visual cortex via relay cells in the lateral geniculate nucleus (LGN) of the dorsal thalamus. Although retinal ganglion cells are the primary source of driving input to LGN neurons, not all retinal spikes are transmitted to the cortex. Here, we investigate the relationship between stimulus contrast and retinogeniculate communication and test the hypothesis that both the time course and strength of retinogeniculate interactions are dynamic and dependent on stimulus contrast...
March 8, 2018: European Journal of Neuroscience
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