Search results for "Ganglion Cells"
showing 6 items of 66 documents
Dynamics, alterations, and consequences of minimally invasive intraocular pressure elevation in rats.
2014
PURPOSE: An important, yet not exclusive, aspect of primary open angle glaucoma is elevated intraocular pressure (IOP) profiles within fluctuations and pressure peaks. The study aimed at establishing minimally invasive methods for recurrent IOP elevation in rats to investigate the impact of IOP dynamics and pathomorphologic retinal alterations during and after IOP elevation. METHODS: Intraocular pressure was elevated unilaterally in Long Evans rats to a level of ≈35 mm Hg for 1 hour in a total of 30 manipulations within 6 weeks, by using two methods: (1) suction-cup oculopression and (2) loop-adjusted oculopression. Retinal thickness (RT) was measured via optical coherence tomography (OCT),…
Retinal neurodegenerative changes in the adult insulin receptor substrate-2 deficient mouse.
2014
Abstract Insulin receptor substrate-2 (Irs2) mediates peripheral insulin action and is essential for retinal health. Previous investigations have reported severe photoreceptor degeneration and abnormal visual function in Irs2-deficient mice. However, molecular changes in the Irs2 − / − mouse retina have not been described. In this study, we examined retinal degenerative changes in neuronal and glial cells of adult (9- and 12-week old) Irs2 − / − mice by immunohistochemistry. 9-week old Irs2 − / − mice showed significant thinning of outer retinal layers, concomitant to Muller and microglial cell activation. Photoreceptor cells displayed different signs of degeneration, such as outer/inner…
Fiat lux: the light became therapy. An overview on the Bright Light Therapy in Alzheimer’s Disease sleep disorders
2020
Background: A system of photosensitive retinal ganglion cells provides ‘non-visual’ information on the circadian sequences of light to the suprachiasmatic nucleus (SCN), which, as the ‘master clock’, synchronizes the chronobiological mechanisms of all the biological clocks. Damage to SCN structure alters circadian behavioral and hormonal rhythms and interferes with a regular sleep-wake pattern. Several studies have shown that, in aging and in Alzheimer’s disease (AD), circadian rhythms change their synchronization with the environment and behavior loses sync with light. Objective: The current overview aims to examine research studies showing the effect of bright light therapy (BLT) on sleep…
Time course of IOP elevation, electroretinographic changes and retinal ganglion cell loss in a rat model of glaucoma induced by laser
2007
International audience; Purpose: To evaluate the time course of intraocular pressure (IOP) elevation, electroretinographic changes and retinal ganglion cell (RGC) loss in a rat model of glaucoma induced by photocoagulation of the trabeculum and the episcleral and limbal veins. Methods: Male Sprague Dawley rats were used at 6 weeks of age. At least 3 of the episcleral veins, the trabeculum and the limbal veins were photocoagulated with a laser at 532nm (Quantel Medical, Vitra) in one eye of the animals. IOP and electroretinogram (ERG) were monitored every 2 weeks during 11 weeks after photocoagulation. Three months after laser photocoagulation, the RGC population was identified with a 5% Flu…
Effect of dietary omega-3 and omega-6 fatty acids on IOP elevation, electroretinographic changes and retinal ganglion cell loss in a laser-induced ra…
2008
International audience; Purpose:To test the efficacy of dietary omega-3 and omega-6 fatty acids in a rat model of glaucoma induced by laser photocoagulation.Methods:Male Sprague Dawley rats were fed for 3 months with a diet containing either: 1) 17% of omega-3 fatty acids (10% EPA + 7% DHA), 2) 10% of omega-6 fatty acids (as GLA), or 3) a combination of both omega-3 and omega-6 fatty acids (10% EPA + 7% DHA + 10% GLA), by comparison with a control group of animals fed with a standard diet deprived of EPA, DHA and GLA (n=10 in each group). After 3 months of diet, glaucoma was induced in one eye of each animal by laser photocoagulation (532nm) of the episcleral veins, the trabeculum and the l…
Motion perception in early glaucoma
2013
Purpose: The aim of our study was to underline the changes in the movement perception for early glaucoma. Our working hypothesis consisted in inquiring if the impairment of the magnocellular pathway may modify the movement perception capabilities in the visual field, more particularly in its peripheral area.Methods: We included 14 healthy subjects and 14 patients with early primary open angle glaucoma. A moving target was presented on a semicircular screen (1.8 m diameter); participants were asked to localize the Ending Point (EP) of each movement. Each stimulus consisted in a white dot (0,72° of diameter) moving horizontally with the imposed velocity profile. Two different laws of motion w…