scholarly journals Photoreceptor inputs to pupil control

2019 ◽  
Author(s):  
Manuel Spitschan
Keyword(s):  
Retinal Ganglion Cells ◽  
Pupil Size ◽  
Ganglion Cells ◽  
Light Level ◽  
Retinal Ganglion ◽  
Pupil Control ◽  
Data Set

AbstractThe size of the pupil depends on light level. Watson & Yellott (2012) developed a unified formula to predict pupil size from luminance, field diameter, age, and number of eyes. Luminance reflects input from the L and M cones in the retina but ignores the contribution of intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin, which are known to control the size of the pupil. We discuss the role of melanopsin in controlling pupil size by reanalysing an extant data set. We confirm that melanopsin-weighted quantities, in conjunction with Watson & Yellott’s formula, adequately model intensity-dependent pupil size. We discuss the contributions of other photoreceptors into pupil control.

scholarly journals The Role of N-Methyl-D-Aspartate Receptor Activation in Homocysteine-Induced Death of Retinal Ganglion Cells

2011 ◽  
Vol 52 (8) ◽  
pp. 5515 ◽  
Author(s):  
Preethi S. Ganapathy ◽  
Richard E. White ◽  
Yonju Ha ◽  
B. Renee Bozard ◽  
Paul L. McNeil ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Receptor Activation ◽  
Retinal Ganglion ◽  
Aspartate Receptor

scholarly journals Nav1.6 promotes inflammation and neuronal degeneration in a mouse model of multiple sclerosis

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Barakat Alrashdi ◽  
Bassel Dawod ◽  
Andrea Schampel ◽  
Sabine Tacke ◽  
Stefanie Kuerten ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Retinal Ganglion Cells ◽  
Axonal Degeneration ◽  
Ganglion Cells ◽  
Neuronal Degeneration ◽  
Retinal Ganglion ◽  
Autoimmune Encephalomyelitis ◽  
Aav Vector ◽  
Α Subunit

Abstract Background In multiple sclerosis (MS) and in the experimental autoimmune encephalomyelitis (EAE) model of MS, the Nav1.6 voltage-gated sodium (Nav) channel isoform has been implicated as a primary contributor to axonal degeneration. Following demyelination Nav1.6, which is normally co-localized with the Na+/Ca2+ exchanger (NCX) at the nodes of Ranvier, associates with β-APP, a marker of neural injury. The persistent influx of sodium through Nav1.6 is believed to reverse the function of NCX, resulting in an increased influx of damaging Ca2+ ions. However, direct evidence for the role of Nav1.6 in axonal degeneration is lacking. Methods In mice floxed for Scn8a, the gene that encodes the α subunit of Nav1.6, subjected to EAE we examined the effect of eliminating Nav1.6 from retinal ganglion cells (RGC) in one eye using an AAV vector harboring Cre and GFP, while using the contralateral either injected with AAV vector harboring GFP alone or non-targeted eye as control. Results In retinas, the expression of Rbpms, a marker for retinal ganglion cells, was found to be inversely correlated to the expression of Scn8a. Furthermore, the gene expression of the pro-inflammatory cytokines Il6 (IL-6) and Ifng (IFN-γ), and of the reactive gliosis marker Gfap (GFAP) were found to be reduced in targeted retinas. Optic nerves from targeted eyes were shown to have reduced macrophage infiltration and improved axonal health. Conclusion Taken together, our results are consistent with Nav1.6 promoting inflammation and contributing to axonal degeneration following demyelination.

scholarly journals Hyperhomocysteinemia-induced death of retinal ganglion cells: The role of Müller glial cells and NRF2

Redox Biology ◽  
2019 ◽  
Vol 24 ◽  
pp. 101199 ◽  
Author(s):  
Soumya Navneet ◽  
Jing Zhao ◽  
Jing Wang ◽  
Barbara Mysona ◽  
Shannon Barwick ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Glial Cells ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Müller Glial Cells

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

1990 ◽  
Vol 4 (1) ◽  
pp. 75-93 ◽  
Author(s):  
Keith Purpura ◽  
Daniel Tranchina ◽  
Ehud Kaplan ◽  
Robert M. Shapley
Keyword(s):  
Retinal Ganglion Cells ◽  
Negative Feedback ◽  
Light Adaptation ◽  
Ganglion Cells ◽  
Human Subjects ◽  
Light Level ◽  
Retinal Ganglion ◽  
M Cell ◽  
Feedback Model ◽  
Light Levels

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

Loss of Retinal Ganglion Cells Following Retinal Ischemia: The Role of Inducible Nitric Oxide Synthase

2002 ◽  
Vol 75 (5) ◽  
pp. 521-528 ◽  
Author(s):  
Arthur H. Neufeld ◽  
Shin-ichiro Kawai ◽  
Sucharita Das ◽  
Smita Vora ◽  
Elizabeth Gachie ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Retinal Ganglion Cells ◽  
Inducible Nitric Oxide Synthase ◽  
Ganglion Cells ◽  
Retinal Ischemia ◽  
Retinal Ganglion ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Neuroactive peptides as markers of retinal ganglion cell populations that differ in anatomical organization and function

1988 ◽  
Vol 1 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Rodrigo O. Kuljis ◽  
Harvey J. Karten
Keyword(s):  
Retinal Ganglion Cells ◽  
Optic Tectum ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Pharmacological Manipulation ◽  
Functional Aspects ◽  
Neuroactive Peptides ◽  
Retinofugal Projections ◽  
And Function

AbstractRecent immunocytochemical studies indicate the existence of several classes of peptide- (PRGC) and catecholamine-containing retinal ganglion cells in anurans, birds, and mammals. Different classes of PRGC project to discrete and seemingly unique layers in the retino-recipient portion of the anuran and avian optic tectum. Peptide-containing retinofugal projections to the frog tectum originate early in development, and are reestablished by some classes of PRGC during regeneration of the optic nerve. These findings indicate that chemically specific, parallel retinofugal pathways presumably subserve different functional aspects of vision in vertebrates. Exciting prospects for research include the correlation of physiologically with immunocytochemically defined classes of retinal ganglion cells, the analysis of the possible role of neuroactive peptides in retinofugal transmission, and the pharmacological manipulation of putative peptidergic retinofugal pathways to analyze their role in visual function.

The role of sirt1 in the retinal ganglion cells cultured by high glucose

2020 ◽  
Author(s):  
Yue Zhou ◽  
Lian-jun Cai ◽  
Li-hui Xu ◽  
Yu Guo ◽  
Nuo Chen ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
High Glucose ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Cells Cultured
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