The early development of the frog retinotectal projection

Development ◽  
1991 ◽  
Vol 113 (Supplement_2) ◽  
pp. 95-104
Author(s):  
Jeremy S. H. Taylor
Keyword(s):  
Ganglion Cell ◽  
Early Development ◽  
Short Distance ◽  
Lateral Wall ◽  
Retinal Ganglion ◽  
Initial Development ◽  
Retinal Axons ◽  
A Chain ◽  
The Brain ◽  
Rostral Part

The guidance of retinal ganglion cell axons has been investigated in embryos of the frog Xenopus. During the initial development of the brain a series of axon tracts are laid down forming a basic ‘scaffold’ or framework. Retinal axons grow through one of these tracts, the tract of the post-optic commissure (tPOC). This is the only tract that extends through the rostral part of the brain at these early stages of development. The origin and development of the tPOC has been studied using antibodies which label neurons at their earliest stages of differentiation. The first sign of the tPOC is a chain of neurons which differentiate simultaneously in the caudolateral part of the diencephalon. Axons from these neurons grow the short distance between adjacent cells interlinking the chain to form a descending tract. A series of other axon projections are then added to the tPOC, each of which is segregated into a particular subregion of the tract. Retinal axons are added to the tract approximately 18 h after its formation. They grow in the sub-pial part of the tract and always occupy the rostralmost edge. Retinal axons follow the tract to the region of the developing tectum where they leave, turn dorsally, and terminate. The reliance of retinal axons on this pre-existing pathway has been demonstrated by experimentally altering the course of the tPOC during its early development. The caudo-lateral wall of the diencephalon has been rotated through 90° at a stage just before the tPOC neurons differentiate. Confirmation of the predicted alteration in the course of the tPOC has been made using immunocytochemistry. In such manipulated brains, retinal axons maintain their strong affinity for the rostral edge of the tPOC, following its altered course through the diencephalon.

The directed growth of retinal axons towards surgically transposed tecta in Xenopus; an examination of homing behaviour by retinal ganglion cell axons

Development ◽  
1990 ◽  
Vol 108 (1) ◽  
pp. 147-158
Author(s):  
J.S. Taylor
Keyword(s):  
Ganglion Cell ◽  
Axon Guidance ◽  
Retinal Ganglion Cell ◽  
Optic Tract ◽  
Retinal Ganglion ◽  
Retinal Axons ◽  
Dorsal Neural Tube ◽  
Abnormal Structure ◽  
Optic Axons ◽  
The Brain

The growth of optic axons towards experimentally rotated tecta has been studied. In stage 24/25 embryos, a piece of the dorsal neural tube, containing the dorsal midbrain rudiment, was rotated through 180 degrees. At later stages of development, the pathways of growing optic axons were investigated by labelling with either horseradish peroxidase or fluorescent dye. It is shown that retinal ganglion cell axons followed well-defined pathways, in spite of the abnormal structure of the brain, and were able to locate displaced tecta. This directed outgrowth of retinal axons in the optic tracts appears to be related either to the tectum or to some other component included in the graft operations. In tadpoles in which the midbrain rudiment was removed, optic axons still followed the normal course of the optic tract. This observation argues against long-range target attraction as being essential in guiding growing retinal axons towards the tectum. An alternative axon guidance mechanism, selective fasciculation, is discussed as a possible alternative to explain the directed axon outgrowth which occurs in both the normal and in these experimentally manipulated tadpoles.

scholarly journals Effects of Iron and Zinc on Mitochondria: Potential Mechanisms of Glaucomatous Injury

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiahui Tang ◽  
Yehong Zhuo ◽  
Yiqing Li
Keyword(s):  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Visual Information ◽  
Ganglion Cells ◽  
Cell Damage ◽  
Current View ◽  
Retinal Ganglion ◽  
Mitochondrial Homeostasis ◽  
Iron And Zinc ◽  
The Brain

Glaucoma is the most substantial cause of irreversible blinding, which is accompanied by progressive retinal ganglion cell damage. Retinal ganglion cells are energy-intensive neurons that connect the brain and retina, and depend on mitochondrial homeostasis to transduce visual information through the brain. As cofactors that regulate many metabolic signals, iron and zinc have attracted increasing attention in studies on neurons and neurodegenerative diseases. Here, we summarize the research connecting iron, zinc, neuronal mitochondria, and glaucomatous injury, with the aim of updating and expanding the current view of how retinal ganglion cells degenerate in glaucoma, which can reveal novel potential targets for neuroprotection.

scholarly journals Visual properties of human retinal ganglion cells

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246952
Author(s):  
Katja Reinhard ◽  
Thomas A. Münch
Keyword(s):  
Ganglion Cell ◽  
Ganglion Cells ◽  
Ex Vivo ◽  
Cell Types ◽  
Similar Response ◽  
Human Retina ◽  
Retinal Ganglion ◽  
Light Responses ◽  
Morphological Studies ◽  
The Brain

The retinal output is the sole source of visual information for the brain. Studies in non-primate mammals estimate that this information is carried by several dozens of retinal ganglion cell types, each informing the brain about different aspects of a visual scene. Even though morphological studies of primate retina suggest a similar diversity of ganglion cell types, research has focused on the function of only a few cell types. In human retina, recordings from individual cells are anecdotal or focus on a small subset of identified types. Here, we present the first systematic ex-vivo recording of light responses from 342 ganglion cells in human retinas obtained from donors. We find a great variety in the human retinal output in terms of preferences for positive or negative contrast, spatio-temporal frequency encoding, contrast sensitivity, and speed tuning. Some human ganglion cells showed similar response behavior as known cell types in other primate retinas, while we also recorded light responses that have not been described previously. This first extensive description of the human retinal output should facilitate interpretation of primate data and comparison to other mammalian species, and it lays the basis for the use of ex-vivo human retina for in-vitro analysis of novel treatment approaches.

scholarly journals Visual properties of human retinal ganglion cells

2019 ◽  
Author(s):  
Katja Reinhard ◽  
Thomas A. Münch
Keyword(s):  
Ganglion Cell ◽  
Ganglion Cells ◽  
Ex Vivo ◽  
Cell Types ◽  
Similar Response ◽  
Human Retina ◽  
Retinal Ganglion ◽  
Light Responses ◽  
Morphological Studies ◽  
The Brain

The retinal output is the sole source of visual information for the brain. Studies in non-primate mammals estimate that this information is carried by several dozens of retinal ganglion cell types, each informing the brain about different aspects of a visual scene. Even though morphological studies of primate retina suggest a similar diversity of ganglion cell types, research has focused on the function of only a few cell types. In human retina, recordings from individual cells are anecdotal or focus on a small subset of identified types. Here, we present the first systematic ex-vivo recording of light responses from 342 ganglion cells in human retinas obtained from donors. We find a great variety in the human retinal output in terms of preferences for positive or negative contrast, spatio-temporal frequency encoding, contrast sensitivity, and speed tuning. Some human ganglion cells showed similar response behavior as known cell types in other primates, while we also recorded light responses that have not been described previously. This first extensive description of the human retinal output should facilitate interpretation of primate data and comparison to other mammalian species, and it lays the basis for the use of ex-vivo human retina for in-vitro analysis of novel treatment approaches.

scholarly journals Retinal ganglion cell defects cause decision shifts in visually evoked defense responses

2020 ◽  
Vol 124 (5) ◽  
pp. 1530-1549
Author(s):  
Rebecca Nicole Lees ◽  
Armaan Fazal Akbar ◽  
Tudor Constantin Badea
Keyword(s):  
Ganglion Cell ◽  
Brain Stem ◽  
Retinal Ganglion Cell ◽  
Genetically Modified ◽  
Visual Stimuli ◽  
Defense Responses ◽  
Retinal Ganglion ◽  
Freezing Response ◽  
Response Choices ◽  
The Brain

Flight and freezing response choices evoked by visual stimuli are controlled by brain stem and thalamic circuits. Genetically modified mice with loss of specific retinal ganglion cell (RGC) subpopulations have altered flight versus freezing choices in response to some but not other visual stimuli. This finding suggests that “threatening” visual stimuli may be computed already at the level of the retina and communicated via dedicated pathways (RGCs) to the brain.

scholarly journals Diversification of multipotential postmitotic mouse retinal ganglion cell precursors into discrete types

2021 ◽  
Author(s):  
Karthik Shekhar ◽  
Irene E Whitney ◽  
Salwan Butrus ◽  
Yi-Rong Peng ◽  
Joshua R Sanes
Keyword(s):  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Neural Progenitor Cells ◽  
Optimal Transport ◽  
Retinal Ganglion ◽  
Rna Seq ◽  
Type Identity ◽  
Fate Restriction ◽  
Fate Determinants ◽  
The Brain

The genesis of broad neuronal classes from multipotential neural progenitor cells has been extensively studied, but less is known about the diversification of a single neuronal class into multiple types. We used single-cell RNA-seq to study how newly-born (postmitotic) mouse retinal ganglion cell (RGC) precursors diversify into ~45 discrete types. Computational analysis provides evidence that RGC type identity is not specified at mitotic exit, but acquired by gradual, asynchronous fate restriction of postmitotic multipotential precursors. Some types are not identifiable until a week after they are generated. Immature RGCs may be specified to project ipsilaterally or contralaterally to the rest of the brain before their type identity has been determined. Optimal transport inference identifies groups of RGC precursors with largely non-overlapping fates, distinguished by selectively expressed transcription factors that could act as fate determinants. Our study provides a framework for investigating the molecular diversification of discrete types within a neuronal class.

scholarly journals Identification of Retinal Ganglion Cell Types and Brain Nuclei expressing the transcription factor Brn3c/Pou4f3 using a Cre recombinase knock-in allele

2020 ◽  
Author(s):  
Nadia Parmhans ◽  
Anne Drury Fuller ◽  
Eileen Nguyen ◽  
Katherine Chuang ◽  
David Swygart ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Visual Information ◽  
Cell Types ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Retinal Ganglion ◽  
Brain Nuclei ◽  
The Brain

AbstractMembers of the POU4F/Brn3 transcription factor family have an established role in the development of retinal ganglion cell types (RGCs), the projection sensory neuron conveying visual information from the mammalian eye to the brain. Our previous work using sparse random recombination of a conditional knock-in reporter allele expressing Alkaline Phosphatase (AP) and intersectional genetics had identified three types of Pou4f3/Brn3c positive (Brn3c+) RGCs. Here, we describe a novel Brn3cCre mouse allele generated by serial Dre to Cre recombination. We use this allele to explore the expression overlap of Brn3c with Brn3a and Brn3b and the dendritic arbor morphologies and visual stimulus properties of Brn3c+ RGC types. Furthermore, we explore Brn3c-expressing brain nuclei. Our analysis reveals a much larger number of Brn3c+ RGCs and more diverse set of RGC types than previously reported. The majority of RGCs having expressed Brn3c during development are still Brn3c positive in the adult, and all of them express Brn3a while only about half express Brn3b. Intersection of Brn3b and Brn3c expression highlights an area of increased RGC density, similar to an area centralis, corresponding to part of the binocular field of view of the mouse. Brn3c+ neurons and projections are present in multiple brain nuclei. Brn3c+ RGC projections can be detected in the Lateral Geniculate Nucleus (LGN), Pretectal Area (PTA) and Superior Colliculus (SC) but also in the thalamic reticular nucleus (TRN), a visual circuit station that was not previously described to receive retinal input. Most Brn3c+ neurons of the brain are confined to the pretectum and the dorsal midbrain. Amongst theses we identify a previously unknown Brn3c+ subdivision of the deep mesencephalic nucleus (DpMe). Thus, our newly generated allele provides novel biological insights into RGC type classification, brain connectivity and midbrain cytoarchitectonic, and opens the avenue for specific characterization and manipulation of these structures.

Morphology, Molecular Characterization, and Connections of Ganglion Cells in Primate Retina

2021 ◽  
Vol 7 (1) ◽  
pp. 73-103
Author(s):  
Ulrike Grünert ◽  
Paul R. Martin
Keyword(s):  
Ganglion Cell ◽  
Nonhuman Primates ◽  
Ganglion Cells ◽  
Expression Patterns ◽  
Cell Types ◽  
Gene Expression Patterns ◽  
Signal Pathways ◽  
Retinal Ganglion ◽  
Signal Features ◽  
The Brain

The eye sends information about the visual world to the brain on over 20 parallel signal pathways, each specialized to signal features such as spectral reflection (color), edges, and motion of objects in the environment. Each pathway is formed by the axons of a separate type of retinal output neuron (retinal ganglion cell). In this review, we summarize what is known about the excitatory retinal inputs, brain targets, and gene expression patterns of ganglion cells in humans and nonhuman primates. We describe how most ganglion cell types receive their input from only one or two of the 11 types of cone bipolar cell and project selectively to only one or two target regions in the brain. We also highlight how genetic methods are providing tools to characterize ganglion cells and establish cross-species homologies.

Scleral Biomechanics in the Glaucomatous Monkey Eye

2009 ◽  
Author(s):  
Michaël J. A. Girard ◽  
Jun-Kyo F. Suh ◽  
Michael Bottlang ◽  
Claude F. Burgoyne ◽  
J. Crawford Downs
Keyword(s):  
Intraocular Pressure ◽  
Optic Nerve ◽  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Nutritional Support ◽  
Lamina Cribrosa ◽  
Collagen Fibers ◽  
Type I ◽  
Retinal Ganglion ◽  
The Brain

The sclera is the outer shell and principal load-bearing tissue of the eye, and consists primarily of avascular lamellae of collagen fibers. Ninety percent of the collagen fibers in the sclera are Type I, which provide the eye with necessary mechanical strength to withstand intraocular pressure (IOP). A small hole pierces the posterior sclera, known as the scleral canal, through which the retinal ganglion cell axons turn and pass out of the eye on their path to the brain. The scleral canal is spanned by a fenestrated connective tissue called the lamina cribrosa that provides structural and nutritional support to the axons as they leave the eye. This region, including the peripapillary sclera (the sclera closest to the canal), the lamina cribrosa, and the contained retinal ganglion cell axons, is collectively known as the optic nerve head or ONH.

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