scholarly journals Connectomic identification and three-dimensional color tuning of S-OFF midget ganglion cells in the primate retina

2018 ◽  
Author(s):  
Lauren E Wool ◽  
Orin S Packer ◽  
Qasim Zaidi ◽  
Dennis M Dacey
Keyword(s):  
Electron Microscopy ◽  
Ganglion Cell ◽  
Ganglion Cells ◽  
Color Space ◽  
Three Dimensional ◽  
Macaque Monkey ◽  
Bipolar Cells ◽  
Peripheral Retina ◽  
Color Processing ◽  
Block Face

AbstractIn the trichromatic primate retina, the ‘midget’ retinal ganglion cell is the classical substrate for red-green color signaling, with a circuitry that enables antagonistic responses between long (L)- and medium (M)-wavelength sensitive cone inputs. Previous physiological studies show that some OFF midget ganglion cells may receive sparse input from short (S)-wavelength sensitive cones, but the effect of S-cone inputs on the chromatic tuning properties of such cells has been unexplored. Moreover, anatomical evidence for a synaptic pathway from S cones to OFF midget ganglion cells through OFF-midget bipolar cells remains ambiguous. In this study we address both questions for the macaque monkey retina. First, we used serial block-face electron microscopy (SBEM) to show that every S-cone in the parafoveal retina synapses principally with a single OFF-midget bipolar cell which in turn forms a private-line connection with an OFF midget ganglion cell. Second, we used patch electrophysiology to characterize the chromatic tuning of OFF midget ganglion cells in the near peripheral retina that receive combined input from L, M and S cones. These ‘S-OFF’ midget cells have a characteristic S-cone spatial signature, but demonstrate heterogeneous color properties due to variable strength of L, M, and S cone input across the receptive field. Together these findings strongly support the hypothesis that the OFF midget pathway is the major conduit for S-OFF signals in primate retina, and redefines the pathway as a chromatically complex substrate that encodes color signals beyond the classically recognized L vs. M and S vs. L+M cardinal mechanisms.Significance statementThe first step of color processing in the visual pathway of primates occurs when signals from short- (S), middle- (M) and long- (L) wavelength sensitive cone types interact antagonistically within the retinal circuitry to create color-opponent pathways. The midget (L vs. M or ‘red-green’) and small bistratified (S vs. L+M, or ‘blue-yellow’) appear to provide the physiological origin of the cardinal axes of human color vision. Here we confirm the presence of an additional S-OFF midget circuit in the macaque monkey fovea with scanning block-face electron microscopy (SBEM) and show physiologically that a subpopulation of S-OFF midget cells combine S, L and M cone inputs along non-cardinal directions of color space, expanding the retinal role in color coding.

scholarly journals Midget retinal ganglion cell dendritic and mitochondrial degeneration is an early feature of human glaucoma

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
James R Tribble ◽  
Asta Vasalauskaite ◽  
Tony Redmond ◽  
Robert D Young ◽  
Shoaib Hassan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Animal Models ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Retinal Ganglion Cell ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Face Scanning ◽  
Block Face ◽  
Scanning Electron

Abstract Glaucoma is characterized by the progressive dysfunction and loss of retinal ganglion cells. However, the earliest degenerative events that occur in human glaucoma are relatively unknown. Work in animal models has demonstrated that retinal ganglion cell dendrites remodel and atrophy prior to the loss of the cell soma. Whether this occurs in human glaucoma has yet to be elucidated. Serial block face scanning electron microscopy is well established as a method to determine neuronal connectivity at high resolution but so far has only been performed in normal retina from animal models. To assess the structure–function relationship of early human glaucomatous neurodegeneration, regions of inner retina assessed to have none-to-moderate loss of retinal ganglion cell number were processed using serial block face scanning electron microscopy (n = 4 normal retinas, n = 4 glaucoma retinas). This allowed detailed 3D reconstruction of retinal ganglion cells and their intracellular components at a nanometre scale. In our datasets, retinal ganglion cell dendrites degenerate early in human glaucoma, with remodelling and redistribution of the mitochondria. We assessed the relationship between visual sensitivity and retinal ganglion cell density and discovered that this only partially conformed to predicted models of structure–function relationships, which may be affected by these early neurodegenerative changes. In this study, human glaucomatous retinal ganglion cells demonstrate compartmentalized degenerative changes as observed in animal models. Importantly, in these models, many of these changes have been demonstrated to be reversible, increasing the likelihood of translation to viable therapies for human glaucoma.

The Retina of Asian and African Elephants: Comparison of Newborn and Adult

2017 ◽  
Vol 89 (2) ◽  
pp. 84-103 ◽  
Author(s):  
Heidrun Kuhrt ◽  
Andreas Bringmann ◽  
Wolfgang Härtig ◽  
Gudrun Wibbelt ◽  
Leo Peichl ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Ganglion Cell ◽  
Glial Cells ◽  
Ganglion Cells ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Retinal Ganglion ◽  
Terrestrial Mammals ◽  
Contrast Perception ◽  
First Time

Elephants are precocial mammals that are relatively mature as newborns and mobile shortly after birth. To determine whether the retina of newborn elephants is capable of supporting the mobility of elephant calves, we compared the retinal structures of 2 newborn elephants (1 African and 1 Asian) and 2 adult animals of both species by immunohistochemical and morphometric methods. For the first time, we present here a comprehensive qualitative and quantitative characterization of the cellular composition of the newborn and the adult retinas of 2 elephant species. We found that the retina of elephants is relatively mature at birth. All retinal layers were well discernible, and various retinal cell types were detected in the newborns, including Müller glial cells (expressing glutamine synthetase and cellular retinal binding protein; CRALBP), cone photoreceptors (expressing S-opsin or M/L-opsin), protein kinase Cα-expressing bipolar cells, tyrosine hydroxylase-, choline acetyltransferase (ChAT)-, calbindin-, and calretinin-expressing amacrine cells, and calbindin-expressing horizontal cells. The retina of newborn elephants contains discrete horizontal cells which coexpress ChAT, calbindin, and calretinin. While the overall structure of the retina is very similar between newborn and adult elephants, various parameters change after birth. The postnatal thickening of the retinal ganglion cell axons and the increase in ganglion cell soma size are explained by the increase in body size after birth, and the decreases in the densities of neuronal and glial cells are explained by the postnatal expansion of the retinal surface area. The expression of glutamine synthetase and CRALBP in the Müller cells of newborn elephants suggests that the cells are already capable of supporting the activities of photoreceptors and neurons. As a peculiarity, the elephant retina contains both normally located and displaced giant ganglion cells, with single cells reaching a diameter of more than 50 µm in adults and therefore being almost in the range of giant retinal ganglion cells found in aquatic mammals. Some of these ganglion cells are displaced into the inner nuclear layer, a unique feature of terrestrial mammals. For the first time, we describe here the occurrence of many bistratified rod bipolar cells in the elephant retina. These bistratified bipolar cells may improve nocturnal contrast perception in elephants given their arrhythmic lifestyle.

scholarly journals Serial Block-Face Scanning Electron Microscopy Reveals That Intercellular Nuclear Migration Occurs in Most Normal Tobacco Male Meiocytes

2021 ◽  
Vol 12 ◽  
Author(s):  
Sergey Mursalimov ◽  
Nobuhiko Ohno ◽  
Mami Matsumoto ◽  
Sergey Bayborodin ◽  
Elena Deineko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Three Dimensional ◽  
Nuclear Migration ◽  
Male Meiosis ◽  
Face Scanning ◽  
Block Face ◽  
Plant Meiosis ◽  
Scanning Electron

Serial block-face scanning electron microscopy (SBF-SEM) was used here to study tobacco male meiosis. Three-dimensional ultrastructural analyses revealed that intercellular nuclear migration (INM) occurs in 90–100% of tobacco meiocytes. At the very beginning of meiosis, every meiocyte connected with neighboring cells by more than 100 channels was capable of INM. At leptotene and zygotene, the nucleus in most tobacco meiocytes approached the cell wall and formed nuclear protuberances (NPs) that crossed the cell wall through the channels and extended into the cytoplasm of a neighboring cell. The separation of NPs from the migrating nuclei and micronuclei formation were not observed. In some cases, the NPs and nuclei of neighboring cells appeared apposed to each other, and the gap between their nuclear membranes became invisible. At pachytene, NPs retracted into their own cells. After that, the INM stopped. We consider INM a normal part of tobacco meiosis, but the reason for such behavior of nuclei is unclear. The results obtained by SBF-SEM suggest that there are still many unexplored features of plant meiosis hidden by limitations of common types of microscopy and that SBF-SEM can turn over a new leaf in plant meiosis research.

The development of the pattern of retinal ganglion cells in the chick retina: mechanisms that control differentiation

Development ◽  
1999 ◽  
Vol 126 (24) ◽  
pp. 5713-5724 ◽  
Author(s):  
K.L. McCabe ◽  
E.C. Gunther ◽  
T.A. Reh
Keyword(s):  
Cell Differentiation ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Receptor Activation ◽  
Peripheral Retina ◽  
Retinal Ganglion ◽  
Fgf Receptor ◽  
Chick Retina ◽  
Regular Arrays

Neurons in both vertebrate and invertebrate eyes are organized in regular arrays. Although much is known about the mechanisms involved in the formation of the regular arrays of neurons found in invertebrate eyes, much less is known about the mechanisms of formation of neuronal mosaics in the vertebrate eye. The purpose of these studies was to determine the cellular mechanisms that pattern the first neurons in vertebrate retina, the retinal ganglion cells. We have found that the ganglion cells in the chick retina develop as a patterned array that spreads from the central to peripheral retina as a wave front of differentiation. The onset of ganglion cell differentiation keeps pace with overall retinal growth; however, there is no clear cell cycle synchronization at the front of differentiation of the first ganglion cells. The differentiation of ganglion cells is not dependent on signals from previously formed ganglion cells, since isolation of the peripheral retina by as much as 400 μm from the front of ganglion cell differentiation does not prevent new ganglion cells from developing. Consistent with previous studies, blocking FGF receptor activation with a specific inhibitor to the FGFRs retards the movement of the front of ganglion cell differentiation, while application of exogenous FGF1 causes the precocious development of ganglion cells in peripheral retina. Our observations, taken together with those of previous studies, support a role for FGFs and FGF receptor activation in the initial development of retinal ganglion cells from the undifferentiated neuroepithelium peripheral to the expanding wave front of differentiation.

scholarly journals Helical fibrillar microstructure of tendon using serial block-face scanning electron microscopy and a mechanical model for interfibrillar load transfer

2019 ◽  
Vol 16 (160) ◽  
pp. 20190547 ◽  
Author(s):  
Babak N. Safa ◽  
John M. Peloquin ◽  
Jessica R. Natriello ◽  
Jeffrey L. Caplan ◽  
Dawn M. Elliott
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Load Transfer ◽  
Three Dimensional ◽  
Helical Structures ◽  
3D Microstructure ◽  
Face Scanning ◽  
Block Face ◽  
Matrix Shear ◽  
Scanning Electron

Tendon's hierarchical structure allows for load transfer between its fibrillar elements at multiple length scales. Tendon microstructure is particularly important, because it includes the cells and their surrounding collagen fibrils, where mechanical interactions can have potentially important physiological and pathological contributions. However, the three-dimensional (3D) microstructure and the mechanisms of load transfer in that length scale are not known. It has been postulated that interfibrillar matrix shear or direct load transfer via the fusion/branching of small fibrils are responsible for load transfer, but the significance of these mechanisms is still unclear. Alternatively, the helical fibrils that occur at the microstructural scale in tendon may also mediate load transfer; however, these structures are not well studied due to the lack of a three-dimensional visualization of tendon microstructure. In this study, we used serial block-face scanning electron microscopy to investigate the 3D microstructure of fibrils in rat tail tendon. We found that tendon fibrils have a complex architecture with many helically wrapped fibrils. We studied the mechanical implications of these helical structures using finite-element modelling and found that frictional contact between helical fibrils can induce load transfer even in the absence of matrix bonding or fibril fusion/branching. This study is significant in that it provides a three-dimensional view of the tendon microstructure and suggests friction between helically wrapped fibrils as a mechanism for load transfer, which is an important aspect of tendon biomechanics.

Neural differentiation in the retina of the larval sea lamprey (Petromyzon marinus)

1989 ◽  
Vol 3 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Kalman Rubinson ◽  
Hilary Cain
Keyword(s):  
Ganglion Cells ◽  
Photoreceptor Cells ◽  
Sea Lamprey ◽  
High Ratio ◽  
Bipolar Cells ◽  
Peripheral Retina ◽  
Radial Gradient ◽  
New Development ◽  
Cell Layers ◽  
Relationship Of

AbstractThe peripheral retina of the sea lamprey develops in a 5-year-long process in which only certain neurons differentiate each year. The growth of cell layers, the differentiation of the neurons, and the morphology of their dendrites and axons were studied with normal, HRP, and Golgi preparations. Ganglion cells are differentiated in 3-year-old larvae, amacrine and horizontal cells in 4-year-old larvae, photoreceptor cells in stage I transformers, and bipolar cells in stage III transformers. Each new development is expressed as a radial gradient of differentiation. As a result of this protracted and stepped process, lamprey retinal neurons, particularly ganglion cells, differentiate in the absence of other cells to which they will ultimately be connected and may express their individual genetic programs more fully than in other vertebrate retinas. This could account for the unusual relationship of the ganglion cell, inner plexiform, and optic nerve layers and for the very high ratio of displaced to orthotopic ganglion cells.

The number and distribution of bipolar to ganglion cell synapses in the inner plexiform layer of the anuran retina

1996 ◽  
Vol 13 (6) ◽  
pp. 1099-1107 ◽  
Author(s):  
Péter Buzás ◽  
Sára Jeges ◽  
Robert Gábriel
Keyword(s):  
Ganglion Cell ◽  
Cross Sections ◽  
Information Transfer ◽  
Ganglion Cells ◽  
Receptive Fields ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Inner Plexiform Layer ◽  
Flow Through

AbstractThe main route of information flow through the vertebrate retina is from the photoreceptors towards the ganglion cells whose axons form the optic nerve. Bipolar cells of the frog have been so far reported to contact mostly amacrine cells and the majority of input to ganglion cells comes from the amacrines. In this study, ganglion cells of frogs from two species (Bufo marinus, Xenopus laevis) were filled retrogradely with horseradish peroxidase. After visualization of the tracer, light-microscopic cross sections showed massive labeling of the somata in the ganglion cell layer as well as their dendrites in the inner plexiform layer. In cross sections, bipolar output and ganglion cell input synapses were counted in the electron microscope. Each synapse was assigned to one of the five equal sublayers (SLs) of the inner plexiform layer. In both species, bipolar cells were most often seen to form their characteristic synaptic dyads with two amacrine cells. In some cases, however, the dyads were directed to one amacrine and one ganglion cell dendrite. This type of synapse was unevenly distributed within the inner plexiform layer with the highest occurrence in SL2 both in Bufo and Xenopus. In addition, SL4 contained also a high number of this type of synapse in Xenopus. In both species, we found no or few bipolar to ganglion cell synapses in the marginal sublayers (SLs 1 and 5). In Xenopus, 22% of the bipolar cell output synapses went onto ganglion cells, whereas in Bufo this was only 10%. We conclude that direct bipolar to ganglion cell information transfer exists also in frogs although its occurrence is not as obvious and regular as in mammals. The characteristic distribution of these synapses, however, suggests that specific type of the bipolar and ganglion cells participate in this process. These contacts may play a role in the formation of simple ganglion cell receptive fields.

scholarly journals Interneuron Circuits Tune Inhibition in Retinal Bipolar Cells

2010 ◽  
Vol 103 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Erika D. Eggers ◽  
Peter D. Lukasiewicz
Keyword(s):  
Ganglion Cell ◽  
Bipolar Cell ◽  
Amacrine Cell ◽  
Ganglion Cells ◽  
Feedback Inhibition ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Light Stimuli ◽  
Cell Inhibition ◽  
Cell Networks

While connections between inhibitory interneurons are common circuit elements, it has been difficult to define their signal processing roles because of the inability to activate these circuits using natural stimuli. We overcame this limitation by studying connections between inhibitory amacrine cells in the retina. These interneurons form spatially extensive inhibitory networks that shape signaling between bipolar cell relay neurons to ganglion cell output neurons. We investigated how amacrine cell networks modulate these retinal signals by selectively activating the networks with spatially defined light stimuli. The roles of amacrine cell networks were assessed by recording their inhibitory synaptic outputs in bipolar cells that suppress bipolar cell output to ganglion cells. When the amacrine cell network was activated by large light stimuli, the inhibitory connections between amacrine cells unexpectedly depressed bipolar cell inhibition. Bipolar cell inhibition elicited by smaller light stimuli or electrically activated feedback inhibition was not suppressed because these stimuli did not activate the connections between amacrine cells. Thus the activation of amacrine cell circuits with large light stimuli can shape the spatial sensitivity of the retina by limiting the spatial extent of bipolar cell inhibition. Because inner retinal inhibition contributes to ganglion cell surround inhibition, in part, by controlling input from bipolar cells, these connections may refine the spatial properties of the retinal output. This functional role of interneuron connections may be repeated throughout the CNS.

Sign in / Sign up

Export Citation Format

Share Document