Retinal input influences pace of neurogenesis but not cell-type configuration of the visual forebrain

2021 ◽  
Author(s):  
Shachar Sherman ◽  
Koichi Kawakami ◽  
Herwig Baier
Keyword(s):  
Visual Information ◽  
Visual Stimulation ◽  
Ganglion Cells ◽  
Neuronal Cell ◽  
Cell Types ◽  
Vertebrate Brain ◽  
Relative Contribution ◽  
Retinal Input ◽  
And Migration ◽  
The Brain

The brain is assembled during development by both innate and experience-dependent mechanisms1-7, but the relative contribution of these factors is poorly understood. Axons of retinal ganglion cells (RGCs) connect the eye to the brain, forming a bottleneck for the transmission of visual information to central visual areas. RGCs secrete molecules from their axons that control proliferation, differentiation and migration of downstream components7-9. Spontaneously generated waves of retinal activity, but also intense visual stimulation, can entrain responses of RGCs10 and central neurons11-16. Here we asked how the cellular composition of central targets is altered in a vertebrate brain that is depleted of retinal input throughout development. For this, we first established a molecular catalog17 and gene expression atlas18 of neuronal subpopulations in the retinorecipient areas of larval zebrafish. We then searched for changes in lakritz (atoh7-) mutants, in which RGCs do not form19. Although individual forebrain-expressed genes are dysregulated in lakritz mutants, the complete set of 77 putative neuronal cell types in thalamus, pretectum and tectum are present. While neurogenesis and differentiation trajectories are overall unaltered, a greater proportion of cells remain in an uncommitted progenitor stage in the mutant. Optogenetic stimulation of a pretectal area20,21 evokes a visual behavior in blind mutants indistinguishable from wildtype. Our analysis shows that, in this vertebrate visual system, neurons are produced more slowly, but specified and wired up in a proper configuration in the absence of any retinal signals.

scholarly journals Molecular codes for cell type specification in Brn3 retinal ganglion cells

2017 ◽  
Vol 114 (20) ◽  
pp. E3974-E3983 ◽  
Author(s):  
Szilard Sajgo ◽  
Miruna Georgiana Ghinia ◽  
Matthew Brooks ◽  
Friedrich Kretschmer ◽  
Katherine Chuang ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Visual Information ◽  
Ganglion Cells ◽  
Neuronal Cell ◽  
Neuronal Morphology ◽  
Retinal Ganglion ◽  
Cell Type ◽  
Type Specification ◽  
The Brain ◽  
Combinatorial Code

Visual information is conveyed from the eye to the brain by distinct types of retinal ganglion cells (RGCs). It is largely unknown how RGCs acquire their defining morphological and physiological features and connect to upstream and downstream synaptic partners. The three Brn3/Pou4f transcription factors (TFs) participate in a combinatorial code for RGC type specification, but their exact molecular roles are still unclear. We use deep sequencing to define (i) transcriptomes of Brn3a- and/or Brn3b-positive RGCs, (ii) Brn3a- and/or Brn3b-dependent RGC transcripts, and (iii) transcriptomes of retinorecipient areas of the brain at developmental stages relevant for axon guidance, dendrite formation, and synaptogenesis. We reveal a combinatorial code of TFs, cell surface molecules, and determinants of neuronal morphology that is differentially expressed in specific RGC populations and selectively regulated by Brn3a and/or Brn3b. This comprehensive molecular code provides a basis for understanding neuronal cell type specification in RGCs.

The Zebrafish Visual System: From Circuits to Behavior

2019 ◽  
Vol 5 (1) ◽  
pp. 269-293 ◽  
Author(s):  
Johann H. Bollmann
Keyword(s):  
Visual System ◽  
Neural Activity ◽  
Visual Information ◽  
Ganglion Cells ◽  
Larval Zebrafish ◽  
Vertebrate Brain ◽  
Visuomotor Transformations ◽  
Behavioral Needs ◽  
The Brain ◽  
Processing Steps

Visual stimuli can evoke complex behavioral responses, but the underlying streams of neural activity in mammalian brains are difficult to follow because of their size. Here, I review the visual system of zebrafish larvae, highlighting where recent experimental evidence has localized the functional steps of visuomotor transformations to specific brain areas. The retina of a larva encodes behaviorally relevant visual information in neural activity distributed across feature-selective ganglion cells such that signals representing distinct stimulus properties arrive in different areas or layers of the brain. Motor centers in the hindbrain encode motor variables that are precisely tuned to behavioral needs within a given stimulus setting. Owing to rapid technological progress, larval zebrafish provide unique opportunities for obtaining a comprehensive understanding of the intermediate processing steps occurring between visual and motor centers, revealing how visuomotor transformations are implemented in a vertebrate brain.

scholarly journals Regeneration of Functional Retinal Ganglion Cells by Neuronal Identity Reprogramming

2020 ◽  
Author(s):  
Xiaohu Wei ◽  
Zhenhao Zhang ◽  
Huan-huan Zeng ◽  
Xue-Feng Wang ◽  
Wenrong Zhan ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Visual Information ◽  
Therapeutic Strategy ◽  
Vision Loss ◽  
Visual Stimulation ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Adult Mice ◽  
Lineage Reprogramming ◽  
The Brain

SUMMARYDegeneration of retinal ganglion cells (RGCs) and their axons underlies vision loss in glaucoma and various optic neuropathies. There are currently no treatments available to restore lost vision in patients affected by these diseases. Regenerating RGCs and reconnecting the retina to the brain represent an ideal therapeutic strategy; however, mammals do not have a reservoir of retinal stem/progenitor cells poised to produce new neurons in adulthood. Here, we regenerated RGCs in adult mice by direct lineage reprogramming of retinal interneurons. We successfully converted amacrine and displaced amacrine interneurons into RGCs, and observed that regenerated RGCs projected axons into brain retinorecipient areas. They convey visual information to the brain in response to visual stimulation, and are able to transmit electrical signals to postsynaptic neurons, in both normal animals and in a diseased model. The generation of functional RGCs in adult mammals points to a therapeutic strategy for vision restoration in patients.

scholarly journals Neuronal apoptosis: signal and cell diversity

1969 ◽  
Vol 40 (1) ◽  
pp. 124-133
Author(s):  
Lina Vanessa Becerra ◽  
Hernán José Pimienta
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Neuronal Response ◽  
Neuronal Cell ◽  
Cell Types ◽  
Point Of View ◽  
Trophic Factors ◽  
Cell Diversity ◽  
Apoptotic Pathways ◽  
The Brain

Programmed cell death occurs as a physiological process during development. In the brain and spinal cord this event determines the number and location of the different cell types. In adulthood, programmed cell death or apoptosis is more restricted but it may play a major role in different acute and chronic pathological entities. However, in contrast to other tissues where apoptosis has been widely documented from a morphological point of view, in the central nervous system complete anatomical evidence of apoptosis is scanty. In spite of this there is consensus about the activation of different signal systems associated to programmed cell death. In the present article we attempt to summarize the main apoptotic pathways so far identified in nervous tissue. Considering that apoptotic pathways are multiple, the neuronal cell types are highly diverse and specialized and that neuronal response to injury and survival depends upon tissue context, (i.e., preservation of connectivity, glial integrity and cell matrix, blood supply and trophic factors availability) what is relevant for the apoptotic process in a sector of the brain may not be important in another.

scholarly journals 6B4 proteoglycan/phosphacan is a repulsive substratum but promotes morphological differentiation of cortical neurons

Development ◽  
1996 ◽  
Vol 122 (2) ◽  
pp. 647-658
Author(s):  
N. Maeda ◽  
M. Noda
Keyword(s):  
Cell Adhesion ◽  
Neurite Outgrowth ◽  
Cortical Neurons ◽  
Tyrosine Phosphatase ◽  
Neuronal Cell ◽  
Morphological Differentiation ◽  
Cell Types ◽  
Thalamic Neurons ◽  
Neurite Extension ◽  
The Brain

6B4 proteoglycan/phosphacan is one of the major phosphate-buffered saline-soluble chondroitin sulfate proteoglycans of the brain. Recently, this molecule has been demonstrated to be an extracellular variant of the proteoglycan-type protein tyrosine phosphatase, PTPzeta (RPTPbeta). The influence of the 6B4 proteoglycan, adsorbed onto the substratum, on cell adhesion and neurite outgrowth was studied using dissociated neurons from the cerebral cortex and thalamus. 6B4 proteoglycan adsorbed onto plastic tissue culture dishes did not support neuronal cell adhesion, but rather exerted repulsive effects on cortical and thalamic neurons. When neurons were densely seeded on patterned substrata consisting of a grid-like structure of alternating poly-L-lysine and 6B4 proteoglycan-coated poly-L-lysine domains, they were concentrated on the poly-L-lysine domains. However, 6B4 proteoglycan did not retard the differentiation of neurons but rather promoted neurite outgrowth and development of the dendrites of cortical neurons, when neurons were sparsely seeded on poly-L-lysine-conditioned coverslips continuously coated with 6B4 proteoglycan. This effect of 6B4 proteoglycan on the neurite extension of cortical neurons was apparent even on coverslips co-coated with fibronectin or tenascin. By contrast, the neurite extension of thalamic neurons was not modified by 6B4 proteoglycan. Chondroitinase ABC or keratanase digestion of 6B4 proteoglycan did not affect its neurite outgrowth promoting activity, but a polyclonal antibody against 6B4 proteoglycan completely suppressed this activity, suggesting that a protein moiety is responsible for the activity. 6B4 proteoglycan transiently promoted tyrosine phosphorylation of an 85x10(3) Mr protein in the cortical neurons, which correlated with the induction of neurite outgrowth. These results suggest that 6B4 proteoglycan/phosphacan modulates morphogenesis and differentiation of neurons dependent on its spatiotemporal distribution and the cell types in the brain.

scholarly journals A method for single-neuron chronic recording from the retina in awake mice

Science ◽  
2018 ◽  
Vol 360 (6396) ◽  
pp. 1447-1451 ◽  
Author(s):  
Guosong Hong ◽  
Tian-Ming Fu ◽  
Mu Qiao ◽  
Robert D. Viveros ◽  
Xiao Yang ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Visual Information ◽  
Single Neuron ◽  
Ganglion Cells ◽  
Ex Vivo ◽  
Neural Circuitry ◽  
Retinal Ganglion ◽  
Chronic Recording ◽  
The Brain

The retina, which processes visual information and sends it to the brain, is an excellent model for studying neural circuitry. It has been probed extensively ex vivo but has been refractory to chronic in vivo electrophysiology. We report a nonsurgical method to achieve chronically stable in vivo recordings from single retinal ganglion cells (RGCs) in awake mice. We developed a noncoaxial intravitreal injection scheme in which injected mesh electronics unrolls inside the eye and conformally coats the highly curved retina without compromising normal eye functions. The method allows 16-channel recordings from multiple types of RGCs with stable responses to visual stimuli for at least 2 weeks, and reveals circadian rhythms in RGC responses over multiple day/night cycles.

The Uptake and Localization of Catecholamines in Chick Embryo Sympathetic Neurons in Tissue Culture

1969 ◽  
Vol 4 (3) ◽  
pp. 677-691
Author(s):  
J. M. ENGLAND ◽  
M. N. GOLDSTEIN
Keyword(s):  
Tissue Culture ◽  
Chick Embryo ◽  
Ganglion Cells ◽  
Sympathetic Neurons ◽  
Neuronal Cell ◽  
Cell Types ◽  
Axon Terminals ◽  
Dense Core Granules ◽  
Insoluble Compounds ◽  
Dorsal Root Ganglion Cells

The uptake of exogenous [3H]dopamine, [3H]norepinephrine,[3H]epinephrine by dissociated chick embryo sympathetic neurons growing in tissue culture was studied by autoradiography. The neurons, growing in a medium containing nerve growth factor, rapidly and specifically took up all three catecholamines for at least 60 days, while no uptake was observed in several other cell types, including satellite cells and chick dorsal-root ganglion cells. The uptake was dependent on the concentration of the catecholamine and the duration of the pulse and was inhibited by cocaine and several sympathomimetic amines. Labelling was visualized only with fixatives which react with catecholamines to form water-insoluble compounds. Autoradiographs showed that the label was much denser over the axons than the cell bodies. The label was distributed uniformly along the axons and did not seem to be preferentially localized at the axon terminals or varicosities which contain aggregates of dense core granules. These observations indicate that a large portion of the exogenous 3[H]catecholamine is localized in an extragranular compartment and suggest that the differentiated function of the sympathetic neuronal cell membrane, which plays an important role in uptake, is retained after prolonged tissue culture.

Form and Function in Cells of the Brain

The Neuron ◽  
2015 ◽  
pp. 23-38
Author(s):  
Irwin B. Levitan ◽  
Leonard K. Kaczmarek
Keyword(s):  
Axonal Transport ◽  
Molecular Motors ◽  
Critical Role ◽  
Neuronal Cell ◽  
Cell Types ◽  
Neuronal Cell Body ◽  
Long Distance ◽  
Form And Function ◽  
And Function ◽  
The Brain

This chapter examines unique mechanisms that the neuron has evolved to establish and maintain the form required for its specialized signaling functions. Unlike some other organs, the brain contains a variety of cell types including several classes of glial cells, which play a critical role in the formation of the myelin sheath around axons and may be involved in immune responses, synaptic transmission, and long-distance calcium signaling in the brain. Neurons share many features in common with other cells (including glia), but they are distinguished by their highly asymmetrical shapes. The neuronal cytoskeleton is essential for establishing this cell shape during development and for maintaining it in adulthood. The process of axonal transport moves vesicles and other organelles to regions remote from the neuronal cell body. Proteins such as kinesin and dynein, called molecular motors, make use of the energy released by hydrolysis of ATP to drive axonal transport.

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