scholarly journals Neuronal development and migration in explant cultures of the adult canary forebrain

1990 ◽  
Vol 10 (9) ◽  
pp. 2931-2939 ◽  
Author(s):  
SA Goldman
Keyword(s):  
Neuronal Development ◽  
Explant Cultures ◽  
And Migration

scholarly journals AdamTS‐A Developmental Function in Neuronal Development and Migration in Drosophila Melanogaster

2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Selena Romero ◽  
Yi Zhu ◽  
Beth Wilson ◽  
James Skeath
Keyword(s):  
Drosophila Melanogaster ◽  
Neuronal Development ◽  
And Migration

scholarly journals Gamma-tubulin distribution in the neuron: implications for the origins of neuritic microtubules.

1992 ◽  
Vol 119 (1) ◽  
pp. 171-178 ◽  
Author(s):  
P W Baas ◽  
H C Joshi
Keyword(s):  
Immunoelectron Microscopy ◽  
Neuronal Development ◽  
Sympathetic Neurons ◽  
Critical Role ◽  
Explant Cultures ◽  
Gamma Tubulin ◽  
Cultured Sympathetic Neurons ◽  
High Degree ◽  
Tubulin Content

Axons and dendrites contain dense microtubule (MT) assays that are not attached to a traditional MT nucleating structure such as the centrosome. Nevertheless, the MTs within these neurites are highly organized with respect to their polarity, and consist of a regular 13-protofilament lattice, the two known characteristics of MTs nucleated at the centrosome. These observations suggest either that axonal and dendritic MTs arise at the centrosome, or that they are nucleated locally, following a redistribution of MT nucleating material from the centrosome during neuronal development. To begin distinguishing between these possibilities, we have determined the distribution of gamma-tubulin within cultured sympathetic neurons. gamma-tubulin, a newly discovered protein which is specifically localized to the pericentriolar region of nonneuronal cells (Zheng, Y., M. K. Jung, and B. R. Oakley. 1991. Cell. 65:817-823; Stearns, T., L. Evans, and M. Kirschner. 1991. Cell. 65:825-836), has been shown to play a critical role in MT nucleation in vivo (Joshi, H. C., M. J. Palacios, L. McNamara, and D. W. Cleveland. 1992. Nature (Lond.). 356:80-83). Because the gamma-tubulin content of individual cells is extremely low, we relied principally on the high degree of resolution and sensitivity afforded by immunoelectron microscopy. Our studies reveal that, like the situation in nonneuronal cells, gamma-tubulin is restricted to the pericentriolar region of the neuron. Furthermore, serial reconstruction analyses indicate that the minus ends of MTs in both axons and dendrites are free of gamma-tubulin immunoreactivity. The absence of gamma-tubulin from the axon was confirmed by immunoblot analyses of pure axonal fractions obtained from explant cultures. The observation that gamma-tubulin is restricted to the pericentriolar region of the neuron provides compelling support for the notion that MTs destined for axons and dendrites are nucleated at the centrosome, and subsequently released for translocation into these neurites.

In vivo functions of small GTPases in neocortical development

2014 ◽  
Vol 395 (5) ◽  
pp. 465-476 ◽  
Author(s):  
Bhavin Shah ◽  
Andreas W. Püschel
Keyword(s):  
Neuronal Development ◽  
Small Gtpases ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
Cellular Processes ◽  
Neuronal Progenitors ◽  
Embryonic Nervous System ◽  
And Migration ◽  
Cytoskeletal Rearrangements

Abstract The complex mammalian cortex develops from a simple neuroepithelium through the proliferation of neuronal progenitors, their asymmetric division and cell migration. Newly generated neurons transiently assume a multipolar morphology before they polarize to form a trailing axon and a leading process that is required for their radial migration. The polarization and migration events during cortical development are under the control of multiple signaling cascades that coordinate the different cellular processes involved in neuronal differentiation. GTPases perform essential functions at different stages of neuronal development as central components of these pathways. They have been widely studied using cell lines and primary neuronal cultures but their physiological function in vivo still remains to be explored in many cases. Here we review the function of GTPases that have been studied genetically by the analysis of the embryonic nervous system in knockout mice. The phenotype of these mutants has highlighted the importance of GTPases for different steps of development by orchestrating cytoskeletal rearrangements and neuronal polarization.

scholarly journals α-TubK40me3 is required for neuronal polarization and migration by promoting microtubule formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuan Xie ◽  
Shaogang Wang ◽  
Mingyi Li ◽  
Lei Diao ◽  
Xingyu Pan ◽  
...  
Keyword(s):  
Neuronal Migration ◽  
Neuronal Development ◽  
Critical Role ◽  
Post Translational Modification ◽  
Mouse Cerebral Cortex ◽  
Microtubule Formation ◽  
And Migration ◽  
Neuronal Polarization ◽  
Microtubule Function

AbstractTri-methylation on lysine 40 of α-tubulin (α-TubK40me3) is a recently identified post-translational modification involved in mitosis and cytokinesis. However, knowledge about α-TubK40me3 in microtubule function and post-mitotic cells remains largely incomplete. Here, we report that α-TubK40me3 is required for neuronal polarization and migration by promoting microtubule formation. α-TubK40me3 is enriched in mouse cerebral cortex during embryonic day (E)14 to E16. Knockdown of α-tubulin methyltransferase SETD2 at E14 leads to the defects in neuronal migration, which could be restored by overexpressing either a cytoplasm-localized SETD2 truncation or α-TubK40me3-mimicking mutant. Furthermore, α-TubK40me3 is preferably distributed on polymerized microtubules and potently promotes tubulin nucleation. Downregulation of α-TubK40me3 results in reduced microtubule abundance in neurites and disrupts neuronal polarization, which could be rescued by Taxol. Additionally, α-TubK40me3 is increased after losing α-tubulin K40 acetylation (α-TubK40ac) and largely rescues α-TubK40ac function. This study reveals a critical role of α-TubK40me3 in microtubule formation and neuronal development.

scholarly journals Conventional and Non-Conventional Roles of Non-Muscle Myosin II-Actin in Neuronal Development and Degeneration

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1926
Author(s):  
Míriam Javier-Torrent ◽  
Carlos A. Saura
Keyword(s):  
Neuronal Development ◽  
Myosin Ii ◽  
Deep Understanding ◽  
Cellular Mechanisms ◽  
Cytoskeletal Dynamics ◽  
And Migration ◽  
Contractile Forces ◽  
Muscle Myosin ◽  
Actin Cytoskeletal Dynamics ◽  
The Brain

Myosins are motor proteins that use chemical energy to produce mechanical forces driving actin cytoskeletal dynamics. In the brain, the conventional non-muscle myosin II (NMII) regulates actin filament cytoskeletal assembly and contractile forces during structural remodeling of axons and dendrites, contributing to morphology, polarization, and migration of neurons during brain development. NMII isoforms also participate in neurotransmission and synaptic plasticity by driving actin cytoskeletal dynamics during synaptic vesicle release and retrieval, and formation, maturation, and remodeling of dendritic spines. NMIIs are expressed differentially in cerebral non-neuronal cells, such as microglia, astrocytes, and endothelial cells, wherein they play key functions in inflammation, myelination, and repair. Besides major efforts to understand the physiological functions and regulatory mechanisms of NMIIs in the nervous system, their contributions to brain pathologies are still largely unclear. Nonetheless, genetic mutations or deregulation of NMII and its regulatory effectors are linked to autism, schizophrenia, intellectual disability, and neurodegeneration, indicating non-conventional roles of NMIIs in cellular mechanisms underlying neurodevelopmental and neurodegenerative disorders. Here, we summarize the emerging biological roles of NMIIs in the brain, and discuss how actomyosin signaling contributes to dysfunction of neurons and glial cells in the context of neurological disorders. This knowledge is relevant for a deep understanding of NMIIs on the pathogenesis and therapeutics of neuropsychiatric and neurodegenerative diseases.

scholarly journals Neuronal development and migration in zebrafish hindbrain explants

2005 ◽  
Vol 149 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Stephanie M. Bingham ◽  
Gesulla Toussaint ◽  
Anand Chandrasekhar
Keyword(s):  
Neuronal Development ◽  
And Migration

scholarly journals Human Chorionic Gonadotropin Stimulates Trophoblast Invasion through Extracellularly Regulated Kinase and AKT Signaling

Endocrinology ◽  
2007 ◽  
Vol 149 (3) ◽  
pp. 979-987 ◽  
Author(s):  
Johanna Prast ◽  
Leila Saleh ◽  
Heinrich Husslein ◽  
Stefan Sonderegger ◽  
Hanns Helmer ◽  
...  
Keyword(s):  
Western Blot ◽  
Chorionic Gonadotropin ◽  
First Trimester ◽  
Akt Signaling ◽  
Trophoblast Cell ◽  
Model Systems ◽  
Trophoblast Invasion ◽  
Invasion And Migration ◽  
Explant Cultures ◽  
And Migration

Chorionic gonadotropin (CG) is indispensable for human pregnancy because it controls implantation, decidualization, and placental development. However, its particular role in the differentiation process of invasive trophoblasts has not been fully unraveled. Here we demonstrate that the hormone promotes trophoblast invasion and migration in different trophoblast model systems. RT-PCR and Western blot analyses revealed expression of the LH/CG receptor in trophoblast cell lines and different trophoblast primary cultures. In vitro, CG increased migration and invasion of trophoblastic SGHPL-5 cells through uncoated and Matrigel-coated transwells, respectively. The hormone also increased migration of first-trimester villous explant cultures on collagen I. Proliferation of the trophoblast cell line and villous explant cultures measured by cumulative cell numbers and in situ 5-bromo-2′-deoxyuridine labeling, respectively, was unaffected by CG. Addition of the hormone activated ERK-1/2 and AKT in SGHPL-5 cells and pure, extravillous trophoblasts. Inhibition of MAPK kinase/ERK and phosphatidylinositide 3-kinase/AKT blocked phosphorylation of the kinases and attenuated CG-dependent invasion of SGHPL-5 cells. Similarly, the inhibitors decreased hormone-stimulated migration in villous explant cultures. Western blot analyses and gelatin zymography suggested that CG increased matrix metalloproteinase (MMP)-2 protein levels and activity in both culture systems. Inhibition of ERK or AKT diminished CG-induced MMP-2 expression. In summary, the data demonstrate that CG promotes trophoblast invasion and migration through activation of ERK and AKT signaling involving their downstream effector MMP-2. Because the increase of CG during the first trimester of pregnancy correlates with rising trophoblast motility, the hormone could be a critical regulator of the early invasion process.

Emerging roles for angiomotin in the nervous system

2020 ◽  
Vol 13 (655) ◽  
pp. eabc0635
Author(s):  
Michael Wigerius ◽  
Dylan Quinn ◽  
James P. Fawcett
Keyword(s):  
Nervous System ◽  
Neuronal Development ◽  
Stem Cell Differentiation ◽  
Normal Brain ◽  
Hippo Signaling ◽  
Scaffolding Proteins ◽  
Contact Points ◽  
The Central Nervous System ◽  
Control Organ ◽  
And Migration

Angiomotins are a family of molecular scaffolding proteins that function to organize contact points (called tight junctions in vertebrates) between adjacent cells. Some angiomotin isoforms bind to the actin cytoskeleton and are part of signaling pathways that influence cell morphology and migration. Others cooperate with components of the Hippo signaling pathway and the associated networks to control organ growth. The 130-kDa isoform, AMOT-p130, has critical roles in neural stem cell differentiation, dendritic patterning, and synaptic maturation—attributes that are essential for normal brain development and are consistent with its association with autism. Here, we review and discuss the evidence that supports a role for AMOT-p130 in neuronal development in the central nervous system.

Demonstration of Retinal Glycogen with Silver Methenamine

1971 ◽  
Vol 29 ◽  
pp. 564-565
Author(s):  
A. W. Sedar ◽  
G. H. Bresnick
Keyword(s):  
Lactic Acid ◽  
Chromic Acid ◽  
Periodic Acid ◽  
Müller Cell ◽  
External Limiting Membrane ◽  
Electron Microscope Level ◽  
Reactive Process ◽  
Inner Limiting Membrane ◽  
Muller Cell ◽  
And Migration

After experimetnal damage to the retina with a variety of procedures Müller cell hypertrophy and migration occurs. According to Kuwabara and others the reactive process in these injuries is evidenced by a marked increase in amount of glycogen in the Müller cells. These cells were considered originally supporting elements with fiber processes extending throughout the retina from inner limiting membrane to external limiting membrane, but are known now to have high lactic acid dehydrogenase activity and the ability to synthesize glycogen. Since the periodic acid-chromic acid-silver methenamine technique was shown to demonstrate glycogen at the electron microscope level, it was selected to react with glycogen in the fine processes of the Müller cell that ramify among the neural elements in various layers of the retina and demarcate these cells cytologically. The Rhesus monkey was chosen as an example of a well vascularized retina and the rabbit as an example of a avascular retina to explore the possibilities of the technique.

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