scholarly journals Mechanical coupling between transsynaptic N-cadherin adhesions and actin flow stabilizes dendritic spines

2015 ◽  
Vol 26 (5) ◽  
pp. 859-873 ◽  
Author(s):  
Anaël Chazeau ◽  
Mikael Garcia ◽  
Katalin Czöndör ◽  
David Perrais ◽  
Béatrice Tessier ◽  
...  
Keyword(s):  
Computer Modeling ◽  
Dendritic Spines ◽  
Live Imaging ◽  
Actin Dynamics ◽  
Primary Neurons ◽  
Mechanical Coupling

A combination of quantitative live imaging of fluorescently tagged actin, N-cadherin, and myosin in primary neurons and computer modeling of actin dynamics shows that a clutch-like mechanism connecting N-cadherin–based transsynaptic adhesions and the actin/myosin network drives the stabilization of dendritic filopodia into spines.

Defective actin dynamics in dendritic spines: cause or consequence of age-induced cognitive decline?

2016 ◽  
Vol 397 (3) ◽  
pp. 223-229 ◽  
Author(s):  
Till Georg Alexander Mack ◽  
Patricia Kreis ◽  
Britta Johanna Eickholt
Keyword(s):  
Dendritic Spines ◽  
Neuronal Excitability ◽  
Replicative Senescence ◽  
Morphological Changes ◽  
Actin Dynamics ◽  
Cellular Processes ◽  
Filament Dynamics ◽  
Neuronal Soma ◽  
Deteriorating Process ◽  
The Brain

Abstract Ageing is a complex deteriorating process that coincides with changes in metabolism, replicative senescence, increased resistance to apoptosis, as well as progressive mitochondria dysfunction that lead to an increase production and accumulation of reactive oxygen species (ROS). Although controversy on the paradigm of the oxidative damage theory of ageing exists, persuasive studies in Caenorhabditis elegans and yeast have demonstrated that manipulation of ROS can modify the process of ageing and influences the damage of proteins, lipids and DNA. In neurons, ageing impacts on the intrinsic neuronal excitability, it decreases the size of neuronal soma and induces the loss of dendrites and dendritic spines. The actin cytoskeleton is an abundant and broadly expressed system that plays critical functions in many cellular processes ranging from cell motility to controlling cell shape and polarity. It is thus hardly surprising that the expression and the function of actin in neurons is crucial for the morphological changes that occur in the brain throughout life. We propose that alterations in actin filament dynamics in dendritic spines may be one of the key events contributing to the initial phases of ageing in the brain.

scholarly journals More than a mere supply of monomers: G-Actin pools regulate actin dynamics in dendritic spines

2017 ◽  
Vol 216 (8) ◽  
pp. 2255-2257 ◽  
Author(s):  
Katalin Schlett
Keyword(s):  
Plasma Membrane ◽  
Dendritic Spines ◽  
Actin Polymerization ◽  
Synaptic Activity ◽  
Actin Dynamics ◽  
Actin Monomer ◽  
Cell Biol ◽  
Local Enrichment

Synaptic activity reshapes the morphology of dendritic spines via regulating F-actin arborization. In this issue, Lei et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201612042) reports a novel, G-actin–dependent regulation of actin polymerization within spine heads. They show that actin monomer levels are elevated in spines upon activity, with G-actin immobilized by the local enrichment of phosphatidylinositol (3,4,5)-triphosphate (PIP3) within the spine plasma membrane.

KCC2 regulates actin dynamics in dendritic spines via interaction with β-PIX

2015 ◽  
Vol 212 (7) ◽  
pp. 2127OIA56
Author(s):  
Olaya Llano ◽  
Sergey Smirnov ◽  
Shetal Soni ◽  
Andrey Golubtsov ◽  
Isabelle Guillemin ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Actin Dynamics

scholarly journals LIM Kinase 1 and Cofilin Regulate Actin Filament Population Required for Dynamin-dependent Apical Carrier Fission from the Trans-Golgi Network

2009 ◽  
Vol 20 (1) ◽  
pp. 438-451 ◽  
Author(s):  
Susana B. Salvarezza ◽  
Sylvie Deborde ◽  
Ryan Schreiner ◽  
Fabien Campagne ◽  
Michael M. Kessels ◽  
...  
Keyword(s):  
Actin Filaments ◽  
Fluorescent Protein ◽  
Live Imaging ◽  
Actin Dynamics ◽  
Lim Kinase ◽  
Trans Golgi Network ◽  
Lim Kinase 1 ◽  
Photoactivatable Gfp ◽  
Green Fluorescent ◽  
Golgi Network

The functions of the actin cytoskeleton in post-Golgi trafficking are still poorly understood. Here, we report the role of LIM Kinase 1 (LIMK1) and its substrate cofilin in the trafficking of apical and basolateral proteins in Madin-Darby canine kidney cells. Our data indicate that LIMK1 and cofilin organize a specialized population of actin filaments at the Golgi complex that is selectively required for the emergence of an apical cargo route to the plasma membrane (PM). Quantitative pulse-chase live imaging experiments showed that overexpression of kinase-dead LIMK1 (LIMK1-KD), or of LIMK1 small interfering RNA, or of an activated cofilin mutant (cofilin S3A), selectively slowed down the exit from the trans-Golgi network (TGN) of the apical PM marker p75-green fluorescent protein (GFP) but did not interfere with the apical PM marker glycosyl phosphatidylinositol-YFP or the basolateral PM marker neural cell adhesion molecule-GFP. High-resolution live imaging experiments of carrier formation and release by the TGN and analysis of peri-Golgi actin dynamics using photoactivatable GFP suggest a scenario in which TGN-localized LIMK1-cofilin regulate a population of actin filaments required for dynamin-syndapin-cortactin–dependent generation and/or fission of precursors to p75 transporters.

Calcium regulation of actin dynamics in dendritic spines

Cell Calcium ◽  
2005 ◽  
Vol 37 (5) ◽  
pp. 477-482 ◽  
Author(s):  
Thomas G. Oertner ◽  
Andrew Matus
Keyword(s):  
Dendritic Spines ◽  
Calcium Regulation ◽  
Actin Dynamics

Live Imaging of Autophagosome Biogenesis and Maturation in Primary Neurons

2021 ◽  
pp. 23-40
Author(s):  
Andrea K. H. Stavoe ◽  
Erika L. F. Holzbaur
Keyword(s):  
Live Imaging ◽  
Primary Neurons

scholarly journals Hippocampal Dendritic Spines Are Segregated Depending on Their Actin Polymerization

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Nuria Domínguez-Iturza ◽  
María Calvo ◽  
Marion Benoist ◽  
José Antonio Esteban ◽  
Miguel Morales
Keyword(s):  
Dendritic Spines ◽  
Hippocampal Neurons ◽  
Actin Polymerization ◽  
Close Contact ◽  
Postsynaptic Membrane ◽  
Actin Dynamics ◽  
Filamentous Actin ◽  
Virtual Absence ◽  
Spine Shape ◽  
Mobile Fraction

Dendritic spines are mushroom-shaped protrusions of the postsynaptic membrane. Spines receive the majority of glutamatergic synaptic inputs. Their morphology, dynamics, and density have been related to synaptic plasticity and learning. The main determinant of spine shape is filamentous actin. Using FRAP, we have reexamined the actin dynamics of individual spines from pyramidal hippocampal neurons, both in cultures and in hippocampal organotypic slices. Our results indicate that, in cultures, the actin mobile fraction is independently regulated at the individual spine level, and mobile fraction values do not correlate with either age or distance from the soma. The most significant factor regulating actin mobile fraction was the presence of astrocytes in the culture substrate. Spines from neurons growing in the virtual absence of astrocytes have a more stable actin cytoskeleton, while spines from neurons growing in close contact with astrocytes show a more dynamic cytoskeleton. According to their recovery time, spines were distributed into two populations with slower and faster recovery times, while spines from slice cultures were grouped into one population. Finally, employing fast lineal acquisition protocols, we confirmed the existence of loci with high polymerization rates within the spine.

[P3-176]: F-ACTIN NANO-ARCHITECTURE IS COMPROMISED IN DENDRITIC SPINES OF PRIMARY NEURONS FROM APP/PS1 MICE AND IS RESTORED BY GLUTAREDOXIN-1

2017 ◽  
Vol 13 (7S_Part_21) ◽  
pp. P1001-P1001
Author(s):  
Debajyoti Das ◽  
Reddy Kommaddi ◽  
Ajit Ray ◽  
Deepak Nair ◽  
Siddharth Nanguneri ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Primary Neurons
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