scholarly journals Rapid WAVE dynamics in dendritic spines of cultured hippocampal neurons is mediated by actin polymerization

2005 ◽  
Vol 95 (5) ◽  
pp. 1401-1410 ◽  
Author(s):  
Yair Pilpel ◽  
Menahem Segal
Keyword(s):  
Dendritic Spines ◽  
Hippocampal Neurons ◽  
Actin Polymerization ◽  
Wave Dynamics ◽  
Cultured Hippocampal Neurons

Change in the shape and density of dendritic spines caused by overexpression of acidic calponin in cultured hippocampal neurons

Hippocampus ◽  
2006 ◽  
Vol 16 (2) ◽  
pp. 183-197 ◽  
Author(s):  
Guillaume Rami ◽  
Olivier Caillard ◽  
Igor Medina ◽  
Christophe Pellegrino ◽  
Abdellatif Fattoum ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Hippocampal Neurons ◽  
Cultured Hippocampal 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.

scholarly journals Overexpression of Tropomyosin Isoform Tpm3.1 Does Not Alter Synaptic Function in Hippocampal Neurons

2021 ◽  
Vol 22 (17) ◽  
pp. 9303
Author(s):  
Chanchanok Chaichim ◽  
Tamara Tomanic ◽  
Holly Stefen ◽  
Esmeralda Paric ◽  
Lucy Gamaroff ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Hippocampal Neurons ◽  
Brain Slices ◽  
Structure And Function ◽  
Spine Morphology ◽  
Dendritic Spine Morphology ◽  
And Function ◽  
Cultured Hippocampal Neurons

Tropomyosin (Tpm) has been regarded as the master regulator of actin dynamics. Tpms regulate the binding of the various proteins involved in restructuring actin. The actin cytoskeleton is the predominant cytoskeletal structure in dendritic spines. Its regulation is critical for spine formation and long-term activity-dependent changes in synaptic strength. The Tpm isoform Tpm3.1 is enriched in dendritic spines, but its role in regulating the synapse structure and function is not known. To determine the role of Tpm3.1, we studied the synapse structure and function of cultured hippocampal neurons from transgenic mice overexpressing Tpm3.1. We recorded hippocampal field excitatory postsynaptic potentials (fEPSPs) from brain slices to examine if Tpm3.1 overexpression alters long-term synaptic plasticity. Tpm3.1-overexpressing cultured neurons did not show a significantly altered dendritic spine morphology or synaptic activity. Similarly, we did not observe altered synaptic transmission or plasticity in brain slices. Furthermore, expression of Tpm3.1 at the postsynaptic compartment does not increase the local F-actin levels. The results suggest that although Tpm3.1 localises to dendritic spines in cultured hippocampal neurons, it does not have any apparent impact on dendritic spine morphology or function. This is contrary to the functional role of Tpm3.1 previously observed at the tip of growing neurites, where it increases the F-actin levels and impacts growth cone dynamics.

scholarly journals Cadherin activity is required for activity-induced spine remodeling

2004 ◽  
Vol 167 (5) ◽  
pp. 961-972 ◽  
Author(s):  
Ko Okamura ◽  
Hidekazu Tanaka ◽  
Yoshiki Yagita ◽  
Yoshinaga Saeki ◽  
Akihiko Taguchi ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Dendritic Spines ◽  
Hippocampal Neurons ◽  
Actin Polymerization ◽  
Fluorescent Protein ◽  
Cytochalasin D ◽  
Dominant Negative ◽  
Spine Head ◽  
Green Fluorescent ◽  
Activity Dependent

Neural activity induces the remodeling of pre- and postsynaptic membranes, which maintain their apposition through cell adhesion molecules. Among them, N-cadherin is redistributed, undergoes activity-dependent conformational changes, and is required for synaptic plasticity. Here, we show that depolarization induces the enlargement of the width of spine head, and that cadherin activity is essential for this synaptic rearrangement. Dendritic spines visualized with green fluorescent protein in hippocampal neurons showed an expansion by the activation of AMPA receptor, so that the synaptic apposition zone may be expanded. N-cadherin-venus fusion protein laterally dispersed along the expanding spine head. Overexpression of dominant-negative forms of N-cadherin resulted in the abrogation of the spine expansion. Inhibition of actin polymerization with cytochalasin D abolished the spine expansion. Together, our data suggest that cadherin-based adhesion machinery coupled with the actin-cytoskeleton is critical for the remodeling of synaptic apposition zone.

Fast imaging of [Ca]i reveals presence of voltage-gated calcium channels in dendritic spines of cultured hippocampal neurons

1995 ◽  
Vol 74 (1) ◽  
pp. 484-488 ◽  
Author(s):  
M. Segal
Keyword(s):  
Calcium Channels ◽  
Dendritic Spines ◽  
Hippocampal Neurons ◽  
Numerical Aperture ◽  
Ccd Camera ◽  
Charge Coupled Device ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels ◽  
Calcium Indicator ◽  
Cultured Hippocampal Neurons

1. Cultured hippocampal neurons were recorded with a patch pipette containing 100 microM of the calcium indicator Fluo-3, and one of their dendrites, carrying dendritic spines, was visualized with a x100, 1.3-numerical aperture oil objective. Calcium spikes evoked by depolarizing the somata and changes in free dendrite and spine calcium concentrations ([Ca]d and [Ca]s, respectively) were monitored with a cooled charge-coupled device (CCD) camera, acquiring images at a rate of 17-20 ms per frame. In the majority of spine-dendrite pairs, [Ca]s rose faster and to a higher level than the adjacent [Ca]d. Likewise, topical application of glutamate evoked a faster and larger change in [Ca]s than in [Ca]d. The rise of intracellular calcium concentration in response to a depolarizing current pulse, but not in response to glutamate, was reduced in the presence of the calcium antagonist verapamil in both dendrites and spines. It is suggested that dendritic spines possess voltage-gated calcium channels.

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