A regulatory role for actin in dendritic spine proliferation
Autor: | Orenda L. Johnson, Charles C. Ouimet |
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Rok vydání: | 2006 |
Předmět: |
Male
musculoskeletal diseases Silver Staining Time Factors Dendritic spine Dendritic Spines Blotting Western Green Fluorescent Proteins Presynaptic Terminals Gene Expression macromolecular substances Biology Transfection Hippocampus Actin remodeling of neurons Organ Culture Techniques medicine Animals Beta-actin Axon Molecular Biology Cell Proliferation Microscopy Confocal Pyramidal Cells General Neuroscience Dendrites Synapsins Actin cytoskeleton Immunohistochemistry Actins Rats Dendritic filopodia Cell biology medicine.anatomical_structure Animals Newborn Neurology (clinical) Neuron Filopodia Developmental Biology |
Zdroj: | Brain Research. 1113:1-9 |
ISSN: | 0006-8993 |
Popis: | Dendritic spines are small protrusions that receive 90% of excitatory cortical synapses and are critically important to neural function. Each dendritic spine is supported by a dynamic actin cytoskeleton that responds to internal and external cues to allow spine development, elongation, retraction and movement. Multiple proteins have roles in spinogenesis, but until now, a regulatory role for actin itself has not been established. Here, we show that, in the acute slice preparation, actin expression increases during a period of rapid spinogenesis. Furthermore, actin overexpression in organotypic hippocampal cultures leads to a significant increase in spine density on CA1 pyramidal cells. Specifically, the number of filopodia (long, thin protrusions without heads) increases by 38% on secondary apical dendrites and 88% on basal dendrites and the number of elongated spines with heads increases by 162% on secondary apical dendrites and 113% on basal dendrites. Synapsin-I immunostaining demonstrated that the majority of filopodia and elongated spines are apposed by axon terminals. Additionally, we show that overexpressed actin enters both new and established spines within 24 h. These data demonstrate that neurons undertaking spinogenesis upregulate actin expression, that actin overexpression per se increases spine density, and that both new and established spines incorporate exogenous actin. |
Databáze: | OpenAIRE |
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