title: Two-Photon Correlation Spectroscopy in Single Dendritic Spines Reveals Fast Actin Filament Reorganization during Activity-Dependent Growth.
abstract: Two-photon fluorescence correlation spectroscopy (2P-FCS) within single dendritic spines of living hippocampal pyramidal neurons was used to resolve various subpopulations of mobile F-actin during activity-dependent structural changes such as potentiation induced spine head growth. Two major classes of mobile F-actin were discovered: very dynamic and about a hundred times less dynamic F-actin. Spine head enlargement upon application of Tetraethylammonium (TEA), a protocol previously used for the chemical induction of long-term potentiation (cLTP) strictly correlated to changes in the dynamics and filament numbers in the different actin filament fractions. Our observations suggest that spine enlargement is governed by a mechanism in which longer filaments are first cut into smaller filaments that cooperate with the second, increasingly dynamic shorter actin filament population to quickly reorganize and expand the actin cytoskeleton within the spine head. This process would allow a fast and efficient spine head enlargement using a major fraction of the actin filament population that was already present before spine head growth.
authors.affiliation: AG Biomolecular Spectroscopy and Single-Molecule Detection, Max Planck-Institute for Biophysical Chemistry, 37077, Göttingen, Germany.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Chen
authors.affiliation: Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, 38106, Braunschweig, Germany.
authors.forename: Yves
authors.initials: Y
authors.lastname: Kellner
authors.affiliation: Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, 38106, Braunschweig, Germany.
authors.forename: Marta
authors.initials: M
authors.lastname: Zagrebelsky
authors.affiliation: AG Biomolecular Spectroscopy and Single-Molecule Detection, Max Planck-Institute for Biophysical Chemistry, 37077, Göttingen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Grunwald
authors.affiliation: Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, 38106, Braunschweig, Germany; AG NIND, HZI, 38124, Braunschweig, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Korte
authors.affiliation: AG Biomolecular Spectroscopy and Single-Molecule Detection, Max Planck-Institute for Biophysical Chemistry, 37077, Göttingen, Germany; Department of Biophysical Chemistry, Institute for Physical and Theoretical Chemistry, TU Braunschweig, 38106, Braunschweig, Germany.
authors.forename: Peter Jomo
authors.initials: PJ
authors.lastname: Walla
mesh_terms: D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D000199:Actins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D056654:CA3 Region, Hippocampal / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D049229:Dendritic Spines / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D015870:Gene Expression; D017774:Long-Term Potentiation / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D061251:Primary Cell Culture; D013050:Spectrometry, Fluorescence / Q000379:methods; D019789:Tetraethylammonium / Q000494:pharmacology
chemical_list: D000199:Actins; D019789:Tetraethylammonium