Rapid formation and remodeling of postsynaptic densities in developing dendrites.
The dynamics of postsynaptic density (PSD) formation and remodeling were investigated in live developing hippocampal tissue slices. Time lapse imaging of transfected neurons expressing GFP-tagged PSD95, a prominent PSD protein, revealed that up to 40% of PSDs in developing dendrites are structurally dynamic; they rapidly (<15 min) appear or disappear, but also grow, shrink and move within shafts and spines. New spines containing PSDs were formed by conversion of dynamic filopodia-like spine precursors in which PSDs appeared de novo, or by direct extension of spines or spine precursors carrying preformed PSDs from the shaft. PSDs are therefore highly dynamic structures that can undergo rapid structural alteration within dendrite shafts, spines and spine precursors, permitting rapid formation and remodeling of synaptic connections in developing CNS tissues.
Marrs
G S
GS
Department of Biological Sciences, 335 Biology Building, University of Iowa, Iowa City, Iowa 52242, USA.
Green
S H
SH
Dailey
M E
ME
D000818:Animals; D022081:Cell Surface Extensions / Q000378:metabolism* / Q000648:ultrastructure; D046508:Culture Techniques; D003712:Dendrites / Q000502:physiology*; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006624:Hippocampus / Q000502:physiology / Q000648:ultrastructure*; D007091:Image Processing, Computer-Assisted; D008164:Luminescent Proteins / Q000378:metabolism; D018613:Microscopy, Confocal; D018715:Microscopy, Video; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013569:Synapses / Q000378:metabolism*; D016704:Synapsins / Q000378:metabolism; D013997:Time Factors
D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; D016704:Synapsins; C033652:postsynaptic density proteins; D049452:Green Fluorescent Proteins