Modular transport of postsynaptic density-95 clusters and association with stable spine precursors during early development of cortical neurons

J Neurosci. 2001 Dec 1;21(23):9325-33. doi: 10.1523/JNEUROSCI.21-23-09325.2001.

Abstract

The properties of filopodia and spines and their association with the postsynaptic density (PSD) protein PSD-95 were studied during early development of cultured cortical neurons using time-lapse confocal microscopy. Neurons were transfected with recombinant PSD-95 constructs fused to green fluorescent protein (GFP) for, on average, either 8 d in vitro (DIV) or 14 DIV. We find that, during 1 hr of imaging, filopodia and spines bearing PSD-95/GFP clusters are significantly more stable (i.e., do not turnover) than those lacking clusters. When present within a spine precursor, a PSD-95/GFP cluster appeared to nucleate a relatively stable structure around which filopodium-spine membranes can move. Although processes bearing clusters were generally stable, in 8 DIV neurons, we observed that a subset ( approximately 10%) of PSD-95/GFP clusters underwent rapid modular translocation between filopodia-spines and dendritic shafts. We conclude that, during early synaptic maturation, prefabricated PSD-95 clusters are trafficked in a developmentally regulated process that is associated with filopodial stabilization and synapse formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport / physiology
  • Cell Surface Extensions / metabolism*
  • Cell Surface Extensions / ultrastructure
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Cerebral Cortex / embryology
  • Cerebral Cortex / metabolism*
  • Disks Large Homolog 4 Protein
  • Fluorescent Dyes
  • Green Fluorescent Proteins
  • Intracellular Signaling Peptides and Proteins
  • Luminescent Proteins / genetics
  • Macromolecular Substances
  • Membrane Proteins
  • Microscopy, Confocal
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons / metabolism*
  • Neurons / ultrastructure
  • Patch-Clamp Techniques
  • Protein Transport / physiology
  • Pseudopodia / metabolism
  • Pseudopodia / ultrastructure
  • Rats
  • Rats, Wistar
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Rhodamines
  • Transfection

Substances

  • Disks Large Homolog 4 Protein
  • Dlg4 protein, rat
  • Fluorescent Dyes
  • Intracellular Signaling Peptides and Proteins
  • Luminescent Proteins
  • Macromolecular Substances
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Recombinant Fusion Proteins
  • Rhodamines
  • postsynaptic density proteins
  • Green Fluorescent Proteins