Induction of spine growth and synapse formation by regulation of the spine actin cytoskeleton

Neuron. 2004 Oct 14;44(2):321-34. doi: 10.1016/j.neuron.2004.09.022.


We explored the relationship between regulation of the spine actin cytoskeleton, spine morphogenesis, and synapse formation by manipulating expression of the actin binding protein NrbI and its deletion mutants. In pyramidal neurons of cultured rat hippocampal slices, NrbI is concentrated in dendritic spines by binding to the actin cytoskeleton. Expression of one NrbI deletion mutant, containing the actin binding domain, dramatically increased the density and length of dendritic spines with synapses. This hyperspinogenesis was accompanied by enhanced actin polymerization and spine motility. Synaptic strengths were reduced to compensate for extra synapses, keeping total synaptic input per neuron constant. Our data support a model in which synapse formation is promoted by actin-powered motility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / physiology*
  • Amino Acid Sequence
  • Animals
  • Cytoskeleton / physiology*
  • Dendrites / physiology*
  • Dendrites / ultrastructure
  • Microfilament Proteins / genetics*
  • Microfilament Proteins / metabolism
  • Microscopy, Electron
  • Models, Neurological
  • Molecular Sequence Data
  • Mutation
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Neuronal Plasticity
  • Patch-Clamp Techniques
  • Pyramidal Cells / cytology*
  • Rats
  • Sequence Homology
  • Synapses / physiology
  • Synapses / ultrastructure
  • Transfection


  • Actins
  • Microfilament Proteins
  • Nerve Tissue Proteins
  • neurabin