Homeostatic regulation of AMPA receptor expression at single hippocampal synapses

Proc Natl Acad Sci U S A. 2008 Jan 15;105(2):775-80. doi: 10.1073/pnas.0706447105. Epub 2008 Jan 3.

Abstract

Homeostatic synaptic response is an important measure in confining neuronal activity within a narrow physiological range. Whether or not homeostatic plasticity demonstrates synapse specificity, a key feature characteristic of Hebbian-type plasticity, is largely unknown. Here, we report that in cultured hippocampal neurons, alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid subtype glutamate receptor (AMPAR) accumulation is increased selectively in chronically inhibited single synapses, whereas the neighboring normal synapses remain unaffected. This synapse-specific homeostatic regulation depends on the disparity of synaptic activity and is mediated by GluR2-lacking AMPARs and PI3-kinase signaling. These results demonstrate the existence of synaptic specificity and the crucial role of AMPAR-gated calcium in homeostatic plasticity in central neurons.

MeSH terms

  • Animals
  • Electrophysiology / methods
  • Excitatory Postsynaptic Potentials
  • Gene Expression Regulation*
  • Hippocampus / metabolism*
  • Immunohistochemistry / methods
  • Long-Term Potentiation
  • Neurons / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Potassium Channels, Inwardly Rectifying / biosynthesis
  • Rats
  • Receptors, AMPA / biosynthesis*
  • Signal Transduction
  • Synapses / metabolism*
  • Synapses / physiology*
  • Transfection

Substances

  • Kir2.1 channel
  • Potassium Channels, Inwardly Rectifying
  • Receptors, AMPA
  • Phosphatidylinositol 3-Kinases