Facilitation of AMPA receptor synaptic delivery as a molecular mechanism for cognitive enhancement

PLoS Biol. 2012 Feb;10(2):e1001262. doi: 10.1371/journal.pbio.1001262. Epub 2012 Feb 21.

Abstract

Cell adhesion molecules and downstream growth factor-dependent signaling are critical for brain development and synaptic plasticity, and they have been linked to cognitive function in adult animals. We have previously developed a mimetic peptide (FGL) from the neural cell adhesion molecule (NCAM) that enhances spatial learning and memory in rats. We have now investigated the cellular and molecular basis of this cognitive enhancement, using biochemical, morphological, electrophysiological, and behavioral analyses. We have found that FGL triggers a long-lasting enhancement of synaptic transmission in hippocampal CA1 neurons. This effect is mediated by a facilitated synaptic delivery of AMPA receptors, which is accompanied by enhanced NMDA receptor-dependent long-term potentiation (LTP). Both LTP and cognitive enhancement are mediated by an initial PKC activation, which is followed by persistent CaMKII activation. These results provide a mechanistic link between facilitation of AMPA receptor synaptic delivery and improved hippocampal-dependent learning, induced by a pharmacological cognitive enhancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Blotting, Western
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / metabolism
  • Cognition / physiology*
  • Enzyme-Linked Immunosorbent Assay
  • Hippocampus / cytology*
  • Hippocampus / physiology
  • Long-Term Potentiation / drug effects*
  • Long-Term Potentiation / physiology
  • Male
  • Maze Learning / drug effects
  • Microscopy, Electron
  • Microscopy, Fluorescence
  • Neural Cell Adhesion Molecules / pharmacology*
  • Neurons / drug effects*
  • Neurons / physiology
  • Patch-Clamp Techniques
  • Phosphorylation
  • Protein Kinase C / metabolism
  • Rats
  • Rats, Wistar
  • Receptor, Fibroblast Growth Factor, Type 1 / metabolism
  • Receptors, AMPA / metabolism*
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Synaptic Transmission / drug effects*
  • Synaptic Transmission / physiology

Substances

  • NCAM protein (681-695), human
  • Neural Cell Adhesion Molecules
  • Receptors, AMPA
  • Fgfr1 protein, rat
  • Receptor, Fibroblast Growth Factor, Type 1
  • Protein Kinase C
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2