A molecular switch for translational control in taste memory consolidation

Eur J Neurosci. 2005 Nov;22(10):2560-8. doi: 10.1111/j.1460-9568.2005.04428.x.

Abstract

In a variety of species memory consolidation following different learning paradigms has been shown to be dependent on protein synthesis. However, it is not known whether modulation of protein synthesis is a critical component of the consolidation process, nor is the identity of any protein(s) subject to translational regulation, known. We report here that phosphorylation of eukaryotic elongation factor-2 (eEF2), an indicator for translational elongation attenuation, is correlated with input that produces taste memory consolidation in the relevant cortex of rat. The temporal pattern of eEF2 phosphorylation is similar to extra-cellular regulated kinase 2 (ERK2) activation and S6K1 phosphorylation, which are known to stimulate translation initiation. In addition, increased eEF2 phosphorylation and increased alphaCaMKII expression is detected in a synaptoneurosomal fraction made from taste cortex following memory consolidation. These results suggest that increased initiation rate together with decreased elongation rate, during memory consolidation, shift the rate-limiting step of protein synthesis, to produce a local switch-like effect in the expression of neuronal proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cerebral Cortex / metabolism
  • Cerebral Cortex / physiology
  • Conditioning, Operant / drug effects
  • Cytosol / enzymology
  • Cytosol / metabolism
  • Enzyme Activation / drug effects
  • Hippocampus / metabolism
  • Hippocampus / physiology
  • Male
  • Memory / physiology*
  • N-Methylaspartate / pharmacology
  • Peptide Elongation Factor 2 / genetics
  • Peptide Elongation Factor 2 / physiology
  • Phosphorylation
  • Rats
  • Rats, Wistar
  • Ribosomal Protein S6 Kinases, 70-kDa / genetics
  • Ribosomal Protein S6 Kinases, 70-kDa / physiology
  • Synaptosomes / enzymology
  • Synaptosomes / physiology
  • Taste / physiology*

Substances

  • Peptide Elongation Factor 2
  • N-Methylaspartate
  • Ribosomal Protein S6 Kinases, 70-kDa
  • ribosomal protein S6 kinase, 70kD, polypeptide 1