A molecular switch for translational control in taste memory consolidation

• Published in: The European journal of neuroscience Vol. 22; no. 10; pp. 2560 - 2568
• Main Authors: Belelovsky, K., Elkobi, A., Kaphzan, H., Nairn, A. C., Rosenblum, K.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.11.2005
• Subjects: Animals; Cerebral Cortex - metabolism; Cerebral Cortex - physiology; Conditioning, Operant - drug effects; Cytosol - enzymology; Cytosol - metabolism; eEF2; Enzyme Activation - drug effects; ERK1/2; Hippocampus - metabolism; Hippocampus - physiology; long-term memory; Male; Memory - physiology; N-Methylaspartate - pharmacology; Peptide Elongation Factor 2 - genetics; Peptide Elongation Factor 2 - physiology; Phosphorylation; rat; Rats; Rats, Wistar; Ribosomal Protein S6 Kinases, 70-kDa - genetics; Ribosomal Protein S6 Kinases, 70-kDa - physiology; Synaptosomes - enzymology; Synaptosomes - physiology; Taste - physiology; translation regulation
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/j.1460-9568.2005.04428.x

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 αCaMKII 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.