The timing of multiple retrieval events can alter GluR1 phosphorylation and the requirement for protein synthesis in fear memory reconsolidation. Learn Mem 2012 Jun 20;19(7):300-6
Date
06/23/2012Pubmed ID
22723052Pubmed Central ID
PMC3381327DOI
10.1101/lm.024901.111Scopus ID
2-s2.0-84864011536 (requires institutional sign-in at Scopus site) 40 CitationsAbstract
Numerous studies have indicated that maintaining a fear memory after retrieval requires de novo protein synthesis. However, no study to date has examined how the temporal dynamics of repeated retrieval events affect this protein synthesis requirement. The present study varied the timing of a second retrieval of an established auditory fear memory and followed this second retrieval with infusions of the protein synthesis inhibitor anisomycin (ANI) into the basolateral amygdala. Results indicated that the memory-impairing effects of ANI were not observed when the second retrieval occurred soon after the first (within 1 h), and that the inhibitor gradually regained effectiveness as the retrieval episodes were spaced further apart. Additionally, if the second of the closely timed retrievals was omitted prior to ANI infusions, long-term memory deficits were observed, suggesting that the altered effectiveness of ANI was due specifically to the second retrieval event. Further experiments revealed that the second retrieval was not associated with a change in Zif268 protein expression but did produce a rapid and persistent dephosphorylation of GluR1 receptors at Ser845, an AMPAR trafficking site known to regulate the stability of GluR2 lacking AMPARs, which have been shown to be important in memory updating. This suggests that the precise timing of multiple CS presentations during the reconsolidation window may affect the destabilization state of the memory trace.
Author List
Jarome TJ, Kwapis JL, Werner CT, Parsons RG, Gafford GM, Helmstetter FJAuthor
Fred Helmstetter PhD Professor in the Psychology / Neuroscience department at University of Wisconsin - MilwaukeeMESH terms used to index this publication - Major topics in bold
AmygdalaAnimals
Anisomycin
Conditioning, Classical
Early Growth Response Protein 1
Fear
Gene Expression Regulation
Male
Mental Recall
Phosphorylation
Protein Biosynthesis
Protein Synthesis Inhibitors
Rats
Rats, Long-Evans
Receptors, AMPA
Serine
Synaptosomes
Time Factors
