Novelty exposure overcomes foot shock-induced spatial-memory impairment by processes of synaptic-tagging in rats

William Almaguer-Melian, Jorge Bergado-Rosado, Nancy Pavón-Fuentes, Esteban Alberti-Amador, Daymara Mercerón-Martínez, Julietta U. Frey

Research output: Contribution to journalArticle

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Abstract

Novelty processing can transform short-term into long-termmemory. We propose that this memory-reinforcing effect of novelty could be explained by mechanisms outlined in the "synaptic tagging hypothesis."Initial short-term memory is sustained by a transient plasticity change at activated synapses and sets synaptic tags. These tags are later able to capture and process the plasticity-related proteins (PRPs), which are required to transform a short-term synaptic change into a long-termone. Novelty is involved in inducing the synthesis of PRPs [Moncada D, et al. (2011) Proc Natl Acad Sci USA 108:12937-12936], which are then captured by the tagged synapses, consolidatingmemory. In contrast to novelty, stress can impair learning, memory, and synaptic plasticity. Here, we address questions as towhether novelty-induced PRPs are able to prevent the loss ofmemory caused by stress and if the latter would not interact with the tag-setting process. We usedwater-maze (WM) training as a spatial learning paradigmto test our hypothesis. Stress was induced by a strong foot shock (FS; 5 x 1 mA, 2 s) applied 5 min after WM training. Our data show that FS reduced long-term but not short-term memory in the WM paradigm. This negative effect onmemory consolidationwas time- and training-dependent. Interestingly, novelty exposure prevented the stress-induced memory loss of the spatial task and increased BDNF and Arc expression. This rescuing effectwas blocked by anisomycin, suggesting that WM-tagged synapses were not reset by FS and were thus able to capture the novelty-induced PRPs, re-establishing FS-impaired long-term memory.

Original languageEnglish (US)
Pages (from-to)953-958
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume109
Issue number3
DOIs
Publication statusPublished - Jan 17 2012

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Keywords

  • Memory reinforcement
  • Memory rescue
  • Novelty exploration

ASJC Scopus subject areas

  • General

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