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Quantitatively and qualitatively different cellular processes are engaged in CA1 during the consolidation and reconsolidation of contextual fear memory
Author(s) -
Barnes Philip,
Kirtley Anne,
Thomas Kerrie L.
Publication year - 2012
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.20879
Subject(s) - memory consolidation , neuroscience , psychology , consolidation (business) , hippocampus , recall , immediate early gene , cognitive psychology , biology , gene expression , gene , biochemistry , accounting , business
Whether the consolidation and reconsolidation long‐term memory relies on qualitatively different molecular and cellular processes is controversial. Using a novel experimental strategy of combining intrahippocampal antisense oligodeoxynucleotides targeting BDNF or zif268 to the block consolidation or reconsolidation of contextual fear memory respectively, and Affymetrix microarray technology, we identified a comprehensive list of nonoverlapping candidate genes regulated in CA1 during the initial stages consolidation and reconsolidation. Using RT‐qPCR in subsequent validation experiments, we estimated that over 80% of the candidates reflect gene transcripts truly regulated following the acquisition or retrieval of contextual fear memory. Statistical and over‐representation bioinformatics analyses revealed that cellular processes and signaling mechanisms were differentially regulated during consolidation and reconsolidation, particularly those associated with pro‐inflammatory cytokine signaling. This predicts that the two mnemonic processes are qualitatively as well as quantitatively distinct. This experimental strategy was further validated because the cytokine interleukin 1 (IL‐1) was reciprocally regulated in CA1 after contextual fear conditioning and fear memory retrieval, and we showed for the first time that that IL‐1 receptor mediated signaling in the hippocampus was necessary for reconsolidation. © 2010 Wiley Periodicals, Inc.