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Identification of flap structure-specific endonuclease 1 as a factor involved in long-term memory formation of aversive learning.

ABSTRACT: We previously proposed that DNA recombination/repair processes play a role in memory formation. Here, we examined the possible role of the fen-1 gene, encoding a flap structure-specific endonuclease, in memory consolidation of conditioned taste aversion (CTA). Quantitative real-time PCR showed that amygdalar fen-1 mRNA induction was associated to the central processing of the illness experience related to CTA and to CTA itself, but not to the central processing resulting from the presentation of a novel flavor. CTA also increased expression of the Fen-1 protein in the amygdala, but not the insular cortex. In addition, double immunofluorescence analyses showed that amygdalar Fen-1 expression is mostly localized within neurons. Importantly, functional studies demonstrated that amygdalar antisense knockdown of fen-1 expression impaired consolidation, but not short-term memory, of CTA. Overall, these studies define the fen-1 endonuclease as a new DNA recombination/repair factor involved in the formation of long-term memories.

SUBMITTER: Saavedra-Rodriguez L

PROVIDER: S-EPMC2699464 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Identification of flap structure specific endonuclease 1 as a factor involved in LTM formation of aversive learning

Project description:We proposed that DNA recombination/repair processes play a role in memory formation. Here, we used microarray analysis of rat amygdala genes to identify possible DNA recombination/repair factors involved in memory consolidation of conditioned taste aversion (CTA). Among the genes that showed statistically significant differential expression, we identified fen-1, encoding a flap-structure specific DNA endonuclease. Amygdalar fen-1 mRNA induction was associated to the illness component of CTA, since it could be observed by the pairing of a flavor and gastrointestinal illness, by the illness itself, but not by the presentation of the flavor alone. No CTA related induction of fen-1 expression was observed in the insular cortex. Importantly, functional validation studies demonstrated that amygdalar suppression of fen-1 expression impaired memory consolidation of CTA. Overall, our studies helped identify a new DNA recombination/repair candidate factor involved in memory formation of aversive experiences. Two comparisons were established between the cRNA samples: CTA versus Flavor-only and CTA versus Toxin-only. For each comparison, the microarray experiment was repeated four times using new biological samples, each consisting of a sample pool from 3 animals. Two of the four biological replicates were performed as dye-swaps in order to correct for dye bias effects.

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