Directly reactivated but not associatively reactivated memories undergo reconsolidation.

Jacek Debiec (1) , Valérie Doyère (2) , Karim Nader (3) , Joseph E. Ledoux (1)

1 W.M. Keck Foundation Laboratory of Neurobiology, Center for Neural Science
2 NAMC - Neurobiologie de l'apprentissage, de la mémoire et de la communication
3 McGill University = Université McGill [Montréal, Canada]

Memory consolidation refers to a process by which newly learned information is made resistant to disruption. Traditionally, consolidation has been viewed as an event that occurs once in the life of a memory. However, considerable evidence now indicates that consolidated memories, when reactivated through retrieval, become labile (susceptible to disruption) again and undergo reconsolidation. Because memories are often interrelated in complex associative networks rather than stored in isolation, a key question is whether reactivation of one memory makes associated memories labile in a way that requires reconsolidation. We tested this in rats by creating interlinked associative memories using a second-order fear-conditioning task. We found that directly reactivated memories become labile, but indirectly reactivated (i.e., associated) memories do not. This suggests that memory reactivation produces content-limited rather than wholesale changes in a memory and its associations and explains why each time a memory is retrieved and updated, the entire associative structure of the memory is not grossly altered.

Domaines: Neurobiologie

Jacek Debiec, Valérie Doyère, Karim Nader, Joseph E. Ledoux. Directly reactivated but not associatively reactivated memories undergo reconsolidation.. Proceedings of the National Academy of Sciences of the United States of America, 2006, 103 (9), pp.3428-3433. ⟨10.1073/pnas.0507168103⟩. ⟨hal-00168737⟩