Memory reconsolidation of an inhibitory avoidance task in mice involves cytosolic ERK2 bidirectional modulation

BOCCIA MM; KRAWCZYK M; BLAKE MG; BARATTI CM; ROMANO A; FELD M

Chicago

Congreso; Neuroscience 2015; 2015

Society for Neuroscience

Reconsolidation has been defined as the process of memory stabilization after retrieval involving, among others, gene expression regulation and posttranslational modifications. Many of these mechanisms are shared with memory consolidation. Here, we studied hippocampal ERK participation on memory reconsolidation of an inhibitory avoidance task in CF1 mice. We found a retrieval induced cytosolic ERK2 activation in the hippocampus (HIP) 15 min after memory reactivation, and an inhibition at 45 min. PD098059, a MEK1/2 (MAPK/ERK kinase) inhibitor, administered in the HIP immediately after retrieval impaired memory in a dose-dependent fashion. However, infusions of the highest dose of PD098059 performed 40 min after retrieval enhanced memory in mice trained with a weaker footshock. These results suggest for the first time that ERK2 is involved in memory reconsolidation in a biphasic fashion. Furthermore, the inhibition of ERK could either impair or enhance mice performance depending on ERK state of activation.