Delayed wave of c-Fos expression in the dorsal hippocampus involved specifically in persistence of long-term memory storage

KATCHE C; BEKINSCHTEIN P; SLIPCZUK L; GOLDIN A; IZQUIERDO I; CAMMAROTA M; MEDINA JH

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

NATL ACAD SCIENCES

Año: 2010 p. 349 - 354

0027-8424

Memory formation is a temporally graded process during whichtranscription and translation steps are required in the first hoursafter acquisition. Although persistence is a key characteristic ofmemory storage, its mechanisms are scarcely characterized. Here,we show that long-lasting but not short-lived inhibitory avoidancelong-term memory is associated with a delayed expression of c-Fosin the hippocampus. Importantly, this late wave of c-Fos isnecessary for maintenance of inhibitory avoidance long-termstorage. Moreover, inhibition of transcription in the dorsal hippocampus24 h after training hinders persistence but not formationof long-term storage. These findings indicate that a delayed phaseof transcription is essential for maintenance of a hippocampusdependentmemory trace. Our results support the hypothesis thatrecurrent rounds of consolidation-like events take place late afterlearning in the dorsal hippocampus to maintain memories.