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

KATCHE, CYNTHIA; BEKINSCHTEIN, PEDRO; SLIPCZUK, LEANDRO; GOLDIN, ANDREA; IZQUIERDO, IVÁN; CAMMAROTA, MARTÍN; MEDINA, JORGE H.

Huerta Grande, Córdoba

Congreso; I Reunión Conjunta de Neurociencias (IRCN). XI Taller Argentino de Neurociencias. XVII Reunión de la Sociedad Argentina de Investigación en Neurociencias (SAN); 2009

The most remarkable feature of the brain is its capacity to collect and store information toproduce appropriate changes in behavior. Memory is a temporally graded process duringwhich transcription and translation steps are required in the first hours after acquisition.Although persistence is a key characteristic of memory storage, little is known about itsmechanisms. Here, we show that long-lasting but not short-lived inhibitory avoidance (IA)long-term memory (LTM), is associated with a delayed expression of c-Fos in thehippocampus. Importantly, this late wave of c-Fos is necessary for maintenance of IA LTMstorage. Moreover, inhibition of transcription in the dorsal hippocampus 24 h after traininghinders persistence, but not formation of LTM. These findings indicate that a delayed phaseof transcription is essential for maintenance of a hippocampus-dependent memory trace.Our results support the hypothesis that recurrent rounds of consolidation-like events takeplace late after learning in the dorsal hippocampus in order to maintain memories.