A late phase of hippocampal mRNA synthesis is required for long-term memory persistence of a one-trial inhibitory avoidance learning

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

Santiago de Chile, Chile

Workshop; Neuronal Signaling and Plasticity; 2008

It is well known that early protein and mRNA synthesis is required for long term memory (LTM) formation and consolidation, but little is known about the molecular mechanisms involved maintenance of memory trace. Here we show that 24 h after acquisition of one-trial associative learning, a novel mRNA synthesis dependent phase in the rat hippocampus is critical for persistence of LTM storage. This requirement may be linked to a previous protein synthesis wave 12h post-training (Neuron 2007, 53(2):261-277). In addition, we show that c-Fos transcription factor is both required early after acquisition for memory formation and during a late critical period for persistence of LTM. Our findings indicate that a delayed stabilization phase is specifically required for maintenance, but not formation of memory trace. We propose that memory formation and memory persistence shares some of the same molecular mechanisms and that recurrent rounds of consolidation-like events take place in the hippocampus for maintenance of the memory trace.