ROLE OF NF-kB IN RECONSOLIDATION AND EXTINCTION IN FEAR CONDITIONING IN MICE

DE LA FUENTE V; ROMANO A

Huerta Grande, Córdoba

Taller; X Taller Argentino de Neurociencias; 2008

Taller Argentino de Neurociencias

There are evidences supporting that the cellular and molecular mechanisms that underlie memory consolidation are different from those that underlie reconsolidation and extinction . Differences may rely, not only in the molecules involved, but also on the activation time of these molecules, and even in the brain areas involved. In addition, little is known about the mechanisms of extinction memory. Contrarily wise, increasing evidence supports the participation of the transcription factor NF-kB in memory. It has already been show that in the crab Chasmagnathus model of associative contextual memory, NF-kB is activated specifically by retrieval and that this activation is required for memory reconsolidation. Besides, the inhibition of NF-kB after memory consolidation and reconsolidation impaired retention in inhibitory avoidance in mice. Now, our aim is to study the role of this transcription factor in reconsolidation and extinction in a paradigm of fear conditioning in mice. We found that hippocampal inhibition of NF-kB after reactivation impairs long-term memory, raising the question if this procedure impedes reconsolidation or facilitates extinction. We also found that the time of NF-kB activation in hippocampal formation differs from what we have observed in extinction, thus supporting the hypothesis that both processes are sustained by different mechanisms.