TRANSCRIPTION FACTOR NF-kB AND THE NEURAL MORPHOLOGIC CHANGES ASSOCIATED TO LEARNING AND MEMORY

VERÓNICA DE LA FUENTE, GASTÓN CALFA, ARTURO ROMANO, LUCAS POZZO-MILLER

Congreso; XXVII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2012

Despite that the idea of storing of memories involv es morphological modifications in synapses was proposed more than 10 0 years ago independently by Cajal and Tanzi, it was only recen tly that solid experimental evidence has confirmed that learning is associated with changes in dendritic spine density. However, little is known about the m olecular mechanisms involved in these morpho logical changes caused by behavioural learning. Besides, the transcription factor NF κ B has been involved in memory consolidation and reconsolidation in different para digms, both in invertebrates and vertebrates. It is also known to trigger the tr anscriptio n of genes with varied functions, including those potentially involved in morphological plasticity. We tested if NF- κ B participates in changes of spine density induced by fear conditioning in hippocampal CA1 pyramidal neurons. We stained mouse hippocampal slices by ballistic delivery of DiI for subsequent confocal imaging of dendritic spines. Our results show that (1)conso lidation induces an increase in spine density in both apical and basal dendrites of CA1 pyramidal neurons;(2)the increase in spine densit y associated to fear conditioning is prevented by intra-hippocampal infusions of NF κ B inhibitors; (3)the increase in spine density caused by fear conditioning persists after a reconsolidation protocol; whether the enduring spine increase after reconsolidation also requires NF-kB signalling is still under investigat ion.