Hippocampal region-specific regulation of NF-kappaB may contribute to learning-associated synaptic reorganisation.

Activity of the transcription factor NF-kappaB is required for memory formation, but the identity and function of the genes it may regulate in this context remain obscure. Here, we comprehensively characterise NF-kappaB throughout the rat hippocampus following passive avoidance training and report significant subregion-specific increased activity across the dorsoventral axis 3h post-learning. Moreover, putative NF-kappaB binding motifs predominated in structural genes previously shown to regulate 3h following avoidance conditioning, the protein products of which may be involved in the subsequent synaptic remodelling required for consolidation. Finally, we assessed the influence of NF-kappaB-mediated transcription on neuritic structure and report that inhibition of NF-kappaB significantly decreases growth and branching of primary hippocampal neurons. These results suggest that NF-kappaB activity following hippocampal learning may contribute to consolidation-associated synaptic reorganisation. Copyright 2009 Elsevier Inc. All rights reserved.