β-Catenin is Required for Memory Consolidation

Identified for its role in development, β-catenin has been implicated in neuronal synapse regulation and remodeling. We examined β-catenin expression in the adult mouse brain and its role in amygdala-dependent learning and memory. We found alterations in β-catenin mRNA and protein phosphorylation during fear memory consolidation. Such alterations correlated with a change in the association of β-catenin with cadherin. Pharmacologically, this consolidation was enhanced with lithium-mediated facilitation of β-catenin. Genetically, the role of β-catenin was confirmed with site-specific deletions of floxed β-catenin in the amygdala. Baseline locomotor, anxiety-related behaviors, and the acquisition or expression of conditioned fear were normal. However, amygdala-specific deletion prevented the normal transfer of newly formed fear learning into long-term memory. Thus, β-catenin within the amygdala may be required for the normal consolidation, but not acquisition, of fear memory. This suggests a general role for β-catenin in synaptic remodeling and stabilization underlying long-term memory in adults.