a-catenins are a group of proteins associated with cadherin cell-cell adhesion molecules and play indispensable roles in the function of the cadherins. a N-catenin is a linker between cadherin adhesion receptors and the Actin cytoskeleton and is essential for stabilizing dendritic spines in rodent hippocampal neurons in culture. A deletion in this protein causes cerebellar and hippocampal lamination defects and impaired startle reaction. a E- and a N-catenin appear to co-localize in cell bodies of neurons in dorsal root ganglia. In mice, a N-catenin was found to occur at the roof plate of the mesencephalon and diencephalon, coinciding with Wnt-1 expression.