Beta-catenin is critical for dendritic morphogenesis.

Regulated growth and arborization of dendritic processes are critical to the formation of functional neuronal networks. Here we identify beta-catenin as a critical mediator of dendritic morphogenesis. We found that increasing the intracellular levels of beta-catenin and other members of the cadherin/catenin complex, namely N-cadherin and alphaN-catenin, enhances dendritic arborization in rat hippocampal neurons, an effect that does not require Wnt/beta-catenin-dependent transcription. Conversely, proteins that sequester beta-catenin decreased dendritic branch tip number and total dendritic branch length. Enhancement of dendritic growth elicited by depolarization requires beta-catenin and increased Wnt release. These results identify Wnt/beta-catenin signaling as an important mediator of dendritic development and suggest that the intracellular level of the cadherin/catenin complex is a limiting factor during critical stages of dendritic morphogenesis.