Wnt signaling regulates neuronal migration in the cerebral cortex

Cortical layers are generated by precisely coordinated cell migration events and the mammalian cortex is particularly susceptible to disorders of migration. Understanding the underlying mechanisms and their regulation is therefore crucial to evaluate how subtle alterations of the migratory process contribute to neurodevelopmental disorders. Here, we evaluated the role of Wnt signaling during different stages of radial migration. Wnt canonical as well as non-canonical signaling are active in migrating layer 2/3 callosal projection neurons. These neurons are important for intracortical network formation, and their migration is of special interest since they have a relatively long and complicated trajectory before reaching their definitive position in supragranular layers. In the first part of my thesis, we showed that canonical Wnt signaling plays a crucial role at the onset of the radial migration during the multipolar-to-bipolar transition. Indeed, we demonstrated that transient down-regulation of canonical Wnt signaling is necessary during the multipolar