UCSF

Neurogenesis occurs in two places in the postnatal brain: the subventricular zone (SVZ) surrounding the lateral ventricles and the subgranular zone of the dentate gyrus in the hippocampus. Once cell fate is determined in new neurons, they must begin a process of maturation that allows them to functionally integrate into an existing neural network. An essential aspect of their maturation is their morphological development, as neuronal functionality depends on branched signaling processes called dendrites. Wnt signaling has been implicated in several aspects of postnatal neurogenesis and morphological maturation, but which Wnt pathways are involved has been ambiguous. Moreover, these pathways have only been examined in the dentate gyrus and never in vivo. My dissertation project examines the role of Wnt signaling in the morphological maturation of neurons born in the SVZ that eventually become olfactory interneurons. We found that Wnt5a is essential for the morphological maturation of olfactory interneurons in vitro and in vivo. In our experiments Wnt5a signals through a non-canonical Wnt pathway and works in direct opposition to the actions of canonical Wnt signaling on dendrite development.