RESUMEN

Newborn neurons maintain a very simple, bipolar shape, while they migrate from their birthplace toward their destinations in the brain, where they differentiate into mature neurons with complex dendritic morphologies. Here, we report a mechanism by which the termination of neuronal migration is maintained in the postnatal olfactory bulb (OB). During neuronal deceleration in the OB, newborn neurons transiently extend a protrusion from the proximal part of their leading process in the resting phase, which we refer to as a filopodium-like lateral protrusion (FLP). The FLP formation is induced by PlexinD1 downregulation and local Rac1 activation, which coincide with microtubule reorganization and the pausing of somal translocation. The somal translocation of resting neurons is suppressed by microtubule polymerization within the FLP The timing of neuronal migration termination, controlled by Sema3E-PlexinD1-Rac1 signaling, influences the final positioning, dendritic patterns, and functions of the neurons in the OB These results suggest that PlexinD1 signaling controls FLP formation and the termination of neuronal migration through a precise control of microtubule dynamics.

Asunto(s)

Movimiento Celular , Extensiones de la Superficie Celular/fisiología , Glicoproteínas de Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neurogénesis , Neuronas/citología , Neuronas/fisiología , Animales , Animales Recién Nacidos , Células Cultivadas , Proteínas del Citoesqueleto , Glicoproteínas/genética , Glicoproteínas/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Glicoproteínas de Membrana/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso/genética , Neuropéptidos/genética , Neuropéptidos/metabolismo , Semaforinas , Transducción de Señal , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/metabolismo