Figure 2.

(A) Reelin signaling, via Rap1 and N-Cadherin, regulates the orientation of multipolar neurons towards the top of the CP. Only the processed protein and most importantly the active central processing fragment diffuse from the MZ into the deeper tissue such as the MMZ. The absence of Reelin signaling results in disoriented migration (represented by the two crossing black arrows) with a reduced movement towards the CP and increased lateral movement in the tangential directions. During the last stages of radial migration, Reelin signaling controls the final somal translocation via inside-out activation of α5β1-Integrin signaling. The absence of Reelin signaling results in a defective final somal translocation. (B) Ephrin-A/EphA forward signaling controls the lateral distribution of neurons by promoting a wider tangential migration during the multipolar stage. Absence of the signal results in a decreased lateral movement. On the other hand, ephrin-B1 reverse signaling has an opposite effect and restricts the tangential migration of mutipolar neurons at the MMZ. Absence of the signal results in a wider lateral movement.