Reelin in the Years: Controlling Neuronal Migration and Maturation in the Mammalian Brain

Figure 2

Diagram depicting the relationship between Reelin-secreting surface neurons and radially migrating neurons expressing the core signaling machinery (right). Surface neurons such as Cajal-Retzius cells (CR) secrete Reelin, which through its central region (yellow region) binds VLDLR and ApoER2 receptors on the surface of radially-migrating neurons. Ligand binding causes the activation of SFKs Src and Fyn, and the phosphorylation of the Dab1 adaptor protein. This event results in the recruitment of Crk/CrkL adaptor proteins mediate further downstream signaling through C3G and Rap1, resulting in the surface expression of N-Cadherin (Ncad), which is required for radial orientation, and activation of Nectin1-Nectin3, and homophilic Cadherin 2 (Cadh2) cell-cell interactions that are required to complete radial migration by somal translocation.