The concentric, six-layered mammalian brain cortex is assembled through series of wawes of embryonal neurons tkat migrace radially from ventricular germinal zones untill they reach their destination in the embryonal neural cortical plate. The younger cells normaly migrace beyond the previously established layers thus forming an inside-out histogenetic pattern in the cortical plate tkat appears within the embryonal pre-plate. In this way the pre-plate is splitted finto the definitive marginal zone and the sub-plate. The process requires presence of both the glycoprotein tkat is located intersticially and called reelin and reelin receptors tkat are confined to membranes of the migrating cells. Two types of reelin receptors have been described so far, the protocadherin and lipoprotein receptors. Reeler mutants are characterized by a defect in the reelin gene reeler. The pre-plate remains undivided and disordered cortical neurons accumulate beneath the pre-plate in reeler animals.

        Key words: central nervous system, neuronal migration, pre-plate, cortical plate, reeler, reelin, protocadherin, cadherin, lipoprotein receptors