Defects of neuronal migration and the pathogenesis of cortical malformations

Conceptual and factual advances in understanding neuronal migration in the past two decades have provided new insight into the pathogenesis of human brain malformations at the cellular, molecular, and functional levels.

Abstract

This chapter focuses on cell movements during corticogenesis. In terms of orientation and directionality of cell movement, migration can be classified into (1) radial—proceeding from the ventricular to the pial surface and (2) tangential—running parallel to the surface of developing brain. With regard to pathway selection, migrating neurons fall into three major categories: (1) gliophilic cells that follow elongated glial fibers and bypass other neurons that are encountered within the sphere of their trajectory, (2) neurophilic cells that follow neuronal, particularly axonal surfaces, and bypass nearby glial shafts, and (3) biphilic cells that display temporal or regional affinities towards either glial or neuronal surfaces. Conceptual and factual advances in understanding neuronal migration in the past two decades have provided new insight into the pathogenesis of human brain malformations at the cellular, molecular, and functional levels. Nevertheless, methodological and conceptual advances made in recent years open new possibilities for understanding the effect of the environment on synaptic connectivity in the human brain at the molecular, cellular and functional levels.