Mechanisms of Neuronal Migration during Corticogenesis

The cerebral cortex plays central roles in many higher-order functions such as cognition, language, consciousness, and the control of voluntary behavior. These processes are performed by the densely interconnected networks of excitatory pyramidal neurons and inhibitory interneurons, and the balanced development of these two types of neuron is quite important. During cortical development, pyramidal neurons and interneurons show quite different migratory behaviors: radial migration and tangential migration, respectively. Pyramidal neurons are generated in the ventricular zone of the dorsal telencepharon, and migrate radially along radial glial fibers toward the pial surface, forming a six-layered cortical structure in an “ inside-out” manner. On the other hand, cortical interneurons are generated in the medial and caudal ganglionic eminence in the ventral telencepharon, and follow long tangential migratory paths into the cortex. Defects in these migration processes result in abnormalities in the cortical layer structure and neuronal networks, which may cause various neurological and psychiatric conditions such as epilepsy and schizophrenia. Accordingly, besides basic scientific interest elucidation of the mechanism of neuronal migration is essential for understanding the pathogenesis of these diseases.
The aim of this Research Topics is to deepen our understanding of two types of neuronal migration during corticogenesis. We welcome contributions of both reviews and original research articles on the mechanisms of radial and tangential migrations in the developing cortex, including movement of neural progenitors, establishment of neuronal polarity, and axon maturation. Articles on evolutional and clinical standpoints are also welcomed.