According to the neurodevelopmental hypothesis, both genetic and environmental factors broadly affect brain development and thus, contribute to the etiology of schizophrenia7. The ontogenic construction of the human cortex is thought to proceed through a series of irreversible cycles of neural stem and progenitor cell proliferation, differentiation to neuroblasts, migration to the brain surface where early neuronal-like cells are formed, and develop into mature neurons with intercellular connections and communicative pathways. Normal human brain development begins with proliferation of neurogenic neuroepithelial precursors, which act as neural stem cells and give rise to the primary progenitor cells, radial glia, that are capable of generating neurons, astrocytes, and oligodendrocytes14. In the developing vertebrate brain, the elongated bipolar radial glia are located at the apical surface of the ventricular zone (VZ) and span the width of the cortex. These cells generate translocating radial glia, intermediate progenitor cells, and neuroblasts that migrate through the intermediate zone (IZ) to the outer cortical zone (CZ), and populate cortical layers. Via this inside-out process, the early born neurons occupy inner layers while the late born neurons migrate
