The sophisticated human behaviors, such as language, tool use, and self awareness, require an extraordinary diversity of the neuronal population in the human brain. Such complexity results from neural stem/progenitor cells (NPCs) in the embryo with the ability to generate every cell type in the brain. The fundamental question in neurobiology is how NPCs self renew and give rise to enormously diverse neuronal cell types, which interconnect with amazing specificity to form functional neural circuits. Until recently, the functional relevance of disturbed neurogenesis to the pathophysiology of psychiatric disorders has just emerged. Schizophrenia is a severe psychiatric illness that affects 0.5-1 percent of the world population. Wile the etiology is poorly understood, emerging evidence hints that certain abnormal modifications in neurodevelopment may contribute to the etiology of psychiatric disorders
