With the term neurodevelopment, we typically refer to a complex process comprising the formation of different neural pathways critical for cognitive functions. The neurodevelopment starts with the embryogenesis and continues throughout postnatal life. Research in this area has focused primarily on elucidating embryonic origins and molecular pathways that produce the diverse types of neurons at the cortical level. A critical challenge to be addressed is understanding how neural stem cells from the subventricular zone may contribute to adult neurogenesis and how these may respond to adverse conditions. Critical neurogenic areas include the subventricular zone (SVZ) and subgranular zone (SGZ), which remain active throughout life, supporting brain plasticity. Apical radial glial (aRG) cells play a key role in forming the neuronal and glial cell diversity in the cerebral cortex by guiding neuronal migration. The concept of fetal programming suggests that maternal conditions can impact neurodevelopment, potentially leading to disorders like autism or ADHD. Studies link genetic factors such as mutations in Zmiz1, WDFY3, and BRINP1 to these disorders, indicating the significance of early developmental influences on long-term brain health. This chapter underscores the intricate biological systems governing CNS development and their implications for neurodevelopmental and psychiatric disorders.