Neural stem cells (NSCs) are primary progenitor cells that generate neurons and glial cells during development and in the adult brain. Traditionally, neurons and glial cells were thought to arise from distinct precursor pools, but recent studies show that radial glia (RG) and a subpopulation of astrocytes function as NSCs. NSCs and intermediate progenitor cells (IPCs) generate diverse cell types in the central nervous system (CNS). The timing and location of NSCs, linked to their neuroepithelial origin, determine the types of neurons produced. Identifying NSCs and IPCs is crucial for understanding brain development and adult neurogenesis, and for developing strategies for brain repair. RG cells, which are neuroepithelial cells, undergo transformations to become astrocytes and play a key role in neurogenesis. RG cells maintain apico-basal polarity and undergo asymmetric divisions to self-renew and produce neurons or IPCs. RG cells also express astroglial markers and form adherens junctions, which are critical for maintaining VZ integrity and RG behavior. The small Rho-GTPase cdc42 regulates adherens junctions and is essential for RG cell identity and self-renewal. RG cells also undergo interkinetic nuclear migration (INM), a process that modulates the exposure of progenitor cell nuclei to neurogenic or proliferative signals, such as Notch. Notch activation maintains cells in a proliferative state and is critical for RG cell identity and self-renewal. RG cells give rise to other glial cells and an astonishing assortment of neuronal types. Different types of neurons are derived from RG in different subregions of the VZ. The diversity in molecular and morphological characteristics of neurons underlies neural circuit formation. RG cells are heterogeneous in terms of their progenitor function, depending on the set of transcription factors they express. Pax6, Emx1, Gsh1, Gsh2, Er81, Sp8, Nkx2.1, Dlx1, Dlx2, and Olig2 have been implicated in the generation of different subsets of forebrain neurons. RG cells also give rise to astrocytes, which are essential for supporting neuronal function and regulating metabolic activity. Some astrocytes divide locally before terminal differentiation and represent a population of aIPCs. This process of astrocytic amplification may occur in the postnatal murine cortex. Astrocytes take cortical positions that mirror the inside-out laminar birth date pattern of cortical neurons with later-born glia taking up superficial cortical positions. NSCs are present in the developing brain and persist in restricted regions of postnatal and adult brains. These cells continue to produce not only glial cells but also neurons. In the early neonatal and adult mammalian brains, new neurons are generated primarily in the SVZ in the walls of the lateral ventricles. These young neurons migrate to theNeural stem cells (NSCs) are primary progenitor cells that generate neurons and glial cells during development and in the adult brain. Traditionally, neurons and glial cells were thought to arise from distinct precursor pools, but recent studies show that radial glia (RG) and a subpopulation of astrocytes function as NSCs. NSCs and intermediate progenitor cells (IPCs) generate diverse cell types in the central nervous system (CNS). The timing and location of NSCs, linked to their neuroepithelial origin, determine the types of neurons produced. Identifying NSCs and IPCs is crucial for understanding brain development and adult neurogenesis, and for developing strategies for brain repair. RG cells, which are neuroepithelial cells, undergo transformations to become astrocytes and play a key role in neurogenesis. RG cells maintain apico-basal polarity and undergo asymmetric divisions to self-renew and produce neurons or IPCs. RG cells also express astroglial markers and form adherens junctions, which are critical for maintaining VZ integrity and RG behavior. The small Rho-GTPase cdc42 regulates adherens junctions and is essential for RG cell identity and self-renewal. RG cells also undergo interkinetic nuclear migration (INM), a process that modulates the exposure of progenitor cell nuclei to neurogenic or proliferative signals, such as Notch. Notch activation maintains cells in a proliferative state and is critical for RG cell identity and self-renewal. RG cells give rise to other glial cells and an astonishing assortment of neuronal types. Different types of neurons are derived from RG in different subregions of the VZ. The diversity in molecular and morphological characteristics of neurons underlies neural circuit formation. RG cells are heterogeneous in terms of their progenitor function, depending on the set of transcription factors they express. Pax6, Emx1, Gsh1, Gsh2, Er81, Sp8, Nkx2.1, Dlx1, Dlx2, and Olig2 have been implicated in the generation of different subsets of forebrain neurons. RG cells also give rise to astrocytes, which are essential for supporting neuronal function and regulating metabolic activity. Some astrocytes divide locally before terminal differentiation and represent a population of aIPCs. This process of astrocytic amplification may occur in the postnatal murine cortex. Astrocytes take cortical positions that mirror the inside-out laminar birth date pattern of cortical neurons with later-born glia taking up superficial cortical positions. NSCs are present in the developing brain and persist in restricted regions of postnatal and adult brains. These cells continue to produce not only glial cells but also neurons. In the early neonatal and adult mammalian brains, new neurons are generated primarily in the SVZ in the walls of the lateral ventricles. These young neurons migrate to the