From the Guidelines
The primary sites of stem cells in the brain are the ventricular zone (VZ) and the subventricular zone (SVZ), where neuroepithelial cells and apical radial glial cells (aRGC) reside and play a crucial role in the generation of neurons and glial cells. The VZ is the initial site of neural stem cell proliferation, where neuroepithelial cells undergo symmetric and asymmetric divisions to produce neurons and glial cells 1. The SVZ, on the other hand, is a secondary site of neural stem cell proliferation, where intermediate progenitors and outer radial glial cells (oRGC) are found, contributing to the expansion of the cerebral cortex 1.
- Key features of these stem cell niches include:
- The presence of neuroepithelial cells and aRGC in the VZ, which are responsible for the generation of neurons and glial cells
- The presence of intermediate progenitors and oRGC in the SVZ, which contribute to the expansion of the cerebral cortex
- The importance of these niches in the development and maintenance of the brain, particularly in the context of neurodegenerative diseases and brain injuries
- The evidence from recent studies, such as the one published in 2020 1, highlights the importance of understanding the biology of these stem cell niches in order to develop potential therapies for neurodegenerative diseases and brain injuries.
- While other studies, such as the one published in 2018 1, focus on the use of cellular models to study neurodegenerative diseases, they do not provide direct evidence on the site of stem cells in the brain.
- Therefore, based on the most recent and highest quality study 1, the ventricular zone (VZ) and the subventricular zone (SVZ) are the primary sites of stem cells in the brain.
From the Research
Site of Stem Cells in the Brain
The site of stem cells in the brain is a crucial aspect of understanding neural development and repair. According to various studies, neural stem cells (NSCs) are found in specific regions of the brain, including:
- The subventricular zone (SVZ) lining the lateral ventricles 2, 3, 4, 5
- The dentate gyrus of the hippocampus, specifically in the subgranular zone (SGZ) 2, 3, 6, 4, 5 These regions are recognized as neurogenic niches, where NSCs persist in the adult mammalian brain and contribute to the production of new neurons and glia cells.
Neurogenic Niches
The subventricular zone and the dentate gyrus of the hippocampus are the two main neurogenic regions in the adult brain. Studies have shown that these regions are capable of widespread neurogenesis and gliogenesis, particularly after injury or other inductive stimuli 3, 4. The subventricular zone is also thought to be the cell type of origin of glioblastoma, the most devastating brain tumor 2.
Distribution of Neural Stem Cells
Neural stem cells are distributed along the entire extent of the ventricular system, with niches capable of neurogenesis and gliogenesis found in various parts of the brain 3. The distribution and function of these niches are crucial for maintaining adult neurogenesis and gliogenesis in response to normal physiological and injury-related pathological cues.