Subventricular zone
| Subventricular Zone | |
|---|---|
| Identifiers | |
| NeuroLex ID | Subventricular Zone |
|
Anatomical terms of neuroanatomy
[]
|
|
The subventricular zone (SVZ) is a term used to describe both embryonic and adult neural tissues in the vertebrate central nervous system (CNS). In embryonic life, the SVZ refers to a secondary proliferative zone containing neural progenitor cells, which divide to produce neurons in the process of neurogenesis. The primary neural stem cells of the brain and spinal cord, termed radial glial cells, reside in the ventricular zone (VZ) (so-called because the VZ lines the developing ventricles). In the developing cerebral cortex, which resides in the dorsal telencephalon, the SVZ and VZ are transient tissues that do not exist in the adult. However, the SVZ of the ventral telencephalon persists throughout life.
The adult SVZ is a paired brain structure situated throughout the lateral walls of the lateral ventricles. It is composed of four distinct layers of variable thickness and cell density, as well as cellular composition. Along with the dentate gyrus of the hippocampus, the SVZ is one of two places where neurogenesis has been found to occur in the adult mammalian brain.
The innermost layer (Layer I) contains a single layer (monolayer) of ependymal cells lining the ventricular cavity; these cells possess apical cilia and several basal expansions that may stand in either parallel or perpendicular to the ventricular surface. These expansions may interact intimately with the astrocytic processes that are interconnected with the hypocellular layer (Layer II).
The secondary layer (Layer II) provides for a hypocellular gap abutting the former and has been shown to contain a network of functionally correlated Glial Fibrillary Acid Protein (GFAP)-positive astrocytic processes that are linked to junctional complexes, yet lack cell bodies except for the rare neuronal somata. While the function of this layer is yet unknown in humans, it has been hypothesized that the astrocytic and ependymal interconnections of Layer I and II may act to regulate neuronal functions, establish metabolic homeostasis, and/or control neuronal stem cell proliferation and differentiation during development. Potentially, such characteristics of the layer may act as a remainder of early developmental life or pathway for cellular migration given similarity to a homologous layer in bovine SVZ shown to have migratory cells common only to higher order mammals.
...
Wikipedia