The Role of Dietary Polyphenols on Adult Hippocampal Neurogenesis: Molecular Mechanisms and Behavioural Effects on Depression and Anxiety

Figure 1

Adult neurogenesis in the mammalian brain. The figure illustrates the two well-known neurogenic sites in the brain: the subventricular zone (SVZ) and the dentate gyrus of the hippocampus (DG). Three types of progenitor cells are found lying adjacent to the ependymal cell layer (E) in the SVZ: A subset of relatively quiescent GFAP+ radial cells (type B cells) in the SVZ has the potential to serve as adult NSCs and generate rapidly dividing, transit-amplifying nonradial NSCs (type C cells), which in turn give rise to neuroblasts (type A cells) that migrate through the rostral migratory stream toward the olfactory bulb. In the adult SGZ, a population of GFAP+ Sox2+ radial cells corresponds to quiescent NSCs (type 1 cells). They coexist with actively proliferating, GFAP+ Sox2+ nonradial NSCs (type 2 cells) that generate both astrocytes and neuroblasts. Neuroblasts then migrate into the granule cell layer and mature into neurons (red cell).