In the past decades, much evidence has confirmed that neurogenesis occursin the adult brain and that neural stem cells reside in the adult central nervous system, overturningthe long-held dogma that we are born with a certain number of nerve cells and that the brain cannot generatenew neurons and renew itself. In the adult brain, neurogenesis occurs mainly in two areas: the hippocampusand the subventricular zone, and self-renewing, multipotent neural stem cells have been isolated andcharacterized in vitro from various regions of the adult central nervous system. Though significantadvances have been made in this field of research, the identification and function of neural stem cellsin the adult central nervous system remain the source of debate and controversy. Neurogenesis is modulatedby several normal and pathologic conditions, suggesting the involvement of the hippocampus and the subventricularzone in a broad range of functions, and that environmental stimuli and pathological conditions may havelong-term consequences on the architecture and functioning of the central nervous system. Neurogenesisis involved in processes such as learning, memory, and depression, and may also be involved in regenerativeattempts after injuries to the central nervous system. However, the contribution of neurogenesis to thesephenomena remains to be elucidated. Neural stem cells also hold the promise to cure a broad range ofneurological diseases and injuries. Cell therapeutic interventions may involve both cell transplantationand the stimulation of endogenous neural progenitor cells.

Keywords: Brain - cytology, Brain - physiology, Brain Diseases - pathology, Multipotent Stem Cells - cytology, Nerve Regeneration, Neurons - cytology, Brain - physiology, Brain Diseases - pathology, Multipotent Stem Cells - cytology, Nerve Regeneration, Neurons - cytology