The role of adult neurogenesis in psychiatric and cognitive disorders.

Neurogenesis in mammals occurs throughout life in two brain regions: the ventricular-subventricular zone (V-SVZ) and the subgranular zone (SGZ) of the hippocampal dentate gyrus. Development and regulation of the V-SVZ and SGZ is unique to each brain region, but with several similar characteristics. Alterations to the production of new neurons in neurogenic regions have been linked to psychiatric and neurodegenerative disorders. Decline in neurogenesis in the SGZ correlates with affective and psychiatric disorders, and can be reversed by antidepressant and antipsychotic drugs. Likewise, neurogenesis in the V-SVZ can also be enhanced by antidepressant drugs. The regulation of neurogenesis by neurotransmitters, particularly monoamines, in both regions suggests that aberrant neurotransmitter signaling observed in psychiatric disease may play a role in the pathology of these mental health disorders. Similarly, the cognitive deficits that accompany neurodegenerative disease may also be exacerbated by decreased neurogenesis. This review explores the regulation and function of neural stem cells in rodents and humans, and the involvement of factors that contribute to psychiatric and cognitive deficits. This article is part of a Special Issue entitled SI:StemsCellsinPsychiatry.