Adult Neurogenesis and Psychiatric Disorders

Abstract

Psychiatric disorders continue to be among the most challenging disorders to diagnose and treat because there is no single genetic or anatomical locus that is causative for the disease. Current treatments are often blunt tools used to ameliorate the most severe symptoms, at the risk of disrupting functional neural systems. There is a critical need to develop new therapeutic strategies that can target circumscribed functional or anatomical domains of pathology. Adult hippocampal neurogenesis may be one such domain. Here, we review the evidence suggesting that adult hippocampal neurogenesis plays a role in emotional regulation and forms of learning and memory that include temporal and spatial memory encoding and context discrimination, and that its dysregulation is associated with psychiatric disorders, such as affective disorders, schizophrenia, and drug addiction. Further, adult neurogenesis has proven to be an effective model to investigate basic processes of neuronal development and converging evidence suggests that aberrant neural development may be an etiological factor, even in late-onset diseases. Constitutive neurogenesis in the hippocampus of the mature brain reflects large-scale plasticity unique to this region and could be a potential hub for modulation of a subset of cognitive and affective behaviors that are affected by multiple psychiatric disorders.

Nerve Growth Factor(s) Mediated Hypothalamic Pituitary Axis Activation Model in Stress Induced Genesis of Psychiatric Disorders

“…In adult brain (also in humans) where neurogenesis keeps going on as a physiological event; as in hippocampal region (dentate gyrus) and subventricular zone (SVZ) of lateral ventricles (69,70); the role of NGFs in induced neurogenesis, remodelling of neuronal connections, and synaptic organizations with new experiences in these brain regions provide individual the ability to adapt to new life situations (71,72), a disruption of which may lead to aberrant behavioural changes alternatively described as psychiatric disorders (73).…”

Neurodevelopmental Perspectives on Wnt Signaling in Psychiatry

“…In the last decade, it has become increasingly clear that neural proliferation continues in some brain areas into adulthood; moreover, that disruptions in adult neurogenesis are linked to psychiatric disorders (as well as neurodegenerative diseases) [115,116], whereas enhancing neurogenesis may be an important mechanism of action for antidepressant and antipsychotic drugs [117,118,119,120]. Wnt signaling is involved in adult neurogenesis of the 2 identified NSC populations in the adult brain (reviewed in [121,122]), which reside within the subventricular zone (SVZ) of the lateral ventricles and subgranular zone (SGZ) of the hippocampal dentate gyrus (DG).…”

Nerve Growth Factor(s) Mediated Hypothalamic Pituitary Adrenal Axis Dysregulation Model in Stress Induced Genesis of Psychiatric Disorders

“…In adult brain (including humans) where neurogenesis keeps going on as a physiological event; as in hippocampal region (dentate gyrus) and subventricular zone (SVZ) of lateral ventricles (69,70); the role of NGFs in induced neurogenesis, remodelling of neuronal connections, and synaptic organizations with new experiences in these brain regions provide individuals with ability to adapt to new life situations (71,72), a disruption of which may lead to aberrant behaviour alternatively described as psychiatric disorders (73).…”