Table 1.

Regulatory factors of adult neurogenesis.

Regulatory factors	Implications on adult neurogenesis	Potential mechanisms	Reference
Genetic Background	Influence neurogenesis in the SGZ		Kempermann and Gage (2002)
Gender	Cell proliferation in the SGZ is higher in females	Ovarian hormone levels (estrogen)	Tanapat et al. (1999)
Aging	Decrease cell proliferation in the SVZ and SGZ	Increased levels of corticosteroids	Kuhn et al. (1996), Cameron and McKay (2001), Jin et al. (2003), Enwere et al. (2004)
Hormones
Estrogen	Stimulate neurogenesis in the SGZ		Tanapat et al. (1999)
Corticosterone	Decrease neurogenesis in the SGZ	Activation of the hypothalamic-pituitary-adrenal axis (HPA)	Tanapat et al. (1999)
Prolactin	Stimulate neurogenesis in the SGZ and SVZ	Activation of the extracellular signal-regulated kinase 5	Tanapat et al. (1999), Wang et al. (2013)
Neurotransmitters
Dopamine	Decrease neurogenesis	Dopamine D2L receptors	Kempermann (2002), Radley and Jacobs (2002), Banasr et al. (2004)
Serotonin	Increase neurogenesis	Serotonin-1A receptors
Acetylcholine	Decrease neurogenesis
Glutamate	Decrease neurogenesis	Metabotropic glutamate receptors, NMDA receptors
Nitric oxide	Decrease neurogenesis
Enriched Environments	Increase the survival of newborn neurons in the SGZ	Peripheral vascular endothelial growth factor	Barnea and Nottebohm (1994), Kempermann et al. (1997), Nilsson et al. (1999), Brown et al. (2003)
Physical exercise	Promote cell proliferation and survival in the SGZ	Peripheral vascular endothelial growth factor	van Praag et al. (1999), Cao et al. (2004)
Physical and psychosocial stress	Decrease cell proliferation and amount of new neurons in the SGZ	Activation of the HPA	Gould and Tanapat (1999), Duman et al. (2001)
Antidepressants	Increased neurogenesis in the SGZ	Brain-derived neurotrophic factor	Eisch et al. (2000)
Drugs of abuse	Decrease cell proliferation and survival in the SGZ		Eisch et al. (2000), Crews et al. (2003)