TABLE 1.

Proliferative activation of stem and progenitor cells of the adult and aged dentate gyrus by different neurogenic stimuli.

System (dentate gyrus)	Neurogenic stimulus	Activation of stem cells (type-1; BrdU+ GFAP+ nestin+ Sox2+)	Activation of progenitor cells (type-2-3)	Cognitive effects	References
Adult	Running	NO	YES	Rescue of contextual memory	Suh et al., 2007; Farioli-Vecchioli et al., 2014; Kronenberg et al., 2003; Steiner et al., 2008; Brandt et al., 2010;
	Running	YES (Hes5+)	–	–	Lugert et al., 2010
	Fluoxetine	NO	YES (and increased neuron survival)	–	Encinas et al., 2006; Micheli et al., 2017, 2018a;
	Fluoxetine (after global ischemia)	YES	YES		Couillard-Despres et al., 2009; Khodanovich et al., 2018
	Learning (enriched environment)	NO	NO (but increased survival of neurons)	Improved spatial learning	Kronenberg et al., 2003; Kempermann et al., 1997;
	Learning (enriched environment preceded or not by hypoxia)	YES	YES (and increased number of neurons)	Improved spatial learning	Salmaso et al., 2012
	Learning (spatial learning)	–	YES (BrdU+) (but increased survival of neurons)	–	Gould et al., 1999; Ambrogini et al., 2000; Döbrössy et al., 2003; Epp et al., 2007
	Nutrient: Hydroxytyrosol	NO*	NO (but increased survival of new neurons)	–	D’Andrea et al., 2020
	Nutrient: Luteolin (in mouse model of Down syndrome and Alzheimer disease Ts65Dn)	YES***	YES	Improved spatial learning and object recognition	Zhou et al., 2019
	Nutrient: Caffeoylquinic acid (in senescence-accelerated prone 8 mouse [SAMP8])	YES	– (increased generation of new neurons BrdU+NeuN+)	Improved spatial memory	Sasaki et al., 2019
	Nutrient: Astragaloside VI (after ischemia)	YES	–	Rescue of spatial memory	Chen et al., 2019
	Nutrient: n-3 PUFA	–	YES	Improved spatial memory	Cutuli et al., 2014
	Electromagnetic fields	YES	YES	Improved spatial learning	Leone et al., 2014
Adult (after corticosterone-induced depression-like state)	Running	–	YES	Rescue of spatial memory	Yau et al., 2012
Aged	Nutrient: Hydroxytyrosol	YES**	YES (and increased survival of neurons)	–	D’Andrea et al., 2020
	Running	NO	YES	Rescue of place recognition memory	Siette et al., 2013; Micheli et al., 2019
	Fluoxetine	NO	NO (and no increase of neuron survival)	No rescue of visuospatial deficit; enhancement of contextual memory and spine density	Micheli et al., 2018a; Couillard-Despres et al., 2009; Li et al., 2015; McAvoy et al., 2015
	Learning (enriched environment)	–	NO (increased survival of neurons)	No improved spatial learning	Kempermann et al., 1998

*Ki67⁺Sox2⁺GFAP⁺ **Ki67⁺Sox2⁺ (Type-1-2a) ***Nestin⁺ (Type-1-2ab) or GFAP⁺.