Date Published: March 31, 2012
Publisher: Impact Journals LLC
Author(s): Benedetta Artegiani, Federico Calegari.
Several studies suggest that an increase in adult neurogenesis has beneficial effects on emotional behavior and cognitive performance including learning and memory. The observation that aging has a negative effect on the proliferation of neural stem cells has prompted several laboratories to investigate new systems to artificially increase neurogenesis in senescent animals as a means to compensate for age-related cognitive decline. In this review we will discuss the systemic, cellular, and molecular changes induced by aging and affecting the neurogenic niche at the level of neural stem cell proliferation, their fate change, neuronal survival, and subsequent integration in the neuronal circuitry. Particular attention will be given to those manipulations that increase neurogenesis in the aged brain as a potential avenue towards therapy.
Stem cells are characterized by their ability to divide to generate additional stem cells and differentiated cell types. Proliferative division can be symmetric or asymmetric, thereby one stem cell generates either two daughter stem cells or one stem cell plus one differentiated cell type, thus, triggering the expansion or self-renewal of the stem cell pool, respectively. Due to these unique features, stem cells are essential during embryonic development for tissue formation and during adulthood to ensure tissue homeostasis, repair, and regeneration [1-5].