[Adult neurogenesis: alterations with aging and Alzheimer's disease development.]

Adult neurogenesis is one of the key mechanisms of the brain plasticity. Increase in the number of cells participating in the rearrangement of the neuronal circuits and synaptic formation facilitates the increase of brain's functional capacity. However, aging as well as neurodegenerative disorders lead to the disruption of the neurogenic niche microenvironment and the loss of molecular control, which in turn results in the significant decline of the neurogenesis. These events may contribute to the cognitive decline and the consequent development of dementia. Alzheimer's disease is a progressive incurable age-related neurodegenerative disorder in the elderly and the most prevalent cause of dementia. Hippocampus and entorhinal cortex are the key neurogenic niches in the adult brain and one of the most vulnerable brain areas during the development of Alzheimer's disease. Thus, neurodegeneration associated with the development of Alzheimer's disease affects adult neurogenesis. However, to date the mechanisms underlying this connection are unclear, and the investigation of these mechanisms is a promising strategy to find the approaches to correct the Alzheimer's disease pathology.