Official websites use. Share sensitive information only on official, secure websites. Adult neurogenesis in the hippocampus is a notable process due not only to its uniqueness and potential impact on cognition but also to its localized vertical integration of different scales of neuroscience, ranging from molecular and cellular biology to behavior.
This review summarizes the recent research regarding the process of adult neurogenesis from these different perspectives, with particular emphasis on the differentiation and development of new neurons, the regulation of the process by extrinsic and intrinsic factors, and their ultimate function in the hippocampus circuit. Arising from a local neural stem cell population, new neurons progress through several stages of maturation, ultimately integrating into the adult dentate gyrus network.
The increased appreciation of the full neurogenesis process, from genes and cells to behavior and cognition, makes neurogenesis both a unique case study for how scales in neuroscience can link together and suggests neurogenesis as a potential target for therapeutic intervention for a number of disorders. The neurogenesis field has made remarkable progress in the past two decades 82 , , , Less than 20 years ago, the neuroscience community's appreciation of adult neurogenesis was quite limited.
Despite having been characterized using a range of techniques, the fact that young neurons continue to be incorporated into the adult brain was not widely accepted until the mid s , Several factors precipitated this shift. First, immunohistological techniques for labeling dividing cells with nucleotide analogs [e. Second, these tracing techniques revealed that the incorporation of young neurons did not simply occur at a persistent low rate of residual development; rather, it was heavily regulated by behavioral factors such as stress, age, exercise, and enrichment.
Finally, the positive identification of adult-born neurons in the human hippocampus, and even in aged individuals, demonstrated that this phenomenon was potentially relevant to human cognition Neurogenesis has been described in several brain regions of multiple species. It was identified early on in songbirds and has since been observed in other bird species, reptiles, and fish In mammals, neurogenesis appears to be considerably more limited, with robust levels limited to the dentate gyrus DG region of the hippocampus and the olfactory bulb OB.
