Neurogenesis in the Adult Hippocampus: History, Regulation, and Prospective Roles.

The hippocampus is one of the sites in the mammalian brain that is capable of continuously generating controversy. Adult neurogenesis is a remarkable process, and yet an intensely debatable topic in contemporary neuroscience due to its distinctiveness and conceivable impact on neural activity. The belief that neurogenesis continues through adulthood has provoked remarkable efforts to describe how newborn neurons differentiate and incorporate into the adult brain. It has also encouraged studies that investigate the consequences of inadequate neurogenesis in neuropsychiatric and neurodegenerative diseases, and explore the potential role of neural progenitor cells in brain repair. The adult nervous system is not static; it is subjected to morphological and physiological alterations at various levels. This plastic mechanism guarantees that the behavior regulation of the adult nervous system is adaptable in response to varying environmental stimuli. Two regions of the adult brain, the olfactory bulb and the hippocampal dentate gyrus, contain new-born neurons that exhibit an essential role in the natural functional circuitry of the adult brain. This article explores current advancements in adult hippocampal neurogenesis by presenting its history and evolution, and studying its association with neural plasticity. The article also discusses the prospective roles of adult hippocampal neurogenesis, and describes the intracellular, extracellular, pathological and environmental factors involved in its regulation.