Neurogenesis in adult humans remains a controversial area of research among neuroscientists. Methodological challenges have hampered investigators from conducting high-quality, in-vivo studies that can help elucidate the presence and/or activity of neurogenesis in human brains. Additionally, the studies that have been done in humans report conflicting results, further adding to the ambiguity surrounding the concept of adult neurogenesis in humans. In this review article, the authors seek to help clarify the concept of adult neurogenesis by providing an overview of the basic concept, as we currently understand it, including its historical birth and evolution. The authors also review and discuss current key studies (pro and con) on adult neurogenesis in humans and animals, as well as research challenges with potential solutions. Finally, the authors discuss the clinical implications of adult neurogenesis in humans, based on what we know so far, including its potential use as a drug target in the development of pharmacological treatments for various neuropsychiatric disorders.
Keywords: Adult human neurogenesis; aging; hippocampus; neuropsychiatric disorders; neurorestoration; olfactory bulb.