Adult stem cells and neurogenesis: historical roots and state of the art

Over the last few years, an impressive number pf papers have addressed the stem cell issue. However, as often occurs when a scientific subject undergoes a period of fast growth, some confusion is generated. To hel reduce the existing uncertainty, this paper focuses on the concept of adult stem cells in relation to the classification of cell populations on the basis their proliferative behavior. Particular attention is dedicated to adult neural stem cells, an issue that has recently seen the most amazing advances. Finally, the concept of adult stem cells in differentiated from that of developmental stem cells for transplantation therapies