We have discovered a factor that causes the impairment of neurogenesis in the aged brain. A mechanism has been identified by which stimuli including exercise re-activate the ability to generate newborn neurons that have declined due to aging. The discovery is expected to contribute to the prevention of diseases and the development of drugs and treatments, using a new target agent that controls neighborhood cells surrounding neural stem cells. We will further analyze the role of cells surrounding neural stem cells, which affect aging and various neurological disorders, to search for a new molecular marker detection method useful for diagnosis. We will develop industrial applications of the findings, including the development of drugs and new medical technology that promote the activation of stem cell-supporting cell populations without manipulating stem cells.