Some areas of the adult brain contain quiescent, or dormant, neural stem cells that can potentially be reactivated to form new neurons. However, the transition from quiescence to proliferation is still poorly understood. A team led by scientists from the Universities of Geneva (UNIGE) and Lausanne (UNIL) has discovered the importance of cell metabolism in this process and identified how to wake up these neural stem cells and reactivate them. Biologists succeeded in increasing the number of new neurons in the brain of adult and even elderly mice. These results, promising for the treatment of neurodegenerative diseases, are to be discovered in the journal Science Advances.