By Jonas Fritze
Neural stem cells exist both in the developing and in the adult brain of mammals. Just like other stem cells, they can divide limitless to make copies of themselves and turn into other cell types. Neural stem cells are restricted to cell types found in the central nervous system, and are therefore considered multipotent stem cells.
During embryonic and fetal development, neural stem cells contribute to a massive production of different brain cells to build up the brain. In the adult brain it is quite different. There, neural stem cells are very few in number, mainly inactive, and exist only in certain areas of the brain. Still, they are essential for some tasks. Since neurons are unable to divide, neural stem cells are the only source of new neurons.1 When the brain is injured from stroke, and neurons die, neural stem cells are activated to produce new neurons to repair the damaged part of the brain.2
The birth of new neurons from neural stem cells is called neurogenesis and is important for creating new memories. Neurogenesis continues throughout life but becomes less efficient with age and in some age-related dementia diseases, such as Alzheimer’s and Parkinson’s disease.3 One way to improve neurogenesis is with physical activity4, which can also be beneficial for healthy aging.5
Neural stem cells have the potential to repair the brain and improve memory and are therefore the target for a lot of research. Knowledge from studying neural stem cells has made it possible for scientists to produce neurons from induced pluripotent stem cells, which will soon be used in clinical trials as a therapy for Parkinson’s disease.6