Today's open access paper is a review of potential approaches that might be used as a basis for therapies to restore a more youthful level of neurogenesis in the aging mammalian brain. Neurogenesis is the process by which new neurons are created by neural stem cell populations and then integrated into neural networks. In adults, neurogenesis is essential to memory, learning, and the limited degree of regeneration that the brain is capable of enacting. Unfortunately, the supply of new neurons declines with age as the underlying stem cells become ever less active. Beyond making the aging brain more resilient, methods of increasing neurogenesis may prove to be enhancement therapies capable of improving cognitive function even in young people.

Any discussion of adult neurogenesis must note the present debate over whether or not it in fact does take place in humans in the same way as it does in mice. It was only in the 1990s that neurogenesis was discovered to take place in some portions of the adult mouse brain, and since then near all work on neurogenesis in general, as well on changes in neurogenesis with age, has focused on mice, given the costs and difficulties inherent in studying human brains and brain tissue. This became a growing concern, careful human studies were undertaken, and in the past few years rigorous evidence has been presented on both sides of the question of adult human neurogenesis, both ruling it out, and demonstrating that it does take place. Considerable debate has taken place over the technical details of these studies and the underlying processes of neurogenesis. Insofar as there is a present weight of evidence, it appears to lean towards the conclusion that humans do in fact exhibit adult neurogenesis.

Rejuvenating subventricular zone neurogenesis in the aging brain