Another benefit of regular exercise is proposed in this recent research: scientists "have, for the first time, been able to demonstrate that moderate exercise significantly increases the number of neural stem cells in the ageing brain. ... neuroscientists have known for some time that, in healthy brains, the creation of new neurons is an ongoing and lifelong mechanism. However, it has also been known for more than a decade that the number of new neurons we produce slowly declines with age. ... Investigating the mechanism by which neural stem cell numbers are altered will undoubtedly increase our understanding of how the brain responds to its environment. Ultimately, this should allow us to discover how to harness the brain's regenerative capacity, and to bring about new and effective treatments for conditions caused by trauma, disease, or even normal ageing. The brain's ability, even at an advanced age, to respond in a positive manner is very exciting as it extends the time-frame in which manipulation is possible."