Professor Gerd Kempermann, speaking at the FENS2008, speculated that the newest stem cell hypothesis is operating from the premise that stem cells are used by the brain for maintenance, not regeneration.
This idea helps to explain why there are so many stem cells in the brain when their natural tendency doesn’t seem to be to replicate into needed cells (taking the place of damaged cells). Instead these cells help the brain compensate for the injured parts, supporting the brain’s ability to properly function.
An interesting and applicable fact is that these cells are stimulated to produce new neurons with exercise and increased cognitive use. The use of your body and your mind increases your brain’s ability to maintain its health and plasticity.
Sounds like a good thing to pay attention to!
So far this research is limited to mice, but Professor Kempermann believes that the same principals will also apply to the human brain.