Rear in Gear and Smarter Too

Darn it, now there’s another good reason to peel yourself off that couch.

Intriguing experiments using mice suggest that regular running and intensive mental exercise may actually spur the growth of new brain cells in adults.

These findings are so provocative because for years scientists thought that the human brain had done pretty much all its growing by the time a child was born and that from there the trajectory was all downhill, brain-cell-wise.

Yet scientists of the Salk Institute for Biological Studies in La Jolla and scientists at Princeton University found that adult mice exercising on a running wheel consistently developed twice as many new brain cells as mice that just lolled around in their wood chips. The brain cell growth occurred in the hippocampus, the area of the brain crucial to the formation of new memories. The same result was observed for mice that faced mental challenges, particularly those involving spatial relationships and timing--tasks that taxed their little hippocampuses.

That the adult brain can produce new neurons is not news; previous animal studies have indicated this can happen. The latest results are so heartening because they give us tantalizing clues as to the circumstances under which this growth happens--as well as when it doesn’t. The lesson seems to come down to use it or lose it. Just as the right kind of mental or physical exercise seems to promote a healthy mind, the absence of mental stimulation may have an equally harmful effect on the brain, by allowing neurons to atrophy and die.

Mother always said too much lying around, too much television, would rot your brain. And once again, the new research indicates, she was right.