Exercise could build brain cells in elderly

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http://www.usatoday.com/news/health/2005-09-20-exercise-brain-cells_x.htm

Exercise could build brain cells in elderly, study suggests

By Kathleen Fackelmann, USA TODAY

Older mice that exercised on a running wheel developed new brain cells

and learned a new task more effectively than older mice that took it

easy all day, a study reports today.

The study showed that regular physical activity helped spur the

production of neurons in the memory region of the mouse brain. If the

findings hold true for humans, they suggest that regular workouts

might give older humans a boost in brainpower and might even help

forestall the forgetfulness and confusion that can plague people as

they get older, says researcher Fred Gage of the Salk Institute for

Biological Studies in La Jolla, Calif.

The findings, reported in today's Journal of Neuroscience, also

suggest that it's never too late to get moving: The mice in the study

were about 70 in human years, and they developed an edge in brainpower

after exercising for just a month.

" The findings are pretty exciting, " says Snowdon, researcher on

aging at the University of Kentucky, who was not involved in the study.

Previous research has shown that exercise could spur the formation of

brain cells in young mice, or mice that in human terms were equivalent

to a 20-year-old. This study is the first to show that exercise helps

older mice.

Gage and his colleagues allowed a group of old mice and a group of

young mice to exercise on a running wheel as much as they wanted. The

mice ran about 2 miles every day. The researchers also kept a third

group of older mice that didn't exercise. After a month of the regular

exercise, the team subjected the mice to a memory test

The researchers taught the mice to find a platform submerged in a pool

of water. After the mice had learned the location of the platform,

they had to find it even when it was hidden in cloudy water.

The Salk team found that the old mice that had worked out on the wheel

performed as well as the young mice: The elderly mice remembered the

location of the platform and swam quickly to the spot without much

trouble.

In contrast, the older mice that didn't get the daily workouts

flunked: These mice, much like older people who are starting to show

declines in memory, had trouble remembering the location of the

platform. In most cases, the mice swam aimlessly in the pool and never

found the platform or found it by chance, Gage says.

When the team examined the animals' brain tissue, they found that

older mice that had been exercising had added significant amounts of

cells in the hippocampus, the part of the brain that helps with memory

and the ability to learn new tasks.

The old mice that didn't exercise seemed to produce very few new brain

cells, a problem that might explain their confusion, Gage says.

This study suggests — but doesn't prove — that people with

brain-destroying diseases such as Alzheimer's might be able to build

replacement brain cells as a result of daily workouts, says

Thies of the Chicago-based Alzheimer's Association.

The new findings also indicate that healthy older people might be able

to reverse some of the normal age-related loss of brain cells with a

daily walk, Gage says.

People shouldn't wait for researchers to confirm these findings,

experts say. Plenty of other research shows regular workouts offer

lots of benefits to both the brain and the body, Snowdon says. The new

study now adds another compelling reason to get moving.