Study shows why exercise boosts brainpower

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Study shows why exercise boosts brainpowerStory Highlights• Exercise builds new brain cells in a region linked with memory and memory loss

• Mice grew new cells in area known to be affected in age-related memory decline

• MRIs showed similar cell growth in human brains after exerciseWASHINGTON

(Reuters) -- Exercise boosts brainpower by building new brain cells in

a brain region linked with memory and memory loss, U.S. researchers

reported Monday.Tests on mice showed they grew new brain cells

in a brain region called the dentate gyrus, a part of the hippocampus

that is known to be affected in the age-related memory decline that

begins around age 30 for most humans.The researchers used

magnetic resonance imaging scans to help document the process in mice

-- and then used MRIs to look at the brains of people before and after

exercise.They found the same patterns, which suggests that people also grow new brain cells when they exercise. " No

previous research has systematically examined the different regions of

the hippocampus and identified which region is most affected by

exercise, " Dr. Small, a neurologist at Columbia University

Medical Center in New York who led the study, said in a statement.Writing in the Proceedings of the National Academy of Sciences, the researchers said they first tested mice.Brain

expert Fred Gage, of the Salk Institute in La Jolla, California, had

shown that exercise can cause the development of new brain cells in the

mouse equivalent of the dentate gyrus.The teams worked together to find a way to measure this using MRI, by tracking cerebral blood volume. " Once

these findings were established in mice, we were interested in

determining how exercise affects the hippocampal cerebral blood volume

maps of humans, " they wrote.They of course could not dissect the brains of people to see if new neurons grew, but they could use MRI to have a peek.They recruited 11 healthy adults and made them undergo a three-month aerobic exercise regimen.

They

did MRIs of their brains before and after. They also measured the

fitness of each volunteer by measuring oxygen volume before and after

the training program.Exercise generated blood flow to the

dentate gyrus of the people, and the more fit a person got, the more

blood flow the MRI detected, the researchers found. " The

remarkable similarities between the exercise-induced cerebral blood

volume changes in the hippocampal formation of mice and humans suggest

that the effect is mediated by similar mechanisms, " they wrote. " Our

next step is to identify the exercise regimen that is most beneficial

to improve cognition and reduce normal memory loss, so that physicians

may be able to prescribe specific types of exercise to improve memory, "

Small said.Copyright 2007 Reuters. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.

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