New York, Nov 23 (IANS): Daily exercise can protect the brain against decline as we age, finds researchers after conducting an animal study.

In lab tests with mice, researchers from Johns Hopkins University found that exercise helped boost levels of an enzyme called SIRT3 which may protect against stressors that contribute to brain cell energy loss.

In tests with mice, researchers discovered that exercise helped boost levels of an enzyme called SIRT3, which may protect against stressors that contribute to brain cell energy loss.

Researchers led by Mark Mattson from the National Institute on Aging and Johns Hopkins' school of medicine used a new animal model to investigate whether they could aid neurons in resisting the energy-depleting stress.

They found that mice that did not produce SIRT3 became highly sensitive to stress when exposed to neurotoxins that cause neurodegeneration and epileptic seizures.

With mice that did produce SIRT3, researchers discovered that exercise on a running wheel increased levels of the enzyme.

"Running wheel exercise increased the amount of SIRT3 in neurons of normal mice and protected them against degeneration," Mattson noted.

In mice lacking the enzyme, running failed to protect the neurons.

"Neurons can be protected against stress through use of a gene therapy technology to increase levels of SIRT3 in neurons," he suggested.

As we grow older or develop neuro-degenerative diseases such as Alzheimer's, our brain cells can stop producing enough energy to remain fully functional.

The findings, published in the journal Cell Metabolism, can help improve therapies for age-related cognitive decline.