Narrator: This is Science Today. Positive thinking and exercise have long been linked to good health, but now for the first time, there may be clinical proof. Neuroscientist Marian Diamond and her colleagues at the University of California, Berkeley discovered a link between the cerebral cortex of the brain, which is related to motor function and thought planning and the thymus gland, which produces disease fighting T-cells.
Diamond: We know when people are busy and active and thinking ahead and using your cortex, they usually don't get sick. So one hypothesized there had to be some kind of direct link between these higher cognitive areas and the immune system.
Narrator: Diamond implanted thymus glands in immune deficient mice and found their abnormally thin cortexes became thick. This link proves the two systems are related and may lead to controlling immune function.
Diamond: It's been said many times that physical exercise improves the immune system, but nobody's ever had a system.
Narrator: Diamond says these findings may lead to such a system. For Science Today, I'm Larissa Branin.