A study published today in the journal Neuroscience, journal of the International Brain Research Organization, confirmed that exercise increases the chemical BDNF brain-derived neurotrophic factor in the hippocampus, a curved, elongated ridge in the brain that controls learning and memory. BDNF is involved in protecting and producing neurons in the hippocampus.

"When you exercise, it's been shown you release BDNF," said study co-author Justin Rhodes, Ph.D., a postdoctoral fellow in the Department of Behavioral Neuroscience at OHSU's School of Medicine and at the Veterans Administration Medical Center in Portland. "BDNF helps support and strengthen synapses in the brain. We find that exercise increases these good things."

Mice bred for 30 generations to display increased voluntary wheel running behavior an "exercise addiction" showed higher amounts of BDNF than normal, sedentary mice. In fact, the BDNF concentration in the active mice increased by as much as 171 percent after seven nights of wheel running.

"These mice are more active than wild mice," Rhodes said, referring to the mice as small and lean, and seemingly "addicted" to exercise. "Wheel running causes a huge amount of activity in the hippocampus. The more running, the more BDNF."

In a study Rhodes also co-authored that extends these findings, to be published in the October edition of the American Psychological Association journal Behavioral Neuroscience, scientists demonstrated that not only do the mice display more of this "good" BDNF chemical in the hippocampus, they grow more neurons there as well.

But those high levels of BDNF and neurogenesis don't necessarily mean an exercise addict learns at a faster rate, Rhodes said. According to the Behaviora
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Contact: Jonathan Modie
modiej@ohsu.edu
503-494-8231
Oregon Health & Science University
26-Sep-2003