13 OF '13
Kohman looking at a test tube
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Don't Want to Lose It? Move It!


"We know exercise can have huge effects on the immune system," Kohman said. The cells of people who exercise "tend to be more efficient, and they can clear out infections faster than in people who live a more sedentary lifestyle."

As America's population ages - by 2030, the number of people ages 65 or older will exceed 72 million, or 19 percent of the U.S. population - Kohman's research is contributing to a greater understanding of age-related effects on the brain.

Her research explores the relationship between the immune system and the central nervous system. In the past, each of these systems was believed to act independently, but recently researchers have determined the two systems communicate constantly, which equips the body to respond efficiently to adverse circumstances like injury or infection. When the body's peripheral immune system detects a problem, messenger proteins carry this news to the brain. In response, the brain galvanizes its healing process.

In one step of this process, called neuroinflammation, particular immune cells are activated within the brain. Though necessary for physical well-being, this step is not without hazards. By simulating bacterial infections in mice, Kohman has discovered that neuroinflammation can also impair learning and memory: mice whose immune systems are busy responding to an infection have increased difficulty learning new tasks. The implication is that this holds true for humans. Periods of illness might correspond to periods of impaired learning.

In addition, the elderly face increased risk to the regulation of their immune systems. Without its finely calibrated practice of checks and balances, low-level inflammation can persist in the brain, even without any apparent cause.

In September 2013, Kohman and colleagues from the University of Illinois at Urbana-Champaign, where she held a post-doctoral fellowship, published a research paper in the Journal of Neuroinflammation that further explores the relationship between age, gender, inflammation and brain function. As the results show, "exercise may be an effective intervention to prevent or reverse the age-related changes in immune activity within the brain."