Obesity

Catherine Kotz, PhD, on Central Circuitry Controlling Physical Activity

Research has shown a connection between the central nervous system and spontaneous physical activity, as well as the effects of exercise on central nervous system function. Orexin, a hormone produced in the hypothalamus that regulates appetite and sleep, has been at the center of this research.

To find out more about the role of orexin, Cardiology Consultant reached out to Catherine Kotz, PhD, who is a professor in the Department of Integrative Biology and Physiology and director of graduate studies at the University of Minnesota and the associate director for research at the Geriatric Research, Education, and Clinical Center at the Minneapolis VA Hospital in Minneapolis, Minnesota.

Her areas of research interest include basic science obesity and neuropeptide regulation of feeding and energy expenditure.

CARDIO CON: Can you tell us more about how central brain circuitry controls physical activity?

Catherine Kotz: My work focuses on nonmotivated physical activity behavior, also termed spontaneous physical activity (SPA). SPA is regulated by brain circuitry and can drive some individuals to move more and, therefore, expend more calories and resist weight gain. More specifically, I study the role that orexin (a neuropeptide) plays in this process. Our work shows that animal models of high orexin function resist obesity during obesogenic conditions.

CARDIO CON: How will knowing more about the role of orexin help providers better care for their patients?

CK: It is helpful to know that there is a high degree of variation in the propensity to move, which is biologically driven by brain circuitry, and which can dramatically impact body weight and weight loss therapies. If a care provider understands that concept, he/she can provide better, more individualized treatment strategies.

CARDIO CON: What is the key take-home message for health care providers?

CK: That while the brain controls spontaneous physical activity, this behavior can be learned and used to benefit weight prevention strategies and cardiovascular outcomes.

CARDIO CON: In your opinion, are physical activity guidelines for reducing obesity in the United States adequate? Are they doing a good enough job?

CK: I think the guidelines are adequate, but there needs to be societal changes to help people know about and adhere to the guidelines. Most individuals do not get enough physical activity throughout their day.