Kevin W. Williams, Ph.D.
Division of Hypothalamic Research
Department of Internal Medicine
The University of Texas Southwestern Medical Center
Dallas, Texas 75390-9077
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Exercise (single bout and/or chronic training) has valuable effects on metabolism. Important in the treatment of Diabetes, metabolic improvements in response to exercise include improved blood glucose regulation. However, the metabolic related circuits in the brain that are altered in response to exercise remain undefined. Within the brain, the melanocortin system is an interface between signals that relay metabolic state and neural pathways governing metabolism.
In this study, we measured the effects of short- and long-term exercise on two types of neurons that comprise the melanocortin brain circuit, which is shared by both humans and mice. Normally, these two neurons — thePOMCs and the NPY/AgRP neurons — have opposing effects on appetite and energy burning. When activated, POMC neurons are associated with reduced appetite, lower blood glucose levels, and higher energy burning. The other type(NPY/AgRP) increases appetite and diminishes metabolism when activated. We found that POMC neurons were activated in response to exercise, while NPY/AgRPwere inhibited.
Interestingly, POMC neurons exhibited sustained activity for up to 2 days after a single bout of exercise.