Grant: Discovery Grants Program - Individual

One of the current health crises facing our country is the obesity "epidemic". Excessive weight and a lack of exercise carry serious health consequences (e.g., heart disease, diabetes, hypertension) that are costly to treat. Physical inactivity (e.g. a sedentary lifestyle) is considered to be a major contributing factor to this "epidemic". One way to address this issue would be to increase participation in exercise. To do this it would be useful to understand the factors that influence motivation to engage in physical activity. My research program addresses this issue by studying the conditions that influence motivation to run in an animal model. In my lab, rats work, by pressing a lever, to obtain an opportunity to run. How hard the animal will work for an opportunity to run tells us how motivated the animal is to run or put another way, how rewarding running is for that animal. The conditions that influence the rewarding value of running have not been as extensively investigated as those for food and water so it may be beneficial to learn more about the rewarding value of running. How does it differ from, and in what ways is it similar to, the rewarding value of food and water? In this project, I will examine why rats did not prefer a longer opportunity to run over a shorter one when given a choice between them. One would assume that a longer period would be more rewarding because it allows for more running. I will also examine factors that influence how rats choose between food and running when given a limited budget to spend on these two commodities and when the prices/cost of the two commodities vary. Finally, I will examine why mice that are bred to run at high rates and considered to be "addicted" to running are not willing to work for running when the opportunity to run is brief.