While sleep is nearly universal throughout the animal kingdom, the physiological functions and biological factors regulating sleep remain unclear. This project seeks to understand how diet and metabolism influence sleep duration using the blind Mexican cavefish as a model system. The Mexican cavefish is an extremely informative system for examining behavioral and genetic adaptations. These fish were trapped in caves ~1-8 million years ago, and have adapted to these nutrient-poor environments by dramatically reducing sleep and developing numerous physiological changes, including altered metabolism, eye-loss, and albinism. This project will determine the evolutionary basis for the reduction in sleep. The differences in habitat between river-dwelling surface and cave populations of these fish present a unique opportunity to examine the effects of ecology and evolutionary history on sleep. Sleep will be measured in fish fed either a high or a low-fat diet to determine whether high-calorie diets are capable of restoring normal sleep in cavefish. Furthermore, genetic hybrid fish will be tested for sleep and other foraging behaviors to determine whether distinct or overlapping genes regulate reduced sleep and altered feeding behaviors. Taken together, these experiments will determine the evolutionary basis for sleep loss in Mexican cavefish.
Work produced in this project will contribute to our understanding of the biological basis of sleep with potential extension to a better understanding of the relationship between diet and sleep in humans. In addition to contributing to scientific knowledge across life disciplines, this project will provide opportunities for student training and outreach in the local community. Teaching laboratories will be developed with a local high school to expose students to behavioral ecology and neuroscience research. All developed lab protocols will be made available online for access and use at other high schools and teaching institutions. Additionally, this project will fund students enrolled in programs for first generation and minority college students to work in the research laboratory.