Sleep in Fish Models

Sleep is a near-universal behavior that is essential for diverse biological processes. Although the duration and timing of sleep vary throughout the animal kingdom, the function of sleep and the evolutionary basis for this conserved behavior remain poorly understood. In recent years, characterization of sleep in fish models has provided fundamental insights into the molecular, cellular, and evolutionary principles of sleep regulation. Here, we outline the breakthroughs in fish for sleep research and the strengths of fish models for sleep investigation. We focus this review on research in zebrafish (Danio rerio) and the Mexican cavefish (Astyanax mexicanus) that investigates the mechanisms of sleep regulation and the evolution of sleep in response to environmental perturbation. We propose that developing new genetic tools and applying the current available toolkit to additional fish models of evolution, behavior, aging, and neurological disorders will augment our understanding of the mechanisms and function of sleep.