Research Projects

Sleep is a common brain state found in both humans and animals, yet its regulation remains a mystery. Two processes interact to regulate sleep: a circadian process that controls sleep timing and a homeostatic process that tracks sleep need and controls the amount of sleep. The circadian clock is well-understood, but the operations and neural architecture of the homeostat are less understood. The study of sleep in Drosophila, a fly with a compact, well-defined nervous system, has many similarities to mammalian sleep. Much of the work on mechanisms of homeostasis has focused on the process by which sleep need increases in proportion to time spent awake, which finds expression in increased sleep in the period following sleep loss. However, the sleep homeostat is plastic and integrates multiple inputs that modulate sleep drive, including time awake. This sleep-plasticity is evolutionarily conserved and has received little attention. Recent discoveries have revealed a surprising form of sleep-plasticity: impairing flight in flies increased sleep via a novel wing sensory circuit. These discoveries allow researchers to explore questions around the generation of sleep need or sleep drive in a tractable system. The proposal addresses three questions: how peripheral sleep modulating inputs are transduced to modulate central sleep regulatory circuits using flight-disruption induced sleep as a model, how different sleep modulatory inputs are integrated, and whether sleep induced by different means serves the same functions by examining the functional consequences of two different sleep modulatory manipulations – social enrichment and flight-disruption.