From Sleep Homeostasis to Cellular Constraints in Neurons

Sleep is a conserved homeostatic process across animal species with nervous systems. The question of why animals sleep has remained one of the central mysteries in biology for millennia. Over the past two decades, major advances in sleep research have begun to clarify both its mechanisms and functions, allowing the outlines of a unifying framework to emerge. In this review, I summarize recent progress in the study of sleep homeostasis, highlight our own work in this area, and discuss how these findings may point toward a broader framework based on cellular constraints in neurons. • Synaptic plasticity contributes to the build-up of sleep need. • Wakefulness challenges neuronal integrity across multiple scales • Cellular constraints may unify mechanisms of sleep homeostasis