Cellular Stress, Energy Constraints and the Energy Allocation Hypothesis of Sleep

Abstract

A growing body of literature demonstrates a critical role for sleep in upregulating diverse biological processes related to protein synthesis, immune function, and cellular housekeeping such as intracellular transport and membrane repair. The energy allocation (EA) hypothesis places sleep in a broader context of resource optimization where sleep–wake partitioning of metabolic operations optimizes resource utilization. The EA hypothesis of sleep carries important implications in health, disease, and homeostatic mechanisms. Specifically, conditions that lead to cellular stress, energy constraints or depression of neuronal activity, such as epilepsy, ischemic stroke or cortical spreading depression, are here proposed to follow similar conserved processes that favor sleep. This review examines the role of local mechanisms, including cytokine release or the accumulation of adenosine, in downregulating wakefulness to favoring sleep, loss of functional connectivity and the upregulation sleep-coupled processes that promote survival.