Thermoregulation and Sleep: Functional Interaction and Central Nervous Control

Each of the wake-sleep states is characterized by specific changes in autonomic activity and bodily functions. The goal of such changes is not always clear. During non-rapid eye movement (NREM) sleep, the autonomic outflow and the activity of the endocrine system, the respiratory system, the cardiovascular system, and the thermoregulatory system seem to be directed at increasing energy saving. During rapid eye movement (REM) sleep, the goal of the specific autonomic and regulatory changes is unclear, since a large instability of autonomic activity and cardiorespiratory function is observed in concomitance with thermoregulatory changes, which are apparently non-functional to thermal homeostasis. Reciprocally, the activation of thermoregulatory responses under thermal challenges interferes with sleep occurrence. Such a double-edged and reciprocal interaction between sleep and thermoregulation may be favored by the fact that the central network controlling sleep overlaps in several parts with the central network controlling thermoregulation. The understanding of the central mechanism behind the interaction between sleep and thermoregulation may help to understand the functionality of thermoregulatory sleep-related changes and, ultimately, the function(s) of sleep. © 2021 American Physiological Society. Compr Physiol 11:1591-1604, 2021.