Sleep and autonomic nervous system

The integrated activity of the autonomic nervous system (ANS) with the somatomotor and the neuroendocrine systems allows an animal to maintain internal homoeostasis and regulate its interaction with the external environment. Significant changes in ANS activity occur on passing from wakefulness to sleep, and this pattern of autonomic activation is profoundly different even between NREMS and REMS. While, during NREMS, the ANS works to maintain body homeostasis in accordance with the reduced metabolic needs of this state, during REMS ANS activity is greatly variable, and not visibly oriented to the maintenance of the stability of physiological variables. Sleep derangements determine an alteration of autonomic activity that can also extend to waking, favoring the development of pathological conditions. In this review, we summarize new insights into the impact of sleep derangements on ANS control of immune, respiratory and cardiovascular function, and into the role of ANS in thermoregulation and energy expenditure.