SLEEP, SLEEP-DEPRIVATION AND INFECTIOUS-DISEASE - STUDIES IN ANIMALS

Common perceptions that the desire for sleep is increased during mild infectious diseases like colds and 'the flu' have fostered beliefs tha t sleep promotes recovery from infectious disease and that lack of sle ep increases susceptibility to infections. However, until recently, th e relationship between infectious disease and vigilance received relat ively little systematic study, At present, several model systems provi de evidence that infectious disease is accompanied by alterations in s leep. Indeed, increased sleepiness, like fever and anorexia, may be vi ewed as a facet of the acute phase response to infectious challenge, R ecent studies also suggest that sleep, sleep deprivation and infectiou s disease may be related via mechanisms of the immune system (Fig. 1). Data are now accumulating to address questions such as whether immune processes alter sleep, whether sleep or sleep deprivation influences immune competence, and whether sleep facilitates recovery from infecti ous disease.