Effects of circadian disruption on physiology and pathology: from bench to clinic (and back).

CHIESA JJ; DUHART JM; CASIRAGHI, L; PALADINO, N; BUSSI, IL; GOLOMBEK, DA

Mechanisms of Circadian Systems in Animals and Their Clinical Relevance

Elsevier

Año: 2015; p. 289 - 320

Nested within the hypothalamus, the suprachiasmatic nuclei (SCN) 7 represent a central biological clock that regulates daily and circadian (i.e., close to 8 24 h) rhythms in mammals. Besides the SCN, a number of peripheral oscillators 9 throughout the body control local rhythms and are usually kept in pace by the cen- 10 tral clock. In order to represent an adaptive value, circadian rhythms must be 11 entrained by environmental signals or zeitgebers, the main one being the daily 12 light?dark (LD) cycle. The SCN adopt a stable phase relationship with the LD cycle 13 that, when challenged, results in abrupt or chronic changes in overt rhythms and, in 14 turn, in physiological, behavioral, and metabolic variables. Changes in entrainment, 15 both acute and chronic, may have severe consequences in human performance and 16 pathological outcome. Indeed, animal models of desynchronization have become a 17 useful tool to understand such changes and to evaluate potential treatments in human 18 subjects. Here we review a number of alterations in circadian entrainment, including 19 jet-lag, social jet-lag (i.e., desynchronization between body rhythms and normal 20 time schedules), shift work, and exposure to nocturnal light, both in human sub- 21 jects and in laboratory animals. Finally, we focus on the health consequences 22 related to circadian/entrainment disorders and propose a number of approaches 23 for the management of circadian desynchronization.