title: Circadian rhythms in the neonate and in old age: what do they tell us about the development and decay of the body clock in humans?
abstract: This overview describes changes in human circadian rhythms in the neonate and in aged subjects. Since a measured circadian rhythm is derived from an endogenous (clock-driven) component and an exogenous component (due to rhythms in the environment and lifestyle), this account attempts to separate these possibilities in any particular case. Experimental methods for distinguishing between these components are described, and it is concluded that the data are rarely clear enough for such distinctions in mechanism to be made with confidence. Nevertheless, the evidence to date suggests that changes to the endogenous and exogenous components during both the development and decay of circadian rhythms are involved. This being the case, and accepting that poorly developed circadian rhythms are often associated with poor general health and development, methods to strengthen circadian rhythms are described.
authors.affiliation: School of Biological Sciences, University of Manchester, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Waterhouse
authors.forename: D S
authors.initials: DS
authors.lastname: Minors
mesh_terms: D000368:Aged / Q000502:physiology; D001683:Biological Clocks; D002940:Circadian Rhythm / Q000502:physiology*; D004777:Environment; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology