title: Natural environmental cues and circadian rhythms of behaviour--a perspective.
abstract: Natural environmental cycles are often extremely difficult to reproduce under laboratory conditions. Laboratory light-dark cycles differ from natural light-dark cycles in terms of intensity and spectral distribution, whilst simulated temperature cycles may differ from natural temperature cycles in waveform. The expression of a free-running rhythm depends upon the 'level' of constant conditions provided. Environmental cues affect the period, phasing, amplitude and activity-rest ratios of circadian rhythms and, if inappropriate, may result in aberrant behaviour patterns which are unlike those observed in nature.
authors.affiliation: Department of Applied Biology, UWIST, Llysdinam Field Centre, Powys, Wales.
authors.forename: R A
authors.initials: RA
authors.lastname: Griffiths
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002940:Circadian Rhythm; D003624:Darkness; D004777:Environment; D008027:Light; D009043:Motor Activity / Q000502:physiology; D013696:Temperature