No lazing on sunny afternoons

摘要

Circadian clocks are biological mechanisms that allow living organisms to adapt their physiology and behaviour to day-night cycles. In particular, a neuronal circadian clock controls rhythms of rest and activity in many animal species, including the fruitfly Drosophila melanogaster. In laboratory conditions, this insect shows a bimodal activity profile, with maximal activity concentrated in the morning and evening. However, the artificial light-dark cycles used in lab experiments only roughly mimic the complex environmental changes associated with alternating day and night. Vanin et al.' report on page 371 of this issue that fruitflies indeed behave very differently when exposed to more natural conditions. Moreover, the authors' results challenge the widely held idea that light and the known elements of the circadian clock are the main players that shape rest-activity rhythms.