Circadian Rhythms in Young and Aged Flies

Fly activity was monitored as described [44 (link)]. Briefly, newly eclosed male flies were trained under 12 h light-darkness (LD) cycles until the beginning of the experiment. Then, young (5 days-old) and aged (21 days-old) flies were placed in glass tubes and monitored for activity with infrared detectors. Fly activity was monitored under LD conditions for 3 days and then released into constant darkness (DD) for at least one week employing commercially available activity monitors (TriKinetics, Waltham, MA). Period and rhythmicity were estimated using the ClockLab software (Actimetrics, Evanston, IL) from data collected under DD. Each experiment was repeated at least two times from two independent biological replicates.