Simulations of Free-running Rhythms, Light Entrainment and the Light-pulse Phase Response Curves for the Locomotor Activity Rhythm inperiodMutant ofDrosophila melanogaster

A single oscillator feedback model, originally developed to account for the circadian behaviour of the nocturnal insect,Hemideina thoracica, has been adapted to simulate some of the properties of the locomotor rhythms ofDrosophila melanogaster, in particular the response of the locomotor activity rhythms of the wild-type andperiodmutants to single light pulses and light entrainment. These simulations are achieved by variations inpertranscription and translocation rates, the time delay in the feedback loop, and degradation rates of the oscillating protein. The model is analogous to the word models of the mechanisms developed from the molecular studies of theDrosophilacircadian system.