A feedback model for an insect circadian clock

Hemideina thoracica is a nocturnal orthopteran insect which exhibits clear circadian locomotor rhythmicity in constant conditions. Analysis of the free-running rhythms leads to the hypothesis that the underlying clock mechanism has two major interacting components, one responsible for the overt locomotor rhythm, and another whose output is not directly related to locomotor activity. A model comprising two linked populations of feedback oscillators accounts for much of the free-run liability seen in the real data.<>