Ticking and talking in the brainstem satiety centre: A phase model of three clocks #

Jake Ahern, Lukasz Chrobok, Hugh Piggins, Alan Champneys

11:10 Wednesday in 2Q42.

Part of the Mathematical modelling of sleep and circadian rhythms: from molecular mechanisms to policy session.

Abstract #

Analysis of the Per2 bioluminescent rhythm previously recorded in the ex vivo mouse dorsal vagal complex (DVC) reveals a characteristic phase relationship between three distinct circadian oscillators: the area postrema (AP), the nucleus of the solitary tract (NTS), and the ependymal cells surrounding the 4th ventricle (4Vep). The data suggests a consistent phasing, where the AP peaks first, followed immediately by the NTS, with the 4Vep in near-antiphase. Wavelet analysis shows that this pattern is not consistently maintained throughout the recording, however, the phase dynamics strongly imply the presence of oscillator interactions. In this talk, I will present a simple phase model that simulates realistic phase dynamics between the three oscillators when the coupling is close to a synchronization transition. The coupling topology suggests that the AP bidirectionally communicates phase information to NTS and 4Vep to synchronize the three structures. Comparing the model with previous experimental manipulations demonstrates its feasibility to explain DVC circadian phasing. Finally, we show that simulating steadily decaying coupling improves the model’s ability to capture experimental phase dynamics.