Oscillators in a regular lattice display phase sub-oscillations that carry Zeitgeber's frequency information.

CANNAS, S.A; NIETO, P. S; VALDEZ, L

Simposio; Simposio Latinoamericano de Cronobiologia; 2017

In mammals, the suprachiasmatic nuclei (SCN) are hypothalamic structures comprised of glial cells and neurons which are functionally heterogeneous circadian oscillators. Because SCN cells function coordinately in order to drive physiological and behavioral circadian rhythms, the SCN can be considered as a network of oscillators which works in synchrony. A subset of SCN cells receive direct environmental light-dark information through the retinohypothalamic tract and this information is communicated to the rest of the network through coupling between SCN cells, ultimately allowing the entrainment of the SCN to the light-dark cycle. Our aim is to understand how phase and period information from the light-dark cycle is transmitted into the SCN oscillator network. To achieve this we study a Kuramoto model on a square lattice on which an external oscillating force with amplitude B and frequency wf perturbs a subset of oscillators. We find that for high coupling strength, the system exhibits phase traveling waves while the effective frequency of each node in the network is set to the external frequency (wf), a phenomenon known as frequency locking. Interestingly, for low coupling strength, the system also displays traveling waves but in this case those oscillators which do not receive direct external stimulus not longer exhibit frequency locking. Nevertheless another phenomena emerge in those nodes: their phases sub-oscillate with a frequency close to that of the external stimulus. We numerically show that phase sub-oscillations are a robust phenomenon which carry Zeitgeber´s frequency information.