Synchronization and network structure in a model for mammalian circadian clock.

GUADALUPE CASCALLARES; PABLO M GLEISER

Buenos Aires

Otro; XV Giambiagi Winter School: Information processing in biological systems: from cells to equations and back.; 2013

Universidad Nacional de Buenos Aires

The circadian rhythm is a 24 h rhythm which can be found in many organisms ranging from cyanobacteria to mammals. Circadian rhythmicity is present in the sleeping and feeding patterns of these organisms. There are also clear patterns of core body temperature, brain wave activity, hormone production, cell regeneration and other biological activities. These daily rhythms are endogenously generated, and continue even in the absence of any environmental cues. In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus constitutes the central circadian pacemaker. Cells of the SCN can be divided in two groups of neurons: the core and the shell. The core receives information from the retino-hypothalamic tract, and sends this information to the shell. They are distinguished by the type of neurotransmitters they express, but little is known about the topology of the SCN cellular network. We analyzed the synchronization properties of two coupled groups of oscillators to mimic the two regions of the SCN. In this analysis, we modeled neurons as phase oscillators and analyzed the influence of one group on the other. Using different intra and intergroup couplings and changing other parameters we observed the effects on the synchronization and the emergence of different frequency and phase oscillation clusters. We compared our results with recent experimental evidence of synchronization in the SCN.