Title
Modeling The Seasonal Adaptation Of Circadian Clocks By Changes In The Network Structure Of The Suprachiasmatic Nucleus
Abstract
The dynamics of circadian rhythms needs to be adapted to day length changes between summer and winter. It has been observed experimentally, however, that the dynamics of individual neurons of the suprachiasmatic nucleus (SCN) does not change as the seasons change. Rather, the seasonal adaptation of the circadian clock is hypothesized to be a consequence of changes in the intercellular dynamics, which leads to a phase distribution of electrical activity of SCN neurons that is narrower in winter and broader during summer. Yet to understand this complex intercellular dynamics, a more thorough understanding of the impact of the network structure formed by the SCN neurons is needed. To that effect, we propose a mathematical model for the dynamics of the SCN neuronal architecture in which the structure of the network plays a pivotal role. Using our model we show that the fraction of long-range cell-to-cell connections and the seasonal changes in the daily rhythms may be tightly related. In particular, simulations of the proposed mathematical model indicate that the fraction of long-range connections between the cells adjusts the phase distribution and consequently the length of the behavioral activity as follows: dense long-range connections during winter lead to a narrow activity phase, while rare long-range connections during summer lead to a broad activity phase. Our model is also able to account for the experimental observations indicating a larger light-induced phase-shift of the circadian clock during winter, which we show to be a consequence of higher synchronization between neurons. Our model thus provides evidence that the variations in the seasonal dynamics of circadian clocks can in part also be understood and regulated by the plasticity of the SCN network structure.
Year
DOI
Venue
2012
10.1371/journal.pcbi.1002697
PLOS COMPUTATIONAL BIOLOGY
Keywords
Field
DocType
neuronal plasticity,computer simulation,circadian clocks
Light effects on circadian rhythm,Ecology,Neuroscience,Circadian rhythm,Biology,Nerve net,Neuroplasticity,Genetics,Suprachiasmatic nucleus,Rhythm,Circadian clock,Network structure
Journal
Volume
Issue
ISSN
8
9
1553-734X
Citations 
PageRank 
References 
3
0.43
4
Authors
5
Name
Order
Citations
PageRank
Christian Bodenstein1346.76
Marko Gosak2133.43
Stefan Schuster336256.87
Marko Marhl4227.31
Matjaz Perc5134994.25