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Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures
Published on: November 11, 2016
Modeling two-oscillator circadian systems entrained by two environmental cycles
1Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil. gaoda@ib.usp.br
Plos One
|September 3, 2011
Summary
Computer simulations of coupled circadian oscillators reveal complex behaviors under conflicting environmental cycles (zeitgebers). High coupling strength relative to zeitgeber strength explains phenomena like phase jumps, guiding future research on circadian rhythm synchronization.
Area of Science:
- Chronobiology
- Computational Biology
- Systems Biology
Background:
- Circadian rhythms synchronize to environmental cues (zeitgebers).
- Conflicting zeitgeber experiments explore rhythm synchronization under dual, out-of-phase cycles.
- Previous interpretations of complex activity patterns were challenging.
Purpose of the Study:
- To model coupled circadian oscillators under conflicting zeitgeber protocols.
- To explain complex phenomena observed in experimental studies.
- To provide a framework for interpreting circadian rhythm synchronization.
Main Methods:
- Developed computer simulations of coupled circadian oscillators.
- Utilized non-linear differential equations to model system dynamics.
- Analyzed 12 distinct phase relationships between two independent zeitgebers, inspired by Pittendrigh and Bruce (1959).
Main Results:
- Simulations replicated non-linear phenomena such as phase jumps and zeitgeber preference switches.
- These complex behaviors emerge when inter-oscillator coupling is high relative to zeitgeber strength.
- Model symmetry manipulations confirmed general applicability across various system configurations.
Conclusions:
- Complex phenomena in conflicting zeitgeber experiments are explained by oscillator coupling and zeitgeber strength.
- Recommends using a comprehensive range of phase relationships (12 conditions) for robust experimental design.
- Highlights the limitations of using only two phase relationships, which can obscure underlying dynamics.
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