Tokuda Isao T, Schmal Christoph, Ananthasubramaniam Bharath, Herzel Hanspeter
Department of Mechanical Engineering, Ritsumeikan University, Kyoto, Japan.
Institute for Theoretical Biology, Humboldt Universität zu Berlin, Berlin, Germany.
Front Physiol. 2020 Apr 28;11:334. doi: 10.3389/fphys.2020.00334. eCollection 2020.
Understanding entrainment of circadian rhythms is a central goal of chronobiology. Many factors, such as period, amplitude, strength, and daylength, govern entrainment ranges and phases of entrainment. We have tested whether simple amplitude-phase models can provide insight into the control of entrainment phases. Using global optimization, we derived conceptual models with just three free parameters (period, amplitude, and relaxation rate) that reproduce known phenotypic features of vertebrate clocks: phase response curves (PRCs) with relatively small phase shifts, fast re-entrainment after jet lag, and seasonal variability to track light onset or offset. Since optimization found multiple sets of model parameters, we could study this model ensemble to gain insight into the underlying design principles. We found complex associations between model parameters and entrainment features. onions of representative models visualize strong dependencies of entrainment on periods, relative strength, and photoperiods. Our results support the use of oscillator theory as a framework for understanding the entrainment of circadian clocks.
理解昼夜节律的同步是时间生物学的核心目标。许多因素，如周期、振幅、强度和日长，决定了同步范围和同步相位。我们测试了简单的振幅-相位模型是否能为同步相位的控制提供见解。通过全局优化，我们推导出了仅具有三个自由参数（周期、振幅和弛豫率）的概念模型，这些模型再现了脊椎动物生物钟的已知表型特征：具有相对小相位偏移的相位响应曲线（PRC）、时差后快速重新同步以及跟踪光开始或结束的季节性变化。由于优化找到了多组模型参数，我们可以研究这个模型集合以深入了解潜在的设计原则。我们发现模型参数与同步特征之间存在复杂的关联。代表性模型的图示显示了同步对周期、相对强度和光周期的强烈依赖性。我们的结果支持使用振荡器理论作为理解昼夜节律生物钟同步的框架。
