Synchronization and entrainment of coupled circadian oscillators
Synchronization and entrainment of coupled circadian oscillators
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DOI：
10.1098/rsfs.2010.0327
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发表时间：
2011-02-06
期刊：
影响因子：
4.4
通讯作者：
Toral, R.
中科院分区：
文献类型：
--
作者：
Komin, N.;Murza, A. C.;Toral, R.
哺乳动物的昼夜节律由位于下丘脑视交叉上核的神经元控制。在生理条件下，神经元系统非常有效地受到24小时明暗循环的影响。到目前为止，大多数研究都强调了由明暗周期施加的周期性在神经元同步中的关键作用。然而，异质性作为这些细胞相互作用的一个自然和永久的成分，似乎在这些生化过程中发挥了重要作用。本文利用视交叉上核神经元为化学耦合修正的Goodwin振子的模型，以猝灭噪声的形式在所有神经元的周期中引入了不可忽略的异质性。研究了系统对明暗周期的响应作为神经元间耦合强度、外力幅值和神经元异质性的函数。我们的结果表明，适量的异质性有助于扩展的系统以更一致的方式对外部强迫做出全局响应。我们提出的神经元在外部周期强迫下的同步机制是基于异质性诱导的振子死亡，与不同周期的自振神经元相比，受阻的振子更容易被外部强迫所缠绕。
Circadian rhythms in mammals are controlled by the neurons located in the suprachiasmatic nucleus of the hypothalamus. In physiological conditions, the system of neurons is very efficiently entrained by the 24 h light-dark cycle. Most of the studies carried out so far emphasize the crucial role of the periodicity imposed by the light-dark cycle in neuronal synchronization. Nevertheless, heterogeneity as a natural and permanent ingredient of these cellular interactions seemingly plays a major role in these biochemical processes. In this paper, we use a model that considers the neurons of the suprachiasmatic nucleus as chemically coupled modified Goodwin oscillators, and introduce non-negligible heterogeneity in the periods of all neurons in the form of quenched noise. The system response to the light-dark cycle periodicity is studied as a function of the interneuronal coupling strength, external forcing amplitude and neuronal heterogeneity. Our results indicate that the right amount of heterogeneity helps the extended system to respond globally in a more coherent way to the external forcing. Our proposed mechanism for neuronal synchronization under external periodic forcing is based on heterogeneity-induced oscillator death, damped oscillators being more entrainable by the external forcing than the self-oscillating neurons with different periods.