Spontaneous synchronization of coupled circadian oscillators
Spontaneous synchronization of coupled circadian oscillators
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DOI：
10.1529/biophysj.104.058388
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发表时间：
2005-07-01
影响因子：
3.4
通讯作者：
Herzel, H
中科院分区：
文献类型：
--
作者：
Gonze, D;Bernard, S;Herzel, H
在哺乳动物中，控制日常节律的昼夜节律起搏器位于视交叉上核(SCN)。昼夜节律振荡是由分子调控网络在单个SCN神经元中产生的。细胞的振荡周期从20到28小时不等，但在组织水平上，SCN神经元表现出显著的同步性，这表明细胞间存在着强大的耦合，其中神经递质被认为发挥了关键作用。我们提出了SCN中一组昼夜节律振荡器的耦合的动力学模型。细胞振荡器是一个三变量模型，描述了生物钟的核心负反馈回路。这种耦合机制是通过神经递质浓度的全球水平结合起来的。全局耦合有效地同步了10,000个细胞的种群。同步的细胞可能会受到24小时的明暗周期的影响。对代表SCN两个区域的两个种群之间相互作用的模拟表明，驱动种群可以是相位领先的。实验上可验证的预测是：1)，单个细胞的相由其内在周期决定；以及2)，当平均神经递质浓度将抑制单个振荡器时，有效的同步实现。然而，由于全球神经递质的振荡，细胞实际上是同步的。
In mammals, the circadian pacemaker, which controls daily rhythms, is located in the suprachiasmatic nucleus (SCN). Circadian oscillations are generated in individual SCN neurons by a molecular regulatory network. Cells oscillate with periods ranging from 20 to 28 h, but at the tissue level, SCN neurons display significant synchrony, suggesting a robust intercellular coupling in which neurotransmitters are assumed to play a crucial role. We present a dynamical model for the coupling of a population of circadian oscillators in the SCN. The cellular oscillator, a three-variable model, describes the core negative feedback loop of the circadian clock. The coupling mechanism is incorporated through the global level of neurotransmitter concentration. Global coupling is efficient to synchronize a population of 10,000 cells. Synchronized cells can be entrained by a 24-h light-dark cycle. Simulations of the interaction between two populations representing two regions of the SCN show that the driven population can be phase-leading. Experimentally testable predictions are: 1), phases of individual cells are governed by their intrinsic periods; and 2), efficient synchronization is achieved when the average neurotransmitter concentration would dampen individual oscillators. However, due to the global neurotransmitter oscillation, cells are effectively synchronized.