Plasticity in the Period of the Circadian Pacemaker Induced by Phase Dispersion of Its Constituent Cellular Clocks
Plasticity in the Period of the Circadian Pacemaker Induced by Phase Dispersion of Its Constituent Cellular Clocks
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DOI：
10.1177/0748730417706581
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发表时间：
2017-06-01
影响因子：
3.5
通讯作者：
Daan, Serge
中科院分区：
文献类型：
--
作者：
Beersma, Domien G. M.;Gargar, Kim A.;Daan, Serge
哺乳动物昼夜节律起搏器通常被认为是一个刚性振荡器，在各种情况下产生输出，仅在相位，周期和/或振幅上不同。然而，起搏器是由许多细胞组成的，每一个细胞都可以以不同的方式对不同的环境做出反应。计算机模拟表明，与恒定黑暗相比，这种起搏细胞网络在光暗循环下的行为不同。这些差异表明，昼夜节律起搏器是可塑性的：起搏器根据环境塑造其特性。结果是，起搏器在光暗周期下的特性不能从恒定黑暗中相同系统的研究中得出。在本文中，我们表明，在耦合振荡器的网络中的相位的色散可以影响系综周期：对于所考虑的类型的耦合，它表明，更同步的细胞，更长的系综周期。这与在哺乳动物中获得的各种数据集一致，甚至与果蝇的数据集一致，其中行为的昼夜变化以与哺乳动物明显不同的方式进行调节。我们的结论是，环境的情况下，如光周期和暴露于光脉冲，否则黑暗修改的相位分布的网络，从而，期间的合奏。我们的研究支持了这样的观点，即昼夜节律周期等特性不仅由时钟基因决定，而且还由调节细胞网络中通信的基因决定。
The mammalian circadian pacemaker is commonly thought to be a rigid oscillator that generates output under a variety of circumstances that differ only in phase, period, and/or amplitude. Yet the pacemaker is composed of many cells that each can respond to varying circumstances in different ways. Computer simulations demonstrate that networks of such pacemaker cells behave differently under a light-dark cycle compared with constant darkness. The differences demonstrate that the circadian pacemaker is plastic: The pacemaker shapes its properties in response to the circumstances. A consequence is that properties of a pacemaker under a light-dark cycle cannot be derived from studies of the same system in constant darkness. In this paper we show that the dispersion of phase in a network of coupled oscillators can influence ensemble period: For the considered type of coupling, it is demonstrated that the more synchronous the cells are, the longer is the ensemble period. This is consistent with various data sets obtained in mammals, and even with a data set from fruit flies, in which circadian variation in behavior is regulated in a distinctly differently way from that in mammals. We conclude that environmental circumstances such as photoperiod and exposure to light pulses in otherwise darkness modify the phase distribution of the network and, thereby, the period of the ensemble. Our study supports the view that such properties as circadian period are not solely determined by clock genes but are also determined by the genes that regulate the communication in cellular networks.