The State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.
Chaos. 2022 Feb;32(2):023101. doi: 10.1063/5.0073480.
In mammals, circadian rhythms throughout the body are orchestrated by the master clock in the hypothalamic suprachiasmatic nucleus (SCN), where SCN neurons are coupled with neurotransmitters to generate a uniform circadian rhythm. How the SCN circadian rhythm is so robust and flexible is, however, unclear. In this paper, we propose a temporal SCN network model and investigate the effects of dynamical rewiring and flexible coupling due to synaptic plasticity on the synchronization of the neural network in SCN. In networks consisting of simple Poincaré oscillators and complex circadian clocks, we found that dynamical rewiring and coupling plasticity enhance the synchronization in inhomogeneous networks. We verified the effect of enhanced synchronization in different architectures of random, scale-free, and small-world networks. A simple mean-field analysis for synchronization in plastic networks is proposed. Intuitively, the synchronization is greatly enhanced because both the random rewiring and coupling plasticity in the heterogeneous network have effectively increased the coupling strength in the whole network. Our results suggest that a proper network model for the master SCN circadian rhythm needs to take into account the effects of dynamical changes in topology and plasticity in neuron interactions that could help the brain to generate a robust circadian rhythm for the whole body.
在哺乳动物中，身体各处的昼夜节律由下丘脑视交叉上核（SCN）中的主时钟协调，SCN 神经元通过神经递质耦合产生一致的昼夜节律。然而，SCN 昼夜节律为何如此强大和灵活尚不清楚。在本文中，我们提出了一个时间 SCN 网络模型，并研究了由于突触可塑性导致的动态重连和灵活耦合对 SCN 神经网络同步的影响。在由简单的庞加莱振荡器和复杂的昼夜节律时钟组成的网络中，我们发现动态重连和耦合可塑性增强了非均匀网络中的同步。我们验证了在不同的随机、无标度和小世界网络结构中增强同步的效果。我们还提出了一种用于研究可塑性网络中同步的简单平均场分析。直观地说，由于非均匀网络中的随机重连和耦合可塑性有效地增加了整个网络的耦合强度，因此同步得到了极大增强。我们的结果表明，用于主 SCN 昼夜节律的适当网络模型需要考虑拓扑动力学变化和神经元相互作用中的可塑性的影响，这有助于大脑为整个身体产生强大的昼夜节律。
