Emergence of Narrowband High Frequency Oscillations from Asynchronous, Uncoupled Neural Firing
Emergence of Narrowband High Frequency Oscillations from Asynchronous, Uncoupled Neural Firing
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DOI：
10.1142/s0129065716500490
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发表时间：
2017-02-01
影响因子：
8
通讯作者：
Fink, Christian G.
中科院分区：
文献类型：
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作者：
Gliske, Stephen V.;Stacey, William C.;Fink, Christian G.
先前的实验研究表明，癫痫发作过程中会出现窄带局部场电位振荡，其中潜在的神经活动似乎完全是异步的。我们推导了一个数学模型来解释这种违反直觉的现象是如何发生的，表明如果一个独立的、完全异步的神经元群体可能会产生窄带振荡，如果每个神经元准周期地发射，而不需要任何固有的振荡细胞或反馈抑制。这种准周期性可以通过具有相似的频率-电流(积分-I)曲线的细胞接收类似的、大量的不相关的突触噪声而发生。因此，这种振荡行为的来源不同于通常的情况(起搏器细胞携带网络，或振荡是网络结构的固有属性)，因为它不需要振荡驱动，也不需要任何特定的网络或细胞属性，除了重复激发持续刺激的细胞。我们还推导了神经棘波计时的可变性程度的界限，这将允许动作电位和突触后电位主导的LFP出现这种振荡。这些结果表明，即使是一个不耦合的网络也可能产生集体节律，这意味着癫痫发作期间经常观察到的抑制崩溃和高突触输入可能会产生窄带振荡。我们认为，这一机制可能解释了为什么如此多不同的癫痫和正常大脑机制可以产生类似的高频振荡。
Previous experimental studies have demonstrated the emergence of narrowband local field potential oscillations during epileptic seizures in which the underlying neural activity appears to be completely asynchronous. We derive a mathematical model explaining how this counterintuitive phenomenon may occur, showing that a population of independent, completely asynchronous neurons may produce narrowband oscillations if each neuron fires quasi-periodically, without requiring any intrinsic oscillatory cells or feedback inhibition. This quasi-periodicity can occur through cells with similar frequency-current (integral-I) curves receiving a similar, high amount of uncorrelated synaptic noise. Thus, this source of oscillatory behavior is distinct from the usual cases (pacemaker cells entraining a network, or oscillations being an inherent property of the network structure), as it requires no oscillatory drive nor any specific network or cellular properties other than cells that repetitively fire with continual stimulus. We also deduce bounds on the degree of variability in neural spike-timing which will permit the emergence of such oscillations, both for action potential- and postsynaptic potential-dominated LFPs. These results suggest that even an uncoupled network may generate collective rhythms, implying that the breakdown of inhibition and high synaptic input often observed during epileptic seizures may generate narrowband oscillations. We propose that this mechanism may explain why so many disparate epileptic and normal brain mechanisms can produce similar high frequency oscillations.