Thalamo-cortical interactions modeled by weakly connected oscillators: could the brain use FM radio principles?
Thalamo-cortical interactions modeled by weakly connected oscillators: could the brain use FM radio principles?
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DOI：
10.1016/s0303-2647(98)00053-7
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发表时间：
1998-09-01
期刊：
影响因子：
1.6
通讯作者：
Izhikevich, EM
中科院分区：
文献类型：
--
作者：
Hoppensteadt, FC;Izhikevich, EM
我们考虑所有的模型的丘脑-皮质系统，满足以下两个假设：（1）每个皮质柱是一个自主振荡器;（2）皮质柱和丘脑之间的连接是弱的。我们的目标是从这些假设中推导出独立于描述系统的方程的丘脑-皮层相互作用的一般原理。我们发现，任何两个皮质柱之间的突触连接的存在并不意味着柱之间的相互作用：它们只有在它们的频率之间存在某种近似共振的关系时才相互作用，这意味着相互作用是频率调制的（FM）。当共振关系成立时，皮质柱通过相位调制相互作用。因此，弱连接的皮层振荡器之间的通信采用了类似于调频收音机的原理：振荡频率对通信信道进行编码，而信息则通过相位调制传输。如果丘脑的输入信号有一个合适的频率，那么它就可以动态地连接任何两个皮质柱，即使是那些有非共振频率的皮质柱，否则它们就不会连接。因此，通过调整其时间活动，丘脑控制了发生在皮层的信息处理。我们的研究结果表明，周期性发放神经元的平均放电率（频率）不携带任何信息，除了识别通信通道。信息（即神经代码）通过峰间间隔的调制来传递。(C)1998爱思唯尔科学爱尔兰有限公司保留所有权利。
We consider all models of the thalamo-cortical system that satisfy the following two assumptions: (I) each cortical column is an autonomous oscillator; (2) connections between cortical columns and the thalamus are weak. Our goal is to deduce from these assumptions general principles of thalamo-cortical interactions that are independent of the equations describing the system. We find that the existence of synaptic connections between any two cortical columns does not guaranfee that the columns interact: They interact only when there is a certain nearly resonant relation between their frequencies, which implies that the interactions are frequency modulated (FM). When the resonance relation holds, the cortical columns interact through phase modulations. Thus, communications between weakly connected cortical oscillators employ a principle similar to that in FM radio: The frequency of oscillation encodes the channel of communication, while the information is transmitted via phase modulations. If the thalamic input has an appropriate frequency, then it can dynamically link any two cortical columns, even those that have non-resonant frequencies and would otherwise be unlinked. Thus, by adjusting its temporal activity, the thalamus has control over information processing taking place in the cortex. Our results suggest that the mean firing rate (frequency) of periodically spiking neuron does not carry any information other than identifying a channel of communication. Information (i.e. neural code) is carried through modulations of interspike intervals. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.