Interaction of cellular and network mechanisms in spatiotemporal pattern formation in neuronal networks.
Interaction of cellular and network mechanisms in spatiotemporal pattern formation in neuronal networks.
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DOI：
10.1523/jneurosci.5218-08.2009
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发表时间：
2009-02-11
期刊：
影响因子：
--
通讯作者：
Booth V
中科院分区：
文献类型：
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作者：
Bogaard A;Parent J;Zochowski M;Booth V
神经元活动的时空模式被认为是大脑认知处理以及病理性大脑状态（例如癫痫发作）的重要特征。在这里，我们研究了在癫痫样同步的背景下生成网络时空模式时神经元的内在特性和网络结构之间的复杂相互作用。我们表明，膜兴奋性特性对不同网络拓扑的网络活动模式有不同的影响。我们认为兴奋性网络由具有 I 型和 II 型之间不同兴奋性特性的神经元组成，这些神经元对外部电流刺激表现出显着不同的尖峰频率响应，尤其是在放电阈值处。我们发现，具有 II 型神经元的网络在一系列网络拓扑中表现出比具有 I 型神经元的相应网络更高的同步和突发能力。这些活动模式的差异在不同的网络大小、连接强度、随机外部输入的大小以及向网络中添加抑制性中间神经元时持续存在，使得它们极有可能与大脑功能相关。此外，我们表明，即使混合比率非常低，混合细胞类型的异质网络也显示出新兴的动态模式。具体来说，将一小部分 II 型细胞添加到 I 型细胞网络中可以显着改变网络活动的模式。这些发现表明，细胞和网络机制可以齐头并进，导致癫痫样放电的产生，这表明单一的致痫机制可能不会单独导致癫痫发作。
Spatiotemporal patterning of neuronal activity is considered to be an important feature of cognitive processing in the brain as well as pathological brain states, such as seizures. Here, we investigate complex interactions between intrinsic properties of neurons and network structure in the generation of network spatiotemporal patterning in the context of seizure-like synchrony. We show that membrane excitability properties have differential effects on network activity patterning for different network topologies. We consider excitatory networks consisting of neurons with excitability properties varying between type I and type II that exhibit significantly different spike frequency responses to external current stimulation, especially at firing threshold. We find that networks with type II-like neurons show higher synchronization and bursting capacity across a range of network topologies than corresponding networks with type I-like neurons. These differences in activity patterning are persistent across different network sizes, connectivity strengths, magnitudes of random external input, and the addition of inhibitory interneurons to the network, making them highly likely to be relevant to brain function. Furthermore, we show that heterogeneous networks of mixed cell types show emergent dynamical patterns even for very low mixing ratios. Specifically, the addition of a small percentage of type II-like cells into a network of type I-like cells can markedly change the patterning of network activity. These findings suggest that cellular as well as network mechanisms can go hand in hand, leading to the generation of seizure-like discharges, suggesting that a single ictogenic mechanism alone may not be responsible for seizure generation.