Self-organised transients in a neural mass model of epileptogenic tissue dynamics
Self-organised transients in a neural mass model of epileptogenic tissue dynamics
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DOI：
10.1016/j.neuroimage.2011.08.060
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发表时间：
2012-02-01
期刊：
影响因子：
5.7
通讯作者：
Baier, Gerold
中科院分区：
文献类型：
--
作者：
Goodfellow, Marc;Schindler, Kaspar;Baier, Gerold
刺激人类癫痫组织可以在脑电图或心电图上引起有节律的、自我终止的反应。这些反应在定位参与癫痫活动产生的组织方面发挥着潜在的重要作用，但潜在的机制尚不清楚。然而，体外证据表明，神经组织中的自我终止振荡是由可兴奋介质中的非平凡时空动力学支撑的。在这项研究中，我们在癫痫样动力学神经质量模型的空间扩展中研究了这一假设。我们证明了该模型在一维和二维上的空间扩展显示了传播的行波，但也显示了响应局部扰动的更复杂的瞬态动力学。具有局部兴奋和抑制回路的神经团公式允许将空间分布的功能异质性直接纳入模型中。我们表明，这种异质性可能导致对单个脉冲扰动的长时间回响反应，具体取决于刺激传递的位置。这导致了这样的假设：致癫痫组织中对局部刺激的长时间节律反应是由于抑制能力减弱的组织区域的重复自激励造成的。与先前的局灶性癫痫发作动力学模型相结合，这一宏观框架是对致痫区概念进行明确空间表述的第一步。最终，更好地了解癫痫发生区的病理生理机制将有助于改进癫痫的诊断和治疗措施。 (C) 2011 Elsevier Inc. 保留所有权利。
Stimulation of human epileptic tissue can induce rhythmic, self-terminating responses on the EEG or ECoG. These responses play a potentially important role in localising tissue involved in the generation of seizure activity, yet the underlying mechanisms are unknown. However, in vitro evidence suggests that self-terminating oscillations in nervous tissue are underpinned by non-trivial spatio-temporal dynamics in an excitable medium. In this study, we investigate this hypothesis in spatial extensions to a neural mass model for epileptiform dynamics.We demonstrate that spatial extensions to this model in one and two dimensions display propagating travelling waves but also more complex transient dynamics in response to local perturbations. The neural mass formulation with local excitatory and inhibitory circuits, allows the direct incorporation of spatially distributed, functional heterogeneities into the model. We show that such heterogeneities can lead to prolonged reverberating responses to a single pulse perturbation, depending upon the location at which the stimulus is delivered.This leads to the hypothesis that prolonged rhythmic responses to local stimulation in epileptogenic tissue result from repeated self-excitation of regions of tissue with diminished inhibitory capabilities. Combined with previous models of the dynamics of focal seizures this macroscopic framework is a first step towards an explicit spatial formulation of the concept of the epileptogenic zone. Ultimately, an improved understanding of the pathophysiologic mechanisms of the epileptogenic zone will help to improve diagnostic and therapeutic measures for treating epilepsy. (C) 2011 Elsevier Inc. All rights reserved.