Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163, Genova, Italy.
Neuroengineering and Neurotechnologies Group, Department of Informatics, Bioengineering, Robotics, System Engineering, University of Genova, 16145, Genova, Italy.
Sci Rep. 2017 Aug 22;7(1):9080. doi: 10.1038/s41598-017-08369-0.
Cultures of dissociated cortical neurons represent a powerful trade-off between more realistic experimental models and abstract modeling approaches, allowing to investigate mechanisms of synchronized activity generation. These networks spontaneously alternate periods of high activity (i.e. network bursts) with periods of quiescence in a dynamic state which recalls the fluctuation of in vivo UP and DOWN states. Network bursts can also be elicited by external stimulation and their spatial propagation patterns tracked by means of multi-channel micro-electrode arrays. In this study, we used rat cortical cultures coupled to micro-electrode arrays to investigate the similarity between spontaneous and evoked activity patterns. We performed experiments by applying electrical stimulation to different network locations and demonstrated that the rank orders of electrodes during evoked and spontaneous events are remarkably similar independently from the stimulation source. We linked this result to the capability of stimulation to evoke firing in highly active and "leader" sites of the network, reliably and rapidly recruited within both spontaneous and evoked bursts. Our study provides the first evidence that spontaneous and evoked activity similarity is reliably observed also in dissociated cortical networks.
分离皮质神经元培养物代表了更现实的实验模型和抽象建模方法之间的一种强大权衡，使我们能够研究同步活动产生的机制。这些网络在动态状态下自发地交替高活动期（即网络爆发）和静止期，这种动态状态让人联想到体内 UP 和 DOWN 状态的波动。网络爆发也可以通过外部刺激来引发，并通过多通道微电极阵列来跟踪其空间传播模式。在这项研究中，我们使用与微电极阵列相连的大鼠皮质培养物来研究自发和诱发活动模式之间的相似性。我们通过向不同的网络位置施加电刺激来进行实验，结果表明，在自发和诱发事件期间，电极的等级顺序非常相似，与刺激源无关。我们将这一结果与刺激在网络的高度活跃和“主导”部位引发放电的能力联系起来，这种放电能够在自发和诱发爆发中可靠而迅速地招募。我们的研究首次提供了证据表明，分离皮质网络中也可靠地观察到自发和诱发活动的相似性。
