Institute for Neuro- and Bioinformatics, University of Luebeck, 23538 Lübeck, Germany ; Graduate School for Computing in Medicine and Life Sciences, University of Luebeck, 23538 Lübeck, Germany.
Institute for Neuro- and Bioinformatics, University of Luebeck, 23538 Lübeck, Germany.
Cogn Neurodyn. 2012 Aug;6(4):367-75. doi: 10.1007/s11571-012-9207-z. Epub 2012 Jun 13.
Cortical slow oscillations occur in the mammalian brain during deep sleep and have been shown to contribute to memory consolidation, an effect that can be enhanced by electrical stimulation. As the precise underlying working mechanisms are not known it is desired to develop and analyze computational models of slow oscillations and to study the response to electrical stimuli. In this paper we employ the conductance based model of Compte et al. (J Neurophysiol 89:2707-2725, 2003) to study the effect of electrical stimulation. The population response to electrical stimulation depends on the timing of the stimulus with respect to the state of the slow oscillation. First, we reproduce the experimental results of electrical stimulation in ferret brain slices by Shu et al. (Nature 423:288-293, 2003) from the conductance based model. We then numerically obtain the phase response curve for the conductance based network model to quantify the network's response to weak stimuli. Our results agree with experiments in vivo and in vitro that show that sensitivity to stimulation is weaker in the up than in the down state. However, we also find that within the up state stimulation leads to a shortening of the up state, or phase advance, whereas during the up-down transition a prolongation of up states is possible, resulting in a phase delay. Finally, we compute the phase response curve for the simple mean-field model by Ngo et al. (EPL Europhys Lett 89:68002, 2010) and find that the qualitative shape of the PRC is preserved, despite its different mechanism for the generation of slow oscillations.
皮层慢波振荡发生在哺乳动物的深睡眠期间，被证明有助于记忆巩固，这种效应可以通过电刺激来增强。由于确切的潜在工作机制尚不清楚，因此希望开发和分析慢波的计算模型，并研究对电刺激的反应。在本文中，我们采用 Compte 等人的基于电导的模型（J Neurophysiol 89:2707-2725, 2003）来研究电刺激的影响。群体对电刺激的反应取决于刺激相对于慢波状态的时间。首先，我们再现了 Shu 等人（Nature 423:288-293, 2003）在雪貂脑片上的电刺激实验结果。然后，我们从基于电导的网络模型中数值获得了相位响应曲线，以量化网络对弱刺激的反应。我们的结果与体内和体外实验一致，表明在向上状态下刺激的敏感性比向下状态弱。然而，我们还发现，在向上状态下，刺激会导致向上状态的缩短，即相位提前，而在向上-向下转变期间，向上状态的延长是可能的，导致相位延迟。最后，我们计算了 Ngo 等人的简单平均场模型的相位响应曲线（EPL Europhys Lett 89:68002, 2010），并发现尽管其产生慢波的机制不同，但 PRC 的定性形状得以保留。
