Department of Experimental Biomedical Sciences and CNR Institute of Neuroscience, University of Padova, Padova, Italy.
Epilepsia. 2010 Aug;51(8):1493-502. doi: 10.1111/j.1528-1167.2009.02472.x. Epub 2010 Jan 7.
Despite intensive studies, our understanding of the cellular and molecular mechanisms underlying epileptogenesis remains largely unsatisfactory. Our defective knowledge derives in part from the lack of adequate experimental models of the distinct phases that characterize the epileptic event, that is, initiation, propagation, and cessation. The aim of our study is the development of a new brain slice model in which a focal seizure can be repetitively evoked at a precise and predictable site.
Epileptiform activities were studied by fast Ca²(+) imaging coupled with simultaneous single and double patch-clamp or extracellular recordings from neurons of entorhinal cortex (EC) slices from Wistar rats and C57BL6J mice at postnatal days 13-17.
In the presence of 4-aminopyridine (4-AP) and low Mg²(+) , activation of layer V-VI neurons by local N-methyl-d-aspartate (NMDA) applications evolved into an ictal discharge (ID) that propagated to the entire EC. NMDA-evoked IDs were similar to spontaneous events. IDs with similar pattern and duration could be repetitively triggered from the same site by successive NMDA stimulations. The high ID reproducibility is an important feature of the model that allowed testing of the effects of currently used antiepileptic drugs (AEDs) on initiation, propagation, and cessation of focal ictal events.
By offering the unique opportunity to repetitively evoke an ID from the same restricted site, this model represents a powerful approach to study the cellular and molecular events at the basis of initiation, propagation, and cessation of focal seizures.
尽管进行了深入研究，但我们对癫痫发生的细胞和分子机制的理解仍远远不能令人满意。我们知识上的缺陷部分源于缺乏足够的实验模型来描述癫痫事件的不同阶段，即起始、传播和终止。我们研究的目的是开发一种新的脑切片模型，能够在精确和可预测的部位重复诱发局灶性癫痫发作。
通过快速 Ca²(+) 成像，结合同时进行的单个和双膜片钳或细胞外记录，研究癫痫样活动，使用来自 Wistar 大鼠和 C57BL6J 小鼠出生后第 13-17 天的内嗅皮层（EC）切片中的神经元。
在 4-氨基吡啶（4-AP）和低镁²(+) 存在的情况下，局部 N-甲基-D-天冬氨酸（NMDA）应用激活 V-VI 层神经元，演变为癫痫发作放电（ID），向整个 EC 传播。NMDA 诱发的 ID 与自发性事件相似。通过连续 NMDA 刺激，可以从同一部位重复触发具有相似模式和持续时间的 ID。高 ID 重现性是该模型的一个重要特征，允许测试目前使用的抗癫痫药物（AEDs）对局灶性癫痫发作起始、传播和终止的影响。
通过提供从同一受限部位重复诱发 ID 的独特机会，该模型代表了一种研究局灶性癫痫发作起始、传播和终止的细胞和分子事件的有力方法。
