Arshad Muhammad Nauman, Naegele Janice R
Department of Biology, Program in Neuroscience and Behavior, Wesleyan University, Middletown, CT, 06459, USA.
Bio Protoc. 2020 Feb 20;10(4):e3533. doi: 10.21769/BioProtoc.3533.
In the pilocarpine model of temporal lobe epilepsy (TLE) in rodents, systemic injections of pilocarpine induce continuous, prolonged limbic seizures, a condition termed "Status Epilepticus" (SE). With appropriate doses, many inbred strains of mice show behavioral seizures within an hour after pilocarpine is injected. With the behavioral scoring system based on a modification of the original Racine scale, one can monitor the seizures behaviorally, as they develop into more prolonged seizures and SE. SE is typically associated with damage to subsets of hippocampal neurons and other structural changes in the hippocampus and generally subsides on its own. However, more precise control of the duration of SE is commonly achieved by injecting a benzodiazepine into the mouse 1 to 3 h after the onset of SE to suppress the seizures. Several days following pilocarpine-induced SE, electrographic and behavioral seizures begin to occur spontaneously. The goal of this protocol is to reliably generate mice that develop spontaneous recurrent seizures (SRS) and show the typical neuropathological changes in the brain characteristic of severe human mesial temporal lobe epilepsy (mTLE), without high mortality. To reduce mortality, multiple subthreshold injections of pilocarpine are administered, which increases the percentage of mice developing SE without concomitant mortality. Precise control of the duration of SE (1 or 3 h) is achieved by suppressing SE with the benzodiazepine Midazolam (Versed). We have found that this protocol is an efficient means for generating mice that subsequently develop characteristics of human mTLE including high-frequency interictal spike and wave activity and SRS. In addition, we and others have shown that this protocol produces mice that show excitotoxic cell death of subsets of hippocampal GABAergic interneurons, particularly in the dentate gyrus and compensatory sprouting of excitatory projections from dentate granule cells (mossy fiber sprouting). Aspects of this protocol have been described in several of our previous publications.
在啮齿动物颞叶癫痫（TLE）的毛果芸香碱模型中，全身注射毛果芸香碱会诱发持续、延长的边缘性癫痫发作，这种情况被称为“癫痫持续状态”（SE）。使用适当剂量时，许多近交系小鼠在注射毛果芸香碱后一小时内会出现行为性癫痫发作。基于对原始拉辛量表的修改所建立的行为评分系统，可以在癫痫发作发展为更持久的发作和癫痫持续状态时，对其进行行为监测。癫痫持续状态通常与海马神经元亚群的损伤以及海马中的其他结构变化相关，并且通常会自行缓解。然而，通过在癫痫持续状态发作后1至3小时向小鼠注射苯二氮䓬来抑制癫痫发作，通常可以更精确地控制癫痫持续状态的持续时间。在毛果芸香碱诱发癫痫持续状态后的几天，脑电图和行为性癫痫发作开始自发出现。本方案的目标是可靠地培育出出现自发性复发性癫痫发作（SRS）并表现出严重人类内侧颞叶癫痫（mTLE）典型脑内神经病理学变化且死亡率低的小鼠。为了降低死亡率，给予多次亚阈值剂量的毛果芸香碱注射，这增加了发生癫痫持续状态的小鼠百分比，同时不会伴随死亡率升高。通过使用苯二氮䓬咪达唑仑（力月西）抑制癫痫持续状态，可精确控制癫痫持续状态的持续时间（1或3小时）。我们发现，该方案是培育随后出现人类mTLE特征（包括高频发作间期棘波和慢波活动以及SRS）的小鼠的有效方法。此外，我们和其他人已经表明，该方案所产生的小鼠表现出海马GABA能中间神经元亚群的兴奋性毒性细胞死亡，特别是在齿状回，以及齿状颗粒细胞兴奋性投射的代偿性发芽（苔藓纤维发芽）。我们之前的几篇出版物中已经描述了该方案的一些方面。
