Validation of High-Throughput Screening of Candidate Antiepileptogenic Drugs

描述(由申请人提供)：了解慢性癫痫(即癫痫发生)演变的机制有助于开发有效的癫痫过程预防性治疗方法。反过来，需要开发和验证临床相关的动物模型，这些模型可以用于基础和临床前研究。目前已有的大多数致痫模型采用突发性刺激(如癫痫持续状态，SE)，导致进行性的神经退行性改变和神经元可塑性改变，最终导致自发性反复发作。虽然这些模型对于基础癫痫研究是必不可少的，但这些模型的固有特征(例如，进展缓慢；发作频率和严重程度在动物之间和时间上的高度变异性；个体发作发生的不可预测性)由于所涉及的时间、劳动力和成本，对临床前抗癫痫药物(AED)的评价构成了巨大的挑战。拟议项目的目标是验证用于快速识别和评估抗癫痫药物和/或疾病修饰药物的高通量筛选试验。我们认为快速点燃致痫模型可用于AED药物的发现。验证将包括分析15种具有既定药理特征的化合物(布美他尼、安定、非氨基甲酸乙琥胺、加巴喷丁、加纳松酮、拉莫三嗪、左乙拉西坦、MK-801；苯妥英钠、瑞替加宾、托吡酯、丙戊酸钠、维卡他林、氮尼沙胺)对5个不同年龄(新生儿、新生儿后、青春期前、青少年和成人)的实验动物快速点燃癫痫发生的影响。每隔5分钟向海马区发出60次电刺激，以超过阈值的电流(总过程持续时间为5小时)诱导快速点燃。在点燃之前，这些动物将接受一次AED注射；将监测和分析癫痫的进展以及脑电和行为发作的模式。选择抗癫痫药是为了根据它们的作用机制和已知的致痫机制，它们有望以不同的方式改变癫痫发作的进程，包括完全预防癫痫发作(抗癫痫作用)，缓解癫痫过程(疾病修饰)，以及根本不影响癫痫发作。作为这项研究的结果，我们将为癫痫发生的快速点燃模型产生一个扩展的药理学概况。然后，编辑后的数据库可用于将新出现的抗癫痫药物与已知的抗癫痫药物进行对照，以确定其有效性。癫痫的渐进性(癫痫发生)决定了开发能够在癫痫早期阶段阻断癫痫过程的治疗方法的必要性。反过来，需要引入和验证实验模型，这些模型将(A)非常接近人类的情况，(B)允许对预期的抗癫痫药物进行大规模筛选。目前的项目旨在引入和验证癫痫发生的动物模型，该模型将允许快速有效地大规模筛选新出现的抗癫痫药物。

DESCRIPTION (provided by applicant): Understanding mechanisms that underlie the evolution of chronic epilepsy (i.e. epileptogenesis) is instrumental for developing effective preventive therapies of the epileptic process. In turn, the development and validation of clinically relevant animal models are needed that could be used for both basic and preclinical studies. The majority of currently available models of epileptogenesis employ a precipitating insult (e.g. status epilepticus, SE), which leads to progressive neurodegenerative and neuronal plastic changes, and culminates in the occurrence of spontaneous recurrent seizures. While being indispensable for basic epilepsy research, the inherent features of these models (e.g. slow progression; high inter-animal and temporal variability of seizure frequency and severity; unpredictability of individual seizure occurrence) represent significant challenges for preclinical antiepileptic drug (AED) evaluation due to time, labor and costs involved. The objective of the proposed project is to validate a high-throughput screening assay for rapid identification and evaluation of antiepileptogenic and/or disease-modifying drugs. We propose that the rapid kindling model of epileptogenesis can be used for AED drug discovery. The validation will consist of analysis of the effects of fifteen compounds with established pharmacological profiles (bumetanide, diazepam, ethosuximide felbamate, gabapentin, ganaxolone, lamotrigine, levetiracetam, MK-801; phenytoin, retigabine, topiramate, valproate sodium, vigabatrin, zonisamide) on rapid kindling epileptogenesis in experimental animals of five different ages (neonatal; post-neonatal; pre-adolescent; adolescent; adult). Rapid kindling will be induced by 60 electrical stimulations delivered to the hippocampus every 5 minutes at a suprathreshold current (total procedure duration is 5 hours). The animals will receive a single injection of an AED prior to kindling; the progression and the pattern of electrographic and behavioral seizures will be monitored and analyzed. AEDs are chosen so that, based on the mechanisms of their action and known mechanisms of epileptogenesis, they are expected to modify seizure progression in different ways, including complete prevention of seizures (antiepileptogenic effect), mitigation of epileptic process (disease modification), and failure to affect seizures at all. As a result of the study, we will generate an expanded pharmacological profile of the rapid kindling model of epileptogenesis. The compiled database can then be used for mapping of emerging antiepileptogenic drugs against known AEDs in terms of their efficiency. The progressive nature of epilepsy (epileptogenesis) dictates the necessity for developing therapies that can block the epileptic process during its early stages. In turn, the introduction and validation of experimental models that would (a) closely resemble human condition, and (b) allow large scale screening of prospective antiepileptogenic drugs are required. The current project is designed to introduce and validate an animal model of epileptogenesis that would allow for the quick and effective screening of emerging antiepileptogenic drugs on a large scale.