Mechanisms of epileptogenesis in KCNA2-/SCN2A-mediated epilepsies

由于对癫痫发作的发生机制缺乏了解，严重耐药性癫痫（如癫痫性脑病（EE））的新有效治疗策略的开发在很大程度上受到阻碍。除了严重程度和耐药性外，EE还伴有智力残疾和其他神经发育障碍。进行性认知退化的原因尚不清楚;在发育过程中频繁发作或基因缺陷本身是最可能的候选人。在这里，我们将使用遗传性癫痫的小鼠模型来研究大脑发育过程中的癫痫发生，并研究KCNA 2基因中功能丧失和功能获得（LOF/GOF）突变的病理生理学，KCNA 2基因编码电压门控K+通道KV1.2，我们最近确定其为EE 1（H）的原因，并与P5，P7和P8合作，SCN 2A基因中的GOF突变，编码电压门控Na+通道NaV1.22。我们将使用Kcna 2和Scn 2a KI小鼠模型以及子宫内电穿孔/病毒转导（IUE/IUVT）技术，以（i）鉴定由KV1.2通道中GOF或LOF突变引起的形态学和转录变化;（ii）表征遗传修饰的皮质神经元的体外和体内活动模式（iii）鉴定触发癫痫发作产生的异常活动模式，以及涉及的皮质区域和细胞类型;（iv）分析癫痫样活动在体内皮层内传播的空间和时间方面，以及（v）检验该活动是由内源性皮层节律的病理放大引起的假设。此外，我们将测试早期药物治疗是否拮抗上述突变的神经病理学后果。

The development of new effective treatment strategies for severe drug-resistant epilepsies such as epileptic encephalopathies (EE) is largely hampered by the lack of knowledge about the mechanisms of seizure generation. Besides the severity and pharmacoresistance, EEs are accompanied by intellectual disability and other neurodevelopmental impairments. The cause of progressive cognitive deterioration is unknown; frequent seizures during development or gene defects themselves are the most likely candidates. Here, we will use mouse models of genetic epilepsies to study epileptogenesis during brain development and investigate the pathophysiology of both loss- and gain-of-function (LOF/GOF) mutations in the KCNA2 gene, encoding the voltage-gated K+ channel KV1.2 that we recently identified as a cause of EE1(H) and, in collaboration with P5, P7 and P8, a GOF mutation in the SCN2A gene, encoding the voltage-gated Na+ channel NaV1.22. We will use Kcna2 and Scn2a KI mouse models as well as in utero electroporation/viral transduction (IUE/IUVT) techniques to (i) identify morphological and transcriptional changes caused by GOF or LOF mutations in KV1.2 channels; (ii) characterize the in vitro and in vivo activity patterns of genetically modified cortical neurons (inhibitory vs excitatory) during age-dependent development of epileptiform activity; (iii) identify aberrant activity patterns triggering seizure generation, and the cortical regions as well as cell types involved; (iv) analyze spatial and temporal aspects of propagation of the epileptiform activity within the in vivo cortex and (v) test the hypothesis that this activity is caused by pathological amplification of endogenous cortical rhythms. In addition, we will test if early pharmacological treatments antagonize the neuropathological consequences of the above mentioned mutations.