Mechanisms underlying continuous spike-waves during slow-wave sleep in a mouse model of focal cortical dysplasia

 描述（由申请人提供）：本研究项目的长期目标是了解与局灶性皮质发育不良（FCD）小鼠模型相关的睡眠、长程感觉运动回路和癫痫回路之间的更广泛关系。FCD和相关的皮质发育畸形（MCDs）与儿童癫痫综合征和认知障碍高度相关。MCDs代表了一个越来越被认可的医学难治性癫痫的原因。更有效的治疗方法的发展将受益于对动物模型中癫痫发生的病理生理学和机制的更深入理解。我们将研究长距离感觉运动电路的特性在单侧单局灶性新生儿冷冻损伤S1（SFFLS 1 R）治疗的小鼠。在目标1中，我们将获得SFFLS 1 R小鼠的24小时EEG数据，以验证我们的初步发现，这些动物在慢波睡眠（CSWS）癫痫样放电过程中产生了连续的棘波。CSWS是一种人类癫痫综合征，与慢波睡眠（ESES）期间癫痫性电持续状态的EEG模式相关。然后，我们将研究的想法，在发作前状态（即潜伏期），异常发作前放电（APD）之前CSWS活动，是CSWS癫痫发作的严重程度在同一动物的生物标志物。在目标2中，我们将研究的假设，大规模重组的远程感觉运动和皮质丘脑电路，除了本地电路，需要支持广义的APD和CSWS在SFFLS 1 R动物。我们将结合联合收割机小鼠遗传学和ChR 2辅助电路映射（CRACM）方法来表征畸形S1中长距离与局部抑制性皮层电路的适应不良重组。在目标3中，我们将进一步使用补充方法来测试SFFLS 1 R小鼠中阵发性癫痫样放电是由作用于其在体内畸形S1中的靶点的长程回路介导的想法。我们将首先使用光学和化学遗传学工具来操纵电路组件在体内，以证明CSWS癫痫发作是否以及在多大程度上是由某些电路组件的激活/失活调制。然后，我们将利用修改后的丰富的环境，以确定是否以及在何种程度上CSWS癫痫发作调制的感觉经验在潜伏期。成功完成本项目后，我们可以在小鼠模型中将慢性自发CSWS/ESES癫痫发作与FCD联系起来。本课题的成功完成，使我们能够将长程神经回路的动态变化与癫痫发作联系起来，这将指导我们理解为什么在病理状态下丘脑皮层神经回路中存在动态双稳态。了解正常睡眠和感觉运动回路转化为癫痫回路的机制，将有助于开发与CSWS/ESES和FCD/MCDs相关的顽固性癫痫的基于回路的治疗策略。慢性FCD动物模型可潜在地用于开发基于行为的疗法和筛选与ESES、MCD癫痫相关的新型疗法的药物靶点。

 DESCRIPTION (provided by applicant): The long-term goal of this research project is to gain an understanding of the broader relationship between sleep, long-range sensorimotor circuits, and epilepsy circuits associated with a mouse model of focal cortical dysplasia (FCD). FCD and related malformations of cortical development (MCDs) are highly correlated with childhood seizure syndromes and cognitive disabilities. MCDs represent an increasingly recognized cause of medically intractable epilepsy. The development of more effective therapies will benefit from a deeper understanding of the pathophysiology and mechanisms of epileptogenesis in animal models. We will study long-range sensorimotor circuit properties in a unilateral single focal neonatal freeze lesion in S1 (SFFLS1R) treated mice. In Aim 1, we will obtain 24-hour EEG data from SFFLS1R mice to validate our preliminary finding that these animals developed continuous spike-waves during slow-wave sleep (CSWS) epileptiform discharges. CSWS is a human epileptic syndrome that is associated with the EEG pattern of electrical status epilepticus during slow wave sleep (ESES). We will then examine the idea that during the pre-ictal state (i.e. latent period), abnormal pre-ictal discharges (APDs) precede CSWS activity and are a biomarker for the severity of CSWS seizures in the same animals. In Aim 2, we will examine the hypothesis that large scale reorganization of long-range sensorimotor and corticothalamic circuits, in addition to local circuits, is required to support generalized APDs and CSWS in SFFLS1R animals. We will combine mouse genetics and the ChR2-assistant circuit mapping (CRACM) approach to characterize the maladaptive reorganization of long- range vs. local inhibitory cortical circuits in the malformed S1. In Aim 3, we will further use complementary approaches to test the idea that paroxysmal epileptiform discharges in SFFLS1R mice are mediated by long- range circuits acting on their targets in the malformed S1 in vivo. We will first use opto- and chemo-genetics tools to manipulate circuit components in vivo to demonstrate whether and to what extent CSWS seizures are modulated by activation/inactivation of certain circuit components. We will then take advantage of the modified enriched environment to determine whether and to what extent CSWS seizures are modulated by sensory experiences during the latent period. Upon successful completion of this project, we can associate chronic spontaneous CSWS/ESES seizures with FCD in a mouse model. Upon successful completion of this project, we can link dynamic changes of long-range circuits with ictogenesis, which will guide our understanding of why dynamic bistability exists in thalamocortical circuits in the pathological state. Understanding the mechanisms by which normal sleeping and sensorimotor circuits are transformed into epileptic circuits will help develop circuit-based treatment strategies for intractable epilepsy associated with CSWS/ESES and FCDs/MCDs. The chronic FCD animal model can potentially be used to develop behavior- based therapies and screen drug targets for novel therapies related to ESES, MCD epilepsy.