Subcortical nodes within epileptic network control the cortical disfacilitation to prompt seizure onset in IGE mouse model

癫痫网络内的皮质下节点控制皮质功能障碍，促进 IGE 小鼠模型癫痫发作

• 批准号: 10229601
• 负责人: Chengwen Zhou
• 金额: $ 34.56万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10229601
• 关键词: Affect; Amygdaloid structure; Anterior; Anterior Hypothalamus; Antiepileptic Agents; Auras; Brain; Cell Nucleus; Chemosensitization; Clinical; Communities; Disease; Electric Stimulation; Emotional; Emotions; Epilepsy; Equilibrium; Event; FOS gene; Family; Functional Magnetic Resonance Imaging; Gene Mutation; Generalized Epilepsy; Generations; Genetic; Halorhodopsins; Hemostatic Agents; Human; Hyperactivity; Hypothalamic structure; Impairment; Knock-in Mouse; Label; Lead; Medial; Microscopic; Modeling; Neurons; Patients; Research Personnel; Resistance; Seizures; Sleep; Somatosensory Cortex; Structure; Synapses; Transgenic Mice; acquired epilepsy; awake; base; in vivo; mouse model; novel therapeutics; optogenetics; prevent; promoter; voltage

Seizures affect more than 3 million people in US, creating tremendous burdens to patients and their families/communities. Some intractable seizures with genetic causes (idiopathic generalized epilepsy, IGE) are resistant to conventional antiepileptic drugs. Although major progress has been made regarding mechanisms of acquired epilepsy, the causes for IGE remain elusive. We have not completely understood how the balance between synaptic/neuron excitation and inhibition is dynamically impaired under some conditions for IGE models. Moreover, functional MRI studies on seizures undeniably indicate that whole-brain networks (cortical and remote subcortical nodes) are involved during epileptic activity, suggesting that seizures are the emerging consequence of whole-brain epileptic network activity at the microscopic, mesoscopic, and macroscopic scales. However, it still remains challenging for clinical researchers to forecast how epileptic network nodes interact at network levels to generate the high-voltage spike-wave discharges (SWDs) during seizures. Specifically, no previous studies have ever focused on exactly how seizure onset and epileptic activity in IGE models are initiated through the interaction between epileptic network nodes at the network level, why seizures in human epileptic patients mostly occur during sleep-wake transition/quiet-awake period, and why seizure- presage conditions such as emotional prodromic aura phenomena can cause seizures in both acquired epilepsy and IGE patients. Thus, we hypothesize that subcortical nodes within epileptic network nodes, specifically anterior hypothalamus nucleus and medial amygdala, control cortical disfacilitation (neurons are hyperpolarized due to the absence of excitatory synaptic activity(Contreras et al., 1996; Timofeev et al., 1996; 2001)) during sleep-wake transition/quiet-awake period and other emotional prodromic auras. The resulting cortical disfacilitation prompts high-voltage slow-wave oscillations (SWOs), which hemostatically potentiate synaptic excitation (not inhibition) of epileptic neuron ensembles/engrams in the cortex. Eventually, these chain events lead to cortical neuron synchronous firing within epileptic network to trigger seizure onset and SWDs. It is the preceding cortical disfacilitation state in our IGE mouse models (present during sleep-wake transition/quiet-awake period and some emotion prodromic aura states) that consequently controls seizure onset and epileptic activity, which offers the network mechanism for IGE models. This proposal will use transgenic mice with neuron GFP expression (driven by activity dependent c-Fos promoter) to identify the epileptic network nodes in both cortex and subcortical structures in heterozygous Gabrg2Q390X or Gabra1A322D KI mice and determine whether the anterior hypothalamus and medial amygdala can cause cortical disfacilitation with optogenetic stimulation in vivo in these KI mice(neuron expressing ChR2/halorhodopsin driven by c-Fos promoter), which eventually induces SWOs and instigates epileptic SWDs in the cortex and generate seizures. New drugs for IGE treatment are proposed for a proof of principle study.

在美国，癫痫发作影响了超过 300 万人，给患者及其家人造成了巨大的负担 家庭/社区。一些由遗传原因引起的顽固性癫痫发作（特发性全身性癫痫，IGE）是 对常规抗癫痫药物产生耐药性。尽管在机制方面取得了重大进展 与获得性癫痫相比，IGE 的病因仍然难以捉摸。我们还没有完全理解如何平衡 在 IGE 的某些条件下，突触/神经元兴奋和抑制之间的动态受损 模型。此外，关于癫痫发作的功能性 MRI 研究无可否认地表明，全脑网络（皮质 和远程皮质下节点）参与癫痫活动，表明癫痫发作是新出现的 全脑癫痫网络活动在微观、中观和宏观上的结果 秤。然而，临床研究人员预测癫痫网络节点如何发生仍然具有挑战性。 在网络层面相互作用，在癫痫发作期间产生高压尖波放电（SWD）。 具体来说，之前没有研究关注 IGE 中癫痫发作和癫痫活动的具体情况。 模型是通过网络层面的癫痫网络节点之间的相互作用启动的，为什么癫痫发作 人类癫痫患者大多发生在睡眠-觉醒过渡/安静-清醒期间，为什么癫痫发作- 情绪前驱现象等预兆条件可能会导致后天和后天癫痫发作 癫痫和 IGE 患者。因此，我们假设癫痫网络节点内的皮层下节点， 特别是下丘脑前核和内侧杏仁核，控制皮质功能障碍（神经元是 由于缺乏兴奋性突触活动而超极化(Contreras et al., 1996; Timofeev et al., 1996; 2001））在睡眠-觉醒过渡/安静-清醒时期和其他情绪前驱光环期间。由此产生的 皮质功能障碍会引发高压慢波振荡 (SWO)，从而增强止血作用 皮质中癫痫神经元群/印迹的突触兴奋（而不是抑制）。最终，这些链条 事件导致癫痫网络内的皮层神经元同步放电，从而触发癫痫发作和 SWD。它 是我们的 IGE 小鼠模型中的前一个皮质功能障碍状态（存在于睡眠-觉醒期间） 过渡/安静清醒期和一些情绪前驱状态），从而控制癫痫发作 发作和癫痫活动，这为 IGE 模型提供了网络机制。本提案将使用 具有神经元 GFP 表达（由活性依赖性 c-Fos 启动子驱动）的转基因小鼠，以鉴定 杂合子 Gabrg2Q390X 或 Gabra1A322D 皮质和皮质下结构中的癫痫网络节点 KI小鼠并确定下丘脑前部和内侧杏仁核是否可以引起皮质 这些 KI 小鼠体内光遗传学刺激的障碍（表达 ChR2/盐视紫红质的神经元 由 c-Fos 启动子驱动），最终诱导 SWO 并引发皮质中的癫痫性 SWD 产生癫痫发作。提议用于 IGE 治疗的新药物用于原理研究验证。