Microcircuits of the Subiculum and Epilepsy

下托和癫痫的微电路

• 批准号: 10459603
• 负责人: Gianmaria MACCAFERRI
• 金额: $ 34.56万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-30 至 2024-03-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10459603
• 关键词: Address; Anatomy; Animal Model; Antiepileptic Agents; Brain; Cells; Chlorides; Computer Models; Coupled; Data; Development; Down-Regulation; Epilepsy; Epileptogenesis; Event; Generations; Hippocampus (Brain); Impairment; Interneurons; Knowledge; Membrane Transport Proteins; Molecular; Mus; Neurons; Pharmacology; Play; Population; Pyramidal Cells; Resolution; Role; Series; Signal Transduction; Slice; Synapses; Synaptic plasticity; Techniques; Temporal Lobe Epilepsy; Testing; antagonist; base; human model; insight; neurochemistry; novel; optogenetics; patch clamp; reconstruction; theories

Project Summary / Abstract A prominent theory regarding the development of epileptic hyper-synchronization in human and animal models of temporal lobe epilepsy proposes a key role for the specific down-regulation of the expression of the KCC2 transporter in subicular pyramidal cells. As KCC2 is essential to maintain the low intracellular chloride concentrations required for hyperpolarizing GABAergic signaling, loss of KCC2 expression would impair GABAergic inhibition and trigger a series of events leading to the emergence of subicular-initiated interictal activity. Furthermore, interictal discharges coupled to synaptic plasticity would result in interictal- ictal transitions and spread hyper-excitability to extra-hippocampal regions. In summary, if the essential aspects of this KCC2-based mechanistic theory of epileptogenesis were correct, the selective pharmacological reduction of KCC2 transporter activity in a naïve subiculum should be sufficient to generate epileptiform activity ranging from interictal-like to, possibly, full ictal-like events. Although this prediction was supported by computational modeling, direct experimental evidence has not yielded definitive results. Our preliminary data show that the application of highly selective KCC2 antagonists on isolated mini-slices of the mouse subiculum generate synchronous interictal-like bursting that depends on depolarizing GABAergic signaling, but are not, apparently, sufficient to trigger ictal-interictal transitions. We will take advantage of a variety of state of the art techniques (simultaneous patch-clamp recordings from synaptically coupled and uncoupled cells, optogenetic control of specific neuronal populations, and high resolution anatomical reconstructions) to investigate the impact of this type of pharmacologically- induced epileptiform activity in subicular mini-slices. We will explore its consequences on intrinsic and synaptic plasticity, reveal the underlying mechanisms played by different interneuron subtypes, and explore whether additional epileptogenic changes and/or synaptic input from extra-subicular regions are necessary to drive interictal-like to ictal-like transitions.

项目概要/摘要 关于人类和动物癫痫超同步化发展的重要理论 颞叶癫痫模型提出了特异性下调表达的关键作用 下锥体细胞中的 KCC2 转运蛋白。由于 KCC2 对于维持低细胞内水平至关重要 超极化 GABA 信号传导所需的氯化物浓度，KCC2 表达的丧失将 损害 GABA 能抑制并引发一系列事件，导致皮下启动的出现 发作间期活动。此外，与突触可塑性相结合的发作间期放电会导致发作间期放电。 发作转变并将过度兴奋传播到海马外区域。 总之，如果这种基于 KCC2 的癫痫发生机制理论的基本方面是 正确，在幼稚下托中选择性药理学降低 KCC2 转运蛋白活性应该 足以产生癫痫样活动，范围从发作间期样事件到可能的完全发作样事件。 尽管这一预测得到了计算模型的支持，但没有直接的实验证据 产生了明确的结果。 我们的初步数据表明，高选择性 KCC2 拮抗剂在分离的迷你切片上的应用 小鼠下托产生同步的发作间期样爆发，这取决于去极化 GABA 信号传导，但显然不足以触发发作间期转变。 我们将利用各种最先进的技术（同时膜片钳记录 来自突触耦合和非耦合细胞，特定神经元群体的光遗传学控制，以及 高分辨率解剖重建）来研究这种类型的药理学影响 在皮下小切片中诱导癫痫样活动。我们将探讨其对内在和 突触可塑性，揭示不同中间神经元亚型所发挥的潜在机制，以及 探索额外的致癫痫变化和/或来自下皮外区域的突触输入是否是 驱动发作间期样向发作期样转变所必需的。