Mechanisms of interictal spike generation

发作间期尖峰产生的机制

• 批准号: 10386878
• 负责人: Kyle Patrick Lillis
• 金额: $ 38.71万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10386878
• 关键词: Acute; Animals; Antiepileptic Agents; Automobile Driving; Brain; Cells; Chlorides; Chronic; Custom; Data; Development; Devices; Electroencephalography; Elements; Epilepsy; Epileptogenesis; Generations; Goals; Hippocampus (Brain); Human; Image; In Vitro; Incubators; Individual; Injections; Interneurons; Kainic Acid; Label; Light; Link; Microscope; Modeling; Molecular; Mus; Neurons; Optics; Output; Pathologic; Pathway interactions; Patients; Pattern; Phase; Phenotype; Population; Preparation; Proteins; Publishing; Resolution; Role; Sampling; Seizures; Slice; Synapses; System; Temporal Lobe Epilepsy; Testing; Unconscious State; awake; base; behavioral phenotyping; calcium indicator; cell type; design; digital; experimental study; gamma-Aminobutyric Acid; in vivo; in vivo imaging; innovation; insight; kainate; microendoscopy; neural network; novel; novel therapeutics; optogenetics; response; tissue culture

Epilepsy is characterized by two pathological electrographic phenotypes: seizures and interictal spikes. Seizures are relatively rare sustained elevations in brain activity or synchronization that often produce a loss of consciousness in patients suffering from epilepsy. Interictal spikes are much more frequent (on the order of 1 per minute), brief (~200ms), and have no behavioral phenotype (patient is typically not aware of interictal spikes). It is well-established that epileptic networks commonly generate both types of discharge and mounting evidence suggests that there is a direct link between interictal spikes and seizure onset. This proposal aims to dissect the basic mechanisms of interictal spike generation, which will offer new insight into the dynamics of epileptic neural networks (and, in turn, inform development of novel therapeutics). The proposed project will investigate the origins of interictal spikes using an experimentally accessible preparation, the organotypic slice culture (which spontaneously develops interictal spikes and seizures during its first weeks in culture), and a custom microscope (the “Incuscope”) specially designed to record and manipulate activity with single-cell resolution, across the entire epileptic network. Imaging the entire epileptic network guarantees that epileptiform activity observed is not driven by external input. Furthermore, the Incuscope is built inside of a tissue culture incubator, enabling continuous, month-long imaging as epileptic activity emerges and evolves. Findings will be validated in intact animals using endomicroscopy-based in vivo imaging of interictal spikes. The primary goals of this project are as follows: 1) Identify subpopulations of early-firing cells during interictal spikes. 2) Optically stimulate early-firing cells to characterize the degree to which their activation is sufficient to initiate spikes. 3) Optically inhibit early-firing cells to characterize the degree to which their activation is necessary to initiate spikes. 4) Repeat experiments 1-3 in long-term (multi- week) recordings to characterize the stability of early-firing cells and correlate observed changes with seizure onset and seizure burden. 5) Repeat experiment 1 in awake mice, using endomicroscopy and the intrahippocampal kainate model of epilepsy, to test whether the same population of cells is involved in generating interictal spikes in vivo.

癫痫的特征是两种病理性电图表型：癫痫发作和发作间期尖峰。 癫痫发作是相对罕见的大脑活动或同步性持续升高，通常会产生 癫痫患者的意识丧失更频繁（关于） 每分钟 1 次）、短暂（约 200 毫秒）并且没有行为表型（患者通常不 众所周知，癫痫网络通常会产生这两种类型。 放电和越来越多的证据表明，发作间期尖峰和 该提案旨在剖析发作间期尖峰产生的基本机制，该机制 将为癫痫神经网络的动态提供新的见解（反过来，为发展提供信息） 的新疗法）。 拟议的项目将使用实验上可用的方法来研究发作间期尖峰的起源 准备，器官切片培养（自发地产生发作间期尖峰和癫痫发作） 在培养的第一周），以及专门设计的定制显微镜（“Incuscope”） 以单细胞分辨率记录和操纵整个癫痫网络的活动。 整个癫痫网络保证观察到的癫痫样活动不是由外部驱动的 此外，Incuscope 内置于组织培养箱内，可实现连续、连续的输入。 随着癫痫活动的出现和发展，为期一个月的成像结果将在完整的动物中得到验证。 使用基于内窥镜的发作间期尖峰体内成像。 该项目的主要目标如下： 1）识别早期放电细胞的亚群 2) 光学刺激早期放电细胞以表征其放电程度。 激活足以启动尖峰 3) 光学抑制早期放电细胞以表征其程度。 4）长期重复实验1-3（多 周）记录来表征早期放电细胞的稳定性并将观察到的变化与 5) 在清醒的小鼠中重复实验 1，使用内窥镜和 海马内红藻氨酸癫痫模型，以测试是否有相同的细胞群参与 在体内产生发作间期尖峰。