Epileptogenic Changes in Local Network Structure Following Injury (Project 2)

损伤后局部网络结构的致癫痫变化（项目 2）

• 批准号: 10713245
• 负责人: Kyle Patrick Lillis
• 金额: $ 7.91万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10713245
• 关键词: Affect; Anatomy; Animal Model; Animals; Area; Behavior; Bilateral; Biological Markers; Biophysics; Brain; Brain Injuries; Calcium; Categories; Chemicals; Chlorides; Cicatrix; Clinical; Contralateral; Contusions; Data; Data Set; Development; Disinhibition; Electroencephalography; Elements; Epilepsy; Epileptogenesis; Evolution; Extracellular Matrix; Family suidae; Fluorescence; Gliosis; Histologic; Human; Image; Imaging Device; Injury; Length; Link; Location; Longitudinal Studies; Magnetic Resonance Imaging; Matrix Metalloproteinases; Measurable; Measures; Mediating; Medical; Microscope; Microscopic; Modeling; Molecular; Neocortex; Neuronal Injury; Neurons; Pathway interactions; Patients; Peripheral; Persons; Phase; Phenotype; Physiological; Pilot Projects; Population; Positron-Emission Tomography; Post-Traumatic Epilepsy; Prevalence; Process; Protease Inhibitor; Publishing; Recurrence; Resolution; Rodent; Seizures; Severities; Site; Speed; Structure; Synapses; Syndrome; Techniques; Technology; Testing; Therapeutic; Therapeutic Intervention; Time; Tissues; Traumatic Brain Injury; Work; brain remodeling; clinical translation; driving force; effective intervention; extracellular; fluorophore; gamma-Aminobutyric Acid; imaging system; in vivo; injured; innovation; microscopic imaging; multimodality; neocortical; network architecture; neuroinflammation; novel; porcine model; prevent; statistics; transport inhibitor; two-photon

Severe traumatic brain injury (TBI) results in post-traumatic epilepsy (PTE), following a latent period of no seizures, in approximately 20% of the civilian population. The factors that influence whether a person develops epilepsy following TBI include severity of injury, patient demographic, and a wide swath of poorly characterized cellular and molecular processes that take place during the latent period. Developing effective interventional therapies to prevent PTE will depend critically on identifying the earliest molecular pathways that are specifically epileptogenic. Acquiring such data in biophysically relevant models has been technically challenging. Neuroinflammatory processes following TBI in rodents have been widely studied, but clinical translatability of findings has been poor. Studies in humans and large gyrencephalic animals have been largely confined to large- scale electrographic recordings and ex vivo physiological and histological analysis. Four findings stand out from these studies as hallmarks of an epileptic brain: 1) gliosis at the site of injury, 2) GABA-mediated synaptic activity that is excitatory rather than inhibitory, 3) a prevalence of non-ictal hypersynchronous electrical activity, and 4) disruption of functional network connectivity at the macro (whole-brain) level. Several lines of published and preliminary data suggest that gliotic tissue resulting from TBI produces an extracellular matrix that stably lowers extracellular chloride. This, in turn, depolarizes the GABA reversal potential (EGABA). We hypothesize that the resulting disinhibition will increase the synchronicity of neuronal activity, beginning at the site of injury, where the gliotic scar forms. We have recently developed a porcine model of neocortical post- traumatic epilepsy and the imaging tools (fluorophores, large-animal 2-photon microscope, and supporting technologies) to longitudinally study the epileptic focus with single-neuron precision and multimodal (chloride and calcium) fluorescence data. In this project, we will simultaneously image intra or extracellular chloride and calcium activity before injury, during the latent period, and after the emergence of spontaneous seizures. We will also chemically alter the extracellular matrix (which in turn alters extracellular chloride) to test for a causal link between extracellular chloride and functional connectivity. We will use these data to evaluate the hypothesis that depolarizing changes in EGABA produces epileptogenic changes in functional network connectivity and that these changes correlate with clinically measurable epileptic phenotypes. This rich dataset will inform development of anti-PTE treatments as follows. If a decrease in extracellular chloride is associated with increased neuronal activity and network connectivity, then treatments that alter the formation of gliotic extracellular matrix (e.g. matrix metalloproteinases) may prevent neuronal synchronization during the latent period and prevent PTE itself. If an increase in intracellular chloride is associated with increased neuronal activity and functional connectivity, then intracellular protease inhibitors or transport inhibitors may be more effective. If neuronal activity and network connectivity are uncorrelated with chloride changes, but predictive of PTE, then it may be necessary to focus on developing treatments that directly manipulate neuronal activity and functional network connectivity in injured neurons.

严重的创伤性脑损伤（TBI）导致创伤后癫痫（PTE），在无症状的潜伏期之后， 在大约20%的平民人口中。影响一个人是否发展的因素 外伤性脑损伤后的癫痫包括损伤的严重程度，患者的人口统计学，以及广泛的特征不明确的 在潜伏期发生的细胞和分子过程。发展有效的干预措施 预防PTE的治疗将主要取决于确定最早的分子途径， 致癫痫的在生物药理学相关模型中获取此类数据在技术上具有挑战性。 啮齿类动物TBI后的神经炎症过程已被广泛研究，但TBI的临床可翻译性 调查结果很差。对人类和大型脑回动物的研究主要局限于大型脑回动物， 比例电图记录和离体生理学和组织学分析。四个发现脱颖而出， 这些研究作为癫痫脑的标志：1）损伤部位的神经胶质增生，2）GABA介导的突触活动 兴奋性而非抑制性，3）非发作性超同步电活动的流行，以及4） 在宏观（全脑）水平上破坏功能性网络连接。几行出版和 初步数据表明，由TBI引起的神经胶质组织产生细胞外基质， 胞外氯这反过来又使GABA逆转电位（EGABA）去极化。 我们假设，由此产生的去抑制将增加神经元活动的同步性，从 受伤的部位，神经胶质瘢痕形成的地方。我们最近开发了一种新皮质后- 创伤性癫痫和成像工具（荧光团，大动物双光子显微镜，和支持 技术）纵向研究癫痫病灶与单神经元精度和多模式（氯化物 和钙）荧光数据。在这个项目中，我们将同时图像内或细胞外氯， 损伤前、潜伏期和自发性癫痫发作后的钙活性。我们 也将化学改变细胞外基质（这反过来又改变细胞外氯），以测试因果关系 细胞外氯化物和功能连接之间的联系。我们将使用这些数据来评估 EGABA去极化改变导致功能性网络连接性癫痫改变的假说 并且这些变化与临床上可测量的癫痫表型相关。 这一丰富的数据集将为抗PTE治疗的开发提供如下信息。如果细胞外 氯化物与神经元活动和网络连接增加有关，然后改变神经元活动和网络连接的治疗。 神经胶质细胞外基质（如基质金属蛋白酶）的形成可阻止神经元同步化 在潜伏期，并防止PTE本身。如果细胞内氯化物的增加与 增加神经元活性和功能连接，然后是细胞内蛋白酶抑制剂或转运 抑制剂可能更有效。如果神经元活动和网络连接与氯无关 如果这些变化是PTE的预测性变化，那么可能有必要专注于开发直接 操纵受损神经元中的神经元活动和功能网络连接。