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）

基本信息

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
项目类别：
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

项目摘要

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.

严重的外伤性脑损伤（TBI）导致创伤后癫痫（PTE），在NO的潜在时期癫痫发作，大约有20％的平民人口。影响一个人是否发展的因素 TBI之后的癫痫包括受伤的严重程度，患者人群和广泛的特征不佳在潜在时期发生的细胞和分子过程。开发有效的介入预防PTE的疗法将严格依赖于确定最早的分子途径癫痫发作。在生物物理相关的模型中获取此类数据在技术上具有挑战性。已广泛研究了啮齿动物TBI后的神经炎症过程，但是发现很差。在人类和大型沟渠动物中的研究主要局限于大型比例电视记录以及离体生理和组织学分析。四个发现脱颖而出这些研究是癫痫大脑的标志：1）损伤部位的神经胶质病，2）GABA介导的突触活动这是兴奋而不是抑制性，3）非典型性超同步电活动的流行率，4）宏（全脑）级别功能网络连接的破坏。出版的几行初步数据表明，由TBI产生的胶质组织产生的细胞外基质稳定降低细胞外氯化物。反过来，这使GABA逆转电势（Egaba）去极化。我们假设由此产生的抑制作用将增加神经元活性的同步性损伤部位，形成胶质性疤痕。我们最近开发了新皮质后的猪模型创伤性癫痫和成像工具（荧光团，大动物2光子显微镜和支撑技术）以单神经元精度和多模式（氯化物）纵向研究癫痫焦点和钙）荧光数据。在这个项目中，我们将同时对细胞内或细胞外氯化物进行图像受伤前，潜在时期以及自发癫痫发作后的钙活性。我们还将通过化学改变细胞外基质（进而改变细胞外氯化物）以检验因果关系细胞外氯化物与功能连通性之间的联系。我们将使用这些数据评估埃加巴的去极化变化会产生功能网络连通性的癫痫发生变化的假设这些变化与临床可测量的癫痫表型相关。这个丰富的数据集将为反特性治疗的开发提供如下的开发。如果细胞外减少氯化物与神经元活性和网络连通性的增加有关，然后改变神经胶质细胞外基质的形成（例如基质金属蛋白酶）可能预防神经元同步在潜在时期，并防止PTE本身。如果细胞内氯化物的增加与神经元活性和功能连通性提高，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通性与氯化物不相关变化，但可以预测PTE，然后可能有必要专注于开发直接的治疗方法操纵受伤神经元中的神经元活性和功能网络连通性。