Synaptic changes and hypersynchronous network activity in mTORopathies

mTORopathies 中的突触变化和超同步网络活动

• 批准号: 10094264
• 负责人: Matthew C Weston
• 金额: $ 34.09万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10094264
• 关键词: Address; Affect; Animal Model; Animals; Automobile Driving; Brain; Calcium; Cells; Cellular Morphology; Characteristics; Chronic; Clinical; DNA Sequence Alteration; Data; Development; Disease; Disease Progression; Disease model; Electrophysiology (science); Epilepsy; Epileptogenesis; FRAP1 gene; Functional disorder; Genes; Genetic; Genetic Diseases; Genetic Models; Goals; Human; Hyperactivity; Image; Impaired cognition; In Vitro; Incidence; Injury; Intellectual functioning disability; Lead; Mediating; Modeling; Molecular; Molecular Genetics; Morphology; Mus; Neurologic; Neurologic Symptoms; Neurons; Outcome; PTEN gene; Pathogenicity; Pathologic; Pathway interactions; Pattern; Phenotype; Physiological; Property; Proteins; Raptors; Seizures; Signal Pathway; Signal Transduction; Structural defect; Structure; Synapses; Synaptic Membranes; Synaptic Transmission; System; TSC1 gene; Testing; Time; Transgenic Mice; Tuberous sclerosis protein complex; United States; Variant; autism spectrum disorder; brain abnormalities; brain morphology; childhood epilepsy; disease phenotype; genetic variant; improved; in vivo; in vivo calcium imaging; loss of function; mTORopathies; migration; mouse model; nervous system disorder; network dysfunction; neuronal excitability; presynaptic; presynaptic neurons; prevent; response to brain injury; spatiotemporal; therapy design; therapy development; transmission process; treatment strategy; two-photon

Project Summary Genetic variants that hyperactivate mechanistic target of rapamycin (mTOR) signaling are among the most common pathological substrates associated with intractable pediatric epilepsy, and hyperactivation of the mTOR pathway is also proposed to mediate epileptogenesis in response to brain injury. Although altered neuronal migration and morphology are hallmarks of many known mTOR-related neurological diseases (mTORopathies) in humans, studies in animal models show that abnormal synaptic transmission and network activity precede or occur in the absence of overt structural changes, and that preventing structural changes does not prevent the neurological symptoms. This highlights the need for a better understanding of the functional changes in the brain. This proposal will test the hypothesis that abnormal synchronous neuronal activity caused by genetic hyperactivation of the mTOR signaling pathway is driven by changes in synaptic transmission. The long-term goal is to understand the genesis of, and then prevent or rescue, this abnormal activity, which may underlie both the high incidence of epilepsy and autism in humans with mTORopathies. In Aim 1, we will address this by testing four genetic models of mTORopathies (Tsc1, Pten, Pik3ca, Szt2) and determining whether there are common synaptic changes. Whether different mTORopathies share common synaptic alterations is an essential question to understanding the mechanistic similarity of these molecularly related diseases. In Aim 2, we will use molecular genetic rescue strategies that dissociate the morphological and synaptic effects of mTOR hyperactivation to test whether synaptic changes are sufficient to induce hypersynchronous activity and epilepsy. In Aim 3, we will use a combination of widefield and 2-photon calcium imaging to track the development and characteristics of hypersynchronous activity in vivo. We will then test whether the synaptic changes we observe in vitro are present at the time and place of hypersynchronous activity onset, and whether they can drive aberrant network activity. We anticipate that defining the functional consequences of mTOR hyperactivation relevant to enhanced neuronal excitability will lead to significant advances in the understanding of disease mechanisms, and aid the development of treatment strategies for mTORpathies and other neurological diseases.

项目概要 过度激活雷帕霉素（mTOR）信号传导机制的基因变异是最常见的变异之一 与顽固性小儿癫痫相关的常见病理基础以及神经元过度激活 mTOR 通路也被认为可以介导脑损伤后的癫痫发生。虽然有所改变 神经元迁移和形态是许多已知的 mTOR 相关神经系统疾病的标志 （mTORopathies）在人类中，动物模型研究表明异常的突触传递和网络 活动先于或在没有明显的结构变化的情况下发生，并且阻止结构变化 不能预防神经系统症状。这凸显了需要更好地理解 大脑的功能变化。该提案将检验异常同步神经元的假设 mTOR 信号通路基因过度激活引起的活动是由突触变化驱动的 传播。长期目标是了解这种异常的起源，然后预防或挽救 活动，这可能是患有 mTORopathies 的人类癫痫和自闭症高发病率的原因。 在目标 1 中，我们将通过测试 mTORopathies 的四种遗传模型（Tsc1、Pten、Pik3ca、Szt2）和 确定是否存在常见的突触变化。不同的 mTORopathies 是否有共同点 突触改变是理解这些分子机制相似性的一个重要问题。 相关疾病。在目标 2 中，我们将使用分子遗传拯救策略来解离形态学 和 mTOR 过度激活的突触效应，以测试突触变化是否足以诱导 超同步活动和癫痫。在目标 3 中，我们将结合使用宽场和 2 光子钙 成像来跟踪体内超同步活动的发展和特征。然后我们将测试 我们在体外观察到的突触变化是否存在于超同步的时间和地点 活动开始，以及它们是否会导致异常的网络活动。我们预计定义功能 mTOR 过度激活与神经元兴奋性增强相关的后果将导致显着的 加深对疾病机制的了解，并有助于制定治疗策略 mTOR 病和其他神经系统疾病。