Synaptic changes and hypersynchronous network activity in mTORopathies

项目摘要 过度激活雷帕霉素(MTOR)信号的机械靶信号的遗传变异是最多的 与儿童难治性癫痫相关的常见病理基础，以及 MTOR通路也被认为在脑损伤后参与癫痫的发生。虽然被更改了 神经元迁移和形态是许多已知的mTOR相关神经疾病的特征 (MTORopathies)在人类动物模型中的研究表明，异常的突触传递和网络 活动先于或发生在没有明显的结构变化和阻止结构变化的情况下 并不能预防神经系统症状。这突显了更好地理解 大脑的功能变化。这一提议将检验异常同步神经元的假设 突触改变是由mTOR信号通路的遗传过度激活引起的活动 变速箱。长期的目标是了解这种异常的成因，然后预防或拯救这种异常 活动，这可能是癫痫和自闭症在患有多发性疾病的人类中高发病率的原因。 在目标1中，我们将通过测试mTORopathies的四种遗传模型(TSC1、Pten、PIK3CA、Szt2)来解决这个问题。 确定是否存在共同的突触变化。不同的移植物是否有共同之处 突触改变是理解这些分子的机制相似性的一个基本问题。 相关疾病。在目标2中，我们将使用分子遗传拯救策略，将形态分离 以及mTOR过度激活的突触效应，以测试突触变化是否足以诱导 过度同步活动和癫痫。在目标3中，我们将使用宽视场和双光子钙的组合 成像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，以及它们是否会驱动异常的网络活动。我们预计，定义功能 与增强的神经元兴奋性相关的mTOR过度激活的后果将导致显著的 了解疾病机制的进展，并有助于制定治疗策略 肿瘤和其他神经系统疾病。

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.