REGULATION OF SYNAPSE AND NETWORK DYNAMICS BY MTOR

描述(申请人提供)：雷帕霉素(MTOR)信号网络的机械性靶点在细胞功能中发挥关键作用，整合生长因子、营养物质可获得性和突触输入提供的信息来调节过程，如合成 大分子、能量代谢和生长。适当平衡的mTOR信号已被证明在大脑中特别重要，在人类和小鼠模型中，编码调节mTOR功能的蛋白质的几个基因的突变或缺失与自闭症、智力残疾和癫痫有关。尽管mTOR通路与神经系统疾病之间有很强的联系，但从遗传缺陷到表型的机制仍不清楚。我之前发表的初步数据显示，过度活跃的mTOR信号会导致突触传递的改变。由于突触传递的改变可以产生改变的网络活动，从而导致神经功能障碍，特别是癫痫发作，这代表了病理性mTOR激活和癫痫之间可能的机制联系。这项研究计划的科学目的是更好地了解：1)mTOR信号级联对突触传递和连接的调节，2)介导mTOR对突触功能影响的分子事件，3)改变mTOR信号的神经元如何影响它们所在的神经回路的功能，以及3)这些变化如何导致癫痫背后的网络同步。这些目标的实现需要分子、细胞和网络水平的方法的集成，包括：1)突触连接的、基因修饰的神经元对的电生理分析，2)细胞和亚细胞结构的定量成像，3)双光子多细胞钙成像和海马微电路的电生理分析。虽然我已经具备了实施前两种方法所需的技能，但我需要从我的导师和合作导师那里获得额外的培训，以执行电路级别的分析。在贝勒医学院简和丹·邓肯神经学研究所的两年指导支持将使我能够学习这些技术，发展专业技能，并出版我需要的额外出版物，以确保获得终身教职。成功完成 该项目将为mTOR信号网络对突触和电路功能的调节提供无与伦比的洞察力，并确定治疗mTOR相关疾病的潜在靶点。它还将建立一个严格的框架，以测试其他神经疾病致病基因对神经元功能的影响，并为领导独立研究项目的职业生涯提供一个良好的开端。

DESCRIPTION (provided by applicant): The mechanistic target of rapamycin (mTOR) signaling network plays a crucial role in cellular function, integrating information provided by growth factors, nutrient availability and synaptic input to regulate processes such as synthesis of macromolecules, energy metabolism and growth. Properly balanced mTOR signaling has proven to be particularly important in the brain, where mutations or deletions in several genes that code for proteins that regulate mTOR function are associated with autism, intellectual disability and epilepsy in humans and mouse models. Despite the strong link between the mTOR pathway and neurological disease, the mechanisms that lead from the genetic defects to phenotypes are still unknown. My previously published and preliminary data show that hyperactive mTOR signaling leads to altered synaptic transmission. Since changes in synaptic transmission can generate the altered network activity that results in neurological disorders, and especially seizures, this represents a possible mechanistic link between pathological mTOR activation and epilepsy. The scientific aims of this research plan are to better understand: 1) th regulation of synaptic transmission and connectivity by the mTOR signaling cascade, 2) the molecular events that mediate mTOR's effect on synaptic function, 3) how neurons that have altered mTOR signaling affect the function of the neural circuits in which they operate and 3) how these changes lead to network synchronizations that underlie epilepsy. The achievement of these objectives requires the integration of molecular, cellular and network-level approaches including: 1) electrophysiological analysis of synaptically connected, genetically-modified neuron pairs, 2) quantitative imaging of cellular and subcellular structures, 3) two-photon multicellular calcium imaging and electrophysiological analysis of hippocampal microcircuits. Although I already possess the skills necessary to implement the first two approaches, I require additional training from my mentor and co-mentor to carry out the circuit- level analysis. Two years of mentored support at the Jan and Dan Duncan Neurological Research Institute at Baylor College of Medicine will allow me to learn these techniques, develop professional skills, and generate additional publications I need to secure a tenure-track faculty position. Successful completion of this project will provide unparalleled insight into the regulation of synaptic and circuit functionby the mTOR signaling network and identify potential targets for treatment of mTOR-related diseases. It will also establish a rigorous framework to test the effects of other neurological disease-causing genes on neuronal function, and an excellent start to a career leading an independent research program.