Trans-synaptic control of presynaptic neurotransmitter release

突触前神经递质释放的跨突触控制

• 批准号: 9158582
• 负责人: EDWARD L STUENKEL
• 金额: $ 43.16万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-15 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9158582
• 关键词: Accounting; Address; Autistic Disorder; Behavior Control; Beryllium; Binding; Biochemical; Biological Assay; Biological Neural Networks; Brain; Brain-Derived Neurotrophic Factor; Central Nervous System Diseases; Code; Communication; Complex; Data; Development; Disease; Elements; Epilepsy; Equilibrium; Evaluation; Exhibits; FRAP1 gene; Family; GTP Binding; Genetic Models; Glutamates; Goals; Guanosine Triphosphate Phosphohydrolases; Health; Hereditary Disease; Hippocampus (Brain); Human; Individual; Intellectual functioning disability; Investigation; Lead; Learning; Link; Location; Maintenance; Maps; Mediating; Memory; Modification; Molecular; Neurons; Neurotrophic Tyrosine Kinase Receptor Type 2; Pathway interactions; Play; Probability; Process; Protein Biosynthesis; Proteins; Receptor Signaling; Recycling; Regulation; Rest; Role; SNAP receptor; Seizures; Signal Pathway; Signal Transduction; Signaling Protein; Site; Slice; Synapses; Synaptic plasticity; System; Testing; Translation Initiation; Translations; Ubiquitin; Ubiquitination; Vesicle; Work; abstracting; autism spectrum disorder; base; in vivo; insight; mossy fiber; multicatalytic endopeptidase complex; mutant; nervous system disorder; neural circuit; neuronal excitability; neuropsychiatric disorder; neurotransmitter release; novel; optical imaging; optogenetics; postsynaptic; presynaptic; response; synaptic function; ubiquitin-protein ligase

Abstract: A severe health burden imposed by many neuropsychiatric and neurological diseases can be linked to limitations in, or disruption of, molecular pathways which guide development, maintenance or plasticity of synaptic connections. Importantly, as many neural circuits are persistently active the individual synaptic connections must undergo continuous and coordinated homeostatic changes to counteract continual synaptic strengthening/weakening and development of network instability. Thus, developing a functional map of sites of activity- dependent dynamic coordination of the molecules and signaling pathways that define the process is central to enabling an understanding of many CNS diseases. The work proposed is uniquely important as it will elucidate novel and yet potent molecular signaling pathways that mediate accurate and reproducible activity-dependent adaptations in synaptic efficacy. Specifically, investigations focus on understanding how post-synaptic sensing of activity via the mTORC1/BDNF signaling pathway mediates increased presynaptic neurotransmitter release during reduced excitatory input to the post-synaptic element. Investigations will test the hypothesis that tomosyn-1 is a central presynaptic target of mTORC1/BDNF/TrkB receptor signaling and that trans-synaptic adjustments in presynaptic neurotransmitter release via this signaling pathway occur via UPS regulation of tomosyn-1 protein levels. We will also define specific sites within the secretory pathway by which tomosyn exerts control over presynaptic neurotransmitter release. Commonality of this trans-synaptic mechanism will also involve comprehensive evaluation at Mossy fiber/CA3 and at CA3/CA1 synapses of hippocampal brain slices, as these circuits are known to exhibit strikingly divergent synaptic plasticity. In addition, we will characterize the E3 ligase responsible for UPS regulation of tomosyn, determine if the E3 ligase activity is sensitive to mTORC1/BDNF/TrkB signaling and if ubiqutination of tomosyn by the E3 ligase regulates tomosyn protein levels and neurotransmitter release. The investigations employ state of the art optical imaging of vesicle cycling, genetic models targeting protein/signaling function, optogenetic control of neuronal excitability and analysis of synaptic function in cultures of hippocampal neurons and hippocampal slices. Biochemical assays will quantify and establish activity dependent control on tomosyn protein via the UPS. This information will significantly advance understanding on mechanisms by which activity- dependent changes in post-synaptic mTORC1 activity coordinate spatial and temporal adjustments in presynaptic neurotransmitter release.

抽象的： 许多神经精神和神经系统疾病造成严重的健康负担 与指导发育的分子途径的限制或破坏有关， 突触连接的维持或可塑性。重要的是，正如许多神经回路一样 持续活跃的单个突触连接必须经历连续和 协调的稳态变化以抵消持续的突触强化/减弱 和网络不稳定的发展。因此，开发活动位点的功能图 - 分子和信号通路的依赖动态协调定义了 该过程对于理解许多中枢神经系统疾病至关重要。提议的工作是 独特重要，因为它将阐明新颖而有效的分子信号传导途径 介导突触功效中准确且可重复的活动依赖性适应。 具体来说，研究重点是了解突触后活动感知如何通过 mTORC1/BDNF 信号通路介导突触前神经递质释放增加 在减少对突触后元件的兴奋性输入期间。调查将测试 假设 tomosyn-1 是 mTORC1/BDNF/TrkB 受体的中央突触前靶标 信号传导以及突触前神经递质释放的跨突触调整 信号通路通过 UPS 对 tomosyn-1 蛋白水平的调节而发生。我们还将定义 Tomosyn 控制突触前的分泌途径中的特定位点 神经递质释放。这种跨突触机制的共性还涉及 海马脑苔藓纤维/CA3和CA3/CA1突触综合评价 切片，因为已知这些电路表现出惊人不同的突触可塑性。此外， 我们将表征负责 tomosyn 的 UPS 调节的 E3 连接酶，确定是否 E3 连接酶活性对 mTORC1/BDNF/TrkB 信号传导敏感，如果 Tomosyn 泛素化 E3 连接酶调节断层合成蛋白水平和神经递质释放。这 研究采用最先进的囊泡循环光学成像、靶向遗传模型 蛋白质/信号功能、神经元兴奋性的光遗传学控制和突触分析 在海马神经元和海马切片培养物中的功能。生化检测将 通过 UPS 量化并建立对 tomosyn 蛋白的活动依赖性控制。这 信息将大大促进对活动机制的理解 突触后 mTORC1 活动坐标空间和时间的依赖性变化 突触前神经递质释放的调整。