Project 7: Dynamics of Synapse Formation and Elimination in vivo

项目7：体内突触形成和消除的动力学

• 批准号: 7495155
• 负责人: MORGAN H. SHENG
• 金额: $ 17.92万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7495155
• 关键词: Address; Animals; Behavior; Belief; Brain; Brain imaging; Chromosome Pairing; Collaborations; Development; Excitatory Synapse; Goals; Image; In Vitro; Label; Learning; Measures; Mediating; Memory; Mission; Molecular; Monitor; Neocortex; Neurons; Optics; Pattern; Physiological; Rate; Rattus; Regulation; Reporter; Sensory; Synapses; Technology; Time; Transgenic Animals; Transgenic Mice; Transgenic Organisms; Ursidae Family; Visual; Visual Cortex; base; experience; gene delivery system; in vivo; interdisciplinary approach; postnatal; promoter; spatiotemporal; success; synaptogenesis

The central hypothesis of this project is that long-term plasticity of the brain is mediated in large part by morphological reorganization of neuronal circuits, and specifically by the selective formation and elimination of synapses. Although this is a widely held belief, the turnover of synapses has been minimally characterized in vivo, and little is known about the developmental, environmental and activity-dependent factors that control synapse remodeling, especially in the intact animal. We will produce PSD-95-GFP transgenic mice and rats with fluorescently-labeled synapses for time-lapse imaging of synapse formation and elimination (turnover) in central neurons. We will measure the pattern and regulation of synapse turnover in vivo, with the goal of correlating these changes to plasticity and behavior. Neuron cultures from these transgenic animals will be used to investigate the molecular and physiological mechanisms that control synapse dynamics. Our specific aims are: 1) Create transgenic mice expressing PSD-95-GFP under a constitutive promoter to label excitatory synapses in brain; 2) Create transgenic mice expressing unstable PSD-95-GFP under an activity-inducible promoter to selectively label newly formed synapses in recently active neurons; 3) Create transgenic rats expressing PSD-95-GFP under constitutive and activity-inducible promoters, using newly developed lentiviral technology; 4) Characterize the dynamics of synapse turnover in visual cortex during postnatal development and its regulation by visual input, using the transgenic PSD-95-GFP animals; 5) Characterize the spatiotemporal patterns and underlying mechanisms of synapse turnover in vitro, using cultured neurons derived from the PSD-95-GFP animals. In collaboration with Tonegawa, Bear, and Liu, this proposal uses a multidisciplinary approach to explore synaptic interactions within neurons, and the morphological correlates of cortical plasticity and learning and memory. The project contributes to multiple objectives of the Center and depends on the combined scientific expertise and facilities of the Center.

该项目的中心假设是，大脑的长期可塑性在很大程度上是通过神经元回路的形态重组，特别是通过选择性形成和消除突触的介导的。尽管这是一种广泛的信念，但突触的营业额在体内的特征很小，对控制突触重塑的发展，环境和活动依赖性因素知之甚少，尤其是在 完整的动物。我们将生产带有荧光标记的突触的PSD-95-GFP转基因小鼠和大鼠，用于中央神经元中突触形成和消除（周转）的延时成像。我们将测量体内突触转移的模式和调节，目的是将这些变化与可塑性和行为相关联。这些转基因动物的神经元培养物将用于研究分子和生理机制 控制突触动力学。我们的具体目的是：1）创建在本构启动子下表达PSD-95-GFP的转基因小鼠，以标记大脑中的兴奋性突触； 2）创建在活性诱导的启动子下表达不稳定PSD-95-GFP的转基因小鼠，以在最近活跃的神经元中有选择地标记新形成的突触； 3）使用新开发的慢病毒技术，在本构和活动诱导的启动子下创建表达PSD-95-GFP的转基因大鼠； 4）使用转基因PSD-95-GFP动物在产后发育过程中视觉皮层的突触转换动力学及其通过视觉输入调节； 5）使用源自PSD-95-GFP动物的培养神经元，表征体外突触转换的时空模式和基本机制。该提案与Tonegawa，Bear和Liu合作，使用多学科方法来探索神经元内的突触相互作用，以及皮质可塑性，学习和记忆的形态相关性。 该项目有助于该中心的多个目标，并取决于科学专业知识和 中心的设施。