Experience-dependent Cellular Plasticity Mechanisms

大脑活动对神经元和神经回路的发育和可塑性是必不可少的，然而我们的 对活动产生功能电路的机制的理解是不完整的。这种缺乏 知识阻碍了我们利用依赖活动的机制来促进回路的能力 可塑性。可塑性诱导刺激诱导神经元蛋白质动力学，包括调节增加和 蛋白质合成减少。我们最近进行了体内蛋白质组学定量分析， 非洲爪哇蝌蚪视觉系统中新合成蛋白质的变化 可塑性诱导的视觉刺激。我们鉴定了许多候选可塑性蛋白(CPP)，包括 一些调节蛋白质合成，而另一些则具有不同的细胞和突触功能。这里 我们将探索可塑性诱导刺激启动依赖于蛋白质合成的级联反应的模型 事件，从上游翻译调节子的从头合成开始，最终以 非洲爪哇视觉经验依赖回路可塑性中不同效应器蛋白的调节合成 使用蛋白质组学、电生理学、体内结构和功能成像以及行为分析。 经典研究揭示了中枢神经系统损伤后发生的电路重连事件。我们已经证明了 视顶盖局部损伤对非洲爪蛙视觉回避行为的损害及其治疗 具有短暂视觉体验的动物有助于损伤回路的恢复。探索灵活性 在依赖经验的塑性机制中，我们将测试新合成的候选塑性 蛋白质是依赖视觉经验对受损的视觉运动回路进行康复所必需的。 这些实验的结果可能确定有助于经验依赖的新机制 神经系统发育中的可塑性。

Brain activity is essential for the development and plasticity of neurons and circuits, however our understanding of the mechanisms by which activity generates functional circuits is incomplete. This lack of knowledge impedes our ability to take advantage of activity-dependent mechanisms to facilitate circuit plasticity. Plasticity-inducing stimuli induce neuronal protein dynamics, including regulated increases and decreases in protein synthesis. We recently conducted a quantitative in vivo proteomic analysis which identified changes in newly synthesized proteins in the Xenopus tadpole visual system in response to plasticity-inducing visual stimulation. We identified numerous candidate plasticity proteins (CPPs), including several that regulate protein synthesis, whereas others have diverse cellular and synaptic functions. Here we will probe the model that plasticity-inducing stimuli initiate a cascade of protein synthesis-dependent events, beginning with de novo synthesis of upstream translational regulators and culminating in the regulated synthesis of diverse effector proteins, in visual experience dependent circuit plasticity in Xenopus, using proteomics, electrophysiology, in vivo structural and functional imaging, and behavioral assays. Classical studies have revealed circuit-rewiring events in response to CNS damage. We have shown that local damage to the optic tectum impairs visual avoidance behavior in Xenopus and that treating injured animals with brief bouts of visual experience facilitates recovery of the injured circuit. To probe the flexibility of experience-dependent plasticity mechanisms, we will test whether newly synthesized candidate plasticity proteins are required for the visual experience-dependent rehabilitation of the injured visuomotor circuit. Results of these experiments may identify novel mechanisms contributing to experience-dependent plasticity in developing nervous systems.