Development and Plasticity of a Retinotectal System

视网膜顶盖系统的发育和可塑性

• 批准号: 6674519
• 负责人: MU-MING POO
• 金额: $ 36.17万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6674519
• 关键词: Xenopus; cell morphology; electronic recording system; electrophysiology; evoked potentials; long term potentiation; neural plasticity; neurophysiology; retina; retinal ganglion; superior colliculus; synaptogenesis; visual fields; visual pathways; visual photoreceptor

DESCRIPTION (provided by applicant): In the developing visual system, the spatiotemporal patterns of visual inputs play an important role in shaping the connections of developing circuits. Using the developing retinotectal system of Xenopus tadpoles and a combination of in vivo whole cell recording and optical imaging techniques, we proposed to examine the development and experience-dependent refinement of visual circuits at the cellular level. In particular, we will examine the potential link between activity-dependent persistent synaptic modifications known as long-term potentiation/depression (LTP/LTD) and developmental refinement of visual circuits. The proposal consists of four parts. In PART I, we will examine the time course of synaptogenesis in the tectum, developmental changes in the synaptic function and plasticity and in the receptive field properties of tectal neurons, using a whole-cell recording method that allows the selective assessment of changes in glutamatergic and GABAergic/glycinergic inputs to the tectal neuron. The modulatory influence of GABAergic/glycinergic inputs on the development of receptive field properties will also be studied. In PART II, we will examine the effects of visual experience-evoked activity on retinotectal synapses and on the development of retinotopic map and receptive field properties. We will also determine the role of spike-timing dependent plasticity in the activity-induced refinement of retinotectal connections. In PART III, we will examine the relationship between activity-induced LTP/LTD and the structural refinement at identified retinotectal connections and the role of cooperative and competitive interactions among converging retinal inputs on the dendrite of single tectal neurons. Finally, in PART IV, we will examine the process by which visual input-induced LTP/LTD and structural modifications of retinotectal connections can be consolidated and become resistant to disruption by subsequent spontaneous spiking activity in the retinotectal system. Taken together, these in vivo studies provide unique opportunities to address several fundamental issues concerning the instructive function of sensory inputs in the refinement of developing neural connections, and are likely to yield new information relevant to our basic understanding of physiology and pathology of the developing nervous system.

描述（由申请人提供）：在发育中的视觉系统中，视觉输入的时空模式在塑造发育中的回路的连接方面发挥着重要作用。利用非洲爪蟾蝌蚪正在发育的视网膜顶盖系统，并结合体内全细胞记录和光学成像技术，我们建议在细胞水平上检查视觉回路的发育和依赖于经验的细化。特别是，我们将研究称为长期增强/抑制（LTP/LTD）的活动依赖性持久突触修饰与视觉回路的发育细化之间的潜在联系。该提案由四个部分组成。在第一部分中，我们将使用全细胞记录方法来检查顶盖突触发生的时间过程、突触功能和可塑性的发育变化以及顶盖神经元的感受野特性，该方法允许选择性评估谷氨酸能的变化以及顶盖神经元的 GABA 能/甘氨酸能输入。还将研究 GABA 能/甘氨酸能输入对感受野特性发展的调节影响。在第二部分中，我们将研究视觉体验诱发的活动对视网膜顶盖突触以及视网膜专题图和感受野特性的发展的影响。我们还将确定尖峰时间依赖性可塑性在活动引起的视网膜顶盖连接细化中的作用。在第三部分中，我们将研究活动诱导的 LTP/LTD 与已识别的视网膜顶盖连接的结构细化之间的关系，以及单个顶盖神经元树突上汇聚的视网膜输入之间合作和竞争相互作用的作用。最后，在第四部分中，我们将研究视觉输入诱导的 LTP/LTD 和视网膜顶盖连接的结构修饰可以巩固并抵抗视网膜顶盖系统中随后自发尖峰活动破坏的过程。总而言之，这些体内研究提供了独特的机会来解决与感觉输入在发育神经连接的细化中的指导功能有关的几个基本问​​题，并且可能产生与我们对发育中神经的生理学和病理学的基本理解相关的新信息。系统。