Development and Plasticity of a Retinotectal System

视网膜顶盖系统的发育和可塑性

• 批准号: 6927832
• 负责人: MU-MING POO
• 金额: $ 36.07万
• 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/6927832
• 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形成发育中的神经回路的连接中起着重要作用。利用爪蟾蝌蚪视网膜系统的发育，结合全细胞记录和光学成像技术，我们提出在细胞水平上研究视觉回路的发育和经验依赖的改进。特别是，我们将研究活动依赖的持续性突触修饰（称为长期增强/抑制（LTP/LTD））与视觉回路的发育完善之间的潜在联系。该提案由四个部分组成。在第一部分中，我们将研究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，使用全细胞记录方法，可以选择性地评估顶盖神经元的谷氨酸能和gaba能/甘氨酸能输入的变化。gaba能/甘氨酸能输入对感受野特性发展的调节影响也将被研究。在第二部分中，我们将研究视觉体验诱发活动对视网膜顶突触的影响，以及对视网膜定位图和感受野特性发展的影响。我们还将确定在活动诱导的视顶连接的细化中，spike-timing依赖的可塑性的作用。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端连接的结构优化之间的关系，以及在单个顶叶神经元树突上汇聚的视网膜输入之间的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和视网膜顶连接的结构修饰可以巩固并抵抗视网膜顶系统随后自发尖峰活动的破坏的过程。综上所述，这些体内研究提供了独特的机会来解决几个基本问题，这些问题涉及到感觉输入在完善发育中的神经连接中的指导功能，并可能产生与我们对发育中的神经系统生理学和病理学的基本理解相关的新信息。