Exploring plasticity of the adult visual system using viral gene delivery

这项研究的长期目标是研究成人的神经可塑性。 哺乳动物的视觉系统通过增加新的感觉输入和开发腺病毒相关载体 当注射到玻璃体中时，有效地转换视网膜细胞。增强而不是消融的实验 感觉输入为回答有关大脑可塑性的基本问题提供了一条新的研究途径 对基因治疗和视网膜的合理设计具有重要意义 假肢。载体可以通过注射到玻璃体而不是注射到玻璃体内来传递治疗性基因 视网膜下腔可避免注射过程对视网膜造成损害的风险。我们选择了红色- 绿色视觉作为一个模型系统，在这个模型系统中，功能增益可以在 视网膜使用视网膜电信号和视网膜电生理学，并在视觉皮质水平 色觉、大脑皮层生理学和功能磁共振成像的行为测试。朝向这些 目标我们提出两个具体目标： 具体目标1.确定视网膜中感光色素和视锥细胞亚型的变化如何影响 初级视皮层视网膜神经节细胞和神经元的反应。来确定神经是如何 经处理的成体细胞的反应不同于未经处理的二色性细胞和三色性细胞 圆锥体类型。为了确定被治疗的猴子用来辨别三原色的机制 以及它们与自然产生的三色垫有何不同。 具体目的2.确定玻璃体内可实现的视锥感光细胞转导水平 携带人L视蛋白基因的新一代重组AAV2载体在人L视蛋白控制下的注射 启动子和增强剂足以将原色(双色)猴子的色觉改变为三色。

The long-term goals of the work proposed in this grant application are to study neural plasticity of the adult mammalian visual system by adding new sensory input and to develop adeno virus associated vectors that efficiently transduce retinal cells when injected into the vitreous. Experiments that enhance rather than ablate sensory input offer a new avenue of research for answering fundamental questions about the plasticity of the adult visual system and have important implications for the rational design of gene therapy and retinal prostheses. Vectors that can deliver the therapeutic gene by injecting into the vitreous rather than into the subretinal space avoid the risk of damage to the retina from the injection procedure. We have chosen red- green color vision as a model system in which gain of function can be monitored quantitatively at the level of the retina using the electroretinogram and retinal electrophysiology and at the level of the visual cortex with behavioral tests of color vision, cortical physiology, and functional magnetic resonance imaging. Toward these goals we propose two specific aims: Specific Aim 1. To determine how changes in the photopigments and cone subtypes in the retina affect the responses of retinal ganglion cells and neurons in the primary visual cortex. To determine how the neural responses of cells in treated adults differ from untreated dichromats and trichromats that were born with three cone types. To determine the mechanism the treated monkeys use to make trichromatic color discriminations and how they differ from naturally produced trichromats. Specific aim 2. To determine whether the level of cone photoreceptor transduction achievable by intravitreal injection of new generation rAAV2 vectors carrying a human L opsin gene under control of the human L opsin promoter and enhancer is sufficient to change a protanopic (dichromatic) monkey's color vision to trichromatic.