Genes and Visual Pigments of Red-Green Color Vision

描述（由申请人提供）：我们的大多数日常活动都是在光照水平下进行的，我们的视觉是基于锥状光感受器。我们的长期目标是帮助了解视锥视觉的基本机制、这些机制如何在视觉障碍中被破坏以及如何预防或逆转视力丧失。对于该应用，将使用心理物理学、自适应光学成像、电生理学和分子生物学的多学科方法来解决三个具体目标： 具体目标1。确定与X染色体视锥细胞色素基因阵列相关的变异，这些变异与人类L和M视锥细胞相对数量的变化相关。在色觉正常的人中，L：M锥比率存在惊人的个体差异。为了检验关于决定视锥细胞是M还是L的机制的假设，将在具有正常色觉且L：M视锥细胞比例存在已知差异的男性的大样本中检查X染色体上含有视锥细胞色素基因的区域。 具体目标2。确定人类视锥嵌合体的遗传差异，提出影响感光器地形的后果。自适应光学成像结合视网膜密度测定将用于可视化视锥光感受器的结构和功能变化及其在视网膜中的地形布置作为基因突变的结果。 具体目标3。探索一种惊人的可塑性神经机制，假设它允许来自环境的信息在整个生命过程中连续重组神经连接。我们将描述一个最近发现的可塑性的成人视觉系统中的长期影响，改变色彩的经验已被发现改变成人的色觉。这将允许假设神经可塑性的作用，建立和维持适当的视觉系统的功能进行测试。

DESCRIPTION (provided by applicant): Most of our daily activities are performed under light levels where our vision is based on cone photoreceptors. Our long term goal is to contribute to an understanding of the basic mechanisms underlying cone-based vision, how these mechanisms are disrupted in vision disorders and how vision loss might be prevented or reversed. For this application a multidisciplinary approach using psychophysics, adaptive optics imaging, electrophysiology, and molecular biology will be used to address three specific aims: Specific Aim 1. Identify variations linked to the X-chromosome cone photopigment gene array that are associated with shifts in the relative numbers of human L and M cones. There is astounding individual variation in the L:M cone ratio among humans with normal color vision. To test hypotheses about the mechanism responsible for determining whether a cone is M or L, the region of the X-chromosome containing the cone photopigment genes will be examined in a large sample of males with normal color vision who have known differences in the ratio of L:M cones. Specific Aim 2. Determine the consequences for the human cone mosaic of identified genetic differences that are proposed to affect the photoreceptor topography. Adaptive optics imaging coupled with retinal densitometry will be used to visualize structural and functional changes in the cone photoreceptors and their topographical arrangement in the retina as the result of genetic mutations. Specific Aim 3. Explore an amazing plastic neural mechanism that is hypothesized to allow information from the environment to instructively reorganize neural connections throughout life. We will characterize a recently discovered plasticity of the adult visual system in which the long term effects of altered chromatic experience have been found to change the color vision of adults. This will allow hypotheses about the role of neural plasticity in establishing and maintaining proper function of the visual system to be tested.