Contribution of the trichromatic cone mosaic to human vision

项目摘要 视觉是数十亿神经元协同工作的结果， 来自外部世界的有用信息。相比之下，只有几百万个圆锥体， 光感受器作为视觉的守门人，通过启动光吸收和转换， 将其转化为视觉系统其他部分可以解码的语言。在视网膜中， 光感受器也是最易受疾病影响的。如果针对他们的治疗方法 救援是在未来发展，并恢复正常的视力与其所有精致的功能， 视觉的潜在神经基质需要在细胞尺度上详细描述。 三色锥镶嵌的性质造成了一些公认的模糊性， 视觉处理例如，单独在一个锥体中的光异构化可以由以下引起： 强度和波长的多种组合使得视觉系统依赖于 比较后感受器电路，以分离这两个基本方面的物理 刺激。感受器后通路编码视网膜图像中的强度和波长变化 通过比较局部空间区域中的三色视锥信号， 保持神秘。这种尚不为人知的空色编码始于视锥的水平 马赛克是由下游继承的，因此限制了下游可用的信息 负责解码视觉场景的彩色和非彩色特性的神经元。的 缺乏关于个体内部和个体之间锥体地形自然变化的信息， 下游神经元中的频谱处理模型的模糊性来源。此外，委员会认为， 一般缺乏工具来直接连接锥体的输出及其随后的电路， 行为阻碍了概述颜色外观的神经基质的进展， 侦测 我们最近开发了工具来a）有效地绘制圆锥体的地形图 用自适应光学辅助密度测定法进行镶嵌，和B）测试由 借助细胞级眼动追踪，有针对性地刺激视网膜。在明知这一 光谱组织在中央视网膜跨越一系列的个人，我们将建立 Aim 1中形成成人视网膜的遗传和发育机制。通过 在同一视网膜中进行伴随的色度和亮度检测测量 随着光学像差的消除，我们将概述后感受器布线策略， 这些经典感知任务的潜在限制。在目标2中，我们将映射 已知光谱类型的视锥细胞的个体和集合到感知上。我们将首先测试 这些假设表征了视锥信号被整合以介导的规则 检测和外观。接下来，我们将详细介绍跨 中央视网膜和测试他们是否符合标准模型的中心环绕 顺从总之，这项工作将奠定基础的计算模型的视觉 处理，建立一个新的实验线，以测试模型预测连接生理学和 感知;并最终为这些工具在细胞规模上的更广泛应用奠定基础 视网膜疾病及其治疗的行为测试。

Project Summary Vision is the result of billions of neurons working in tandem to extract ecologically meaningful information from the external world. In contrast, only a few million cone photoreceptors serve as the gatekeepers for vision, by initiating light absorption and converting it into a language that the rest of the visual system can decode. In the retina, cone photoreceptors are also among the most vulnerable to disease. If therapies aimed at their rescue are to evolve in the future and restore normal vision with all its exquisite features, the underlying neural substrates for vision need to be detailed on a cellular scale. The properties of the trichromatic cone mosaic pose few well recognized ambiguities for visual processing. The photoisomerization in one cone alone, for instance, can arise from numerous combinations of intensity and wavelength leaving the visual system to rely on comparisons in postreceptoral circuitry to divorce these two elementary aspects of physical stimuli. Postreceptoral pathways encode intensity and wavelength variations in the retinal image by comparing trichromatic cone signals in a local region of space, the mechanisms of which remain mysterious. This, yet unknown, spatiochromatic code initiated at the level of the cone mosaic is inherited by, and consequently constrains the information available to downstream neurons responsible for decoding chromatic and achromatic properties of the visual scene. The lack of information on the natural variation in cone topography within and between individuals is a source of ambiguity for models of spectral processing in downstream neurons. Furthermore, the general lack of tools to directly link the outputs of the cones and their ensuing circuits onto behavior has hindered progress in outlining the neural substrates for color appearance and detection. We have recently developed tools to a) efficiently map the topography of the cone mosaic with adaptive optics assisted densitometry and b) test the visual sensations elicited by targeted stimulation of the retina with help of cellular-scale eye tracking. With knowledge of the spectral organization in the central retina across a range of individuals, we will establish the genetic and developmental mechanisms shaping the adult human retina in Aim 1. By undertaking concomitant chromatic and luminance detection measurements in the same retinae with optical aberrations removed, we will outline the postreceptoral wiring strategies that dictate the underlying limits for these classical perceptual tasks. In Aim 2, we will map the output of individual and collection of cone cells of known spectral type onto perception. We will first test hypotheses that characterize the rules by which cone signals are integrated to mediate detection and appearance. Next, we will detail the spatial grain of color signaling across the central retina and test whether they fall in line with standard models of center-surround opponency. Together, this work will lay the foundation for computational models of visual processing, establish a new line of experiments to test model predictions linking physiology and perception; and eventually set the stage for a wider application of these tools to cellular-scale behavioral testing in retinal disease and their therapies.