High Resolution Mapping of Foveal Ganglion Cell Receptive Fields in the Living Primate Eye

通过几个世纪的研究，已经确定了微小中央凹对视力的重要性， 观察其通过伤害或疾病造成的破坏性后果。虽然证据 这表明，中央凹含有完整的二十几类神经节细胞， 对于周边视网膜，我们对这些中央凹细胞的生理学知之甚少。我们认识上的这种差距是 从这种微妙的和地形复杂的电生理记录中获得挑战的结果 结构我们实验室开发的一种方法克服了这些挑战， 同时钙成像的数百个中心凹视网膜神经节细胞的荧光反应， 对视觉刺激的反应。因为这项技术可以记录单个细胞而不会对活体细胞造成损害， 眼睛，我们可以研究相同的细胞数月甚至数年，提供了机会来表征细胞的特性。 与任何现有方法相比，可以更彻底地提高每个电池的性能。由于第一 在提交的提案中，我们对钙指标的表达方式进行了重大改进， GCamMP6s，在神经节细胞中，表达程度增加到更大的偏心率， 从每个细胞的信号，以及随着时间的推移减少神经节细胞的损失。此外，我们还设计了一个 一种新的检眼镜，带有两个独立的自适应光学系统，其中一个专用于高分辨率刺激 第二个专用于高分辨率神经节细胞记录。我们还开发了一个广泛的 视觉刺激的电池，以表征每个细胞在空间，时间和颜色上的反应。该电池将 包括白色噪声刺激，该刺激能够识别到 视网膜中央凹神经节细胞感受野。为了帮助细胞分类，这些生理学观察将被 补充了神经节细胞树突状细胞形态的离体和体内组织学分析。 有了这些改进，我们将对生理学和解剖学进行全面的调查。 调节灵长类中心凹视觉的中心凹神经节细胞。

The importance for vision of the tiny fovea has been established by centuries of investigation as well as observations of the devastating consequences of its damage through injury or disease. Though evidence suggests that the fovea contains the full complement of the two dozen or so classes of ganglion cells found in peripheral retina, we know little about the physiology of these foveal cells. This gap in our understanding is the result of challenges in obtaining electrophysiological recordings from this delicate and topographically-complex structure. These challenges have been overcome by a method developed in our laboratory that allows simultaneous calcium imaging of the fluorescence responses of hundreds of foveal retinal ganglion cells in response to visual stimuli. Because this technique allows recording from single cells without damage in the living eye, we can study the same cells for months or even years, offering the opportunity to characterize the performance of each cell more thoroughly than has been possible with any prior method. Since the first submission of the proposal, we have made significant improvements in the expression of calcium indicator, GCamMP6s, in ganglion cells that increases the extent of expression to greater eccentricities, the fluorescence signal from each cell, as well as reducing the loss of ganglion cells over time. Moreover, we have designed a new ophthalmoscope with two independent adaptive optics systems, one dedicated to high resolution stimulus delivery and a second dedicated to high resolution ganglion cell recording. We have also developed an extensive battery of visual stimuli to characterize the responses of each cell in space, time, and color. This battery will include a white noise stimulus capable of identifying the locations and classes of single cone inputs to the receptive fields of foveal ganglion cells. To assist in cell classification, these physiological observations will be supplemented with ex vivo and in vivo histological analysis of the morphology of ganglion cell dendritic arbors. Armed with these improvements, we will undertake a comprehensive survey of both the physiology and anatomy of the foveal ganglion cell classes that mediate primate foveal vision.