Mechanisms of Synaptic Processing in the Retina

项目总结 该项目涉及NEI的一项基本研究优先事项，即 了解视网膜网络如何处理视觉图像。哺乳动物的视网膜 含有大约20种不同类型的视网膜神经节细胞，每种细胞 特有的接受场特性。大多数神经节细胞类型都是图像细胞 形成为它们由基本上相同的神经元阵列组成 对视野进行完全采样。我们的方法一直是针对特定的， 解剖和生理鉴定的神经节细胞，并执行 对光诱发的输入进行量化分析，以便深入了解 调节生理反应的连接性和神经通路。在这 提案我们将解决三个目标。目标1建议检验以下假设 AMPA和海人藻酸受体在外丛状层的选择性表达 有助于神经节细胞的时间调谐。目标2建议检查 N-甲基-D-天冬氨酸受体在大鼠脑内感受野特性形成中的作用 方向选择性的神经节细胞，以及维持活跃的神经节细胞。我们会 用亚单位特异性拮抗剂检测NMDA受体功能的差异 在跑道上和跑道上。Aim 3，与罗伯特·史密斯在 宾夕法尼亚大学将使用现实的计算模型预测 突触电导，并估计电压钳位误差的大小 神经节细胞的记录。

PROJECT SUMMARY This project addresses a basic research priority of the NEI, which is to understand how retinal networks process visual images. The mammalian retina contains about 20 different types of retinal ganglion cell each having characteristic receptive field properties. Most ganglion cell types are image- forming in that they comprise an array of essentially identical neurons that completely sample the visual field. Our approach has been to target specific, anatomically and physiologically identified ganglion cells, and perform quantitative analyses of the light-evoked inputs in order to gain insights into the connectivity and neural pathways that mediate physiological responses. In this proposal we will address three aims. Aim 1 proposes to test the hypothesis that selective expression of AMPA and kainate receptors in the outer plexiform layer contribute to temporal tuning in the ganglion cells. Aim 2 proposes to examine the role of NMDA receptors in generating the receptive field properties of direction-selective ganglion cells, and ON brisk-sustained ganglion cells. We will use subunit-specific antagonists to probe differences in NMDA receptor function in the ON and OFF pathways. Aim 3, in collaboration with Robert Smith at University of Pennsylvania, will use realistic computational models to predict the synaptic conductances, and estimate the magnitude of voltage-clamp errors in the ganglion cell recordings.