Signal Processing in the Inner Retina

描述(申请人提供)：哺乳动物的视网膜包含至少15-20种视网膜神经节细胞，每种细胞都能对视觉场景中不同的、有时是复杂的特征做出最好的反应。总而言之，这些不同的神经节细胞反应为我们提供了我们在视觉世界中导航所使用的所有信息。每种类型的视网膜神经节细胞通过从突触前收集信息来监控视网膜表面的一块斑块，这是它的感受野 双极细胞和无长突细胞，分别有12种和30种以上。虽然有助于神经节细胞光反应的无长突细胞和双极细胞连接的一般模式是已知的，但IPL令人望而生畏的复杂性阻碍了我们对构成区分神经节细胞光反应的调节特性的特定联系的理解 神经节细胞类型。我们已经开发了一个光遗传学和基于病毒的技术工具箱，它将使我们能够追踪和功能描述杆状优势小鼠和视锥优势地地鼠视网膜中双极细胞、无长突细胞和神经节细胞之间的联系。在三个特定的目标中，我们的目标是：1)检验神经节细胞获得不同时间光反应的假设，部分是通过将具有不同时间反应的双极细胞的兴奋性输入相加来实现的。2)测试神经节细胞从不同类型的具有不同时间特性的无长突细胞获得直接输入的假设， 3)确定在促肾上腺皮质激素释放激素(CRH)启动子控制下表达cre重组酶的特定类型的无长突细胞的功能联系及其在视觉中的作用。我们的工作将确定特定视网膜内回路的连接和功能，并为理解已知的视网膜内回路变化提供背景。 发生在光感受器退化之后，无论是由于遗传疾病还是年龄起病。

DESCRIPTION (provided by applicant): The mammalian retina contains at least 15-20 types of retinal ganglion cells each tuned to respond best to different and sometimes complex features in a visual scene. Together, these diverse ganglion cell responses provide us with all of the information that we use to navigate in the visual world. Each type of retinal ganglion cell monitors a patch on the retinal surface, its receptive field, by collecting inputs from presynaptic bipolar and amacrine cells of which there are more than 12 and 30 types, respectively. While the general patterns of amacrine and bipolar cell connectivity that contribute to he ganglion cell light response are known, the daunting complexity of the IPL has impeded our understanding of the specific connections that underlie the tuning properties that distinguish the ganglion cell types. We have developed a toolbox of optogenetic and virally-based techniques that will enable us to trace and functionally characterize the connections between bipolar, amacrine, and ganglion cells in both the rod dominant mouse and cone dominant ground squirrel retinas. In three specific aims, our goals are to: 1) test the hypothesis that ganglio cells obtain different temporal light responses, in part, by summing the excitatory inputs of bipolar cells with different temporal responses. 2) test the hypothesis that ganglion cells obtain direct input from different types of amacrine cells with different temporal properties and, 3) determine the functional connections and the role in vision of a specific amacrine cell type that expresses cre recombinase under the control of the corticotropin releasing hormone (CRH) promoter. Our work will define the wiring and functions of specific inner retinal circuits i health, and provide the background for understanding circuit changes that are known to occur following photoreceptor degeneration, whether from genetic or age-onset disease.