Signal Processing in the Inner Retina

描述（由申请人提供）：哺乳动物视网膜包含至少15-20种视网膜神经节细胞，每种细胞都对视觉场景中不同的，有时是复杂的特征做出最佳反应。总之，这些不同的神经节细胞反应为我们提供了在视觉世界中导航所需要的所有信息。每一种类型的视网膜神经节细胞通过收集突触前的输入来监测视网膜表面的一小块，即它的接受野

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.