ROD AND CONE SIGNALING PATHWAYS IN MAMMALIAN RETINA

描述（由申请人提供）：在这个竞争性更新申请中，我们建议继续并扩展我们对黑暗适应小鼠视网膜中双极细胞（BC），无突细胞（AC）和神经节细胞（GC）水平的杆状和锥体信号通路的研究。我们将重点研究BC和AC突触回路介导杆、M-锥和M/ s -锥信号向三种α神经节细胞（alphaGCs）的传递，并确定甘氨酸能和gaba能ACs如何通过AC锥BC GC反馈通路和AC GC前馈突触调节alphaGCs中的光诱发信号。有三个具体目的：(1)将三个alphaGC回路中的生理BC类型与解剖BC类型相关联，并确定杆/锥细胞与BC之间以及BC与alphaGC之间可能的突触接触；(2)通过分析野生型、Tralpha-/-和gnat2plf3小鼠的BCs和alphaGC的光诱发阳离子电流（IC），确定杆状和锥体介导的BCs和alphaGC输入的相对强度以及3个alphaGC电路的信号整合机制；(3)通过双标签和双电压箝位技术确定甘氨酸能和GABAergic AC对alphaGCs光诱发抑制和BC突触输入的相对贡献，以及GABAergic AC和alphaGCs之间可能的突触连接。我们的研究目标是了解哺乳动物视网膜网络如何处理视觉图像，这是NEI的基础研究重点，并提供关于个体视网膜神经元和突触如何在疾病状态下功能障碍的关键信息，如先天性静止性夜盲症和青光眼，这是NEI的转化研究重点。此外，对健康和患病眼睛中特定哺乳动物视网膜回路的了解将有助于开发新的基因/药物治疗视网膜疾病，如视网膜色素变性和青光眼，以及设计有效的视网膜假体装置。

DESCRIPTION (provided by applicant): In this competing renewal application, we propose to continue and extend our investigations on rod and cone signaling pathways at the bipolar cell (BC), amacrine cell (AC) and ganglion cell (GC) levels in the dark-adapted mouse retina. We will focus our efforts to study the BC and AC synaptic circuitries mediating rod, M-cone and M/S-cone signal transmission to three types of alpha ganglion cells (alphaGCs), and to determine how glycinergic and GABAergic ACs regulate light-evoked signals in alphaGCs via the AC cone BC GC feedback pathways and the AC GC feedforward synapses. There are three specific aims: (1) to correlate physiological BC types with anatomical BC types in the three alphaGC circuitries and to identify possible synaptic contacts between rods/cones and BCs and between BCs and alphaGCs; (2) to determine the relative strengths of rod- and cone-mediated inputs to BCs and alphaGCs and mechanisms of signal integration in the 3 alphaGC circuitries by analyzing BCs' and alphaGCs' light-evoked cation currents ( IC) in wildtype, Tralpha-/- and Gnat2cplf3 mice; and (3) to determine relative glycinergic and GABAergic AC contributions to alphaGCs' light-evoked inhibitory and BC synaptic inputs and possible synaptic connectivity between individual GABAergic ACs and alphaGCs by double label and dual voltage clamp techniques. The goal of our research is to understand how mammalian retinal networks process visual images, a basic research priority of the NEI, and to provide crucial information on how individual retinal neurons and synapses dysfunction in disease states, such as congenital stationary night blindness and glaucoma, a translational research priority of the NEI. Moreover, knowledge of specific mammalian retinal circuitries in healthy and diseased eyes will be useful for developing new gene/drug therapies for retinal disorders, such as retinitis pigmentosa and glaucoma, as well as for designing effective retinal prosthetic devices.