Amacrine Cell Circuitry Mediating Visual Function

描述（由申请人提供）：我们对视网膜活动最深刻的理解来自于研究，这些研究表明了已识别的无突细胞类型如何介导特定的视觉功能。多轴突无突细胞的眼球抑制和图像-背景分离，星爆无突细胞的定向选择性运动检测，以及所有无突细胞对视杆视觉的处理都是由明确定义的视网膜回路介导的复杂功能的例子，该回路涉及特定的无突细胞类型。这些研究的策略是确定无突细胞产生的兴奋和抑制信号是如何整合形成有意义的视网膜活动的。在视网膜中还有另外的24个无毛细胞，它们的形态和分层已经被很好地定义，但它们的视觉功能作用仍然不清楚。这是本提案的目标，以调查许多这些不太明确的无毛细胞的视觉功能的作用。我们的策略是利用我们最近对神经节细胞功能的研究，这些研究已经定义了十几种不同的“特征检测器”，这些“特征检测器”是由分布在整个内丛状层深度的十几种不同神经节细胞类型的整齐分层的树突形成的。这些研究确定了每种神经节细胞类型到达树突的兴奋和抑制的空间、时间、分层和相位特性。这些反应的抑制成分反映了不同无毛细胞类型的空间、时间、分层和相位特性，其过程与每种神经节细胞类型的树突共层。我们将在视网膜切片中记录特定的无毛细胞类型，并将它们的时空相位和分层特性与与它们共分层的神经节细胞的抑制特性联系起来。通过这种关联过程，我们希望能够描述特定的无毛细胞在产生视觉功能的不同组成部分中的作用。

DESCRIPTION (provided by applicant): Our deepest understanding of retinal activity has been derived from studies that show how identified amacrine cell types mediate specific visual functions. Saccadic suppression and figure-ground separation by the polyaxonal amacrine cells, directional selective movement detection by the starburst amacrine cells, and the processing of rod vision by the All amacrine cells are examples of sophisticated function mediated by well-defined retinal circuitry involving specific amacrine cell types. The strategy in those studies was to determine how excitatory and inhibitory signals generated by amacrine cells are integrated to form meaningful retinal activity. There exist an additional two dozen amacrine cells in the retina whose morphology and stratification has been well defined, but whose visual functional roles still remain obscure. It is the goal of this proposal to investigate the visual functional role of many of these less defined amacrine cells. Our strategy is to utilize our recent studies of ganglion cell function that have defined a dozen different "feature detectors" formed by the neatly stratified dendrites of a dozen different ganglion cell types distributed throughout the depth of the inner plexiform layer. These studies define the space, time, stratification and phase properties of excitation and inhibition arriving at the dendrites of each ganglion cell type. The inhibitory components of these responses reflect the space, time, stratification and phase properties of different amacrine cell types whose processes costratify with the dendrites of each ganglion cell type. We will record from specific amacrine cell types in retinal slices and correlate their space time phase and stratification properties with the inhibitory properties of the ganglion cells with which they costratify. Through this correlation process we hope to be able to describe the role of specific amacrine cells in generating different components of visual function.