SYNAPTIC TRANSMISSION AND ITS MODULATION IN THE RETINA

视网膜中的突触传递及其调节

• 批准号: 7994760
• 负责人: PETER D LUKASIEWICZ
• 金额: $ 39.47万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-05-01 至 2012-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7994760
• 关键词: Amacrine Cells; Brain; Cells; Conflict (Psychology); Goals; Lateral; Light Adaptations; Mediating; Output; Pathway interactions; Photoreceptors; Principal Investigator; Process; Relative (related person); Retina; Retinal; Retinal Ganglion Cells; Role; Shapes; Signal Pathway; Signal Transduction; Stream; Synaptic Transmission; Visual; Visual system structure; cell type; ganglion cell; horizontal cell; neural circuit; outer plexiform layer; programs; receptive field; response

DESCRIPTION (provided by applicant): Spatial and contrast information are first processed by the visual system within the retina. The processing of these aspects of the visual scene depends on the center-surround, receptive field organization of retinal ganglion cells. While it is known that activation of the concentric regions of the receptive field produces opponent responses in ganglion cells, the retinal circuitry responsible for this receptive field organization remains poorly understood. The center signal is carried by the input-output pathway consisting of photoreceptors, bipolar cells and ganglion cells. However, the lateral pathways that mediate surround signals remain unclear. Conflicting evidence suggests that either horizontal cells in the outer retina or amacrine cells in the inner retina mediate surround signaling. The relative roles of these pathways in ganglion cell receptive field formation are poorly understood. Different features of the visual world are extracted by 10-15 different ganglion cell types, which are then sent to the brain in distinct processing streams. The receptive field organization of these distinct ganglion cells may be uniquely shaped by different inner and outer retinal surround contributions. Ganglion cell receptive fields can also be altered by light adaptation, but it is not known how the inner and outer retina contributes to these changes. The goal of this proposal is to determine the circuitry and synaptic mechanisms responsible for the receptive field variety found across ganglion cells. Electrophysiological, pharmacological and anatomical approaches will be used to determine how inner and outer retinal surround pathways shape the receptive fields in morphologically distinct ganglion cells. Three specific aims will determine 1) the roles of the outer retina in GC receptive field organization 2) determine the roles of the inner retina in GC receptive field organization and 3) determine how light adaptation modifies the inner and outer retinal contributions to GC receptive field organization. By defining the precise roles of inner and outer plexiform layers that mediate surround signaling in specific GC types, we will develop a more complete picture of how spatial and contrast information is processed by distinct visual signaling pathways.

描述（由申请人提供）：空间和对比度信息首先由视网膜内的视觉系统处理。视觉场景的这些方面的处理取决于视网膜神经节细胞的中心-环绕、感受野组织。虽然已知感受野的同心区域的激活在神经节细胞中产生对抗反应，但负责该感受野组织的视网膜回路仍然知之甚少。中心信号通过由光感受器、双极细胞和神经节细胞组成的输入-输出通路传递。然而，介导周围信号的侧向通路仍不清楚。现有证据表明，外视网膜中的水平细胞或内视网膜中的无长突细胞介导环绕信号。这些通路在神经节细胞感受野形成中的相对作用知之甚少。视觉世界的不同特征由10-15种不同的神经节细胞类型提取，然后以不同的处理流发送到大脑。这些不同的神经节细胞的感受野组织可能是独特的形状不同的内部和外部视网膜周围的贡献。神经节细胞感受野也可以通过光适应而改变，但尚不清楚内部和外部视网膜如何促成这些变化。这个提议的目标是确定负责跨神经节细胞发现的感受野多样性的电路和突触机制。电生理学、药理学和解剖学方法将用于确定内部和外部视网膜环绕通路如何在形态上不同的神经节细胞中形成感受野。三个具体目标将确定1）外视网膜在GC感受野组织中的作用，2）确定内视网膜在GC感受野组织中的作用，以及3）确定光适应如何改变内视网膜和外视网膜对GC感受野组织的贡献。通过定义在特定GC类型中介导周围信号的内外丛状层的确切作用，我们将开发一个更完整的图片，空间和对比度信息是如何通过不同的视觉信号通路处理的。