CIRCUITRY OF LONG RANGE EXCITATION IN THE RETINA

视网膜长程激发电路

• 批准号: 2710968
• 负责人: Jonathan B Demb
• 金额: $ 2.62万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2710968
• 关键词: amacrine cells; cats; confocal scanning microscopy; electron microscopy; ganglion cell; immunocytochemistry; neural transmission; neuroanatomy; neurotransmitters; psychophysics; retina; synapses; visual pathways

The goal of this proposal is to characterize the input of long-range amacrine cells to the Y/Alpha subclass of the cat retina. Although physiological responses of Y cells from retinal stimulation outside the receptive field (a recurring misnomer) have been reported for more than thirty years and have been subsequently characterized, its anatomical basis is not understood. The candidate proposes two hypotheses for the anatomical substrate: many neurons that locally pass signals horizontally or a single neuron with a long axon. Based on the latter, experiments are proposed to demonstrate long-range amacrine cells in the cat retina and then to determine if their morphological (light and EM) features and histochemical markers are consistent with the second hypothesis. The results of such experiments would generally add to our knowledge of retinal circuitry and specifically may reveal the morphological basis for visual response modulation by peripheral stimulation. The experiments entail an in vitro cat retinal preparation in which intracellular fills will be made of Alpha ganglion cells (easily localized for injection microscopically because of their large size) and of long- range amacrine cells (identified by their transport of fluorescent beads from a distant retinal infection site). The stated goal is to fill all of the amacrine cell types that send long axons to the area centralis. The candidate fails to describe the criteria to identify and classify amacrine cells into that category. Will displaced amacrine cell types be included? It is also not clear how one knows that all long- range amacrine cell types are injected and how to exclude incompletely filled ganglion cells. This first goal relies heavily on the resolution of the confocal microscope. The second aim extends the analysis to include electron microscopic confirmation of synaptic connection. This will be a laborious effort process but the structure of the synaptic vesicle may suggest which neurotransmitter is released by the long-range amacrine cell. The third project would be to combine those previous approaches with immunocytochemistry to identify specific neurotransmitter candidates. These latter projects are described clearly and well-justified, assuming the first goal is met.

该建议的目的是表征远程的输入 无链氨酸细胞到猫视网膜的Y/α子类。虽然 Y细胞在视网膜刺激外的生理反应 已经报道了接受场（反复出现的错误称呼） 超过三十年，随后被描述了 解剖基础尚不理解。候选人提出了两个 解剖基板的假设：许多局部的神经元 水平传递信号或具有长轴突的单个神经元。基于 在后者上，提出了实验以证明远程 猫视网膜中的无聚细胞，然后确定其是否是否 形态学（光和EM）特征和组织化学标记是 与第二个假设一致。这样的结果 实验通常会增加我们对视网膜电路的了解 并且可能会揭示视觉的形态学基础 通过周围刺激调节反应调节。 实验需要进行体外猫视网膜制剂，其中 细胞内填充将由α神经节细胞制成（易于定位 在显微镜上进行注射，因为它们的尺寸较大）和长期 范围的无大细胞（通过荧光运输鉴定 来自遥远的视网膜感染部位的珠子）。既定的目标是填补 所有将长轴突发送到该区域的无长血管细胞类型 中心。候选人未能描述识别和 将无长血性细胞分类为该类别。将移位的无链氨氨酸细胞 包括类型？还不清楚一个人如何知道所有长期 注入范围的无大细胞类型以及如何排除 未完全填充的神经节细胞。第一个目标很大程度上依赖 共聚焦显微镜的分辨率。 第二个目标扩展了分析以包括电子显微镜 确认突触连接。这将是一项费力的努力 过程但是突触囊泡的结构可能表明 神经递质由远距离的无大细胞释放。这 第三个项目是将以前的方法与 免疫细胞化学以鉴定特定的神经递质候选物。 这些后一个项目被描述了清晰，完善的， 假设第一个目标已达到。