FUNCTION OF AMACRINE CELLS IN THE RETINA

视网膜无精细胞的功能

• 批准号: 2161432
• 负责人: RALPH J. JENSEN
• 金额: $ 7.61万
• 依托单位: SOUTHERN COLLEGE OF OPTOMETRY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-30 至 1996-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2161432
• 关键词: GABA receptor; acetylcholine; amacrine cells; anticholinergic agent; cell cell interaction; cholinergic receptors; electrophysiology; fluorescence microscopy; fluorescent dye /probe; gamma aminobutyrate; inhibitor /antagonist; laboratory rabbit; microelectrodes; microinjections; neural information processing; neural transmission; photobiology; photostimulus; potassium; retinal ganglion; stimulus /response; synapses; video recording system; voltage /patch clamp

The long-term goal of the proposed research is to understand the nature of the synaptic interactions that take place within the inner plexiform layer of the mammalian retina, and how these interactions contribute to the receptive field properties of ganglion cells. In this research proposal, neurotransmission between cholinergic (CH) amacrine cells and ganglion cells in the rabbit retina will be examined. The overall strategy is to stimulate CH amacrine cells either chemically (with local microinjecton of K+) or electrically (with a metal microelectrode) while monitoring the responses from ganglion cells. The specific aims are: (1) to determine the magnitude and spatial extent of CH input to ganglion cells, (2) to determine if GABA is co-released with acetylcholine upon stimulation of CH cells, (3) to examine how the responses of ganglion cells to CH cell stimulation are influenced by light stimuli, and (4) to investigate possible interactions between CH cells. I have developed a technique by which CH amacrine cells and ganglion cells, labeled with fluorescent dyes, can be visualized under an epifluorescence microscope in the living, superfused rabbit retina. Under the microscope, a recording microelectrode will be positioned near a selected ganglion cell body and the stimulating probe positioned near an CH cell body. All manipulations will be done using a low-light-level video system to minimize photobleaching. Four experiments will be conducted, each addressing a specific aim. In the first experiment, ganglion cells will be recorded extracellularly and the effects of stimulation of neighboring CH cells will be evaluated. In the second experiment, intracellular recordings will be made from ganglion cells to examine possible release of GABA from CH cells. In this experiment, the effects of acetylcholine (that is co-released) will be blocked pharmacologically to unmask and GABA effect. In the third experiment, ganglion cells will be recorded extracellularly and light stimuli presented just moments before CH cell stimulation. Of particular interest is the possibility that light-induced inhibitory mechanisms may modulate the release of acetylcholine or postsynaptic effects thereof in directionally selective ganglion cells. In the fourth experiment (addresses the last specific aim), the effects of CH cell stimulation on the response of a ganglion cell to stimulation of second CH cell will be analyzed.

拟议研究的长期目标是了解性质 内部丛状发生的突触相互作用 哺乳动物视网膜的层，以及这些相互作用如何促进 神经节细胞的接受场特性。 在这项研究建议中，胆碱能（CH）之间的神经传递 将检查兔视网膜中的无长血性细胞和神经节细胞。 总体策略是刺激化学的CH无大细胞 （用K+的局部微型注射子）或电（用金属 微电极）在监测神经节细胞的响应时。 这 具体目的是：（1）确定 对神经节细胞的输入，（2）确定GABA是否与 乙酰胆碱在刺激CH细胞时，（3）以检查如何 神经节细胞对CH细胞刺激的反应受到 光刺激和（4）研究CH之间可能的相互作用 细胞。 我已经开发了一种技术，通过该技术 用荧光染料标记的细胞可以在 活着的超级兔视网膜中的落荧光显微镜。 在显微镜下，记录微电极将位于 选定的神经节细胞体和位于附近的刺激探针 CH细胞体。 所有操作将使用低光级别进行 视频系统以最大程度地减少光漂白。 四个实验将是 进行，每个都针对特定目标。 在第一个实验中， 神经节细胞将被细胞外记录 将评估相邻CH细胞的刺激。 在第二个 实验，细胞内记录将由神经节细胞进行 检查可能从CH细胞中释放GABA。 在这个实验中， 乙酰胆碱的影响（共同发布）将被阻塞 从药理上揭示和GABA效应。 在第三个实验中， 神经节细胞将被细胞外记录和轻刺激 在CH细胞刺激之前就呈现了片刻。 特别 兴趣是光引起的抑制机制可能 调节其在其中释放乙酰胆碱或突触后作用 定向选择性神经节细胞。 在第四个实验中 （解决最后的特定目的），CH细胞刺激对 神经节细胞对刺激第二CH细胞的反应将是 分析。