DEVELOPMENT OF COMPLEX RETINAL FIELDS

复杂视网膜区域的发育

• 批准号: 2838357
• 负责人: NORBERTO M GRZYWACZ
• 金额: $ 28.32万
• 依托单位: SMITH-KETTLEWELL EYE RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-12-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2838357
• 关键词: Chelonia; acetylcholine; brain electrical activity; calcium metabolism; cobalt; computer simulation; dark adaptation; dendrites; developmental neurobiology; electronic recording system; fluorescence microscopy; histology; imaging /visualization /scanning; infrared microscopy; neostigmine; neural information processing; neuropharmacology; potassium; retina; retinal ganglion; synapses; visual fields; visual pathways; visual stimulus

The long-term objective of the proposed research is to understand what processes contribute to the development of image information processing in the retinas of embryos and neonatal animals. This basic research could have important implications for future cure of genetic diseases of the retina. To achieve the objectives of the research, a theoretical framework was proposed, which shows how dendritic growth, light exposure, and spontaneous waves of activity (common to immature isolated retinas, but as yet not studied in vivo) can contribute to the development of retinal information processing. The specific questions being asked are: 1) Do developing retinas have spontaneous waves of activity in vivo? If so, what are the properties of this activity? To answer these questions, the eyes of developing turtles will be recorded with two electrodes simultaneously and the results analyzed with a new mathematical technique. The experiments will be performed under normal conditions and visually- and pharmacologically-abnormal ones. The data will then be compared to computer simulations performed with the theoretical framework. 2) Are spontaneous waves mediated by extracellular potassium and cholinergic synapses? To answer this question, a new technique for optically imaging Ca2+ in ganglion cells will be used. This technique will allow to obtain the waves' spatio-temporal profile across cells and thus, to test the predictions made by a recent model of these waves. In particular, this model predicts the effects of neostigmine, a cholinesterase inhibitor, Cs+ and TEA, two K+-currents blockers, and Co2+, a synaptic blocker. 3) Does spontaneous activity contribute to the development of receptive- field size and orientation selectivity? To test whether waves contribute to the development of these properties, a technique to implant intraocularly a piece of polymer that slowly releases drugs mixed with it was developed. In the proposed experiments, the drugs will be neostigmine and Co2+. Incidence of orientation selectivity and receptive-field size will be measured for each of these conditions as a function of age, and the results compared to those of new computer simulations.

拟议研究的长期目标是了解什么 过程有助于开发图像信息处理 胚胎和新生动物的视网膜。 这项基础研究可能 对未来治愈遗传疾病的重要意义 视网膜。 为了实现研究的目标，理论上 提出了框架，其中显示了树突状的生长，光暴露， 和自发的活性波（不成熟的孤立视网膜共有 但是尚未在体内研究）可以为发展做出贡献 视网膜信息处理。 提出的具体问题是： 1）发展视网膜在体内有自发的活性波吗？ 如果 那么，此活动的特性是什么？ 要回答这些问题， 发育海龟的眼睛将用两个电极记录 同时使用新的数学技术进行了分析。 实验将在正常条件下进行，并在视觉上进行 - 和药理学上的。 然后将数据与 使用理论框架执行的计算机模拟。 2）是由细胞外钾介导的自发波和 胆碱能突触？ 要回答这个问题，这是一种新技术 将使用神经节细胞中的光学成像Ca2+。 这项技术 将允许在细胞和 因此，要测试这些波的最新模型做出的预测。 在 特别是，该模型预测了Neostigmine的影响，A 胆碱酯酶抑制剂，CS+和TEA，两个K+ - 电流阻滞剂和CO2+，， 突触阻滞剂。 3）自发活动有助于接受的发展 场大小和方向选择性？ 测试波是否贡献 为了开发这些特性，一种植入技术的技术 眼内一块聚合物，该聚合物慢慢释放了与之混合的药物 是开发的。 在拟议的实验中，这些药物将是新生氨酸 和二氧化碳+。 定向选择性和接受场大小的发生率 将根据年龄的函数对每个条件进行测量，并且 与新计算机模拟的结果相比。