DEVELOPMENT OF COMPLEX RETINAL FIELDS

拟议研究的长期目标是了解 图像信息处理的发展， 胚胎和新生动物的视网膜。 这项基础研究可以 对未来治疗遗传性疾病有重要意义， 视网膜。 为实现研究目标， 提出了一个框架，该框架显示了树突状生长，光照， 和自发活动波（常见于未成熟的分离视网膜， 但尚未进行体内研究）可以促进 视网膜信息处理 提出的具体问题如下： 1)发育中的视网膜在体内是否有自发活动波？ 如果 那么这个活动的性质是什么呢？ 为了回答这些问题， 发育中的海龟的眼睛会被两个电极记录下来 同时，用一种新的数学方法分析了结果。 实验将在正常条件下进行，目视检查- 和药理学上异常的 然后将数据与 计算机模拟与理论框架。 2)是由细胞外钾介导的自发波， 胆碱能突触 为了回答这个问题，一种新的技术， 将使用光学成像神经节细胞中的Ca2+。 这种技术 将允许获得波在细胞间的时空分布， 因此，为了测试这些波的最新模型所做的预测。 在 特别是，该模型预测了新斯的明， 胆碱酯酶抑制剂，Cs+和TEA，两种K+电流阻断剂，以及Co2+， 突触阻滞剂 3)自发活动是否有助于接受性的发展- 磁场大小和方向选择性？ 为了测试波是否 对于这些特性的发展， 在眼内植入一种聚合物， 开发了 在拟议的实验中，药物将是新斯的明 CO2+。 取向选择性和接收场大小的影响 将测量这些条件中的每一个作为年龄的函数， 这些结果与新的计算机模拟结果进行了比较。

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.