NEURAL MECHANISMS OF VISION

这项研究涵盖了视觉中突触递质的功能 系统。一般说来，突触递质影响特定的接受器。 字段属性，而不是特定单元格类型。泛化可以 关于一些递质：快速作用的抑制性递质 GABA和甘氨酸影响触发特征，如方向性敏感性 和方位敏感性，而兴奋性递质乙酰胆碱 影响细胞的自发活动和反应能力。这 该提案旨在发现可以对哪些内容进行概括 单胺类递质(多巴胺、去甲肾上腺素和吲哚胺)， 视网膜和皮质的研究。 兔视网膜是哺乳动物视网膜的一个很好的模型。为了 从各种细胞类型中进行需要记录的泛化，以及 兔视网膜至少有16个，都可以用 合理的频率。这些单元格类型包括在 猫，还有许多在猴子身上发现的，除了一些颜色 编码类型。然而，对于光和暗适应的实验， 最好使用CAT，因为可以区分明视和暗视状态 通过光谱敏感度。除了多巴胺和吲哚乙胺的作用 自从最近的工作以来，我们计划研究乙酰胆碱的毒鼠碱效应。 已经表明，在脑组织中既有烟碱受体，也有毒碱受体 视网膜，它们可能是突触前的，扮演着不同的角色。 就大脑皮层的实验而言，猫是一个很好的模型。再说一次，焦点 将关于突触递质激动剂和拮抗剂对 细胞的感受场。我们计划研究 去甲肾上腺素及其激动剂和拮抗剂，主要关注 我们已经展示了诸如响应性和敏感度之类的属性 受视网膜中单胺类物质的影响。 我们的总体目标是描述突触递质的一般作用 在视觉系统中，这将有助于预测 视觉系统上的各种药物。此外，我们的数据可以放入 与有关解剖定位和细胞效应的数据一起 突触发射器提供接线图，显示如何输入到 细胞被组织起来以产生细胞的属性，就像我们所拥有的 建议将GABA和乙酰胆碱的输入定向选择性地 视网膜中的细胞，提供定向选择性。

This research covers the function of synaptic transmitters in the visual system. In general, synaptic transmitters affect particular receptive field properties, rather than particular cell types. Generalizations can be made about some transmitters: the fast-acting inhibitory transmitters GABA and glycine affect trigger features such as directional sensitivity and orientation sensitivity, while the excitatory transmitter acetylcholine affects the spontaneous activity and responsiveness of cells. This proposal intends to discover what generalizations can be made about monoamine transmitters (dopamine, noradrenaline, and indoleamines), with investigations on both retina and cortex. A good model for the mammalian retina is the rabbit retina. In order to make generalizations one needs to record from a variety of cell types, and the rabbit retina contains at least 16, which can all be recorded with reasonabale frequency. These cell types include all those found in the cat, and many found in the monkey, with the exception of some of the color coded types. For experiments on light and dark adaptation, however, the cat is preferred, because photopic and scotopic states can be distinguished by spectral sensitivity. In addition to dopamine and indoleamine effects we plan to study the muscarinic effects of acetylcholine, since recent work has suggested that there are muscarinic as well as nicotinic receptors in the retina, and that they may be presynaptic and play a different role. For experiments on the cortex the cat is a good model. Again, the focus will be on the effects of synaptic transmitter agonists and antagonists on the receptive fields of cells. We plan to study the effect of noradrenaline and its agonists and antagonists, looking primarily at properties such as responsiveness and sensitivity, which we have shown are affected by monoamines in the retina. Our overall goal is to describe the general action of synaptic transmitters in the visual system, which will be useful in predicitng the action of various drugs on the visual system. In addition, our data can be put together with data on the anatomical localization and cellular effects of synaptic transmitters to provide a wiring diagram, showing how inputs to a cell are organised to produce the properties of the cell, as we have proposed for the GABA and acetylcholine inputs to directionally selective cells in the retina, giving directional selectivity.