FUNCTIONAL ORGANIZATION OF VERTEBRATE VISUAL SYSTEMS

这个项目试图了解更多关于视网膜突触的知识 机械装置。特别是，我们正在寻求发现什么是物质 在特定的突触连接使用，以及这些物质有什么作用 在视网膜细胞上。现在人们普遍认为，有两种基本类型的 物质在大脑突触释放；神经递质 在神经细胞中启动快速兴奋和抑制反应，以及 神经调节剂，在神经细胞中调节缓慢而持久的事件。 该项目的下一个五年将侧重于以下行动： 谷氨酸，一种经典的神经递质，与多巴胺之间的相互作用， 一种经典的神经调节剂，作用于双极细胞、无长突细胞和神经节细胞 鱼(白色鲈鱼视网膜)。我们还将学习药理学和 新发现的GABA受体/通道GABA-c的分子生物学 感受器，来自白鲈鱼或杂交黑鱼视网膜。最后，录音 将由斑马鱼的锥形感光器制成，这种感光器最大限度地吸收 在光谱的紫外线区域。 未来五年计划的具体项目包括： 1)视网膜双极、无长突和视网膜氨基酸门控通道的研究 神经节细胞及其对多巴胺和其他神经活性物质的调节 物质。这个项目最初的重点是谷氨酸介导的 双极细胞的反应。视网膜切片中的双极细胞是电压- 用贴片电极钳制，并表征谷氨酸反应。 2)药理及分子生物学性质的研究 视网膜水平细胞和非洲爪哇卵母细胞中的GABA-c受体。这 项目将研究最能激活这些的GABA的构象 新的感受器。该项目的这一部分将在结构上采用- 限制性GABA类似物和分离的杆状(H4)水平细胞 白色鲈鱼或杂交低音视网膜。其他研究将涉及到表达 非洲爪哇卵母细胞中编码组成这些亚单位的基因(S) 新的感受器。 3)对紫外光的响应特性进行了研究 光感受器。本项目将探索紫外线的响应特性。 从斑马鱼身上分离出来的敏感球果。吸力电极将 记录这些光感受器产生的电流。

This project is attempting to learn more about retinal synaptic mechanisms. In particular, we are seeking to discover what substances are used at specific synaptic junctions and what effects these substances have on retinal cells. It is now generally believed that two basic types of substances are released at brain synapses; neurotransmitters which initiate fast excitatory and inhibitory responses in neural cells, and neuromodulators which mediate slow, long lasting events in nerve cells. The next five years of this project will focus on the action of, and interaction between, glutamate, a classic neurotransmitter,and dopamine, a classic neuromodulator, on bipolar, amacrine and ganglion cells of the fish (white perch retina). We also will study the pharmacology and molecular biology of a newly identified GABA receptor/channel, the GABA-c receptor, from white perch or hybrid bass retinas. Finally, recordings will be made from cone photoreceptors of zebrafish that absorb maximally in the ultraviolet region of the spectrum. Specific projects planned for the next five years include: 1) A study of amino acid-gated channels in retinal bipolar, amacrine and ganglion cells and their modulation by dopamine and other neuroactive substances. This project is focusing initially on the glutamate-mediated responses of bipolar cells. Bipolar cells in retinal slices are voltage- clamped with patch electrodes and the glutamate responses characterized. 2) A study of the pharmacological and molecular biological properties of GABA-c receptors in retinal horizontal cells and in Xenopus oocytes. This project will examine the conformation of GABA that best activates these novel receptors. This part of the project will employ conformationally- restricted GABA analogues and isolated rod (H4) horizontal cells from the white perch or hybrid bass retinas. Other studies will involve expressing in Xenopus oocytes the gene(s) encoding the subunits that make up these novel receptors. 3) An investigation of the response properties of ultraviolet-sensitive photoreceptors. This project will explore the response properties of UV- sensitive cones isolated from the zebrafish. Suction electrodes will record the currents generated by these photoreceptors.