RETINAL PHARMACOLOGY OF DIRECTIONAL GANGLION CELLS

方向敏感(DS)视网膜神经节细胞存在于大多数 所有，脊椎动物的视网膜。然而，关于这一事件的直接信息知之甚少。 产生方向性敏感的视网膜机制。这个项目 建议研究DS细胞及其无长突细胞的输入 细胞内和细胞外记录技术与药理学 操纵。 使用甲鱼和兔的超融合视网膜眼罩，观察 突触递质/调节器及其拮抗剂可以在 DS单元的特定响应属性。这些结果，再加上 相同药剂在低钙/高镁灌流液中的阻断作用 突触传递，将决定某些突触相互作用 发生在DS神经节细胞膜上。基于细胞外的信息 录音和突触药理学间接表明几个 无长突细胞传入神经节细胞膜的特化区域 对方向敏感负有责任。为了确认 这些DS细胞的底层布线图案，它们将被 注射细胞内的染料。随后的组织化学染色 各种无长突细胞神经递质的标志物将可视化 这些细胞之间的相互作用。 哺乳动物视网膜中DS细胞的神经回路的知识可能 进一步探讨DS后人类视动性眼震的诊断价值 细胞为辅助光学系统提供主要输入，该辅助光学系统 对这种眼球运动负责。

Directionally sensitive (DS) retinal ganglion cells exist in most, if not all, vertebrate retinas. Yet little direct information is known about the retinal mechanism which generate directional sensitivity. This project proposes to study the DS cell and its amacrine cell inputs by use of intracellular and extracellular recording techniques and pharmacological manipulations. Using a superfused retinal eyecup of turtle and rabbit, the effects of synaptic transmitters/modulators and their antagonists can be tested on specific response properties of the DS cell. These results, coupled with the effects of the same agents in low Ca++/high Mg++ perfusate which blocks synaptic transmission, will determine whether certain synaptic interactions occur on the DS ganglion cell membrane. Information based on extracellular recordings and synaptic pharmacology indirectly suggests that several amacrine cell inputs to specialized regions of the ganglion cell membrane are responsible for directional sensitivity. In order to confirm the underlying wiring pattern of these DS cells, they will be stained by injection of intracellular dyes. Subsequent staining with histochemical markers for various amacrine cell naurotransmitters will visualize the interactions between these cells. Knowledge of the neural circuitry for DS cells in the mammalian retina may further the diagnostic usefulness of human optokinetic nystagmus since DS cells provide a major input to the accessory optic system which is responsible for such eye movements.