ANATOMY AND PHYSIOLOGY OF NOVEL GANGLION CELL TYPES IN MACAQUE RETINA

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 该项目的目标是使用我们称为“逆行光动力学”的新逆行追踪方法来确定神经节细胞类型的形态学和生理学以及中枢连接。我们已经使用罗丹明-葡聚糖逆行标记猕猴神经节细胞的示踪剂注射在主要的视网膜目标：上级丘，pretectum，和LGN。正如逆行转运后预期的那样，示踪剂被隔离在神经节细胞体和近端树突内的细胞器样结构中。这种颗粒标记单独不允许明确靶向特定的细胞类型在体外。然而，当标记的细胞在显微镜下观察落射光照明，发光的细胞器似乎爆裂在细胞质中形成一个烟花状的展示释放的荧光团迅速扩散到整个树枝状树。同时，细胞质内荧光强度的大幅增加产生明亮且完整的细胞内染料染色。光染色的细胞保持解剖学和生理学上的活力，我们在体外的目标形态不同类型的细胞内记录和分析的感受野特性。此外，通过采用生物素化形式的罗丹明葡聚糖，可以在组织固定后使用辣根过氧化物酶（HRP）组织化学来永久恢复大量细胞的详细形态以用于解剖分析。这种方法使我们能够快速表征几个新的神经节细胞群，项目在主要的视觉通路的LGN。其中一些细胞群显示出新颖的颜色对手属性，并将成为新研究项目的持续重点。 其中一组，巨大的单层细胞，具有独特的感光性，并形成了实验室中另一个项目的基础。我们也有兴趣在进一步的免疫组织化学研究的黑视素反应细胞在视网膜以及他们的中央终端，并已招募了合作者在丹麦为此。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this project is to determine the morphology and physiology and central connections of ganglion cell types using a new retrograde tracing method that we have called 'retrograde photodynamics'. We have used rhodamine-dextrans to retrogradely label macaque monkey ganglion cells from tracer injections in the major retinal targets: the superior colliculus, pretectum, and LGN. As expected after retrograde transport, the tracer is sequestered in organelle-like structures within ganglion cell bodies and proximal dendrites. This particulate labeling alone does not allow unambiguous targeting of specific cell types in vitro. However when labeled cells were observed microscopically under epifluorescent illumination, the glowing organelles seem to burstcreating a fireworks-like display in the cytoplasmand the liberated fluorophore rapidly diffuses throughout the dendritic tree. At the same time, a large increase in fluorescence intensity within the cytoplasm gives rise to a bright and complete intracellular dye stain. Photostained cells remain anatomically and physiologically viable; we target morphologically distinct types in vitro for intracellular recording and analysis of receptive field properties. Further, by employing the biotinylated form of rhodamine dextran, it is possible to use horseradish peroxidase (HRP) histochemistry after tissue fixation to permanently recover the detailed morphology of large numbers of cells for anatomical analysis. This method enables us to rapidly characterize several new ganglion cell populations that project in the primary visual pathway to the LGN. Some of these cell groups show novel color-opponent properties and will be a continuing focus of new research projects. One of these groups, the giant monostratified cells, are uniquely photosensitive and form the basis for another project in the lab. We are also interested in further immunohistochemical studies of melanopsin-reactive cells in the retina as well as their central terminals, and have enlisted a collaborator in Denmark to this end.