Mednick A S, Springer A D
Department of Anatomy, New York Medical College, Valhalla 10595.
J Comp Neurol. 1988 Feb 1;268(1):49-59. doi: 10.1002/cne.902680106.
The distribution of retinal ganglion cells (RGCs) in goldfish was determined by removing an eye and applying cobaltous-lysine to the optic nerve for 24 hr. This procedure allowed the cobalt label to be in continuous contact with the cut ends of the optic axons and thereby backfilled many RGCs. RGC density was determined across three different sizes of retinae by using fish with different eye sizes. Confirming earlier work, we found that RGC density diminished as retinal area increased. However, irrespective of the retinal size, the density of RGCs was elevated along the temporal boundary between the dorsal and the ventral retina. A conservative estimate indicated that the RGC density in the temporal retina was at least 1.8-2.5 times higher than the mean RGC density of the entire retina. Thus, the goldfish retina does not appear to have a homogeneous distribution of RGCs as was previously considered. Small and large retinae differed with respect to the percentage of cells in the RGC layer that was RGCs. In small retinae, even when the noncobalt-filled cells (glia and displaced amacrine cells) were added to the cobalt-filled RGCs, the density of all cell types was elevated in the temporal retina relative to the remainder of the retina. Furthermore, in small retinae, the percentage of cells in the RGC layer that was RGCs (75%) was constant across the radial and circumferential aspects of the retina. In marked contrast, in medium-large retinae, a homogeneous distribution of cells across the entire retina resulted when the noncobalt-filled cells were added to the cobalt-filled cells. However, the percentage of cells that was cobalt-filled RGCs was significantly greater in the temporal retina (50%) than in the remainder of the retina (35%). In large retinae, as in small retinae, the percentage of cells that was RGCs did not vary as a function of distance from the optic disc. These data suggest that, in the course of retinal maturation, cell density in the temporal retina is elevated initially and then declines subsequently to the level of the surrounding retina. Over time, more displaced to the level of the surrounding retina. Over time, more displaced amacrine cells may be added to the tissue surrounding the temporal retina. Alternatively, more RGCs outside the temporal retina may become displaced amacrine cells. Such events could account for the growth-associated, disproportionate decrease in the percentage of cells that is RGCs in the tissue surrounding the temporal retina.(ABSTRACT TRUNCATED AT 400 WORDS)
通过摘除一只眼睛并将赖氨酸钴应用于视神经24小时，确定了金鱼视网膜神经节细胞（RGCs）的分布。这一过程使钴标记物与视神经轴突的切断端持续接触，从而使许多RGCs被逆向标记。通过使用具有不同眼睛大小的金鱼，在三种不同大小的视网膜上测定了RGC密度。正如早期研究结果所证实的，我们发现随着视网膜面积的增加，RGC密度降低。然而，无论视网膜大小如何，RGCs的密度在背侧和腹侧视网膜之间的颞侧边界处都会升高。保守估计表明，颞侧视网膜中的RGC密度至少比整个视网膜的平均RGC密度高1.8 - 2.5倍。因此，金鱼视网膜似乎并不像之前所认为的那样具有均匀的RGC分布。大小不同的视网膜在RGC层中RGCs所占细胞百分比方面存在差异。在小视网膜中，即使将未被钴填充的细胞（神经胶质细胞和移位无长突细胞）添加到被钴填充的RGCs中，相对于视网膜的其余部分，颞侧视网膜中所有细胞类型的密度仍然升高。此外，在小视网膜中，RGC层中RGCs所占细胞的百分比（75%）在视网膜的径向和圆周方向上是恒定的。与之形成显著对比的是，在中等大小和大的视网膜中，当将未被钴填充的细胞添加到被钴填充的细胞中时，整个视网膜会出现细胞均匀分布的情况。然而，被钴填充的RGCs在颞侧视网膜中所占细胞的百分比（50%）明显高于视网膜的其余部分（35%）。在大视网膜中，与小视网膜一样，RGCs所占细胞的百分比不会随着与视盘距离的变化而变化。这些数据表明，在视网膜成熟过程中，颞侧视网膜中的细胞密度最初升高，随后下降至周围视网膜的水平。随着时间的推移，更多的细胞会移位至周围视网膜的水平。随着时间的推移，可能会有更多的移位无长突细胞添加到颞侧视网膜周围的组织中。或者，颞侧视网膜外的更多RGCs可能会变成移位无长突细胞。这些事件可以解释与生长相关的、颞侧视网膜周围组织中RGCs所占细胞百分比不成比例的下降情况。（摘要截选至400字）
