Hitchcock P F, Easter S S
J Neurosci. 1986 Apr;6(4):1037-50. doi: 10.1523/JNEUROSCI.06-04-01037.1986.
In this paper we describe the dendritic morphology of ganglion cells that have been retrogradely stained with HRP taken up by the cut optic nerve. This technique produces an extensive Golgi-like filling of the cells. From their appearance in the retinal whole-mount, they were classified as four types, according to the sizes of the soma and dendritic field, the thickness of the primary dendrites, and the density of the arbors. Each type was subdivided according to the level(s) of stratification of the dendrites within the inner and outer plexiform layer(s) to yield a total of 15 subtypes (four for three types, three for the other). The retina of the goldfish grows by a balloon-like expansion, and by the addition of new neurons, in annuli, at the margin. Therefore, a similar cell type may be examined at a variety of stages of development in the same retina, as well as in the retinae from fish of various ages. We have used a computer-assisted microscope to do so, quantitatively, for one large and easily identified subtype. In small fish (ca. 4 cm long), the number of dendritic branch points, the total dendritic length, and the dendritic field sizes of these cells are constant inside a central zone extending to 70-80% of the retinal radius. The magnitudes of all three numeric descriptors decrease closer to the margin. In large fish (ca. 14 cm long), the central zone extends to more than 90% of the retinal radius, and the same pattern holds. The area of the dendritic fields and the total dendritic lengths are both greater in the central zone of the large fish than in the small, but the number of branches is the same in both. This suggests that once a cell has achieved the "mature" number of dendritic branches, further growth is interstitial. A comparison of dendritic morphologies across the retina shows that the pattern of dendritic outgrowth in peripheral retina is initially directed parallel to the margin, and, later, toward the margin. This suggests that dendritic growth is impeded by the dendrites present in more central retina and proceeds preferentially where they are absent. Cells of the same age are at different distances from the optic disk in the small and large retinae. In some cases, they have quite different dendritic morphologies. This implies that dendritic development depends not only on the age and subtype of the cell, but on extrinsic factors as well.(ABSTRACT TRUNCATED AT 400 WORDS)
在本文中，我们描述了经切断的视神经摄取辣根过氧化物酶（HRP）逆行标记的神经节细胞的树突形态。该技术使细胞呈现出广泛的类似高尔基体的填充。从视网膜整装标本中的外观来看，根据细胞体和树突野的大小、初级树突的粗细以及树突分支的密度，它们被分为四种类型。每种类型又根据树突在内、外丛状层内的分层水平进一步细分，总共产生15个亚型（三种类型各有四种，另一种有三种）。金鱼的视网膜通过类似气球膨胀的方式生长，并在边缘以环状添加新的神经元。因此，在同一视网膜的不同发育阶段以及不同年龄鱼的视网膜中，都可以检查到类似的细胞类型。我们使用计算机辅助显微镜对一种大且易于识别的亚型进行了定量研究。在小鱼（约4厘米长）中，这些细胞的树突分支点数、总树突长度和树突野大小在延伸至视网膜半径70 - 80%的中央区域内是恒定的。这三个数值描述符的大小在更靠近边缘处减小。在大鱼（约14厘米长）中，中央区域延伸至超过视网膜半径的90%，且同样的模式成立。大鱼中央区域的树突野面积和总树突长度都比小鱼的大，但两者的分支数相同。这表明一旦细胞达到“成熟”的树突分支数，进一步的生长就是间隙性的。对整个视网膜树突形态的比较表明，周边视网膜中树突生长的模式最初是平行于边缘的，后来则朝向边缘。这表明树突生长受到更中央视网膜中已有树突的阻碍，并且优先在没有这些树突的地方进行。在小鱼和大鱼的视网膜中，相同年龄的细胞与视盘的距离不同。在某些情况下，它们具有截然不同的树突形态。这意味着树突发育不仅取决于细胞的年龄和亚型，还取决于外在因素。（摘要截选至400字）
