Straznicky C, Tóth P, Nguyen V S
Department of Anatomy and Histology, School of Medicine, Flinders University of South Australia, Adelaide.
Exp Brain Res. 1990;79(2):345-56. doi: 10.1007/BF00608244.
The retrograde transport of horseradish peroxidase (HRP) and cobaltic-lysine complex (CLC) was used to morphologically characterize large ganglion cells (GCs) and to determine their distribution in retinal wholemounts and in sectioned material in the retina of Bufo marinus. Large GCs, amounting to about 0.5% of total GC population, were defined to be those with very large dendritic field sizes varying between 0.1 mm2 to 0.6 mm2 and cell soma sizes of between 100 microns 2 to 400 microns 2. These cells were subdivided into 3 major groups, Types I, II and III, on the basis of their dendritic field sizes, aborization patterns and the strata of dendritic branching within the inner plexiform layer (IPL). The majority of large neurons (about 90%) were classified as Type I GCs with symmetrical dendritic arbor. These cells had either bistratified branching in the scleral and vitreal sublamina of the IPL (65% of Type I Cells) or unistratified branching in the scleral (26%) or in the vitreal (9%) sublamina. Their dendritic field sizes increased linearly from the retinal centre from 0.13 mm +/- 0.02 mm2 (mean and S.D.) to 0.58 +/- 0.11 mm2 in the retinal periphery. Type II GCs (about 9% of large GC population) were characterized by an asymmetrical dendritic aborization directed towards the ciliary margin with unistratified branching in the scleral sublamina of the IPL. The mean dendritic field sizes of these cells were 0.26 +/- 0.09 mm2. Type III GCs, the least frequent (about 1%) category of large GCs had sparsely branching, elongated dendritic branching aligned approximately parallel with the nasotemporal axis of the retina. The unistratified dendritic branches of these neurons were located in the vitreal sublamina of the IPL with a mean dendritic field size of 0.42 +/- 0.11 mm2. The dendritic field sizes of Types II and III GCs did not increase with retinal eccentricity. Type I GCs were distributed unevenly across the retina, the density being greatest in the visual streak, along the nasotemporal meridian of the retina. The dendritic field sizes of these cells increased towards the retinal periphery, resulting in a constant dendritic field coverage factor across the retina. Each retinal point was covered by the dendritic fields of 4-5 adjacent GCs. In contrast, Types II and III GCs had only discontinuous dendritic coverage. The identification of morphological types of large GCs with previously described functional classes of GCs in the anuran retina is discussed.
利用辣根过氧化物酶（HRP）和钴赖氨酸复合物（CLC）的逆行运输，对海蟾蜍视网膜中的大型神经节细胞（GCs）进行形态学特征分析，并确定它们在视网膜整装标本和切片材料中的分布。大型GCs约占GCs总数的0.5%，定义为树突野大小非常大，在0.1平方毫米至0.6平方毫米之间，细胞体大小在100平方微米至400平方微米之间的细胞。根据这些细胞的树突野大小、分支模式以及在内网状层（IPL）内树突分支的层次，将它们细分为3个主要组，即I型、II型和III型。大多数大型神经元（约90%）被归类为具有对称树突分支的I型GCs。这些细胞在IPL的巩膜和玻璃体亚层中具有双分层分支（占I型细胞的65%），或者在巩膜（26%）或玻璃体（9%）亚层中具有单分层分支。它们的树突野大小从视网膜中心的0.13平方毫米±0.02平方毫米（平均值和标准差）线性增加到视网膜周边的0.58±0.11平方毫米。II型GCs（约占大型GCs群体的9%）的特征是树突分支不对称，朝向睫状缘，在IPL的巩膜亚层中具有单分层分支。这些细胞的平均树突野大小为0.26±0.09平方毫米。III型GCs是大型GCs中最不常见的类别（约1%），具有稀疏分支、细长的树突分支，大致与视网膜的鼻颞轴平行排列。这些神经元的单分层树突分支位于IPL的玻璃体亚层中，平均树突野大小为0.42±0.11平方毫米。II型和III型GCs的树突野大小不随视网膜离心率增加。I型GCs在整个视网膜上分布不均匀，密度在视觉条纹处最大，沿着视网膜的鼻颞子午线。这些细胞的树突野大小向视网膜周边增加，导致整个视网膜上的树突野覆盖因子恒定。视网膜的每个点被4-5个相邻GCs的树突野覆盖。相比之下，II型和III型GCs只有不连续的树突覆盖。讨论了将大型GCs的形态类型与无尾目视网膜中先前描述的GCs功能类别进行鉴定的问题。
