MORPHOLOGICAL DIVERSITY OF DISPLACED RETINAL GANGLION-CELLS IN THE RAT - A LUCIFER YELLOW STUDY
MORPHOLOGICAL DIVERSITY OF DISPLACED RETINAL GANGLION-CELLS IN THE RAT - A LUCIFER YELLOW STUDY
复制标题
DOI：
10.1002/cne.902690206
复制
发表时间：
1988-03-08
影响因子：
2.5
通讯作者：
DANN, JF
中科院分区：
文献类型：
--
作者：
BUHL, EH;DANN, JF
采用荧光染料快蓝（Fast Blue）在色素沉着大鼠上丘内注射，逆行标记视网膜神经节移位细胞（DRGCs）。固定后，细胞内注射路西法黄以测定其树突形态和分布。路西法黄填充的预标记神经元的图像重建显示drgc的异质性种群。它们在内丛状层内分层多样，并根据树突形态对细胞进行分类。目前的样本主要由未分层的神经元组成，其树突分布在内层丛状层的狭窄膜下。它们的特征是位于中心的躯体和密集分支的树突网络，分支模式内很少重叠。相比之下，双分层DRGCs具有松散且分枝稀疏的树突结构，而弥漫性分层神经元包含高度的树突交叉，最终形成一个复杂的网络，其中体细胞位置偏向外围。一种类型的DRGC与1型神经元有着惊人的相似之处(Perry, 1979; Proc. R. Soc。Lond。(医学杂志。[j] [4]；它们的特点是面积大（15.5亩）。m。+ -。2.2 .mu。M s.d)，树突场直径平均为288 .mu。M (d) + (d)。62 .mu。M)，平均大于其他移位细胞群，但小于神经节细胞层的1型细胞。由于移位和未移位的1型神经元的分层模式难以区分，因此有理由认为本研究中充满路西法黄的细胞代表了正常1型神经节细胞的移位对应物。因此，尽管胞体位于细胞核内层的异常位置，细胞的树突形态畅通无阻地发展成正常的分层模式，尽管胞体和树突场的大小都减小了。如果移位是一种发育异常，那么这种大小的减小可能是由于体细胞在向神经节细胞层迁移过程中错误地停留在细胞核内层的过度拥挤造成的。这也可以解释在本研究中发现的移位细胞的异质性，因为发育错误的随机性将确保各种神经节细胞类型包括在移位人群中。
Displaced retinal ganglion cells (DRGCs) wre retrogradely labelled by injections of the fluorescent dye Fast Blue into the superior colliculi of pigmented rats. Following fixation these cells were intracellularly injected with Lucifer Yellow to determine their dendritic morphology and distribution. Graphic reconstruction of Lucifer Yellow-filled prelabelled neurones revealed a heterogeneous population of DRGCs. Their stratification within the inner plexiform layer was diverse and cells were classified according to their dendritic morphology. The present sample consists largely of unistratifying neurones, the dendrites of which arborized within a narrow sublamina of the inner plexiform layer. They were characterized by a centrally located soma and densely branched dendritic network with little overlap within the branching pattern. In contrast, bistratifying DRGCs possessed a loose and sparsely branched dendritic structure, while diffusely stratifying neurones contained a high degree of dendritic crossing, culminating in a complex network, in which the soma position was biased toward the periphery. One type of DRGC bore a striking resemblance to type 1 neurones (Perry, 1979; Proc. R. Soc. Lond. [Biol.] 204: 363-375) in the ganglion cell layer. They were characterized by a large soma (15.5 .mu.m .+-. 2.2 .mu.m s.d.) and a dendritic field diameter averaging 288 .mu.m (s.d. .+-. 62 .mu.m) and were on average larger than the rest of the displaced population but smaller than type 1 cells in the ganglion cell layer. Since the stratification patterns of the displaced and nondisplaced type 1 neurones were indistinguishable, it is reasonable to assume that the Lucifer Yellow-filled cells in the present study represent the displaced counterpart of regular type 1 ganglion cells. Therefore, it appears that despite the aberrant location of the soma within the inner nuclear layer, the dendritic morphology of the cell develops unimpeded into a normal stratification pattern, although both soma and dendritic field size are reduced. If displacement is a developmental aberration, this size decrease may arise from overcrowding within the inner nuclear layer where the soma becomes lodged erroneously during its migration to the ganglion cell layer. This would also account for the heterogeneity of displaced cells found in the present study, since the randomness of a developmental error would ensure that a variety of ganglion cell types was included in the displaced population.