Araki M, Hanihara T, Saito T
Department of Anatomy, Jichi Medical School, Tochigi, Japan.
J Neurocytol. 1988 Apr;17(2):179-88. doi: 10.1007/BF01674205.
Our previous immunohistochemical studies using specific anti-opsin antibodies have shown that in the normal postnatal rat retina, opsin-like immunoreactive materials can be seen not only in photoreceptor cells but also in some cells of the inner nuclear layer (INL). To characterize these ectopic opsin-like immunoreactive cells further, we have now studied developing rat retinae at the light and electron microscopic levels using both opsin immunocytochemistry and 5'-nucleotidase (5'-N) cytochemistry. Since photoreceptor cells are specifically stained in both methods, we investigated whether these methods would also stain some of the cells in the INL. Opsin-like immunoreactive cells in the INL always showed a characteristic nuclear structure, which was clearly distinguished from that of other INL cells and resembled rod cell nucleus because of the presence of conspicuous masses of condensed heterochromatin. Moreover, these opsin-like immunoreactive cells in the INL occasionally also displayed a ciliary process. They could only be seen in the INL until about day 25 of postnatal life. In the INL, 5'-N activity was found exclusively in cells showing rod-like nuclear features, and the timing of appearance and disappearance of 5'-N-positive cells in the INL was similar to that of the opsin-like immunoreactive cells. Numerous degenerating cells were observed in the INL at around day 10, some of which showed 5'-N reaction product at the cell surface. These results indicate that during postnatal development of the rat retina, some cells in the INL express several phenotypic properties characteristic of rod cells. It is suggested that these cells might undergo either cell degeneration or phenotypic conversion during the subsequent maturation of the retina.
我们之前使用特异性抗视蛋白抗体进行的免疫组织化学研究表明，在正常出生后的大鼠视网膜中，视蛋白样免疫反应性物质不仅可见于光感受器细胞，也可见于内核层（INL）的一些细胞中。为了进一步表征这些异位视蛋白样免疫反应性细胞，我们现在利用视蛋白免疫细胞化学和5'-核苷酸酶（5'-N）细胞化学技术，在光镜和电镜水平上研究了发育中的大鼠视网膜。由于在这两种方法中光感受器细胞均被特异性染色，我们研究了这些方法是否也会使INL中的一些细胞染色。INL中的视蛋白样免疫反应性细胞总是呈现出一种特征性的核结构，与其他INL细胞的核结构明显不同，并且由于存在明显的凝聚异染色质块，类似于杆状细胞核。此外，INL中的这些视蛋白样免疫反应性细胞偶尔也会显示出睫状突。它们在出生后约25天之前只能在INL中看到。在INL中，5'-N活性仅在呈现杆状核特征的细胞中被发现，并且INL中5'-N阳性细胞出现和消失的时间与视蛋白样免疫反应性细胞相似。在出生后第10天左右，在INL中观察到大量变性细胞，其中一些在细胞表面显示出5'-N反应产物。这些结果表明，在大鼠视网膜出生后的发育过程中，INL中的一些细胞表达了杆状细胞的几种表型特征。有人认为，在视网膜随后的成熟过程中，这些细胞可能会发生细胞变性或表型转化。
