Cheon E W, Kaneko Y, Saito T
Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan.
J Comp Neurol. 1998 Jun 29;396(2):267-74.
The adult newt regenerates a functional retina following removal or destruction of the original retina. We studied the order of appearance of cell types in the regenerating retina by using immunohistochemical techniques. An antibody that recognizes the alpha subunit (260 kDa) of voltage-dependent Na+ channels was found to label a 255-kDa band in Western blots of crude membrane fractions from the normal retina. Cryosections of normal retina revealed intense Na+ channel immunoreactivity in somata and axons of ganglion cells, weaker immunoreactivity in somata of amacrine cells, and no immunoreactivity in the inner plexiform layer. In the same sections, immunoreactivity to a monoclonal antibody (RB-1) specific to newt cones was intense in the photoreceptor layer. In regenerating retinas, double staining with the Na+ channel antibody as a possible marker of ganglion cells and RB-1 antibody first revealed immunoreactive cells at the intermediate stage (three to five cells thick), which does not exhibit segregated synaptic layers. Na+ channel-immunoreactive ganglion cells appeared before the RB-1-immunoreactive photoreceptors. Because ganglion cells also appear before photoreceptor cells in normal development, common mechanisms may control both the generation and the regeneration of the newt retina.
成年蝾螈在其原始视网膜被移除或破坏后能再生出功能性视网膜。我们运用免疫组织化学技术研究了再生视网膜中细胞类型出现的顺序。一种识别电压依赖性钠离子通道α亚基（260 kDa）的抗体，在正常视网膜粗膜组分的蛋白质免疫印迹中标记出一条255-kDa的条带。正常视网膜的冰冻切片显示，神经节细胞的胞体和轴突中有强烈的钠离子通道免疫反应性，无长突细胞的胞体中有较弱的免疫反应性，在内网状层则无免疫反应性。在同一切片中，对蝾螈视锥细胞特异的单克隆抗体（RB-1）的免疫反应性在光感受器层很强。在再生视网膜中，用作为神经节细胞可能标志物的钠离子通道抗体和RB-1抗体进行双重染色，首先在中间阶段（三到五层细胞厚）发现了免疫反应性细胞，此阶段未表现出分离的突触层。钠离子通道免疫反应性神经节细胞出现在RB-1免疫反应性光感受器之前。由于在正常发育过程中神经节细胞也出现在光感受器细胞之前，共同的机制可能控制着蝾螈视网膜的生成和再生。
