Straznicky C, Hiscock J
Department of Anatomy and Histology, Flinders University of South Australia School of Medicine, Adelaide.
Arch Histol Cytol. 1994 May;57(2):151-60. doi: 10.1679/aohc.57.151.
Wholemounts and sectioned retina from adults of two lizard species, Pogona vitticeps and Varanus gouldii, were studied by immunohistochemistry for neuropeptide Y (NPY)-like immunoreactivity. In both species the morphology of two classes of amacrine cells (types A and B) were described. Cell somata were located mostly in the inner nuclear layer (INL) but were occasionally displaced into the ganglion cell layer (GCL). In the Pogona retina, type A cells had large somata and dendritic arbor that branched in sublamina (S) 1 and 2/3 of the inner plexiform layer (IPL). Type B amacrine cells had smaller somata and dendritic arbor branching mostly in S5 of the IPL. In the Varanus retina, the levels of dendritic branching of types A and B amacrine cells in the IPL were similar to those in Pogona although branching in the middle of the IPL occurred at S3. NPY-immunoreactive cells with small somata and narrow to medium sized dendritic fields were predominant. Unclassified cells also displayed NPY-like immunoreactivity; however, their dendritic morphology could not be determined due to the faint and inconsistent staining. In transverse retinal sections three bands of NPY-like immunoreactivity were evident in the IPL of both species, to which the unclassified cells also contributed. In both species type A cells were most numerous. Total NPY-immunoreactive cells were estimated to be 8,600 in Pogona and 32,860 in Varanus. In both species types A and B cells were non-uniformly distributed across the retina. The most apparent non-uniformity in distribution was observed in type A cells in Varanus. Peak cell density was found across the horizontal meridian of the retina from where cell density decreased towards the dorsal and ventral retinal margins. The results of this study provide evidence for the presence of NPY-immunoreactive amacrine cells in the lizard retina of which two types were morphologically characterized. Cross-species comparisons were also made among NPY-immunoreactive amacrine cells, and their possible function/s discussed.
利用免疫组织化学方法，对鬃狮蜥（Pogona vitticeps）和砂巨蜥（Varanus gouldii）这两种成年蜥蜴的视网膜整体标本和切片进行了研究，以检测其神经肽Y（NPY）样免疫反应性。在这两个物种中，均描述了两类无长突细胞（A 型和 B 型）的形态。细胞体大多位于内核层（INL），但偶尔也会移位到神经节细胞层（GCL）。在鬃狮蜥视网膜中，A 型细胞具有较大的细胞体和树突分支，这些分支在内网状层（IPL）的 1 层和 2/3 层中分支。B 型无长突细胞的细胞体和树突分支较小，主要在 IPL 的 5 层中分支。在砂巨蜥视网膜中，IPL 中 A 型和 B 型无长突细胞的树突分支水平与鬃狮蜥相似，尽管 IPL 中部的分支发生在 3 层。具有小细胞体和窄至中等大小树突野的 NPY 免疫反应性细胞占主导地位。未分类的细胞也显示出 NPY 样免疫反应性；然而，由于染色微弱且不一致，无法确定它们的树突形态。在横向视网膜切片中，两种物种的 IPL 中均可见三条 NPY 样免疫反应带，未分类的细胞也对其有贡献。在这两个物种中，A 型细胞数量最多。估计鬃狮蜥中总的 NPY 免疫反应性细胞有 8600 个，砂巨蜥中有 32860 个。在这两个物种中，A 型和 B 型细胞在视网膜上的分布都不均匀。在砂巨蜥的 A 型细胞中观察到最明显的分布不均匀。在视网膜的水平子午线上发现了细胞密度峰值，从该位置细胞密度向视网膜的背侧和腹侧边缘降低。本研究结果为蜥蜴视网膜中存在 NPY 免疫反应性无长突细胞提供了证据，其中两种类型在形态上得到了表征。还对 NPY 免疫反应性无长突细胞进行了跨物种比较，并讨论了它们可能的功能。
