Pow D V, Crook D K, Wong R O
Department of Physiology and Pharmacology, University of Queensland, Brisbane, Australia.
Vis Neurosci. 1994 Nov-Dec;11(6):1115-34. doi: 10.1017/s0952523800006933.
We have studied, by immunocytochemistry, the ontogeny of GABA, glycine, glutamate, glutamine, and taurine-containing cells in the rabbit retina. Amacrine cells show GABA immunoreactivity by embryonic day 25 (E25) and throughout postnatal life. By contrast, ganglion cells and horizontal cells are only transiently GABA-immunoreactive (-IR); few appear GABA-IR by the third postnatal week. At maturity, glycine is present in amacrine cells and in some bipolar cells. During development, putative ganglion cells transiently contained glycine between E25 and postnatal day 3 (P3), whereas immunolabelling in presumed amacrine cells and bipolar cells persists after birth. Ganglion cells, bipolar cells, photoreceptors, and some amacrine cells are glutamate-IR in the adult retina. Glutamate immunoreactivity first appears in the somata and processes of cytoblastic cells by E20 and is prominent by E25. Surprisingly, ganglion cells are not strongly glutamate-IR until just before eye-opening, at postnatal day 10 (P10), coincident with the appearance of glutamine in their somata and in Müller glial cells. Bipolar cells are glutamate-IR before they or Müller cells contain high levels of glutamine (at P10). Glutamate immunoreactivity in photoreceptors is progressively restricted to the inner segments by eye-opening. At no stage are presumed horizontal cells glutamate-IR or glutamine-IR, but some amacrine cells show glutamate- and glutamine-IR by P10. Taurine is localized to photoreceptors and Müller glial in the adult retina. Some cytoblasts are taurine-IR at E20; with ensuing development, taurine labelling becomes restricted primarily to Müller cells and photoreceptors; some putative bipolar cells may also be labelled. However, for a few days around birth, cells resembling horizontal cells, also show taurine immunoreactivity. The early appearance and often transient expression of these amino acids in retinal cells suggests that these neuroactive molecules may be involved in the structural and functional development of the retina.
我们通过免疫细胞化学方法研究了家兔视网膜中含γ-氨基丁酸（GABA）、甘氨酸、谷氨酸、谷氨酰胺和牛磺酸的细胞的个体发生。无长突细胞在胚胎第25天（E25）时就显示出GABA免疫反应性，并且在出生后的整个生命过程中均有表达。相比之下，神经节细胞和水平细胞只是短暂地呈现GABA免疫反应性（-IR）；在出生后第三周时，只有少数细胞呈现GABA-IR。成熟时，甘氨酸存在于无长突细胞和一些双极细胞中。在发育过程中，假定的神经节细胞在E25至出生后第3天（P3）之间短暂含有甘氨酸，而在假定的无长突细胞和双极细胞中的免疫标记在出生后持续存在。在成年视网膜中，神经节细胞、双极细胞、光感受器和一些无长突细胞呈谷氨酸-IR。谷氨酸免疫反应性首先在E20时出现在成神经细胞的胞体和突起中，并在E25时变得明显。令人惊讶的是，神经节细胞直到出生后第10天（P10）睁眼前不久才强烈呈现谷氨酸-IR，此时它们的胞体和米勒胶质细胞中出现谷氨酰胺。双极细胞在它们或米勒细胞含有高水平谷氨酰胺之前（P10）就呈谷氨酸-IR。光感受器中的谷氨酸免疫反应性在睁眼时逐渐局限于内段。在任何阶段，假定的水平细胞都不呈谷氨酸-IR或谷氨酰胺-IR，但一些无长突细胞在P10时呈现谷氨酸和谷氨酰胺-IR。在成年视网膜中，牛磺酸定位于光感受器和米勒胶质细胞。一些成神经细胞在E20时呈牛磺酸-IR；随着发育的进行，牛磺酸标记主要局限于米勒细胞和光感受器；一些假定的双极细胞也可能被标记。然而，在出生前后的几天里，类似水平细胞的细胞也显示出牛磺酸免疫反应性。这些氨基酸在视网膜细胞中的早期出现和通常短暂的表达表明，这些神经活性分子可能参与了视网膜的结构和功能发育。
