神经紧张素样免疫反应无长突细胞在鸡视网膜的定位——光镜与免疫电镜研究

LOCALIZATION OF NEUROTENSIN-LIKE IMMUNOREACTIVE AMACRINE CELLS IN THE CHICK RETINA:A LIGHT AND ELECTRON MICROSCOPIC STUDY

本实验用光镜和电镜免疫组织化学方法研究神经紧张素(neurotensin,NT)样免疫反应无长突细胞在鸡视网膜的定位。实验结果表明,NT 样免疫反应无长突细胞呈卵圆形,位于内核层内缘的第2或第3排细胞内,直径约7μm,胞体发出突起伸入内网层,在内网层的第1亚层形成细疏的丛网,突起在内网层的第3、4亚层形成致密的丛网。电镜下,NT 阳性无长突细胞的胞质内含分布均匀、电子密度高的过氧化物酶反应产物,核圆形,核膜无凹陷。NT 阳性无长突细胞的突起接受其他未标记无长突细胞和双极细胞的突起突触传入,NT 阳性无长突细胞的突起分别与来源于末标记的无长突细胞和双极细胞的突起形成突触传出。上述两种突触联系均可见于内网层的第1、3和4亚层。此外,NT 阳性突起又可形成突触传出与可能起源于节细胞,不含突触小泡的突起和位于内核层最内层的细胞体形成突触。文中还对突触成分的辨认和 NT 阳性无长突细胞的神经回路等问题进行了讨论。

Immunohistochemistry was utilized to investigate the light and electron micros- copic localization of neurotensin-like (NT) immunoreactive amacrine cells in the chicken retina.The results showed that the NT-immunoreactive cell bodies were oval and situated in either the second or third row of cells from the inner border of the inner nuclear layer.The processes of such cells extended into the inner plexiform layer where they ramified as a fine plexus in sublamina 1 and as a dense plexus in sublamina 3 and 4. At the ultrastructural level,NT positive soma exhibited a rather dense and evenly distributed immune reaction product throughout their cytoplasm.The nucleus of NT-amacrine cells possessed a round,unindented nuclear membrane.NT positive processes of such cells receive synaptic input from processes of unlabeled amacrine and bipolar cells.They formed synaptic output onto processes of nonimmuno- reactive amacrine cells and bipolar cells.Moreover,each of the above synaptic relationships were identified in each of sublamina 1 and 3 to 4 of the inner plexi form layer.In addition,NT positive processes fromed synaptic output to processes devoid of synaptic vesicles,which may originated from ganglion cells.They also formed synaptic output to somas situated in the innermost cell row of the inner nuclear layer. Identification of synaptic elements and retinal circuitry were also discussed.