Kalloniatis M, Fletcher E L
Department of Optometry, University of Melbourne, Parkville, Victoria, Australia.
J Comp Neurol. 1993 Oct 8;336(2):174-93. doi: 10.1002/cne.903360203.
Postembedding immunocytochemistry was used to determine the cellular localization of the amino acid neurotransmitters glutamate, aspartate, gamma-aminobutyric acid (GABA), and glycine in the avian retina. The through retinal pathway was glutamatergic, with all photoreceptors, bipolar cells, and ganglion cells being immunoreactive for glutamate. Bipolar cells displayed the highest level of glutamate immunoreactivity, with the cell bodies terminating just below the middle of the inner nuclear layer. All lateral elements, horizontal cells, amacrine cells, and interplexiform cells were immunoreactive for glycine or GABA. The GABAergic neurons consisted of two classes of horizontal cells and amacrine cells located in the lower part of the inner nuclear layer. GABA was also localized in displaced amacrine cells in the ganglion cell layer, and a population of ganglion cells that co-localize glutamate and GABA. Both the horizontal cells and GABAergic amacrine cells had high levels of glutamate immunoreactivity, which probably reflects a metabolic pool. At least two types of horizontal cells in the avian retina could be discriminated on the basis of the presence of aspartate immunoreactivity in the H2 horizontal cells. Glycine was contained in a subclass of amacrine cells, with their cell bodies located between the bipolar cells and GABAergic amacrine cells, two subclasses of bipolar cells, displaced amacrine cells in the ganglion cell layer, and ganglion cells that colocalize glutamate and glycine. Glycinergic amacrine cells had low levels of glutamate. We have also identified a new class of glycinergic interplexiform cell, with its stellate cell body located in the middle of the inner nuclear layer among the cell bodies of bipolar cells. Neurochemical signatures obtained by analyzing data from serial sections allowed the classification of subclasses of horizontal cells, bipolar cells, amacrine cells, and ganglion cells.
采用包埋后免疫细胞化学方法确定禽类视网膜中氨基酸神经递质谷氨酸、天冬氨酸、γ-氨基丁酸（GABA）和甘氨酸的细胞定位。整个视网膜通路是谷氨酸能的，所有光感受器、双极细胞和神经节细胞对谷氨酸均有免疫反应。双极细胞显示出最高水平的谷氨酸免疫反应性，其细胞体终止于内核层中部下方。所有侧向成分，即水平细胞、无长突细胞和网间细胞对甘氨酸或GABA均有免疫反应。GABA能神经元由两类水平细胞和位于内核层下部的无长突细胞组成。GABA也定位于神经节细胞层中的移位无长突细胞以及共定位谷氨酸和GABA的一群神经节细胞中。水平细胞和GABA能无长突细胞均有高水平的谷氨酸免疫反应性，这可能反映了一个代谢池。根据H2水平细胞中天冬氨酸免疫反应性的存在情况，可以区分禽类视网膜中至少两种类型的水平细胞。甘氨酸存在于无长突细胞的一个亚类中，其细胞体位于双极细胞和GABA能无长突细胞之间，双极细胞的两个亚类、神经节细胞层中的移位无长突细胞以及共定位谷氨酸和甘氨酸的神经节细胞中。甘氨酸能无长突细胞的谷氨酸水平较低。我们还鉴定出一类新的甘氨酸能网间细胞，其星状细胞体位于内核层中部双极细胞的细胞体之间。通过分析连续切片数据获得的神经化学特征允许对水平细胞、双极细胞、无长突细胞和神经节细胞的亚类进行分类。
