Localization of the presynaptic cytomatrix protein piccolo at ribbon and conventional synapses in the rat retina:: Comparison with bassoon
Localization of the presynaptic cytomatrix protein piccolo at ribbon and conventional synapses in the rat retina:: Comparison with bassoon
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DOI：
10.1002/cne.1344
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发表时间：
2001-10-15
影响因子：
2.5
通讯作者：
Brandstätter, JH
中科院分区：
文献类型：
--
作者：
Dick, O;Hack, I;Brandstätter, JH
近年来，对突触后密度的分子组装的研究取得了重大进展，而对突触前活动区的组成却知之甚少。短笛和巴松是两种结构相关的突触前细胞基质蛋白，它们高度集中于大鼠脑兴奋性和抑制性突触的活性区。本研究采用免疫细胞化学方法观察了短笛在大鼠视网膜突触的细胞和超微结构定位，并与大管进行了比较。这两种蛋白在视网膜的外层和内部丛状层显示出强烈的点状免疫荧光。它们在谷氨酸能带突触和常规gaba能和甘氨酸能突触的突触前被发现。虽然这两种蛋白在所有光感受器带突触和一些常规无腺细胞突触中共表达，但在双极细胞带突触中只有Piccolo蛋白存在。我们的数据显示了视网膜突触的突触前装置的分子组成的相似之处，但也存在差异，这些差异可能解释了视网膜中色带和传统无突细胞突触以及感光细胞和双极细胞色带突触之间观察到的功能差异。(C) 2001 Wiley-Liss, Inc。
In recent years significant progress has been made in the elucidation of the molecular assembly of the postsynaptic density at synapses, whereas little is known as yet about the components of the presynaptic active zone. Piccolo and Bassoon, two structurally related presynaptic cytomatrix proteins, are highly concentrated at the active zones of both excitatory and inhibitory synapses in rat brain. In this study we used immunocytochemistry to examine the cellular and ultrastructural localization of Piccolo at synapses in the rat retina and compared it with that of Bassoon. Both proteins showed strong punctate immunofluorescence in the outer and the inner plexiform layers of the retina. They were found presynaptically at glutamatergic ribbon synapses and at conventional GABAergic and glycinergic synapses. Although the two proteins were coexpressed at all photoreceptor ribbon synapses and at some conventional amacrine cell synapses, at bipolar cell ribbon synapses only Piccolo was present. Our data demonstrate similarities but also differences in the molecular composition of the presynaptic apparatuses of the synapses in the retina, differences that may account for the functional differences observed between the ribbon and the conventional amacrine cell synapses and between the photoreceptor and the bipolar cell ribbon synapses in the retina. (C) 2001 Wiley-Liss, Inc.