Brandstätter J H, Wässle H, Betz H, Morgans C W
Abteilung für Neuroanatomie, Max-Planck-Institut für Hirnforschung, Frankfurt am Main, Germany.
Eur J Neurosci. 1996 Apr;8(4):823-8. doi: 10.1111/j.1460-9568.1996.tb01268.x.
The two neuronal plasma membrane proteins synaptosomal associated protein 25 kDa (SNAP-25) and syntaxin form, in current models of synaptic vesicle exocytosis, a docking complex on the presynaptic plasma membrane. This docking complex interacts with the integral synaptic vesicle protein, synaptobrevin. We have examined, in the rat retina, the distribution of SNAP-25 and syntaxin using light and electron microscopic immunocytochemistry. SNAP-25 immunoreactivity was present in the outer and inner nuclear layers at the membranes of photoreceptor and amacrine cell somata, in the outer plexiform layer in the terminals of photoreceptor cells and throughout the inner plexiform layer in the terminals of bipolar and amacrine cells. In contrast, syntaxin immunoreactivity was not found in the terminals of photoreceptor and bipolar cells, but only in the terminals of amacrine cells. Because of the absence of detectable syntaxin from the terminals of photoreceptor and bipolar cells, we propose that either a novel syntaxin isoform or a syntaxin-like protein exists at the ribbon synapses formed by these neurons.
在目前的突触小泡胞吐模型中，两种神经元质膜蛋白，即25 kDa的突触体相关蛋白（SNAP - 25）和 syntaxin，在突触前质膜上形成一个对接复合体。这个对接复合体与突触小泡整合蛋白突触结合蛋白相互作用。我们利用光镜和电镜免疫细胞化学技术研究了大鼠视网膜中SNAP - 25和syntaxin的分布。SNAP - 25免疫反应性存在于外核层和内核层中光感受器和无长突细胞胞体的膜上，存在于外网状层中光感受器细胞的终末，以及在内网状层中双极细胞和无长突细胞终末的整个区域。相比之下，在光感受器和双极细胞的终末未发现 syntaxin免疫反应性，仅在无长突细胞的终末发现。由于在光感受器和双极细胞的终末未检测到可检测的syntaxin，我们推测在这些神经元形成的带状突触处存在一种新的syntaxin异构体或一种类似syntaxin的蛋白。
