Vesicular glutamate transporter expression in supraoptic neurones suggests a glutamatergic phenotype.
Vesicular glutamate transporter expression in supraoptic neurones suggests a glutamatergic phenotype.
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DOI：
10.1111/j.1365-2826.2006.01410.x
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发表时间：
2006-04
影响因子：
3.2
通讯作者：
Hatton GI
中科院分区：
文献类型：
--
作者：
Ponzio TA;Ni Y;Montana V;Parpura V;Hatton GI
视上核（SON）的大细胞神经内分泌细胞从其树突和末梢释放肽催产素（OT）和加压素（VP）。除了含有肽的大型致密核心囊泡外，这些细胞的轴突末端还含有透明的微囊泡，这些微囊泡已被证明含有谷氨酸。使用多标记共聚焦显微镜，我们研究了星形胶质细胞以及 SON 的 VP 和 OT 神经元中囊泡谷氨酸转运蛋白 (VGLUT) 的存在。使用针对 VGLUT 同种型 1-3、OT、VP 和神经胶质纤维酸性蛋白 (GFAP) 的抗体同时探测 SON，揭示了 SON 神经元的体细胞和树突中存在 VGLUT-2。在 OT 和 VP 神经元以及 GFAP-ir 星形胶质细胞和腹侧神经胶质层的其他细胞中也检测到了 VGLUT-3 的免疫反应性 (-ir)。还检查了个体 SON 神经元中 VGLUT-2 和 VGLUT-3 的共定位，并且可以在两种类型的 SON 神经元中检测到具有两种抗体的 VGLUT-ir。尽管 VGLUT-1-ir 在 SON 的侧面很强，但在细胞核内仅可见稀疏标记，并且未观察到与 SON 神经元或星形胶质细胞的共定位。使用逆转录酶-聚合酶链式反应探测SON或SON加上其周围的核周区，并检测到所有三种VGLUT亚型的mRNA的存在。这些结果表明，SON神经元树突及其神经垂体末梢中存在类似的递质排列，并且大细胞神经内分泌体和树突可能具有谷氨酸能传递能力。
Magnocellular neuroendocrine cells of the supraoptic nucleus (SON) release the peptides oxytocin (OT) and vasopressin (VP) from their dendrites and terminals. In addition to peptide-containing large dense-core vesicles, axon terminals from these cells contain clear microvesicles that have been shown to contain glutamate. Using multilabelling confocal microscopy, we investigated the presence of vesicular glutamate transporters (VGLUTs) in astrocytes as well as VP and OT neurones of the SON. Simultaneous probing of the SON with antibodies against VGLUT isoforms 1–3, OT, VP and glial fibrillary acidic protein (GFAP) revealed the presence of VGLUT-2 in somata and dendrites of SON neurones. Immunoreactivity (-ir) for VGLUT-3 was also detected in both OT and VP neurones as well as in GFAP-ir astrocytes and other cells of the ventral glial lamina. Colocalisation of VGLUT-2 and VGLUT-3 in individual SON neurones was also examined and VGLUT-ir with both antibodies could be detected in both types of SON neurones. Although VGLUT-1-ir was strong lateral to the SON, only sparse labelling was apparent within the nucleus, and no colocalisation with either SON neurones or astrocytes was observed. The SON or the SON plus its surrounding perinuclear zone was probed using the reverse transcriptase-polymerase chain reaction and the presence of mRNA for all three VGLUT isoforms was detected. These results suggest that similar arrangements of transmitters exist in SON neuronal dendrites and their neurohypophysial terminals and that magnocellular neuroendocrine somata and dendrites may be capable of glutamatergic transmission.