VGLUT1 and VGAT are sorted to the same population of synaptic vesicles in subsets of cortical axon terminals
VGLUT1 and VGAT are sorted to the same population of synaptic vesicles in subsets of cortical axon terminals
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DOI：
10.1111/j.1471-4159.2009.06251.x
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发表时间：
2009-09-01
影响因子：
4.7
通讯作者：
Conti, Fiorenzo
中科院分区：
文献类型：
--
作者：
Fattorini, Giorgia;Verderio, Claudia;Conti, Fiorenzo
谷氨酸和GABA介导大多数兴奋性和抑制性突触传递;它们分别被称为VGLUT 1 -3和VGAT的特异性囊泡转运蛋白摄取和积累在突触囊泡中。最近的研究表明，VGLUT 2和VGLUT 3与VGAT共表达。由于这些信息与我们对突触生理学和可塑性的理解相关，我们研究了VGLUT 1和VGAT是否在大鼠皮层神经元中共表达。在皮质文化和V层皮质终端，我们观察到一个人口的终端表达VGLUT 1和VGAT。包埋后免疫胶体金染色显示VGLUT 1 +/VGAT+终末形成对称性和非对称性突触。三重标记研究显示，GABA能突触表达VGLUT 1和谷氨酸能突触表达VGAT。免疫分离研究表明，抗VGAT免疫分离的囊泡含有VGLUT 1和抗VGLUT 1免疫分离的囊泡含有VGAT。最后，囊泡含有VGAT居民在amatergic终端进行积极的再循环。总之，我们表明，在新皮质VGLUT 1和VGAT共表达的轴突终端形成对称和不对称的突触的子集，VGLUT 1和VGAT被分类到相同的囊泡和囊泡在突触表达的囊泡异源转运蛋白参与外内吞循环。
Glutamate and GABA mediate most of the excitatory and inhibitory synaptic transmission; they are taken up and accumulated in synaptic vesicles by specific vesicular transporters named VGLUT1-3 and VGAT, respectively. Recent studies show that VGLUT2 and VGLUT3 are co-expressed with VGAT. Because of the relevance this information has for our understanding of synaptic physiology and plasticity, we investigated whether VGLUT1 and VGAT are co-expressed in rat cortical neurons. In cortical cultures and layer V cortical terminals we observed a population of terminals expressing VGLUT1 and VGAT. Post-embedding immunogold studies showed that VGLUT1+/VGAT+ terminals formed both symmetric and asymmetric synapses. Triple-labeling studies revealed GABAergic synapses expressing VGLUT1 and glutamatergic synapses expressing VGAT. Immunoisolation studies showed that anti-VGAT immunoisolated vesicles contained VGLUT1 and anti-VGLUT1 immunoisolated vesicles contained VGAT. Finally, vesicles containing VGAT resident in glutamatergic terminals undergo active recycling. In conclusion, we demonstrate that in neocortex VGLUT1 and VGAT are co-expressed in a subset of axon terminals forming both symmetric and asymmetric synapses, that VGLUT1 and VGAT are sorted to the same vesicles and that vesicles at synapses expressing the vesicular heterotransporter participate in the exo-endocytotic cycle.