Vesicular glutamate transporters in the spinal cord, with special reference to sensory primary afferent synapses
Vesicular glutamate transporters in the spinal cord, with special reference to sensory primary afferent synapses
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DOI：
10.1002/cne.20012
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发表时间：
2004-05-03
影响因子：
2.5
通讯作者：
Schneider, SP
中科院分区：
文献类型：
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作者：
Alvarez, FJ;Villalba, RM;Schneider, SP
脊髓感觉突触是神经递质能的，但以前的研究发现突触囊泡结构的巨大多样性，并提出了额外的神经递质。几个囊泡谷氨酸转运蛋白（VGLUT）的鉴定同样揭示了一个意想不到的分子多样性之间的含谷氨酸的终端。因此，我们定量研究VGLUT 1和VGLUT 2含量的脊髓感觉传入神经中枢突触，通过共聚焦和电子显微镜免疫细胞化学。VGLUT 1定位（在LIII/LIV和左心室内侧最丰富）与皮肤和肌肉机械感受器的起源一致。因此，大多数VGLUT 1免疫反应性消失后，神经根切断术和共定位标记皮肤（SSEA 4）和肌肉（小清蛋白）机械感受器。与postembedding胶体金，强烈的VGLUT 1免疫反应被发现在88-95%（取决于所使用的抗体）的C-II背角肾小球终端和大腹角突触接受axoaxonic接触。VGLUT 1与CGRP部分共定位在一些大的致密核心囊泡（LDCV）中。然而，免疫染色的神经肽能传入VGLUT 1抗体之间是不一致的，而与光学显微镜弱。VGLUT 2免疫反应性在所有脊髓板层中广泛存在，LII和侧LV中的强度较高，补充了VGLUT 1分布。VGLUT 2免疫反应性没有改变后，神经根切断术，这表明一个优惠的内在起源。然而，弱VGLUT 2免疫反应性可检测到初级感觉伤害感受器表达凝集素（GSA-IB 4）结合，并在83-90%的C-I肾小球终末在LII。在含LDCV的传入纤维的小透明囊泡和LIII中50-60%的C-II终末中发现了额外的弱VGLUT 2免疫反应性。这些结果表明在不同的脊髓初级传入纤维中表达的VGLUT同种型组合的多样性。(C)2004 Wiley-Liss，Inc.
Spinal cord sensory synapses are glutamatergic, but previous studies have found a great diversity in synaptic vesicle structure and have suggested additional neurotransmitters. The identification of several vesicular glutamate transporters (VGLUTs) similarly revealed an unexpected molecular diversity among glutamate-containing terminals. Therefore, we quantitatively investigated VGLUT1 and VGLUT2 content in the central synapses of spinal sensory afferents by using confocal and electron microscopy immunocytochemistry. VGLUT1 localization (most abundant in LIII/LIV and medial LV) is consistent with an origin from cutaneous and muscle mechanoreceptors. Accordingly, most VGLUT1 immunoreactivity disappeared after rhizotomy and colocalized with markers of cutaneous (SSEA4) and muscle (parvalbumin) mechanoreceptors. With postembedding colloidal gold, intense VGLUT1 immunoreactivity was found in 88-95% (depending on the antibody used) of C-II dorsal horn glomerular terminals and in large ventral horn synapses receiving axoaxonic contacts. VGLUT1 partially colocalized with CGRP in some large dense-core vesicles (LDCVs). However, immunostaining in neuropeptidergic afferents was inconsistent between VGLUT1 antibodies and rather weak with light microscopy. VGLUT2 immunoreactivity was widespread in all spinal cord laminae, with higher intensities in LII and lateral LV, complementing VGLUT1 distribution. VGLUT2 immunoreactivity did not change after rhizotomy, suggesting a preferential intrinsic origin. However, weak VGLUT2 immunoreactivity was detectable in primary sensory nociceptors expressing lectin (GSA-IB4) binding and in 83-90% of C-I glomerular terminals in LII. Additional weak VGLUT2 immunoreactivity was found over the small clear vesicles of LDCV-containing afferents and in 50-60% of C-II terminals in LIII These results indicate a diversity of VGLUT isoform combinations expressed in different spinal primary afferents. (C) 2004 Wiley-Liss, Inc.