Differential distribution of vesicular glutamate transporters in the rat cerebellar cortex
Differential distribution of vesicular glutamate transporters in the rat cerebellar cortex
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DOI：
10.1016/s0306-4522(02)00943-0
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发表时间：
2003-01-01
期刊：
影响因子：
3.3
通讯作者：
Kaneko, T
中科院分区：
文献类型：
--
作者：
Hioki, H;Fujiyama, F;Kaneko, T
用免疫细胞化学和囊泡谷氨酸转运体1和2(VGluT1和VGluT2)的原位杂交组织化学方法研究了大鼠小脑皮质兴奋性轴突终末的化学结构。化学耗竭下橄榄复合体神经元的3-乙酰基吡啶处理几乎完全消除了分子层的VGluT2免疫反应性，使VGluT1免疫反应性明显保持不变。另一方面，海人酸致小脑皮层神经元剥夺后，VGluT1在分子层的免疫反应性大量丧失。在小脑颗粒层，VGluT1和VGluT2免疫阳性反应均见于苔藓状纤维终末，且两种免疫反应主要共存于单轴突终末。VGluT2基因在下橄榄复合体中有表达，VGluT1和VGluT2mRNAs存在于发送苔藓纤维的脑干前核，如脑桥、桥脑被盖网状核、外侧网状核和楔形外核。这些结果表明，爬行纤维和平行纤维分别选择性地使用VGluT2和VGluT1，而苔藓纤维同时使用VGluT1和VGluT2来积聚谷氨酸进入突触小泡。由于已知攀升纤维和平行纤维终末分别产生抑制和促进突触，VGluT1和VGluT2可能具有与这些突触特征相关的不同性质。因此，下一个有趣的问题将是确定共表达VGluT1和VGluT2的苔藓纤维终末是突触促进还是突触抑制。(C)2003年IBRO。爱思唯尔科学有限公司出版。版权所有。
The chemical organization of excitatory axon terminals in the rat cerebellar cortex was examined by immunocytochemistry and in situ hybridization histochemistry of vesicular glutamate transporters 1 and 2 (VGluT1 and VGluT2). Chemical depletion of the inferior olivary complex neurons by 3-acetylpyridine treatment almost completely removed VGluT2 immunoreactivity from the molecular layer, leaving VGluT1 immunoreactivity apparently intact. On the other hand, neuronal deprivation of the cerebellar cortex by kainic acid injection induced a large loss of VGluT1 immunoreactivity in the molecular layer. In the cerebellar granular layer, both VGluT1 and VGluT2 immunoreactivities were found in mossy fiber terminals, and the two immunoreactivities were mostly colocalized in single-axon terminals. Signals for mRNA encoding VGluT2 were found in the inferior olivary complex, and those for VGluT1 and VGluT2 mRNAs were observed in most brainstem precerebellar nuclei sending mossy fibers, such as the pontine, pontine tegmental reticular, lateral reticular and external cuneate nuclei.These results indicate that climbing and parallel fibers selectively use VGluT2 and VGluT1, respectively, whereas mossy fibers apply both VGluT1 and VGluT2 together to accumulate glutamate into synaptic vesicles. Since climbing-fiber and parallel-fiber terminals are known to make depressing and facilitating synapses, respectively, VGluT1 and VGluT2 might have distinct properties associated with those synaptic characteristics. Thus, it would be the next interesting issue to determine whether mossy-fiber terminals co-expressing VGluT1 and VGluT2 show synaptic facilitation or depression. (C) 2003 IBRO. Published by Elsevier Science Ltd. All rights reserved.