摘要
Objective To examine the vesicular glutamate transporters （VGluTs： VGluT 1-VGluT3） in the peripheral vestibular system. Methods The vestibular structures, including Scarpa＇s ganglion （vestibular ganglion, VG）, maculae of utricle and saccule, and ampullary cristae, from normal Sprague-Dawley rats were processed immunohistochemically for VGluTs, by avidin-biotinylated peroxidase complex method, with 3-3＇-diaminobenzidine （DAB） as chromogen. Results （1） VGluT 1 was localized to partial neurons of VG and to the putative primary afferent fibers innervating vestibular end-organs. （2） Intense VGluT3 immunoreactivity was detected in large number of sensory epithelia cells, and weak labeling of VGluT3- positive afferent fibers was in the maculae and ampullary cristae. （3） No or very weak VGluT2 immunoreactivity was observed in the VG and acoustic maculae. Conclusion These results provide the morphological support that glutamate exists in the peripheral vestibular system, and it may play an important role in the centripetal vestibular transmission.
目的检查囊泡膜谷氨酸转运体(vesicular glutamate transporter,VGluT)在前庭外周系统中的分布特征。方法采用ABC (avidin-biotinylated peroxidase complex)免疫组织化学方法,二氨基联苯作为染色剂,观察VGluT1-3在正常成年SD大鼠前庭外周系统,包括球囊、椭圆囊、壶腹嵴和前庭神经节 (Scarpa神经节)的表达。结果 (1) VGluT1样免疫阳性产物位于前庭神经节和传入纤维支配的前庭外周终末感受器。(2)大部分感觉上皮细胞表达高密度的VGluT3样免疫阳性产物,但在球囊斑和椭圆囊斑,VGluT3样免疫阳性传入纤维表达较弱。(3)在上述部位, 没有或仅有很弱的VGluT2样免疫反应。结论 VGluT1和VGluT3参与了初级前庭传入纤维和毛细胞中将谷氨酸转运入囊泡的过程,可能在调节前庭终末感受器通过前庭核向大脑传递信息的传导通路中具有重要作用。
