Ultrastructural Localization of a Voltage‐gated K+ Channel a Subunit (Kv1.2) in the Rat Cerebellum
Ultrastructural Localization of a Voltage‐gated K+ Channel a Subunit (Kv1.2) in the Rat Cerebellum
复制标题
大鼠小脑中电压门控 K+ 通道 a 亚基 (Kv1.2) 的超微结构定位
DOI：
--
复制
发表时间：
1996
影响因子：
3.4
通讯作者：
J. Priestley
中科院分区：
文献类型：
--
作者：
N. McNamara;S. Averill;Graham P. Wilkin;J. O. Dolly;J. Priestley
采用高特异性单克隆抗体和预包埋免疫细胞化学方法检测了K+通道亚基Kv1.2在大鼠小脑中的分布。光镜下，浦肯野细胞基部的篮细胞针状区免疫反应性最强，篮细胞和高尔基细胞体染色较浅，颗粒细胞和分子层呈点状。电镜观察了Kv1.2 α亚基在这些标记结构中的超微结构位置。结果表明，针刺的标记仅限于轴突前端丛，紧靠浦肯野轴突起始段的区域相对缺乏染色。篮状细胞亲本轴突未免疫染色，但细突染色较重。在颗粒细胞层的髓系轴突和小脑内侧核也可见免疫反应，染色最集中在轴突的旁结旁区。在一些苔藓纤维终末可见不同寻常的染色模式，染色仅限于苔藓纤维肾小球的细突起。这些突起接触的结构包括毗邻的胶质突。小脑内侧核浦肯野细胞体、树突、轴突起始段和末梢未见免疫染色。在这项研究中，a亚基Kv1.2定位于小脑的许多不同类型的细胞。每一种神经元类型的亚单位都有不同的亚细胞分布。
A highly specific monoclonal antibody and pre‐embedding immunocytochemistry were employed to examine the distribution of the K+ channel a subunit Kv1.2 in the rat cerebellum. At the light microscopic level, the heaviest immunoreactivity was seen in the basket cell pinceau at the base of Purkinje cells, with lighter staining of basket and Golgi cell bodies and a punctate pattern in the granule cell and molecular layers. Electron microscopy was performed to identify the ultrastructural location of Kv1.2 α subunit in these labelled structures. This revealed that the labelling of the pinceau was confined to the preterminal axonal plexus, the area immediately around the Purkinje axon initial segment being relatively devoid of staining. Basket cell parent axons were not immunostained, but gave rise to heavily stained fine processes. Immunoreactivity was also seen in myelinated axons in the granule cell layer and in the medial cerebellar nucleus, the staining being most concentrated at the juxtaparanodal regions of the axons. An unusual pattern of staining was seen in some mossy fibre terminals, with staining restricted to fine protuberances of mossy fibre glomeruli. Structures contacted by these protuberances included adjoining glial processes. Immunostaining was absent from Purkinje cell bodies, dendrites, their axon initial segments and their terminals in the medial cerebellar nucleus. In this study, the a subunit Kv1.2 was localized to a number of different cell types in the cerebellum. Each neuronal type displays a distinct subcellular distribution of the subunit.