Négyessy L, Vidnyánszky Z, Kuhn R, Knöpfel T, Görcs T J, Hámori J
Department of Anatomy, Semmelweis University Medical School, Budapest, Hungary.
J Comp Neurol. 1997 Sep 8;385(4):641-50. doi: 10.1002/(sici)1096-9861(19970908)385:4<641::aid-cne9>3.0.co;2-3.
The cellular and subcellular localization of the mGluR5 metabotropic glutamate receptor subtype was studied in the rat cerebellar cortex, by using the preembedding immunoperoxidase and immunogold techniques. Light microscopic observations revealed an abundant, intense labeling of neurons in the granular layer as well as in the molecular layer. Lugaro and Golgi cells exhibited an intense mGluR5 immunoreactivity, while only a fraction of the neurons in the molecular layer were found to be mGluR5 immunopositive. In addition to a dense plexus of immunoreactive dendrites in the molecular layer of the cerebellar cortex, the mGluR5 immunopositive Golgi cell dendrites resembling axons at the light microscopic level were also labeled in the granular layer. At the ultrastructural level, mGluR5 immunoreactivity was present in neuronal elements postsynaptic to axon terminals of different morphology. By using a pre-embedding immunogold method, it was found that mGluR5 immunoreactivity is accumulated at the plasma membranes extrasynaptically as well as at the periphery of the postsynaptic specializations, mainly of the parallel fiber synaptic contacts. These findings provide morphological evidence that mGluR5 is expressed by a population of neurons in the cerebellar cortex and can synaptically be activated via the parallel fiber system.
运用包埋前免疫过氧化物酶和免疫金技术，对大鼠小脑皮质中代谢型谷氨酸受体5（mGluR5）亚型的细胞和亚细胞定位进行了研究。光学显微镜观察显示，颗粒层和分子层中的神经元有丰富且强烈的标记。卢加罗细胞和高尔基细胞呈现出强烈的mGluR5免疫反应性，而分子层中只有一部分神经元被发现mGluR5免疫阳性。除了小脑皮质分子层中有密集的免疫反应性树突丛外，在颗粒层中，光镜水平下类似轴突的mGluR5免疫阳性高尔基细胞树突也被标记。在超微结构水平上，不同形态轴突终末的突触后神经元成分中存在mGluR5免疫反应性。通过运用包埋前免疫金方法发现，mGluR5免疫反应性在突触外质膜以及突触后特化结构的周边积累，主要是在平行纤维突触接触处。这些发现提供了形态学证据，表明mGluR5在小脑皮质的一群神经元中表达，并且可以通过平行纤维系统在突触处被激活。
