Petralia R S, Wenthold R J
Laboratory of Neurochemistry, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892.
J Comp Neurol. 1992 Apr 15;318(3):329-54. doi: 10.1002/cne.903180309.
Since four AMPA-type excitatory amino acid receptor subunits have been cloned recently, it is now possible to localize these important molecules in the nervous system. A comprehensive study of AMPA receptor immunocytochemistry was carried out on vibratome sections of rat brain, which were immunolabeled with antibodies made against peptides corresponding to the C-terminal portions of AMPA-receptor subunits: GluR1, GluR2/3, and GluR4. Labeling was most prominent in forebrain structures such as the olfactory bulb and tubercle, septal nuclei, amygdaloid complex, hippocampus, induseum griseum, habenula, and interpeduncular nucleus, and in the cerebellum. Different patterns of immunolabeling were evident with the antibodies to the four subunits, with marked contrast between densely and lightly stained structures with antibody to GluR1, widespread dense staining with antibody to GluR2/3, and moderate staining with antibody to GluR4. In the parietal cortex, some non-pyramidal neurons were more densely stained than pyramidal cells with antibodies to GluR1. Neurons of the main olfactory bulb, other than granule cells, were most densely stained with antibody to GluR1. In the cerebellum, Bergmann glia were densely stained with antibodies to GluR1 and 4, while neurons, other than granule cells, were most densely stained with antibody to GluR2/3. Immunolabeling patterns of all antibodies were consistent with that of previous in situ hybridization histochemistry studies and with the overall pattern of 3H-AMPA binding. Electron microscopy of thin sections taken from immunolabeled vibratome sections of hippocampus and cerebral cortex showed staining which was restricted mainly to postsynaptic densities and adjacent dendritoplasm, and to neuron cell body cytoplasm. We saw no convincing examples of stained presynaptic terminals, and only limited evidence of glial staining, excepting Bergmann glia.
由于最近已克隆出四种AMPA型兴奋性氨基酸受体亚基，现在有可能在神经系统中定位这些重要分子。我们对大鼠脑振动切片进行了AMPA受体免疫细胞化学的全面研究，这些切片用针对与AMPA受体亚基（GluR1、GluR2/3和GluR4）C末端部分相对应的肽段制备的抗体进行免疫标记。标记在诸如嗅球和结节、隔核、杏仁复合体、海马、灰被、缰核和脚间核等前脑结构以及小脑中最为显著。针对这四种亚基的抗体呈现出不同的免疫标记模式，用抗GluR1抗体染色的结构在浓染和淡染之间有明显对比，用抗GluR2/3抗体染色呈现广泛的浓染，用抗GluR4抗体染色呈现中度染色。在顶叶皮质中，一些非锥体神经元用抗GluR1抗体染色比锥体细胞更浓。除颗粒细胞外，主嗅球的神经元用抗GluR1抗体染色最浓。在小脑中，伯格曼胶质细胞用抗GluR1和4抗体染色浓，而除颗粒细胞外的神经元用抗GluR2/3抗体染色最浓。所有抗体的免疫标记模式与先前的原位杂交组织化学研究结果以及3H-AMPA结合的总体模式一致。对取自海马和大脑皮质免疫标记振动切片的超薄切片进行电子显微镜观察，结果显示染色主要局限于突触后致密物和相邻的树突质以及神经元细胞体细胞质。我们没有看到有说服力的突触前终末染色实例，除了伯格曼胶质细胞外，胶质细胞染色的证据也很有限。
