Senba E, Simmons D M, Swanson L W
Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037.
Neuroscience. 1990;38(3):629-41. doi: 10.1016/0306-4522(90)90057-b.
The distribution of seven kinds of neuropeptide precursor mRNA-containing neurons was investigated in the rat main and accessory olfactory bulbs, where various peptides have previously been identified immunohistochemically, by means of in situ hybridization using [35S]cRNA probes. In the glomerular layer, numerous preprothyrotropin-releasing hormone mRNA-expressing neurons, moderate numbers of preprosomatostatin and preproenkephalin A neurons, and a small number of preprocholecystokinin neurons were detected. In the external plexiform layer, numerous medium sized preprocholecystokinin and preprocorticotropin-releasing hormone neurons, and a small number of beta-preprotachykinin A neurons were observed. In addition, small preprovasoactive intestinal polypeptide and preprothyrotropin-releasing hormone neurons were evenly distributed in the external plexiform layer. Medium to large sized beta-preprotachykinin A neurons formed a thin layer in the mitral cell layer. In the granule cell layer, in addition to numerous small preproenkephalin A neurons, moderate numbers of small beta-preprotachykinin A and preprocorticotropin-releasing hormone neurons, and a small number of preprothyrotropin-releasing hormone neurons, were identified. Large sized preprosomatostatin neurons were located in the deep layer of the granule cell layer. The distribution patterns of these neurons, as a whole, confirmed previous studies based on immunohistochemistry, although peptide precursor mRNA-expressing neurons were far more numerous than those immunoreactive to the respective neuropeptides. Moreover, mRNA-expressing neurons were observed in areas where no immunoreactive neurons had been observed (e.g. preprovasoactive intestinal polypeptide and preprosomatostatin neurons in the mitral cell layer of the assessory olfactory bulb). The distribution patterns were generally similar in the main and accessory olfactory bulbs.
利用[35S]cRNA探针原位杂交技术，研究了大鼠主嗅球和副嗅球中七种含神经肽前体mRNA的神经元分布情况，此前已通过免疫组织化学方法在这些部位鉴定出多种肽。在肾小球层，检测到大量表达促甲状腺激素释放激素前体mRNA的神经元、中等数量的生长抑素前体和脑啡肽A前体神经元，以及少量胆囊收缩素前体神经元。在外侧丛状层，观察到大量中等大小的胆囊收缩素前体和促肾上腺皮质激素释放激素前体神经元，以及少量β-速激肽A前体神经元。此外，血管活性肠肽前体和促甲状腺激素释放激素前体的小神经元均匀分布于外侧丛状层。中等至大尺寸的β-速激肽A前体神经元在僧帽细胞层形成一层薄层。在颗粒细胞层，除了大量小的脑啡肽A前体神经元外，还鉴定出中等数量的小β-速激肽A前体和促肾上腺皮质激素释放激素前体神经元，以及少量促甲状腺激素释放激素前体神经元。大尺寸的生长抑素前体神经元位于颗粒细胞层深层。总体而言，这些神经元的分布模式证实了此前基于免疫组织化学的研究结果，尽管表达肽前体mRNA的神经元数量远多于对相应神经肽免疫反应阳性的神经元。此外，在未观察到免疫反应阳性神经元的区域（如副嗅球僧帽细胞层中的血管活性肠肽前体和生长抑素前体神经元）也观察到了表达mRNA的神经元。主嗅球和副嗅球的分布模式总体相似。
