Kimura Y, Furukawa M
Department of Otorhinolaryngology, Ishikawa Prefectural Central Hospital, Kanazawa.
Nihon Jibiinkoka Gakkai Kaiho. 1998 May;101(5):620-6. doi: 10.3950/jibiinkoka.101.5_620.
The vertebrate olfactory system is capable of recognizing and discriminating thousands of different odorant molecules. In vitro biochemical studies have shown that some odorants elicit an increase in the intercellular second messenger cyclic AMP, whereas other odorants cause an increase in the second messenger inositol triphosphate (IP3). If IP3 plays an important role in the signal transduction, calcium-binding protein will be needed. We investigated the expression of calretinin, which belongs to the E-F hand family, in the neonatal and adult olfactory mucosa and olfactory bulb. Mice were sacrificed on postnatal day 1 (P1), day 3 (P3), day 10 (P10) and 12 weeks as adults. The olfactory mucosa of the nasal septum and the olfactory bulb were stained with anti-calretinin antibody at a 1:1000 dilution for 48 hours. The results were as follows. 1) Olfactory mucosa: In the P1 mouse, the olfactory nerves running in the submucosal layer and olfactory cells in the epithelium were positive. In the epithelium, immunopositive spots were seen exclusively in the upper half of the epithelium. In the P3, P10 and adult mice, these spots were seen throughout the olfactory cell layer. However, the basal cell layer and supporting cells were negative. 2) Olfactory bulb: In all stages, the olfactory nerve layer and the glomerular layer were strongly stained. In the external plexiform layer, many cells were positive. Their shape was bipolar and the size of the cell body was thought to be about 20 microns. They were thought to be tufted cells. However, there is a possibility that these cells are short axon cells in the external plexiform layer. In the granule layer, some granule cells were positive. In the P1 mouse, the immunopositive spots were exclusively seen in the upper half of the epithelium. In contrast, in the P3 mouse, these spots were seen throughout the olfactory cell layer. Judging from our results, it is suspected that the important change in neurogenesis of olfactory cells occurred between P1 and P3. In the olfactory bulb, from P1 to adult mice, calretinin was positive in the olfactory nerve layer, the glomerulus and periglomerular cells. In contrast, mitral cells were negative. Most reports state that calcium binding protein appears in periglomerular cells. However, in the external plexiform layer, many cells were positive. As their shape was bipolar and the cell body was a little larger than the periglomerular cells, these cells were thought to be tufted cells.
脊椎动物的嗅觉系统能够识别和区分数千种不同的气味分子。体外生化研究表明，一些气味剂会使细胞间第二信使环磷酸腺苷（cAMP）增加，而其他气味剂则会使第二信使肌醇三磷酸（IP3）增加。如果IP3在信号转导中起重要作用，那么就需要钙结合蛋白。我们研究了属于E-F手家族的钙视网膜蛋白在新生和成年小鼠嗅觉黏膜及嗅球中的表达。在出生后第1天（P1）、第3天（P3）、第10天（P10）和成年期（12周）处死小鼠。鼻中隔的嗅觉黏膜和嗅球用1:1000稀释的抗钙视网膜蛋白抗体染色48小时。结果如下。1）嗅觉黏膜：在P1小鼠中，黏膜下层的嗅神经和上皮中的嗅细胞呈阳性。在上皮中，免疫阳性斑点仅在上皮的上半部分可见。在P3、P10和成年小鼠中，这些斑点在整个嗅细胞层均可见。然而，基底层细胞和支持细胞呈阴性。2）嗅球：在所有阶段，嗅神经层和肾小球层均被强烈染色。在外侧丛状层，许多细胞呈阳性。它们的形状为双极型，细胞体大小约为20微米。它们被认为是簇状细胞。然而，这些细胞有可能是外侧丛状层中的短轴突细胞。在颗粒层，一些颗粒细胞呈阳性。在P1小鼠中，免疫阳性斑点仅在上皮的上半部分可见。相比之下，在P3小鼠中，这些斑点在整个嗅细胞层均可见。根据我们的结果，怀疑嗅细胞神经发生的重要变化发生在P1和P3之间。在嗅球中，从P1到成年小鼠，钙视网膜蛋白在嗅神经层、肾小球和球周细胞中呈阳性。相比之下，二尖瓣细胞呈阴性。大多数报告称钙结合蛋白出现在球周细胞中。然而，在外侧丛状层，许多细胞呈阳性。由于它们的形状为双极型，细胞体比球周细胞稍大，这些细胞被认为是簇状细胞。
