Analysis of olfactory information transmission mechanism by bio-imaging

本研究通过多种实验来阐明脊椎动物嗅觉信息传递机制的细节。在非洲爪蟾，主要和较低的腔室内衬的嗅觉上皮和犁鼻器，分别，和中室内衬由一个特定的感觉上皮，中室上皮。这三个嗅觉感受器的糖复合物的表达模式各不相同。根据嗅腺的缺失和感受细胞微细结构的差异，推测中室上皮可能是一个检测水中气味分子的嗅觉器官。此外，嗅上皮、中室上皮和犁鼻器分别投射到主嗅球的背侧区、腹侧区和副嗅球。这些结果表明，存在三个独立的嗅觉通路在非洲爪蟾。然后，仓鼠MOB的嗅球表现出与13种凝集素的糖缀合物的差异表达模式。这些结果表明，从概率的角度来看，单个肾小球在糖残基的种类和体积方面彼此不同。最后，大鼠的三个嗅觉受体器官，即，马塞拉（MO）的嗅上皮、犁骨鼻器和隔嗅器共同由排列在胚胎鼻窝内的原始嗅上皮发育而来。在MO的情况下，原始嗅觉上皮内衬鼻中隔转化为周围的MO呼吸上皮，和剩余的原始嗅觉上皮分化为MO上的鼻中隔。此外，在本研究中，生物成像的结果并不令人满意。

In the present study, various examinations were carried out to clarify the details of olfactory information transmision mechanism in the vertebrates. In Xenopus laevis, the main and lower chambers were lined by the olfactory epithelium and vomer onasal organ, respectively, and the middle chamber was lined by a specific sensory epithelium, the middle chamber epithelium. These three olfactory receptor organs showed the different expression patterns of glycoconjugates with each other. Judging from the absence of associated olfactory gland and the difference in fine structure of receptor cells, the middle chamber epithelium was suggested to be an olfactory organ to detect odoriferous molecules in water. In addition, the olfactory epithelium, middle chamber epithelium, vomeronasal organ projected to the dorsal region of the main olfactory bulb (MOB), ventral region of the MOB, and the accessory olfactory bulb, respectively. These findings suggested the presence of three independent olfactory pathways in Xenopus laevis. Then, olfactory glomeruli of the hamster MOB showed the differential expression patterns of glycoconjugates with 13 kinds of lectins. These results suggested that individual glomeruli were different with each other in the kind and volume of sugar residues from the viewpoint of probability. Lastly, the three olfactory receptor organs of rats, i.e., olfactory epithelium, vomer onasal organ, and septal olfactory organ of Masera (MO), developed in common from the primitive olfactory epithelium lining the embryonic nasal pit. In the case of the MO, the primitive olfactory epithelium lining the nasal septum transformed to the respiratory epithelium around the MO, and the remaining primitive olfactory epithelium differentiated to the MO on the nasal septum. Further, results by bio-imaging were not satisfactory in the present study.