Study of olfactory-compatible smell sensor prototype by using odorant receptors

嗅觉系统可以在几秒钟内通过纳米级分子结构的差异来区分手性气味，而仪器分析很难识别或区分每一对中的一对。同样，人工气味传感器在气味识别方面也没有实现嗅觉兼容的性能。在本研究中，我们试图开发一个嗅觉相容的人工鼻原型，通过开发其关键技术，包括气味感受器表达的元素传感器和气味信息处理算法。1.通过共表达RTP1和RTP2(Saito，H.等，Cell，119：679-691(2004))的两个伴侣，在HEK293细胞中表达了一些气味受体，显示了表达其受体的嗅觉感受器神经元的反应重复性和原始气味反应性。这种基本传感器将通过保留气味感受器在气味识别方面的优异性能来创新人工鼻子技术。为了将许多其他气味受体重新招募到新的人工鼻子中，有必要找到另一个伴侣来帮助其他受体在培养细胞中表达。2.部分揭示了花香手性香料对之间受体密码的差异和同一性。3.在豚鼠离体鼻附壁全脑嗅皮层获得的电生理数据支持我们提出的受体敏感度依赖的气味信息分级编码算法的假说。我们继续收集典型气味的受体编码数据，并构建表达气味受体的基本气味传感器阵列。目前，这种方法被提出发展创新的人工鼻作为嗅觉相容的传感器。

The olfactory system can discriminate between chiral odorants by differences in nano-scale molecular structures in a few seconds, whereas instrumental analyses hardly identify or separate one of each pair from another. Similarily, artificial odor sensors have not realized olfactory-compatible performance in odor discrimination. In this study, we have attempted to develop a prototype of olfactory compatible artificial nose by developing its key technology including odorant-receptor-expressed elemental sensors and algorithm of odor information processing. The results are summarized as follows : 1. A few of odorant receptors were functionally expressed in HEK293 cells by coexpressing two chaperones of RTP1 and RTP2 (Saito, H., et al., Cell, 119 : 679-691 (2004)), showing response reproducibility and original odor responsiveness of olfactory receptor neurons expressing its receptors. This elemental sensor would innovate artificial nose technology by conserving excellent performance of odorant receptors in odor discrimination. For recruitment of many other odorant receptors into a new artificial nose, it is necessary to find another chaperone to help the other receptors be expressed in cultured cells. 2. Difference and identity of receptor codes between a floral chiral odorant pair has been partially revealed. 3. Electrophysiological data obtained in the olfactory cortex of guinea-pig isolated whole brain with nose attached have supported our hypothesis of algorithm of receptor-sensitivity-dependent hierarchical odor information coding. We have continued to collect receptor code data for typical odorants and to construct array of elemental odor sensors expressing odorant receptors. At present, this approach forwarded to develop innovative artificial nose as olfactory-compatible sensors.