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剂，而仪器分析很难识别或区分每对中的一个。类似地，人工气味传感器在气味辨别中没有实现嗅觉兼容性能。本研究以嗅觉兼容型人工鼻为研究对象，通过对嗅觉兼容型人工鼻关键技术的研究，包括气味受体表达的元件传感器和气味信息处理算法的研究，初步构建了嗅觉兼容型人工鼻的原型系统。主要研究结果如下：1.一些气味受体通过共表达RTP 1和RTP 2的两种分子伴侣在HEK 293细胞中功能性表达（Saito，H.，例如，Cell，119：679-691（2004）），显示了表达其受体的嗅觉受体神经元的反应再现性和原始气味反应性。这种元素传感器将通过保存气味受体在气味辨别中的优异性能来创新人工鼻技术。为了将许多其他气味受体招募到新的人工鼻中，有必要找到另一种伴侣来帮助其他受体在培养的细胞中表达。2.部分揭示了花中手性气味物质受体密码子的差异和同一性。3.在豚鼠离体全脑嗅觉皮层获得的电生理数据支持了我们的假设受体敏感性依赖的层次气味信息编码算法。我们继续收集典型气味物的受体编码数据，并构建表达气味物受体的元素气味传感器阵列。目前，这种方法正被用于开发创新的人工鼻作为嗅觉兼容传感器。

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.