Theory to identify odorants which evoke innate fear/attractive behaviors to wild animals

利用遗传操作的方法，我们已经阐明了起源于背嗅球的嗅觉神经通路先天地调节对捕食者气味的恐惧反应。通过关注引起对气味的恐惧反应的神经通路，我们鉴定了一系列被称为“恐惧气味”的气味，其在诱导冻结行为方面具有比TMT强10倍以上的生物活性。通过使用“恐惧气味”，我们开发了可以区分先天反应和恐惧反应的生物标记。因此，我们澄清了皮肤/核心体温和心率在先天恐惧反应中特别改变。我们还确定了在先天性恐惧反应过程中发生变化的血清“恐惧标记物”。我们构建了小鼠气味受体的表达文库，并筛选了与能够诱导小鼠先天性恐惧反应的气味相互作用的气味受体。我们鉴定了多种气味受体，它们特异性地与能够诱导小鼠显著恐惧反应的气味相互作用。然后，我们分析了“恐惧气味剂”，它可以诱导小鼠的恐惧反应，也诱导其他动物物种的恐惧反应。我们观察到“恐惧气味”不仅可以在小鼠中诱导显著的恐惧反应，还可以在包括鹿在内的一些动物物种中诱导显著的恐惧反应。

Using genetic manipulation method, we have clarified that the olfactory neural pathway which originates from the dorsal olfactory bulb innately regulates fear responses to predator odorants. By focusing on the neural pathway which induces fear responses to odorants, we identified a series of odorants named "fear odors" which have more than 10 times stronger bioactivity than TMT with respect to inducing freezing behaviors. By use of "fear odorants" we developed biological markers which can distinguish innate and fear responses. As a result, we clarified that cutaneous/core body temperature and heart rate is specifically changed in innate fear responses. We also identified serum "fear markers" which change during innate fear responses.We constructed expression libraries of murine odorant receptors and screened for odorant receptors which interact with odorants that can induce innate fear responses in mice. We identified multiple odorant receptors which specifically interact with odorants that can induce prominent fear responses in mice. We then analyzed whether "fear odorants," which can induce fear responses in mice, also induce fear responses in other animal species. We observed "fear odorants" can induce prominent fear responses not only in mice but also in some animal species including deer.