Identification of a pheromone that increases anxiety in rats
Identification of a pheromone that increases anxiety in rats
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DOI：
10.1073/pnas.1414710112
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发表时间：
2014-12-30
影响因子：
11.1
通讯作者：
Mori, Yuji
中科院分区：
文献类型：
--
作者：
Inagaki, Hideaki;Kiyokawa, Yasushi;Mori, Yuji
化学通讯在各种哺乳动物的社会生活中起着重要的作用。其中一些化学物质被称为信息素。老鼠在受到压力时会向空气中释放一种特殊的气味。这种与压力有关的气味会增加其他老鼠的焦虑水平；因此，引起焦虑的分子有可能存在于与压力有关的气味剂中。在这里，我们试图通过使用声惊吓反射作为生物测定系统来检测焦虑活性来确定负责的分子。在对压力相关气味进行连续分馏后，我们在最终馏分中检测到4-甲基戊醛和己醛仍然具有焦虑特性。使用合成分子，我们发现微量的二元混合物，而不是单独的两种分子，会增加大鼠的焦虑。此外，我们确定混合物增加了一种特定类型的焦虑，并在实验模型中引起与焦虑相关的行为反应，这与声惊吓反射不同。神经机制分析表明，与焦虑相关的神经回路只有在两种嗅觉系统同时感知到这两种分子时才会被激活。我们得出结论，这种混合物是一种信息素，会增加老鼠的焦虑。据我们所知，这是第一个确定老鼠信息素的研究。我们的研究结果有助于进一步研究大鼠信息素，从而提高我们对哺乳动物化学通讯的理解。
Chemical communication plays an important role in the social lives of various mammalian species. Some of these chemicals are called pheromones. Rats release a specific odor into the air when stressed. This stress-related odor increases the anxiety levels of other rats; therefore, it is possible that the anxiety-causing molecules are present in the stress-related odorants. Here, we have tried to identify the responsible molecules by using the acoustic startle reflex as a bioassay system to detect anxiogenic activity. After successive fractionation of the stress-related odor, we detected 4-methylpentanal and hexanal in the final fraction that still possessed anxiogenic properties. Using synthetic molecules, we found that minute amounts of the binary mixture, but not either molecule separately, increased anxiety in rats. Furthermore, we determined that the mixture increased a specific type of anxiety and evoked anxiety-related behavioral responses in an experimental model that was different from the acoustic startle reflex. Analyses of neural mechanisms proposed that the neural circuit related to anxiety was only activated when the two molecules were simultaneously perceived by two olfactory systems. We concluded that the mixture is a pheromone that increases anxiety in rats. To our knowledge, this is the first study identifying a rat pheromone. Our results could aid further research on rat pheromones, which would enhance our understanding of chemical communication in mammals.