Brechbühl Julien, Moine Fabian, Tosato Monique Nenniger, Sporkert Frank, Broillet Marie-Christine
Department of Pharmacology and Toxicology, Faculty of Biology and Medicine, University of Lausanne Lausanne, Switzerland.
University Center of Legal Medicine, Lausanne-Geneva Lausanne, Switzerland.
Front Neurosci. 2015 Jul 28;9:253. doi: 10.3389/fnins.2015.00253. eCollection 2015.
In the wild, animals have developed survival strategies relying on their senses. The individual ability to identify threatening situations is crucial and leads to increase in the overall fitness of the species. Rodents, for example have developed in their nasal cavities specialized olfactory neurons implicated in the detection of volatile cues encoding for impending danger such as predator scents or alarm pheromones. In particular, the neurons of the Grueneberg ganglion (GG), an olfactory subsystem, are implicated in the detection of danger cues sharing a similar chemical signature, a heterocyclic sulfur- or nitrogen-containing motif. Here we used a "from the wild to the lab" approach to identify new molecules that are involuntarily emitted by predators and that initiate fear-related responses in the recipient animal, the putative prey. We collected urines from carnivores as sources of predator scents and first verified their impact on the blood pressure of the mice. With this approach, the urine of the mountain lion emerged as the most potent source of chemical stress. We then identified in this biological fluid, new volatile cues with characteristic GG-related fingerprints, in particular the methylated pyridine structures, 2,4-lutidine and its analogs. We finally verified their encoded danger quality and demonstrated their ability to mimic the effects of the predator urine on GG neurons, on mice blood pressure and in behavioral experiments. In summary, we were able to identify here, with the use of an integrative approach, new relevant molecules, the pyridine analogs, implicated in interspecies danger communication.
在野外,动物们依靠自身的感官发展出了生存策略。个体识别威胁情况的能力至关重要,这会提高物种的整体适应性。例如,啮齿动物在其鼻腔中发育出了专门的嗅觉神经元,这些神经元参与检测编码即将到来的危险的挥发性线索,如捕食者的气味或警报信息素。特别是,嗅觉子系统格鲁内贝格神经节(GG)的神经元参与检测具有相似化学特征(含杂环硫或氮基序)的危险线索。在这里,我们采用了一种“从野外到实验室”的方法来识别捕食者无意中释放的、能在受体动物(假定的猎物)中引发恐惧相关反应的新分子。我们收集了食肉动物的尿液作为捕食者气味的来源,并首先验证了它们对小鼠血压的影响。通过这种方法,美洲狮的尿液成为化学应激最有效的来源。然后,我们在这种生物液体中鉴定出了具有与GG相关特征指纹的新挥发性线索,特别是甲基化吡啶结构、2,4-二甲基吡啶及其类似物。我们最终验证了它们所编码的危险性质,并证明了它们在GG神经元、小鼠血压和行为实验中模拟捕食者尿液作用的能力。总之,我们通过综合方法在这里鉴定出了新的相关分子——吡啶类似物,它们参与种间危险信号传递。