title: Detection and avoidance of a carnivore odor by prey.
abstract: Predator-prey relationships provide a classic paradigm for the study of innate animal behavior. Odors from carnivores elicit stereotyped fear and avoidance responses in rodents, although sensory mechanisms involved are largely unknown. Here, we identified a chemical produced by predators that activates a mouse olfactory receptor and produces an innate behavioral response. We purified this predator cue from bobcat urine and identified it to be a biogenic amine, 2-phenylethylamine. Quantitative HPLC analysis across 38 mammalian species indicates enriched 2-phenylethylamine production by numerous carnivores, with some producing >3,000-fold more than herbivores examined. Calcium imaging of neuronal responses in mouse olfactory tissue slices identified dispersed carnivore odor-selective sensory neurons that also responded to 2-phenylethylamine. Two prey species, rat and mouse, avoid a 2-phenylethylamine odor source, and loss-of-function studies involving enzymatic depletion of 2-phenylethylamine from a carnivore odor indicate it to be required for full avoidance behavior. Thus, rodent olfactory sensory neurons and chemosensory receptors have the capacity for recognizing interspecies odors. One such cue, carnivore-derived 2-phenylethylamine, is a key component of a predator odor blend that triggers hard-wired aversion circuits in the rodent brain. These data show how a single, volatile chemical detected in the environment can drive an elaborate danger-associated behavioral response in mammals.
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Ferrero
authors.forename: Jamie K
authors.initials: JK
authors.lastname: Lemon
authors.forename: Daniela
authors.initials: D
authors.lastname: Fluegge
authors.forename: Stan L
authors.initials: SL
authors.lastname: Pashkovski
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Korzan
authors.forename: Sandeep Robert
authors.initials: SR
authors.lastname: Datta
authors.forename: Marc
authors.initials: M
authors.lastname: Spehr
authors.forename: Markus
authors.initials: M
authors.lastname: Fendt
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Liberles
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology; D002335:Carnivora / Q000502:physiology* / Q000652:urine; D046008:Lynx / Q000652:urine; D008297:Male; D051379:Mice; D009812:Odorants / Q000032:analysis*; D018034:Olfactory Receptor Neurons / Q000502:physiology; D010627:Phenethylamines / Q000652:urine; D011235:Predatory Behavior / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010627:Phenethylamines; C029261:phenethylamine