The Vomeronasal Organ Mediates Interspecies Defensive Behaviors through Detection of Protein Pheromone Homologs

* Highlights
* Mice display innate fear-like behavior to diverse predator odors
* Mup proteins purified from cats and rats are sufficient to evoke this behavior
* Vomeronasal sensory neurons are necessary for both detection and response
* Predator Mups and mouse Mup pheromones activate different subsets of neurons

* Summary
* Potential predators emit uncharacterized chemosignals that warn receiving species of danger. Neurons that sense these stimuli remain unknown. Here we show that detection and processing of fear-evoking odors emitted from cat, rat, and snake require the function of sensory neurons in the vomeronasal organ. To investigate the molecular nature of the sensory cues emitted by predators, we isolated the salient ligands from two species using a combination of innate behavioral assays in naive receiving animals, calcium imaging, and c-Fos induction. Surprisingly, the defensive behavior-promoting activity released by other animals is encoded by species-specific ligands belonging to the major urinary protein (Mup) family, homologs of aggression-promoting mouse pheromones. We show that recombinant Mup proteins are sufficient to activate sensory neurons and initiate defensive behavior similarly to native odors. This co-option of existing sensory mechanisms provides a molecular solution to the difficult problem of evolving a variety of species-specific molecular detectors.[/url]
Woot! Smell me and cower!

Surprising? Surprising to whom? Dogs peeing on trees? Cats peeing on bushes? I'd say it was freaking likely that a fear signal was comprised at least in part by components of predator's urine.


My speculation: I'm almost certain that there are similar things in play with humans. perhaps not fear, but some complex behavioral modifiers, especially wrt mate selection, but probably aggression, social heirarchy, etc. I know a lot of the sensory bio folks think that there are a lot of pheromones etc that influence human behavior. There's spotty research that's pretty compelling on this score, but it's only the tip of the iceberg. Hard to study, since you can't put humans through controlled experiments, plus we're too genetically heterogeneous, and thus too much experimental noise. But cool stuff.

Now here's a thought: an online community is one of the first small-scale, interpersonal societies that functions without olfactory input. How does this alter interpersonal interactions?