Green | August 24, 2008 | 18 comments

The nose really can smell danger

source: http://blogs.discovermagazine.com/80beats/2008/08/22/mammals-have-a-nose-for-danger-literally/

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CHARMOSH
A mouse’s nose has a cluster of specialized cells that respond to the chemical signals sent out by fellow mice that are in distress, researchers report, meaning that mice can literally smell fear. A lump of nerve cells in the nose tip called the Grueneberg ganglion responds to the “fear pheromones” of imperiled creatures, sending a signal straight to the brain. As Grueneberg ganglia are known to exist in rodents, cats, apes, and humans, researchers say it’s likely that the cells perform the same function in all mammals.

In a new study, researchers dosed water dishes with mouse alarm pheromones, and put the dishes in cages with both normal mice and mice whose ganglia had been removed. The contrast was very striking, [lead researcher Marie-Christine] Broillet said. “The normal mouse immediately gets scared and goes to the corner of the box and freezes,” she said. But mice without the ganglia carried on as before, seemingly unaware of the danger signals. Both groups were able to sniff out cookies hidden in their cages, however, suggesting the altered group’s sense of smell was otherwise unaffected [National Geographic News].

The findings, reported in the journal Science [subscription required], solve an old puzzle about the function of the Grueneberg ganglion; when it was discovered in 1973 scientists couldn’t determine its purpose, and it was then forgotten for over 30 years. Researchers rediscovered the structure a few years ago when mice were genetically engineered to produce a green fluorescent protein in their neurons, Broillet says. Scientists were surprised to see the clusters of green neurons sitting all alone at the tip of the mice’s noses [Science News].

Warning systems that help animals detect a threat to their own species provide a clear boost in survival odds, so researchers say it makes sense that the ganglia evolved early and are present throughout the mammalian family tree. Even certain plants release alarm pheromones to produce bitter and astringent tannins, so they can become less appetizing to hungry animals. In modern life, our own response to alarm pheromones might be hard to notice, but it is entirely possible that we still inadvertently react to their presence [Ars Technica].

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18 comments // The nose really can smell danger

  • BerryHippieGurl
    • 0
      BerryHippieGurl  

    • I toatally agree with you bigloutech, I can sence that too. But when it comes to fear I only get an adreniline rush but I don't think I ever smelled fear before. Perhaps we don't know what it smells like, if one scientist was to conduct experiments and such then tell us what it would or should smell like will we ever know then what fears smells like. Just a theory I suppose to put out there and make you ponder the possiblities lol.

    • 3 years ago
  • LindseyIndigo
    • 0
      LindseyIndigo  

    • Poor little mouses. Scientists know more about mouse physiology than they do about humans. Unfortunately, that's because they spend a lot of time cutting them up.

    • 3 years ago
  • bigloutech
    • 0
      bigloutech  

    • i don't know about you guys, but i've been to a few bars in my life and it's pretty easy to sense when violence is in the air. i'm not sure if i smell it, or if it's just common sense.

    • 3 years ago
  • harechrishna
    • 0
      harechrishna  

    • one's sense of smell is so important. i think smell is connected to emotional intelligence to. its all instinct. like when we smell rotting food we recoil in disgust. its ancestral memory.

      i read an article in sciam that claimed 40% of schizophrenics have a damage olfactory nerves. maybe certain people have trouble bonding because they cannot smell (subconsciously) other people.

      and think, dogs are smart, but in a social sense. they are always looking to you to see what's going on.

    • 3 years ago
  • lloves_earth
  • haleyann
  • kewal91
    • 0
      kewal91  

    • well i dont think it maters.. Jammer.... the society 2day is very unaware of pain... i mean you could probably find a kid who thinks getting shot woudnt hurt too bad...

    • 3 years ago
  • mookster_07
    • 0
      mookster_07  

    • As i understand it Jammer, scientists have already found the ganglion of fear receptors in our noses. Although we can find it externally, I wonder if our brain registers it internally? We are receiving the information, but is our brain really processing it. Do we know we are smelling fear?

    • 3 years ago
  • J_Jammer
  • purplefox
    • 0
      purplefox  

    • It's interesting that our (as in mammals such as us and rats) ability to 'smell danger' is heavily reliant on others in a social group - shows how interconnected we all are. Though I wonder if we can detect fear from other animals (and if it has the same effect) or if the scent is more species-specific.

    • 3 years ago
  • satanskidney
  • ChrisWT
  • J_Jammer
    • 0
      J_Jammer [removed]  

    • I heard this on NPR. It's interesting that they pinpointed the exact location on the nose where they sense such. More interesting will be when they find it on humans. Think of someone removing fear from a human senses....that would make for a great fighter.

    • 3 years ago
  • IKilledBambi
  • jahbini
  • orangeseverywhere
  • TravG73
  • marpunk
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