What's that smell?

When you think of your sense of smell you think of the smells you love such as fresh baked cookies and the smells you hate such as the smell of rotten eggs. Although we love and hate certain scents, have you ever questioned why you love certain scents but are repulsed by others? Not only are we repulsed by the smell of rotten eggs, but it also signifies there could be Hydrogen sulfide near by which could indicate a gas leak. Is our aversion to this smell hardwired in to our brain to suspect danger or do we learn it? Researchers such as those from the National Science foundation, the National Institutes of health, Teasley endowment to Georgia tech and Dr. Bozza from Northwestern try to figure out the answer to this question.

The National Science foundation, the National Institutes of health, and the Teasley endowment to Georgia tech performed a new study to test if pacific corals and fish can smell a bad area of coral. They tested 3 species of coral larvae and 15 species of fish by allowing them to swim in different streams of water from different habitats, one from a healthy habitat and one from a degrading habitat. They found that all 3 species of coral larvae and all 15 species of fish preferred the healthy habitat water. The reason behind this was that these fish and larvae could smell the difference between a healthy habitat and degrading habitat by the seaweed. These chemical signals coming off the seaweed drive away the fish and larvae from settling there which is why it’s so hard to repopulate the damaged coral reef. Their aversion to the smell of seaweed allows them to pick proper and safe homes. This leads to the question whether they learned to avoid the smell of seaweed or was it already hardwired in their brain?

Dr. Bozza from Northwestern University gave a talk about his research and how he was interested in finding out how much of smell is hardwired or learned by using mice. In a mouse’s olfactory system there are a group of receptors called TAAR’s, which detect low concentrations of amines, such as what is found in cat urine, a known mice predator. For his experiment he placed mice in to a compartment where they could either spend time in a room that smelt like amines or a room that didn’t.  When they calculated how much time the mice spent in the odor room and non-odor room they learned that mice are aversive to amines and when a single TAAR gene is deleted they no longer avoid the aversive smells.  This leads to the question as to whether this aversion to amines was hardwired for protection or learned for protection by the mice. Through Dr. Bozza’s research, the National Science foundation, the National Institute of health, and the Teasley foundation of Georgia tech more is being learned about the olfactory system in animals and the reasons behind preferences and aversions to certain smells.

Works cited

Georgia Institute of Technology. "Fish and coral smell a bad neighborhood: Marine protected areas might not be enough to help overfished reefs recover." ScienceDaily. ScienceDaily, 21 August 2014. <www.sciencedaily.com/releases/2014/08/140821141334.htm>.

Pacifico et al., An Olfactory Subsystem that Mediates High-Sensitivity Detection of Volatile Amines, Cell Reports (2012),

 http://dx.doi.org/10.1016/j.celrep.2012.06.006

Pictures

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