New analysis by researchers Greece and U.S. found that such insects such as fruit flies can distinguish between normal and heavy isotope of hydrogen (deuterium), which adds the value of the new theory of how the sense of smell.
Dr. Efthimios Skulakis (Efthimios Skoulakis) of Biomedetsinskogo Research Center in Vari, Greece and his colleagues placed fruit flies or fruit flies (Drosophila melanogaster) with acetophenone (acetophenone), odorant molecules are often used in perfumes, in the maze of T-shaped . In one branch of the maze molecule containing normal hydrogen, while in other hydrogen atoms in the molecule have been replaced with deuterium. Insects can choose the branch, which they preferred.
Fruit flies, which have been known to have a strong sense of smell, gave a definite preference for a molecule with a high content of hydrogen and showed an aversion to a molecule containing deuterium, which is increased in proportion as the hydrogen is replaced. When fruit flies genetically modified, depriving them of the ability to smell, they do not show any preference.
Dr. Skulakis said that these results support a new theory of smell, first derived in 1996, co-authored by Luca Turin (Luca Turin), biophysicist, who now works at the Massachusetts Institute of Technology in Cambridge in the United States. The new theory implies that the odorous substances found their vibrations, rather than their form.
Deuterium differs from the normal hydrogen isotope so that its core comprises a proton and a neutron, proton and not only. This is roughly double the weight of an atom of deuterium, and so long as it has properties similar to those of a normal hydrogen, a large mass means that the link between the deuterium and the other atoms within the molecules vibrate more slowly.
The basic theory of how the olfactory sense, is that the odoriferous molecules are found in the olfactory receptor proteins membranes due to their shape, which fit in shape to a cavity located in the protein, like a key in the lock. If the molecule is suitable, the signal sent to the brain.
Turin same theory is that the electrons of odorous substances are able to penetrate the membrane receptor binding elements only if the molecule is vibrated at the correct frequency accurate. Once the odorant with normal hydrogen will have different vibrational properties of odor deuterium two components will smell different, even if their shape will remain the same.
As a further confirmation of the scientists investigated the reaction of Drosophila to nitrites (nitriles), organic compounds having similar vibrational frequencies in the same binding element of the carbon content of deuterium. Fruit flies have shown an aversion to nitriles, as expected.
People have not been seen ability to distinguish between compounds containing heavy hydrogen and normal, but the doctor Turin announced the existence of unpublished information about the existence of this ability, at least one dog that ignores smelling substance, discovered that the molecule contains deuterium.
The research paper was published in the journal Proceedings of the National Academy of Sciences (PNAS).
Original: Physorg Translation: M. Potter