Sense of smell is complemented by the detection of molecular vibrations
Human beings have the ability to identify vibrational characteristics in the sense of smell to differentiate between the odors of different chemicals.
This research has been published online in the journal PLoS ONE.
Molecular vibration refers to the periodic motion of the atoms in the molecules.
Previously, researchers found that fruit flies have vibrational mechanism that helps them to identify the presence of deuterium in odorants. Deuterium is an isotope of hydrogen that alters the frequency of the vibrations of the molecules. So you can say that the hydrogen containing molecules are similar to the deuterium containing molecules but their vibrational states are different.
Researchers were of the opinion that with a limited number of smell receptors in our noses, there must be a combination of shape and vibrational senses that can help us in differentiation of smell of one chemical that is very similar in shape to another.
Researchers in this study asked the participants to differentiate between the forms of musks with vibrational component (deuterated) and without vibrational component (undeuterated).
Researchers found that the participants were able to differentiate between deuterated musk and the undeuterated musk.
Researchers have noted that musk odor and molecular structure have some relation, and musks are at the upper end of the molecular weight scale for odorants. They have also pointed that a small number of receptors and possibly one is involved in detecting the musk odor.
Researchers are of the opinion that if the sense of smell has some form of vibrational components than the smell receptor probably covers one part of the vibrational range. Based on these findings, they suggested that smell of musk is achieved after completion of three conditions, i.e. Molecular size is large, one or more receptors of smell can detect molecular vibrations in the range of 1380–1550 cm-1 and the range of frequencies in that region is intense.
Gane, S., Georganakis, D., Maniati, K., Vamvakias, M., Ragoussis, N., Skoulakis, E., & Turin, L. (2013). Molecular Vibration-Sensing Component in Human Olfaction PLoS ONE, 8 (1) DOI: 10.1371/journal.pone.0055780