Odors: from chemical structures to gaseous plumes

Abstract

We are immersed within an odorous sea of chemical currents that we parse into individual odors with complex structures. Odors have been posited as determined by the structural relation between the molecules that compose the chemical compounds and their interactions with the receptor site. But, naturally occurring smells are parsed from gaseous odor plumes. To give a comprehensive account of the nature of odors the chemosciences must account for these large distributed entities as well. We offer a focused review of what is known about the perception of odor plumes for olfactory navigation and tracking, which we then connect to what is known about the role odorants play as properties of the plume in determining odor identity with respect to odor quality. We end by motivating our central claim that more research needs to be conducted on the role that odorants play within the odor plume in determining odor identity.

Keywords: Odor identity; Odor plume; Odor receptor; Olfaction; Olfactory quality.

Figure 1.

The figure shows 2D-chemical structures of isotopic variants of Ethyl acetate. Ethyl acetate depicted in the top panel is composed of Hydrogen atoms while the same molecule in the bottom panel is deuterated (composed of Deuterium atoms). Similar to how water is composed of a mixture of H₂O and D₂O molecules, an ethyl acetate odor plume is likely composed of a mixture of the hydrogenated and deuterated forms of the molecule.