title: Molecular vibration-sensing component in Drosophila melanogaster olfaction.
abstract: A common explanation of molecular recognition by the olfactory system posits that receptors recognize the structure or shape of the odorant molecule. We performed a rigorous test of shape recognition by replacing hydrogen with deuterium in odorants and asking whether Drosophila melanogaster can distinguish these identically shaped isotopes. We report that flies not only differentiate between isotopic odorants, but can be conditioned to selectively avoid the common or the deuterated isotope. Furthermore, flies trained to discriminate against the normal or deuterated isotopes of a compound, selectively avoid the corresponding isotope of a different odorant. Finally, flies trained to avoid a deuterated compound exhibit selective aversion to an unrelated molecule with a vibrational mode in the energy range of the carbon-deuterium stretch. These findings are inconsistent with a shape-only model for smell, and instead support the existence of a molecular vibration-sensing component to olfactory reception.
authors.affiliation: Institute of Cellular and Developmental Biology, Biomedical Sciences Research Centre Alexander Fleming, Vari 16672, Greece.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Franco
authors.forename: Luca
authors.initials: L
authors.lastname: Turin
authors.forename: Andreas
authors.initials: A
authors.lastname: Mershin
authors.forename: Efthimios M C
authors.initials: EM
authors.lastname: Skoulakis
mesh_terms: D000818:Animals; D003214:Conditioning, Classical / Q000187:drug effects; D003463:Cues; D003903:Deuterium / Q000494:pharmacology; D004192:Discrimination, Psychological / Q000187:drug effects; D004331:Drosophila melanogaster / Q000502:physiology*; D012677:Sensation / Q000187:drug effects / Q000502:physiology*; D012903:Smell / Q000187:drug effects / Q000502:physiology*; D014732:Vibration
chemical_list: D003903:Deuterium