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Updated: Aug 8, 2026

Assaying Surface Expression of Chemosensory Receptors in Heterologous Cells
Published on: February 23, 2011
Sensory evidence for olfactory receptors with opposite chiral selectivity
E H Polak1, A M Fombon, C Tilquin
1Université Paris VI, Laboratoire de neurophysiologie Comparée, France.
Abstract:
Human odor responses to alpha-ionone enantiomers were measured by psycho-physical methods. Surprisingly, subjects' relative sensitivities for these enantiomers were found to diverge widely, some subjects being much more sensitive to (+) than to (-) and vice versa. In 63 subjects the (+)/(-) threshold concentration ratio varied over 4 orders of magnitude. Nine subjects with extreme (+)/(-) ratios were further tested several times over a 7-month period and retained stable ratios. These same nine subjects, when tested for threshold sensitivity to carvone enantiomers, showed (+)/(-) ratios that varied only in a narrow range and did not correlate with their ionone ratios. It is suggested that odor discrimination of alpha-ionone enantiomers involves at least two receptor types of opposite chiral selectivity and that their distribution varies independently in the human population.
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