Supersensitive detection and discrimination of enantiomers by dorsal olfactory receptors: evidence for hierarchical odour coding
| Autor: | Makoto Emura, Hiroshi Hamana, Akio Tsuboi, Takaaki Sato, Miwako Kizumi, Junzo Hirono, Shigeyoshi Itohara, Ko Kobayakawa, Reiko Kobayakawa |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Dorsum
Olfactory system Male Transgene Stereoisomerism Mice Transgenic Wine Cyclohexane Monoterpenes Biology Article Olfactory Receptor Neurons Lactones Mice Discrimination Psychological Animals Humans Gene Knock-In Techniques Receptor chemistry.chemical_classification Mice Inbred BALB C Multidisciplinary Highly sensitive Mice Inbred C57BL Biochemistry chemistry Odorants Monoterpenes Enantiomer Lactone |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | Enantiomeric pairs of mirror-image molecular structures are difficult to resolve by instrumental analyses. The human olfactory system, however, discriminates (−)-wine lactone from its (+)-form rapidly within seconds. To gain insight into receptor coding of enantiomers, we compared behavioural detection and discrimination thresholds of wild-type mice with those of ΔD mice in which all dorsal olfactory receptors are genetically ablated. Surprisingly, wild-type mice displayed an exquisite “supersensitivity” to enantiomeric pairs of wine lactones and carvones. They were capable of supersensitive discrimination of enantiomers, consistent with their high detection sensitivity. In contrast, ΔD mice showed selective major loss of sensitivity to the (+)-enantiomers. The resulting 108-fold differential sensitivity of ΔD mice to (−)- vs. (+)-wine lactone matched that observed in humans. This suggests that humans lack highly sensitive orthologous dorsal receptors for the (+)-enantiomer, similarly to ΔD mice. Moreover, ΔD mice showed >1010-fold reductions in enantiomer discrimination sensitivity compared to wild-type mice. ΔD mice detected one or both of the (−)- and (+)-enantiomers over a wide concentration range, but were unable to discriminate them. This “enantiomer odour discrimination paradox” indicates that the most sensitive dorsal receptors play a critical role in hierarchical odour coding for enantiomer identification. |
| Databáze: | OpenAIRE |
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