title: A combined perceptual, physico-chemical, and imaging approach to 'odour-distances' suggests a categorizing function of the Drosophila antennal lobe.
abstract: How do physico-chemical stimulus features, perception, and physiology relate? Given the multi-layered and parallel architecture of brains, the question specifically is where physiological activity patterns correspond to stimulus features and/or perception. Perceived distances between six odour pairs are defined behaviourally from four independent odour recognition tasks. We find that, in register with the physico-chemical distances of these odours, perceived distances for 3-octanol and n-amylacetate are consistently smallest in all four tasks, while the other five odour pairs are about equally distinct. Optical imaging in the antennal lobe, using a calcium sensor transgenically expressed in only first-order sensory or only second-order olfactory projection neurons, reveals that 3-octanol and n-amylacetate are distinctly represented in sensory neurons, but appear merged in projection neurons. These results may suggest that within-antennal lobe processing funnels sensory signals into behaviourally meaningful categories, in register with the physico-chemical relatedness of the odours.
authors.affiliation: Biozentrum, Neurobiologie und Genetik, Universität Würzburg, Würzburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Niewalda
authors.forename: Thomas
authors.initials: T
authors.lastname: Völler
authors.forename: Claire
authors.initials: C
authors.lastname: Eschbach
authors.forename: Julia
authors.initials: J
authors.lastname: Ehmer
authors.forename: Wen-Chuang
authors.initials: WC
authors.lastname: Chou
authors.forename: Marc
authors.initials: M
authors.lastname: Timme
authors.forename: André
authors.initials: A
authors.lastname: Fiala
authors.forename: Bertram
authors.initials: B
authors.lastname: Gerber
mesh_terms: D000818:Animals; D057506:Arthropod Antennae / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology; D004331:Drosophila melanogaster / Q000502:physiology*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D009154:Mutation / Q000235:genetics; D009812:Odorants / Q000032:analysis*; D018034:Olfactory Receptor Neurons / Q000502:physiology; D010465:Perception / Q000502:physiology*