title: The coding of odour-intensity in the honeybee antennal lobe: local computation optimizes odour representation.
abstract: We investigated strategies involved in odour intensity coding by the primary olfactory centre of insects, the antennal lobe (AL), the structural and functional analogue of the olfactory bulb. Using calcium imaging in the honeybee, we simultaneously measured the projection neuron output responses and a compound signal dominated by receptor neuron input in identified olfactory glomeruli to odours spanning seven log units of concentration. A comparison of the two processing levels indicates that the intercellular computation within the AL modulates and contrast-enhances the primary olfactory signals. As a result the AL network optimizes the olfactory code: odour representation is improved at lower concentrations, the relative activity of olfactory glomeruli allows encoding odour quality over up to four log-unit concentrations, and odour-intensity is reliably represented in the overall excitation across AL.
authors: Institut für Biologie - Neurobiologie, Freie Universität Berlin, Königin-Luise Str. 28-30, 14195 Berlin, Germany.
authors: Silke
authors: S
authors: Sachse
authors: C Giovanni
authors: CG
authors: Galizia
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D000818:Animals; D001516:Bees; D002118:Calcium / Q000378:metabolism; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods; D004056:Differential Threshold / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes / Q000378:metabolism; D000441:Hexanols / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D009433:Neural Inhibition / Q000187:drug effects; D000442:Octanols / Q000494:pharmacology; D009812:Odorants; D009830:Olfactory Bulb / Q000187:drug effects / Q000502:physiology*; D009833:Olfactory Pathways / Q000187:drug effects / Q000502:physiology*; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000502:physiology*; D012679:Sense Organs / Q000187:drug effects / Q000502:physiology*; D013268:Stimulation, Chemical
chemical_list: D000447:Aldehydes; D005456:Fluorescent Dyes; D000441:Hexanols; D000442:Octanols; C008664:nonanal; D002118:Calcium