title: Olfactory coding in the honeybee lateral horn.
abstract: Olfactory systems dynamically encode odor information in the nervous system. Insects constitute a well-established model for the study of the neural processes underlying olfactory perception. In insects, odors are detected by sensory neurons located in the antennae, whose axons project to a primary processing center, the antennal lobe. There, the olfactory message is reshaped and further conveyed to higher-order centers, the mushroom bodies and the lateral horn. Previous work has intensively analyzed the principles of olfactory processing in the antennal lobe and in the mushroom bodies. However, how the lateral horn participates in olfactory coding remains comparatively more enigmatic. We studied odor representation at the input to the lateral horn of the honeybee, a social insect that relies on both floral odors for foraging and pheromones for social communication. Using in vivo calcium imaging, we show consistent neural activity in the honeybee lateral horn upon stimulation with both floral volatiles and social pheromones. Recordings reveal odor-specific maps in this brain region as stimulations with the same odorant elicit more similar spatial activity patterns than stimulations with different odorants. Odor-similarity relationships are mostly conserved between antennal lobe and lateral horn, so that odor maps recorded in the lateral horn allow predicting bees' behavioral responses to floral odorants. In addition, a clear segregation of odorants based on pheromone type is found in both structures. The lateral horn thus contains an odor-specific map with distinct representations for the different bee pheromones, a prerequisite for eliciting specific behaviors.
authors.affiliation: Research Center on Animal Cognition, Université de Toulouse (UPS), 118 Route de Narbonne, 31062 Toulouse Cedex 9, France; Research Center on Animal Cognition, Centre National de la Recherche Scientifique (CNRS), 118 Route de Narbonne, 31062 Toulouse Cedex 9, France.
authors.forename: Edith
authors.initials: E
authors.lastname: Roussel
authors.affiliation: Research Center on Animal Cognition, Université de Toulouse (UPS), 118 Route de Narbonne, 31062 Toulouse Cedex 9, France; Research Center on Animal Cognition, Centre National de la Recherche Scientifique (CNRS), 118 Route de Narbonne, 31062 Toulouse Cedex 9, France; Evolution, Genomes, and Speciation Lab, CNRS (UPR 9034), 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Carcaud
authors.affiliation: Research Center on Animal Cognition, Université de Toulouse (UPS), 118 Route de Narbonne, 31062 Toulouse Cedex 9, France; Research Center on Animal Cognition, Centre National de la Recherche Scientifique (CNRS), 118 Route de Narbonne, 31062 Toulouse Cedex 9, France.
authors.forename: Maud
authors.initials: M
authors.lastname: Combe
authors.affiliation: Research Center on Animal Cognition, Université de Toulouse (UPS), 118 Route de Narbonne, 31062 Toulouse Cedex 9, France; Research Center on Animal Cognition, Centre National de la Recherche Scientifique (CNRS), 118 Route de Narbonne, 31062 Toulouse Cedex 9, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Giurfa
authors.affiliation: Evolution, Genomes, and Speciation Lab, CNRS (UPR 9034), 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France. Electronic address: sandoz@legs.cnrs-gif.fr.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Sandoz
mesh_terms: D000447:Aldehydes; D000818:Animals; D057506:Arthropod Antennae / Q000502:physiology*; D001516:Bees / Q000502:physiology*; D002118:Calcium / Q000032:analysis; D035264:Flowers / Q000737:chemistry; D000441:Hexanols; D009812:Odorants; D009833:Olfactory Pathways / Q000502:physiology; D010675:Pheromones; D011984:Sensory Receptor Cells
chemical_list: D000447:Aldehydes; D000441:Hexanols; D010675:Pheromones; C036260:1-hexanol; D002118:Calcium; C031639:caprylic aldehyde