title: Insulin effects on honeybee appetitive behaviour.
abstract: Worker honeybees (Apis mellifera) carry out multiple tasks throughout their adult lifespan. It has been suggested that the insulin/insulin-like signalling pathway participates in regulating behavioural maturation in eusocial insects. Insulin signalling increases as the honeybee worker transitions from nurse to food processor to forager. As behavioural shifts require differential usage of sensory modalities, our aim was to assess insulin effects on olfactory and gustatory responsiveness as well as on olfactory learning in preforaging honeybee workers of different ages. Adults were reared in the laboratory or in the hive. Immediately after being injected with insulin or vehicle (control), and focusing on the proboscis extension response, bees were tested for their spontaneous response to odours, sucrose responsiveness and ability to discriminate odours through olfactory conditioning. Bees injected with insulin have higher spontaneous odour responses. Sucrose responsiveness and odour discrimination are differentially affected by treatment according to age: whereas insulin increases gustatory responsiveness and diminishes learning abilities of younger workers, it has the opposite effect on older bees. In summary, insulin can improve chemosensory responsiveness in young workers, but also worsens their learning abilities to discriminate odours. The insulin signalling pathway is responsive in young workers, although they are not yet initiating outdoor activities. Our results show strong age-dependent effects of insulin on appetitive behaviour, which uncover differences in insulin signalling regulation throughout the honeybee worker's adulthood.
authors.affiliation: Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, (C1428EHA) Buenos Aires, Argentina.
authors.forename: Carolina
authors.initials: C
authors.lastname: Mengoni Goñalons
authors.affiliation: Université de Toulouse, UPS, Centre de Recherches sur la Cognition Animale, CNRS, F-31062, Toulouse Cedex 9, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Guiraud
authors.affiliation: Université de Toulouse, UPS, Centre de Recherches sur la Cognition Animale, CNRS, F-31062, Toulouse Cedex 9, France.
authors.forename: María Gabriela
authors.initials: MG
authors.lastname: de Brito Sanchez
authors.affiliation: Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, (C1428EHA) Buenos Aires, Argentina walter@fbmc.fcen.uba.ar.
authors.forename: Walter M
authors.identifier: 0000-0001-6411-489X
authors.initials: WM
authors.lastname: Farina
mesh_terms: D000375:Aging / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects / Q000502:physiology*; D001516:Bees / Q000187:drug effects / Q000502:physiology*; D003214:Conditioning, Classical / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects; D004777:Environment; D007328:Insulin / Q000494:pharmacology*; D009812:Odorants / Q000032:analysis; D013649:Taste / Q000187:drug effects
chemical_list: D007328:Insulin
keywords: Apis mellifera; Associative learning; Chemosensory perception; Insulin; Odour discrimination; Sucrose