title: Brief sensory experience differentially affects the volume of olfactory brain centres in a moth.
abstract: Experience modifies behaviour in animals so that they adapt to their environment. In male noctuid moths, Spodoptera littoralis, brief pre-exposure to various behaviourally relevant sensory signals modifies subsequent behaviour towards the same or different sensory modalities. Correlated with a behavioural increase in responses of male moths to the female-emitted sex pheromone after pre-exposure to olfactory, acoustic or gustatory stimuli, an increase in sensitivity of olfactory neurons within the primary olfactory centre, the antennal lobe, is found for olfactory and acoustic stimuli, but not for gustatory stimuli. Here, we investigated whether anatomical changes occurring in the antennal lobes and in the mushroom bodies (the secondary olfactory centres) possibly correlated with the changes observed in behaviour and in olfactory neuron physiology. Our results showed that significant volume changes occurred in glomeruli (olfactory units) responsive to sex pheromone following exposure to both pheromone and predator sounds. The volume of the mushroom body input region (calyx) also increased significantly after pheromone and predator sound treatment. However, we found no changes in the volume of antennal lobe glomeruli or of the mushroom body calyx after pre-exposure to sucrose. These findings show a relationship of antennal lobe sensitivity changes to the pheromone with changes in the volume of the related glomeruli and the output area of antennal lobe projection neurons elicited by sensory cues causing a behavioural change. Behavioural changes observed after sucrose pre-exposure must originate from changes in higher integration centres in the brain.
authors.affiliation: Neuroéthologie-RCIM, INRA-Université d'Angers, UPRES EA 2647, USC INRA 1330, SFR 4207 QUASAV, 42 Rue Georges Morel, 49071, Beaucouzé, France. sylvia.anton@angers.inra.fr.|Institut d'Ecologie et des Sciences de l'Environnement de Paris, INRA, Route de Saint Cyr, 78026, Versailles cedex, France. sylvia.anton@angers.inra.fr.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Anton
authors.affiliation: Laboratoire Récepteurs et Canaux Ioniques Membranaires (RCIM), UPRES EA 2647, USC INRA 1330 SFR, 4207 QUASAV, Université d'Angers, UFR Sciences, Angers, France.
authors.forename: Marie-Ange
authors.initials: MA
authors.lastname: Chabaud
authors.affiliation: Institut d'Ecologie et des Sciences de l'Environnement de Paris, INRA, Route de Saint Cyr, 78026, Versailles cedex, France.
authors.forename: Daniela
authors.initials: D
authors.lastname: Schmidt-Büsser
authors.affiliation: Institut d'Ecologie et des Sciences de l'Environnement de Paris, INRA, Route de Saint Cyr, 78026, Versailles cedex, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Gadenne
authors.affiliation: Institut d'Ecologie et des Sciences de l'Environnement de Paris, INRA, Route de Saint Cyr, 78026, Versailles cedex, France.|Department of Entomology, University College of Agriculture & Environmental Sciences, The Islamia University of Bahawalpur, Bahawalpur, Pakistan.
authors.forename: Javaid
authors.initials: J
authors.lastname: Iqbal
authors.affiliation: IMAC, SFR QUASAV 4207, Université d'Angers, Beaucouzé, France.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Juchaux
authors.affiliation: Laboratoire Récepteurs et Canaux Ioniques Membranaires (RCIM), UPRES EA 2647, USC INRA 1330 SFR, 4207 QUASAV, Université d'Angers, UFR Sciences, Angers, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: List
authors.affiliation: Institut d'Ecologie et des Sciences de l'Environnement de Paris, INRA, Route de Saint Cyr, 78026, Versailles cedex, France.|Centre de Recherches sur la Cognition Animale, Université de Toulouse, UPS, 118 Route de Narbonne, 31062, Toulouse, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Gaertner
authors.affiliation: Centre de Recherches sur la Cognition Animale, CNRS, 118 Route de Narbonne, 31062, Toulouse, France.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Devaud
mesh_terms: D000818:Animals; D005260:Female; D017950:Ganglia, Sensory / Q000166:cytology / Q000378:metabolism*; D008297:Male; D024521:Mushroom Bodies / Q000166:cytology; D018034:Olfactory Receptor Neurons / Q000166:cytology / Q000378:metabolism*; D018411:Spodoptera / Q000166:cytology / Q000378:metabolism*
keywords: Antennal lobe; Multimodal interaction; Mushroom body; Pheromone; Sensory experience; Spodoptera littoralis