Mushroom Body Efferent Neurons Responsible For Aversive Olfactory Memory Retrieval In Drosophila

Julien Séjourné (1) , Pierre-Yves Plaçais (1) , Yoshinori Aso (1) , Igor Siwanowicz (1) , Séverine Trannoy (1) , Vladimiros Thoma (1) , Stevanus Rio Tedjakumala (1) , Gerald M. Rubin (1) , Paul Tchénio (1) , Kei Ito (1) , Guillaume Isabel (1) , Hiromu Tanimoto (1) , Thomas Preat (1)

1 GDSM, CNRS

Aversive olfactory memory is formed in the Drosophila mushroom bodies (MB). Memory retrieval requires MB output, but it remains unknown how a memory trace in the MB drives conditioned avoidance of a learned odour. To identify neurons involved in olfactory memory retrieval, we performed an anatomical and functional screen of defined sets of MB extrinsic neurons. Here we show that MB-V2 neurons are essential for retrieval of both short- and long-lasting memory, but neither for memory formation nor for memory consolidation. We further show that MB-V2 are cholinergic efferent neurons that project from the MB vertical lobes to the middle superiormedial protocerebrum and the lateral horn (LH). Notably, the odour response of MB-V2 neurons is modified after conditioning. As the LH is implicated in innate responses to repellent odorants, we propose that during memory retrieval, MB-V2 neurons reinforce the olfactory pathway involved in innate odour avoidance.

Mots clés: Memory; Behaviour; Learning; Neuroimaging; Animal behaviour; Neurogenetics

Julien Séjourné, Pierre-Yves Plaçais, Yoshinori Aso, Igor Siwanowicz, Séverine Trannoy, et al.. Mushroom Body Efferent Neurons Responsible For Aversive Olfactory Memory Retrieval In Drosophila. Nature Neuroscience, 2011, ⟨10.1038/nn.2846⟩. ⟨hal-00653182⟩