Activity of defined mushroom body output neurons underlies learned olfactory behavior in Drosophila.

ABSTRACT: During olfactory learning in fruit flies, dopaminergic neurons assign value to odor representations in the mushroom body Kenyon cells. Here we identify a class of downstream glutamatergic mushroom body output neurons (MBONs) called M4/6, or MBON-?2?'2a, MBON-?'2mp, and MBON-?5?'2a, whose dendritic fields overlap with dopaminergic neuron projections in the tips of the ?, ?', and ? lobes. This anatomy and their odor tuning suggests that M4/6 neurons pool odor-driven Kenyon cell synaptic outputs. Like that of mushroom body neurons, M4/6 output is required for expression of appetitive and aversive memory performance. Moreover, appetitive and aversive olfactory conditioning bidirectionally alters the relative odor-drive of M4?' neurons (MBON-?'2mp). Direct block of M4/6 neurons in naive flies mimics appetitive conditioning, being sufficient to convert odor-driven avoidance into approach, while optogenetically activating these neurons induces avoidance behavior. We therefore propose that drive to the M4/6 neurons reflects odor-directed behavioral choice.

SUBMITTER: Owald D 

PROVIDER: S-EPMC4416108 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature