Accurate perception of taste information is crucial for animal survival. In adult Drosophila, gustatory receptor neurons (GRNs) perceive chemical stimuli of one specific gustatory modality associated with a stereotyped behavioural response, such as aversion or attraction. We show that GRNs of Drosophila larvae employ a surprisingly different mode of gustatory information coding. Using a novel method for calcium imaging in the larval gustatory system, we identify a multimodal GRN that responds to chemicals of different taste modalities with opposing valence, such as sweet sucrose and bitter denatonium, reliant on different sensory receptors. This multimodal neuron is essential for bitter compound avoidance, and its artificial activation is sufficient to mediate aversion. However, the neuron is also essential for the integration of taste blends. Our findings support a model for taste coding in larvae, in which distinct receptor proteins mediate different responses within the same, multimodal GRN.

Nature Communications 7: Article number: 10687 (2016); Published: 11 February 2016; Updated: 14 March 2016. The affiliation details for Martino Colombo, Rémy Bruggmann and Richard Benton are incorrect in this article. The correct affiliations for these authors are listed below. Martino Colombo, RémyBruggmann Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Berne, Berne 3012, Switzerland.

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