Sensing of amino acids in a dopaminergic circuitry promotes rejection of an incomplete diet in Drosophila.
The brain is the central organizer of food intake, matching the quality and quantity of the food sources with organismal needs. To ensure appropriate amino acid balance, many species reject a diet lacking one or several essential amino acids (EAAs) and seek out a better food source. Here, we show that, in Drosophila larvae, this behavior relies on innate sensing of amino acids in dopaminergic (DA) neurons of the brain. We demonstrate that the amino acid sensor GCN2 acts upstream of GABA signaling in DA neurons to promote avoidance of the EAA-deficient diet. Using real-time calcium imaging in larval brains, we show that amino acid imbalance induces a rapid and reversible activation of three DA neurons that are necessary and sufficient for food rejection. Taken together, these data identify a central amino-acid-sensing mechanism operating in specific DA neurons and controlling food intake.
University of Nice-Sophia Antipolis, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; CNRS, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; INSERM, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France.
Marianne
M
Bjordal
University of Nice-Sophia Antipolis, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; CNRS, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; INSERM, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France.
Nathalie
N
Arquier
Institut de Génomique Fonctionnelle, CNRS UMR5203, INSERM U661, Université Montpellier 1 & 2, 34094 Montpellier, France.
Julie
J
Kniazeff
Institut de Génomique Fonctionnelle, CNRS UMR5203, INSERM U661, Université Montpellier 1 & 2, 34094 Montpellier, France.
Jean Philippe
JP
Pin
University of Nice-Sophia Antipolis, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; CNRS, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France; INSERM, Institute of Biology Valrose, Parc Valrose, 06108 Nice, France. Electronic address: leopold@unice.fr.
Pierre
P
Léopold
D000601:Amino Acids, Essential / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000502:physiology*; D004435:Eating; D009474:Neurons / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D000601:Amino Acids, Essential; D029721:Drosophila Proteins; D005680:gamma-Aminobutyric Acid; C585051:GCN2 protein, Drosophila; D011494:Protein Kinases