PT - JOURNAL ARTICLE AU - KJ Weaver AU - S Raju AU - RA Rucker AU - TS Chakraborty AU - RA Holt AU - SD Pletcher TI - Behavioral dissection of hunger states in <em>Drosophila</em> AID - 10.1101/2022.11.11.516105 DP - 2022 Jan 01 TA - bioRxiv PG - 2022.11.11.516105 4099 - http://biorxiv.org/content/early/2022/11/14/2022.11.11.516105.short 4100 - http://biorxiv.org/content/early/2022/11/14/2022.11.11.516105.full AB - Hunger is a motivational drive that promotes feeding, and it can be generated by the physiological need to consume nutrients as well as the hedonic properties of food. Brain circuits and mechanisms that regulate feeding have been described, but which of these contribute to the generation of motive forces that drive feeding is unclear. Here, we describe our first efforts at behaviorally and neuronally distinguishing hedonic from homeostatic hunger states in Drosophila melanogaster and propose that this system can be used as a model to dissect the molecular mechanisms that underlie feeding motivation. We visually identify and quantify behaviors exhibited by hungry flies and find that increased feeding duration is a behavioral signature of hedonic feeding motivation. Using a genetically-encoded marker of neuronal activity, we find that the mushroom body (MB) lobes are activated by hedonic food environments, and we use optogenetic inhibition to implicate a PAM&gt;α’/β’ MB circuit in hedonic feeding motivation. The identification of discrete hunger states in flies and the development of behavioral assays to measure them offers a framework to begin dissecting the molecular and circuit mechanisms that generate motivational states in the brain.Competing Interest StatementThe senior author (S.D.P) is a share holder in the company, Flidea, which has developed technology related to the FLIC feeding system