RT Journal Article SR Electronic T1 Cellular Basis of Bitter-Driven Aversive Behaviors in Drosophila Larva JF eneuro JO eNeuro FD Society for Neuroscience SP ENEURO.0510-19.2020 DO 10.1523/ENEURO.0510-19.2020 VO 7 IS 2 A1 Jaekyun Choi A1 Seungyun Yu A1 Min Sung Choi A1 Sooin Jang A1 I Joon Han A1 G. Larisa Maier A1 Simon G. Sprecher A1 Jae Young Kwon YR 2020 UL http://www.eneuro.org/content/7/2/ENEURO.0510-19.2020.abstract AB Feeding, a critical behavior for survival, consists of a complex series of behavioral steps. In Drosophila larvae, the initial steps of feeding are food choice, during which the quality of a potential food source is judged, and ingestion, during which the selected food source is ingested into the digestive tract. It remains unclear whether these steps employ different mechanisms of neural perception. Here, we provide insight into the two initial steps of feeding in Drosophila larva. We find that substrate choice and ingestion are determined by independent circuits at the cellular level. First, we took 22 candidate bitter compounds and examined their influence on choice preference and ingestion behavior. Interestingly, certain bitter tastants caused different responses in choice and ingestion, suggesting distinct mechanisms of perception. We further provide evidence that certain gustatory receptor neurons (GRNs) in the external terminal organ (TO) are involved in determining choice preference, and a pair of larval pharyngeal GRNs is involved in mediating both avoidance and suppression of ingestion. Our results show that feeding behavior is coordinated by a multistep regulatory process employing relatively independent neural elements. These findings are consistent with a model in which distinct sensory pathways act as modulatory circuits controlling distinct subprograms during feeding.