A closed-loop optogenetic screen for neurons controlling feeding in Drosophila

Abstract

Feeding is an essential part of animal life that is greatly impacted by the sense of taste. Although the characterization of taste-detection at the periphery has been extensive, higher-order taste and feeding circuits are still being elucidated. Here, we use an automated closed-loop optogenetic activation screen to detect novel taste and feeding neurons in Drosophila melanogaster. Out of 122 Janelia FlyLight Project GAL4 lines preselected based on expression pattern, we identify six lines that acutely promote feeding and 35 lines that inhibit it. As proof of principle, we follow up on R70C07-GAL4, which labels neurons that strongly inhibit feeding. Using split-GAL4 lines to isolate subsets of the R70C07-GAL4 population, we find both appetitive and aversive neurons. Furthermore, we show that R70C07-GAL4 labels putative second-order taste interneurons that contact both sweet and bitter sensory neurons. These results serve as a resource for further functional dissection of fly feeding circuits.

Neural circuit plasticity underlying learning and memory in Drosophila melanogaster: from synaptic connections to behavior

“…The cell-specific targeting nature of the split-GAL4 technique made it one of the most platitudinous systems in mapping and manipulating the fly nervous system. With an array of accessible genetic constructs and manipulation tools, this system is employed in various studies ranging from investigating neural circuits and connectomics Eichler et al, 2017;Li et al, 2020), to dissecting simple and complex behaviors, notably feeding (Lau et al, 2021), locomotion (Bidaye et al, 2014) and learning and memory Saumweber et al, 2018).…”