From Sensory Detection to Motor Action: The Comprehensive Drosophila Taste-Feeding Connectome

In Drosophila, the gustatory system is distributed across multiple body parts and tightly couples sensory input to value-based behaviors such as feeding, foraging, and social interactions. Despite this, it has remained one of the least mapped sensory modalities at the EM connectome level. Here, we present the first complete wiring diagram of the adult gustatory system, comprehensively reconstructing gustatory receptor neurons (GRNs) from all peripheral organs in a contiguous EM volume spanning brain, cervical connective, and ventral nerve cord. By integrating this male dataset with existing female and male datasets, we generate a pan-CNS, cross-sex connectome, identify GRN types and subtypes via connectivity-based clustering, assign molecular identities, and uncover sexually dimorphic circuits. We also map all feeding motor neurons and trace how GRN pathways connect to motor and endocrine targets. Using computational approaches, we predict how sensory input is transformed into feeding, foraging, ingestion, and social behaviors, as well as feedforward neuroendocrine regulation. This defines the action space of the gustatory system and provides a unique framework for understanding how internal states shape taste-driven decisions.