TY - JOUR T1 - <em>Drosophila</em> gustatory projections are segregated by taste modality and connectivity JF - bioRxiv DO - 10.1101/2021.12.08.471796 SP - 2021.12.08.471796 AU - Stefanie Engert AU - Gabriella R. Sterne AU - David T. Harris AU - Kristin Scott Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/12/09/2021.12.08.471796.abstract N2 - Gustatory sensory neurons detect caloric and harmful compounds in potential food and convey this information to the brain to inform feeding decisions. To examine the signals that gustatory neurons transmit and receive, we reconstructed gustatory axons and their synaptic sites in the adult Drosophila melanogaster brain, utilizing a whole-brain electron microscopy volume. We reconstructed 87 gustatory projections from the proboscis labellum in the right hemisphere and 57 in the left, representing the majority of labellar gustatory axons. Morphology- and connectivity-based clustering revealed six distinct clusters, likely representing neurons recognizing different taste modalities. Gustatory neurons contain a nearly equal number of interspersed pre-and post-synaptic sites, with extensive synaptic connectivity among gustatory axons. The vast majority of synaptic connections are between morphologically similar neurons, although connections also exist between distinct neuronal subpopulations. This study resolves the anatomy of labellar gustatory projections, reveals that gustatory projections are likely segregated based on taste modality, and uncovers synaptic connections that may alter the transmission of gustatory signals.Competing Interest StatementThe authors have declared no competing interest. ER -