@article {69949, title = {Proprioceptive limit detectors mediate sensorimotor control of the Drosophila leg}, journal = {Nat Commun}, year = {2026}, month = {2026 Feb 12}, abstract = {

Many animals possess mechanosensory neurons that fire when a limb nears the limit of its physical range, but the function of these proprioceptive limit detectors remains poorly understood. Here, we investigate a class of proprioceptors on the Drosophila leg called hair plates. Using calcium imaging in behaving flies, we find that a hair plate on the fly coxa (CxHP8) detects the limits of anterior leg movement. By reconstructing CxHP8 axons in an electron microscopy dataset, we found that they are wired to excite posterior leg movement and inhibit anterior leg movement. Consistent with this connectivity, optogenetic activation of CxHP8 neurons elicited posterior postural reflexes, while silencing altered the swing-to-stance transition during walking. Finally, we use comprehensive reconstruction of peripheral morphology and downstream connectivity to predict the function of other hair plates distributed across the fly leg. Our results suggest that each hair plate is specialized to control specific sensorimotor reflexes that are matched to the joint limit it detects. They also illustrate the feasibility of predicting sensorimotor reflexes from a connectome with identified proprioceptive inputs and motor outputs.

}, doi = {10.1038/s41467-026-69333-z}, url = {https://doi.org/10.1038/s41467-026-69333-z}, author = {Pratt, Brandon G. and Dallmann, Chris J. and Chou, Grant M. and Siwanowicz, Igor and Walling-Bell, Sarah and Cook, Andrew and Sustar, Anne and Azevedo, Anthony and Tuthill, John C.} } @article {70047, title = {Distributed control circuits across a brain-and-cord connectome}, journal = {bioRxiv}, year = {2025}, month = {2025 Aug 02}, abstract = {

Just as genomes revolutionized molecular genetics, connectomes (maps of neurons and synapses) are transforming neuroscience. To date, the only species with complete connectomes are worms\ and sea squirts\ (103-104 synapses). By contrast, the fruit fly is more complex (108 synaptic connections), with a brain that supports learning and spatial memory and an intricate ventral nerve cord analogous to the vertebrate spinal cord. Here we report the first adult fly connectome that unites the brain and ventral nerve cord, and we leverage this resource to investigate principles of neural control. We show that effector cells (motor neurons, endocrine cells and efferent neurons targeting the viscera) are primarily influenced by local sensory cells in the same body part, forming local feedback loops. These local loops are linked by long-range circuits involving ascending and descending neurons organized into behavior-centric modules. Single ascending and descending neurons are often positioned to influence the voluntary movements of multiple body parts, together with endocrine cells or visceral organs that support those movements. Brain regions involved in learning and navigation supervise these circuits. These results reveal an architecture that is distributed, parallelized and embodied (tightly connected to effectors), reminiscent of distributed control architectures in engineered systems.

}, doi = {10.1101/2025.07.31.667571}, url = {https://www.biorxiv.org/content/early/2025/08/02/2025.07.31.667571}, author = {Bates, Alexander Shakeel and Phelps, Jasper S. and Kim, Minsu and Yang, Helen H. and Matsliah, Arie and Ajabi, Zaki and Perlman, Eric and Delgado, Kevin M. and Osman, Mohammed Abdal Monium and Salmon, Christopher K. and Gager, Jay and Silverman, Benjamin and Renauld, Sophia and Collie, Matthew F. and Fan, Jingxuan and Pacheco, Diego A. and Zhao, Yunzhi and Patel, Janki and Zhang, Wenyi and Serratosa Capdevilla, Laia and Roberts, Ruair{\'\i} J.V. and Munnelly, Eva J. and Griggs, Nina and Langley, Helen and Moya-Llamas, Borja and Maloney, Ryan T. and Yu, Szi-Chieh and Sterling, Amy R. and Sorek, Marissa and Kruk, Krzysztof and Serafetinidis, Nikitas and Dhawan, Serene and St{\"u}rner, Tomke and Klemm, Finja and Brooks, Paul and Lesser, Ellen and Jones, Jessica M. and Pierce-Lundgren, Sara E. and Lee, Su-Yee and Luo, Yichen and Cook, Andrew P. and McKim, Theresa H. and Kophs, Emily C. and Falt, Tjalda and Negr{\'o}n Morales, Alexa M. and Burke, Austin and Hebditch, James and Willie, Kyle P. and Willie, Ryan and Popovych, Sergiy and Kemnitz, Nico and Ih, Dodam and Lee, Kisuk and Lu, Ran and Halageri, Akhilesh and Bae, J. Alexander and Jourdan, Ben and Schwartzman, Gregory and Demarest, Damian D. and Behnke, Emily and Bland, Doug and Kristiansen, Anne and Skelton, Jaime and Stocks, Tom and Garner, Dustin and Salman, Farzaan and Daly, Kevin C. and Hernandez, Anthony and Kumar, Sandeep and The BANC-FlyWire Consortium and Dorkenwald, Sven and Collman, Forrest and Suver, Marie P. and Fenk, Lisa M. and Pankratz, Michael J. and Jefferis, Gregory S.X.E. and Eichler, Katharina and Seeds, Andrew M. and Hampel, Stefanie and Agrawal, Sweta and Zandawala, Meet and Macrina, Thomas and Adjavon, Diane-Yayra and Funke, Jan and Tuthill, John C. and Azevedo, Anthony and Seung, H. Sebastian and de Bivort, Benjamin L. and Murthy, Mala and Drugowitsch, Jan and Wilson, Rachel I. and Lee, Wei-Chung Allen} } @article {65833, title = {Reconstruction of motor control circuits in adult Drosophila using automated transmission electron microscopy}, journal = {Cell}, volume = {184}, year = {2021}, month = {2021 Feb 04}, abstract = {

Many animals use coordinated limb movements to interact with and navigate through the environment. To investigate circuit mechanisms underlying locomotor behavior, we used serial-section electron microscopy (EM) to map synaptic connectivity within a neuronal network that controls limb movements. We present a synapse-resolution EM dataset containing the ventral nerve cord (VNC) of an adult female Drosophila melanogaster. To generate this dataset, we developed GridTape, a technology that combines automated serial-section collection with automated high-throughput transmission EM. Using this dataset, we reconstructed 507 motor neurons, including all those that control the legs and wings. We show that a specific class of leg sensory neurons directly synapse onto the largest-caliber motor neuron axons on both sides of the body, representing a unique feedback pathway for fast limb control. We provide open access to the dataset and reconstructions registered to a standard atlas to permit matching of cells between EM and light microscopy data. We also provide GridTape instrumentation designs and software to make large-scale EM data acquisition more accessible and affordable to the scientific community.

}, doi = {10.1101/2020.01.10.902478}, author = {Maniates-Selvin, Jasper T. and Hildebrand, David Grant Colburn and Graham, Brett J. and Kuan, Aaron T. and Thomas, Logan A. and Nguyen, Tri and Buhmann, Julia and Azevedo, Anthony W. and Shanny, Brendan L. and Funke, Jan and Tuthill, John C. and Lee, Wei-Chung Allen} }