@article {68828, title = {Organization of an Ascending Circuit that Conveys Flight Motor State}, journal = {bioRxiv}, year = {2023}, month = {2023 Jun 09}, abstract = {

Natural behaviors are a coordinated symphony of motor acts which drive self-induced or reafferent sensory activation. Single sensors only signal presence and magnitude of a sensory cue; they cannot disambiguate exafferent (externally-induced) from reafferent sources. Nevertheless, animals readily differentiate between these sources of sensory signals to make appropriate decisions and initiate adaptive behavioral outcomes. This is mediated by predictive motor signaling mechanisms, which emanate from motor control pathways to sensory processing pathways, but how predictive motor signaling circuits function at the cellular and synaptic level is poorly understood. We use a variety of techniques, including connectomics from both male and female electron microscopy volumes, transcriptomics, neuroanatomical, physiological and behavioral approaches to resolve the network architecture of two pairs of ascending histaminergic neurons (AHNs), which putatively provide predictive motor signals to several sensory and motor neuropil. Both AHN pairs receive input primarily from an overlapping population of descending neurons, many of which drive wing motor output. The two AHN pairs target almost exclusively non-overlapping downstream neural networks including those that process visual, auditory and mechanosensory information as well as networks coordinating wing, haltere, and leg motor output. These results support the conclusion that the AHN pairs multi-task, integrating a large amount of common input, then tile their output in the brain, providing predictive motor signals to non-overlapping sensory networks affecting motor control both directly and indirectly.

}, doi = {10.1101/2023.06.07.544074}, url = {https://doi.org/10.1101/2023.06.07.544074}, author = {Han S. J. Cheong and Kaitlyn N. Boone and Marryn M. Bennett and Farzaan Salman and Jacob D. Ralston and Kaleb Hatch and Raven F. Allen and Alec M. Phelps and Andrew P. Cook and Jasper S. Phelps and Mert Erginkaya and Wei-Chung A. Lee and Gwyneth M. Card and Kevin C. Daly and Andrew M. Dacks} } @article {68274, title = {Biomechanical origins of proprioceptive maps in the Drosophila leg}, journal = {bioRxiv}, year = {2022}, month = {2022 Aug 09}, abstract = {

Proprioception, the sense of body position and movement, is essential for effective motor control. Because proprioceptive sensory neurons are embedded in complex and dynamic tissues, it has been challenging to understand how they sense and encode mechanical stimuli. Here, we find that proprioceptor neurons in the\ Drosophila\ femur are organized into functional groups that are biomechanically specialized to detect features of tibia joint kinematics. The dendrites of position and vibration-tuned proprioceptors receive distinct mechanical signals via the\ arculum, an elegant mechanical structure that decomposes movement of the tibia joint into orthogonal components. The cell bodies of position-tuned proprioceptors form a\ goniotopic\ map of joint angle, whereas the dendrites of vibration-tuned proprioceptors form a\ tonotopic\ map of tibia vibration frequency. Our findings reveal biomechanical mechanisms that underlie proprioceptor feature selectivity and identify common organizational principles between proprioception and other topographically organized sensory systems.

}, doi = {10.1101/2022.08.08.503192}, url = {https://doi.org/10.1101/2022.08.08.503192}, author = {Akira Mamiya and Pralaksha Gurung and Igor Siwanowicz and Anne Sustar and Chenghao Chen and Jasper S. Phelps and Aaron T. Kuan and Alexandra Pacureanu and Wei-Chung Allen Lee and Natasha Mhatre and John C. Tuthill} }