1
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Lesser E, Azevedo AW, Phelps JS, Elabbady L, Cook A, Syed DS, Mark B, Kuroda S, Sustar A, Moussa A, Dallmann CJ, Agrawal S, Lee SYJ, Pratt B, Skutt-Kakaria K, Gerhard S, Lu R, Kemnitz N, Lee K, Halageri A, Castro M, Ih D, Gager J, Tammam M, Dorkenwald S, Collman F, Schneider-Mizell C, Brittain D, Jordan CS, Macrina T, Dickinson M, Lee WCA, Tuthill JC. Synaptic architecture of leg and wing premotor control networks in Drosophila. Nature 2024; 631:369-377. [PMID: 38926579 DOI: 10.1038/s41586-024-07600-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
Animal movement is controlled by motor neurons (MNs), which project out of the central nervous system to activate muscles1. MN activity is coordinated by complex premotor networks that facilitate the contribution of individual muscles to many different behaviours2-6. Here we use connectomics7 to analyse the wiring logic of premotor circuits controlling the Drosophila leg and wing. We find that both premotor networks cluster into modules that link MNs innervating muscles with related functions. Within most leg motor modules, the synaptic weights of each premotor neuron are proportional to the size of their target MNs, establishing a circuit basis for hierarchical MN recruitment. By contrast, wing premotor networks lack proportional synaptic connectivity, which may enable more flexible recruitment of wing steering muscles. Through comparison of the architecture of distinct motor control systems within the same animal, we identify common principles of premotor network organization and specializations that reflect the unique biomechanical constraints and evolutionary origins of leg and wing motor control.
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Affiliation(s)
- Ellen Lesser
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Anthony W Azevedo
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Jasper S Phelps
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Neuroengineering Laboratory, Brain Mind Institute and Institute of Bioengineering, EPFL, Lausanne, Switzerland
| | - Leila Elabbady
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Andrew Cook
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | | | - Brandon Mark
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Sumiya Kuroda
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Anne Sustar
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Anthony Moussa
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Chris J Dallmann
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Sweta Agrawal
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Su-Yee J Lee
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Brandon Pratt
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | | | - Stephan Gerhard
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- UniDesign Solutions LLC, Zurich, Switzerland
| | - Ran Lu
- Zetta AI, LLC, Sherrill, NY, USA
| | | | - Kisuk Lee
- Zetta AI, LLC, Sherrill, NY, USA
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | | | | | - Dodam Ih
- Zetta AI, LLC, Sherrill, NY, USA
| | | | | | - Sven Dorkenwald
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
- Computer Science Department, Princeton University, Princeton, NJ, USA
| | | | | | | | - Chris S Jordan
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | | | | | - Wei-Chung Allen Lee
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - John C Tuthill
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA.
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2
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Azevedo A, Lesser E, Phelps JS, Mark B, Elabbady L, Kuroda S, Sustar A, Moussa A, Khandelwal A, Dallmann CJ, Agrawal S, Lee SYJ, Pratt B, Cook A, Skutt-Kakaria K, Gerhard S, Lu R, Kemnitz N, Lee K, Halageri A, Castro M, Ih D, Gager J, Tammam M, Dorkenwald S, Collman F, Schneider-Mizell C, Brittain D, Jordan CS, Dickinson M, Pacureanu A, Seung HS, Macrina T, Lee WCA, Tuthill JC. Connectomic reconstruction of a female Drosophila ventral nerve cord. Nature 2024; 631:360-368. [PMID: 38926570 DOI: 10.1038/s41586-024-07389-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 04/04/2024] [Indexed: 06/28/2024]
Abstract
A deep understanding of how the brain controls behaviour requires mapping neural circuits down to the muscles that they control. Here, we apply automated tools to segment neurons and identify synapses in an electron microscopy dataset of an adult female Drosophila melanogaster ventral nerve cord (VNC)1, which functions like the vertebrate spinal cord to sense and control the body. We find that the fly VNC contains roughly 45 million synapses and 14,600 neuronal cell bodies. To interpret the output of the connectome, we mapped the muscle targets of leg and wing motor neurons using genetic driver lines2 and X-ray holographic nanotomography3. With this motor neuron atlas, we identified neural circuits that coordinate leg and wing movements during take-off. We provide the reconstruction of VNC circuits, the motor neuron atlas and tools for programmatic and interactive access as resources to support experimental and theoretical studies of how the nervous system controls behaviour.
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Affiliation(s)
- Anthony Azevedo
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Ellen Lesser
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Jasper S Phelps
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Neuroengineering Laboratory, Brain Mind Institute and Institute of Bioengineering, EPFL, Lausanne, Switzerland
| | - Brandon Mark
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Leila Elabbady
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Sumiya Kuroda
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Anne Sustar
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Anthony Moussa
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Avinash Khandelwal
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Chris J Dallmann
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Sweta Agrawal
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Su-Yee J Lee
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Brandon Pratt
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Andrew Cook
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | | | - Stephan Gerhard
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- UniDesign Solutions, Zurich, Switzerland
| | - Ran Lu
- Zetta AI, Sherrill, NJ, USA
| | | | - Kisuk Lee
- Zetta AI, Sherrill, NJ, USA
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | | | | | | | | | | | - Sven Dorkenwald
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
- Computer Science Department, Princeton University, Princeton, NJ, USA
| | | | | | | | - Chris S Jordan
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | | | | | | | | | - Wei-Chung Allen Lee
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - John C Tuthill
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA.
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3
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Syed DS, Ravbar P, Simpson JH. Inhibitory circuits coordinate leg movements during Drosophila grooming. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.05.597468. [PMID: 38895414 PMCID: PMC11185647 DOI: 10.1101/2024.06.05.597468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Limbs execute diverse actions coordinated by the nervous system through multiple motor programs. The basic architecture of motor neurons that activate muscles which articulate joints for antagonistic flexion and extension movements is conserved from flies to vertebrates. While excitatory premotor circuits are expected to establish sets of leg motor neurons that work together, our study uncovered an instructive role for inhibitory circuits. Using electron microscopy data for the Drosophila nerve cord, we categorized ~120 GABAergic inhibitory neurons from the 13A and 13B hemi-lineages into classes based on similarities in morphology and connectivity. By mapping their synaptic partners, we uncovered redundant pathways for inhibiting specific groups of motor neurons, disinhibiting antagonistic counterparts, or inducing alternation between flexion and extension. We tested the function of specific inhibitory neurons through optogenetic activation and silencing, using quantitative leg movement assays for coordination during grooming. Behavior experiments and modeling demonstrate that inhibition can induce rhythmic motion, highlighting the importance of inhibitory circuits in motor control.
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Affiliation(s)
- Durafshan Sakeena Syed
- UC Santa Barbara, Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, Santa Barbara, CA, USA
| | - Primoz Ravbar
- UC Santa Barbara, Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, Santa Barbara, CA, USA
| | - Julie H. Simpson
- UC Santa Barbara, Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, Santa Barbara, CA, USA
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4
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Braun J, Hurtak F, Wang-Chen S, Ramdya P. Descending networks transform command signals into population motor control. Nature 2024; 630:686-694. [PMID: 38839968 PMCID: PMC11186778 DOI: 10.1038/s41586-024-07523-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 05/06/2024] [Indexed: 06/07/2024]
Abstract
To convert intentions into actions, movement instructions must pass from the brain to downstream motor circuits through descending neurons (DNs). These include small sets of command-like neurons that are sufficient to drive behaviours1-the circuit mechanisms for which remain unclear. Here we show that command-like DNs in Drosophila directly recruit networks of additional DNs to orchestrate behaviours that require the active control of numerous body parts. Specifically, we found that command-like DNs previously thought to drive behaviours alone2-4 in fact co-activate larger populations of DNs. Connectome analyses and experimental manipulations revealed that this functional recruitment can be explained by direct excitatory connections between command-like DNs and networks of interconnected DNs in the brain. Descending population recruitment is necessary for behavioural control: DNs with many downstream descending partners require network co-activation to drive complete behaviours and drive only simple stereotyped movements in their absence. These DN networks reside within behaviour-specific clusters that inhibit one another. These results support a mechanism for command-like descending control in which behaviours are generated through the recruitment of increasingly large DN networks that compose behaviours by combining multiple motor subroutines.
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Affiliation(s)
- Jonas Braun
- Neuroengineering Laboratory, Brain Mind Institute & Interfaculty Institute of Bioengineering, EPFL, Lausanne, Switzerland
| | - Femke Hurtak
- Neuroengineering Laboratory, Brain Mind Institute & Interfaculty Institute of Bioengineering, EPFL, Lausanne, Switzerland
| | - Sibo Wang-Chen
- Neuroengineering Laboratory, Brain Mind Institute & Interfaculty Institute of Bioengineering, EPFL, Lausanne, Switzerland
| | - Pavan Ramdya
- Neuroengineering Laboratory, Brain Mind Institute & Interfaculty Institute of Bioengineering, EPFL, Lausanne, Switzerland.
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5
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Zhu Y, Cho K, Lacin H, Zhu Y, DiPaola JT, Wilson BA, Patti GJ, Skeath JB. Loss of dihydroceramide desaturase drives neurodegeneration by disrupting endoplasmic reticulum and lipid droplet homeostasis in glial cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.01.573836. [PMID: 38260379 PMCID: PMC10802327 DOI: 10.1101/2024.01.01.573836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Dihydroceramide desaturases convert dihydroceramides to ceramides, the precursors of all complex sphingolipids. Reduction of DEGS1 dihydroceramide desaturase function causes pediatric neurodegenerative disorder hypomyelinating leukodystrophy-18 (HLD-18). We discovered that infertile crescent (ifc), the Drosophila DEGS1 homolog, is expressed primarily in glial cells to promote CNS development by guarding against neurodegeneration. Loss of ifc causes massive dihydroceramide accumulation and severe morphological defects in cortex glia, including endoplasmic reticulum (ER) expansion, failure of neuronal ensheathment, and lipid droplet depletion. RNAi knockdown of the upstream ceramide synthase schlank in glia of ifc mutants rescues ER expansion, suggesting dihydroceramide accumulation in the ER drives this phenotype. RNAi knockdown of ifc in glia but not neurons drives neuronal cell death, suggesting that ifc function in glia promotes neuronal survival. Our work identifies glia as the primary site of disease progression in HLD-18 and may inform on juvenile forms of ALS, which also feature elevated dihydroceramide levels.
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Affiliation(s)
- Yuqing Zhu
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
| | - Kevin Cho
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Mass Spectrometry and Metabolic Tracing, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Haluk Lacin
- Division of Biological and Biomedical Systems, University of Missouri-Kansas City, Kansas City, MO 64110, USA
| | - Yi Zhu
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
| | - Jose T DiPaola
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
| | - Beth A Wilson
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
| | - Gary J Patti
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Mass Spectrometry and Metabolic Tracing, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - James B Skeath
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St. Louis, MO 63110, USA
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6
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Yoshikawa S, Tang P, Simpson JH. Mechanosensory and command contributions to the Drosophila grooming sequence. Curr Biol 2024; 34:2066-2076.e3. [PMID: 38657610 PMCID: PMC11179149 DOI: 10.1016/j.cub.2024.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/14/2024] [Accepted: 04/02/2024] [Indexed: 04/26/2024]
Abstract
Flies groom in response to competing mechanosensory cues in an anterior-to-posterior order using specific legs. From behavior screens, we identified a pair of cholinergic command-like neurons, Mago-no-Te (MGT), whose optogenetic activation elicits thoracic grooming by the back legs. Thoracic grooming is typically composed of body sweeps and leg rubs in alternation, but clonal analysis coupled with amputation experiments revealed that MGT activation only commands the body sweeps: initiation of leg rubbing requires contact between the leg and thorax. With new electron microscopy (EM) connectome data for the ventral nerve cord (VNC), we uncovered a circuit-based explanation for why stimulation of posterior thoracic mechanosensory bristles initiates cleaning by the back legs. Our previous work showed that flies weigh mechanosensory inputs across the body to select which part to groom, but we did not know why the thorax was always cleaned last. Here, the connectome for the VNC enabled us to identify a pair of GABAergic inhibitory neurons, UMGT1, that receives diverse sensory inputs and synapses onto both MGT and components of its downstream circuits. Optogenetic activation of UMGT1 suppresses thoracic cleaning, representing a mechanism by which mechanosensory stimuli on other body parts could take precedence in the grooming hierarchy. We also anatomically mapped the pre-motor circuit downstream of MGT, including inhibitory feedback connections that may enable rhythmicity and coordination of limb movement during thoracic grooming. The combination of behavioral screens and connectome analysis allowed us to identify a neural circuit connecting sensory-to-motor neurons that contributes to thoracic grooming.
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Affiliation(s)
- Shingo Yoshikawa
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Paul Tang
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Julie H Simpson
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
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7
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Dallmann CJ, Luo Y, Agrawal S, Chou GM, Cook A, Brunton BW, Tuthill JC. Presynaptic inhibition selectively suppresses leg proprioception in behaving Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.20.563322. [PMID: 37961558 PMCID: PMC10634730 DOI: 10.1101/2023.10.20.563322] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Controlling arms and legs requires feedback from proprioceptive sensory neurons that detect joint position and movement. Proprioceptive feedback must be tuned for different behavioral contexts, but the underlying circuit mechanisms remain poorly understood. Using calcium imaging in behaving Drosophila, we find that the axons of position-encoding leg proprioceptors are active across behaviors, whereas the axons of movement-encoding leg proprioceptors are suppressed during walking and grooming. Using connectomics, we identify a specific class of interneurons that provide GABAergic presynaptic inhibition to the axons of movement-encoding proprioceptors. The predominant synaptic inputs to these interneurons are descending neurons, suggesting they are driven by predictions of leg movement originating in the brain. Calcium imaging from both the interneurons and their descending inputs confirmed that their activity is correlated with self-generated but not passive leg movements. Overall, our findings elucidate a neural circuit for suppressing specific proprioceptive feedback signals during self-generated movements.
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Affiliation(s)
- Chris J. Dallmann
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
- Present address: Department of Neurobiology and Genetics, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Yichen Luo
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Sweta Agrawal
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
- Present address: School of Neuroscience, Virginia Tech, Blacksburg, VA, USA
| | - Grant M. Chou
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Andrew Cook
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | | | - John C. Tuthill
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
- Lead contact
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8
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Lee SYJ, Dallmann CJ, Cook AP, Tuthill JC, Agrawal S. Divergent neural circuits for proprioceptive and exteroceptive sensing of the Drosophila leg. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.23.590808. [PMID: 38712128 PMCID: PMC11071415 DOI: 10.1101/2024.04.23.590808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Somatosensory neurons provide the nervous system with information about mechanical forces originating inside and outside the body. Here, we use connectomics to reconstruct and analyze neural circuits downstream of the largest somatosensory organ in the Drosophila leg, the femoral chordotonal organ (FeCO). The FeCO has been proposed to support both proprioceptive sensing of the fly's femur-tibia joint and exteroceptive sensing of substrate vibrations, but it remains unknown which sensory neurons and central circuits contribute to each of these functions. We found that different subtypes of FeCO sensory neurons feed into distinct proprioceptive and exteroceptive pathways. Position- and movement-encoding FeCO neurons connect to local leg motor control circuits in the ventral nerve cord (VNC), indicating a proprioceptive function. In contrast, signals from the vibration-encoding FeCO neurons are integrated across legs and transmitted to auditory regions in the brain, indicating an exteroceptive function. Overall, our analyses reveal the structure of specialized circuits for processing proprioceptive and exteroceptive signals from the fly leg. They also demonstrate how analyzing patterns of synaptic connectivity can distill organizing principles from complex sensorimotor circuits.
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9
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Eckstein N, Bates AS, Champion A, Du M, Yin Y, Schlegel P, Lu AKY, Rymer T, Finley-May S, Paterson T, Parekh R, Dorkenwald S, Matsliah A, Yu SC, McKellar C, Sterling A, Eichler K, Costa M, Seung S, Murthy M, Hartenstein V, Jefferis GSXE, Funke J. Neurotransmitter classification from electron microscopy images at synaptic sites in Drosophila melanogaster. Cell 2024; 187:2574-2594.e23. [PMID: 38729112 PMCID: PMC11106717 DOI: 10.1016/j.cell.2024.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 10/04/2023] [Accepted: 03/13/2024] [Indexed: 05/12/2024]
Abstract
High-resolution electron microscopy of nervous systems has enabled the reconstruction of synaptic connectomes. However, we do not know the synaptic sign for each connection (i.e., whether a connection is excitatory or inhibitory), which is implied by the released transmitter. We demonstrate that artificial neural networks can predict transmitter types for presynapses from electron micrographs: a network trained to predict six transmitters (acetylcholine, glutamate, GABA, serotonin, dopamine, octopamine) achieves an accuracy of 87% for individual synapses, 94% for neurons, and 91% for known cell types across a D. melanogaster whole brain. We visualize the ultrastructural features used for prediction, discovering subtle but significant differences between transmitter phenotypes. We also analyze transmitter distributions across the brain and find that neurons that develop together largely express only one fast-acting transmitter (acetylcholine, glutamate, or GABA). We hope that our publicly available predictions act as an accelerant for neuroscientific hypothesis generation for the fly.
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Affiliation(s)
- Nils Eckstein
- HHMI Janelia Research Campus, Ashburn, VA, USA; Institute of Neuroinformatics UZH/ETHZ, Zurich, Switzerland
| | - Alexander Shakeel Bates
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK; Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK; Department of Neurobiology and Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Andrew Champion
- Drosophila Connectomics Group, Department of Zoology, University of Cambridge, Cambridge, UK
| | - Michelle Du
- HHMI Janelia Research Campus, Ashburn, VA, USA
| | - Yijie Yin
- Drosophila Connectomics Group, Department of Zoology, University of Cambridge, Cambridge, UK
| | - Philipp Schlegel
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK; Drosophila Connectomics Group, Department of Zoology, University of Cambridge, Cambridge, UK
| | | | | | | | | | | | - Sven Dorkenwald
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Arie Matsliah
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Szi-Chieh Yu
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Claire McKellar
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Amy Sterling
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Katharina Eichler
- Drosophila Connectomics Group, Department of Zoology, University of Cambridge, Cambridge, UK
| | - Marta Costa
- Drosophila Connectomics Group, Department of Zoology, University of Cambridge, Cambridge, UK
| | - Sebastian Seung
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Mala Murthy
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Gregory S X E Jefferis
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK; Drosophila Connectomics Group, Department of Zoology, University of Cambridge, Cambridge, UK.
| | - Jan Funke
- HHMI Janelia Research Campus, Ashburn, VA, USA.
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10
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Lesser E, Azevedo AW, Phelps JS, Elabbady L, Cook A, Sakeena Syed D, Mark B, Kuroda S, Sustar A, Moussa A, Dallmann CJ, Agrawal S, Lee SYJ, Pratt B, Skutt-Kakaria K, Gerhard S, Lu R, Kemnitz N, Lee K, Halageri A, Castro M, Ih D, Gager J, Tammam M, Dorkenwald S, Collman F, Schneider-Mizell C, Brittain D, Jordan CS, Macrina T, Dickinson M, Lee WCA, Tuthill JC. Synaptic architecture of leg and wing premotor control networks in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.30.542725. [PMID: 37398440 PMCID: PMC10312524 DOI: 10.1101/2023.05.30.542725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Animal movement is controlled by motor neurons (MNs), which project out of the central nervous system to activate muscles. MN activity is coordinated by complex premotor networks that allow individual muscles to contribute to many different behaviors. Here, we use connectomics to analyze the wiring logic of premotor circuits controlling the Drosophila leg and wing. We find that both premotor networks cluster into modules that link MNs innervating muscles with related functions. Within most leg motor modules, the synaptic weights of each premotor neuron are proportional to the size of their target MNs, establishing a circuit basis for hierarchical MN recruitment. In contrast, wing premotor networks lack proportional synaptic connectivity, which may allow wing steering muscles to be recruited with different relative timing. By comparing the architecture of distinct limb motor control systems within the same animal, we identify common principles of premotor network organization and specializations that reflect the unique biomechanical constraints and evolutionary origins of leg and wing motor control.
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Affiliation(s)
- Ellen Lesser
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Anthony W. Azevedo
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Jasper S. Phelps
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Leila Elabbady
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Andrew Cook
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | | | - Brandon Mark
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Sumiya Kuroda
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Anne Sustar
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Anthony Moussa
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Chris J. Dallmann
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Sweta Agrawal
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Su-Yee J. Lee
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Brandon Pratt
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | | | - Stephan Gerhard
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- UniDesign Solutions LLC, Switzerland
| | | | | | - Kisuk Lee
- Zetta AI, LLC, USA
- Princeton Neuroscience Institute, Princeton University, NJ, USA
| | | | | | | | | | | | - Sven Dorkenwald
- Princeton Neuroscience Institute, Princeton University, NJ, USA
- Computer Science Department, Princeton University, NJ, USA
| | | | | | | | - Chris S. Jordan
- Princeton Neuroscience Institute, Princeton University, NJ, USA
| | | | | | - Wei-Chung Allen Lee
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, MA, USA
| | - John C. Tuthill
- Department of Physiology and Biophysics, University of Washington, WA, USA
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11
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Nunes WVB, Oliveira DS, Dias GDR, Carvalho AB, Caruso ÍP, Biselli JM, Guegen N, Akkouche A, Burlet N, Vieira C, Carareto CMA. A comprehensive evolutionary scenario for the origin and neofunctionalization of the Drosophila speciation gene Odysseus (OdsH). G3 (BETHESDA, MD.) 2024; 14:jkad299. [PMID: 38156703 PMCID: PMC10917504 DOI: 10.1093/g3journal/jkad299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 11/22/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
Odysseus (OdsH) was the first speciation gene described in Drosophila related to hybrid sterility in offspring of mating between Drosophila mauritiana and Drosophila simulans. Its origin is attributed to the duplication of the gene unc-4 in the subgenus Sophophora. By using a much larger sample of Drosophilidae species, we showed that contrary to what has been previously proposed, OdsH origin occurred 62 MYA. Evolutionary rates, expression, and transcription factor-binding sites of OdsH evidence that it may have rapidly experienced neofunctionalization in male sexual functions. Furthermore, the analysis of the OdsH peptide allowed the identification of mutations of D. mauritiana that could result in incompatibility in hybrids. In order to find if OdsH could be related to hybrid sterility, beyond Sophophora, we explored the expression of OdsH in Drosophila arizonae and Drosophila mojavensis, a pair of sister species with incomplete reproductive isolation. Our data indicated that OdsH expression is not atypical in their male-sterile hybrids. In conclusion, we have proposed that the origin of OdsH occurred earlier than previously proposed, followed by neofunctionalization. Our results also suggested that its role as a speciation gene might be restricted to D. mauritiana and D. simulans.
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Affiliation(s)
- William Vilas Boas Nunes
- Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (Unesp), 2265 Cristóvão Colombo Street, 15054-000 São José do Rio Preto, Brazil
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, Université de Lyon, Université Lyon 1, CNRS, Bât. Grégor Mendel, 43 Boulevard 11 Novembre 1918, 69622 Villeurbanne, France
| | - Daniel Siqueira Oliveira
- Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (Unesp), 2265 Cristóvão Colombo Street, 15054-000 São José do Rio Preto, Brazil
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, Université de Lyon, Université Lyon 1, CNRS, Bât. Grégor Mendel, 43 Boulevard 11 Novembre 1918, 69622 Villeurbanne, France
| | - Guilherme de Rezende Dias
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, CCS sl A2-075, 373 Carlos Chagas Filho Avenue, 21941-971 Rio de Janeiro, Brazil
| | - Antonio Bernardo Carvalho
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, CCS sl A2-075, 373 Carlos Chagas Filho Avenue, 21941-971 Rio de Janeiro, Brazil
| | - Ícaro Putinhon Caruso
- Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (Unesp), 2265 Cristóvão Colombo Street, 15054-000 São José do Rio Preto, Brazil
| | - Joice Matos Biselli
- Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (Unesp), 2265 Cristóvão Colombo Street, 15054-000 São José do Rio Preto, Brazil
| | - Nathalie Guegen
- Faculté de Médecine, iGReD, Université Clermont Auvergne, CNRS, INSERM, 4 Bd Claude Bernard, 63000 Clermont-Ferrande, France
| | - Abdou Akkouche
- Faculté de Médecine, iGReD, Université Clermont Auvergne, CNRS, INSERM, 4 Bd Claude Bernard, 63000 Clermont-Ferrande, France
| | - Nelly Burlet
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, Université de Lyon, Université Lyon 1, CNRS, Bât. Grégor Mendel, 43 Boulevard 11 Novembre 1918, 69622 Villeurbanne, France
| | - Cristina Vieira
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, Université de Lyon, Université Lyon 1, CNRS, Bât. Grégor Mendel, 43 Boulevard 11 Novembre 1918, 69622 Villeurbanne, France
| | - Claudia M A Carareto
- Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (Unesp), 2265 Cristóvão Colombo Street, 15054-000 São José do Rio Preto, Brazil
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12
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Yin C, Morita T, Parrish JZ. A cell atlas of the larval Aedes aegypti ventral nerve cord. Neural Dev 2024; 19:2. [PMID: 38297398 PMCID: PMC10829479 DOI: 10.1186/s13064-023-00178-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 11/28/2023] [Indexed: 02/02/2024] Open
Abstract
Mosquito-borne diseases account for nearly 1 million human deaths annually, yet we have a limited understanding of developmental events that influence host-seeking behavior and pathogen transmission in mosquitoes. Mosquito-borne pathogens are transmitted during blood meals, hence adult mosquito behavior and physiology have been intensely studied. However, events during larval development shape adult traits, larvae respond to many of the same sensory cues as adults, and larvae are susceptible to infection by many of the same disease-causing agents as adults. Hence, a better understanding of larval physiology will directly inform our understanding of physiological processes in adults. Here, we use single cell RNA sequencing (scRNA-seq) to provide a comprehensive view of cellular composition in the Aedes aegypti larval ventral nerve cord (VNC), a central hub of sensory inputs and motor outputs which additionally controls multiple aspects of larval physiology. We identify more than 35 VNC cell types defined in part by neurotransmitter and neuropeptide expression. We also explore diversity among monoaminergic and peptidergic neurons that likely control key elements of larval physiology and developmental timing, and identify neuroblasts and immature neurons, providing a view of neuronal differentiation in the VNC. Finally, we find that larval cell composition, number, and position are preserved in the adult abdominal VNC, suggesting studies of larval VNC form and function will likely directly inform our understanding adult mosquito physiology. Altogether, these studies provide a framework for targeted analysis of VNC development and neuronal function in Aedes aegypti larvae.
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Affiliation(s)
- Chang Yin
- Department of Biology, University of Washington, Seattle, WA, 98195, USA
- Division of Education, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA
| | - Takeshi Morita
- Division of Education, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY, 10065, USA
- Howard Hughes Medical Institute, New York, NY, 10065, USA
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, WA, 98195, USA.
- Division of Education, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA.
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13
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Cooney PC, Huang Y, Li W, Perera DM, Hormigo R, Tabachnik T, Godage IS, Hillman EMC, Grueber WB, Zarin AA. Neuromuscular basis of Drosophila larval rolling escape behavior. Proc Natl Acad Sci U S A 2023; 120:e2303641120. [PMID: 38096410 PMCID: PMC10743538 DOI: 10.1073/pnas.2303641120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 10/06/2023] [Indexed: 12/18/2023] Open
Abstract
When threatened by dangerous or harmful stimuli, animals engage in diverse forms of rapid escape behaviors. In Drosophila larvae, one type of escape response involves C-shaped bending and lateral rolling followed by rapid forward crawling. The sensory circuitry that promotes larval escape has been extensively characterized; however, the motor programs underlying rolling are unknown. Here, we characterize the neuromuscular basis of rolling escape behavior. We used high-speed, volumetric, Swept Confocally Aligned Planar Excitation (SCAPE) microscopy to image muscle activity during larval rolling. Unlike sequential peristaltic muscle contractions that progress from segment to segment during forward and backward crawling, muscle activity progresses circumferentially during bending and rolling escape behavior. We propose that progression of muscular contraction around the larva's circumference results in a transient misalignment between weight and the ground support forces, which generates a torque that induces stabilizing body rotation. Therefore, successive cycles of slight misalignment followed by reactive aligning rotation lead to continuous rolling motion. Supporting our biomechanical model, we found that disrupting the activity of muscle groups undergoing circumferential contraction progression leads to rolling defects. We use EM connectome data to identify premotor to motor connectivity patterns that could drive rolling behavior and perform neural silencing approaches to demonstrate the crucial role of a group of glutamatergic premotor neurons in rolling. Our data reveal body-wide muscle activity patterns and putative premotor circuit organization for execution of the rolling escape response.
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Affiliation(s)
- Patricia C. Cooney
- Grueber Laboratory, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY10027
- Department of Neuroscience, Columbia University, New York, NY10027
| | - Yuhan Huang
- Department of Biology, Texas A&M University, College Station, TX77843
- Zarin Laboratory, Texas A&M Institute for Neuroscience, Texas A&M University, College Station, TX77843
| | - Wenze Li
- Laboratory for Functional Optical Imaging, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY10027
- Department of Electrical Engineering, Columbia University, New York, NY10027
| | - Dulanjana M. Perera
- Department of Multidisciplinary Engineering, Texas A&M University, College Station, TX77843
| | - Richard Hormigo
- Grueber Laboratory, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY10027
| | - Tanya Tabachnik
- Grueber Laboratory, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY10027
| | - Isuru S. Godage
- Department of Multidisciplinary Engineering, Texas A&M University, College Station, TX77843
- Department of Engineering Technology and Industrial Distribution, Texas A&M University, College Station, TX77843
- J. Mike Walker ‘66 Department of Mechanical Engineering, Texas A&M University, College Station, TX77843
| | - Elizabeth M. C. Hillman
- Laboratory for Functional Optical Imaging, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY10027
- Department of Biomedical Engineering, Columbia University, New York, NY10027
- Laboratory for Functional Optical Imaging, Kavli Institute for Brain Science, Columbia University, New York, NY10032
| | - Wesley B. Grueber
- Grueber Laboratory, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY10027
- Department of Neuroscience, Columbia University, New York, NY10027
- Department of Physiology and Cellular Biophysics, Jerome L. Greene Science Center, New York, NY10027
| | - Aref A. Zarin
- Department of Biology, Texas A&M University, College Station, TX77843
- Zarin Laboratory, Texas A&M Institute for Neuroscience, Texas A&M University, College Station, TX77843
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14
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Tanaka R, Zhou B, Agrochao M, Badwan BA, Au B, Matos NCB, Clark DA. Neural mechanisms to incorporate visual counterevidence in self-movement estimation. Curr Biol 2023; 33:4960-4979.e7. [PMID: 37918398 PMCID: PMC10848174 DOI: 10.1016/j.cub.2023.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 10/07/2023] [Accepted: 10/09/2023] [Indexed: 11/04/2023]
Abstract
In selecting appropriate behaviors, animals should weigh sensory evidence both for and against specific beliefs about the world. For instance, animals measure optic flow to estimate and control their own rotation. However, existing models of flow detection can be spuriously triggered by visual motion created by objects moving in the world. Here, we show that stationary patterns on the retina, which constitute evidence against observer rotation, suppress inappropriate stabilizing rotational behavior in the fruit fly Drosophila. In silico experiments show that artificial neural networks (ANNs) that are optimized to distinguish observer movement from external object motion similarly detect stationarity and incorporate negative evidence. Employing neural measurements and genetic manipulations, we identified components of the circuitry for stationary pattern detection, which runs parallel to the fly's local motion and optic-flow detectors. Our results show how the fly brain incorporates negative evidence to improve heading stability, exemplifying how a compact brain exploits geometrical constraints of the visual world.
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Affiliation(s)
- Ryosuke Tanaka
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
| | - Baohua Zhou
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA; Department of Statistics and Data Science, Yale University, New Haven, CT 06511, USA
| | - Margarida Agrochao
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Bara A Badwan
- School of Engineering and Applied Science, Yale University, New Haven, CT 06511, USA
| | - Braedyn Au
- Department of Physics, Yale University, New Haven, CT 06511, USA
| | - Natalia C B Matos
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
| | - Damon A Clark
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA; Department of Physics, Yale University, New Haven, CT 06511, USA; Department of Neuroscience, Yale University, New Haven, CT 06511, USA; Wu Tsai Institute, Yale University, New Haven, CT 06511, USA; Quantitative Biology Institute, Yale University, New Haven, CT 06511, USA.
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15
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Bazzi W, Monticelli S, Delaporte C, Riet C, Giangrande A, Cattenoz PB. Gcm counteracts Toll-induced inflammation and impacts hemocyte number through cholinergic signaling. Front Immunol 2023; 14:1293766. [PMID: 38035083 PMCID: PMC10684909 DOI: 10.3389/fimmu.2023.1293766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 10/26/2023] [Indexed: 12/02/2023] Open
Abstract
Hemocytes, the myeloid-like immune cells of Drosophila, fulfill a variety of functions that are not completely understood, ranging from phagocytosis to transduction of inflammatory signals. We here show that downregulating the hemocyte-specific Glial cell deficient/Glial cell missing (Glide/Gcm) transcription factor enhances the inflammatory response to the constitutive activation of the Toll pathway. This correlates with lower levels of glutathione S-transferase, suggesting an implication of Glide/Gcm in reactive oxygen species (ROS) signaling and calling for a widespread anti-inflammatory potential of Glide/Gcm. In addition, our data reveal the expression of acetylcholine receptors in hemocytes and that Toll activation affects their expressions, disclosing a novel aspect of the inflammatory response mediated by neurotransmitters. Finally, we provide evidence for acetylcholine receptor nicotinic acetylcholine receptor alpha 6 (nAchRalpha6) regulating hemocyte proliferation in a cell autonomous fashion and for non-cell autonomous cholinergic signaling regulating the number of hemocytes. Altogether, this study provides new insights on the molecular pathways involved in the inflammatory response.
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Affiliation(s)
- Wael Bazzi
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Sara Monticelli
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Claude Delaporte
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Céline Riet
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Angela Giangrande
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Pierre B. Cattenoz
- Université de Strasbourg, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
- CNRS, UMR 7104, Illkirch, France
- Inserm, UMR-S 1258, Illkirch, France
- IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
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16
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Yang HH, Brezovec LE, Capdevila LS, Vanderbeck QX, Adachi A, Mann RS, Wilson RI. Fine-grained descending control of steering in walking Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.15.562426. [PMID: 37904997 PMCID: PMC10614758 DOI: 10.1101/2023.10.15.562426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Locomotion involves rhythmic limb movement patterns that originate in circuits outside the brain. Purposeful locomotion requires descending commands from the brain, but we do not understand how these commands are structured. Here we investigate this issue, focusing on the control of steering in walking Drosophila. First, we describe different limb "gestures" associated with different steering maneuvers. Next, we identify a set of descending neurons whose activity predicts steering. Focusing on two descending cell types downstream from distinct brain networks, we show that they evoke specific limb gestures: one lengthens strides on the outside of a turn, while the other attenuates strides on the inside of a turn. Notably, a single descending neuron can have opposite effects during different locomotor rhythm phases, and we identify networks positioned to implement this phase-specific gating. Together, our results show how purposeful locomotion emerges from brain cells that drive specific, coordinated modulations of low-level patterns.
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Affiliation(s)
- Helen H. Yang
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115 USA
| | - Luke E. Brezovec
- Department of Neurobiology, Stanford University, Stanford, CA 94305 USA
| | | | | | - Atsuko Adachi
- Department of Biochemistry and Molecular Biophysics, Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027 USA
| | - Richard S. Mann
- Department of Biochemistry and Molecular Biophysics, Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027 USA
| | - Rachel I. Wilson
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115 USA
- Lead contact
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17
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Schlegel P, Yin Y, Bates AS, Dorkenwald S, Eichler K, Brooks P, Han DS, Gkantia M, Dos Santos M, Munnelly EJ, Badalamente G, Capdevila LS, Sane VA, Pleijzier MW, Tamimi IFM, Dunne CR, Salgarella I, Javier A, Fang S, Perlman E, Kazimiers T, Jagannathan SR, Matsliah A, Sterling AR, Yu SC, McKellar CE, Costa M, Seung HS, Murthy M, Hartenstein V, Bock DD, Jefferis GSXE. Whole-brain annotation and multi-connectome cell typing quantifies circuit stereotypy in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.27.546055. [PMID: 37425808 PMCID: PMC10327018 DOI: 10.1101/2023.06.27.546055] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The fruit fly Drosophila melanogaster combines surprisingly sophisticated behaviour with a highly tractable nervous system. A large part of the fly's success as a model organism in modern neuroscience stems from the concentration of collaboratively generated molecular genetic and digital resources. As presented in our FlyWire companion paper 1 , this now includes the first full brain connectome of an adult animal. Here we report the systematic and hierarchical annotation of this ~130,000-neuron connectome including neuronal classes, cell types and developmental units (hemilineages). This enables any researcher to navigate this huge dataset and find systems and neurons of interest, linked to the literature through the Virtual Fly Brain database 2 . Crucially, this resource includes 4,552 cell types. 3,094 are rigorous consensus validations of cell types previously proposed in the hemibrain connectome 3 . In addition, we propose 1,458 new cell types, arising mostly from the fact that the FlyWire connectome spans the whole brain, whereas the hemibrain derives from a subvolume. Comparison of FlyWire and the hemibrain showed that cell type counts and strong connections were largely stable, but connection weights were surprisingly variable within and across animals. Further analysis defined simple heuristics for connectome interpretation: connections stronger than 10 unitary synapses or providing >1% of the input to a target cell are highly conserved. Some cell types showed increased variability across connectomes: the most common cell type in the mushroom body, required for learning and memory, is almost twice as numerous in FlyWire as the hemibrain. We find evidence for functional homeostasis through adjustments of the absolute amount of excitatory input while maintaining the excitation-inhibition ratio. Finally, and surprisingly, about one third of the cell types proposed in the hemibrain connectome could not yet be reliably identified in the FlyWire connectome. We therefore suggest that cell types should be defined to be robust to inter-individual variation, namely as groups of cells that are quantitatively more similar to cells in a different brain than to any other cell in the same brain. Joint analysis of the FlyWire and hemibrain connectomes demonstrates the viability and utility of this new definition. Our work defines a consensus cell type atlas for the fly brain and provides both an intellectual framework and open source toolchain for brain-scale comparative connectomics.
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18
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Tanaka R, Zhou B, Agrochao M, Badwan BA, Au B, Matos NCB, Clark DA. Neural mechanisms to incorporate visual counterevidence in self motion estimation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.04.522814. [PMID: 36711843 PMCID: PMC9881891 DOI: 10.1101/2023.01.04.522814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In selecting appropriate behaviors, animals should weigh sensory evidence both for and against specific beliefs about the world. For instance, animals measure optic flow to estimate and control their own rotation. However, existing models of flow detection can confuse the movement of external objects with genuine self motion. Here, we show that stationary patterns on the retina, which constitute negative evidence against self rotation, are used by the fruit fly Drosophila to suppress inappropriate stabilizing rotational behavior. In silico experiments show that artificial neural networks optimized to distinguish self and world motion similarly detect stationarity and incorporate negative evidence. Employing neural measurements and genetic manipulations, we identified components of the circuitry for stationary pattern detection, which runs parallel to the fly's motion- and optic flow-detectors. Our results exemplify how the compact brain of the fly incorporates negative evidence to improve heading stability, exploiting geometrical constraints of the visual world.
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Affiliation(s)
- Ryosuke Tanaka
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
- Present Address: Institute of Neuroscience, Technical University of Munich, Munich 80802, Germany
| | - Baohua Zhou
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Department of Statistics and Data Science, Yale University, New Haven, CT 06511, USA
| | - Margarida Agrochao
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Bara A. Badwan
- School of Engineering and Applied Science, Yale University, New Haven, CT 06511, USA
| | - Braedyn Au
- Department of Physics, Yale University, New Haven, CT 06511, USA
| | - Natalia C. B. Matos
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
| | - Damon A. Clark
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Department of Physics, Yale University, New Haven, CT 06511, USA
- Department of Neuroscience, Yale University, New Haven, CT 06511, USA
- Wu Tsai Institute, Yale University, New Haven, CT 06511, USA
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19
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Chen N, Zhang Y, Rivera-Rodriguez EJ, Yu AD, Hobin M, Rosbash M, Griffith LC. Widespread posttranscriptional regulation of cotransmission. SCIENCE ADVANCES 2023; 9:eadg9836. [PMID: 37267358 PMCID: PMC10413644 DOI: 10.1126/sciadv.adg9836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 05/01/2023] [Indexed: 06/04/2023]
Abstract
While neurotransmitter identity was once considered singular and immutable for mature neurons, it is now appreciated that one neuron can release multiple neuroactive substances (cotransmission) whose identities can even change over time. To explore the mechanisms that tune the suite of transmitters a neuron releases, we developed transcriptional and translational reporters for cholinergic, glutamatergic, and GABAergic signaling in Drosophila. We show that many glutamatergic and GABAergic cells also transcribe cholinergic genes, but fail to accumulate cholinergic effector proteins. Suppression of cholinergic signaling involves posttranscriptional regulation of cholinergic transcripts by the microRNA miR-190; chronic loss of miR-190 function allows expression of cholinergic machinery, reducing and fragmenting sleep. Using a "translation-trap" strategy, we show that neurons in these populations have episodes of transient translation of cholinergic proteins, demonstrating that suppression of cotransmission is actively modulated. Posttranscriptional restriction of fast transmitter cotransmission provides a mechanism allowing reversible tuning of neuronal output.
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Affiliation(s)
- Nannan Chen
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
| | - Yunpeng Zhang
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
| | - Emmanuel J. Rivera-Rodriguez
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
| | - Albert D. Yu
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
- Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02454-9110, USA
| | - Michael Hobin
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
| | - Michael Rosbash
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
- Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02454-9110, USA
| | - Leslie C. Griffith
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
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20
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Ehrhardt E, Whitehead SC, Namiki S, Minegishi R, Siwanowicz I, Feng K, Otsuna H, Meissner GW, Stern D, Truman J, Shepherd D, Dickinson MH, Ito K, Dickson BJ, Cohen I, Card GM, Korff W. Single-cell type analysis of wing premotor circuits in the ventral nerve cord of Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.542897. [PMID: 37398009 PMCID: PMC10312520 DOI: 10.1101/2023.05.31.542897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
To perform most behaviors, animals must send commands from higher-order processing centers in the brain to premotor circuits that reside in ganglia distinct from the brain, such as the mammalian spinal cord or insect ventral nerve cord. How these circuits are functionally organized to generate the great diversity of animal behavior remains unclear. An important first step in unraveling the organization of premotor circuits is to identify their constituent cell types and create tools to monitor and manipulate these with high specificity to assess their function. This is possible in the tractable ventral nerve cord of the fly. To generate such a toolkit, we used a combinatorial genetic technique (split-GAL4) to create 195 sparse driver lines targeting 198 individual cell types in the ventral nerve cord. These included wing and haltere motoneurons, modulatory neurons, and interneurons. Using a combination of behavioral, developmental, and anatomical analyses, we systematically characterized the cell types targeted in our collection. Taken together, the resources and results presented here form a powerful toolkit for future investigations of neural circuits and connectivity of premotor circuits while linking them to behavioral outputs.
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Affiliation(s)
- Erica Ehrhardt
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
- Institute of Zoology, University of Cologne, Zülpicher Str 47b, 50674 Cologne, Germany
| | - Samuel C Whitehead
- Physics Department, Cornell University, 271 Clark Hall, Ithaca, New York 14853, USA
| | - Shigehiro Namiki
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - Ryo Minegishi
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - Igor Siwanowicz
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - Kai Feng
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
- Queensland Brain Institute, University of Queensland, 79 Upland Rd, Brisbane, QLD, 4072, Australia
| | - Hideo Otsuna
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - FlyLight Project Team
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - Geoffrey W Meissner
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - David Stern
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - Jim Truman
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - David Shepherd
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Life Sciences Building, Southampton SO17 1BJ
| | - Michael H. Dickinson
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
- California Institute of Technology, 1200 E California Blvd, Pasadena, California 91125, USA
| | - Kei Ito
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
- Institute of Zoology, University of Cologne, Zülpicher Str 47b, 50674 Cologne, Germany
| | - Barry J Dickson
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - Itai Cohen
- Physics Department, Cornell University, 271 Clark Hall, Ithaca, New York 14853, USA
| | - Gwyneth M Card
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
| | - Wyatt Korff
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr, Ashburn, Virginia 20147, USA
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21
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Hamid A, Gutierrez A, Munroe J, Syed MH. The Drivers of Diversity: Integrated genetic and hormonal cues regulate neural diversity. Semin Cell Dev Biol 2023; 142:23-35. [PMID: 35915026 DOI: 10.1016/j.semcdb.2022.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 07/06/2022] [Accepted: 07/17/2022] [Indexed: 11/17/2022]
Abstract
Proper functioning of the nervous system relies not only on the generation of a vast repertoire of distinct neural cell types but also on the precise neural circuitry within them. How the generation of highly diverse neural populations is regulated during development remains a topic of interest. Landmark studies in Drosophila have identified the genetic and temporal cues regulating neural diversity and thus have provided valuable insights into our understanding of temporal patterning of the central nervous system. The development of the Drosophila central complex, which is mostly derived from type II neural stem cell (NSC) lineages, showcases how a small pool of NSCs can give rise to vast and distinct progeny. Similar to the human outer subventricular zone (OSVZ) neural progenitors, type II NSCs generate intermediate neural progenitors (INPs) to expand and diversify lineages that populate higher brain centers. Each type II NSC has a distinct spatial identity and timely regulated expression of many transcription factors and mRNA binding proteins. Additionally, INPs derived from them show differential expression of genes depending on their birth order. Together type II NSCs and INPs display a combinatorial temporal patterning that expands neural diversity of the central brain lineages. We cover advances in current understanding of type II NSC temporal patterning and discuss similarities and differences in temporal patterning mechanisms of various NSCs with a focus on how cell-intrinsic and extrinsic hormonal cues regulate temporal transitions in NSCs during larval development. Cell extrinsic ligands activate conserved signaling pathways and extrinsic hormonal cues act as a temporal switch that regulate temporal progression of the NSCs. We conclude by elaborating on how a progenitor's temporal code regulates the fate specification and identity of distinct neural types. At the end, we also discuss open questions in linking developmental cues to neural identity, circuits, and underlying behaviors in the adult fly.
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Affiliation(s)
- Aisha Hamid
- Department of Biology, University of New Mexico, Albuquerque, NM 87113, USA
| | - Andrew Gutierrez
- Department of Biology, University of New Mexico, Albuquerque, NM 87113, USA
| | - Jordan Munroe
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
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22
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Sen SQ. Generating neural diversity through spatial and temporal patterning. Semin Cell Dev Biol 2023; 142:54-66. [PMID: 35738966 DOI: 10.1016/j.semcdb.2022.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 06/08/2022] [Accepted: 06/08/2022] [Indexed: 11/19/2022]
Abstract
The nervous system consists of a vast diversity of neurons and glia that are accurately assembled into functional circuits. What are the mechanisms that generate these diverse cell types? During development, an epithelial sheet with neurogenic potential is initially regionalised into spatially restricted domains of gene expression. From this, pools of neural stem cells (NSCs) with distinct molecular profiles and the potential to generate different neuron types, are specified. These NSCs then divide asymmetrically to self-renew and generate post-mitotic neurons or glia. As NSCs age, they experience transitions in gene expression, which further allows them to generate different neurons or glia over time. Versions of this general template of spatial and temporal patterning operate during the development of different parts of different nervous systems. Here, I cover our current knowledge of Drosophila brain and optic lobe development as well as the development of the vertebrate cortex and spinal cord within the framework of this above template. I highlight where our knowledge is lacking, where mechanisms beyond these might operate, and how the emergence of new technologies might help address unanswered questions.
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Affiliation(s)
- Sonia Q Sen
- Tata Institute for Genetics and Society, UAS-GKVK Campus, Bellary Road, Bangalore, India.
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23
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Ramdya P, Ijspeert AJ. The neuromechanics of animal locomotion: From biology to robotics and back. Sci Robot 2023; 8:eadg0279. [PMID: 37256966 DOI: 10.1126/scirobotics.adg0279] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 05/05/2023] [Indexed: 06/02/2023]
Abstract
Robotics and neuroscience are sister disciplines that both aim to understand how agile, efficient, and robust locomotion can be achieved in autonomous agents. Robotics has already benefitted from neuromechanical principles discovered by investigating animals. These include the use of high-level commands to control low-level central pattern generator-like controllers, which, in turn, are informed by sensory feedback. Reciprocally, neuroscience has benefited from tools and intuitions in robotics to reveal how embodiment, physical interactions with the environment, and sensory feedback help sculpt animal behavior. We illustrate and discuss exemplar studies of this dialog between robotics and neuroscience. We also reveal how the increasing biorealism of simulations and robots is driving these two disciplines together, forging an integrative science of autonomous behavioral control with many exciting future opportunities.
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Affiliation(s)
- Pavan Ramdya
- Neuroengineering Laboratory, Brain Mind Institute and Institute of Bioengineering, EPFL, Lausanne, Switzerland
| | - Auke Jan Ijspeert
- Biorobotics Laboratory, Institute of Bioengineering, EPFL, Lausanne, Switzerland
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24
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Truman JW, Riddiford LM. Drosophila postembryonic nervous system development: a model for the endocrine control of development. Genetics 2023; 223:iyac184. [PMID: 36645270 PMCID: PMC9991519 DOI: 10.1093/genetics/iyac184] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/13/2022] [Indexed: 01/17/2023] Open
Abstract
During postembryonic life, hormones, including ecdysteroids, juvenile hormones, insulin-like peptides, and activin/TGFβ ligands act to transform the larval nervous system into an adult version, which is a fine-grained mosaic of recycled larval neurons and adult-specific neurons. Hormones provide both instructional signals that make cells competent to undergo developmental change and timing cues to evoke these changes across the nervous system. While touching on all the above hormones, our emphasis is on the ecdysteroids, ecdysone and 20-hydroxyecdysone (20E). These are the prime movers of insect molting and metamorphosis and are involved in all phases of nervous system development, including neurogenesis, pruning, arbor outgrowth, and cell death. Ecdysteroids appear as a series of steroid peaks that coordinate the larval molts and the different phases of metamorphosis. Each peak directs a stereotyped cascade of transcription factor expression. The cascade components then direct temporal programs of effector gene expression, but the latter vary markedly according to tissue and life stage. The neurons read the ecdysteroid titer through various isoforms of the ecdysone receptor, a nuclear hormone receptor. For example, at metamorphosis the pruning of larval neurons is mediated through the B isoforms, which have strong activation functions, whereas subsequent outgrowth is mediated through the A isoform through which ecdysteroids play a permissive role to allow local tissue interactions to direct outgrowth. The major circulating ecdysteroid can also change through development. During adult development ecdysone promotes early adult patterning and differentiation while its metabolite, 20E, later evokes terminal adult differentiation.
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Affiliation(s)
- James W Truman
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
| | - Lynn M Riddiford
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
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25
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Chen N, Zhang Y, Rivera-Rodriguez EJ, Yu AD, Hobin M, Rosbash M, Griffith LC. Widespread post-transcriptional regulation of co-transmission. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.01.530653. [PMID: 36909471 PMCID: PMC10002718 DOI: 10.1101/2023.03.01.530653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
While neurotransmitter identity was once considered singular and immutable for mature neurons, it is now appreciated that one neuron can release multiple neuroactive substances (co-transmission) whose identities can even change over time. To explore the mechanisms that tune the suite of transmitters a neuron releases, we developed transcriptional and translational reporters for cholinergic, glutamatergic, and GABAergic signaling in Drosophila . We show that many glutamatergic and GABAergic cells also transcribe cholinergic genes, but fail to accumulate cholinergic effector proteins. Suppression of cholinergic signaling involves posttranscriptional regulation of cholinergic transcripts by the microRNA miR-190; chronic loss of miR-190 function allows expression of cholinergic machinery, reducing and fragmenting sleep. Using a "translation-trap" strategy we show that neurons in these populations have episodes of transient translation of cholinergic proteins, demonstrating that suppression of co-transmission is actively modulated. Posttranscriptional restriction of fast transmitter co-transmission provides a mechanism allowing reversible tuning of neuronal output. One-Sentence Summary Cholinergic co-transmission in large populations of glutamatergic and GABAergic neurons in the Drosophila adult brain is controlled by miR-190.
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Affiliation(s)
- Nannan Chen
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
| | - Yunpeng Zhang
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
| | - Emmanuel J. Rivera-Rodriguez
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
| | - Albert D. Yu
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
- Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02454-9110, USA
| | - Michael Hobin
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
| | - Michael Rosbash
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
- Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02454-9110, USA
| | - Leslie C. Griffith
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02454-9110, USA
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26
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Yoon S, Shin M, Shim J. Inter-organ regulation by the brain in Drosophila development and physiology. J Neurogenet 2022:1-13. [DOI: 10.1080/01677063.2022.2137162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Sunggyu Yoon
- Department of Life Sciences, College of Natural Science, Hanyang University, Seoul, Republic of Korea
| | - Mingyu Shin
- Department of Life Sciences, College of Natural Science, Hanyang University, Seoul, Republic of Korea
| | - Jiwon Shim
- Department of Life Sciences, College of Natural Science, Hanyang University, Seoul, Republic of Korea
- Research Institute for Natural Science, Hanyang University, Seoul, Republic of Korea
- Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
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27
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Corrales M, Cocanougher BT, Kohn AB, Wittenbach JD, Long XS, Lemire A, Cardona A, Singer RH, Moroz LL, Zlatic M. A single-cell transcriptomic atlas of complete insect nervous systems across multiple life stages. Neural Dev 2022; 17:8. [PMID: 36002881 PMCID: PMC9404646 DOI: 10.1186/s13064-022-00164-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/10/2022] [Indexed: 12/15/2022] Open
Abstract
Molecular profiles of neurons influence neural development and function but bridging the gap between genes, circuits, and behavior has been very difficult. Here we used single cell RNAseq to generate a complete gene expression atlas of the Drosophila larval central nervous system composed of 131,077 single cells across three developmental stages (1 h, 24 h and 48 h after hatching). We identify 67 distinct cell clusters based on the patterns of gene expression. These include 31 functional mature larval neuron clusters, 1 ring gland cluster, 8 glial clusters, 6 neural precursor clusters, and 13 developing immature adult neuron clusters. Some clusters are present across all stages of larval development, while others are stage specific (such as developing adult neurons). We identify genes that are differentially expressed in each cluster, as well as genes that are differentially expressed at distinct stages of larval life. These differentially expressed genes provide promising candidates for regulating the function of specific neuronal and glial types in the larval nervous system, or the specification and differentiation of adult neurons. The cell transcriptome Atlas of the Drosophila larval nervous system is a valuable resource for developmental biology and systems neuroscience and provides a basis for elucidating how genes regulate neural development and function.
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Affiliation(s)
- Marc Corrales
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Physiology, Development, and Neuroscience, Cambridge University, Cambridge, UK
| | - Benjamin T Cocanougher
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Zoology, Cambridge University, Cambridge, UK
| | - Andrea B Kohn
- Department of Neuroscience and Whitney Laboratory for Marine Biosciences, University of Florida, Gainesville/St. Augustine, FL, 32080, USA
| | - Jason D Wittenbach
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Xi S Long
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Andrew Lemire
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Albert Cardona
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Physiology, Development, and Neuroscience, Cambridge University, Cambridge, UK.,MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, UK
| | - Robert H Singer
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Leonid L Moroz
- Department of Neuroscience and Whitney Laboratory for Marine Biosciences, University of Florida, Gainesville/St. Augustine, FL, 32080, USA.
| | - Marta Zlatic
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA. .,Department of Zoology, Cambridge University, Cambridge, UK. .,MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, UK.
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28
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Jiao W, Spreemann G, Ruchti E, Banerjee S, Vernon S, Shi Y, Stowers RS, Hess K, McCabe BD. Intact Drosophila central nervous system cellular quantitation reveals sexual dimorphism. eLife 2022; 11:74968. [PMID: 35801638 PMCID: PMC9270032 DOI: 10.7554/elife.74968] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 06/09/2022] [Indexed: 12/15/2022] Open
Abstract
Establishing with precision the quantity and identity of the cell types of the brain is a prerequisite for a detailed compendium of gene and protein expression in the central nervous system (CNS). Currently, however, strict quantitation of cell numbers has been achieved only for the nervous system of Caenorhabditis elegans. Here, we describe the development of a synergistic pipeline of molecular genetic, imaging, and computational technologies designed to allow high-throughput, precise quantitation with cellular resolution of reporters of gene expression in intact whole tissues with complex cellular constitutions such as the brain. We have deployed the approach to determine with exactitude the number of functional neurons and glia in the entire intact larval Drosophila CNS, revealing fewer neurons and more glial cells than previously predicted. We also discover an unexpected divergence between the sexes at this juvenile developmental stage, with the female CNS having significantly more neurons than that of males. Topological analysis of our data establishes that this sexual dimorphism extends to deeper features of CNS organisation. We additionally extended our analysis to quantitate the expression of voltage-gated potassium channel family genes throughout the CNS and uncover substantial differences in abundance. Our methodology enables robust and accurate quantification of the number and positioning of cells within intact organs, facilitating sophisticated analysis of cellular identity, diversity, and gene expression characteristics.
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Affiliation(s)
- Wei Jiao
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Gard Spreemann
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Evelyne Ruchti
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Soumya Banerjee
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Samuel Vernon
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Ying Shi
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - R Steven Stowers
- Department of Microbiology and Cell Biology, Montana State University
| | - Kathryn Hess
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Brian D McCabe
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
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29
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Agrawal S, Tuthill JC. The two-body problem: Proprioception and motor control across the metamorphic divide. Curr Opin Neurobiol 2022; 74:102546. [PMID: 35512562 DOI: 10.1016/j.conb.2022.102546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/11/2022] [Accepted: 03/27/2022] [Indexed: 11/17/2022]
Abstract
Like a rocket being propelled into space, evolution has engineered flies to launch into adulthood via multiple stages. Flies develop and deploy two distinct bodies, linked by the transformative process of metamorphosis. The fly larva is a soft hydraulic tube that can crawl to find food and avoid predators. The adult fly has a stiff exoskeleton with articulated limbs that enable long-distance navigation and rich social interactions. Because the larval and adult forms are so distinct in structure, they require distinct strategies for sensing and moving the body. The metamorphic divide thus presents an opportunity for comparative analysis of neural circuits. Here, we review recent progress toward understanding the neural mechanisms of proprioception and motor control in larval and adult Drosophila. We highlight commonalities that point toward general principles of sensorimotor control and differences that may reflect unique constraints imposed by biomechanics. Finally, we discuss emerging opportunities for comparative analysis of neural circuit architecture in the fly and other animal species.
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Affiliation(s)
- Sweta Agrawal
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA.
| | - John C Tuthill
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
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30
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Cellular diversity and gene expression profiles in the male and female brain of Aedes aegypti. BMC Genomics 2022; 23:119. [PMID: 35144549 PMCID: PMC8832747 DOI: 10.1186/s12864-022-08327-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/18/2022] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Aedes aegypti is a medically-important mosquito vector that transmits arboviruses including yellow fever, dengue, chikungunya, and Zika viruses to humans. The mosquito exhibits typical sexually dimorphic behaviors such as courtship, mating, host seeking, bloodfeeding, and oviposition. All these behaviors are mainly regulated by the brain; however, little is known about the function and neuron composition of the mosquito brain. In this study, we generated an initial atlas of the adult male and female brain of Ae. aegypti using 10xGenomics based single-nucleus RNA sequencing. RESULTS We identified 35 brain cell clusters in male and female brains, and 15 of those clusters were assigned to known cell types. Identified cell types include glia (astrocytes), Kenyon cells, (ventral) projection neurons, monoaminergic neurons, medulla neurons, and proximal medulla neurons. In addition, the cell type compositions of male and female brains were compared to each other showing that they were quantitatively distinct, as 17 out of 35 cell clusters varied significantly in their cell type proportions. Overall, the transcriptomes from each cell cluster looked very similar between the male and female brain as only up to 25 genes were differentially expressed in these clusters. The sex determination factor Nix was highly expressed in neurons and glia of the male brain, whereas doublesex (dsx) was expressed in all neuron and glia cell clusters of the male and female brain. CONCLUSIONS An initial cell atlas of the brain of the mosquito Ae. aegypti has been generated showing that the cellular compositions of the male and female brains of this hematophagous insect differ significantly from each other. Although some of the rare brain cell types have not been detected in our single biological replicate, this study provides an important basis for the further development of a complete brain cell atlas as well as a better understanding of the neurobiology of the brains of male and female mosquitoes and their sexually dimorphic behaviors.
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31
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Dvořáček J, Bednářová A, Krishnan N, Kodrík D. Dopaminergic muhsroom body neurons in Drosophila: flexibility of neuron identity in a model organism? Neurosci Biobehav Rev 2022; 135:104570. [DOI: 10.1016/j.neubiorev.2022.104570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/03/2022] [Accepted: 02/03/2022] [Indexed: 11/28/2022]
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32
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A pair of commissural command neurons induces Drosophila wing grooming. iScience 2022; 25:103792. [PMID: 35243214 PMCID: PMC8859526 DOI: 10.1016/j.isci.2022.103792] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 01/03/2022] [Accepted: 01/13/2022] [Indexed: 12/17/2022] Open
Abstract
In many behaviors such walking and swimming, animals need to coordinate their left and right limbs. In Drosophila, wing grooming can be induced by activation of sensory organs called campaniform sensilla. Flies usually clean one wing at a time, coordinating their left and right hind legs to sweep the dorsal and ventral surfaces of the wing. Here, we identify a pair of interneurons located in the ventral nerve cord that we name wing projection neurons 1 (wPN1) whose optogenetic activation induces wing grooming. Inhibition of wPN1 activity reduces wing grooming. They receive synaptic input from ipsilateral wing campaniform sensilla and wing mechanosensory bristle neurons, and they extend axonal arbors to the hind leg neuropils. Although they project contralaterally, their activation induces ipsilateral wing grooming. Anatomical and behavioral data support a role for wPN1 as command neurons coordinating both hind legs to work together to clean the stimulated wing. A pair of ventral cord neurons, wPN1, is sufficient and necessary for wing grooming wPN1 receive contacts from two types of wing mechanosensors wPN1 are cholinergic and have commissural projections Single-side activation of wPN1 drives both hind legs to clean the ipsilateral wing
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33
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Torres-Méndez A, Pop S, Bonnal S, Almudi I, Avola A, Roberts RJV, Paolantoni C, Alcaina-Caro A, Martín-Anduaga A, Haussmann IU, Morin V, Casares F, Soller M, Kadener S, Roignant JY, Prieto-Godino L, Irimia M. Parallel evolution of a splicing program controlling neuronal excitability in flies and mammals. SCIENCE ADVANCES 2022; 8:eabk0445. [PMID: 35089784 PMCID: PMC8797185 DOI: 10.1126/sciadv.abk0445] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/08/2021] [Indexed: 05/08/2023]
Abstract
Alternative splicing increases neuronal transcriptomic complexity throughout animal phylogeny. To delve into the mechanisms controlling the assembly and evolution of this regulatory layer, we characterized the neuronal microexon program in Drosophila and compared it with that of mammals. In nonvertebrate bilaterians, this splicing program is restricted to neurons by the posttranscriptional processing of the enhancer of microexons (eMIC) domain in Srrm234. In Drosophila, this processing is dependent on regulation by Elav/Fne. eMIC deficiency or misexpression leads to widespread neurological alterations largely emerging from impaired neuronal activity, as revealed by a combination of neuronal imaging experiments and cell type-specific rescues. These defects are associated with the genome-wide skipping of short neural exons, which are strongly enriched in ion channels. We found no overlap of eMIC-regulated exons between flies and mice, illustrating how ancient posttranscriptional programs can evolve independently in different phyla to affect distinct cellular modules while maintaining cell-type specificity.
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Affiliation(s)
- Antonio Torres-Méndez
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona 08003, Spain
- Francis Crick Institute, London, UK
| | | | - Sophie Bonnal
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona 08003, Spain
| | - Isabel Almudi
- Centro Andaluz de Biología del Desarrollo (CABD), CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
- Department of Genetics, Microbiology and Statistics and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | | | | | - Chiara Paolantoni
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Ana Alcaina-Caro
- Centro Andaluz de Biología del Desarrollo (CABD), CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
| | | | - Irmgard U. Haussmann
- Department of Life Science, School of Health Sciences, Birmingham City University, Birmingham B5 3TN, UK
| | - Violeta Morin
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Fernando Casares
- Centro Andaluz de Biología del Desarrollo (CABD), CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
| | - Matthias Soller
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
- Birmingham Centre for Genome Biology, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | | | - Jean-Yves Roignant
- Center for Integrative Genomics, Génopode Building, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | | | - Manuel Irimia
- Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona 08003, Spain
- ICREA, Barcelona, Spain
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Lu J, Behbahani AH, Hamburg L, Westeinde EA, Dawson PM, Lyu C, Maimon G, Dickinson MH, Druckmann S, Wilson RI. Transforming representations of movement from body- to world-centric space. Nature 2022; 601:98-104. [PMID: 34912123 PMCID: PMC10759448 DOI: 10.1038/s41586-021-04191-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 10/28/2021] [Indexed: 12/21/2022]
Abstract
When an animal moves through the world, its brain receives a stream of information about the body's translational velocity from motor commands and sensory feedback signals. These incoming signals are referenced to the body, but ultimately, they must be transformed into world-centric coordinates for navigation1,2. Here we show that this computation occurs in the fan-shaped body in the brain of Drosophila melanogaster. We identify two cell types, PFNd and PFNv3-5, that conjunctively encode translational velocity and heading as a fly walks. In these cells, velocity signals are acquired from locomotor brain regions6 and are multiplied with heading signals from the compass system. PFNd neurons prefer forward-ipsilateral movement, whereas PFNv neurons prefer backward-contralateral movement, and perturbing PFNd neurons disrupts idiothetic path integration in walking flies7. Downstream, PFNd and PFNv neurons converge onto hΔB neurons, with a connectivity pattern that pools together heading and translation direction combinations corresponding to the same movement in world-centric space. This network motif effectively performs a rotation of the brain's representation of body-centric translational velocity according to the current heading direction. Consistent with our predictions, we observe that hΔB neurons form a representation of translational velocity in world-centric coordinates. By integrating this representation over time, it should be possible for the brain to form a working memory of the path travelled through the environment8-10.
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Affiliation(s)
- Jenny Lu
- Department of Neurobiology and Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Amir H Behbahani
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Lydia Hamburg
- Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Elena A Westeinde
- Department of Neurobiology and Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Paul M Dawson
- Department of Neurobiology and Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Cheng Lyu
- Laboratory of Integrative Brain Function and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Gaby Maimon
- Laboratory of Integrative Brain Function and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Michael H Dickinson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Shaul Druckmann
- Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Rachel I Wilson
- Department of Neurobiology and Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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35
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Bello-Rojas S, Bagnall MW. Clonally related, Notch-differentiated spinal neurons integrate into distinct circuits. eLife 2022; 11:83680. [PMID: 36580075 PMCID: PMC9799969 DOI: 10.7554/elife.83680] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/24/2022] [Indexed: 12/30/2022] Open
Abstract
Shared lineage has diverse effects on patterns of neuronal connectivity. In mammalian cortex, excitatory sister neurons assemble into shared microcircuits. In Drosophila, in contrast, sister neurons with different levels of Notch expression (NotchON/NotchOFF) develop distinct identities and diverge into separate circuits. Notch-differentiated sister neurons have been observed in vertebrate spinal cord and cerebellum, but whether they integrate into shared or distinct circuits remains unknown. Here, we evaluate how sister V2a (NotchOFF)/V2b (NotchON) neurons in the zebrafish integrate into spinal circuits. Using an in vivo labeling approach, we identified pairs of sister V2a/b neurons born from individual Vsx1+ progenitors and observed that they have somata in close proximity to each other and similar axonal trajectories. However, paired whole-cell electrophysiology and optogenetics revealed that sister V2a/b neurons receive input from distinct presynaptic sources, do not communicate with each other, and connect to largely distinct targets. These results resemble the divergent connectivity in Drosophila and represent the first evidence of Notch-differentiated circuit integration in a vertebrate system.
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Affiliation(s)
- Saul Bello-Rojas
- Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States
| | - Martha W Bagnall
- Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States
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36
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Hamid R, Sant HS, Kulkarni MN. Choline Transporter regulates olfactory habituation via a neuronal triad of excitatory, inhibitory and mushroom body neurons. PLoS Genet 2021; 17:e1009938. [PMID: 34914708 PMCID: PMC8675691 DOI: 10.1371/journal.pgen.1009938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 11/08/2021] [Indexed: 11/18/2022] Open
Abstract
Choline is an essential component of Acetylcholine (ACh) biosynthesis pathway which requires high-affinity Choline transporter (ChT) for its uptake into the presynaptic terminals of cholinergic neurons. Previously, we had reported a predominant expression of ChT in memory processing and storing region of the Drosophila brain called mushroom bodies (MBs). It is unknown how ChT contributes to the functional principles of MB operation. Here, we demonstrate the role of ChT in Habituation, a non-associative form of learning. Odour driven habituation traces are laid down in ChT dependent manner in antennal lobes (AL), projection neurons (PNs), and MBs. We observed that reduced habituation due to knock-down of ChT in MBs causes hypersensitivity towards odour, suggesting that ChT also regulates incoming stimulus suppression. Importantly, we show for the first time that ChT is not unique to cholinergic neurons but is also required in inhibitory GABAergic neurons to drive habituation behaviour. Our results support a model in which ChT regulates both habituation and incoming stimuli through multiple circuit loci via an interplay between excitatory and inhibitory neurons. Strikingly, the lack of ChT in MBs shows characteristics similar to the major reported features of Autism spectrum disorders (ASD), including attenuated habituation, sensory hypersensitivity as well as defective GABAergic signalling. Our data establish the role of ChT in habituation and suggest that its dysfunction may contribute to neuropsychiatric disorders like ASD.
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Affiliation(s)
- Runa Hamid
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research (CSIR-CCMB), Hyderabad, India
| | - Hitesh Sonaram Sant
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research (CSIR-CCMB), Hyderabad, India
| | - Mrunal Nagaraj Kulkarni
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research (CSIR-CCMB), Hyderabad, India
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37
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Chen C, Agrawal S, Mark B, Mamiya A, Sustar A, Phelps JS, Lee WCA, Dickson BJ, Card GM, Tuthill JC. Functional architecture of neural circuits for leg proprioception in Drosophila. Curr Biol 2021; 31:5163-5175.e7. [PMID: 34637749 PMCID: PMC8665017 DOI: 10.1016/j.cub.2021.09.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/30/2021] [Accepted: 09/15/2021] [Indexed: 11/30/2022]
Abstract
To effectively control their bodies, animals rely on feedback from proprioceptive mechanosensory neurons. In the Drosophila leg, different proprioceptor subtypes monitor joint position, movement direction, and vibration. Here, we investigate how these diverse sensory signals are integrated by central proprioceptive circuits. We find that signals for leg joint position and directional movement converge in second-order neurons, revealing pathways for local feedback control of leg posture. Distinct populations of second-order neurons integrate tibia vibration signals across pairs of legs, suggesting a role in detecting external substrate vibration. In each pathway, the flow of sensory information is dynamically gated and sculpted by inhibition. Overall, our results reveal parallel pathways for processing of internal and external mechanosensory signals, which we propose mediate feedback control of leg movement and vibration sensing, respectively. The existence of a functional connectivity map also provides a resource for interpreting connectomic reconstruction of neural circuits for leg proprioception. To understand how diverse proprioceptive signals from the Drosophila leg are integrated by downstream circuits, Chen et al. use optogenetics and calcium imaging to map functional connectivity between sensory and central neurons. This work identifies parallel neural pathways for processing leg vibration vs. joint position and movement.
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Affiliation(s)
- Chenghao Chen
- Department of Physiology and Biophysics, University of Washington, 1705 N.E. Pacific Street, Seattle, WA 98195, USA; Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Sweta Agrawal
- Department of Physiology and Biophysics, University of Washington, 1705 N.E. Pacific Street, Seattle, WA 98195, USA
| | - Brandon Mark
- Department of Physiology and Biophysics, University of Washington, 1705 N.E. Pacific Street, Seattle, WA 98195, USA
| | - Akira Mamiya
- Department of Physiology and Biophysics, University of Washington, 1705 N.E. Pacific Street, Seattle, WA 98195, USA
| | - Anne Sustar
- Department of Physiology and Biophysics, University of Washington, 1705 N.E. Pacific Street, Seattle, WA 98195, USA
| | - Jasper S Phelps
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Wei-Chung Allen Lee
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Barry J Dickson
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Gwyneth M Card
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - John C Tuthill
- Department of Physiology and Biophysics, University of Washington, 1705 N.E. Pacific Street, Seattle, WA 98195, USA.
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38
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Schlegel P, Bates AS, Stürner T, Jagannathan SR, Drummond N, Hsu J, Serratosa Capdevila L, Javier A, Marin EC, Barth-Maron A, Tamimi IFM, Li F, Rubin GM, Plaza SM, Costa M, Jefferis GSXE. Information flow, cell types and stereotypy in a full olfactory connectome. eLife 2021; 10:e66018. [PMID: 34032214 PMCID: PMC8298098 DOI: 10.7554/elife.66018] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/24/2021] [Indexed: 12/19/2022] Open
Abstract
The hemibrain connectome provides large-scale connectivity and morphology information for the majority of the central brain of Drosophila melanogaster. Using this data set, we provide a complete description of the Drosophila olfactory system, covering all first, second and lateral horn-associated third-order neurons. We develop a generally applicable strategy to extract information flow and layered organisation from connectome graphs, mapping olfactory input to descending interneurons. This identifies a range of motifs including highly lateralised circuits in the antennal lobe and patterns of convergence downstream of the mushroom body and lateral horn. Leveraging a second data set we provide a first quantitative assessment of inter- versus intra-individual stereotypy. Comparing neurons across two brains (three hemispheres) reveals striking similarity in neuronal morphology across brains. Connectivity correlates with morphology and neurons of the same morphological type show similar connection variability within the same brain as across two brains.
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Affiliation(s)
- Philipp Schlegel
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | | | - Tomke Stürner
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | | | - Nikolas Drummond
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Joseph Hsu
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | | | - Alexandre Javier
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Elizabeth C Marin
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Asa Barth-Maron
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Imaan FM Tamimi
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Feng Li
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Stephen M Plaza
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Marta Costa
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Gregory S X E Jefferis
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
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39
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Mark B, Lai SL, Zarin AA, Manning L, Pollington HQ, Litwin-Kumar A, Cardona A, Truman JW, Doe CQ. A developmental framework linking neurogenesis and circuit formation in the Drosophila CNS. eLife 2021; 10:67510. [PMID: 33973523 PMCID: PMC8139831 DOI: 10.7554/elife.67510] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/10/2021] [Indexed: 01/02/2023] Open
Abstract
The mechanisms specifying neuronal diversity are well characterized, yet it remains unclear how or if these mechanisms regulate neural circuit assembly. To address this, we mapped the developmental origin of 160 interneurons from seven bilateral neural progenitors (neuroblasts) and identify them in a synapse-scale TEM reconstruction of the Drosophila larval central nervous system. We find that lineages concurrently build the sensory and motor neuropils by generating sensory and motor hemilineages in a Notch-dependent manner. Neurons in a hemilineage share common synaptic targeting within the neuropil, which is further refined based on neuronal temporal identity. Connectome analysis shows that hemilineage-temporal cohorts share common connectivity. Finally, we show that proximity alone cannot explain the observed connectivity structure, suggesting hemilineage/temporal identity confers an added layer of specificity. Thus, we demonstrate that the mechanisms specifying neuronal diversity also govern circuit formation and function, and that these principles are broadly applicable throughout the nervous system.
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Affiliation(s)
- Brandon Mark
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, United States
| | - Sen-Lin Lai
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, United States
| | - Aref Arzan Zarin
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, United States
| | - Laurina Manning
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, United States
| | - Heather Q Pollington
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, United States
| | - Ashok Litwin-Kumar
- Mortimer B Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, United States
| | - Albert Cardona
- Janelia Research Campus, Howard Hughes Medical Institute, MRC Laboratory of Molecular Biology, Department of Physiology, Development & Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - James W Truman
- Janelia Research Campus, Howard Hughes Medical Institute, Friday Harbor Laboratories, University of Washington, Friday Harbor, United States
| | - Chris Q Doe
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, United States
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40
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Rossi AM, Jafari S, Desplan C. Integrated Patterning Programs During Drosophila Development Generate the Diversity of Neurons and Control Their Mature Properties. Annu Rev Neurosci 2021; 44:153-172. [PMID: 33556251 DOI: 10.1146/annurev-neuro-102120-014813] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
During the approximately 5 days of Drosophila neurogenesis (late embryogenesis to the beginning of pupation), a limited number of neural stem cells produce approximately 200,000 neurons comprising hundreds of cell types. To build a functional nervous system, neuronal types need to be produced in the proper places, appropriate numbers, and correct times. We discuss how neural stem cells (neuroblasts) obtain so-called area codes for their positions in the nervous system (spatial patterning) and how they keep time to sequentially produce neurons with unique fates (temporal patterning). We focus on specific examples that demonstrate how a relatively simple patterning system (Notch) can be used reiteratively to generate different neuronal types. We also speculate on how different modes of temporal patterning that operate over short versus long time periods might be linked. We end by discussing how specification programs are integrated and lead to the terminal features of different neuronal types.
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Affiliation(s)
- Anthony M Rossi
- Department of Biology, New York University, New York, NY 10003, USA; .,Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Shadi Jafari
- Department of Biology, New York University, New York, NY 10003, USA;
| | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA;
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41
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Brunet Avalos C, Sprecher SG. Single-Cell Transcriptomic Reveals Dual and Multi-Transmitter Use in Neurons Across Metazoans. Front Mol Neurosci 2021; 14:623148. [PMID: 33597849 PMCID: PMC7883486 DOI: 10.3389/fnmol.2021.623148] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/07/2021] [Indexed: 11/17/2022] Open
Abstract
Neurotransmitter expression is widely used as a criterion for classifying neurons. It was initially thought that neurons express a single type of neurotransmitter, a phenomenon commonly recognized as Dale's principle: “one neuron, one transmitter.” Consequently, the expression of a single neurotransmitter should determine stable and distinguishable neuronal characteristics. However, this notion has been largely challenged and increasing evidence accumulates supporting a different scenario: “one neuron, multiple neurotransmitters.” Single-cell transcriptomics provides an additional path to address coexpression of neurotransmitters, by investigating the expression of genes involved in the biosynthesis and transmission of fast-acting neuromodulators. Here, we study neuronal phenotypes based on the expression of neurotransmitters, at single-cell resolution, across different animal species representing distinct clades of the tree of life. We take advantage of several existing scRNAseq datasets and analyze them in light of neurotransmitter plasticity. Our results show that while most neurons appear to predominantly express a single type of neurotransmitter, a substantial number of neurons simultaneously expresses a combination of them, across all animal species analyzed.
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Affiliation(s)
| | - Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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42
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Agrawal S, Dickinson ES, Sustar A, Gurung P, Shepherd D, Truman JW, Tuthill JC. Central processing of leg proprioception in Drosophila. eLife 2020; 9:e60299. [PMID: 33263281 PMCID: PMC7752136 DOI: 10.7554/elife.60299] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 12/01/2020] [Indexed: 12/28/2022] Open
Abstract
Proprioception, the sense of self-movement and position, is mediated by mechanosensory neurons that detect diverse features of body kinematics. Although proprioceptive feedback is crucial for accurate motor control, little is known about how downstream circuits transform limb sensory information to guide motor output. Here we investigate neural circuits in Drosophila that process proprioceptive information from the fly leg. We identify three cell types from distinct developmental lineages that are positioned to receive input from proprioceptor subtypes encoding tibia position, movement, and vibration. 13Bα neurons encode femur-tibia joint angle and mediate postural changes in tibia position. 9Aα neurons also drive changes in leg posture, but encode a combination of directional movement, high frequency vibration, and joint angle. Activating 10Bα neurons, which encode tibia vibration at specific joint angles, elicits pausing in walking flies. Altogether, our results reveal that central circuits integrate information across proprioceptor subtypes to construct complex sensorimotor representations that mediate diverse behaviors, including reflexive control of limb posture and detection of leg vibration.
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Affiliation(s)
- Sweta Agrawal
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Evyn S Dickinson
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Anne Sustar
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Pralaksha Gurung
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - David Shepherd
- School of Natural Sciences, Bangor UniversityBangorUnited Kingdom
| | - James W Truman
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
- Friday Harbor Laboratories, University of WashingtonFriday HarborUnited States
| | - John C Tuthill
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
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43
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Luan H, Diao F, Scott RL, White BH. The Drosophila Split Gal4 System for Neural Circuit Mapping. Front Neural Circuits 2020; 14:603397. [PMID: 33240047 PMCID: PMC7680822 DOI: 10.3389/fncir.2020.603397] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022] Open
Abstract
The diversity and dense interconnectivity of cells in the nervous system present a huge challenge to understanding how brains work. Recent progress toward such understanding, however, has been fuelled by the development of techniques for selectively monitoring and manipulating the function of distinct cell types-and even individual neurons-in the brains of living animals. These sophisticated techniques are fundamentally genetic and have found their greatest application in genetic model organisms, such as the fruit fly Drosophila melanogaster. Drosophila combines genetic tractability with a compact, but cell-type rich, nervous system and has been the incubator for a variety of methods of neuronal targeting. One such method, called Split Gal4, is playing an increasingly important role in mapping neural circuits in the fly. In conjunction with functional perturbations and behavioral screens, Split Gal4 has been used to characterize circuits governing such activities as grooming, aggression, and mating. It has also been leveraged to comprehensively map and functionally characterize cells composing important brain regions, such as the central complex, lateral horn, and the mushroom body-the latter being the insect seat of learning and memory. With connectomics data emerging for both the larval and adult brains of Drosophila, Split Gal4 is also poised to play an important role in characterizing neurons of interest based on their connectivity. We summarize the history and current state of the Split Gal4 method and indicate promising areas for further development or future application.
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Affiliation(s)
| | | | | | - Benjamin H. White
- Laboratory of Molecular Biology, National Institute of Mental Health, NIH, Bethesda, MD, United States
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44
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Veling MW, Li Y, Veling MT, Litts C, Michki N, Liu H, Ye B, Cai D. Identification of Neuronal Lineages in the Drosophila Peripheral Nervous System with a "Digital" Multi-spectral Lineage Tracing System. Cell Rep 2020; 29:3303-3312.e3. [PMID: 31801091 PMCID: PMC6913890 DOI: 10.1016/j.celrep.2019.10.124] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 09/27/2019] [Accepted: 10/29/2019] [Indexed: 11/19/2022] Open
Abstract
Elucidating cell lineages provides crucial understanding of development. Recently developed sequencing-based techniques enhance the scale of lineage tracing but eliminate the spatial information offered by conventional approaches. Multi-spectral labeling techniques, such as Brainbow, have the potential to identify lineage-related cells in situ. Here, we report nuclear Bitbow (nBitbow), a “digital” version of Brainbow that greatly expands the color diversity for scoring cells, and a suite of statistical methods for quantifying the lineage relationship of any two cells. Applying these tools to the Drosophila peripheral nervous system (PNS), we determined lineage relationship between all neuronal pairs. This study demonstrates nBitbow as an efficient tool for in situ lineage mapping, and the complete lineage relationship among larval PNS neurons opens new possibilities for studying how neurons gain specific features and circuit connectivity. Veling et al. report a multi-color labeling system and statistical methods for mapping cell lineages. They identify the lineage relationship of all neurons in the peripheral nervous system of Drosophila larvae and show the utility of this technique in mapping neurons in the CNS.
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Affiliation(s)
- Macy W Veling
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ye Li
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mike T Veling
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Christopher Litts
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nigel Michki
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hao Liu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Bing Ye
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA; Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Dawen Cai
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA.
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45
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Court R, Namiki S, Armstrong JD, Börner J, Card G, Costa M, Dickinson M, Duch C, Korff W, Mann R, Merritt D, Murphey RK, Seeds AM, Shirangi T, Simpson JH, Truman JW, Tuthill JC, Williams DW, Shepherd D. A Systematic Nomenclature for the Drosophila Ventral Nerve Cord. Neuron 2020; 107:1071-1079.e2. [PMID: 32931755 PMCID: PMC7611823 DOI: 10.1016/j.neuron.2020.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/30/2020] [Accepted: 08/05/2020] [Indexed: 11/30/2022]
Abstract
Drosophila melanogaster is an established model for neuroscience research with relevance in biology and medicine. Until recently, research on the Drosophila brain was hindered by the lack of a complete and uniform nomenclature. Recognizing this, Ito et al. (2014) produced an authoritative nomenclature for the adult insect brain, using Drosophila as the reference. Here, we extend this nomenclature to the adult thoracic and abdominal neuromeres, the ventral nerve cord (VNC), to provide an anatomical description of this major component of the Drosophila nervous system. The VNC is the locus for the reception and integration of sensory information and involved in generating most of the locomotor actions that underlie fly behaviors. The aim is to create a nomenclature, definitions, and spatial boundaries for the Drosophila VNC that are consistent with other insects. The work establishes an anatomical framework that provides a powerful tool for analyzing the functional organization of the VNC.
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Affiliation(s)
- Robert Court
- School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, UK
| | - Shigehiro Namiki
- HHMI-Janelia Research Campus, Ashburn, VA 20147, USA; RCAST, University of Tokyo, Tokyo 153-8904, Japan
| | | | - Jana Börner
- Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Gwyneth Card
- HHMI-Janelia Research Campus, Ashburn, VA 20147, USA
| | - Marta Costa
- Virtual Fly Brain, University of Cambridge, Cambridge, CB2 3EJ, UK
| | - Michael Dickinson
- Division of Biology and Biological Engineering, The California Institute of Technology, Pasadena, CA 91125, USA
| | - Carsten Duch
- iDN, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Wyatt Korff
- HHMI-Janelia Research Campus, Ashburn, VA 20147, USA
| | - Richard Mann
- Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10027, USA
| | - David Merritt
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rod K Murphey
- Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Andrew M Seeds
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Troy Shirangi
- Department of Biology, Villanova University, Villanova, PA 19085, USA
| | - Julie H Simpson
- Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - James W Truman
- HHMI-Janelia Research Campus, Ashburn, VA 20147, USA; Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
| | - John C Tuthill
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Darren W Williams
- Centre for Developmental Neurobiology, King's College London, London WC2R 2LS, UK
| | - David Shepherd
- School of Natural Sciences, Bangor University, Bangor LL57 2UW, Bangor, UK.
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46
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Pop S, Chen CL, Sproston CJ, Kondo S, Ramdya P, Williams DW. Extensive and diverse patterns of cell death sculpt neural networks in insects. eLife 2020; 9:59566. [PMID: 32894223 PMCID: PMC7535934 DOI: 10.7554/elife.59566] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/06/2020] [Indexed: 11/20/2022] Open
Abstract
Changes to the structure and function of neural networks are thought to underlie the evolutionary adaptation of animal behaviours. Among the many developmental phenomena that generate change programmed cell death (PCD) appears to play a key role. We show that cell death occurs continuously throughout insect neurogenesis and happens soon after neurons are born. Mimicking an evolutionary role for increasing cell numbers, we artificially block PCD in the medial neuroblast lineage in Drosophila melanogaster, which results in the production of ‘undead’ neurons with complex arborisations and distinct neurotransmitter identities. Activation of these ‘undead’ neurons and recordings of neural activity in behaving animals demonstrate that they are functional. Focusing on two dipterans which have lost flight during evolution we reveal that reductions in populations of flight interneurons are likely caused by increased cell death during development. Our findings suggest that the evolutionary modulation of death-based patterning could generate novel network configurations. Just like a sculptor chips away at a block of granite to make a statue, the nervous system reaches its mature state by eliminating neurons during development through a process known as programmed cell death. In vertebrates, this mechanism often involves newly born neurons shrivelling away and dying if they fail to connect with others during development. Most studies in insects have focused on the death of neurons that occurs at metamorphosis, during the transition between larva to adult, when cells which are no longer needed in the new life stage are eliminated. Pop et al. harnessed a newly designed genetic probe to point out that, in fruit flies, programmed cell death of neurons at metamorphosis is not the main mechanism through which cells die. Rather, the majority of cell death takes place as soon as neurons are born throughout all larval stages, when most of the adult nervous system is built. To gain further insight into the role of this ‘early’ cell death, the neurons were stopped from dying, showing that these cells were able to reach maturity and function. Together, these results suggest that early cell death may be a mechanism fine-tuned by evolution to shape the many and varied nervous systems of insects. To explore this, Pop et al. looked for hints of early cell death in relatives of fruit flies that are unable to fly: the swift lousefly and the bee lousefly. This analysis showed that early cell death is likely to occur in these two insects, but it follows different patterns than in the fruit fly, potentially targeting the neurons that would have controlled flight in these flies’ ancestors. Brains are the product of evolution: learning how neurons change their connections and adapt could help us understand how the brain works in health and disease. This knowledge may also be relevant to work on artificial intelligence, a discipline that often bases the building blocks and connections in artificial ‘brains’ on how neurons communicate with one another.
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Affiliation(s)
- Sinziana Pop
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Chin-Lin Chen
- Neuroengineering Laboratory, Brain Mind Institute and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Connor J Sproston
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Shu Kondo
- Genetic Strains Research Center, National Institute of Genetics, Shizuoka, Japan
| | - Pavan Ramdya
- Neuroengineering Laboratory, Brain Mind Institute and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Darren W Williams
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
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47
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Bates AS, Schlegel P, Roberts RJV, Drummond N, Tamimi IFM, Turnbull R, Zhao X, Marin EC, Popovici PD, Dhawan S, Jamasb A, Javier A, Serratosa Capdevila L, Li F, Rubin GM, Waddell S, Bock DD, Costa M, Jefferis GSXE. Complete Connectomic Reconstruction of Olfactory Projection Neurons in the Fly Brain. Curr Biol 2020; 30:3183-3199.e6. [PMID: 32619485 PMCID: PMC7443706 DOI: 10.1016/j.cub.2020.06.042] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/07/2020] [Accepted: 06/12/2020] [Indexed: 12/21/2022]
Abstract
Nervous systems contain sensory neurons, local neurons, projection neurons, and motor neurons. To understand how these building blocks form whole circuits, we must distil these broad classes into neuronal cell types and describe their network connectivity. Using an electron micrograph dataset for an entire Drosophila melanogaster brain, we reconstruct the first complete inventory of olfactory projections connecting the antennal lobe, the insect analog of the mammalian olfactory bulb, to higher-order brain regions in an adult animal brain. We then connect this inventory to extant data in the literature, providing synaptic-resolution "holotypes" both for heavily investigated and previously unknown cell types. Projection neurons are approximately twice as numerous as reported by light level studies; cell types are stereotyped, but not identical, in cell and synapse numbers between brain hemispheres. The lateral horn, the insect analog of the mammalian cortical amygdala, is the main target for this olfactory information and has been shown to guide innate behavior. Here, we find new connectivity motifs, including axo-axonic connectivity between projection neurons, feedback, and lateral inhibition of these axons by a large population of neurons, and the convergence of different inputs, including non-olfactory inputs and memory-related feedback onto third-order olfactory neurons. These features are less prominent in the mushroom body calyx, the insect analog of the mammalian piriform cortex and a center for associative memory. Our work provides a complete neuroanatomical platform for future studies of the adult Drosophila olfactory system.
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Affiliation(s)
- Alexander S Bates
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Philipp Schlegel
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK; Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | | | - Nikolas Drummond
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Imaan F M Tamimi
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Robert Turnbull
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Xincheng Zhao
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK; Department of Entomology, College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Elizabeth C Marin
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Patricia D Popovici
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Serene Dhawan
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Arian Jamasb
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Alexandre Javier
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | | | - Feng Li
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Oxford OX1 3SR, UK
| | - Davi D Bock
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, VT 05405, USA
| | - Marta Costa
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Gregory S X E Jefferis
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK; Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
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48
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Chen HM, Yao X, Ren Q, Chang CC, Liu LY, Miyares RL, Lee T. Enhanced Golic+: highly effective CRISPR gene targeting and transgene HACKing in Drosophila. Development 2020; 147:dev181974. [PMID: 32467238 DOI: 10.1242/dev.181974] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 05/04/2020] [Indexed: 11/20/2022]
Abstract
Gene targeting is an incredibly valuable technique. Sometimes, however, it can also be extremely challenging for various intrinsic reasons (e.g. low target accessibility or nature/extent of gene modification). To bypass these barriers, we designed a transgene-based system in Drosophila that increases the number of independent gene targeting events while at the same time enriching for correctly targeted progeny. Unfortunately, with particularly challenging gene targeting experiments, our original design yielded numerous false positives. Here, we deliver a much-improved technique, named Enhanced Golic+ (E-Golic+). E-Golic+ incorporates genetic modifications to tighten lethality-based selection while simultaneously boosting efficiency. With E-Golic+, we easily achieve previously unattainable gene targeting. Additionally, we built an E-Golic+-based, high-efficiency genetic pipeline for transgene swapping. We demonstrate its utility by transforming GAL4 enhancer-trap lines into tissue-specific Cas9-expressing lines. Given the superior efficiency, specificity and scalability, E-Golic+ promises to expedite development of additional sophisticated genetic/genomic tools in Drosophila.
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Affiliation(s)
- Hui-Min Chen
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Xiaohao Yao
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Qingzhong Ren
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Chuan-Chie Chang
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Ling-Yu Liu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Rosa Linda Miyares
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Tzumin Lee
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
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49
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Estacio-Gómez A, Hassan A, Walmsley E, Le LW, Southall TD. Dynamic neurotransmitter specific transcription factor expression profiles during Drosophila development. Biol Open 2020; 9:9/5/bio052928. [PMID: 32493733 PMCID: PMC7286294 DOI: 10.1242/bio.052928] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The remarkable diversity of neurons in the nervous system is generated during development, when properties such as cell morphology, receptor profiles and neurotransmitter identities are specified. In order to gain a greater understanding of neurotransmitter specification we profiled the transcription state of cholinergic, GABAergic and glutamatergic neurons in vivo at three developmental time points. We identified 86 differentially expressed transcription factors that are uniquely enriched, or uniquely depleted, in a specific neurotransmitter type. Some transcription factors show a similar profile across development, others only show enrichment or depletion at specific developmental stages. Profiling of Acj6 (cholinergic enriched) and Ets65A (cholinergic depleted) binding sites in vivo reveals that they both directly bind the ChAT locus, in addition to a wide spectrum of other key neuronal differentiation genes. We also show that cholinergic enriched transcription factors are expressed in mostly non-overlapping populations in the adult brain, implying the absence of combinatorial regulation of neurotransmitter fate in this context. Furthermore, our data underlines that, similar to Caenorhabditis elegans, there are no simple transcription factor codes for neurotransmitter type specification. This article has an associated First Person interview with the first author of the paper. Summary: Transcriptome profiling of cholinergic, GABAergic and glutamatergic neurons in Drosophila identified multiple transcription factors as potential regulators of neurotransmitter fate.
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Affiliation(s)
- Alicia Estacio-Gómez
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, London SW7 2AZ, UK
| | - Amira Hassan
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, London SW7 2AZ, UK
| | - Emma Walmsley
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, London SW7 2AZ, UK
| | - Lily Wong Le
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, London SW7 2AZ, UK
| | - Tony D Southall
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, London SW7 2AZ, UK
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50
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Azevedo AW, Dickinson ES, Gurung P, Venkatasubramanian L, Mann RS, Tuthill JC. A size principle for recruitment of Drosophila leg motor neurons. eLife 2020; 9:e56754. [PMID: 32490810 PMCID: PMC7347388 DOI: 10.7554/elife.56754] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/01/2020] [Indexed: 11/28/2022] Open
Abstract
To move the body, the brain must precisely coordinate patterns of activity among diverse populations of motor neurons. Here, we use in vivo calcium imaging, electrophysiology, and behavior to understand how genetically-identified motor neurons control flexion of the fruit fly tibia. We find that leg motor neurons exhibit a coordinated gradient of anatomical, physiological, and functional properties. Large, fast motor neurons control high force, ballistic movements while small, slow motor neurons control low force, postural movements. Intermediate neurons fall between these two extremes. This hierarchical organization resembles the size principle, first proposed as a mechanism for establishing recruitment order among vertebrate motor neurons. Recordings in behaving flies confirmed that motor neurons are typically recruited in order from slow to fast. However, we also find that fast, intermediate, and slow motor neurons receive distinct proprioceptive feedback signals, suggesting that the size principle is not the only mechanism that dictates motor neuron recruitment. Overall, this work reveals the functional organization of the fly leg motor system and establishes Drosophila as a tractable system for investigating neural mechanisms of limb motor control.
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Affiliation(s)
- Anthony W Azevedo
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Evyn S Dickinson
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Pralaksha Gurung
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Lalanti Venkatasubramanian
- Department of Biochemistry and Molecular Biophysics, Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Richard S Mann
- Department of Biochemistry and Molecular Biophysics, Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
| | - John C Tuthill
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
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