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Rodrigues DT, Padilha HA, Soares ATG, de Souza MEO, Guerra MT, Ávila DS. The Caenorhabditis elegans neuroendocrine system and their modulators: An overview. Mol Cell Endocrinol 2024; 586:112191. [PMID: 38382589 DOI: 10.1016/j.mce.2024.112191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 02/23/2024]
Abstract
In this review we seek to systematically bring what has been published in the literature about the nervous system, endocrine system, neuroendocrine relationships, neuroendocrine modulations and endocrine disruptors in the alternative model Caenorhabditis elegans. The serotonergic, dopaminergic, GABAergic and glutamatergic neurotransmitters are related to the modulation of the neuroendocrine axis, leading to the activation or inhibition of several processes that occur in the worm through distinct and interconnected pathways. Furthermore, this review addresses the gut-neuronal axis as it has been revealed in recent years that gut microbiota impacts on neuronal functions. This review also approaches xenobiotics that can positively or negatively impact the neuroendocrine system in C. elegans as in mammals, which allows the application of this nematode to screen new drugs and to identify toxicants that are endocrine disruptors.
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Affiliation(s)
- Daniela Teixeira Rodrigues
- Graduation Program in Biological Sciences- Toxicological Biochemistry, Federal University of Santa Maria, RS, Brazil
| | | | | | | | | | - Daiana Silva Ávila
- Graduation Program in Biological Sciences- Toxicological Biochemistry, Federal University of Santa Maria, RS, Brazil; Graduation Program in Biochemistry, Federal University of Pampa, Uruguaiana, RS, Brazil.
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2
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Lanza E, Lucente V, Nicoletti M, Schwartz S, Cavallo IF, Caprini D, Connor CW, Saifuddin MFA, Miller JM, L’Etoile ND, Folli V. See Elegans: Simple-to-use, accurate, and automatic 3D detection of neural activity from densely packed neurons. PLoS One 2024; 19:e0300628. [PMID: 38517838 PMCID: PMC10959381 DOI: 10.1371/journal.pone.0300628] [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: 10/13/2023] [Accepted: 02/29/2024] [Indexed: 03/24/2024] Open
Abstract
In the emerging field of whole-brain imaging at single-cell resolution, which represents one of the new frontiers to investigate the link between brain activity and behavior, the nematode Caenorhabditis elegans offers one of the most characterized models for systems neuroscience. Whole-brain recordings consist of 3D time series of volumes that need to be processed to obtain neuronal traces. Current solutions for this task are either computationally demanding or limited to specific acquisition setups. Here, we propose See Elegans, a direct programming algorithm that combines different techniques for automatic neuron segmentation and tracking without the need for the RFP channel, and we compare it with other available algorithms. While outperforming them in most cases, our solution offers a novel method to guide the identification of a subset of head neurons based on position and activity. The built-in interface allows the user to follow and manually curate each of the processing steps. See Elegans is thus a simple-to-use interface aimed at speeding up the post-processing of volumetric calcium imaging recordings while maintaining a high level of accuracy and low computational demands. (Contact: enrico.lanza@iit.it).
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Affiliation(s)
- Enrico Lanza
- Center for Life Nano- and Neuro-Science@Sapienza, Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Valeria Lucente
- Center for Life Nano- and Neuro-Science@Sapienza, Istituto Italiano di Tecnologia (IIT), Rome, Italy
- D-tails s.r.l., Rome, Italy
| | - Martina Nicoletti
- Center for Life Nano- and Neuro-Science@Sapienza, Istituto Italiano di Tecnologia (IIT), Rome, Italy
- Department of Engineering, Campus Bio-Medico University, Rome, Italy
| | - Silvia Schwartz
- Center for Life Nano- and Neuro-Science@Sapienza, Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Ilaria F. Cavallo
- Center for Life Nano- and Neuro-Science@Sapienza, Istituto Italiano di Tecnologia (IIT), Rome, Italy
- D-tails s.r.l., Rome, Italy
| | - Davide Caprini
- Center for Life Nano- and Neuro-Science@Sapienza, Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Christopher W. Connor
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Mashel Fatema A. Saifuddin
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States of America
| | - Julia M. Miller
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States of America
| | - Noelle D. L’Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States of America
| | - Viola Folli
- Center for Life Nano- and Neuro-Science@Sapienza, Istituto Italiano di Tecnologia (IIT), Rome, Italy
- D-tails s.r.l., Rome, Italy
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3
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Li Y, Chitturi J, Yu B, Zhang Y, Wu J, Ti P, Hung W, Zhen M, Gao S. UBR-1 ubiquitin ligase regulates the balance between GABAergic and glutamatergic signaling. EMBO Rep 2023; 24:e57014. [PMID: 37811674 PMCID: PMC10626437 DOI: 10.15252/embr.202357014] [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: 02/16/2023] [Revised: 09/16/2023] [Accepted: 09/21/2023] [Indexed: 10/10/2023] Open
Abstract
Excitation/inhibition (E/I) balance is carefully maintained by the nervous system. The neurotransmitter GABA has been reported to be co-released with its sole precursor, the neurotransmitter glutamate. The genetic and circuitry mechanisms to establish the balance between GABAergic and glutamatergic signaling have not been fully elucidated. Caenorhabditis elegans DVB is an excitatory GABAergic motoneuron that drives the expulsion step in the defecation motor program. We show here that in addition to UNC-47, the vesicular GABA transporter, DVB also expresses EAT-4, a vesicular glutamate transporter. UBR-1, a conserved ubiquitin ligase, regulates DVB activity by suppressing a bidirectional inhibitory glutamate signaling. Loss of UBR-1 impairs DVB Ca2+ activity and expulsion frequency. These impairments are fully compensated by the knockdown of EAT-4 in DVB. Further, glutamate-gated chloride channels GLC-3 and GLC-2/4 receive DVB's glutamate signals to inhibit DVB and enteric muscle activity, respectively. These results implicate an intrinsic cellular mechanism that promotes the inherent asymmetric neural activity. We propose that elevated glutamate in ubr-1 mutants, being the cause of the E/I shift, potentially contributes to Johanson Blizzard syndrome.
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Affiliation(s)
- Yi Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanChina
| | - Jyothsna Chitturi
- Lunenfeld‐Tanenbaum Research Institute, Mount Sinai HospitalUniversity of TorontoTorontoONCanada
| | - Bin Yu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanChina
| | - Yongning Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanChina
| | - Jing Wu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanChina
| | - Panpan Ti
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanChina
| | - Wesley Hung
- Lunenfeld‐Tanenbaum Research Institute, Mount Sinai HospitalUniversity of TorontoTorontoONCanada
| | - Mei Zhen
- Lunenfeld‐Tanenbaum Research Institute, Mount Sinai HospitalUniversity of TorontoTorontoONCanada
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanChina
- Key Laboratory of Vascular Aging of the Ministry of Education, Tongji Hospital of Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
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4
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Randi F, Sharma AK, Dvali S, Leifer AM. Neural signal propagation atlas of Caenorhabditis elegans. Nature 2023; 623:406-414. [PMID: 37914938 PMCID: PMC10632145 DOI: 10.1038/s41586-023-06683-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/27/2023] [Indexed: 11/03/2023]
Abstract
Establishing how neural function emerges from network properties is a fundamental problem in neuroscience1. Here, to better understand the relationship between the structure and the function of a nervous system, we systematically measure signal propagation in 23,433 pairs of neurons across the head of the nematode Caenorhabditis elegans by direct optogenetic activation and simultaneous whole-brain calcium imaging. We measure the sign (excitatory or inhibitory), strength, temporal properties and causal direction of signal propagation between these neurons to create a functional atlas. We find that signal propagation differs from model predictions that are based on anatomy. Using mutants, we show that extrasynaptic signalling not visible from anatomy contributes to this difference. We identify many instances of dense-core-vesicle-dependent signalling, including on timescales of less than a second, that evoke acute calcium transients-often where no direct wired connection exists but where relevant neuropeptides and receptors are expressed. We propose that, in such cases, extrasynaptically released neuropeptides serve a similar function to that of classical neurotransmitters. Finally, our measured signal propagation atlas better predicts the neural dynamics of spontaneous activity than do models based on anatomy. We conclude that both synaptic and extrasynaptic signalling drive neural dynamics on short timescales, and that measurements of evoked signal propagation are crucial for interpreting neural function.
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Affiliation(s)
- Francesco Randi
- Department of Physics, Princeton University, Princeton, NJ, USA
- Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Anuj K Sharma
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Sophie Dvali
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Andrew M Leifer
- Department of Physics, Princeton University, Princeton, NJ, USA.
- Princeton Neurosciences Institute, Princeton University, Princeton, NJ, USA.
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5
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Atanas AA, Kim J, Wang Z, Bueno E, Becker M, Kang D, Park J, Kramer TS, Wan FK, Baskoylu S, Dag U, Kalogeropoulou E, Gomes MA, Estrem C, Cohen N, Mansinghka VK, Flavell SW. Brain-wide representations of behavior spanning multiple timescales and states in C. elegans. Cell 2023; 186:4134-4151.e31. [PMID: 37607537 PMCID: PMC10836760 DOI: 10.1016/j.cell.2023.07.035] [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: 11/03/2022] [Revised: 07/05/2023] [Accepted: 07/28/2023] [Indexed: 08/24/2023]
Abstract
Changes in an animal's behavior and internal state are accompanied by widespread changes in activity across its brain. However, how neurons across the brain encode behavior and how this is impacted by state is poorly understood. We recorded brain-wide activity and the diverse motor programs of freely moving C. elegans and built probabilistic models that explain how each neuron encodes quantitative behavioral features. By determining the identities of the recorded neurons, we created an atlas of how the defined neuron classes in the C. elegans connectome encode behavior. Many neuron classes have conjunctive representations of multiple behaviors. Moreover, although many neurons encode current motor actions, others integrate recent actions. Changes in behavioral state are accompanied by widespread changes in how neurons encode behavior, and we identify these flexible nodes in the connectome. Our results provide a global map of how the cell types across an animal's brain encode its behavior.
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Affiliation(s)
- Adam A Atanas
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Computational and Systems Biology Program, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jungsoo Kim
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ziyu Wang
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Eric Bueno
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - McCoy Becker
- Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Di Kang
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jungyeon Park
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Talya S Kramer
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA; MIT Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Flossie K Wan
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Saba Baskoylu
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ugur Dag
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Elpiniki Kalogeropoulou
- School of Computing, University of Leeds, Leeds, UK; School of Biology, University of Leeds, Leeds, UK
| | - Matthew A Gomes
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Cassi Estrem
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Netta Cohen
- School of Computing, University of Leeds, Leeds, UK
| | - Vikash K Mansinghka
- Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Steven W Flavell
- Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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6
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Mizumoto K, Jin Y, Bessereau JL. Synaptogenesis: unmasking molecular mechanisms using Caenorhabditis elegans. Genetics 2023; 223:iyac176. [PMID: 36630525 PMCID: PMC9910414 DOI: 10.1093/genetics/iyac176] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/22/2022] [Indexed: 01/13/2023] Open
Abstract
The nematode Caenorhabditis elegans is a research model organism particularly suited to the mechanistic understanding of synapse genesis in the nervous system. Armed with powerful genetics, knowledge of complete connectomics, and modern genomics, studies using C. elegans have unveiled multiple key regulators in the formation of a functional synapse. Importantly, many signaling networks display remarkable conservation throughout animals, underscoring the contributions of C. elegans research to advance the understanding of our brain. In this chapter, we will review up-to-date information of the contribution of C. elegans to the understanding of chemical synapses, from structure to molecules and to synaptic remodeling.
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Affiliation(s)
- Kota Mizumoto
- Department of Zoology, University of British Columbia, Vancouver V6T 1Z3, Canada
| | - Yishi Jin
- Department of Neurobiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Jean-Louis Bessereau
- Univ Lyon, University Claude Bernard Lyon 1, CNRS UMR 5284, INSERM U 1314, Melis, 69008 Lyon, France
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7
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Bray SR, Wyss LS, Chai C, Lozada ME, Wang B. Adaptive robustness through incoherent signaling mechanisms in a regenerative brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.523817. [PMID: 36711454 PMCID: PMC9882340 DOI: 10.1101/2023.01.20.523817] [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: 01/22/2023]
Abstract
Animal behavior emerges from collective dynamics of interconnected neurons, making it vulnerable to connectome damage. Paradoxically, many organisms maintain significant behavioral output after large-scale neural injury. Molecular underpinnings of this extreme robustness remain largely unknown. Here, we develop a quantitative behavioral analysis pipeline to measure previously uncharacterized long-lasting latent memory states in planarian flatworms during whole-brain regeneration. By combining >20,000 animal trials with neural population dynamic modeling, we show that long-range volumetric peptidergic signals allow the planarian to rapidly reestablish latent states and restore coarse behavior after large structural perturbations to the nervous system, while small-molecule neuromodulators gradually refine the precision. The different time and length scales of neuropeptide and small-molecule transmission generate incoherent patterns of neural activity which competitively regulate behavior and memory. Controlling behavior through opposing communication mechanisms creates a more robust system than either alone and may serve as a generic approach to construct robust neural networks.
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Affiliation(s)
- Samuel R. Bray
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Livia S. Wyss
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Maria E. Lozada
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA
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8
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Lu Y, Ahamed T, Mulcahy B, Meng J, Witvliet D, Guan SA, Holmyard D, Hung W, Wen Q, Chisholm AD, Samuel ADT, Zhen M. Extrasynaptic signaling enables an asymmetric juvenile motor circuit to produce symmetric undulation. Curr Biol 2022; 32:4631-4644.e5. [PMID: 36182701 PMCID: PMC9643663 DOI: 10.1016/j.cub.2022.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 06/17/2022] [Accepted: 09/01/2022] [Indexed: 01/28/2023]
Abstract
In many animals, there is a direct correspondence between the motor patterns that drive locomotion and the motor neuron innervation. For example, the adult C. elegans moves with symmetric and alternating dorsal-ventral bending waves arising from symmetric motor neuron input onto the dorsal and ventral muscles. In contrast to the adult, the C. elegans motor circuit at the juvenile larval stage has asymmetric wiring between motor neurons and muscles but still generates adult-like bending waves with dorsal-ventral symmetry. We show that in the juvenile circuit, wiring between excitatory and inhibitory motor neurons coordinates the contraction of dorsal muscles with relaxation of ventral muscles, producing dorsal bends. However, ventral bending is not driven by analogous wiring. Instead, ventral muscles are excited uniformly by premotor interneurons through extrasynaptic signaling. Ventral bends occur in anti-phasic entrainment to activity of the same motor neurons that drive dorsal bends. During maturation, the juvenile motor circuit is replaced by two motor subcircuits that separately drive dorsal and ventral bending. Modeling reveals that the juvenile's immature motor circuit is an adequate solution to generate adult-like dorsal-ventral bending before the animal matures. Developmental rewiring between functionally degenerate circuit solutions, which both generate symmetric bending patterns, minimizes behavioral disruption across maturation.
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Affiliation(s)
- Yangning Lu
- Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Tosif Ahamed
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Ben Mulcahy
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Jun Meng
- Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Daniel Witvliet
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Sihui Asuka Guan
- Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Douglas Holmyard
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Quan Wen
- Department of Physics and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; School of Life Sciences, University of Science and Technology, Hefei, Anhui 230027, China
| | - Andrew D Chisholm
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Aravinthan D T Samuel
- Department of Physics and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Mei Zhen
- Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1X5, Canada.
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9
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Miyazaki S, Kawano T, Yanagisawa M, Hayashi Y. Intracellular Ca2+ dynamics in the ALA neuron reflect sleep pressure and regulate sleep in Caenorhabditis elegans. iScience 2022; 25:104452. [PMID: 35707721 PMCID: PMC9189131 DOI: 10.1016/j.isci.2022.104452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/03/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022] Open
Abstract
The mechanisms underlying sleep homeostasis are poorly understood. The nematode Caenorhabditis elegans exhibits 2 types of sleep: lethargus, or developmentally timed, and stress-induced sleep. Lethargus is characterized by alternating cycles of sleep and motion bouts. Sleep bouts are homeostatically regulated, i.e., prolonged active bouts lead to prolonged sleep bouts. Here we reveal that the interneuron ALA is crucial for homeostatic regulation during lethargus. Intracellular Ca2+ in ALA gradually increased during active bouts and rapidly decayed upon transitions to sleep bouts. Longer active bouts were accompanied by higher intracellular Ca2+ peaks. Optogenetic activation of ALA during active bouts caused transitions to sleep bouts. Dysfunction of CEH-17, which is an LIM homeodomain transcription factor selectively expressed in ALA, impaired the characteristic patterns of ALA intracellular Ca2+ and abolished the homeostatic regulation of sleep bouts. These findings indicate that ALA encodes sleep pressure and contributes to sleep homeostasis. ALA gradually increases its activity during motion bouts during lethargus in C. elegans Dysfunction or artificial activation of ALA perturbs the sleep structure ALA plays a crucial role in homeostatic sleep regulation
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Affiliation(s)
- Shinichi Miyazaki
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- PhD Program in Humanics, School of Integrative and Global Majors, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Taizo Kawano
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Life Science Center for Survival Dynamics (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
- R&D Center for Frontiers of Mirai in Policy and Technology (F-MIRAI), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yu Hayashi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 603-8363, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Corresponding author
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10
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Chen L, Liu Y, Su P, Hung W, Li H, Wang Y, Yue Z, Ge MH, Wu ZX, Zhang Y, Fei P, Chen LM, Tao L, Mao H, Zhen M, Gao S. Escape steering by cholecystokinin peptidergic signaling. Cell Rep 2022; 38:110330. [PMID: 35139370 DOI: 10.1016/j.celrep.2022.110330] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/19/2021] [Accepted: 01/11/2022] [Indexed: 11/26/2022] Open
Abstract
Escape is an evolutionarily conserved and essential avoidance response. Considered to be innate, most studies on escape responses focused on hard-wired circuits. We report here that a neuropeptide NLP-18 and its cholecystokinin receptor CKR-1 enable the escape circuit to execute a full omega (Ω) turn. We demonstrate in vivo NLP-18 is mainly secreted by the gustatory sensory neuron (ASI) to activate CKR-1 in the head motor neuron (SMD) and the turn-initiating interneuron (AIB). Removal of NLP-18 or CKR-1 or specific knockdown of CKR-1 in SMD or AIB neurons leads to shallower turns, hence less robust escape steering. Consistently, elevation of head motor neuron (SMD)'s Ca2+ transients during escape steering is attenuated upon the removal of NLP-18 or CKR-1. In vitro, synthetic NLP-18 directly evokes CKR-1-dependent currents in oocytes and CKR-1-dependent Ca2+ transients in SMD. Thus, cholecystokinin peptidergic signaling modulates an escape circuit to generate robust escape steering.
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Affiliation(s)
- Lili Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Yuting Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Pan Su
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Haiwen Li
- Center for Quantitative Biology, Peking University, Beijing 100871, P.R. China; LMAM, School of Mathematical Sciences, Peking University, Beijing 100871, P.R. China
| | - Ya Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Zhongpu Yue
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Ming-Hai Ge
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Zheng-Xing Wu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Yan Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Peng Fei
- School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Li-Ming Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
| | - Louis Tao
- Center for Quantitative Biology, Peking University, Beijing 100871, P.R. China
| | - Heng Mao
- LMAM, School of Mathematical Sciences, Peking University, Beijing 100871, P.R. China
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P.R. China.
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11
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Takács-Vellai K, Farkas Z, Ősz F, Stewart GW. Model systems in SDHx-related pheochromocytoma/paraganglioma. Cancer Metastasis Rev 2021; 40:1177-1201. [PMID: 34957538 PMCID: PMC8825606 DOI: 10.1007/s10555-021-10009-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/04/2021] [Indexed: 11/17/2022]
Abstract
Pheochromocytoma (PHEO) and paraganglioma (PGL) (together PPGL) are tumors with poor outcomes that arise from neuroendocrine cells in the adrenal gland, and sympathetic and parasympathetic ganglia outside the adrenal gland, respectively. Many follow germline mutations in genes coding for subunits of succinate dehydrogenase (SDH), a tetrameric enzyme in the tricarboxylic acid (TCA) cycle that both converts succinate to fumarate and participates in electron transport. Germline SDH subunit B (SDHB) mutations have a high metastatic potential. Herein, we review the spectrum of model organisms that have contributed hugely to our understanding of SDH dysfunction. In Saccharomyces cerevisiae (yeast), succinate accumulation inhibits alpha-ketoglutarate-dependent dioxygenase enzymes leading to DNA demethylation. In the worm Caenorhabditis elegans, mutated SDH creates developmental abnormalities, metabolic rewiring, an energy deficit and oxygen hypersensitivity (the latter is also found in Drosophila melanogaster). In the zebrafish Danio rerio, sdhb mutants display a shorter lifespan with defective energy metabolism. Recently, SDHB-deficient pheochromocytoma has been cultivated in xenografts and has generated cell lines, which can be traced back to a heterozygous SDHB-deficient rat. We propose that a combination of such models can be efficiently and effectively used in both pathophysiological studies and drug-screening projects in order to find novel strategies in PPGL treatment.
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Affiliation(s)
| | - Zsolt Farkas
- Department of Biological Anthropology, Eötvös Loránd University, Budapest, Hungary
| | - Fanni Ősz
- Department of Biological Anthropology, Eötvös Loránd University, Budapest, Hungary
| | - Gordon W Stewart
- Division of Medicine, University College London, Gower Street, London, WC1E 6BT, UK
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12
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Bhat US, Shahi N, Surendran S, Babu K. Neuropeptides and Behaviors: How Small Peptides Regulate Nervous System Function and Behavioral Outputs. Front Mol Neurosci 2021; 14:786471. [PMID: 34924955 PMCID: PMC8674661 DOI: 10.3389/fnmol.2021.786471] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/11/2021] [Indexed: 11/13/2022] Open
Abstract
One of the reasons that most multicellular animals survive and thrive is because of the adaptable and plastic nature of their nervous systems. For an organism to survive, it is essential for the animal to respond and adapt to environmental changes. This is achieved by sensing external cues and translating them into behaviors through changes in synaptic activity. The nervous system plays a crucial role in constantly evaluating environmental cues and allowing for behavioral plasticity in the organism. Multiple neurotransmitters and neuropeptides have been implicated as key players for integrating sensory information to produce the desired output. Because of its simple nervous system and well-established neuronal connectome, C. elegans acts as an excellent model to understand the mechanisms underlying behavioral plasticity. Here, we critically review how neuropeptides modulate a wide range of behaviors by allowing for changes in neuronal and synaptic signaling. This review will have a specific focus on feeding, mating, sleep, addiction, learning and locomotory behaviors in C. elegans. With a view to understand evolutionary relationships, we explore the functions and associated pathophysiology of C. elegans neuropeptides that are conserved across different phyla. Further, we discuss the mechanisms of neuropeptidergic signaling and how these signals are regulated in different behaviors. Finally, we attempt to provide insight into developing potential therapeutics for neuropeptide-related disorders.
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Affiliation(s)
- Umer Saleem Bhat
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Navneet Shahi
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Siju Surendran
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Kavita Babu
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
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13
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Marques F, Falquet L, Vandewyer E, Beets I, Glauser DA. Signaling via the FLP-14/FRPR-19 neuropeptide pathway sustains nociceptive response to repeated noxious stimuli in C. elegans. PLoS Genet 2021; 17:e1009880. [PMID: 34748554 PMCID: PMC8601619 DOI: 10.1371/journal.pgen.1009880] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 11/18/2021] [Accepted: 10/15/2021] [Indexed: 12/13/2022] Open
Abstract
In order to thrive in constantly changing environments, animals must adaptively respond to threatening events. Noxious stimuli are not only processed according to their absolute intensity, but also to their context. Adaptation processes can cause animals to habituate at different rates and degrees in response to permanent or repeated stimuli. Here, we used a forward genetic approach in Caenorhabditis elegans to identify a neuropeptidergic pathway, essential to prevent fast habituation and maintain robust withdrawal responses to repeated noxious stimuli. This pathway involves the FRPR-19A and FRPR-19B G-protein coupled receptor isoforms produced from the frpr-19 gene by alternative splicing. Loss or overexpression of each or both isoforms can impair withdrawal responses caused by the optogenetic activation of the polymodal FLP nociceptor neuron. Furthermore, we identified FLP-8 and FLP-14 as FRPR-19 ligands in vitro. flp-14, but not flp-8, was essential to promote withdrawal response and is part of the same genetic pathway as frpr-19 in vivo. Expression and cell-specific rescue analyses suggest that FRPR-19 acts both in the FLP nociceptive neurons and downstream interneurons, whereas FLP-14 acts from interneurons. Importantly, genetic impairment of the FLP-14/FRPR-19 pathway accelerated the habituation to repeated FLP-specific optogenetic activation, as well as to repeated noxious heat and harsh touch stimuli. Collectively, our data suggest that well-adjusted neuromodulation via the FLP-14/FRPR-19 pathway contributes to promote nociceptive signals in C. elegans and counteracts habituation processes that otherwise tend to rapidly reduce aversive responses to repeated noxious stimuli.
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Affiliation(s)
- Filipe Marques
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Laurent Falquet
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Elke Vandewyer
- Neural Signaling and Circuit Plasticity Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Isabel Beets
- Neural Signaling and Circuit Plasticity Group, Department of Biology, KU Leuven, Leuven, Belgium
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14
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Connectomes across development reveal principles of brain maturation. Nature 2021; 596:257-261. [PMID: 34349261 DOI: 10.1038/s41586-021-03778-8] [Citation(s) in RCA: 140] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 06/29/2021] [Indexed: 01/23/2023]
Abstract
An animal's nervous system changes as its body grows from birth to adulthood and its behaviours mature1-8. The form and extent of circuit remodelling across the connectome is unknown3,9-15. Here we used serial-section electron microscopy to reconstruct the full brain of eight isogenic Caenorhabditis elegans individuals across postnatal stages to investigate how it changes with age. The overall geometry of the brain is preserved from birth to adulthood, but substantial changes in chemical synaptic connectivity emerge on this consistent scaffold. Comparing connectomes between individuals reveals substantial differences in connectivity that make each brain partly unique. Comparing connectomes across maturation reveals consistent wiring changes between different neurons. These changes alter the strength of existing connections and create new connections. Collective changes in the network alter information processing. During development, the central decision-making circuitry is maintained, whereas sensory and motor pathways substantially remodel. With age, the brain becomes progressively more feedforward and discernibly modular. Thus developmental connectomics reveals principles that underlie brain maturation.
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15
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Ji N, Venkatachalam V, Rodgers HD, Hung W, Kawano T, Clark CM, Lim M, Alkema MJ, Zhen M, Samuel ADT. Corollary discharge promotes a sustained motor state in a neural circuit for navigation. eLife 2021; 10:e68848. [PMID: 33880993 PMCID: PMC8139836 DOI: 10.7554/elife.68848] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
Animals exhibit behavioral and neural responses that persist on longer timescales than transient or fluctuating stimulus inputs. Here, we report that Caenorhabditis elegans uses feedback from the motor circuit to a sensory processing interneuron to sustain its motor state during thermotactic navigation. By imaging circuit activity in behaving animals, we show that a principal postsynaptic partner of the AFD thermosensory neuron, the AIY interneuron, encodes both temperature and motor state information. By optogenetic and genetic manipulation of this circuit, we demonstrate that the motor state representation in AIY is a corollary discharge signal. RIM, an interneuron that is connected with premotor interneurons, is required for this corollary discharge. Ablation of RIM eliminates the motor representation in AIY, allows thermosensory representations to reach downstream premotor interneurons, and reduces the animal's ability to sustain forward movements during thermotaxis. We propose that feedback from the motor circuit to the sensory processing circuit underlies a positive feedback mechanism to generate persistent neural activity and sustained behavioral patterns in a sensorimotor transformation.
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Affiliation(s)
- Ni Ji
- Department of Physics and Center for Brain Science, Harvard UniversityCambridgeUnited States
| | - Vivek Venkatachalam
- Department of Physics and Center for Brain Science, Harvard UniversityCambridgeUnited States
| | - Hillary Denise Rodgers
- Department of Physics and Center for Brain Science, Harvard UniversityCambridgeUnited States
- Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai HospitalTorontoCanada
- Departments of Molecular Genetics, and Physiology, University of TorontoTorontoCanada
| | - Taizo Kawano
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai HospitalTorontoCanada
- Departments of Molecular Genetics, and Physiology, University of TorontoTorontoCanada
| | - Christopher M Clark
- Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Maria Lim
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai HospitalTorontoCanada
- Departments of Molecular Genetics, and Physiology, University of TorontoTorontoCanada
| | - Mark J Alkema
- Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai HospitalTorontoCanada
- Departments of Molecular Genetics, and Physiology, University of TorontoTorontoCanada
| | - Aravinthan DT Samuel
- Department of Physics and Center for Brain Science, Harvard UniversityCambridgeUnited States
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16
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Maertens T, Schöll E, Ruiz J, Hövel P. Multilayer network analysis of C. elegans: Looking into the locomotory circuitry. Neurocomputing 2021. [DOI: 10.1016/j.neucom.2020.11.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Morrison M, Fieseler C, Kutz JN. Nonlinear Control in the Nematode C. elegans. Front Comput Neurosci 2021; 14:616639. [PMID: 33551783 PMCID: PMC7862714 DOI: 10.3389/fncom.2020.616639] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/28/2020] [Indexed: 11/26/2022] Open
Abstract
Recent whole-brain calcium imaging recordings of the nematode C. elegans have demonstrated that the neural activity associated with behavior is dominated by dynamics on a low-dimensional manifold that can be clustered according to behavioral states. Previous models of C. elegans dynamics have either been linear models, which cannot support the existence of multiple fixed points in the system, or Markov-switching models, which do not describe how control signals in C. elegans neural dynamics can produce switches between stable states. It remains unclear how a network of neurons can produce fast and slow timescale dynamics that control transitions between stable states in a single model. We propose a global, nonlinear control model which is minimally parameterized and captures the state transitions described by Markov-switching models with a single dynamical system. The model is fit by reproducing the timeseries of the dominant PCA mode in the calcium imaging data. Long and short time-scale changes in transition statistics can be characterized via changes in a single parameter in the control model. Some of these macro-scale transitions have experimental correlates to single neuro-modulators that seem to act as biological controls, allowing this model to generate testable hypotheses about the effect of these neuro-modulators on the global dynamics. The theory provides an elegant characterization of control in the neuron population dynamics in C. elegans. Moreover, the mathematical structure of the nonlinear control framework provides a paradigm that can be generalized to more complex systems with an arbitrary number of behavioral states.
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Affiliation(s)
- Megan Morrison
- Department of Applied Mathematics, University of Washington, Seattle, WA, United States
| | - Charles Fieseler
- Department of Neurobiology, University of Vienna, Vienna, Austria
| | - J. Nathan Kutz
- Department of Applied Mathematics, University of Washington, Seattle, WA, United States
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18
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Abstract
Caenorhabditis elegans' behavioral states, like those of other animals, are shaped by its immediate environment, its past experiences, and by internal factors. We here review the literature on C. elegans behavioral states and their regulation. We discuss dwelling and roaming, local and global search, mate finding, sleep, and the interaction between internal metabolic states and behavior.
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Affiliation(s)
- Steven W Flavell
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Young-Jai You
- Division of Biological Science, Graduate School of Science, Nagoya University, 464-8602, Japan
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19
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Lorenzo R, Onizuka M, Defrance M, Laurent P. Combining single-cell RNA-sequencing with a molecular atlas unveils new markers for Caenorhabditis elegans neuron classes. Nucleic Acids Res 2020; 48:7119-7134. [PMID: 32542321 PMCID: PMC7367206 DOI: 10.1093/nar/gkaa486] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 05/11/2020] [Accepted: 05/27/2020] [Indexed: 12/11/2022] Open
Abstract
Single-cell RNA-sequencing (scRNA-seq) of the Caenorhabditis elegans nervous system offers the unique opportunity to obtain a partial expression profile for each neuron within a known connectome. Building on recent scRNA-seq data and on a molecular atlas describing the expression pattern of ∼800 genes at the single cell resolution, we designed an iterative clustering analysis aiming to match each cell-cluster to the ∼100 anatomically defined neuron classes of C. elegans. This heuristic approach successfully assigned 97 of the 118 neuron classes to a cluster. Sixty two clusters were assigned to a single neuron class and 15 clusters grouped neuron classes sharing close molecular signatures. Pseudotime analysis revealed a maturation process occurring in some neurons (e.g. PDA) during the L2 stage. Based on the molecular profiles of all identified neurons, we predicted cell fate regulators and experimentally validated unc-86 for the normal differentiation of RMG neurons. Furthermore, we observed that different classes of genes functionally diversify sensory neurons, interneurons and motorneurons. Finally, we designed 15 new neuron class-specific promoters validated in vivo. Amongst them, 10 represent the only specific promoter reported to this day, expanding the list of neurons amenable to genetic manipulations.
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Affiliation(s)
- Ramiro Lorenzo
- Laboratory of Neurophysiology, ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Brussels, Belgium
- Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET-CICPBA-UNCPBA, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro (FCV-UNCPBA), Tandil, Argentina
| | - Michiho Onizuka
- Laboratory of Neurophysiology, ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Matthieu Defrance
- Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles, Brussels, Belgium
| | - Patrick Laurent
- Laboratory of Neurophysiology, ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), Brussels, Belgium
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20
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Epidermal Growth Factor Signaling Promotes Sleep through a Combined Series and Parallel Neural Circuit. Curr Biol 2019; 30:1-16.e13. [PMID: 31839447 DOI: 10.1016/j.cub.2019.10.048] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 07/12/2019] [Accepted: 10/23/2019] [Indexed: 11/20/2022]
Abstract
Sleep requires sleep-active neurons that depolarize to inhibit wake circuits. Sleep-active neurons are under the control of homeostatic mechanisms that determine sleep need. However, little is known about the molecular and circuit mechanisms that translate sleep need into the depolarization of sleep-active neurons. During many stages and conditions in C. elegans, sleep requires a sleep-active neuron called RIS. Here, we defined the transcriptome of RIS and discovered that genes of the epidermal growth factor receptor (EGFR) signaling pathway are expressed in RIS. Because of cellular stress, EGFR directly activates RIS. Activation of EGFR signaling in the ALA neuron has previously been suggested to promote sleep independently of RIS. Unexpectedly, we found that ALA activation promotes RIS depolarization. Our results suggest that ALA is a drowsiness neuron with two separable functions: (1) it inhibits specific behaviors, such as feeding, independently of RIS, (2) and it activates RIS. Whereas ALA plays a strong role in surviving cellular stress, surprisingly, RIS does not. In summary, EGFR signaling can depolarize RIS by an indirect mechanism through activation of the ALA neuron that acts upstream of the sleep-active RIS neuron and through a direct mechanism using EGFR signaling in RIS. ALA-dependent drowsiness, rather than RIS-dependent sleep bouts, appears to be important for increasing survival after cellular stress, suggesting that different types of behavioral inhibition play different roles in restoring health. VIDEO ABSTRACT.
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21
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Serotonin modulates behavior-related neural activity of RID interneuron in Caenorhabditis elegans. PLoS One 2019; 14:e0226044. [PMID: 31800640 PMCID: PMC6892467 DOI: 10.1371/journal.pone.0226044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/17/2019] [Indexed: 11/29/2022] Open
Abstract
Animals change their behaviors in response to external stimuli, and numerous neurotransmitters are involved in these behavioral changes. In Caenorhabditis elegans, serotonin (5-HT) affects various behaviors such as inhibition of locomotion, stimulation of egg laying, and pharyngeal pumping. Previous research has shown that the neural activity of the RID interneuron increases when the worm moves forward, and the RID is necessary for sustaining forward locomotion. However, the relationship between 5-HT and neural activity of RID, and how it modulates the behavior of the worm has not been investigated. In this article, we reveal the relationship among 5-HT, RID activity, and the behavior of worms using a custom-made tracking and imaging system. We simultaneously measured the neural activity of the RID and behavior in worms with three conditions: mock animals, animals pre-exposed to 5-HT, and 5-HT receptor mod-1 mutants. As shown in previous research, the neural activity of the RID increased during the transition from backward to forward, whereas it decreased during the transition from forward to backward in mock animals. These changes in neural activity were not observed in animals pre-exposed to 5-HT and mod-1 mutants. Moreover, RID activity was correlated with the velocity of the worm in mock animals. However, this correlation was not observed in animals pre-exposed to 5-HT and mod-1 mutants. Our results demonstrate that 5-HT modulates the activity of the RID interneuron, and we infer that the RID plays a role in modulating forward locomotion by changing its activity through 5-HT.
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22
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Cuentas-Condori A, Mulcahy B, He S, Palumbos S, Zhen M, Miller DM. C. elegans neurons have functional dendritic spines. eLife 2019; 8:e47918. [PMID: 31584430 PMCID: PMC6802951 DOI: 10.7554/elife.47918] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 10/03/2019] [Indexed: 12/15/2022] Open
Abstract
Dendritic spines are specialized postsynaptic structures that transduce presynaptic signals, are regulated by neural activity and correlated with learning and memory. Most studies of spine function have focused on the mammalian nervous system. However, spine-like protrusions have been reported in C. elegans (Philbrook et al., 2018), suggesting that the experimental advantages of smaller model organisms could be exploited to study the biology of dendritic spines. Here, we used super-resolution microscopy, electron microscopy, live-cell imaging and genetics to show that C. elegans motor neurons have functional dendritic spines that: (1) are structurally defined by a dynamic actin cytoskeleton; (2) appose presynaptic dense projections; (3) localize ER and ribosomes; (4) display calcium transients triggered by presynaptic activity and propagated by internal Ca++ stores; (5) respond to activity-dependent signals that regulate spine density. These studies provide a solid foundation for a new experimental paradigm that exploits the power of C. elegans genetics and live-cell imaging for fundamental studies of dendritic spine morphogenesis and function.
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Affiliation(s)
| | - Ben Mulcahy
- Lunenfeld-Tanenbaum Research InstituteUniversity of TorontoTorontoCanada
| | - Siwei He
- Neuroscience ProgramVanderbilt UniversityNashvilleUnited States
| | - Sierra Palumbos
- Neuroscience ProgramVanderbilt UniversityNashvilleUnited States
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research InstituteUniversity of TorontoTorontoCanada
| | - David M Miller
- Department of Cell and Developmental BiologyVanderbilt UniversityNashvilleUnited States
- Neuroscience ProgramVanderbilt UniversityNashvilleUnited States
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23
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Nance J, Frøkjær-Jensen C. The Caenorhabditis elegans Transgenic Toolbox. Genetics 2019; 212:959-990. [PMID: 31405997 PMCID: PMC6707460 DOI: 10.1534/genetics.119.301506] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/01/2019] [Indexed: 12/30/2022] Open
Abstract
The power of any genetic model organism is derived, in part, from the ease with which gene expression can be manipulated. The short generation time and invariant developmental lineage have made Caenorhabditis elegans very useful for understanding, e.g., developmental programs, basic cell biology, neurobiology, and aging. Over the last decade, the C. elegans transgenic toolbox has expanded considerably, with the addition of a variety of methods to control expression and modify genes with unprecedented resolution. Here, we provide a comprehensive overview of transgenic methods in C. elegans, with an emphasis on recent advances in transposon-mediated transgenesis, CRISPR/Cas9 gene editing, conditional gene and protein inactivation, and bipartite systems for temporal and spatial control of expression.
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Affiliation(s)
- Jeremy Nance
- Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, New York 10016
| | - Christian Frøkjær-Jensen
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division (BESE), KAUST Environmental Epigenetics Program (KEEP), Thuwal 23955-6900, Saudi Arabia
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24
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Brennan C, Proekt A. A quantitative model of conserved macroscopic dynamics predicts future motor commands. eLife 2019; 8:46814. [PMID: 31294689 PMCID: PMC6624016 DOI: 10.7554/elife.46814] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 05/22/2019] [Indexed: 12/12/2022] Open
Abstract
In simple organisms such as Caenorhabditis elegans, whole brain imaging has been performed. Here, we use such recordings to model the nervous system. Our model uses neuronal activity to predict expected time of future motor commands up to 30 s prior to the event. These motor commands control locomotion. Predictions are valid for individuals not used in model construction. The model predicts dwell time statistics, sequences of motor commands and individual neuron activation. To develop this model, we extracted loops spanned by neuronal activity in phase space using novel methodology. The model uses only two variables: the identity of the loop and the phase along it. Current values of these macroscopic variables predict future neuronal activity. Remarkably, our model based on macroscopic variables succeeds despite consistent inter-individual differences in neuronal activation. Thus, our analytical framework reconciles consistent individual differences in neuronal activation with macroscopic dynamics that operate universally across individuals. How can we go about trying to understand an object as complex as the brain? The traditional approach is to begin by studying its component parts, cells called neurons. Once we understand how individual neurons work, we can use computers to simulate the activity of networks of neurons. The result is a computer model of the brain. By comparing this model to data from real brains, we can try to make the model as similar to a real brain as possible. But whose brain should we try to reproduce? The roundworm C. elegans, for example, has just 302 neurons in total. Advances in brain imaging mean it is now possible to identify each of these neurons and compare its activity across worms. But doing so reveals that the activity of any given neuron varies greatly between individuals. This is true even among genetically identical worms performing the same behavior. Researchers trying to model the roundworm brain have attempted to model the average activity of each neuron across many worms. They hoped they could use these averages to predict the behavior of other worms from their neuronal activity. But this approach did not to work. Even in roundworms, the coordinated activity of many neurons is required to generate even simple behaviors. Averaging the activity of neurons across worms thus scrambles the information that encodes each behavior. Brennan and Proekt have now overcome this problem by developing a more abstract model that treats the nervous system as a whole. The model takes into account changes in the activity of neurons, and in the worms’ behavior, over time. A model of this type built using one set of worms can predict the behavior of another set of worms. This approach may work because in evolution natural selection acts at the level of behaviors, and not at the level of individual neurons. The activity of individual neurons can thus vary between animals, even when those neurons encode the same behavior. This means it may also be possible to model the human brain without knowing the activity of each of its billions of neurons.
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Affiliation(s)
- Connor Brennan
- Departmentof Neuroscience, University of Pennsylvania, Philadelphia, United States
| | - Alexander Proekt
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, United States
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25
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Mulcahy B, Witvliet D, Holmyard D, Mitchell J, Chisholm AD, Meirovitch Y, Samuel ADT, Zhen M. A Pipeline for Volume Electron Microscopy of the Caenorhabditis elegans Nervous System. Front Neural Circuits 2018; 12:94. [PMID: 30524248 PMCID: PMC6262311 DOI: 10.3389/fncir.2018.00094] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/08/2018] [Indexed: 01/01/2023] Open
Abstract
The “connectome,” a comprehensive wiring diagram of synaptic connectivity, is achieved through volume electron microscopy (vEM) analysis of an entire nervous system and all associated non-neuronal tissues. White et al. (1986) pioneered the fully manual reconstruction of a connectome using Caenorhabditis elegans. Recent advances in vEM allow mapping new C. elegans connectomes with increased throughput, and reduced subjectivity. Current vEM studies aim to not only fill the remaining gaps in the original connectome, but also address fundamental questions including how the connectome changes during development, the nature of individuality, sexual dimorphism, and how genetic and environmental factors regulate connectivity. Here we describe our current vEM pipeline and projected improvements for the study of the C. elegans nervous system and beyond.
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Affiliation(s)
- Ben Mulcahy
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Daniel Witvliet
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Douglas Holmyard
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada.,Nanoscale Biomedical Imaging Facility, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
| | - James Mitchell
- Center for Brain Science, Department of Physics, Harvard University, Cambridge, MA, United States
| | - Andrew D Chisholm
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Yaron Meirovitch
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Aravinthan D T Samuel
- Center for Brain Science, Department of Physics, Harvard University, Cambridge, MA, United States
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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Guo M, Ge M, Berberoglu MA, Zhou J, Ma L, Yang J, Dong Q, Feng Y, Wu Z, Dong Z. Dissecting Molecular and Circuit Mechanisms for Inhibition and Delayed Response of ASI Neurons during Nociceptive Stimulus. Cell Rep 2018; 25:1885-1897.e9. [PMID: 30428355 DOI: 10.1016/j.celrep.2018.10.065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/05/2018] [Accepted: 10/17/2018] [Indexed: 10/27/2022] Open
Abstract
The mechanisms by which off-response neurons stay quiescent during stimulation are largely unknown. Here, we dissect underlying molecular and circuit mechanisms for the inhibition of off-response ASI neurons during nociceptive Cu2+ stimulation. ASIs are inhibited in parallel by sensory neurons ASER, ADFs, and ASHs. ASER activates RIC interneurons that release octopamine (OA) to inhibit ASIs through SER-3 and SER-6 receptors. ADFs release 5-HT that acts on the SER-1 receptor to activate RICs and subsequently inhibit ASIs. Furthermore, it is an inherent property of ASIs that only a delayed on response is evoked by Cu2+ stimulation even when all inhibitory neurons are silenced. Ectopic expression of the ion channel OCR-2, which functions synergistically with OSM-9, in the cilia of ASIs can induce an immediate on response of ASIs upon Cu2+ stimulation. Our findings elucidate the molecular and circuit mechanisms regulating fundamental properties of ASIs, including their inhibition and delayed response.
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Affiliation(s)
- Min Guo
- Bio-Medical Center, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Minghai Ge
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Michael A Berberoglu
- Bio-Medical Center, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Jie Zhou
- Bio-Medical Center, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Long Ma
- Bio-Medical Center, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Juan Yang
- Bio-Medical Center, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Qiyan Dong
- Bio-Medical Center, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Yanni Feng
- Bio-Medical Center, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Zhengxing Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhiqiang Dong
- Bio-Medical Center, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
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27
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Morrison LM, Edwards SL, Manning L, Stec N, Richmond JE, Miller KG. Sentryn and SAD Kinase Link the Guided Transport and Capture of Dense Core Vesicles in Caenorhabditis elegans. Genetics 2018; 210:925-946. [PMID: 30401764 PMCID: PMC6218223 DOI: 10.1534/genetics.118.300847] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 08/27/2018] [Indexed: 11/18/2022] Open
Abstract
Dense core vesicles (DCVs) can transmit signals by releasing neuropeptides from specialized synaptic regions called active zones. DCVs reach the active zone by motorized transport through a long axon. A reverse motor frequently interrupts progress by taking DCVs in the opposite direction. "Guided transport" refers to the mechanism by which outward movements ultimately dominate to bring DCVs to the synaptic region. After guided transport, DCVs alter their interactions with motors and enter a "captured" state. The mechanisms of guided transport and capture of DCVs are unknown. Here, we discovered two proteins that contribute to both processes in Caenorhabditis elegans SAD kinase and a novel conserved protein we named Sentryn are the first proteins found to promote DCV capture. By imaging DCVs moving in various regions of single identified neurons in living animals, we found that DCV guided transport and capture are linked through SAD kinase, Sentryn, and Liprin-α. These proteins act together to regulate DCV motorized transport in a region-specific manner. Between the cell body and the synaptic region, they promote forward transport. In the synaptic region, where all three proteins are highly enriched at active zones, they promote DCV pausing by inhibiting transport in both directions. These three proteins appear to be part of a special subset of active zone-enriched proteins because other active zone proteins do not share their unique functions.
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Affiliation(s)
- Logan M Morrison
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma 73104
| | - Stacey L Edwards
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma 73104
| | - Laura Manning
- Department of Biological Sciences, University of Illinois at Chicago, Illinois 60607
| | - Natalia Stec
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma 73104
| | - Janet E Richmond
- Department of Biological Sciences, University of Illinois at Chicago, Illinois 60607
| | - Kenneth G Miller
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma 73104
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28
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Kaltdorf KV, Theiss M, Markert SM, Zhen M, Dandekar T, Stigloher C, Kollmannsberger P. Automated classification of synaptic vesicles in electron tomograms of C. elegans using machine learning. PLoS One 2018; 13:e0205348. [PMID: 30296290 PMCID: PMC6175533 DOI: 10.1371/journal.pone.0205348] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/24/2018] [Indexed: 11/18/2022] Open
Abstract
Synaptic vesicles (SVs) are a key component of neuronal signaling and fulfil different roles depending on their composition. In electron micrograms of neurites, two types of vesicles can be distinguished by morphological criteria, the classical “clear core” vesicles (CCV) and the typically larger “dense core” vesicles (DCV), with differences in electron density due to their diverse cargos. Compared to CCVs, the precise function of DCVs is less defined. DCVs are known to store neuropeptides, which function as neuronal messengers and modulators [1]. In C. elegans, they play a role in locomotion, dauer formation, egg-laying, and mechano- and chemosensation [2]. Another type of DCVs, also referred to as granulated vesicles, are known to transport Bassoon, Piccolo and further constituents of the presynaptic density in the center of the active zone (AZ), and therefore are important for synaptogenesis [3]. To better understand the role of different types of SVs, we present here a new automated approach to classify vesicles. We combine machine learning with an extension of our previously developed vesicle segmentation workflow, the ImageJ macro 3D ART VeSElecT. With that we reliably distinguish CCVs and DCVs in electron tomograms of C. elegans NMJs using image-based features. Analysis of the underlying ground truth data shows an increased fraction of DCVs as well as a higher mean distance between DCVs and AZs in dauer larvae compared to young adult hermaphrodites. Our machine learning based tools are adaptable and can be applied to study properties of different synaptic vesicle pools in electron tomograms of diverse model organisms.
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Affiliation(s)
- Kristin Verena Kaltdorf
- Imaging Core Facility, Biocenter, University of Würzburg, Würzburg, Germany
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
- Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
| | - Maria Theiss
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
- Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
| | | | - Mei Zhen
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Thomas Dandekar
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
- * E-mail: (PK); (CS); (TD)
| | - Christian Stigloher
- Imaging Core Facility, Biocenter, University of Würzburg, Würzburg, Germany
- * E-mail: (PK); (CS); (TD)
| | - Philip Kollmannsberger
- Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
- * E-mail: (PK); (CS); (TD)
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29
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Chew YL, Tanizawa Y, Cho Y, Zhao B, Yu AJ, Ardiel EL, Rabinowitch I, Bai J, Rankin CH, Lu H, Beets I, Schafer WR. An Afferent Neuropeptide System Transmits Mechanosensory Signals Triggering Sensitization and Arousal in C. elegans. Neuron 2018; 99:1233-1246.e6. [PMID: 30146306 PMCID: PMC6162336 DOI: 10.1016/j.neuron.2018.08.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/22/2018] [Accepted: 08/02/2018] [Indexed: 11/05/2022]
Abstract
Sensitization is a simple form of behavioral plasticity by which an initial stimulus, often signaling danger, leads to increased responsiveness to subsequent stimuli. Cross-modal sensitization is an important feature of arousal in many organisms, yet its molecular and neural mechanisms are incompletely understood. Here we show that in C. elegans, aversive mechanical stimuli lead to both enhanced locomotor activity and sensitization of aversive chemosensory pathways. Both locomotor arousal and cross-modal sensitization depend on the release of FLP-20 neuropeptides from primary mechanosensory neurons and on their receptor FRPR-3. Surprisingly, the critical site of action of FRPR-3 for both sensory and locomotor arousal is RID, a single neuroendocrine cell specialized for the release of neuropeptides that responds to mechanical stimuli in a FLP-20-dependent manner. Thus, FLP-20 peptides function as an afferent arousal signal that conveys mechanosensory information to central neurons that modulate arousal and other behavioral states.
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Affiliation(s)
- Yee Lian Chew
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Yoshinori Tanizawa
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Yongmin Cho
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA
| | - Buyun Zhao
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Alex J Yu
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada
| | - Evan L Ardiel
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada
| | - Ithai Rabinowitch
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Jihong Bai
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Catharine H Rankin
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada; Department of Psychology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA
| | - Isabel Beets
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK; Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3000, Leuven, Belgium
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK.
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30
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Towlson EK, Vértes PE, Yan G, Chew YL, Walker DS, Schafer WR, Barabási AL. Caenorhabditis elegans and the network control framework-FAQs. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170372. [PMID: 30201837 PMCID: PMC6158218 DOI: 10.1098/rstb.2017.0372] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2018] [Indexed: 12/31/2022] Open
Abstract
Control is essential to the functioning of any neural system. Indeed, under healthy conditions the brain must be able to continuously maintain a tight functional control between the system's inputs and outputs. One may therefore hypothesize that the brain's wiring is predetermined by the need to maintain control across multiple scales, maintaining the stability of key internal variables, and producing behaviour in response to environmental cues. Recent advances in network control have offered a powerful mathematical framework to explore the structure-function relationship in complex biological, social and technological networks, and are beginning to yield important and precise insights on neuronal systems. The network control paradigm promises a predictive, quantitative framework to unite the distinct datasets necessary to fully describe a nervous system, and provide mechanistic explanations for the observed structure and function relationships. Here, we provide a thorough review of the network control framework as applied to Caenorhabditis elegans (Yan et al. 2017 Nature550, 519-523. (doi:10.1038/nature24056)), in the style of Frequently Asked Questions. We present the theoretical, computational and experimental aspects of network control, and discuss its current capabilities and limitations, together with the next likely advances and improvements. We further present the Python code to enable exploration of control principles in a manner specific to this prototypical organism.This article is part of a discussion meeting issue 'Connectome to behaviour: modelling C. elegans at cellular resolution'.
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Affiliation(s)
- Emma K Towlson
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Petra E Vértes
- Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge CB2 0SZ, UK
| | - Gang Yan
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, MA 02115, USA
- School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China
| | - Yee Lian Chew
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Denise S Walker
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - William R Schafer
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Albert-László Barabási
- Center for Complex Network Research and Department of Physics, Northeastern University, Boston, MA 02115, USA
- Center for Cancer Systems Biology, Dana Farber Cancer Institute, Boston, MA 02115, USA
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
- Center for Network Science, Central European University, Budapest 1051, Hungary
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31
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Hinaux H, Bachem K, Battistara M, Rossi M, Xin Y, Jaenichen R, Le Poul Y, Arnoult L, Kobler JM, Grunwald Kadow IC, Rodermund L, Prud'homme B, Gompel N. Revisiting the developmental and cellular role of the pigmentation gene yellow in Drosophila using a tagged allele. Dev Biol 2018; 438:111-123. [PMID: 29634916 DOI: 10.1016/j.ydbio.2018.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/28/2018] [Accepted: 04/06/2018] [Indexed: 10/17/2022]
Abstract
Pigmentation is a diverse and ecologically relevant trait in insects. Pigment formation has been studied extensively at the genetic and biochemical levels. The temporality of pigment formation during animal development, however, is more elusive. Here, we examine this temporality, focusing on yellow, a gene involved in the formation of black melanin. We generated a protein-tagged yellow allele in the fruit fly Drosophila melanogaster, which allowed us to precisely describe Yellow expression pattern at the tissue and cellular levels throughout development. We found Yellow expressed in the pupal epidermis in patterns prefiguring black pigmentation. We also found Yellow expressed in a few central neurons from the second larval instar to adult stages, including a subset of neurons adjacent to the clock neurons marked by the gene Pdf. We then specifically examined the dynamics of Yellow expression domain and subcellular localization in relationship to pigment formation. In particular, we showed how a late step of re-internalization is regulated by the large low-density lipoprotein receptor-related protein Megalin. Finally we suggest a new function for Yellow in the establishment of sharp pigmentation pattern boundaries, whereby this protein may assume a structural role, anchoring pigment deposits or pigmentation enzymes in the cuticle.
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Affiliation(s)
- Hélène Hinaux
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Katharina Bachem
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Margherita Battistara
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Matteo Rossi
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Yaqun Xin
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Rita Jaenichen
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Yann Le Poul
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Laurent Arnoult
- Aix-Marseille Université, CNRS, IBDM, Institut de Biologie du Développement de Marseille, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
| | - Johanna M Kobler
- Technical University of Munich, School of Life Sciences, ZIEL - Institute for Food And Health, Liesel-Beckmann-Str. 4, 85354 Freising, Germany; Chemosensory Coding, Max-Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Planegg-Martinsried, Germany
| | - Ilona C Grunwald Kadow
- Technical University of Munich, School of Life Sciences, ZIEL - Institute for Food And Health, Liesel-Beckmann-Str. 4, 85354 Freising, Germany
| | - Lisa Rodermund
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Benjamin Prud'homme
- Aix-Marseille Université, CNRS, IBDM, Institut de Biologie du Développement de Marseille, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
| | - Nicolas Gompel
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany.
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32
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Meng J, Ma X, Tao H, Jin X, Witvliet D, Mitchell J, Zhu M, Dong MQ, Zhen M, Jin Y, Qi YB. Myrf ER-Bound Transcription Factors Drive C. elegans Synaptic Plasticity via Cleavage-Dependent Nuclear Translocation. Dev Cell 2017; 41:180-194.e7. [PMID: 28441531 DOI: 10.1016/j.devcel.2017.03.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 01/20/2017] [Accepted: 02/24/2017] [Indexed: 11/16/2022]
Abstract
Synaptic refinement is a critical step in nervous system maturation, requiring a carefully timed reorganization and refinement of neuronal connections. We have identified myrf-1 and myrf-2, two C. elegans homologs of Myrf family transcription factors, as key regulators of synaptic rewiring. MYRF-1 and its paralog MYRF-2 are functionally redundant specifically in synaptic rewiring. They co-exist in the same protein complex and act cooperatively to regulate synaptic rewiring. We find that the MYRF proteins localize to the ER membrane and that they are cleaved into active N-terminal fragments, which then translocate into the nucleus to drive synaptic rewiring. Overexpression of active forms of MYRF is sufficient to accelerate synaptic rewiring. MYRF-1 and MYRF-2 are the first genes identified to be indispensable for promoting synaptic rewiring in C. elegans. These findings reveal a molecular mechanism underlying synaptic rewiring and developmental circuit plasticity.
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Affiliation(s)
- Jun Meng
- Institute of Developmental and Regenerative Biology, Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Xiaoxia Ma
- Institute of Developmental and Regenerative Biology, Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Huaping Tao
- Institute of Developmental and Regenerative Biology, Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Xia Jin
- Institute of Developmental and Regenerative Biology, Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Daniel Witvliet
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - James Mitchell
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Ming Zhu
- National Institute of Biological Sciences, Beijing, Beijing 102206, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, Beijing 102206, China
| | - Mei Zhen
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Yishi Jin
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA 92093, USA; Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yingchuan B Qi
- Institute of Developmental and Regenerative Biology, Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
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33
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Iannacone MJ, Beets I, Lopes LE, Churgin MA, Fang-Yen C, Nelson MD, Schoofs L, Raizen DM. The RFamide receptor DMSR-1 regulates stress-induced sleep in C. elegans. eLife 2017; 6. [PMID: 28094002 PMCID: PMC5241116 DOI: 10.7554/elife.19837] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 12/16/2016] [Indexed: 11/22/2022] Open
Abstract
In response to environments that cause cellular stress, animals engage in sleep behavior that facilitates recovery from the stress. In Caenorhabditis elegans, stress-induced sleep(SIS) is regulated by cytokine activation of the ALA neuron, which releases FLP-13 neuropeptides characterized by an amidated arginine-phenylalanine (RFamide) C-terminus motif. By performing an unbiased genetic screen for mutants that impair the somnogenic effects of FLP-13 neuropeptides, we identified the gene dmsr-1, which encodes a G-protein coupled receptor similar to an insect RFamide receptor. DMSR-1 is activated by FLP-13 peptides in cell culture, is required for SIS in vivo, is expressed non-synaptically in several wake-promoting neurons, and likely couples to a Gi/o heterotrimeric G-protein. Our data expand our understanding of how a single neuroendocrine cell coordinates an organism-wide behavioral response, and suggest that similar signaling principles may function in other organisms to regulate sleep during sickness. DOI:http://dx.doi.org/10.7554/eLife.19837.001 People often feel fatigued and sleepy when they are sick. Other animals also show signs of sleepiness when ill – they stop eating, move less, and are less responsive to changes in their environment. Sickness-induced sleep helps both people and other animals to recover, and many scientists believe that this type of sleep is different than nightly sleep. Studies of sickness-induced sleep have made use of a simple worm with a simple nervous system. In this worm, a single nerve cell releases chemicals that cause the worm to fall asleep in response to illness. Animals exposed to one of these chemicals, called FLP-13, fall asleep even when they are not sick. As such, scientists would like to know which cells in the nervous system FLP-13 interacts with, what receptor the cells use to recognize this chemical, and whether it turns on cells that induce sleep or turns off the cells that cause wakefulness. Now, Iannacone et al. show that FLP-13 likely causes sleep by turning down activity in the cells in the nervous system that promote wakefulness. The experiments sifted through genetic mutations to determine which ones cause the worms not to fall asleep when FLP-13 is released. This revealed that worms with a mutation that causes them to lack a receptor protein called DMSR-1 do not become sleepy in response to FLP-13. This suggests that DMSR-1 must be essential for FLP-13 to trigger sleep. About 10% of cells in the worm’s nervous system have the DMSR-1 receptor. Some of these neurons tell the worm to move forward or to forage around for food. The experiments also showed that FLP-13 is probably not the only chemical that interacts with the DMSR-1 receptor, but the identities of these other chemicals remain unknown. Additional experiments are now needed to determine if sickness-induced sleepiness in humans and other mammals is triggered by a similar mechanism. If it is, then drugs might be developed to treat people experiencing fatigue associated with sickness as well as other unexplained cases of fatigue. DOI:http://dx.doi.org/10.7554/eLife.19837.002
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Affiliation(s)
- Michael J Iannacone
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Isabel Beets
- Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Lindsey E Lopes
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Matthew A Churgin
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, United States
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, United States
| | - Matthew D Nelson
- Department of Biology, Saint Joseph's University, Philadelphia, United States
| | - Liliane Schoofs
- Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
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