1
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Costa AC, Ahamed T, Jordan D, Stephens GJ. A Markovian dynamics for Caenorhabditis elegans behavior across scales. Proc Natl Acad Sci U S A 2024; 121:e2318805121. [PMID: 39083417 DOI: 10.1073/pnas.2318805121] [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: 11/02/2023] [Accepted: 07/01/2024] [Indexed: 08/02/2024] Open
Abstract
How do we capture the breadth of behavior in animal movement, from rapid body twitches to aging? Using high-resolution videos of the nematode worm Caenorhabditis elegans, we show that a single dynamics connects posture-scale fluctuations with trajectory diffusion and longer-lived behavioral states. We take short posture sequences as an instantaneous behavioral measure, fixing the sequence length for maximal prediction. Within the space of posture sequences, we construct a fine-scale, maximum entropy partition so that transitions among microstates define a high-fidelity Markov model, which we also use as a means of principled coarse-graining. We translate these dynamics into movement using resistive force theory, capturing the statistical properties of foraging trajectories. Predictive across scales, we leverage the longest-lived eigenvectors of the inferred Markov chain to perform a top-down subdivision of the worm's foraging behavior, revealing both "runs-and-pirouettes" as well as previously uncharacterized finer-scale behaviors. We use our model to investigate the relevance of these fine-scale behaviors for foraging success, recovering a trade-off between local and global search strategies.
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Affiliation(s)
- Antonio C Costa
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
| | - Tosif Ahamed
- Janelia Research Campus, HHMI, Ashburn, VA 20147
| | - David Jordan
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Greg J Stephens
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
- Biological Physics Theory Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan
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2
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Waalkes MR, Leathery M, Peck M, Barr A, Cunill A, Hageter J, Horstick EJ. Light wavelength modulates search behavior performance in zebrafish. Sci Rep 2024; 14:16533. [PMID: 39019915 PMCID: PMC11255219 DOI: 10.1038/s41598-024-67262-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 07/09/2024] [Indexed: 07/19/2024] Open
Abstract
Visual systems have evolved to discriminate between different wavelengths of light. The ability to perceive color, or specific light wavelengths, is important as color conveys crucial information about both biotic and abiotic features in the environment. Indeed, different wavelengths of light can drive distinct patterns of activity in the vertebrate brain, yet what remains incompletely understood is whether distinct wavelengths can invoke etiologically relevant behavioral changes. To address how specific wavelengths in the visible spectrum modulate behavioral performance, we use larval zebrafish and a stereotypic light-search behavior. Prior work has shown that the cessation of light triggers a transitional light-search behavior, which we use to interrogate wavelength-dependent behavioral modulation. Using 8 narrow spectrum light sources in the visible range, we demonstrate that all wavelengths induce motor parameters consistent with search behavior, yet the magnitude of search behavior is spectrum sensitive and the underlying motor parameters are modulated in distinct patterns across short, medium, and long wavelengths. However, our data also establishes that not all motor features of search are impacted by wavelength. To define how wavelength modulates search performance, we performed additional assays with alternative wavelengths, dual wavelengths, and variable intensity. Last, we also tested blind larvae to resolve which components of wavelength dependent behavioral changes potentially include signaling from non-retinal photoreception. These findings have important implications as organisms can be exposed to varying wavelengths in laboratory and natural settings and therefore impose unique behavioral outputs.
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Affiliation(s)
- Matthew R Waalkes
- Department of Biology Morgantown, West Virginia University, Morgantown, WV, USA
| | - Maegan Leathery
- Department of Biology Morgantown, West Virginia University, Morgantown, WV, USA
| | - Madeline Peck
- Department of Biology Morgantown, West Virginia University, Morgantown, WV, USA
| | - Allison Barr
- Department of Biology Morgantown, West Virginia University, Morgantown, WV, USA
| | - Alexander Cunill
- Department of Biology Morgantown, West Virginia University, Morgantown, WV, USA
| | - John Hageter
- Department of Biology Morgantown, West Virginia University, Morgantown, WV, USA
| | - Eric J Horstick
- Department of Biology Morgantown, West Virginia University, Morgantown, WV, USA.
- Department of Neuroscience Morgantown, West Virginia University, Morgantown, WV, USA.
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3
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Faerberg DF, Aprison EZ, Ruvinsky I. Accelerated hermaphrodite maturation on male pheromones suggests a general principle of coordination between larval behavior and development. Development 2024; 151:dev202961. [PMID: 38975828 PMCID: PMC11266794 DOI: 10.1242/dev.202961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/04/2024] [Indexed: 07/09/2024]
Abstract
Environment in general and social signals in particular could alter development. In Caenorhabditis elegans, male pheromones hasten development of hermaphrodite larvae. We show that this involves acceleration of growth and both somatic and germline development during the last larval stage (L4). Larvae exposed to male pheromones spend more time in L3 and less in the quiescent period between L3 and L4. This behavioral alteration improves provision in early L4, likely allowing for faster development. Larvae must be exposed to male pheromones in late L3 for behavioral and developmental effects to occur. Latter portions of other larval stages also contain periods of heightened sensitivity to environmental signals. Behavior during the early part of the larval stages is biased toward exploration, whereas later the emphasis shifts to food consumption. We argue that this organization allows assessment of the environment to identify the most suitable patch of resources, followed by acquisition of sufficient nutrition and salient information for the developmental events in the next larval stage. Evidence from other species indicates that such coordination of behavior and development may be a general feature of larval development.
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Affiliation(s)
- Denis F. Faerberg
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Erin Z. Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
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4
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Lee H, Boor SA, Hilbert ZA, Meisel JD, Park J, Wang Y, McKeown R, Fischer SEJ, Andersen EC, Kim DH. Genetic variants that modify neuroendocrine gene expression and foraging behavior of C. elegans. SCIENCE ADVANCES 2024; 10:eadk9481. [PMID: 38865452 PMCID: PMC11168454 DOI: 10.1126/sciadv.adk9481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 04/30/2024] [Indexed: 06/14/2024]
Abstract
The molecular mechanisms underlying diversity in animal behavior are not well understood. A major experimental challenge is determining the contribution of genetic variants that affect neuronal gene expression to differences in behavioral traits. In Caenorhabditis elegans, the neuroendocrine transforming growth factor-β ligand, DAF-7, regulates diverse behavioral responses to bacterial food and pathogens. The dynamic neuron-specific expression of daf-7 is modulated by environmental and endogenous bacteria-derived cues. Here, we investigated natural variation in the expression of daf-7 from the ASJ pair of chemosensory neurons. We identified common genetic variants in gap-2, encoding a Ras guanosine triphosphatase (GTPase)-activating protein homologous to mammalian synaptic Ras GTPase-activating protein, which modify daf-7 expression cell nonautonomously and promote exploratory foraging behavior in a partially DAF-7-dependent manner. Our data connect natural variation in neuron-specific gene expression to differences in behavior and suggest that genetic variation in neuroendocrine signaling pathways mediating host-microbe interactions may give rise to diversity in animal behavior.
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Affiliation(s)
- Harksun Lee
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Sonia A. Boor
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Zoë A. Hilbert
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Joshua D. Meisel
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jaeseok Park
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Ye Wang
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ryan McKeown
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Sylvia E. J. Fischer
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Harvard Medical School Initiative for RNA Medicine, Boston, MA 02115, USA
| | - Erik C. Andersen
- Department of Biology, Johns Hopkins University, Baltimore, MD 21212, USA
| | - Dennis H. Kim
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
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5
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Haley JA, Chalasani SH. C. elegans foraging as a model for understanding the neuronal basis of decision-making. Cell Mol Life Sci 2024; 81:252. [PMID: 38849591 DOI: 10.1007/s00018-024-05223-1] [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: 12/14/2023] [Revised: 03/27/2024] [Accepted: 03/30/2024] [Indexed: 06/09/2024]
Abstract
Animals have evolved to seek, select, and exploit food sources in their environment. Collectively termed foraging, these ubiquitous behaviors are necessary for animal survival. As a foundation for understanding foraging, behavioral ecologists established early theoretical and mathematical frameworks which have been subsequently refined and supported by field and laboratory studies of foraging animals. These simple models sought to explain how animals decide which strategies to employ when locating food, what food items to consume, and when to explore the environment for new food sources. These foraging decisions involve integration of prior experience with multimodal sensory information about the animal's current environment and internal state. We suggest that the nematode Caenorhabditis elegans is well-suited for a high-resolution analysis of complex goal-oriented behaviors such as foraging. We focus our discussion on behavioral studies highlighting C. elegans foraging on bacteria and summarize what is known about the underlying neuronal and molecular pathways. Broadly, we suggest that this simple model system can provide a mechanistic understanding of decision-making and present additional avenues for advancing our understanding of complex behavioral processes.
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Affiliation(s)
- Jessica A Haley
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA, 92093, USA
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Sreekanth H Chalasani
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
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6
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Sridhar G, Vergassola M, Marques JC, Orger MB, Costa AC, Wyart C. Uncovering multiscale structure in the variability of larval zebrafish navigation. ARXIV 2024:arXiv:2405.17143v1. [PMID: 38855549 PMCID: PMC11160889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Animals chain movements into long-lived motor strategies, exhibiting variability across scales that reflects the interplay between internal states and environmental cues. To reveal structure in such variability, we build Markov models of movement sequences that bridges across time scales and enables a quantitative comparison of behavioral phenotypes among individuals. Applied to larval zebrafish responding to diverse sensory cues, we uncover a hierarchy of long-lived motor strategies, dominated by changes in orientation distinguishing cruising versus wandering strategies. Environmental cues induce preferences along these modes at the population level: while fish cruise in the light, they wander in response to aversive stimuli, or in search for appetitive prey. As our method encodes the behavioral dynamics of each individual fish in the transitions among coarse-grained motor strategies, we use it to uncover a hierarchical structure in the phenotypic variability that reflects exploration-exploitation trade-offs. Across a wide range of sensory cues, a major source of variation among fish is driven by prior and/or immediate exposure to prey that induces exploitation phenotypes. A large degree of variability that is not explained by environmental cues unravels motivational states that override the sensory context to induce contrasting exploration-exploitation phenotypes. Altogether, by extracting the timescales of motor strategies deployed during navigation, our approach exposes structure among individuals and reveals internal states tuned by prior experience.
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Affiliation(s)
- Gautam Sridhar
- Sorbonne University, Paris Brain Institute (ICM), Inserm U1127, CNRS UMR 7225, Paris, France
| | - Massimo Vergassola
- Laboratoire de Physique de l’Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005 Paris, France
| | - João C. Marques
- Champalimaud Research, Champalimaud Centre for the Unknown, Avenida Brasília, Doca de Pedrouços, Lisboa 1400-038, Portugal
| | - Michael B. Orger
- Champalimaud Research, Champalimaud Centre for the Unknown, Avenida Brasília, Doca de Pedrouços, Lisboa 1400-038, Portugal
| | - Antonio Carlos Costa
- Sorbonne University, Paris Brain Institute (ICM), Inserm U1127, CNRS UMR 7225, Paris, France
- Laboratoire de Physique de l’Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005 Paris, France
| | - Claire Wyart
- Sorbonne University, Paris Brain Institute (ICM), Inserm U1127, CNRS UMR 7225, Paris, France
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7
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Sridhar G, Vergassola M, Marques JC, Orger MB, Costa AC, Wyart C. Uncovering multiscale structure in the variability of larval zebrafish navigation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.16.594521. [PMID: 38798455 PMCID: PMC11118365 DOI: 10.1101/2024.05.16.594521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Animals chain movements into long-lived motor strategies, resulting in variability that ultimately reflects the interplay between internal states and environmental cues. To reveal structure in such variability, we build models that bridges across time scales that enable a quantitative comparison of behavioral phenotypes among individuals. Applied to larval zebrafish exposed to diverse sensory cues, we uncover a hierarchy of long-lived motor strategies, dominated by changes in orientation distinguishing cruising and wandering strategies. Environmental cues induce preferences along these modes at the population level: while fish cruise in the light, they wander in response to aversive (dark) stimuli or in search for prey. Our method enables us to encode the behavioral dynamics of each individual fish in the transitions among coarse-grained motor strategies. By doing so, we uncover a hierarchical structure to the phenotypic variability that corresponds to exploration-exploitation trade-offs. Within a wide range of sensory cues, a major source of variation among fish is driven by prior and immediate exposure to prey that induces exploitation phenotypes. However, a large degree of variability is unexplained by environmental cues, pointing to hidden states that override the sensory context to induce contrasting exploration-exploitation phenotypes. Altogether, our approach extracts the timescales of motor strategies deployed during navigation, exposing undiscovered structure among individuals and pointing to internal states tuned by prior experience.
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8
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Marquina-Solis J, Feng L, Vandewyer E, Beets I, Hawk J, Colón-Ramos DA, Yu J, Fox BW, Schroeder FC, Bargmann CI. Antagonism between neuropeptides and monoamines in a distributed circuit for pathogen avoidance. Cell Rep 2024; 43:114042. [PMID: 38573858 PMCID: PMC11063628 DOI: 10.1016/j.celrep.2024.114042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 02/06/2024] [Accepted: 03/19/2024] [Indexed: 04/06/2024] Open
Abstract
Pathogenic infection elicits behaviors that promote recovery and survival of the host. After exposure to the pathogenic bacterium Pseudomonas aeruginosa PA14, the nematode Caenorhabditis elegans modifies its sensory preferences to avoid the pathogen. Here, we identify antagonistic neuromodulators that shape this acquired avoidance behavior. Using an unbiased cell-directed neuropeptide screen, we show that AVK neurons upregulate and release RF/RYamide FLP-1 neuropeptides during infection to drive pathogen avoidance. Manipulations that increase or decrease AVK activity accelerate or delay pathogen avoidance, respectively, implicating AVK in the dynamics of avoidance behavior. FLP-1 neuropeptides drive pathogen avoidance through the G protein-coupled receptor DMSR-7, as well as other receptors. DMSR-7 in turn acts in multiple neurons, including tyraminergic/octopaminergic neurons that receive convergent avoidance signals from the cytokine DAF-7/transforming growth factor β. Neuromodulators shape pathogen avoidance through multiple mechanisms and targets, in agreement with the distributed neuromodulatory connectome of C. elegans.
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Affiliation(s)
- Javier Marquina-Solis
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Likui Feng
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA
| | | | - Isabel Beets
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Josh Hawk
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Daniel A Colón-Ramos
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA; Instituto de Neurobiología José del Castillo, Recinto de Ciencias Médicas, Universidad de Puerto Rico, San Juan, PR 00901, USA; Wu Tsai Institute, Yale University, New Haven, CT 06510, USA
| | - Jingfang Yu
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Bennett W Fox
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA.
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9
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Istiban MN, De Fruyt N, Kenis S, Beets I. Evolutionary conserved peptide and glycoprotein hormone-like neuroendocrine systems in C. elegans. Mol Cell Endocrinol 2024; 584:112162. [PMID: 38290646 PMCID: PMC11004728 DOI: 10.1016/j.mce.2024.112162] [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: 11/30/2023] [Revised: 01/11/2024] [Accepted: 01/15/2024] [Indexed: 02/01/2024]
Abstract
Peptides and protein hormones form the largest group of secreted signals that mediate intercellular communication and are central regulators of physiology and behavior in all animals. Phylogenetic analyses and biochemical identifications of peptide-receptor systems reveal a broad evolutionary conservation of these signaling systems at the molecular level. Substantial progress has been made in recent years on characterizing the physiological and putative ancestral roles of many peptide systems through comparative studies in invertebrate models. Several peptides and protein hormones are not only molecularly conserved but also have conserved roles across animal phyla. Here, we focus on functional insights gained in the nematode Caenorhabditis elegans that, with its compact and well-described nervous system, provides a powerful model to dissect neuroendocrine signaling networks involved in the control of physiology and behavior. We summarize recent discoveries on the evolutionary conservation and knowledge on the functions of peptide and protein hormone systems in C. elegans.
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Affiliation(s)
- Majdulin Nabil Istiban
- Neural Signaling and Circuit Plasticity, Department of Biology, KU Leuven, 3000, Leuven, Belgium
| | - Nathan De Fruyt
- Neural Signaling and Circuit Plasticity, Department of Biology, KU Leuven, 3000, Leuven, Belgium
| | - Signe Kenis
- Neural Signaling and Circuit Plasticity, Department of Biology, KU Leuven, 3000, Leuven, Belgium
| | - Isabel Beets
- Neural Signaling and Circuit Plasticity, Department of Biology, KU Leuven, 3000, Leuven, Belgium.
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10
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Emmons SW. FUNCTIONS OF C. ELEGANS NEURONS FROM SYNAPTIC CONNECTIVITY. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.08.584145. [PMID: 38562755 PMCID: PMC10983851 DOI: 10.1101/2024.03.08.584145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Despite decades of research on the C. elegans nervous system based on an anatomical description of synaptic connectivity, the circuits underlying behavior remain incompletely described and the functions of many neurons are still unknown. Updated and more complete chemical and gap junction connectomes of both adult sexes covering the entire animal including the muscle end organ have become available recently. Here these are analyzed to gain insight into the overall structure of the connectivity network and to suggest functions of individual neuron classes. Modularity analysis divides the connectome graph into ten communities that can be correlated with broad categories of behavior. A significant role of the body wall musculature end organ is emphasized as both a site of significant information convergence and as a source of sensory input in a feedback loop. Convergence of pathways for multisensory integration occurs throughout the network - most interneurons have similar indegrees and outdegrees and hence disperse information as much as they aggregate it. New insights include description of a set of high degree interneurons connected by many gap junctions running through the ventral cord that may represent a previously unrecognized locus of information processing. There is an apparent mechanosensory and proprioceptive field covering the entire body formed by connectivity of the many mechanosensory neurons of multiple types to two interneurons with output connections across the nervous system. Several additional significant, previously unrecognized circuits and pathways are uncovered, some involving unstudied neurons. The insights are valuable for guiding theoretical investigation of network properties as well as experimental studies of the functions of individual neurons, groups of neurons, and circuits.
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Affiliation(s)
- Scott W Emmons
- Department of Genetics and Dominic P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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11
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Zhao Y, Huang CX, Gu Y, Zhao Y, Ren W, Wang Y, Chen J, Guan NN, Song J. Serotonergic modulation of vigilance states in zebrafish and mice. Nat Commun 2024; 15:2596. [PMID: 38519480 PMCID: PMC10959952 DOI: 10.1038/s41467-024-47021-0] [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: 10/22/2023] [Accepted: 03/12/2024] [Indexed: 03/25/2024] Open
Abstract
Vigilance refers to being alertly watchful or paying sustained attention to avoid potential threats. Animals in vigilance states reduce locomotion and have an enhanced sensitivity to aversive stimuli so as to react quickly to dangers. Here we report that an unconventional 5-HT driven mechanism operating at neural circuit level which shapes the internal state underlying vigilance behavior in zebrafish and male mice. The neural signature of internal vigilance state was characterized by persistent low-frequency high-amplitude neuronal synchrony in zebrafish dorsal pallium and mice prefrontal cortex. The neuronal synchronization underlying vigilance was dependent on intense release of 5-HT induced by persistent activation of either DRN 5-HT neuron or local 5-HT axon terminals in related brain regions via activation of 5-HTR7. Thus, we identify a mechanism of vigilance behavior across species that illustrates the interplay between neuromodulators and neural circuits necessary to shape behavior states.
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Affiliation(s)
- Yang Zhao
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Chun-Xiao Huang
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Yiming Gu
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Yacong Zhao
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Wenjie Ren
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Yutong Wang
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Jinjin Chen
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China
| | - Na N Guan
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China.
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China.
- Frontiers Science Center for Intelligent Autonomous Systems, Tongji University, Shanghai, China.
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Jianren Song
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, 200434, China.
- Clinical Center for Brain and Spinal Cord Research, Tongji University, 200092, Shanghai, China.
- Frontiers Science Center for Intelligent Autonomous Systems, Tongji University, Shanghai, China.
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
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12
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Manley J, Vaziri A. Whole-brain neural substrates of behavioral variability in the larval zebrafish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.03.583208. [PMID: 38496592 PMCID: PMC10942351 DOI: 10.1101/2024.03.03.583208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Animals engaged in naturalistic behavior can exhibit a large degree of behavioral variability even under sensory invariant conditions. Such behavioral variability can include not only variations of the same behavior, but also variability across qualitatively different behaviors driven by divergent cognitive states, such as fight-or-flight decisions. However, the neural circuit mechanisms that generate such divergent behaviors across trials are not well understood. To investigate this question, here we studied the visual-evoked responses of larval zebrafish to moving objects of various sizes, which we found exhibited highly variable and divergent responses across repetitions of the same stimulus. Given that the neuronal circuits underlying such behaviors span sensory, motor, and other brain areas, we built a novel Fourier light field microscope which enables high-resolution, whole-brain imaging of larval zebrafish during behavior. This enabled us to screen for neural loci which exhibited activity patterns correlated with behavioral variability. We found that despite the highly variable activity of single neurons, visual stimuli were robustly encoded at the population level, and the visual-encoding dimensions of neural activity did not explain behavioral variability. This robustness despite apparent single neuron variability was due to the multi-dimensional geometry of the neuronal population dynamics: almost all neural dimensions that were variable across individual trials, i.e. the "noise" modes, were orthogonal to those encoding for sensory information. Investigating this neuronal variability further, we identified two sparsely-distributed, brain-wide neuronal populations whose pre-motor activity predicted whether the larva would respond to a stimulus and, if so, which direction it would turn on a single-trial level. These populations predicted single-trial behavior seconds before stimulus onset, indicating they encoded time-varying internal modulating behavior, perhaps organizing behavior over longer timescales or enabling flexible behavior routines dependent on the animal's internal state. Our results provide the first whole-brain confirmation that sensory, motor, and internal variables are encoded in a highly mixed fashion throughout the brain and demonstrate that de-mixing each of these components at the neuronal population level is critical to understanding the mechanisms underlying the brain's remarkable flexibility and robustness.
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Affiliation(s)
- Jason Manley
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA
- The Kavli Neural Systems Institute, The Rockefeller University, New York, NY 10065, USA
| | - Alipasha Vaziri
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA
- The Kavli Neural Systems Institute, The Rockefeller University, New York, NY 10065, USA
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13
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Ji H, Chen D, Fang-Yen C. Automated multimodal imaging of Caenorhabditis elegans behavior in multi-well plates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579675. [PMID: 38405855 PMCID: PMC10888940 DOI: 10.1101/2024.02.09.579675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Large-scale assays of behavior in model organisms play an important role in genetic screens, drug testing, and the elucidation of gene-behavior relationships. We have developed an automated, high-throughput imaging and analysis method for assaying behaviors of the nematode C. elegans . We use high-resolution optical imaging to longitudinally record the behaviors of 96 animals at a time in multi-well plates, and computer vision software to quantify the animals' locomotor activity, behavioral states, and egg laying events. To demonstrate the capabilities of our system we used it to examine the role of serotonin in C. elegans behavior. We found that egg-laying events are preceded by a period of reduced locomotion, and that this decline in movement requires serotonin signaling. In addition, we identified novel roles of serotonin receptors SER-1 and SER-7 in regulating the effects of serotonin on egg laying across roaming, dwelling, and quiescent locomotor states. Our system will be useful for performing genetic or chemical screens for modulators of behavior.
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14
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Louis M. Drosophila flight: How flies control casts and surges. Curr Biol 2024; 34:R91-R94. [PMID: 38320480 DOI: 10.1016/j.cub.2023.12.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
In the absence of directional cues, most foraging animals explore space by turning and zigzagging in search of sensory information. Recent progress in the identification of the neural correlates of turns in flies offers exciting new perspectives on the evolution of neural circuits controlling fundamental aspects of orientation responses.
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Affiliation(s)
- Matthieu Louis
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
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15
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Boor SA, Meisel JD, Kim DH. Neuroendocrine gene expression coupling of interoceptive bacterial food cues to foraging behavior of C. elegans. eLife 2024; 12:RP91120. [PMID: 38231572 PMCID: PMC10945577 DOI: 10.7554/elife.91120] [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] [Indexed: 01/18/2024] Open
Abstract
Animal internal state is modulated by nutrient intake, resulting in behavioral responses to changing food conditions. The neural mechanisms by which internal states are generated and maintained are not well understood. Here, we show that in the nematode Caenorhabditis elegans, distinct cues from bacterial food - interoceptive signals from the ingestion of bacteria and gustatory molecules sensed from nearby bacteria - act antagonistically on the expression of the neuroendocrine TGF-beta ligand DAF-7 from the ASJ pair of sensory neurons to modulate foraging behavior. A positive-feedback loop dependent on the expression of daf-7 from the ASJ neurons acts to promote transitions between roaming and dwelling foraging states and influence the persistence of roaming states. SCD-2, the C. elegans ortholog of mammalian anaplastic lymphoma kinase (ALK), which has been implicated in the central control of metabolism of mammals, functions in the AIA interneurons to regulate foraging behavior and cell-non-autonomously control the expression of DAF-7 from the ASJ neurons. Our data establish how a dynamic neuroendocrine daf-7 expression feedback loop regulated by SCD-2 functions to couple sensing and ingestion of bacterial food to foraging behavior. We further suggest that this neuroendocrine feedback loop underlies previously characterized exploratory behaviors in C. elegans. Our data suggest that the expression of daf-7 from the ASJ neurons contributes to and is correlated with an internal state of 'unmet need' that regulates exploratory foraging behavior in response to bacterial cues in diverse physiological contexts.
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Affiliation(s)
- Sonia A Boor
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical SchoolBostonUnited States
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Joshua D Meisel
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
- Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
| | - Dennis H Kim
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical SchoolBostonUnited States
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16
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Abstract
Foraging animals optimize feeding decisions by adjusting both common and rare behavioral patterns. Here, we characterize the relationship between an animal's arousal state and a rare decision to leave a patch of bacterial food. Using long-term tracking and behavioral state classification, we find that food leaving decisions in Caenorhabditis elegans are coupled to arousal states across multiple timescales. Leaving emerges probabilistically over minutes from the high arousal roaming state, but is suppressed during the low arousal dwelling state. Immediately before leaving, animals have a brief acceleration in speed that appears as a characteristic signature of this behavioral motif. Neuromodulatory mutants and optogenetic manipulations that increase roaming have a coupled increase in leaving rates, and similarly acute manipulations that inhibit feeding induce both roaming and leaving. By contrast, inactivating a set of chemosensory neurons that depend on the cGMP-gated transduction channel TAX-4 uncouples roaming and leaving dynamics. In addition, tax-4-expressing sensory neurons promote lawn-leaving behaviors that are elicited by feeding inhibition. Our results indicate that sensory neurons responsive to both internal and external cues play an integrative role in arousal and foraging decisions.
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Affiliation(s)
- Elias Scheer
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller UniversityNew YorkUnited States
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller UniversityNew YorkUnited States
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17
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Boor SA, Meisel JD, Kim DH. Neuroendocrine Gene Expression Coupling of Interoceptive Bacterial Food Cues to Foraging Behavior of C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.15.549072. [PMID: 37503081 PMCID: PMC10369937 DOI: 10.1101/2023.07.15.549072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Animal internal state is modulated by nutrient intake, resulting in behavioral responses to changing food conditions. The neural mechanisms by which internal states are generated and maintained are not well understood. Here, we show that in the nematode Caenorhabditis elegans, distinct cues from bacterial food - interoceptive signals from the ingestion of bacteria and gustatory molecules sensed from nearby bacteria - act antagonistically on the expression of the neuroendocrine TGF-beta ligand DAF-7 from the ASJ pair of sensory neurons to modulate foraging behavior. A positive-feedback loop dependent on the expression of daf-7 from the ASJ neurons acts to promote transitions between roaming and dwelling foraging states and influence the persistence of roaming states. SCD-2, the C. elegans ortholog of mammalian Anaplastic Lymphoma Kinase (ALK), which has been implicated in the central control of metabolism of mammals, functions in the AIA interneurons to regulate foraging behavior and cell-non-autonomously control the expression of DAF-7 from the ASJ neurons. Our data establish how a dynamic neuroendocrine daf-7 expression feedback loop regulated by SCD-2 functions to couple sensing and ingestion of bacterial food to foraging behavior. We further suggest that this neuroendocrine feedback loop underlies previously characterized exploratory behaviors in C. elegans. Our data suggest that the expression of daf-7 from the ASJ neurons contributes to and is correlated with an internal state of "unmet need" that regulates exploratory foraging behavior in response to bacterial cues in diverse physiological contexts.
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Affiliation(s)
- Sonia A. Boor
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Joshua D. Meisel
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114
| | - Dennis H. Kim
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115
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18
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Mountoufaris G, Nair A, Yang B, Kim DW, Anderson DJ. Neuropeptide Signaling is Required to Implement a Line Attractor Encoding a Persistent Internal Behavioral State. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.01.565073. [PMID: 37961374 PMCID: PMC10635056 DOI: 10.1101/2023.11.01.565073] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Internal states drive survival behaviors, but their neural implementation is not well understood. Recently we identified a line attractor in the ventromedial hypothalamus (VMH) that represents an internal state of aggressiveness. Line attractors can be implemented by recurrent connectivity and/or neuromodulatory signaling, but evidence for the latter is scant. Here we show that neuropeptidergic signaling is necessary for line attractor dynamics in this system, using a novel approach that integrates cell type-specific, anatomically restricted CRISPR/Cas9-based gene editing with microendoscopic calcium imaging. Co-disruption of receptors for oxytocin and vasopressin in adult VMH Esr1 + neurons that control aggression suppressed attack, reduced persistent neural activity and eliminated line attractor dynamics, while only modestly impacting neural activity and sex- or behavior-tuning. These data identify a requisite role for neuropeptidergic signaling in implementing a behaviorally relevant line attractor. Our approach should facilitate mechanistic studies in neuroscience that bridge different levels of biological function and abstraction.
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19
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Huang YC, Luo J, Huang W, Baker CM, Gomes MA, Meng B, Byrne AB, Flavell SW. A single neuron in C. elegans orchestrates multiple motor outputs through parallel modes of transmission. Curr Biol 2023; 33:4430-4445.e6. [PMID: 37769660 PMCID: PMC10860333 DOI: 10.1016/j.cub.2023.08.088] [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: 03/15/2023] [Revised: 07/24/2023] [Accepted: 08/30/2023] [Indexed: 10/03/2023]
Abstract
Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neurons in the circuits that generate behaviors have a remarkable capacity for flexibility as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of adaptive behaviors remains unknown. Here, we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg laying and locomotion while also biasing the animals toward low-speed dwelling behavior over minutes. The acute effects of HSN on egg laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal compartments. The long-lasting effects on dwelling are mediated in part by HSN release of serotonin, which is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal that neurons can borrow serotonin from one another to control behavior.
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Affiliation(s)
- Yung-Chi Huang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jinyue Luo
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Wenjia Huang
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Casey M Baker
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew A Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Bohan Meng
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexandra B Byrne
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Steven W Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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20
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Bechtel W, Bich L. Using neurons to maintain autonomy: Learning from C. elegans. Biosystems 2023; 232:105017. [PMID: 37666409 DOI: 10.1016/j.biosystems.2023.105017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/06/2023]
Abstract
Understanding how biological organisms are autonomous-maintain themselves far from equilibrium through their own activities-requires understanding how they regulate those activities. In multicellular animals, such control can be exercised either via endocrine signaling through the vasculature or via neurons. In C. elegans this control is exercised by a well-delineated relatively small but distributed nervous system that relies on both chemical and electric transmission of signals. This system provides resources to integrate information from multiple sources as needed to maintain the organism. Especially important for the exercise of neural control are neuromodulators, which we present as setting agendas for control through more traditional electrical signaling. To illustrate how the C. elegans nervous system integrates multiple sources of information in controlling activities important for autonomy, we focus on feeding behavior and responses to adverse conditions. We conclude by considering how a distributed nervous system without a centralized controller is nonetheless adequate for autonomy.
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Affiliation(s)
- William Bechtel
- Department of Philosophy; University of California, San Diego; La Jolla, CA 92093-0119, USA.
| | - Leonardo Bich
- IAS-Research Centre for Life, Mind and Society; Department of Philosophy; University of the Basque Country (UPV/EHU); Avenida de Tolosa 70; Donostia-San Sebastian, 20018; Spain.
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21
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Yeon J, Porwal C, McGrath PT, Sengupta P. Identification of a spontaneously arising variant affecting thermotaxis behavior in a recombinant inbred Caenorhabditis elegans line. G3 (BETHESDA, MD.) 2023; 13:jkad186. [PMID: 37572357 PMCID: PMC10542565 DOI: 10.1093/g3journal/jkad186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 06/26/2023] [Accepted: 08/02/2023] [Indexed: 08/14/2023]
Abstract
Analyses of the contributions of genetic variants in wild strains to phenotypic differences have led to a more complete description of the pathways underlying cellular functions. Causal loci are typically identified via interbreeding of strains with distinct phenotypes in order to establish recombinant inbred lines (RILs). Since the generation of RILs requires growth for multiple generations, their genomes may contain not only different combinations of parental alleles but also genetic changes that arose de novo during the establishment of these lines. Here, we report that in the course of generating RILs between Caenorhabditis elegans strains that exhibit distinct thermotaxis behavioral phenotypes, we identified spontaneously arising variants in the ttx-1 locus. ttx-1 encodes the terminal selector factor for the AFD thermosensory neurons, and loss-of-function mutations in ttx-1 abolish thermotaxis behaviors. The identified genetic changes in ttx-1 in the RIL are predicted to decrease ttx-1 function in part via specifically affecting a subset of AFD-expressed ttx-1 isoforms. Introduction of the relevant missense mutation in the laboratory C. elegans strain via gene editing recapitulates the thermotaxis behavioral defects of the RIL. Our results suggest that spontaneously occurring genomic changes in RILs may complicate identification of loci contributing to phenotypic variation, but that these mutations may nevertheless lead to the identification of important causal molecules and mechanisms.
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Affiliation(s)
- Jihye Yeon
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Charmi Porwal
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Patrick T McGrath
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
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22
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Ding J, Peng L, Moon S, Lee HJ, Patel DS, Lu H. An expanded GCaMP reporter toolkit for functional imaging in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2023; 13:jkad183. [PMID: 37565483 PMCID: PMC10542313 DOI: 10.1093/g3journal/jkad183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 07/16/2023] [Indexed: 08/12/2023]
Abstract
In living organisms, changes in calcium flux are integral to many different cellular functions and are especially critical for the activity of neurons and myocytes. Genetically encoded calcium indicators (GECIs) have been popular tools for reporting changes in calcium levels in vivo. In particular, GCaMPs, derived from GFP, are the most widely used GECIs and have become an invaluable toolkit for neurophysiological studies. Recently, new variants of GCaMP, which offer a greater variety of temporal dynamics and improved brightness, have been developed. However, these variants are not readily available to the Caenorhabditis elegans research community. This work reports a set of GCaMP6 and jGCaMP7 reporters optimized for C. elegans studies. Our toolkit provides reporters with improved dynamic range, varied kinetics, and targeted subcellular localizations. Besides optimized routine uses, this set of reporters is also well suited for studies requiring fast imaging speeds and low magnification or low-cost platforms.
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Affiliation(s)
- Jimmy Ding
- Interdisciplinary Bioengineering Graduate Program, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Lucinda Peng
- Interdisciplinary Bioengineering Graduate Program, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Sihoon Moon
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Hyun Jee Lee
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Dhaval S Patel
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Hang Lu
- Interdisciplinary Bioengineering Graduate Program, Georgia Institute of Technology, Atlanta, GA 30332, USA
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
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23
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Lee H, Boor SA, Hilbert ZA, Meisel JD, Park J, Wang Y, McKeown R, Fischer SEJ, Andersen EC, Kim DH. Genetic Variants That Modify the Neuroendocrine Regulation of Foraging Behavior in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.09.556976. [PMID: 37745484 PMCID: PMC10515746 DOI: 10.1101/2023.09.09.556976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
The molecular mechanisms underlying diversity in animal behavior are not well understood. A major experimental challenge is determining the contribution of genetic variants that affect neuronal gene expression to differences in behavioral traits. The neuroendocrine TGF-beta ligand, DAF-7, regulates diverse behavioral responses of Caenorhabditis elegans to bacterial food and pathogens. The dynamic neuron-specific expression of daf-7 is modulated by environmental and endogenous bacteria-derived cues. Here, we investigated natural variation in the expression of daf-7 from the ASJ pair of chemosensory neurons and identified common variants in gap-2, encoding a GTPase-Activating Protein homologous to mammalian SynGAP proteins, which modify daf-7 expression cell-non-autonomously and promote exploratory foraging behavior in a DAF-7-dependent manner. Our data connect natural variation in neuron-specific gene expression to differences in behavior and suggest that genetic variation in neuroendocrine signaling pathways mediating host-microbe interactions may give rise to diversity in animal behavior.
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Affiliation(s)
- Harksun Lee
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
| | - Sonia A. Boor
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, 02139, USA
| | - Zoë A. Hilbert
- Department of Biology, Massachusetts Institute of Technology; Cambridge, 02139, USA
| | - Joshua D. Meisel
- Department of Biology, Massachusetts Institute of Technology; Cambridge, 02139, USA
| | - Jaeseok Park
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
| | - Ye Wang
- Department of Molecular Biosciences, Northwestern University; Evanston, 60208, USA
| | - Ryan McKeown
- Department of Molecular Biosciences, Northwestern University; Evanston, 60208, USA
| | - Sylvia E. J. Fischer
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
| | - Erik C. Andersen
- Department of Molecular Biosciences, Northwestern University; Evanston, 60208, USA
| | - Dennis H. Kim
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School; Boston, 02115, USA
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24
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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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25
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Bukwich M, Campbell MG, Zoltowski D, Kingsbury L, Tomov MS, Stern J, Kim HR, Drugowitsch J, Linderman SW, Uchida N. Competitive integration of time and reward explains value-sensitive foraging decisions and frontal cortex ramping dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.05.556267. [PMID: 37732217 PMCID: PMC10508756 DOI: 10.1101/2023.09.05.556267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
The ability to make advantageous decisions is critical for animals to ensure their survival. Patch foraging is a natural decision-making process in which animals decide when to leave a patch of depleting resources to search for a new one. To study the algorithmic and neural basis of patch foraging behavior in a controlled laboratory setting, we developed a virtual foraging task for head-fixed mice. Mouse behavior could be explained by ramp-to-threshold models integrating time and rewards antagonistically. Accurate behavioral modeling required inclusion of a slowly varying "patience" variable, which modulated sensitivity to time. To investigate the neural basis of this decision-making process, we performed dense electrophysiological recordings with Neuropixels probes broadly throughout frontal cortex and underlying subcortical areas. We found that decision variables from the reward integrator model were represented in neural activity, most robustly in frontal cortical areas. Regression modeling followed by unsupervised clustering identified a subset of neurons with ramping activity. These neurons' firing rates ramped up gradually in single trials over long time scales (up to tens of seconds), were inhibited by rewards, and were better described as being generated by a continuous ramp rather than a discrete stepping process. Together, these results identify reward integration via a continuous ramping process in frontal cortex as a likely candidate for the mechanism by which the mammalian brain solves patch foraging problems.
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Affiliation(s)
- Michael Bukwich
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138
- Center for Brain Science, Harvard University, Cambridge, MA, 02138
- Current address: Sainsbury Wellcome Centre, University College London, London, W1T 4JG, UK
| | - Malcolm G Campbell
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138
- Center for Brain Science, Harvard University, Cambridge, MA, 02138
| | - David Zoltowski
- Department of Statistics, Stanford University, Stanford, CA, 94305
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305
| | - Lyle Kingsbury
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138
- Center for Brain Science, Harvard University, Cambridge, MA, 02138
| | - Momchil S Tomov
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138
- Center for Brain Science, Harvard University, Cambridge, MA, 02138
- Current address: Motional AD LLC, Boston, MA 02210
| | - Joshua Stern
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138
- Center for Brain Science, Harvard University, Cambridge, MA, 02138
| | - HyungGoo R Kim
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138
- Center for Brain Science, Harvard University, Cambridge, MA, 02138
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon 16419, Republic of Korea
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jan Drugowitsch
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115
| | - Scott W Linderman
- Department of Statistics, Stanford University, Stanford, CA, 94305
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305
| | - Naoshige Uchida
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138
- Center for Brain Science, Harvard University, Cambridge, MA, 02138
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Madirolas G, Al-Asmar A, Gaouar L, Marie-Louise L, Garza-Enríquez A, Rodríguez-Rada V, Khona M, Dal Bello M, Ratzke C, Gore J, Pérez-Escudero A. Caenorhabditis elegans foraging patterns follow a simple rule of thumb. Commun Biol 2023; 6:841. [PMID: 37580527 PMCID: PMC10425387 DOI: 10.1038/s42003-023-05220-3] [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: 08/04/2022] [Accepted: 08/04/2023] [Indexed: 08/16/2023] Open
Abstract
Rules of thumb are behavioral algorithms that approximate optimal behavior while lowering cognitive and sensory costs. One way to reduce these costs is by simplifying the representation of the environment: While the theoretically optimal behavior may depend on many environmental variables, a rule of thumb may use a smaller set of variables that performs reasonably well. Experimental proof of this simplification requires an exhaustive mapping of all relevant combinations of several environmental parameters, which we performed for Caenorhabditis elegans foraging by covering systematically combinations of food density (across 4 orders of magnitude) and food type (across 12 bacterial strains). We found that worms' response is dominated by a single environmental variable: food density measured as number of bacteria per unit surface. They disregard other factors such as biomass content or bacterial strain. We also measured experimentally the impact on fitness of each type of food, determining that the rule is near-optimal and therefore constitutes a rule of thumb that leverages the most informative environmental variable. These results set the stage for further investigations into the underlying genetic and neural mechanisms governing this simplification process, and into its role in the evolution of decision-making strategies.
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Affiliation(s)
- Gabriel Madirolas
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Alid Al-Asmar
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Lydia Gaouar
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Leslie Marie-Louise
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Andrea Garza-Enríquez
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Valentina Rodríguez-Rada
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Mikail Khona
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Martina Dal Bello
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Christoph Ratzke
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Cluster of Excellence EXC 2124 "Controlling Microbes to Fight Infections" (CMFI), University of Tübingen, Calwerstrasse 7/1, 72076, Tübingen, Germany
| | - Jeff Gore
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alfonso Pérez-Escudero
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France.
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
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27
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Faerberg DF, Aprison EZ, Ruvinsky I. Periods of environmental sensitivity couple larval behavior and development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.552015. [PMID: 37609125 PMCID: PMC10441318 DOI: 10.1101/2023.08.04.552015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The typical life cycle in most animal phyla includes a larval period that bridges embryogenesis and adulthood1. Despite the great diversity of larval forms, all larvae grow, acquire adult morphology and function, while navigating their habitats to obtain resources necessary for development. How larval development is coordinated with behavior remains substantially unclear. Here, we describe features of the iterative organization of larval stages that serve to assess the environment and procure resources prior to costly developmental commitments. We found that male-excreted pheromones accelerate2-4 the onset of adulthood in C. elegans hermaphrodites by coordinately advancing multiple developmental events and growth during the last larval stage. The larvae are sensitive to the accelerating male pheromones only at the end of the penultimate larval stage, just before the acceleration begins. Other larval stages also contain windows of sensitivity to environmental inputs. Importantly, behaviors associated with search and consumption of food are distinct between early and late portions of larval stages. We infer that each larval stage in C. elegans is subdivided into two epochs: A) global assessment of the environment to identify the most suitable patch and B) consumption of sufficient food and acquisition of salient information for developmental events in the next stage. We predict that in larvae of other species behavior is also divided into distinct epochs optimized either for assessing the habitat or obtaining the resources. Thus, a major role of larval behavior is to coordinate the orderly progression of development in variable environments.
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Affiliation(s)
- Denis F. Faerberg
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Erin Z. Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
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28
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Aprison EZ, Dzitoyeva S, Ruvinsky I. Serotonergic signaling plays a deeply conserved role in improving oocyte quality. Dev Biol 2023; 499:24-30. [PMID: 37121310 PMCID: PMC10247452 DOI: 10.1016/j.ydbio.2023.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/02/2023]
Abstract
Declining germline quality is a major cause of reproductive senescence. Potential remedies could be found by studying regulatory pathways that promote germline quality. Several lines of evidence, including a C. elegans male pheromone ascr#10 that counteracts the effects of germline aging in hermaphrodites, suggest that the nervous system plays an important role in regulating germline quality. Inspired by the fact that serotonin mediates ascr#10 signaling, here we show that serotonin reuptake inhibitors recapitulate the effects of ascr#10 on the germline and promote healthy oocyte aging in C. elegans. Surprisingly, we found that pharmacological increase of serotonin signaling stimulates several developmental processes in D. melanogaster, including improved oocyte quality, although underlying mechanisms appear to be different between worms and flies. Our results reveal a plausibly conserved role for serotonin in maintaining germline quality and identify a class of therapeutic interventions using available compounds that could efficiently forestall reproductive aging.
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Affiliation(s)
- Erin Z Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Svetlana Dzitoyeva
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA.
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29
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Dag U, Nwabudike I, Kang D, Gomes MA, Kim J, Atanas AA, Bueno E, Estrem C, Pugliese S, Wang Z, Towlson E, Flavell SW. Dissecting the functional organization of the C. elegans serotonergic system at whole-brain scale. Cell 2023; 186:2574-2592.e20. [PMID: 37192620 PMCID: PMC10484565 DOI: 10.1016/j.cell.2023.04.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 03/07/2023] [Accepted: 04/17/2023] [Indexed: 05/18/2023]
Abstract
Serotonin influences many aspects of animal behavior. But how serotonin acts on its diverse receptors across the brain to modulate global activity and behavior is unknown. Here, we examine how serotonin release in C. elegans alters brain-wide activity to induce foraging behaviors, like slow locomotion and increased feeding. Comprehensive genetic analyses identify three core serotonin receptors (MOD-1, SER-4, and LGC-50) that induce slow locomotion upon serotonin release and others (SER-1, SER-5, and SER-7) that interact with them to modulate this behavior. SER-4 induces behavioral responses to sudden increases in serotonin release, whereas MOD-1 induces responses to persistent release. Whole-brain imaging reveals widespread serotonin-associated brain dynamics, spanning many behavioral networks. We map all sites of serotonin receptor expression in the connectome, which, together with synaptic connectivity, helps predict which neurons show serotonin-associated activity. These results reveal how serotonin acts at defined sites across a connectome to modulate brain-wide activity and behavior.
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Affiliation(s)
- Ugur Dag
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ijeoma Nwabudike
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Di Kang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew A Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jungsoo Kim
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Adam A Atanas
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA; Computational and Systems Biology Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Eric Bueno
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Cassi Estrem
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sarah Pugliese
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ziyu Wang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Emma Towlson
- Department of Computer Science, Department of Physics and Astronomy, Hotchkiss Brain Institute, Alberta Children's Research Hospital, University of Calgary, Calgary, AB, Canada
| | - Steven W Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Thapliyal S, Beets I, Glauser DA. Multisite regulation integrates multimodal context in sensory circuits to control persistent behavioral states in C. elegans. Nat Commun 2023; 14:3052. [PMID: 37236963 DOI: 10.1038/s41467-023-38685-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Maintaining or shifting between behavioral states according to context is essential for animals to implement fitness-promoting strategies. How the integration of internal state, past experience and sensory inputs orchestrates persistent multidimensional behavioral changes remains poorly understood. Here, we show that C. elegans integrates environmental temperature and food availability over different timescales to engage in persistent dwelling, scanning, global or glocal search strategies matching thermoregulatory and feeding needs. Transition between states, in each case, involves regulating multiple processes including AFD or FLP tonic sensory neurons activity, neuropeptide expression and downstream circuit responsiveness. State-specific FLP-6 or FLP-5 neuropeptide signaling acts on a distributed set of inhibitory GPCR(s) to promote scanning or glocal search, respectively, bypassing dopamine and glutamate-dependent behavioral state control. Integration of multimodal context via multisite regulation in sensory circuits might represent a conserved regulatory logic for a flexible prioritization on the valence of multiple inputs when operating persistent behavioral state transitions.
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Affiliation(s)
- Saurabh Thapliyal
- Department of Biology, University of Fribourg, 1700, Fribourg, Switzerland.
| | - Isabel Beets
- Neural Signaling and Circuit Plasticity Group, Department of Biology, KU Leuven, 3000, Leuven, Belgium
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31
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Ji H, Fouad AD, Li Z, Ruba A, Fang-Yen C. A proprioceptive feedback circuit drives Caenorhabditis elegans locomotor adaptation through dopamine signaling. Proc Natl Acad Sci U S A 2023; 120:e2219341120. [PMID: 37155851 PMCID: PMC10193984 DOI: 10.1073/pnas.2219341120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 04/14/2023] [Indexed: 05/10/2023] Open
Abstract
An animal adapts its motor behavior to navigate the external environment. This adaptation depends on proprioception, which provides feedback on an animal's body postures. How proprioception mechanisms interact with motor circuits and contribute to locomotor adaptation remains unclear. Here, we describe and characterize proprioception-mediated homeostatic control of undulatory movement in the roundworm Caenorhabditis elegans. We found that the worm responds to optogenetically or mechanically induced decreases in midbody bending amplitude by increasing its anterior amplitude. Conversely, it responds to increased midbody amplitude by decreasing the anterior amplitude. Using genetics, microfluidic and optogenetic perturbation response analyses, and optical neurophysiology, we elucidated the neural circuit underlying this compensatory postural response. The dopaminergic PDE neurons proprioceptively sense midbody bending and signal to AVK interneurons via the D2-like dopamine receptor DOP-3. The FMRFamide-like neuropeptide FLP-1, released by AVK, regulates SMB head motor neurons to modulate anterior bending. We propose that this homeostatic behavioral control optimizes locomotor efficiency. Our findings demonstrate a mechanism in which proprioception works with dopamine and neuropeptide signaling to mediate motor control, a motif that may be conserved in other animals.
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Affiliation(s)
- Hongfei Ji
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA19104
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH43210
| | - Anthony D. Fouad
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA19104
| | - Zihao Li
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA19104
| | - Andrew Ruba
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA19104
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA19104
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH43210
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104
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32
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Vogt MC, Hobert O. Starvation-induced changes in somatic insulin/IGF-1R signaling drive metabolic programming across generations. SCIENCE ADVANCES 2023; 9:eade1817. [PMID: 37027477 PMCID: PMC10081852 DOI: 10.1126/sciadv.ade1817] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 03/08/2023] [Indexed: 05/30/2023]
Abstract
Exposure to adverse nutritional and metabolic environments during critical periods of development can exert long-lasting effects on health outcomes of an individual and its descendants. Although such metabolic programming has been observed in multiple species and in response to distinct nutritional stressors, conclusive insights into signaling pathways and mechanisms responsible for initiating, mediating, and manifesting changes to metabolism and behavior across generations remain scarce. By using a starvation paradigm in Caenorhabditis elegans, we show that starvation-induced changes in dauer formation-16/forkhead box transcription factor class O (DAF-16/FoxO) activity, the main downstream target of insulin/insulin-like growth factor 1 (IGF-1) receptor signaling, are responsible for metabolic programming phenotypes. Tissue-specific depletion of DAF-16/FoxO during distinct developmental time points demonstrates that DAF-16/FoxO acts in somatic tissues, but not directly in the germline, to both initiate and manifest metabolic programming. In conclusion, our study deciphers multifaceted and critical roles of highly conserved insulin/IGF-1 receptor signaling in determining health outcomes and behavior across generations.
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Huang YC, Luo J, Huang W, Baker CM, Gomes MA, Byrne AB, Flavell SW. A single neuron in C. elegans orchestrates multiple motor outputs through parallel modes of transmission. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.02.532814. [PMID: 37034579 PMCID: PMC10081309 DOI: 10.1101/2023.04.02.532814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neuron classes in the circuits that generate behavior have a remarkable capacity for flexibility, as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of highly coordinated behaviors remains unknown. Here we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg-laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg-laying and locomotion while also biasing the animals towards low-speed dwelling behavior over longer timescales. The acute effects of HSN on egg-laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal projections. The long-lasting effects on dwelling are mediated by HSN release of serotonin that is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal for the first time that neurons can borrow serotonin from one another to control behavior.
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Affiliation(s)
- Yung-Chi Huang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jinyue Luo
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Wenjia Huang
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA, USA
| | - Casey M. Baker
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew A. Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alexandra B. Byrne
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA, USA
| | - Steven W. Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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34
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Yu H, Liu D, Li S, Wang J, Liu J, Liu C. Probing the flexible internal state transition and low-dimensional manifold dynamics of human brain with acupuncture. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2022.104494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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35
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Xuan Z, Yang S, Clark B, Hill SE, Manning L, Colón-Ramos DA. The active zone protein Clarinet regulates synaptic sorting of ATG-9 and presynaptic autophagy. PLoS Biol 2023; 21:e3002030. [PMID: 37053235 PMCID: PMC10101500 DOI: 10.1371/journal.pbio.3002030] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/08/2023] [Indexed: 04/14/2023] Open
Abstract
Autophagy is essential for cellular homeostasis and function. In neurons, autophagosome biogenesis is temporally and spatially regulated to occur near presynaptic sites, in part via the trafficking of autophagy transmembrane protein ATG-9. The molecules that regulate autophagy by sorting ATG-9 at synapses remain largely unknown. Here, we conduct forward genetic screens at single synapses of C. elegans neurons and identify a role for the long isoform of the active zone protein Clarinet (CLA-1L) in regulating sorting of autophagy protein ATG-9 at synapses, and presynaptic autophagy. We determine that disrupting CLA-1L results in abnormal accumulation of ATG-9 containing vesicles enriched with clathrin. The ATG-9 phenotype in cla-1(L) mutants is not observed for other synaptic vesicle proteins, suggesting distinct mechanisms that regulate sorting of ATG-9-containing vesicles and synaptic vesicles. Through genetic analyses, we uncover the adaptor protein complexes that genetically interact with CLA-1 in ATG-9 sorting. We also determine that CLA-1L extends from the active zone to the periactive zone and genetically interacts with periactive zone proteins in ATG-9 sorting. Our findings reveal novel roles for active zone proteins in the sorting of ATG-9 and in presynaptic autophagy.
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Affiliation(s)
- Zhao Xuan
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Sisi Yang
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Benjamin Clark
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Sarah E. Hill
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Laura Manning
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Daniel A. Colón-Ramos
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico, San Juan,Puerto Rico
- Wu Tsai Institute, Yale University, New Haven, Connecticut, United States of America
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36
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Starkey J, Hageter J, Kozol R, Emmerich K, Mumm JS, Dubou ER, Horstick EJ. Thalamic neurons drive distinct forms of motor asymmetry that are conserved in teleost and dependent on visual evolution. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.20.533538. [PMID: 36993391 PMCID: PMC10055245 DOI: 10.1101/2023.03.20.533538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Brain laterality is a prominent feature in Bilateria, where neural functions are favored in a single brain hemisphere. These hemispheric specializations are thought to improve behavioral performance and are commonly observed as sensory or motor asymmetries, such as handedness in humans. Despite its prevalence, our understanding of the neural and molecular substrates instructing functional lateralization is limited. Moreover, how functional lateralization is selected for or modulated throughout evolution is poorly understood. While comparative approaches offer a powerful tool for addressing this question, a major obstacle has been the lack of a conserved asymmetric behavior in genetically tractable organisms. Previously, we described a robust motor asymmetry in larval zebrafish. Following the loss of illumination, individuals show a persistent turning bias that is associated with search pattern behavior with underlying functional lateralization in the thalamus. This behavior permits a simple yet robust assay that can be used to address fundamental principles underlying lateralization in the brain across taxa. Here, we take a comparative approach and show that motor asymmetry is conserved across diverse larval teleost species, which have diverged over the past 200 million years. Using a combination of transgenic tools, ablation, and enucleation, we show that teleosts exhibit two distinct forms of motor asymmetry, vision-dependent and - independent. These asymmetries are directionally uncorrelated, yet dependent on the same subset of thalamic neurons. Lastly, we leverage Astyanax sighted and blind morphs, which show that fish with evolutionarily derived blindness lack both retinal-dependent and -independent motor asymmetries, while their sighted surface conspecifics retained both forms. Our data implicate that overlapping sensory systems and neuronal substrates drive functional lateralization in a vertebrate brain that are likely targets for selective modulation during evolution.
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37
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Legionella pneumophila and Free-Living Nematodes: Environmental Co-Occurrence and Trophic Link. Microorganisms 2023; 11:microorganisms11030738. [PMID: 36985310 PMCID: PMC10056204 DOI: 10.3390/microorganisms11030738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/03/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023] Open
Abstract
Free-living nematodes harbor and disseminate various soil-borne bacterial pathogens. Whether they function as vectors or environmental reservoirs for the aquatic L. pneumophila, the causative agent of Legionnaires’ disease, is unknown. A survey screening of biofilms of natural (swimming lakes) and technical (cooling towers) water habitats in Germany revealed that nematodes can act as potential reservoirs, vectors or grazers of L. pneumophila in cooling towers. Consequently, the nematode species Plectus similis and L. pneumophila were isolated from the same cooling tower biofilm and taken into a monoxenic culture. Using pharyngeal pumping assays, potential feeding relationships between P. similis and different L. pneumophila strains and mutants were examined and compared with Plectus sp., a species isolated from a L. pneumophila-positive thermal source biofilm. The assays showed that bacterial suspensions and supernatants of the L. pneumophila cooling tower isolate KV02 decreased pumping rate and feeding activity in nematodes. However, assays investigating the hypothesized negative impact of Legionella’s major secretory protein ProA on pumping rate revealed opposite effects on nematodes, which points to a species-specific response to ProA. To extend the food chain by a further trophic level, Acanthamoebae castellanii infected with L. pneumphila KV02 were offered to nematodes. The pumping rates of P. similis increased when fed with L. pneumophila-infected A. castellanii, while Plectus sp. pumping rates were similar when fed either infected or non-infected A. castellanii. This study revealed that cooling towers are the main water bodies where L. pneumophila and free-living nematodes coexist and is the first step in elucidating the trophic links between coexisting taxa from that habitat. Investigating the Legionella–nematode–amoebae interactions underlined the importance of amoebae as reservoirs and transmission vehicles of the pathogen for nematode predators.
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Ding J, Peng L, Moon S, Lee HJ, Patel DS, Lu H. An expanded GCaMP reporter toolkit for functional imaging in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.06.531342. [PMID: 36945463 PMCID: PMC10028802 DOI: 10.1101/2023.03.06.531342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
In living organisms, changes in calcium flux are integral to many different cellular functions and are especially critical for the activity of neurons and myocytes. Genetically encoded calcium indicators (GECIs) have been popular tools for reporting changes in calcium levels in vivo . In particular, GCaMP, derived from GFP, are the most widely used GECIs and have become an invaluable toolkit for neurophysiological studies. Recently, new variants of GCaMP, which offer a greater variety of temporal dynamics and improved brightness, have been developed. However, these variants are not readily available to the Caenorhabditis elegans research community. This work reports a set of GCaMP6 and jGCaMP7 reporters optimized for C. elegans studies. Our toolkit provides reporters with improved dynamic range, varied kinetics, and targeted subcellular localizations. Besides optimized routine uses, this set of reporters are also well-suited for studies requiring fast imaging speeds and low magnification or low-cost platforms.
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Affiliation(s)
- Jimmy Ding
- These authors contributed equally
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Lucinda Peng
- These authors contributed equally
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Sihoon Moon
- These authors contributed equally
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Hyun Jee Lee
- These authors contributed equally
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Dhaval S. Patel
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Present address: NemaLife Inc, Lubbock, TX 79409, USA
| | - Hang Lu
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
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39
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Caenorhabditis elegans as a Model System to Study Human Neurodegenerative Disorders. Biomolecules 2023; 13:biom13030478. [PMID: 36979413 PMCID: PMC10046667 DOI: 10.3390/biom13030478] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/18/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
In recent years, advances in science and technology have improved our quality of life, enabling us to tackle diseases and increase human life expectancy. However, longevity is accompanied by an accretion in the frequency of age-related neurodegenerative diseases, creating a growing burden, with pervasive social impact for human societies. The cost of managing such chronic disorders and the lack of effective treatments highlight the need to decipher their molecular and genetic underpinnings, in order to discover new therapeutic targets. In this effort, the nematode Caenorhabditis elegans serves as a powerful tool to recapitulate several disease-related phenotypes and provides a highly malleable genetic model that allows the implementation of multidisciplinary approaches, in addition to large-scale genetic and pharmacological screens. Its anatomical transparency allows the use of co-expressed fluorescent proteins to track the progress of neurodegeneration. Moreover, the functional conservation of neuronal processes, along with the high homology between nematode and human genomes, render C. elegans extremely suitable for the study of human neurodegenerative disorders. This review describes nematode models used to study neurodegeneration and underscores their contribution in the effort to dissect the molecular basis of human diseases and identify novel gene targets with therapeutic potential.
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Bodas DS, Maduskar A, Kaniganti T, Wakhloo D, Balasubramanian A, Subhedar N, Ghose A. Convergent Energy State-Dependent Antagonistic Signaling by Cocaine- and Amphetamine-Regulated Transcript (CART) and Neuropeptide Y (NPY) Modulates the Plasticity of Forebrain Neurons to Regulate Feeding in Zebrafish. J Neurosci 2023; 43:1089-1110. [PMID: 36599680 PMCID: PMC9962846 DOI: 10.1523/jneurosci.2426-21.2022] [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: 12/11/2021] [Revised: 11/28/2022] [Accepted: 12/22/2022] [Indexed: 01/06/2023] Open
Abstract
Dynamic reconfiguration of circuit function subserves the flexibility of innate behaviors tuned to physiological states. Internal energy stores adaptively regulate feeding-associated behaviors and integrate opposing hunger and satiety signals at the level of neural circuits. Across vertebrate lineages, the neuropeptides cocaine- and amphetamine-regulated transcript (CART) and neuropeptide Y (NPY) have potent anorexic and orexic functions, respectively, and show energy-state-dependent expression in interoceptive neurons. However, how the antagonistic activities of these peptides modulate circuit plasticity remains unclear. Using behavioral, neuroanatomical, and activity analysis in adult zebrafish of both sexes, along with pharmacological interventions, we show that CART and NPY activities converge on a population of neurons in the dorsomedial telencephalon (Dm). Although CART facilitates glutamatergic neurotransmission at the Dm, NPY dampens the response to glutamate. In energy-rich states, CART enhances NMDA receptor (NMDAR) function by protein kinase A/protein kinase C (PKA/PKC)-mediated phosphorylation of the NR1 subunit of the NMDAR complex. Conversely, starvation triggers NPY-mediated reduction in phosphorylated NR1 via calcineurin activation and inhibition of cAMP production leading to reduced responsiveness to glutamate. Our data identify convergent integration of CART and NPY inputs by the Dm neurons to generate nutritional state-dependent circuit plasticity that is correlated with the behavioral switch induced by the opposing actions of satiety and hunger signals.SIGNIFICANCE STATEMENT Internal energy needs reconfigure neuronal circuits to adaptively regulate feeding behavior. Energy-state-dependent neuropeptide release can signal energy status to feeding-associated circuits and modulate circuit function. CART and NPY are major anorexic and orexic factors, respectively, but the intracellular signaling pathways used by these peptides to alter circuit function remain uncharacterized. We show that CART and NPY-expressing neurons from energy-state interoceptive areas project to a novel telencephalic region, Dm, in adult zebrafish. CART increases the excitability of Dm neurons, whereas NPY opposes CART activity. Antagonistic signaling by CART and NPY converge onto NMDA-receptor function to modulate glutamatergic neurotransmission. Thus, opposing activities of anorexic CART and orexic NPY reconfigure circuit function to generate flexibility in feeding behavior.
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Affiliation(s)
- Devika S Bodas
- Indian Institute of Science Education and Research, Pune, Pune 411008, India
| | - Aditi Maduskar
- Indian Institute of Science Education and Research, Pune, Pune 411008, India
| | - Tarun Kaniganti
- Indian Institute of Science Education and Research, Pune, Pune 411008, India
| | - Debia Wakhloo
- Indian Institute of Science Education and Research, Pune, Pune 411008, India
| | | | - Nishikant Subhedar
- Indian Institute of Science Education and Research, Pune, Pune 411008, India
| | - Aurnab Ghose
- Indian Institute of Science Education and Research, Pune, Pune 411008, India
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41
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Godini R, Pocock R. Characterization of the Doublesex/MAB-3 transcription factor DMD-9 in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2023; 13:jkac305. [PMID: 36454093 PMCID: PMC9911054 DOI: 10.1093/g3journal/jkac305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 09/30/2022] [Accepted: 11/10/2022] [Indexed: 12/05/2022]
Abstract
DMD-9 is a Caenorhabditis elegans Doublesex/MAB-3 Domain transcription factor (TF) of unknown function. Single-cell transcriptomics has revealed that dmd-9 is highly expressed in specific head sensory neurons, with lower levels detected in non-neuronal tissues (uterine cells and sperm). Here, we characterized endogenous dmd-9 expression and function in hermaphrodites and males to identify potential sexually dimorphic roles. In addition, we dissected the trans- and cis-regulatory mechanisms that control DMD-9 expression in neurons. Our results show that of the 22 neuronal cell fate reporters we assessed in DMD-9-expressing neurons, only the neuropeptide-encoding flp-19 gene is cell-autonomously regulated by DMD-9. Further, we did not identify defects in behaviors mediated by DMD-9 expressing neurons in dmd-9 mutants. We found that dmd-9 expression in neurons is regulated by 4 neuronal fate regulatory TFs: ETS-5, EGL-13, CHE-1, and TTX-1. In conclusion, our study characterized the DMD-9 expression pattern and regulatory logic for its control. The lack of detectable phenotypes in dmd-9 mutant animals suggests that other proteins compensate for its loss.
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Affiliation(s)
- Rasoul Godini
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria 3800, Australia
| | - Roger Pocock
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria 3800, Australia
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42
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Yu J, Vogt MC, Fox BW, Wrobel CJJ, Fajardo Palomino D, Curtis BJ, Zhang B, Le HH, Tauffenberger A, Hobert O, Schroeder FC. Parallel pathways for serotonin biosynthesis and metabolism in C. elegans. Nat Chem Biol 2023; 19:141-150. [PMID: 36216995 PMCID: PMC9898190 DOI: 10.1038/s41589-022-01148-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 08/19/2022] [Indexed: 02/06/2023]
Abstract
The neurotransmitter serotonin plays a central role in animal behavior and physiology, and many of its functions are regulated via evolutionarily conserved biosynthesis and degradation pathways. Here we show that in Caenorhabditis elegans, serotonin is abundantly produced in nonneuronal tissues via phenylalanine hydroxylase, in addition to canonical biosynthesis via tryptophan hydroxylase in neurons. Combining CRISPR-Cas9 genome editing, comparative metabolomics and synthesis, we demonstrate that most serotonin in C. elegans is incorporated into N-acetylserotonin-derived glucosides, which are retained in the worm body and further modified via the carboxylesterase CEST-4. Expression patterns of CEST-4 suggest that serotonin or serotonin derivatives are transported between different tissues. Last, we show that bacterial indole production interacts with serotonin metabolism via CEST-4. Our results reveal a parallel pathway for serotonin biosynthesis in nonneuronal cell types and further indicate that serotonin-derived metabolites may serve distinct signaling functions and contribute to previously described serotonin-dependent phenotypes.
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Affiliation(s)
- Jingfang Yu
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Merly C Vogt
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY, USA
| | - Bennett W Fox
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Chester J J Wrobel
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Diana Fajardo Palomino
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Brian J Curtis
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Bingsen Zhang
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Henry H Le
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Arnaud Tauffenberger
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY, USA.
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
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43
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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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44
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Dag U, Nwabudike I, Kang D, Gomes MA, Kim J, Atanas AA, Bueno E, Estrem C, Pugliese S, Wang Z, Towlson E, Flavell SW. Dissecting the Functional Organization of the C. elegans Serotonergic System at Whole-Brain Scale. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.15.524132. [PMID: 36711891 PMCID: PMC9882198 DOI: 10.1101/2023.01.15.524132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Serotonin controls many aspects of animal behavior and cognition. But how serotonin acts on its diverse receptor types in neurons across the brain to modulate global activity and behavior is unknown. Here, we examine how serotonin release from a feeding-responsive neuron in C. elegans alters brain-wide activity to induce foraging behaviors, like slow locomotion and increased feeding. A comprehensive genetic analysis identifies three core serotonin receptors that collectively induce slow locomotion upon serotonin release and three others that interact with them to further modulate this behavior. The core receptors have different functional roles: some induce behavioral responses to sudden increases in serotonin release, whereas others induce responses to persistent release. Whole-brain calcium imaging reveals widespread serotonin-associated brain dynamics, impacting different behavioral networks in different ways. We map out all sites of serotonin receptor expression in the connectome, which, together with synaptic connectivity, helps predict serotonin-associated brain-wide activity changes. These results provide a global view of how serotonin acts at defined sites across a connectome to modulate brain-wide activity and behavior.
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Affiliation(s)
- Ugur Dag
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA,These authors contributed equally to this work
| | - Ijeoma Nwabudike
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA,These authors contributed equally to this work
| | - Di Kang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA,These authors contributed equally to this work
| | - Matthew A. Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jungsoo Kim
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Adam A. Atanas
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA,Computational and Systems Biology Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Eric Bueno
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Cassi Estrem
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sarah Pugliese
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ziyu Wang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Emma Towlson
- Department of Computer Science, Department of Physics and Astronomy, Hotchkiss Brain Institute, Alberta Children’s Research Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Steven W. Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA,Corresponding Author:
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45
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Davis K, Mitchell C, Weissenfels O, Bai J, Raizen DM, Ailion M, Topalidou I. G protein-coupled receptor kinase-2 (GRK-2) controls exploration through neuropeptide signaling in Caenorhabditis elegans. PLoS Genet 2023; 19:e1010613. [PMID: 36652499 PMCID: PMC9886303 DOI: 10.1371/journal.pgen.1010613] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/30/2023] [Accepted: 01/12/2023] [Indexed: 01/19/2023] Open
Abstract
Animals alter their behavior in manners that depend on environmental conditions as well as their developmental and metabolic states. For example, C. elegans is quiescent during larval molts or during conditions of satiety. By contrast, worms enter an exploration state when removed from food. Sensory perception influences movement quiescence (defined as a lack of body movement), as well as the expression of additional locomotor states in C. elegans that are associated with increased or reduced locomotion activity, such as roaming (exploration behavior) and dwelling (local search). Here we find that movement quiescence is enhanced, and exploration behavior is reduced in G protein-coupled receptor kinase grk-2 mutant animals. grk-2 was previously shown to act in chemosensation, locomotion, and egg-laying behaviors. Using neuron-specific rescuing experiments, we show that GRK-2 acts in multiple ciliated chemosensory neurons to control exploration behavior. grk-2 acts in opposite ways from the cGMP-dependent protein kinase gene egl-4 to control movement quiescence and exploration behavior. Analysis of mutants with defects in ciliated sensory neurons indicates that grk-2 and the cilium-structure mutants act in the same pathway to control exploration behavior. We find that GRK-2 controls exploration behavior in an opposite manner from the neuropeptide receptor NPR-1 and the neuropeptides FLP-1 and FLP-18. Finally, we show that secretion of the FLP-1 neuropeptide is negatively regulated by GRK-2 and that overexpression of FLP-1 reduces exploration behavior. These results define neurons and molecular pathways that modulate movement quiescence and exploration behavior.
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Affiliation(s)
- Kristen Davis
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Center for Excellence in Environmental Toxicology (CEET), Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Christo Mitchell
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Olivia Weissenfels
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Jihong Bai
- Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
| | - David M. Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
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46
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Preusser F, Neuschulz A, Junker JP, Rajewsky N, Preibisch S. Long-term imaging reveals behavioral plasticity during C. elegans dauer exit. BMC Biol 2022; 20:277. [PMID: 36514066 DOI: 10.1186/s12915-022-01471-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 11/18/2022] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND During their lifetime, animals must adapt their behavior to survive in changing environments. This ability requires the nervous system to undergo adjustments at distinct temporal scales, from short-term dynamic changes in expression of neurotransmitters and receptors to longer-term growth, spatial and connectivity reorganization, while integrating external stimuli. The nematode Caenorhabditis elegans provides a model of nervous system plasticity, in particular its dauer exit decision. Under unfavorable conditions, larvae will enter the non-feeding and non-reproductive stress-resistant dauer stage and adapt their behavior to cope with the harsh new environment, with active reversal under improved conditions leading to resumption of reproductive development. However, how different environmental stimuli regulate the exit decision mechanism and thereby drive the larva's behavioral change is unknown. To fill this gap and provide insights on behavioral changes over extended periods of time, we developed a new open hardware method for long-term imaging (12h) of C. elegans larvae. RESULTS Our WormObserver platform comprises open hardware and software components for video acquisition, automated processing of large image data (> 80k images/experiment) and data analysis. We identified dauer-specific behavioral motifs and characterized the behavioral trajectory of dauer exit in different environments and genetic backgrounds to identify key decision points and stimuli promoting dauer exit. Combining long-term behavioral imaging with transcriptomics data, we find that bacterial ingestion triggers a change in neuropeptide gene expression to establish post-dauer behavior. CONCLUSIONS Taken together, we show how a developing nervous system can robustly integrate environmental changes activate a developmental switch and adapt the organism's behavior to a new environment. WormObserver is generally applicable to other research questions within and beyond the C. elegans field, having a modular and customizable character and allowing assessment of behavioral plasticity over longer periods.
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Affiliation(s)
- Friedrich Preusser
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 10115, Berlin, Germany. .,Institute for Biology, Humboldt University of Berlin, 10099, Berlin, Germany.
| | - Anika Neuschulz
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 10115, Berlin, Germany.,Institute for Biology, Humboldt University of Berlin, 10099, Berlin, Germany
| | - Jan Philipp Junker
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 10115, Berlin, Germany
| | - Nikolaus Rajewsky
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 10115, Berlin, Germany
| | - Stephan Preibisch
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA.
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47
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Shoenhard H, Jain RA, Granato M. The calcium-sensing receptor (CaSR) regulates zebrafish sensorimotor decision making via a genetically defined cluster of hindbrain neurons. Cell Rep 2022; 41:111790. [PMID: 36476852 PMCID: PMC9813870 DOI: 10.1016/j.celrep.2022.111790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 09/21/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
Decision making is a fundamental nervous system function that ranges widely in complexity and speed of execution. We previously established larval zebrafish as a model for sensorimotor decision making and identified the G-protein-coupled calcium-sensing receptor (CaSR) to be critical for this process. Here, we report that CaSR functions in neurons to dynamically regulate the bias between two behavioral outcomes: escapes and reorientations. By employing a computational guided transgenic strategy, we identify a genetically defined neuronal cluster in the hindbrain as a key candidate site for CaSR function. Finally, we demonstrate that transgenic CaSR expression targeting this cluster consisting of a few hundred neurons shifts behavioral bias in wild-type animals and restores decision making deficits in CaSR mutants. Combined, our data provide a rare example of a G-protein-coupled receptor that biases vertebrate sensorimotor decision making via a defined neuronal cluster.
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Affiliation(s)
- Hannah Shoenhard
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Roshan A. Jain
- Department of Biology, Haverford College, Haverford, PA 19041, USA
| | - Michael Granato
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA,Lead contact,Correspondence:
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48
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Aprison EZ, Dzitoyeva S, Ruvinsky I. The serotonin circuit that coordinates germline proliferation and egg laying with other reproductive functions in Caenorhabditis elegans. Proc Biol Sci 2022; 289:20220913. [PMID: 36448283 PMCID: PMC9709507 DOI: 10.1098/rspb.2022.0913] [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: 05/11/2022] [Accepted: 11/10/2022] [Indexed: 12/03/2022] Open
Abstract
Behaviour and physiology are altered in reproducing animals, but neuronal circuits that regulate these changes remain largely unknown. Insights into mechanisms that regulate and possibly coordinate reproduction-related traits could be gleaned from the study of sex pheromones that can improve the reproductive success of potential mating partners. In Caenorhabditis elegans, the prominent male pheromone, ascr#10, modifies reproductive behaviour and several aspects of reproductive physiology in hermaphrodite recipients, including improving oocyte quality. Here we show that a circuit that contains serotonin-producing and serotonin-uptaking neurons plays a key role in mediating effects of ascr#10 on germline development and egg laying behaviour. We also demonstrate that increased serotonin signalling promotes proliferation of germline progenitors in adult hermaphrodites. Our results establish a role for serotonin in maintaining germline quality and highlight a simple neuronal circuit that acts as a linchpin that couples food intake, mating behaviour, reproductive output, and germline renewal and provisioning.
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Affiliation(s)
- Erin Z. Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Svetlana Dzitoyeva
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
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49
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Post RJ, Bulkin DA, Ebitz RB, Lee V, Han K, Warden MR. Tonic activity in lateral habenula neurons acts as a neutral valence brake on reward-seeking behavior. Curr Biol 2022; 32:4325-4336.e5. [PMID: 36049479 PMCID: PMC9613558 DOI: 10.1016/j.cub.2022.08.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 12/16/2021] [Accepted: 08/09/2022] [Indexed: 11/16/2022]
Abstract
Survival requires both the ability to persistently pursue goals and the ability to determine when it is time to stop, an adaptive balance of perseverance and disengagement. Neural activity in the lateral habenula (LHb) has been linked to negative valence, but its role in regulating the balance between engaged reward seeking and disengaged behavioral states remains unclear. Here, we show that LHb neural activity is tonically elevated during minutes-long periods of disengagement from reward-seeking behavior, both when due to repeated reward omission (negative valence) and when sufficient reward has been consumed (positive valence). Furthermore, we show that LHb inhibition extends ongoing reward-seeking behavioral states but does not prompt task re-engagement. We find no evidence for similar tonic activity changes in ventral tegmental area dopamine neurons. Our findings support a framework in which tonic activity in LHb neurons suppresses engagement in reward-seeking behavior in response to both negatively and positively valenced factors.
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Affiliation(s)
- Ryan J Post
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA; Cornell Neurotech, Cornell University, Ithaca, NY 14853, USA
| | - David A Bulkin
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA; Cornell Neurotech, Cornell University, Ithaca, NY 14853, USA
| | - R Becket Ebitz
- Department of Neuroscience, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Vladlena Lee
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
| | - Kasey Han
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
| | - Melissa R Warden
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA; Cornell Neurotech, Cornell University, Ithaca, NY 14853, USA.
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50
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Geng S, Li Q, Zhou X, Zheng J, Liu H, Zeng J, Yang R, Fu H, Hao F, Feng Q, Qi B. Gut commensal E. coli outer membrane proteins activate the host food digestive system through neural-immune communication. Cell Host Microbe 2022; 30:1401-1416.e8. [PMID: 36057258 DOI: 10.1016/j.chom.2022.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/01/2022] [Accepted: 08/05/2022] [Indexed: 12/13/2022]
Abstract
The gastrointestinal tract facilitates food digestion, with the gut microbiota playing pivotal roles in nutrient breakdown and absorption. However, the microbial molecules and downstream signaling pathways that activate food digestion remain unexplored. Here, by establishing a food digestion system in C. elegans, we discover that food breakdown is regulated by the interaction between bacterial outer membrane proteins (OMPs) and a neural-immune pathway. E. coli OmpF/A activate digestion by increasing the neuropeptide NLP-12 that acts on the receptor CCKR. NLP-12 is homologous to mammalian cholecystokinin, known to stimulate dopamine, and we found that loss of dopamine receptors or addition of a dopamine antagonist inhibited OMP-mediated digestion. Dopamine and NLP-12-CKR-1 converge to inhibit PMK-1/p38 innate immune signaling. Moreover, directly inhibiting PMK-1/p38 boosts food digestion. This study uncovers a role of bacterial OMPs in regulating animal nutrient uptake and supports a key role for innate immunity in digestion.
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Affiliation(s)
- Shengya Geng
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Qian Li
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Xue Zhou
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Junkang Zheng
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Huimin Liu
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Jie Zeng
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Ruizhi Yang
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Herui Fu
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Fanrui Hao
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Qianxu Feng
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China
| | - Bin Qi
- Center for Life Sciences, School of Life Sciences, State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650500, China.
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