1
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Bokman E, Pritz CO, Ruach R, Itskovits E, Sharvit H, Zaslaver A. Intricate response dynamics enhances stimulus discrimination in the resource-limited C. elegans chemosensory system. BMC Biol 2024; 22:173. [PMID: 39148065 PMCID: PMC11328493 DOI: 10.1186/s12915-024-01977-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 08/08/2024] [Indexed: 08/17/2024] Open
Abstract
BACKGROUND Sensory systems evolved intricate designs to accurately encode perplexing environments. However, this encoding task may become particularly challenging for animals harboring a small number of sensory neurons. Here, we studied how the compact resource-limited chemosensory system of Caenorhabditis elegans uniquely encodes a range of chemical stimuli. RESULTS We find that each stimulus is encoded using a small and unique subset of neurons, where only a portion of the encoding neurons sense the stimulus directly, and the rest are recruited via inter-neuronal communication. Furthermore, while most neurons show stereotypical response dynamics, some neurons exhibit versatile dynamics that are either stimulus specific or network-activity dependent. Notably, it is the collective dynamics of all responding neurons which provides valuable information that ultimately enhances stimulus identification, particularly when required to discriminate between closely related stimuli. CONCLUSIONS Together, these findings demonstrate how a compact and resource-limited chemosensory system can efficiently encode and discriminate a diverse range of chemical stimuli.
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Affiliation(s)
- Eduard Bokman
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Christian O Pritz
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rotem Ruach
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eyal Itskovits
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hadar Sharvit
- Department of Statistics and Data Science, Center for Interdisciplinary Data Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alon Zaslaver
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel.
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2
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Kwon Y, Kim J, Son YB, Lee SA, Choi SS, Cho Y. Advanced Neural Functional Imaging in C. elegans Using Lab-on-a-Chip Technology. MICROMACHINES 2024; 15:1027. [PMID: 39203678 PMCID: PMC11356251 DOI: 10.3390/mi15081027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Revised: 08/05/2024] [Accepted: 08/06/2024] [Indexed: 09/03/2024]
Abstract
The ability to perceive and adapt to environmental changes is crucial for the survival of all organisms. Neural functional imaging, particularly in model organisms, such as Caenorhabditis elegans, provides valuable insights into how animals sense and process external cues through their nervous systems. Because of its fully mapped neural anatomy, transparent body, and genetic tractability, C. elegans serves as an ideal model for these studies. This review focuses on advanced methods for neural functional imaging in C. elegans, highlighting calcium imaging techniques, lab-on-a-chip technologies, and their applications in the study of various sensory modalities, including chemosensation, mechanosensation, thermosensation, photosensation, and magnetosensation. We discuss the benefits of these methods in terms of precision, reproducibility, and ability to study dynamic neural processes in real time, ultimately advancing our understanding of the fundamental principles of neural activity and connectivity.
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Affiliation(s)
- Youngeun Kwon
- Department of Chemical Engineering, Myongji University, Yongin 17058, Republic of Korea; (Y.K.); (J.K.); (Y.B.S.)
| | - Jihye Kim
- Department of Chemical Engineering, Myongji University, Yongin 17058, Republic of Korea; (Y.K.); (J.K.); (Y.B.S.)
| | - Ye Bin Son
- Department of Chemical Engineering, Myongji University, Yongin 17058, Republic of Korea; (Y.K.); (J.K.); (Y.B.S.)
| | - Sol Ah Lee
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Shin Sik Choi
- Department of Bio-Pharmaceutical Sciences, Myongji University, Yongin 17058, Republic of Korea;
- The Natural Science Research Institute, Department of Food and Nutrition, Myongji University, Yongin 17058, Republic of Korea
- elegslab Inc., Seoul 06083, Republic of Korea
| | - Yongmin Cho
- Department of Chemical Engineering, Myongji University, Yongin 17058, Republic of Korea; (Y.K.); (J.K.); (Y.B.S.)
- elegslab Inc., Seoul 06083, Republic of Korea
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3
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Romussi S, Giunti S, Andersen N, De Rosa MJ. C. elegans: a prominent platform for modeling and drug screening in neurological disorders. Expert Opin Drug Discov 2024; 19:565-585. [PMID: 38509691 DOI: 10.1080/17460441.2024.2329103] [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: 11/13/2023] [Accepted: 03/06/2024] [Indexed: 03/22/2024]
Abstract
INTRODUCTION Human neurodevelopmental and neurodegenerative diseases (NDevDs and NDegDs, respectively) encompass a broad spectrum of disorders affecting the nervous system with an increasing incidence. In this context, the nematode C. elegans, has emerged as a benchmark model for biological research, especially in the field of neuroscience. AREAS COVERED The authors highlight the numerous advantages of this tiny worm as a model for exploring nervous system pathologies and as a platform for drug discovery. There is a particular focus given to describing the existing models of C. elegans for the study of NDevDs and NDegDs. Specifically, the authors underscore their strong applicability in preclinical drug development. Furthermore, they place particular emphasis on detailing the common techniques employed to explore the nervous system in both healthy and diseased states. EXPERT OPINION Drug discovery constitutes a long and expensive process. The incorporation of invertebrate models, such as C. elegans, stands as an exemplary strategy for mitigating costs and expediting timelines. The utilization of C. elegans as a platform to replicate nervous system pathologies and conduct high-throughput automated assays in the initial phases of drug discovery is pivotal for rendering therapeutic options more attainable and cost-effective.
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Affiliation(s)
- Stefano Romussi
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
| | - Sebastián Giunti
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Natalia Andersen
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - María José De Rosa
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
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4
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Hoyer J, Kolar K, Athira A, van den Burgh M, Dondorp D, Liang Z, Chatzigeorgiou M. Polymodal sensory perception drives settlement and metamorphosis of Ciona larvae. Curr Biol 2024; 34:1168-1182.e7. [PMID: 38335959 DOI: 10.1016/j.cub.2024.01.041] [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: 07/23/2023] [Revised: 12/04/2023] [Accepted: 01/16/2024] [Indexed: 02/12/2024]
Abstract
The Earth's oceans brim with an incredible diversity of microscopic lifeforms, including motile planktonic larvae, whose survival critically depends on effective dispersal in the water column and subsequent exploration of the seafloor to identify a suitable settlement site. How their nervous systems mediate sensing of diverse multimodal cues remains enigmatic. Here, we uncover that the tunicate Ciona intestinalis larvae employ ectodermal sensory cells to sense various mechanical and chemical cues. Combining whole-brain imaging and chemogenetics, we demonstrate that stimuli encoded at the periphery are sufficient to drive global brain-state changes to promote or impede both larval attachment and metamorphosis behaviors. The ability of C. intestinalis larvae to leverage polymodal sensory perception to support information coding and chemotactile behaviors may explain how marine larvae make complex decisions despite streamlined nervous systems.
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Affiliation(s)
- Jorgen Hoyer
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Kushal Kolar
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Athira Athira
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Meike van den Burgh
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Daniel Dondorp
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Zonglai Liang
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Marios Chatzigeorgiou
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway.
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5
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Gebehart C, Büschges A. The processing of proprioceptive signals in distributed networks: insights from insect motor control. J Exp Biol 2024; 227:jeb246182. [PMID: 38180228 DOI: 10.1242/jeb.246182] [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: 01/06/2024]
Abstract
The integration of sensory information is required to maintain body posture and to generate robust yet flexible locomotion through unpredictable environments. To anticipate required adaptations in limb posture and enable compensation of sudden perturbations, an animal's nervous system assembles external (exteroception) and internal (proprioception) cues. Coherent neuronal representations of the proprioceptive context of the body and the appendages arise from the concerted action of multiple sense organs monitoring body kinetics and kinematics. This multimodal proprioceptive information, together with exteroceptive signals and brain-derived descending motor commands, converges onto premotor networks - i.e. the local neuronal circuitry controlling motor output and movements - within the ventral nerve cord (VNC), the insect equivalent of the vertebrate spinal cord. This Review summarizes existing knowledge and recent advances in understanding how local premotor networks in the VNC use convergent information to generate contextually appropriate activity, focusing on the example of posture control. We compare the role and advantages of distributed sensory processing over dedicated neuronal pathways, and the challenges of multimodal integration in distributed networks. We discuss how the gain of distributed networks may be tuned to enable the behavioral repertoire of these systems, and argue that insect premotor networks might compensate for their limited neuronal population size by, in comparison to vertebrate networks, relying more heavily on the specificity of their connections. At a time in which connectomics and physiological recording techniques enable anatomical and functional circuit dissection at an unprecedented resolution, insect motor systems offer unique opportunities to identify the mechanisms underlying multimodal integration for flexible motor control.
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Affiliation(s)
- Corinna Gebehart
- Champalimaud Foundation, Champalimaud Research, 1400-038 Lisbon, Portugal
| | - Ansgar Büschges
- Department of Animal Physiology, Institute of Zoology, Biocenter Cologne, University of Cologne, Zülpicher Strasse 47b, 50674 Cologne, Germany
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6
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Moroz LL, Romanova DY. Chemical cognition: chemoconnectomics and convergent evolution of integrative systems in animals. Anim Cogn 2023; 26:1851-1864. [PMID: 38015282 PMCID: PMC11106658 DOI: 10.1007/s10071-023-01833-7] [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] [Accepted: 11/16/2023] [Indexed: 11/29/2023]
Abstract
Neurons underpin cognition in animals. However, the roots of animal cognition are elusive from both mechanistic and evolutionary standpoints. Two conceptual frameworks both highlight and promise to address these challenges. First, we discuss evidence that animal neural and other integrative systems evolved more than once (convergent evolution) within basal metazoan lineages, giving us unique experiments by Nature for future studies. The most remarkable examples are neural systems in ctenophores and neuroid-like systems in placozoans and sponges. Second, in addition to classical synaptic wiring, a chemical connectome mediated by hundreds of signal molecules operates in tandem with neurons and is the most information-rich source of emerging properties and adaptability. The major gap-dynamic, multifunctional chemical micro-environments in nervous systems-is not understood well. Thus, novel tools and information are needed to establish mechanistic links between orchestrated, yet cell-specific, volume transmission and behaviors. Uniting what we call chemoconnectomics and analyses of the cellular bases of behavior in basal metazoan lineages arguably would form the foundation for deciphering the origins and early evolution of elementary cognition and intelligence.
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Affiliation(s)
- Leonid L Moroz
- Department of Neuroscience, University of Florida, Gainesville, USA.
- Whitney Laboratory for Marine Bioscience, University of Florida, Saint Augustine, USA.
| | - Daria Y Romanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia
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7
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Tomioka M, Umemura Y, Ueoka Y, Chin R, Katae K, Uchiyama C, Ike Y, Iino Y. Antagonistic regulation of salt and sugar chemotaxis plasticity by a single chemosensory neuron in Caenorhabditis elegans. PLoS Genet 2023; 19:e1010637. [PMID: 37669262 PMCID: PMC10503759 DOI: 10.1371/journal.pgen.1010637] [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: 01/24/2023] [Revised: 09/15/2023] [Accepted: 08/20/2023] [Indexed: 09/07/2023] Open
Abstract
The nematode Caenorhabditis elegans memorizes various external chemicals, such as ions and odorants, during feeding. Here we find that C. elegans is attracted to the monosaccharides glucose and fructose after exposure to these monosaccharides in the presence of food; however, it avoids them without conditioning. The attraction to glucose requires a gustatory neuron called ASEL. ASEL activity increases when glucose concentration decreases. Optogenetic ASEL stimulation promotes forward movements; however, after glucose conditioning, it promotes turning, suggesting that after glucose conditioning, the behavioral output of ASEL activation switches toward glucose. We previously reported that chemotaxis toward sodium ion (Na+), which is sensed by ASEL, increases after Na+ conditioning in the presence of food. Interestingly, glucose conditioning decreases Na+ chemotaxis, and conversely, Na+ conditioning decreases glucose chemotaxis, suggesting the reciprocal inhibition of learned chemotaxis to distinct chemicals. The activation of PKC-1, an nPKC ε/η ortholog, in ASEL promotes glucose chemotaxis and decreases Na+ chemotaxis after glucose conditioning. Furthermore, genetic screening identified ENSA-1, an ortholog of the protein phosphatase inhibitor ARPP-16/19, which functions in parallel with PKC-1 in glucose-induced chemotactic learning toward distinct chemicals. These findings suggest that kinase-phosphatase signaling regulates the balance between learned behaviors based on glucose conditioning in ASEL, which might contribute to migration toward chemical compositions where the animals were previously fed.
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Affiliation(s)
- Masahiro Tomioka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yusuke Umemura
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yutaro Ueoka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Risshun Chin
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Keita Katae
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Chihiro Uchiyama
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yasuaki Ike
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yuichi Iino
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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8
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Becerra D, Calixto A, Orio P. The Conscious Nematode: Exploring Hallmarks of Minimal Phenomenal Consciousness in Caenorhabditis Elegans. Int J Psychol Res (Medellin) 2023; 16:87-104. [PMID: 38106963 PMCID: PMC10723751 DOI: 10.21500/20112084.6487] [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: 06/16/2022] [Revised: 10/21/2022] [Accepted: 03/13/2023] [Indexed: 12/19/2023] Open
Abstract
While subcellular components of cognition and affectivity that involve the interaction between experience, environment, and physiology -such as learning, trauma, or emotion- are being identified, the physical mechanisms of phenomenal consciousness remain more elusive. We are interested in exploring whether ancient, simpler organisms such as nematodes have minimal consciousness. Is there something that feels like to be a worm? Or are worms blind machines? 'Simpler' models allow us to simultaneously extract data from multiple levels such as slow and fast neural dynamics, structural connectivity, molecular dynamics, behavior, decision making, etc., and thus, to test predictions of the current frameworks in dispute. In the present critical review, we summarize the current models of consciousness in order to reassess in light of the new evidence whether Caenorhabditis elegans, a nematode with a nervous system composed of 302 neurons, has minimal consciousness. We also suggest empirical paths to further advance consciousness research using C. elegans.
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Affiliation(s)
- Diego Becerra
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
- Doctorado en Ciencias, mención Biofísica y Biología Computacional, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
| | - Andrea Calixto
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
- Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
- Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
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9
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Lin A, Qin S, Casademunt H, Wu M, Hung W, Cain G, Tan NZ, Valenzuela R, Lesanpezeshki L, Venkatachalam V, Pehlevan C, Zhen M, Samuel AD. Functional imaging and quantification of multineuronal olfactory responses in C. elegans. SCIENCE ADVANCES 2023; 9:eade1249. [PMID: 36857454 PMCID: PMC9977185 DOI: 10.1126/sciadv.ade1249] [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: 07/26/2022] [Accepted: 02/01/2023] [Indexed: 05/21/2023]
Abstract
Many animals perceive odorant molecules by collecting information from ensembles of olfactory neurons, where each neuron uses receptors that are tuned to recognize certain odorant molecules with different binding affinity. Olfactory systems are able, in principle, to detect and discriminate diverse odorants using combinatorial coding strategies. We have combined microfluidics and multineuronal imaging to study the ensemble-level olfactory representations at the sensory periphery of the nematode Caenorhabditis elegans. The collective activity of C. elegans chemosensory neurons reveals high-dimensional representations of olfactory information across a broad space of odorant molecules. We reveal diverse tuning properties and dose-response curves across chemosensory neurons and across odorants. We describe the unique contribution of each sensory neuron to an ensemble-level code for volatile odorants. We show that a natural stimuli, a set of nematode pheromones, are also encoded by the sensory ensemble. The integrated activity of the C. elegans chemosensory neurons contains sufficient information to robustly encode the intensity and identity of diverse chemical stimuli.
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Affiliation(s)
- Albert Lin
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Shanshan Qin
- Center for Brain Science, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Helena Casademunt
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Min Wu
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Gregory Cain
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Nicolas Z. Tan
- Department of Physics, Northeastern University, Boston, MA, USA
| | | | - Leila Lesanpezeshki
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | | | - Cengiz Pehlevan
- Center for Brain Science, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Aravinthan D.T. Samuel
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
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10
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Albrecht PA, Fernandez-Hubeid LE, Deza-Ponzio R, Romero VL, Gonzales-Moreno C, Carranza AD, Moran Y, Asis R, Virgolini MB. Reduced acute functional tolerance and enhanced preference for ethanol in Caenorhabditis elegans exposed to lead during development: Potential role of alcohol dehydrogenase. Neurotoxicol Teratol 2022; 94:107131. [DOI: 10.1016/j.ntt.2022.107131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 09/13/2022] [Accepted: 09/29/2022] [Indexed: 11/24/2022]
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11
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Yu YV, Xue W, Chen Y. Multisensory Integration in Caenorhabditis elegans in Comparison to Mammals. Brain Sci 2022; 12:brainsci12101368. [PMID: 36291302 PMCID: PMC9599712 DOI: 10.3390/brainsci12101368] [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: 08/31/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 11/30/2022] Open
Abstract
Multisensory integration refers to sensory inputs from different sensory modalities being processed simultaneously to produce a unitary output. Surrounded by stimuli from multiple modalities, animals utilize multisensory integration to form a coherent and robust representation of the complex environment. Even though multisensory integration is fundamentally essential for animal life, our understanding of the underlying mechanisms, especially at the molecular, synaptic and circuit levels, remains poorly understood. The study of sensory perception in Caenorhabditis elegans has begun to fill this gap. We have gained a considerable amount of insight into the general principles of sensory neurobiology owing to C. elegans’ highly sensitive perceptions, relatively simple nervous system, ample genetic tools and completely mapped neural connectome. Many interesting paradigms of multisensory integration have been characterized in C. elegans, for which input convergence occurs at the sensory neuron or the interneuron level. In this narrative review, we describe some representative cases of multisensory integration in C. elegans, summarize the underlying mechanisms and compare them with those in mammalian systems. Despite the differences, we believe C. elegans is able to provide unique insights into how processing and integrating multisensory inputs can generate flexible and adaptive behaviors. With the emergence of whole brain imaging, the ability of C. elegans to monitor nearly the entire nervous system may be crucial for understanding the function of the brain as a whole.
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Affiliation(s)
- Yanxun V. Yu
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430070, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430070, China
- Correspondence: or
| | - Weikang Xue
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430070, China
| | - Yuanhua Chen
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430070, China
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12
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Ackley C, Washiashi L, Krishnamurthy R, Rothman JH. Large-Scale Gravitaxis Assay of Caenorhabditis Dauer Larvae. J Vis Exp 2022:10.3791/64062. [PMID: 35723485 PMCID: PMC9359452 DOI: 10.3791/64062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/03/2024] Open
Abstract
Gravity sensation is an important and relatively understudied process. Sensing gravity enables animals to navigate their surroundings and facilitates movement. Additionally, gravity sensation, which occurs in the mammalian inner ear, is closely related to hearing - thus, understanding this process has implications for auditory and vestibular research. Gravitaxis assays exist for some model organisms, including Drosophila. Single worms have previously been assayed for their orientation preference as they settle in solution. However, a reliable and robust assay for Caenorhabditis gravitaxis has not been described. The present protocol outlines a procedure for performing gravitaxis assays that can be used to test hundreds of Caenorhabditis dauers at a time. This large-scale, long-distance assay allows for detailed data collection, revealing phenotypes that may be missed on a standard plate-based assay. Dauer movement along the vertical axis is compared with horizontal controls to ensure that directional bias is due to gravity. Gravitactic preference can then be compared between strains or experimental conditions. This method can determine molecular, cellular, and environmental requirements for gravitaxis in worms.
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Affiliation(s)
- Caroline Ackley
- Molecular Cellular and Developmental Biology, University of California;
| | - Lindsey Washiashi
- Molecular Cellular and Developmental Biology, University of California
| | | | - Joel H Rothman
- Molecular Cellular and Developmental Biology, University of California
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13
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Hori S, Mitani S. The transcription factor unc-130/FOXD3/4 contributes to the biphasic calcium response required to optimize avoidance behavior. Sci Rep 2022; 12:1907. [PMID: 35115609 PMCID: PMC8814005 DOI: 10.1038/s41598-022-05942-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 01/13/2022] [Indexed: 11/12/2022] Open
Abstract
The central neural network optimizes avoidance behavior depending on the nociceptive stimulation intensity and is essential for survival. How the property of hub neurons that enables the selection of behaviors is genetically defined is not well understood. We show that the transcription factor unc-130, a human FOXD3/4 ortholog, is required to optimize avoidance behavior depending on stimulus strength in Caenorhabditis elegans. unc-130 is necessary for both ON responses (calcium decreases) and OFF responses (calcium increases) in AIBs, central neurons of avoidance optimization. Ablation of predicted upstream inhibitory neurons reduces the frequency of turn behavior, suggesting that optimization needs both calcium responses. At the molecular level, unc-130 upregulates the expression of at least three genes: nca-2, a homolog of the vertebrate cation leak channel NALCN; glr-1, an AMPA-type glutamate receptor; and eat-4, a hypothetical L-glutamate transmembrane transporter in the central neurons of optimization. unc-130 shows more limited regulation in optimizing behavior than an atonal homolog lin-32, and unc-130 and lin-32 appear to act in parallel molecular pathways. Our findings suggest that unc-130 is required for the establishment of some AIB identities to optimize avoidance behavior.
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Affiliation(s)
- Sayaka Hori
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, 162-8666, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, 162-8666, Japan.
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14
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Raithel CU, Gottfried JA. Using your nose to find your way: Ethological comparisons between human and non-human species. Neurosci Biobehav Rev 2021; 128:766-779. [PMID: 34214515 PMCID: PMC8359807 DOI: 10.1016/j.neubiorev.2021.06.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 06/10/2021] [Accepted: 06/25/2021] [Indexed: 02/08/2023]
Abstract
Olfaction is arguably the least valued among our sensory systems, and its significance for human behavior is often neglected. Spatial navigation represents no exception to the rule: humans are often characterized as purely visual navigators, a view that undermines the contribution of olfactory cues. Accordingly, research investigating whether and how humans use olfaction to navigate space is rare. In comparison, research on olfactory navigation in non-human species is abundant, and identifies behavioral strategies along with neural mechanisms characterizing the use of olfactory cues during spatial tasks. Using an ethological approach, our review draws from studies on olfactory navigation across species to describe the adaptation of strategies under the influence of selective pressure. Mammals interact with spatial environments by abstracting multisensory information into cognitive maps. We thus argue that olfactory cues, alongside inputs from other sensory modalities, play a crucial role in spatial navigation for mammalian species, including humans; that is, odors constitute one of the many building blocks in the formation of cognitive maps.
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Affiliation(s)
- Clara U Raithel
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, 3400 Hamilton Walk, Stemmler Hall, Room G10, Philadelphia, PA, 19104, USA; Department of Psychology, School of Arts and Sciences, University of Pennsylvania, 425 S. University Avenue, Stephen A. Levin Building, Philadelphia, PA, 19104, USA.
| | - Jay A Gottfried
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, 3400 Hamilton Walk, Stemmler Hall, Room G10, Philadelphia, PA, 19104, USA; Department of Psychology, School of Arts and Sciences, University of Pennsylvania, 425 S. University Avenue, Stephen A. Levin Building, Philadelphia, PA, 19104, USA
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15
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Ijomone OM, Gubert P, Okoh COA, Varão AM, Amara LDO, Aluko OM, Aschner M. Application of Fluorescence Microscopy and Behavioral Assays to Demonstrating Neuronal Connectomes and Neurotransmitter Systems in C. elegans. NEUROMETHODS 2021; 172:399-426. [PMID: 34754139 PMCID: PMC8575032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The nematode Caenorhabditis elegans (C. elegans) is a prevailing model which is commonly utilized in a variety of biomedical research arenas, including neuroscience. Due to its transparency and simplicity, it is becoming a choice model organism for conducting imaging and behavioral assessment crucial to understanding the intricacies of the nervous system. Here, the methods required for neuronal characterization using fluorescent proteins and behavioral tasks are described. These are simplified protocols using fluorescent microscopy and behavioral assays to examine neuronal connections and associated neurotransmitter systems involved in normal physiology and aberrant pathology of the nervous system. Our aim is to make available to readers some streamlined and replicable procedures using C. elegans models as well as highlighting some of the limitations.
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Affiliation(s)
- Omamuyovwi M. Ijomone
- The Neuro- Lab, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
- Department of Human Anatomy, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
| | - Priscila Gubert
- Department of Biochemistry, Laboratório de Imunopatologia Keizo Asami, LIKA, Federal University of Pernambuco, Recife, Brazil
- Postgraduate Program in Pure and Applied Chemistry, Federal University of Western of Bahia, Bahia, Brazil
| | - Comfort O. A. Okoh
- The Neuro- Lab, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
| | - Alexandre M. Varão
- Postgraduate Program in Pure and Applied Chemistry, Federal University of Western of Bahia, Bahia, Brazil
| | - Leandro de O. Amara
- Postgraduate Program in Pure and Applied Chemistry, Federal University of Western of Bahia, Bahia, Brazil
| | - Oritoke M. Aluko
- The Neuro- Lab, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
- Department of Physiology, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
| | - Michael Aschner
- Departments of Molecular Pharmacology and Neurosciences, Albert Einstein College of Medicine, NY, USA
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16
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Rawsthorne H, Calahorro F, Holden-Dye L, O’ Connor V, Dillon J. Investigating autism associated genes in C. elegans reveals candidates with a role in social behaviour. PLoS One 2021; 16:e0243121. [PMID: 34043629 PMCID: PMC8158995 DOI: 10.1371/journal.pone.0243121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/29/2021] [Indexed: 11/18/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterised by a triad of behavioural impairments and includes disruption in social behaviour. ASD has a clear genetic underpinning and hundreds of genes are implicated in its aetiology. However, how single penetrant genes disrupt activity of neural circuits which lead to affected behaviours is only beginning to be understood and less is known about how low penetrant genes interact to disrupt emergent behaviours. Investigations are well served by experimental approaches that allow tractable investigation of the underpinning genetic basis of circuits that control behaviours that operate in the biological domains that are neuro-atypical in autism. The model organism C. elegans provides an experimental platform to investigate the effect of genetic mutations on behavioural outputs including those that impact social biology. Here we use progeny-derived social cues that modulate C. elegans food leaving to assay genetic determinants of social behaviour. We used the SAFRI Gene database to identify C. elegans orthologues of human ASD associated genes. We identified a number of mutants that displayed selective deficits in response to progeny. The genetic determinants of this complex social behaviour highlight the important contribution of synaptopathy and implicates genes within cell signalling, epigenetics and phospholipid metabolism functional domains. The approach overlaps with a growing number of studies that investigate potential molecular determinants of autism in C. elegans. However, our use of a complex, sensory integrative, emergent behaviour provides routes to enrich new or underexplored biology with the identification of novel candidate genes with a definable role in social behaviour.
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Affiliation(s)
- Helena Rawsthorne
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
| | - Fernando Calahorro
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
| | - Lindy Holden-Dye
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
| | - Vincent O’ Connor
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
| | - James Dillon
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
- * E-mail:
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17
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Filipowicz A, Lalsiamthara J, Aballay A. TRPM channels mediate learned pathogen avoidance following intestinal distention. eLife 2021; 10:65935. [PMID: 34032213 PMCID: PMC8177887 DOI: 10.7554/elife.65935] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 05/24/2021] [Indexed: 12/13/2022] Open
Abstract
Upon exposure to harmful microorganisms, hosts engage in protective molecular and behavioral immune responses, both of which are ultimately regulated by the nervous system. Using the nematode Caenorhabditis elegans, we show that ingestion of Enterococcus faecalis leads to a fast pathogen avoidance behavior that results in aversive learning. We have identified multiple sensory mechanisms involved in the regulation of avoidance of E. faecalis. The G-protein coupled receptor NPR-1-dependent oxygen-sensing pathway opposes this avoidance behavior, while an ASE neuron-dependent pathway and an AWB and AWC neuron-dependent pathway are directly required for avoidance. Colonization of the anterior part of the intestine by E. faecalis leads to AWB and AWC mediated olfactory aversive learning. Finally, two transient receptor potential melastatin (TRPM) channels, GON-2 and GTL-2, mediate this newly described rapid pathogen avoidance. These results suggest a mechanism by which TRPM channels may sense the intestinal distension caused by bacterial colonization to elicit pathogen avoidance and aversive learning by detecting changes in host physiology.
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Affiliation(s)
- Adam Filipowicz
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, United States
| | - Jonathan Lalsiamthara
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, United States
| | - Alejandro Aballay
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, United States
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18
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Ferkey DM, Sengupta P, L’Etoile ND. Chemosensory signal transduction in Caenorhabditis elegans. Genetics 2021; 217:iyab004. [PMID: 33693646 PMCID: PMC8045692 DOI: 10.1093/genetics/iyab004] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/05/2021] [Indexed: 12/16/2022] Open
Abstract
Chemosensory neurons translate perception of external chemical cues, including odorants, tastants, and pheromones, into information that drives attraction or avoidance motor programs. In the laboratory, robust behavioral assays, coupled with powerful genetic, molecular and optical tools, have made Caenorhabditis elegans an ideal experimental system in which to dissect the contributions of individual genes and neurons to ethologically relevant chemosensory behaviors. Here, we review current knowledge of the neurons, signal transduction molecules and regulatory mechanisms that underlie the response of C. elegans to chemicals, including pheromones. The majority of identified molecules and pathways share remarkable homology with sensory mechanisms in other organisms. With the development of new tools and technologies, we anticipate that continued study of chemosensory signal transduction and processing in C. elegans will yield additional new insights into the mechanisms by which this animal is able to detect and discriminate among thousands of chemical cues with a limited sensory neuron repertoire.
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Affiliation(s)
- Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Noelle D L’Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, CA 94143, USA
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19
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Modzelewska K, Brown L, Culotti J, Moghal N. Sensory regulated Wnt production from neurons helps make organ development robust to environmental changes in C. elegans. Development 2020; 147:dev186080. [PMID: 32586974 DOI: 10.1242/dev.186080] [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: 11/03/2019] [Accepted: 06/13/2020] [Indexed: 11/20/2022]
Abstract
Long-term survival of an animal species depends on development being robust to environmental variations and climate changes. We used C. elegans to study how mechanisms that sense environmental changes trigger adaptive responses that ensure animals develop properly. In water, the nervous system induces an adaptive response that reinforces vulval development through an unknown backup signal for vulval induction. This response involves the heterotrimeric G-protein EGL-30//Gαq acting in motor neurons. It also requires body-wall muscle, which is excited by EGL-30-stimulated synaptic transmission, suggesting a behavioral function of neurons induces backup signal production from muscle. We now report that increased acetylcholine during liquid growth activates an EGL-30-Rho pathway, distinct from the synaptic transmission pathway, that increases Wnt production from motor neurons. We also provide evidence that this neuronal Wnt contributes to EGL-30-stimulated vulval development, with muscle producing a parallel developmental signal. As diverse sensory modalities stimulate motor neurons via acetylcholine, this mechanism enables broad sensory perception to enhance Wnt-dependent development. Thus, sensory perception improves animal fitness by activating distinct neuronal functions that trigger adaptive changes in both behavior and developmental processes.
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Affiliation(s)
- Katarzyna Modzelewska
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Louise Brown
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada
| | - Joseph Culotti
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada
| | - Nadeem Moghal
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
- Princess Margaret Cancer Centre/University Health Network, Toronto, Ontario, M5G 1L7, Canada
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20
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Takeishi A, Takagaki N, Kuhara A. Temperature signaling underlying thermotaxis and cold tolerance in Caenorhabditis elegans. J Neurogenet 2020; 34:351-362. [DOI: 10.1080/01677063.2020.1734001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Asuka Takeishi
- Neural Circuit of Multisensory Integration RIKEN Hakubi Research Team, RIKEN Cluster for Pioneering Research (CPR), RIKEN Center for Brain Science (CBS), Wako, Japan
| | - Natsune Takagaki
- Graduate School of Natural Science, Konan University, Kobe, Japan
- Institute for Integrative Neurobiology, Konan University, Kobe, Japan
| | - Atsushi Kuhara
- Graduate School of Natural Science, Konan University, Kobe, Japan
- Institute for Integrative Neurobiology, Konan University, Kobe, Japan
- Faculty of Science and Engineering, Konan University, Kobe, Japan
- AMED-PRIME, Japan Agency for Medical Research and Development, Tokyo, Japan
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21
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Carducci P, Squillace V, Manzi G, Truppa V. Touch improves visual discrimination of object features in capuchin monkeys (Sapajus spp.). Behav Processes 2020; 172:104044. [PMID: 31954810 DOI: 10.1016/j.beproc.2020.104044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 01/03/2020] [Accepted: 01/13/2020] [Indexed: 11/25/2022]
Abstract
Primates perceive many object features through vision and touch. To date, little is known on how the synergy of these two sensory modalities contributes to enhance object recognition. Here, we investigated in capuchin monkeys (N = 12) whether manipulating objects and retaining tactile information enhanced visual recognition of geometrical object properties on different scales. Capuchins were trained to visually select the rewarded one of two objects differing in size, shape (larger-scale) or surface structure (smaller-scale). Objects were explored in two experimental conditions: the Sight condition prevented capuchins from touching the chosen object; the Sight and Touch condition allowed them to touch the selected object. Our results indicated that tactile information increased the capuchins' learning speed for visual discrimination of object features. Moreover, the capuchins' learning speed was higher in both size and shape discrimination compared to surface discrimination regardless of the availability of tactile input. Overall, our data demonstrated that the acquisition of tactile information about object features was advantageous for the capuchins and allowed them to achieve high levels of visual accuracy faster. This suggests that information from touch potentiated object recognition in the visual modality.
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Affiliation(s)
- Paola Carducci
- Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197, Rome, Italy; Sapienza University of Rome, Department of Environmental Biology, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | - Valerio Squillace
- Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197, Rome, Italy
| | - Giorgio Manzi
- Sapienza University of Rome, Department of Environmental Biology, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Valentina Truppa
- Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197, Rome, Italy.
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22
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Pathak A, Chatterjee N, Sinha S. Developmental trajectory of Caenorhabditis elegans nervous system governs its structural organization. PLoS Comput Biol 2020; 16:e1007602. [PMID: 31895942 PMCID: PMC6959611 DOI: 10.1371/journal.pcbi.1007602] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 01/14/2020] [Accepted: 12/11/2019] [Indexed: 11/22/2022] Open
Abstract
A central problem of neuroscience involves uncovering the principles governing the organization of nervous systems which ensure robustness in brain development. The nematode Caenorhabditis elegans provides us with a model organism for studying this question. In this paper, we focus on the invariant connection structure and spatial arrangement of the neurons comprising the somatic neuronal network of this organism to understand the key developmental constraints underlying its design. We observe that neurons with certain shared characteristics-such as, neural process lengths, birth time cohort, lineage and bilateral symmetry-exhibit a preference for connecting to each other. Recognizing the existence of such homophily and their relative degree of importance in determining connection probability within neurons (for example, in synapses, symmetric pairing is the most dominant factor followed by birth time cohort, process length and lineage) helps in connecting specific neuronal attributes to the topological organization of the network. Further, the functional identities of neurons appear to dictate the temporal hierarchy of their appearance during the course of development. Providing crucial insights into principles that may be common across many organisms, our study shows how the trajectory in the developmental landscape constrains the structural organization of a nervous system.
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Affiliation(s)
- Anand Pathak
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
| | | | - Sitabhra Sinha
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
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23
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Da Silva JD, Oliveira S, Pereira-Sousa J, Teixeira-Castro A, Costa MD, Maciel P. Loss of egli-1, the Caenorhabditis elegans Orthologue of a Downstream Target of SMN, Leads to Abnormalities in Sensorimotor Integration. Mol Neurobiol 2019; 57:1553-1569. [PMID: 31797327 DOI: 10.1007/s12035-019-01833-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 11/12/2019] [Indexed: 11/28/2022]
Abstract
The connectome of Caenorhabditis elegans has been extensively studied and fully mapped, allowing researchers to more confidently conclude on the impact of any change in neuronal circuits based on behavioral data. One of the more complex sensorimotor circuits in nematodes is the one that regulates the integration of feeding status with the subsequent behavioral responses that allow animals to adapt to environmental conditions. Here, we have characterized a Caenorhabditis elegans knockout model of the egli-1 gene (previously known as tag-175). This is an orthologue of the stasimon/tmem41b gene, a downstream target of SMN, the depleted protein in spinal muscular atrophy (SMA), which partially recapitulates the SMA phenotype in fly and zebrafish models when mutated. Surprisingly, egli-1 mutants reveal no deficits in motor function. Instead, they show functional impairment of a specific neuronal circuit, leading to defects in the integration of sensorial information related to food abundance, with consequences at the level of locomotion adaptation, egg laying, and the response to aversive chemical stimuli. This work has demonstrated for the first time the relevance of egli-1 in the nervous system, as well as revealed a function for this gene, which had remained elusive so far.
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Affiliation(s)
- Jorge Diogo Da Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Stéphanie Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Joana Pereira-Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Andreia Teixeira-Castro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Marta Daniela Costa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal. .,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
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24
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DiLoreto EM, Chute CD, Bryce S, Srinivasan J. Novel Technological Advances in Functional Connectomics in C. elegans. J Dev Biol 2019; 7:E8. [PMID: 31018525 PMCID: PMC6630759 DOI: 10.3390/jdb7020008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 02/08/2019] [Accepted: 02/13/2019] [Indexed: 12/11/2022] Open
Abstract
The complete structure and connectivity of the Caenorhabditis elegans nervous system ("mind of a worm") was first published in 1986, representing a critical milestone in the field of connectomics. The reconstruction of the nervous system (connectome) at the level of synapses provided a unique perspective of understanding how behavior can be coded within the nervous system. The following decades have seen the development of technologies that help understand how neural activity patterns are connected to behavior and modulated by sensory input. Investigations on the developmental origins of the connectome highlight the importance of role of neuronal cell lineages in the final connectivity matrix of the nervous system. Computational modeling of neuronal dynamics not only helps reconstruct the biophysical properties of individual neurons but also allows for subsequent reconstruction of whole-organism neuronal network models. Hence, combining experimental datasets with theoretical modeling of neurons generates a better understanding of organismal behavior. This review discusses some recent technological advances used to analyze and perturb whole-organism neuronal function along with developments in computational modeling, which allows for interrogation of both local and global neural circuits, leading to different behaviors. Combining these approaches will shed light into how neural networks process sensory information to generate the appropriate behavioral output, providing a complete understanding of the worm nervous system.
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Affiliation(s)
- Elizabeth M DiLoreto
- Biology and Biotechnology Department, Worcester Polytechnic Institute, Worcester, MA 01605, USA.
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25
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Nkambeu B, Salem JB, Leonelli S, Marashi FA, Beaudry F. EGL-3 and EGL-21 are required to trigger nocifensive response of Caenorhabditis elegans to noxious heat. Neuropeptides 2019; 73:41-48. [PMID: 30454862 DOI: 10.1016/j.npep.2018.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/09/2018] [Accepted: 11/12/2018] [Indexed: 02/06/2023]
Abstract
Caenorhabditis elegans (C. elegans) is a widely used model organism to examine nocifensive response to noxious stimuli, including heat avoidance. Recently, comprehensive analysis of the genome sequence revealed several pro-neuropeptide genes, encoding a series of bioactive neuropeptides. C. elegans neuropeptides are involved in the modulation of essentially all behaviors including locomotion, mechanosensation, thermosensation and chemosensation. The maturation of pro-neuropeptide to neuropeptide is performed by ortholog pro-protein convertases and carboxypeptidase E (e.g. EGL-3 and EGL-21). We hypothesized that C. elegans egl-3 or egl-21 mutants will have a significant decrease in mature neuropeptides and they will display an impaired heat avoidance behavior. Our data has shown that thermal avoidance behavior of egl-3 and egl-21 mutants was significantly hampered compared to WT(N2) C. elegans. Moreover, flp-18, flp-21 and npr-1 mutant C. elegans displayed a similar phenotype. EGL-3 pro-protein convertase and EGL-21 carboxypeptidase E are essential enzymes for the maturation of pro-neuropeptides to active neuropeptides in C. elegans. Quantitative mass spectrometry analyses with egl-3 and egl-21 mutant C. elegans homogenates demonstrated that proteolysis of ProFLP-18 and ProFLP-21 are severely impeded, leading to a lack of mature bioactive neuropeptides. Not only FLP-21 but also FLP-18 related mature neuropeptides, both are ligands of NPR-1 and are needed to trigger nocifensive response of C. elegans to noxious heat.
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Affiliation(s)
- Bruno Nkambeu
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada
| | - Jennifer Ben Salem
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada
| | - Sophie Leonelli
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada
| | - Fatemeh Amin Marashi
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada
| | - Francis Beaudry
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada.
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26
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Salem JB, Nkambeu B, Arvanitis DN, Beaudry F. Deciphering the Role of EGL-3 for Neuropeptides Processing in Caenorhabditis elegans Using High-Resolution Quadrupole–Orbitrap Mass Spectrometry. Neurochem Res 2018; 43:2121-2131. [DOI: 10.1007/s11064-018-2636-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/07/2018] [Accepted: 09/10/2018] [Indexed: 01/13/2023]
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